AU2004202246A1 - Plank Support Stand - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD

PATENT

Plank Support Stand The following statement is a full description of this invention, including the best method of performing it known to me: The invention relates to a plank support stand. More particularly, though not exclusively, the invention relates to structures used to support planks upon which tradespersons can walk and/or other work operations may take place. Such stands might be useful to plasterers, painters, bricklayers or other tradespersons or home handypersons.

Known plank support scaffolds comprise a trestle or other frame erected at or near respective end portions of a plank or planks. Step ladders can be used at either end of a plank to support the same in a raised horizontal orientation to enable a person to sit and/or stand upon the plank to work. Some scaffold structures include lengths of tubing to be inter-engaged to form a stable structure.

The above-described known structures suffer from instability and are time-consuming to erect. Also, such structures are often large and cumbersome, not lending themselves well to transportation in the trunk of a motor vehicle.

Accordingly, it is the object of the: present invention to overcome or substantially ameliorate at least one of the above disadvantages and/or more generally to provide an improved plank support stand.

The present invention resides in a plank support stand including support legs, and a plank support head connecting the legs for supporting one or more planks in a generally horizontal orientation, said plank support head including clamping means

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for clamping said one or more planks and means for actuating said clamping means so as to fix the plank to said stand.

Preferably, the plank support stand comprises a single pair of said legs, each having a stabilising foot.

Preferably, one of said pair of legs is substantially vertical and the other of said pair of legs is inclined, at least one said leg having one or more step members for user access to said supported planks.

In one form, the plank support head includes a hinged member connecting said legs, said hinged member having said clamping means, and means for causing hinging of said hinged member such that the clamping means clamps against opposed edge portions of the plank. Preferably, the means for hinging includes means bearing against an underside of said plank to urge closing of said hinged member against the plank edge portions.

In a further form, the plank support head includes a cross rail extending between said legs, at least an opposed pair of end clamps mounted on said rail and wherein said clamp actuating means urges said end clamps to engage edges of said plank.

The plank support head may further include one or more intermediate clamps mounted on said rail, and may further include means for causing one or more said intermediate clamps to pull down on said planks.

In one preferred form, the clamp actuating means includes lever means connected to one of said end clamps to actuate said clamping.

Preferably, the lever means includes a lever having a first pivotable connection to a clamp actuating rod, a second pivotable connection which travels along a mounting slot transverse to the actuating rod, and means for causing said travel along the mounting slot to cause axial movement of said actuating rod.

In an alternative form, the clamp actuating means includes gear means mounted within said rail, said gear means being connected to one of said end clamps to actuate said clamping. Preferably, the gear means comprises a pinion driving a rack which is connected to said end clamp.

In another preferred form said means for actuating said clamping means includes extendable linkage mean, including includes a pivoting strut linkage between a stationary element of said plank support stand and said clamping means, the linkage pivoting between an overcentred extended position and a retracted position to close and open the clamping means.

Preferably the linkage includes two links, the first link having one end pivotably attached to said stationary element of the plank support stand, the second link having one end pivotably attached to a clamp slidably mounted to the plank support stand, said links being pivotally attached to each other.

In an alternative form said means for actuating said clamping means includes a clamp actuating rod, and said pivoting strut means includes two links, the first link having one end pivotally attached to said stationary element of said plank support stand, the second link having one end pivotally attached to said clamp actuating rod, said links being pivotally attached to each other.

Preferably said first link is provided with means of selective engagement with said stationary element of said plank support stand.

Preferably said first and second links are provided with means of selective engagement with each other.

Preferably said second link is provided with means of selective engagement with said clamp actuating rod.

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In an alternative form said second link is provided with means of selective engagement with said clamp.

Preferably said second link is an adjustable link having adjustment means for changing the length of the link.

Preferably said stationary element of said plank support stand is a support leg of said plank support stand.

Preferably said plank support stand. further includes locking means for locking said strut means in said extended position.

