JPS6219993B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic nailing machine that automatically feeds nails using a nail holding band in which a large number of nails are held at predetermined intervals by upright tabs. Regarding the feeding mechanism.

Automatic nailing machines are known that include a nose unit that is equipped with a nail holding band that removably holds a number of nails by upright tabs and automatically feeds the nails into a driving chamber. The nose unit of this nail gun is provided with a feed pawl extending from the back surface of the groove to the guide groove of the nail holding band, and this feed pawl is connected to a driving means such as a piston/cylinder device to drive the guide groove. On the other hand, a feed hole is formed at the base of the nail holding band, and a feed pawl engages with the feed hole, and for example, the forward movement of the feed pawl drives the nails one by one. It will automatically send you to your room.

In addition, in order to prevent the feed claw from frictionally engaging with the retaining band and causing the retaining band to move backwards when the feed claw moves forward, there is a non-return claw that engages with the shaft of the nail held by the tab of the retaining band. There is a nose unit with This prevents the nail holding band from being fed back even if the feeding pawl frictionally engages with the nail holding band during backward movement.

However, when the above-mentioned non-return pawl is provided, the feed pawl does not engage with the feed hole of the nail holding band even though it has moved backward a predetermined distance (for example, backward movement), and therefore the next front When moving to , only the feed claw moved and the nail holding band was not fed. This situation is shown in FIG.

In FIG. 5, the nail 3 held by the tab 2 of the nail holding band 1 has its nail shaft 7 engaged with the non-return pawl 4 to prevent the holding band 1 from being fed back. When the feed claw 5 moves rearward (arrow A) in this state, the nail holding band 1 wraps around the nail shank that is locked to the non-return claw 4, so that the feed claw 5 is moved to the rearmost position. Despite the movement, the tip of the feed claw 5 is not inserted into the next feed hole 6. Therefore, even if the feed claw 5 moves forward (arrow B), the holding band 1 does not move. These inconveniences became more noticeable as the height of the tab increased. This is thought to be because the radius of rotation of the tab that rotates around the nail shaft increases.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a nail feed mechanism for an automatic nailer in which the feed pawl reliably engages the next feed hole in the nail retaining band when the feed pawl is retracted.

To achieve this objective, the present invention provides a method for driving a nail retaining band that removably holds a number of nails at predetermined intervals by supporting the shank on tabs extending along and upright from the side edge. It has a groove for guiding the nail into the chamber, and extends from the back side of the guide groove so as to engage with a feed hole formed at the base of the nail holding band, and is connected to a driving means to advance the holding band and pick up one nail. An automatic nail equipped with a feed pawl that automatically feeds the nail into the driving chamber, and a check pawl that engages with a nail shaft supported by a tab so as to prevent the nail holding band from retreating when the feed pawl retreats. In the nose unit of the driving machine, a second check pawl is formed in the guide groove at at least one of a front position and a rear position of the feed pawl in the feeding direction of the holding band, and the second check pawl The steep front end surface of the pawl is arranged at a position where one of the nails on the nail holding band engages with the tip edge of the feed hole of the holding band placed in the driving chamber, and the second non-return pawl is positioned rearward. To provide a nose unit of a nailing machine, which is characterized by being gently sloped towards the target.

According to the present invention, since the second non-return pawl prevents the base of the nail holding band from being fed backwards, the dove does not rotate around the nail shaft, and this prevents the feed pawl from moving in a predetermined position. If the feed pawl moves backward a long distance, the feed pawl will surely engage with the next feed hole. Therefore, the forward movement of the feed pawl ensures advancement of the nail holding band.

In an embodiment of the present invention, the height of the second locking pawl from the guide groove surface is approximately equal to the thickness of the base of the nail retaining band, thereby preventing the base of the nail retaining band from moving backwards and retaining the nail retaining band. A smooth forward movement of the belt can be obtained. Further, it is preferable that the second non-return pawl is provided at both the front position and the rear position of the feed pawl, thereby improving the reliability of preventing the holding band from being fed back.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a nose unit 10 of an automatic nailer. A nail retaining band 1 shown in FIG. 1A is inserted into the nose unit 10 in the direction shown by arrow C from the bottom of the figure.

