GB2109675A - Improvements in and relating to trestles - Google Patents

Abstract

A carpenters trestle formed from metal leg assemblies (16 and 18), each comprising a pair of splayed apart limbs, secured at opposite ends of a metal bridging channel member (14) in which is removably and replaceably received the stock (12) of a wooden workbench member (10). The leg assemblies are foldable and are hinged to brackets (22 and 24) on the metal bridging channel (14) and pivoted struts (48 and 50) hold the leg assemblies (16 and 18) in their opened out condition. The inner ends of the struts have threaded pins that slide in a slot (28) in member (14) and that are clamped therein. The limbs of each assembly may be hinged to one another for folding. The workbench member may be replaced by power tools. <IMAGE>

Description

SPECIFICATION Improvements in and relating to trestles Field of Invention This invention concerns trestles and in particular trestles used by carpenters and other workmen.

Background to the Invention A conventional carpenters' trestle is formed from timber and generally comprises a bridging member on which work to be sawn or otherwise worked on can be rested having legs protruding from each end of the bridging member.

The bridging member is normally integrally formed with the legs and in consequence when the bridging member becomes damaged (as is inevitable during use) as by saw cuts etc., the testle eventually becomes unusable and has to be disgarded.

It is, therefore, one object of the present invention to provide an improved trestle in which damage to the bridging member does not necessarily result in a loss of the trestle per se.

It is another object of the present invention to provide a trestle the overall size of which can be reduced for storage and transportation, but without loosing any of the rigidity and sturdiness normally required of such a device.

Summary of the Invention According to one aspect of the present invention a trestle comprises: 1. An elongate metal member, 2. Two metal leg assemblies having splayed apart legs which are attached to brackets located at opposite ends of the said elongate metal member, and 3. A wooden workbench member removably secured to the elongate metal member to allow the workbench member to be removed and replaced or repaired.

According to a preferred feature of the invention the leg assemblies are hinged to brackets located on the underside of the elongate metal member adjacent opposite ends thereof.

According to a further preferred feature of the invention, means is provided for retaining the leg assemblies either in their opened out condition in which they serve as legs or in a folded condition in which the leg assemblies are folded against the underside of the elongate metal member to reduce the space required for storing and transporting the trestle.

According to a further preferred feature of the invention, the elongate wooden workbench member is formed in two parts, a lower member which is secured to the elongate metal member and an upper plank member which actually forms the working surface.

According to another feature of the invention, the elongate metal member is in the form of a channel in which a wooden stock is fitted, the sides of the channel section serving to locate the stock and nuts, bolts, screws or other retaining devices are used to retain the stock within the channel section.

According to another aspect of the invention, the elongate metal member may be drilled and/or tapped and the like so that different devices or mechanism may be mounted thereon in place of the wooden stock. Thus, for example, the metal member may be adapted to receive a power tool.

Where the leg assemblies are hinged to the underside of the elongate metal member, the length of one of the brackets may be longer than the length of the other so as to allow the two leg assemblies to be folded one above the other, one of the leg assemblies lying flush against the underside of the elongate metal member and the other lying flush and parallel to the first mentioned folded up leg assembly.

The leg assemblies are conveniently rigidly formed with splayed apart limbs which are fixed in position. However, according to another aspect of the invention, the two limbs of each leg assembly may be themselves hinged together at their upper end so as to allow the two limbs of each leg assembly to be collapsed inwardly towards each other to further reduce the overall space required by the trestle when in its collapsed condition.

Conveniently a bracing plate or strut is provided between the limbs of each leg assembly to hold them in their splayed apart condition and where the leg assembly limbs are themselves hinged, relative one to the other, the bracing plate or strut is adapted to be removable from one or both of the limbs or is rendered adjustable relative to at least one of the limbs to allow for the limbs to be moved inwardly from their splayed apart condition.

Conveniently the means for retaining the leg assemblies in their opened out condition comprises for each leg assembly a strut hinged to the leg assembly at one end, the other end being held captive in a slideway or like guide means located on the underside of the elongate metal member with means being provided for retaining the captive end of the strut at different positions along the length of the guide means commensurate with at least the opened out condition of the leg assembly and the fully folded condition of the leg assembly.

