JPS5857979A - Shifter for printing member - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a print member shifter for use in an impact printer having a print member on which characters are formed in two circumferential rows. The shifter moves the printing member from a first operative position in which one circumferential row of printed characters is aligned with the print hammer to a second operative position in which a second circumferential string of characters is aligned with the print hammer. Designed to move quickly and accurately.

In recent years, the "-? Izzy" wheel or "Simpulus"
Serial percussion printers using printing elements called ``printers'' are becoming increasingly popular. A "dizzy" wheel has a four-tally boss and from this boss extends a plurality of radial spokes, each spoke carrying a character pad at its end; supports embossed/engraved letters. "Simdel"
is a cup-shaped printed member around which the letters are carried. A daisy wheel is considered to be one in which the spokes are bent at essentially right angles. Each printed member supports a number of characters, including letters, numbers and symbols, and these characters are designed as aligned characters. The print can be made by attaching any of these types of print members to a rotating drive shaft with its bushings extending from a drive motor, which drive motor can be indexed by appropriate control logic to hammer forward the desired character. This is done by aligning the If both of these printing members are lightweight and small, their inertia is relatively small and they can be rotated quickly during the printing sequence. This allows high speed printing. The printing components of these printers can generally be installed and removed using simple mechanical operations.
Users have great flexibility in selecting and changing type styles. This is because, in order to change the expired character alignment set, the user simply needs to replace the print member and place another print member in the printing machine.

In many cases, it has become desirable to increase the number of characters carried by a given print member. Obviously increasing to a very large number of characters1
One way is to further increase the slip. This increases the capacity of the printed member, but
This also increases the diameter of the wheel, increasing the inertia of the printed member. Unfortunately, the operating speed of the printer must be reduced as the printing member becomes too large. Logically increasing the size of a print member will increase the number of characters in a given size print member. This creates more than one string on the printed member, i.e. inner and outer concentric strings for the "Dizzy" wheel, and upper and lower circumferential strings for the "SimGuru". This is accomplished by forming strings of characters. With this type of print member, very large character capacities can be achieved without increasing the inertia of the print member.

U.S. Patent No. 3,651,915 (“Printing mechanism for electric office machine”, Foxins), U.S. Pat.
No. 4,106,611 ("Serial Printing Device", Suzuki et al.), both of which have two rows of letters on the circumference, are shown. It is in the form of a print wheel. Additionally, U.S. Patent No. 365191
In both No. 6 and No. 41075611, the book, 2
A "Simdel" type print member having letters on the circumference of the rows is also disclosed. In order to position the selected character to be printed in front of the printing hammer, it is necessary to provide some suitable table mechanism for repositioning the printing member. Therefore, U.S. Patent No. 36519
In No. 15, the print wheel is mounted on a carrier member that is raised and lowered onto a movable rond for vertical movement. US Patent No. 3651
In No. 91<5, the axial drive shaft of the illustrated print wheel is supported by an arm so that the arm can move in an arc, and the axial drive shaft of the illustrated print wheel is moved along the axis by a positioning electromagnet. I am forcing it to move in that direction. U.S. Patent No. 39217
In No. 87, the print wheel is adapted to be shifted by a pivoting motor drive arm acting on a shaft supporting it. Also, US Patent No. 4106
In No. 611, the illustrated print wheel is shifted by a crank arm that is retracted to both upper and lower positions by shifting a solenoid, and the illustrated print wheel is shifted by a crank arm that is retracted to both upper and lower positions by shifting a solenoid, and the illustrated "shim pull" (with four rows of letters circumferentially ) is allowed to slide vertically along its axis.

In such multiple circumferential row print member systems, the primary factor controlling print speed is the setting of the post-shift delay time during which the print member oscillates and falls to its "home" position. It was found that Such delays are inherent in mechanical linkage systems where a driver moves a connecting link relative to a fixed stop. If printing occurs immediately after a vibrating shift of the printing member, the printed characters will not be on the typing baseline and the printed page will look unsightly.

