JPH06127201A - Caster - Google Patents

Abstract

PURPOSE:To enable high-speed traveling by absorbing vibration of wheels which move vertically on uneven road surface to prevent adverse effect on cargo during the traveling. CONSTITUTION:A supporting arm 18 of L-form as viewed from the side is connected rotatably in vertical direction by a rotating center shaft 15 between the lower ends opposite to each other of a support leg body 14 of a turning table 7. A wheel 23 is applied rotatably to the lower end of the supporting arm 18. A supporting rod 25 is fixed horizontally to the upper end of the supporting arm 18. A supporting body 31 in which the supporting rod 25 is inserted supportedly and movably in forward and backward directions is connected rotatably between the upper ends opposite to each other of the support leg body 14 by a pivot shaft 32. The support rod 25 is always energized supportedly between the supporting body 31 and a spring retaining body 29 at the top of the supporting rod 25, and a spring to always hold a wheel 23 at a specified ground contact position through the supporting arm 18 is installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caster, and more particularly to a caster used for vehicles such as trucks, aerial work vehicles and trailers for carrying heavy objects.

[0002]

2. Description of the Related Art Conventionally, as a caster used for this type of vehicle, as described in, for example, Japanese Patent Laid-Open No. 4-71902, a turning table is rotatably attached to a lower portion of a mounting base. A configuration is known in which a wheel for grounding is rotatably mounted on an axle between lower ends of supporting legs integrally projecting downward relative to a lower end of a table.

[0003]

In the configuration described in the above publication, the opposing supporting legs, on which the wheels are rotatably mounted, are integrally projected to the lower end portion of the turning table. While traveling up and down following the unevenness, the vibration due to the vertical movement of the wheels is directly transmitted to the mounting base, and the vibration is also transmitted to the vehicle body mounted on this mounting base. There is a risk of adversely affecting the load loaded on the vehicle and damaging the load depending on the load. Moreover, the swing function between the mounting base and the swing table may impair the swing function due to the impact due to vibration. When considering vibration,
Regarding the traveling speed, for example, low-speed traveling of 4 to 6 km / h is the limit, and high-speed traveling of 10 km / h or more is often difficult.
There is a problem.

The present invention has been made in view of the above points, and can reliably absorb the vibration due to the vertical movement of the wheels when traveling on the road surface, and the vibration is attached to the mounting base and the mounting base. It can be surely prevented from being transmitted to the vehicle body, adversely affecting the load loaded on the vehicle body,
The purpose of the present invention is to provide a caster that can reliably prevent the risk of damage to the cargo, and that does not impair the swivel function of the swivel table due to the impact of wheel vibrations and that enables safe high-speed traveling. is there.

[0005]

The casters of the present invention are
A mounting base, a swivel table having a supporting leg that is mounted rotatably on the mounting base and protrudes downward relative to the lower end, and a rotation center axis between the opposing supporting legs of the swivel table. A support arm rotatably supported in the up-and-down direction and having a substantially L-shape in side view, a grounding wheel rotatably mounted on the lower end of the support arm, and a support arm positioned between the opposing support legs. And a support rod horizontally fixed to the upper end of the support arm and having a spring retainer at the tip, and a support rod rotatably supported by a support shaft between the upper portions of the opposing support legs. A support body that is inserted so as to be able to move forward and backward, and a spring that is provided between the support body and the spring retainer and that always biases and supports the support rod and that always holds the wheel of the support arm at a predetermined ground contact position; It is equipped with.

[0006]

In the caster of the present invention, when the wheel moves up and down while following the unevenness of the road surface while the vehicle is traveling on the road surface, the support arm around which the wheel is mounted is vertically rotated about the rotation center axis of the support leg. At the same time, the support rod fixed to the upper end of this support arm is guided by the support against the spring and is moved back and forth, and the vertical vibration of the wheel is absorbed by this spring. It is possible to prevent the vibration due to the vibration from being transmitted to the turning table and the mounting base.