Conveniently the guide means is an elongate slot in an elongate spine or flange which protrudes below the elongate metal member and the means holding the said other end of the strut captive in the said guide means comprises a lockable device for clamping the said other end of the strut onto the spine or flange to hold the leg assembly to which the strut is connected at the desired position.

Conveniently the limbs forming each leg assembly include feet at their lower end which may be adjustable to compensate for unevenness in a floor on which the trestle stands.

The invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a side elevation of a trestle constructed in accordance with the invention, and Fig. 2 is a plan view from below showing the trestle with the leg assemblies folded beneath the bridging section thereof.

Detailed Description of Drawings Referring to Fig. 1, a carpenters' trestle comprises a wooden workbench member or plank 10 secured to a wooden stock 12 so as to form a generally 'T' section member, the stock of which is at least partly contained within a metal channel section 14 which constitutes a bridge between two leg assemblies generally designated 1 6 and 1 8 respectively.

The bridge is drilled at least on its underside so as to allow nuts or bolts or screws to pass into the stock 1 2 for securing the latter into the channel section 14. Reference is made here to Fig. 2 which shows the heads of screws 20 which secure the stock 1 2 into the channel section.

Un the underside of the channel section bridge 14 are provided two brackets 22 and 24 and an elongate central spine or flange 26 having an elongate slot 28 therein.

The slot 28 is shown as a single slot but it will be appreciated that the central region of the slot 28 will not be required and to this end two slots separated by a solid flange section may be provided in the alternative.

Hinge or pivot pins 30 and 32 extend between opposite sides of the brackets 22 and 24 respectively (see Fig. 2) and are held axially in position by means of enlarged ends formed as by preening over the protruding ends of the pins 30 and 32. The enlarged heads are designated by reference numeral 34.

It will be appreciated that the pins 30 and 32 may in fact be in the form of hexagonal bolts in which event a hexagonal nut may be screw threaded onto a protruding end of the bolt to hold the latter in position.

Each leg assembly comprises a splayed apart pair of limbs, the limbs of leg assembly 1 6 being denoted by reference numeral 36 and those of leg assembly 1 8 by reference numeral 38.

It will be seen that the position of the axis of the pivot pin 30 is in fact displaced relative to the axis of the pivot pin 32 by a distance commensurate V\/ILffI Llle thickness of the limbs of the leg assembly 1 8 so that the latter can be folded under the trestle to lie flush with the underside of the channel section 14 and will then allow the limbs of the leg section 1 6 to be folded against the leg assembly 1 8. To this end the bracket 22 is longer than the bracket 24.

The limbs are welded or otherwise secured to subassemblies 40 and 42 respectively which are held captive on the pins 30 and 32 respectively and are furthermore welded or otherwise secured to at least one bracing strut 44 in the case of limbs 36 and 46 in the case of limbs 38.

Although not shown, where the limbs 36 and 38 are to be adjustable inwardly towards one another so as to reduce the width of the splayed apart limbs for storage or transportation, the rigid fixing between the ends of the limbs and the subassemblies 40 and 42 respectively and any rigid fixing between the bracing struts 44 and 46 and the limbs to which they are attached, must be dispensed with and articulating joints or lost motion connections must be provided as appropriate with provision for securing the limbs either in their splayed apart position (as shown in Fig. 2) or in a condensed, moved together, position (not shown).

The leg assemblies 16 and 18 are maintained rigid with the bridging member 14 by means of further struts 48 and 50. These struts are pivotally joined to the bracing struts 44 and 46 and to this end each bracing strut includes a bracket located between the two splayed apart limbs 36 or 38 respectively with a pin which passes through the bracket and holds captive one end of one of the struts 48 or 50 as the case may be.

The other end of each strut 48 or 50 is held captive by means of a threaded pin 52 or 54 respectively having an enlarged head at one end and a threaded collar 56 or 58 respectively screwed onto it's protruding threaded end. Each of the coliars 56 and 58 includes a protruding lever 60 and 62 respectively by which the latter can be twisted and tightened onto the protruding threaded end so as to tighten and clamp the strut 48 against the spine 26. In this way the upper end of each of the struts 48 and 50 can be secured in position at any desired location along the length of the slot 28 by which it is guided.