The nail retaining band 1 is made of flexible synthetic resin,
Shafts 7 of nails 3 are passed through tabs 2, 2 extending along and upright from the side edges of the base 8, so that a large number of nails 3 are held at predetermined intervals in the nail retaining band 1. Removably retained. The base 8 of the nail retaining band is provided with perforations 6 at intervals corresponding to the spacing of the nails or tabs.
is provided, which engages with a feed pawl (described later) to advance the nail holding band 1. Feed hole 6 of this nail holding band
is slightly elongated in the lateral direction to assist in breaking the used retaining band.

In the nose unit 10 of FIG. 1, when the nail 3 held by the nail holding band 1 is sent to the driving chamber,
The driving bit 11 is driven into the nose piece 1 by power.
It moves rapidly in two directions, removes the nail 3 from the tab 2, and drives it into the object. These operations and structures are well known and do not form a main part of the present invention, so further explanation will be omitted.

In FIGS. 2 and 3, the nose unit 1
The internal structure of 0 is shown. The nose unit 10 has a U-shaped groove 14 (FIG. 3) for guiding the nail holding band 1 into the driving chamber 13. A cover 15 is provided at a predetermined interval (height) above the base surface on which the U-shaped groove 14 is formed (on the left side in FIG. 2) so as to guide the nail holding band. is rotatably supported by a support shaft 16, and the spring 1
7 urges the cover 15 to open.
Also, latch 18 (first
), the cover 15 can be easily opened by operating the latch lever 19.

The guide groove 14 of the nose unit 10 has a hole extending a predetermined length (a length corresponding to the spacing between the feed holes) in the longitudinal direction of the nail holding band 1, that is, in the feeding direction, at a position corresponding to the feed hole 6 of the nail holding band 1. 20 is formed, and a feed pawl 5 extends into this hole 20 from the back side of the guide groove 14. This feed pawl 5 is connected to a piston 23 of a piston/cylinder device 22 provided on the back surface of the base of the nose unit. The piston 23 is normally biased upward in the figure by the spring 24, but when a pressure fluid such as pressurized oil or pressurized air is sent into the cylinder 25, it descends. As a result, the feed pawl 5 moves backward in the feeding direction of the nail holding band 1. When the pressure fluid in the cylinder 25 is removed, the piston 23 is returned by the spring 24. Due to this return, the feed claw 5 also moves to the forwardmost position of the hole 20 (at the top in the figure).

The front end surface of the feed pawl 5 is shaped to hook onto the front edge, that is, the tip edge, of the feed hole 6 of the nail holding band 1, and the rear surface is gently sloped. Therefore, the feed pawl 5 does not act to feed the nail holding band 1 when moving from the forwardmost position (the position in FIG. 2) to the rearmost position (downward in FIG. 2) of the hole 20;
When the feed pawl 5 engages with the next feed hole 6 at the rearmost position and moves to the frontmost position, the nail holding band 1 is advanced.

When the feed pawl 5 moves backward, that is, from the forwardmost position of the hole 20 to the rearmost position, the feed pawl 5 does not actively move the nail holding band 1 backward, but the feed pawl 5 and the holding band move backward. Frictional contact with the base 8 of 1 may cause the retaining band 1 to move backwards. In order to prevent this backward movement, a check pawl 4 is provided which projects from the cover 15 in the direction of the retaining band 1 by the force of a not-so-strong spring 27. This check pawl 4 engages with the nail shaft 7 of the nail holding band 1 to prevent the holding band from moving backwards.

However, as shown in FIG.
When moving backward, the tip presses the base 8 of the retaining band 1 with a strong force, so the tab 2 is moved around the shaft 7 of the nail stopped by the non-return pawl 4 as described above with reference to FIG. It turns out that it works to rotate. For this reason, even if the feed pawl 5 moved to the rearmost position, it sometimes did not engage with the next feed hole 6.

