Patent GB-1061498-A (GB)
Title: Improvements in or relating to switch-controlling timers
IPC: G04C21/20
Filed: 1965-05-19
Abstract: 1,061,498. Time switches. GENERAL TIME CORPORATION. May 19, 1965 [May 19, l964], No. 21285/65. Heading H2B. A combined time switch and audible alarm is provided with manually operable controls such that (i) the switch may be automatically closed at a preset time without audible alarm, (ii) the said closing of the switch is followed after a short interval by an audible alarm, (iii) the alarm may be silenced for a period of 9 to 10 minutes (" drowse " function), (iv) the switch may be operated manually, and (v) the switch may'be automatically held closed for a settable interval of up to 60 minutes without interfering with the setting of the main timer (" sleep " function). A synchronous motor (26) (Fig. 3, not.shown) drives normal clock hands (12,13, 14). A manually settable cam gear (193), with indicator hand (15), causes the hour-hand assembly to move axially at the set time. A control lever 50 is loosely pivoted at 23 and a wire spring 74 urges it anticlockwise and also towards the hour gear 42 where it is normally latched by an opening 67 engaging a stepped lug 51 on baseplate 21. The initial axial movement of gear 42 at the preselected time lifts lever 50 off step 65 on to step 66 thereby permitting it a degree of anti-clockwise rotation. This causes an arm 52 to slide an operating member 25. and close a switch (24) (Figs. 2, 3 and 4, not shown,). Com-. pletion of the axial movement of hour gear 42 releases lever 50 from step 66, permitting further anticlockwise rotation which removes an extension 63 of lever 50 from beneath a lug 62 on an alarm-restraining lever 61. This then allows a vibrator blade 28 to move into the stray field of motor (26) and sound an audible alarm in known manner. This action can only occur if a manually set lever 83 has been moved anticlockwise (in Fig. 5) to a position wherein boss 82 does not prevent movement of lever. 50 (as in Fig. 6, not shown). Lever 83 can; however; be set by a knob (16) (Fig. 1, not shown) on shaft 80 to an " OFF " position such that movement of lever 50 is prevented (as shown in Fig. 5), or to an intermediate position limiting movement of lever 50 to that indicated by the broken line wherein the switch is closed but full movement to release the alarm is prevented. Moving lever 83 to the " OFF." position (Fig. 5) causes boss 82 to restore, the lever 50 to the latched position in readiness for timed release when lever 83 is subsequently moved anticlockwise. Lever 83 may also be turned clockwise from the Fig. 5 position to an " ON " position wherein an inclined edge 81 lifts lever 50 free of lug 51 but boss 82 limits its rotation to the broken line position so that the switch is closed but the alarm is held silent. The " sleep " and " drowse " functions are provided by a cam 90 which can be returned to its rest position by the timing gear when displaced over a limited range up to 60 minutes. A knob (17) (Fig. 1, not shown) can turn cam 90 a desired amount clockwise (from the. position shown in Fig. 5), whereupon its edge 110 moves arm 52 to slide member 25 and close the switch 24. This action occurs without interference with control lever 50 since the arm 52 is resiliently mounted thereon by a slot engaging a pin 54 and a spring 55 urging it against a lug 56 extending from lever 50. When cam 90 has been time-driven back to its Fig. 5 position spring 55 causes lever 52 to reopen the switch. An integral part 112 of cam 90 (Fig. 8 and 10, not shown) engages an extension 113 of alarmrestraining lever 61 to maintain the alarm silent during this " sleep " function. The " drowse " function is initiated by depression of a slide member (18) (not shown in Fig. 5) which moves the cam 90 a small amount (Fig. 11, not shown) thereby silencing the alarm for a short period.