JP3141814U - A swivel caster that supports multiple wheels on a radial frame tip - Google Patents

Abstract

[PROBLEMS] To travel on a flat ground with both front and rear wheels supporting the wheel load, and on uneven terrain, the wheels and the radial frame can revolve around the frame support shaft while supporting the load. And
A plurality of wheels are supported on the tip of a radial frame, and the radial frame is supported on a free end of a swivel fork by a frame support shaft. A direction of the swivel fork and a course of the wheel are determined in a predetermined manner. A swivel caster that can be guided and aligned in the direction of travel is configured, and a radial frame is supported by a frame support shaft on a free end of a swivel fork that is pivotally supported on a revolving part that is suspended from the top plate. A plurality of wheels are equally distributed at the tip of the frame and supported by the axle, and each horizontal distance between the turning part, the preceding and succeeding wheels on the flat ground, and the frame frame supporting shaft, that is, the preceding wheel eccentricity and the subsequent wheel eccentricity. In addition, the frame support shaft eccentricity is set.
[Selection] Figure 1

Description

  The present invention relates to a swivel caster in which a plurality of wheels are equally distributed and supported at the tip of a radial frame, and the frame is supported by a swivel support.

  Conventional swivel casters are based on industrial casters (see Non-Patent Document 1) and are composed of a top plate, a fork, a swivel unit, a single wheel and an axle. However, since it is equipped with relatively small-diameter wheels, there is a problem of poor running performance on rough terrain including road surface irregularities, steps and soft ground.

  In order to solve the above problems and enable traveling on uneven steps or uneven terrain, a plurality of small-diameter wheels are equally distributed on the radial frame tip and supported as fixed casters that are supported by fixed support brackets. Patent Document 1 to Patent Document 4 and the like have been presented as “stepped traveling wheels”.

"Industrial casters" JIS B 8923 JP 2002-35041 A JP 2004-275497 A JP-A-10-243967 JP 2007-210577 A

  Among the above-described embodiments, Patent Document 1 includes a normal turning caster as a front wheel of a wheelchair, and an auxiliary wheel body that radially supports an idle wheel is attached to a side portion of the leg wheel so that it can travel in steps. However, the configuration as a wheelchair is complicated, and the auxiliary wheel body is unnecessary for normal traveling.

  In Patent Document 2, a motorized auxiliary unit that can be attached to and detached from the front or rear of a wheelchair has a cross wheel as a stepped running wheel, but there is no turning function as a turning caster, and rotation of driving means on both the left and right sides Steering control is performed by controlling the speed difference, the driving means and the control means are complicated, and there are various problems in handling such as mounting and dismounting of the unit.

  Patent Document 3 includes a plurality of traveling wheels that can be driven coaxially with the planetary gear of the planetary gear mechanism on both the front and rear wheels of the wheelchair, and a drive motor. Therefore, it is necessary to simplify the driving means and the control means.

  In Patent Document 4, a plurality of driven wheels that can be driven coaxially with a planetary gear of a planetary gear mechanism as a stepped traveling revolution wheel are supported in a planetary shape, and a sun drive for driving a wheel device revolution is provided at the center of the gear mechanism. A gear is provided so that the driven wheel can revolve around the sun gear. However, in practice, the drive mechanism and its control means have a complicated configuration, and there are the same problems as in Patent Document 3.

  In Patent Document 1 to Patent Document 4 described above, a plurality of wheels are equally arranged on the planetary frame tip and supported by a fixed support bracket, and the action of the trail due to the eccentricity of the swivel caster, that is, in the traveling direction. Since there is no following action of the wheel path, in order to maintain the traveling direction of the vehicle body and perform steering control, complicated driving means for driving the wheels on both sides of the vehicle body by a motor and a planetary gear mechanism and its control means are required. There is a problem.

  The present invention has been made in view of the above-mentioned problems in the prior art, and its object is to support a plurality of wheels on the tip of a radial frame, and turn the radial frame around the frame support shaft. Supports the free end of a fork (the top plate, swivel and fork are hereinafter collectively referred to as a swivel fork), and guides and aligns the direction of the swivel fork and the course of the wheel in a predetermined direction of travel. On a flat ground, the wheel is supported by both the front and rear wheels, and on a rough terrain, the wheel and the radial frame are integrally revolved around the frame support shaft to apply the load. It is supposed to be able to run with support.

