GB1393109A - Detent mechanism eg for a timer - Google Patents

Abstract

1393109 Latches SEIKO KOKI KK 17 Nov 1972 [18 Nov 1971] 53219/72 Heading E2A [Also in Division H1] A detent mechanism, suitable for use with switch contacts of a timer, comprises a movable part 1 or 21, means 6 or 25 for urging the movable part away from a predetermined position, the movable part being manually movable in the opposite direction; means actuated by the movement of the movable part in said opposite direction for effecting relative movement between an abutment member 5 or 21a and a substantially planar detent member 3 or 22 so that the latter is releasably held in engagement with the abutment member, this engagment holding the movable part in the said predetermined position, further movement of the movable part in the said opposite direction releasing the said engagement; and a movable member 11 or 23 for causing at least a part of the detent member to be tilted in a direction perpendicular to its plane so as to release the said engagement. Two embodiments are described for use with the timing mechanism of Specification 1393108 (see Division H1). In the first a detent member 3 is flexibly pivoted at 2b on a triangular plate 2 having a fixed pivot 2c and coupled to slidable member 1 by means of pin 2a and slot 1b. Springs 6 and 7 act as shown on member 1 and detent 3. When manual pressure on portion 1d moves member 1 to actuate contact blade 8b the detent 3 is pivoted back such that a fixed pin 5 abuts portion 3b (Fig 2, not shown) and on release of the manual pressure portion 3c engages pin 5 to latch member 1 with contact blades 8b, 8c closed (Fig 3, not shown). Member 1, and hence the switch contacts, may be restored by momentary further pressure on 1d which lifts a tongue 3d above pin 5 such that the detent 3 is freed from the pin and the condition shown in Figure 1 is restored. Alternatively, since in the latched condition detent 3 is raised to lie partly over the end of a shaft 11, axial movement of shaft 11 by the timing mechanism (not shown) will tilt the detent 3 out of the plane of the drawing to clear pin 5 and allow member 1 to restore. In the second embodiment (Fig 5) the detent 22 has a fixed pivot 24a and the abutment pin 21a is carried on slidable member 21. The switch contacts of Fig 1 are replaced by a microswitch M.S. and a timer shaft 23 acts on the detent 22 via a pushrod or lever 27.