AU2011205071B2 - A bar chair - Google Patents

Abstract

A BAR CHAIR Abstract A bar chair (10) configured to support metal mesh (11). The bar chair (10) includes a body (14) providing an engaging portion (15) within which a bar (13) of the mesh is s located. The bar chair (10) is locatable in a first orientation and a second orientation, the orientations being 900 displaced. 14- 2 33ti 22-

Description

S&F Ref: P006726 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address The Australian Steel Company (Operations) Pty Ltd, of Applicant: an Australian company, ACN 069 426 955, of Level 40, 259 George Street, Sydney, New South Wales, 2000, Australia Actual Inventor(s): Ross Bourke Address for Service: Spruson & Ferguson St Martins Tower Level 35 31 Market Street Sydney NSW 2000 (CCN 3710000177) Invention Title: A bar chair Associated Provisional Application Details: [33] Country: [31] Appl'n No(s): [32] Application Date: AU 2010903387 28 Jul 2010 The following statement is a full description of this invention, including the best method of performing it known to me/us: 5845c(5480946_1) 1 A BAR CHAIR FIELD OF THE INVENTION The present invention relates to bar chairs that support metal rods and/or mesh, and more particularly but not exclusively to bar chairs employed in the concrete industry to support reinforcing mesh and bars. BACKGROUND OF THE INVENTION When forming concrete structures, such as slabs, reinforcing mesh and bars are employed to aid the slab in resisting tensile forces. When the slab is being poured, the mesh and bars need to be raised to a desired position within the wet concrete so that upon curing the mesh and bars are at a desired position. This is usually achieved by the use of bar chairs. Bar chairs are positioned beneath the reinforcing mesh and bars to maintain the mesh and bars at the desired height relative to the form work. However, it is a disadvantage of the bar chairs that once they are in position it is difficult for workmen to move across the mesh and bars. This also presents a safety risk. It is a further disadvantage of known bar chairs is that they are time consuming to install. OBJECT OF THE INVENTION It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages. SUMMARY OF THE INVENTION There is disclosed herein a bar chair including: a body providing; first contact portions and second contact portions, the first contact portions being located in a first plane and the second contact portions being located in a second plane, first contact portions being provided to engage a supporting surface to locate the body in a first position, while the second contact portions are provided to engage the supporting surface locate the body in a second position, and 2 an engaging part to engage a first item to be supported by the bar chair, with the body being angularly moveable about the engaging part so the item is supported at a position above said surface with said supporting body in the first or second position, wherein said engaging part includes a slot having a neck and an enlarged portion, with said item being moveable along said neck to be located in said enlarged portion, with the neck inhibiting movement of the item when the item is located in the enlarged portion, wherein said body is resiliently deformed to provide for movement of the item along said neck. Preferably, the planes are inclined by about 900 relative to each other. Preferably, the planes are inclined by an angle no greater than 900 relative to each other. Preferably, the body includes, a centre of gravity spaced from the engaging part so the body is urged by gravity to move angularly about the engaging part away from the first position to the second position when displaced from the first position. Preferably, said engaging part is a clip. Preferably, said slot is inclined to said first and second planes by an acute angle. Preferably, said slot is inclined to both planes by approximately 45'. Preferably, enlarged portion is shaped to captively locate the item therein and to provide for angular movement of the body about the enlarged portion. Preferably, the engaging part is a slot, extending into said body, along which the item can move. Preferably, the bar chair further includes a catch operatively associated with the slot to extend across the slot and urged into position closing the slot to retain the item in the slot, the catch being resilient deflectable to a position permitting the item to move into the slot. Preferably, the bar chair further includes an engaging part to engage a second item.

