AU2018228275B2

AU2018228275B2 - Composite support pole

Info

Publication number: AU2018228275B2
Application number: AU2018228275A
Authority: AU
Inventors: Mark Anthony Russo
Original assignee: World Wide Window Cleaning Supplies Ip Pty Ltd
Current assignee: World Wide Window Cleaning Supplies Ip Pty Ltd
Priority date: 2017-03-01
Filing date: 2018-03-01
Publication date: 2022-10-20
Anticipated expiration: 2038-03-01
Also published as: AU2018228275A1; AU2021100579B4; CN212079865U; AU2021100579A4; WO2018157209A1

Abstract

A composite support pole for supporting an overhead load at a free end thereof and including at least one composite support member. The support member includes a tensile wall for, in use, bearing tensile load, the tensile wall formed as a cylindrical segment having a circular arc which defines a tensile wall arc length. The support member also includes a compressive wall which opposes the tensile wall, for, in use, bearing compressive load, the compressive wall formed as a cylindrical segment having a circular arc which defines a compressive wall arc length that is greater than the tensile wall arc length. The support member further includes a pair of opposing side walls extending between the tensile and compressive walls, the side walls being planar or having a curvature that is less than that the curvature of the tensile and compressive walls.

Description

Title of Invention

COMPOSITE SUPPORT POLE Cross Reference

[0001 ] The present application claims priority from Australian provisional patent application No. 2017900689 filed 1 March 2017, the disclosure of which will be taken to be incorporated into this specification.

Technical Field

[0002] The present invention generally relates to a support member formed from composite materials. More particularly, the invention relates to a composite support pole which can be used in one example, for window cleaning. The invention has been developed for use in overhead cleaning of elevated windows and it will be convenient to hereinafter describe the invention in the context of this exemplary application. However, it is to be appreciated that the invention is not limited to this application and could be used for supporting an overhead device or load in other applications for example painting, general surface cleaning, landscaping, audio/visual recording or in carpentry.

Background of Invention

[0003] The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.

[0004] The cleaning of high windows or windows that are elevated beyond a ground floor can be problematic. Whilst the use of a ladder or an elevated platform such as free-standing or suspended scaffolding provides access to elevated windows, these arrangements can be accompanied by safety issues and can also be costly and can require extended installation time. These arrangements are therefore not appropriate in many instances. [0005] For the above reasons, support poles have been developed which facilitate the cleaning of elevated overhead windows to be performed economically, safely and efficiently from a convenient distance beneath the window, typically a ground floor. Where increased pole length is required, a number of poles are typically connected in a telescopic arrangement to form an extension pole which allows for convenient adjustment of total pole length. Conventional window cleaning poles are historically formed of tubular aluminium and are water-fed via a hose extending the length of the pole allowing for the cleaning element at the free-end of the pole to be kept moist and for a rinsing water supply to applied to the window during the cleaning process.

[0006] In addition to the requirement for window-cleaning poles to be sufficiently strong and stiff to resist the loads applied by gravity, it is also necessary for the pole to be sufficiently strong and stiff when a cleaning element connected to the free-end thereof is pressed against an overhead window. In window-cleaning applications, the load applied to the pole by the operator (which is resisted by the window) is typically greater than the load applied by gravity. The support pole must therefore be capable of not only resisting the bending loads applied by gravity but also the, bending loads applied by the operator in pressing the cleaning element against the window, which will generally be applied in the reverse direction of the bending loads applied by gravity.

[0007] Whilst it is desirable to produce longer poles capable of reaching increased heights, pole length is limited by the maximum weight that is suitable for safe and efficient manual handling. At the expense of pole strength, pole weight may be lowered by reducing pole diameter or pole wall thickness. However, a prescribed minimum pole strength is required of the pole to support the overhead weight of the cleaning element, the water supply and the pole itself. In this regard, maximum pole length is essentially dependent upon the compromise struck between pole strength and pole weight.

[0008] To this end, tubular support poles formed of composite materials such as carbon fibre have been developed having improved strength to weight ratios as compared to aluminium. These improvements have allowed for the development of window cleaning poles that facilitate ground floor cleaning of windows as high as five stories and sometimes even higher. [0009] Notwithstanding these advances, it is desirable to provide a new and alternative support pole capable of safely reaching ever greater elevation. Moreover, existing high-performance support poles are typically costly due to the relatively high volume of composite materials therein. It is therefore also desirable to provide an improved support pole capable of achieving at least equivalent elevation to existing high-performance (i.e. high-length) support poles, but at reduced production cost.

[0010] Before turning to a summary of the invention it is useful to provide an explanation of some of the terms that will be used to define the spatial relationship of various parts thereof. In this respect, spatial references throughout this specification will generally be based upon a window cleaning pole manually held by an operator standing on a ground surface and orientating the free-end of the pole toward a window. Whilst the term "ground surface" is used for convenience, it will be understood as referring to the surface on which the operator is standing which may, in some instances, may be an elevated platform such as when an operator is standing on scaffolding. With this environment as a basis, terms such as "upper", "upward", "topside", "lower", "downward" and "underside" will be generally be understood with reference to the ground surface. Similarly, it will be understood that a support pole always has a longitudinal axis parallel to the length of the pole and a transverse axis perpendicular to the longitudinal axis. The term 'composite support pole' will also be generally understood as referring to a support pole formed from composite materials.

Summary of Invention

[001 1 ] The present invention provides a composite support pole for supporting an overhead load at a free end thereof, the support pole including at least one composite support member, the support member including:

a tensile wall for, in use, bearing tensile load, the tensile wall formed as a cylindrical segment having a circular arc which defines a tensile wall arc length;

a compressive wall, which opposes the tensile wall for, in use, bearing compressive load, the compressive wall formed as a cylindrical segment having a circular arc which defines a compressive wall arc length that is greater than the tensile wall arc length; and a pair of opposing side walls extending between the tensile and compressive walls, the side walls being planar or having a degree of curvature that is less than that the curvature of the tensile and compressive walls.

