JPS59179367A - Brake device for printer - Google Patents

Abstract

PURPOSE:To greatly raise braking performance, shorten the time of stoppage, and increase the speed of printing by making braking operation by means of an operating cam turning given times every one printing cycle. CONSTITUTION:A brake shoe 54 made of an elastic metal plate is provided to a cam follower 46 in such a way that its braking face is faced a brake drum 56 fixed to a reset cam shaft. When a printing section is ended, a motor signal V becomes a high level, transistors T3 and T1 go OFF, a transistor T2 turns ON, a motor circuit is shortcircuited, and the motor is braked by counter electromotive force. The cam follower 46 is turned by the cam 48, each hammer is retracted by a retracting cam 42, and at the same time the brake drum 56 is pressingly touched by the brake shoe 54 to brake and stop the motor 8 quickly.

Description

[Detailed description of the invention] be.

Various printers are used as output devices for information processing devices, calculators, and the like. Among these printers, the printing operation is stopped at the end of each printing cycle or each line of printing cycle, and operations such as paper feeding are performed during that time, and the printer is restarted to print the next cycle. I have an intermittent printer that starts up. In this type of printer, it is necessary to stop the operating parts such as the platen or type draught in a predetermined position in a short period of time in order to increase the printing speed. Conventionally, the motor drive circuit was short-circuited and the back electromotive force was used to brake the motor and stop it, but this method had a limit on the amount of time it could stop, which hindered the ability to increase printing speed.

The present invention aims to solve the above-mentioned problems and provide a device that can quickly stop operation.

In accordance with this objective, the device according to the invention provides for an intermittent start-up printer that performs a series of printing operations in one printing cycle.
An operating cam that rotates a predetermined amount in one print cycle, a cam follower that follows the operating cam, a brake seat formed on the cam follower, and a brake drum that faces the brake shoe and is driven by a motor and is provided on a shaft. - The actuating cam is configured to press the brake shoe against the brake drum at a predetermined timing at the end of a printing cycle to apply braking.

1 and 2, a type drum 10 is continuously rotated during a printing cycle by a drive motor 8 (FIG. 3) and has a plurality of type characters formed on its outer periphery. 10a passes through the printing position in a predetermined order. A plurality of digits of hammers 12 are arranged in alignment facing the printing position of the type drum 10, and a recording paper 14 and an ink ribbon 16 are inserted between the type drum 10 and the hammers 12. Each number 12 has a shaft 12e.
are rotatably supported by the springs 18 and 18 respectively.
is constantly urged toward the type drum 10, and the other end of the nozzle rests against an armature 38, which will be described later.

The hammer 12 is pressed against the spring 18 to move the type drum 1
A reset cam 20 is provided to move the character drum 10 away from 0 and into a print standby state, and to rotate the character drum 20 in synchronization with the character drum 10, the rotational driving force of the character drum 10 is generated by the gear 22, pinion 24, and gear 26. and is transmitted to the reset camshaft 60 via the pinion 28. A type detection plate 32 is fixed to the side surface of the gear 22, and a detection contact 64 provided near the type detection plate 62 detects the position of the type on the type drum 10.

The type arrangement is such that three-digit hammers 12 are controlled by one electromagnetic means, and each type is arranged with a pitch shifted by 73 lines in the row direction within a type set of every three digits, and the type The detection plate 62 also has a detection pattern corresponding to this 1/3 type hit deviation, and the reset camshaft 60 is set so that one rotation of the reset camshaft 60 corresponds to one character pitch of the type drum 10.

The reset cam 20 has 3 digits every 3 digits in the circumferential direction.
When the resent portions come into contact with the hammer 12, the hammer 12 is moved against the urging spring 18 to a printing standby state away from the type drum 10. During printing, when the shoulder portion 12a of the hammer falls into the depressed portion 20bK of the reset cam 20, printing is performed as will be described later.

