JPH0444117Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is an extendable device that can be incorporated into a chair or table, for example, to adjust the height and length of the table top, chair back, or headrest. This invention relates to a member length adjustment mechanism.

(Prior Art) In general, as this type of length adjustment mechanism, as shown in Japanese Patent Application Laid-Open No. 59-57603, a base plate fixed to an outer cylinder constituting a telescoping member is mounted in the longitudinal direction of the outer cylinder. A support body is provided on the inner cylinder constituting the telescopic member, and a lock pawl that engages with the engagement portion is attached to the support body via a pivot. A spring is provided between the lock pawl and the support body to allow the lock pawl to swing, and a spring is provided between the lock pawl and the support body to constantly bias the lock pawl in the direction of engaging the engaging portion. A regulating body having a regulating piece that forms an inclined surface for disengaging the locking pawl from the engaging portion when the inner cylinder extends relative to the outer cylinder, and restricting the engagement of the locking pawl to the engaging portion; The lock pawl is attached to the support body so as to be able to reciprocate between an engagement position that allows the lock pawl to engage with the engagement portion and a restriction position that releases the engagement, and first and second control pieces that contact first and second control pieces formed on both sides of the substrate in the direction in which the engagement portion is disposed to reciprocate the regulation body between an engagement position and a regulation position with respect to the support body; A device equipped with a piece has been developed.

(Problems to be Solved by the Invention) However, in the length adjustment mechanism having the above structure, the regulating body for disengaging the locking pawl from the engaging portion is separately formed, and It is necessary to support the regulation body on the support body so that it can freely reciprocate, and also requires first and second contact pieces for operating the regulation body, so that the space for assembling the regulation body and the contact pieces is limited. Not only does this require a large number of parts, it takes time and effort to assemble, and the overall mechanism is complicated, large, and heavy.

Further, a leg body equipped with the above-described length adjustment mechanism is used for a chair, one end of the outer tube is fixed to the chair body, and a seat is assembled to one end of the inner tube to adjust the height of the seat. In this case, the engagement of the locking pawl with the engaging portion reliably locks the movement of the inner cylinder in the storing direction with respect to the outer cylinder, so that the seat can be moved to a desired height. However, since the inner cylinder is free to move in the pull-out direction relative to the outer cylinder, for example, when moving the chair, if you lift the seat, the seat will automatically move into the chair body. There is a problem in that the inner cylinder moves upward relative to the outer cylinder, and the inner cylinder cannot be retracted into the outer cylinder unless the inner cylinder is pulled out to the maximum position relative to the outer cylinder. There are also some problems.

This invention was developed in view of the above circumstances.
The objective is to provide a length adjustment mechanism for an extendable member that has a simple structure with a small number of parts, and that can reliably lock the movement of the inner cylinder relative to the outer cylinder not only in the storage direction but also in the withdrawal direction. is to provide.

(Means for Solving the Problems) The present invention is a length adjustment mechanism of an extendable member in which an inner cylinder 2 is freely inserted into an outer cylinder 1, and the inner cylinder 2 and the outer cylinder 1 are connected to each other. A guide portion 3 extending in the radial direction is formed on one side, and the lock body 4 is provided on the guide portion 3 so as to be freely movable only in the radial direction, and an engaging portion 6 with which the lock body 4 engages is provided on the other side in the vertical direction. a plurality of biasing means 7 for urging the lock body 4 to a position where it engages with the engagement part 6; and a cam for moving the lock body 4 to a position where it is disengaged from the engagement part 6. This device is characterized by being provided with a control body 8 having a surface 8a and an operating lever 9 for the control body 8.

(Function) According to the present invention, the engagement of the locking body 4 with the engaging portion 6 makes it impossible to move the inner cylinder 2 with respect to the outer cylinder 1, and the control lever 9 is controlled via the operating lever 9. By simply operating the body 8, the engagement between the lock body 4 and the engaging portion 6 can be released, and the inner tube 2 can be moved relative to the outer tube 1.

(Example) The length adjustment mechanism of the telescopic member according to the present invention will be explained below according to the example shown in the drawings.

