GB956565A - Push button electric switch - Google Patents

Abstract

956,565. Press-button retraction switches; snap-action switches. ANSUL CHEMICAL CO. July 15, 1960[Dec. 14, 1959], No. 24702/60. Heading H2B. A press-button switch comprises fixed contacts 28 carried by a housing 22 and having recesses 26 for receiving a roller contact 30 mounted on a U-shaped carrier 34 rotatable about a pin 42 whose ends slide in slots 46 in the arms 35 of a member 36 pivoted about a fixed pin 38. The member 36 houses a compression spring 48 bearing on the base 44 of carrier 34, has stops 60 normally engaging the arms 58 of a torsion spring 56 on the pin 42, has cam. surfaces 54 engaging the ends of the roller axle 32 and carries pins 78 slidable in cam slots 76 formed in the arms 72 of a pushbutton 62, further slots 74 receiving the ends of the pin 38. When the button 62 is depressed against the spring 64 to pivot member 36 anti-clockwise, the roller 30 remains in contact with the left-hand recess 26 until lifted therefrom by the surfaces 54, during which time the carrier 34 rotates clockwise to increase the stress in springs 48, 56 by movement of the base 44, one edge of which engages a spring arm 58, Figs. 4 and 5 (not shown). When the roller 30 has left the recess 26 the carrier 34 is rotated anti-clockwise by the stressed springs 48, 56 to catch up with the member 36, further rotation of members 34, 36 enabling the roller 30 to engage the right-hand recess under the action of spring 48. Upon release, members 62, 72 are forced upwards by the spring 64 and the switch mechanism is restored to its original position by a reverse action to that described above. If desired, the spring 56 may be omitted. In a modification, Fig. 9, a notch 177 is formed in each cam slot 176 so that if the button 162 is released slowly after operation the pins 178 engage the notches 177 to lock the switch mechanism in the operated position, restoration being effected by pressing the button 162 and releasing it suddenly as in normal retractive operation. In another modification, Fig. 12 (not shown), the arms of the torsion spring extend into the coil of the compression spring through an aperture in the carrier base, the arms normally engaging the aperture edges and engaging respectively an edge and a side of the coil during switch operation. In a further modification, Figs. 13 and 14 (not shown), the button-biasing spring is omitted, restoration of the switch mechanism being effected by manually withdrawing the button. Specifications 837,432, 837,434, 837,435 and 956,566 are referred to.