JPS5919149Y2 - Fixed force spring inner end fixing device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for fixing the inner end of a constant force spring to an output drum.

2. Description of the Related Art Conventionally, springs for retracting safety belts and mainsprings for retracting cords in electrical appliances, etc., have a type in which the inner end of a constant force spring is fixed to an output drum.

The inner end fixing device for the spring in this case is as shown in FIG. The output drum 11 is abutted and fixed to the locking part 14 with a screw 16.
A through hole 15 is bored in the peripheral edge 17 of the through hole 15.
I was inserting tools from there.

For this reason, it is necessary to drill holes in the drum 11, which has the disadvantage that machining and screwing operations are difficult and efficiency is extremely low.

The object of this invention is to provide an inner end fixing device for a constant force spring that can eliminate the drawbacks of the conventional devices as described above.

This invention will be explained with reference to embodiments shown in FIG. 2 and subsequent figures.

Reference numeral 1 denotes an output drum, which has an insertion gap 2 extending inward from its outer periphery, an engagement protrusion 3 facing inward along this insertion gap, and a constant force spring 4. The inner end is inserted into the insertion gap 2 and is fitted and locked into the engagement hole 5 provided near the tip of the engagement protrusion 3. This state is shown in Fig. 4. The rear spring 4 is wound clockwise around the outer circumference of the drum 1, and is used in combination so as to be wound by another winding drum 6 as shown in FIG. It shows the fully wound state, and at that time, the spring 4 of a minimum weight or more remains on the drum 1.

This prevents the spring 4 from coming off the protrusion 3.

In the above-mentioned device, the engaging protrusion 3 may have a pin shape other than the shape shown in the figure, or may have a plurality of pieces instead of just one, and the through hole 5 of the spring 4 may have a long shape as shown in the third figure. Holes are preferred, but holes of other shapes may also be used.

This device is as described above, and the inner end of the constant force spring is inserted into the insertion gap provided in the output drum, and the engagement protrusion formed along the insertion gap is provided near the tip of the spring. Since the retaining hole is locked, there is no need to provide screw holes or machined holes for inserting tools as in conventional products, and there is no need to use tools at all when fixing the spring. It has the excellent effect of being extremely easy to work with and extremely efficient.

[Brief explanation of the drawing]

Fig. 1 is a front view of the conventional one, Fig. 2 is a front view of an embodiment of this invention, Fig. 3 is a partially cutaway front view of the constant force spring in the same above, and Fig. 4 shows the state when fixed in the above. The partially cutaway front view shown in FIG. 1... Output drum, 2... Insertion gap,
3... Engaging protrusion, 4... Constant force spring,
5...Engagement hole.

Claims (1)

[Scope of utility model registration request] An insertion gap is formed inward from the outer periphery of the output drum, and an engaging protrusion is formed inward along this insertion gap, and the inner end of the constant force spring is inserted into the insertion gap. An inner end fixing device for a constant force spring, in which a retaining hole provided near the tip of the constant force spring is engaged with the engaging protrusion.