JPS5913995B2 - printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Linep 5 printer that is most suitable as a recording output machine for small-sized office equipment such as calculators or electronic cash registers.

Conventionally, a typical line printer of this kind is one in which a plurality of hammers each aim at the type on a continuously rotating type drum, and each hammer has a trigger lever that responds to the print 10 signal. The actuator of the electromagnetic solenoid, which is activated by the arrival of the drum, moves it within the rotation trajectory of the pawl of the ratchet wheel, which is continuously rotating, and the pawl applies a sudden striking force, thereby elastically driving it in the direction of the type drum. one or more than one
5 type wheels were provided, and the type wheels on each type wheel could be selected and stopped individually and printed all at once using a common hammer, or the type wheels that had been selected and stopped could be pressed against the platen to print. There are things etc.

However, although these zero-marking devices have almost reached the desired level in terms of printing speed, they have a complex structure and a large number of parts, and are still unsatisfactory in terms of maintenance, inspection, and economic efficiency. In recent years, these 25 types of small office equipment have become rapidly popular and become cheaper.
Its shortcomings had become impossible to overlook. For this reason, a line printer has recently been invented that has a simple structure, has a small number of parts, and is sufficiently satisfactory in terms of maintenance, inspection, and economy, and has filed an application as Japanese Patent Application No. 51-134772. 30 Therefore, the present invention is to provide a printer that can maintain stable printing operation over a long period of time by further improving the printer described in the above-mentioned application.

Hereinafter, an embodiment will be described in which the present invention is applied to a line 35 printer that uses one electromagnetic solenoid to control the driving of two print hammers.

In the drawing, reference numeral 1 denotes a machine frame, on which a type drum 2 made of an elastic material such as hard rubber is installed horizontally to allow one rotation. Type letters 3 are engraved, and each digit has a plurality of said type letters 3, and as can be seen from FIG. 2, the letters 3 in adjacent digits are arranged in a staggered manner. has been done.

Reference numeral 4 denotes an ink roller, which is installed on the machine frame 1 and normally comes into pressure contact with the type drum 2, and is rotated by the friction thereof to apply ink to the type characters 3.

Reference numeral 5 denotes a leaf spring formed by cutting a single spring material board to the same number as the number of digits mentioned above, and the common side portion 5a of these J is integrated into a base 6 made of synthetic resin by insert molding, and the base It is supported by the machine frame 1 via a stand 6.

Print hammers 8 made of synthetic resin are inserted into the free end of each of these leaf springs 5 facing the type drum 2, facing each digit position of the type drum 2 with a printing paper 7 interposed therebetween, and arranged in the direction of the digits. The printing hammers 8 are integrally supported by the formation, so that the printing hammers 8 are independently biased to move toward the printing position. 9 is the same number of first leaf springs as the number of digits, ClO is a second leaf spring facing each of these first leaf springs 9, and both of these are made by cutting a single spring material board. The base ends of the common sides are connected to a support column 11 made of synthetic resin by insert molding, and the support column 11 is horizontally installed on the machine frame 1.

As a result of this configuration, the first spring 9 and the second spring 10 form a set of leaf springs, and the same number of leaf springs as the print hammers 8 are provided.
The free ends of the first leaf spring 9 and the second leaf spring 10 are bent into a semicircular shape so as to be able to sandwich one print hammer 8 from above and below, so that the respective free ends 9a and 10a are printed. Engagement stepped portion 8a of hammer 8
, 8b. Here, one engagement step 8a of the print hammer 8 corresponding to the first leaf spring 9 is a simple vertical surface, while the other engagement step 18b is particularly shown in FIG. As understood from A, it projects in the printing position direction, and its projecting end surface is formed in a semicircular shape that is substantially the same as the shape of the tip portion 10a of the second leaf spring 10. 12 is a first cam group consisting of a plurality of eccentric cams 12a located between the first and second leaf springs 9 and 10, respectively, and corresponding to the girders;
Each of these eccentric cams 12a elastically moves the first and second leaf springs 9 and 10 in the vertical direction alternately as it rotates, and engages the engagement stepped portions 8a and 10a of the print hammer 8 with their tips 9a and 10a. Each eccentric cam 1 is designed to alternately release the engagement between each eccentric cam 1 and 8b.
2a are set such that their eccentric directions are opposite to each other so that adjacent ones have a phase difference of 180 degrees.

