JPH028106Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a spring clutch that connects two shaft parts and can transmit unidirectional rotation to the left or right.

[Prior art]

As shown in FIG. 6, the present applicant formed an engagement groove 5a into which the inwardly bent end 6a of the coil spring 6 is fitted in one shaft portion 5, and a receiver 5b outside the engagement groove. A spring clutch that transmits rotation in one direction between the shaft and the shaft was proposed in Japanese Utility Model Application Publication No. 57-122058, but in the above spring clutch, if the transmission rotation direction is to be reversed, the receiver 5b is used.
It is necessary to prepare a shaft part with a different position and a coil spring with a different winding direction, and the shaft part becomes a dedicated separate part, resulting in a large number of parts and high cost.

[Purpose of invention]

In view of the above-mentioned drawbacks, the present invention proposes a spring clutch that reduces the number of parts and costs by using coil springs with different winding directions, an engaging part that the coil springs can selectively engage, and a shaft part provided with a protrusion. .

[Structure of the idea]

The present invention consists of a first shaft portion having a circular hole, a second shaft portion that fits into the circular hole with a margin, and a coil spring that is inserted between the two shaft portions and comes into contact with the inner surface of the hole. In a spring clutch whose one end is bent inward and engaged with the second shaft,
The second shaft portion is provided with two engaging portions that engage with the bent pieces of the coil spring, and protrusions that come into contact with the bent corners of the coil spring are provided on the opposite sides of the respective engaging portions.

〔Example〕

The invention will be explained with reference to embodiments in the drawings. In the spring clutch, as shown in FIGS. 1 to 4, the second shaft portion 2 is fitted into the circular hole 1a of the first shaft portion 1 with a margin,
The coil spring 3 or 4 is inserted between the first shaft part 1 and the second shaft part 2 and comes into contact with the inner surface of the hole 1a.

The second shaft portion 2 is provided with engaging portions 2a and 2b as notches formed in the axial direction, and a protrusion 2 is provided on the right or left side of the outer side of the engaging portion, in the middle of both engaging portions in the figure.
c is formed.

The coil spring 3 is wound right-handed in FIG. 3, and the coil spring 4 is wound left-handed, and one end of each is bent inward to form bent pieces 3a, 4a.

When the spring clutch is assembled so that rotation is transmitted in the clockwise direction, the bent piece 3a of the coil spring 3 is attached to the second shaft portion 2 as shown in FIGS. 1 and 3.
When the second shaft portion 2 is rotated clockwise in FIG. 3, the outer bent corner portion 3b of the bent piece 3a is engaged with the engaging portion 2a of 3b is pushed, the coil spring 3 is urged in the direction of winding and opening, and the outer periphery of the coil spring 3 is pressed against the hole wall of the hole 1a of the first shaft part 1, and the rotation of the second shaft part 2 is caused by the frictional force. The signal is transmitted to the single shaft portion 1.

When the spring clutch is assembled so that rotation is transmitted in the counterclockwise direction, the bent piece 4a of the coil spring 4 is attached to the second shaft portion 2 as shown in FIGS. 1 and 4.
When the outer bent corner 4b of the bent piece 4a is brought into contact with the protrusion 2c and the second shaft part 2 is rotated counterclockwise in FIG. Part 4b
is pushed, the coil spring 4 is urged in the unwinding direction, and the outer periphery of the coil spring 4 is pressed against the hole wall of the hole 1a of the first shaft part 1, and the rotation of the second shaft part 2 is caused by the friction force. It is transmitted to the shaft part 1.

When the second shaft portion 2 is rotated counterclockwise in FIG. 3 and clockwise in FIG.
It is not transmitted to the shaft portion 1.

When rotation is transmitted from the first shaft portion 1 to the second shaft portion 2, the rotation is rotated counterclockwise in FIG. 3 and clockwise in FIG. 4.

When the spring clutch is configured as described above, the coil springs 3 and 4 with different winding directions are prepared, and the two engaging portions 2a and 2b and the engaging portions 2a and 2 are connected to each other.
On the outside of b, there is a protrusion 2 on the opposite side to the winding direction of the coil spring.
It is possible to selectively combine one second shaft part 2 provided with c to support rotation transmission in both directions, and there is no need to prepare second shaft parts for clockwise rotation and counterclockwise rotation, respectively. The number of parts and costs can be reduced.

The cross-sectional shape of the coil springs 3 and 4 is not circular,
It may be semicircular, rectangular, oval, etc.

In the above description, the engaging portions 2a and 2b are provided so as to share the protrusion 2c, but two combinations of the engaging portion and the protrusion may be provided with an interval between them.

Although the above-mentioned engaging parts 2a and 2b were formed by notches,
a long groove in which the bent pieces of the coil springs 3 and 4 can engage;
It may be any hole, recess, etc.

Fig. 5 shows a modified example in which a base part 2d is provided on the opposite side of the axis from the protrusion 2c in order to stably attach the coil spring 3 or 4, and the height H of the base part 2d is It is desirable to make the wire diameter approximately half of the wire diameter φ.

[Effect of idea]

Since the present invention is configured as described above, rotation in either the left or right direction can be transmitted by selectively combining or exchanging coil springs with different winding directions for the first shaft portion and the second shaft portion. It is possible to provide a spring clutch which has excellent practical effects, such as the need to prepare two second shaft parts with different protrusion positions relative to the mating part, and the number of parts and cost can be reduced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is an exploded perspective view of the spring clutch, FIG. 2 is a cross-sectional side view, and FIGS. 3 and 4 are plan views showing the first shaft portion in cross-section. , FIG. 5 is a sectional side view of a modified example of the second shaft portion, and FIG. 6 is an exploded perspective view of essential parts of a spring clutch already proposed by the applicant. DESCRIPTION OF SYMBOLS 1...First shaft part, 1a...Circular hole, 2...Second shaft part, 2a, 2b...Engaging part, 2c...Protrusion,
3, 4... Coil spring, 3a, 4a... Bent piece,
3b, 4b...bent corners.

Claims (1)

[Scope of utility model registration request] Consisting of a first shaft portion having a circular hole, a second shaft portion that fits into the circular hole with a margin, and a coil spring that enters between the two shaft portions and contacts the inner surface of the hole,
In a spring clutch in which one end of a coil spring is bent inward and engaged with a second shaft part, the second shaft part is provided with two engagement parts with the bent pieces of the coil spring,
A spring clutch that has protrusions that touch the bent corners of the coil spring on the opposite side of each engaging part.