[0012] The present invention provides a novel composite support pole capable of improved performance whilst supporting a load at a free-end thereof. By way of example, the present invention may be used to support an elevated cleaning element such a window-cleaning squeegee to facilitate the cleaning of elevated cleaning surfaces such as building walls or windows. A support pole according to the present invention may also be used to support paint rollers in painting applications, microphones or cameras in audio-visual recording applications. Other applications include the support of power tools in carpentry applications or cutting devices such as hedge trimmers or chainsaws in landscaping applications. The present invention may also be applicable to any other application in which it is desirable to support a load at a free-end of a pole.

[0013] In any of the above-noted example applications, it will be appreciated that a load is applied to the support pole which creates bending forces that be resisted by the tensile and compressive walls of the support pole. In applications where the load is applied by gravity acting upon the mass of the load and upon the mass of the pole, the load will be generally downward and therefore the tensile wall of the support pole will be located on a topside of the support pole whilst the compressive wall is located on an underside of the support pole. Conversely, in the particular application of window-cleaning, the free-end of the support pole is pressed against an overhead window such that the top side of the pole bears a compressive load and the underside of the pole bears a tensile load. This load distribution will reverse when the operator removes the window cleaning element from the window due to gravity being the prevailing force. However, as noted above, the bending load applied to the pole by the operator will typically be greater than that of gravity and therefore it is necessary to design window-cleaning poles to accommodate the particular loads applied during cleaning operation as opposed to the loads applied by gravity.

[0014] In designing a support pole to bear the resistant load applied by a window or when designing a pole purely for supporting an overhead weight (i.e. resisting gravity) the maximum expected force to be applied to the pole is generally unidirectional and is generally known. Accordingly, it is possible for a given application to identify which of the walls will bear a compressive load and which will bear a tensile load. Advantageously, the present invention optimises the apportionment of composite materials in recognition of the unidirectional load distribution and in view of the material properties of composite materials.

[0015] In particular, the present invention advantageously optimises material distribution by providing a compressive wall having greater arc length than the tensile wall. In this regard, the present invention provides a reduction in composite materials at the tensile side of the pole in light of composite materials having significantly greater strength when under tensile load as compared to when under compressive load. The present invention thus distributes additional composite material at the compressive side of the pole where it is required relative to the material distribution at the tensile side which is reduced with a consequent reduction in total pole mass. To this extent, a cross section of a support pole according to the present invention defines a load bearing profile optimised for the unidirectional load applied by the window against the pole during the cleaning process.

[0016] By way of example, during a window-cleaning application where the maximum load applied to the pole is expected to be applied by the operator in pressing the cleaning element against window, the operator will orientate the pole with the tensile or narrower side of the pole facing toward the window (i.e. generally downward) and the compressive or wider side of the pole facing away from the window (i.e. generally upward). In this manner, the support pole is configured to resist the maximum load which it is expected to undergo. It will be appreciated that the downward-facing tensile wall will often also undergo a compressive load applied by gravity prior to and after contact between the cleaning element and the window. However, as noted above, the load applied by gravity is generally less than the load applied to the pole during abutment between the cleaning element and the window and therefore, during window-cleaning applications, the support pole will be orientated in this manner so as to accommodate the maximum loads. This orientation (i.e. wider side facing upward) will be similarly appropriate where the support pole is connected to a paint roller, chainsaw, hedge trimmer etc. and any other application where it may be necessary for an operator to press downward on the pole against an overhead object. [0017] In contrast, in applications of the present invention in which a load is to be merely supported overhead, for example supporting audio visual recording equipment, the maximum load expected to be borne by the pole is due to gravity and therefore the pole may be orientated with the wider (compressive wall) facing downward.

[0018] Each of the tensile and compressive walls in a pole according to the present invention is formed as a cylindrical segment and therefore defines a circular arc. The use of circular arcs advantageously provides the most efficient material distribution resulting in an improved strength to weight ratio as compared to alternative linear or curvilinear profiles. Moreover, cylindrical segments are ergonomically advantageous when manually gripping a portion of the support pole. Cylindrical segments are also more readily clamped compared to linear or curvilinear profiles and are therefore advantageous in instances when pole clamps are employed to clamp together two or more telescopic support members in order to form an extension pole.

[0019] The cross-section of the support member described above provides a number of advantages over alternative profiles such as trapezoidal, circular, elliptical, or rounded-cornered triangular pole profiles. Specifically, support members according to the present invention are more readily clamped and ergonomically superior as compared to trapezoidal, elliptical and radially-cornered triangular profiles. Moreover, as noted above, the present invention distributes composite material more efficiently to provide improved unidirectional load-bearing properties as compared to all of the above alternative profiles and by that more efficient distribution, strength, weight and cost savings can arise.

[0020] The pair of side walls of a composite support pole according to the present invention extends between the ends of the tensile and compressive walls thereby being functionally analogous to the 'web' in a steel I-beam. Accordingly, the tensile and compressive walls, analogous to the I-beam flanges, resist bending moments applied to the pole whilst the side walls resist shear forces.

[0021 ] In a particular form of the invention the side walls are linear in cross- section and therefore are planar in length. In this form of the invention the cross- section of the support member may therefore be described as a trapezoid having rounded upper and lower sections or ends. The use of linear side walls is advantageous in that it reduces material use as compared to curved or curvilinear walls. Moreover, the use of linear side walls minimises lateral forces applied to the tensile and compressive walls and directs load longitudinally along the compressive and tensile walls. In certain forms of the invention, the fibres in the composite tensile and compressive walls will be laid generally longitudinally therefore increasing wall strength along the longitudinal axis. In this regard, the use of linear walls facilitates load to be borne along the direction of the fibres and reduces load being undesirably transmitted transversely to the direction of the fibres. Furthermore, the provision of linear side walls results in side walls that are shorter than if formed by a circular arc. This, in turn, reduces the amount of material required in the side walls. In some forms of the invention, the cross-sectional profile of the present invention may reduce the perimeter length by approximately 6% when compared to a circular profile.

[0022] Notwithstanding the above-noted benefits of linear side walls, in alternative forms of the invention, the side walls may have a relatively minor degree of curvature which is less than the curvature (i.e. having lesser concavity) than the tensile and compressive walls. In this regard, forms of the invention having curved side walls do not define a circular pole member and may still represent an improvement over existing pole profiles.