A holding arm 12b is formed at one end of the hammer 12, and the holding arm 12b engages with an armature 68 of an electromagnet 66 to hold the hammer 12 in a printing standby state. The armature arrow 8 is always urged clockwise in FIG. 2 by the spring 40, and its tip can engage with the holding arm 12b of the hammer 12. The armature 38 engages three adjacent hammers 12 at the same time, and can select which hammer 12 will be used for printing by both the armature arrow 8 and the set cam 20.

A retraction cam 42 is provided near the hammer 12 so as to be rotatable by a shaft 44, and all the hammers 12 are connected to the retraction cam 42.
It is designed so that it can be rotated to the retracted state at the same time. A cam follower 46 is fixed at one end to the shaft 44 of the retraction cam 42, and the cam follower 46 engages with an operating cam 48 fixed to one end of the type drum 10 by a spring 47. The actuating cam 48 rotates the retracting cam 42 via the cam follower 46 for each rotation, that is, for each printing cycle, and the retracting action is performed for each printing cycle until the printed object is stopped.

In order to hold the hammer 12 in both the printing standby state and the retracted state, the holding arm 12b of the hammer 12 is provided with a first holding step 50 and a second holding step 52. The first holding stage 50 shallowly holds the hammer 12 in a print standby state, while the second holding stage 52 holds the hammer 12 in a deep retracted state, and by holding the hammer 12 in the deep retracted state, the state shown in FIG. As shown, the hammer 12 is completely spaced apart from the reset cam 20.

According to the present invention, the cam follower 46 is provided with a brake shoe 54 made of an elastic metal plate, and the brake shoe 54 faces the brake drum 56 fixed to the reset camshaft 30.

FIG. 3 shows the starting and quick stopping circuit of the drive motor 8,
The drive circuit of the motor 8 is connected to the output terminals of complementary connected PNP and NPN transistors T, , T2, and the output terminal of the PNP l-transistor T is connected to the input terminal.

The operation of this device will be explained below.

FIG. 4 shows a timing chart, in which the print command P causes the motor control signal ■ to go to a low level. As a result, the transistors T3 and T shown in FIG. 3 are turned on, T2 is turned off, and the motor 8 is started. After this, the required electromagnet 66 is activated at the required time by the reset cam pulse RP and character pulse CP obtained from the detection contact 64, and the magnet is released and printing is performed. When the printing section ends, the motor signal (2) becomes high level, transistors T8 and T are turned off and T2 is turned on, the motor circuit is short-circuited, and the motor is braked by the back electromotive force. Subsequently, the cam follower 46 is rotated by the cam 48, and the retracting cam 42 (7) retracts each hammer.At the same time, the brake shoe 5
4 is in pressure contact with the brake drum 56 as shown in FIG.
Apply the brakes. Therefore, the motor 8 rapidly decelerates and stops.

As is clear from the above description, according to the present invention, since braking is eliminated by the actuating cam that rotates a predetermined amount in one printing cycle, the braking ability can be greatly increased, the stopping time can be shortened, and the printing speed can be increased. be able to.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention, Fig. 2 is a side view of the same, Fig. 3 is a motor drive circuit diagram, Fig. 4 is an operation timing chart, and Figs. 5 and 6 are FIG. 2 is a side view showing essential parts of the present invention. 8...Motor, 10...Type drum, 12...
- Hammer, 20... Reset cam, 66
・・Electromagnet, 42・・Retraction cam, 46・・Cam follower, 48・・・Activating cam, 54・・・・
Brake shoe, 41 73 questions 740 RP f -JL-,. CPM■…” ■Saturday and Sunday 54 years old 60 420-

Claims (2)

[Claims] (1) - In an intermittent start-up printer that performs a series of printing operations in a printing cycle, - an operating cam that rotates a predetermined amount in a printing cycle, a cam follower that follows the operating cam, and a brake shoe formed on the cam follower; It consists of a brake drum provided on a shaft facing the brake shoe and driven by a motor, and is configured to apply braking by pressing the brake shoe against the brake drum by the actuating cam at a predetermined timing at the end of the printing cycle. A printer braking device characterized by: (2) A braking device for a printer according to claim 1, further comprising an electric braking circuit that short-circuits a motor drive circuit.