JP5486480B2 - Caster with shock absorbing mechanism - Google Patents

Description

  The present invention relates to an improvement of a caster having a buffering mechanism that efficiently buffers a load applied to a wheel of the caster and reduces the size of the caster.

A caster having this type of shock absorbing mechanism is a shock absorber that cushions the load applied to the mounting base plate by the elastic force of a coil spring provided between the yoke portion and the support lever portion. For example, as shown in FIG. When the coil spring 32 is externally fitted with the guide pin (or adjusting shaft) 31 as a core material, the upper holder 33 of the coil spring 32 is pushed down so as to be always parallel to the presser piece 34, so that the coil spring 32 is There is a possibility that the elastic force cannot be sufficiently exerted and damage is caused by interference with each other because it does not expand and contract along the axis of the guide pin 31 serving as the core material and is biased to one side.
On the other hand, in order to expand and contract the coil spring along the axis of the guide pin, the present applicant has proposed a caster having a buffer mechanism of Japanese Patent Publication No. 7-77842, and has obtained a corresponding result.
That is, the caster having the buffer mechanism includes a pair of brackets that hang down from both sides of the mounting portion, a fixed abutting surface portion that extends to the rear side of the bracket, and a middle portion of the bracket that pivots forward and backward. A wheel support arm that extends, a wheel that is pivotally supported in front of the wheel support arm, a movable contact surface portion that is provided behind the wheel support arm and that can contact the bottom surface of the fixed contact surface portion, A pressing lid that faces the lower side of the movable abutting surface and is opposed to the lower surface of the movable abutting surface, and protrudes from the upper surface of the pressing lid at the center position in the front-rear direction or the back of the movable abutting surface corresponding thereto. A fulcrum portion that is set to a surface or a spherical surface, converts the displacement of the movable abutting surface portion that tilts in conjunction with the wheel support arm and pivots to the vertical movement of the pressing lid portion, and the fulcrum portion that opens upward and opens the pressing lid portion. It has a bottomed cylindrical shape with an upper edge that can collide with the part And an adjustment screw that protrudes from the bottom surface of the casing, passes through the pressing lid portion and the movable abutting surface portion, and is attached to the fixed abutting surface portion so as to be adjustable in length. It is characterized in that it is provided with a projecting means that protrudes further upward to support the pressing lid portion and urges the pressing lid portion upward so as to be lowered.
As a result of further research and development, the present applicant has developed a structure that can efficiently convert the repulsive force of the coil spring, which is a spring means, into a buffering action with a small number of parts.

Japanese Patent Publication No. 7-77842

  The present invention was devised in view of the above circumstances, and the main problem thereof is that the spring of the coil spring is expanded and contracted by using the spring holding piece to extend and contract the coil spring along the axis of the guide pin. An object of the present invention is to provide a caster having a buffer mechanism that can be expanded and contracted without losing force.

In order to solve the above-mentioned problems, the present invention provides
A yoke part pivotally attached to the lower side of the mounting base, a support lever part pivotally attached to the yoke part at a midway position and pivotally supporting a wheel at the tip, and a guide fixed to the yoke part and extending downward A pin, a coil spring that is externally fitted to the guide pin and restrained at the lower end, an upper holder that is in contact with the upper end of the coil spring, and an upper portion that is provided at the rear of the support lever and is loaded on at least the mounting base A caster having a buffer mechanism that consists of a spring pressing piece that pushes down the holder and buffers the load applied to the mounting base plate by the elastic force of the coil spring.
The spring presser piece has a pair of presser arms that extend to the left and right across the guide pin.
The support lever is formed with a pair of left and right wheel support arms, a long hole connecting the upper part of the pair of support arms and penetrating the guide pin, a horizontal piece part, and fixed below the horizontal piece part It consists of a spring retainer piece,
The tip of the presser arm can abut on the vicinity of the axial position of the guide pin on the upper holder.
In the invention of claim 2,
The spring pressing piece has a substantially semi-circular hole for fitting a guide pin, and a pressing arm is provided so as to surround the right and left of the hole.
In the invention of claim 3,
The spring pressing piece portion includes a pair of pressing arms that hang down from the bottom surface of the horizontal piece portion.