[0023] As noted above, the arc length of the tensile wall is less than the arc length of the compressive wall in view of the unequal tension/compression bearing properties of composite materials such as fibre-based composite materials. In particular forms of the invention, the ratio of the compressive wall arc length to the tensile wall arc length is between 4: 1 and 1 .2:1 . More particularly, the ratio of the compressive wall arc length to the tensile wall arc length may be between 3: 1 and 1.5: 1 . In a particular form of the invention, the ratio of the compressive wall arc length to the tensile wall arc length is 2: 1 . That is, the arc length of the compressive wall is twice the arc length of the tensile wall. This form of the invention is particularly applicable to carbon fibre composites in which the tensile modulus is approximately twice that of the compression modulus such that the tensile wall may be formed with half the material of the compressive wall. It will be appreciated that the ratios between the arc length of the tensile and compressive walls may vary depending on the type of composite material used and may be optimised according to the particular tension/compression modulus of that material.

[0024] It will be appreciated that tensile and compressive walls, when viewed in cross section, define circular arcs which curve around respective centre points, the distance between the centre point and a point on the arc defining the radii of the arcs. In some forms of the invention, the arcs may be concentric such that each arc curves about a common centre point. In a particular form of the invention, the circular arc of the tensile wall has a radius equal to a radius of the circular arc defining the compressive wall. In a particular form of the invention the circular arcs of the tensile and compressive walls are concentric and have equal radius. It will be appreciated that in this form of the invention the tensile and compressive walls therefore define discrete segments of a common cylinder.

[0025] In a particular embodiment of the present invention, the tensile and compressive walls, when viewed in cross section, define segments of a common cylinder and the tensile wall arc length is equal to the common radius of the cylindrical segments. In this regard, the tensile wall arc length proportionate to the total l circumference of the circular cross section of the common cylinder is equal to — (i.e.

2n

1 radian or approximately 57.3°). In forms of the i nvention where the ratio of the compressive wall arc length to the tensile wall arc length is 2: 1 the compressive wall arc length would therefore define an arc equal to 2 radians or approximately 1 14.3°

[0026] In some forms of the invention, the cross sectional profile of the support member may be generally symmetrical about a central axis extending between respective midpoints of the compressive wall arc length and the tensile wall arc length. Advantageously, the provision of a symmetrical profile facilitates an even distribution of load across the support member. As discussed in the foregoing, the support pole defines a longitudinal axis extending along the length of the pole and a transverse axis, perpendicular to the longitudinal axis, extending between the opposing sidewalls. It is to be appreciated that the central axis extending between the tensile and compressive walls is therefore perpendicular to both the longitudinal and the transverse axes. It will also be appreciated that the 'midpoints' on the circular arcs of the tensile and compressive walls may also the uppermost or lowermost points on the cross section.

[0027] Embodiments of the present invention in which the support member is symmetrical about the central axis are also advantageous in respect of the ergonomics and comfort of the pole whilst being held by the operator. Moreover, symmetrical profiles are typically more convenient to manufacture as compared to asymmetrical profiles. It will, however, be appreciated that the invention may be performed using an asymmetrical profile in some instances. By way of example, the support member may include opposing side walls of uneven length thereby providing an asymmetrical profile.

[0028] A support pole according to the present invention may include a single support member. In this instance, an implement may be connected to a free-end of the support member whilst an operator manually grips the opposite end. In the context of window cleaning, a squeegee implement may be connected to a free-end of the support member whilst a window-cleaner grips the opposite end whilst raising the pole and squeegee overhead in order to clean elevated windows.

[0029] In an alternative form of the present invention the support pole includes a plurality of support members. This form of the invention advantageously allows for a support pole of longer total length to be formed by connecting a number of individual support members in series to facilitate, for example, the cleaning of windows having greater elevation than may be reached using a single support member. Moreover, this form of the invention allows an operator to adjust the length of the support pole in accordance with the operating height of a particular application.

[0030] In a particular form of the invention, each support member in the plurality of support members is hollow and has sequentially decreasing size to permit telescopic coupling or engagement between adjacent support members. By way of example, a support pole according to the present invention may comprise a first and second support member, the second support member having equal length to the first support member but having a lesser width or diameter than the first support member such that the second support member is able to telescopically sleeve within an internal passageway defined by the first support member. This form of the invention advantageously allows an operator to adjust the extent to which the second support member protrudes from within the first support member and thereby provides an extension pole in which pole length may be conveniently adjusted. A support pole according to the present invention may include a third support member sized for sleeving within the second support member and a fourth support member sized for sleeving within the third support member and so on until the desired potential length of the support pole is achieved. It will be appreciated that the sequential size reduction in each additional support member also reduces the overall weight of the support pole borne by the operator during use, compared to a support pole comprising a single support member of a length equal to the total extended length of a plurality of support members that are telescopically connected.

[0031 ] It will be appreciated that when support members are telescopically sleeved together, the unique non-circular cross section of the support members prevents rotation of the support members relative to each other. In this regard, the present invention provides another advantage over existing circular telescopic poles.

[0032] It is to be appreciated that the term 'free-end' refers to the distal or outermost end of the support pole at the opposite end from the end which is grasped by the operator. In the instances where the support pole is comprised of a single support member, the free-end of the support pole is at the opposite end of the support member to that which is gripped by the operator. In instances where a plurality of support members are connected to form a longer support pole, the free-end of the support pole is the distal end of the final support member in the series of support members, again, opposite to the end of the pole which is gripped by the operator.

[0033] The support pole of the present invention may further include at least one clamp for connecting adjacent support members where a support pole is provided with a plurality of support members. In forms of the invention where adjacent support members are telescopically engaged, the clamp(s) may operate to arrest telescopic movement between adjacent members thereby permitting the support pole to be retracted when the clamp(s) are disengaged and for the support pole to be retained in an extended configuration when the clamp(s) are engaged. In alternative forms of the invention where the plurality of support members are not configured for telescopic engagement, the clamp(s) may operate to connect adjacent support members in series. In either alternative, a clamp suitable for use with the present invention may include a pair of opposing curved clamping faces shaped for engagement with the tensile and compressive walls.

