GB1578751A

GB1578751A - Saw trestles

Info

Publication number: GB1578751A
Application number: GB773776A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-02-27
Filing date: 1976-02-27
Publication date: 1980-11-12

Description

(54).IMPROVEMENTS IN OR RELATING TO SAW TRESTLES (71) We, JOHN THOMAS WATKINS, 8, Hemwood Road, St. Leonard's Park, Windsor, Berkshire, a British subject, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to saw trestles, sometimes referred to as saw horses. Conventional forms of saw trestle comprise a narrow horizontal member supported at each end upon two inclined legs which are secured at their upper ends to the horizontal member. The trestle is used by placing work upon the horizontal member and holding it there manually. Such an arrangement is not entirely satisfactory as even small workpieces cannot be held firmly by the user.

According to the present invention, a saw trestle comprises a top structure of elongate form, first and second clamping jaw members mounted separately on the top of the top structure, at least one of the members being movable along the longitudinal axis of the top structure towards and away from the other member, a mechanism for moving at least the one member, and a base structure including legs for supporting the trestle in an erected condition, the trestle being convertible into a collapsed condition in which it is of substantially lamellar shape.

The base structure may include leg assemblies defining the legs and attached to the top structure in such manner as to permit the assemblies to be moved between an erected condition and a folded condition in which the assemblies lie adjacent the top structure.

Alternatively, the top structure may include means for receiving the legs for supporting the trestle in an erected condition, the legs being detachable from the receiving means when the trestle is to assume a collapsed condition.

By way of example only, embodiments of the invention will now be described in greater detail with reference to the accompanying of which: Fig. 1 is a side view partly in section of part of a first embodiment, Fig. 2 is an end view of the first embodiment in an erected condition, Fig. 3 is a perspective view of the first embodiment in an erected condition, and also showing an attachment, Fig. 4 is a perspective view of part of a second embodiment, Fig. 5 is a perspective view of the first embodiment modified by the attachment of a further clamping device, Fig. 6 is a side view of the first embodiment in a collapsed condition, Fig. 7 is a side view partly in section of part of a fourth embodiment, and Fig. 8 is an end view of a part of a fifth embodiment. Fig. 1 shows only the top structure of the saw trestle.The structure comprises an elongate member 1 which may be of wood or metal having side and end walls 2, 3 respectively. Located centrally of the upper surface of the member 1 and disposed longitudinally thereof is a narrow slot 4.

At one end of the member 1 is a fixed jaw member 5 which is secured in position by a bolt 6 which passes through the upper part of the member 1 as shown. At the other end of the member 1 is a movable jaw member 7 secured by a bolt 8 to a carriage 9 located beneath the upper part of the member 1 and in screw-threaded engagement with a screw rod 10 also located beneath the upper part of the member 1. One end of the rod 10 is rotatably mounted in the end wall 3 adjacent the movable jaw member 7 while the other end of the rod 10 passes through the other end wall 3 and a handle 11 is secured to the projecting end of the rod. The rod is held in position by retainers 12.

It will be appreciated that the bolt 8 passes through the slot 4 and that rotation of the handle 11 causes the movable jaw member 7 to move towards and away from the fixed jaw member 5.

The top structure is supported upon two leg assemblies 13 and 14. Each assembly is of A form when seen in elevation and has a substantially vertical leg 15 and an in dined leg 16 which merge at their upper ends into a common portion which fits into the top structure from beneath and is pivotally connected thereto by a pivot pin 17. To give the trestle greater stability each leg has an out-turned part 18. Each leg also has an adjustable foot 19 having a base of rubber or plastics material. This enables the trestle to be levelled on uneven or rough surfaces.

When in the erected condition shown in Figs. 2 and 3, the leg assemblies are locked in position by suitable means. For example, a leg brace may be used which may be pivotally secured at one end to the top structure or to the leg assembly and releasably secured at the other end to the leg assembly or the top structure. In this way, the brace can be released to permit the leg assembly to be folded into a position adjacent the top structure as shown in Fig. 6.

Each leg assembly is fitted with a leg brace although they are not shown in Fig. 3.

Other means may be used to lock the leg assemblies in place when in the erected position, for example locking pins or catches may be used instead of the braces described above.

The trestle is normally stored in the folded condition shown in Fig. 6. To bring the trestle into use, the leg assemblies are folded down into the positions shown in Fig. 3 and locked in position. Material to be cut is then placed upon the top structure 1 and clamped in position by operating the handle 11 to bring the movable jaw member 7 into a clamping position. The material is then firmly held between the clamping members and does not need to be held by the user.

It will be appreciated that a user can stand close to the trestle when this is necessary, the vertical legs 15 being located substantially in line with one of the longitudinal edges of the top structure.

It will be understood that other forms of supporting leg may be used. For example four quite separate legs may be used in conjunction with leg receiving sockets on the top structure 1. To erect such a trestle, the legs are inserted or plugged into the sockets and secured therein by suitable retaining means. To collapse the trestle the legs are removed and may be secured beneath the top structure by suitable clips or other attachment means.

The upper surface of the top structure guides the movable jaw member 7 for movement towards and away from the fixed jaw member. The method of driving the movable jaw member 7 ensures that the latter cannot move away from that upper surface and this assists in ensuring a firm grip on an article secured between the jaw members.

If desired both jaw members may be movable, the rod 10 having suitably threaded portions for that purpose. In addition, the or each movable jaw member may have a quick release device enabling the jaw member to be uncoupled from the rod 10 and moved by hand to a new position in which it is then re-coupled to the rod 10 and the handle 11 operated to effect the final clamping movement of the or each clamping member.

The mounting of the or each jaw member may be such as to allow limited pivotal movement of the member about a vertical axis. Such movement enables the jaw member to adapt its position according to the edge contour of an article to be clamped and this assists firm clamping of the article.

Further the operative face of each jaw member may be adapted to receive one or other of a number of different "facings".

For example, metal facings might be used to clamp metal articles and soft facings, for example of a plastics material, might be used to clamp articles whose surfaces might also have different configurations adapted to co-operate with differently-shaped articles.

The facings may plug into the front faces of the jaw members or they may be slid into position in keyways in the side faces of the jaw members.

The trestle shown in Fig. 3 has an extension flap 21. One edge of the flap 21 is attached to a longitudinal edge of the top structure 1 to locate the flap in the position substantially co-planar with the upper surface of the top structure. Legs 22 pivotally attached to the flap support the latter along its other edge. The legs 22 may be held in place by suitable fitments on the legs 16 or they may be locked in position by locking means attached to the flap itself.

The flap 21 provides a substantial extension of the upper surface of the trestle and this provides a user with a useful working surface.

Preferably, the flap 21 is attached to the trestle on the side of the latter above the inclined legs 16, this leaves the other side free for sawing operations.

The flap 21 need not be co-extensive with the top structure. The flap could be longer or shorter.

Fig. 5 shows the trestle modified by the fitting of a vertically operating elongate clamping device 23. The device comprises an elongate clamping plate 24 at each end of which are screw mechanisms 25 fitted with operating handles 26. The screw mechanisms located in threaded holes in the upper surface of the top structure 1 (as shown), the jaw members 5, 7 being removed, or in threaded holes in the jaw members 5, 7. In the latter case, it is, of course, essential to ensure that the or each movable jaw member is correctly loacted to receive the screw mechanism 25.

Downward clamping of an article can also be achieved by using jaw members 26, 27 with inclined jaw faces as shown in Fig.

4 in conjunction with an elongate clamping plate 28 having correspondingly inclined end faces 26a, 27a. Closing movement of the jaw members 26, 27 forces the clamping plate downwardly.

Fig. 7 shows an embodiment of the invention in which there is a fixed jaw member 29 of short length, and a movable jaw member 30 of considerably greater length.

As in the embodiment of Fig. 1, the fixed jaw member is secured to the top structure while the movable jaw member 30 is coupled to a threaded rod 31, the coupling 32 passing through a longitudinal slot in the top structure. In the embodiment shown in Fig. 7, coupling 32 is located adjacent the operative face of the movable jaw member 30 whilst a second coupling 33 adjacent the rear face of the movable jaw member 30 holds the rear end of the member 30 in position. Coupling 33 also passes through the longitudinal slot mentioned above.

As can be seen in Fig. 7, the jaws when in abutting relationship as shown provide a working surface albeit a narrow one. Also each jaw member has a number of spaced holes or recesses 34 adapted to receive plugin jaw attachments 35 between which articles may be clamped. The holes or recesses may be aligned longitudinally or they may be arranged in a number of spaced rows.

Each attachment 35 has a leg 36 which fits into a hole or recess 34, and a clamping face 37.

If desired, the width of the jaw members in any of the embodiments described above may be greater than the side-to-side width of the top structure so that the jaw members overhang the top structure. Alternatively, the jaw members may be adapted to receive wide extension pieces.

WHAT WE CLAIM IS: 1. A saw trestle comprising a top structure of elongate form, first and second clamping jaw members mounted separately on the top of the top structure, at least one of the members being movable along the longitudinal axis of the top structure towards and away from the other member, a mechanism for moving at least the one member, and a base structure including legs for supporting the trestle in an erected condition, the trestle being convertible into a collapsed condition in which it is of substantially lamellar shape.

2. A saw trestle as claimed in claim 1 in which the base structure includes leg assemblies defining the legs and attached to the top structure in such manner as to per mit -the assemblies to be moved between an erected condition and a folded condition in which the assemblies lie adjacent the top structure.

3. A trestle as claimed in claim 1 in which the top structure includes means for receiving the legs for supporting the trestle in an erected condition, the legs being detachable from the receiving means when the trestle is to assume a collapsed condition.

4. A saw trestle as claimed in claim 2 in which there are two leg assemblies each being pivotally secured to the top structure at or adjacent a different end thereof.

5. A saw trestle as claimed in claim 2 in which each leg assembly includes a first leg which is substantially normal to the structure when in the erected condition, and a second leg inclined to the first leg.

6. A saw trestle as claimed in claim 5 in which releasable means are provided for locking the leg assemblies in an erected condition.

7. A saw trestle as claimed in any one of the preceding claims in which the top structure includes an elongate upper part along which the or each movable jaw member is movable and in which the mechanism includes a component located beneath the upper part, the or each movable jaw member being coupled to the component by a member located in a longitudinal slot in the upper part.

8. A saw trestle as claimed in claim 7 in which the component is a threaded rod and in which the member located in the slot includes a component in screw-threaded engagement with the rod.

9. A saw trestle as claimed in any one of the preceding claims in which the top structure receives along one side thereof, a flap which when in position forms an extension of the upper surface of the top structure.

10. A saw trestle as claimed in claim 9 in which the flap includes supporting legs for supporting the flap in position on the trestle.

11. A saw trestle as claimed in any one of the preceding claims in which the or each jaw member is pivotally mounted in such manner as to be capable of movement about a vertical axis.

12. A saw trestle as claimed in any one of the preceding claims in which the or each jaw member is adapted to receive a jaw facing.

13. A saw trestle as claimed in claim 1

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Claims

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of which are screw mechanisms 25 fitted with operating handles 26. The screw mechanisms located in threaded holes in the upper surface of the top structure 1 (as shown), the jaw members 5, 7 being removed, or in threaded holes in the jaw members 5, 7. In the latter case, it is, of course, essential to ensure that the or each movable jaw member is correctly loacted to receive the screw mechanism 25.

Downward clamping of an article can also be achieved by using jaw members 26, 27 with inclined jaw faces as shown in Fig.

4 in conjunction with an elongate clamping plate 28 having correspondingly inclined end faces 26a, 27a. Closing movement of the jaw members 26, 27 forces the clamping plate downwardly.

Fig. 7 shows an embodiment of the invention in which there is a fixed jaw member 29 of short length, and a movable jaw member 30 of considerably greater length.

As in the embodiment of Fig. 1, the fixed jaw member is secured to the top structure while the movable jaw member 30 is coupled to a threaded rod 31, the coupling 32 passing through a longitudinal slot in the top structure. In the embodiment shown in Fig. 7, coupling 32 is located adjacent the operative face of the movable jaw member 30 whilst a second coupling 33 adjacent the rear face of the movable jaw member 30 holds the rear end of the member 30 in position. Coupling 33 also passes through the longitudinal slot mentioned above.

As can be seen in Fig. 7, the jaws when in abutting relationship as shown provide a working surface albeit a narrow one. Also each jaw member has a number of spaced holes or recesses 34 adapted to receive plugin jaw attachments 35 between which articles may be clamped. The holes or recesses may be aligned longitudinally or they may be arranged in a number of spaced rows.

Each attachment 35 has a leg 36 which fits into a hole or recess 34, and a clamping face 37.

If desired, the width of the jaw members in any of the embodiments described above may be greater than the side-to-side width of the top structure so that the jaw members overhang the top structure. Alternatively, the jaw members may be adapted to receive wide extension pieces.

WHAT WE CLAIM IS: 1. A saw trestle comprising a top structure of elongate form, first and second clamping jaw members mounted separately on the top of the top structure, at least one of the members being movable along the longitudinal axis of the top structure towards and away from the other member, a mechanism for moving at least the one member, and a base structure including legs for supporting the trestle in an erected condition, the trestle being convertible into a collapsed condition in which it is of substantially lamellar shape.
2. A saw trestle as claimed in claim 1 in which the base structure includes leg assemblies defining the legs and attached to the top structure in such manner as to per mit -the assemblies to be moved between an erected condition and a folded condition in which the assemblies lie adjacent the top structure.
3. A trestle as claimed in claim 1 in which the top structure includes means for receiving the legs for supporting the trestle in an erected condition, the legs being detachable from the receiving means when the trestle is to assume a collapsed condition.
4. A saw trestle as claimed in claim 2 in which there are two leg assemblies each being pivotally secured to the top structure at or adjacent a different end thereof.
5. A saw trestle as claimed in claim 2 in which each leg assembly includes a first leg which is substantially normal to the structure when in the erected condition, and a second leg inclined to the first leg.
6. A saw trestle as claimed in claim 5 in which releasable means are provided for locking the leg assemblies in an erected condition.
7. A saw trestle as claimed in any one of the preceding claims in which the top structure includes an elongate upper part along which the or each movable jaw member is movable and in which the mechanism includes a component located beneath the upper part, the or each movable jaw member being coupled to the component by a member located in a longitudinal slot in the upper part.
8. A saw trestle as claimed in claim 7 in which the component is a threaded rod and in which the member located in the slot includes a component in screw-threaded engagement with the rod.
9. A saw trestle as claimed in any one of the preceding claims in which the top structure receives along one side thereof, a flap which when in position forms an extension of the upper surface of the top structure.
10. A saw trestle as claimed in claim 9 in which the flap includes supporting legs for supporting the flap in position on the trestle.
11. A saw trestle as claimed in any one of the preceding claims in which the or each jaw member is pivotally mounted in such manner as to be capable of movement about a vertical axis.
12. A saw trestle as claimed in any one of the preceding claims in which the or each jaw member is adapted to receive a jaw facing.
13. A saw trestle as claimed in claim 1

in conjunction with a further clamping device comprising a clamping plate and two screw mechanims, in which the jaw members are detachable and the top structure is adapted to receive each of the two screw mechanisms carrying the clamping plate in place of the jaw members, the arrangement being such that when received by the top structure, the clamping plate is located above the top structure, and the screw mechanisms are operable to move the clamping plate towards and away from the upper surface of the top structure.
14. A saw trestle as claimed in claim 1 in which each clamping member is adapted to receive a further adjustable clamping device operable when secured in position to grip articles between itself and the upper surface of the top structure.
15. A saw trestle as claimed in claim 14 in conjunction with the further clamping device and in which the further clamping device comprises two screw mechanisms each adapted to engage one of the jaw members and a clamping plate carried by the screw mechanisms, the latter mechanisms being operable to move the clamping plate towards and away from the top surface of the top structure.
16. A saw trestle as claimed in any one of claims 1 to 12 in which the surfaces of the jaw members that face one another are inclined downwardly and outwardly towards the respective end of the top structure.
17. A saw trestle as claimed in claim 1 in which each jaw member has at least one hole or recess in its upper surface for receiving a jaw attachment member.
18. A saw trestle as claimed in claim 17 in which each jaw member has a plurality of holes or recesses, the latter being aligned in a single longitudinal row or in several spaced longitudinal rows.
19. A saw trestle as claimed in any one of the preceding claims in which the jaw members together provide, when in abutting relationship, a working surface substantially co-extensive in length with the top structure.
20. A saw trestle as claimed in any one of the preceding claims in which the jaw members extend laterally beyond the sides of the top structure.
21. A saw trestle substantially as herein described with reference to and as illustrated by Figs. 1, 2 and 6 or Fig. 3 or Fig. 4 or Fig. 5 or Fig. 7 or Fig. 8 of the accompanying drawings