At this time, since the support body for guiding the forward / backward movement of the support rod is rotatably supported by the supporting leg body opposite thereto by the support shaft, the support arm is vertically moved around the rotation center axis. When the support arm is rotated, the support body is rotated about the support shaft by the support rod at the upper end portion of the support arm, and the spring is always expanded and contracted with respect to the support body in the set orthogonal state. This spring does not expand or contract in a state of being inclined with respect to the support rod, and therefore, deterioration of the spring is prevented or deterioration of the function of the spring is prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of an embodiment of the present invention will be described below with reference to the drawings.

In the drawing, reference numeral 1 is a mounting base, which has a rectangular plate-shaped base body 2 to be mounted on a mounting portion of a vehicle body or the like, and a hollow cylindrical body 3 is provided below the base body 2. An annular engaging recess 4 is formed on the outer peripheral portion of the upper end of the cylindrical body 3 that is integrally projected, and an inner peripheral portion of the engaging recess 4 intersects with an upper peripheral portion of the cylindrical body 3. A substantially semicircular annular groove 5 is formed in the outer peripheral portion of the cylindrical body 3, and a substantially semicircular annular groove 6 is formed in the outer peripheral portion of the lower portion of the cylindrical body 3.
Mounting holes 2a are formed at the four corners of the base body 2.

A turning table 7 has a plate-shaped table body 8 and a hollow turning body on which the cylindrical body 3 is rotatably fitted. 9 are integrally fixed to each other, and an annular engaging projection 10 for the engaging concave portion 4 is formed at an upper end portion of the revolving body 9, and an annular inner wall portion for an outer peripheral portion of the cylindrical body 3 is formed. A substantially semicircular annular groove 11 facing the annular groove 5 is formed at the intersection of the upper end portion and the engaging projection 10.
A substantially semicircular annular groove 12 facing the annular groove 6 is formed in the lower portion of the annular inner wall portion. A large number of steel balls 13 are respectively rotatably housed between the upper and lower annular grooves 5 and 11 and between the annular grooves 6 and 12 which face each other with the cylindrical body 3 fitted in the revolving structure 9. A revolving structure 9 is rotatably attached to and supported by the cylindrical body 3 on the upper and lower steel balls 13.

Further, supporting legs 14 are integrally projected in parallel to the lower end of the table body 8 at a distance from each other with a space therebetween, and the supporting legs 14 rotate between the opposing lower ends of the supporting legs 14. The central shaft 15 is horizontally mounted. This rotation center axis
15 is a bolt 16 which is horizontally mounted between the lower ends of the opposite supporting legs 14.
And a nut 17 screwed to one end of the bolt 16.

Further, a pair of left and right support arms 18 are located between the opposing supporting legs 14 and are pivotally supported on the pivot center shaft 15 so as to be pivotable in the vertical direction. The pair of support arms 18 are each formed in a substantially L shape in a side view, and the bent portion of the middle portion is pivotally supported in the up-down direction by the rotation center shaft 15, and the pair of support arms 18 is formed. A prismatic trunnion 19 is integrally fixed by fitting the mounting shafts 20 at both ends between the upper ends of the trunnions 19, and is located below the trunnion 19 between the pair of support arms 18. The connecting plate 21 is integrally fixed. Wheels 23 for grounding are rotatably mounted on the lower ends of the pair of support arms 18 by axles 22.

Further, the trunnion 19 fixed between the upper ends of the pair of support arms 18 is formed with threaded holes 24 penetrating in the front-rear direction in the left and right side portions, respectively. A screw shaft portion 26 at the base end portion of a support rod 25 disposed horizontally between the opposing supporting leg bodies 14 is screwed to the screw shaft portion 26, and the trunnion 19 is attached to the left and right screw shaft portions 26. Lock nuts 27 are respectively screwed and fixed on the outer side of the. Further, an adjusting nut 30 is screwed to the screw shaft portion 28 at the tip of the left and right support rods 25 so as to be adjustable forward and backward via a spring retainer 29 made of a washer or the like.
A cylindrical stopper 40 is integrally provided on the left and right portions of the spring retainer 29 at the opening edge of an insertion hole 39 through which the left and right support rods 25 are inserted.