[0034] It will be appreciated that a composite support pole according to the present invention may be formed from a plurality of layers of fibre material, such as glass or carbon fibre, surrounded by a matrix material such as resin. In this regard, each of the tensile, side and compressive walls are formed by a discrete number of fibre layers. In some forms of the invention, the tensile and compressive walls are formed with the same number of fibre layers as the side walls. In an alternative form of the invention, each of the tensile, compressive and side walls comprise a plurality of fibre layers and the number of layers in the tensile and compressive walls is equal to the number of layers in the side walls in addition to at least one reinforcement layer. In this regard, the tensile and compressive walls are formed with additional reinforcement layers in order to distribute more fibre material in the tensile and compressive walls where compressive and tensile bending forces are to be absorbed. The tensile and compressive walls may each include at least two reinforcement layers or three, four, five or more reinforcement layers. It will be appreciated that any of the compressive, tensile or side walls may be provided with reinforcement such that the thickness of the pole walls may be varied to manipulate and optimise the mechanical performance of the pole.

[0035] In a particular form of the invention, the side walls are formed of five fibre layers. By way of example, in forms of the invention where the tensile and compressive walls include three reinforcement layers, the tensile and compressive walls will therefore be formed by eight fibre layers. It will be appreciated that the number of fibre layers in the side walls may vary depending on the intended pole application. Additional fibre layers increase pole strength however it will appreciated that additional materials also increase weight and often cost. Therefore, depending on the application, it may be desirable to have a support pole formed of fewer or more layers than five. Similarly, the number of reinforcement layers will vary depending on performance, weight and cost considerations and may be specific to each particular application. [0036] The support member(s) of the present invention may be formed from glass fibre. Alternatively, the support member(s) may be formed from carbon fibre. In another alternative, a combination of glass/carbon fibre may be used. It is to be appreciated that various other fibre composite materials may be used, the particular material selection being a function of performance requirements and cost. By way of example, in applications requiring a relatively long support pole, carbon fibre may be selected in view of its advantageous strength to weight ratio. In other applications, a glass fibre pole or glass/carbon mixture may be used in order to reduce cost, given that carbon fibre is more expensive that glass fibre at present. Irrespective of the materials used or the number or fibre layers used to construct the pole walls, the advantageous unidirectional load bearing profile of the present invention allows for less material to be used than would otherwise be required of poles formed with alternative profiles such as circular, triangular, trapezoidal etc. and which are to achieve the same performance.

[0037] In a particular form of the invention, the support pole includes an adaptor member connected to the free-end of the support pole facilitating connection between the support pole and an implement. In this regard, an implement such as a cleaning tool, a paint roller or a window squeegee may be conveniently connected to the free- end of the support pole. In one form of the invention, the adaptor member has a pair of first and second opposite ends and includes a hollow circular region at the first end defining an aperture for receiving a circular member extending from the implement; and a connection region at the second end for connection to the free-end of the support pole, the connection region having a profile equivalent to the profile of the support pole to facilitate connection thereto and a transition region between the first and second ends in which the profile of the second end transitions into a circular profile of the hollow circular region. This form of the invention advantageously allows for circular handles of various implements to be received within the hollow region of the adaptor member in order to connect the implement to the support pole, via the adaptor member.

[0038] In a particular form of the invention, the support member(s) define an internal passageway and the support pole further includes a flexible tube extending through the passageway for delivering a liquid to the free-end of the support pole. In applications wherein the present invention is used for window cleaning, the flexible tube may deliver water, a cleaning agent or a mixture of the two to a squeegee at the free-end of the support pole. In alternative applications where an electrical device such as a microphone is supported at the free-end of the support pole, the internal passageway may contain electrical wiring extending to the electrical device.

Brief Description of Drawings

[0039] For a better understanding of the invention and to show how it may be performed, embodiments thereof will now be described, by way of non-limiting example only, with reference to the accompanying drawings.

[0040] Figure 1 illustrates the operation of a support pole according to the present invention being utilised in a window-cleaning application.

[0041 ] Figure 2 illustrates a closer perspective of the operator and pole lower end, as illustrated in Figure 1 .

[0042] Figure 3 is a perspective view of a portion of a composite support member according to the present invention.

[0043] Figure 4 is a cross sectional perspective of the composite support member illustrated in Figure 3.

[0044] Figure 5 is a cross sectional perspective of the composite support member illustrated in Figures 3 and 4 with geometrical indicators.

[0045] Figure 6 is a perspective view of an inner support member telescopically sleeved within an outer support member.

[0046] Figure 7 is a partially exploded view of the composite support pole illustrated in Figure 1.

[0047] Figure 8 is a perspective view of the adaptor member illustrated in Figure 7.

[0048] Figure 9 is a perspective view of the other side of the composite support pole illustrated in Figure 7 with a hose extending through an internal passageway in the pole. [0049] Figure 10 is a view of the composite support pole illustrated in Figures 1 , 7 and 9 and a hinge connecting the upper end of the support pole to a cleaning brush.

[0050] Figure 1 1 is a closer perspective of the hinge illustrated in Figure 10.

[0051 ] Figure 12 is an exploded view of the hinge illustrated in Figure 1 1.

[0052] Figure 13 illustrates a 45° adaptor which may be u sed as an alternative to the hinge arrangement illustrated in Figures 10-12.

[0053] Figure 14 is a cross sectional view of an alternative composite support member which includes four reinforcement layers on the compressive and tensile walls.

[0054] Figure 15 illustrates an alternative embodiment of a composite pole cross- section according to the present invention.

[0055] Figure 16 illustrates specific radian ratios of the composite pole cross section illustrated in Figure 15.

[0056] Figure 17 illustrates another alternative embodiment of the present invention comprising a plurality of composite layers.

Detailed Description

[0057] Figure 1 illustrates an operator 18 standing upon ground surface outside a building 22 and utilising a composite support pole 10 to clean an overhead window 20. Composite support pole 10 is manually gripped by the operator 18 at a lower end 24 to support and control pole 10 during use. In the illustrated window-cleaning application, the pole 10 is inclined with respect to the ground surface such that the opposite end of the pole is elevated above the operator 18 and therefore comprises an upper end 26 which also defines a free end of the support pole. A cleaning element 14 is connected to the upper end 26 which, under the control of the operator 18, contacts the overhead window 20 during the cleaning process. A hose 28 extends between the lower end 24 and the upper end 26 through an internal passageway defined by pole 10 to provide a water supply the cleaning element 14 and facilitate the cleaning of overhead window 20. Hose 28 extends out from the lower end 24 and is connected to a suitable water source such as a mains water supply or an electric water pump (not illustrated).