Preferably said locking means is latch means.

Preferred forms of the present invention will be described by way of example with reference to the accompanying drawings, wherein: Fig. 1 is a front elevation view of a stand according to a first embodiment of the present invention; Fig. 2 is a detail of the head portion of the stand of Fig. 1; Fig. 3 is a plan view of the stand head portion of Fig.2; Fig. 4 is a cross-section of the portion shown in Fig.2, taken along line 4-4; Fig. 5 illustrates a wider plank secured by the stand of Fig. 2; Fig. 6 is a front elevation view of a stand according to a second embodiment of the present invention; Fig. 7 is a detail of the head portion of the stand of Fig. 6; Fig. 8 is a plan view of the clamp drive cam lever mechanism of the stand shown in Fig. 6; Figs. 9A to 9C show the clamp drive arrangement of Fig. 6 in a series of successive positions between an unclamped configuration and a clamped configuration; Figs. 10 and 11 are front elevations of a variant of the stand shown in Fig.6, with an additional plank pull-down mechanism; Figs. 12, 13 and 14A to 14C illustrate an alternative cam lever arrangement for the stand of Figs. 6 to 11; Figs. 15 and 16 are front elevations of a multiple plank clamping arrangement employing a gear drive; Figs 17 and 18 are, respectively, plan and elevation views of a gear drive and locking arrangement for the embodiment of Figs. 15 and 16; Figs 19 and 20 illustrate engagement of locking formations on the clamp and the plank; Fig. 21 is a perspective view of a plank support stand according to a third embodiment of the present invention; Fig. 22 is a front elevation view of the plank support stand of Fig. 21 showing the plank support stand in a clamped configuration; Fig. 23 is a front elevation view of the plank support stand of Fig. 21 showing the plank support stand in an unclamped configuration; Fig. 24 is a schematic front elevation view of the plank support stand of Fig.

21 showing the positions of a handle for the plank support stand in an unclamped configuration and a clamped configuration; Fig. 25 is a rear perspective view of an strut arrangement of the plank support stand of Fig. 21 shown in a clamped configuration; Fig. 26 is a rear perspective view of the strut arrangement of Fig. 25 in an unclamped configuration; Fig. 26a is a perspective view of a bolt latch of the plank support stand of Fig.

21; Fig. 26b is a perspective view of a fist link of the strut arrangement of Fig. Fig. 26c is an elevation of the link of Fig. 26b; Fig. 26d is a top view of the link of Fig. 26b; Fig. 26e is an end view of the link of Fig. 26b; Fig. 26f is an elevation of a second link of the strut arrangement of Fig. with a spring bolt attached to it; Fig. 26g is a top view of the link of Fig. 26f; Fig. 26h is an end view of the link of Fig. 26f; Fig. 26i is an elevation of the spring bolt of Fig. 26b; Fig. 26j is a top view of the spring bolt of Fig. 26e; Fig. 26k is an end view of the spring bolt of Fig. 26e; Fig. 27 is an exploded view of a clamp assembly of the plank support stand of Fig. 21; Fig. 28 is a front elevation view of the clamp assembly of Fig. 27; Fig. 29 is an exploded view of an alternative embodiment of the clamp assembly of the plank support stand of Fig. 21; Fig. 30 is a front elevation of the clamp assembly of Fig. 29; Fig. 31 is a perspective view of a frame including two plank support stands embodying the present invention; Fig. 32 is a perspective view of a frame including two plank support stands embodying the present invention, a frame extension and an extendable outrigger; Fig. 33 is an end view of the frame of Fig. 32; Fig. 34 is an end view of the frame extension of Fig. 32; Fig. 35 is a front view of the frame extension of Fig. 34; Fig. 36 is a front view of the extendable outrigger of Fig. 32; Fig. 37 is an end view of the outrigger of Fig. 36; Fig. 38 is a sketch of a frame and plank assembly with attached handrail; Figs 39 and 40 illustrate a clamp assembly for attachment of the handrail; Figs 41 and 42 are elevations of a further variant of the stand configured as a sawhorse, in its collapsed and operating positions respectively; and Fig. 43 is an elevation of a deck arrangement using two pairs of the stands of Figs 41 and 4 2 Referring now to the drawings, there is illustrated in Figs. 1 5 a plank support stand according to a first embodiment of the present invention. The illustrated plank support is adapted to co-operate with one or more similar stands at spaced locations along the length of the plank or other elongated work support member, to support the plank in a generally horizontal orientation.

