JPH0727087Y2 - Two-feed prevention device in nail supply device of nailer - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preventive device for a nail supply device of a nailing machine, which prevents double feed due to overlapping operation of a trigger lever for starting.

[0002]

2. Description of the Related Art In a conventional nailing machine (a nailing machine that completes driving a nail by a single impact), the air used to return the impact piston after the impact stroke to the initial position is used. Equipped with a return air chamber that accumulates pressure during the striking stroke, and an automatic nail supply system that uses the air pressure in this chamber to drive the feed piston / cylinder mechanism that supplies nails in synchronization with the driving operation is adopted. ing. Such a single-striking nail driving machine requires a large amount of power for one striking, and thus has a problem that the machine becomes large.

On the other hand, in a nailing machine of a continuous hammering type in which one nail is hammered multiple times to hammer the nail, since the hammering power per hammering is small, a relatively small machine is used. Can be used to drive long-sized nails or to drive hard materials such as concrete. However, in this type of continuous hammering type nailing machine, compressed air is supplied to the return air chamber after every multiple strokes in order to raise and return the piston. Cannot be adopted. This is because the nails will be fed many times during repeated hits.

Further, in this type of continuous hammering type nailing machine, the nails are fed so that the head can project again from a nail to be nailed, which is defectively hammered, and can be hit again. A nail supply device having a structure in which a feed piston / cylinder mechanism is operated by lever operation is adopted.
However, in the usual case, the lever is arranged on the left side surface in the vicinity of the trigger lever that activates the nail driver, and is configured to be able to be pushed by the thumb of the right hand holding the grip. For this reason, the nail feeding operation is very troublesome for a left-handed worker.

[0005]

An object of the present invention is to provide a nail supply device in which a nail can be fed by operating a trigger lever for starting a nailing machine, and two nails are not fed even if the trigger levers are operated repeatedly. It is an object of the present invention to provide a double feed prevention device.

[0006]

In order to achieve the above object, the two-feed preventing device in the nail feeding device of the nailing machine according to the present invention has a feed piston / cylinder mechanism for feeding and driving a nail. And a feed valve for supplying and discharging compressed air for operation to the nail supply device, a trigger lever for starting a nailing machine by a manual operation, and a contact arm operated by contact with a driven material. A nailing machine, which operates by operating the trigger lever to control the operation of the feed valve, and a stopper plate that moves forward and backward along the movement locus of the trigger lever.
The stopper plate is advanced on the movement locus of the trigger lever by the first operation of the trigger lever to be engaged with the trigger lever, and the stopper plate is retracted from the movement locus of the trigger lever when engaged with the contact arm. A cam mechanism and control means for holding the stopper plate in the retracted position by driving a nail driver are provided.

[0007]

According to the above construction, the nail feed valve is actuated by the operation of the trigger lever for starting the nailer before or after the nailing operation of the nailer, and the feed valve is operated accordingly. The nail supply device is activated to feed the nail. When the nail driving operation is performed, first, when the contact arm is pressed against the driven material, the stopper plate is held at the retracted position by the cam mechanism and the control means. Nail feeding is prepared.

As described above, since the nail can be fed only by operating the trigger lever, even if the operator is left-handed, it can be easily operated. Since the stopper plate is advanced to the movement locus of the trigger lever and engaged with the trigger lever by the first operation of the trigger lever, the trigger lever cannot be operated again. For this reason, the nail supply device cannot operate either, so that double feed is reliably prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 (a) and 1 (b) are explanatory views of a nail supply device 1 and its operating mode in a continuous hammering type nailer driven by compressed air. Is.

The nail feeding device 1 has a feed piston / cylinder mechanism slidably accommodating a feed piston 3 for feeding and driving a nail in a feed cylinder 2 and connecting a feed means (not shown) for connecting nails. Become, feed piston 3
By reciprocating, the feeding means feeds the nails of the connecting nails one by one to the injection port of the nailing machine. Air passages 7 and 8 are formed in the front and rear portions of the feed cylinder 2, and the compressed air from the front air passage 7 acts only on the front end surface of the bulging portion 9 formed on the peripheral surface of the feed piston 3. ,
Compressed air from the rear air passage 8 is supplied to the feed piston 3
It is configured to act on the rear end face 10. The feed valve 4 supplies and discharges the compressed air for operating the feed piston / cylinder mechanism.

The feed valve 4 constantly connects the front air passage 7 of the feed cylinder 2 to the compressed air supply source 11, and selectively connects the rear air passage 8 to the compressed air supply source 11 and the atmosphere. The spring 12 is always urged to connect the rear air passage 8 to the compressed air supply source 11. The feed valve 4 is operated in the reverse direction by the compressed air supplied from the pilot valve 13 through the air passage 14, and the compressed air is supplied by the nail feed connected to the pilot valve 13. It is controlled by the valve 16.

The pilot valve 13 is a feed valve 4
To selectively connect the air passage 13 communicating with the compressed air supply source 15 or the atmosphere 16 to the compressed air supply source 15 at one end and the nail feed valve 17 at the other end in the valve cylinder 18. A valve stem 20 having a through hole 19 therein is slidably accommodated. Also, the valve stem 2
The end surface of the No. 0 nail feed valve 17 side is formed to have a larger area than the opposite end surface.

The nail feed valve 17 slides a valve stem 23 provided in a valve cylinder 22 so that the air passage 21 communicates with the other end of the pilot valve 13.
Is opened and closed with respect to the atmosphere, and one end 23a of the valve stem 23 projects to the outside due to the elasticity of the spring 24.
An exhaust hole 22a is formed in the valve cylinder 22.

Here, an operation mode of the nail supply device 1 having the above-mentioned structure will be described. Before the operation of the nail feed valve 17, each valve is in the state shown in FIG. 1 (a). Therefore, by pushing the protruding end 23a of the valve stem 23 of the nail feed valve 17 when the nailer is operated as shown in FIG. 2B, the air passage 21 communicating with the pilot valve 13 is opened to the atmosphere through the exhaust hole 22a. One end of the pilot valve 13 is rapidly depressurized to operate, the compressed air supply source 15 and the air passage 14 are opened, and compressed air is supplied to the feed valve 4. As a result, the rear air passage 8 of the feed valve 4 is connected to the atmosphere. For this reason, the air pressure acting on the rear end surface of the feed piston 3 of the feed piston / cylinder mechanism is rapidly reduced, and the feed piston 3 operates rearward. After that, when the pressing operation of the nail feed valve 17 against the valve stem 23 is released, the valve stem 23 is returned to the original position by the force of the spring 24 as shown in FIG. 1, and similarly, from the one end of the pilot valve 13. Since the exhaust is stopped, the compressed air from the compressed air supply source 16 is supplied to both sides of the valve stem 20 through the through holes 19, and the valve stem 20 also returns to its original position due to the difference in pressure receiving area at both ends thereof. Therefore, the air passage 1 communicating with the feed valve 4
4 is exhausted and the feed valve 4 is moved to its original position by the force of the spring 12, so that the feed piston
Compressed air is supplied to the air passages 7 and 8 at the front and rear of the cylinder mechanism, and the feed piston 3 is operated forward due to the difference in pressure receiving area, whereby nail feeding is performed. Similarly, nail feeding is continued by repeating the operation mode of FIGS. 1 (a) and 1 (b).

As described above, the nail supply device 1 is controlled by the operation of the nail feed valve 17, and the operation of the nail feed valve 17 is performed by the trigger lever 5 for starting the nail driver. The trigger lever 5 is mounted by a manual operation so as to move in parallel with the operating direction of the valve stem 23 of the nail feed valve 17, and cooperates with the contact arm 6 pressed against the material to be driven to start the nail driving machine. A trigger valve (not shown) is operated to operate. As shown in FIG. 2A, an operation lever 25 for operating the nail feed valve 17 is pivotally supported on its side surface. Operating lever 2
5 is a rotation stopper 26 formed on the trigger lever 5,
The nail feed valve 1 protruding at a right angle from the trigger lever 5
7 is held in a state of facing the protruding end 23a of the valve stem 23 of No. 7, and is rotatably supported on the nail feed valve 17 side. The peripheral surface 25a at the base end, which is the center of rotation of the operating lever 25, is formed as a cam portion. Further, a step portion 27 is formed on the trigger lever 5.
The step portion 27 is formed with a stop surface 27a orthogonal to the operation direction of the trigger lever 5 and an inclined surface 27b provided at the end of the stop surface 27a.

