Patent GB-192465-A (GB)
Title: Improvements in electric time switches
IPC: G04C23/22
Filed: 1921-10-31
Abstract: 192,465. Horstmann, E. H., Horstmann, A., and Horstmann Gear Co., Ltd. Oct. 31, 1921. Clockwork actuation; mercury &c. switches.-Consists in the tilting at predetermined times of sealed mercury switches of the type shown in Fig. 1, in which contact is made between two or more leads x<3>, x<4> by a blob of mercury x. The switch X is mounted in a cradle a<1> pivoted at a<3>, but the cradle may be modified in various ways to enable it to cooperate with the different types of clockwork used. Figs. 6 and 8 show the switch actuated by one type of clockwork. The clockwork portion K is detachable from the switch portion G, and is constructed to cause a disc F to rotate half a revolution at each predetermined time. The disc F carries a pin f which acts on pallets e<1>, e<2> on a lever E mounted on the same axis a<3> as the switch X and causes the latter to tilt. The clockwork mechanism is more clearly shown in Fig. 22 and comprises a train of wheels K<3>, K<8>, K<10> driven from the main spring. The train is normally at rest, a pin K<13> on the wheel K<10> resting on the downturned end F<4> or a lever F<3>, which has been moved into the correct position by a pin K<5> on the wheel K<8> co-operating with a detent F<5> on the lever F<3>. At the predetermined time, the actuating lever on the time dial lifts the end F<2> of the lever F<3>, the other end of which then comes clear of the pin K<13>. The wheel K<10> then rotates till stopped by a pin K<12> engaging the end F<4>, but further lifting of the end F<2> frees this also. When the actuating lever has passed, the end F<2> drops, and the end F<4> moves to its extreme right-hand position clear of the pins K<12>, K<13>, and the train of wheels runs on till the pin K<5> has moved once round and again moves the lever F<3> into the path of the pin K<13>. The disc F is also geared to the wheel K<3>. the arrangement being such that it makes half a revolution for each revolution of the wheel K<8>. The disc F may also be made to turn through one-third of a circle only at each actuation, and the lever E, Fig. 6, in this case has three stationary positions. According to other modifications two switches may be mounted on the same axis a<3>, one above and one below it. and both actuated by a common lever E, and various combined operations of two switches may be thus obtained. Fig. 11 shows the switch X mounted in a modified carrier and actuated bv the type of clockwork described in Specification 14825/11. The switch is brought " on " and " off " by the thrust-piece p<1> alternately engaging pins o<4>, o<5> on a lever O. Fig. 13 shows an. other modification in which the same movement of a thrust-piece p<3> tilts the cradle Àb<3> of the switch by means of a pin o<14> (shown dotted). By using a series of pins o<14>, a series of mercury switches may be tilted in succession. Fig. 15 shows another modification, in which the thrustpiece p<3> only acts in one direction and is pivoted to the lever o<15>. At the determined time the piece p<3> is thrust out and withdrawn and a ratchet wheel S is rotated one step. With the wheel s move pins s<4>, s<5> which successively lift cradle extensions b<8>, b<9>. Arrangements are described in all the above modifications for adjusting the relative position of parts and for latching the switch X in its stationary positions. Other combinations of the above types of clockwork and cradle are also described, and in further modifications the mercury switch contains three or more contacts and the co-operating clockwork gives it three or more different movements. Specifications 27290/05, 23161/09, 165/14, 10067/15, and 189,476 are also referred to.