US3842958A

US3842958A - Shift mechanism

Info

Publication number: US3842958A
Application number: US00365253A
Authority: US
Inventors: M Link
Original assignee: Triumph Werke Nuernberg AG
Current assignee: TA Triumph Adler AG
Priority date: 1972-07-06
Filing date: 1973-05-30
Publication date: 1974-10-22
Anticipated expiration: 1991-10-22
Also published as: DE2233169A1; FR2191478A5; IT970936B; JPS4956718A

Abstract

A type element of a single element printer is shifted to print upper or lower case type characters by a crank which is rotatably driven through 180* with each actuation of a shift key to pivot a shifting lever of a mechanism for rotating the type element. The crank is connected to the shifting lever by means of a tape which is drawn around a roller of a pivotal guide arm and secured to a slide member mounted on a pin of the crank which extends through an elongated slot in the guide arm. The crank is rotatably driven by a drive mechanism coupled to a power roll by a half-turn clutch, and a detent arrangement is provided to accurately position the crank at rotational positions spaced 180* apart.

Description

United States Patent 1191 11 1 3,842,958

Link 1 Oct. 22, 1974 [5 SHIFT MECHANISM 3.5l6,528 6/1970 Davidge el al 197/16 [75] Inventor: Manfred Link, Nuernberg, Germany 3s8]86O 6H9. Schaefer X [73] Assignee: Triumph Werke Nuernberg A.G., Primary Examiner-Robert E. Pulfrey Nuernberg, Germany Assistant Examiner-R. T. Rader [22] Filed y 30 1973 Attorney, Agent, or Firm-Joseph R. Spalla [21] Appl. No.: 365,253 [57] ABSTRACT A type element of a single element printer is shifted to [30] Foreign Application Pri -fly Dat print upper or lower case type characters by a crank July 6 1972 Germany 223369 which is rotatably driven through 180 with each actuation of a shift key to pivot a shifting lever of a mecha- [52] US. Cl. 1. 197/18 for rotating type elemem' The crank is 511 1111. C1 B4lj 23/04 "acted Shifting ever by means a taPe which [58] Field of Search U 197/16 7 18 48 49 is drawn around a roller of a pivotal guide arm and secured to a slide member mounted on a pin of the crank which extends through an elongated slot in the [56} References cued guide arm. The crank is rotatably driven by a drive mechanism coupled to a power roll by a half-turn UNITED STATES PATENTS clutch, and a detent arrangement is provided to accu- 2,989,l66 6/1961 Walker et a]. t. l97/l6 rately position the crank at rotational positions spaced 3,227,259 l/l966 Howard l97/49 I809 apart 3,228,510 1/1966 Howard 197/49 3,467,233 9/1969 .Iablowski .1. 197/16 4 Claims, 1 Drawing Figure SHIFT MECHANISM This invention relates to a single element typewriter, and more particularly to a shift mechanism for shifting a type element to print upper case or lower case type characters.

in a single element typewriter, a plurality of type characters are located at different positions on a type element, and the printing of a selected type character is effected by orienting the type element to impact the desired type character against the platen. As is conventional, both lower and upper case type characters are arranged on different portions of the type element with the printing of corresponding type characters being controlled by common type key mechanisms. Upon op eration of the type key mechanisms, type characters are selected from whichever group of type characters are presented for printing, and the printing may be shifted to another group of type characters by rotating the type element to present the other group for printmg.

Typically, the print element is rotated in response to the movement of an associated drive member which is moved by means of a tape upon the operation of either a character selecting mechanism or a shifting mechanism. Such an arrangement is shown for example, in U.S. Pat. Nos. 2,897,876 and 3,077,971, and it is essential that the shifting be effected quickly between exactly defined positions. Moreover, it is desirable that the shifting movement have a sine-shaped characteris tic to quickly bring the moving members to rest.

Accordingly, an object of the present invention is to provide a shifting mechanism having a simple construction as well as a fast and reliable operation.

Still other objects, features and advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the invention, taken in conjunction with the accompanying drawing, wherein the single FIG- URE shows diagrammatically a single element printer having a shifting mechanism constructed in accordance with the present invention.

