Electric Time-thiciribution in cities, in which there is general or extensive time-distribution, must be divided into districts and must have a separate circuit in each district. For this purpose Hipp con structed a master clock, which, besides keeping the train and pendulum moving, very ingeniously set in operation each minute a clock-work which has as many contact-makers as are needed for a certain number of circuits without interfering in any way with the proper action of the clock. Hipp's construction, although exceedingly reliable in its operation, is somewhat complicated and rather expensive.
General Time-distribution.—The " time-distributor " (ft/. 126, fig. t3), a less complicated arrangement constructed by Spellier for the same purpose, has also a number of contacts (six in the cut), and is operated by clock work impelled by a weight (fig. 13). The clock-work is released by the action of an electro-magnet, which is electrically connected with an ordi nary master clock for that purpose. The cord and weight of the drum drive the train i, 2, 3, 4, 5, 6, 7, 8, 9, to; the arbor of wheel io has a "fly" to regulate the speed. The arbor of wheels 8, 9 carries a mechanism called the " locking-frame," which arrests the train when inoperative. The arm b of the locking-frame C rests upon the armature A of the electro-magnet Once every minute the master clock closes for one second the circuit of an electric battery whose current actuates the electro-magnet .34 which attracts its armature A; thereby the arm b of the locking-frame looses its support and the train which is released begins to move. The armature being attracted for one second only, will be brought back to its former position of the weight W. The wheels 6, 7, whose arbor operates the contact-maker and which drive the wheels 8, 9, make one revolution in operating the contact-maker while the wheels 8, 9 make four revolutions, which the armature A, having returned to its original position, would pre vent were the locking-frame not so arranged as to shorten during its first three revolutions and to lengthen at the completion of its fourth revolu tion. Figure 9 shows the locking-frame and the principle of operation. The brass block B is fastened to the arbor of wheels 8, 9 (fig. 13), and revolves with it. The frame has four projections (PPPP) having holes in which the rods RR of the frame FF slide. The frame, being a little longer than the block B, is allowed to make a lateral movement. Two springs (ss') fastened to the block press against the frame at n, and press the right side of the frame, if free, close up to the block B. To the left
of the frame a short projection carries a little roller (r) which is placed just opposite the arbor a of wheel 6 (fig. 13).
This arbor bears a cam A, which, when in the position shown in the Figure, presses the frame toward the armature; when the arm b rests on the armature the train of the time-distributor stops. The moment the armature is attracted by the electro-magnet the arm b loses its support, and both the cam and the locking-frame move in the direction indicated by the arrows; the little roller r then leaves the cam, and the frame is pressed by the springs ss' toward the arbor a. This of course moves the arm b near to the block /1, and allows the arm b while revolving to pass the armature until the cam again comes into contact with the roller and presses the frame in the opposite direction, thereby moving the arm b toward the armature, by which the arm will he stopped. This process takes place in about four seconds, in which time the arbor of wheel 6 ope rates the contact-maker, of which Figure 8 (A/. 126) shows a separate view. The contact springs s, s, s, s, s, s are fastened to the front plate T of the time-distributor, and arc insulated from it by hard-rubber blocks H. The centre contact C is fastened to the arbor of wheel 6 and revolves with it. Every rubber block has a double set of springs arranged as shown in Figure 10, which also shows the centre contact and its attitude to the contact springs.
One pole of the battery is connected with the front plate T of the time distributor, and thereby electrically communicates with the centre contact C, while the other pole connects with the different clock circuits, each of which terminates in its corresponding set of contact springs. If now the centre contact C revolves, it will, during the course of its revolutions, come in contact with each set of contact springs, thereby sending an electric cur rent in successive order through the different clock circuits connected with their respective contact springs. Figure 12 shows in a general way a com plete arrangement for electric time-distribution. Once every minute the master clock R closes the battery B and energizes the electromagnet JI of the time-distributor T, which magnet attracts the armature A and thereby releases the arm b of the locking-frame, whereupon the train of the time-distributor, being then started, revolves time centre contact C.