JPS6048312B2 - Automatic nailer's nail dry-driving prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention operates a striking drive section in the nail gun main body by operating a starting operation mechanism consisting of a contact arm and a trigger lever, and by pressing a pusher, a large number of nails are fired. In an automatic nailing machine that can drive nails into a workpiece one by one, which are fed into a nose that serves as a nail-driving section from a magazine in which nails are arranged and stored, the nails stored in the magazine run out. The present invention relates to a dry-driving prevention device that locks the starting operation mechanism and stops the operation of the hammering drive unit when a nail is damaged or when only a few nails remain.

2. Description of the Related Art Generally, an automatic nailer is widely known in which a long magazine for storing a large number of nails in an array is connected to one side of a nose, which serves as a nail driving section, which projects from the nailer main body.

This nailer has a contact arm that is movable back and forth so that its tip can freely protrude and retract from the tip of the nose, and is resiliently biased in the protruding direction, and a trigger that is pivotally attached to the nailer body. The striking piston built into the nailer body is activated by operating the starting operation mechanism consisting of a lever.
A trigger valve that sends an activation signal to a striking drive unit consisting of a cylinder mechanism is actuated, and the nose is moved from the magazine to the nose by the pressure of a pusher that is constantly pulled in the nose direction by a spring member along the longitudinal direction of the magazine. This is a mechanism in which nails are fed into the nose and driven into the member one by one by a driver, which is a nail driving member that moves reciprocally within the nose following the operation of the striking drive unit. be.

By the way, the number of nails that can be stored in the magazine is regulated, and there is a limit to the number of nails that can be stored in the magazine. Therefore, if the worker continues to count the number of nails being driven into the workpiece during nail driving work, the trigger may be triggered even though there are no more nails in the magazine. The valve is actuated, and the driver does not strike the nail, and the striking piston, which constitutes the striking piston/cylinder mechanism installed inside the nail gun, drives the piston into the lower part of the striking cylinder. This directly hits the bumper member arranged to receive the nail at the dead center position, which not only accelerates the wear of the bumper member, but also causes unnecessary vibration in the nailer body. Conventionally, in order to prevent blank driving of nails as described above, a pusher that presses the nails in the magazine is engaged with a contact arm that is an operating member that operates a trigger valve, and the pusher is moved toward the nose side. This locks the reciprocating movement of the contact arm and stops the trigger valve operation while a few nails remain in the magazine, or automatically stops the trigger valve when there are no more nails in the nose. A device has been devised in which the reciprocating movement of the contact arm is locked and the operation of the trigger valve is stopped.

However, in the case of the conventional type described above, the tip of the contact arm is locked in a state protruding from the tip of the nose, so an operator who has not confirmed the above-mentioned locked state may try to drive the nail further in this state by contacting the contact arm. The tip of the arm is forced into the part to be driven. The locking part of the contact arm could be destroyed.

Therefore, the present invention was proposed in order to eliminate the above-mentioned conventional drawbacks, and includes a pusher that presses the nail in the magazine toward the nose side, and a contact arm. The trigger lever is engaged with a starting operation mechanism consisting of a triculper, and the trigger lever is rendered inoperable to start, automatically stopping the operation of the impact drive section within the nailer main body, and allowing the contact arm to reciprocate. There is an attempt to provide a new dry firing prevention device.

The gist of the present invention is to provide a contact arm that is movable back and forth so that its tip can freely protrude and enter from the tip of the nose, and is resiliently biased in the protruding direction;
A starting operation mechanism consisting of a trigger lever pivotally mounted on the nailer body, the trigger lever becoming ready for starting operation only when the tip of the contact arm moves back so as to protrude beyond the tip of the nose. In an automatic nailing machine, the starting operation mechanism is operated to drive the nails fed into the nose from the magazine into the nose one by one by the pressure of the pusher member, one by one. A starting operation mechanism locking means is disposed between the mechanism and the pusher member to disable the trigger lever from starting operation while the contact arm is allowed to reciprocate, and the mechanism is loaded into the magazine when driving a nail. The device is characterized in that the locking means for the gate starting operation mechanism can be activated when the remaining nails run out or while a few nails remain.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

Note that this embodiment is applied to a pneumatic automatic nailer using compressed air as a driving source. FIG. 1 is a partially sectional side view of the pneumatic automatic nailer, and FIG. 2 is an enlarged right side view of the magazine in FIG.

