JP2551667Y2 - Paper thickness adjustment mechanism for electric stapler - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for adjusting the thickness of spelled paper in an electric stapler.

[0002]

2. Description of the Related Art Generally, a magazine containing a staple and a driver for hitting and a drive link disposed on both sides of the magazine are rotatably supported coaxially and driven by a cam or the like linked to an electric motor. In a spelling mechanism in which a driving link is actuated by means and a driver in a magazine is driven downward by the driving link and staples are driven into spelling paper, the leading end of the driven driver is stopped at the surface of the spelling paper. Is not always constant, the actual operating stroke of the drive link depends on the paper thickness. On the other hand, the drive stroke of a drive unit such as a cam for driving the drive link is always constant.
That is, when the paper is thick, the driver held by the drive link is stopped at the surface of the paper, and the drive link stops before the maximum operation stroke. Therefore, a paper thickness adjusting spring is provided to absorb the difference between the two strokes.

That is, in normal spelling, when the leg of the staple penetrating the paper hits the clincher groove and starts to bend (clinch), the working load applied to the drive link becomes maximum, and thereafter decreases sharply. For this reason, when the operation weight reaches the maximum clinch weight, the drive link cannot operate, and the operation amount of the drive means is absorbed by the bending of the adjusting spring. Then, when the spring load of the adjustment spring reaches the clinch load, the drive link is further driven by the spring force of the adjustment spring, and spelling is performed. However, once the leg of the staple is bent, the load applied to the drive link after that is sharply reduced, so that the drive link after reaching the clinch load is operated at once by the spring force of the adjusting spring that has reached the clinch load. Since the maximum clinch load varies,
The amount of deflection of the adjusting spring is considered to be as large as possible. Therefore, especially when the amount of deflection is large, the impact noise is also large.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a paper thickness adjusting mechanism in an electric stapler which can reduce an impact sound caused by a paper thickness adjusting spring.

[0005]

In order to achieve the above object, a paper thickness adjusting mechanism in the electric stapler according to the present invention is provided on a base frame so as to be rotatable in a vertical direction, and a pair of drive links are provided on both sides of the magazine. And a pair of drive links are integrally connected at the rear end, and the respective rear portions of the drive link and the magazine are rotatably supported on the base frame, and the front end of the drive link is connected to the front end of the magazine. A cam roller is rotatably supported on a roller shaft connecting the rear portions of the drive links on both sides, and a drive shaft provided in parallel with the roller shaft on the base frame includes a drive gear and an eccentric cam operatively connected to an electric motor. The eccentric cam and the cam roller are arranged side by side, and the cam roller is pressed by the rotated eccentric cam to lower the drive link. And a long hole is formed in the upper part of the drive link, and the roller shaft is loosely fitted in the long hole, and the roller shaft and the upper rear end of the drive link are separated by a paper thickness. When the drive link is at the upper end position, the roller shaft abuts on the rear end of the long hole, and the drive link operates downward so that the amount of deflection of the tension spring is a predetermined value. The roller shaft is set so as to contact the front end of the long hole when corresponding to a clinch load.

[0006]

According to the above construction, when the eccentric cam rotates, the force is transmitted to the roller shaft to operate the drive link. When the operating load of the drive link is equal to or less than the mounting load of the extension spring, the roller shaft is in contact with the rear end of the long hole of the drive link. Subsequently, when the driver starts clinching to bend the staple legs by penetrating the spell sheet on the spelling table, if the operating load of the drive link is significantly increased, the drive link cannot operate and stops. However, since the eccentric roller continues to press the roller shaft, the roller shaft moves forward through the long hole, and the tension spring expands. Then, the spelled sheet up to the set maximum thickness has its spring bent and reaches a predetermined clinch load before the roller shaft hits the front end of the long hole, and the drive link operates by the spring force. When the load exceeds a predetermined clinch load, the tension spring is bent and the roller shaft comes into contact with the front end of the elongated hole, so that the tension spring cannot be bent further. Instead, the roller shaft directly presses and drives the drive link, which in turn activates the driver to bend the staple legs to complete the spelling.

