IMPROVED WORK BENCH AND CLAMPING DEVICE FOR A WORK BENCH TOP

Abstract: A work bench has a rectangular top (10), of which a pair of opposite sides are slotted. A third side carries a slide (18) bearing a pair of jaws (20,22) each independently movable towards or away from the other, and each rotatable about a vertical axis. A second slide (28) engaqes the slots in th work bench top and is movable towards or away from the first slide, and similarly carries a pair of independently movable and rotatable jaws. Each jaw has its own lead screw, which may be operable by a knob or handle, or a separate detachable handle with magnetic retaining means (68) may be employed.

Description: The present invention relates to work benches, and its object is to provide a work bench with a clamping device which is particularly adapted to the gripping of articles of complex shape. United States Patent 4,527,786 discloses a work bench having a pair of vice assemblies mounted on a frame, each vice assembly having a movable jaw and a fixed jaw, one vice assembly heing movable towards and away from the other, and with the movable jaws being capable of swivelling. The present invention may be regarded as a development of this arrangement, and provides improved means whereby objects of irregular shape may be securely gripped. Attention may also be drawn to U.S. Patent 2,322,380 which discloses a vice with split jaws mounted for rotation on a turntable. The present invention is defined in the claims appended hereto, and an embodiment of it will now be described with reference to the accompanying drawings, in which:- Figure 1 is a diagrammatic plan view of the vice portion of a work table top; Figures 1-1 and 1-2 are sections respectively along the lines AA and BB of Figure 1; Figure 1-3 is an isometric drawing of the work bench top of Figure 1; Figures 2 and 3 are sections along the line BB of Figure 1 showing alternative arrangements of the operating handles; Figure 4 is a diagrammatic overall view of the framework of a work bench on which the clamping arrangement of Figure 1 is mounted; Fiqure 5 shows a detail of a handle suitable for use in operating the clamp of the present invention; and Figures 6A - 6F are diagrams illustrating the manner in which the clamp of the present invention clamps an irregular shaped object, in comparison with the clamps of the prior art. Referring now to the drawings, a work bench comprises a rectangular frame 10 forming the workbench top, and supported on legs 12 which may be arranged to fold for storage. One pair of opposite sides of the rectangular frame are provided with slots 14,16. A third side carries a slide 18 along which a pair of jaws 20,22 are independently movable, each being coupled to its respective lead screw 24,26. A second movable slide 28 is parallel to the first slide 18 and similarly carries a pair of jaws 30,32 each independently operable for movement along the slide by its respective lead screw 34,36. This second slide is movable towards or away from the first slide 18 by means of a further lead screw 38, heing kept parallel to the first by means of pairs of pins 40,42, and 44,46 riding in the slots 14,16. Each of the vice jaws 20,22,30,32 is freely rotatable about a vertical axis 50,52,54,56. This enables each jaw to accommodate itself to the shape of an object being gripped by the clamping arrangement, so that objects of any shape can be securely held. For the same purpose, it will be noted each of the jaws of each pair is movable independently of the other. In order to obtain this independent movement, it is necessary for sound design that the two lead screws of each slide i.e. 24 and 26 for slide 18 and 34,36 for slide 28, should be closely adjacent to one another, and this makes it difficult to provide both of them with operating handles of adequate size. While the operating handles could be at opposite ends of the slides, as indicated in Figure 3, it is more convenient in practice that all four of the lead screws 24,26,34,36 should be operable from the front of the work bench. In the Figures, two alternative means of dealing with this problem are shown. The arrangement of Figure 2 depends on the appreciation that when the two jaws of a slide are advanced into position and tightened to grip an object it is only the tightening of the second of the two that requires any appreciable force to be exerted. It is therefore possible to provide one of the two leading screws with a relatively small knob, such as the knurled knob 60 of Figure 2 by which the first jaw to be adjusted can be brought into position to contact the object being gripped quite lightly, and the second lead screw is provided with a more substantial handle, extending beyond the knob 60, and which can then be tightened until the object to held is firmly gripped. In a second solution, each of the four lead screws 24,26,34,36, ends in a shank of non-circular, preferably square, section, and a handle of special construction is provided to engage these shanks. The handle is shown in part section in Fiqure 5 and comprises a barrel 64 having a deep recess 66 of corresponding section such as to engage the shanks of the lead screws. A permanent magnet 68 is inserted deeply into this recess and secured in position, so that when the handle is applied to the shank of one of the lead screws the magnet secures it temporarily in position. Figures 6A - 6F comprise a series of diagrams showing the manner in which an object of irregular shape is gripped by the clamping jaws of the present invention and, for comparison, how a similar object would be held by the prior art arrangements acknowledged above. In each case, the upper diagram represents the operation of the present invention, and the lower left and right diagrams represent respectively the operation of the arrangements of U.S. Patent 4,527,786 and U.S. Patent 2,322,380. Attention is drawn particularly to diagram E and F which relate to the butt-joining of separate sections, an operation for which work benches of this kind are frequently employed.

Claims: 1. A work bench having a top (10) comprising a rectangular frame and provided with clamping means comprising a first slide (18) forming or secured to one member of the frame, and carrying a pair of vice jaws (20,22) movable relatively to one another, a second movable slide (28) parallel to the first and carrying a second pair of jaws (30,32) movable relative to one another, and means (38) for moving the second slide towards or away from the first, and in which at least one of the vice jaws is rotatable, characterised in that each jaw is independently movable along its slide, and each jaw is rotatable about an axis (50,52,54,56) so that the jaws can conform to the shape of a work piece beinq gripped. 2. A work bench according to Claim 1 in which two opposite sides of the rectangular top are slotted (14,16) to form guides for the movable slide. 3. A work bench according to Claim 1 or Claim 2 in which the two jaws (20,22,30,32) on each slide (18,28) are each provided with a separate lead screw (24,26,34,36), the two lead screws being closely adjacent. 4. A work bench according to Claim 3 in which one of the said lead screws of each slide is provided with a knob (60) small enough to clear the second lead screw, while the second lead screw is provided with an operating handle (62) extending beyond the knob. 5. A work bench according to Claim 3 in which each of the lead screws ends in a shank of non-circular section, and a handle having a barrel (64) with a recess (66) of corresponding shape is provided with a permanent magnet (68) inserted at the bottom of the recess so as to secure the handle temporarily on a lead screw shank.

Inventors: YANG, TAI-HER
Applicants: YANG, TAI-HER
Application year: 1986
Main classification: B25H1
IPC codes: B25B1, B25H1