Inside the main body 2 of the nailing machine 1, there is a striking piston/cylinder mechanism (not shown) that is driven by the pressure of compressed air supplied from the tip 3a of a grip part 3 protruding from the side of the main body 2. is built-in. Then, the grip portion 3
A trigger valve 4 for sending an activation signal to the striking piston/silling mechanism is disposed near the base end of the trigger valve 4. This trigger valve 4 includes an operating stem portion 5, and this stem portion 5 is always urged to protrude outward (downward in the figure) by a compression coil spring built into the valve 4. . Further, a nose 6 serving as a nail driving portion is provided on the nailer main body 2 and protrudes coaxially with a striking cylinder constituting the above-mentioned striking piston/cylinder mechanism. A driver guide hole is formed in the nose 6, and reciprocally guides a driver 8, which serves as a nail driving member integrally connected to the striking piston that reciprocates within the striking cylinder. A nail supply hole 9 is provided in one side of the nose 6 (on the right side in FIG. 1) in the axial direction of the nose 6,
An elongated magazine 10 is integrally connected to the opening of the nail supply hole 9, which is formed by making two plate-like bodies facing each other and having a hollow center. Further, magazine holding parts 11, 11 protruding from the grip part 3 are connected to one side of the magazine 10 (back side in FIG. 1), and hold the magazine 10 in a well-balanced manner. A large number of nails (not shown) are housed in the magazine 10 in alignment along the side wall of the magazine 10.

A pusher 12 is disposed within the magazine 10 to push the nail toward the nail supply hole 9 side of the nose 6 through the tension of a spring member (not shown). This pusher 12
is a plate-like body so as to be able to slide along opposing side walls in the magazine 10, and the magazine 10 is provided on the rear end side.
The locking piece 14 has a locking piece 14 that engages with the pusher lock pawl 13 pivotally attached to the base end of the locking piece 14, and the locking piece 14 has a locking piece 14 on the upper side in the figure that allows the pusher 12 to be applied to the tensile force of the spring member. It has a finger hook 15 that resists and pulls toward the rear end of the magazine 10.

Further, a locking piece 16 is provided at the upper end of the pusher 12 in the drawing to engage with a concave portion 30 of a pusher hooking portion 31 which will be described later as a starting operation mechanism locking means. In addition,
The tip 16a side of the lock piece 16 is upwardly bent so as to be easily engaged with the recessed portion 30. That is, when loading nails into the magazine 10, hook the finger on the finger hook 15 and pull the pusher 12 toward the rear end of the magazine 10, and at the same time lock the locking piece 14 on the lock claw 13,
By pulling the pusher 12, a nail is loaded between the open portion, that is, the nose 6 and the nail pressing surface 17 of the pusher 12. When loading of nails is completed, the lock claw 13 is rotated counterclockwise to release the engagement between the lock claw 13 and the locking piece 14. Then, the group of nails loaded in the magazine 10 is pushed by the pusher 12 in the direction of the nail supply hole 9 formed in one side of the nose '6. On the other hand, a trigger lever 18 having a U-shaped cross section and constituting one side of a starting operation mechanism 100 for actuating the trigger valve 4 is connected to the connecting portion between the nailer main body 2 and the grip portion 3. The bottom wall 18a of the lever 18 is pivotally mounted so as to face the operating stem portion 5 constituting the trigger valve 4.

