JP2010030573A - Universal caster and dolly using this universal caster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate straightforward movement and turning operation of a dolly employing universal casters as all front and rear wheels, and, in particular, provide the universal caster capable of improving vertical movement of the dolly occurring at the time of turning, and provide the dolly having the universal casters installed therein. <P>SOLUTION: The universal caster comprises a main shaft installed to a top plate attached to the rear surface of a body of a dolly with an inclination angle to form a caster angle, a fork installed through a bearing for accepting the main shaft and a wheel having a wheel axis located at a position of the fork offset from an extension line of the main shaft. The universal caster described above is provided with a correction means for making correction for keeping the total length always constant even if the main shaft and the bearing turn due to vertical movement of the caster at the time of turning. If the front wheel and the rear wheel are installed with inclinations opposite to each other, for example, straight forward movement is facilitated by the front wheel or the rear wheel, and further turning operation is facilitated by the rear wheel or the front wheel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a universal caster improved so that traveling performance of a cart with all front and rear wheels as a universal caster is improved, and a cart using the caster.

A cart with all wheels as free casters can be moved in all directions, but there are difficulties in operation in straightness and course changes.
As a countermeasure, there has been one in which the straightness is improved by tilting the main shaft of the free caster with respect to the horizontal surface of the carriage in order to improve the straightness of the carriage. (For example, see Patent Document 1)
Japanese Patent Laid-Open No. 2001-1706 (second page, FIG. 1)

A universal caster and a vehicle equipped with the universal caster shown in Patent Document 1 use the universal caster by attaching the axis of the universal caster to the traveling direction of the carriage 11 in a state where both the front and rear wheels are inclined rearward. However, the cart is straight.
However, when the vehicle is moved backward by the carriage using the free caster having the main shaft inclined as described above, the axis of the wheel rotates and moves between the ground contact surface of the wheel and the carriage as shown by the dotted line in FIG. There was a drawback that the interval changed.
This is because the universal caster has an action of positioning the center of the wheel, that is, the axle, behind the main shaft, which is always the axial center, in the moving direction. As a result, when the moving direction of the carriage is changed, the bracket 3 to which the wheel is attached rotates and moves to a position indicated by a dotted line in FIG.
Since this universal caster is attached to the inclined projection 7 inclined with respect to the carriage surface, the bracket 3 and the wheel also change their height to the ground contact surface due to their rotational movement. Therefore, every time the traveling direction of the carriage is reversed, the carriage moves up and down due to the rotational movement of the main shaft by changing the direction of the wheels, and a heavy load has to require a great deal of labor.
In addition, both the front and rear wheels of the free caster have the drawback that the main shaft is inclined in the same direction to improve the straight traveling performance, so that although the free caster is a free caster, the direction changeability is somewhat sacrificed.
The present invention has been made to eliminate such drawbacks, and the free caster whose height of the cart does not change even if the main shaft of the free caster is inclined and attached to the cart or the traveling direction is reversed. It is an object of the present invention to provide a universal caster that can provide a cart that can be easily changed in direction and a cart that uses the caster.

