WO2007144849A2

WO2007144849A2 - Roller shutter assembly

Info

Publication number: WO2007144849A2
Application number: PCT/IB2007/052297
Authority: WO
Inventors: Paul Stefanus Millard
Original assignee: Paul Stefanus Millard
Priority date: 2006-06-15
Filing date: 2007-06-15
Publication date: 2007-12-21
Also published as: WO2007144849A3

Abstract

The invention relates to a roller shutter assembly (14) which includes a roller assembly (30) having a rotation axis (32) about which it is rotatable. A shutter curtain (34) comprising a series of interconnected elongated slats (36) forms part of the roller shutter assembly. The curtain has a captive end (38) and a free end (40). The captive end is secured to the roller assembly such that the curtain is movable between an operatively open condition in which it is rolled up on the roller assembly to uncover an opening with which the roller shutter assembly is associated in use, and an operatively closed condition in which it is unrolled from the roller assembly and projects from the roller assembly for covering such opening. A drive system (46) drives the shutter curtain between its open and its closed conditions. The invention extends to a kit for forming a roller shutter assembly, and to a roller shutter installation (10).

Description

ROLLER SHUTTER ASSEMBLY

THIS INVENTION relates to roller shutters. More particularly, it relates to a roller shutter assembly, and to a kit for forming a roller shutter assembly. The invention relates also to a roller shutter installation.

In accordance with one aspect of the invention there is provided a roller shutter assembly which includes: a roller assembly having a rotation axis about which it is rotatable; a shutter curtain comprising a series of interconnected elongated slats, each slat extending substantially parallel to the rotation axis of the roller assembly, the shutter curtain having a captive end and a free end, the captive end being secured to the roller assembly such that the shutter curtain is movable, during rotation of the roller assembly about its rotation axis, between an operatively open condition in which it is rolled up on the roller assembly to uncover an opening with which the roller shutter assembly is associated in use, and an operatively closed condition in which it is unrolled from the roller assembly and projects from the roller assembly for covering or closing such opening; and a drive system for driving the shutter curtain between its open condition and its closed condition, the drive system including a drive unit having a rotary power output, a drive train having a rotary power input, the drive train being operatively connected to one of the roller assembly and the shutter curtain for moving the shutter curtain upon rotation of the rotary power input of the drive train, and a clutch rotatingly connecting the power output of the drive unit and the power input of the drive train.

The assembly may include a mounting structure for mounting the assembly on a structure related to said opening with which the assembly is associated in use, the roller assembly being rotatably supported on the mounting structure, and the drive system being mounted on the mounting structure. The clutch may be configured to resist transfer of rotary motion between the power output of the drive unit and the power input of the drive train when torque transferred between the power output and the power input reaches a predetermined maximum so that a torque overload condition exists. A said torque overload condition occurs, for example, when movement of the shutter curtain is resisted or prevented during normal operating conditions thereof. The clutch thus resists damage to the drive unit and to other moving parts of the roller shutter assembly when a torque overload conditions exist.

The clutch may be configured automatically to resume transmission of rotary motion from the power output of the drive unit to the power input of the drive train when a said torque overload condition ceases to exist.

The power output of the drive unit may be in the form of a power output shaft, the power input of the drive train being in the form of a power input shaft, with the clutch connecting the power output shaft and the power input shaft.

The drive train may be operatively connected to the shutter curtain, the drive train including an elongated drive shaft rotatably supported on the mounting structure for rotation about a drive shaft rotation axis spaced from and parallel to the rotation axis of the roller assembly, the drive shaft being drivingly connected to the power input of the drive train, and a drive gear or wheel mounted on the drive shaft at or adjacent each end of the shaft, the drive gears or wheels engaging and interacting with complementary driven formations extending, on an operatively lower face of and adjacent end edges of the shutter curtain, alongside the end edges of the shutter curtain.

Each drive gear or wheel and its associated driven formation may be arranged to operate in the general fashion of a rack-and-pinion arrangement.

The drive train may include a rotatably supported power input shaft spaced from and parallel to the elongated drive shaft, a drive wheel mounted on the power input shaft, a driven wheel mounted on the elongated drive shaft, and an endless flexible power transmission element drivingly connecting the drive wheel and the driven wheel. The roller assembly may include a roller assembly shaft rotatably supported on the mounting structure and defining the rotation axis of the roller assembly, and a plurality of roller wheels mounted on and spaced along the length of the roller assembly shaft, the captive end of the shutter curtain being connected to the roller wheels.

The roller assembly may include an urging mechanism acting on the roller assembly shaft, the urging mechanism being arranged to urge the roller assembly shaft for rotation in a direction which causes the shutter curtain to be rolled up on the roller assembly towards its open condition.

The drive system may include at least one adjustable tensioner for tensioning the endless flexible element.

The drive system may include at least one rotatably supported deflector for deflecting the endless flexible element.

In one embodiment, the drive wheel, the driven wheel, each tensioner, and each deflector may be in the form of a toothed wheel, the endless flexible element being in the form of a toothed belt. In another embodiment, the drive wheel, the driven wheel, each tensioner, and each deflector wheel may be in the form of a sprocket, the endless flexible element being in the form of a chain. In a further embodiment, the drive wheel, the driven wheel, each tensioner, and each deflector wheel may be in the form of a pulley, the endless flexible element being in the form of a V-belt.

The drive unit may include an electric rotary motor. The drive unit may also include a gearbox operatively connected to the rotary motor, the power output shaft of the drive unit being provided by or drivingly connected to the gearbox.

The mounting structure may be in the form of a housing in which the roller assembly and the drive system are housed, the housing being provided with mounting formations for mounting it on a structure.

