JPH0129025Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a nose of a fastener driving machine such as a nailing machine.

FIG. 5 shows an overall structural diagram of a fastener driving machine with a conventional structure. When the trigger 1 is pulled to move the first operator 2, the material contact member 3 is arranged to be able to move up and down at the same time.
Abut the lower end of the second operator 5 against the material to be driven 4.
When the switch 6 is moved, the fastener 8, which has been previously fed into the nose 7 by an appropriate means, is driven out by a driver (not shown) built into the main body 9. When the trigger 1 is released or the material contacting member 3 is separated from the material to be driven 4 and the material contacting member 3 is returned to its original position by the spring 10, the driving process is completed. FIG. 6 shows a portion (cross section AA) where the nose 7 and the material contacting member 3 come into contact and slide. In the figure, the cross-sectional shape of the nose 7 is usually circular or rectangular, and the inner wall 11 of the material contacting member 3 surrounding the nose 7 is also designed to match the former shape. To enable sliding, the outer periphery of the nose 7 and the inner wall 11 of the material contact member 3
A certain amount of clearance δ is required between
If the gap δ is too large, the amount of backlash will increase and the aim during driving may become inaccurate, which is not preferable. Therefore, it is appropriate that the gap δ is usually about 0.5 to 1 mm.

As described above, the material contacting member 3 is arranged to be movable up and down in the longitudinal direction of the nose 7, but its return downward is achieved only by the restoring force of the spring 10. Therefore, if peeled pieces generated from the material 4 to be driven during driving, dust in the atmosphere, dirt, etc. adhere to or accumulate on the outer periphery of the nose 7 or the inner wall 11 of the material contacting member 3, the sliding resistance in this area increases. This makes it difficult for the material contacting member 3 to return downward. In particular, when a highly adhesive material such as asphalt shingle is used as the material to be driven 4, the above phenomenon becomes more pronounced, and in some cases, the lower end of the material contacting member 3 may be connected to the material to be driven. There were cases in which the material contacting member 3 did not return downward even when it was released. In this state, trigger 1
Simply pulling the button would cause Fuasuna 8 to be fired, which was a safety issue as it could cause accidental firing.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to increase the safety of this type of driving machine.

The present invention reduces the contact area between the outer periphery of the nose and the inner wall of the material contacting member, and provides contact areas and escape grooves alternately on the outer periphery.The small contact area makes it easier to shear deposits. The outer circumferential shape of the nose was devised, focusing on the fact that the required shearing resistance force is reduced, and the deposits escape into the escape groove and are less likely to remain in the contact area, reducing sliding resistance.

The present invention will be specifically explained with reference to Examples. 1st
Fig. 2 shows the overall structure of the driving machine according to the present invention and its cross section B-B. In this structure, as in the conventional example, the fastener 8 is not fired unless both the trigger 1 is pulled and the material contact member 3 is pushed upward. Several protrusions 12 are provided at equal intervals in the longitudinal direction of the nose 7 on the outer periphery of the nose 7, and the gap δ between the circumscribed circle connecting the vertices of the protrusions 12 and the inner wall of the material contacting member 3 is It is kept at the same level as the conventional example. Therefore, the amount of backlash of the material contacting member 3 is appropriately suppressed, and at the same time, the portion that the inner wall 11 of the material contacting member 3 contacts is only near the top of the convex portion 12.
A sufficient clearance space 13 is formed between the convex portion 12 and the convex portion 12 . Therefore, the contact sliding area of the material contacting member 3 with the inner wall 11 is small, and most of the deposits such as peeling pieces, dirt, dust, etc. escape into the gap space 13, so the sliding resistance at this part is reduced. increase can be prevented. For this reason, when the material contacting member 3 is separated from the material to be driven 4, it returns downward by the spring 10, so that erroneous firing can be prevented.

As a specific example of the present invention, half-moon-shaped convex portions 12 are provided at equal intervals on the outer circumference of the nose 7, and a gap δ between the circumscribed circle connecting the apexes of the convex portions and the inner wall 11 of the material contacting member 3.
The figure shows an appropriate amount (δ=0.5-1mm),
As shown in FIG. 3, the same effect can be obtained by setting the gap δ between the outer periphery of the nose 7 and the inner wall 11 to an appropriate amount and providing a plurality of relief grooves 14 on the outer periphery.

Further, as shown in FIG. 4, the same effect can be obtained by forming the outer circumferential portion of the nose 7 by an aggregate of continuous convex portions 15 of arbitrary shapes.

According to the present invention, a plurality of convex portions are provided on the outer periphery of the nose to reduce the contact area with the inner wall of the material contacting member and create a gap space through which deposits can escape. Since it is possible to prevent an increase in sliding resistance due to deposits and to ensure the return of the material contacting member, safety against erroneous firing is improved.

[Brief explanation of the drawing]

FIG. 1 is a side view of the fastener driving machine according to the present invention, and FIG. 2 is a sectional view taken along line BB in FIG. FIGS. 3 and 4 are also sectional views taken along the line BB in FIG. 1, and show modifications of the present invention. Figure 5 is a side view of a conventional fastener driving machine, and Figure 6 is A-A in Figure 5.
FIG. In the figure, 3 is a material contact member, 6 is a switch,
7 is a nose, 8 is a fastener, and 12 is a convex portion.

Claims (1)

[Scope of utility model registration request] A drive unit that performs a driving operation using compressed air or electricity as a power source, a switch for operating the drive unit, a nose that drives out the fastener, and a switch that comes into contact with the outer periphery of the nose to operate the switch. A fastener driving machine equipped with a material contacting member that moves up and down, wherein a plurality of protrusions extending in the longitudinal direction are provided on the outer periphery of the nose at a portion where the material contacting member slides into contact. the nose of the machine.