JPS6120787A - Paper feeder - Google Patents

Abstract

PURPOSE:To obtain a paper feeding mechanism with a support shaft axially attached in a slit of a feeder lever and at the same time, its end axially attached to a shaft provided on a rotating disc so that a platen may rotate normally and reversely with the feeder lever by rotating the rotating disc normally and reversely. CONSTITUTION:If a motor rotates in an arrow direction A at a paper feed action command signal, a rotating disc 20 reverses and a feeder lever 27 which is axially attached to a pin 30 of the rotating disc 20 slides with its slit 28 guided by a support shaft 26 and engages with a rachet 13 having a pawl 29 which rotates with a platen 12 integrally. If the motor 19 rotates further, the pawl 29 feeds the rachet 13 by one tooth stroke and the feeder lever again separates from the ratchet 13. At that time, an actuator 25 is pushed up to the large diameter part of a detection cam 23 and a limit switch turns ON, then OFF. The pawl feed amount is controlled based on an ON-OFF signal of the switch. When paper feed is reversed, the motor 19 has only to be reversed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a paper feeding device for a printing device such as an electronic typewriter, and more particularly to a device for feeding a platen by pawing a ratchet wheel.

2. Description of the Related Art Structures and Problems Therein, in recent years, a large number of printing apparatuses whose printing operations are electronically controlled have appeared. These paper feeding devices generally connect a gear provided on a platen shaft to a motor provided with a rotation detection encoder via a reduction gear to rotate the platen and feed the paper. In addition, there is also a device that has a ratchet wheel on the platen shaft and uses a cam to move the platen back and forth.

A conventional paper feeding device will be described below with reference to the drawings. FIG. 1 is a side view of the main parts of a conventional paper feeding device, in which 1 is a platen, 2 is a platen shaft, 3 is a ratchet wheel engaged with the platen shaft 2, and 4 is a cam driven by a motor (not shown). ,
Reference numeral 5 denotes a rotating body pivotally connected to the platen shaft 2, and is biased by a spring 6 so that a cam follower portion 5a maintains contact with the cam 4. 7 is a ratchet pawl pivotally connected to a shaft 8 fixed to the rotating body 5; 9 is a spring that urges the ratchet pawl 7 to engage with the ratchet wheel 3;
Reference numeral 1o designates a switching member which rotates around the same rotation center as the rotating body 5 by a switching lever (not shown) and switches the engagement position between the ratchet pawl 7 and the ratchet wheel 3, and 11 a stopper.

The operation of the paper feeding device configured as above will be described below.

A carriage on which a printing mechanism is placed performs a printing operation while reciprocating parallel to a platen holding printing paper at an appropriate interval, and the platen is rotated every time one line of printing is completed to feed the paper. First, when the cam 4 is rotated by the driving force of the motor, the cam follower section 5 & is pushed, and the rotating body 5 rotates clockwise against the urging force of the spring 6. As the rotating body 6 rotates, the ratchet pawl 7 moves to the right and slides on the top surface of the switching member 1o, and when it is removed from the switching member 1o, the ratchet pawl 7 and the ratchet wheel 3 engage, and the rotating body 5 hits the stopper 11. The platen 1 rotates by feeding the claws until they touch each other.

The stroke by which the cam 4 drives the cam follower part 5a is equivalent to four teeth of the ratchet wheel 3, and the switching member 1o is arbitrarily rotated.
By running the ratchet pawl 7 idly, the feed amount can be changed to a total of three stages: 3-tooth feed and 2-tooth feed. If one tooth is set for 10 print lines, this corresponds to three stages: 2 lines, 1,000 lines, and 1 line advance.

However, in the above-mentioned configuration, a motor capable of feeding two lines per revolution of the cam 4 must be used, even though paper is normally fed line by line.

In addition, due to the cam-driven claw feed configuration, the platen 1 can only be rotated in one direction, and if the paper is fed too far, the platen 1 must be manually rotated in the opposite direction. There were also some complaints.

Purpose of the Invention The purpose of the present invention is to provide a compact and low power motor that can drive the vehicle.
Moreover, it is an object of the present invention to provide a paper feeding device that allows the platen to rotate in both forward and reverse directions.

