WO2004073805A1

WO2004073805A1 - Inclination controlling device of treadmill and foldable treadmill using same

Info

Publication number: WO2004073805A1
Application number: PCT/KR2004/000349
Authority: WO
Inventors: Seon-Kyung Yoo
Original assignee: Tobeone Company Limited
Priority date: 2003-02-21
Filing date: 2004-02-20
Publication date: 2004-09-02
Also published as: US20070004561A1; US7722507B2; KR20040075722A; KR100587159B1

Abstract

The present invention provides a inclination controlling device of treadmill comprising a belt support frame 110, a first link member 120 pivotally connected to the belt support frame 110, a second link member 130 pivotally connected to the belt support frame 110, and a base frame 140 pivotally connected to both the first link member 120 and the second link, member 130 respectively thereby controlling an inclination angle of the belt support frame 110 with wider range.

Description

INCLINATION CONTROLLING DEVICE OF TREADMILL AND FOLDABLE TREADMILL USING SAME

FIELD OF THE INVENTION

The present invention relates to an exercise apparatus in general and, more particularly, to an inclination controlling device of a treadmill and foldable treadmill using same, whose inclination angle can be controlled more widely including a downward inclination as well as an upward inclination in order to enable users to run or walk on the treadmill in various conditions.

Cross-Reference to Related Application

The present application claims the benefit of Korea Patent application No. 2003-0011094 filed Feb. 21 , 2003, which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

A treadmill known as a running machine is widely used indoors such as at home or in a sports center as it allows users to have an effect of exercising while working or running on its endless rotating belt in narrow space. Recently, a demand for treadmills is drastically increasing due to the advantages of its safety and convenience because users can exercise indoors using treadmill even in the cold winter. Users of a treadmill can strengthen the cardiopulmonary function and muscles of legs, and can control weight by consuming calories efficiently while running or walking on a treadmill. To maximize this exercise effect, a treadmill with an inclination controlling device has been produced lately. A treadmill comprises a foot plate which upholds load resulting from users, a belt rotating endlessly around the footplate on which users can run or walk continuously, an operating motor for the belt, a holding post used as arm supports while exercising, an inclination controlling device which supports the load of the footplate and controls the inclination. As illustrated in FIG. 1 , the conventional treadmill 1 includes a support frame 10 which upholds weight or impact by running or walking thereon, a link member 20 pivotally connected to one end 11 of the support frame for rotating relative to the support frame 10, a fixed member 30 which is connected to the support frame 10 to uphold a rear part of the support frame 10, a base 40 pivotally connected to one end 21 of the link member 20 for rotating and settling on the ground, an actuator 50 which connects the base 40 with the link member 20.

The fixed member 30 has one end 31 welded to a support frame 10, the other end 32 which maintains a constant angle with a ground, and a roller 32a on the ground movable with a support frame 10 according to an operation of the actuator 50.

The actuator 50 has one end 51a pivotally connected to a link member 20 for rotating relative to the link member 20 and can control an inclination angle of the support frame 10 by means of contracting or extending a bar 51 because the bar 51 controls an angle between the link member 20 and the base 40 thereby allowing the link member 2 to rotate relative to the base 40.

In the conventional treadmill shown at FIG. 1 as described above, the angle θ between the link member 20 and the base 40 gets smaller and the height of the joint 11 gets lower while the bar 51 of the actuator 50 is being contracted. On the contrary, while the bar 51 is being extended, the angle θ gets bigger and the height of a joint 11 gets higher. As a result, the treadmill can have various slope for running or walking.

However, the inclination controlling device of the conventional treadmill counts on a height deviation amount of the joint 11 caused by a rotation of the link member 20 in view of controlling the inclination angle of the support frame because the distance from the joint 11 to the ground is consistent regardless of operation of the actuator 50. Therefore, the conventional treadmill has a limit not to control the inclination angle in wide range.

Besides, the fixed member 30 should be formed short to make steep inclination angle in the conventional inclination controlling device. But in this case, the conventional treadmill cannot substantially provide with a downward inclination because of the short length of the fixed member 30. Moreover, in case of the steep inclination of the support frame 10, moments are concentrated near the actuator

50 thereby causing weakening the durability of links.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an inclination controlling device of a conventional treadmill. FIG. 2 through FIG. 8 relates to an inclination controlling device of a treadmill in accordance with the first embodiment of the present invention.

