Patent GB-1004794-A (GB)
Title: Printing apparatus
IPC: B41J1/16
Filed: 1963-08-06
Abstract: 1,004,794. Selective printings. INTERNATIONAL BUSINESS MACHINES CORPORATION. Aug. 6, 1963 [Aug. 30, 1962], No. 30929/63. Heading B6F. Type-case machines; type-case actions; types, dies and printing surfaces.-A printer comprises a bar 51, Fig. 1, movable to present a selected type character mounted on a type bearing finger 53 of a type element 50 to a printing station, a plurality of type elements 50 each being detachably mounted on said bar. Each type element 50 comprises a flexible sheet metal comb and the type characters are formed on the face of each type bearing finger 53 proximate the distal end thereof. Each type element has a plurality of type characters forming a portion of an alphabet, a complete alphabet being provided by assembling a plurality of the type elements 50 in a releasable manner on the support tube 51 so that each element is individually removable and replaceable in the assembly. Each type element further comprises a base portion 52, Fig. 3, including a mounting extension 54 between a pair of horizontal positioning shoulders 55 and 56. The mounting extension 54 is provided with lateral retaining hook means 61, 62 for engagement with gripping fingers 77, 78 of spring clips 75. The type elements 50 are mounted on the supporting tube 51 by inserting them through aligned upper and lower slits 70 and 71 in the tubes. The lower slits 71 are provided with apertures 72 for insertion of the spring clips 75, the gripping fingers 77, 78 of which engage the hook means 61, 62 as the mounting extension 54 penetrates the passageway formed by the said slits 70 and 71. The horizontal reciprocating motion of the type carrier which brings the various type fingers into various print stations may be provided by a rack and pinion gear arrangement 155, 154 connected to a reversible drive member (not shown). A flag member 156, attached to the upper side of the tube 51 moves through a detector means 157 which through a control means (not shown) connected to the pinion drive gear limits the stroke of the tube 51 and reverses its direction. Hammer-impression arrangements.-Printing by operation of hammers 15, Fig. 2, to strike the fingers 53 of the type elements 50 may be performed at rest or on-the-fly. Each hammer 15 comprises a body portion 16 having a slot 17 and all the hammers are pivotally mounted on a common stationary rod 18. Each hammer further comprises a striking arm 19 released for impression by an individual holding magnet 21 having an energizing coil 22 and a firing arm 20 co-operating with a cantilever leaf spring 25 made up of a plurality of springs 29 to 32 of progressively decreasing lengths, the cantilever leaf spring being mounted on a bail 26. In operation rotation of cams 37 and 36 causes cam followers 40 and 39 to drop arm 35 and its associated bail 34 common to all hammers so that the spring 29 extends beyond the edge of bail 34 and to drop bail 26 so that the spring 29 is disposed to the right of the firing arm 20, respectively. As the shaft 38 continues to rotate the cam follower 39 raises the bail 26 upwardly so that the spring 29 engages the right-hand side of the arm 20, whilst the bail 34 is moved to the position shown in Fig. 2. When the coil 22 is de-energized the control magnet 21 releases the hammer 15 and the spring 29 pivots the hammer about rod 18, whereby the tip of the spring 29 slides off the firing arm 20 and comes to rest against the bail 34. Following impression the hammer 15 rebounds from the platen 10, assisted by a return spring 23, attached to a fixed support 24, the spring 23 acting against finger 33 engaging the firing arm 20, so as to hold the hammer after rebound in a position slightly spaced from the edges of the holding magnet 21. Specification 1,002,052 is referred to.