JPH0418778Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a stopper device that prevents the chisel from falling off the tool body in impact tools that use compressed air, such as air chippers. be.

(Prior Art) A conventional impact tool having a configuration as shown in FIG. The ring is vibrated in the axial direction and simultaneously rotated so that the radial axes of the locking ball 5 and the through hole 6 are aligned on the same line. This often happens, and when such a situation occurs, the locking ball 5 escapes through the through hole 6 and the chisel 2 pops out, which is extremely dangerous.

(Problems to be Solved by the Invention) The present invention attempts to provide a ring stopper device capable of suppressing the rotation of the ring 8 in the above-mentioned prior art, thereby eliminating the danger of a chisel or the like falling off. be.

(Devised solution) A circumferential groove consisting of a deep groove and a shallow groove is provided at the tip of the cylinder housing, and a through hole is provided in which a locking ball such as a chisel can be installed so as to be retractable in the radial direction. A torsion spring is attached to the ring, and a ring is rotatably and axially slidably fitted to the tip, and a through hole is provided at an appropriate position in the ring for accommodating the ball in the through hole. A locking ball is installed in the through hole, and the outer end of the torsion spring is engaged with the ring, and the inner end of the torsion spring is engaged with the shallow groove. .

(Example) An example will be described with reference to FIGS. 1 to 3.

8 is a ring that prevents the locking ball 5 from escaping, and is rotatable at the tip of the cylinder housing 7;
It is fitted so as to be slidable in the axial direction, and corresponds to the ring 3 in FIG. 4. Reference numeral 9 denotes a stop ring attached to the cylinder housing 7, which is engaged with the ring 8 at the right end in FIG. 1 to prevent the ring 8 from moving to the right in the figure.

10 is a torsion spring for suppressing the rotation of the ring 8, and as shown in FIGS. 2 and 3, an L-shaped locking piece 11 is provided at the outer end facing outward and toward the winding direction of the coil. A locking piece 12 is provided at the inner end facing in the centripetal direction.

The torsion spring 10 is attached to the cylinder housing 7
The L-shaped locking piece 11 at the outer end is inserted into a radial through hole 14 provided in the ring 8, and the locking piece 12 at the inner end is inserted into a hole 15 bored at the bottom of the circumferential groove 13 toward the center of the cylinder housing 7.

The circumferential groove 13 consists of a deep groove 13a on the front end side of the cylinder housing 7 and a shallow groove 13b on the rear side thereof. The depth of the deep groove 13a varies depending on the number of coil turns of the torsion spring 10, but when the spring 10 is twisted in the winding direction, the inner diameter D (Figs. 2 and 3) of the spring becomes smaller. The torsion spring 10 is formed deeper to prevent it from hitting the groove bottom, and plays an important role when installing or removing the torsion spring 10 from the groove 13. Further, the depth of the shallow groove 13b is equal to the wire diameter d of the torsion spring 10. Further, the through hole 14 provided in the ring 8 is provided in the shape of a hole that is slightly larger in the circumferential direction than the bending length l of the L-shaped locking piece 11.

(Function) When fitting the locking ball 5 into the through hole 16 provided in the cylinder housing 7, the ring 8 is twisted in a direction that reduces the inner diameter D of the spring 10 against the elastic force of the spring 10. The ring 8 is rotated in the winding direction of the coil, and the through hole 17 of the ring 8 is aligned with the mounting portion of the cylinder housing 9.
7, the locking ball 5 is fitted.

Next, when the torsion spring 10 is released, the ring 8 is rotated by the elastic force of the torsion spring 10 and returns to its original state, and the locking ball 5 escapes from the through hole 17 formed in the ring 8. to prevent In this manner, when the ring 8 is in the free state, the positions of the locking ball 5 and the through hole 17 are shifted, so that the locking ball does not protrude.

(Effects of the invention) The present invention uses a torsion spring as the spring that stops the ring 8, and attaches it to a circumferential groove provided at the tip of the cylinder housing, and places one end of the spring on the ring side.
Since the other end is engaged with the cylinder housing side with a locking piece, even if severe impact vibration is applied in the axial direction of the impact tool, the action of the torsion spring prevents the ring from rotating and moving in the axial direction. However, since the ring is locked, the chipper fixing ball held by the ring will not fly out during work. Therefore, according to the present invention, the tipper will never come off accidentally, and is extremely safe.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of the stopper device of the present invention. Figure 2 is a front view of the torsion spring. Figure 3 is also a longitudinal side view. FIG. 4 is a longitudinal sectional side view of a conventional stopper device. In the figure: 1...Free piston, 2...Chisel, 3...Ring, 4...Compression spring, 5
... Locking ball, 6 ... Through hole, 7 ... Cylinder housing, 8 ... Ring, 9 ... Stop ring, 10 ... Torsion spring, 11 ... L-shaped locking piece, 12 ... (inner end ) locking piece, 13...
Circumferential groove, 13a...Deep groove, 13b...Shallow groove, 14...
... (radial direction) through hole, 15 ... (provided in the shallow groove) hole, 16 ... (cylinder housing) through hole, 17 ... (ring) through hole.

Claims (1)

[Scope of utility model registration request] A circumferential groove 13 consisting of a deep groove 13a and a shallow groove 13b and a through hole 16 into which a locking ball 5 such as a chisel can be installed in a radial direction are provided at the tip of the cylinder housing 7. A torsion spring 10 is installed inside, and a ring 8 is fitted to the tip so as to be rotatable and slidable in the axial direction.
Further, the ring 8 has a through hole 17 at an appropriate position for accommodating the ball 5 in the through hole 16,
The locking ball 5 is installed in the through hole 16, and the outer end 11 of the torsion spring 10 is attached to the ring 8.
while engaging the inner end 12 with the shallow groove 13b.
A stopper device for an impact tool, characterized in that the stopper device is engaged with the impact tool.