JPH0130119Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a headrest locking device, and more particularly to a headrest locking device that allows the headrest to be adjusted vertically with respect to the backrest of a seat.

Conventionally, as described in Japanese Utility Model Publication No. 51-24664, this type of headrest locking device includes a notch provided in the headrest support rod and a cylindrical support member inserted into the top of the backrest. It is known that the upper end of the member is provided with a contact piece and a spring that biases the operation piece in the direction of engagement with the notch of the headrest support rod. By inserting the headrest support rod into the hole of the support member and engaging a portion of the operating piece in the notch of the headrest support rod, the length of the headrest support rod protruding from the backrest portion can be adjusted.

However, in this case, in addition to the support member and the operating piece, many parts such as a spring and a pin for preventing the operating piece from coming off are required, so the structure is complicated and assembly is difficult.

The present invention was devised in view of these conventional drawbacks, and its purpose is to provide a headrest locking device that has as few parts as possible, has a simple structure, and is easy to assemble.

In order to achieve the above object, the present invention provides a slit and a groove on the circumferential surface of a cylindrical support member, and fits a locking spring made of a single spring wire into the slit and groove. By operating a knob at one end, the headrest support rod is locked in a vertically adjustable manner.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In the drawing, reference numeral 1 denotes a back frame installed inside the backrest of the seat. A cylinder 2 is fixed to the top of the back frame, and a cut groove 2a is formed in the upper end of the cylinder 2. . On the other hand, 3 is a headrest, and two headrest support rods 4 are fixed to the lower surface of this headrest 3, and a plurality of vertical position adjustment notches 4a are formed in the side surface of one of the support rods 4 in the axial direction. There is.

A support member 5 is inserted into the cylindrical body 2 of the back frame 1, and is integrally molded into a cylindrical shape from synthetic resin. A substantially circular flange 6 and a tongue piece 7 projecting outward from the flange are provided at the upper end of the support member 5. The flange 6 and the tongue piece 7
An upper slit 9 reaching the central hole 8 is formed in the horizontal direction between the two. Incidentally, a stopper 10 is provided protruding from the inner surface of the upper slit 9, as shown in FIGS. 3 and 5. A horizontal lower slit 11 reaching the central hole 8 is formed at the lower part of the peripheral surface of the support member 5, and a vertical groove 12 is formed in the vertical direction between the upper slit 9 and the lower slit 11 to connect these slits. ing. A protrusion 13 is provided on the upper outer circumferential surface of the support member 5 to engage with the cut groove 2a of the cylinder body 2 to prevent the support member from rotating, and the lower end portion is latched to the lower edge of the cylinder body 2. Claw 1
4 is provided.

Reference numeral 15 denotes a locking spring made of a single spring wire, which has a knob portion 16 at the tip of a horizontal upper end portion 15a;
The intermediate portion 15b is vertical, and the lower end portion 15c is bent horizontally. Upper end 1 of the locking spring 15
5a, intermediate portion 15b, and lower end portion 15c are fitted into the upper slit 9, vertical groove 12, and lower slit 11 of the support member 5, respectively, and the knob portion 16 is located on the upper surface of the tongue piece 7. And locking spring 1
5 is rotatable around an intermediate portion 15b fitted in the vertical groove 12, as shown in FIG. 4, and the rotation angle is regulated by a stopper 10 provided on the inner surface of the upper slit 9. There is.

Next, the operation of the headrest locking device having the above structure will be explained.

First, as shown in FIG. is engaged with the cut groove 2a and is prevented from rotating, and the claw 14 is engaged with the cylindrical body 2a.
It is locked to the lower edge of the holder to prevent it from coming off. At this time,
Since the locking spring 15 is sandwiched between the support member 5 and the cylindrical body 2, it will not fall off.

Next, as shown in Figure 2, attach the headrest support rod 4.
When inserted into the center hole 8 of the support member 5, the lower end 15c of the locking spring 15 is pushed outward (in the direction of arrow A in FIGS. 4 and 8) by the tapered tip 4b of the headrest support rod 4. This causes the locking spring 1
The upper end portion 15a of the headrest support rod 5 rotates inward and comes into pressure contact with the circumferential surface of the headrest support rod 4. At this time, locking spring 1
The upper and lower ends 15a and 15c of 5 are in an open state from the natural position. Further, when the headrest support rod 4 is inserted to the position where the notch 4a and the upper end 15a of the locking spring 15 correspond, the upper end 15a of the locking spring 15
5a is fitted into the notch 4a by its own spring force (the state shown by the dashed line in FIG. 4), and the headrest support rod 4
is locked.

