GB1052574A - - Google Patents

Abstract

1,052,574. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION. April 27, 1965 [June 26, 1964], No. 17601/65. Heading B6F. A typewriter is provided with two space bars for providing spaces of two and three units respectively and an expand space control which when operated increases the spaces provided by these bars to three and four units respectively. Normal operation, Fig. 1 (not shown).-Depression of the two unit space bar 2 rotates the rod 10 to depress a lever 32 to move a link 40, whereby a pivoted arm 41 throws a cam 48 into contact with a drive roller 52 to cause a lever 46 to rotate anticlockwise to move a rod 60 in direction 61 to cause the escapement mechanism (not shown) to produce a 2-unit space. Rotation of the lever 46 also moves a rod 54, to swing an actuating lever 66 carrying an ear 68. This latter has no effect in the case of the two unit space bar. Operation of the three-unit space bar produces the same movements as described above, but also operates lever 24, which through a link 34 interposes the arm 70 in the path of the ear 68, so that when the latter moves it moves the arm 70 further and with it a pivoted arm 72 which operates on a bail 74 to move a rod 82 leading towards the escapement mechanism, thereby producing a 3-unit space. Operation of space-expand facility, Fig. 2 (exploded).-The space-expand key 90 can take one of two stable positions and on depression is arranged to pull the rod 97 to rotate the frame 100 clockwise about the axis 62, so causing a bar 106 to bear down on projections 124, 136 of the upwardly spring-b ased members 116, 118. If the two-unit space bar is depressed then rotation of the actuating lever 66 described above moves towards the member 118. If the space expand lever is not operated member 118 is in its uppermost position and projection 154 passes beneath the projection 138 on member 118. If, however, the member 118 is depressed due to the action of the space expand lever, the projection 154 contacts 138 to rotate the member 118 so that its U-shaped limb 130 moves the bail 74 to the rear the resulting movement of rod 82 causing the escapement mechanism to produce a 3-unit space. Likewise when the 3-unit space-bar is depressed then member 72 is rotated as described above and this moves a bar 152 so that a projection 136 towards member 116. Similar interaction or non-interaction occurs between these latter so that if the space expand lever is operated bail 78 is moved rearwardly to cause rod 84 to move so that the escapement mechanism produces a 4-unit space.