GB2059822A - Vices - Google Patents

Abstract

A vice comprises a fixed jaw 2 mounted on a vice body, a movable platform 4 mounting a movable jaw and fully supported by and mounted for movement with respect to the vice body in a direction away from a fixed jaw 2 on the body for an opening movement and in a direction towards the fixed jaw for a closing movement. <IMAGE>

Description

SPECIFICATION Vices This invention relates to vices and is particularly, though not necessarily exclusively, concerned with vices for application to machines for holding workpieces during metal cutting and the like operations.

Vices both hand and power operated of many kinds are already in widespread use. In the main they employ parallel jaws which are ideal for holding parallel-sided workpieces or specially shaped jaws for holding a particular workpiece, although attempts have been made to provide vices with segmental jaws capable of different degrees of movement and whereby different shapes of workpiece can be accommodated without the need to change the jaws. It is equally the case that in the main, machine vices have a movable jaw driven towards a fixed jaw spaced from the body of the vice, with the slider on which the movable jaw is mounted in dove tail engagement with a base to the vice. Such constructions whilst being generally satisfactory are subjected to bending moments and are expensive.

It is a first object of the invention to provide a vice that is robust in construction and yet is relatively cheap to manufacture, and a second object of the invention is to provide a segmental or multi-jaw vice that is robust in character and yet relatively cheap to manufacture, and which are ideally suited to industrial use.

According to a first aspect of the present invention a vice comprises a fixed jaw mounted on a vice body, a movable platform fully supported by and mounted for movement over substantially the full length of the vice body, the mounting of the platform on the vice body being such as to maintain full support for the platform over the full length of movement and to hold the platform against movement in a direction perpendicular to its intended direction of movement, there being mounted on the platform at least one jaw member, and there being means for moving the platform to push the jaw on the platform away from the fixed jaw on the body for an opening movement and pull the platform and hence the jaw on the platform in a direction towards the fixed jaw for a closing movement.

Thus the vice body may be an open bottomed casting in which is formed parallel sided channels in which the movable platform is located.

Thus, with a feed screw housed in the vice body and located behind the fixed jaw and with the feed screw passing through a nut secured to one end of the platform, rotation of the feed screw causes movement of the nut along the screw to cause the or each jaw secured thereon to move towards or away from the fixed jaw, with the platform sliding below the fixed jaw. Thus the movable platform is fully supported along the whole of its length over the maximum movement available. This also allows a greater maximum opening of the jaws for a given size of vice in comparison with conventional vices. Alternatively the platform could slide directly below the fixed jaw and be held against movement in a direction perpendicular to the intended direction of movement by the underside of the fixed jaw and by a base to the vice on which the movable platform rests.As a still further possiblity the movable platform can engage in parallel sided channels formed in the casting and be in sliding engagement with the fixed jaw.

By so arranging the construction that the movable jaw is pulled towards a fixed jaw on the vice body for clamping a workpiece, there is the avoidance of unnecessary bending moments, and any bending moments that do arise are in a direction to hold the platform in position, and the production costs of the vices of the invention by the avoidance of the need for dovetail connections between the movable platform and the vice base considerably simplifies the manufacture of the vice and the costs of production.

In place of a fixed jaw on the vice, a rotatable jaw could be provided. However, it is highly advantageous to provide a multi-jaw construction and which has major advantages in the olding securely of irregular shaped components, tapered components or multiple members of components which although are of the same nominal size can be of different dimension consequent upon manufacturing tolerances.

Therefore, according to a second aspect of the invention, a vice as defined above comprises a fixed jaw and a movable platform, there being on the movable platform, at least two jaw members movable with respect to each other, said relatively movable jaw members each engaging force equalising mechanism mounted on the movable platform, the movable jaw members sliding along with the movable platform below the fixed jaw, thereby providing positive support for the movable jaw members over the maximum movement of the movable platform. Thus, as the vice is operated to clamp, e.g., an irregular shaped workpiece the jaw members on contacting the workpiece effect a relative forward and rearward movement through the force equalising mechanism to enable both jaw members to be brought firmly into contact with the workpiece.Naturally if a number of identical workpieces or a parallel sided workpiece is to be gripped the two relatively movable jaw members will contact the workpiece or workpieces together.

The simplicity of construction and the robust nature of the vice with its reduced manufacturing costs, and particularly when of a multi-jaw construction, provides a vice that is ideally suited to multiple applications in industry.

The force equalising mechanism mounted on the movable platform may take the form of a circular plate-like member mounted in a circular hole of corresponding diameter in the movable platform, the circular plate having rotatably mounted thereon means for engagement with each jaw of the pair. Thus, relative movement of the jaw members is caused by the rotation of the plate-like member in the movable platform. In a construction with two pairs of movable jaws, a rotatable plate-like member is provided for each pair, with both rotatable members themselves mounted within the corresponding holes in a larger circular plate-like member, it being the larger circular plate-like member that is mounted in a corresponding hole in the movable platform.

