Patent GB-690103-A (GB)
Title: Improvements in or relating to tools adapted for use in blind riveting
IPC: B21J15/04
Filed: 1950-01-26
Abstract: 690,103. Blind-riveting. BRITISH UNITED SHOE MACHINERY CO., Ltd., and HENSHAW, J. N. Jan. 25, 1951 [Jan. 26, 1960], No. 2040/50. Class 83 (iv). In a blind-riveting tool of the type wherein mandrel-gripping jaws are displaced by an actuating device to set a rivet, and wherein relative movement between the jaws and actuating device due to increase in resistance automatically increases the grip on the mandrel, a device under the control of the operator and movable independently of the actuating device is provided for controlling movement of the jaws into gripping engagement with the mandrel. The tool, operated by lazy-tongs mechanism, is similar in many respects to that described in Specification 348,818, [Group VII]. Movement of the gripping jaws 145, 147 within the actuating sleeve 113 is controlled by an L-shaped plate 159 slidable transversely of the casing 111 through slots therein, and normally held in the position shown in Fig. 1 by a spring 171 acting between the casing 111 and an arcuate fingerpiece 169. In this position the jaws are held open, being held back relative to the sleeve 113 against the action of a spring 155 by the engagement of the block 153, to which they are attached, with a shoulder 175 on the wider part 165 of the plate 159. Slots 114; 116 in the sleeve 113 allow independent movement of the sleeve and plate. Initially the tool is held with the nosepiece 115 uppermost, the lazy tongs expanding under their own weight so that the sleeve 113 is moved to its forward position, and the jaws being open. A mandrel stem is inserted between the jaws, and the fingerpiece 169 is pressed down so that the shoulder 175 releases the block 153 for spring- urged forward movement which results in the jaws closing round the mandrel stem. The tool may now be held in any position. The plate 159 is prevented from returning to its operative position under the action of its spring 171 until, during a rivet-setting stroke of the sleeve 113, the block 153 is withdrawn from engagement with a surface 179 of the plate. If after one stroke a further pull on the mandrel is necessary to set the rivet and break the mandrel stem, the lazy tongs are expanded and, the jaws being open due to return of the plate 159 to its operative position, the nosepiece 115 is pushed down the mandrel stem until it re-engages the rivet. By leaving the plate 159 in its operative position on re-collapsing the lazy tongs, the jaws do not immediately re-grip the mandrel stem, so that the final setting stages are performed with the lazy tongs partially collapsed. In a modification for use where several operative strokes are necessary for complete setting, the shoulder 175 of the plate 159 is located further to the right, viewing Fig. 1, so that initially the jaws are further away from the nosepiece 115. In use, having re-engaged the nosepiece with the rivet after the first stroke, the operator partially collapses the lazy tongs to give the desired mechanical advantage, then pushes in the fingerpiece 169 so that the jaws grip the mandrel stem, and then completes collapse of the lazy tongs. Specifications 405,993, 426,635, 490,047, [all in Group VII], 504,928, 507,358; 564,383, 587,938, 606,825 and 613,882, [all in Group VII], are referred to in the Complete Specification, and Specification 568,013 also in the Provisional Specification.