Patent GB-190404743-A (GB)
Title: Improvements in and relating to Carriage-returning and Line Spacing Mechanism for Typewriters and like Machines.
Inventor: DUFUR DOUGLAS STEPHEN
Filed: 1904-02-26
Granted: 1904-05-05
Abstract: 4743. Dufur, D. S. Feb. 28, A.D. 1903, [date applied for under Patents Act, A.D. 1901]. Type-writers and like machines.-Relates to a pneumatic device for returning to its initial position a reciprocatory member, such as a typewriter carriage or part of a linotype machine, which is moved in one direction by the operation of keys. The device also effects the rotation of the platens of typewriters for line-spacing purposes. A pneumatic cylinder F, Fig. 1, is supported on one of the legs a of the stand or table carrying the machine, a guide A<3> being provided for the outer end of the piston-rod G<2>. The piston-rod is reciprocated by a swinging arm E provided with a stirrup E' for the foot of the operator. The piston G, Fig. 2, slides between two abutments G<3>, G4 on the piston-rod. The end of the rod has a bore G<5> so arranged in connection with radial apertures G<6> that, when the piston bears against the abutment G<3>, no communication exists between the two ends of the cylinder, while when the piston is against the abutment G<4> communication is established by the bore G<5> and apertures G<6>. The front end of the cylinder F<3> is provided with air passages F<6>, the back end having an orifice F<4> connected by a flexible pipe I with the end H<2>, Fig. 5, of a second cylinder H, Figs. 1 and 5, supported by standards on the stand of the machine. The other end of the cylinder has air passages H<7>, Fig. 5. The piston-rod H<5> has a bent portion H<8> and also carries a pin R', Fig. 1, to which is attached a cord R<2> passing over a pulley R<3> and carrying a weight R for the purpose of overcoming the frictional resistance of the piston in the cylinder during the movement of the platen while the operator is writing. A shaft M, Figs. 1 and 3, is mounted in a support d<2>, Fig. 3, journalled on the end of the platen shaft and in a bracket d<3> secured to the carriage, Fig. 1. A pawl M<4>, Fig. 3. slides in a cross-arm M<3> on the shaft M, and is pressed by a spring into engagement with a crownwheel K on the platen shaft. The shaft M is rocked by an arm N connected by a spring bar P, Fig. 1, to the bent portion H<8> of the piston-rod, and is provided with a joint M<2>, Fig. 3, to allow the platen to be raised from the carriage. When the shaft M is rocked, the ratchet moves the crown-wheel through a distance regulated by a pin O on the shaft which engages one or other of three arms on an adjustable stop 0'. The three arms are of different lengths, and allow the ratchet to move the crown-wheel through distances of one, two, and three teeth respectively. After line has been written, the operator pushes the foot-lever forwards, and the air is driven from the cylinder F to the second cylinder, and the piston in the latter is operated, rocking the shaft M. The ratchet rotates the platen through the pre-determined distance for line-spacing, and further movement of the piston draws the carriage along to the limit of its movement. When the foot-lever is retracted, communication is set up between the two ends of the cylinder F, the piston in the cylinder H being unaffected by this movement.