One end 19a at the tip of the operating stem portion 5 engages with the bottom wall 18a of the trigger lever 18, and the other end 19b engages with the upper end of the operating barrel portion 28 of the second contact arm 22, which will be described later. A contact lever 19 having a U-shaped cross section is rotatably mounted around a support shaft 19c. On the other hand, the contact arm 20 constituting the other part of the starting operation mechanism 100 for operating the trigger valve 4 is divided into a first contact arm 21 and a second contact arm 22. The first contact arm 21 is arranged so as to be able to reciprocate along the longitudinal direction of the front nose 6, and the tip 21a of the first contact arm 21 is connected to a bent piece 24 formed at the base end. The nose 6 is normally operated by a large-diameter compression coil spring 25 serving as a first resilient member disposed between the step 23a of the protrusion 23 protruding from one side of the machine body 2. It is urged to protrude beyond the tip 6a. The second contact arm 22 has a cylindrical overall shape as shown in FIG. An operation cylinder part 28 that reciprocates through an annular spacer 27 in the insertion hole 26 formed therein, an annular flange part 29 formed at the lower end of the cylinder part 28 in the figure, and an annular flange part 29 of the pusher 12. A pusher hooking portion 31 having a concave portion 30 serving as a starting operation mechanism locking means that engages with the lock piece 16, and a cylindrical connecting portion 3 that joins the pusher hooking portion 31 and the flange portion 29.
It is composed of 2. The cylindrical connecting portion 32 is fitted into a fitting hole 33 formed in the bent piece 24 of the first contact farm 21, and a second A small-diameter compression coil spring 34 is provided as a resilient member. Therefore, the entire second contact arm 22 is held so as to be pushed upward in the figure by the biasing force of the small diameter compression coil spring 34 described above. Next, the operation of this embodiment having the above configuration will be explained with reference to FIGS. 4 and 5.

H As shown in FIG. 4A, the first contact arm 21
The tip 21a of the contact arm 21 is pressed against a member to be driven (not shown), and the first contact arm 21 is pushed up so that the tip 21a and the tip 6a of the nose 6 are flush with each other.

Then, the base end side of the first contact arm 21 moves upward in the figure against the biasing forces of the large-diameter compression coil spring 25 and the small-diameter compression coil spring 34. Then, the second contact arm 22 is pushed upward in the figure by the biasing force of the small-diameter compression coil spring 34, and the operation cylinder portion 28 located on the other end side of the second contact arm 22 is It moves in the insertion hole 26 upward in the figure. Then, the upper end 28a of the operation cylinder section 28
is the other end 19b of the contact lever 19 so that the contact lever 19 rotates clockwise about the support shaft 19c.
Push up in the upward direction in the figure. In this state, still
The operating stem portion 5 of the trigger valve 4 cannot be pushed upward in the figure, and the trigger valve 4 cannot be operated. Then, as shown in FIG. 4B, while maintaining the state in which the first contact arm 21 is pushed up, that is, the state shown in FIG. 4A, the trigger lever 18 is
The trigger lever 18 is rotated counterclockwise until the bottom wall 18a of the trigger lever 18 comes into contact with the locking protrusion 35 protruding from the lower part of the grip part 3.

With this rotational operation, one end 19a of the contact lever 19 is pushed upward in the figure by the bottom wall 18a of the trigger lever 18, causing the contact lever 19 to rotate counterclockwise. Then, top. The other end 19b of the contact lever 19 is pressed downward in the figure, and attempts to push down the second contact arm 22 in the downward direction in the figure. However, the biasing force of the large-diameter compression coil spring 25 and the small-diameter compression coil spring 34
Overcoming the biasing force of the compression coil spring in the trigger valve 4 that biases the stem portion 5 downward in the figure,
The pushed-up state of the second contact arm 22 can be maintained. Then, the operating stem portion 5 is pushed upward in the figure by the third rotation operation (lifting operation) of the trigger lever 18, and the trigger valve 4 is activated. Then, by repeatedly operating the contact arm 20 and trigger lever 18 described above, the nails in the magazine 10 are driven into the workpiece one by one, and the pusher 12, which is pressing the nails in the magazine 4 and 10, gradually Close to the nose 6 side, as shown in FIG. It engages with the recessed portion 30 .