Structure of the Invention The paper feeding device of the present invention includes a platen, a ratchet wheel engaged with the rotating shaft of the platen, a rotating body having a rotating shaft parallel to the rotating shaft of the platen, and the rotating body. A rotationally driven motor, a support shaft provided on a line connecting the rotation axis of the platen and the rotation axis of the rotating body, and the support shaft pivoted to an elongated hole provided at approximately the midpoint in the longitudinal direction, The middle point is used as a fulcrum, one end is provided with a claw that can engage with the claw mold, the other end is rotatably pivoted to a shaft provided on the rotating body, and the mold is rotated intermittently. and a feed rod that engages with the ratchet wheel to feed the platen with its claws.This makes it possible to use a small, low-power motor, and also enables forward and reverse rotation of the platen. be.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a side view of essential parts of a paper feeding device according to an embodiment of the present invention. In FIG. 2, reference numeral 12 is a platen that wraps printing paper (not shown) around it and feeds the paper by rotating itself.A printing mechanism (not shown) performs printing, and when the -line printing is completed, the platen 12 is rotated clockwise. and feed the paper. Reference numeral 13 denotes a ratchet wheel which is engaged with the rotating shaft 14 of the platen 12. The ratchet wheel 13 is engaged with a detent lever 17 which is biased by a torsion spring 16 with the shaft 15 as the rotating shaft, thereby preventing unnecessary rotation.

18 is a rotating shaft provided parallel to the platen shaft 14, 19 is a motor, and 2o is a rotating body. A pinion 21 and a gear 22 provided on the outer periphery of the rotating body 2o mesh with each other to increase and decelerate the driving force of the motor 19. The rotating body 20 is rotated about the rotating shaft 18. 23 is a detection cam that rotates in synchronization with the rotating body 20, and 24 is a limit switch that turns 0N-OFF by the operation of the actuator 26. As the detection cam 23 rotates, the actuator 25 moves up and down, turning the limit switch 24 to 0N.
-Turn it off and detect the rotation of the rotating body 2o.

26 is a support shaft provided on a line connecting the platen shaft 14 and the shaft 18 of the rotating body; 27 is a feed lever provided with an elongated hole portion 28 that is pivotally connected to the support shaft 26; A mating claw portion 29 is provided, and the other end is provided with a pin 3 implanted in the rotating body 2o.
It is rotatably pivoted at 0.

Regarding the paper feeding device of this embodiment configured as above,
The operation will be explained below.

FIG. 2 shows a state in which paper feeding is started. The bin 30 is at the farthest position from the platen shaft 14, and the claw portion 2e of the feed lever 27 is completely separated from the ratchet wheel 13. At this time, the limit switch 24 is in a position where the actuator 25 is not pushed up by the detection cam 23, and the limit switch 24 is in an OFF state. First, when a paper feed operation command signal is input from the printing device to a control means (not shown), the motor 19 starts rotating in the direction indicated by the arrow, and the rotating body 2o starts rotating in the direction opposite to the direction indicated by the arrow M.

Figure 3 shows that the rotating body 20 has a rotation angle of 160° from the state shown in Figure 2.
It shows the state of rotation. In this state, the feed lever 27
The elongated hole portion 28 slides while being guided by the support shaft 26, and the claw portion 2
9 is just before it engages with the ratchet wheel 13. At this time, the limit switch 24 is turned on when the rotation angle of the rotating body 20 is around 90°.
It becomes.

FIG. 4 shows a state in which the rotating body 2o has rotated by a rotation angle of 20o0. In this state, the claw portion 29 engages with the ratchet wheel 13 and moves the ratchet wheel 13 by one tooth in the opposite direction to the arrow mark. The limit switch 24 remains in the ON state. During pawl feeding, the detent lever 17 climbs over the top of one tooth of the ratchet wheel 13 and settles on the trough of the next tooth, thereby preventing unnecessary rotation of the ratchet wheel 13.

When the motor 19 continues to rotate further, the pawl portion 29 engages the pawl wheel 1.
Leave again from 3. When the rotation angle of the rotating body 2o reaches approximately 270 degrees, the actuator 25 of the limit switch 24 falls from the large radius surface frame of the detection cam 23 to the small surface.
The switch turns OFF.

A signal when the limit switch 24 is switched from ON to OFF is input to the control means. At this time, if the claw feeding is completed by the signal from the paper feed amount setting means, the input to the motor 9 is cut off, and the rotating body 2o rotates by inertia to the initial position shown in FIG. 2 and stops.