In this embodiment, stand 10 includes a single pair of collapsible, telescopic legs 12 connected at their tops by a plank support head 15. A stabilising foot 13 is provided at the bottom of each leg 12, and a telescopic cross-brace 14 extends between the legs 12 for additional rigidity.

The plank support head 15 consists of a pair of plates 11 joined by a central hinge 17, each plate being rigidly affixed to the upper end of a respective leg 12, for example by welding or bolting. The edge portion of each plate 11 of head 15 has a plank clamping portion 23 which clamps the opposed edges of the plank 22, with an inturned lip 16 which fits over the edge of the plank to prevent to limit upwards movement of the plank.

A tensioning arrangement is provided, comprising a threaded passage, formed by a nut attached to the centre of the hinge, through which passes a bolt 18 to which is affixed a plank engagement plate 21. The bolt has a winged head 19.

In use, a plank will be fitted into the stand, either by sliding the stand onto the edge of the plank or by opening up the angle of the hinged cross-member and inserting the plank from above, and the legs of the stand frame are then moved apart to bring the clamping portions of the cross-member to bear against the edges of the plank.

Tightening of bolt 18 by manipulation of the winged head 19 causes the engagement plate 21 to move upwardly against the undersurface of the plank 22 and urges the plank against the underside of the lips 16. Further tightening pushes the hinge line of the cross-member 15 down, decreasing the angle between the two plates and firmly clamping the edges of the plank.

The cross-brace 14 is then adjusted and tightened to stiffen the frame.

As apparent from comparison of Fig. 2 with Fig. 5, the illustrated plank support is adapted to accommodate planks of different widths.

To remove the plank, the cross-brace is disconnected and the bolt 18 loosened to allow the plank 22 to be lifted or slid out. The legs can be swung to a generally parallel position and telescoped down to their shortest length, to minimise the space required for transport and storage. Because each frame has just a single leg on each side, with the stabilising feet being removable if required, the units stack efficiently in the back of a vehicle or at a storage shed.

In one version of the stand of Figs 1-5, a pair of the stands can be provided as a kit with a work support plank member of narrow but deep section to act as a sawhorse or similar work support. A further variant of this stand arrangement is described later with reference to Figs 41-43.

In Figs. 6 to 9C of the accompanying drawings there is schematically depicted a plank support stand 30 according to a second embodiment of the present invention. This stand may support either a single plank (see Fig. 6) or multiple planks in side-by-side orientation (Fig. 7).

In common with the first embodiment, the stand of Figs. 6-9C also has a single pair of legs 12a and 12b with plank support head 25 and a cross-brace 14 extending therebetween. Stand 30 includes one vertical leg 12a and one outwardly angled leg 12b, so that the stand may be positioned close against a wall (not shown) while maintaining sufficient stability in the direction transverse to the plank. Stabilising feet 13 provide stability in the direction parallel to the plank. Legs 12a, 12b are telescopically adjustable to allow adjustment of the height of the platform to be formed, while one or both of the legs, preferably the inclined leg 12b, has step treads 24 thereon.

In an unillustrated embodiment, the stand may further provide means for attachment of handrail support at one or both sides of the stand.