With this construction the two jaw members of each pair can be provided with relative movement by rotation of the larger plate-like member, and relative movement of the jaws of a pair caused by rotation of the plate-like member mounted in the larger plate-like member. Preferably a coverplate is provided below the movable platform to hold the force equalising mechanism in place.

Alternatively, when one pair of jaws are provided, a pivotal member can be provided set within a hole in the movable platform, and having a short axle for engaging in a corresponding hole through a coverplate below the movable platform. Again the pivotal member is provided with rotational means capable of engaging each jaw. When two pairs of movable jaws are provided, two pivotal members are provided each having a short axle for engaging in corresponding holes in a larger pivotal member, the larger pivotal member having a short axle for engaging in a corresponding hole in the coverplate below the movable platform.

As a still further alternative the movable jaw members may be spaced from the movable platform by the force equalising mechanism towards one end of the movable jaws and by a support bar towards the other end of the movable jaws. The latter construction may have advantages in certain cutting applications in providing clearance between the movable jaw members and the platform with the avoidance of swarf becoming trapped between the two.

To allow the vice to accommodate a larger number of workpieces of a great variety of shapes it is advisable in practice to provide more than two relatively movable jaw members although it will be remembered that to ensure that the force equalising mechanism functions correctly there must be provided two jaw members, four jaw members, eight jaw members, sixteen jaw members, and so on.

Several embodiments of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a schematic sectional side elevation of a machine vice in accordance with the invention; Figure 2 is a section on the line ll-ll of Fig.

1; Figure 3 is a schematic sectional side elevation of a second embodiment of the invention; Figure 4 is a plan view of part of Fig. 3 with certain parts removed for clarity; Figure 5 is a schematic sectional side elevation of a third embodiment of the invention; Figure 6 is an exploded sectional end view of the force equalising mechanism of Fig. 5; Figure 7 is a schematic sectional side elevation of a fourth embodiment of the invention; Figure 8 is a plan view of Fig. 7 with certain parts removed for clarity; and Figure 9 corresponds to Fig. 7 but shows a modified form of connection between the screw and the moving platform.

In Figs. 1 and 2 a machine vice is formed as a casting having a base plate 1 to enable the vice to be secured in a machine, on which is mounted a fixed jaw 2. A slideway is provided in the casting by recesses 3 in which is slidably mounted a platform 4 having a threaded nut 5 secured to one end. A feed screw 6 passes through the nut 5 secured at one end to a fixed jaw and at the other end in a boss 8, the nut 5 being secured to one end of the sliding platform 4. Mounted at the opposite end of the platform 4 is a jaw 9 which may be secured with respect to the platform or pivotally mounted on the platform.

Thus a construction is provided which avoids totally the use of any dovetail connection between the movable jaw and the vice body or base and which considerably simplifies tlt,e manufacture of the vice without any detriment as to performance. Indeed by drawing the movable jaw towards the fixed jaw with the platform 4 passing below the fixed jaw to bring about clamping of a workpiece, undesirable bending moments created by the clamping action are substantially reduced, and the platform 4 is fully supported over the full length of the maximum opening of the vice.

As is shown variously across Figs. 3 to 8, the vice of the invention can, with major advantage, be provided with movable jaws, which jaws are mounted for relative movement through force equalising mechanism provided on the sliding platform. Thus as is shown in Figs. 3 and 4 lhe sliding platform 4 may be provided with a circular hole in which is rotatably mounted a circular plate 10, the plate 10 having two holes in each of which is mounted a further plate 11 and mounted on the further plates 11 are rotatable members 1 2 for engagement with jaw members 1 3 resting on the sliding platform 4, with part of the jaw members passing below the fixed jaw for full support. Below the platform 4 is a coverplate 14 to hold the force equalising mechanism in place.Thus the pair of jaws engaged by the rotatable members 1 2 of one plate 11 can, as a pair, move relative to the pair of jaws engaged by the members 1 2 of the second plate 11 consequent upon rotation of the plate 10 and the jaws of each pair can move relative to each other consequent upon the rotation of the plate 11. As the four jaws are moved by the slidable platform 4 into contact with, e.g., an irregularly shaped workpiece, the pairs of jaws can move relative to each other and the jaws of each pair move relative to each other to enable all four jaws to be brought into contact with the workpiece.

Although four jaws are shown in Figs. 3 and 4 it will be understood that the principle would apply if two jaws were mounted on the slidable platform 4 or if eight, sixteen, etc.

jaws were mounted on the movable platform, with an appropriate number of circular plates associated with each adjacent pair of jaws.

The same general principles apply to the construction shown in Figs. 5 and 6. In this embodiment as in shown more particularly by Fig. 6, the sliding platform 4 has a circular hole 1 5 in which is located the force equalising mechanism, the boss 1 6 of a first rotatable plate 1 7 locating in a bore 1 8 of a coverplate 19, the plate 1 7 having two bores 20 in which are fitted the bosses 21 of two further circular plates 22 on each of which are rotatably mounted two connecting means 23 to engage the movable jaws.