The clutch may include a housing, an input clutch component located in the housing, the clutch being provided with a connection formation by means of which the power output shaft of the drive unit is drivingly connected to the clutch, an output clutch component located in the housing, the clutch being provided with a connection formation by means of which the power input shaft of the drive train is connected to the clutch, at least one coupling element located in the housing for interacting with the input clutch component and the output clutch component, each coupling element having a coupling condition in which it rotatingly couples the input clutch component and the output clutch component, to permit transmission of rotary motion from the input clutch component to the output clutch component, and an uncoupled condition in which it resists transmission of rotary motion from one of the input clutch component and the output clutch component to the other one of said clutch components, and an urging arrangement located in the housing, the urging arrangement permanently urging each coupling element towards its coupling condition, the urging arrangement and each coupling element being arranged such that when torque transmitted from one of the input clutch component and the output clutch component to the other one of said clutch components reaches said predetermined maximum torque, each coupling element automatically assumes its uncoupled condition, so that transmission of rotary motion between the clutch components and, accordingly, between the drive unit and the drive train is interrupted or resisted.

The input clutch component of the clutch may be irrotatably received in the housing, such that the housing, in use, rotates with the input clutch component, the output clutch component being rotatably supported in the housing, such that with each coupling element in its coupling condition, the input clutch component and the output clutch component rotate with the housing about the rotation axis, and with each coupling element in its uncoupled condition, the housing and the input clutch component rotate relative to the output clutch component about the rotation axis.

The input clutch component of the clutch may be slideably received in the housing for sliding along the rotation axis of the clutch, such that it is moveable along said rotation axis relative to the output clutch component, with the urging arrangement acting on the input clutch component, each coupling element being located between the two clutch components, and the urging arrangement being arranged to urge the input clutch component and, accordingly each coupling element, towards the output clutch component. The housing of the clutch and the input clutch component may be provided with complementary slide formations, the slide formations interacting with each other to permit sliding of the input clutch component along the rotation axis of the clutch relative to the housing.

The input clutch component and the output clutch component of the clutch may each define a coupling face, the input clutch component and the output clutch component being arranged such that their coupling faces face each other, and each coupling element being in the form of a roller element located between the coupling faces of the clutch components, the coupling faces of the input and output clutch components being provided with complementary recesses or seats radially spaced from the rotation axis of the clutch for receiving or seating each roller element when the roller element is in its coupling condition, and the coupling face of the output clutch component being provided with an annular track surrounding the rotation axis of the clutch and connecting each recess or seat provided in said coupling face, the annular track being shallower than each recess or seat in the coupling face of the output clutch component, such that each roller element is moved from its recess or seat to run along the track when in its uncoupled condition.

The clutch may include a plurality of coupling elements, the coupling faces of the input and the output components each being provided with a like plurality of recesses or seats that are circumferentially spaced about the rotation axis of the clutch.

The urging arrangement of the clutch may include an urging face provided by the input clutch component or by a component fast therewith, the urging face facing in the opposite direction than the coupling face of the input clutch component, and at least one spring acting on and held captive under compression between the housing of the clutch and the urging face.

The sliding formations of the housing of the clutch may be in the form of a plurality of elongated sliding pins fast with the housing, the sliding pins having longitudinal axes which are spaced from and parallel to the rotation axis of the clutch, the sliding formations of the input clutch component being in the form of openings spaced from the rotation axis of the clutch, with one said spring being received over each sliding pin, and a free end of each sliding pin being received through one of the openings in the input clutch component.

The urging arrangement of the clutch may be arranged to permit adjustment of an urging force exerted thereby on each coupling element, so that said predetermined maximum torque transferable between the two clutch components and, accordingly, between the drive unit and the drive train is adjustable.

The clutch may include an adjustment arrangement for adjusting the urging force exerted by the urging arrangement on each coupling element for permitting said adjustment of the predetermined maximum transferable torque.

The housing of the clutch may be of two-part construction, the connection formation associated with the input clutch component being fast with or provided by one part of the housing, the connection formation associated with the output clutch component being fast with or provided by the other part of the housing, the housing being constructed such that the two parts thereof are moveable relative to each other along the rotation axis of the clutch to provide for adjustment of the urging force exerted by the springs.

Each driven formation may be of composite construction, being constituted by a plurality of driven components each of which is secured to one of the slats of the shutter curtain.

Adjacent slats may be interconnected by means of complimentary interlocking formations provided at and extending longitudinally along abutting side edges thereof, the interlocking formations being constructed to provide for relative movement of adjacent slats about said side edges thereof.

The assembly may further include a control system for controlling operation of the drive unit and, accordingly, movement of the shutter curtain.

The control system may be a remote control system permitting operation of the drive unit from a position remote from the roller shutter assembly. In accordance with another aspect of the invention there is provided a kit for forming a roller shutter assembly, the kit including a roller shutter assembly as hereinbefore described, and two elongated guide formations for mounting on a structure defining an opening with which the assembly is to be used, the guide formations receiving end edges of the slats of the shutter curtain, for guiding movement of and supporting the shutter curtain.

Each guide formation may be generally in the form of an elongated channel.

In accordance with a further aspect of the invention there is provided a roller shutter installation which includes a structure defining an opening, and a kit as hereinbefore described mounted on the structure, the mounting structure of the roller shutter assembly of the kit being mounted on the structure, and the two guide formations of the kit being mounted along side edges of the opening, with the end edges of the slats of the shutter curtain being received by the guide formations.