The telescopic member shown in the figure includes an outer cylinder 1 having an oval cross section, and an inner cylinder 2 having an oval cross section smaller than the outer cylinder 1 and slidably inserted into the outer cylinder 1. The inner cylinder 2 consists of a pair of opposing side walls 21, 21 and both opposing side walls 2.
Arc-shaped connecting side wall 2 connecting both ends of 1 and 21
2 and 22, and spacers 10 and 20 are provided at the upper end of the outer cylinder 1 and the lower end of the inner cylinder 2, respectively, to fill the gap between the inner peripheral surface of the outer cylinder 1 and the outer peripheral surface of the inner cylinder 2. During assembly, a length adjustment mechanism according to the present invention is interposed between the outer cylinder 1 and the inner cylinder 2.

The telescopic member shown in the figure is installed between the head rest of the seat and the seat back so that the height of the head rest can be adjusted. It can also be used to adjust the height and length of etc.

The length adjustment mechanism shown in the figure basically includes a guide part 3 formed in the inner cylinder 1, a lock body 4 provided movably along the guide part 3,
An engaging portion 6 of the lock body 4 formed on the substrate 5, a spring 7 that urges the lock body 4 in a direction to engage the engaging portion 6, and a spring 7 that biases the lock body 4 in the direction of engaging the lock body 4 with the engaging portion. The control body 8 includes a control body 8 having a first cam surface 8a that is moved to a position where it is removed from the control body 6, and an operating lever 9 of the control body 8. Next, this length adjustment mechanism will be explained in detail.

In the embodiment shown in the figure, the guide portion 3 is formed in the inner tube 2, and specifically, the guide portion 3 is formed at the lower end of the opposing side walls 21, 21 of the inner tube 2. direction, i.e. the outer cylinder 1 of the inner cylinder 2
Elongated holes extending in a direction perpendicular to the sliding direction of the guide portion 3 are formed to face each other.
It has become.

A cylindrical lock body 4 is placed between the guide parts 3 made of long holes, and the lock body 4 is inserted through the guide part 3 so as to be perpendicular to the sliding direction of the inner cylinder 2 (the vertical direction in FIG. 1). It can only be moved in the direction shown.

Further, in the outer cylinder 1, a substrate 5 made of a rectangular metal plate is inserted into the outer cylinder 1 and the inner cylinder 2, and is tightly fitted into the outer cylinder 1 at one end in the length direction of the substrate 5. The bracket 50 is inserted and fixed, and the bracket 50 is attached to the lower end of the outer cylinder 1 by bolts 50a.
By stopping the substrate 5, the substrate 5 is erected within the cylinders 1 and 2.

A through hole 51 extending in the sliding direction of the inner cylinder 2 is formed in the substrate 5, and a plurality of grooves communicating with the through hole 51 and extending in a direction perpendicular to the through hole 51 are formed. Joining portions 6 are formed at predetermined intervals along the length direction of the outer cylinder 1.

On the other hand, a control body 8 consisting of a pair of plates arranged with the substrate 5 in between is formed, and the control body 8 is
An elongated through hole 81 is formed in the lower part of the guide portion 3 extending in the radial direction, and one of the opposing inner edges of the through hole 81 is connected to the lock body 4. A first cam surface 8a guides the lock body 4 in a direction to separate from the engaging portion 6, and a second cam surface 8b guides the lock body 4 in a direction to engage the engaging portion 6. .

Further, a connecting pin 82 is provided at the upper end of the control body 8, and the connecting pin 82 is inserted into a long hole 25 formed at the upper end of the inner cylinder 2, while an operating lever is provided outside the upper end of the inner cylinder 2. The lever 9 is swingably supported via a pivot 91, and one end of the lever 9 is connected to the connecting pin 82.

A spring 7 is interposed between the control body 8 and the inner cylinder 2, and the spring force of the spring 7 moves the control body 8 downward in FIG.
The lock body 4 is inserted through the second cam surface 8b,
The control body 8 is moved to a position where it engages with the engagement portion 6, and the control body 8 is moved against the spring 7 by a swinging operation of the operation lever 9 in the direction of the first arrow X. Then, the lock body 4
is moved to a position where it is disengaged from the engaging portion 6 via the first cam surface 8a.

Next, the operation of the length adjustment mechanism having the above configuration will be explained.

