Patent GB-191020314-A (GB)
Title: Improvements in Typewriting Machines.
IPC: B41J11/36
Filed: 1910-08-31
Granted: 1911-04-27
Abstract: 20,314. Underwood Typewriter Co., and Cooper, J. J. Aug. 31. [Cognate Applications, 24,887/10 and 24,888/10.] Platen rotation for blanking. Relates to means for filling in a continuous strip of invoice-forms, of the kind wherein the platen may be rotated through an adjustable distance in two stages, the first stage being effected by the line-spacing mechanism, and the second and complementary stage being effected in a continuous movement by means of a hand-wheel which is coupled to the platen by a pawl. (1) Means are provided whereby the pawl is returned automatically to zero position. In the arrangement shown in Fig. 2, the coupling-pawl C engaging the wheel B is pivoted at c to a radius-arm D formed on a sleeve E' which is rotatable on the platenspindle a. The sleeve E<1> is secured by a stud e to a sleeve E<2> which is formed with the hand-wheel F. A coiled spring H is secured at one end to a pin g on a sleeve G and is secured at the other end to a drum J which is held against rotation by a tie-rod. The tension of the spring may be varied by adjusting the sleeves E<1>, E<2>. The pawl is formed with a tappet P adapted to engage the stops described below, these being carried by a disk L which is held against rotation by a tie-rod. When the tappet engages the forward-stop, such as the stop M, Fig. 8, the pawl is tripped, and the arm D is then returned by the spring H. When the tappet engages the back or zero-stop, such as the stop N, Fig. 8, the pawl is caused to re-engage the wheel B. The rocking movement of the pawl is limited by means of a tail-piece p. The pawl is held in the set positions by a locking-device such as a spring-pressed ball R, which is adapted to engage notches in a disk Q on the pivot c of the pawl. In the arrangement shown in Fig. 5, the driving-device for the pawl C consists of a hand-crank T, which is provided with a toothed segment S gearing with a pinion s, which is secured to a sleeve carrying the radius-arm D of the pawl. The returning-spring H' is coiled about the pivot t of the crank, and is secured at the ends to the carriage and to the crank. When the crank is swung upwards, the platen is turned until the pawl is released, as described with reference to Fig. 8, the spring H<1> then returning the parts to the normal position shown. To prevent over-running of the platen, the stop-carrying disk L, instead of being fixed, is mounted with slight rotational freedom, and is connected by a link v to a bell-crank lever u, which is formed with a detent U<1> adapted to engage a ratchet-wheel on the platen-spindle a. (2) The stops for limiting the travel of the pawl C are of two kinds, termed respectively " direct " and " indirect," the latter stops being adapted to permit the platen to have a maximum travel of nearly two revolutions before being arrested. The " direct " stops M, N are adapted to engage directly the tappet P, while the " indirect" stops M<Î>, N<Î> are adapted to engage a radius-arm O<Î>, which is formed with a stop 0 to engage the tappet. The stops M, N are carried by brackets which project from the periphery of the disk L, and are secured by screws which enter holes l. The stops M<Î>, N<Î> are formed by screws which enter the holes l and project such a distance as to engage the arm O<Î> but to be clear of the tappet P. When two "direct " stops M, N, Fig. 8, are used the arc x through which the platen travels may be adjusted from nearly 360 degrees downwards. When two " indirect " stops M<Î>, N<Î>, Fig. 11, are used, the platen rotates through one revolution before the tappet picks up the stop 0, the arm Ox then being carried forward through the arc y until arrested by the stop M<Î>, whereupon the pawl is tripped by engagement of the tappet with the stop 0. By adjusting the stops M<Î>, N<Î> the travel of the platen may be varied from nearly two revolutions downwards. In some cases, one " direct " and one "indirect" stop may be employed, the same effect being obtained as when two " direct " stops are used. In the maximum adjustment the forward-stop and the back-stop are practically in coincidence and one of them may be dispensed with.