The structure of the installation on which the kit is mounted may be in the form of a pickup truck, the pickup truck having an open-topped loading space for receiving a load to be transported, the loading space being defined by a load bed of the truck and a peripheral wall enclosing the load bed, the peripheral wall comprising a pair of opposed side walls and a pair of opposed end walls, one end wall being a front end wall adjacent or defined by a cabin of the truck, and the roller shutter assembly being located in the loading space at or adjacent the front end wall of the loading space such that the rotation axis of the roller assembly is horizontal and parallel to the front end wall, and the two guide formations respectively mounted on and extending along or adjacent upper edges of the respective side walls of the loading space, with end edges of the slats being received by the guide formations.

The invention is now described, by way of example, with reference to the accompanying diagrammatic drawings.

In the drawings: Figure 1 shows, schematically, a three-dimensional view of part of an installation in accordance with the invention, the installation including a roller shutter assembly in accordance with the invention;

Figure 2 shows, schematically, a top plan elevation of part of the installation shown in Figure 1 ;

Figure 3 shows, schematically and fragmentarily, a top plan elevation of the roller assembly in accordance with the invention, a shutter curtain forming part of the assembly being omitted in this figure;

Figure 4 shows, schematically, a sectional side elevation of the roller assembly shown in Figure 3, the section being taken at IV - IV in Figure 3;

Figure 5 shows, schematically and on an enlarged scale, a top plan elevation of part of the roller assembly in accordance with the invention;

Figure 6 shows, schematically, an axial cross-sectional view of a clutch forming part of the roller shutter assembly in accordance with the invention; Figure 7 shows, schematically, a face-on elevation of an output clutch component forming part of the clutch shown in Figure 6;

Figure 8 shows, schematically, a sectional side elevation of the output clutch component shown in Figure 7, the section being taken at VIII - VIII in Figure 7; and

Figure 9 shows, schematically, a face-on elevation of an input clutch component forming part of the clutch shown in Figure 6.

With reference to Figure 1 of the drawings, an installation in accordance with the invention is generally designated by reference numeral 10. The installation 10 includes a structure which, in this example, is in the form of a pickup truck 1 1 (shown in part only) having a generally box-shaped open-topped loading space 12, and a roller shutter assembly 14 in accordance with the invention mounted on the pickup truck 11 and located in the loading space 12. In other examples, the structure on which the assembly 14 is mounted can be in the form of a building structure defining an opening, for example a garage door opening.

The loading space 12 of the pickup truck 1 1 is defined by a flat rectangular load bed 16 and a peripheral wall extending along and projecting operatively upwardly from the edges of the load bed 16. The peripheral wall comprises a front wall 18 located adjacent a cabin 19 of the pickup truck 1 1 , a rear wall 20 in the form of a tailgate located at a rear end of the load bed 16, and two side walls, 22, 24 located on and extending along the respective sides of the load bed 16.

Referring now to the roller shutter assembly 14, it includes a mounting formation in the form of a generally box-shaped housing 26 comprising a top wall 26.1 (not shown in Figure 3), a bottom wall 26.2, a rear wall 26.3, a front wall 26.4 and two end walls 26.5, 26.6. As can be seen, the roller shutter assembly 14 is in use mounted on the pickup truck 1 1 by means of the housing 26. In other applications, for example when used in the context of a garage, the roller shutter assembly 14 will also be mounted on a building structure by means of the housing 26. The rear wall 26.3 and the front wall 26.4 are parallel to each other, with the front wall 26.4 being located adjacent the front wall 18 of the truck 11 , and the rear wall 26.3 being spaced rearwardly, relative to the load bed 16, from the front wall 26.4. In turn, the end walls 26.5, 26.6 are located adjacent to and parallel to the side walls 22, 24 of the truck 1 1 . The housing 26 further includes a bracket formation 28 projecting operatively forwardly from the front wall 26.4 thereof. The bracket formation 28 is thus essentially a forward extension of the top wall 26.1 of the housing 26, being shaped such that it is received or hooked over the upper edge of the front wall 18 of the truck 1 1 . At ends thereof, the housing 26 is provided with horizontally outwardly projecting flaps 26.7, 26.8, by means of which the housing 26 is mounted on the pickup truck 11 .

The roller shutter assembly 14 further includes a roller assembly 30 (not shown in Figure 3, but see Figure 4) located in and rotatably mounted on the housing 26. The roller assembly 30 comprises an elongated shaft 31 and a plurality of wheels 33, only one of which is visible, spaced along the length of the shaft 31 . Each of the wheels 33 includes three spokes by means of which it is secured to the shaft 31 . The shaft 31 is rotatably supported in the housing 26, such that it is rotatable about a horizontal rotation axis 32, the rotation axis 32 being parallel to the front wall 18 of the truck 1 1 . The shaft 31 of the roller assembly 30 is rotatably supported by means of two seats 35, 37 (shown in concept only) respectively fast with and projecting inwardly from the end walls 26.5, 26.6 of the housing 26.

The roller shutter assembly 14 further includes a shutter curtain 34 comprising a plurality of elongated interlocking slats 36, each slats 36 having a longitudinal axis which is parallel to the rotational axis 32. The shutter curtain 34 has a captive end 38 which is secured to the wheels 33 of the roller assembly 30, and a free end 40 which is displaceable, as hereinafter described, along the load bed 16. The shutter curtain 34, upon rotation of the roller assembly 30, is moveable between an open condition in which it is rolled up on the roller assembly 30, and a closed condition (Figure 4) in which it is unrolled from the roller assembly 30 and projects rearwardly from the housing 26 towards the tailgate 20 over the loading space 12, to cover or close the open top of the loading space 12. To permit such movement of the shutter curtain 34 between its open condition and its closed condition, the roller shutter 14 also includes two elongated guide rails 42, 44 (shown in concept only) respectively secured to the side walls 22, 24 of the truck 1 1 . The guide rails 42, 44 are located at upper edges of the side walls 22, 24 and extend longitudinally therealong, each guide rail 42, 44 being channel-shaped and receiving one of the end edges of the shutter curtain 34. The guide rails 42, 44, thus guide movement of and support the shutter curtain 34.

