GB1054714A - - Google Patents

Abstract

1,054,714. Selective printing. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 26, 1964 [March 28, 1963], No. 12946/64. Heading B6F. Hammer impression arrangements.-A selective printer for printing of characters with magnetic ink comprises a printing hammer 2, Fig. 1, driven by a first spring 5, the drive being augmented by a second spring 17, which is selectively operable. The first spring is used for printing small surface characters only, such as 2, 5 and 7, whereas both springs are used to actuate the hammer for printing other digits or special marks, Fig. 2. In operation, when the selected character has been set by stripping a rotatable type wheel 1 and provided a cam 7 has released a lower end 6 of a hammer bell crank lever 4, the hammer 2 mounted on a leaf spring 3 attached to an arm 4a of the bell crank lever 4 is released for impression by energization of an electromagnet 8 whose armature 9 in turn releases a hook 10 on an arm 4b, whereby the first spring 5 drives the bell crank and hammer to effect impression. The thus driven bell crank 4 is arrested by a resilient stop member 11 and the hammer 2 completes the impression under its own momentum. The arm 4a is provided with a resilient pad 12 of e.g. foam rubber to receive the hammer 2 after impression and prevent rebound. The hammer is restored by the cam 7. When the other digits are to be printed a further magnet 16 is energized whose armature 15 releases a hook 14 on a lever 13 having a projection 18 engaging the lever 4 and the second spring 17 whose torsional mounting helps to drive the lever 4. The two magnets 8 and 16 are energized by way of terminal 24, Fig. 2, the line of magnet 16 including a normally closed relay contact 23a. When any of the small surface characters are selected a relay 23 is energized via diodes 22 included in the control circuit whereby the relay contact 23a is opened and the circuit to the magnet 16 interrupted. Type-wheel machines; type wheel actions.-The printer is provided with a rotatable type wheel 1, Fig. 1, carrying on its periphery fourteen characters, Fig. 2, i.e. ten digits and four special symbols. When a desired character is to be printed the character is selected by energization of one of fourteen magnets 20 and the wheel stopped.