  In order to achieve the above object, the swivel caster for supporting a plurality of wheels on the radial frame tip of the present invention is configured such that the radial frame is pivoted on the free end of the swivel fork supported on the swivel portion below the top plate by the frame support shaft. A plurality of wheels are equally distributed at the tip of the radial frame and supported by an axle, and each horizontal distance between the turning portion and the preceding wheel on the ground, the frame supporting shaft and the following wheel, that is, the preceding wheel eccentricity When the frame support shaft eccentricity and the subsequent wheel eccentricity are arranged side by side, the subsequent wheel is equal to the sum of the preceding wheel eccentricity and the interaxial distance by setting the preceding wheel eccentricity and the inter-axial distance between the preceding and subsequent wheels in advance. An eccentricity and a frame support shaft eccentricity equal to the sum of the wheel eccentricity and ½ of the distance between the shafts are set.

  The effect | action by said structure is described below. That is, under flat ground running conditions, both the leading and trailing wheels are grounded to support the wheel load, the leading wheel eccentricity and the trailing wheel eccentricity are used as trails, and the courses of both wheel grounding points along with the turning direction of the turning fork are It is possible to guide the vehicle backward and align it in a predetermined direction of travel, and in rough terrain conditions including steps, when the wheel is prevented from traveling and rotating, the wheel and the radial frame are integrated into the frame support. While supporting the wheel load by revolving around the shaft, using the frame support shaft eccentricity as a trail, the direction of the turning fork and the direction of the wheel contact point are guided to the rear of the turning part to align with the predetermined traveling direction. It will run while.

  The details of the function as a trail due to the preceding wheel eccentricity, the subsequent wheel eccentricity, and the frame support shaft eccentricity are as follows. That is, when the direction of the turning fork and the course of the wheel are deflected laterally around the turning part in the predetermined traveling direction from the traveling direction, the leading position at each of the preceding and succeeding wheel eccentric positions at the rear of the turning part under the flat ground traveling condition. A moment around the turning part is generated by each drag in the traveling direction at the following two wheel contact points, and the course of both wheels is guided to the rear of the turning part together with the direction of the turning fork, and the above-mentioned lateral deflection In this condition, the wheel and the radial frame are integrally revolved around the frame support shaft under rough terrain conditions including steps. For the above-mentioned lateral deflection, a moment around the turning part is generated by the drag in the traveling direction at the wheel contact point below the frame support shaft eccentricity behind the turning part. The path of the wheel together with the direction, and guided to the rear side winding part, declining the deflection to the side, the same moment, can travel in alignment in a predetermined direction of travel.

  The effect of the swivel caster of the present invention for supporting a plurality of wheels on the radial frame tip is as follows. That is, when the leading and trailing wheels are grounded to support the wheel load and the turning direction of the turning fork and the course of the wheels are deflected to the side in the predetermined traveling direction under the flat ground traveling condition, the leading wheel eccentricity and the following wheel By using the eccentric as a trail, the direction of the turning fork and the course of the contact points of both wheels can be corrected in a predetermined traveling direction.

  Also, when the preceding wheel is prevented from advancing and rotating on rough terrain including road surface irregularities and steps, the wheel revolves around the frame support shaft integrally with the radial frame, and loads the subsequent wheel while supporting the wheel load. When the directional direction of the swivel fork and the course of the wheel are deflected to the side of the predetermined travel direction, the direction of the swivel fork and the ground contact point of both wheels It is possible to travel while correcting the course of the vehicle in a predetermined traveling direction.

  Due to the above effects, when the turning caster of the present invention is used together with the main wheels in carts, hand carts, wheelchairs, etc., the body load is shared by both the leading and trailing wheels on a flat ground, Travels in the same way as a wheelchair, etc., and on uneven terrain such as road surface unevenness, steps and soft ground, the wheel and the radial frame revolve around the frame support shaft as described above, and the shared load of the wheel When the direction of the turning fork and the course of the wheel are deflected to the side in the predetermined direction of travel, the frame support shaft eccentricity behind the turning section acts as a trail, Regardless of this, it is possible to always travel along with the turning fork by guiding and aligning the course of the wheel in a predetermined traveling direction and correcting the deflection.

  The swivel caster for supporting a plurality of wheels on the radial frame tip of the present invention solves the problems in the above-mentioned background art in Patent Documents 1 to 4, and is widely used as a swivel caster for ordinary carts and wheelchairs. Can be applied.

