Patent GB-711531-A (GB)
Title: Balancing arrangement, particularly for hydro extractors
IPC: D06F34/08
Filed: 1949-04-20
Abstract: 711,531. Centrifugal machines. KAHN, L. M. July 20, 1950 [April 20, 1949], No. 10536/49. Class 23 [Also in Group XXXV] The cylinder of a hydroextractor is balanced during rotation by varying the quantity of fluid in one or more pockets offset from the axis o the cylinder, the pocket o: pockets first subjected to the variation being predetermined or being selected in accordance with the degree of vibration. A rotary cylinder 21 of a washing machine is spun for hydro extraction and has pockets 29 30 supplied with balancing liquid through pipes 31, 40 having solenoid operated valves 36 42 automatically controlling flow A switch 59 causes electric current to pass through the windings of electromagnets 54 ... 58 when the vibration exceeds a certain amount. Adjacent each of the magnets but at pro-  gressively increasing distances therefrom are reeds 49 ... 53 vibrated by cylinder out of balance. If the vibration is small only the reed 49 will be retained by its magnet to operate solenoid 74 closing a circuit which opens valve 36 to supply liquid to the pocket 29. If the supplied liquid balances the cylinder and the vibration ceases the switch 59 opens and the valve 36 closes to cut off supply of liquid to the pocket 29. If the vibration is increased by the supplied liquid the reed 50 is also retained by its magnet to operate solenoid 80 to close the valve 36 and open the valve 43 to transfer the liquid supply to the pocket 30 until vibration ceases. If the 'initial vibration is larger so' that the reeds, 49, 50, 51 are retained by their magnets, the solenoid 88 closes the valve 43 and opens the valve 36 to supply pocket 29. If the supplied liquid increases the vibration the reed 52 will also be held by its magnet to operate solenoid 92 so that the liquid supply is transferred from the pocket 29 to the pocket 30 untilvibration ceases. If the initial vibration is still larger so that reeds 49-52 are retained, the pocket 30 is supplied. Should vibration then increase the reed 53 is retained and the solenoid 99 closes a circuit to cut off the drive motor 24 and light a warning lamp. In a modification of the electrical circuit, Figs. 14, 15 (not shown), the switch 59 is replaced by an electromagnet vibration pickup and the reeds and electromagnets by thermionic valves. In a modification of the washing cylinder, Fig. 6 (not shown), liquid is supplied by a pipe at one end of the cylinder and the pockets are formed in the tumbling ribs. In a further modification, Figs. 12, 13 (not shown) the liquid is sprayed by a nozzle having its elevation adjustable by ,electromagnets into two different sized pockets having segmental mouths at different radii. The larger of the pockets may be filled with liquid or alternatively the pocket may be replaced by a weight and balance may be attained by supplying liquid to the other pocket. More than two pockets may be fitted to the cylinders, the balancing liquid being supplied successively to the pockets until balance is attained. The invention may be applied to washers having a vertical axis and the balancing liquid may be water or mercury. Instead of adding liquid to correct out of balance the pockets may be initially filled and liquid removed to attain balance. The arrangements to correct out of balance due to radial displacement of the centre of gravity may be combined with an arrangement, Figs. 10, 11 (not shown), in which out of balance due to longitudinal displacement of the centre of gravity is corrected. In this construction liquid is supplied to coils fitted at each end of the cylinder. Specifications 663,829 and 682,769 are referred to.