[0058] During the window-cleaning procedure illustrated in Figure 1 , it will be appreciated that the cleaning element 14 contacts the outside surface of window 20 such that a force F is applied to the cleaning element by the window 20 and in an outward direction from window 20. The outward force F is applied to the support pole even in instances where the support pole is resting against window 20 and is amplified in instances where the operator 18, whilst controlling the pole lower end 24, presses the cleaning element against the window 20.

[0059] During application of force F to the cleaning element 14, it will be appreciated that a unidirectional load is applied to the pole 10. It will be appreciated that the application of force F results in an upper side (non-window facing) of the pole 10 bearing a compressive load whilst an underside (window facing) side of the pole 10 bears a tensile load. In this regard, and as illustrated in Figure 2, support pole 10 includes a compressive wall 30 and a tensile wall 32 which will be discussed in greater detail in reference to Figures 3 to 5.

[0060] Support pole 10 includes a plurality of support members 1 1 which permits the length of pole 10 to be adjusted by an operator as necessary, for example depending on the height of the particular window to be cleaned. A section of one support member 1 1 is shown in Figure 3 which illustrates the compressive wall 30, the tensile wall 32 and a pair of straight side walls 34 extending between the tensile and compressive walls 32, 30. Tensile wall 32 and compressive wall 30 are each formed as a cylindrical segment (i.e. a portion of a cylinder) which, when viewed in cross section, therefore define circular arcs.

[0061 ] Referring to Figures 3 or 4, it will be appreciated that the cross sectional profile of a support member according to the present invention has a unique non- circular or rounded-trapezium profile which conveys a number of advantages over existing support pole profiles, which will be discussed in greater detail below.

[0062] Figure 4 illustrates a cross-section of support member 11 in which the respective cylindrical segments define a compressive wall circular arc 38 and a tensile wall circular arc 36. Each of the circular arcs 36, 38 have a respective arc length. As illustrated in Figure 4, the length of the compressive wall arc 38 is larger than the length of the tensile wall circular arc 36. To this extent, the compressive wall 30 comprises a greater volume of composite material as compared to the tensile wall 32. Advantageously, this profile optimises material distribution in recognition of the material properties of composite materials. In particular, this cross sectional profile provides a reduced distribution of material at the tensile side of the support member 1 1 in light of composite materials having greater strength when bearing tensile load, as compared to when bearing compressive load. The selective apportionment of composite material represents a significant advantage over existing composite poles, for example circular poles, which are vastly more prone to failure on the side of the pole that is bearing compressive load. In this regard, the present invention increases the compressive strength of the pole with the increased apportionment of composite material on the side of the pole intended to bear compressive load. In this regard, the present invention advantageously reduces the discrepancy between (or in some cases equalises) the tensile and compressive limits of the pole.

[0063] Turning now to Figure 5, the dimensions of the cross-section illustrated in Figure 4 will be described in greater detail. As illustrated in Figure 5, compressive wall circular arc 38 and tensile wall circular arc 36 are concentric, sharing a common centre point C. The distance between a point on compressive wall arc 38 to centre point C defines a compressive wall arc radius Rc. Similarly, the distance between a point on tensile wall arc 36 and centre point C defines a tensile wall arc radius Rt. In the illustrated embodiment, the compressive and tensile wall arcs 38, 36 are concentric and the radii Rc and Rt are equal such that the wall arcs 38, 36 define portions of a common circle. Accordingly, with reference to Figure 3, compressive wall 30 and tensile wall 32 define portions of a common cylinder. Relative to centre point C, the compressive wall circular arc 38 and tensile wall circular act 36 define arc angles Be and 9t respectively. In the illustrated embodiment, the length of the compressive wall circular arc 38 is double the length of the tensile wall circular arc 36 such that 9c is double 0t. Furthermore, in the illustrated embodiment, the radii Rc and Rt are equal to the arc length of the tensile wall circular arc 36. Accordingly, Qi is

1

equal to— (i.e. 1 radian or approximately 57.3°) and Qc is double this angle and therefore equal to 2 radians or approximately 1 14.6° The distance between the midpoint of the compressive and tensile wall arcs 36, 38 defines the diameter 0 of the support member 1 1 .

[0064] Still referring to Figure 5, it will be appreciated that the cross sectional profile of the support member 1 1 is symmetrical about a central axis X which extends between a midpoint on the compressive wall circular arc 38 and a midpoint on the tensile wall circular arc 36. Advantageously, the symmetrical profile facilitates the even distribution of load across the support member profile.

[0065] It will be appreciated that the diameter 0 of the support member will vary and that a support pole 10 may include a plurality of support members 1 1 , each having a different diameter. However, in the following example of the geometry of the illustrated embodiment, the diameter 0 is assumed to be 22.60mm. In this example, the radii Rc and Rt are therefore 1 1 .3mm and the length of tensile wall arc 36 is 1 1 3mm. As noted above, the length of the compressive wall arc is double that of the tensile wall arc such that the length of compressive wall arc 38 is 22.6mm. Furthermore, according to this particular geometry, the length L of sidewalls are approximately equal to 1 .46 multiplied by the radii (1 1 .3mm) and therefore L is approximately equal to 16.5mm.

[0066] It is to be appreciated that the above merely exemplifies one possible geometrical arrangement of support member 1 1 . In alternative configurations, radii Rc and Rt may not be equal. Similarly, circular arcs 36 and 38 may, in alternative arrangements, be non-concentric.

[0067] As noted above, the ratio of the compressive wall arc length to the tensile wall arc length is 2: 1 . The provision of a compressive wall 30 having an arc length double that of the tensile wall 32 advantageously optimises the distribution of composite material insofar as particular composite materials such as carbon fibre are approximately twice as strong under tension as they are under compression. It will be appreciated that use of alternative composite materials such as glass fibre may lead a person skilled in the art to select an alternative arc length ratio as deemed appropriate for the particular properties of the composite material being used. Notwithstanding these variations in arc length ratio, it will appreciated that all fibre composite materials are typically stronger in tension than in compression. Accordingly, variations in arc length ratio are unified under the inventive concept of providing a compressive wall arc length that is greater than the tensile wall arc length.