As an embodiment of the present invention, the radial frame (4) is pivotally supported by the frame support shaft (5) on the free end of the swivel fork (3) supported on the swivel portion (2) below the top plate (1), A plurality of wheels (6) are equally distributed at the tip of the radial frame and supported by the axle (7), and each horizontal distance between the turning portion and the preceding wheel, the frame supporting shaft and the following wheel on the flat ground, that is, When the preceding wheel eccentricity (a), the frame support shaft eccentricity (c) and the subsequent wheel eccentricity (b) are arranged in parallel, the preceding wheel eccentricity (a) corresponding to the vicinity of 20% of the outer diameter of the wheel (6) in advance, By setting the inter-axis distance (d) of the preceding and subsequent wheels, as shown in Equation 1, the following wheel eccentricity (b) equal to the sum of the preceding wheel eccentricity (a) and the inter-axis distance (d), and , Eq. 2, equal to the sum of the wheel eccentricity (a) and 1/2 of the inter-shaft distance (d), the preceding wheel eccentricity (a) and the subsequent wheel eccentricity. Frame support shaft eccentric corresponding to the center value and b) a (c), the set, respectively.

  The operation of the above embodiment will be described next with reference to the drawings.

Under the flat ground traveling condition shown in FIG. 5, the wheel load is supported by both the leading and trailing wheels, the leading wheel eccentricity (a) and the trailing wheel eccentricity (b) travel as a so-called trail, and the direction of the turning fork (3) is directed. When the course of the wheel (6) is deflected from the predetermined traveling direction (X) to the side deviation direction (X ') of the deflection angle (θ), the turning wheel (2) is located at the position of the preceding wheel eccentricity (a) behind the turning part (2). As the product of the drag (F1) in the traveling direction at the preceding wheel contact point and the distance (y1) between the traveling direction (X) axis, that is, the arm of the moment around the turning section shown in Equation 3, The moment (F1 · y1) of the drag around the turning portion axis and the distance (y2) between the drag (F2) in the traveling direction at the subsequent wheel contact point at the position of the subsequent wheel eccentricity (b) and the traveling direction (X) axis, , Morme around the turning part shown in Equation 5 As the product with the arm of the torsion, the directing direction of the turning fork (3) and the course of both wheels are determined by the mutual action by the moment (F2 · y2) around the turning portion axis of the same resistance shown in Equation 6. Can be traveled in alignment with the predetermined direction of travel (X) from the laterally deviated direction (X ′) by gradually decreasing the deflection angle (θ) and the same moment.

In FIG. 6, when the wheel (6) is prevented from traveling and rotating on rough terrain including road surface irregularities and steps, the wheel revolves around the frame support shaft (5) together with the radial frame (4). The wheel load is supported, the load is transferred to the succeeding wheel so that it can travel on rough terrain, and the direction of the turning fork (3) and the course of the wheel (6) are determined from the predetermined traveling direction (X). When the deflection angle (θ) is deflected in the lateral deviation direction (X ′), the drag force (F) in the traveling direction at the lower wheel contact point of the lower part of the wheel support shaft eccentricity (c) behind the turning portion (2) and the traveling direction ( X) The distance from the axis (y), that is, the moment (F · y) around the pivoting part axis of the same resistance shown in Formula 8 as the product of the moment arm around the pivoting part shown in Formula 7 Deflection by guiding the direction of the fork (3) and the course of the wheel (6) to the rear of the turning part (Θ) and the same moment are gradually reduced to align with the predetermined traveling direction (X) from the side deviation direction (X ′), that is, the frame support shaft eccentricity (c) acts as a trail. The deflection of (X ′) is corrected in a predetermined traveling direction (X).

  1 and 2, three wheels (6) are supported on an axle (7) of an arm-like tip of a three-pronged radial frame (4), and the frame support shaft (5) of the frame is connected to a swing fork. (3) is supported at the lower end, and as shown in the above formulas (1) and (2), the preceding wheel eccentricity (a), the subsequent wheel eccentricity (b) and the frame support shaft frame eccentricity ( c) is set respectively.

  In FIG. 3, four wheels (6) are supported on the axle (7) of the arm-shaped tip of the cross-shaped radial frame (4), and the frame support shaft (5) of the frame is connected to the turning fork (3 ), And in the same manner as described above, the preceding wheel eccentricity (a), the subsequent wheel eccentricity (b), and the frame support shaft eccentricity (c) are moved backward from the turning portion (2) according to Equations 1 and 2. , Each set. When the revolution radius (r) from the frame support shaft (5) to the axle (7) is set to be equal between the first embodiment and the second embodiment, the wheel center distance (d) is the same as that of the first embodiment. The second embodiment is smaller than the first embodiment, and in the rough terrain running condition, the vertical vibration frequency in the revolution state of the wheel increases, but the vertical amplitude can be reduced.

