Abstract An electric motor assembly for driving a helical feed screw for use in a vending machine. The helical feed screw is intermittently operated through cycles of similar duration and must be accurately positioned at the end of each cycle. Operation of the motor is initiated by the insertion of coins and is continued for the remainder of a cycle by a holding circuit. An actuating member for the holding circuit switch is positioned adjacent a cam which rotates with the helical feed screw. A pawl is positioned between and engages the switch actuating member and the cam. The cam has a notch indicating the end of the cycle which notch receives the pawl thereby allowing the switch actuating member to open the holding circuit and stop the motor. The pawl also has a dog which engages the edge of the cam notch to prevent reverse rotation of the cam at the end of the cycle. The pawl transmits cam forces to the switch actuating member only along the longitudinal axis thereof. The pawl and switch enclosure are mounted on a commmon mounting pin. The spring biasing the pawl and the switch enclosure are secured to the gear train housing by a common fastener.
An electric motor assembly in which the motor is intermittently operated through cycles of similar duration, in which an output shaft is connected to said motor through a gear train located in a housing, and in which a switch controlling a holding circuit for said motor is located in an enclosure, an actuating member for said switch movable between a holding circuit closing position and a holding circuit open position, said switch actuating member extending out of said switch enclosure, a cam synchronously rotatable with said shaft, said cam being contoured to permit said switch actuating member to move to the motor holding circuit open position when said shaft is at the end of each cycle and to move said actuating member to the motor holding circuit closed position during the remainder of said shaft cycle, a pawl pivotally mounted on a pin extending outwardly from said gear train housing with said pawl positioned to contact both said cam and said switch actuating member, said switch enclosure being mounted on said pin and being located outwardly of said pawl, and a U-shaped spring positioned between said gear housing and said switch enclosure, said spring engaging and biasing said pawl against said cam, said spring having a loop formed at the free end of one leg, a fastener extending through said switch enclosure and said loop to attach said switch enclosure and said spring to said gear train housing, the other leg of said U-shaped spring contacting said pawl.
Claim 2
Dependent Claim
248 words
An electric motor assembly in which the motor is intermittently operated through cycles of similar duration, in which an output shaft is connected to said motor through a gear train located in a housing, and in which a switch controlling a holding circuit for said motor is located in an enclosure, an actuating member for said switch movable between a holding circuit closing position and a holding circuit open position, said switch actuating member extending out of said switch enclosure, a cam synchronously rotatable with said shaft, said cam being contoured to permit said switch actuating member to move to the motor holding circuit open position when said shaft is at the end of each cycle and to move said actuating member to the motor holding circuit closed position during the remainder of said shaft cycle, a pawl pivotally mounted on a pin extending outwardly from said gear train housing with said pawl positioned to contact both said cam and said switch actuating member, said switch enclosure being mounted on said pin and being located outwardly of said pawl, and a U-shaped spring positioned between said gear housing and said switch enclosure, said spring engaging and biasing said pawl against said cam, said spring having a loop formed at the free end of one leg, a fastener extending through said switch enclosure and said loop to attach said switch enclosure and said spring to said gear train housing, the other leg of said U-shaped spring contacting said pawl.