Reference numeral 13 denotes a second cam group consisting of 14 eccentric cams 13a that can come into contact with the intermediate portions of the leaf springs 5 corresponding to each digit,
With the rotation of these eccentric cams 13a, the print hammer 8 is forcibly returned from the printing position to the rest position against the spring force of the leaf spring 5. In particular, the return action is effective against the spring force of the leaf spring 5. In order to perform the rotation in opposite phases, the eccentric cams 13a are set so that their eccentric directions are opposite to each other so that adjacent eccentric cams 13a have a phase difference of 180 degrees. ing.

14 is one set of leaf springs 9, 10 forming the pair.
and the other set of leaf springs 9 and 10 adjacent to each other in a digit-corresponding manner. Two solenoid cores 1
6, and each of the 14 solenoid cores 16 is a synthetic resin-made solenoid core 16 installed upright on a printed circuit board 17 disposed on the machine frame 1 at a position facing each of the second leaf springs 10 below. The engagement pieces 18 are held by engagement means so as to be arranged in the digit direction.

Reference numeral 19 denotes a print guard disposed in the machine frame 1 so as to substantially surround the type drum 2 and ink roller 4 to prevent printing paper from becoming dirty; 20 indicates the print guard so as to form a paper guide path 21 for guiding the printing paper 7; 19, and an opening 22, at a position facing each of the type drum 2 and the print hammer 8.
23 is formed.

24 is a rubber paper feed roller, 25 is a drive motor,
This serves as a driving source for the type drum 2, the first cam group 12, the second cam group 13, and the paper feed roller 24.

In the above, the type drum 2, the first and second cam groups 1
2 and 13 are constantly rotated, and the first cam group 1
2 and the second cam group 13 have the same rotational speed, and the time required for one rotation of the first cam group 12 is equal to the time required for one rotation of the first cam group 13. It is set to be the same as the time required to travel in minutes. Next, the printing operation of the line printer having the above configuration will be explained using → digit as an example.

That is, as the eccentric cam 12a of the first cam group 12 rotates, the first leaf spring 9 and the second leaf spring 10, which is in a pair of relationship opposite to the first leaf spring 9, rotate their tip portions 9a, 10a. Engagement stepped portion 8a of print hammer 8,
8b and the operation of alternately releasing the engaged state as shown in FIGS. 3A and 3B are repeated. As long as these three states are repeated, the print hammer 8 is held at the rest position. The print signal is synchronized with the eccentric cam 12a, and is delivered to the electromagnetic solenoid 14 when the second leaf spring 10 is pressed downward, ie, to the disengaged position, by the eccentric cam 12a as shown in FIG. The solenoid 14 attracts the pressed second leaf spring 10 with its solenoid core 16 and holds it in the disengaged position. In this held state, the first leaf spring 9 is moved upward by the continued rotation of the eccentric cam 12a, and the tip end 9a of the first leaf spring 9 is moved upward.
is disengaged from the engagement stepped portion 8a of the print hammer 8. Then, the print hammer 8 is rapidly moved onto the type drum 2 by the spring force of the leaf spring 5, and strikes a predetermined type 3 through the printing paper 7 to perform printing. The eccentric cam 13a of the second cam group 13 is sufficiently far away from the leaf spring 5 immediately before the above-described hitting action of the print hammer 8 is performed. After the above-mentioned hitting action is completed, the eccentric cam 13a moves the print hammer 8 against the spring force of the leaf spring 5.
, the tip portions 9 of both leaf springs 9, 10 whose opposing distance has already been restored to the minimum due to the rotation of the eccentric cam 12a.
The print hammer 8 is forcibly moved from the print position to the print body stop position so as to be inserted between the two leaf springs 9 and 10a.
The engagement with each tip portion 9a, 10a of 0 is restored and preparations are made for the next printing operation. The same printing operation as above is performed for multiple digits, but in that case, the printing operation is performed for the digits that are in the preceding phase relationship, and then the printing operation is performed for the digits that are in the opposite phase relationship. After one line of printing is performed, the printing paper 7 is fed by one line.
In the line printer as described above, the engagement operation (or disengagement operation) between the tip portions 9a and 10a of the first and second leaf springs 9 and 10 and the engagement step portions 8a and 8b of the print hammer 8 is performed. changes from the state shown in FIG. 3A to the state shown in FIG. 3B, and vice versa.
A case will be considered in which the rotation is performed alternately as the eccentric cams 12a of the first cam group 12 rotate.

