Patent GB-1132301-A (GB)
Title: Data printing apparatus
IPC: G03G15/32
Filed: 1966-04-20
Abstract: 1,132,301. Selective printer. SPERRY RAND CORP. 20 April, 1966 [30 April, 1965] No. 17337/66. Heading B6F. [Also in Division F2] Electrographic element printer; print head traversing.-In an electrographic printer in which characters are formed by the selective energization of one or more elements in a reciprocating print head, the print head 334 is traversed across the record web in a continuous constant movement along a guide shaft 336 by an electric motor through a clutch actuated in response to an electrical control system and when the head reaches the end of the guide shaft a mechanism deactivates the clutch. The motor (582), Fig. 10 (not shown), drives, through gearing (584, 585, 587, 588) a shaft (589) to which is fixed a sleeve anchoring one end of a helical clutch spring (600). The spring extends over an adjacent sleeve (598), Fig. 15, not shown, of a driving pulley 581 around which travels a belt 338 to which is firmly attached the printing head 334. The spring 600 is normally freely rotating about the pulley sleeve (598) but when a type head movement is required the control signal operates an electromagnet 615, Fig. 6. This pivots a latching lever 607 holding a lever 602 against the bias of a spring and the lever 602, carrying a nylon shoe (601), Fig. 16, not shown, is used against the clutch spring 600 to effect drive to the pulley 581 and belt 338. When the carriage reaches the right-hand end of a line, the driving pulley 581 will have made just one revolution. A cam surface (617), Fig. 16, restores the lever 602 clockwise disengaging the shoe (601) and the lever 602 is relatched by the lever 607. Carriage-return; left-hand margin alignment.- At the same time as the shoe (601) is released, a drawn-band which has been tensioning a spring during travel of the carriage in letter-spacing direction, draws the carriage back to the left where a detent roller 620 settles in a recess 619 to align the head in correct position for printing a fresh line. Carriage - shock - absorbing buffer.-A stop member (625) and spring (626) are positioned on the extreme left end of shaft 336 to cushion the arrival of the print head. Print-head construction and mounting.-The printing-head 334, claimed in Specification 1,132,302 is formed of insulation material with sixteen individual styli assemblies each having a tungsten electrode pin (334), Fig. 3, protruding in the form of a digit " 8 " slightly slanted to the left. Each pin has a stainless steel sleeve slidably confined in a channel in the head and biased by a spring of conducting material which also forms the electrical connection to each pin and associated energizing circuits. A protecting cap 351 with electrode clearance holes encloses the head and is spring loaded to engage the record paper. A thermoplastic gasket 353 e.g. polytetrafluoroethylene provides a seal to isolate and support individual styli. The printing head 334 slides along the shaft 336 and may be moved horizontally away from the platen during carriage return either automatically or by a hand lever (560), Fig. 13. The horizontal movement is maintained by slide bar (550) riding in a slot (551) provided in a longitudinally extending guide member (552). Paper-web support.-A roll of record web material rests upon an arcuate support extending behind the platen. See Fig. 10 (not shown). Feed-rollers.-There are three sets of feed rollers 518, (520), 522 coacting directly with the platen and all three sets are simultaneously raised for insertion of the record web by a pair of cam plates (535, 536), Figs. 8 and 11, mounted on the platen support shaft 506 on either side of the platen and operated by a lever 530. Cutting.-A tear-off blade 531 is mounted to extend across the platen on the assembly for the feed-rollers 518. Line-spacing.-The platen is automatically line-spaced by means of a spring clutch 572 located on the left side of the printer, Fig. 6. Manual control of line-spacing may also be controlled from the keyboard or single linespacing may be performed manually by rotation of a handle (575) which drives the platen via a unidirectional spring clutch. The clutch slips when the lever is moved in the reverse direction.