GB2063111A - Vices - Google Patents

Abstract

A vice has a main screw (18) which produces a simple translational movement of a movable vice jaw (16) towards or away from a fixed vice jaw (12). In additional to this translational movement, one of the vice jaws (16) is shiftable angularly about a vertical axis (52); this movement is produced by a second clamping screw (20), so that the vice can be adjusted to avoid line or point contact between the vice jaws and the workpiece. Preferably, a third clamping screw (22) which produces a controlled angular adjustment of one of the vice jaws (16) about a horizontal axis. This adjustment also may help in achieving better contact between vice jaws and workpiece. The movable jaw may be carried on a tube (30) in which operates the main screw (18). The tube has openings accepting a projection (32) in a body carrying the fixed jaw for stepwise translational adjustment of the jaw (16). The tube and movable jaw may be removed from the body and attached to a sash cramp. <IMAGE>

Description

SPECIFICATION Vices This invention relates to vices. It is particularly but not exclusively applicable to bench vices, of both the woodworking and metalworking varieties.

In a conventional bench vice, the only controllable relative movement which can occur between the two jaws of the vice is a translational fore-and-aft movement. This is usually satisfactory for gripping a parallel-sided workpiece which extends across the full width of the vice jaws, but when the object to be gripped is to be held off-centre of the jaws, there is inevitably a tendency for the structure of the vice to distort to a position in which the jaws do not lie parallel, as seen in plan view. This is a consequence of the flexibility which is unavoidable in any structure, and of the lateral offset between the lines of action of the clamping force exerted by the vice screw and of the reaction force exerted by the workpiece on the jaws.The effect of this distortion is that there may only be point or line contact between the vice jaws and the workpiece, so that the workpiece is not very securely held.

According to one aspect of the present invention, a vice has an open-topped, open-ended gap formed between two clamping cheeks, one of the clamping cheeks being guided for translational movement towards and away from the other, such translational movement being produced by a first clamping arrangement, and the vice also includes a second, independently operable clamping arrangement constructed to provide a controlled continuous angular adjustment of one of the clamping cheeks about a generally vertical axis.

Thus, with such a vice, a workpiece may be clamped by simultaneous manipulation of both the first and second clamping arrangements, in such a way that a more extended area of contact between clamping cheeks and workpiece is obtained than if only the first clamping arrangement were provided, even when the workpiece is offset from the centre of the clamping cheeks. By providing the second clamping arrangement, it may be possible to construct the vice with a lighter, more flexible structure, having more generous clearances than would otherwise be possible, since any distortions which may occur can easily be offset by use of the second clamping arrangement.One possible consequence of using a more flexible vice structure with greater play is that, when clamping approximately parallelsided work-pieces which extend across the full width of the clamping cheeks, there may be no need to adjust the second clamping arrangement to shift the clamping cheeks away from a parallel position, since the flexibility or play in the structure may allow the clamping cheeks to adapt themselves to slight departures from parallelism of the sides of the workpiece.

Another consequence which may result from improved gripping oftheworkpiece is that smaller operating handles may be used for the clamping arrangements, since less force may be needed to grip a workpiece effectively.

Yet a further consequence is that it is possible to grip a tapered workpiece using such a vice, possibly with one or both ends of the workpiece extending laterally out of the clamping gap of the vice, without using any auxiliary packing blocks or the like.

Preferably the clamping cheeks are interconnected by a connecting structure lying beneath the clamp ing gap, and the clamping cheeks overhang the connecting structure, at least at one end of the clamping gap. With this arrangement, it is also possible to clamp a iong workpiece vertically in the said one end of the clamping gap.

In one possible arrangement, the first and second clamping arrangements are constructed both to effect movements of the same clamping cheek. In the case of a bench vice, this would normally be the front, moving, clamping cheek, and such an arrangement would have the advantage that all the clamp ing manipuiations could be performed from the front of the vice, without the user having to reach over the workpiece.

