Pressure actuated lighting time switch - has pushbutton which is arranged about rotary latching or setting ring with relative angular movement

摘要

The time switch is arranged so that depression of the push-button evacuates an air-filled chamber against a resetting force. The refilling of this chamber takes place automatically via a valve during a pre-determined, preferably adjustable, time period, thus re-releasing the push-button (2). Round the latter is rotatably fitted a locking or setting ring (4), which is axially fixed, but can be rotated through a given angle relative to the push-button in a blocking position holding down the depressed push-button. The push-button and the setting ring respectively have a radially protruding lug and an L-shaped groove, which interengage. The 'L'-shank of the groove, extending in the depression direction, releases the lug after a given time period. The transverse shank of the 'L' lies over the depressed lug in the locking position of the ring. The groove(s) may be located on the ring inner side, while the lug(s) may be provided on the push-button.