Referring to Figs. 7 to 9C, the plank support head 25 comprises a fixed length tubular cross beam 27 extending between the upper ends of the legs 12a, 12b, which acts as a rail for slidable mounting blocks carrying a pair of generally C-shaped plank edge clamps 29, and a clamp drive mechanism. As shown in Fig. 7, a one-plank system can be extended to accommodate two or more planks by adding similarly-mounted

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shaped intermediate clamping members 28.

In the embodiment of Figs. 6 to 9C, the clamp drive mechanism consists of a pullrod 39 mounted through the clamp mountings 38 under the cross-beam, actuated by the lever arrangement illustrated in detail in Figs. 8 and 9A to 9C.

Figs. 9A to 9C is a series of front elevations showing operation of the cam lever clamp drive mechanism from the unclamped position (Fig. 9A) to the clamped position (Fig.

9C). The lever mechanism includes a lever mounting box 48 fixed to the bottom of the rail 27, having a generally vertical slot 50 which slidably receives the end pivot pin 52 of an L-shaped clamp actuating lever 43. The lever has a further pivotable mounting pin 54 at its elbow, connected to the end of the pullrod 39. As the lever handles 45 are depressed, the pullrod is pulled to the right (as shown), which in turn brings the left end clamp 29 across to engage against the edge of the plank (not shown). The mounting for the right end clamp bears against the lever mounting box 48, thus clamping the plank or planks between the two end clamps, held down by their engagement under the top flanges of the end clamps and, where applicable, the intermediate clamp 28 (Fig. As may best be seen in Fig. 9C, the top of the guide slot 50 ends above the axis of the pullrod, so that clamp is held in the clamped position by overcentreovercentring of the lever.

Preferably, the recesses of the C- and I-clamps which receive the edge of the plank are tapered, for example as shown in Fig. 7, to provide a tight engagement with the plank edge.

To unclamp the planks for removal, the user lifts the lever handles 45. Compression spring 40 assists return of the far left end clamp to the unclamped position Figs. 10 and 11 illustrate a variation on the embodiment of Figs. 6 to 9C, further include an intermediate clamp with a pull-down mechanism. The mounting blocks 37, 38 of the two end clamps 29 have downward extensions, to which are pivotably connected linkages 33, 34 to a vertical pullrod 35 which carries the top flanges 15 of the intermediate clamp. As the clamping lever is actuated, reducing the distance between the two end clamps, the top flangesl 5 are pulled down to bear against the planks. Thus, the planks are simultaneously clamped from the top and from the sides.

The compression spring 40 serves to release both the top and side clamping upon release of the clamping lever.

In the construction of Figs. 10 and 11, the end clamps may be simply an L-section, or have only a small top flange, for improved ease of installing and removing the planks.

Figs. 12 to 14C show an alternative clamping lever arrangement for the plank stand of Figs. 6 to 11. In this embodiment, the far side end clamp is fixed while the near side end clamp moves with the pullrod 39. The lever mounting box 48 is similar to that in Figs. 12 to 14C, with the L-shaped lever replaced by a pivotable link 57 with a handle 58. As the handle is lifted, the link pivots to near horizontal, pushing the end clamp across into engagement with the edge of the plank. Pressing down the handle will release the clamp.

Figs. 15 to 18 show a head arrangement adapted for multiple planks, incorporating a rack and pinion gear clamp drive located inside the tubular beam 27. The clamp drive includes a pinion gear 60 actuated by a drive handle 62, the pinion meshing with a rack 63 attached to the near side end clamp. The far side end clamp is fixed, while the intermediate clamps are attached to the mounting of the near side end clamp by a pull rod 39 to assist plank release.

The arrangement includes a pawl 64 for preventing accidental unclamping of the plank support by allowing rotation of the pinion in the clamping direction only when the pawl is engaged. The pawl may be external to the tubular beam, engaging an external ratchet gear 66 linked to the drive pinion, as shown in Figs 15 and 16, or alternatively may be attached to the pivot axis of a handle 68, directly engaging the pinion inside the tube as shown in Figs. 17 and 18.