According to the present invention, the spring pressing piece portion is disposed on the upper portion of the upper holder of the coil spring that is externally fitted to the guide pin fixed to the yoke portion so as to be able to collide with the supporting lever portion. Since the tip of the pair of presser arms abuts the vicinity of the axial position of the guide pin along both sides of the guide pin, the coil spring fitted around the guide pin can be expanded and contracted in parallel with the axial line of the guide pin. it can.
As a result, the spring force of the coil spring can be sufficiently exerted, and the coil spring is not biased during compression and does not press the guide pin, thereby extending the life.

It is a side view at the time of no load of the caster which has a buffer mechanism. It is the side view which fractured | ruptured a part which shows the buffer mechanism. It is a side view at the time of load of the caster which has a buffer mechanism. It is the side view which fractured | ruptured a part which shows the buffer mechanism. It is a rear view of FIG. (A) is a top view of a spring pressing piece part, (b) is a side view. It is an enlarged view of the buffer mechanism at the time of no load. It is an enlarged view of the buffer mechanism at the time of load. (A) is an enlarged view of the buffer mechanism when there is no load when the spring pressing piece is not used, and (b) is an enlarged view when loaded.

  A preferred embodiment of a caster having a buffer mechanism according to the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, a caster 1 having a buffer mechanism according to the present embodiment includes a substantially channel-shaped yoke portion 3 that is pivotably mounted below a mounting base 2, and left and right side walls of the yoke portion 3. 3A, a support lever portion 4 pivotally attached by a first pivot P1 at a midway position and having a wheel 5 pivotally supported by an axle P2 at the tip thereof. A buffer mechanism 10 is provided between the unit 3 and the unit 3.

  In this embodiment, the caster portion has a ring-shaped bearing portion (not shown) interposed between the mounting base 2 and the yoke portion 3, and a shaft is provided at the center between the mounting base 2 and the yoke portion 3. It has a known configuration in which the yoke portion 3 is pivotable with respect to the mounting base 2 around the shaft by passing through the upper and lower sides and connecting the two.

[Support lever part]
The support lever portion 4 extends forward, supports the wheel 5 by the axle P2, and a pair of support arm portions 4A pivotally attached to the left and right side walls 3A of the yoke portion 3 by the first pivot P1 at a midway position. It has a horizontal piece 4B that is bridged between the upper parts of the arms 4A and serves as an upper wall that connects the two, and a spring pressing piece 15 that is fixed to the lower surface of the horizontal piece 4B.

[Buffer mechanism]
As clearly shown in FIGS. 7 to 8, the buffer mechanism 10 is attached to the yoke portion 3 and extends downward, and is provided behind the support lever 4 and extends laterally through the guide pin 11. A frame piece portion 4B, a coil spring 12 that is externally fitted with the guide pin 11 as a core and whose lower end is constrained, and an upper holder 13 that is in contact with the upper end of the coil spring 12 and is movable up and down along the guide pin 11; The spring holding piece 15 is provided between the horizontal piece 4B and the upper holder 13.

[guide pin]
The guide pin 11 is attached to the yoke portion 3 by a pin latching portion 6.
That is, a pin latching portion 6 having a channel-shaped cross section is pivotally attached to the yoke portion 3 by the third pivot P3 inside the yoke portion 3 in the direction opposite to the axle P2 with respect to the first pivot P1 of the yoke portion 3. Has been.
Although the pin latching part 6 is pivotally attached to the yoke part 3, it may be fixed.

A hole is formed in the center of the bottom wall of the pin latching portion 6, and the guide pin 11 is fitted in an inclined posture downward, and the head of the guide pin 11 is latched on the bottom wall. It has been.
A buffer pad 7 is fixed to the back surface of the bottom wall of the pin latching portion 6, and cushioning is performed between a later-described horizontal piece 4 </ b> B and the pin latching portion 6.
Further, in the illustrated example, since the third pivot P3 is horizontally mounted so as to be in contact with the head of the guide pin 11, the vertical movement of the guide pin 11 is restricted.

[coil spring]
As will be described later, the guide pin 11 passes through the horizontal piece 4B provided on the support lever 4 and extends obliquely downward beyond the spring pressing piece 15 so that the coil spring 12 is guided by the guide pin 11. It is externally fitted so as to be concentric with the axis.

