Patent GB-190125374-A (GB)
Title: Improvements in Electric Clocks and Time Pieces.
Inventor: LOWNE ROBERT MANN
Filed: 1901-12-12
Granted: 1902-12-11
Abstract: 25,374. Lowne, R. M. Dec. 12. Electric clocks. - An ordinary pendulum is arranged to operate a rotating commutator switch which controls a divided electric circuit containing (1) an electromagnet by means of which impulses are given to the pendulum, and (2) one or more pairs of electromagnets actuating time-indicating devices, the arrangements being such that the current passes only during the exact time of performing the necessary work. Fig. 1 shows the pendulum apparatus and switch, and Fig. 2 the indicating-apparatus, according to one arrangement. The ordinary pendulum fork a carries an arm l<1>, which lifts a lightly-weighted lever l bearing a pawl l<2>, the movement of which is limited by a fixed pawl l' and a stop n. The fall of the lever l thus operates a ratchet-wheel on the spindle g<1>, half of which is cut away as shown in Fig. 3, so as alternately to deflect and release two spring arms g<2>, which make electrical contact with fixed arms g<3>, g<4>. One or other of two electromagnets h, h<1>, Fig. 2, is thus energized to operate the time-indicating device. Another electromagnet d, Fig. 1, is energized at the same time, to deflect a spring e giving impulses to the pendulum. The armature is held at one end in contact with the magnet by means of a rod and a spring. When the armature c<1> of the magnet d is attracted, the end of an extension arm e<1> attached to it is brought below a pivoted stop f, which retains it in its lowest position with the spring e deflected. A loose finger b, attached to an arm a<1> of the pendulum fork, then engages a projection c on the armature extension, white another finger a<2> on the same arm a' depresses an arm f <2>, and thus moves the stop f out of the way. The armature being thus released, the spring e raises it, and gives an impulse to the pendulum by means of the finger b and arm a<1>. The finger b immediately escapes from the projection c, and does not engage it again until the armature is again depressed. Instead of this arrangement, the magnet d may act to wind up a spring or weight which actuates a train controlled by an ordinary escapement, and this train may operate the switch g<1>. as well as maintain the pendulum in motion. The time-indicating device is operated by the magnets h, h<1> by means of a swinging armature j, which acts to oscillate a lever o. The end of this lever has rollers o' on which rest the curved ends of ratchet levers p, p<1>, one of which rises as the other falls, so that the ratchet-wheel q progresses at each stroke of the lever o, and moves hands or other indicating-devices. The lever o also carries a make-and-break contact i<2>, which puts the magnet which has just acted out of the circuit and puts the other one in. For large public clocks and the like, the magnets h, h<1> may work a relay for introducing a powerful current to actuate the indicating-mechanism. To prevent the indicator magnets from acting before the pendulum magnet d, the latter is made of greater resistance than the former, so that it acts while the others remain inoperative until, the armature c' being depressed, a short-circuit, excluding the magnet d, is made by the contact k, k<1>. Curb pins for limiting the movements of levers are arranged as shown in Fig. 7, being attached to a loose plate which is held by a spring against a fixed plate, so that there is only a frictional resistance capable of yielding to some extent. The indicating-apparatus may be combined with or separate from the pendulum apparatus, and there may be a series of indicators controlled by one pendulum apparatus either directly or by means of relays.