Patent GB-784276-A (GB)
Title: Improvements in or relating to assembly machine for circuit components
IPC: H05K13/04
Filed: 1955-12-28
Abstract: 784,276. Making electrical components; bending. GENERAL MILLS, Inc. Dec. 28, 1955 [Dec. 28, 1954], No. 37175/55. Classes 83 (2) and 83 (4). A machine for mounting electrical components, e.g. condensers, transistors, coils, resistors, on a circuit board comprises means for inserting the leads of the electrical component through holes in a circuit board, movable members for engaging the leads which project through the circuit board and bend them outwardly away from each other over against the underside of the board to force them into engagement with the circuits of the circuit board and means to operate said members. A resistor 26 comprising a body 16 and leads 18 and 20 is fed to the machine from an inclined shoot 14 on to notched sides 34 and 36 of an anvil 28. As this resistor is carried downwardly to be attached to the circuit board, an inserter head 30 slides past and supports the end resistor in the shoot and bends the leads of the resistor on the anvil downwardly by means of its grooved fingers 82 and 84. The head comprises a guide bar 40 and a spring-loaded inserter block 30 slidable thereon the head being carried by a yoke 62 pneumatically reciprocable between guides 66 and 68. Compressed air is supplied to the air cylinder 72 from a two-position four-way valve 80 controlled by a solenoid switch 81 either manually or automatically. The anvil is mounted on a pivoted carriage 104 (Fig. 6) locked in position by a pivoted spring-loaded arm 106 whilst the leads are being initially bent. The upper portion of the arm 106 has a cam surface 120 (Fig. 5) which is engaged by a release and actuator arm 122 secured to the yoke 62. When the yoke descends the arm 122 pivots the arm 106 so that the pin 110 of a spring-loaded crank arm 108 is freed from a notch in the arm 106 and the anvil is rotated out of the way of the descending inserter head against the action of a spring 126 the actuator arm 122 engaging a roller 130 on the crank arm 108 to hold the carriage in the retracted position. The resistor 26 is supported in the bending fingers 82 and 84 and the downwardly moving head inserts the bent leads into the holes in the circuit board 92 positioned on the table 132 and held in place by guides 134, 136 and 138. The table has an opening 140 (Fig. 7) for receiving crimping mechanism for crimping the projecting leads. Pivoted spring- loaded crimping fingers 156 and 158 are mounted on a platform 154 which is raised into the table opening 140 by a piston rod 152 and piston 150 operated by an arm 142 on the yoke which depresses the plunger 144 of an air valve. The upper end of the piston rod has a tapered head 162 which wedges between the fingers and when the platform is arrested by stops 164 and 168 the. head is forced between the fingers to move them apart and bend the leads outwardly and tightly against the conductive part of the printed circuit on the lower surface of the board 92. As the finger 158 rotates it depresses a plunger 91 on a switch 89 which returns the solenoid valve 80 to its original position. The yoke automatically rises and releases the plunger 144 and the crimping piston drops under the action of the spring 180. When the platform 154 engages shoulders on the stop rods 170, 172 the tapered head of the piston rod is withdrawn from between the fingers and they close. When the yoke reaches its uppermost position the guide bar 40 moves above the leading resistor in the shoot and permits it to slide forwardly on to the anvil which has returned to its initial position and the machine is ready for the next operation. Finally, the crimped joints are dipped in solder.