Then, the movement of the second contact arm 22 in the upward direction in the figure is locked. In this state, no matter how much the first contact arm 21 is pushed up, the second contact arm 22 cannot be pushed upward in the figure, and the first contact arm 21 is powered by a large-diameter compression coil spring. 25 and small diameter compression coil spring 3
The nose 6 simply moves back and forth in the longitudinal direction by the biasing force 4, that is, repeatedly misses. Therefore, during nail driving work, the operator does not have to count the number of nails driven into the workpiece, but can operate the trigger valve 4 by checking the magazine 1.
It can be automatically stopped while several nails 50 remain in the container. At that time, the first contact arm 21
Since the reciprocating movement is free, by pushing up the first contact arm 21, the recessed part 3 of the pusher hooking part 31 of the second contact arm 22 is pushed up.
0 and the lock piece 16 of the pusher 12 will not be destroyed. The locking piece 16 of the pusher 12 and the concave portion 30 of the pusher latching portion 31 may be engaged with each other when the nails stored in the magazine 10 run out. As described above, according to the present invention, when there are no more nails stored in the magazine, or when a few nails remain, the trigger lever is rendered inoperable, and the impact drive in the nailer body is Since the operation can be automatically stopped, dry driving of nails can be reliably prevented.

Therefore, the nail gun member is protected, and unnecessary vibrations are not generated in the nailer body.
Further, when the operation of the impact drive section is stopped, the contact arm can be pushed up, so there is no possibility that the locking portion between the contact arm and the pusher will be destroyed as in the prior art.

[Brief explanation of drawings]

1 to 5 are diagrams showing one embodiment of the present invention, in which FIG. 1 is a partially sectional side view of a pneumatic automatic nailer, and FIG.
The figures are an enlarged right side view of the magazine in Fig. 1, Fig. 3 is an enlarged longitudinal sectional view showing the connected state of the first contact arm and the second contact arm in Fig. 1, and Figs. FIG. B is an enlarged longitudinal sectional view showing the operating state of the contact arm and the trigger lever, and FIG. 5 is an enlarged longitudinal sectional view showing the state in which the pusher is engaged with the second contact arm. 1...Pneumatic automatic nailer, 2...
・Nailer main body, 6...Nose, 6a...
...Nose tip, 10...Magazine, 12...
...Pusher, 18...Trigger lever, 2
0...Contact arm, 21...First contact arm, 21a...Tip of first contact arm, 22...Second contact arm , 31...Pusher latching part, 1?0.
...Start operation mechanism.

Claims (1)

[Claims] 1 Consists of a contact arm that is movable back and forth so that its tip can freely protrude and enter from the tip of the nose and is elastically biased in the protruding direction, and a trigger lever that is pivotally attached to the nailer body, The trigger lever is provided with a starting operation mechanism that enables the trigger lever to be operated only when the tip of the arm moves back so as to protrude from the tip of the nose. In an automatic nailing machine that is capable of driving nails fed into the nose from a magazine into a workpiece one by one, the contact arm has a first contact having a workpiece contact surface at one end. arm, and a second contact arm having an operating part of a starting operation mechanism at one end, and at each other end of each of the first and second contact arms, upward movement of the first contact arm is controlled. The second contact arm is connected to the second contact arm through a spring so as to be able to transmit information, and the second contact arm is provided with a pusher latching portion, and the pusher is provided with a locking piece, and the pusher latching portion and the locking piece engage with each other. A nail blank driving prevention device for an automatic nailing machine, characterized in that the upward movement of the second contact arm can be prevented by: