Patent GB-299305-A (GB)
Title: Improvements in actions for typewriting machines
IPC: B41J1/08
Filed: 1928-10-09
Abstract: 299,305. Royal Typewriter Co., Inc., (Assignees of Michelsen, W. 0.). Oct. 22, 1927, [Convention date]. Relay type-bar actions; case-shift mechanism. - In a sliding type-bar machine, each type-bar is provided with a number of groups of types and is associated with a group of keylever equal in number to the number of types in a group, each key-lever controlling power-operated means comprising a lever for moving the type-bar for impression, and one or more of the key-levers controlling also one or more latches for coupling the power-operated lever to a movable support for the type-bar. In the action shown in the Figure, the type-bar 1, provided with two pairs a, b and c, d of types, is mounted on a rocking support 2 and is controlled by either of a pair of key-levers 40, 41. The support is formed with guide-lugs 4 and is provided with a guide-plate 6 having guide-lugs 7. The support is formed with faces 65, 66 for engaging a stop 64 and is held in normal position by a spring 63. The type-bar is connected by a link 9 to a rock-arm 12 which is connected by a link 22 to a bellcrank 24, the arm and bell-crank being mounted on a bracket 15 which is adjustable by means of a screw 18. The bell-crank is connected by a link 30 to a loose arm 35 on a constantly rotating shaft 33 provided with a ratchet-wheel 34 which co-operates with a pawl 39 pivoted on the arm. A spring 31 connected to the link 30 normally maintains a lug 55 on the arm in contact with the head 54 of a lever 45 connected to a spring 47. A spring 39<1> normally maintains the pawl in contact with the head and out of engagement with the ratchet-wheel. The key-levers 40, 41 are connected by links 42, 50 to a rock-arm 43 and a bell-crank 51 having lugs 44, 52 engaging the lever 45. The bell-crank 51 is connected by a link 57 to a latch 58 having a slot 59 for engaging a pin 60 on the bell-crank 24. The latch has pin-and-slot engagement 61 with the support 2 and is connected thereto by a spring 62. When the key-lever 40 is depressed, the support remains at rest and impression is effected from the type c or a as determined by the position of the platen A. Depression of the key-lever 40 causes the arm 43 to rock the lever 45, and the pawl is moved into engagement with the ratchet-wheel, the arm 35 thereupon being rocked and causing the type-bar to move for impression. At the moment of impression, an adjustable guard 38 trips the pawl and the returning-springs restore the mechanism to the normal position. If the key-lever is held in depressed position, the pawl abuts on the head 54 until the key-lever is released, whereupon the pawl returns to the normal position. The guard is formed on a rocking plate 37 engaging a pin 69 on a revoluble adjusting-member 68. When the key-lever 41 is depressed, the action operates in the abovedescribed manner and the latch 58 is moved into engagement with the pin 60 so that the support is rocked and impression is effected from the type d or b as determined by the position of the platen. In a modification, the rock-arm 43 is omitted ahd the link 42 is connected directly to the lever 45, the bell-crank 51 having a returning- spring, and an adjustable eccentric engaging the lever. When the type-bar is provided with more than two types, the additional key-levers are associated with the above-described latch-device and a variable shift-stop for the support.