GB2034211A - Vices - Google Patents

Abstract

A vice for clamping workpieces 54 of irregular shapes and sizes has an anchoring member (22) slidable along a guide bar (16) and a chain (52) which can be selectively locked in a notch (26) in the member (22) at a desired position along the chain, which is then tensioned over the workpiece by tightening a screw member (42). <IMAGE>

Description

SPECIFICATION Improvements in Vices This invention relates to vices for gripping and holding workpieces which require to be rigidly held while some job is performed on them.

Conventional vices normally have two relatively movable jaws between which a workpiece can be clamped by rotating a threaded shaft which is axially fixed with respect to one jaw but which is axially movable, by rotation, with respect to the other. A problem that exists with this type of vice is that it is generally not adaptable to accommodate with the same ease both bulky and smailer items. If a vice is constructed to take larger workpieces then it is made larger and heavier. The threaded shaft is bigger and therefore more expensive to produce, owing to the extensive machining required to form the thread.

Furthermore, conventional vices generally only hold a workpiece in one plane and in order to prevent movement in other planes the vice normally has toothed, or at least serrated, jaws.

The jaws may damage more delicate workpieces, particularly if the vice is tightened considerably to grip a workpiece especially firmly.

Finally, large conventional vices may be difficult to transport and to carry to on-site locations such as development areas and building sites.

It is an object of this invention therefore, to provide a vice which can accommodate both large and small workpieces but which is transportable with relative ease. Furthermore, it is an object to provide a vice which without requiring accurate machining and large quantities of heavy material, is relatively cheap to produce.

It is another object of this invention to provide a vice in which the workpiece is prevented from moving in all planes, whereby the vice does not require to be tightened considerably in order to prevent movement in a given plane.

In accordance with this invention there is provided a vice having a frame which comprises a longitudinal guide which displaceably carries an anchoring member, and a support on which is mounted a screw mechanism to which is attached a flexible elongate member, the elongate member being engageable with the anchoring member to grip a workpiece between itself and the frame and the screw mechanism being operable to tighten said elongate member.

Preferably, said elongate member comprises a chain.

Thus a vice according to the invention can accommodate both large and small workpieces and workpieces of irregular or awkward shape with the same relative ease, by sliding the anchoring member along the longitudinal guide to any desired position and then by engaging the elongate member over the workpiece with the anchoring member. There are therefore no long threaded screws which have to be turned for any great length of time to open or close the vice. The screw mechanism need only be given a few turns to take the slack from the elongate member to grip the workpiece between the elongate member and the frame.

Preferably the frame further comprises two transversely spaced longitudinal pieces between which extends in substantially the same plane, the longitudinal guide.

In this way a workpiece clamped between the elongate member and the frame is prevented from moving relative to the vice in any plane.

Consequently, delicate workpieces, such as wood or p.v.c. coated cable trays and the like, can be gripped sufficiently firmly without the vice being tightened considerably. Angle irons interposed between the elongate member, especially if in the form of a chain, and the edges of a delicate workpiece, completely remove any danger of damage to the workpiece if the screw mechanism is tightened further.

Finally, a vice of this type is relatively inexpensive to produce owing to the relatively small amount of material used; this is because there is no long threaded portion to protect from fouling, corrosion or from mechanical damage. As a consequence of this feature a vice in accordance with the invention is lighter by comparison with known vices and is therefore more easily transportable than known vices.

The invention is further described hereinafter, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of the table of a vice in accordance with one embodiment of this invention; Fig. 2 is a detailed partial section through a screw mechanism diagrammatically shown in Fig.

1; Fig. 3 is a section along the line Ill-Ill in Fig.

1; Fig. 4 is a perspective view of a vice in accordance with second embodiment of the invention; and Fig. 5 is a fragmentary detail view of the vice of Fig. 4.

The vice illustrated in Fig. 1 comprises a substantially rectangular frame 1 0 having two transverse pieces or supports 12 in the form of angle irons and two longitudinal pieces 14 in the form of bars. Extending between the two transverse pieces 12 is a bar or guide 1 6 having a top edge 1 8 which lies in the plane containing the uppermost parts 20 of the bars 14. Carried on the bar 16 is a yoke or anchoring member 22 which is illustrated in greater detail in Fig. 3 and which comprises a yoke piece 24 having a notch 26 cut therein. The yoke piece 24 is welded to a carrier member 28 which straddles and which is displaceable along the bar 1 6. The carrier member has two downwardly projecting arms 30 which are clamped together beneath the bar by nuts and bolts 32.Butterfly nuts may be employed if the yoke member 22 is to be regularly changed for other types of yoke member which are further described below.

To one transverse bar 12 is welded a screw mechanism 34 which is shown in greater detail in Fig. 2 and which comprises a plate 36 securely welded to the bar 12. In the plate 36 is formed a spherical seat 38 and a bore 40 which passes through the centre of the seat 38. A screw piece 42 has a spherical head 44 which is constructed to co-operate with the seat 38 in ball-and-socket type relationship. Through the centre of the screw piece 42 is a threaded bore 46 which is adapted to receive a screw 48. The diameter of the bore 40 is greater than the diameter of the screw 48 so that the assembly of screw and screw piece 42 can be swivelled, at least in the plane of the drawing. The screw piece 42 is provided with a handle 50 by which means the screw piece can be rotated relative to the screw 48 to screw the latter into or out of the former.Attached to the end of the screw adjacent the transverse bar 12 is a chain 52 which is oriented so that it can flex in the plane of the drawing (Fig. 2) and which is adapted to engage in the groove 26 in the yoke piece 24 (Fig. 3).

The mode of operation of a vice in accordance with this invention is now described.