The first clamping arrangement may comprise a screw-and-nut arrangement. Preferably the most forwardly-projecting of the parts on which the clamping cheeks are mounted is arranged, during the said translational movement, to remain axially stationary relative to the most forwardly-projecting of the components of the said screw-and-nut arrangement. This is the arrangement which is found on most bench vices and has the advantage that the projection of the clamping screw from the rest of the vice does not increase as the vice is either opened or closed.

In addition to the second clamping arrangement, the vice may also include a third independentlyoperable clamping arrangement constructed to produce tilting of one of the cheeks about an axis lying generally horizontal and at right angles to the direction of the said translational movement. This may make it possible to achieve even better clamping of a workpiece.

To allow rapid adjustment of the distance between the clamping cheeks, a fixed body portion of the vice, on which one of the clamping cheeks is mounted, may be connected to a moving part on which the other clamping cheek is mounted, by means of an intermediate member, which is movable step-wise relative to the fixed body portion, and the first clamping arrangement will then be constructed to produce a continuous relative movement between the intermediate member and the moving part.

It may also be possible so to design a bench vice according to the invention that at least part of its clamping mechanism can be easily removed from the bench, and used for other clamping jobs. For example, a sash cramp head could be fitted to turn the mechanism into a sash cramp.

According to a further aspect of the invention, a clamping system includes two opposed clamping cheeks; a first clamping arrangement constructed to produce a translational movement of one cheek relative to the other, and second and third independently-operable clamping arrangements constructed to produce tilting of one of the cheeks relative to the other about two axes lying generally at right angles to one another and generally parallel to the surface of the clamping cheeks.

The invention may be carried into practice in various ways, but three specific embodiments will now be described by way of example, with reference to the accompanying drawings, of which: Figure 1 is an exploded is metric view of a bench vice embodying the invention; Figure 2 is a longitudinal section through the vice of Figure 1; Figure 3 is a longitudinal section through a sash cramp head designed for use with the vice of Figure 1; Figure 4 is a partly exploded perspective view of a second form of bench vice embodying the invention; Figure 5 is an isometric view of a machine vice embodying the invention; and Figure 6 is a view, in section on a horizontal plane, through the moving jaw of the machine vice of Figure 5.

The vice shown in Figures 1 and 2 consists of a fixed body portion 10, which incorporatesastation- ary jaw 12, and within which is received a moving jaw carrier assembly 14 having at its front end a moving jaw 16. The assembly 14 also incorporates, at its front end, three adjusting screws for the moving jaw 16. Afirst adjusting screw 18 allows the moving jaw to be moved towards and away from the stationary jaw 12, in much the same way as the clamping screw in a simple parallel vice; the other two adjusting screws 20 and 22 allow the attitude of the moving jaw 16 to be varied by tilting it about vertical and horizontal axes, respectively.In this way, it is possible to adjust the vice to exert a clamping pressure over much of the area of its jaws even when the jaws are acting against surfaces of a workpiece which are not parallel, or when elastic deformation occurs in the structure of the vice.

The construction of the vice will now be described in greater detail.

The fixed body portion 10 includes two sets of mounting flanges 24 and 26. By using the mounting flanges 24, the vice may be mounted with the upper edges of its jaws level with the working surface of the bench on which it is mounted; this is illustrated in Figure 2, and is the normal arrangement for a woodworking vice. Alternatively, by using the mounting flanges 26, the vice may be mounted wholly above the level of the working surface of the bench, as is normal with a metal-working bench vice.

Below the stationary jaw 12, the body portion 10 has a passage 28 of generally rectangular crosssection, within which is received a tube 30, also of generally rectangular cross-section, which forms part of the moving jaw carrier assembly 14, and from which the remainder of that assembly is supported.

The fore-and-aft position of the tube 30 within the body portion 10 can be adjusted step-wise, while the effect of the vice adjusting screw 18 is to move the remainder of the moving jaw carrier assembly relative to the tube 30. In this way, separate coarse and fine adjustments of the distance between the vice jaws 12 and 16 are provided, and the range of movement of the jaw 16 provided by the adjusting screw 18 need be no greater than the size of one of the steps of adjustment of the position of the tube 30.