That is, considering the state transformation from A to B in Figure 3, first,
As the eccentric cam 12a rotates in the direction of the arrow in FIG. At this moment, the print hammer 8 receives a moving force in the direction of arrow 26 (printing direction) due to the action of the leaf spring 5 and engages with the inner surface of the tip 10a. The outer surface of the connecting step portion 8b collides with the outer surface of the connecting step portion 8b, resulting in a state of surface engagement. Since such a collision occurs between surfaces as described above, the phenomenon in which the tip 10b of the second leaf spring 10 gradually scrapes off the material of the print hammer 8 due to the collision as described above is prevented. Ru. Next, considering the change from the state shown in FIG. Tip part 10 of second leaf spring 10
a is disengaged from the other engagement step 8b, but in this disengagement process, the second leaf spring 10 is disengaged from the other engagement step 8b.
As it moves downward while drawing an arcuate locus as shown by the arrow 27 in the middle, the inner surface of the tip 10a and the arcuate surface of the engaging stepped portion 8b gradually rotate with relative rotation in a state of surface contact. Disengaged. Therefore, since surface contact rotation and sliding is also used in this case, the engaging step portion 8b is prevented from being scraped off by the tip portion 10b of the second leaf spring 10. Therefore, even if the alternating disengagement operation between the print hammer 8 and both leaf springs 9 and 10 is repeated at high speed and for a long time, the engagement stepped portion 8b of the print hammer 8 will be deformed and printing will not be possible. It is possible to reliably prevent a decrease in the accuracy of operation, and to maintain stable printing operation over a long period of time. As described above, the present invention includes a print hammer to which a biasing force is applied to move the print hammer to a printing position, and each free end of the print hammer is engageable, and both have the function of holding the print hammer in a rest position. two leaf springs; a first cam for alternately disengaging each free end of the two leaf springs from the print hammer; and actuation by a printing command synchronized with the operation of the cam. an electromagnetic solenoid for maintaining the print hammer and one of the two rigid leaf springs in a disengaged state at least until the cam disengages the other leaf spring; and the cam and the electromagnetic solenoid. and a second cam for forcibly returning the print hammer, which has been moved to the printing position by disengaging the two leaf springs from each other, to the rest position. The shape of at least one free end is approximately the same as the shape of the engaging portion of the print hammer, and the two are configured to engage face-to-face, so that the engaging portion of the print hammer is deformed by the scraping action of the leaf spring. Therefore, it is possible to provide a printer that can maintain stable printing operation over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a vertical side view of a line printer according to an embodiment of the present invention, FIG. 2 is an exploded perspective view thereof, and FIGS. 3A and B are side views of one digit of the main parts showing different operating states. It is a diagram. In the drawing, 2 is to the type drive, 3 is the type, 5 is the leaf spring, 7 is the printing paper, 8 is the print hammer, 8a, 8b are the engagement steps, 9 is the first leaf spring, 10 is the second leaf 12 is a first cam group, 13 is a second cam group, 14 is an electromagnetic solenoid, 15 is an electromagnetic coil, and 16 is a solenoid core.

Claims (1)

[Claims] 1 a print hammer to which a biasing force is applied to move the print hammer to the printing position; two leaf springs each having a free end engageable with the print hammer and both having the function of holding the print hammer in a rest position; a first cam for alternately disengaging each free end of the two leaf springs from the print hammer; an electromagnetic solenoid for maintaining a disengaged state with one of the leaf springs at least until the cam disengages the other leaf spring;
A printer comprising: a second cam for forcibly returning the print hammer, which has been moved to a printing position by disengaging both of the two leaf springs by the cam and an electromagnetic solenoid, to a rest position; A printer characterized in that the shape of at least one free end of the leaf spring is substantially the same as the shape of the engaging portion of the print hammer, so that the two are surface-engaged.