Patent GB-795277-A (GB)
Title: Improvements in and relating to a method for attaching lugs to panels
Inventor: WILLIS GRANT NOBLE
IPC: H05K13/04
Filed: 1956-08-29
Abstract: 795,277. Making electrical components; sheet-metal joints. CINCH MANUFACTURING CORPORATION. Aug. 29, 1956, No. 26451/56. Classes 83 (2) and 83 (4). [Also in Groups XXX and XXXVI] A method of attaching metal lugs, e.g. electrical terminals, to an apertured panel, e.g. printed circuit panels, comprises feeding a clip consisting of a series of detachably connected lugs to the panel to position the leading lug in alignment with an aperture in the panel, separating the said leading lug from the clip and inserting it into the said aperture. An automatic lug feeding and attaching machine is mounted on a base 20 provided with a bed 22 for supporting the panel 9. A column 24 carries a vertically reciprocable ram 28 which may be hand or motor-operated. The ram carries a plunger 32 for inserting the lugs into the panel, said plunger being slidably accommodated in a housing 36 carried on an arm 34 which has a track 40 along which the lugs are fed to the plunger. The lugs are assembled in clips and are gravity fed from a magazine 44 to the track 40, one at a time under the control of an escapement 46 (Fig. 6) including a spring-loaded gate 48. When a clip is on the track below the magazine it holds the gate closed but the gate opens when the track below the magazine is empty and allows the next clip to fall on to the track. The clips are fed along the track by reciprocable spring-loaded drivers 54 each having a pivotal pawl 56 for engaging the clips and an outwardly extending tab 58 accommodated for limited longitudinal movement in a slot 60, in a slider 66 longitudinally reciprocable along the arm, said slider being reciprocated by a bell-crank 70 attached to a vertical pin 72 actuated by a shoulder 74 on the ram 28. In operation, each time the ram descends the slider moves to the right, engaging the tab 58 of each driver and carrying with it the driver and pawl which ratchets over the lugs in the clip. When the ram is raised a spring 76 acting on the bell-crank returns the slider and the drivers are urged to the left by springs 64, each pawl thereupon resiliently feeding a clip. Forward movement of the clips is limited by the plunger 32, the lower end of which has an L-shaped crosssection forming a vertical shoulder 80 inclined to the axis of the track (Fig. 7) and against which the stem 4 of the lug engages. The bottom face 82 of the plunger drivingly engages one or both ears 8 of the lug. A thermostatically controlled electric heater 84 attached to the side of the housing 36 applies heat to the clip to soften the solder holding the lugs together. Extending along the plunger is a retainer 90 having its lower end of J-shaped cross-section (Fig. 7) forming a lip 92 in alignment with the plunger shoulder 80. The retainer is reciprocated by the plunger with a limited lost-motion connection by having a flange 94 disposed between shoulders 96 and 98 on the plunger. The retainer has a lower hole 100 which, in the upper position of retainer and plunger (Fig. 9) registers with a bore 102 in the housing 36 and the lower end of a groove 104 in the plunger. A ball 106 in the bore 102 is biased into the hole 100 and groove 104 by a spring 108 and locks the retainer and housing in the upper position and an upper hole 110 in the contact retainer is located adjacent another groove 112 in the plunger. During the initial downward movement of the plunger the retainer does not move and this permits the plunger to carry a lug down and tuck it between the lip 92 of the contact retainer and the shoulder 80 of the plunger. At the same time the ball reaches the upper end of the groove 104 and is forced back into the bore 102, thereby freeing the retainer from the housing 36 so that it travels downwardly with the plunger, the lip 92 supporting the lug against the plunger shoulder 80 in the proper position for insertion into the slot in the panel. Finally, a co-operating die (not shown) in the bed 22 stakes the protruding head of the lug against the underside of the panel. At the lowermost position of the plunger and retainer the hole 110 registers with bore 102 and the ball drops into the upper groove 112 of the plunger. This holds the retainer in its lowermost position while the plunger is being retracted until the lower end of the groove forces the ball back into the bore 102, whereupon the plunger returns the retainer to its initial position and the hole 100 again registers with the bore 102, allowing the ball to drop into the lower plunger groove and condition the plunger and retainer for the next down ward stroke.