US3605612A

US3605612A - Pre-positioning means for paper and ribbon inker in selective printing machines

Info

Publication number: US3605612A
Application number: US817767A
Authority: US
Inventors: John G Clary
Original assignee: Addmaster Corp
Current assignee: Addmaster Corp
Priority date: 1969-04-21
Filing date: 1969-04-21
Publication date: 1971-09-20
Anticipated expiration: 1988-09-20

Abstract

A PRESSER DEVICE FOR MOVING A PAPER STRIP AND PRINTING RIBBON AT A CONTROLLED RATE OF SPEED AGAINST TYPE MEMBERS PRIOR TO STRIKING MOVEMENT OF PRINTING HAMMERS WHEREBY TO REDUCE PRINTING NOISE.

Description

Sept. 20, 19'" (:L RY 3,605,612

FEE-POSITIONING MEANS FOR PAPER AND RIBBON INKER IN SELECTIVE PRINTING MACHINES Filed April 21, 1969 2 Sheets-Sheet 1 Sept. 20, 1971 J. G. CLARY 5 PREPOSITIQNING MEANS FOR PAPER AND RIBBON INKER IN SELECTIVE PRINTING MACHINES Filed April 21. 1969 2 Sheets-Sheet 2 X MA/ United States Patent 3,605,612 Patented Sept. 20, 1971 3,605,612 PRE-POSITIONING MEANS FOR PAPER AND RIBBON INKER IN SELECTIVE PRINTING MACHINES John G. Clary, Pasadena, Calif., assignor to Addmaster Corporation, San Gabriel, Calif. Filed Apr. 21, 1969, Ser. No. 817,767 Int. Cl. B41j 31/12; B41k l/40 US. Cl. 101-96 Claims ABSTRACT OF THE DISCLOSURE A presser device for moving a paper strip and printing ribbon at a controlled rate of speed against type members prior to striking movement of printing hammers whereby to reduce printing noise.

In certain types of data printing devices, such as used in printing calculating machines and as exemplified by the machine disclosed and claimed in the H. L. Clary et al. US. Pat. No. 3,151,546, issued on Sept. 8, 1964, a paper strip forming a record medium is guided over differentially settable type members and over a printing ribbon located intermediate the type members and the paper strip. After the type members have been advanced to digitized positions, printing hammers impact the paper strip and ribbon against the type characters so as to transmit a visible imprint from the type characters to the strip. In such cases, the ribbon must normally be spaced from the type members so that it will not catch on the type characters as the type members are advanced. Also, the paper must normally be spaced from the printing ribbon so as to not rub against the same during advancement of the strip. Otherwise, problems would be encountered in threading the tape through the printer and an ink-streaked appearance would be transferred to the tape.

Although printers of the above type operate satisfac torily, they create a considerable amount of noise during printing. I have discovered that this is due to a large extent to the diaphragm effect of the paper as the hammers strike the same. That is, the paper normally forms a relatively large flexible surface which is spaced from the type characters and is therefore unsupported at the printing point. When the hammers strike the paper prior to impacting it against the type characters, the entire unsupported surface of the paper vibrates the surrounding air, creating a loud sound. This extends to the free end of the paper which extends outside the machine.

Also, in printers of the above type, an appreciable amount of energy is absorbed by the paper and ribbon as the spring-impelled hammers carry the same into contact with the type characters. Thus, a relatively large amount of energy must be initially imparted to the hammers to create a visible imprint and this further increases the generation of noise. Further, it has been found that a noticeable amount of smudging of the printed type characters occurs, possibly due to minute relative shifting between the paper and the printing ribbon during the printing impact of the hammers.

It therefore becomes a principal object of the present invention to reduce the printing noise in printers of the above type.

Another object is to reduce the force necessary to impel printing hammers against the paper record medium during the printing operation.

Another object is to reduce smudging of printed type characters in printers of the above type.

The manner in which the above and other objects of the invention are accomplished will be readily understood on reference to the following specification when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a sectional view through a printer of an adding machine embodying a preferred form of the present invention.

FIG. 2 is a front view of the printer and is taken sub stantially along the line 2-2 of FIG. 1.

FIG. 3 is an enlarged sectional plan view taken along line 33 of FIG. 1.

The illustrated embodiment of the present invention is disclosed in connection with the commercially available Addmaster Adding Machine, and for the sake of brevity, only those parts which comprise the printing device are disclosed herein. Reference may be had to the above noted Clary et al. patent for a more complete disclosure of the adding machine.

The printer comprises a plurality of rockable type sectors 11 arranged side-by-side for independent movement about a common axis. Each sector has a series of type characters 12 spaced around the periphery thereof and ranging in value from Zero to 9. Means (not shown) are provided for differentially advancing the type sectors to position selected ones of the type characters at a printing line PL located directly below an elongated inking ribbon 13. The latter extends across all of the type sectors and is suitably advanced in an endwise direction during machine operations.

The printer is supported by a pair of side frame plates 14 and 15 which are held in spaced relation by certain structural members including a pair of print hammer guide bars 16, 17, a hammer spring support plate 18, and a pair of paper guide members 20 and 21. The latter members form a guide chute for guiding a paper tape 22 from a suitable supply roll (not shown) to a position over the printing line. Means (not shown) pushes the paper endwise in the chute as an incident to each machine operation. The guide member 21 has rearwardly extending tabs, one of which is shown at 23, for supporting a thin flexible shroud 24 having a thickness on the order of .010 inch. The latter is attached to each tab at 25 and extends forwardly to form part of the paper guide chute. Openings 26 are formed in the shroud in alignment with the different type characters at the printing line. Since the paper is pushed endwise, the sides of the chute must be spaced apart sutliciently to permit free passage of the paper therethrough.

