| 摘要 |
492,721. Fluid - blast switches. LANGE, E. March 24, 1937, No. 8666. Addition to 455,115. [A Specification was laid open to inspection under Sect. 91 of the Acts, Sept. 28, 1937.] [Class 38 (v)] The invention described in the parent Specification is modified in order that the arc at the outlet should not be produced until adequate pressure is developed to rupture it, by providing a switchoperating lever which acts directly on the movable contact of the principal break disposed in the confined space and co-operates with means for causing the movable contact of the other break to open the circuit at the outlet after the first break has been formed. The fixed contact 16 has an outlet closed by valve 17 and co-operates with a contact 15 mounted on the bell 12 which is slidable on guides 9 in the insulating chamber 11. Contact 15 is integral with socket 14 with which the rod contact 13 co-operates. In order to produce the arc in the bell before contacts 15, 16 separate, 13 is extended downwards and provided with a pin 21 engaging in a slot 22 for direct operation by lever 20, this lever having a pin 37 engaging a cam slot in an arm 35 pivoted at 36. The forked free end of 35 is engaged by a pin on a bell-crank lever 30, which is pivoted at 42 and has a pin-and-slot connection with levers 26 pivoted to the bell at 27. When 20 is rotated, contact 13 is lowered at once to draw an arc, but owing to the part 38 of the cam slot being concentric, no movement of lever 30 and the bell occurs. When pin 37 enters part 39 of the slot, the pressure developed by the arc in the bell is adequate to open the valve, and accordingly slot-part 39 is so made as to tilt arm 35 outwards, so drawing down the bell and opening contacts 15, 16. Part 40 of the slot being also concentric, no further deflection of arm 35 occurs while the rod 13 moves on downwards. When 13 clears partition 10, the fluid escapes from apertures 43 and valve 17 closes. The fluid may be liquid, air, or other gas and in the latter case may be maintained under pressure.
|
