Patent GB-656615-A (GB)
Title: Improvements in or relating to a clothes washing machine
IPC: D06F39/00
Filed: 1948-07-12
Abstract: 656,615. Washing and drying machines. APEX ELECTRICAL MANUFACTURING CO. July 12, 1948, No. 18673. Convention date, July 12, 1947. [Class 138 (ii)] [Also in Group II] A washing machine comprises means for imparting a wobbling movement to a container on a frame 14, a shaft 46 rotated at the period of the wobbling movement, and masses 81, 83 in dynamic unbalance on the shaft adapted to generate a couple in opposition to the inertial reaction of the container, the frame being supported by means adapted to yield vertically and laterally with respect to a supporting surface. General construction.-The container comprises an annular basket 17 inside a generally-spherical two-part tub 15, 16, the tub and basket being supported on a column 18 formed with an integral conical apron 19. The basket 17 is formed of two sections welded together along the line 40 and provided with opposed notches 41 along their meeting edges for discharge of fluid from the basket. Ridges 43 in the bottom of the basket inclined to the radii of the basket with their outer ends advanced in the direction of rotation serve to impart a roll-over motion to the contents during the washing operation. The tub is provided with a lid 57 having a depending flange 61 to return any water splashed out of the basket. A central hole 62 serves as a finger hole for removing the cover and a shallow cone 63 spot-welded to the cover prevents ejection of water through the hole. A carrying handle 69 is bolted to the casing of a motor 66 and to the upper section of the tub. Driving shafts.-A hollow shaft 27 extends through the column 18 and is supported by ballbearings 28, 29. The upper end of the shaft 27 carries a ball-bearing 32, the axis of which is at an angle of about 7 degrees to the axis of the shaft. The bearing 32 supports a hub 33 for the basket so that the basket and hub may rotate about the slightly-inclined axis. Threaded into the hub 33 is a universal joint member 36 which receives a spherical head 47 formed on a central shaft 46. The head 47 is fitted with a transverse pin 49 engaging in slots 51 in the member 36 so that a universal joint driving connection is thus provided between the shaft 46 and the hub 33. By selectively driving and braking the shafts 27 and 46, the basket 17 may be given either a wobbling motion for washing or a rotating movement for centrifuging. During the wobbling motion the axis of the basket follows two conical paths, the apices of the cones being at the centre of the bearing 32. During centrifuging the basket rotates about its own inclined axis and the excess water climbs up the wall of the basket and escapes through the openings 41 into the tub which is provided with a drain opening 56. The shafts 27 and 46 are provided with pulleys 52 and 54 driven by belts from pulleys 86 and 88, respectively. Clutch and brake mechanism.-The pulleys 86, 88 are mounted to float on the shaft 68 of the motor 66 and are urged towards an intermediate clutch disc 103 by springs 94 and 97, respectively (Fig. 6). The clutch disc 103 is fixed to the shaft 68 by a pin 104 and its upper and lower faces may coact with clutch facings 102 on the pulleys 86 and 88 to couple either pulley to the motor shaft. The clutching and unclutching as well as braking of the pulleys is accomplished by a non-rotating ring 106 disposed around the clutch disc 103. The ring 106 is supported between two arms extending from a clutch operating lever 108 which is pivoted at its opposite end to a fixed bracket 138. In Figs. 1 and 6 the lower pulley is held away from the clutch disc 103 and braked by engagement with the ring 106. By raising the ring 106 slightly, both pulleys are held clear of the clutch disc and braked while still further movement of the ring permits the lower pulley to be driven by the clutch disc while the upper one is still braked. The position of the ring 106 is controlled by a hand wheel 113 (Fig. 1) fixed to a control shaft 114, the lower end of which carries a threaded member which engages with a nut held against rotation by the lever 108. Opposite faces of this nut are formed with slots which engage with the edges of a slotted portion of the lever 108 (Fig. 4, not shown). Rotation of the hand wheel 113 from "Wash" position, through "Off" position to "Dry" thus raises the nut and therefore the lever 108 about its pivot. Supporting means.-The machine is supported by four feet 71, each including a large rubber suction cup 74 to grip a smooth supporting surface and prevent crawling of the machine during operation. The cup 74 has an intermediate portion 77 to give vertical and lateral flexibility, and a base portion which extends into a flanged metal cup 72 secured to the base 14. A very small bleed hole 76 in each cup facilitates removal of the machine from its supporting surface after use. During use the vibration of the machine forces air out from beneath the suction cups more quickly than it can be sucked in again through the bleed holes and the machine remains securely held on its supporting surface. Balancing weights.-Vibration of the machine during washing is minimized by the rotating weights 81, 83 which are in static balance and dynamic unbalance and set up a force opposing the reaction due to the wobbling of the container. The weight 81 is fixed to the head of the shaft 27 by a screw 82 and a diametricallyopposed weight 83 is secured to the pulley 52 by a bolt 84. The couple created by the weights is preferably sufficient to balance the mass of the basket 17 and the reaction force of an average load of clothes and water. Vibration responsive means for retarding rotation of container.-Means may be provided for slowing down the container if excessive vibration occurs during the extracting operation. Thus the fixed pin 137 of Fig. 5 (not shown) is replaced by a movable fulcrum for the clutch lever, and mechanism is provided for moving the fulcrum so as to declutch and brake the pulley 88. As shown in Fig. 8 one end of the clutch lever 108a is bifurcated and is pivoted by a pin 137a to one arm 154 of a bell-crank lever pivoted at 156 on a bracket 157. A coiled compression spring 162 which is stronger than the spring 94 urges the outer end of the arm 154 downwardly so that normally the action of the brake and clutch mechanism is the same as previously described. When, however, the second arm 155 of the bell-crank is forced to the right from the position shown in Fig. 8 the pin 137a will be raised and the lever 108a will be rotated about a nut 131 as a fulcrum. This lowers the ring 106 to brake and declutch the pulley 88 and thus decelerate the basket. This actuation of the arm 155 is effected by a vibration-control plate 166 supported by modified suction cups 74a. These cups are formed with ears 167 to which dished portions 169 at the margin of the plate 166 are screwed. The arm 155 extends through an opening 171 in the plate 166 which is partially closed by a plate 172 adjustably mounted on the plate 166 by bolts 173 passing through slots in the plate 166. The plate 172 has a central opening 176 in which is fitted a rubber grommet 177. If the load in the basket is unbalanced, as the centrifuge gains speed the body of the machine will vibrate with respect to the plate 166 which will remain substantially stationary since it is mounted near the bottoms of the suction cups. If the vibration is excessive, the grommet 177 will engage the arm 155 and hammer against it rapidly, rotating the bell-crank and reducing the speed of rotation. The sensitiveness of the vibration control may be altered by shifting the plate 172 to the right or left. Modification.-A flexible shaft may be substituted for the shaft 46 and its universal joint. Specification 636,528 is referred to.