JPH0750242Y2 - Castor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a caster such as a twin-wheel free wheel with a stopper that is used by being attached to the lower portion of a chair, desk, etc. for home or office use.

(B) Conventional Technology Conventional casters of the above-mentioned example include, for example, Japanese Patent Application No. 58-2.
There are casters with a braking device as described in 6682.

That is, a partition wall integrally formed in the center of a semi-cylindrical wheel cover is provided, and the left and right wheels are rotatably attached to the partition wall via an axle, and the partition wall is provided with a through hole for sliding a lock slider, Each of the wheel covers is formed with a hole for inserting a push button, and the push button inserted into the hole so that the push button can be pushed and retracted allows a cam having a heart-shaped cam groove to be loosely fitted in the push button and one end. Is fixed to the holder and the other end of which is positioned in the cam groove, and a lock slider attached to the lower end of the push button,
It is a caster configured to separate the stopper piece of the lock slider from the braking inner wheel of the wheel.

However, in the caster of the conventional structure described above, the predetermined outer surface of the cylindrical body is flattened to form a flat surface portion, and the cam groove is formed on the flat surface portion to form the cam. , Not only the amount of pin projection from the hole bore becomes longer, but also the distance between the hole bore and the groove bottom portion of the heart-shaped cam groove changes when the cam rotates due to the push operation of the push button. , If the pin projection amount is too long, the rotation of the cam is obstructed by this pin, and if the pin projection amount is too short, this pin comes off the cam groove,
In any case, there is a problem that it is difficult to obtain a smooth movement of the cam.

Further, since the above-mentioned pin is implanted in the holder, the implanting strength is low, the implanting of the pin is damaged at an early stage, and the pin falls off, resulting in a problem that the cam operation cannot be obtained.

(C) Problem to be solved by the invention With this invention, by smoothly setting the structure of the pin, cam and cam groove, smooth movement of the cam can be obtained, and the stopper operation can be reliably performed over a long period of time. The purpose is to provide casters that can be obtained.

(D) Means for Solving the Problems This invention is directed to the heart-shaped cam groove by exposing its linear guide portion and fixing the hook-shaped engaging portion to the pin engaging portion of the holder to form an outer peripheral groove of the holder. And a cam groove into which the guide portion of the pin is inserted in a continuous portion along which the cam groove into which the guide portion of the pin is inserted is formed from the outer surface of the cylinder itself toward the inside of the cylinder. It is a caster having a configuration in which the depth is formed uniformly.

(E) Effect of the Invention According to the present invention, a heart-shaped body having a uniform groove depth inwardly extending from the arc-shaped outer peripheral portion of the cylindrical body without forming a flat portion on the cylindrical body as in the prior art. Since the cam groove is formed, even if the cam rotates due to the push operation of the push button, the gap between the bore of the hole holding the cam and the groove bottom of the heart-shaped cam groove is always constant and does not change. Therefore, there is an effect that a smooth movement of the cam can be obtained by the pin having the predetermined protrusion amount.

In addition, it is possible to reduce the number of conventional cutting steps for forming the flat surface portion and to shorten the protruding length of the guide portion from the hole bore.

Further, the pin engaging with the above-mentioned cam groove is fixed by engaging the continuous groove portion with the concave groove on the outer periphery of the holder and engaging the hook-shaped engaging portion with the pin engaging portion of the holder. Since the load applied to this pin causes the guide part of the pin to fall out of the cam groove, and there is no grit on the pin, it is securely fixed and the smooth cam operation described above is maintained for a long period of time. Can
As a result, there is an effect that the good stopper operation of the caster can be performed for a long period of time.

(E) Embodiment of the Invention One embodiment of the invention will be described in detail below with reference to the drawings.

The drawings show casters. In FIGS. 1, 2, and 3, the casters 1 are made of synthetic resin and have a semi-cylindrical wheel cover 2, and a partition wall 3 integrally formed in the center of the wheel cover 2. And a metal axle 5 press-fitted and fixed in the shaft hole 4 of the partition wall 3, and wheels 6, 6 made of hard synthetic resin rotatably attached to both left and right ends of the axle 5.

As shown in FIG. 4, an inner gear 7 for braking is integrally formed on each of the wheels 6, 6 described above, while a convex through hole 9 for sliding the lock slider 8 is formed in the partition wall 3 described above. ,
Also, the wheel cover 2 has a hole 11 for inserting the push button 10.
Is formed.

The hole portion 11 is a round hole formed in the center of a substantially cylindrical holder 12 integrally formed with the wheel cover 2 and the partition wall 3 so as to communicate with the above-mentioned through hole 9.