Figs. 19 and 20 are, respectively, plan and cross-section views of a clamp and plank construction including a plurality of complementary locking formations in the clamp 29 and plank 22. The plank 22 has a series of notches 70 along its length, which receive matching lugs 72 inside the C-shaped clamp 29. Such formations assist locking of the plank in the clamp, and is especially advantageous where the stand is to be used at the end of a plank, for example at the junction of two planks laid end-toend, as illustrated in Fig. 19.

In Figs. 21 to 28 of the accompanying drawings there is schematically depicted a plank support stand 80 according to a third embodiment of the present invention. This stand may support either a single plank or multiple planks in side-by-side orientation.

In common with the first embodiment, the stand of Figs. 21-28 also has a single pair of telescopically adjustable legs 12a and 12b with plank support head 25 extending therebetween. Stabilising feet 13 provide stability in the direction parallel to the plank.

As best shown in Figs. 22 and 23, the plank support head 25 comprises a fixed length tubular cross beam 27 extending between the upper ends of the legs 12a, 12b, which acts as a rail for slidable mounting blocks 82, 84 carrying plank edge clamps 29a and 29b, and a clamp drive mechanism.

Similarly to the embodiment shown in Figs. 15 and 16, the clamp drive mechanism consists ofa pullrod 39 mounted through the clamp mountings 82 and 84 under the cross-beam 27. The clamp drive mechanism is actuated by a pivoting strut mechanism 86 illustrated in detail in Figs. 25 and 26.

The pivoting strut mechanism 86 includes a linkage arrangement consisting of two links a first link 88 and a second link 90 pivotally attached to each other by a pivot pin 92. The first link 88 has one end pivotably attached to the plank support leg 12a, while the second link 90 has one end pivotably attached to the sliding block 82.

The links 88 and 90 are sized and positioned so as to extend past the straight line to an overcentred extended position to move the clamping means (29a, 29b, and 29c) is in the clamped configuration. To accommodate a wide range of plank widths, link 88 can be provided with means of selective engagement (not shown) with the plank support leg 12 to adjust the distance between said clamping means in its closed position.

Alternatively, the links 88 and 90 may include means of selective engagement (not shown) with each other. It will be appreciated by those skilled in the art that such means of selective engagement can include a plurality of holes provided on the link 88 and/or the link 90 for receiving pivot pins therethrough.

To achieve fine adjustment of the clamping mechanism, the link 90 is an adjustable link having adjustment means 110 for changing the length of the link As best shown in Figs. 25 and 26, the adjustment means 110 includes a pivot nut for receiving a pivot pin 116, and a bolt 114 threadably connected to the link To secure the pivoting strut mechanism 86 in its overcentred extended position, the plank support stand 80 is further provided with a bolt latch 120 including a socket 122 fixed to the link 88, and a latch body 124 fixed to the link As shown in Figs. 26a and 26f- 26k, the latch body 124 houses a latch bolt 126 and includes a longitudinal groove 125 adapted to receive a pin 128 of the latch bolt 126.

The bolt 126 is axially slidable within the latch body 124 and spring-biased by means of a compression spring 127 disposed in the latch body 124.

As best shown in Fig. 25, the latch bolt 126 engages the socket 122 to lock the pivoting strut means 86 in its overcentred extended position. It will be appreciated by those skilled in the art that any other suitable locking means can be used for this purpose.

The pivoting strut mechanism 86 is further provided with a handle 100 including a sleeve portion 102 within which a handle bar 104 is axially slidable. The sleeve portion 102 is fixed to the first link 88 so that the handle bar 104 and the first link 88 form an X-shaped configuration. The handle bar 104 is provided with a pin 106 for preventing the fall out of the handle bar from the sleeve 102.

As shown in Fig. 24, when the handle bar 104 is retracted from the sleeve 102, it can act as a lever, with a pivot point 130 acting as a fulcrum, to facilitate the disengagement of the clamps 29a, 29b, and 29c.