Next, between the upper portions of the supporting legs 14 facing each other, the support 31 is positioned slightly forward of the axis line in the direction perpendicular to the rotation center shaft 15, and the support body 31 is rotatably supported by the support shaft 32. It is supported. The support body 31 is formed in a prismatic shape, and the left and right portions thereof are formed with insertion holes 33 through which the left and right support rods 25 are inserted so as to be able to move forward and backward. A stopper 35 with which the front edge 34 of the upper end of the support arm 18 comes into contact is formed. In addition, a hollow cylindrical upper limit stopper 41 is inserted into the left and right support rods 25 between the support 31 and the spring retainer 29.

A coil spring 36 is wound around the left and right support rods 25 arranged between the upper portions of the opposing supporting legs 14, and one end of the coil spring 36 is attached to the spring retainer 29. The coil spring 36 is in pressure contact with the other end of the coil spring 36 and is in pressure contact with the front end surface of the support 31. Then, the left and right support rods 25 are always urged forward by the coil springs 36,
The front edge portions 34 of the supporting arms 18 facing each other by the left and right support rods 25 are supported in contact with the stoppers 35 of the support body 31,
The wheels 23 at the lower end of the opposing support arms 18 are always held at a predetermined ground contact position. Further, when the wheel 23 is largely turned upward and rotated and the respective coil springs 36 are greatly compressed by the left and right support rods 25 to a set value, the upper limit stopper
The stopper 42 of the spring retainer 29 is attached to the locking portion 42 at the inner end of 41.
40 is in contact with the left and right coil springs 36 so that the coil springs 36 are not compressed more than a set value. In the figure, 37 is a steel ball insertion groove / lubrication hole for the turning part of the turning table 7.
The nipple is detachably screwed to the 38.

Next, the operation of the above embodiment will be described.

The mounting base 1 is arranged at a mounting position on the vehicle body of various vehicles such as a trolley, and the bolts inserted through the mounting holes 2a of the mounting base 1 to the mounting positions and the nuts screwed to the bolts are attached to the mounting bases 1. The mounting base 1 is fixed to the mounting position of the vehicle body. Then, by pulling various vehicles equipped with this caster by self-propelled or towed vehicle, the wheels 23 of each caster travel on the road surface.However, when the road surface travels, each wheel 23 becomes uneven on the road surface. Following this, the vehicle travels while rotating up and down about each rotation center shaft 15.

That is, when each wheel 23 is rotated up and down, the left and right support arms 18 around which each wheel 23 is mounted are vertically rotated about the rotation center axis 15 of the supporting leg 14 which faces the wheel 23. The left and right support rods 25 fixed to the trunnions 19 at the upper ends of the left and right support arms 18 are guided by the insertion holes 33 of the support body 31 against the respective coil springs 36 to move back and forth. Wheels at spring 36
23 vertical vibrations are absorbed. Therefore, each wheel
The vibration due to the vertical movement of 23 is prevented from being transmitted to the turning table 7 and the mounting base 1, and the vibration of each wheel 23 is also prevented from being transmitted to the vehicle body.

At this time, since the support 31 for guiding the forward and backward movement of the left and right support rods 25 is rotatably supported by the support shaft 14 opposite to each other by the support shaft 32, the left and right support arms 18 rotate. When it is rotated vertically about the motion center shaft 15, the support 31 is rotated vertically about the support shaft 32 by the left and right support rods 25 at the upper ends of the left and right support arms 18. To be done.
That is, the wheel 23 rides on the convex portion of the road surface and moves upward as shown by the chain line in FIG. 1, and the left and right support arms 18 having the wheel 23 as shown by the chain line in FIG. The left and right support arms are rotated clockwise.
The left and right support rods 25 are pulled against the coil springs 36 by the trunnions 19 at the upper ends of the spring retainers 29.
Since it tries to rotate in the direction to lift the tip of the side,
The support 31 is rotated clockwise by the left and right support rods 25 around the support shaft 32 as shown by the chain line in FIG. 1. Therefore, the rotation of the left and right support arms 18 causes the left and right support rods 25 and The support 31 is integrally rotated in the clockwise direction as shown by the chain line in FIG.