Further, one end (not shown) of the contact arm 6 is arranged so as to project from the tip of the injection port of the nailing machine, and the other end 6a is arranged so as to face the operation lever 25 from the side opposite to the nail feed valve 17. When the one end is pressed against the material to be driven, the one end moves relative to the nailing machine to enable the operation of the trigger valve by the trigger lever 5, and the other end presses the operation lever 25. Then, it is configured to rotate to the nail feed valve 17 side.

Next, as shown in FIGS. 2 (a) to 2 (d),
In the vicinity of the trigger lever 5, the trigger lever 5 advances and retreats on the movement locus, and the first operation of the trigger lever 5 advances the trigger lever 5 on the movement locus to engage the trigger lever 5 for re-operation. A stopper plate 30 for blocking is arranged. The stopper plate 30 is formed by forming a long piece 30a and a short piece 30b into a substantially L shape, and the tip of the short piece 30b is bent inward. A through hole 31 is formed in the long piece 30a. Further, the stopper plate 30 is urged by the spring 32 arranged inside the short piece 30b so as to advance on the movement locus of the trigger lever 5.

Control means is provided for holding the stopper plate 30 in the retracted position by driving a nail driver. In this control means, a control stem 33 penetrating the through hole 31 of the stopper plate 30 is slidably provided in the housing 34, and the control stem 33 is compressed from one end 35 of the housing 34 based on the operation of the nailing machine. The stopper plate 3 is reciprocated by the supply / exhaust of air and the spring 38.
It controls the operation of zero. That is,
A constricted portion 36 and an engaging groove 37 are formed on the peripheral surface of the control stem 33 via a guide surface 38, and a position and an engaging groove where the stopper plate 30 engages with the constricted portion 36 via a through hole 31. It is slidably provided at a position engaging with 37. When engaged with the constricted portion 36, the tip of the stopper plate 30 can project onto the stop surface 27a of the stepped portion 27 of the trigger lever 5, and when engaged with the engagement groove 37, the stopper plate 30 is engaged. The tip of the can reach only the inclined surface 27b of the step 27, and is held at the retracted position. Normally, it is held at a position where it engages with the engagement groove 37. Compressed air is supplied when the nail driver is operated, and is exhausted after the operation.

Further, when the trigger lever 5 is at the initial position before actuation, only when the operation lever 25 rotates, the cam portion 25a at the base end thereof has the short piece 30 of the stopper plate 30.
It is formed so as to engage with the tip of b.

In the above construction, when the nail is fed before (or after) the nail driving operation, the trigger lever 5 is pressed without pressing the contact arm 6 against the material to be driven, as shown in FIG. 2 (b). When the pulling operation is performed, the operating lever 25 pushes in the protruding end 23a of the valve stem 23 of the nail feed valve 17, so that the feed piston 3 operates rearward as described above. At the same time, as the trigger lever 5 moves, the short piece 30b of the stopper plate 30 slidably contacts the stepped portion 27 inclined surface 27b of the trigger lever 5 and is retracted from the movement path thereof, so that the stopper plate 30 and the control stem 33 are moved. The engagement with the engagement groove 37 is released, and the control stem 33 is pushed by the spring 38 to move. After that, when the pulling operation of the trigger lever 5 is released and the return movement is performed as shown in FIG. 7C, the pressing operation of the nail feed valve 17 against the valve stem 23 is also released, so that the feed piston 3 is The nails are sent forward. At the same time, when the step 27 of the trigger lever 5 returns beyond the long piece 30a of the stopper plate 30 due to the return movement of the trigger lever 5, the spring 32 contacting the short piece 30b tries to move the stopper plate 30 toward the trigger lever 5,
At this time, the cam portion 25a of the operating lever 25 is attached to the stopper plate 3
Since the angle is such that the stopper plate 30 does not engage with 0, the stopper plate 30 advances onto the stop surface 27a, and the stopper plate 30 moves toward the control stem 33.
Engages the waist 36. As a result, even if the trigger lever 5 is pulled again, the trigger lever 5 cannot be operated due to the engagement between the step portion 27 and the stopper plate 30. In this way, once the trigger lever 5 has been pulled and cannot be re-operated, no more than two nails are fed. Therefore, for example, nails whose heads are lifted due to defective driving can be repeatedly driven without feeding the nails.

