GB916003A - Machine for assembling fastener units - Google Patents

Abstract

916,003. Assembling screws and washers. BARWOOD MANUFACTURING CO. Inc., L. J. April 13, 1961, No. 13252/61. Class 83 (2). In a machine for assembling screws and washers in which a washer is threaded upwardly on to a screw suspended by its head in a fixed position, the operation of the machine is stopped unless the availability of a screw and a washer are satisfactorily checked by the completion of electric circuits through a screw and a washer at checking positions. The washer is a metal washer having a plastic insert. Feeding screws. The screws 10 are supplied by a vibratory tray type magazine to the top of an inclined slideway comprising spaced rails 21 and adjustable bars 22, 38 engaging the heads of the screws 10. When the leading screw engages stop pin 23 a first control circuit is completed through the pin 23 and the screw to start the washer feed and to actuate compressed air cylinders 30 and 25. A transfer bar 24 is actuated through a resilient connection 28 by the cylinder 25 to transfer the leading screw into engagement with a stop-bar 29 determining the assembly position and moved by the cylinder 30 until halted by an adjustable stop 34. A resilient hold-down plate 36 engages the head of the screw. Feeding washers. The washers 11 are fed by a vibratory tray type magazine on to a conveyer belt 51. The belt is pressed upwards by a spring-loaded bar 52 and the washers 11 are held down by an adjustable member 53. At one point on the belt the presence of a washer lifts a control which causes an air jet to blow washers in the outlet of the magazine back into the tray. The washers 11 leaving the belt 51 are pushed along a guide until the leading washer rests between spring-loaded pivoted arms 63 on a vertically movable plunger 60 in engagement with a contact 66. A pivoted member 68 retains the washer on the plunger 60. A second control circuit completed through the contact 66 and the leading washer de-energizes a solenoid 78 to allow a spring-loaded clamp 76 to grip a washer 11 in the feed path to stop feeding of the washers. Assembly. The second control circuit also initiates upward movement of the plunger 60. A plate 72 secured to the plunger 60 releases a rod 69 to allow the retaining member 68 to swing clear. As the plunger 60 threads the washer 11 on to the screw 10, the plate 72 actuates in turn switches LS2, LS3 which respectively return the transfer and stop-bars 24, 29 and lower the plunger 60. The assembly is freed by an ejector rod 64 in the plunger 60 and is blown clear by an air blast. When the plunger 60 reaches its initial position, a switch LS1 operates to restart the cycle if a screw is in position to complete the first control circuit.