As illustrated in Figs. 27 and 28, each clamp 29 can be adapted to receive within its Cchannel used in conjunction with a clamp insert 140 for locking to the plank edge. To this end the clamp 29 is provided with openings 144a,b,c adapted to receive projections 142 a,b,c formed on the clamp insert 140. The overall width of the clamp insert 140 including the projection 142 is such that the clamp insert 140 can be received within the C-shaped portion of the clamp 29, as illustrated in Fig. 28.

The clamp insert has pins 148 adapted to engage with recesses (not shown) in the side of the planks to help lock the planks in position.

As illustrated in Fig. 31, two plank support stands 150a and 150b can be connected to each other by two cross braces 151a and 151b to form a frame 152. When viewed in elevation, the cross braces 15 la and 15 lb form an X-shaped configuration. Each of the cross braces includes an inner tube 154a, 154b insertable into the outer sleeve 156a, 156b so that the length of the cross brace 151 can be adjusted by moving the inner tube 154 and the outer sleeve 156 relative to each other. The cross braces 151 are also provided with locking means so that the position of the inner tube 154 relative to the position of the outer sleeve can be temporarily locked.

As illustrated in Figs. 32 and 33, for extra height the frame 152 can further include two frame extensions 160a and 160b interposed between an upper and a lower portion of the support leg 12, and an extendable outrigger 170.

The frame extension 160 includes two telescopically adjustable frame members 162a and 162b, and two cross members 164 and 166 extending therebetween. Likewise, the length of the outrigger 170 is adjustable by sliding an inner tube 172 through a sleeve 174. The outrigger 170 can be locked by locking means 176.

In use, to clamp one or more planks between the clamps 29a, 29b, and 29c, the user forces the pivoting strut mechanism 86 to its overcentred extended position. As a result, the pullrod 39 is pulled to the right (as shown in Fig. 22), which in turn brings the left end clamp 29a across to engage against the left edge of the plank 150. The plank 150 then pushes the intermediate clamp 29b into engagement with the second plank 152 which in turn bears agamnst the right end clamp 29c fixed to the cross bar 27. As a result, the clamps 29a, 29b, and 29c are held in the clamped position by overcentering of the links 88 and 90. The user then pushes the handle bar 104 down and locks the overcentred mechanism by the bolt latch 120.

To unclamp the planks for removal, the user first unlocks the bolt latch 120. The user then lifts the handle bar 104 as shown in Fig. 24 and uses it as a lever to move the pivoting strut mechanism 86 away from the overcentre position. As a result, the pullrod 39 and the left end clamp 29a mounted to the sliding block 82 move across to the left side of the plank support stand 10 thereby disengaging the plank 150 and the clamp 29a. As the distance between the clamp 29a and the intermediate clamp 29b reaches a predetermined distance sufficient to allow removal of the plank 150, a nut attached to the pullrod 39 starts to bear against the clamp mounting 84 to which the intermediate clamp 29b is fixed. As a result, the clamp 29b moves away from the fixed clamp 29c to disengage the plank 152.

Fig 38 is a sketch of a frame and plank assembly with a handrail 180 attached to the edge plank, or to all the planks.

Figs 39 and 40 show a clamp arrangement 182 for attaching the handrail 180 to one or more planks of the assembly, in the open position (Fig. 39) and closed position (Fig The clamp is generally similar in operation to one or more embodiments of the clamp of the plank support head, having a cross-rail 184 supporting a pair of Cchannels 186 and an lever-operated actuating mechanism 188. Clamps (not shown) attach the handrail to the cross-rail 184.

