JPH0659745B2 - Printing mechanism for small printers - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a printing mechanism for a small printer, and more particularly to a printing mechanism for a small printer characterized by a shift mechanism for a plurality of printing wheels.

[Prior Art] A small printer that is installed in a desktop computer or an electronic register, selects a predetermined type of printing while running based on a print command, and stamps a symbol such as @, * ,: in addition to numbers. Function is required.

For this reason, in the conventional small size printer, the numbers and symbols are arranged in a row in one type wheel, but since many type characters are provided in one type wheel, the diameter thereof becomes large, thus hindering downsizing of the printer mechanism. Had a problem. further,
When the numbers and symbols are arranged in a row in one type ring, the desired type must be selected from many types, and thus it takes time to select the type and the stamping speed also decreases. Was there. Further, as disclosed in Japanese Patent Laid-Open No. 58-134752, a number stamping hammer and a symbol printing hammer are provided side by side on each of two type wheels to meet the above request, but the printer has a complicated mechanism and the like. There was a problem that it hindered the miniaturization of the mechanism. In addition, JP-A-58-1
In the example of No. 34752, the printing position of the symbols and the printing position of the numbers are shifted by one line with respect to the recording paper, and it is necessary to perform complicated control such as feeding the recording paper after stamping the symbols and further stamping the numbers. It was

[Problems to be Solved by the Invention] The present invention has been made in view of the above problems, and an object of the present invention is to greatly simplify and downsize a printing mechanism, and to achieve high-speed stamping. To provide a printing mechanism for a small printer. Another object is to provide a printing mechanism for a small-sized printer that is easy to control.

[Means for Solving the Problems] Type wheel holding means for holding and rotating two horizontally aligned type wheels, and a type wheel arranged on the inner peripheral side of the type wheel and pushing out the type wheel from the inner peripheral side 1 Two hammer means, a type wheel positioning means having a claw portion for rotatably holding the type wheel holding means, and an inclined cam portion for moving the type wheel positioning means up and down, the type wheel holding means, the hammer means and the type character. The wheel positioning means is mounted, and has a traveling means that travels along the platen, and a frame member that slidably supports the traveling means and that has a protrusion that engages with a claw portion of the type wheel positioning means. By the traveling of the printing means, the printing wheel positioning means is rotated by engaging the claw portion with the projection to raise or lower the inclined cam portion of the running means, and one of the printing wheels is selectively printed with the hammer means arranged. It is characterized by being placed in a position.

[Operation] Since the type wheel positioning means is positioned by raising or lowering the inclined cam portion of the traveling means by the projection, one of the two type wheels faces the hammer at a predetermined position of the traveling means.

[Embodiment] Therefore, an embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 shows an embodiment of the present invention. In the drawing, reference numeral 10 is a carriage which is guided by a guide rail 2 fixed to a printer frame and is mounted so as to be able to travel in the digit feeding direction. . A shaft 11 is integrally formed on the upper surface of the carriage 10, and two character wheels 13a and 13b for numbers and symbols are fixed to the upper end of the carriage 11 and a character wheel gear 12 is fixed to the lower end of the character wheel holder. The member 17 is loosely fitted.

The type ring gear 12 is meshed with two worms 30, 40 (FIG. 3) which are arranged parallel to the traveling direction of the carriage 10 and rotate in mutually opposite directions. Both worms 3
Type wheels 13a, 13b by rotating 0, 40
Performs rotation for type selection. Further, it is configured such that by stopping one of the worms 40, the carriage 10 is moved by the digit through the type ring gear 12, and by stopping the other worm 30, the carriage 10 is returned to the home position. There is.

By the way, reference numeral 18 in the figure denotes the above-described two type wheels 13
A plate-shaped shift lever loosely fitted between the type wheel holding member 17 and the type ring gear 12 in order to selectively shift a and 13b to the print position. Projections 21a, 2 extending radially as
1b is formed to project. Further, on its lower surface, projecting pieces with slopes 19 and 19 facing in mutually opposite directions are formed in a protruding manner. The shift lever 18 is provided on both sides of the shaft 11 formed on the carriage 10 with trapezoidal guides 22 and 22 having upward inclined surfaces 22a and top surfaces 22b opposite to each other. It is mounted via 19. The shift lever 18 is mounted on the carriage 10 so that the shift lever 18 can be rotated left and right by hitting the protrusions 21a and 21b against the protrusion 7 (FIG. 4) provided on the frame. Each time the carriage 10 passes through the protrusion 7, the shift lever 18 moves up and down while being guided by the guides 22, 22 according to the traveling direction of the carriage 10, and selectively shifts one of the two type wheels 13a, 13b to be described later. The hammer 24 is configured to be positioned at the installed printing position.