Referring now in detail to the FIGURE in the drawing, there is shown a single element printer, generally indicated 11, having a type element 13 with a plurality of type characters 15 at different positions for printing on a suitable recording medium, not shown. As is conventional, printing is effected by impacting the type element 13 against the recording medium which may be suitably supported on a platen, not shown, and the type element 13 is mounted on a carriage 17 for movement along the platen to print a line of type. The type element 13 is rotatably supported on the carriage 17 by suitable means, not shown, and a selected type character 15 is printed by orienting the type element 13 so that the desired type character 15 will be impacted against the recording medium. The rotational orienting movement of the typehead is effected by a rotating means, generally indicated [9, which is acted upon by a type key mechanism, not shown, which controls the movement of the type element 13 to position the selected character 15 for printing. The plurality of type characters 15 includes both upper and lower case char acters which are arranged on different portions of the type element 13 with the type key mechanism controlling the printing of corresponding type characters 15. The type key mechanisms select type characters 15 from whichever group of type characters 15 is presented for printing, for example the lower case type character, and to print a type character from the upper case type characters, the rotating means 19 is acted upon by a shifting mechanism, generally indicated 21, which may be controlled by a suitable shift key to effect l rotational movements of the type element to present the upper case type characters for printing. The recording medium, the platen, the keyboard and the key actuating mechanism as well as other portions of the printing aren't shown since they form no part of the invention and may be desirably conventional.

As shown, the type element 13 is carried by a spindle 23 having an attached wheel 25 which is acted upon by the rotating means 19 for enabling rotational move ment of the type element 13 at any position of the carriage along the platen. The rotating means 19 includes a tape 27 drawn around pulleys 29, 31 at the opposite ends of the carriage movement with one end of the tape 27 secured to the wheel 25 and the other end attached to the carriage 17. The pulleys 29, 31 are carried on the ends of a pair of

corresponding levers

33, 35 which may be pivotally supported on opposite sides of the typewriter frame with the lever 35, hereinafter referred to as a shifting lever, being acted upon by the shifting mechanism 21 in a manner to be explained below, and with the lever 33 being connected to the type key mechanism by a suitable link 37. The type key mechanism controls the orientation of the type element 13 in a conventional manner by pivoting the lever 33 to pull on the tape 27 and thus rotate the type element 13.

Since the printing of corresponding upper and lower case type characters 15 is controlled by common type key mechanisms, the particular type characters 15 selected depends on which set of type characters 15 are presented for printing. To change or shift the printing from lower to upper case type characters 15, the type element 13 is rotated and this is accomplished by pivoting the shifting arm 35 to pull against the tape 27 and rotate the type element. However, the shifting must be accurate and the shifting movement should desirably have a sine-shaped characteristic so as to bring the moving parts quickly to rest and avoid backlash. As is conventional, the pivoting of the shifting lever 35 is effected by a shifting mechanism 21 which is actuated by a suitable shift key which may be located on the keyboard area of the single element printer.

In accordance with the present invention, the shifting lever 35 is pivoted by a shifting mechanism 21 in the form of a shift crank, generally indicated 39, which is connected to the shifting lever 35 by means of a suitable band 41 and rotatably driven by drive means, generally indicated 43. As shown, the crank 39 is in the form of a crank plate 45 rotatably supported by a suitable shaft 47 and having a crank pin 49 spaced radially from the axis of rotation. The crank pin 49 is connected to the shifting lever 35 by the band 41 having one end secured to the shifting lever 35 by a suitable adjustable connector 51 while the other end of the band 41 is secured to a slide member 53 which is mounted on the end of the crank pin 49 so as to pivot the shift lever 35 in response to the rotational movement of the shift crank 39. To guide the band from the shifting lever 35 to the crank pin 49, the band 41 is drawn around a defleeting pulley 55 rotatably mounted on a guide arm 57 which is pivotally supported and has an elongated slot 59 through which the crank pin 49 is received.

The shift crank 39 is rotatably driven by the drive means 43 which includes a drive gear 61 rotatably supported by a suitable shaft 63 and meshing with the gear teeth 65 formed circumferentially on the crank plate 45. The drive gear is rotatably driven by a drive shaft 67 of a power roll 69 which is coupled to the drive gear 61, by a half-turn clutch 71 with each actuation of the shift key. The half-turn clutch 71 may be desirably conventional and couples the drive shaft 67 to the drive gear 61 for 180 of rotational movement, whereupon the half-turn clutch 71 discontinues the rotational drive. To accurately position the type element 13 at the shifted positions, the crank plate 45 has a peripheral surface 73 with diametrically opposite detent notches 75 for receiving a detent member in the form of a roller 77 carried on one end of a lever 79 and resiliently urged against the peripheral surface 73 by resilient biasing means in the form of a spring 81 stretched between the lever 79 and a suitable portion of the printer.