FIG. 1 shows a state in which the operating lever 9 is not operated. At this time, the control body 8 is moved downward by the spring force of the spring 7, so the lock body 4 is Said second cam surface 8
the engaging portion 6 along the guide portion 3 via b
The inner tube 2 is moved to the side and fitted into the engaging portion 6, and therefore the inner tube 2 cannot slide with respect to the outer tube 1 in both the direction of being pulled out and the direction of being stored. There isn't.

In order to change the length of the telescopic member from the state shown in FIG. 1, it is sufficient to swing the operating lever 9 in the direction of arrow X in FIG. 1, and by swinging the operating lever 9, The control body 8 moves upward against the spring 7, and accordingly, the fifth
As shown in the figure, the lock body 4 moves along the guide portion 3 via the first cam surface 8a in a direction away from the engaging portion 6, and
As a result, the inner tube 2 can freely slide relative to the outer tube 1 in either the pull-out direction or the storage direction.

Then, when the inner cylinder 2 is slid by a predetermined amount in a desired direction with respect to the outer cylinder 1 and the operation of the operating lever 9 is released, the control body 8 is moved downward by the spring force of the spring 7. As the control body 8 moves downward, the lock body 4 is urged toward the engaging portion 6 via the second cam surface 8b.

Thus, when the lock body 4 is in a position facing one of the engaging parts 6, the lock body 4 is immediately fitted into the engaging part 6, and the position of the lock body 4 is in the position opposite to the engaging part 6. If it is misaligned with respect to the engagement part 6, slide the inner cylinder 2 slightly with respect to the outer cylinder 1 in the pull-out direction or the storage direction so that the lock body 5 faces the engagement part 6. Then, the lock body 5 fits into the engaging portion 6, and thereby the telescopic member can be adjusted to a desired length.

In the above embodiment, a spring 7 is interposed between the control body 8 and the inner cylinder 2 to urge the lock body 4 to a position where it engages with the engagement portion 6. It may be interposed between the lever 9 and the inner cylinder 2, or between the lock body 4 and the inner cylinder 2.

Furthermore, in the above embodiment, the guide portion 3 was provided on the inner tube 2 and the engaging portion 6 was provided on the outer tube 1, but the guide portion 3 was provided on the outer tube 1 and the engaging portion 6 was provided on the inner tube 2. The engaging portions 6 may be provided respectively.

(Effects of the invention) As described above, according to the invention, the engagement of the locking body 4 with the engaging portion 6 normally causes the inner cylinder 2 to move not only in the storage direction with respect to the outer cylinder 1 but also in the withdrawal direction. Of course, the movement of the control body 8 can be reliably locked by the simple operation of operating the control body 8 via the operation lever 9.
By releasing the engagement between the lock body 4 and the engaging portion 6, the inner cylinder 2 can be moved with respect to the outer cylinder 1, and the structure is simple with a small number of parts, and the overall structure is simple. This made it possible to downsize the expandable member.

[Brief explanation of the drawing]

The drawing shows one embodiment of the present invention.
The figure is a front view with the outer cylinder cut away, Figure 2 is a front view with the outer cylinder and inner cylinder cut away, Figure 3 is a side view with the outer cylinder and inner cylinder cut away, and Figure 4 is the front view with the outer cylinder cut away. Figure 1-
The enlarged line sectional view, FIG. 5, is an explanatory diagram showing a state in which the inner cylinder is free to slide relative to the outer cylinder. 1...Outer cylinder, 2...Inner cylinder, 3...Guide part, 4
... Lock body, 6 ... Engagement part, 7 ... Spring (biasing means), 8 ... Control body, 8a ... First cam surface (cam surface) 9 ... Operation lever.

Claims (1)

[Scope of utility model registration request] This is a length adjustment mechanism of an extensible member in which an inner cylinder 2 is freely inserted into an outer cylinder 1, and a guide part 3 extending in the radial direction is formed in one of the inner cylinder 2 and the outer cylinder 1. A lock body 4 is provided on the guide part 3 so as to be freely movable only in the radial direction, and a plurality of engaging parts 6 with which the lock body 4 engages are formed in the longitudinal direction on the other hand. a control body 8 having a cam surface 8a that moves the lock body 4 to a position where it is disengaged from the engagement portion 6; and an operating lever 9 of the control body 8. A length adjustment mechanism for a telescopic member, characterized in that it is provided with: