US3715978A

US3715978A - Printer hammer mechanism

Info

Publication number: US3715978A
Application number: US00069317A
Authority: US
Inventors: J Raider
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 1970-09-03
Filing date: 1970-09-03
Publication date: 1973-02-13
Anticipated expiration: 1990-02-13
Also published as: DE2139327A1; FR2101772A5; JPS5140486B1

Abstract

A printer has a type cartridge with a plurality of characterbearing type levers, alternate levers having faces on the back at different levels. Print hammers for each print position have striking faces covering both levels, and selection of the type levers is made by operating an interposer between the printer hammers and type levers to the desired level.

Description

O v United States Patent 11 1 1 1 Raider Feb. 13, 1973 [54] PRINTER HAMMER MECHANISM R26,240 7/1967 Wasserman ..101 93 c 75 I 3,575,107 4/1971 McDonell ..l0l/93 C Jemfw s Endlcott N Y 3,332,343 7/1967 Sims ..101/93 c Assignee; International B sine M hi 2,936,704 5/1960 Hense ..101/93 C Armonk 3,331,316 7/1967 Bretti ..197 90 x [22] Filed: Sept. 3, 1970 Primary ExaminerWi1liam B. Penn [21 1 A l N 69 317 Attorney-l-Ianifin and Jancin and Francis V. Giolma i [57] ABSTRACT i. i A printer has a type cartridge with a plurality of [58] Fieid 1 g 90 character-bearing type levers, alternate levers having faces on the back at different levels. Print hammers for each print position have striking faces covering 56 R i C t d 1 e erences I e both levels, and selection of the type levers is made by UNITED STATES PATENTS operating an interposer between the printer hammers 3,241 480 3/1966 Cunningham ..101 93 c and type levers to the desired level l kfisgz 2 Claims, 3 Drawing Figures 3,306,191 2/1967 Sharples 3,433,153 Harrington et al ..l0l/93 C PATENTEUFEB 1 3 1973 JERRY w. RAIDER v T/w M ATTORNEY 1 PRINTER HAMMER MECHANISM DESCRIPTION OF PRIOR ART 7 Heretofore, with moving type carriers having levermounted type characters, print hammers have been used, which engage the type letters at a single level, which has been actuated levers impact a particular type lever, and an adjacent type lever as it moves past the actuated print hammer.

BRIEF SUMMARY OF THE INVENTION Generally stated, it is an object of this invention to provide an improved printer mechanism.

Another object of the invention is to provide a printer mechanism in which the probability of interference between an operated print hammer and an adjacent type lever is minimized.

More specifically, it is an object of this invention to provide for having character-bearing type levers in a printer which have differently located areas of contact with a plurality of print hammers past which they are moved.

Yet another object of the invention is to provide for using two groups of character-bearing type elements having different levels of contact with a plurality of print hammers past which they are moved, and for utilizing an interposer between the print hammers and the type levers for selecting which group will be actuated.

Another object of the invention is to provide alternate character-bearing type levers with actuating surface portions at different levels and for utilizing an lnterposer between the type levers and each of a plurality of print hammers, which interposer is selectively moved to one or the other of two operating levels to select which of two adjacent type levers will be actuated by the print hammer.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accom panying drawing.

DESCRIPTION OF THE DRAWING DESCRIPTION OF A PREFERRED EMBODIMENT FIG. 1 shows a portion of a printer apparatus of one type with which the present invention may be used, and comprises a type cartridge 10 having a plurality of individual type carrier elements represented by the type carrier element 11, movable in a continuous path on a stationary frame 12. A portion of the path of motion of the type carrier elements 1 1 includes a straight portion along a guide rail 120 at the print line. The printer apparatus of FIG. 1 is a front printer but is generally similar to the back printer, which is described in U. S. Pat. No. 3,241,480, which issued on Mar. 22, 1966, to James M. Cunningham and in accordance with well-known operational principles thereof a paper document or form 13 is positioned behind an ink ribbon 14 or the like, which in turn is positioned immediately adjacent the type carrier elements 11 over the print line portion thereof. The ribbon 14 may be fed along the print line in any suitable manner while the paper document 13 is fed transversely to the direction of motion of the type along the guide rail 12a. Generally, printing occurs while the paper document 13 is stationary relative to the print line. On completion of a print cycle the paper document 13 is advanced one or more spaces to a position where a new line of data may be printed. The means for feeding the paper document 13 properly timed with respect to the operation of the print mechanism are well-known in the art and are not shown herewith.

In the printer apparatus of FIG. 1 the arrangement shown is for a front printer. Details of the type carrier element 11 used in the front printer, as shown in FIG.