The step-wise adjustment of the tube 30 is provided by means of a pin 32 which is mounted within the passage 28, as can be seen from Figure 1, and which co-operates with a series of holes 34 formed in the underside of the tube 30. The tube 30 is a fairly close fit within the passage 28 as far as laterai clearances are concerned, but the vertical depths of the tube 30 and the passage 28 are such that, at the front end of the passage, the tube 30 may be lifted manually far enough to clear the pin 32. The tube can then be shifted longitudinally to allow a different one of the holes 34 to be engaged over the pin 32. Except when adjusting the position of the tube 30 in this way, the weight of the jaw carrier assembly 14 tends to tilt the rear end of the tube 30 upwards within the passage 28.To iimit this movement, so that the tube 30 normally lies horizontal, a rounded ridge 36 is provided at the rear of the passage 28, and, as can be seen from Figure 2, this ridge acts on the upper surface of the tube 30. It is therefore necessary to tilt the jaw carrier assembly 14 to the position shown in chain dotted line in Figure 2 before the position of the tube 30 can be adjusted, and as soon as such an adjustment has been completed, the tube 30 returns naturally to a horizontal position.

The remainder of the jaw carrier portion 14 (that is, apart from the tube 30) includes a hollow slide 38, also of generally rectangular cross-section, which is slidingly received within the front end of the tube 30.

The front end of the slide 38 is closed by a plate 40, within which the adjusting screw 18 isjournalled at its front end, with an adjusting handle of the screw accessible to the user of the vice, and the remainder of the screw housed within the slide 38. The screw 18 is threaded into a nut 42 at the front end of a smail-diameter tube 44 which is received within the slide 38 and the tube 30, and is secured at its rear end to the tube 30 by a vertical pin 46. The journailing of the screw 18 in the plate 40 is arranged to transmit axial forces in both fore and aft directions, so that the screw 18 can be used to produce sliding movement of the slide 38 into and out of the tube 30.

The moving jaw 16 is mounted on the front end of the slide 38 through the intermediary of a rocker 48, which is mounted on the slide 38 by means of a bolt 50 permitting rocking about a transverse horizontal axis, and on which the jaw 16 is mounted by means of a pivot pin 52 allowing rocking about a vertical axis.

As indicated above, these rocking movements are controlled by the adjusting screws 22 and 20, respectively.

The adjusting screw 22 is screwed into a vertical tapped hole in a flange 54 attached to the rear of the plate 40. The upper end of the screw bears against the bight portion of a U-shaped thrust member 56, whose legs pass upwards, one on each side of the adjusting screw 18, and are guided for vertical sliding between upward extensions 58 of the flange 54. The upper ends of the legs of the thrust member 56 emerge through two slots 60 in the upper surface of the guide 38, and bear against the underside of a web 62 of the rocker 48. The bolt 50 lies to the rear of the points at which the thrust member 56 bears on the web 62, so that, by raising the thrust member by means of the screw 22, the rocker 48 and the jaw 16 can be tilted away from the front of the vice.

The vice is so arranged that, when the thrust member 56 is completely retracted into the guide 38, so that the attitude of the jaw 16 is controlled by the engagement of the web 62 against the upper surface of the guide 38, the jaws 12 and 16 converge slightly in the upwards direction when not under load. This convergence is chosen to be just sufficient to offset the deformation of the various parts of the vice which will occur when the vice is exerting a normal value of clamping force, at the centre of its jaws; under these conditions, the jaws will then lie parallel to one another, as seen in side view.However, if it is for any reason required to rock the jaw 16 towards the jaw 12 (for example if a greater than average clamping force is being exerted, resulting in a greater deformation of the vice structure, or if a tapered workpiece is being gripped), the screw 22 can be adjusted to raise the front end of the rocker 48, and thereby produce the required adjustment.