A workpiece 54, which may be an electrical cable tray as illustrated in Fig. 1, or a box section or other article which is to be worked on by an operator, is placed across the frame 10 with one edge 56 lying against the upstanding edge 1 3 of the transverse bar 12. The yoke member 22 is then displaced along the bar 1 6 until the leading edge 25 of the yoke piece 24 lies against the other edge 58 of the workpiece 54. Then the chain 52 is placed over the workpiece and engaged in the notch 26 in the yoke piece 24. In the drawings the chain is shown as having extended hinge pins 53 for catching on the lower edge 27 of the notch 26 (see Fig. 3).This is the most advantageous form of the chain but of course an ordinary chain could be employed to engage with teeth on the yoke piece or indeed could be replaced entirely by a rope or cable having knots or the like for engagement with the notch 26.

In any event the chain is loosely engaged in the notch 26. By rotating the screw piece 42 by its handle 50, the screw 48 is screwed out of the screw piece and so that slack in the chain is taken up and the workpiece can clamped in the vice to almost any degree of tightness desired. By means of the spherical surface 38 and 44 in the screw mechanism 34 the adjacent region of the chain always addresses the workpiece at an angle. The same applies to the region of the chain on the other side of the workpiece as this region enters the notch 26. In this way, the forces on the workpiece are mostly straight downward so that there is little tendency for workpiece such as the tray 54, to buckle under the stress.

To release the workpiece, the screw mechanism is merely unscrewed a few turns until the chain is releasable from the notch 26. To keep the screw piece 42 in position when the chain is slack, retaining members 41 are disposed on the plate 36 which engage with an annular groove 43 in the screw piece 42. To accommodate much larger or wider work-pieces the yoke member 22 need only be shifted along the bar 1 6 to the required distance and the chain engaged further along its length.

Thus the length of the screw 48 is immaterial and need only be sufficient to take up slack in the chain. Consequently, the whole vice requires little accurate workmanship to manufacture, can be constructed from presently available parts and is thus relatively inexpensive to produce.

The vice could be used on an appropriate surface but could also be supplied with its own legs. These would be fitted in holes, for instance holes 15, in the transverse bars 12.

As already mentioned, the yoke member 22 could be constructed so as to be replaceable so that differently shaped edges 25 of the yoke piece 26 could be employed whereby pipes, for instance, could be more efficiently gripped.

Figs. 4 and 5 show a modification to the vice of Figs.1,2 and 3 and like parts are denoted by like reference numerals and will not be further described. The embodiment of vice of Figs. 4 and 5 differs from that of Figs. 1 to 3 in that it has folding legs 60 hinged to the transverse pieces 62 and 63 and in that the guide bar 66 is of angle iron construction.

As can be seen from Fig. 4, the legs 60 are pivoted to the transverse pieces 62 and 63 and are interconnected in pairs by pivoted straps 64 and 65, a tool tray 67 being formed integrally with the straps 65. The transverse pieces 62 and 63 are flat plates between which the guide bar 66 is welded with the flanges of the guide bar sloping upwardly apart at 450 to the horizontal. The chain anchoring member 82 comprises a flat plate 68 which is provided with the notch 26 for the chain 52 and to which smaller locking plates 69 are strongly welded at 450. The guide bar 62 has cutouts 70 at one end and the spacing between the free edges of the locking plates 69 of the anchoring member 68 is such as to permit the anchoring member to be placed on the guide bar 66.The anchoring member 68 is then free to slide along the guide bar 66 to any desired position until the locking plates 69 engaging beneath the flanges of the guide bar to resist the pull of the chain 52 when the screw piece 42 is tightened with a workpiece in place, as described with reference to Figs. 1 to 3. The screw mechanism 74 includes a bracket 76 welded to the transverse piece 63 so that the screw 48 is steeply inclined to the horizontal, as in Fig. 2.

In use, the workpiece (not shown in Figs. 4 and 5) is placed on the vice so as to rest on the longitudinal pieces 14 or on at least one of these pieces and on the guide bar 1 8 and is pushed against the upstanding edge portion 13 of the transverse piece 63. The anchoring member 82 is then pushed up to the workpiece and the chain 52 is hooked in the notch 26 whereupon the screw piece 42 is tightened. This locks the workpiece firmly in position without having to apply such a high tension in the chain as would lead to damage to the workpiece.

Claims (8)

Claims

1. A vice having a frame which comprises a longitudinal guide which displaceably carries an anchoring member, and a support on which is mounted a screw mechanism to which is attached a flexible elongate member, the elongate member being engageable with the anchoring member to grip a workpiece between itself and the frame and the screw mechanism being operable to tighten said elongate member.

2. A vice as claimed in claim 1, in which said elongate member comprises a chain.

3. A vice as claimed in claim 1 or 2, in which the anchoring member has a notch in which the elongate member can be received, the latter having means for engaging the anchoring member, whereby the tensile force in the elongate member is transmitted by the anchoring member to the longitudinal guide.

4. A vice as claimed in claim 1,2 or 3, in which the anchoring member is freely slidable along the longitudinal guide.

5. A vice as claimed in claim 4, in which the longitudinal guide comprises a guide bar and the anchoring member embraces the guide bar.

6. A vice as claimed in claim 5, in which the guide bar has inclined lower faces against which inclined parts of the anchoring member engage when the screw mechamism is tightened.

7. A vice as claimed in any preceding claim, in which the frame comprises two transversely spaced longitudinal pieces between which is arranged the longitudinal guide parallel to and in substantially the same plane as the longitudinal pieces.

8. A vice constructed and adapted to be used substantially as herein described with reference to and as illustrated in the accompanying drawings.