JP3536654B2 - Staple forming mechanism for electric stapler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a staple forming mechanism for forming a straight staple into a U-shaped staple by a forming plate.

[0002]

2. Description of the Related Art In general, in an electric stapler, a sheet-like staple formed by connecting straight staples in a sheet form is used so that as many staples as possible can be continuously punched out. And then punching out after forming into a U-shape sequentially. As shown in FIG. 5, the staples are formed by projecting pieces 3 formed at the upper and lower ends of the needle passage end of the sheet-like staple.
When the leading staple 32 is fed to 0 and 31, the forming plate 33 is driven downward to push both sides of the staple 32 and to bend it into a U-shape.

[0003]

However, since the staples 32 are made of metal, when the both sides of the staples 32 are pressed downward by the forming plate 33 during molding, the central portion is lifted, and thus the upper convex piece is formed. 30 is also pushed up as shown in FIG. For this reason, the central portion of the staple 32 is bent upward, and the staple 32 is not easily squared by the forming plate 33. Therefore, the springback is easy to work after molding, and the leg part is slightly returned from the bent state, so the angle between the crown part and the leg part should be a right angle, but it will be obtuse as shown in the figure. In some cases, poor driving of the material to be sewn occurs.

[0004] On the other hand, it is conceivable to narrow the needle passage in advance, but if the needle passage is narrow, there is a problem that sheet-like staples are jammed inside the needle passage and feeding failure occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a staple forming mechanism for an electric stapler capable of forming staples having extremely small springback by solving the above problems.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, a staple forming mechanism for an electric stapler according to the present invention comprises a staple passage for feeding sheet staples formed by connecting straight staples in a sheet form. A forming plate and a driver driven by a motor are arranged above the tip of the needle, and forming is performed when the leading staple is fed into upper and lower convex pieces projecting forward from the center of the upper and lower ends of the needle path. By driving the plate downward by a motor, pressing both sides of the staple needle protruding from the convex piece and bending it into a U-shape to form staples,
Then, in an electric stapler in which a formed staple is driven toward a material to be sewn by a driver, when the forming plate is operated downward on the convex piece, the upper convex piece is pushed down in conjunction with this to push up and down the upper convex piece. A pusher for pressing the sheet staple in the piece was arranged.

[0007]

FIG. 1 is a perspective view of a main part of an electric stapler, wherein reference numeral 1 denotes a cartridge, and 2 denotes a drive link. The cartridge 1 has a storage section for storing roll-shaped staples formed by connecting straight staples in a roll form, and derives the outermost roll-shaped staples from this storage section and supplies them to the spelling section (front end). And a needle passage 4 is provided. As shown in FIG. 2, the needle passage 4 is formed between an upper guide plate 4a for guiding the upper surface of the staple and a lower guide plate 4b for guiding the lower surface. A vertical face plate 5 is arranged at the front end of the needle passage 4 so as to oppose the spelling portion. As shown in FIG. 2, convex pieces 6a and 6b protrude forward from the center of the distal ends of the upper guide plate 4a and the lower guide plate 4b of the needle passage 4.

Although not shown, a base (not shown) is provided at the lower portion of the cartridge 1, and a spelling table on which a material 8 to be sewn is placed is provided at the front end of the base.

A forming plate 9 and a driver 10 are arranged above the spelling portion. As shown in FIG. 3, a pair of holding pieces 11 are formed to protrude forward from the upper center of the forming plate 9, and the driver 10 is engaged with and held by the holding pieces 11. Engaging pieces 12 are formed on both side ends of the forming plate 9, and a shaft 13 is inserted into the engaging pieces 12. The shaft 13 is linked to the drive link 2, and the drive link 2 is further driven by a motor. It is configured to swing around the support shaft 14 as a fulcrum.
Therefore, when the motor is operated, the drive link 2 swings, and in conjunction with this, the forming plate 9 and the driver 10 are driven vertically.