The roller shutter assembly 14 further includes a drive system 46 for driving movement of the shutter curtain 34 between its open condition and its closed condition. The drive system 46 includes a drive unit comprising an electrical rotary motor 48 and a gearbox 50 operatively connected to the motor 48. The gearbox 50 is provided with a rotary power output in the form of a shaft 52. The drive system 46 further includes a drive train 54 by means of which the shaft 52 is drivingly connected to the shutter curtain 34. The drive unit, in this example, is powered by a battery of the pickup truck 11 . Naturally, instead, it can be provided with its own power source.

The drive train 34 includes, inter alia, a rotary power input in the form of a shaft 56, and an elongated shaft 58 rotatably mounted on the housing 26 for rotation about a rotational axis parallel to the rotation axis 32. Adjacent its ends, the shaft 58 is rotatably supported by means of bearings 60, 62 mounted on the housing 26. The shaft 58 is, between its respective ends, also rotatably supported by means of bearings (not shown) which are mounted on mounting plates 64, 66 (shown only in Figure 3) fast with and extending transversely across an interior of the housing 26.

To permit transmission of rotational motion from the shaft 56 of the drive train 54 to the shaft 58, a pulley 68 is mounted on the shaft 56, and a pulley 70 is mounted, between its ends, on the shaft 58. The pulleys 68, 70 are radially aligned and are drivingly interconnected by means of an elongated endless flexible element in the form of a belt 71 . As can be seen in Figure 4, the pulley 68 is located below and forwardly, relative to the load bed 16, of the pulley 70, such that the drive train 54 further includes a deflector pulley 72 and a belt tensioner pulley 74. The deflector pulley 72 and the tensioner pulley 74 are rotatably supported about rotational axes parallel to the horizontal axis 32.

Rotation of the rotary motor 48 thus, by virtue of the interconnection thereof to the drive train 54, causes the shaft 58 to rotate in the same direction as the direction of the rotation of the rotary motor 48. For example, when the rotary motor 48 rotates in a direction indicate by arrow 75, the shaft 58 rotates in the same direction, with consequential movement of the shutter curtain 34, as will become more apparent hereunder, towards its open condition.

Drive gears 76, 78, forming part of the drive train 54, are mounted, at ends thereof, on the shaft 58. Each drive gear 76, 78 is spaced longitudinally inwardly from an associated bearing 60, 62, and is generally in the form of a toothed gear, the teeth of the gears 76, 78, however, being somewhat longer than conventional teeth of a toothed gear, such that each tooth is more or less in the form of a finger. Two driven formations are, in turn, provided on an under face of the shutter curtain 34, each driven formation extending along one of the sides of the shutter curtain 34. As can be seen in Figure 4, the driven formations terminate shy of the captive end of the shutter curtain 34. The driven formations are, as described in more detail hereunder, complementary to the drive gears 76, 78, such that the drive gears 76, 78 engage the driven formations to effect movement of the shutter curtain 34, upon operation of the rotary motor 48, between its open condition and its closed condition. Each driven formation comprises a plurality of driven components 80, each component 80 being secured to the underside of one of the slats 36, being spaced somewhat inwardly from an end edge of the slat 36. Each driven component 80 is provided with two spaced recesses which are more or less complementahly shaped to the teeth of each drive gear 76, 78, for receiving the teeth. The drive gears, 76, 78 and their associated driven formations 80 are thus generally in the form of rack-and-pinion arrangements. The roller shutter assembly 14 is further provided with two handles 82, 84 mounted on and projecting operatively upwardly from the flaps 26.7, 26.8 of the housing 26. The roller shutter assembly 14 is thus essentially in the form of a transportable unit, comprising the housing 26 and all it contents, and the two guide rails 42, 44.

A clutch 86 rotatingly connects the output shaft 52 to the input shaft 56. The clutch 86 is described in further detail hereunder, but briefly, it is in the form of a so- called slip-clutch, arranged to transmit rotational motion during ordinary operating conditions, and to slip during torque overload conditions, i.e. the clutch 86 is arranged to resist and interrupt transmission of rotational motion when a said torque overload condition occurs. Typically, a torque overload condition will occur when movement of the shutter curtain 34 is resisted or prevented. The clutch 86 is arranged automatically to slip when a said torque overload condition occurs, and when the torque overload condition ceases to exist, automatically to resume transmission of rotational motion, which, as will be appreciated, translates into movement of the shutter curtain 34.

The roller shutter assembly 14 yet further includes a control system 87 (shown in concept only, see Figure 3) which is remotely operable and which is operatively connected to the electric rotary motor 48. The remote control system 87 includes a remote control receiver, such that operation of the motor 48 can be controlled from a location remote from the pickup truck assembly 10, by means of a remote control transmitter. The remote control system 87 is in the form of a remote control system conventionally used in the context of automated garage doors and, accordingly, is not described in any further detail.

Referring now in particular to Figures 6 - 9, the clutch 86 includes a housing 92 defining a hollow circular cylindrical interior. The housing 92 is of two-part construction, comprising a roughly cup-shaped shell 94 having one open end, and a closure disc 96 closing said open end of the shell 94. The shell 94, at its open end is provided with an internal screw thread 98, and the disc 96 is provided with an external screw thread 100, by means of which screw threads 27, 28 the two parts of the housing 92 are releasably connected together. The clutch 86 includes an input clutch component in the form of a squat cylinder or input disc 102 (hereinafter referred to as the input disc 102). The input disc 102 is irrotatably, i.e. relative to the housing 92, received or located in the shell 94 of the housing 92 and radiates outwardly from a rotation axis 104 of the clutch 86. The shell 22 at its end opposite from its open end is provided with an outwardly projecting, centrally located connection formation 106 defining a passage 108 which is circular cylindrical and is concentric about the rotation axis 104 of the clutch for receiving the output shaft 52 of the rotary motor 48. The shaft 52 is secured to the connection formation 106 by means of a key 1 10.

The input disc 102 is, as mentioned, irrotatably received in the housing 92, but is arranged such that displacement or movement thereof along the rotation axis 104 of the clutch 86 relative to the shell 94 is permitted. Said movement is enabled by sliding formations which are described in more detail hereunder.

The clutch 86 further includes an output clutch component in the form of a squat cylinder or output disc 1 12 (hereinafter referred to as the output disc 1 12), the output disc 1 12 also being located in the housing 92. The output disc 1 12 is provided with an output shaft connection formation for connecting the input shaft 54 of the rotationally driven component 16 thereto. In this example, the connection formation is in the form of a stub shaft 1 14 projecting form the disc 1 12. In this example, the input shaft 54, although not shown as such, is thus connected to the stub shaft 1 14. In other examples (not shown), the input shaft 54 and the disc 1 12 are directly connected together. In such examples, the disc 1 12 will be provided with a central opening for receiving the input shaft 54. As will be appreciated, in such examples, the input shaft 54 will be secured to the output disc 1 12 by means of a key or other securing formation.

To permit passing of the shaft 1 14, or in said other examples the input shaft 54, the disc 96 is provided with a central opening 1 16, which passes the shaft 1 14 or the input shaft 54, as the case may be, with clearance. As can be seen, a free end of the shaft 1 14 projects from the housing 92. A roller bearing 1 18 is, in this example, received over the shaft 114, the bearing 1 18 rotatingly supporting the shaft 1 14 and being located on an exterior of the housing 92. The bearing 1 18 is covered by a cap 120 secured to the disc 96. The cap 120 is provided with a central opening 122 concentric about the rotation axis 104 of the clutch 86, which opening 122 passes the shaft 1 14 with rotating clearance. Although not shown as such, a seal can be provided between the cap 120 and the shaft 1 14 for resisting contamination of the bearing 118. The output disc 1 12 is thus rotatably received in the housing 92, and it is fixed against movement along the rotation axis 104 of the clutch 86.

The input disc 102 is provided with a coupling face 124, which coupling face is substantially flat, and the output disc 1 12 is provided with a substantially similar coupling face 126, the coupling faces 124, 126 being spaced from each other along the rotation axis 104 and facing each other.

Referring now in particular to Figure 7 of the drawings, a face-on elevation of the coupling face 126 of the output disc 1 12 is shown. The output disc 1 12, on its coupling face 126, is provided with a plurality of, in this example eight, dome-shaped recesses or seats 128. The recesses or seats 128 are circumferentially spaced around the rotation axis 104, and each recesses or seat 128 is somewhat shy of being semi- spherical. An annular track 130 intrudes into the coupling face 126 of the disc 1 12, the annual track 130, as can be seen in Figure 8, being shallower than the recesses or seats 128 and connecting the recesses or seats 128 together.

Turning now in particular to Figure 9, which shows an axial face-on elevation of the input disc 102, the input disc 102 is provided with eight semi-spherical recesses or seats 132, the recesses or seats 132 being circumferentially spaced about the rotation axis 104. The spacing of the recesses or seats 128 and the recesses or seats 132 are such that they can be aligned, as will become more apparent hereunder.

The clutch 86 further includes a plurality of coupling elements, in this example eight, each of which is in the form of a ball bearing 134. Each ball bearing 134 is displaceable between a coupling condition in which it is received in aligned recesses or seats 128, 132, to couple the input disc 102 to the output disc 1 12, and an uncoupled condition in which it is unseated from the associated seat 128. For illustrative purposes, the ball bearings 134 are shown as being somewhat loosely received in the recesses 128, 132. In practice, they will be snugly received in the recesses 128, 132. When the ball bearings 134 are in their coupling conditions, transmission of rotary motion, and accordingly torque, from the rotary motor 48 to the roller assembly 30 is permitted. In turn, as will become more apparent hereunder, when a torque overload condition exists, each ball bearing 134 is displaced into its uncoupled condition, in which uncoupled condition transmission of rotary motion, and accordingly torque, from the rotary motor 48 to the roller assembly 30 is interrupted or resisted. When assuming its uncoupled condition, each ball bearing 134 is, by virtue of the recesses or seats 128 being shallower than the recesses or seats 132, unseated from its recess or seat 134 and caused to roll along the annular track 130.

The clutch 86 includes an urging arrangement which permanently causes each bearing 134 to be urged towards its coupling condition. The urging arrangement includes an urging plate 136 which provides an urging face 138. The urging plate 136, which is also in the form of a disc, is connected to the disc 102. The urging face 138 faces in the opposite direction than the coupling face 124 of the disc 102. Although the input disc 102 and the urging plate 136, in the illustrated example, are two components which are connected together, it is to be appreciated that, in other examples, they can be integrally formed with each other to form a single component, the urging plate portion of said component being in the form of a flange radiating from the disc portion of said single component. In such examples, the urging face 138 will thus be provided by the input disc 102.

