Patent GB-704283-A (GB)
Title: Improvements in and relating to drive mechanism for washing machines
IPC: D06F37/36
Filed: 1951-11-19
Abstract: 704,283. Hydraulic couplings. BRITISH THOMSON-HOUSTON CO., Ltd. Nov. 19, 1951 [Nov. 18, 1950], No. 27085/51. Class 69 (2). [Also in Groups VIII and XXIV] A torque transmission device includes a coupling having driving and driven parts positioned in a housing to which a fluid supply means is connected, the coupling being adapted to be floatingly supported for rotation of the driven part when fluid is admitted to the housing. The invention is described as applied to a washing machine of the same general type as described in Specification 625,324. The driving motor 49 is bolted to a casting 50 which is bolted at 46 to members 42 and 44 forming a casing for the motor and driving mechanism. The mounting of the motor casing in the machine casing is as described in Specification 646,403, [Group VIII]. The motor shaft 56 is hollow and operates through a reduction gear 60, 61, 64, 65 and a concentric inner shaft 66, with which is rigid the lower recessed disc 70 of a hydraulic clutch 71. The upper disc 74 of the clutch 71 is rigid with a plate 75 which carries diametrically - opposed upstanding spindles 81. Each of the spindles 81 carries a gear 93 in mesh with splines 89 formed on a shaft 88 which is journalled in a bore 87 of the shaft 66. Rigid with the shaft 88 is the driven member 84 of a clutch 83, 84. The member 84 has raised fingers 86 which engage slots 85 on the driving member 83 of the clutch when the member 84 is moved vertically upwards against the action of a spring 90. The member 83 is rigid with the shaft 66. Each pinion 93 has an eccentric hub 94 (Fig. 3) on which is mounted a link 95 which is pivotally connected to a toothed sector 97. Each sector 97 is journalled on a pivot rigid with the plate 75, and meshes with a pinion 100 carried by the agitator shaft 15. The plate 75 is connected rigidly via the spindles 81 and a plate 92a, with the spin shaft 14, The gears 64, 65 also function as an oil pump which has an inlet pipe 104 from a sump in the casing member 44, and an outlet 105 (Fig. 5). A piston valve biased to the position shown by a spring 114 and operated by a solenoid 109, selectively controls the oil supply from duct 105 to either duct 111 or duct 112. Duct 111 leads via ducts 116 and 118 (Fig. 7) to the bore 87 in the shaft 66, and thence via a flat 119 (Fig. 2) on the shaft 88 to the space in the driving element 83 of the clutch 82 below the driven element 84. The duct 111 also leads to a safety valve 120 adjustable by a screw 124 in the wall of the casting 50. The duct 112 leads to the spaces beneath and within the fluid coupling disc 70. A branch duct 113 from the duct 112 leads to the surface of the shaft 66. The hydraulic clutch 71 could be replaced by a friction clutch and the clutch 82 could be replaced by friction or hydraulic clutches. Operation. At the commencement of a washing cycle the solenoid 109 is energized so that the oil pump outlet is connected to the underside of the clutch element 84 which is thereby raised and transmits the motor drive to the pinions 93. This results in oscillatory movement of the agitator shaft 15. The driven member 74 of the hydraulic clutch is held from turning by the engagement of a brake lining 101 on the rim of the member 74, with a flange 72 of the casting 50. When the solenoid 109 is de-energized by the action of a conventional programmeselector switch (not shown), the pump output in diverted to the duct 112. The clutch 82 disengages under the action of spring 90, oil in the member 83 being displaced upwardly around the periphery of the member 84. Oil is pumped into the space 80 and raises the clutch member 74 against the weight of the spin basket, and disengages the brake lining 101. The drive from the motor then acts via plates 75 and 92a to the spin shaft 14. The time required for liquid to flow from the sump to the coupling 70, 74 or the clutch 83, 84 is longer than the starting period of the motor 49 which thus requires no starting capacitor &c.