3 Preferably, the further engaging part to engage the second item is a slot extending into said body. Preferably, the bar chair further includes a catch operatively associated with the further engaging part slot to aid in retaining the second item in the slot, the catch of the further engaging part slot being resiliently deflectable to a position providing for movement of the second item into the slot. Preferably, said first contact portions include at least two spaced contact surfaces, and said second contact portions includes at least two spaced contact surfaces. Preferably, the contact portions and central gravity are positioned so that in moving from said first position to said second position, the body moves angularly through approximately 900. In a first preferred form, said body is molded from plastics materials. In an alternative preferred form, said body is cut from sheet plastics materials. Preferably, said engaging part is located at a higher position when said body is in said second portion relative to first position. Preferably, the centre of gravity is spaced from the engaging part toward the second plane. Preferably, the first contact portions and the second contact portions are convex arcuate surfaces. BRIEF DESCRIPTION OF THE DRAWINGS A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Figure 1 is a schematic side elevation of a bar chair in a first operative position; Figure 2 is a schematic side elevation of the bar chair of Figure 1 in a second operative position; 4 Figure 3 is a schematic side elevation of a modification of the bar chair of Figures 1 and 2; Figure 4 is a schematic isometric view of the bar chair of Figure 3; and Figure 5 is a schematic isometric view of a modification of the bar chair of Figures 3 and 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the accompanying drawings, there is schematically depicted a bar chair 10. The bar chair 10 is configured to support metal mesh 11, typically used to reinforce a concrete slab. The mesh 11 includes first parallel bars 12 and second parallel bars 13. The bars 12 are generally perpendicular to the bars 13. The bar chair 10 includes a body 14 typically molded from plastics material or cut from a sheet of plastics material. The body 14 may also be integrally formed. The body 14 includes an engaging part 15 which in this embodiment is a clip. The part 15 includes a slot 16 consisting of a neck 17 and an enlarged portion 18. The neck 17 has a transverse cross section smaller than the enlarged portion 18. During installation a selected one of the bars 13 is moved along the neck 17 to be located in the enlarged portion 18. The bar 13 is of greater cross section than the cross section of the neck 17. To provide for movement of the bar 13 along the neck 17, the body 14 is resiliently deformed. Upon the bar 13 being located in the enlarged portion 18, the neck 17 resumes its normal configuration so that the bar 13 is captively located in the enlarged portion 18. The enlarged portion 18 has a larger cross section than the bar 13 so that the body 14 can move angularly freely about the bar 13. The body 14 further includes first contact portions 19 that are located in a plane 20 and provide arcuate convex contact surfaces that engage the supporting surface 21 that would be typically part of a ground surface or a form worksheet upon which concrete is to be formed. The body 14 includes a pair of second contact portions 22 that provide convex arcuate contact surfaces. The portions 22 are located in a plane 23. The plane 23 is inclined to the plane 5 20 by an angle no greater than 900. Preferably, the plane 23 is inclined to the plane 20 by approximately 900. When the mesh 11 is supported by the contact portions 19, the mesh 11 is maintained at a first height. When the mesh 11 is supported by the contact portions 22, the mesh 11 is supported at a raised position (as shown in Figure 2, that is a raised position relative to that shown in Figure 1). The body 14 has a centre of gravity 24 that is located between the enlarged portion 18 and the plane 23 and is preferably approximately mid-way between the contact portions 22 so that a gravitational force 25, being applied to the body 14, will urge the body 14 to move angularly in the direction 26 to automatically assume the position as shown in Figure 2. The body 14 moves to the position shown in Figure 2 when the mesh 11 is raised to a position allowing the body 14 to orient itself in a position shown in Figure 2. Preferably, the body 14 has a recess 27 that is positioned remote from both surfaces 20 and 23 and projects generally upward when the body 14 is resting on the contact portions 19. The recess 27 is configured to receive one of the bars 12 or 13 to support the mesh 11 at a third position. The above described preferred embodiment has a number of particular advantages including being able to support the mesh at a lowered position (Figure 1) and a raised position (Figure 2). In the lowered position, the mesh is closer to the surface 21 and therefore makes it easier for workmen to move over the mesh 11. This also at least partly addresses safety issues in respect of walking over the mesh 11. In the raised position (Figure 2), the mesh 11 is correctly located and therefore permitting pouring of the concrete. Preferably, the portions 19 are spaced by a recess, and the contact portions 22 are spaced by a recess so that concrete can be located between the portions 19, and/or the portions 22. If the chair 11 is coloured to match the colour of the concrete, the chair 11 should not be visible. Preferably, the slot 17 has a longitudinal axis that is inclined to both planes by acute angles, more preferably the slot 17 is inclined to the planes 20 and 23 by approximately 900.

6 Preferably, the enlarged portion 18 (and therefore the rod 13) is located so that when the body 14 is supported on the portions 19, the enlarged portion 18 is located above but between the contact portions 19. However, when the body 14 is supported on the contact portions 22, the enlarged portion 18 (and therefore the rod 13) is located above but between the contact portions 22. By having the enlarged portions so located forces on the rod 13 help maintain the body 14 correctly oriented and stable. The body 14 has a depth (measured perpendicular to the plane of the drawings provided) which ensures the slot enlarged portion 18 provides a passage of sufficient length that the rod 13 is engaged and maintains the body 14 generally perpendicular to the rod 13. In the embodiment of Figures 3 and 4, the engaging portion 15 is an arcuate slot 30 that extends inwardly of the body 14. In this embodiment a second engaging portion 31 is provided, the second engaging portion 31 also being an arcuate slot 32. The slot 30 is arcuate in the opposite direction to the slot 32. Preferably the slots 30 and 32 terminate inwardly of the body 14 so as to be vertically aligned when the bar chair 10 is resting on the surface 21. The slots 30 and 31 are shaped to aid in retaining the bar 13 located in the slot 30, while the slot 32 is configured to retain a further bar 33. The bar 33 would be part of a second mesh panel (having the bar 13), that is stacked on the first mesh panel located below. In the embodiment of Figure 5, one or both of the slots 30 and 32 is provided with a catch 34 in the form of a fin or projection. The catch 34 can be resiliently displaced angularly in the direction 35 by engagement with the bar 33 when the bar 33 moves in the direction 36 along the slot 32. Accordingly the catch 34 provides for movement of the bar 33 from the position "A" to the position "B". However once the bar 33 has passed the catch 34, the catch 34 moves resiliently to the position as shown in Figure 5 and prevents movement of the bar 33 in a direction opposition the direction 36, that is a direction exiting the slot 32. An advantage of the above described bar chair 10 is that the body 14 is moveable angularly freely about the rod 13 so that upon a workman merely lifting the mesh 11, the bar chair 10 will, under the influence of gravity, move from the position as shown in Figure 1 to the position as shown in Figure 2. This makes it easier and therefore quicker for workmen to correctly locate the mesh 11 prior to pouring.