[0068] As noted above, composite support pole 10 comprises a plurality of composite support members. Turning now to Figure 6, there is illustrated a pair of support members comprising a first support member 40 and a second support member 42. Second support member 42 is sized slightly smaller than first support member 40 such that second support member 42 may be fitted within the opening defined by first support member 40. The sectional profile of second support member 42 is therefore scaled down in in size but otherwise equivalent to the sectional profile of first support member 40. In this regard, a telescopic engagement is permitted between the first and second support members 40, 42.

[0069] The telescopic engagement noted above with reference to Figure 6 will be further described with reference to Figure 7 which illustrates a cut-away perspective of composite support pole 10. As illustrated in Figure 7, support pole 10 comprises five support members including a first support member 64 which is the outermost support member in the series, a second support member 66 telescopically sleeved within the first support member 64, a third support member 68 telescopically sleeved within the second support member 66, a fourth support member 70 telescopically sleeved within the third support member 66 and a fifth support member 72 which is also the innermost support member and is telescopically sleeved within the fourth support member 66.

[0070] As illustrated in Figure 7, the five support members 64, 66, 68, 70, 72 are sequentially decreasing in size to permit telescopic or sleeving engagement between adjacent support members and therefore allowing the length of pole 10 to be adjusted by the operator. Four clamps 44 are connected to the edge of each support member into which another support member is inserted i.e. all support members except the fifth support member 72. Each clamp 44 is associated with a pair of support members comprising an outer support member and an inner support member which is telescopically sleeved within the outer support member. Each clamp 44 includes a collar portion 46 for engaging the outer support member and a clamping portion 48 for engaging the inner support member. [0071 ] The collar portion 46 and clamping portion 48 of each clamp 44 are similar to conventional tube clamps in that they include a pair of flexibly deformable arms which define an aperture into which a respective support member is inserted. During operation, the end of each arm is pulled together by, for example, a bolt, which operates to reduce the size of the aperture and thereby clamp the support member within the aperture. However, in contrast to a conventional tube clamp, the clamping arms in the collar portion 46 and clamping portion 48 are shaped to correspond with the unique, non-circular profile of the support members.

[0072] To describe the function of clamps 44, particular reference will be made to the second clamp 44 illustrated in Figure 7 which is the clamp associated with the second support member 66 and the third support member 68 however it will be appreciated that each of clamps 44 operate in a similar manner. In the context of the clamp 44 between the second support member 66 and the third support member 68, the second support member 66 will comprise the outer support member and the third support member 68 will comprise the inner support member.

[0073] Still referring to Figure 7, collar portion 46 includes a pair of clamping arms extending substantially around perimeter of the outer support member i.e. the second support member 66. A pair of bolts 50 connects the ends 60 of the collar portion clamping arms and, when tightened, flexibly deforms the arms of the collar portion 46 to secure the collar portion 46 to the edge of the second support member 66. Clamping portion 48 is connected to the collar portion 46 via connection portion 52 and is generally similar in profile and function to the collar portion 46 except scaled down in size so as to correspond with the reduced size of the inner support member (i.e. the third support member 68) which is sleeved within the outer support member (i.e. the second support member 66). In this regard, clamping portion 48, when tightened, operates to clamp the inner support member (the third support member 68) and thereby retain the inner support member against movement relative to the collar member 46 and therefore relative to the second support member 66 to which the collar portion 46 is secured. Whereas the ends 60 of the collar portion arms are secured by collar bolts 50, the ends 62 of the clamping portion arms are associated with a cam lever 54 which permits manual adjustment between a clamped mode in which the inner support member is clamped by the clamping portion 48 and an undamped mode in which the inner support member is undamped and therefore permitted to telescopically slide within the outer support member. A clamping bolt 58 extends through the ends 62 of the arms of the clamping portion 48 and also through an opening in the cam lever 54. When manually actuated to the clamped mode, cam 56 is compressed between a head of the bolt 58 and one of the ends 62 of the arms thereby exerting a clamping load on the inner support member.

[0074] When in the clamped mode, telescopic movement between the second support member 66 and the third support member 68 is prevented. In this regard, operation of the four clamps 44 by the operator allows for the length of the support pole 10 to be extended or contracted as necessary, depending on the height of a particular overhead window. Referring again to Figure 1 , it will be appreciated that support pole 10 is illustrated with each of the support members in a retracted position. In an application requiring cleaning of a higher window, the operator may toggle one or more of the clamps 44 to their undamped mode position in order to extend one or more of the inner support members from a retracted position to an extended or partially extended position. One in the desired position, the operator toggles the clamp to its clamped mode in order to retain the particular support member in the desired extended/partially extended position.

[0075] Having discussed the profile and operation of the support pole above, it will be appreciated that, in addition to the improvements in strength-to-weight ratio afforded by the unique sizing of the compressive and tensile walls, the support pole 10 provides a number of additional advantages insofar as its user friendliness. Still referring to Figure 1 , it will be appreciated that the support member that is manually gripped by an operator 18 is the outermost support member. Having regard to the unique non-circular profile of support members 1 1 as discussed above, it will also now be appreciated that support pole 10 is economically advantageous and easier to grasp than a conventional circular pole. In addition to being more comfortable for an operator to handle, the unique profile of the support member is less likely to rotate in an operators hand and provides more control to the operator during use. Moreover, when a plurality of support members are sleeved together to create a support pole of adjustable length, the unique profile of the present invention inherently prevents relative rotation between the sleeved support members. [0076] Referring again to Figure 7, it will be noted that the innermost or fifth support member 72 is comprised in this embodiment by an adaptor member 72 which facilitates connection of a utility implement such as a cleaning element to the free end of the pole 10. Figure 8 illustrates a truncated version of adaptor member 72 which, as illustrated in Figure 7, may have a length equal or similar to the length of the other support members. However, in alternative embodiments of the invention, the adaptor member may be formed as the relatively short member illustrated in Figure 8, to allow for convenient changing of the adaptor member depending on the type of implement required for connection to pole 10.