Means for Solving the Invention

In order to solve the above problems, the present invention has the following configuration.
The universal caster according to claim 1 includes a top plate attached to the back side of the carriage main body, a main shaft attached with an inclination of the attachment angle, and a bifurcated fork provided via a bearing that receives the main shaft. The wheel having the axle is provided at a position different from the extension line of the main shaft of the fork.
If the traveling direction of the wheel is reversed, the vertical movement of the cart body caused by the inclination of the main shaft to the mounting surface and the mounting position of the wheel provided with the axle at a position different from the extension line of the main shaft. A free caster is provided by providing correction means for correcting.
According to such a free caster, unnecessary force for moving the cart up and down necessary for the start of the movement of the cart is unnecessary as in the case of a free caster without height correction means even if the traveling direction is reversed. Swivel caster.
According to a second aspect of the present invention, there is provided a universal caster according to the first aspect, wherein an elliptical inclined groove is provided so as to go around the outer periphery of the main shaft of the universal caster or the inner periphery of the bearing, and a ball for guiding the rotation of the inclined groove. By providing a height correction means comprising a bearing, a free caster in which the wheel moves up and down according to the change of the direction of the wheel is provided.
Such a free caster is such that the height direction between the ground contact surface of the wheel and the top plate is always kept constant even if the direction of the wheel changes.
According to a third aspect of the present invention, the universal caster is a universal caster that is mounted by reversing the mounting relationship between the main shaft and the bearing described in the second aspect. That is, the bearing was attached to the top plate, and the main shaft was attached to the bearing.
By providing such a universal caster with the same height correction means as described in claim 2, the same operation and effect as in claim 2 can be obtained.
According to a fourth aspect of the present invention, there is provided a universal caster according to any one of the first to third aspects, wherein a height correction means comprising a caster in which the top of the universal caster is always in contact with the top of the fork of the top of the fork. By providing it, it became a free caster.
Even when the direction of the swivel caster is changed, the top of the caster provided on the top of the fork is always in contact with the back side of the top plate, so that the distance between the carriage and the wheel ground contact surface is constant. The interval is kept constant.
According to a fifth aspect of the present invention, the bogie according to any one of the first to fourth aspects is attached to the front wheel and the rear wheel of the main body of the bogie body, and the inclination of the main shaft of the front wheel and the rear wheel is opposed to each other. It was made into a cart by arranging it.
In this way, the inclination of the main shaft of the free caster is opposed to the front and rear wheels, so that the straightness as one free caster and cart can be changed easily as the cart with the other free caster.

The invention's effect

According to the present invention, the following effects can be obtained by providing correction means for correcting the vertical movement of the wheel that occurs when the direction of the wheel changes in the universal caster that is mounted with the shaft center inclined. did it.
That is, even if the traveling direction of the wheel changes, the vertical movement of the wheel is corrected, so that it is possible to always move horizontally and to carry a load that is not susceptible to vibration.
Since the vertical movement at the time of turning was corrected and lost, the turning of the wheel became smoother, and the reversing operation of the traveling direction could be moved with a smaller force.
By arranging this universal caster as the front and rear wheels of the carriage so that the inclinations of the main shafts face each other, the straight movement and direction changeability of the carriage can be further facilitated while using the front and rear wheels. It was possible to obtain effects such as the ability to obtain a cart.

The present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a universal caster of the present invention, and FIG. 2 is an explanatory view showing an essential part of FIG.
As shown in FIGS. 1 and 2, the universal caster 10 of the present invention is attached to the back side of a cart (not shown), and has a top plate 11 having an inclined surface 13 at the center thereof, and attached to the inclined surface 13 of the top plate. The main shaft 15, a cylindrical bearing 18 attached to the main shaft in a rotatable state, and a wheel 25 attached to the bearing.
The top plate 11, the main shaft 15, the bearing 18, and the wheel 25 will be described in more detail.
The top plate 11 is rectangular and has a plurality of mounting holes 12 provided in the periphery for mounting on the carriage, and also has an inclined surface 13 for attaching a main shaft 15 as a caster at the center.
The main shaft 15 has a columnar shape and is attached obliquely to the top plate surface because it is attached to the inclined surface 13 of the top plate 11.
That is, the main shaft is set to have a so-called caster angle by crossing with the ground contact surface.
The bearing 18 has a cylindrical shape in which one end of the main shaft 15 can be inserted, and is arranged so as to move up and down with respect to the main shaft 15 in the direction indicated by the arrow in the drawing.
A wheel is attached to the bearing 18 via a bifurcated fork 26 provided for attaching an axle 28 of a tire 29.
The tip of the fork 26 is formed in a bowl shape, and an axle 28 serving as the center of the tire 29 is attached thereto.
That is, the tire 29 is provided with an axle 28 that is the center of rotation at a position in a so-called offset state that is separated from the center line of the main shaft 15 and the bearing 18.
As described above, the configuration in which the main shaft 15 and the bearing 18 move up and down will be described in detail with reference to the drawings.
As shown in FIG. 2, the surface of the main shaft 15 attached to the inclined surface 13 of the top plate 11 is provided with an inclined groove 22 that makes a round around the main shaft to form an ellipse. Further, a ball bearing 23 that rotates in an inclined groove 22 provided in the main shaft is provided in the cylindrical bearing 18.
This ball bearing is mounted in a rotatable state at a predetermined position in the bearing. Therefore, when the traveling direction of the wheel 25 changes, the bearing 18 rotates, and the ball bearing 23 provided in the bearing moves along the inclined groove 22, so that the main shaft 15 and the bearing 18 are shown in the drawing. It moves up and down in the A direction indicated by the arrow.
The inclined groove 22 and the ball bearing 23 form a correcting means 20 that moves the main shaft 15 and the bearing 18 up and down to correct their height.