The adjusting screw 20 is journalled in the rocker 48, with its axis transverse and horizontal, and meshes with a worm gear sector 64 which is attached to the moving jaw 16, below the level of the pivot pin 52. Axial movement of the screw 20 in the rocker 48 is restricted, on the one hand, by the adjusting handle of the screw, and on the other hand, by a split pin and washer arrangement 66 at the other end of the screw. Thus, rotation of the screw 20 will result in movement of the jaw 16 about the vertical axis of the pivot pin 52, and this movement can take place in either direction from the position in which the jaws 12 and 16 are parallel, as seen in plan view. The extent of the movement is indicated by a calibrated sector 68 attached to the jaw 16, which sector overlies part of the top surface of the rocker 48, on which an index mark 70 is provided.As with the movement of the jaw 16 about a horizontal axis, the movement about the pin 52 can be used to compensate for non-parallelism of the workpiece, and/or distortions of the structure of the vice; it will be appreciated that, although such distortions will not affect the plan parallelism of the jaws when the line of action of the clamping force lies centrally of the width of the vice, this will not be true when clamping a workpiece in a position offset from the centre of the jaws.

As indicated above, the vice is designed to be suitable for use as both a woodworking and a metal-working vice. For this reason, the gripping surfaces of the jaws 12 and 16 are comparatively shallow vertically, and the jaws overhang towards one another from their supporting structure; these features are normal for a metal-working vice. A normal woodworking vice has deeper jaws, with soft linings, and to provide effectively similar jaws in the present vice, snap-in plastic linings 72 are provided, which extend the clamping surfaces downwards by having filler portions 74 which occupy the recessed space belowthe main clamping surface of each jaw 12 or 16. The linings 72 are held in place by integrally moulded studs 76 which snap into holes 78 in the jaws 12 and 16.

Each of the jaws 12 and 16 is also provided, in its upper surface, with a row of circular holes 82 (two in the jaw 16 and three in the jaw 12), within which clamping pegs 80 can be received. These pegs allow awkwardly-shaped workpieces to be gripped while resting on the tops of the jaws; the pegs 80 can simply rotate within the holes 82, to align themselves with the surface of the workpiece. Because the jaw 16 can be adjusted both by the screw 18 and the screw 20, even clamping pressures on the pegs can be obtained, even when using two pegs in each of the jaws 12 and 16. This arrangement of clamping pegs is generally similar to that shown in Patent No.

1,422,521.

It will be appreciated that the whole of the moving jaw assembly 14 can be removed from the passage 28 in the fixed body portion 10. When this is done, the assembly 14 can be used as a sash cramp, simply by mounting a sash cramp head on the tube 30.

Figure 3 shows a suitable design of sash cramp head, and it will be seen that it incorporates most of the features of the body portion 10, with the exception of the mounting flanges 24 and 26. To identify the features of the sash cramp head, the reference numerals used for corresponding features of the body portion 10 have been used, but with the addition of a prime. One feature which is additional to the features of the body portion 10 is the provision of a leaf spring 84, which tends to rock the sash cramp head 10' to keep the pin 32' and the ridge 36' in engagement with the tube 30. This is necessary because, when being used as a sash cramp, the weight of the jaw carrier assembly 14will not necessarily act to maintain this engagement.

The metal-working bench vice shown in Figure 4 consists of a fixed body portion 110, and a moving jaw assembly 114. The jaw assembly 114 has the moving jaw 116 of the vice rigidly mounted thereon, while the other jaw 112 of the vice is mounted on the body portion 110 in such away that it can be rocked relative to the body portion by manipulation of two screws 120 and 122. More particularly, the screw 120 allows the jaw 112 to be rocked around a vertical axis, while the screw 122 allows the jaw 112 to be rocked around a transverse horizontal axis. As with the vice previously described, these movements allow the clamping pressure to be exerted evenly over the whole clamping area, despite possible distortions of the structure of the vice or nonparallelism of the workpiece.

The construction of the vice will now be described in greater detail.