[0077] Adaptor member 72 includes, at a first end, a hollow circular region 76 defining a circular aperture 74 for receiving a circular member extending from the implement (not shown) such as the handle of a cleaning squeegee or a paint brush. At a second end which is opposite to the first end, adaptor member 72 includes a connection region 73 having the equivalent non-circular or rounded trapezium profile to the support pole 10. The connection region 73 is therefore configured for telescopic sleeving within the fourth support member 70 and for engagement with a clamp 44, as illustrated in Figure 7. A transition region 80 is located between the first and second ends in which the profile of the connection region 73 transitions into the profile of the hollow circular region 76.

[0078] Turning now to Figure 9, there is illustrated a reverse perspective of the support pole 10 that is illustrated in Figure 7, with the addition of a hose 28 extending through an internal passageway defined by the support pole 10. As noted above, and illustrated in Figure 1 , in cleaning applications it is typically desirable to supply the cleaning element connected to the free end of the pole with a water supply in order to facilitate the cleaning process. The function of hose 28 is best shown with reference to Figure 10 which illustrates support pole 10 in its retracted condition. Hose 28, protrudes from the pole lower end 24, extends through the length of support pole 10 and emerges from the pole upper end 26. A hose fork 82 is provided to divide the hose fluid flow across both sides of a cleaning brush 84.

[0079] In contrast to Figure 1 which illustrates a cleaning element 14 connected directly to an adaptor member, Figure 10 illustrates a hinge mechanism is provided at the pole upper end 26. Hinge 86 is connected to the adaptor member 72 and facilitates adjustment of the angle between support pole 10 and cleaning brush 84. Figure 1 1 provides a closer perspective of the hinge 86 which includes an adjustment knob 88. Turning to Figure 12, there is illustrated an exploded view of hinge 86 which comprises a pair of outer discs 90 secured to a square female connector 94. A square male connector 96 is secured to adaptor member 72. Male connector 96 is sized to sleeve within female connector 96 and to be secured thereto by a bolt or pin or other equivalent fastener (not shown) which extends through respective apertures 98 in the male and female connectors 94, 96. Hinge 86 further includes a pair of inner discs 92 positioned between the outer discs 90 and secured to an implement support 100 which, as illustrated in Figure 1 1 , is connected to the cleaning brush 84 via a mounting bracket 102. Referring again to Figure 12, inner discs 92 are sandwiched between outer discs 90. A bolt 104 extends through a central aperture in the outer discs 90, inner discs 92 and knob 88. The head 106 of bolt 104 is hexagonal and seats within a corresponding hexagonal recess 108 in the exterior surface of one of the outer discs 90. Bolt 106 engages with a nut 1 10 which is also hexagonal and is similarly seated within a hexagonal recess in an external surface of knob 88. Accordingly, rotation of nut 106 is controlled by rotation of knob 88 and bolt 104 is secured against rotation relative to outer discs 90. In this regard, rotation of knob 88 tightens the nut 88 onto bolt 106 and operates to compress the outer discs 90 onto the inner discs 92 to prevent relative rotation therebetween. The interior surface of outer discs 90 and the exterior surface of inner discs 92 are corrugated to provide a series of radial gripping teeth which facilitates engagement between the inner and outer discs 92, 90. In this manner, an operator may loosen knob 88 to adjust the angle between the implement support 100 and the support pole 10. Once the desired angle is obtained, the operator may tighten knob 88 thereby engaging the inner and outer sides 92, 90 and securing the support member 100 are the desired angle, relative to the support pole.

[0080] Figure 13 illustrates a 45° adaptor 120 which may be used as an alternative to the hinge arrangement illustrated in Figures 10-12 in order to connect a free end of the support pole to a cleaning element. Adaptor 120 includes a square male connector 122 for insertion into a female connector on the cleaning element, for example the female connector 102 illustrated in Figure 1 1 . Male connector 122 includes a pair of opposing apertures 122 facilitating a pin connection to the cleaning element. Adaptor 120 further includes a stem 124 having a longitudinal axis which is angled 45° from a longitudinal axis of the male con nector 122. Stem 124 is formed with an equivalent non-circular profile as each of the support members. Stem 124 is shaped and sized for insertion into the innermost support member of the support pole and can be retained in place by a suitably sized pole clamp. Adaptor 120 may replace the adaptor member 72 illustrated in Figure 8. Advantageously, 45° adaptor 120 can be connected to the support pole in one orientation only and in which the cleaning element will be angled toward the tensile wall of the support pole. In this regard, the use of 45° adaptor 120 can prevent an operator from accidently operating the support pole in an undesirable inverted orientation (in which the smaller tensile wall faced upwards) as this would result in the cleaning element facing away from the overhead cleaning surface which would alert the operator that the support pole has been inverted from the desired orientation. Use of 45° a daptor 120 therefore helps to ensure the support pole is operated in the desired orientation for overhead window cleaning i.e. the smaller tensile wall facing downwards and the larger compressive wall facing upwards.

[0081 ] Turning now to Figure 14, there is illustrated an cross section of a support member according to the present invention with four reinforcement layers 1 12 provided on the inside of each of the tensile wall 32 and the compressive wall 30. In particular embodiments of the present invention, the compressive and tensile walls 30, 32 may be formed with additional layers of composite material comprising reinforcement layers 1 12 in order to provide greater strength, stiffness or other improvements in performance. In the illustrated embodiment in Figure 14, four reinforcement layers are provided such that the compressive and tensile walls 30, 32 are four layers thicker than the side walls 34. In particular forms of the invention, side walls 34 may be formed by 5 layers of composite material. When the four reinforcement layers 1 12 are included, each of the inside of the tensile and compressive walls 32, 30 will therefore comprise a total of nine layers of composite material. In alternative forms of the invention, various quantities of reinforcement layers may be used, for example 2, 3, 4, 5 or more reinforcement layers may be used. Alternatively, support members of the present invention may be provided with no reinforcement layers in which case the compressive and tensile walls 30, 32 will be formed with the same number of layers as the side walls 34. [0082] Figures 15 to 17 illustrate an alternative pole cross section according to an embodiment of the present invention, in which the compressive and tensile walls are longer i.e. more rounded as compared to the previously described and illustrated pole cross-sections. Figure 16 includes specific radian ratios of the alternative cross- section and Figure 17 illustrates a further alternative wherein the pole structure is comprised of a plurality of layers. The modified profile illustrated in Figures 15 to 17 provides a lesser bend at the interface between the sidewalls 340 and the compressive wall 300 and tensile walls 320 as compared to the cross sections illustrated in Figures 3 and 4. This modified cross section may assist and simply the manufacturing process insofar as the additional curvature can improve tensile and compressive strength such that less reinforcement is required at the tensile and compressive walls 320, 240. As illustrated in Figure 16, it will be appreciated that the radius C_w of the compressive wall arc in the cross sections illustrated in Figures 15 - 17 is larger than the radius Tw of the tensile wall arc. However, as discussed and illustrated in the foregoing, in alternative embodiments of the invention, the arc of the tensile wall can have a radius equal to a radius of the circular arc defining the compressive wall.