By the way, a pusher 15 is arranged on the convex pieces 6a and 6b. The pusher 15 is interlocked with the forming plate 9, and is linked to a shaft 13 that is engaged with the forming plate 9 via a forming support plate 16. That is, the pusher 1
5 has a pressing piece 18 protruding forward at the bottom,
A pair of shaft holes 19 and 20 are formed in the upper and lower portions, and shafts 21 and 22 penetrate the shaft holes 19 and 20, respectively. A guide groove 23 is formed in the front part of the forming support plate 16 in a vertical direction, and the guide groove 23 is engaged with both sides of the shaft 13 of the forming plate 9. In the rear part of the forming support plate 16, two upper and lower engagement holes 24 and 25 are formed.
The shafts 21 and 22 of the pusher 15 are engaged with 4 and 25, respectively. Before the spelling operation, the pressing piece 18 of the pusher 15
Are configured not to press the upper surface of the upper guide plate 4a of the needle passage 4.

In the above configuration, when the feeding means 7 is operated to feed the rolled staples 3 forward along the inside of the needle passage 4, the leading staple contacts the back surface of the face plate 5 and stops. At this time, the leading staple 3a is located between the upper and lower convex pieces 6a and 6b of the needle path 4 as shown in FIG. 4 (a). Then, when the drive link 2 of FIG. 1 is operated by the motor, the forming plate 9 and the driver 10 are driven downward. When the forming plate 9 is operated downward, as shown in FIG. 4 (a), the staple 3a comes into contact with the upper surface of the portion protruding from both sides of the projections 6a, 6b of the leading staple 3a.
The both sides of a are bent downward. When the forming plate 9 moves further downward and the shaft 13 shown in FIG. 1 reaches the lower end of the guide groove 23 of the forming support plate 16, the forming support plate 16 is forcibly moved downward together with the forming plate 9. When the forming support plate 16 moves downward, the pressing piece 18 presses the upper guide plate 4a of the needle passage 4 downward as shown in FIG. For this reason, the needle passage 4 becomes narrower, and the central portion of the leading staple is strongly pressed from above and below by the projection 6a of the upper guide plate 4a and the projection 6b of the lower guide plate 4b. When both sides of the staple 3a are bent in this state, the crown 26 and the leg 27 are bent.
And the squaring is performed reliably.

When the forming plate 9 moves upward after bending, the U-shaped staple is pushed into the concave groove 28 at the center of the face plate 5 shown in FIG. Next, the forming plate 9 and the driver 1
0 is driven downward, the forming plate 9
Molds the staple needle that has newly become the top into a U-shape,
The driver 10 plate strikes the formed staples in the grooves 28 toward the material to be sewn 8 arranged below the cartridge 1.

As described above, when the forming plate 9 is operated downward, the pusher 15 pushes down the upper convex portion of the needle passage 4 in conjunction with this operation, and the upper and lower convex portions 6a, 6b
Since the central portion of the leading staple 3a is pressed, the central portion is prevented from curving upward when the forming plate 9 bends both sides of the staple 3a. For this reason, since the crown 26 pressed by the convex pieces 6a and 6b and the bent leg 27 are squared securely, even if the forming plate 9 moves upward after the forming, the formed staples are formed. Springback is extremely small. Therefore, much better driving can be performed than in the past.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of an electric stapler according to the present invention.

FIG. 2 is a perspective view of a main part of a staple forming mechanism.

FIG. 3 is an exploded perspective view of a pusher portion and a peripheral portion thereof.

FIGS. 4 (a) and 4 (b) are explanatory views of an operation mode of the staple forming mechanism, respectively.

FIG. 5 is an explanatory view of a forming mode by a conventional staple forming mechanism.

[Explanation of symbols]

3 sheet staples 3a Leading staple 4 Needle passage 6a Upper convex piece 6b Lower convex piece 9 Forming plate 10 Driver

Claims (1)

(57) [Claims] 1. A forming plate and a driver driven by a motor are disposed above a leading end of a needle passage for feeding a sheet staple formed by connecting straight staples in a sheet shape. When the leading staple is fed into the upper and lower protruding pieces projecting forward from the center of the upper and lower ends, the forming plate is driven downward by a motor to push both sides of the staple protruding from the above-mentioned protruding piece. In an electric stapler that bends into a U-shape to form a staple, and then drives the formed staple toward a material to be sewn by a driver, when the forming plate is actuated downward on the convex piece, it is interlocked with this That the pusher that pushes down the upper convex piece and presses the sheet staples in the upper and lower convex pieces is placed. Staple forming mechanism in the electric stapler according to symptoms.