In operation, the type element 13 may be shifted from lower to upper case characters by actuating a shift key to couple the drive gear 61 to the drive shaft 67 by means of the half-turn clutch 71 for rotating the shift crank 39 through 180. As the crank plate 45 is rotatably driven, the detent roller 77 is removed from the detent notch 75 against the urging of the spring 81, while the crank pin 49 moves through the elongated slot 59 of the guide arm 57 to pivot the shifting lever 35. Upon completing the 180 of rotation, the drive gear 61 is disconnected by the half-turn clutch 71 while the detent roller 77 is urged into the detent notch 75 of the crank plate 45 thereby accurately positioning the type element 13 with the upper case type characters 13 presented for printing. Similarily, the type element 13 may be shifted to print the lower case type characters by again operating the half-turn clutch 71 to rotate the crank plate 45 through 180, whereupon the crank pin 49 will move along the elongated slot 59 in an opposite direction, thereby enabling the shift lever 35 to return to its previous position and rotate the type element 13 to present the lower case type characters 15 for printing.

What is claimed is:

1. In a single element typewriter having a type element with upper and lower case characters arranged on different portions and rotatable to present the upper and lower case type characters for printing, and rotating means including a shift lever pivotally movable for controlling the rotation of the type element, the improvement comprising:

a shift crank supported for rotational movement,

a crank pin secured to said shift crank at a location radially spaced from the axis of rotation of said shift crank and extending therefrom in an axial direction, a band,

means connecting said band between the shift lever and the crank pin for pivoting the shift lever in response to the rotational movement of the shift crank, and

drive means operable with each actuation for rotating the shift crank substantially to rotate the type element to present a different case of type characters for printing.

2. In a single element typewriter according to claim 1, said connecting means comprising:

a guide arm pivotally supported adjacent said shift crank with an elongated slot formed therein for receiving the crank pin and having a deflecting roller mounted thereon for guiding the band toward the crank pin, and

a slide member connecting the band to the crank pin and being slidable along said guide arm in response to the rotational movement of said shift crank.

3. In a single element typewriter according to claim said shift crank being in the form of a crank plate mounted on a rotatable shaft with the crank pin being radially spaced from the axis of rotation of the crank plate,

said crank plate having a peripheral surface with detents formed therein at 180 apart,

a detent member cooperable with said crank plate for engagement with the detents formed in the periphery thereof, and

resilient biasing means urging said detent member into engagement with the peripheral surface of said crank plate to bring said detent member into cooperating engagement with the detents of the crank plate to stop the rotational movement thereof.

4. In a single element typewriter according to claim said shift crank being in the form of a crank plate mounted on a rotatable shaft with the crank pin being radially spaced from the axis of rotation of the crank plate,

resilient biasing means urging said detent member into engagement with the peripheral surface of said crank plate to bring said detent member into cooperating engagement with the detents of the crank plate to stop the rotational movement thereof. t 11 1F

Claims

1. In a single element typewriter having a type element with upper and lower case characters arranged on different portions and rotatable to present the upper and lower case type characters for printing, and rotating means including a shift lever pivotally movable for controlling the rotation of the type element, the improvement comprising: a shift crank supported for rotational movement, a crank pin secured to said shift crank at a location radially spaced from the axis of rotation of said shift crank and extending therefrom in an axial direction, a band, means connecting said band between the shift lever and the crank pin for pivoting the shift lever in response to the rotational movement of the shift crank, and drive means operable with each actuation for rotating the shift crank substantially 180* to rotate the type element to present a different case of type characters for printing.

2. In a single element typewriter according to claim 1, said connecting means comprising: a guide arm pivotally supported adjacent said shift crank with an elongated slot formed therein for receiving the crank pin and having a deflecting roller mounted thereon for guiding the band toward the crank pin, and a slide member connecting the band to the crank pin and being slidable along said guide arm in response to the rotational movement of said shift crank.

3. In a single element typewriter according to claim 2: said shift crank being in the form of a crank plate mounted on a rotatable shaft with the crank pin being radially spaced from the axis of rotation of the crank plate, said crank plate having a peripheral surface with detents formed therein at 180* apart, a detent member cooperable with said crank plate for engagement with the detents formed in the periphery thereof, and resilient biasing means urging said detent member into engagement with the peripheral surface of said crank plate to bring said detent member into cooperating engagement with the detents of the crank plate to stop the rotational movement thereof.

4. In a single element typewriter according to claim 1: said shift crank being in the form of a crank plate mounted on a rotatable shaft with the crank pin being radially spaced from the axis of rotation of the crank plate, said crank plate having a peripheral surface with detents formed therein at 180* apart, a detent member cooperable with said crank plate for engagement with the detents formed in the periphery thereof, and resilient biasing means urging said detent member into engagement with the peripheral surface of said crank plate to bring said detent member into cooperating engagement with the detents of the crank plate to stop the rotational movement thereof.