The moving jaw assembly 114 comprises a slide 138 which is guided for sliding movement in a passage 128 in the body portion 110. The slide 138 consists of a steel channel, and is a fairly close sliding fit, both laterally and vertically, in the passage 128. A casting 139 is fixed to the front end of the slide 138 by screws 141, and carries the moving jaw 116. It will be appreciated that this is a lighter and cheaper, but somewhat less rigid construction than those in which the casting 139 and the slide 138 together form a single casting; however, any distor tions which result from the increased flexibility of the guide 138 can easily be offset by the use of the adjusting screws 120 and 122.

In conventional fashion, an adjusting screw 118 is journalled at its front end in the casting 139, and extends within the guide 138 to engage in a nut which is mounted rigidly on the body portion 110, within the passage 128. Thus, the rotation of the screw 118 will produce fore and aft movements of the jaw 116.

The jaw 112 is mounted on the fixed body portion 110 through the intermediary of a rocker 148, which is mounted on the body portion for tilting about a transverse horizontal axis, and on which the jaw 112 is mounted for tilting around a vertical axis. The pivotal connection between the body portion 110 and the rocker 148 is provided by two pivot pins 150, which project from the body portion 110 into lugs 151 formed on the rocker 148. The screw 122 is threaded into a fore-and-aft extending threaded hole in an upwards continuation of the body portion 110, and is provided at its rear end with a knurled handle 123. At its front end, it bears against the rear of the rocker 148, above the level of the pivot pins 150. A tension spring 153 extends between the rocker and the body portion, in order to maintain the rocker in contact with the tip of the adjusting screw 122.

The arrangement is such that, by adjustment of the screw 122, it would be possible to tilt the jaw 112 in either direction from the vertical. However, as mentioned in connection with the previouslydescribed vice, it may be convenient for the jaw to have a reference position in which it converges slightly with the moving jaw 116 in the upward direction. To provide this reference position, a stiffnut 155 is screwed on to the screw 122, in front of the body portion 110, to provide a stop to rearwards movement of the screw beyond the reference position. It will be appreciated that this allows the reference position to be set as accurately as required, without imposing any particular requirements as to the accuracy of manufacture of the vice.

The pivotal connection between the vice jaw 112 and the rocker 148 is provided by a pivot pin 152, which is received in a pair of iugs projecting forwards from the main part of the rocker, and in a lug 157 on the rear surface of the jaw 112. The adjusting screw 120 is threaded into a barrel nut 121 which is mounted in the rocker 148 for pivoting around a vertical axis. At its rear end, the screw 120 has a knurled handle 125, while at its front end, it is formed with a part-spherical tip 127, which is connected to the rest of the screw by a necked-down portion, and which is received within a recess 129 in the rear surface of the jaw 112. In plan view, the recess 129 is undercut, so that movements of the screw 120 to the rear as well as to the front will be transmitted to the vice jaw 112 to produce rocking movements thereof.The relative sizes of the neckeddown portion of the screw 120 and the narrowest part of the recess 129 are such that the screw 120 can pivot as necessary relative to the jaw 112. At the same time, the axis of the screw 120 has to pivot relative to the rocker 148, and this is allowed by the pivotal mounting of the barrel nut 121.

The machine vice shown in Figures 5 and 6 comprises a base casting 250, a moving jaw assembly 252, and a clamping screw 254. The design of the base casting and the clamping screw is largely conventional; the base casting includes a fixed jaw 256, slideways 258 for the moving jaw assembly 252, and, at the end remote from the fixed jaw 256, a threaded bore through which the clamping screw 254 passes. The moving jaw assembly 252 includes a jaw carrier block 260 which is connected to the end of the clamping screw 254 and is guided by the slideways 258.Although it is not clearly shown in the drawing, a retainer plate is attached by screws to the underside of the jaw carrier block 260, and runs against the underside of the slideways 258, while the jaw carrier block itself has surfaces which run against the top and side surfaces of the slideways, so that the moving jaw assembly is guided in much the same way as the moving jaw of a conventional machine vice.

