GB515212A - Improvements in electric signalling systems - Google Patents

Abstract

515,212. Electric signalling systems. KENT, Ltd., G., and COOKE, G. P. May 20, 1938, No. 15138. [Class 40 (i)] In a device for transmitting values such as liquid levels, the movement is made to store energy in a spring which is then released suddenly to operate a magneto which transmits an impulse.. In the form shown in Fig. 1 a counterbalanced float 1 rotates a wheel 6 toothed at 7. One of these teeth engages and moves an arm 9 so rotating a shaft 10 against the action of a spring 14 which presses on a cam 13. On sufficient rotation the tooth 7 becomes disengaged from the arm 9 and the energy in the spring is released thus turning the shaft 10 rapidly and causing the magneto 11 to transmit an impulse along the wire 21. The rotation of the armature is limited to an angle under 180 degrees so that impulses may be semidirectional, but their sign will depend on the direction of rotation. In the receiving device rectifiers are arranged so that current flows through either coil 17 or coil 18 according to the size of the impulse so that an armature 19 is attracted to one side or the other. This motion is transmitted via the shaft 20 to the ratchet and pawl device 27 and 28 which operates the pointer 29. In the modification of the transmitter shown in Fig. 2, the pulley 3 is fast with the disc 32 which has a pin 33 carrying a roller 35 urged by the spring 34 against a fixed face cam 36, which is provided with equally spaced recesses. The unrecessed parts of the cam 36 hold the forward end of the pin between one of three pairs of lugs 37 on a disc 38 connected to the armature spindle 39 of the magneto. On rotation of the pulley 3 the magneto spindle rotates until the roller moves opposite a recess in the face 36 whereupon the pin is freed from the lugs 37 and springs 40, 41 bring the magneto spindle back to its normal position causing an impulse to be transmitted and the forward end of the pin 33 moves between another pair of lugs 37.