Patent GB-1098414-A (GB)
Title: Stepping mechanisms for programme control mechanisms
IPC: H01H43/12
Filed: 1965-03-29
Abstract: 1,098,414. Electromagnetic interrupters. SIEMENS-SCHUCKERTWERKE A.G. March 29, 1965 [March 28, 1964; Oct. 23, 1964 (2)], No. 13314/65. Heading H2B. [Also in Division F2] In a rotational step-by-step mechanism of a switch cam drum 4 in a washing machine programme control mechanism, a driving member 44 has inclined slots 45 surfaces of which co-act with fixed axis rollers 46 so that when the driving member is rightwardly axially displaced, against a spring 32, by energization of a fixed solenoid 22, it rotates and, through oneway clutching ratchet teeth 48, 49 axially displaces, against springs 53, and rotates a ring 50 in axially slidable driving connection with a wheel 10 rotatably fast with the cam drum. The wheel 10 has ratchet teeth 14 co-acting with a spring-loaded pawl (15) on a stationary, screw-adjustable, pivot (17) to prevent'backrunning. The driving member 44 is riveted to the solenoid armature 30. Contact blades 35, 36 are arranged to ensure full rightward armature displacement in the event of a short duration timed energization of the solenoid, and may be so controlled by an armature extension 31, through cams or control surfaces, (not shown), that they are opened at or shortly before the end of the armature travel so as to reduce the surplus energy of the armature. The ring 50 has axially extending coupling segments 55 slidingly engaging corresponding internal recesses (56) in the wheel 10. Tapered internal teeth 57 at the ends of the segments 55 engage, at the end of the rightward movement of the ring 50, in corresponding tapered external teeth 26 on a fixed wheel 25 to arrest the ring 50, the wheel 10 and the cam drum and prevent spinning. The arresting engagement of the teeth 57, 26 is facilitated by axially extending portions 45a of the slots 45 which limit the final travel of the driving member 44 to axial movement only. The segments 55 desirably comprise material of high abrasive strength and elasticity, e.g. plastics or hard rubber. Noise is reduced and armature impact is damped by a cellular rubber disc 41 which is engaged by a flux-guide 40 also riveted to the armature. A cup-shaped housing 21 of the solenoid 22 is mounted within the cam drum 4, being secured, together with the wheel 25, by screws 23 to a member 1 rotatably supporting the wheel 10. The cam drum 4 at its open end has teeth 8 in engagement with teeth 9 of the wheel 10 and at its outer end has an end face 5 rotatably mounted by its trunnions 6 in an end plate 3. Further means for rotating the cam drum may comprise a longitudinally displaceable push-rod extending through the trunnion 6 and one-way coupled to the armature 30 to effect stepping movement thereof, or a programme-stage-skipping actuating shaft which is connected to the cam drum through a spring- loaded one-way facial ratchet toothed one-way clutch (Figs. 6, 7, not shown) and also serves for programme indication by means of a pointer. To reduce sound waves and heat, the cam drum, consisting of an injection or compression moulding of resilient, dimensionally stable and abrasion-resistant material such as polycarbonate-based plastics, is provided with axially extending ridges (190) connected together by circumferentially extending cam paths 59, thus forming an apertured basket-like structure. The end face 5 is also apertured and has provided thereon an indicating scale read through a window recess. A contact arrangement 19 is mounted between the support member 1 and the end plate 3 and comprises two sets of switching camfollower levers 20 operable by the cam drum. A fixed marking member, provided on the support 1, may co-operate with an adjusting scale on the wheel 10. Dowels 75 of the support member 1 are provided for the coaxial attachment of a further unit, e.g. a timing mechanism.