Six circumferentially spaced sliding pins 140 are mounted on the interior of the shell 94, the pins 140 being mounted on a wall of the shell 94 providing its closed end. Longitudinal axes of the pins 140 are parallel to one another and parallel to the rotation axis 104 of the clutch 86. The urging plate 136, in turn, is provided with six openings 142 through which free end portions of the pins 140 are slideably received. The urging plate 136 and the input disc 102 are thus slidable relative to the pins 140, so that the input disc, although irrotatably mounted on the shell 94, is slideable relative thereto along the rotation axis 104. The pins 140 and the openings 142 define slide formations permitting said movement of the input disc 102 along the rotation axis 104. Further, a coil spring 144 is received over each sliding pin 140, the springs 144 being held captive between and acting on the wall providing the closed end of the shell 94 and the urging plate 136. The springs 144 are arranged to be under compression, so that they permanently urge the input disc 102 towards the output disc 1 12, thereby urging each ball bearing 134 into its coupling condition.

In use when a torque overload condition exists, each ball bearing will be unseated form its associated recess 128, causing the springs 144 to be compressed and the input disc 102 to move away form the output disc 1 12, and roll along the track

130. When it reaches the next recess 128, each ball bearing 134 will, if the torque overload condition has ceased to exist, by virtue of an urging force exerted by the springs 144, be seated in said recess 128 and remain there, so that rotary motion can again be transferred. In turn, if the torque overload condition still exists, each bearing

134 will continue to roll along the track 130. Thus, in use, if a torque overload condition ceases to exist, the clutch 86 will automatically resume to transfer rotary motion. Thus, upon a torque overload condition, the clutch 86 will slip.

The clutch 86 further includes an adjustment arrangement for adjusting the urging force exerted by the springs 144 on the input disc 102. The adjustment arrangement is constituted by the screw threads 98, 100 of the shell 94 and the disc 96. By threading the disc 96 deeper into the interior of the shell 94, the compression under which the springs 144 are held is increased, i.e. the urging force exerted thereby is increased, so that said maximum torque which can be transferred is increased. In turn, by loosening the disc 96, the compression under which the springs are held is decreased, thereby lowering the maximum torque which can be transmitted.

As mentioned above, during normal operating conditions, each of the ball bearings 134 is in its coupled condition, so that the input disc 102 is coupled to the output disc 1 12, thereby permitting transmission of rotary movement, and accordingly torque, from the rotary motor 48 to the roller assembly 30. In turn, when a torque overload condition occurs, such as for example when movement of the shutter curtain 34 is for some reason obstructed, or when the roller assembly 30 malfunctions in a fashion which resists rotation thereof, the torque transmitted from the disc 102 to the disc 1 12 will overcome the urging force exerted by the springs 144 and, accordingly, transfer of rotary motion is resisted, thereby protecting the motor 48 against overload. With each bearing 134 in its uncoupled condition, transfer of rotary motion from the output disc 1 12 to the input disc 102 is thus also resisted. The clutch 86 thus also acts to protect the rotary motor 48 against damage arising from torque overload conditions induced by movement of the roller assembly 30.

In use, when the shutter curtain 34 is in its open condition, a load can be received onto the load bed 16 of the truck 11 , i.e. into its loading space 12. Once a load has been loaded into the loading space 12, the open top of the loading space 12 can be closed by means of the shutter curtain 34. To effect such closing, the electric rotary motor 48 is energized, by means of the remote control unit 87, which results in movement of the shutter curtain 34 into its closed condition, in a direction opposite to that indicated by arrow 88 (Figures 2 and 4). Naturally, when the top of the loading space 12 is to be opened, for example, when the load received on the load bed 16 is to be unloaded from the truck 1 1 , the rotary motor 48 is again energized, to effect movement of the shutter curtain 34 into its open condition in the direction opposite to that indicated by arrow 88. As will be appreciated, the remote control system 87 is configured to control operation of the electric motor 48 such that the motor 48 rotates in one direction upon opening of the shutter curtain 34, and rotates in the other direction upon closing of the shutter curtain 34.

If movement of the shutter curtain 34 is at any time resisted or prevented, the clutch 86 will slip, thereby protecting the rotary motor 48 and also the other rotating parts of the roller shutter assembly 14 against damage which can occur. The clutch 86, by virtue of its particular construction, will continue slipping until the shutter curtain 34 is again free to move, at which time it will transmit rotary motion, thereby effecting further movement of the shutter curtain 34.

Although not shown as such in any of the drawings, the roller shutter assembly 14 is provided with limit switches, typically operatively connected to the control system 87, which automatically cause operation of the electric motor 48 to terminate when the shutter curtain 34 reaches either of its open or closed conditions.

Although the invention is hereinbefore described with particular reference to a pickup truck assembly, it is to be appreciated that the roller shutter assembly in accordance with the invention can equally advantageously be applied in the context of trailers, garage doors, or the like. The invention as described illustrated thus provides a remote controlled roller shutter assembly, the roller shutter assembly including a clutch which resists damage to any of the rotary parts of the assembly. Furthermore, because the roller shutter assembly is essentially in the form of a unit, it can easily be installed and, if required, be removed .

Claims

CLAIMS:

1. A roller shutter assembly which includes: a roller assembly having a rotation axis about which it is rotatable; a shutter curtain comprising a series of interconnected elongated slats, each slat extending substantially parallel to the rotation axis of the roller assembly, the shutter curtain having a captive end and a free end, the captive end being secured to the roller assembly such that the shutter curtain is movable, during rotation of the roller assembly about its rotation axis, between an operatively open condition in which it is rolled up on the roller assembly to uncover an opening with which the roller shutter assembly is associated in use, and an operatively closed condition in which it is unrolled from the roller assembly and projects from the roller assembly for covering or closing such opening; and a drive system for driving the shutter curtain between its open condition and its closed condition, the drive system including a drive unit having a rotary power output, a drive train having a rotary power input, the drive train being operatively connected to one of the roller assembly and the shutter curtain for moving the shutter curtain upon rotation of the rotary power input of the drive train, and a clutch rotatingly connecting the power output of the drive unit and the power input of the drive train.