The moving jaw of the machine vice is shown at 262, and rests on the flat top surface of the jaw carrier block 260. At one side of the vice, the jaw 262 is connected to the carrier block 260 by a pivotal connection 264 arranged with its axis vertical, while at the other side of the vice, a thumbscrew arrangement 266 connects the jaw 262 to the jaw carrier block. As with the vices previously described, this allows the moving jaw 262 to be adjusted to an angular position which matches the angle of a tapered workpiece, so that the workpiece can be clamped with the centre of the clamping pressure near the centre of the jaws. The moving jaw can swing in both directions about the pivot 264 from the position parallel to the fixed jaw 256. This allows a tapered workpiece to be clamped with its thicker end at whichever side of the vice is more convenient.

The detailed construction of the pivotal connection 264 and of the thumbscrew arrangement 266 will now be described. The pivotal connection is provided by a pivot pin 268, whose iower end is screwed into the jaw carrier block 260. The moving jaw 262 has a vertical pivot bore which fits over the pin 268; the jaw is held on the pin by a spring clip 270 which is pressed over a reduced-diameter spigot at the top of the pin 268. The thumbscrew arrangement 266 includes a thumbscrew 272 which passes through a barrel nut 274 received in a socket 276 integral with the jaw carrier block 260. The barrel nut 274 can turn about a vertical axis in the sock 276. The thumbscrew 272 is formed with a part-spherical tip, which is received in an undercut recess 278 (see Figure 6) - formed in the moving jaw 262. A short cylindrical stub 280 is pressed into the recess 278 above the part-spherical tip, to keep the thumbscrew in place.

The size of the opening of the recess 278 and the diameter of the neck of the thumbscrew immediately adjacent its part-spherical tip are such that the jaw can pivot as far as necessary relative to the thumbscrew 272. At the same time, the thumbscrew and the barrel nut 274 will turn slightly about the axis of the socket 276; the openings in the wall of the socket through which the thumbscrew passes are made sufficiently wide to allow this movement.

Claims (31)

1. A vice having an open-topped, open-ended gap formed between two clamping cheeks, one of the clamping cheeks being guided for translational movement towards and away from the other, such translational movement being produced by a first clamping arrangement, and the vice also including a second, independently operable clamping arrangement constructed to provide a controlled continuous angular adjustment of one of the clamping cheeks about a generally vertical axis.

2. A vice as claimed in Claim 1 in which the clamping cheeks are interconnected by a connecting structure lying beneath the clamping gap, and in which the clamping cheeks overhang the connecting structure, at least at one end of the clamping gap.

3. A vice as claimed in Claim 1 or Claim 2 in which the second clamping arrangement is so constructed that the associated clamping cheek can be adjusted angularly in both directions from a position in which it lies parallel to the other clamping cheek.

4. A vice as claimed in Claim 1 or Claim 2 or Claim 3 in which the clamping cheek associated with the second clamping arrangement is mounted on a cheek carrier, and calibrations are provided on the cheek and/or on the cheek carrier, to indicate the angle of taper of the gap between the cheeks.

5. A vice as claimed in any of Claims 1 to 4 in which the said second clamping arrangement comprises a worm meshing with a worm gear or worm gear sector attached to the associated clamping cheek.

6. A vice as claimed in any of Claims 1 to 4 in which the second clamping arrangement comprises a screw arranged with its axis generally parallel to the direction of the said translational movement.

7. A vice as claimed in any of Claims 1 to 6 in which the clamping cheek associated with the second clamping arrangement is arranged to pivot about an axis lying generally equidistant from the two ends of that clamping cheek.

8. A vice as claimed in any of Claims 1 to 6 in which the clamping cheek associated with the second clamping arrangement is arranged to pivot about an axis lying close to one end of that clamping cheek.

9. A vice as claimed in any of Claims 1 to 8 in which the first and second clamping arrangements are constructed both to effect movements of the same clamping cheek.

10. A vice as claimed in any of Claims 1 to 8 in which the clamping cheek associated with the second clamping arrangement is mounted on a fixed body portion of the vice.

