GB461195A - Improvements in electrical systems for the remote indication of speed - Google Patents

Abstract

461,195. Electric signalling systems. WOOLNOUGH, G. L., GRAY, A. H., HARWOOD, H. V., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Aug. 12, 1935, No. 22727. [Class 40 (i)] In a system for the remote indication of speed, e.g. wind velocity, the speed of a wattmeter shaft &c., control means, operated by a member moved through a predetermined distance at a speed determined by the speed to be measured, effect the control of indicating means which provide an indication of the time between actuation of the control means and the completion of a predetermined time interval. As shown, control contacts 3 are operated by a member 4 which is driven at the speed to be measured through a slipping clutch 7. A drum controller 1 is driven at constant speed by a motor 2 and is provided with contacts S1 ... S10 which at the commencement of a time interval corresponding to the time of one revolution are closed, but are successively opened during the time interval. When the contacts 3 are closed, a relay A is operated and circuits are closed through the S contacts which remain closed to operate corresponding relays W and indicating devices X, the number of devices X operated being dependent upon the speed at which the member 4 is operated. The operated relays W lock up over contacts h<1> ... h<10> and the contacts of a slow-acting relay 9 which is operated by the contacts 3 and effects cancellation of the previous indication. At the completion of each revolution of the drum a resetting coil 8 is operated to restore the member 4. The speed indicating apparatus is used in association with wind direction indicating apparatus 18 and the arrangement is such that if the wind velocity falls to a negligible value an impulse is transmitted to cause the direction indicator to be moved into a predetermined position and retained therein until the wind velocity again increases. The impulse is transmitted by contacts 13 on the drum controller in the event that relay 15 remains inoperative as the result of non-operation of contacts 3 during the time interval. The impulse transmitted over lead 16 operates relay 17 and thereby operates magnet 24 which moves a catch 26 into contact with the periphery of a disc 20 and closes contacts 27 which closes the circuit of one or other of the relays 28, 29 over a commutator 21. The relays 28, 29 operate coils 31, 32 of the control switches of a motor 23 which drives, through a clutch 30, the shaft 18 until the catch 26 falls into the notch 33 and contacts 34 are closed to short-circuit the switches 31, 32 and thereby stop the motor. Upon the next closure of the contacts 3 in response to increased wind velocity, a resetting coil 37 is operated to release relay 17.