The push button 10 described above is provided at the bottom of the cylindrical head portion 13,
Spacer shaft 14, cam shaft 15, engagement shaft 16, taper cone 17
With a push button made of synthetic resin integrally formed in this order, the cylindrical cam 18 is loosely fitted on the cam shaft 15 of the push button 10, and in this state, the cam 18 and the push button 10 are inserted into the hole 11 described above. After that, the lock slider 8 located in the through hole 9 is moved upward, and the locking hole 19 of the lock slider 8 is moved.
Insert the taper cone 17 and the engagement shaft 16 into the
As shown in the figure, these respective elements 10, 18 and 8 are assembled.

In the lock slider 8 described above, the stopper pieces 21, 21 are integrally formed on the slider base 20 along the axial direction of the axle 5, and the outer surface of the partition wall 3 at the hole edge of the through hole 9 is formed in the portion orthogonal to the axial direction of the axle 5. A pair of sliding guide protrusions 22,22 corresponding to
Is a slider made of synthetic resin integrally formed with.

Further, the lock slider 8 is formed with the above-mentioned locking hole 19 and a recess for receiving a spring which communicates with the locking hole 19.
Forming 23.

Then, as shown in FIGS. 2 and 3, the recess 23 of the lock slider 8 assembled to the lower end of the push button 10 and the center of the bottom of the through hole 9 facing the recess 23 are integrated with the partition wall 3 described above. A return spring 25 is stretched between the formed spring seat 24.

On the other hand, in the cam 18 described above, as shown in FIG. 5, a heart-shaped cam groove 27 having a uniform groove depth is formed from the non-planar outer peripheral portion of the synthetic resin cylindrical body 26 toward the inside of the cylindrical body 26. As the cam, the cam 18 is rotatably fitted on the cam shaft 15 of the push button 10 described above.

The pin 28 faces the above-mentioned heart-shaped cam groove 27, and its structure is as shown in FIGS. 6 and 7.

That is, a pin hole 29 communicating with the heart-shaped cam groove 27 is formed at one end of the holder 12 forming the hole 11, and the holder 12 is formed in a rectangular shape at the other end of the holder 12. The pin locking portion 30 is integrally formed.

Further, the above-mentioned pin 28 has a linear guide portion 31 inserted into the pin hole 29, and a hook-shaped retaining engagement portion 32 that engages with the pin locking portion 30, and a concave groove on the outer periphery of the holder 12. It is a metal pin having a circular cross section, which is integrally formed by a continuous portion 34 along a line 33.

Further, the partition wall 3 at the outer edge portion on one side of the holder 12 described above is provided with a mounting hole 35 for mounting the pin 28 described above.

Then, as shown in FIG. 7, the pin hole 29 and the pin 28 of the holder 12 are
When the pin 28 is attached in the direction of the arrow in the figure, the guide portion 31 of the pin 28 is inserted into the heart-shaped cam groove 27 through the pin hole 29, and at the same time the attachment hole is attached. 35
The engaging portion 32 of the pin 28 through the pin engaging portion 30 on the holder 12 side.
, The pin 28 can be attached to the holder 12 with one touch as shown in FIG.

Here, the relationship between the guide portion 31 of the pin 28 and the push button 10 and the cam 18 is as follows.

That is, as shown in FIGS. 1 to 3, the push button
During braking when 10 protrudes from the wheel cover 2, the guide portion 31 of the pin 28 has a heart-shaped cam groove as shown by an imaginary line α in FIG.
When the push button 10 is pressed from this state as shown in FIG. 8, the guide portion 31 moves in the direction of arrow a along the heart-shaped cam groove 27 of FIG. It is located at the locking portion of the heart-shaped cam groove 27 as shown by a virtual line β.

When the push button 10 is pressed again after the guide portion 31 is in the phantom line β position shown in FIG. 5 and is not being braked, the guide portion 31 moves in the arrow b direction along the heart-shaped cam groove 27 shown in FIG. Then, the position returns to the position indicated by the virtual line α, and thereafter, such an operation is repeated each time the push button 10 is pressed.

In this way, the marker 36 for recognizing braking is formed in the lower region of the head 13 of the push button 10 protruding from the wheel cover 2 when the wheels 6, 6 are stopped.

As the marker 36, a color different from that of the push button 10 may be printed and applied by, for example, hot stamping means, or a ring body may be fitted at a predetermined position of the push button 10.

