Patent GB-1109059-A (GB)
Title: A typewriter or like office machine
IPC: B41J11/14
Filed: 1966-04-13
Abstract: 1,109,059. Typewriters &c. SCM CORPORATION. 13 April, 1966 [29 April, 1965], No. 16224/66. Heading B6F. Margin stop arrangements.-The left and right hand margin stops 810, 794, respectively, Fig. 19, are mounted on a toothed wheel 8 of a rotatively mounted control member 3 which translates rotary movement into carriage movements by means of a flexible cable 4 within the limits set by the adjustable position of the margin stops. The control member 3 is of a size that a complete carriage travel is made with about twothirds of a revolution. The control member 3 comprises also the carriage-return spring, a spring (860) rotatively biasing margin stops in opposite directions, a series of tabulator stops 6 (see below), and a gear-wheel 5 which meshes with a pinion 122 on a shaft 120 carrying an escapement ratchet (118). The left and right margin stops 810, 790 are set by keys (700, 734) on the keyboard and operate a three-claw actuator (720) which controls two sets of dogs (822, 824, 826) and (770, 776, 782) by engagement with the cam surfaces (834, 836, 836) and (774, 780, 786) cause either arm (814 or 794) to move outwardly of the central axis. This occurs in any position of the arms (814, 794) since the pawls are arranged to engage either one or two but never three of the dogs. Movement of one of the arms outwardly disconnects the toothed end from the gear 868 and allows the respective margin stops to be moved to the required position. The carriage halts in the left or right margin position when the stops 810, 790 engage an abutment lever 886 either from the clockwise or counterclockwise direction. Line-lock.-A line lock is actuated by the right margin stop and blocks the type-levers from printing. This stop 790 pivots abutment 886 clockwise and an attached arm 920 which operates on a lock 932 by a link 930. The lock 932 pivots a tab 938 into the path of a finger 940 of a universal bar 146. Margin release.-This may be effected by a key connected to a link 944 pivoted to a bellcrank 946 having an ear 952 that pushes the abutment 886 axially so that the nose 902 is clear of the margin stops. Right margin alarm.-A bell 990 provides a warning of approach to the right margin four to eight spaces in advance. The approaching stop 790 engages an actuator 976, pivots it clockwise about its slotted pivot on a carrier (960) which is, in turn, pivoted clockwise against a spring bias (970) so that when the stop passes an arm 964 attached to the carrier (960) swings back and a hammer 968 hits the bell 990. The arrangement of the actuator 976 on the carrier (960) prevents the alarm bell sounding during margin stop adjustments. Escapement mechanism.-The main function wheel 3 has a large toothed gear 5 which is equivalent to a normal carriage rack. The gear 5 meshes with a pinion (112), Fig. 3, on a shaft (120) carrying a ratchet wheel (118) which is controlled by two pawls biased together and both pivoted on a rocker (100) mounted on adjustable screw pivots in a bracket (102). When the rocker is actuated pawl (108) releases a ratchet tooth but pawl (112) engages the next. A pin (126) on pawl 112 arrests rotation after one letter-space by engagement with the pawl (108). Return movement of the rocker 100 displaces pawl 112 but as pawl 108 has been aligned with pawl 112 no further rotation of the ratchet occurs. Letter-space action.-A projection 144 on a type-lever 140 engages an arcuate bail 146 having a foot 148 that contacts a finger 150 integral with the rocker 100. Tabulator stops.-The tabulator stops 6 comprise pins 6 spaced in two annular rows in the function wheel 3 which is of a size that all letterspace positions in a line are covered by less than one revolution. The stops are pushed from the back of the wheel to project from the front and are resiliently held in the apertures by annular spring coils. Tabulator stop setting and clearing.-The stops 6 are set by a key (200), Fig. 11, via a lost-motion connection (204, 206, 208), arm (210) and actuator (216). This operates a lever (224), Fig. 10, and a turned-in end (242) sets a tabulator stop 6. Clearing is effected by key (280), lost-motion connection (284, 286, 280), arm (210), and actuator (216). -This time a lug (222) on the actuator (216) operates a lever 228 to effect restoring of the tabulator stops. Tabulating; tabulating key-actions.-The tabulating key (300), Fig. 11, is mounted on parallel arms (302, 304) pivoted at (308, 310) to a pivotal bracket (306) and when operated pulls on a link 326, pivots bell-crank (330), Fig. 10. A lower arm of bell-crank is connected by a link (336) to a double rotative stop arm (364). Rotation of the stop arm (364) allows both a lower counterstop (344) to engage a set outer stop and an upper arm (352) to engage an inner row stop. The levers 344, 352 are spring biased together. Tabulator governor; carriage retardation.- Attached to the ratchet-wheel shaft (120), Fig. 21, are a pair of friction washers (400, 402), brake felt washers (404, 406) and a central toothed wheel 408. They are adjustably tightened together by a nut (412) so that when a shoulder 424 of a bail (420), pivoted by a tabulator key action, intercepts a tooth, a braking action is introduced. Back-spacing and key-action therefor.-The depression of a back-space key draws a link (506), Fig. 8, forwardly pivoting a bell-crank (512) and moving a slotted pawl 522 to the left so that the end of the slot (536) moves the ratchet-wheel 118 in the reverse direction. The pawl (522) is adjustably secured to the bellcrank (512) by slotted connection (524, 530). Variable letter-spacing.- Half-letter-spacing may be effected, e:g. for correcting errors. Key (600), Fig. 9, does this by turning a lever (654) clockwise, drawing a link (620) towards the front of the machine, pivoting lever (616) and via link (626), Fig. 8, rocks a bell-crank (634) adjustably carrying a half-space pawl (650). The bell-crank (634) has an arm (640) which pivots the escapement rocker and holding pawl (108). Portable machines.-The abolition of the usual carriage racks, margin stops, tabulator stops, makes the construction suitable for portable machines.