This is the case, for example, in the device disclosed in U.S. Pat. It is an object of the present invention to move the printed member accurately and at high speed from one circumferential string to the other. To provide a shift mechanism capable of eliminating the problem of vibration that has been a problem during kneading at a main home position. Smooth and accurate shifting is achieved by a crank arm that is movable in an arc between two end-of-travel positions defined by fixed limit stops and that can be coupled to the print member via a shift cam and slider arrangement. This driving connection creates a driving contact between the crank arm and the shift cam between the two end-of-travel positions, and this driving contact occurs when the crank arm reaches its limit of travel and reaches the two end-of-travel positions. The actual negative value becomes zero. In this way, when the crank arm strikes the fixed stop, the striking force is isolated from the printing member.

The present invention may be realized in one form by reference to the following detailed description and drawings.

With particular reference to the drawings, FIG.
0, the print wheel is shown with radial spokes and two congruent circular strings, each spoke having an outer letter 12 and an inner letter 14. The print wheel is removably mounted on a drive shaft 16, which drives the print wheel motor 18 with the drive power ff! As shown by arrow A, it can be rotated in both clockwise and counterclockwise directions. Is it possible to do this at an appropriate angle? As disclosed and fully described in U.S. Pat. A hammer can advantageously be used in this device. The selected character is struck by the force applied to the hammer 20 for a suitable period of time, and is then struck against the ink ribbon 22 and placed on the platen 2.
The information is recorded on a receiving sheet 24 supported by 6. In this manner, perfectly shaped characters are transferred from the ink cylinder 22 to the sheet.

Print speed -10 is coupled to the output shaft 28 of the print wheel motor 18 via a universal coupling 30, which rotates the print wheel in a direction perpendicular to its axis while being actively driven by the motor. expressed so that it can be shifted within the space of . A print wheel drive shaft 7) 16 is connected at one end to a universal coupling 30 and carries a print wheel at the other end, the drive shaft 16 being suitably journaled for rotation through a shifter cam 32. .

In this way, the shaft can move in the direction of the arrow while being rotated on its axis. Shifter 32 is shown as generally pear-I shaped and slot 34
extends inwardly from one end toward a center of rotation defined by a pivot shaft 36, which is secured to a carriage (not shown). As will be fully understood by those familiar with percussion printers of this general design, the rotation and shifting of the printing member, the mounting and driving of the recan, and the mounting and driving of the hammer are carried out on the carriage; The carriage is allowed to move back and forth parallel to the axis of the platen. The movement of the shifter cam 32 is restricted to movement within the slot 34 and is supported by one end of the long leg 40 of the crank 42. This is done by a slider (which may be in the form of a roller 39 as shown in FIGS. 4 and 5). A roughly shaped crank 42 has a pivot pin 44 (fixed to the carriage) disposed on its two parts 46.
mounted to rotate around. crank 42
The short leg 48 is formed with a slot 50 through which a drive link 52 passes. The bin 52 has a solenoid drive shaft 56 extending from the solenoid 5B at both ends.
It is fixed in a clevis 54 formed at the end of the.

A return compression spring 60 is mounted around the shaft 56 to maintain the solenoid drive shaft at a normal protrusion potential relative to the solenoid when the solenoid 58 is energized. The spring 60 is adapted to press against the body of the solenoid at one end and against the short leg 48 of the crank 42 at the other end. Top and bottom stop pads 62 and 64
(fixed to the carriage) is positioned adjacent to the operating path of the long leg 40 and is configured to limit the movement of the crank 42 to a predetermined arc of movement under the action of either a solenoid 58 or a compression spring 60. The operation of this shifter is as follows. That is, in the illustrated normal position, the solenoid is deenergized and the solenoid drive shaft 56 is fully extended under the action of the compression spring 60. The print wheel is in the lowered position as shown in FIG. When the solenoid 58 is energized, the solenoid drive shaft 56 is electromagnetically drawn in the direction of arrow B. This movement causes the crank 42 to rotate around the pivot pin 44 in the direction of the arrow C, and this rotation continues until it hits the lower fixed shaft (Fe2), and the slider pin 3'8'1 is rotated clockwise. The slider will move in an arc to the slot 3.
4, the shifter cam 32 is rotated counterclockwise as shown by the arrow, and the stiffness causes the print wheel 1 to rotate.
0 is the place shown in Figure 3! rise towards. solenoid v5
The deenergization of 8 causes the return compression spring 60 to move the linkage device in the opposite direction, ie, in the direction opposite to arrows B, C and D, positioning the crank 42 against the upper fixed stop pad 62.