The member 20 also has openings 27 formed therein in alignment with openings 26. Such member is curved at 28 and extends upwardly to cooperate with a transparent guide member 30 to guide the paper upwardly after pass- 111g the printing line. The member 30 has a serrated tearolf edge 31, permitting the paper to be torn therealong.

Elongated printing hammers 32 are aligned with respective ones of the type sectors 11 and are guided for endwise movment at the upper end thereof in openings formed in the guide bar 16. The lower ends of the hammers have openings 33 therein which are guided over the guide bar 17. The hammers have print heads 34 of relatively soft plastic material secured to the lower ends thereof.

The various print hammers are urged downwardly by respective spring fingers 35 pivotally connected thereto at 39 and secured at 36 to the member 18. Normally, the hammers are held in their upper illustrated positions by a three-lobed cam 37 which engages a follower bail 38 pivotally supported at 40 and underlying the various Spring fingers.

According to the present invention, a pair of spaced presser members 41 and 42 are provided. Since such members are similar, only one will be described in detail.

The latter is slideably mounted between two adjacent print hammers 32 and terminates at its lower end in a laterally extending flange 43 which is guided along the forward edges of the two adjacent hammers and, in turn, terminates in two spaced presser feet 44 which extend through two of the openings 27 in the member 20. The presser member is pivotally connected at 45 to a bail 46 fulcrumed at 47 and urged downwardly by a tension spring 48. Normally, however, the bail 46 and presser members are held in their illustrated upper positions by a three-lobed cam 50.

Both earns 37 and 50 are mounted on a printer control shaft 51 which is rotated one-third of a revolution in a clockwise direction during each machine operation.

It will be noted that the cam 50 has a relatively steep cam surface 52 on each of its lobes and at approximately 210 degrees in each machine cycle, such surface passes below an edge 53 on bail 46 permitting the springs 48 to lower the same and the presser members at a controlled rate of speed. In doing so, the presser feet 44 engage the paper 22 and press the same down against the shroud 24 which flexes against the printing ribbon 13 to move the same downwardly against the aligned type character. This movement is slow enough to prevent generation of sound due to movement of the paper. Thus, the ribbon is maintained in intimate contact with the type character and the paper is maintained substantially in contact with the ribbon. At this time, a radially extending shoulder 54 on one of the lobes of cam 37 passes under an edge 55 of bail 38, permitting the spring fingers 35 to impel the print hammers 32 downwardly at an uncontrolled and high rate of speed to impact the paper against the printing ribbon 13 and aligned type character 12. Since the paper is held against the shroud 24 at this time, no violent movement will be imparted along the paper to its free end which would otherwise tend to generate a sound. Thereafter, the succeeding lobes of the cams 37 and 50 raise the hammers and presser members to their illustrated positions whereby the ribbon 13 may rise above the type characters 12 sufficiently to clear the same. Also, the paper 22 is freed to be readily moved endwise along the paper chute.

I claim:

1. A printer for a calculating machine or the like comprising a plurality of type members each having a plurality of type characters thereon,

means for differentially advancing said type characters to present different ones of said type characters to a printing line,

means for guiding a paper strip to said printing line and over said type members,

a thin flexible guide member intermediate said type members and said strip for normally maintaining said strip spaced from said type members,

printing impression means operable to strike said strip at said printing line whereby to transfer an imprint from said type characters at said printing line to said strip,

a presser device operable to press said strip against said guide member and to press said guide member towards said type members adjacent said printing line, and

cyclically operable means including a control member for first causing operation of said presser device and for thereafter causing operation of said impression means while said presser device presses said strip against said guide member.

2. A printer according to claim 1 comprising means for supporting a printing ribbon intermediate said type members and said guide member at said printing line and in spaced relation to said type characters,

said presser device being effective upon pressing said strip and said guide member toward said type members to press said ribbon against said type characters at said printing line.

3. A printer for a calculating machine or the like comprising a plurality of type members each having a plurality of type characters thereon,

means for differentially advancing said type members to present different ones of said type characters to a printing line,

means of guiding a paper strip to said printing line and over said type members,

printing hammers aligned with respective ones of said type members and operable to strike said strip whereby to transfer an imprint from said type characters at said printing line to said strip,

a printing ribbon intermediate said guide member and said type members at said printing line,

means supporting said ribbon against said guide member and normally space from said type members,

presser device operable to press said strip toward said type members whereby to cause said guide member to press said ribbon against said type characters, and

cyclically operable means including a control member for first causing operation of said presser device and for thereafter causing operation of said hammers while said presser device is pressing said strip towards said type members.

4. A printer according to claim 3' wherein said last mentioned means is effective to cause movement of said presser device at a controlled rate of speed.

5. A printer according to claim 4 comprising means on certain of said hammers for guiding said presser device toward and away from said strip.

References Cited UNITED STATES PATENTS 2,427,418 9/ 1947 Rast 101-90 2,901,969 9/1959 Rabinow 101-93 3,001,470 9/1961 Nessel 101-96 3,031,954 5/1962 Oldenburg et a1. 101-408X 3,139,169 6/ 1964 Wagemann l01-93X 3,151,546 10/1964 Clary 101-93 3,218,965 11/1965 Simons et a1. 101-93 2,869,454 1/1959 Lang 101-93 WILLIAM B. PENN, Primary Examiner US. Cl. X.R.