Improvements in Detent Devices for Adjusting the Carriage Displacement of Type-writing Machines.

摘要

8274. Sch³ler, F. April 5. Typewriters.-Variable spacing is effected (1) by providing the carriage rack with several sets of teeth gearing with corresponding detents or with one pair of adjustable detents, and (2) by means of several ratchet-wheels arranged radially about a common axis or in line on a spindle and movable successively into gear with the detents. (1) The carriage rack has four sets of teeth arranged at rightangles and is carried by spindles u, u1 turning in the carriage. To the spindle u is secured by means of a pin and slot v a finger-button c carrying a disk s. A pin t on the disk s is held by a spring in engagement with one of four holes in the carriage. Four pairs of detents e, f are mounted radially in a frame x which is rotatable about pins k, l. A bail g, pivoted on the pins k, l and passing beneath the key-levers h, carries a spring-pressed pin m which engages either of four holes in the frame x. The pin l is elongated and on it is splined a spur-wheel q having a grooved collar z which is engaged by the disk s. When. the button c is moved to the right, the wheel q is brought into gear with a spur-wheel p on the spindle u so that the carriage rack and the detent-carrying frame x are rotated simultaneously. The several sets of teeth of-the carriage rack may be arranged side by side instead of radially. (2) Three ratchet-wheels 4, 5, 6, Fig. 4, having different numbers of teeth are journaled in a star-shaped frame 21. The spindle of each ratchet-wheel carries a pinion which can gear with the carriage rack. The frame 21 is rotated to bring any ratchet-wheel into action by means of a knob on the shaft 14 and is held in position by spring-pressed pins. The detents 26 are mounted on a support 28 carried by a frame 8 turning on pivots 10, 11. The detents are held together by a spring and oneis able to move aterally. When the frame 8 is rocked, the movable detent is pressed aside by a tooth of the ratchetwheel which then passes between the detents, the next tooth being engaged by the fixed detent. In the form shown in Fig. 8, the three ratchet-wheels 4, 5, 6 are carried by a shaft 38 having a long pinion 39 which gears with the carriage rack 1. The shaft 38 can be moved lengthways nnd held in one or other of three positions by a spring-pressed pin 37 which engages grooves in the shaft.