The operation of this shift mechanism has been devised as one in which the print wheel is rapidly moved vertically to position the selected circumferential row of characters in the proper position.

An understanding of FIGS. 4 and 5 will clearly demonstrate the advantages achieved with the shifter of the present invention in completely eliminating the effects of set vibrations on the printed member. Each of these drawings shows the limit position of the shifter cam 320 stroke position. At both limit positions of this arcuate movement, the long leg 40 of the crank 42 returns to the compression spring 6.
0 or solenoid P58 against the fixed pad 62 or 64, respectively. When the crank reaches the "strike" position in this way, it bounces and vibrates until it settles into its still home position. During this vibratory contact, slider 273 moves in line with slot 34 and is effectively isolated from the shifter cam. In this way, the shifter cam and print wheel smoothly and quickly move from their fully raised position to their fully lowered position during the setting of the crank, and are silently set.

A graph illustrating the advantages of the present invention is shown in FIG. 7, as previously discussed. Compare this with the graph of a known prior art shift mechanism shown in FIG. 7th
In the figure, the trajectory of the vertical movement of the print wheel drive shaft 16, both rising and falling, rises and falls smoothly from start to finish. However, in FIG. 6, the trajectory of the vertical movement of the print wheel drive shaft in both the raising and lowering modes of the prior art apparatus reveals that generally irregular movements occur as the printing member is set to its home position. It shows. In order to strike a character immediately after it has been shifted from one character circle to another, care must be taken to ensure that the next character is properly positioned at the baseline being typed. Become. Thus, in prior art devices, the printer had to be operated at a slower speed, or else the set of printing members had to take the chance that the struck characters would not deviate too far from the target potential. . Both of these are undesirable, and both are eliminated by the novel shifter mechanism of the present invention.

Although the invention has been illustrated as having a print wheel, it will be apparent that suitable mechanical modifications may be made to enable use of this isolation shift principle with "simply" type print members. Furthermore, while the invention has been described by way of example, it is further understood that many changes in construction details may be made;
And it is to be understood that combinations and arrangements of parts may be made without departing from the spirit and scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the print member shifter with respect to the print member drive and platen; FIG. 2 is an elevational view of the print wheel in its normal lowered position; FIG. 3 is an elevational view showing the print wheel of FIG. 2 in a shifted raised position; FIG. 4 is an elevational view of the shifter mechanism with the print wheel shown in its normal lowered position. FIG. 5 is an elevational view similar to FIG. 4 with the print wheel shown in its normal raised position.FIG. 6 is a graph illustrating the time versus displacement characteristics of a shift mechanism known in the prior art. FIG. 7 is a graph showing the relationship between time and displacement of the shift mechanism of the present invention. 10...Print wheel 12...Outer letter 14...Inner letter 16...Drive shaft 1B...Print wheel motor 20...Hammer 22...Ink ribbon 24...Sheet 30... Universal coupling 32...Shifter 34...Squat 38...Slide bin 42...Crank 58...Solenoid 60...Compression spring 62.64...Pad representative Akira Asamura 4 other people ≧

Claims (1)

[Claims] A printed member having two circumferential rows of characters is moved between two working positions, and in one working position the characters of one circumferential row are aligned with the striking member. a shifting device for a printing member for aligning the characters of the other circumferential row with the striking member in the other operating position, the device supporting said printing member rotatably about its axis II; means for driving said axis support means; universal means for coupling said axis support means and said rotation means; and said rotation means for moving said print member between said two operating positions. shifting means coupled to the axis support means; and drive means coupled to the shifting means for moving the shifting means between two end-of-travel positions, the two end-of-travel positions being the two end-of-travel positions. a drive connection between said drive means and said shift means between said two end-of-travel positions i, and said drive connection is associated with said two end-of-travel positions i; A printing member shifting device comprising: the driving means having substantially zero displacement;