11. A vice as claimed in any of Claims 1 to 10 in which the second clamping arrangement is constructed to be capable of resisting angular movements of the associated clamping cheek in either sense about the said vertical axis.

12. A vice as claimed in any of Claims 1 to 11 in which the first clamping arrangement comprises a screw-and-nut arrangement.

13. A vice as claimed in Claim 12 in which the most forwardly-projecting of the parts on which the clamping cheeks are mounted is arranged, during the said translational movement, to remain axially stationary relative to the most forwardly-projecting of the components of the said screw-and-nut arrangement.

14. A vice as claimed in any of Claims 1 to 13 which also includes a third independently-operable clamping arrangement constructed to produce tilting of one ofthe cheeks about an axis lying generally horizontal and at right angles to the direction of the said translational movement.

15. A vice as claimed in Claim 14 which includes means arranged to limit tilting of the cheek about the said horizontal axis, and thereby to establish a reference position for the cheek, the limiting means preventing movement of the cheek from the reference position to a position in which the clamping cheeks diverge in the upward direction.

16. Avice as claimed in Claim 15 in which the limiting means is so arranged that in the reference position the clamping cheeks converge slightly in the upwards direction, and the third clamping arrangement is constructed, when operated, to increase the said convergence.

17. A vice as claimed in Claim 15 or Claim 16 in which the limiting means is arranged to allow adjustment of the reference position.

18. A vice as claimed in any of Claims 1 to 17 which is provided with circular bores adjacent each of the clamping cheeks and extending transversely of the direction of the said translational movement, for the reception of clamping pegs.

19. A vice as claimed in any of Claims 1 to 18 in which both clamping cheeks are supported directly from below.

20. A vice as claimed in any of Claims 1 to 19, which includes a fixed body portion on which one of the clamping cheeks is mounted and a moving part on which the other clamping cheek is mounted, and which is arranged to slide relative to the fixed body portion to produce the relative translational movement of the clamping cheeks.

21. A vice as claimed in Claim 20 in which the fixed body portion has mounting means arranged to allow the vice to be secured to a working surface, wholly above the working surface.

22. A vice as claimed in Claim 20 or Claim 21, in which the fixed body portion has mounting means arranged to allow the vice to be secured with the body portion generally below a working surface, and the upper edges of the clamping cheeks generally level with the working surface.

23. A vice as claimed in Claim 20 or Claim 21 or Claim 22, in which the fixed body portion and the moving part are connected by an intermediate member, which is movable stepwise relative to one of the fixed body portion and the moving part, and in which vice the first clamping arrangement is constructed to produce a continuous relative movement between the intermediate member and the other of the fixed body portion and the moving part.

24. A vice as claimed in Claim 23 in which the intermediate member comprises an elongate member which is received for step-wise movement within a passage formed in the fixed body portion.

25. An assembly comprising the intermediate member, moving part, and associated clamping cheek of a vice as claimed in Claim 24.

26. A sash cramp comprising an assembly as claimed in Claim 25, with a sash cramp head fitted over the intermediate member.

27. A vice as claimed in any of Claims 1 to 24 in which each clamping cheek affords a vertically comparatively shallow clamping surface, beneath which a recessed region is provided.

28. A vice as claimed in Claim 27 in which each clamping cheek is provided with a soft lining affording a clamping surface extending to a lower level than the clamping surfaces of the clamping cheeks proper, each lining including a support portion which abuts against a vertical surface within the said recessed region to provide support for the lower part of the lining.

29. A vice substantially as herein described, with reference to Figures 1 and 2, or Figure 4, or Figures 5 and 6, of the accompanying drawings.

30. A clamp substantially as herein described, with reference to Figures 1, 2 and 3 of the accompanying drawings.

31. A clamping system including two opposed clamping cheeks; a first clamping arrangement constructed to produce a translational movement of one cheek relative to the other, and second and third independently-operable clamping arrangements constructed to produce tilting of one of the cheeks relative to the other about two axes lying generally at right angles to one another and generally parallel to the surfaces of the clamping cheeks.