Next, when the nail driving machine is driven, the contact arm 6 is first pressed against the material to be driven, as shown in FIG. Since the contact arm 6 moves relative to the nail driver and the other end 6a pushes the operating lever 25 to rotate it toward the nail feed valve 17 side, the cam portion 25a at the base end of the operating lever 25 at that time is the trigger lever. 5
Short piece 30 of the stopper plate 30 that has advanced on the movement trajectory of the
The tip of the stopper plate 30 is retracted from the stop surface 27a of the step portion 27 of the trigger lever 5 to the inclined surface 27b by the action of the cam mechanism. As a result, the trigger lever 5 can be pulled. When the trigger lever 5 is pulled, the nail driver is activated. However, since the operation lever 25 is rotated by operating the contact arm 6, the nail feed valve 17 does not operate.

By the way, when the trigger lever 5 is operated, the stopper plate 30 is further pushed in the retracted direction by the inclined surface 27b of the stepped portion 27, so that the engagement between the stopper plate 30 and the constricted portion 36 of the control stem 33 is released. It Then, when compressed air is supplied to the end portion of the housing 34 of the control stem 33 along with the operation of the nail driver, the control stem 33 moves to a position where the engagement groove 37 and the stopper plate 30 are engaged with each other. To do. Further, although the compressed air is exhausted by releasing the pulling operation of the trigger lever 5, the control stem 33
The stopper plate 30 engages with the engaging groove 37 of the stopper plate 3
0 is held in the retracted position, and the next nail feeding is prepared.

As described above, according to the nail supply device 1, since the nail can be fed only by operating the trigger lever 5 for starting the nail driver, even if the operator is left-handed, it can be easily operated. You can Since the stopper plate 30 is advanced to the movement locus of the trigger lever 5 and engaged with the trigger lever 5 by the first operation of the trigger lever 5, the trigger lever 5 cannot be operated again. For this reason, the nail supply device 1 cannot operate either, so that double feed is reliably prevented.

When the contact arm is operated first, the nail feeding is not performed, and the nail driving operation can be repeated any number of times. Therefore, the double feed preventing device is particularly suitable for a continuous hammering machine. It is valid.

[Brief description of drawings]

1 (a) and 1 (b) are explanatory views of an operation mode of a nail supply device according to the present invention.

2 (a), (b), (c), and (d) are explanatory views of an operation mode of the double feed preventing device in the nail supply device.

[Explanation of symbols]

 1 Nail Supply Device 3 Trigger Lever 4 Feed Valve 5 Trigger Lever 6 Contact Arm 30 Stopper Plate

Claims (1)

[Scope of utility model registration request] 1. A nail supply device having a feed piston / cylinder mechanism for supplying and driving a nail, a feed valve for supplying and discharging compressed air for operation to the nail supply device, and a trigger for starting a nailing machine by a manual operation. A nailing machine comprising a lever and a contact arm operated by contact with a material to be driven, a nail feed valve which operates by operating the trigger lever to control the operation of the feed valve,
A stopper plate that moves back and forth on the movement locus of the trigger lever, and the stopper plate is advanced to the movement locus of the trigger lever by the first operation of the trigger lever to engage with the trigger lever and engage with the contact arm. A nail mechanism for a nailing machine, comprising a cam mechanism for sometimes retracting the stopper plate from the movement locus of the trigger lever, and a control means for holding the stopper plate in the retracted position by driving the nailing machine. Double feed prevention device in the feeding device.