Piezoelectric ignition switch for gas appliance - has hammer raised by cam surfaces as gas tap control is turned on

摘要

The control and piezoelectric igniter for a gas appliance includes a body formed of moulded plastic (1) with a square section container (3) for a piezoelectric element (4). The rotary control (18) is connected via a shaft (17) to the valve (31) controlling the flow of gas. Parallel to this shaft there is an intermediate shaft (7) carrying two cams (8,9), a spring holding this shaft in one of its extreme positions. A further shaft parallel to these two shafts provides a pivoting support for the hammer (13) which is spring biased towards the piezoelectric element. Of the two cams (8,9) one is engaged by a projecting rib (16) on the control shaft and the other engages a part of the hammer support (19) so that the rotation of the control knob is transmitted to lift the hammer back so that it may strike the piezoelement.