The necessity of the correction means 20 that is a feature of the present invention will be described in more detail with reference to the drawings. FIG. 3 is an explanatory diagram for explaining the necessity of the correcting means shown in FIG.
As shown in FIG. 3, the main shaft 15 attached to the inclined surface 13 of the top plate 11 and the bearing 18 are separated from the central shaft 5 by a distance H with the direction of arrow C in the drawing as the traveling direction. The wheel 25 provided with is positioned in the direction indicated by the solid line in FIG.
When the traveling direction changes to the direction indicated by the arrow D in the figure, the wheel 25 is positioned in the direction indicated by the dotted line in the figure.
This is because the main caster is tilted and the wheel 25 is always located at the rear of the traveling direction in the universal caster provided with the axle separated from the central axis of the main shaft by a distance H.
Accordingly, when the traveling direction of the wheel 25 having the axle 28 separated from the central axis 5 of the main shaft 15 by H is reversed in the direction indicated by the arrow D, the axle 28 also moves to the opposite side from the central axis 5 in the figure. And the ground contact surface 6 of the wheel 25 also changes.
In other words, the distance between the top plate 11 and the ground contact surface 6 of the wheel changes, and such a universal caster has an interval between the top plate 11 and the ground contact surface 6 of the wheel 25 each time the direction is changed. , Will move up and down. When such a free caster is attached to the carriage, the carriage height of the carriage will move up and down each time the direction is changed, especially in the direction of raising the carriage, it requires a lot of force to push the carriage. turn into.
As a countermeasure, according to the present invention, the height correcting means 20 is provided so that the height between the carriage and the wheel is always constant even if the traveling direction of the carriage changes.
This correction means 20 is the same as the height corresponding to the height change that occurs when the free caster is reversed from the traveling direction.
That is, as shown in FIG. 2, the correction amount is the distance between the high and low positions of the elliptical inclined groove 22 provided on the main shaft 15.

A modification of the universal caster 10 shown in FIG. 1 will be described with reference to the drawings. FIG. 4 is a modified example of FIG.
As shown in FIG. 4, a universal caster 30 shown as a modified example has a main shaft 35 and a bearing 38 mounted in the opposite manner to the example of FIG.
The top plate and wheels are the same as in the above example, except that a cylindrical bearing 38 is fixed to the inclined surface 33 of the top plate 31 and the main shaft 35 is inserted into the bearing.
It is also possible to provide a correction means 40 for correcting the height by providing an elliptical inclined groove 42 on the cylindrical surface of the main shaft 35 and a ball bearing similar to that shown in FIG. The same.
However, the arrangement position of the inclined groove 42 and the inclination direction are different, and a ball bearing (not shown) is also set to enter the groove.
A wheel is attached to one end of the main shaft 35 formed in this way, and such a free caster can also obtain the same operations and effects as the above-described example.

Another example of the caster according to the present invention will be described with reference to the drawings. FIG. 5 is a partially exploded perspective view showing another example of the universal caster of the present invention, and FIG. 6 is an explanatory view showing the assembled state of FIG.
As shown in FIG. 5, a universal caster 50 shown in another example of the present invention is attached to the back side of a cart (not shown) and has a top plate 51 having an inclined surface 53 at the center thereof, and an inclined surface 53 of the top plate. A cylindrical main shaft 55 attached to the shaft, a bearing 58 attached to the main shaft so as to be rotatable and movable up and down via a correction means 60, and a wheel 65 provided via a bearing plate 59 to which the bearing 58 is attached. It consists of.
A cylindrical main shaft 55, a cylindrical bearing 58 rotatably provided on the main shaft, and a wheel 65 are the same as those in the above-described example, and different top plate 51, bearing plate 59 and correction means 60 are Further details will be described.