FIG. 2 is a perspective view illustrating the inclination controlling device of a treadmill in accordance with the present invention. FIG. 3 is an exploded view illustrating the inclination controlling device of a treadmill in accordance with the present invention.

FIG. 4 is a side view illustrating the inclination controlling device of a treadmill in accordance with the present invention.

FIG. 5 is a side view illustrating an upward inclination by the inclination controlling device of a treadmill in accordance with the present invention.

FIG. 6 is a side view illustrating a downward inclination by the inclination controlling device of a treadmill in accordance with the present invention.

FIG. 7 is a perspective view illustrating a treadmill with the inclination controlling device in accordance with the present invention. FIG. 8 is a perspective view illustrating the treadmill folding the inclination controlling device.

DETAILED DESCRIPTION OF THE INVENTION

summary of Invention

As a solution for the above problem, the present invention is designed to provide with an inclination controlling device of a treadmill, whose inclination angle can be controlled in the wide range including a downward inclination as well as an upward inclination in order to enable users to exercise in various exercise condition.

It is another purpose of the present invention to provide with an inclination controlling device of a treadmill with enhanced durability by means of preventing load or impact by users from being concentrated on a specific member. The present invention also enables to protect joints (such as a knee joint) of users from an excessive impact when using a treadmill.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an inclination controlling device comprising a belt support frame, a first link member which is pivotally connected to the belt support frame, a second link member which is pivotally connected to the belt support frame and positioned at a regular interval from the first link member, a base which is pivotally connected to both first link member and second link member relatively for rotating, and an actuator to let the belt support frame move relative to the base frame. And thus, it enables to control an inclination of the belt support frame with wider range because the inclination controlling device of a treadmill is formed as a four link structure pivotally connecting the belt support frame, the first link member, the base frame and second link member one another. That is, a second pivotal joint connecting the belt support frame with the second link member goes down when a first pivotal joint connecting the belt support with the first link member goes up, and, likewise, the second pivotal joint goes up when the first pivotal joint goes down. Accordingly the inclination connecting the first pivotal joint with the second pivotal joint can be realized in wider range.

In addition, due to the four-link structure with four pivotal joints, impacts on a footplate during exercise can be absorbed in the pivotal joints or transformed to elastic energy in each member so that reactive impacts on user's knee and ankle joint during an exercise can be minimized.

Herein, it is preferable that the first link member is longer than the second link member because different lengths of the links connecting the belt support frame with the base frame permit the inclination to be controlled widely and easily.

It is desirable that the angle between the first link member and the base frame is acute angle defined between 5° and 60° and the angle between the second link member and the base frame is defined between 75° and 90° when the first pivotal joint is positioned at the nearest to the base frame.

Moreover, when the first pivotal joint is positioned at the nearest to the base frame, the first pivotal joint is positioned lower than the second pivotal joint so that users can enjoy running or working on a downward inclination condition.

Besides, when the first pivotal joint is positioned at the furthest from the base frame, the first pivotal joint is higher than the sceond pivotal joint so that users can enjoy running or working on an upward inclination condition.

Herein, it is preferable that the angle between the first link member and the base frame is defined either between 35° and 50° or between 75° and 90°. When the angle between the first link member and the base frame is within the range between 0° and 45°, the first pivotal joint can be higher with efficient rate. And when the angle between the first link member and the base frame reaches 90°, the steepest inclination is embodied. It can suit user's taste in exercise through installing the ranges of the angle in manufacturing process by adjusting fit with conditions in advance in which users want to exercise. Also, in view of controlling the inclination angle of the belt support frame, it is desirable that the actuator is operated by a contraction or extension of the bar, wherein the actuator is pivotally connected on the base frame and one end of the operating bar can be pivotally connected to one of the first link member, the second link member and the belt support frame.

Meanwhile, the actuator includes a motor, a pinion engaged with the motor and driven by the motor, and a transfer gear engaged with both the pinion and the first link member, wherein the transfer gear can be engaged with the second link member instead of the first link member. The treadmill device has a holding post having a handle and the base frame is pivotally connected to the holding post for rotating relative to the holding post thereby enabling users to keep the treadmill folded in a narrow space when it is not in use.