Figs 41 and 42 show a stand generally similar to that of Figs 1 to 5, adapted for use as a collapsible sawhorse. In common with the stand of Fig 1, stand 200 has a pair of legs 202 each permanently fixed, for example by welding or other suitable means, to clamping plates 204 hinged together along the centre line of the stand, with a collapsible cross-brace 206 connecting the legs 202. In the case of Figs 41 and 42 the cross-brace 206 has a central pivot 208 and end pivots 210 attaching to the legs, so that the legs can move between a collapsed position illustrated in Fig 41, in which the jaws of the clamping plates are open, to an extended position (Fig 42) in which the jaws clamp onto a work support member. In the extended position, the two arms of the cross-brace are pressed down past the horizontal to an overcentred locking position. This mechanism has the advantage of being easily operated by the user's foot. If desired, additional locking means such as latch (not shown) may be included.

In the embodiment of Figs 41-42, the clamping plates are adapted to receive a work support member 212 of standard lumber section, such as nominal 100mm by to facilitate replacement of the work support if damaged by a saw cut or similar. As the stand is adapted to retain only a single size plank, the tensioning arrangement of the embodiment of Figs 1-5 may be omitted.

A pair of the stands, with an appropriately sized piece of lumber therebetween, therefore forms a work stand which is collapsible for storage and transport and easily assembled on site.

Fig. 43 is a sketch of a deck arrangement utilising a four of the sawhorse stands of Figs 41-42. In this arrangement, the work support member 212 is replaced with an aluminium or other lightweight deck 214 extending between two pairs of the stands.

Each corner of the deck 214 has formations 216 of similar section to the standard lumber section for which the stand is adapted, so that one stand can be clamped onto each corner to provide an elevated deck. If desired, the deck may also be provided with means for attachment of a handrail (not shown).

In this specification, the word "comprising is to be understood in its "open" sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of'. A corresponding meaning is to be attributed to the corresponding words "comprise, comprised and comprises" where they appear.

While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

It will further be understood that any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates.

Claims (36)

1. A plank support stand including support legs, and a plank support head connecting the legs for supporting one or more planks in a generally horizontal orientation, said plank support head including clamping means for clamping said one or more planks and means for actuating said clamping means so as to fix the plank to said stand.

2. A plank support stand according to claim 1, comprising a single pair of said legs.

3. A plank support stand according to claim 2, wherein each said leg has a stabilising foot.

4. A plank support stand according to claim 2 or 3, wherein one of said pair of legs is substantially vertical and the other of said pair of legs is inclined. A plank support stand according to any of claims 2 to 4, wherein at least one said leg has one or more step members for user access to said supported planks.

6. A plank support stand according to claim 1, wherein said plank support head includes a hinged member connecting said legs, said hinged member having said clamping means, and means for causing hinging of said hinged member such that the clamping means clamps against opposed edge portions of the plank.

7. A plank support stand according to claim 6, wherein said means for hinging includes means bearing against an underside of said plank to urge closing of said hinged member against the plank edge portions.

8. A plank support stand according to claim 1, wherein said plank support head includes a cross rail extending between said legs, at least an opposed pair of end clamps mounted on said rail and wherein said clamp actuating means urges said end clamps to engage edges of said plank.

9. A plank support stand according to claim 8, wherein said plank support head further includes one or more intermediate clamps mounted on said rail. A plank support stand according to claim 8 or 9, wherein said end clamps are substantially C-shaped to engage an edge of the plank.

11. A plank support stand according to claim 10 wherein said C-shape is tapered so as to tighten against upper and lower surfaces of the planks when said clamping is actuated.

12. A plank support stand according to claim 9, wherein said one or more intermediate clamps are substantially I-shape to engage edges of two adjacent planks.

13. A plank support stand according to claim 9 or 12, including means for causing one or more said intermediate clamps to pull down on said planks.

14. A plank support stand according to claim 8, wherein said clamp actuating means includes lever means connected to one of said end clamps to actuate said clamping. A plank support stand according to claim 14, wherein said lever means includes a lever having a first pivotable connection to a clamp actuating rod.