As shown in FIGS. 5 and 6, since the top plate 51 is provided with the inclined surface 53 projecting toward the mounting surface side of the carriage, both ends thereof are bent toward the mounting surface side of the carriage, and the top portion is formed. A plurality of mounting holes 52 for mounting on the carriage are provided on the surface further bent into a bowl shape. The main shaft 55 is attached to the inclined surface of such a top plate as in the above example.
A bearing plate 59 made of a rectangular plate is attached to the other end side of the bearing 58 whose one end is inserted into the main shaft 55, and a tire is attached via forks extending on both sides on one end side of the bearing plate. Wheel 65 is formed.
On one end side of the bearing plate 59, a height adjusting correcting unit 60 made of a second caster is provided in the same direction as the protruding direction of the bearing 58. The second caster is also referred to as a surface caster, which may be either a spherical shape at the top or a wheel type referred to as a hammer caster, but the illustrated one is a surface caster.
When the universal caster using the correcting means 60 is attached to a cart or the like, it is arranged at such a height that the top of the second caster always contacts the back side of the top plate 51 with the weight of the cart or the like. Yes.
As shown in FIG. 6, the main shaft 55 and the bearing 58 are mounted in a state in which the main shaft 55 and the bearing 58 can move up and down as indicated by arrows in the figure, so that the bearing 58 moves up and down even if the traveling direction of the universal caster 50 changes. Thus, the top of the second caster rotates along the circle indicated by the dotted line in FIG. 5 while always contacting the back surface of the top plate.
As described above, as shown by the dotted line in FIG. 6, the top of the second caster, which is the height correction means 60, is arranged with respect to the top plate disposed parallel to the mounting surface of the carriage by the vertical movement of the bearing 58. By always making contact, the vertical movement of the free caster due to the change of direction is absorbed.
According to this universal caster, it is possible to eliminate the need for an inclination groove for height correction on the main shaft or the like.

A cart using a free caster provided with a height correcting means of the present invention will be described with reference to the drawings. FIG. 7 is an explanatory view of a cart using a free caster having a height correcting means of the present invention.
As shown in FIG. 7, the cart 70 of the present invention is provided with a front wheel 74 and a rear wheel 76 each consisting of a pair of free casters at both ends on the back side of the cart body on which a load is placed. These universal casters are the universal casters of the above-described examples, and the front wheels and the rear wheels are attached to face each other so that the respective caster angles are opposite to each other.
For example, as shown in FIG. 7, when the main shafts of the pair of front wheels 74 are tilted backward, the main shafts of the pair of rear wheels 76 are tilted forward and indicated by an arrow F in the drawing.
Conversely, when the main shafts of the pair of front wheels are tilted forward, the pair of rear wheels may be mounted so as to tilt backward.
When the direction of the cart 70 is changed, the cart 70 can move smoothly without moving up and down by the height correction means described above. Further, by attaching the caster angles of the universal casters so as to be opposite to each other with the front and rear wheels, the following operation is performed.
That is, in the example shown in FIG. 7, the distance between the top of the main shaft of the front wheel and the ground contact position of the wheel is set wide, and the straightness of the universal caster is improved. Further, since the distance between the top of the main shaft and the ground contact position of the wheel is reduced, the rear wheel is attached in a manner that improves the rotation.
Therefore, it is a cart that is superior in direction change compared to a cart in which the caster angle of the universal caster is set in the same direction for both the front and rear wheels.
Further, the front and rear wheels are opposite to those in FIG. 7, and the same operation and effect can be obtained even with a cart in which the main shaft of the front wheel is inclined forward as indicated by the arrow F in the drawing and the main shaft of the rear wheel is inclined rearward. Can do. In this example, straightness can be achieved with the rear wheels, and ease of turning can be obtained with the front wheels.

