Patent GB-190226965-A (GB)
Title: Improvements in Type-writing Machines
Inventor: JOHNSON JAMES YATE
Filed: 1902-12-06
Granted: 1903-02-26
Abstract: 26,965. Johnson, J. Y., [Hill, H., Harrison, - J. S., and Prendergast, C. F.]. Dec. 6. Type-writers.-Relates to machines in which the type are carried on a wheel or segment, and the positioning of the segment, actuation of the type hammer, and feed of the carriage are all effected by means of an electromagnet, the circuit of which is closed when a key is depressed. The rear ends of the keys in each half of the keyboard engage beneath a universal bar C, of which a fragment only is shown in Fig. 1. On the depression of a key, the bar C is lifted, carrying with it the plate P and jointed rod or link c. The links c pass through holes in the base A, and are connected with a contact-plate which closes the circuit of the solenoid or electromagnet G whenever either link is lifted. When the core I of the solenoid is lifted, the hook i lifts the rear end of a lever N and depresses the front portion n<4>, Figs. 1 and 6, which is pivoted at n<6>. The roller n is consequently moved downwards in the slot m, and the half-cylinder M and shaft J are rotated, carrying with them the arm K and type segment L. In order to determine which half of the slot m shall be traversed by the roller, that is to say, in which direction the segment L will move, a pin p on the plate P rocks a lever O as it rises, and a bevelled surface on the lever O throws the arm n<4> laterally to a sufficient extent to determine the movement of the roller n in the slot m. With the rear end of each key lever is associated a spring-tensioned pin V, Figs. 4 and 6, the upper end of which is projected into the path of a tappet arm u when the key is depressed. The arm K, which drives the type segment, is loose on the shaft J, and the arm is adapted to slide a plate R. Rigidly fixed on the shaft J is a collar T, which carries the plate R with it when the parts are in the position shown in Fig. 4. The relative position shown there is maintained by the engagement of the projections r<1>, t, u<1>, and pin r<2>, which prevent the plate R from sliding rearwards so as to disengage the shoulders r<4>, t. When, however, the tappet arm u strikes a pin V, the projection u<1> moves aside from the pin r' and the plate R moves rearwards, the dog r engaging with a fixed rack S so as to lock the type segment in position in spite of the fact that the shaft J and collar T continue to rotate. In a modification, a yielding spring connection is interposed between the arm n<4> and the roller which moves in the cam-slot, the type-carrier arm K being then rigidly attached to the shaft J. The carriage-feed mechanism is shown in Fig. 20. The carriage is slidably mounted on transverse ways, and bears a rack y<1>, adapted to be engaged by a pawl y<2> pivotally supported at y<3> upon a plate Z which slides in guides z. An in clined slot z<1> in the plate Z is engaged by a roller on the end of a lever Y', Figs. 1 and 20, the rear end of which is lifted by a hook i<3> whenever the circuit of the solenoid G is closed. Fig. 20 shows the parts in their position after a key has been depressed. The downward movement of the lever Y' has moved the plate Z and pawl y<2> towards the left, and at the same time the arm z<3> has depressed the pin x<8> and turned the cam-plate X' so as to lift the pin y<5> and pawl y<2>, which is thus engaged with the rack y<1>. When the key is released, the lever Y' rises, moving the plate Z and pawl y<2> towards the right and carrying the rack y' with them. When the cam-plate X<1> abuts against the stop z<4> it is turned to lower the pawl y clear of the rack. At this moment the link s<6> has rocked the arm S<1> far enough to the right to bring a projection thereon over the toe s<4> of the check-pawl arm s, thus temporarily applying a positive check to further movement of the carriage. The depression of the spacing-key x<4>, Fig. 1, closes the electric circuit by lifting the slotted plate x<10> and link c, and at the same time actuates the bell-crank lever x<9> and levers x<1>, x<7> so as to disconnect the actuating- bar w<3> of the impression mechanism from the lever X, and also to throw back the hook i and put the lever N out of action. The solenoid therefore only actuates the lever Y' which effects the carriage feed. The impression mechanism comprises the hook i<2>, lever X, bar w<3>, link w<2>, and a togglelever actuating a hammer bar to strike the paper against the type segment L.