On the other hand, at one end of the carriage 10, as shown in FIG. 2, one hammer lever 23 extending inward from the upper part of the type wheel 13 or a shaft 25 formed integrally with the carriage 10 is rotatable. A hammer 24 is attached to the tip of the lever 23 of the shift lever 1.
It is fitted so that either one of the type wheels 13a and 13b positioned in 8 can rotate in the same plane, and its tip is formed on the back surface corresponding to the type wheel 15 on the type wheel 13a or 13b. It opposes the raised portion 16.
In addition, a shaft 27 extending outward at a right angle to the traveling direction of the carriage 10 is integrally formed on the hammer lever 23 in the vicinity of a shaft supporting portion for the carriage 10, and the swing lever 26 is centered on the shaft 27. It is mounted as a swingable. The traveling direction of the carriage 10 is the forward direction (second
In the left travel direction in the drawing), the teeth 5a of the rack 5 are
To engage the hammer lever 23 with the shaft 2 of the carriage 10.
Swing horizontally around 5. Printing is performed by pushing out the convex portion 16 provided on the type wheel 13a (or 13b). Further, in the reverse stroke (traveling stroke to the right in FIG. 2), the rocking lever 26 is provided with the slope 5 provided on the upper girder side of the tooth 5a.
Only the swing lever 26 swings up and down over the point b, and the hammer lever 23 is not pushed out.

In addition, reference numeral 29 in the drawing denotes an ink roller provided on the shift lever 18, reference numeral 50 in FIG. 3 denotes a motor which is a drive source of the printer of the present embodiment, and 60 denotes paper which meshes with the worm 40. A feed gear, 61 is a worm shaft frictionally fitted to the gear 60, 62 is a paper feed roller, and 63 is a platen. In the apparatus configured as described above, when one worm 30 is rotated and the other worm 40 is stopped, the carriage 10 is returned to the home position side from the upper girder side in the left direction in the drawing, One of the protrusions 21a formed in the direction perpendicular to the shift lever 18 hits the protrusion 7 on the frame provided immediately before the home position from the left side in the drawing,
The shift lever 18 is rotated clockwise in the drawing with the type wheel holding member 17 as a fulcrum (FIG. 4 (a)). Therefore, the shift lever 18 is guided by the upward slope 22 a of the guide 22 formed to project on the carriage 10, and the top surface 22 thereof is guided.
The type wheel 13 supported by being pushed up while rotating to b
Is moved up and the character type wheel 13b is positioned at the printing position of the mark Δ in the figure where the character type wheel 13a has been positioned up to that point ((b) in the figure).

In this state, the carriage 10 sequentially moves to the left in the drawing from the home position side while holding the character type wheel 13b at the printing position in order to print on the next line. At the stage of the digit, that is, at the next digit of the second or third digit where the symbol is printed in the normal recording, the other protrusion 21b protruding laterally of the shift lever 18 is the protrusion on the frame. 7, the shift lever 18 is rotated counterclockwise in the figure ((c) in the figure). As a result, the shift lever 18 moves to the guide 2
In order to prepare for the subsequent number printing, the character type wheel 13a is returned to the place where the character type wheel 13b was positioned while being guided by the slopes 22a of Nos. 2 and 22.

[Effects] As described above, according to the present invention, when the traveling means travels, the type wheel positioning means is rotated with the claw portion engaging with the protrusion, and the inclined cam portion of the traveling means is raised or lowered. By selectively positioning one of the printing wheels at the printing position where the hammer means is arranged, the predetermined printing wheel is automatically positioned at the printing position where the hammer means is placed only by the movement of the traveling means. No complicated control is required to select the type wheel, and it is possible to sufficiently control even low-performance integrated circuits used in desktop calculators and electronic registers.

In addition, since two type wheels can be arranged, it is possible to arrange the type characters in a plurality of type wheels in a printer that requires a large number of type characters, such as arranging numbers and symbols in each type wheel. It is possible to make the diameter of the ring as small as possible. The effect of the diameter of the type wheel on the external dimensions of the printer is reduced, and therefore the printer can be downsized.

Furthermore, since the characters arranged in one character ring are only symbols or numbers, the number of characters included in one character is halved, so the time required for character selection can be reduced.
There is an effect that a high-speed small printer can be obtained.

Furthermore, by setting the projection of the frame member that engages with the type wheel positioning means to any digit, the print digit of symbols and numbers can be set freely. For example, in the case of a small printer having 12 print digits, Generally, the setting is 2 digits for symbols and 10 digits for numbers, but it is possible to set 10 digits for symbols and 2 digits for numbers, and it is possible to sufficiently cope with new uses of a printer not limited to a desktop computer or an electronic register. .

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an apparatus showing an embodiment of the present invention. FIG. 2 is a top view of the type wheel mechanism. FIG. 3 is a side view of the same device shown in section. 4 (a) to 4 (c) are explanatory views showing the shift operation of the type wheel. 5 ... Rack, 10 ... Carriage 12 ... Type wheel gear 13a, 13b ... Type wheel 18 ... Shift lever 21a, 21b ... Protrusion 22 ... Guide 23 ... Hammer lever 24 ... Hammer 30, 40 ... … Worm

Claims (1)

[Claims] 1. A type wheel holding means for holding and rotating two horizontally overlapping type wheels, and one hammer arranged on the inner peripheral side of the type wheel and pushing out the type wheel from the inner peripheral side. Means, a type wheel positioning means for rotatably holding the type wheel holding means and having a claw portion, and an inclined cam part for moving the type wheel positioning means up and down, the type wheel holding means and the hammer means. And a frame member having the type wheel positioning means mounted thereon and traveling along a platen; and a frame member having a protrusion that slidably supports the traveling means and that engages with the claw portion of the type wheel positioning means. The type wheel positioning means is rotated by the claw portion engaging with the projection and is raised or lowered by the traveling cam of the traveling means to raise or lower the inclined cam portion of the traveling means. Select one of the above Print mechanism in small printer, characterized in that to position the arranged print position means.