In the figure, 37 is a shaft connecting portion integrally formed with the wheel cover 2 and the partition wall 3, and 38 is a mounting shaft fitted into the shaft connecting portion 37.

The illustrated embodiment is configured as described above, and the operation will be described below.

During braking shown in FIG. 3, the stopper pieces 21, 21 of the lock slider 8 are meshed with the inner gears 7, 7 of the left and right wheels 6, 6 by the spring force of the return spring 25. It does not rotate under braking condition.

In addition, this braking state can be confirmed by the marker 36 formed on the push button 10.

When the push button 10 is pushed down from the braking state shown in FIG. 3 described above, the guide portion 31 of the pin 28 moves along the heart-shaped cam groove 27 shown in FIG. The guide portion 31 is locked by the locking portion of the cam 18,
Since the lock slider 8 is held in the downward movement position as shown in FIG. 8, the stopper pieces 21, 21 of the lock slider 8 are held at positions separated from the inner gears 7, 7 of the left and right wheels 6, 6, and It is possible to set the wheels 6, 6 in the free rotation state.

In addition, from the non-braking state shown in FIG.
When 10 is pressed again, the guide portion 31 of the pin 28 moves in the direction of arrow b in the figure along the heart-shaped cam groove 27 shown in FIG. Returning to the position, the stopper pieces 21, 21 of the lock slider 8 are urged by the spring force of the return spring 25 to move the left and right wheels to the left and right wheels.
As shown in FIG. 3, the inner gears 7 and 7 of 6 and 6 are again engaged with each other to be in a braking state.

Hereinafter, every time the push button 10 is pressed, the braking state shown in FIG. 3 and the non-braking state shown in FIG. 8 are alternately repeated.

By the way, according to the present invention, as shown in FIG. 5, the above-mentioned cylindrical body 26 has a uniform groove depth in which the cylindrical body 26 is in a non-planar state as it is, that is, an inward direction from an arc-shaped outer peripheral portion. Since the heart-shaped cam groove 27 is formed, even if the cam 18 rotates around the cam shaft 15 in accordance with the pressing operation of the push button 10, the bore of the hole 11 of the holder 12 that holds the cam 18 is formed. Since the interval between the heart-shaped cam groove 27 and the groove bottom is always constant and invariable, there is an effect that the cam 18 can be smoothly moved by the pin 28 having a predetermined protrusion amount.

In addition, it is possible to reduce the number of cutting steps for forming the conventional flat surface portion and to shorten the protruding length of the guide portion 31 from the hole 11 bore.

[Brief description of drawings]

 The drawings show an embodiment of the present invention. Fig. 1 is a side view of a caster, Fig. 2 is a side view of the inside of the caster, and Fig. 3 is a sectional view taken along the line III-III in Fig. 2 during braking. FIG. 4 is an exploded perspective view of the caster, FIG. 5 is a perspective view of the cam, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 2, and FIG. 7 is an explanatory view showing the attachment of the pin. The figure is a cross-sectional view during non-braking. 2 ... Wheel cover, 3 ... Bulkhead 5 ... Axle, 6 ... Wheel 7 ... Inner gear, 8 ... Lock slider 9 ... Through hole, 10 ... Push button 18 ... Cam, 21 ... Stopper piece 26 …… Cylindrical body, 27 …… Heart-shaped cam groove 30 …… Pin locking part, 31 …… Linear guide part 32 …… Engagement part, 33 …… Recessed groove 34 …… Continuously connected part

Claims (1)

[Scope of utility model registration request] 1. A semi-cylindrical wheel cover (2) is provided with a partition wall (3) on which a wheel is rotatably mounted via an axle (5), and the partition wall is provided with a transparent member for sliding a lock slider. A hole (9) is formed in the wheel cover, and a hole (11) for inserting a push button is formed in the wheel cover. The push button (10) inserted into the hole so as to project and retract allows the push button to play freely. The cam (18) having the fitted heart-shaped cam groove (27), and the linear guide portion (31) facing the heart-shaped cam groove, and the pin engaging portion (3) of the holder (12).
0) Fix the hook-shaped engaging part (32) to the outer peripheral groove (3
The stopper of the lock slider is provided via a pin (28) having a guide portion and an engaging portion integrated with each other in a continuous portion (34) along with 3) and a lock slider (8) attached to the lower end of the push button. The cam groove (27) for inserting the guide portion (31) of the pin is provided in the cylindrical body (26) of the cylindrical body itself by providing a structure for engaging and disengaging the piece (21) with respect to the inner gear (7) of the wheel. A caster having a uniform groove depth from the outer surface toward the inside of the cylinder.