In the still further embodiment shown in Figs. 7 and 8, the movable jaw members are spaced from the sliding platform to provide a space into which swarf can pass thereby avoiding any possibility of swarf becoming trapped and affecting the efficiency of the force equalising mechanism. Thus in contrast to the earlier embodiments where the force equalising mechanism is set wholly within the depth of the sliding platform with the jaw members resting on the sliding platform, in this embodiment a first member 24 is rotatably mounted on the sliding platform by having a boss 25 engaging in a corresponding bore 26 in the platform, the further rotatable members 27 being mounted on the first member 24 by each having a boss 28 engaging in a corresponding bore 29 in the first member.

Again rotatable means 30 are mounted on the members 27 to engage the movable jaws.

Towards the end of the movable platform a spacer bar 31 is provided on which rest the movable jaw members, thereby providing a space 32 for the clearance of swarf.

In the above embodiments the screw is vertically spaced from the platform and in certain circumstances where excessive loading is involved there can be applied undesirable stresses to the connection between the screw and the platform. In Fig. 9 a modified construction is shown which eliminates this potential problem. The construction of Fig. 9 is based on the construction of Fig. 7 but it will be appreciated that it could be applied to all embodiments. Thus in Fig. 9 the moving platform 33 has a recess 34 in which engages a projection 35 on a screw 36. On the vice body is an extension 37 supporting a nut 38 in engagement with the screw 39. The nut and projection could simply be a heavy duty bolt the head of which has been partly machined away to form the projection 35. Thus there is in this embodiment the substantial elimination of applied bending moments at the connection between the screw and the platform.

Claims (17)

1. A vice comprising a fixed jaw mounted on a vice body, a movable platform fully supported by and mounted for movement over substantially the full length of the vice body, the mounting of the platform on the vice body being such as to maintain full support for the platform over the full length of movement and to hold the platform against movement in a direction perpendicular to its intended direction of movement, there being mounted on the platform at least one jaw member, and there being means for moving the platform to push the jaw on the platform away from the fixed jaw on the body for an opening movement and pull the platform and hence the jaw on the platform in a direction towards the fixed jaw for a closing movement.

2. A vice as in Claim 1 wherein the vice body is an open bottomed casting in which is formed parallel sided channels in which the movable platform is located.

3. A vice as in Claim 1 or Claim 2 wherein the movable platform slides below the fixed jaw.

4. A vice as in any of Claims 1 to 3 comprising a fixed jaw and a movable platform, there being on the movable platform, at least two jaw members movable with respect to each other, said relatively equalising mechanism mounted on the movable platform, the movable jaw members sliding along with the movable platform below the fixed jaw.

5. A vice as in Claim 4 wherein the force equalising mechanism is mounted on the movable platform is a circular plate-like member mounted in a circular hole of corresponding diameter in the movable platform, the circular plate having rotatably mounted thereon means for engagement with each jaw of the pair.

6. A vice as in Claim 5 wherein, with two pairs of movable jaws, a rotatable plate-like member is provided for each pair, with both rotatable members themselves mounted within the corresponding holes in a larger circular plate-like member, it being the larger circular plate-like member that is mounted in a corresponding hole in the movable platform.

7. A vice as in any of Claims 4 to 6 wherein a coverplate is provided below the movable platform to hold the force equalising mechanism in place.

8. A vice as in Claim 4 wherein a pivotal member is set within a hole in the movable platform and has a short axle for engaging in a corresponding hole in a cover-plate below the movable platform, the pivotal member being provided with rotational means for engaging the movable jaws.

9. A vice as in Claim 8 wherein, with two pairs of movable jaws provided, two pivotal members are provided each having a short axle for engaging in corresponding holes in a larger pivotal member, the larger pivotal member having a short axle for engaging in a corresponding hole in the coverplate below the movable platform.

10. A vice as in Claim 4 wherein the movable jaw members are spaced from the movable platform by the force equalising mechanism towards one end of the movable jaws and by a support bar to the other end of the movable jaws.

11. A vice as in Claim 10 wherein a pivotal member is mounted on the movable platform with a short axle engaging in a corresponding bore in the movable platform, the pivotal member having rotatably mounted thereon means for engagement with each jaw of the pair.

1 2. A vice as in Claim 11 wherein with two pairs of movable jaws, a rotatable member is provided for each pair with both rotatable members mounted on a larger rotatable member with short axles engaging in corresponding bores in a larger rotatable member it being the larger rotatable member that engages the movable platform.

1 3. A vice substantially as hereinbefore described with reference to Figs. 1 and 2 of the accompanying drawings.

14. A vice substantially as hereinbefore described with reference to Figs. 3 and 4 of the accompanying drawings.

1 5. A vice substantially as herein before described with reference to Figs. 5 and 6 of the accompanying drawings.

1 6. A vice substantially as hereinbefore described with reference to Figs. 7 and 8 of the accompanying drawings.

17. A vice substantially as hereinbefore described with reference to Fig. 9 of the accompanying drawings.