1, include one or more pivotally mounted type levers 11a, for each carrier element, each lever with a type character 11b on the free end of the lever. The type carrier elements 11 are, as described in the Cunningham patent, slidably mounted on the guide rail 12a. As shown, printing occurs when the type characters 11b on the'type levers Ila impact against the ribbon 14, paper document 13 and a platen 23 positioned behind the document 13. The impacting occurs at various pri nt positions along the print line to eventually form a complete line of data. For this purpose, a plurality of print hammers 24 are mounted, as shown in FIGS. 1, 2 and 3, by way of example, on a shaft 25 and are biased away from the document 13 by means of a spring 26. The print hammers 24 are disposed to be moved to impact the type characters against the document by means of electromagnets (not shown) through the medium of push rods represented by the push rod 30. Each print hammer 24 is individually operable, and operation of the various print hammers 24 occurs selectively at random positions along the print line in accordance with instructions from suitable control means (not shown), which may comprise a type tracking device and a co-acting storage device, which indicates 'the particular data to be printed. Further details of a suitable control system may be more fully understood by reference to U. S. Pat. No. 2,993,437 of F. M. Demer and E. J. Grenchus for a High Speed Printer, which issued July 25, 1961.

According to the present invention, the characters on a type chain are as shown, spaced relatively close together. The spacing closely approaches the theoretical minimum dictated by the width of the type character 11b. The effective spacing of the type levers is increased by causing selective operation of the different type levers through utilizing an interposer 32, associated with each type hammer 24, and which may be selectively operated by means of a suitable electromagnetic operation device 35 to either an upper level, as shown in full lines in FIG. 1, or to a lower level as shown by the dotted outline. The adjacent face 24a of the print hammer 24 is wide enough to span both positions of the interposer 32. Adjacent type levers 11a, as shown in FIG. 3, are provided with striking surfaces a and 15! positioned in line with the upper and the lower positions of the interposer 32, respectively.

As shown in FIGS. 2 and 3, the hammer assembly of the present invention, though physically covering two print positions at once, does not effectively span more than one position at any one time because of the interposer 32.

The present invention allows a print hammer 24 to spend more than twice as much time in penetrating the type line without hitting an adjacent type lever. Also, it increases the contact area between the print hammer and the type lever, thereby decreasing wear. This is accomplished by having two kinds of type levers. Half of the type levers have a striking surface or face on the back of the type lever, which is twice the width of the type lever spacing, and this face 15u will be located, for example, at an upper level. The other half will have a face 151 of equal width located at a lower level, as shown in FIGS. 1, 2 and 3. The interposer 32 between the type hammer 24 and the type levers'lla will be moved to an upper level u or to a lower level 1 during the time that the paper is indexed. If the interposer 32 is at the level u, a type character with a face at level u will be hit by the type hammer 24 and printed. If the interposer 32 is at a level I, a character with a face at level l.will be printed.

For example, a 48-character set on a type chain would be divided into two equal groups; 24 of the characters would be placed in the group u and on type levers with faces 15u at level u, the other 24 characters would be placed in group 2 and on type levers with faces at a level 151. As soon as a new line to be printed is read into a print storage buffer (not shown), a low power actuator 34 at each column would position its interposer 32 according to which group the character to be printed in that column falls. Then printing would take place as usual.

Other equivalent configurations of the invention would include eliminating the interposer 32 and shifting the print hammer 24 (now spanning a single level) to two different levels to obtain the same effect. In another embodiment, separate type hammers 24 could be provided for each level and the push rods could be moved to select the particular type hammers. While the width of the faces 15:: and 151 on the type levers 110, as shown, is twice the character spacing, making the width smaller would allow the type lever mass to be reduced without effecting the function of the invention, which provides an effective double spacing of the type levers even though they are actually positioned side by side.

Whilethe invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. In a front printer,

a plu'ralityof character-bearing type members movable along a straight line path adjacent a print line on a document, said type members being also movable in a direction toward said document, and said type members having one striking surface on each type member with the striking surfaces of adacent type members being spaced different amounts in a direction perpendicular of the print line,

a plurality of print hammers positioned along the print line operable to actuate selected ones of said type members to move them toward said document to perform a printing operation on said document, and

means including an interposer associated with each print hammer positioned between said print hammers and said type members, said interposers being selectively movable perpendicular of said print line to align with the striking surface of different ones of said type members, thereby providing selective impact between said type members and said type hammers.

2. The invention as defined in claim 1 characterized by said type members comprising pivotally mounted levers positioned in 'side-by-side relationand said type member striking surface portions extending beyond said levers in a direction along the print line, but at different distances perpendicular of said print line, so as to be in overlapping and yet non-interfering relation.

Claims

1. In a front printer, a plurality of character-bearing type members movable along a straight line path adjacent a print line on a document, said type members being also movable in a direction toward said document, and said type members having one striking surface on each type member with the striking surfaces of adjacent type members being spaced different amounts in a direction perpendicular of the print line, a plurality of print hammers positioned along the print line operable to actuate selected ones of said type members to move them toward said document to perform a printing operation on said document, and means including an interposer associated with each print hammer positioned between said print hammers and said type members, said interposers being selectively movable perpendicular of said print line to align with the striking surface of different ones of said type members, thereby providing selective impact between said type members and said type hammers.