  In FIG. 4, the vehicle body (9) of the wheelchair (8) is equipped with the turning caster of the present invention as the front wheel of the main driving wheel (10), and as described above, the preceding wheel eccentricity (a) and the following wheel eccentricity. (B) and the frame support shaft eccentricity (c) as a trail, the turning caster always travels while correcting the course of the swivel caster in a predetermined vehicle body traveling direction. It is possible to travel in the same way as a wheelchair that supports a load and is equipped with a normal swivel caster, and on uneven terrain that includes a step, the shared load is supported by the integral revolving action of the wheels and the radial frame, and the uneven terrain is supported. Can improve the performance on rough terrain than a normal wheelchair.

  In the turning caster which supports a plurality of wheels to a radial frame tip of the present invention, it is an elevation view of the side of an embodiment equipped with three wheels. Example 1   It is a bottom view seen from the A arrow of FIG.   In the turning caster which supports a plurality of wheels to a radial frame tip of the present invention, it is an elevation view of the side of an embodiment equipped with four wheels. (Example 2)   It is an elevational view of an embodiment of the present invention in which a turning caster for supporting a plurality of wheels on a radial frame tip is applied as a front wheel of a wheelchair. (Example 3)   In FIG. 2, it is a bottom view which shows the effect | action in the state which supported and supported the load with both the front and back wheels, and was deflected from the advancing direction (X) to the side deviation direction (X ') position.   In the rough terrain traveling condition in FIG. 2, the wheels and the radial frame integrally revolve around the frame support shaft while supporting the load, and travel from the traveling direction (X) to the laterally offset direction (X ′). It is a bottom view which shows the effect | action in the deflected state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Top plate 2 Turning part 3 Turning fork 4 Radial frame 5 Frame support shaft 6 Wheel 7 Axle 8 Wheelchair 9 Body frame 10 Driving wheel r Revolving radius (Axle rotation radius around the frame support shaft)
a Precedence wheel eccentricity b Subsequent wheel eccentricity c Frame support shaft eccentricity d Center distance (between the preceding and subsequent wheels)
X Travel direction X 'side deviation direction θ Deflection angle (angle between X and X')
F Drag Y in the direction of travel at the revolving wheel contact point F Fy arm F moment around the turning part F1 F1 force around the turning point F1 Drag in the direction of movement at the preceding wheel contact point Y1 F1 moment around the turning part Arm F1 · y1 F1 moment around the turning part F2 Drag in the traveling direction at the following wheel contact point Y2 F2 moment arm around the turning part F2 · y2 F2 moment around the turning part

Claims (1)

  A radial frame (4) is pivotally supported by a frame support shaft (5) on a free end of a swivel fork (3) supported on a swivel portion (2) below the top plate (1), and a plurality of pieces are provided at the tip of the radial frame. The wheels (6) are equally distributed and supported by the axle (7), and the horizontal distance between the turning portion and the preceding wheel on the flat ground, the frame supporting shaft and the following wheel, that is, the preceding wheel eccentricity (a), the frame When the support shaft eccentricity (c) and the following wheel eccentricity (b) are arranged in parallel, the preceding wheel eccentricity (a) and the inter-axis distance (d) between the preceding and following wheels are set in advance. The following wheel eccentricity (b) equal to the sum of a) and the inter-shaft distance (d) and the frame support shaft eccentricity (c) equal to the sum of the wheel eccentricity (a) and 1/2 of the inter-axis distance (d) Are set, and in flat road conditions, both the leading and trailing wheels are grounded to support the wheel load, leading wheel eccentricity (a) and rear Using the wheel eccentricity (b) as a trail, the vehicle travels along the direction of the turning fork (3) along the direction of both wheel contact points to the rear of the turning part and aligns with a predetermined traveling direction, When the traveling and rotation of the wheel (6) is prevented, the wheel and the radial frame (4) are integrally revolved around the frame support shaft (5) and the wheel load is reduced. The frame support shaft eccentricity (c) is used as a trail, and the traveling direction of the wheel fork (3) is guided to the rear of the turning portion along with the directing direction of the turning fork (3) to match the predetermined traveling direction. A swivel caster for supporting a plurality of wheels on a radial frame tip.

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