[Upper holder]
A cylindrical upper holder 13 is fitted on the upper end of the coil spring 12 with a cross-sectional channel with the opening facing downward, and a cylindrical lower holder 18 with a cross-sectional channel with the opening facing upward at the lower end. Is fitted.
In the present invention, the shape of the upper holder 13 is not limited to the above-described embodiment, and may be a simple plate as long as the upper holder 13 can be pushed down in parallel with the upper end of the coil spring 12.

[Lower holder]
A nut 19 is screwed to the lower end of the guide pin 11 to restrain the lower holder 18 from descending.
The lower holder 18 has a shape obtained by inverting the upper holder 13. However, the lower holder 18 may be configured to be in contact with the lower end of the coil spring 12 and to be compressed by the upper holder 13.

[Horizontal part]
The horizontal piece 4B is integrally formed at the rear of the support lever 4 as described above, and has a long hole-like through hole 14 through which the guide pin 11 is inserted. The guide pin 11 does not interfere with the swinging of the support lever portion 4.
The posture of the guide pin 11 is maintained by the through hole 14 of the horizontal piece 4B.

[Spring presser part]
The spring pressing piece 15 is fixed below the horizontal piece 4B.
In the case of the present embodiment, as shown in FIG. 6, a substantially semicircular hole 16 is formed on the rear side of the rectangular plate so as to be externally fitted to the center of the guide pin 11.
Moreover, the both sides of the hole part 16 are a pair of presser arms 17, and the bottom surface 17a at the rear end is chamfered in an arc shape.

Because of the above configuration, when a load is applied to the mounting base 2 from the state of FIGS. 2 and 7 where no load is applied to the mounting base 2, the wheel 5 is pivoted as shown in FIGS. The supporting lever portion 4 that is supported swings in the clockwise direction in the drawing around the first pivot P1.
As a result, the tips of the pair of presser arms 17 of the spring presser piece 15 press down substantially the center of the upper holder 13 evenly.

Since the upper holder 13 is pushed down along the axis of the guide pin 11, the coil spring 12 whose lower end is constrained to a fixed position by the lower holder 18 can also be pushed down along the axis of the guide pin 11 in parallel.
As a result, the coil spring 12 is not subjected to an unbalanced load and does not collide with the guide pin 11, so that the spring force of the coil spring can be sufficiently exerted, and parts can be damaged. Absent.
The present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Caster 2 Mounting base 3 York part 4 Support lever part 4A Support arm part 4B Horizontal piece part 5 Wheel 6 Pin latch part 7 Buffer pad 10 Buffer mechanism 11 Guide pin 12 Coil spring 13 Upper holder 15 Spring press piece part 16 Hole 17 Presser arm 18 Lower holder 19 Nut

Claims (3)

A yoke part pivotally attached to the lower side of the mounting base, a support lever part pivotally attached to the yoke part at a midway position and pivotally supporting a wheel at the tip, and a guide fixed to the yoke part and extending downward A pin, a coil spring that is externally fitted to the guide pin and restrained at the lower end, an upper holder that is in contact with the upper end of the coil spring, and an upper portion that is provided at the rear of the support lever and is loaded on at least the mounting base A caster having a buffer mechanism that consists of a spring pressing piece that pushes down the holder and buffers the load applied to the mounting base plate by the elastic force of the coil spring.
The support lever is fixed to a pair of left and right wheel support arms, a horizontal piece part that connects the upper part of the pair of support arms and has a long hole that penetrates the guide pin, and is fixed below the horizontal piece part. Spring presser piece and
The spring presser piece portion has a pair of presser arms extending left and right across the guide pin,
A caster having a buffering mechanism, wherein the tip of the presser arm can abut on the upper holder in the vicinity of the axial position of the guide pin.   The spring pressing piece has a substantially semicircular hole for fitting the guide pin, and a pressing arm is provided so as to surround the left and right of the hole. A caster having a buffer mechanism.   2. The caster having a buffer mechanism according to claim 1, wherein the spring pressing piece part is composed of a pair of holding arms that hang down from the bottom surface of the horizontal piece part.

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