The left and right support rods 25 and the support 31
By integrally rotating the support rods 25 and the support body 31, the relative positions of the support rods 25 and the support body 31 do not change.
Is always expanded and contracted in a set orthogonal state, and the left and right coil springs 36 do not expand and contract because they are inclined with respect to the respective support rods 25.
The deterioration of the left and right coil springs 36 and the deterioration of the functions of the left and right coil springs 36 are prevented.

In the above-mentioned embodiment, the case where the base end portions of the two support rods 25 are screwed to the right and left portions of the trunnion 19 and fixed is described, but the present invention is not limited to this, and the wheels 23 are supported. Depending on the load, for example, one support rod 25 may be screwed and fixed to the trunnion 19.

Further, in the above-described embodiment, the screw shaft portions 26 of the two support rods 25 are respectively screwed into the left and right screw holes 24 of the trunnion 19, and the lock nuts are attached to the screw shaft portions 26 of the left and right support rods 25. Although the case where the 27 are respectively screwed and fixed has been described, the present invention is not limited to this, and instead of the screw holes 24, penetrating holes are formed through the left and right portions of the trunnion 19, and the left and right inserting holes serve as the support rods 25. The bolt head may be inserted, and the bolt heads integrally formed at the end portions of the left and right bolts may be brought into contact with the opening edge portions of the respective insertion holes.

[0023]

According to the present invention, a supporting arm, which is substantially L-shaped in a side view, is rotatably supported in the up-down direction by a rotation center shaft between opposing supporting legs of a revolving table. A wheel is rotatably mounted on the lower end of the support arm, a support rod is horizontally fixed to the upper end of the support arm, and a support body inserted through the support rod to move back and forth is supported between the opposing support legs. A spring that is rotatably supported by a support rod and always supports the support rod between the spring retainer at the tip of the support rod and the support body, and always holds the wheel of the support arm at a predetermined ground contact position. Since it is provided, it is possible to reliably absorb the vibration due to the vertical movement of the wheels when traveling on the road surface, and it is possible to reliably prevent this vibration from being transmitted to the mounting base and the vehicle body mounted on the mounting base. Adversely affects the loaded cargo Or, cargo can be securely prevent the risk of damaging the, without turning function of the turntable is impaired by the impact due to the vibration of the wheel, it is possible to enable safe high speed driving.

Further, since the support body in which the support rod is movably inserted and supported is rotatably supported by the support shaft between the opposing support legs, the support body is interlocked with the forward and backward rotation of the support rod. Since the spring does not rotate and tilt with respect to the support rod from the set position, the spring whose one end is in pressure contact with the end surface of this support always expands and contracts along the support rod and is tilted with respect to the support rod. Therefore, the coil spring can sufficiently absorb the vibration of the wheel.

Further, since the vibration absorbing mechanism for the wheel is provided between the upper portions of the opposing supporting legs, the vibration absorbing mechanism for this wheel is housed between the opposing supporting legs and can be made compact as a whole. In addition, the vibration absorbing mechanism of the wheel can be protected by the supporting legs that face each other.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a caster showing an embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a side view of the same.

FIG. 4 is a rear view of the same.

FIG. 5 is a side view of a support arm on which the wheels are mounted.

[Explanation of symbols]

 1 Mounting base 7 Revolving table 14 Support leg 15 Rotation center shaft 18 Support arm 23 Wheel 25 Support rod 29 Spring retainer 31 Support 32 Support shaft 36 Spring

Claims (1)

[Claims] 1. A mounting base, a revolving table having a supporting leg rotatably mounted on the mounting base and protruding downward relative to a lower end portion, and a rotating table between the opposing supporting legs of the revolving table. The support arm, which is rotatably supported in the up-down direction on the center axis of movement, is substantially L-shaped in side view, and the grounding wheel rotatably mounted on the lower end of the support arm is opposed to the support arm. A support rod that is horizontally fixed to the upper end of the support arm and has a spring retainer at its tip, which is located between the support legs, and is pivotally supported by a support shaft between the upper portions of the opposing support legs. A support body inserted through the support rod so as to move back and forth, and provided between the support body and the spring retainer to constantly support the support rod to keep the wheel of the support arm at a predetermined ground contact position. A spring that holds the Casters characterized by.