Patent GB-1256233-A (GB)
Title: Alarm clock time switch
IPC: G04C23/16
Filed: 1968-10-22
Abstract: 1,256,233. Time switches; retractive switches. SUNBEAM CORP. 22 Oct., 1968 [6 May, 1968], No. 50184/68. Heading H1N. [Also in Division G3] A time switch is provided with means for holding its contacts closed for a selectively adjustable timed interval and comprising a continuously driven ratchet wheel and biased selector means movable from a first position into engagement with the ratchet wheel and returned by the rotation thereof, said contacts being opened when the selector means is restored to its first position. As shown, a combined time switch and audible alarm is provided with manually set 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 periods of about 8 minutes, (iv) the switch may be operated manually, or (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. An electric alarm clock mechanism, preferably as in Specification 1,055,499 (see Division G3) is mounted between plates 33 and 34 (Fig. 2) and drives seconds and minutes spindles 50, 56, with an hour hand sleeve 60 which is axially movable by a spring-loaded alarm lever 71 when apertures in a disc 59 carried on sleeve 60 coincide with lugs 63a on gear 63, settable by a knob (66, Figs. 3 and 4, not shown). Lever 71 is pivoted at 72e and its end 71b normally restrains a magnetic alarm reed 77, but upon axial movement of disc 59 the reed 77 is freed for subsequent vibration by the alternating field across plates 33 and 34 due to the motor winding. The movement is mounted on a plastics moulding 83 which carries contact blades 94, 95 (better seen in Fig. 9) biased towards the closed condition, and a control spindle 92 at one end may operate the contacts manually or may be set to provide timed operation with or without alarm. Spindle 92 carries a member 102 secured thereon and a member 107 free thereon but urged by spring 111 so that a projection 107b tends to move away from contact blade 95, allowing the contacts to close. Member 107 is normally restrained at 107d by an extension 71c of alarm lever 71 (see also Fig. 16) such that 107b holds the contacts open. As shown in Fig. 16 the spindle 92 is set for " alarm ". When extension 71c is withdrawn by the alarm clock mechanism, member 107 rotates under spring 111, its surface 110a engaging stop surface 109a on member 102, and contacts 94, 95 close (Fig. 17, not shown). A plate-like member 97 is normally held depressed against action of a spring 115 by a projection 107c engaging its arm 97a and causing portion 112 to silence reed 77. At the set time, when 71c releases 107, the projection 107c frees member 97 and the end 97e of its arm 97d engages a ratchet wheel 80b which is driven by the clockwork at approximately one revolution per hour. After a short delay of about 8 minutes the end 97e leaves the ratchet wheel 80b and member 97 rises (dotted position in Fig. 17, not shown) allowing reed 77 to vibrate. The alarm may be silenced for about 8 minutes by depression of member 97 by means of a tab 97f. The spindle 92 may be set slightly anticlockwise from the Fig. 16 position such that surface 109a allows member 107 to rotate sufficiently for the contacts 94, 95 to close but not enough for projection 107c to release member 97 (Fig. 15, not shown), and reed 77 is thus prevented from vibrating. The spindle 92 may be set further anti-clockwise such that surface 109a on member 102 engages surface 110a to hold member 107 in the Fig. 16 position and maintain contacts 94, 95 open even if lever 71 is released. If spindle 92 is turned even further anticlockwise projection 107b is rotated clear of contact 95 and the contacts are thus manually closed (with the projection 107c still engaging arm 97a and the alarm blocked). A spindle 93 at the other end of moulding 83 may be rotated to close contacts 94, 95 for an interval of up to about 60 minutes depending upon the amount of rotation of the spindle 93. This positions a sector-like member 118 (Fig. 9), against action of spring 119, such that a rack 118f thereon moves over the clock-driven ratchet wheel 80b a corresponding amount, and a lug 118g (see also Fig. 16) allows blade 94 to engage blade 95. Member 118 is then slowly returned by ratchet wheel 80b until rack 118f is free and the contacts 94, 95 open. In a modification (Figs. 21 to 23, not shown) the alarm is reacted from one side of the mechanism by a manually operable plunger (121) having a camming action on member 97.