JPS6317859Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shaft locking device using a spring clutch.

Conventionally, this type of shaft locking device uses gear meshing, or uses only the forward rotation side locking force of a spring clutch. Here, forward rotation means that a load is applied in the direction that reduces the diameter of the spring, tightening and locking the core metal, and reverse rotation is the opposite of normal rotation, in which a load is applied in the direction that increases the diameter of the spring. , slipping with a small force.

However, the conventional locking device described above firstly requires a lock release mechanism, and secondly, the structure is complicated, resulting in high cost. Thirdly, if an overload is applied, it will be difficult to release the lock, which may be dangerous.
There were other drawbacks.

The present invention was developed in view of the above-mentioned drawbacks of the conventional art, and utilizes the spring clutch's slip characteristics in both forward and reverse rotational directions to allow stepless angle adjustment without a lock release mechanism. ,
The object of the present invention is to provide a shaft locking device that can be applied to angle adjustment mechanisms of reclining headrests, footrests, etc. of various chairs.

In order to achieve such an object, the present invention provides a rotating device having a shaft with one end attached to a fixed member and the other end fixed to a rotating member, a spring inserted into the shaft, and a spring attached to the fixed member. It consists of a bolt that is attached so that it can move in a straight direction, and a movable piece that is screwed into the bolt.One hook of the spring is fixed to a fixed member, and the other hook of the spring is locked to the movable piece. be.

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1A, 1B, and 1C are a side view, a top view, and a front view showing one embodiment of the present invention, in which 1 and 2 are brackets fixed to each mating part, and 3 is fixed to the bracket 2. It is also a cored metal serving as a shaft which is rotatably attached to the bracket 1 with an E-ring or the like. Further, the bolt 4 is rotatably inserted into the mounting pieces 1a, 1a provided on both sides of the bracket 1, and is secured with an E-ring 7, and a spring hook moving piece 5 is screwed onto the bolt 4. It is inserted. Reference numeral 6 denotes a spring, and this spring 6 has a coil portion having a smaller diameter than the outer diameter of the core bar 3, and one hook 6a is engaged with the bracket 1, and the other hook 6b is engaged with the recess of the spring hook moving piece 5. I am making it match. As shown in FIG. 3, the movable piece 5 at this time has two triangular prisms 5c, 5c arranged at appropriate intervals on the upper surface of a cubic main body 5b, which has a screw hole 5a through which the bolt 4 is screwed. They are provided with their apex angles facing each other. In this embodiment, the gap between the triangular prisms 5c and 5c is the spring 6.
The hook 6b is formed to have a width equivalent to the width of the hook 6b, and rotation of the movable piece 5 is restrained by engaging the hook 6b in the recess formed by this gap and the upper surface of the main body 5b. Therefore, when the bolt 4 rotates, the moving piece 5 moves straight along the bolt 4 without rotating together with the bolt 4.

Next, to explain the operation of the shaft locking device configured as described above, the spring hook moving piece 5 moves in the direction a or b by the rotation of the bolt 4, and the movement of the spring hook moving piece 5 moves the core metal 3. The tightening force of the spring 6 can be freely changed. The locking force can be adjusted by changing the free inner diameter of the spring 6 relative to the core metal 3. That is, if the spring moving piece 5 is moved in the direction a, the free inner diameter of the spring 6 becomes smaller, increasing the locking force, locking the rotation of the bracket 2 in both the forward and reverse directions, and exceeding the above locking force. When a load is applied to the bracket 2, the bracket 2 is able to rotate in the direction of the load (forward or reverse direction) while producing a slip between the spring 6 and the core metal 3. On the other hand, when the spring moving piece 5 is moved in the direction b, the locking force decreases, and when the free inner diameter of the spring 6 is larger than the diameter of the core metal 3, the locking force becomes zero.

Therefore, when this device is applied to a reclining mechanism, for example, the position is maintained by the locking force against a pressing force less than the locking force of the spring, but the angular position can be freely changed by applying a load of a force greater than the locking force. This also provides an escape route in case of inadvertent force being applied, and is useful for preventing danger. In the case of this device, the same locking force is obtained for rotations in directions c and d.

In addition, FIGS. 2A, 2B, and 2C are side views, top views, and front views showing other embodiments of the present invention, and the same members as those in the embodiment shown in FIG. This embodiment then differs from the embodiment shown in FIG. 1 only in the formation of the spring hook moving piece 5.
That is, as shown in FIG. 4, the movable piece 5' is formed so that the opposing gap between the triangular prisms 5'c and 5'c provided on the main body 5'b is larger than the width of the hook 6b of the spring 6. The only difference is that it is wider than the embodiment shown in FIG. Therefore, in this embodiment, when the hook 6b is loosely inserted into the recess formed by the opposing gap between the triangular prisms 5'c and 5'c and the upper surface of the main body 5'b, the hook 6b is pushed by the biasing force of the spring 6. It abuts and is locked on one triangular prism 5'c (the second
A free gap t is maintained between the other triangular prism 5'c and the hook 6b, in which the hook 6b can move. Therefore, unlike the embodiment of FIG. 1 in which the same locking force is obtained in both rotational directions of the bracket 12, the hook 6b is a free end when the bracket 2 is rotated in the c direction, and Since this is the direction in which the inner diameter of the spring 6 is enlarged, the frictional force between the spring 6 and the core metal 3 is reduced when the bracket 2 is rotated in the c direction, and the bracket 2 can be rotated with a small force. On the other hand, the same locking force as in the embodiment shown in FIG. 1 is applied to the rotation of the bracket 2 in the d direction.

As explained in detail above, since the present invention has the above structure, a lock release mechanism is not required, the structure is simple and can be provided at low cost, and stepless angle adjustment is possible without unlocking. ,
It is possible to prevent danger even if overload is applied inadvertently. Furthermore, by moving the spring hook moving piece, the locking force of the spring can be changed arbitrarily.
This adjustment produces practical effects such as being able to reduce and stabilize variations in locking force.

[Brief explanation of drawings]

Figure 1 A, B, and C are side views, top views, and front views showing one embodiment of the present invention; Figures 2 A, B, and C are side views, plan views, and other views showing other embodiments of the present invention; Front view,
Figure 3 A, B, and C are plan views of the moving piece of the present invention;
FIGS. 4A, 4B and 4C are a plan view, a side view and a front view of other embodiments of the moving piece. 1, 2... Bracket, 3... Core metal, 4... Bolt, 5, 5'... Spring hook moving piece, 6...
Spring, 6a, 6b... hook.

Claims (1)

[Scope of utility model registration request] In a rotating device having a shaft with one end attached to a fixed member and the other end fixed to a rotating member, a spring inserted into the shaft, a bolt rotatably attached to the fixed member, and a screw threaded into the bolt. 1. A shaft locking device comprising a movable piece inserted into the shaft, one hook of the spring being fixed to a fixed member, and the other hook of the spring being locked to the movable piece.