GB584083A - Improvements relating to quick make and break electrical switches, circuit breakers,or like mechanisms - Google Patents

Abstract

584,083. Snap-action switches. DENNIS, J. P., and DENNIS, H. P. Dec. 6, 1944, No. 24353. [Class 38 (v)] A switch has a snap action effected by toggle levers one of which is tubular and encloses a helical controlling spring. Fig.. 2 shows a switch having contact arms 4 carried by a spindle 3 the end of which is loosely mounted in a boss 10 carrying plates 9 forming one of the toggle levers. As shown in Fig. 3 the second toggle lever 6 is pivoted at 11 between the plates 9 and is slotted at the other end to enable it to slide over a pin 12 fixed to the switch casing. The lever 6 is hollow and encloses a spring 8 which abuts against the pin 12 and causes the levers to snap past the dead centre position when the lever 9 is rotated by a handle 20. The latter has a notch 22 the sides of which engage a screw or other abutment 21 fixed to the spindle 18 of the boss 10. Connection between the plates 9 and spindle 3 is made by a disc 15 on the spindle which carries a projection 16 engaging in gaps 17 in the plates. A spring 25 coiled round the boss 10 engages at its ends with the projection 16 and a yoke 24 on the plates 9. Fig. 3 shows the parts when the switch is in the off position. When the handle 20 is turned in a direction to close the switch no movement of the toggles and spindle 3 takes place until the wall 22 of the notch strikes the screw 21. Continued movement of the handle turns the toggle 9, the shoulder 17a of the gap 17 abutting against the projection 16 and causing the spindle 3 to rotate. The spring 8 produces a quick make. When the handle 20 is rotated in the reverse direction the yoke 24 winds the spring 25 while the friction of the contacts 4 with the jaws 5 holds the spindle 3 stationary. As the lever 6 passes the dead-centre both springs 8, 25 combine to produce a quick break.