2. An assembly as claimed in Claim 1 , which includes a mounting structure for mounting the assembly on a structure related to said opening with which the assembly is associated in use, the roller assembly being rotatably supported on the mounting structure, and the drive system being mounted on the mounting structure.

3. An assembly as claimed in Claim 2, in which the clutch is configured to resist transfer of rotary motion between the power output of the drive unit and the power input of the drive train when torque transferred between the power output and the power input reaches a predetermined maximum so that a torque overload condition exists.

4. An assembly as claimed in Claim 3, in which the clutch is configured automatically to resume transmission of rotary motion from the power output of the drive unit to the power input of the drive train when a said torque overload condition ceases to exist.

5. An assembly as claimed in Claim 4, in which the power output of the drive unit is in the form of a power output shaft, the power input of the drive train being in the form of a power input shaft, with the clutch connecting the power output shaft and the power input shaft.

6. An assembly as claimed in Claim 5, in which the drive train is operatively connected to the shutter curtain, the drive train including an elongated drive shaft rotatably supported on the mounting structure for rotation about a drive shaft rotation axis spaced from and parallel to the rotation axis of the roller assembly, the drive shaft being drivingly connected to the power input of the drive train, and a drive gear or wheel mounted on the drive shaft at or adjacent each end of the shaft, the drive gears or wheels engaging and interacting with complementary driven formations extending, on an operatively lower face of and adjacent end edges of the shutter curtain, alongside the end edges of the shutter curtain.

7. An assembly as claimed in Claim 6, in which each driven formation is of composite construction, being constituted by a plurality of driven components each of which is secured to one of the slats of the shutter curtain.

8. An assembly as claimed in Claim 7, in which each drive gear or wheel and its associated driven formation are arranged to operate in the general fashion of a rack- and-pinion arrangement.

9. An assembly as claimed in Claim 8, in which the drive train includes a rotatably supported power input shaft spaced from and parallel to the elongated drive shaft, a drive wheel mounted on the power input shaft, a driven wheel mounted on the elongated drive shaft, and an endless flexible power transmission element drivingly connecting the drive wheel and the driven wheel.

10. An assembly as claimed in Claim 9, in which the roller assembly includes a roller assembly shaft rotatably supported on the mounting structure and defining the rotation axis of the roller assembly, and a plurality of roller wheels mounted on and spaced along the length of the roller assembly shaft, the captive end of the shutter curtain being connected to the roller wheels.

11 . An assembly as claimed in Claim 10, in which the roller assembly includes an urging mechanism acting on the roller assembly shaft, the urging mechanism being arranged to urge the roller assembly shaft for rotation in a direction which causes the shutter curtain to be rolled up on the roller assembly towards its open condition.

12. An assembly as claimed in Claim 1 1 , in which the drive system includes at least one adjustable tensioner for tensioning the endless flexible element.

13. An assembly as claimed in Claim 12, in which the drive system includes at least one rotatably supported deflector for deflecting the endless flexible element.

14. An assembly as claimed in Claim 13, in which the drive wheel, the driven wheel, each tensioner, and each deflector is in the form of a toothed wheel, the endless flexible element being in the form of a toothed belt.

15. An assembly as claimed in Claim 13, in which the drive wheel, the driven wheel, each tensioner, and each deflector wheel is in the form of a sprocket, the endless flexible element being in the form of a chain.

16. An assembly as claimed in Claim 13, in which the drive wheel, the driven wheel, each tensioner, and each deflector wheel is in the form of a pulley, the endless flexible element being in the form of a V-belt.

17. An assembly as claimed in any one of Claims 13 - 16 inclusive, in which the drive unit includes an electric rotary motor.

18. An assembly as claimed in Claim 17, in which the drive unit includes a gearbox operatively connected to the rotary motor, the power output shaft of the drive unit being provided by or drivingly connected to the gearbox.

19. An assembly as claimed in Claim 18, in which the mounting structure is in the form of a housing in which the roller assembly and the drive system are housed, the housing being provided with mounting formations for mounting it on a structure.

20. An assembly as claimed in any one of Claims 5 - 19 inclusive, in which the clutch includes a housing, an input clutch component located in the housing, the clutch being provided with a connection formation by means of which the power output shaft of the drive unit is drivingly connected to the clutch, an output clutch component located in the housing, the clutch being provided with a connection formation by means of which the power input shaft of the drive train is connected to the clutch, at least one coupling element located in the housing for interacting with the input clutch component and the output clutch component, each coupling element having a coupling condition in which it rotatingly couples the input clutch component and the output clutch component, to permit transmission of rotary motion from the input clutch component to the output clutch component, and an uncoupled condition in which it resists transmission of rotary motion from one of the input clutch component and the output clutch component to the other one of said clutch components, and an urging arrangement located in the housing, the urging arrangement permanently urging each coupling element towards its coupling condition, the urging arrangement and each coupling element being arranged such that when torque transmitted from one of the input clutch component and the output clutch component to the other one of said clutch components reaches said predetermined maximum torque, each coupling element automatically assumes its uncoupled condition, so that transmission of rotary motion between the clutch components and, accordingly, between the drive unit and the drive train is interrupted or resisted.