As described above, according to the present invention, since the tension spring does not bend more than a certain amount, it is possible to prevent an abnormally loud noise from being generated, and the operating environment of the electric stapler is improved.

[0008]

FIG. 1 shows an electric stapler. This electric stapler uses sheet staples in which straight staples are connected in a sheet shape. The magazine 2 on the base frame 1 is vertically rotated by an electric motor, and the staple cartridge 3 mounted on the magazine 2 at the time of vertical rotation. , The sheet-like staples are sent forward, and the sheet-like staples are formed into a U-shape in order from the leading staple, and are then struck toward the spelling base 4 at the front end of the base frame 1, and the staple legs are spelled on the spelling base 4 The paper 5 is penetrated and spelled.

[0009] As shown in FIG.
Erection pieces 1a, 1b on both sides of the central part and one side of the rear
Are formed. An electric motor 6 and an intermediate gear 7 linked to an output shaft thereof are provided on the rear standing piece 1b, and a drive shaft 8 penetrates an upper part of the central standing piece 1a. It is engaged with a drive gear 9 fixed to the section. An eccentric cam 10 fixed to the center of the drive shaft 8 is disposed between the two center standing pieces 1a, and the magazine 2 and a pair of drive links 11 disposed on both sides of the magazine 2 are connected to each other. Is provided. The rear ends of both drive links 11 are connected by a connection wall 11a.
The lower end of the rear end of the magazine 2 and a pair of drive links 11
The support shaft 15 passes through the shaft holes 12 and 13 at the rear lower end and the lower shaft hole 14 of the central standing piece 1a to rotatably support the magazine 2 and the drive link 11. A roller shaft 17 is supported by the drive link 11, and a cam roller 18 is rotatably supported on the roller shaft 17. The cam roller 18 is provided in parallel with the eccentric cam 10, and the cam roller 1
8 and the eccentric cam 10 are covered with a cam cover 19, and the cam roller 18 and the eccentric cam 10
Are connected by

Next, the front ends of the two drive links 11 are connected by a connecting shaft 21 (see FIG. 1).
The connecting shaft 21 penetrates a projecting piece 23 on the front surface of a driver 22 (see FIG. 3) disposed at the front of the magazine 2. The position where the lower surface of the front end of the magazine 2 contacts the spelling table 4 of the base frame 1 and the position where the protrusion 24 formed laterally from the lower end of the magazine 2 engages the curved arm 25 formed on the base frame 1. Is the rotation range of the magazine 2. The driver 22 is configured to move up and down relatively to the magazine 2.

In the above configuration, when the electric motor 6 is operated, its output is transmitted from the intermediate gear 7 to the drive gear 9 to rotate the drive shaft 8, so that the eccentric cam 10 rotates. Accordingly, when the eccentric cam 10 rotates from the state of FIG. 3 as shown in FIG. 5 and the outer peripheral surface thereof presses the outer peripheral surface of the cam roller 18, the cam roller 18 is moved away from the drive shaft 8 of the eccentric cam 10. When the magazine 2 is pushed out and the magazine 2 is rotated downward, on the contrary, when the outer peripheral surface of the eccentric cam 10 tries to move away from the outer peripheral surface of the cam roller 18, the cam roller 18 is pulled back by the cam cover 19 so as to approach the drive shaft 8. Therefore, the magazine 2 is driven to rotate upward, and the drive link 11 returns without fail.

As described above, when the drive link 11 is driven in the up-down direction, the driver 22 also moves up and down. However, the magazine 2 follows this due to frictional resistance with the surroundings, so that the magazine 2 also turns up and down. I do. The magazine 2 also moves downward with the downward movement of the driver 22, but the lower surface of the front end of the magazine 2 comes into contact with the upper surface of the spelling paper 5 and stops (see FIG. 4).
On the other hand, the drive link 11 and the driver 22 further continue to move downward, so that the staples 27 supplied to the ejection section 26 at the front of the magazine 2 are ejected toward the spelling table 4, and the legs of the staples 27 are placed on the spelling table 4. The spelling paper 5 is penetrated and spelled.

