Patent GB-1252051-A (GB)
IPC: D06F34/20
Filed: 1969-04-18
Abstract: 1,252,051. Door fastening devices. FICHTEL & SACHS A.G. 18 April, 1969 [20 April, 1968], No. 19870/69. Heading E2A. A door securing device for a washing machine for preventing a door of the machine being opened when the machine is full of wash liquor and/or if the machine has a rotatable drum for centrifuge operation, when the drum is rotating, and the machine being of the kind incorporating a wash liquor container resiliently mounted in a case, the door providing access to the case or to the drum if provided, is characterised in that the container and/or the drum, if provided is or are operative on a sensing means which responds to a change of position of the container relative to the case caused by increase in the weight of fluid within the container and/or to the displacement of the axis of rotation of the drum caused by centrifugal force on the drum during rotation and by locking means for the door which means is operated by the response of the sensing means. In a first embodiment, Figs. I and 2 in which a washing machine comprises a door 102 mounted on a hinge 103 and carrying a locking member 104, a drum 106 is arranged in a wash liquor container 110 which is fixed to a frame 108 of the machine by springs 107 and dampers 105, and the locking member is rendered operative to maintain the door locked during high speed rotation of the drum. The locking device comprises an arcuately movable body 211 suspended by springs 212 within an annular projection 217 of the container 110 and is provided with a bore 213 for a locking pin 214 which is connected through linkage 215, 216 to the locking member 104. The arrangement is such that during oscillations of the drum, the pin 214 is prevented from entering the bore 213 and releasing the locking member 104. The body 211 may be supported on springs from below, in which case the pin 214 is also prevented from entering the bore 213 due to displacement of the body 211 due to the weight of wash liquor in the container 110. In another embodiment, Figs. 4 and 5, a rod 402 is connected to the container 110 and to a locking pin 428, through a lifting mass 401 which comprises a plate 425 having a pair of bores 413, 412, and an upper plate 426 with bores 412, 413. The plates are connected by webs 427 between which is a ratchet wheel 411 which is mounted on a shaft 418 and which is engageable with an anchor member 404. Gear wheels 416 and 417 are freely rotatable on shaft 418 and are engageable with teeth 414 on rod 403 and 415 on rod 402 respectively. The plate 426 includes a pin 428 which is engageable with a pin 429 movably mounted on a casing 101 of the machine and is connected to the locking member 104. Springs 423, 424 extend between the wheels 411, 416 and 417. The arrangement is such that oscillations of the drum or the container 110 cause the pin 428 to rise into engagement with the pin 429 and prevents release of the member 104. When such oscillations stop, the lifting mass 401 sinks slowly to the position in which the pin 428 is free of the pin 429 to allow operation of member 104. In another embodiment Figs. 6 and 8, a sensing means 605 is connected directly or indirectly with the drum 106, container 110 or the machine frame 108 and is slidable on a plate 614. A lever 604 pivoted on a pin 623 carries a pivotable weight 601 having a toothed edge 602 engageable with a spring- loaded pawl 603 which is pivotal on the lever 604 about a pivot 615. A lever 616, also pivoted about the pivot 615 carries weights 617 at its ends and transmits movements of the sensing means 608 to the weight 601 through a roller 620 mounted on the lever 616. A diaphragm 613 is fixed on the plate 614 and is provided with an aperture 611 in alignment with an aperture 624 in the plate 614, for passage of a locking pin 612 which controls, through linkage 634, 635 the locking member 104. The arrangement is such that the pin 612 is prevented from entering both apertures by any movement of the weight 601 from its rest position, the weight 601 being located between the diaphragm and the plate 614. In operation, oscillation of the drum 106 or the container 110 or movement of the latter due to weight of wash liquor therein, moves the sensing means 605, which through the pawl 603 rotates the weight 601 to the position in which it blocks movement of the pin 612. In a further embodiment, Figs. 9 and 10, a sensing device 102 is connected to the drum 106 or to the container 110 via a pivotable weight 901 and to a locking mechanism 925, which works through a lever 929 on a lock member 931 to prevent operation of the latter during operation of the machine. A one-way coupling 907, 908, Fig. 9, is provided between the sensing means 902 and the weight 901 and a free-wheel coupling 903 is provided between the weight 901 and a casing 919, 921, Fig. 10 A gear unit 904 and an anchor mechanism 905 is arranged between the weight 901 and the coupling 903. The weight 901 is formed with an arm which forms the locking mechanism 925 and the weight is carried on a hollow shaft 963 which also supports a gear wheel 906 of the unit 904. A lever 910 mounted on a pivot 924 and acting as a pendulum, is engageable at tips 914 and 915 with a ratchet wheel 909 which is rotatable in an anticlockwise direction only. The ratchet wheel carries a pinion 911 which engages teeth 916 of a double gear 917, smaller teeth 918 of which engage internal teeth 920 of the gear wheel 906. Outer teeth of wheel 906 are engageable with a rack 907 on the sensing means 902 to form the free wheel coupling. In the rest position of the drum 106, the sensing means 902 is held by a spring 956 and is entrained with the wheel 906 in dependence upon movement of the drum by a slide member 945, which carries the sensing means, the member 945 being connected to the drum 106 or container 110 by a spring-loaded cable (962), Fig. 12 (not shown). In the unlocked position in which the lock member 931 is free to be moved to its unlocked position, the locking mechanism 925 is moved clear of the lever 929 which can then slide back. The lever 929 and a lever 936 operate spring loaded contacts 943, Fig. 13 (not shown), in the electric supply circuit to the machine and carried on springs 941, 942. In the use of the machine, closure of the machine door and operation of the lock member 931 to the Fig. 10 position, closes contacts (943). If the container 110 moves downwardly under weight of the wash liquor, the mechanism 925 is rotated to bring a projection 926 behind a surface 928 of the lever 929 to lock the latter in a position in which it prevents release of the member 931. For oscillatory movements of the drum or container, the sensing means 902 effects rotation of the wheel 906 and hence movement of the weight 901 and maintains the locking mechanism 925 in its locking position with respect to the lever 929. Under condition of vigorous oscillation, a stop projection 975 abuts a resilient projection 973 which releases the free wheel coupling 903 and so releases the wheel 906 and the weight 901. In another arrangement, Fig. 15 (not shown) an electrical sensing means (1504) is operative to change a capacitor 1501 which energises an electro magnet to operate a door locking means into a releasing or locking position in dependence upon the charging of the capacitor (1501). In a further embodiment Fig. 16 (not shown) movements of the container 110 are transmitted to a hydraulic circuit which functions to move a door locking means (1609) into locked position against a spring loaded piston (1603). According to Fig. 17, the locking member 104 comprises a spring-loaded actuating lever 1701 and a pawl 1702 mounted on a common pivot 1704. A pin 1706 on the pawl projects through a bore 1705 in the lever to permit limited movement of the lever relative to the pawl. In another arrangement, Fig. 18 (not shown) the actuation is spring-loaded against a pawl (1802) to prevent undue force being applied to the pawl. According to Fig. 19 (not shown) the wash liquor container 110 is connected to a sensing means through a spring-balance arrangement which affords comparatively large travel of the sensing means for slight deflections of the container 110. In the arrangement according to Fig. 20 (not shown) a spring loaded locking pin (2002) is movable to a looking position by a lever 2003 which is actuated by the lifting mass 401 of the Figs. 4, 5 arrangement. In a similar arrangement, Fig. 21 (not shown) a pin (2104) is operative upon the hinge of the door of the machine.