Patent GB-262996-A (GB)
Title: Improvements in carriage-feeding mechanism for typewriting machines
IPC: B41J19/46
Filed: 1926-03-03
Abstract: 262,996. Fairweather, W. C., (Underwood Typewriter Co.). March 3, 1926. Letter spacing mechanism, - Escapement mechanism suitable for portable machines comprises a pair of dogs vibrating independently about a common axis, one dog being vibrated by the universal bar and serving to vibrate the other dog to effect letter-spacing feed of the carriage. Dogs 59, 60 co-operating with an escapement wheel 58 are formed on rocking plates 61, 62 having ears 63, 64 engaging a common pivot 65. Normally the plate 62 is held in contact with a stop-screw 71 by a spring 72, and a lug 69 on the plate 61 is held in contact with the plate 62 by a spring 70, the dog 59 engaging one of the escapement wheel teeth, and the gap 68 between the dogs being narrower than the teeth. The spring 72 is adjustable by a screw 73. A universal bail 75 operated by heels 76 on the type-levers 32 is connected to a frame 78 supported at the front by a tongue 79 and at the rear by rocking arms 80, the frame having a lug 81 for engaging a screw 82 on the plate 62. When a type-lever approaches the printing point the universal bail is operated and both the plates 61, 62 are rocked, the escapement wheel tooth leaving the dog 59 and after a slight drop being caught on the flat top of the dog 60. On release of the universal bail, the plate 62 is returned by the spring 72, the tooth rides down an incline 60<a> on the dog 60, pushes aside the dog 59 and passes through the gap, the plate 61 being thereupon rocked by the spring 70 to restore, the dog 59 to position for intercepting the approaching tooth. To facilitate the passage of the teeth through the gap, they are each formed with an incline 58<b> and the dog 59 is cut away at the side adjacent the teeth. The release and rearrest of the escapement wheel are timed, by adjusting the screw 82. To reduce the clicking noise of the dog 59, the plate 62 is provided with a blade, spring 96 abutting on the lug 69 of the plate 61. The escapement wheel and feedpinion 55 are mounted on a stud secured to the back plate 57 of the carriage-shift frame 45, and the pivot 65 of the escapement is mounted in ears 66 on a plate 67 secured to the back plate. The lug 81 engages the screw 82 in either the normal or shift position of the carriage. The dog 59 permits reverse movement of the escapement wheel for back-spacing or carriage-return. Space-key actions.-The space-bar 22 operates the above-described escapement independently of the universal bail by means of a link 91 having an arm 92 adapted to engage the end 62a of the rocking plate 62 in either normal or shirt position of the carriage. The space-bar is secured to arms 84 on a rock-shaft 85 which is mounted on lugs 86 on the comb 23 and is provided with an arm 90 connected to the link 91. A stop-pad 89 co-operates with the space-bar and an arm 88 thereon to limit the movement of the space-bar. Carriage-releasing arrangements. - The feedrack 47, Fig. 1, is secured to arms 48 pivoted on the carriage 40, one or both arms engaging a release-lever 50 which is pivoted on the platen shaft 51 and is formed with a finger 54 held in contact with the carriage by a spring 53. The finger 54 is bent to adjust the feed-rack with respect to the feed-pinion 55.