On the other hand, this present provides with a foldable treadmill comprising a footplate; an inclination controlling device including a belt support frame upholding the footplate and controlling an inclination angle of the footplate, a first link member pivotally connected to the belt support fame, a second link member pivotally connected to the belt support fame, a base frame pivotally connected to the first link member and the second link member respectively; a holding assembly including a holding post longitudinally set up, a support connected to lower one end of the holding post; a hinge formed at the holding assembly for letting said inclination controlling device rotate relative to the holding assembly. And thus, users can keep the treadmill folded in a narrow space when it is not in use. It is preferable that the hinge is formed rotatably connecting the holding post with the base frame.

The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

Detailed Description Preferred Embodiments

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

As illustrated in FIG. 2 through FIG. 8, a treadmill with an inclination controlling device in accordance with the first embodiment of the present invention comprises a footplate 60, an belt 70 that moves around the footplate endlessly, a motor 80 driving the belt to rotate via a connection belt 81 , and an inclination controlling device that upholds loads or impacts on the footplate 60 and controls an inclination angle of the footplate 60.

Herein, the inclination controlling device 100 thereof has a belt support frame 110 which upholds the footplate 60 loaded by users, a first link member 120 pivotally connected to one side of the belt support frame 110 for rotating, a second link member 130 pivotally connected to the other side for rotating at a regular interval from first link member 120, a base frame 140 pivotally connected to both the first link member 120 and the second link member 130 respectively, and an actuator 150 pivotally connected to the base frame 140 letting the belt support frame 110 controlled to move relative to the base frame 140. The belt support frame 110 has a rectangular form to securely hold the footplate 60 from loads and impacts. That is, protrusions 111 around four edges of the rectangular form in the belt support frame 110 are fit to convex portions 61 of the footplate 60. The first link member 120 includes a first pivot joint 121 which is pivotally connected to one side of the belt frame 110 for rotating, and a third pivot joint 123 which is pivotally connected to one side of the base frame 140 for rotating.

The second link member 130 includes a second pivot joint 132 which is pivotally connected to the belt support frame 110 at an interval of d1 from the first pivot joint 121 , and a fourth pivot joint 134 which is pivotally connected to one side of the base frame 140 at an interval of d2 relative to the base frame 140 for rotating.

Laid on the ground horizontally, the base frame 140 has a foldable hinge pivotally connected to one side of a holding assembly 90 thereby enabling the treadmill to be folded when it is not use. And the base frame 140 is connected to one side to the first link member 120 and to the second link member 130 at the interval of d2 respectively.

The actuator 150 includes a driving part 151 and a bar 152 formed as leadscrew whose one end is inserted into the driving part 151 and engaged with the driving part 151 in proper length. Therefore, as the driving part 151 rotates, the bar 152 gets contracted or extended according to the rotation direction of the driving part 151. Herein, one end of actuator 150 (driving part 151) is pivotally connected to the base frame 140 and one end 152b of the bar 152 is pivotally connected to the belt support frame 110, so that an inclination angle of the belt support frame 110 can be controlled as the driving part 151 rotates and the bar 152 gets contracted or extended.

As described above, the belt support frame 110, the first link member 120, the second link member and the base frame 140 make up a trapezoid-shaped four-link structure and rotate relative to each other. Preferably, the first link member 120 is much longer than the second link member 130 in order to control the inclination angle of the belt support frame 110 with wider range thereby attaining steep inclination.

In the horizontal condition of the belt support frame shown in FIG. 4, it is preferred that the belt support frame 110 poses as low as possible. However, in case that the belt support frame 110 poses too low in the horizontal condition, excessive stress could be concentrated on the first link member 120 and the bar 152. Therefore, it is desirable to maintain the proper distance H between the belt support frame 110 and the ground. Concretely, the distance H is preferable to be 100 mm to 250mm to satisfy the both conditions properly.

In addition, during running or walking on a treadmill, most of loads or impacts by a user are mainly concentrated on a front portion A of the belt support frame 110. In the conventional inclination controlling devices 1 , such a concentrated loads make damages or troubles of the treadmill since the loads are transmitted and concentrated on the actuator 50 and the link members 20. However, in the inclination controlling device in accordance with the first embodiment of the present invention illustrated in FIG. 4, the loads Fp by a user is distributed to the first link member 120 and the bar 152 respectively as an amount of reaction force F1 , Fa of a sine component of the angle α, γ. Furthermore, even though there is a little difference caused by values of angle α and the angle γ, force component in horizontal direction is set off and a moment does not work on the base frame 140. That is, the inclination controlling device of the present invention make external forces from user shared effectively, and thus each member 110,120,130,140 making up the four-link structure has an improved durability thereby removing the possibility of breakage. Moreover, the inclination controlling device can be manufactured with reduced cost by applying a lower capacity of actuator 150 thereto and users can run or walk on the treadmill with the inclination controlling device feeling more comfortable due to properly shared the external forces.

It is also possible to design the ratio of d1 over d2 variously where the d1 is a distance from the first pivotal joint 121 to the second pivotal joint 132, and the d2 is a distance from the third pivotal joint 123 to the fourth pivotal joint 134. When the d1 is equal to the d2, external force will be distributed effectively but this will cause that an inclination angle cannot be controlled. That is, the belt support frame 110 is always parallel to the base frame140. When the d1 is much longer than the d2, external force can not be shared effectively while wide range of an inclination angle can be controlled. Therefore, there exists an optimized ratio of d1 over d2 (d1/d2). Preferably, the ratio of d1 over d2 is defined between 0.3 and 0.9 to harmonize both the control range of inclination angle and the effective external load sharing.

It is desirable that the second link member 130 is pivotally fixed at a point which is very close to the end of base frame 140. That is, the d4 shown in Fig. 4 is defined between 25mm and 80mm in view of improving the load sharing characteristics and durability.

Referring to the FIG. 2 through FIG. 6., components shown as 71, 72 are rollers to guide and drive the belt 70 to rotate endlessly around the footplate 60, a component shown as 91 is a handle formed at the end of holding post 90, and a component shown as 92a is a control panel showing exercise conditions.

Hereinafter, an operation mechanism in accordance with the first embodiment will be readily apparent by following description referring to FIG. 4 through FIG. 6.

Illustrated in FIG. 6, when the first pivotal joint 121 is positioned at the nearest to the base frame 140, that is, when a length of the bar 152 of the actuator 150 is the shortest, a height of the first pivotal joint 121 is lower than that of the second pivotal joint 132 thereby realizing downward inclination by the inclination controlling device of a treadmill. Herein, an angle β between the second link member 130 and base frame 140 is 90° while an angle α between the first link member 120 and base frame 140 is an acute angle between 5° and 60°. More specifically, it is preferable that the angle α is defined between 5° and 30° in order to realize steeper downward inclination, and that the angle is defined between 30° and 60° in order to realize steeper upward inclination.

Preferably, the angle β is less than 90° in that the second pivot joint 132 is getting higher and then lower when the second link member 130 is rotating over

90° thereby causing the footplate 60 to be fluctuated which results in an concentration of stresses on the first link member 120 and the second link member 130 and causing unpleasantness to users.

As shown in FIG. 5, when the bar 152 is extended by operating the actuator 150, the angle β gets smaller within the range less than 90° and the height of the second pivot joint 132 gets lower. Simultaneously, the angle α gets bigger and the height of the first pivot joint 121 gets higher. Accordingly, the inclination angle of the belt support frame 110 is converted to plus value (upward inclination) from minus value (downward inclination) as the bar 152 is extended, and then significantly steep upward inclination can be realized according to the extension amount of the bar 152.

Herein, it is preferable that the angle α is defined either between 35° and 50° or between 75° and 90° when the bar 152 of the actuator 150 is extended maximally. More concretely, the first pivot joint 121 can be higher with efficient rate for the amount of rotation Δα of the first link member 120 within the range between 0° and 45°. When the angle between the first link member and the base frame reaches 90°, the steepest slope is embodied. It can suit user's taste in exercise through installing the ranges of in manufacturing process by adjusting fit with conditions in advance in which users want to exercise. More specifically, when some users want to enjoy running in downward inclination condition as well as upward inclination i.e. in the wide range of inclination angle, the maximum value of the angle is preferably 45°. Likewise, when other users want to enjoy running or walking in very steep upward inclination, the maximum value of the angle is preferably 90°.

As the bar 152 of the actuator 150 gets extended, the belt support frame 110 moves in direction of 110b. That is, the belt support frame moves in direction of 110b by a length of d3-d3' as the second link member 130 rotates by the amount of rotation Δβ . (Herein, d3' in FIG. 5 become shorter than d3 in FIG. 6). Considering that users tend to move forward to grasp a handle 91 when the inclination of the footplate 60 goes up, the inclination controlling device 100 enables users to feel more comfortable and keep exercising on the footplate 60 even when the inclination of the footplate 60 is going up gradually. In general, treadmill should be equipped with the footplate 60 long enough for users' exercise radius. Meanwhile the inclination controlling device can have a shorter footplate 60 by the length of d3-d3' when the inclination of the footplate 60 goes up thereby saving a space for the treadmill. .

The inclination controlling device 100 in accordance with the present invention provides with versatility from a downward inclination to a significant steep upward inclination according to contraction or extension of the bar 152 so that user can feel more satisfaction with enjoying various exercise conditions.

As explained above, the inclination controlling device 100 in accordance with the present invention is formed as four-link structure by pivotally connecting the belt support frame 110, the first link member 120, the second link member 130 and the base frame 140 one another. Therefore, in controlling the inclination angle of the belt support frame, when the first pivot joint 121 is rising from the base frame 140, the second pivot joint 132 is contrariwise dropping toward the base frame 140. Likewise when the first pivot joint 121 is dropping toward the base frame 140, the second pivot joint 132 is contrariwise rising from the base frame 140 thereby controlling the inclination angle widely.

In addition, Having the four-link structure with the four pivotal joints 121,123,132,134 pivotally connecting link members 110,120,130,140 one another can absorb external impacts or forces on the footplate 60 during an exercise by transforming external impacts or forces into elastic energy of link members 110,120,130 bent slightly or damping on each pivotal joints 121 ,123,132,134 thereby minimizing the reactive impacts on user's knee or ankle joint

The actuator 150 also limits the movement of four-link structure as illustrated in the first embodiment where the actuator is pivotally connected to the base frame 140 and one end of the bar 152 is pivotally connected to the belt support frame 110. Meanwhile, one end of the bar 152 constituting actuator can be connected to either the first link member 120 or the second link member 130 instead of the belt support frame 110 without any change of effect. Although the current embodiment detailed above deals with inclination controlling device with a bar type actuator, as far as the four-link structure is included in the treadmill inclination controlling device, the present invention also include an inclination controlling device manually operated with a handle, and an inclination controlling device applying other type of actuator comprising a pinion driven by a motor, a transfer gear engaged with both the pinion and the first link member(or the second link member) instead of bar type actuator.

As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. An inclination controlling device of a treadmill comprising: a belt support frame; a first link member pivotally connected to said belt support frame; a second link member pivotally connected to said belt support frame and positioned at an regular interval from said first link member; and a base frame pivotally connected to both said first link member and said second link member respectively.

2. The inclination controlling device of a treadmill according to claim 1 , wherein said first link member is longer than said second link member.

3. The inclination controlling device of a treadmill according to claim 2, wherein the angle between said first link member and the base frame is defined between 5° and 60°, when a first pivotal joint connecting said first link member with said belt support frame is positioned at the nearest to said base frame.

4. The inclination controlling device of a treadmill according to claim

2, wherein the angle between said second link member and the base frame is defined between 75° and 90°, when a first pivotal joint connecting said first link member with said belt support frame is positioned at the nearest to said base frame.

5. The inclination controlling device of a treadmill according to claim 2, wherein a first pivotal joint connecting said first link member with said belt support frame is positioned lower than a second pivotal joint connecting the second link member with said belt support frame, when said first pivotal joint connecting said first link member with said belt support frame is positioned at the nearest to said base frame.

6. The inclination controlling device of a treadmill according to claim 2, wherein a first pivotal joint connecting said first link member with said belt support frame is positioned higher than a second pivotal joint connecting the second link member with the belt support frame, when said first pivotal joint connecting said first link member with said belt support frame is positioned at the furthest from said base frame.

7. The inclination controlling device of a treadmill according to claim 6, wherein the angle between said first link member and said base frame is defined between 75° and 90°, when said first pivotal joint is positioned at the furthest from said base frame.

8. The inclination controlling device of a treadmill according to claim 6, wherein the angle between said first link member and said base frame is defined between 35° and 50°, when said first pivotal joint is positioned at the furthest from said base frame.

9. The inclination controlling device of a treadmill according to claim 2, wherein the ratio of d1 over d2 is defined between 0.3 and 0.9 where said d1 is a distance between a first pivotal joint connecting said first link member with said belt support frame and a second pivotal joint connecting the second link member with said belt support frame, and said d2 is a distance between a third pivotal joint connecting said first link member with said base frame and a fourth pivotal joint connecting said second link member with said base frame.

10. The inclination controlling device of a treadmill according to claim 2, wherein the distance from the bottom side of said base frame to the upper side of said belt support frame is defined between 100mm and 250mm when said base frame is parallel to said belt support frame.

11. The inclination controlling device of a treadmill according to claim 2, wherein a fourth pivotal joint connecting said second link member with said base frame is positioned between 25mm and 80mm from the end of said base frame.

12. The inclination controlling device of a treadmill according to one of from claim 1 to claim 11, further comprising an actuator driving said belt support frame relative to said base frame.

13. The inclination controlling device of a treadmill according to claim 12, wherein said actuator includes: a motor; a pinion engaged with said motor and driven by said motor; and a transfer gear engaged with both said pinion and said first link member.

14. The inclination controlling device of a treadmill according to claim 12, wherein said actuator includes: a motor; a pinion driven in engagement with said motor; and a transfer gear engaged with both said pinion and said second link member.

15. The inclination controlling device of a treadmill according to claim 12, wherein said actuator is operated by contraction or extension of said bar.

16. The inclination controlling device of a treadmill according to claim 15, wherein said actuator is fixed to said base frame.

17. The inclination controlling device of a treadmill according to claim 15, wherein said actuator is fixed to said base frame, and one end of said bar is connected to said first link member.

18. The inclination controlling device of a treadmill according to claim 15, wherein said actuator is fixed to said base frame, and one end of said bar is connected to said second link member.

19. The inclination controlling device of a treadmill according to claim 15, wherein said actuator is fixed to said base frame, and one end of said bar is connected to said belt support frame.

20. The inclination controlling device of a treadmill according to claim

1 , wherein said treadmill has a holding post having a handle; and said base frame is pivotally connected to said holding post for rotating relative to said holding post.

21. An inclination controlling device of a treadmill comprising: a belt support frame; a first link member pivotally connected to said belt support frame; a second link member which is shorter than said first link member, and pivotally connected to said belt support frame; a base frame pivotally connected to both said first link member and said second link member respectively; an actuator for driving said belt support frame relative to said base frame by means of contraction and extension of a bar movement; wherein, one end of said actuator is pivotally connected to said base frame, and one end of said bar is pivotally connected to said belt support frame.

22. A foldable treadmill comprising: a footplate; an inclination controlling device including a belt support frame upholding said footplate and controlling an inclination angle of said footplate, a first link member pivotally connected to said belt support fame, a second link member pivotally connected to said belt support fame, a base frame pivotally connected to said first link member and said second link member respectively; a holding assembly including a holding post longitudinally set up, a support connected to lower one end of said holding post; a hinge formed at said holding assembly for letting said inclination controlling device rotate relative to said holding assembly.

23. The foldable treadmill according to claim 22, wherein said inclination controlling device includes an actuator letting said belt support frame move relative to said base frame.

24. An inclination controlling device of a treadmill including a holding assembly having a holding post longitudinally set up and a support connected to lower end of said holding post, a footplate, an inclination controlling device upholding said footplate and controlling an inclination angle of said footplate: characterized in that said inclination controlling device is pivotally connected to said holding assembly for rotating.