[0083] The above description of the present invention has been presented in the context of a window cleaning pole in which the maximum operational load applied to the pole is, as illustrated in Figure 1 , the outward force of a window 20. In this context, the upper surface of the pole bears a compressive load whilst the underside of the pole bears a tensile load. For this reason, in window cleaning applications the operator will orientate the larger compressive wall 30 facing upward and the smaller tensile wall 32 facing downward. It will, however, be appreciated that in alternative applications where support pole 10 may be used to support a load hanging freely overhead, the maximum force applied to the pole will be the gravitational force acting downward on the mass of the load and on the mass of pole. In such an application, the maximum force applied to the pole is downward and therefore the underside of the pole will be in compression and the upper side of the pole will be intension. Accordingly, for these type of applications (for example the supporting of overhead recording equipment such as a camera) an operator may reverse the orientation of the pole such that the compressive wall 30 is facing downward and the tensile wall 32 is facing upward to correspond with the load profile of the particular application. [0084] The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description.

[0085] Throughout the description and claims of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.

Claims

The claims defining the invention are as follows:

1. A composite support pole for supporting an overhead load at a free end thereof, the support pole including at least one composite support member, the support member including:

• a tensile wall for, in use, bearing tensile load, the tensile wall formed as a cylindrical segment having a circular arc which defines a tensile wall arc length;

• a compressive wall which opposes the tensile wall, for, in use, bearing compressive load, the compressive wall formed as a cylindrical segment having a circular arc which defines a compressive wall arc length that is greater than the tensile wall arc length; and

• a pair of opposing side walls extending between the tensile and compressive walls, the side walls being planar or having a curvature that is less than that the curvature of the tensile and compressive walls.

2. A composite support pole according to claim 1 , the pair of side walls being linear.

3. A composite support pole according to claim 1 or 2, the ratio of the compressive wall arc length to the tensile wall arc length being between 4: 1 and 1 .2: 1

4. A composite support pole according to any one of the preceding claims, the ratio of the compressive wall arc length to the tensile wall arc length being between 3: 1 and 1.5: 1

5. A composite support pole according to any one of the preceding claims, the ratio of the compressive wall arc length to the tensile wall arc length being 2:1

6. A composite support pole according to any one of the preceding claims, the circular arc of the tensile wall having a radius equal to a radius of the circular arc defining the compressive wall.

7. A composite support pole according to claim 6, the circular arcs of the tensile and compressive walls being concentric.

8. A composite support pole according to claim 6 or 7, the tensile wall arc length being equal to the radius of the cylindrical segments.

9. A composite support pole according to any one of the preceding claims, the cross sectional profile of the support member being symmetrical about a central axis extending between a midpoint on the compressive wall circular arc and a midpoint on the tensile wall circular arc.

10. A composite support pole according to any one of the preceding claims including a single composite support member.

1 1 . A composite support pole according to any one claims 1 to 9 including a plurality of composite support members.

12. A composite support pole according to claim 1 1 , the plurality of support members having sequentially decreasing size to permit telescopic engagement between adjacent support members.

13. A composite support pole according to claim 12 including a plurality of clamps for connecting adjacent support members.

14. A composite support pole according to claim 13, the plurality of clamps facilitating adjustment of the telescopic engagement between adjacent support members to permit operator adjustment of support pole length.

15. A composite support pole according to claim 13 or 14, each clamp including a pair of curved clamping faces for engaging the tensile and compressive walls of the support members.

16. A composite support pole according to any one of the preceding claims, each of the tensile, compressive and side walls comprising a plurality of fibre layers, the number of layers in the tensile and compressive walls being equal to the number of layers in the side walls in addition to at least one reinforcement layer.

17. A composite support pole according to claim 16, the tensile and compressive walls including at least two reinforcement layers.

18. A composite support pole according to claim 16, the tensile and compressive walls including at least three reinforcement layers.

19. A composite support pole according to claim 16, the tensile and compressive walls including at least four reinforcement layers.

20. A composite support pole according to claim 16, the tensile and compressive walls including at least five reinforcement layers.

21 . A composite support pole according to any one of claims 16 to 20, the side walls being formed of five fibre layers.

22. A composite support pole according to any one of the preceding claims, the support member(s) being formed of a carbon and glass fibre composite material.

23. A composite support pole according to any one of claims 1 to 22, the support member(s) being formed of a carbon fibre composite material.

24. A composite support pole according to claim 23 including an adaptor member connected to the free-end of the support pole facilitating connection between the support pole and an implement.

25. A composite support pole according to claim 24, the adaptor member having a pair of first and second opposite ends and including:

• a hollow circular region at the first end defining an aperture for receiving a circular member extending from the implement; and

• a connection region at the second end for connection to the free-end of the support pole, the connection region having a profile equivalent to the profile of the support pole to facilitate connection thereto; and • a transition region between the first and second ends in which the profile of the second end transitions into a circular profile of the hollow circular region.

26. A composite support pole according to claim 25, the implement being a

cleaning tool.

27. A composite support pole according to any one of the preceding claims, the support member(s) defining an internal passageway and the support pole further including a flexible tube extending through the passageway for delivering a liquid to the free-end of the support pole.