16. A plank support stand according to claim 15, wherein said lever has a second pivotable connection which travels along a mounting slot transverse to the actuating rod, and means for causing said travel along the mounting slot to cause axial movement of said actuating rod.

17. A plank support stand according to claim 16, wherein said lever is L-shaped, having said first pivotable connection as a fulcrum point of the lever.

18. A plank support stand according to claim 17, wherein said lever includes an actuating handle for pivoting the lever.

19. A plank support stand according to claim 8, wherein said clamp actuating means includes gear means mounted within said rail, said gear means being connected to one of said end clamps to actuate said clamping. A plank support stand according to claim 19, wherein said gear means comprises a pinion driving a rack which is connected to said end clamp.

21. A plank support stand according to any preceding claim, wherein said clamping means includes one or more locking formations which engage with complementary formations on said plank.

22. A work support stand including support legs, and a support head connecting the legs for supporting a work support member in a generally horizontal orientation, said support head including clamping means for clamping said work support member and means for actuating said clamping means so as to fix the work support member to said stand.

23. A work support stand according to claim 23, wherein said support head includes a hinged member connecting said legs, said hinged member having said clamping means, and means for causing hinging of said hinged member such that the clamping means clamps against opposed edge portions of the work support member.

24. A work support according to claim 22 or 23, including an elongated work support member supported between a pair of said work support stands. A plank support stand according to claim 1 wherein said means for actuating said clamping means includes pivoting strut means.

26. A plank support stand according to claim 25 wherein said pivoting strut means includes a linkage between a stationary element of the plank support stand and said clamping means, the linkage being pivotable between a retracted position and an extended position.

27. A plank support stand according to claim 25 wherein the linkage includes two links, the first link having one end pivotably attached to said stationary element of the plank support stand, the second link having one end pivotably attached to a clamp slidably mounted to the plank support stand, said links being pivotally attached to each other.

28. A plank support stand according to claim 25 wherein said means for actuating said clamping means includes a clamp actuating rod, and said pivoting strut means includes two links, the first link having one end pivotally attached to a stationary element of said plank support stand, the second link having one end pivotally attached to said clamp actuating rod, said links being pivotally attached to each other to move between extended and retracted positions.

29. A plank support stand according to claim 27 wherein said first link is provided with means of selective engagement with said stationary element of said plank support stand. A plank support stand according to claim 27 wherein said first and second links are provided with means of selective engagement with each other.

31. A plank support stand according to claim 27 wherein said second link is provided with means of selective engagement with said clamp actuating rod.

32. A plank support stand according to claim 27 wherein said second link is provided with means of selective engagement with said clamp.

33. A plank support stand according to claim 27 or 28 wherein said second link is an adjustable link having adjustment means for changing the length of the link.

34. A plank support stand according to claim 27 or 28 wherein said stationary element is a support leg of said plank support stand.

35. A plank support stand according to claim 27 or 28 further including a handle for urging said strut means into an overcentred extended position, said extended position preventing movement of said clamping means away from engagement with said one or more planks.

36. A plank support stand according to claim 27 or 28 further including a lever handle for urging said strut means away between said extended and retracted position to engage and release said clamping means.

37. A plank support stand according to claim 36 wherein said lever handle includes an elongated member movably mounted in a sleeve so as to be axially slidable relative to said sleeve, said sleeve being fixed to one of said links.

39. A plank support stand according to claim 26 further includes locking means for locking said pivoting strut means in said extended position. A plank support stand according to claim 39 wherein said locking means is latch means.

41. A frame including a first and a second plank support stands according to claim 1, said stands being connected to each other by a cross member.

42. A frame according to claim 41 wherein said cross member includes two cross braces forming an 'X'-shaped configuration when said frame is viewed in elevation.

43. A frame according to claim 41 or 42 further including a handrail attached to said plank.

44. A plank support stand as herein described, with reference to any of the accompanying drawings. Dated this 25th day of May, 2004, Bradley John Reinhard Patent Attorneys for the Applicant Halford Co.