Where the pins 52 and 54 are in the form of hexagonal headed bolts or the like, the bolt head is conveniently welded or otherwise secured to the strut 48 or 50 so as to prevent the latter from being twisted and turned about its axis when the collar 56 is rotated.

As best seen in Fig. 2, each of the struts 48 and 50 may be bifurcated and formed from two parallel members which straddle the spine 26 at their upper end and the bracket (60 or 62) (shown in dotted outline in Fig. 1) at their lower ends.

The limbs 36 and 38 may have to stand on uneven ground and a degree of levelling can be provided for by provid',ny adjustable feet such as at 64 at the lower end of each of the limbs 36 and 38.

Claims (14)

1. A trestle comprising: (1) an elongate metal member.

(2) two metal leg assemblies having splayed apart legs which are attached to opposite ends of the said elongate metal member, and (3) a wooden workbench member removably secured to the elongate metal member to allow the workbench member to be removed and replaced or repaired.

2. A trestle as claimed in claim 1 in which the leg assemblies are hinged to brackets located on the underside of the elongate metal member adjacent opposite ends thereof.

3. A trestle as claimed in claim 2 in which means is provided for retaining the leg assemblies either in their opened out condition in which they serve as legs or in a folded-in condition in which the leg assemblies are folded against the underside of the elongate metal member to reduce the space required for storing and transporting the trestle.

4. A trestle as claimed in any of claims 1 to 3 in which the elongate wooden workbench member is formed in two parts a lower member (or stock) which is secured to the elongate metal member and an upper plank member which is secured to the lower member and forms the working surface.

5. A trestle as claimed in claim 4 in which the elongate metal member is in the form of a channel in which the wooden stock is fitted, the sides of the channel section serving to locate the stock and nuts, bolts, screws or other retaining devices are used to retain the stock within the channel section.

6. A trestle as claimed in any of the preceding claims in which the elongate metal member is drilled and/or tapped or the like so that different devices or mechanisms such as power tools may be mounted thereon in place of the workbench member.

7. A trestle as claimed in any of claims 2 to 6 in which the length of one of the brackets is longer than the length of the other so as to allow the two leg assemblies to be folded one above the other, one of the leg assemblies lying flush against the underside of the elongate metal member and the other lying flush and parallel to the first mentioned folded up leg assembly.

8. A trestle as claimed in any of claims 2 to 7 in which the leg assemblies are rigidly formed with splayed apart limbs which are fixed in position.

9. A trestle as claimed in any of claims 2 to 7 in which the two limbs of each leg assembly are themselves hinged together at their upper end so as to allow the two limbs of each leg assembly to be collapsed inwardly towards each other to further reduce the overall space required by the trestle when in its collapsed condition.

10. A trestle as claimed in any of claims 1 to 9 in which a bracing plate or strut is provided between the limbs of each leg assembly to hold them in their splayed apart condition.

11. A trestle as claimed in claims 9 and 10 in which the bracing plate or strut is adapted to be removable from one or both of the limbs (or is rendered adjustable relative to at least one of the limbs), to allow for the limbs to be moved inwardly from their splayed apart condition.

12. A trestle as claimed in any of the preceding claims in which the means for retaining the leg assemblies in their opened out condition comprises, for each leg assembly, a strut hinged to the leg assembly at one end and held captive at the other end in a slideway or like guide means located on the underside of the elongate metal member, and means is provided for retaining the captive end of the strut at different positions along the length of the guide means commensurate with at least the opened out condition of the leg assembly and the fully folded condition of the leg assembly.

13. A trestle as claimed in claim 12 in which the guide means is an elongate slot in an elongate spine or flange which protrudes below the elongate metal member and the means holding the end of the strut captive in the said guide means comprises a lockable device for clamping the strut onto the spine or flange to hold the leg assembly (to which the strut is connected) at the desired position.

14. A trestle as claimed in any of the preceding claims in which the limbs forming each leg assembly include feet at their lower end which are adjustable to compensate for unevenness in a floor on which the trestle stands.

1 5. A trestle constructed arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawing.