JP2017071327A - Step straddle mechanism and baby carriage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoch-making step straddle mechanism having a cushioning function for alleviating an impact at a collision of auxiliary wheels with a step in addition to a high step straddle capability for easily straddling the step, and a baby carrier having the step straddle mechanism.SOLUTION: A step straddle mechanism comprises front wheels 300 being main wheels at a rear side with respect to a progressing direction of a vehicle body, and auxiliary wheels 2 at a front side in a non-grounding state, and also comprises auxiliary wheel holders 5 which are protruded frontward of the front wheels 300 from wheel holders 1 to which the front wheels 300 are pivoted. The auxiliary wheel holders 5 comprise the auxiliary wheels 2 so as to be movable to an oblique rear-upward direction from front positions of the front wheels 300, and compression coil springs 3 being cushioning members for elastically supporting the vehicle body including the wheel holders 1 with respect to the auxiliary wheels 2 at a straddle of a step.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a step-over mechanism for getting over an obstacle without being tripped over an obstacle such as a step used in a handcart such as a stroller.

For wheelbarrows such as baby carriages (strollers) and silver cars (walking aids), especially in the case of strollers used when taking infants to the outdoors, the body size is smaller, lighter, and compact when not in use. In consideration of straight running stability during running, etc., relatively small small wheels are used on the front, rear, left and right sides of the vehicle body.
In addition, in order to have both the functions of straight running stability during traveling and rotation (turning, operability) such as direction change, a so-called twin wheel caster having two small wheels that can be swung and swiveled is used. It is often applied to the front wheel side of the undercarriage.

By the way, by using a twin-wheel caster with small wheels, because it is a small wheel, it is difficult to get over the step when encountering a step at the boundary between the roadway and the sidewalk in a pedestrian crossing, etc. collide.
When the wheel collides with a step (rising part), the vehicle body turns forward with the momentum of the collision, or the impact transmitted to the vehicle body adversely affects the infant's body placed in the stroller. The impact when it collides with a step is unexpectedly great, and there is a need for a solution to the safety of using a stroller, such as placing a heavy burden on the infant's head.

  Therefore, Patent Document 1 and Patent Document 2 listed below disclose a step-over technology that enables a user to get over a step.

JP 2011-046244 A Utility Model Registration No. 3166358

However, in the prior art described in Patent Document 1 and Patent Document 2 above, the auxiliary wheel is not grounded via the sub-holder at the front position of the front wheel that is pivotally supported by the main holder attached to the lower part of the leg frame. It is equipped with. The auxiliary wheel is pressed downward by the elastic member (pressing spring) interposed between the sub-holder and the main holder through the sub-holder that rotates up and down around the rotation shaft (swing shaft) with respect to the main holder. Yes.
Thus, the auxiliary wheel is pressed downward by the elastic member through the sub-holder, specifically, vertically downward with respect to the ground. In other words, with the conventional technology in which the pressing direction of the auxiliary wheel by the elastic member is substantially parallel to the rising wall surface of the step where the auxiliary wheel collides, it is physically impossible to reduce the impact when the auxiliary wheel collides with the step. There is a structural problem.
Therefore, the conventional technique has a problem that a large impact is directly transmitted to the vehicle body when the auxiliary wheel collides with a step.

In addition, the conventional technology adopts a configuration in which the sub-holder for supporting the auxiliary wheel is attached to the main holder so that the sub-holder can be moved up and down (oscillated) by the rotation shaft. Or the appearance is not good. There is also a problem of causing a malfunction in which the movement (swinging) of the sub holder is slowed by dirt (inclusions) such as dirt and sand from the road surface that enters between the sub holder and the main holder during traveling.
As described above, the level difference overriding mechanism of the prior art has many problems that have to be solved for practical use.

  The present invention was devised as an example of dealing with the above-mentioned conventional situation, and in addition to a high step climbing ability to easily climb over a step, a buffer function that softens the impact when an auxiliary wheel collides with the step. Providing a groundbreaking step climbing mechanism equipped with a stroller and a stroller equipped with a step climbing mechanism.

  In order to solve the above-mentioned problems, the stroller provided with the step climbing mechanism and the step climbing mechanism according to the present invention includes means including at least the configurations according to the following independent claims.

The step climbing mechanism of the present invention has a main wheel and an auxiliary wheel, and the main wheel is rearward with respect to the traveling direction of the vehicle body, and the auxiliary wheel having a smaller diameter than the main wheel is ungrounded on the front side. A step-over mechanism having a configuration comprising: an auxiliary wheel holder portion protruding from a wheel holder on which the main wheel is pivotally supported toward the front of the main wheel, and the auxiliary wheel holder portion including the auxiliary wheel And a buffer member that elastically supports the vehicle body including the wheel holder with respect to the auxiliary wheel when the step is over the level difference. It is characterized by.
Here, examples of the buffer member include an elastic member such as a spring material or a rubber material that can sufficiently exert an elastic action for reducing an impact at the time of a collision with a step of the auxiliary wheel.

  Further, as a preferred embodiment, the auxiliary wheel holder portion is integrally formed from the lower end side of the wheel holder below the rotating shaft support portion of the main wheel with respect to the wheel holder toward the front of the main wheel. The auxiliary wheel has an auxiliary wheel support space in which a lower surface portion is opened from a front surface portion that is rotatably supported and can move in an obliquely rearward and upwardly inclined direction, and the auxiliary wheel support space Inclined guide elongated holes that are opened obliquely rearwardly upward from the front position of the main wheel are provided on both side walls of the auxiliary wheel holder portion, and the axles of the auxiliary wheels are supported by the inclined guide elongated holes. In addition, the buffer member is provided in an externally closed form so as to urge the bearing member provided on the axle in a diagonally downward direction.

  Further, the stroller of the present invention is a stroller having a front wheel and a rear wheel around a vehicle body, and is characterized in that the step climbing mechanism is used on the front wheel side.

  According to such a configuration, when the auxiliary wheel that is movable in the obliquely rearward upward direction from the front of the main wheel in a non-grounded state collides with the step, the auxiliary wheel is inclined rearwardly upward against the elastic force of the buffer member. Move to. That is, the auxiliary wheel moves in the height direction of the step and rides on the step, so that the main wheel can get over the step. At the same time, the impact at the time of step collision is reduced by the movement of the auxiliary wheel in the diagonally rearward upward direction against the elastic force of the buffer member (elastic deformation of the buffer member). That is, it is possible to provide a buffer support structure that elastically supports the vehicle body via the wheel holder at the time of a step collision of the auxiliary wheels.

  In addition, the auxiliary wheel is supported and supported in the auxiliary wheel support space of the auxiliary wheel holder portion, and the buffer member is provided in an externally closed form, so that the appearance is simple and the step collision. Smooth movements such as oblique rearward movement of the auxiliary wheel against the time buffer member can be stably continued without being affected by dust from the road surface. In addition, because of its simple structure, it can be manufactured and provided at a low cost.

  According to the present invention, the step can be easily overcome, and at the same time, the impact when the auxiliary wheel collides with the step can be reduced. That is, it is possible to provide an innovative step climbing mechanism and a stroller equipped with a step climbing mechanism having a buffering function at the time of a step collision in addition to a high step climbing ability.

It is explanatory drawing which showed an example of the whole structure of the stroller to which the level | step climbing mechanism which concerns on embodiment of this invention was applied. It is explanatory drawing which showed the same level | step climbing mechanism, (a) is a vertical side view, (b) is the bb line cross-sectional plan view of (a). It is explanatory drawing which removed and showed the obstruction | occlusion cover of the bearing member and compression coil spring of the auxiliary wheel of the level | step climbing mechanism, (a) is the side view which showed the slanting front downward movement limit state of the auxiliary wheel, (b ) Is an enlarged side view partially enlarged. It is explanatory drawing which decomposed | disassembled and showed the same step climbing mechanism. It is explanatory drawing which removed and showed the obstruction | occlusion cover of the bearing member and compression coil spring of the auxiliary wheel of the level | step climbing mechanism, (a) is the side view which showed the diagonal back-up movement state of the auxiliary wheel, (b) These are the bb line transverse plane views of (a). It is explanatory drawing which showed the state immediately after the auxiliary wheel of the same level | step climbing mechanism collided with the level | step difference. It is explanatory drawing which showed the state when the auxiliary | assistant wheel of the same level | step climbing mechanism moved to the diagonally upward direction against the compression coil spring. It is explanatory drawing which showed the state in which the auxiliary wheel of the same level | step climbing mechanism got on the level | step difference. It is explanatory drawing which showed the state by which the front wheel (main wheel) of the level | step difference climbing mechanism climbed on the level | step difference, and the auxiliary | assistant wheel was returned diagonally forward and moved to the movement limit.

Hereinafter, an embodiment of the stroller A to which the step climbing mechanism according to the present invention is applied will be described in detail with reference to the drawings as appropriate. In addition, although embodiment of this invention contains the form of illustration, it is not limited only to these. That is, the present invention can be modified in various ways as long as it belongs to the technical scope.
In the present embodiment, Fr is the front side of the vehicle body 1 (front direction, traveling direction) according to the direction viewed from a guardian (user) who holds the push rod (gripping portion) 103 at the rear of the vehicle body 100 and pushes the stroller A manually. , Rr is the rear side (rear) of the vehicle body 1, L is the left side of the vehicle body 1, and R is the right side of the vehicle body 1.

≪Stroller A≫
FIG. 1 is an explanatory view (perspective view) showing an example of the overall configuration of a stroller A in which a step climbing mechanism according to an embodiment of the present invention is applied to the front wheel 300 side around a vehicle body 100. FIG.
The stroller A is a well-known form of the overall configuration excluding the front wheel side including the front leg rod 101 around the vehicle body 100 to which the step climbing mechanism is attached. For example, as shown in FIG. 1, the stroller A is attached to and supported by a vehicle body (vehicle body frame) 100 formed of a pair of left and right front leg rods 101 and rear leg rods 102, a hand push rod 103, and the like. It has a basic configuration of a baby seat (baby carrier) 200 on which an infant is placed. A front wheel 300 and a rear wheel 400 are provided at the lower ends of the front leg rod 101 and the rear leg rod 102 around the vehicle body 100.

  In addition, although illustration is abbreviate | omitted about a specific structural drawing (mechanism figure), the folding which can fold the vehicle body 100 compactly at the time of non-use of carrying or storing from the expanded state at the time of use shown in FIG. It has a mechanism.

  In the vehicle body 100 having such a configuration, a step climbing mechanism is provided on the front wheel 300 side at the lower end of the pair of left and right front leg rods 101.

<< Step climbing mechanism >>
Next, a step climbing mechanism for easily passing over the step D without tripping over the step D when the stroller A encounters the step D while the baby stroller A is traveling will be described.
2 to 5 are explanatory views showing an embodiment of the step climbing mechanism, FIG. 2 is a longitudinal side view and a cross-sectional plan view, and FIG. 3 shows the bearing member 10 and the compression coil spring 3 of the auxiliary wheel 2. FIG. 4 is a side view and an enlarged side view showing the state of the limit of the diagonally downward movement of the auxiliary wheel 2 with the closing cover 12 removed, FIG. 4 is an exploded perspective view, and FIG. 5 is an auxiliary wheel. 2 is a side view and a cross-sectional plan view of a state in which the closing cover 12 between the bearing member 12 and the compression coil spring 3 is removed and the auxiliary wheel 2 is moved obliquely rearward and upward. Here, description will be made with reference to FIG. 1 as appropriate.

  As shown in FIGS. 1 and 2, the step-over mechanism includes a wheel holder 1 that can be swung and pivoted on a lower end of a front leg 101 of a vehicle body 100, and an auxiliary wheel 2 that is pivotally supported by an auxiliary wheel holder portion 5 described later. And a buffer member 3 that elastically supports the vehicle body 100 via the wheel holder 1 with respect to the auxiliary wheel 2 at the time of a step collision.

≪Axle holder 1≫
As shown in FIGS. 2 and 4, the axle holder 1 includes an upper side member 1 a attached to the lower end of the front leg rod 101 and a lower side member on which the two front wheels 300 are rotatable and pivotally supported so as to be vertically movable. It is a so-called caster formed of two members 1b and formed so that the lower member 1b is connected to the upper member 1a by the connecting shaft member 4 so as to be swingable.
And as shown in FIG. 2, the wheel holder 1 is made to protrude toward the front of the front wheel 300 from the lower side member 1b, and is provided with the auxiliary wheel holder part 5. As shown in FIG.

≪Auxiliary wheel holder 5≫
As shown in FIGS. 2 and 3, the auxiliary wheel holder portion 5 is provided on the front wheel 300 from the lower end portion side of the lower side member 1 b below the rotation shaft 6 that becomes the rotation shaft support portion P of the front wheel 300 with respect to the lower side member 1 b. It is integrally formed with a predetermined size and protruding shape facing forward. That is, the auxiliary wheel holder 5 is integrally formed with the wheel holder 1.
As shown in FIGS. 2 and 4, the auxiliary wheel holder portion 5 has the lower surface portion opened from the front surface portion that allows the auxiliary wheel 2 to move in a diagonally rearwardly upward and diagonally downward direction and is rotatably supported. An auxiliary wheel support space 7 is provided.

The auxiliary wheel support space 7 has a size that can accommodate the auxiliary wheel 2 so that the auxiliary wheel 2 can move in an obliquely rearward upward direction and an obliquely forward downward direction with a part of the outer periphery of the auxiliary wheel 2 facing the outside at all times. The lower surface side is opened from the front surface portion.
As described above, the auxiliary wheel 2 is made to be an auxiliary wheel in an accommodation form in which both the high step climbing ability and the buffering function, which are problems of the present invention, are effective without exposing the entire auxiliary wheel 2 to the outside. By providing the holder portion 5, the entire wheel holder 1 including the auxiliary wheel holder portion 5 has a simple structure, and as a result, the appearance can be improved and the design can be improved.
Further, by adopting an external closing form by the buffer member 3 including the auxiliary wheel 2 and the closing cover 12 of the bearing member 10 to be described later, the movement of the auxiliary wheel 2 and the buffer member 3 due to dirt such as dirt and sand from the road surface. It can be said that this is an effective method because it can be a simple structure that can surely prevent malfunctions such as sluggish movement.

In addition, inclined guide elongated holes 8 are provided in the side wall portions 5a of the auxiliary wheel holder portion 5 forming the auxiliary wheel support space 7 so as to open at a predetermined inclination angle θ from the front position of the front wheel 300 in the oblique rearward upward direction. ing.
Here, as shown in FIG. 3 (b), the inclination angle θ is an oblique rearward rising angle of the step D with respect to the rising surface portion d, and when the auxiliary wheel 2 collides with the step D, When the weight of the vehicle body 100 or the like is applied, the auxiliary wheel 2 smoothly moves in the oblique rearward upward direction at the inclination angle θ (FIG. 3 (a) and FIG. 6 and FIG. 8).

The inclined guide long hole 8 has an opening width capable of slidably supporting and guiding both ends of the axle 9 of the auxiliary wheel 2 from the front position of the front wheel 300 in a slanting rearward direction at an inclination angle θ with respect to the rising surface portion d of the step D. It is formed on both side walls 5 a of the auxiliary wheel holder 5 with a predetermined length directed.
In this way, bearing members 10 are provided at both ends of the axle 9 of the auxiliary wheel 2 supported by the inclined guide long hole 8, as shown in FIGS. The bearing member 10 is formed in a substantially square shape, and slides in a receiving groove portion 11 provided on both wall surface portions 5a of the auxiliary wheel holder portion 5 from a front position of the front wheel 300 toward an obliquely rearward upward direction at an inclination angle θ. The axle 9 of the auxiliary wheel 2 is rotatably supported by being engaged and accommodated.

The housing groove portion 11 is formed on both side wall portions 5a of the auxiliary wheel holder portion 5 within a predetermined range in the diagonally rearward upward direction with a predetermined groove depth and groove width from the periphery of the oblique front downward hole edge of the inclined guide long hole 8. ing.
Then, as shown in FIGS. 3 and 5A, the buffer member 3 and the bearing member 10 that are exposed in a state in which a part is accommodated in the accommodating groove portions 11 of the both wall surface portions 5 of the auxiliary wheel holder portion 5 are closed. The external cover form is covered with the cover 12.

  As shown in FIG. 2B, FIG. 4 and FIG. 5B, the closing cover 12 is slightly larger along the groove shape of the receiving groove portion 11, and is formed between the buffer member 3 and the bearing member 10. It is formed in a spherical shape on the outer surface that covers the exposed portion from the receiving groove portion 11 and is fixedly attached to a standing upright portion of the receiving groove portion 11 with a claw locking structure.

≪Buffer member 3≫
Next, the shock absorbing member 3 that elastically supports the vehicle body 100 via the wheel holder 1 with respect to the auxiliary wheel 2 at the time of a step collision of the auxiliary wheel 2 will be described.
Examples of the buffer member 3 include a spring material and a rubber material. In the present embodiment, a compression coil spring is used (hereinafter, the buffer member is referred to as a “compression coil spring”). In the present embodiment, the auxiliary wheel 2 collides with the step D due to the force (N) by which the guardian pushes the vehicle body 100 with the hand pusher 103 and the traveling speed (km / h) of the vehicle body 100 on a flat road surface. The compression coil spring 3 is set to an appropriate spring constant (wire diameter, coil outer diameter, effective number of turns, etc.) that effectively performs a buffering function in accordance with the impact received by the vehicle body 100. .
As a result, the compression coil spring 3 includes the bearing member 10 and the housing groove portion housed in the housing groove portion 11 in the housing groove portion 11 provided in the both wall surface portions 5a of the auxiliary wheel holder portion 5, as shown in FIGS. 11 is attached to the auxiliary wheel 2 with an appropriate spring constant that effectively performs a buffering function in response to an impact at the time of a collision with the step D, by being interposed between the rear end of the groove rising at an oblique rear end of 11 In contrast, the vehicle body 100 can be elastically supported.

In the step climbing mechanism according to the present embodiment configured as described above, when the auxiliary wheel 2 collides with the step D, the oblique rear upward tilt angle that moves obliquely rearward upward, that is, with respect to the rising surface portion b of the step D The inclination angle θ is preferably set in the range of 50 to 60 °.
The reason is that if the inclination angle θ is 50 ° or less, the amount of movement of the auxiliary wheel 2 in the step height direction can be increased, but the resistance of the bearing member 10 that supports the axle 9 of the auxiliary wheel 2 with respect to the inclined guide long hole 8. Becomes too large and the auxiliary wheel 2 does not move quickly along the inclined guide slot 8. That is, an effective buffer function by the compression coil spring 3 cannot be obtained.
On the other hand, when the inclination angle θ is 60 ° or more, an effective buffering function by the compression coil spring 3 can be obtained immediately after the collision with the step D, and the auxiliary wheel 2 moves quickly in an oblique rearward and upward direction. This is because it is considered that the amount of movement in the step height direction when climbing up cannot be expected to be large, and the step climbing ability (function) such as limiting the step height that can be overcome is reduced.
Therefore, in the present embodiment, it is preferable to set the oblique rear rising inclination angle θ of the auxiliary wheel 2 with respect to the rising surface portion b of the step D within a range of 50 to 60 °, and particularly preferably 55 °.

  In this embodiment, as shown in FIGS. 2 and 4, the attachment of the rotary shaft 6 of the front wheel 300 to the lower side member 1 b constituting the wheel holder 1 is made to be included in the lower side member 1 b so as to be movable up and down. The vehicle body 100 is elastically supported and held by a compression spring 14 interposed between the movable member 13 and the movable member 13. That is, it becomes a buffer support structure that prevents vibrations and impacts from being transmitted to the baby seat 200 on which the infant rides by absorbing vibrations and impacts received by the front wheels 300 from the road surface while the stroller A is traveling. Although not shown, a similar buffer support structure can be employed on the rear wheel 400 side.

[Description of operation]
Next, with respect to the stroller in which the step climbing mechanism according to the present embodiment configured as described above is applied to the front wheel 300 side around the vehicle body 100, operation when climbing over the step D (step climbing and shock buffering). Will be described.
6 to 9 show in steps the operation of the step climbing mechanism when the stroller A gets over the step D, FIG. 6 shows a state immediately after the auxiliary wheel 2 collides with the step D, and FIG. FIG. 8 shows a state in which the auxiliary wheel D moves in the diagonally upward direction against the compression coil spring 3, FIG. 8 shows a state in which the auxiliary wheel 2 rides on the step D, and FIG. It shows a state in which the vehicle rides on the level difference D and the auxiliary wheel 2 is returned to the limit of movement by moving diagonally forward.

  When the stroller A encounters the step D while the stroller A travels and the auxiliary wheel 2 collides with the step D as shown in FIG. 6, the auxiliary wheel 2 resists the compression coil spring 3 due to the continuous pushing force of the stroller A in the traveling direction. Then, it moves in an oblique rearward upward direction along the inclined guide elongated hole 8 (state shown in FIG. 7). In other words, the auxiliary wheel 2 moves in the height direction of the step D. At this time, the impact at the time of the step collision is reduced by the movement of the auxiliary wheel 2 that moves against the elastic force of the compression coil spring 3 in the oblique rearward upward direction. That is, the compression coil spring 3 fulfills a buffering function that softens the impact from being transmitted to the vehicle body 100 when the auxiliary wheel 2 collides with the step D.

  As the auxiliary wheel 2 moves in the height direction of the step D, the auxiliary wheel 2 rides on the step D as shown in FIG. When the auxiliary wheel 2 rides on the step D, the front wheel 300 is lifted in the height direction of the step D. When the front wheel 300 is lifted in the height direction of the step D, the front wheel 300 rides on the step D having a height that is difficult to get over by the front wheel 300 alone (state of FIG. 9). That is, the front wheel 300 can easily get over the step D without tripping over the step D.

  As the front wheel 300 rides on the step D and the load load such as the weight of the vehicle body 100 applied to the auxiliary wheel 2 is released, as shown in FIG. It moves to the movement limit of the slanting front downward direction along the line and prepares for the next step D that it encounters. At this time, the compression coil spring 3 also returns from the contracted state to the original state.

As described above, according to the embodiment of the present invention, when the stroller A travels, the auxiliary wheel 2 provided so as to be movable in the obliquely upward direction from the front of the front wheel 300 in a non-grounded state collides with the step D. The auxiliary wheel 2 moves in the diagonally upward direction, which is the height direction of the step D, with the collision with the step D, so that it is possible to get over the step D having a height that is difficult to get on with the front wheel 300 alone. At the same time, when the impact at the step D collision is applied to the compression coil spring 3 due to the movement of the auxiliary wheel 2 in the diagonally rearward upward direction against the elastic force of the compression coil spring 3, the compression coil spring 3 pushes the stroller A and the traveling speed. To absorb the shock by shrinking properly. That is, it is possible to provide a buffer support structure that elastically supports the vehicle body 100 via the wheel holder 1 when the auxiliary wheel 2 is stepped.
Thereby, during the travel of the stroller A1, it is possible to effectively perform a buffering function to reduce the impact when the auxiliary wheel 2 collides with the step D, and it is possible to prevent the impact from being transmitted from the vehicle body 100 to the baby seat 200. Therefore, it is possible to realize and provide the stroller A including the step climbing mechanism that can solve the problem caused by the impact of adversely affecting the infant's body riding the baby seat 200.

  Further, the auxiliary wheel 2 is supported and contained in the auxiliary wheel support space 7 of the auxiliary wheel holder portion 5 provided integrally with the wheel holder 1, and the bearing member 10 provided on the axle 9 of the auxiliary wheel 2, As a result, the entire wheel holder 1 including the auxiliary wheel holder portion 5 has a simple structure. As a result, the appearance is excellent and the design is excellent, and it is possible to reliably prevent malfunctions such as movement of the auxiliary wheel 2 and dull movement of the compression coil spring 3 caused by dirt such as dirt and sand from the road surface. it can. As a result, the stroller A provided with the step climbing mechanism capable of obtaining high reliability can be provided by maintaining the high step climbing ability and the stable continuity of the buffer function over a long period of time.

The embodiments of the present invention have been described in detail with reference to the drawings. However, specific configurations are not limited to these embodiments, and the scope of the present invention described in the claims is not deviated. Even if there is a design change or the like, it is included in the present invention.
In addition, the embodiments described in the above drawings can be combined with each other as long as there are no contradictions or problems with the problems and configurations.
Moreover, the description content of each figure can become independent embodiment, respectively, and embodiment of this invention is not limited to one embodiment which combined each figure.

A Stroller 100 Car body 101 Front leg kit 102 Rear leg kit 103 Hand barb 200 Baby seat 300 Front wheel (main wheel)
400 Rear wheel 1 Wheel holder 1a Upper side member 1b Lower side part 2 Auxiliary wheel 3 Compression coil spring (buffer member)
DESCRIPTION OF SYMBOLS 5 Auxiliary wheel holder part 5a Both-side wall part 6 Rotating shaft of front wheel 7 Auxiliary wheel support space 8 Inclined guide long hole 9 Axle of auxiliary wheel 10 Bearing member P Rotating shaft support part of front wheel D Step d D Rising surface part

Claims (4)

A step-over mechanism that includes a main wheel and an auxiliary wheel, and the main wheel is provided on the rear side with respect to the traveling direction of the vehicle body, and the auxiliary wheel having a smaller diameter than the main wheel is provided on the front side in an ungrounded state. There,
An auxiliary wheel holder part that protrudes toward the front of the main wheel from a wheel holder on which the main wheel is pivotally supported;
The auxiliary wheel holder portion is provided with a buffer member for elastically supporting the vehicle body with respect to the auxiliary wheel while the auxiliary wheel is movable in an obliquely rearward upward direction from the front position of the main wheel. A step-over mechanism that features   The auxiliary wheel holder portion is integrally formed from the lower end portion side of the wheel holder below the rotation shaft support portion of the main wheel with respect to the wheel holder toward the front of the main wheel, and the auxiliary wheel is inclined. 2. The step climbing mechanism according to claim 1, further comprising an auxiliary wheel support space having a bottom surface opened from a front surface portion that is movable in a rearward and obliquely forward and downward direction and is rotatably supported. 3.   The auxiliary wheels are provided with inclined guide elongated holes that are opened in a diagonally upward direction at a predetermined inclination angle from the front position of the main wheel, on both side walls of the auxiliary wheel holder portion having the auxiliary wheel support space. The axle member is supported by the inclined guide long hole, and the buffer member is provided in a predetermined range in a diagonally upward direction from a bearing member of the axle in an externally closed form. The step climbing mechanism according to claim 2. A stroller with front and rear wheels around the underbody,
A stroller comprising the step climbing mechanism according to any one of claims 1 to 3 on the front wheel side.

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