  It is a perspective view which shows the universal caster of this invention.   It is explanatory drawing which decomposes | disassembles and shows the principal part of FIG.   It is explanatory drawing explaining the necessity of the correction | amendment means shown in FIG.   It is explanatory drawing which decomposes | disassembles and shows the principal part of the modification of the universal caster shown in FIG.   FIG. 6 is a partially exploded perspective view showing a universal caster according to another example of the present invention.   It is explanatory drawing which shows the assembly state of FIG.   It is explanatory drawing of the trolley | bogie using the free caster which has a height correction means of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Universal caster 11 Top plate 13 Inclined surface 15 Main shaft 18 Bearing 20 Correction means 22 Inclined groove 25 Wheel 26 Fork 30 Free caster 31 Top plate 33 Inclined surface 35 Main shaft 38 Bearing 40 Correction means 42 Inclined groove 50 Free caster 51 Top plate 55 Main shaft 58 Bearing 59 Bearing plate 60 Correction means 65 Wheel 70 Bogie 72 Bogie body 74 Front wheel 76 Rear wheel

Claims (5)

A top plate to be attached to the back side of the cart body;
The top plate is a main shaft provided with an inclined mounting angle;
A wheel mounted on a main shaft or a bifurcated fork provided via a bearing mounted on the main shaft, and a wheel mounted with the axle mounted at a position different from the extension line of the main shaft;
Changing the traveling direction of the wheel corrects the vertical movement of the main body of the carriage caused by the inclination of the main shaft to the mounting surface and the mounting position of the wheel provided with the axle at a position different from the extension line of the main shaft. In addition, a universal caster comprising correction means for correcting the distance between the ground contact surface of the wheel and the carriage main body to be constant even if the traveling direction of the carriage main body changes. Attached to the back side of the cart body, and a top plate having an inclined surface in a part thereof,
A cylindrical main shaft attached to the inclined surface of the top plate;
This main shaft is a cylindrical bearing provided in a rotatable state around its outer periphery,
A wheel having the axle disposed at a position different from the extension line of the main shaft through a forked shape formed integrally with the bearing;
When the traveling direction of the wheel changes and the distance between the ground contact surface of the wheel and the cart body changes, the outer circumference of the main shaft or the bearing is adjusted so that the distance is corrected to be constant corresponding to the change. A free caster having an elliptical inclined groove provided so as to go around the inner periphery and a correcting means comprising a ball bearing for guiding the rotation of the inclined groove. Attached to the back side of the cart body, and a top plate having an inclined surface in a part thereof,
A cylindrical bearing for attaching one end to the inclined surface of the top plate;
Via a bifurcated fork provided integrally with the main shaft rotating in the bearing, a wheel provided with the axle at a position different from the extension line of the main shaft;
When the traveling direction of the wheel is changed and the distance between the ground contact surface of the wheel and the carriage body is changed, the outer periphery of the main shaft or the bearing is corrected so as to uniformly correct the distance corresponding to the change. A free caster having an elliptical inclined groove provided so as to make one round of the inner periphery thereof and a correcting means comprising a ball bearing for guiding the rotation of the inclined groove. Attached to the back side of the cart body, and a top plate having an inclined surface in a part thereof,
A cylindrical main shaft attached to the inclined surface of the top plate;
A cylindrical bearing that is rotatable at one end of the main shaft and is movable up and down;
A plate-like bearing plate provided at one end of the bearing;
Via a bifurcated fork formed by bending both sides of one end of the bearing plate, a wheel provided with the axle at a position different from the extension line of the main shaft;
Height correction consisting of a caster that is provided on one end side of the bearing plate so as to protrude in the same direction as the previous bearing, and that rotates on the flat surface around the inclined surface provided on the top plate. Swivel caster having means. The top plate attached to the back side of the main body of the carriage is provided with a fork for attaching a wheel via a main shaft attached obliquely, and the wheel attached to the fork is at a position different from the extension line of the main shaft. A universal caster body with the axle disposed,
When this universal caster body changes its traveling direction, the vertical movement of the carriage body caused by the inclination of the main shaft and the mounting position of the wheel provided with the axle at a position different from the extension line of the main shaft is corrected. And a free caster having a correction means that makes the distance between the carriage main body and the wheel installation surface constant.
A bogie characterized in that the universal casters are arranged in pairs on the front wheel and the rear wheel of the bogie body, and the inclination of the main shaft of the front wheel and the rear wheel is opposed to each other.

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