Patent GB-690174-A (GB)
Title: Improvements in or relating to tools adapted for use in blind riveting
IPC: B21J15/04
Filed: 1950-03-16
Abstract: 690,174. Blind-riveting. BRITISH UNITED SHOE MACHINERY CO., Ltd., BALL, A., and McQUEEN, R. D. March 15, 1951 [March 16, 1950], No. 6572/50. Class 83 (iv). In a blind-riveting tool of the type wherein abutment means hold the rivet up to the work while an actuating device is moved away therefrom on operation of a manually-operated member so that mandrel-gripping jaws are displaced relative to the rivet to set the latter, and wherein relative movement between the jaws and actuating device due to increase in resistance automatically increases the grip on the mandrel, a first tilting plate clutch drive acts when an operative stroke is applied to the manually-operated member to move the actuating device away from the abutment means, a second tilting plate clutch device which may be rendered inoperative at will being provided to oppose movement of the actuating device towards the abutment means when a reverse stroke is applied to the manually-operated member. The first clutch device comprises an assembly P of four plates 37, 38, 39, 40 urged forwards by a spring 41 along a bar 17 which is slidable in a body 11 and is spring-urged forwards. A reduced forward portion 27 of the bar 17 extends through bearings 29, 31 and is connected to the mandrel-pulling mechanism. A pin 45 on a pivoted operating arm 13 bears against the plate 40 so that when the arm 13 is swung towards the body 11 the assembly P will be tilted into gripping engagement with the bar 17 and the latter will be moved rearwardly. The second clutch device comprises an assembly W of three washers 50, 51, 52 mounted on the bar portion 27 between the bearings 29, 31 and urged forwards by a spring 53. One end of a pin 55 which passes through the bearing 31 bears against the washer 52 while the other end bears against a washer 57 which abuts a flange 58 of the casing 59 which houses the mandrelpulling mechanism. The flange 58 is retained slidably within the body I by a lip 60 of a cap 61. The cap 61, which can rotate but not slide on the casing 59, is slidable on the end of the body 11, two positions of the cap relative to the body being defined by the engagement of two inwardly directed pins 65 in the cap with the ends of two curved slots 63 in the body 11. With the cap 61 in its outer position shown in Fig. 1 the assembly W is inoperative and offers no resistance to movement of the bar 17. When the cap is turned to its inner position, the flange 58, washer 57 and pin 55 are pushed back and the assembly W is moved away from the bearing 31 against the action of the spring 53 and is tilted slightly. In this position the assembly W permits rearward movement of the bar 17 but prevents forward spring-urged movement thereof by gripping the portion 27 frictionally. With the parts in the positions shown in Fig. 1, the stem of a mandrel and rivet assembly is inserted between the jaws 72, and a latch 81 is depressed to allow the jaws to move forward under spring action to grip the stem. If several operative strokes are necessary to set the rivet the cap 61 is turned to its inner position and the arm 13 is swung towards the body 11 so that the assembly P moves the bar 17 and hence the jaws 72 rearwardly to pull the mandrel. When the assembly P reaches a shoulder 89 on the body 11, the arm 13 is swung away from the body 11, the assembly P sliding forward under the action of the spring 41 along the bar 17 which is itself held against forward movement by the assembly W. Operative and reverse strokes are applied to the arm 13 until the rivet is set and the mandrel stem broken. After a reverse stroke the cap 61 is returned to its outer position so that the assembly W releases its grip on the bar 17 which is consequently spring- urged forwards together with the sleeve 69. Before the latter reaches its initial position forward movement of the jaws 72 is arrested by the latch 81, whereupon the jaws open and the broken-off portion of the mandrel is discharged through the nosepiece 67. When a rivet is to be set by a single operative stroke of the arm 13, the cap 61 is left in its outer position. Specifications 348,818, 490,047, [both in Group VII], 504,928, 507,358, 587,938 and 613,882, [both in Group VII], are referred to in the Complete Specification and Specification 568,013 also in the Provisional Specification.