For this reason, in the present invention, the guide groove 14 is provided with a second check pawl 30 at at least one of the front position and the rear position of the feed pawl 5 in the feeding direction of the nail holding band. This second check pawl 30 has a shape that protrudes from the surface of the guide groove 14. Its front end surface is steeply formed to be approximately perpendicular to the groove surface 14, and when one of the nails 3 on the nail retaining band 1 is properly positioned within the driving chamber 13, It is arranged at a position to engage with the tip edge of one of the feed holes 6 of the holding band 1. Moreover, this second non-return pawl 30 is sloped gently toward the rear. Therefore, the second non-return pawl 30 does not resist the forward movement of the holding band 1 at all, but acts to prevent the backward movement by engaging with the tip edge of the feed hole 6. . In order to achieve both smooth forward feeding and prevention of backward feeding, the second non-return pawl 3
This height from the plane of the guide groove 14 is preferably approximately equal to the thickness of the base 8 of the nail retaining band 1, as shown. In addition, in order to improve the reliability of preventing reverse feeding, as shown in the figure, a second
Preferably, a check pawl 30 is provided. The second non-return pawl 30 at the front closes the holding band 1 when the feed pawl 5 retreats.
The second non-return claw 3 at the rear acts to stop the
This is because 0 acts as a restraint.

Regarding the action of this second non-return pawl 30, Fig. 4a
This will be explained in more detail using .

FIG. 4a shows a state in which the feed pawl 5 is retreating from the forwardmost position of the guide groove 20, and the inclined rear surface of the feed pawl 5 is pushing up the base 8 of the holding band 1 slightly. In the position shown in FIG. 4b, the feed pawl 5 separates from the hole 6 and pushes up the base 8 significantly. This situation is also shown in FIG. In this state, the nail retaining band 1 bends so that the tab rotates around the nail shaft 7 engaged with the first non-return pawl 4 (Fig. 5), but the second non-return pawl 30 holds the nail. Base 8 of band 1
Since the reverse movement of the tab is prevented, the tab does not rotate and the base 8 is simply pushed up from the surface of the guide groove 14. Therefore, when the feed claw 5 moves to the rearmost position of the hole 20 as shown in FIG. 4c, the feed claw 5 will surely enter the next feed hole 6, and the tab as shown in FIG. Engagement errors due to rotation are eliminated.

As described above, according to the present invention, errors in feeding the holding band can be eliminated with a very simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a front view of the nose unit of an automatic nailer according to the present invention, FIG. 1A is a plan view of the nail holding band, FIG. 4a to 4c are diagrams illustrating the operation of the nail holding band feeding mechanism according to the present invention, and FIG. 5 is a diagram illustrating the operation of the conventional nail holding band feeding mechanism. 1...Nail retaining band, 2...Tab, 3...Nail, 4...
...First check claw, 5... Feed claw, 6... Feed hole of nail holding band, 7... Nail shaft, 10... Nose unit, 11... Driving bit, 13... Driving chamber,
14... Guide groove, 15... Cover, 20... Long hole, 22... Piston/cylinder device, 23...
Piston, 24... Spring, 30... Second check pawl.

Claims (1)

[Scope of Claims] 1. A nail holding band that removably holds a number of nails at predetermined intervals is guided into a driving chamber by supporting the shaft portion on tabs extending along and upright from the side edge. In the nose unit of an automatic nailing machine, the nose unit of an automatic nailer is equipped with a feed pawl that is connected to a drive means to advance the holding band and automatically feed the nails one by one to the driving chamber, and the guide groove has a feed pawl for advancing the holding band and automatically feeding the nails one by one to the driving chamber. at least one of the forward position and the rear position of the feed claw in the direction
A non-return pawl is formed on one side, and the steep front end surface of the non-return pawl engages with the leading edge of the hole in the retaining band when one of the nails on the nail retaining band is placed in the driving chamber. 1. A nose unit for a nailing machine, wherein the non-return claw is gently sloped toward the rear. 2. The nose unit according to item 1 above, wherein the height of the non-return pawl from the guide groove surface is approximately equal to the thickness of the nail retaining band. 3. The unit according to item 1, wherein the non-return pawl is provided at a front position and a rear position of the feed pawl, respectively.