21 . An assembly as claimed in Claim 20, in which the input clutch component of the clutch is irrotatably received in the housing, such that the housing, in use, rotates with the input clutch component, the output clutch component being rotatably supported in the housing, such that with each coupling element in its coupling condition, the input clutch component and the output clutch component rotate with the housing about the rotation axis, and with each coupling element in its uncoupled condition, the housing and the input clutch component rotate relative to the output clutch component about the rotation axis.

22. An assembly as claimed in Claim 21 , in which the input clutch component of the clutch is slideably received in the housing for sliding along the rotation axis of the clutch, such that it is moveable along said rotation axis relative to the output clutch component, with the urging arrangement acting on the input clutch component, each coupling element being located between the two clutch components, and the urging arrangement being arranged to urge the input clutch component and, accordingly each coupling element, towards the output clutch component.

23. An assembly as claimed in Claim 22, in which the housing of the clutch and the input clutch component are provided with complementary slide formations, the slide formations interacting with each other to permit sliding of the input clutch component along the rotation axis of the clutch relative to the housing.

24. An assembly as claimed in Claim 23, in which the input clutch component and the output clutch component of the clutch each defines a coupling face, the input clutch component and the output clutch component being arranged such that their coupling faces face each other, and each coupling element being in the form of a roller element located between the coupling faces of the clutch components, the coupling faces of the input and output clutch components being provided with complementary recesses or seats radially spaced from the rotation axis of the clutch for receiving or seating each roller element when the roller element is in its coupling condition, and the coupling face of the output clutch component being provided with an annular track surrounding the rotation axis of the clutch and connecting each recess or seat provided in said coupling face, the annular track being shallower than each recess or seat in the coupling face of the output clutch component, such that each roller element is moved from its recess or seat to run along the track when in its uncoupled condition.

25. An assembly as claimed in Claim 24, in which the clutch includes a plurality of coupling elements, the coupling faces of the input and the output components each being provided with a like plurality of recesses or seats that are circumferentially spaced about the rotation axis of the clutch.

26. An assembly as claimed in Claim 25, in which the urging arrangement of the clutch includes an urging face provided by the input clutch component or by a component fast therewith, the urging face facing in the opposite direction than the coupling face of the input clutch component, and at least one spring acting on and held captive under compression between the housing of the clutch and the urging face.

27. An assembly as claimed in Claim 26, in which the sliding formations of the housing of the clutch are in the form of a plurality of elongated sliding pins fast with the housing, the sliding pins having longitudinal axes which are spaced from and parallel to the rotation axis of the clutch, the sliding formations of the input clutch component being in the form of openings spaced from the rotation axis of the clutch, with one said spring being received over each sliding pin, and a free end of each sliding pin being received through one of the openings in the input clutch component.

28. An assembly as claimed in Claim 27, in which the urging arrangement of the clutch is arranged to permit adjustment of an urging force exerted thereby on each coupling element, so that said predetermined maximum torque transferable between the two clutch components and, accordingly, between the drive unit and the drive train is adjustable.

29. An assembly as claimed in Claim 28, in which the clutch includes an adjustment arrangement for adjusting the urging force exerted by the urging arrangement on each coupling element for permitting said adjustment of the predetermined maximum transferable torque.

30. An assembly as claimed in Claim 29, in which the housing of the clutch is of two-part construction, the connection formation associated with the input clutch component being fast with or provided by one part of the housing, the connection formation associated with the output clutch component being fast with or provided by the other part of the housing, the housing being constructed such that the two parts thereof are moveable relative to each other along the rotation axis of the clutch to provide for adjustment of the urging force exerted by the springs.

31 . An assembly as claimed in any one of the preceding claims, in which adjacent slats are interconnected by means of complimentary interlocking formations provided at and extending longitudinally along abutting side edges thereof, the interlocking formations being constructed to provide for relative movement of adjacent slats about said side edges thereof.

32. An assembly as claimed in any one of the preceding claims, which includes a control system for controlling operation of the drive unit and, accordingly, movement of the shutter curtain.

33. An assembly as claimed in Claim 32, in which the control system is a remote control system permitting operation of the drive unit from a position remote from the roller shutter assembly.

34. A kit for forming a roller shutter assembly, the kit including a roller shutter assembly as claimed in any one of Claims 2 - 33 inclusive, and two elongated guide formations for mounting on a structure defining an opening with which the assembly is to be used, the guide formations receiving end edges of the slats of the shutter curtain, for guiding movement of and supporting the shutter curtain.

35. A kit as claimed in Claim 34, in which each guide formation is generally in the form of an elongated channel.

36. A roller shutter installation which includes a structure defining an opening, and a kit as claimed in Claim 34 or Claim 35 mounted on the structure, the mounting structure of the roller shutter assembly of the kit being mounted on the structure, and the two guide formations of the kit being mounted along side edges of the opening, with the end edges of the slats of the shutter curtain being received by the guide formations.

37. An installation as claimed in Claim 36, in which the structure on which the kit is mounted is in the form of a pickup truck, the pickup truck having an open-topped loading space for receiving a load to be transported, the loading space being defined by a load bed of the truck and a peripheral wall enclosing the load bed, the peripheral wall comprising a pair of opposed side walls and a pair of opposed end walls, one end wall being a front end wall adjacent or defined by a cabin of the truck, and the roller shutter assembly being located in the loading space at or adjacent the front end wall of the loading space such that the rotation axis of the roller assembly is horizontal and parallel to the front end wall, and the two guide formations respectively mounted on and extending along or adjacent upper edges of the respective side walls of the loading space, with end edges of the slats being received by the guide formations.