Since the thickness of the spelling sheet 5 is not always constant, the electric stapler is provided with a sheet thickness adjusting mechanism described below.

First, as shown in FIGS. 2 and 3, the roller shaft 17 of the cam roller 18 is loosely fitted in a long hole 28 formed in the upper part of the drive link 11 and extending substantially forward and backward. Further, the roller shaft 17 and an engagement piece 29 formed at a position behind the elongated hole 28 of the drive link 11 are connected by a tension spring 30 for adjusting the paper thickness. When the drive link 11 is at the upper end position, the roller shaft 17
Abuts against the rear end of the elongated hole 28, and when the tension spring 30 bends when the drive link 11 responds to a predetermined clinch load applied when the drive link 11 operates downward, the roller shaft 17 is elongated. 28 is formed so as to contact the front end. The clinch load is set to the maximum value of the spelling load of the maximum spellable sheet thickness in a normal case.

According to the paper thickness adjusting mechanism, the eccentric cam 10
Is rotated, the force is transmitted to the roller shaft 17 and the drive link 11 is operated. When the operation load of the drive link 11 is equal to or less than the attachment load of the extension spring 30, the roller shaft 17 is in a state of contact with the rear end of the long hole 28 of the drive link 11. Subsequently, when the driver 22 starts clinching to bend the staple legs by penetrating the stencil sheet 5 on the spelling base 4 and the operating load of the drive link 11 increases significantly, the drive link 11 cannot operate. Stop (see FIG. 4). However, since the eccentric cam 10 keeps pressing the roller shaft 17, the roller shaft 17 moves forward through the long hole 28, and the extension spring 30 is bent and extended. Then, the spring of the spelling sheet 5 up to the set maximum thickness is bent, and the roller shaft 17 reaches a predetermined clinch load before or before the front end of the long hole 28, and the drive link 11 is operated by the spring force. However, when the load exceeds a predetermined clinch load, the spring bends and the roller shaft 17 comes into contact with the front end of the elongated hole 28, so that the spring cannot be bent further. Instead, as shown in FIG. 5, the roller shaft 17 directly presses and drives the drive link 11, and the drive link 11 activates the driver 22 to bend the staple legs 27 to complete the spelling. As described above, since the tension spring 30 does not bend more than the predetermined amount of bending L shown in the figure, abnormally loud noise is not generated.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an electric stapler according to the present invention.

FIG. 2 is an exploded perspective view of a magazine, a drive link, and a base frame of the electric stapler.

FIG. 3 is a side view of an outline of a main part of the electric stapler in a spelling operation start state.

FIG. 4 is a side view of an outline of main parts in an operating state of the electric stapler during spelling.

FIG. 5 is a side view of an outline of a main part when the staple of the electric stapler is completed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base frame 2 Magazine 5 Spell paper 6 Electric motor 10 Eccentric cam 11 Drive link 17 Roller shaft 18 Cam roller 22 Driver 28 Slot 28 Tension spring

Claims (1)

(57) [Scope of request for utility model registration] 1. A pair of drive links are provided on a base frame so as to be rotatable in a vertical direction on both sides of a magazine, and the pair of drive links are integrally coupled at a rear end. The rear part is rotatably supported on the base frame, the front end of the drive link is connected to the front end of the magazine, and the cam roller is rotatably supported on a roller shaft connecting the rear parts of the drive links on both sides. A drive gear and an eccentric cam operatively connected to an electric motor are fixed to a drive shaft provided in parallel with the roller shaft, and the eccentric cam and the cam roller are arranged side by side, and the cam roller is rotated by the rotated eccentric cam. The drive link is pressed down to drive the drive link downward, and a long slot is formed in the upper portion of the drive link substantially in the front and rear direction. The roller shaft and the upper rear end of the drive link are connected by a tension spring for adjusting the paper thickness, and when the drive link is at the upper end position, the roller shaft is positioned behind the slot. The roller shaft contacts the front end of the elongated hole when the drive link operates downward and the amount of deflection of the tension spring corresponds to a predetermined clinch load. Paper thickness adjustment mechanism for electric stapler.