GB2033951A

GB2033951A - Clamp

Info

Publication number: GB2033951A
Application number: GB7846462A
Authority: GB
Original assignee: DE STA CO Metallerzeugnisse GmbH
Current assignee: DESTACO Europe GmbH
Priority date: 1978-09-29
Filing date: 1978-11-29
Publication date: 1980-05-29
Also published as: IT1123367B; GB2033951B; FR2437273A1; DE2842501B1; FR2437273B3; DE2842501C2; IT7926119A0

Abstract

A clamping device comprising a clamping arm 4 pivotally mounted on two intermediate straps 13, a grip connector member 8 pivotally mounted on said intermediate straps 13, and two bearing plates 1 pivotally mounted on one end of said clamping arm 4 and on said grip connector member 8, the intermediate straps 13 being movable within the outer limiting planes of the bearing plates 1, the grip connector member 8 and the clamping arm 4 being arranged between the bearing plates 1, and the grip connector member 8 having a concave portion 8' such that in the extreme clamping position (as shown) the concave portion 8' of the grip connector member 8 extends around the end 2 of the clamping arm 4 pivotally mounted on the bearing plates 1. <IMAGE>

Description

SPECIFICATION Clamping Device The invention relates to a clamping device comprising, all pivotally linked to one another, a clamping arm, two intermediate straps, a grip connector member and two bearing plates, on which the joints for the grip connector member and the clamping arm are mounted, the intermediate straps being arranged movably within the outer limiting planes of the two bearing plates.

Clamping devices of the above-mentioned type are generally known and are used particularly in the welding of car bodies. Corresponding body parts are clamped together with a plurality of such clamping devices, whereupon the body parts held clamped together are welded with so-called welding tongs.

In so doing, it is desirable that as much space as possible is available between adjacent clamping devices for the introduction of the welding tongs, which means that the clamping devices should be made as narrow as possible.

Hitherto known clamping devices do not meet this requirement, since the grip connector member with two lateral jaws surrounds the flanks of the other parts of the mechanism from outside, which then results, for example, in widths of the mechanism of approximately 50 mm.

A further disadvantage of such clamping devices consists in that due to the construction of the parts and especially of the grip connector member, the end dead-centre position (extreme clamping position) corresponds to an exact thickness value of the workpiece to be clamped. If the dimensions, critical in this respect, of the workpiece to be clamped vary, which can occur at any time, then the ideal extreme clamping position can no longer be set exactly, since the clamping arm and especially the grip connector member cannot compensate for such tolerance variations.

The object of the present invention is to provide a clamping device in which, on one hand, the requirement for as narrow a design as possible is satisfied and, on the other hand, tolerance variations on the workpiece are compensated without prejudice to perfect clamping.

According to the invention, there is provided a clamping device comprising a clamping arm pivotally mounted on two intermediate straps, a grip connector member pivotally mounted on said intermediate straps, and two bearing plates pivotally mounted on one end of said clamping arm and on said grip connector member, the intermediate straps being movable within the outer limiting planes of the bearing plates, the grip connector member and the clamping arm being arranged between the bearing plates, and the grip connector member having a concave portion such that in the extreme clamping position the concave portion of the grip connector member extends around that end of the clamping arm pivotally mounted on the bearing plates.

Thus, the grip connector member is arranged, as it were, on the inside of the clamping mechanism, so that lateral bearing jaws which have needlessly made such mechanisms wider can be omitted and, on the other hand, owing to the stirrup-shaped design of the grip connector member, its shaping alone advantageously imparts thereto an elasticity which can absorb tolerance variations without prejudicing the required clamping action.

An exemplary embodiment of a clamping device according to the invention is described in detail hereinafter by reference to accompanying drawings wherein: Figure 1 is a side view of the clamping device in the extreme clamping position; Figure 2 is a front view of the clamping device shown in Figure 1 and Figure 3 shows the clamping device of Figures 1 and 2 in the opened position.

As shown in the drawings, a clamping device comprises a clamping arm 4 pivotally mounted on a pair of intermediate straps 13 by means of a pivot joint 6. A grip connector member 8 is also pivotally mounted on the intermediate straps 13 by means of a pivot joint 5. Two bearing plates 1 are pivotally mounted on the clamping arm 4 at a pivot joint 6' and on the grip connector member 8 at a pivot joint 3.

The moving parts, namely, the curved grip connector member 8, the intermediate straps 1 3 and the clamping arm 4 lie, as shown in Figure 2, between the outer limiting planes of the two bearing plates 1 which are connected to one another by a solid riveted joint 7 and a connecting plate 1 4 shown in broken lines.

The pair of intermediate straps 13, connected flexibly by joint 5 to the grip connector member 8 and by the joint 6 to the clamping arm 4, likewise moves within the outer limiting planes of the bearing plates 1 or above or laterally next to these. For the purpose of the extreme clamping position the two bearing plates 1 are provided in a known way with recesses 1 5. The clamping arm 4 pivots about the joint 6' of the bearing plates 1.

As shown in Figure 1, the curved portion 8' of the grip connector member 8 surrounds in the extreme clamping position the end 2 and the joint 6' of the clamping arm 4. This design in the form of a curve 8' imparts to the grip connector member a certain elasticity, but does not prejudice the clamping effect required to secure a workpiece.

The clamping arm 4 and the grip connector member 8 are provided in a known way with rounded ends 16, so that the grip member 12 and the clamping lever 9 which are provided with a matching concave surface can be welded on in a desired arrangement.

For the purpose of a desired extreme clamping position and end dead-centre position, the contact face 10 on the grip connector member 8 protrudes beyond the junction path plane 11 of the grip connector member 8, so that this face 1 C can be machined more simply to the desired size.

Claims

1. A clamping device comprising a clamping arm pivotally mounted on two intermediate straps, a grip connector member pivotally mounted on said intermediate straps, and two bearing plates pivotally mounted on one end of said clamping arm and on said grip connector member, the intermediate straps being movable within the outer limiting planes of the bearing plates, the grip connector member and the clamping arm being arranged between the bearing plates, and the grip connector member having a concave portion such that in the extreme clamping position the concave portion of the grip connector member extends around that end of the clamping arm pivotally mounted on the bearing plates.

2. A clamping device as claimed in claim 1, wherein the grip connector member has a planar clamping surface which extends beyond a junction path plane of the grip connector member.

3. A clamping device substantially as herein described with reference to the accompanying drawings.