A slide switch (not shown) provided on the keyboard of the printing device for selecting the paper feed amount has three positions: 1 line, 1 ÷ line, and 2 line feed, and one of these three positions is set to 1 line feed. If this is the case, one tooth of the ratchet wheel 13 is reserved for ten rows, so it will be moved by two teeth.

The control means receives a paper feeding amount setting signal for one line feed from the slide switch, turns F two signals from the limit switch 24, and stops supplying drive current to the motor 9 at the same time as counting the second signal. At this time, since the motor 9 continues to rotate due to inertia, the control means supplies a brake current to the motor 19 so that it stops when the rotation angle of the rotating body 2o changes from 2700 to 3-600 degrees. Similarly,
When the slide switch is in the upward position by one, the control means counts three signals from the limit switch 24 and controls the motor 19 to advance the ratchet wheel 13 by three teeth. Similarly, when the slide switch is in the 2nd row position, the ratchet wheel 13 is moved by 4 teeth.

Further, when a paper feed operation signal for rotating the platen in the reverse direction is input to the control means, the motor 19 starts rotating in the opposite direction of the arrow mark 7. At this time, the rotating body 20 rotates in the direction of the arrow, and the claw portion 29 engages with the ratchet wheel 13 from the opposite side,
Rotate the platen in the opposite direction. Since the detection cam 23 is made symmetrically, the limit switch 24 is 0N-OFF.
The operation is performed in the same manner as when the platen rotates forward.

As described above, according to this embodiment, the feed lever 27 is operated so as to be able to rotate forwardly and reversely using the support shaft 26 provided on the line connecting the platen shaft 14 and the rotation shaft 18 of the rotating body as a fulcrum, and the ratchet wheel 13 By adopting a configuration in which the paper is fed with a claw, it is possible to realize a paper feeding device that can not only rotate forward as in the conventional case but also forward and reverse, and has a small motor and low power.

Effects of the Invention The paper feeding device of the present invention has an elongated hole provided at approximately the midpoint of the feed lever pivotally attached to a support shaft, and one end rotatably pivoted to a shaft provided on a rotating body. By rotating the feed lever in both forward and reverse directions, the claw provided at the other end of the feed lever is used to feed the ratchet wheel, which is locked to the platen shaft, in the forward and reverse directions. Unlike configurations where the platen cannot be sent,
The simple configuration allows the platen to be fed in both forward and reverse directions, and because it does not consume unnecessary power, the motor can be made smaller and have lower power, which reduces the size of the device. An excellent effect of realizing energy saving can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a side view of main parts of a conventional paper feeding device, FIG. 2 is a side view of main parts of a paper feeding device according to an embodiment of the present invention, FIGS.
This figure is a side view of a main part for explaining the operation of FIG. 2. 12...Platen, 13...Rawl wheel, 1
4...Platen shaft, 17...Detent lever, 19...Motor, 20...
Rotating body, 21...Pinion, 23...Detection cam, 24...Limit switch, 26...
...Spindle, 27...Feed lever, 28...Mountain/long hole section, 29...Claw section.

Claims (2)

[Claims] (1) A platen, a ratchet wheel engaged with the rotating shaft of the platen, a rotating body having a rotating shaft parallel to the rotating axis of the platen, a motor that rotationally drives the rotating body, and rotation of the platen. A support shaft provided on a line connecting the shaft and the rotation axis of the rotating body, and a long hole provided at approximately the midpoint in the longitudinal direction are pivotally connected to the support shaft, with the approximately midpoint serving as a fulcrum, and the claw is attached to one end. A pawl that can be engaged with the wheel is provided, the other end is rotatably pivoted to a shaft provided on the rotary body to rotate together with the rotary body, and the pawl is intermittently engaged with the ratchet wheel to generate the pawl. A paper feeding device comprising a feeding rod for feeding paper. (2) a rotation detector that generates a rotation signal in accordance with the rotation of the rotating body; a paper feed amount setting means that sets a paper feed amount that is an integral multiple of the teeth of the ratchet wheel; A paper feeding device according to claim 1, comprising control means for driving and controlling a motor in response to a generated paper feeding amount setting signal, a rotation signal from the rotation detector, and a paper feeding operation command signal. .