Patent GB-658760-A (GB)
Title: Improvements in bell ringing apparatus
IPC: G10K1/34
Filed: 1948-08-06
Abstract: 658,760. Control of motors. GILLETT & JOHNSON, Ltd., and LAMBERT, D. R. Aug. 6, 1948, No. 20821. [Class 38(iii)] [Also in Group XXXVIII] The shaft 2 of a power-assisted church or like bell is coupled to a shaft 7 mounted in a housing 42 containing a control device comprising four mercury switches. When the ordinary manual main switch (not shown) is closed, an A.C. motor (not shown) swings the bell in a clockwise direction, Fig. 1. An arm 10, frictionally mounted on the shaft 7, is thereby held against a stop 11 and, through a flexible coupling 53, holds a starting control switch 3 in its normal closed position. After a time the effect of gravity on the bell overcomes the force of the motor and the bell begins to swing back, moving the arm 10 against a second stop 12 to open the switch 3 and disconnect .the motor. The bell swings back freely beyond its central position, and then begins to swing clockwise again, closing the switch 3 and reconnecting the motor. This process continues, with the motor assisting the bell in its clockwise swings so that the amplitude of oscillation increases with each swing. A cam 21 fixed to the shaft 7 rocks an arm 20 carrying a change-over switch 4 which is biassed counterclockwise towards its starting position. When the amplitude of oscillation reaches the desired amount, the arm 20 is engaged by a latch 22 and holds the switch 4 in its maintaining " position. This cuts the starting control switch 3 out of the motor circuit and connects in its place a maintaining switch 5, biassed clockwise towards. its open position and carrying a rocking arm 27 from which is pivotally suspended an arm 28 bearing a long and a short detent 30 and 31 respectively. When the amplitude of oscillation, on a counterclockwise swing, reaches the value at which the change-over switch 4 is actuated to its maintaining position, a pin 33 carried on an arm 32 fixed to the shaft 7 passes below the short detent 31 and engages the long detent 30. Early in the subsequent clockwise swing the pin 33 engages the lower end of the short detent 31 and lifts the rocking arm 27, closing the maintaining switch 5 for a short time until the pin 33 moves clear of the short detent 31: Thus the motor is connected for a short time in each clockwise swing. When the amplitude of oscillation reaches a desired normal maximum value, the pin 33 moves past both detents and on its return merely pushes the long detent 30 aside without effect on the switch 5, the motor remaining disconnected. If the amplitude of oscillation reaches a predetermined abnormal maximum, a cam 41 engages a weighted lever 37 to release a cut-out switch 6 which swings to its open position and interrupts the motor circuit, which remains open until the switch 6 is reset by hand. When the main switch is opened, a winding 25 is de-energized and releases the latch 22 so that the change-over switch 4 returns to its starting position. A winding 17 is also deenergized and releases a latch 14, which then holds the starting control switch 3 in the closed position when the bell comes to rest. Specification 633,025 is referred to.