7 A further advantage of the above described preferred embodiment is that the bar chair 10 is easily installed and maintained in a correct orientation and position since the rod 11 is captively located in the enlarged portion 18. Still further advantages of the above described preferred embodiment are provided by the arcuate surfaces of the contact portions 19 and 22. By being a convex and arcuate, the body 14 engages the surface 21 with line contact. Accordingly, irrespective of whether the concrete is poured and allowed to set with the body 14 in the position of Figure 1 or Figure 2, when the formwork having the surface 21 is removed, there is very little of the contact portions 19 (or the contact portions 22) exposed. Preferably, the body 14 is coloured grey so that it approximates the colour of the concrete. This overcomes or substantially ameliorates having to patch portions of a concrete sealing adjacent which the bar chairs are located. Having the slot 17 inclined to the planes 20 and 23, as described above, ensures the bar 13 is at all times biased into the enlarged portion 18. By also having the enlarged portion 18 located relative to the contact portions 19 and 22 as described above, the bar chair 10 is stable as weight urges the body 14 to the position shown in Figure 1 or the position shown in Figure 2, depending on the position selected.

Claims (20)

1. A bar chair including: a body providing; first contact portions and second contact portions, the first contact portions being located in a first plane and the second contact portions being located in a second plane, first contact portions being provided to engage a supporting surface to locate the body in a first position, while the second contact portions are provided to engage the supporting surface locate the body in a second position, and an engaging part to engage a first item to be supported by the bar chair, with the body being angularly moveable about the engaging part so the item is supported at a position above said surface with said supporting body in the first or second position, wherein said engaging part includes a slot having a neck and an enlarged portion, with said item being moveable along said neck to be located in said enlarged portion, with the neck inhibiting movement of the item when the item is located in the enlarged portion, wherein said body is resiliently deformed to provide for movement of the item along said neck.

2. The bar chair of claim 1, wherein the planes are inclined by about 900 relative to each other.

3. The bar chair of claim 1 or 2, wherein the planes are inclined by an angle no greater than 900 relative to each other.

4. The bar chair of claim 1, 2 or 3, wherein the body includes, a centre of gravity spaced from the engaging part so the body is urged by gravity to move angularly about the engaging part away from the first position to the second position when displaced from the first position.

5. The bar chair of any one of claims 1 to 4, wherein said engaging part is a clip.

6. The bar chair of any one of claims 1 to 5, wherein said slot is inclined to said first and second planes by an acute angle. 9

7. The bar chair of any one of claims 1 to 6, wherein said slot is inclined to both planes by approximately 450.

8. The bar chair of any one of claims 1 to 7, wherein enlarged portion is shaped to captively locate this item therein and to provide for angular movement of the body about the enlarged portion.

9. The bar chair of any one of claims 1 to 5, wherein the engaging part is a slot, extending into said body, along which the item can move.

10. The bar chair of claim 9, further including a catch operatively associated with the slot to extend across the slot and urged into position closing the slot to retain the item in the slot, the catch being resilient deflectable to a position permitting the item to move into the slot.

11. The bar chair of any one of claims 1 to 10 including a further engaging part to engage a second item.

12. The bar chair of claim 11, wherein the further engaging part to engage the second item is a slot extending into said body.

13. The bar chair of claim 12, further including a catch operatively associated with the further engaging part slot to aid in retaining the second item in the slot, the catch of the further engaging part slot being resiliently deflectable to a position providing for movement of the second item into the slot.

14. The bar chair of any one of claims 1 to 13, wherein said first contact portions include at least two spaced contact surfaces, and said second contact portions includes at least two spaced contact surfaces.

15. The bar chair of any one of claims 1 to 14, wherein the contact portions and central gravity are positioned so that in moving from said first position to said second position, the body moves angularly through approximately 900. 10

16. The bar chair of any one of claims 1 to 15, wherein said body is molded from plastics materials.

17. The bar chair of any one of claims 1 to 16, wherein said body is cut from sheet plastics materials.

18. The bar chair of any one of claims 1 to 17, wherein said engaging part is located at a higher position when said body is in said second portion relative to first position.

19. The bar chair of any one of claims 1 to 18, wherein the centre of gravity is spaced from the engaging part toward the second plane.

20. The bar chair of any one of claims 1 to 19, wherein the first contact portions and the second contact portions are convex arcuate surfaces. The Australian Steel Company (Operations) Pty Ltd Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON