Apparatus for engaging a workpiece

Abstract

 The invention provides apparatus for engaging a workpiece including a slide (4) for moving on a longitudinally extending track (6) and having clamping faces (14, 16) clampable against the track (6), a pivotable member (12) on the slide (4) for moving the clamping faces (14, 16) against the track (6) in a first stage of pivotal movement of the pivotable member (12), a jaw member (18) for engaging the workpiece slidably mounted on the slide (4) and having a face for cooperating with the pivotal member (12) to urge the jaw member (18) towards the workpiece in a second stage of pivotal movement of the pivotable member (12). In use the slide (4) is first damped onto a support and then by continuing to apply the pivotal member (12) the jaw member (18) is urged towards the workpiece to engage it firmly.

Description

Field of invention

[0001] The invention relates to apparatus for engaging work pieces and in particular to clamps which hold work pieces between a pair of jaw members.

Background of invention

[0002] Clamping jaws are known which are brought together by a screw threaded member. The clamping action can be controlled but the screw threaded member has an operating handle which requires considerable space for its operation and setting the jaws to clamp and/or release a workpiece can require a substantial amount of manipulation. It is amongst the objects of the invention to provide a clamping arrangement which is compact and convenient to use.

Summary of Invention

[0003] The invention provides apparatus for engaging a workpiece including a slide for moving along a longitudinally extending track and having clamping faces clampable against the track, a pivotable member on the slide for moving the clamping faces against the track in a first stage of pivotal movement of the pivotable member, a jaw member for engaging the workpiece slidably mounted on the slide and having a face for engaging, directly or indirectly, the pivotal member to urge a workpiece engaging face of the jaw member towards the workpiece in a second stage of pivotal movement of the pivotable member. In use the apparatus will clamp to a support with the track in an initial stage of pivotal movement of the member and then press the jaw member towards the workpiece, in a subsequent stage of movement of the pivotable member. A single movement of the pivotal member secures the slide and then causes the workpiece to be firmly clamped. The apparatus can be easily adjusted along the track yet it permits proper engagement of the workpiece. The jaw member may engage the workpiece directly or may mount an adaptor for engaging particular kinds of workpieces such as printed circuit boards. The apparatus is compact and convenient to operate.

[0004] Preferably the pivotal member has parts projecting radially outwards at two angularly off-set positions one for operating the clamping faces and another for engaging the face of the jaw member and a radiussed part for keeping the clamping faces in a clamping position whilst the jaw member is urged towards the workpiece. Conveniently the radially outward projecting parts are arranged to strengthen the clamping engagement whilst the jaw member is urged towards the jaw member. Preferably resilient means urge the pivot member towards the opposed face of the jaw member. A simple form of pivotal member can be used to achieve the object of the invention. The pivotal member may be a solid locking arm with the aforesaid radially projecting and radiussed parts arranged close to the pivot and also having a handle part at a larger radius for moving the pivotal member. The resilient means can be used to ensure that the jaw member comes to rest in a predetermined position with respect to the slide.

[0005] The track may be a tubular member with the slide surrounding the track or located internally of the track. Preferably however the track is formed by a support with a slot. Conveniently then the slide includes a slide body for aligning with the track having one clamping face, a mounting member extending transversely through the slide body and supporting another oppositely facing clamping face, the pivotable member being secured in the mounting member to bear against the slide body. Preferably the jaw member has a recess in which the slide body and pivotable member are slidably mounted to provide a compact overall arrangement.

Drawings

[0006] 

Figure 1 shows an exploded view of an apparatus according to the invention;

Figure 2 shows a plan view of a clamping arrangement including the apparatus of Figure 1 partly in dotted lines to show underlying parts;

Figure 3 shows a plan view of the apparatus of Figure 1;

Figures 4,5,6 and 7 show a section through the apparatus of Figure 1 during successive stages of operation;

Figure 8 shows a longitudinal section along a modified apparatus of the invention;

Figure 9 shows a section along line IX-IX in Figure 8;

Figure 10 shows an elevation of the apparatus of Figure 8;

Figure 11 shows the same elevation as Figure 10 but with a pivotal member removed; and

Figures 12,13 and 14 show successive stages of operation of the modified embodiment of Figure 8.

Specific description

[0007] With reference to Figures 1 to 7, an apparatus 2 for engaging a workpiece has a slide 4 movable on a track 6. The track 6 is formed by a flat support 8 with a slot 10. The slide 4 mounts a pivotable member 12 which operates a pair of clamping faces at 14,16 to engage the support 8. The slide 4 is set inside a jaw member 18 for clamping against a workpiece (not shown). The member 18 has an internal face 20 for engaging the pivotable member 12.

[0008] The pivotable member 12 is mounted by a transverse pivot pin 34 on a bolt-like member 32 passing through a slide body 30 and has a portion 23 near the pivot for engaging the slide 4 or jaw member 18 and a portion 25 further away from the pivot for manual operation of the pivotal member 12. The lower surface of the slide body 30 forms the clamping face 14.

[0009] The portion 23 has a front edge at 22 forming a first radially projecting part 22 for engaging the face 20 of the jaw member. The portion 23 has two recessed parts passing to either side of the bolt 32 forming radially projecting parts 24 for engaging the slide body 30. The parts 24 are contiguous with radiussed parts 26 for reasons to be explained.

[0010] A compression spring 28 mounted on a stud on the slide body 30 and acting as a resilient means urges the slide body 30 towards the face 20 of the jaw member. The bolt 32 mounts a nut 28 and washer 39 which forms the clamping face 16. The slide body 30 and pivotal member 12 are received inside a recess 40 passing through the jaw member 20. Mutually engaging shoulders 42 are provided for aligning the jaw member 18 during its sliding movement on the slide body 30.

[0011] The slide has a raised part 44 supporting the bolt 32 at the rear. The jaw member 18 has a part 46 for limiting pivotal movement of the member 12.

[0012] With reference particularly to Figure 2, in a clamping arrangement, the aforesaid apparatus 2 can be used in combination with a fixed clamp 52 bolted to the support 8.

[0013] With reference to Figures 4 to 7, in use the apparatus 2 is slid towards the fixed jaw member or clamp 52 until a workpiece is engaged on opposite sides. The pivotal.member 12 is in the position shown in Figure 4 and the apparatus 2 can be slid freely along the slot 10. When the workpiece is engaged the portion 25 is depressed in the direction of arrow A until the position shown in Figure 7 is reached. The following effects occur.

[0014] In Figure 5 the radially extending part 24 is pushed down as shown by arrow B onto the slide body 30 on either side of the raised part 44. The bolt 32 is pulled up as shown by arrow C at the same time with the result that the clamping faces 14 and 16 clamp the support 8 between them, locking the slide 4 in position on the support 8.

[0015] In Figure 6, this first clamping action is reinforced but at the same time the radially extending part 22 starts pushing the jaw member 18 forward in the direction of arrow D. The spring 28 is somewhat compressed. The dimensions of the jaw member 18 and the slide 4 are such that this sliding movement remains possible after the slide 4 has been clamped in position as described previously.

[0016] In Figure 6, the radiussed parts 26 slide over the slide body 30 whilst maintaining clamping pressure so that there is no change in respect of the engagement of the slide 4 with the support 8. The part 22 continues to push the jaw member 18 forward until the final position shown in Figure 7 is reached.

[0017] If the workpiece and the clamping arrangement cannot absorb the clamping pressure the pivotal member 12 can be arrested before it has completed its downward movement, friction between the part 22 and the face 20 of the jaw member being sufficient to hold it in position. If the pivotal member 12 is forced further down, the bolt 32 can tilt to a limited extent to avoid excessive stress on the workpiece. If the various surfaces are subject to wear, the spring 28 will take up the play in respect of the movement in the direction of the slot 10 whilst the nut 38 can be adjusted to increase the clamping action between the faces 14 and 16 of the slide 4 and the support 12.

[0018] The apparatus is shown slidably mounted in a slot. It is also possible to modify the apparatus to slide it on and lock it onto a tubular member, replacing the bolt 32 by a band or such like which envelopes the tubular member.

[0019] The jaw member 18 may be adapted as at 60 to mount support posts (not shown) and adaptor devices for clamping glass or similar sheet material. Such adaptor devices may permit rotation of the workpeice.

[0020] With reference to Figures 8 to 14, the same reference numerals have been used for parts of corresponding function. The track 6 is formed by a tubular member 61 from an aluminium extrusion which can be secured by screws to the side of a work top or on top having regard to the nature of the application. The slide 30 is modified substantially and includes a forwardly biassed upturned flap 60 interposed between the front of the pivotal member 12 and the internal face 20 of the jaw member 18. The flap 60 is connected by a thin strip of material to the body proper so as to yield readily. The body 30 also includes an apertured extension 62 at the rear, which has a resilient action to replace the spring 28. The nut 38 may carry a short extension to enable it to be adjusted in situ. By using the flap 60 the pivotal member 12 can be made of metal; the body 30 of a resilient tough plastic material and the jaw member 18 can be made of a hard mterial without being materially damaged by the pivotal member 12. Finally the support posts for clamping sheet material can be made short in the form of revolvable jaws 64 having V-shaped notches and be located in the clamping faces proper. The clamping faces have sideways extending parts 72 thus providing large clamping faces areas and a more rugged construction.

[0021] In use when the track 6 is secured at a work top edge, the sidewways extending parts of the clamping faces can be arranged to project above the work top surfaces and mount the revolvable V-jaws 64 to provide a relatively unobstructed work area.

[0022] Friction between the pivotable member 12 and the slide body 30 does not lead to forward movement of the slide body as the member is pressed towards the track because the body is restrained by the bolt 32 mounting the pivotable member 12 and passed through the slide body 30.

[0023] The slide 30 fits neatly into the jaw member recess and their relative sliding action and mutual retention is provided compactly and with a relatively simple geometry.

Claims

1. Apparatus having a pair of jaw members movable relative to each other along a longitudinally extending track to clamp a workpiece
characterised in that
at least one jaw member (18) is slidably mounted on a slide (4) itself slidable along the track (6) and with opposed faces (14,16) for clamping against the track, a pivotable member (12) being mounted on the slide to urge the faces (14,16) into gripping contact with the track (6) in an initial stage of pivotal movement and to urge the jaw member (18) towards the work piece along the track (6) in a subsequent stage of pivotal movement.

2. Apparatus according to claim 1 further characterised in that the pivotal member (12) has parts (22,24) projecting radially outwards at two angularly off-set positions, one part (22) serving to urge the opposed faces (14,16) towards each other and the other part (24) serving to urge the jaw member (18) towards the workpiece and a radiussed part (26) for maintaining the clamping faces (14,16) in their clamping position during the subsequent stage of pivotal movement.

3. Apparatus according to claim 2 further chacterised in that the parts (22,24) are angularly off-set in such a way that the clamping engagement between the faces (14,16) and the track (6) is strengthened as the subsequent stage of the pivotal movement to urge the jaw member (18) towards the workpeice commences.

4. Apparatus according to any of the preceding claims further characterised in that resilient means (18) interposed between the jaw member (18) and the slide (4) urge the jaw member (18) away from the other jaw member (52) and towards the slide (4) to thereby ensure that the jaw member (18) is in a proper position to be urged towards the workpiece along the track (6).

5. Apparatus according to any of the preceding claims further chacterised in that the slide (4) has a slide body (30) for aligning with the track and having one clamping face (14), a mounting member (32) extending through the slide body (30) transversely to the track (6) and supporting the other clamping face (16) at one end, the pivotable member (12)being pivotably secured on the other end of the member (32) to bear against the slide body (30) to urge the faces (14,16) into gripping contact with the track (6).

6. Apparatus according to claim 5 further characterised in that the slide (4) and thepivotable member (12) are substantially retained in a recess (40) formed in the jaw member (18).

7. Apparatus according to any of the preceding claims further characterised in that a resilient low friction member (60) is interposed between opposed sides of the jaw member (18) and the pivotable member (12).

8. Apparatus according to claim 7 further characterised in that the member is a flap (60) resiliently attached to the slide (4).

9. Apparatus according to any of claims 4, 5 and 7 further characterised in that the slide (30) is of a plastics material integrally moulded with the flap (60) and with a resilient extension (62) to urge the jaw member (18) away from the other jaw member (52) and towards the flap (60).

10. Apparatus according to any of the preceding claims in which the jaw members (18) and (52) have workpiece engaging faces extending sideways of a track forming tubular support member (61) and are adapted to receive revolvable V jaws (64) in the sideways extending parts (72) .

Drawing