In addition, the support member 5 of the headrest support rod 4
When changing the protrusion length from the headrest 3, that is, the height of the headrest 3, the knob 16 of the locking spring 15 is
Move the upper end 1 of the locking spring 15 in the direction of arrow B in the figure.
5a from the notch 4a of the headrest support rod 4. In this state, the headrest support rod 4 can be moved up and down, and when pushed to a predetermined position, the upper end 15a of the locking spring 15 will fit into the notch 4a again, and the headrest support rod 4 will be locked in this position. In particular, when adjusting the height of the headrest 3, the lower end 15c of the locking spring 15 comes into pressure contact with the circumferential surface of the support rod 4 to apply a braking force, so that the support rod 4 does not move more than necessary. Therefore, head rest 3
This can solve the problem of falling to the bottom or being pulled out.

As described above, the intermediate portion 15b of the locking spring 15 is rotatably fitted into the vertical groove 12, so that the locking spring 15 can rotate about the intermediate portion 15b as a fulcrum. When the locking spring is inserted into the center hole 8 of the support member 5, the locking spring rotates and the upper end 15a retreats outward, making insertion easier, and the upper end 15a of the locking spring fits into the notch 4a. When this is done, the lower end portion 15c retracts outward and no unreasonable twisting force is applied to the locking spring, which has the advantage of extending the life of the locking spring.

As is clear from the above explanation, according to the present invention, the headrest locking device is composed of two parts, the support member and the locking spring, so the number of parts is extremely small and the structure is simple. Assembly is also very simple because the support member can be assembled by simply fitting it into the slit and groove of the support member.

Also, when adjusting the vertical position of the headrest, if the upper end of the locking spring is operated in the direction of disengaging from the notch, the locking spring rotates about the middle part as a fulcrum, and the lower end comes into pressure contact with the circumferential surface of the support rod. Therefore, braking force is applied to the support rod, and the problem of the headrest moving more than necessary can be solved. Furthermore, since the locking spring is rotatable around the middle part, when inserted into the center hole of the support member of the headrest support rod,
Since the upper end of the locking spring retracts outward, insertion is easy, and while the upper end of the locking spring is fitted into the notch, the lower end retracts outward.
A large torsional force does not always act on the locking spring, which has the effect of contributing to improving the life of the locking spring.

[Brief explanation of the drawing]

Fig. 1 is an overall perspective view of the headrest locking device according to the present invention, Fig. 2 is a sectional view of the main part thereof, Fig. 3 is a front view of a support member to which a locking spring is attached, and Fig. 4 is a plan view. 5 is a partial cross-sectional view taken along the line - in FIG. 4, FIG. 6 is a cross-sectional view taken along the line - in FIG. 3, FIG. 7 is a sectional view taken along the line - in FIG. It is. DESCRIPTION OF SYMBOLS 1...Back frame, 2...Cylinder body, 3...Head rest, 4...Head rest support rod, 4a...
... Notch, 5 ... Support member, 8 ... Center hole, 9
... Upper slit, 11 ... Lower slit, 12
... Vertical groove, 15 ... Locking spring, 15a ... Upper end portion, 15c ... Lower end portion, 16 ... Knob portion.

Claims (1)

[Scope of utility model registration request] A cylindrical support member that is inserted into the top of the backrest of the seat and has horizontal upper and lower slits that penetrate inside and outside the circumference and vertical grooves that connect the upper and lower slits, and one end that is fixed to the headrest. is,
the other end is inserted into the central hole of the support member,
A head rest support rod is provided with a notch for adjusting the vertical position in the insertion part, and a single spring is fitted into the slit and vertical groove of the support member and has a knob portion protruding outward at the tip of its upper end. A locking spring made of a wire rod is provided, the lower end of the locking spring protrudes from the lower slit into the central hole and comes into pressure contact with the circumferential surface of the headrest support rod, and the intermediate portion is rotatably fitted into the vertical groove. 1. A headrest locking device, characterized in that the upper end portion can project into the central hole from the upper slit and engage with a notch in the headrest support rod by the torsional elasticity of the locking spring.