US20070225126A1

Movatterモバイル変換

Info

Publication number: US20070225126A1
Application number: US11/384,380
Authority: US
Inventors: Seon-Kyung Yoo
Original assignee: TOBEONE Co Ltd
Current assignee: TOBEONE Co Ltd
Priority date: 2006-03-21
Filing date: 2006-03-21
Publication date: 2007-09-27

Abstract

The present invention provides an inclination control device of a treadmill comprising: a pair of support members pivotally connected with at least one first hinge at the track part for extending from the track part to the ground; a pair of housings having a housing hinge respectively for being pivotally connected with each of the second hinge at the support members, and having female thread; a pair of screw rod engaging respectively with the female thread of each of the housing so as to be extruded from or inserted into by relative rotation therebetween; a pair of driving pulleys combined with each of the screw rod for rotating together with the screw rod; a belt engaging with the driving pulleys; a pinion engaging with the belt for transmitting a driving force via the belt to the driving pulleys; a motor for letting pinion rotate; and a bracket for rotatably fixing the pinion and the driving pulleys, and having a pair of bracket hinges on its both sides to be pivotally combined with each of the third hinges of the track part, whereby the first hinge, the second hinge and the third hinge form a three-linked structure so as to stably support the impact and/or load from a user's running in addition to enhance durability and to save the manufacture cost.

Description

BACKGROUND

1. Field of the Invention

The present invention relates to a treadmill, more particularly, to an actuator for stably controlling an inclination of the track part of a treadmill and an inclination control device of a treadmill.

2. Discussion of Related Art

A treadmill known as a running machine is widely used indoors such as at home or in a sports center because it allows a user to effectively exercise by working or running on its endlessly rotating track belt even in the narrow space. In view that a user can exercise indoors using treadmill even in the cold winter, the demand for treadmills is recently drastically increasing due to the advantages of its safety and convenience because.

By using a treadmill, the user thereof can strengthen the cardiopulmonary function and muscles of legs, and can control weight by consuming calories efficiently while running or walking on the treadmill. To maximize this exercise effect, a treadmill with an inclination control device came to be lately produced.

More specifically, a treadmill generally comprises a track part on which user put their feet for running or walking, and an inclination control device for supporting the track part and to control the inclination.

As illustrated inFIGS. 1 and 2, the conventional treadmill comprises atrack part10 on which user run or walk, asupport part20 located at a bottom of the treadmill for controlling the inclination of thetrack part10 while sustaining the load or impact transmitted from thetrack part10.

Thetrack part10 has asupport frame11 which upholds weight of user; a belt rotating endlessly, which enables a user to run or walk continuously on the upper side of thetrack part10; a pair ofrollers13 supporting both sides of thebelt12; amotor14 as a driving unit for driving making one of therollers13 rotate; andconnection part15 linked with theactuator30.

Thesupport part20 includes abase frame21 installed on the ground, and asupport member22, having its one end fixed to abase frame21 and theother end22apivotally connected to atrack part10.

The actuator includes aextendable rod32, of which one end32ais pivotally connected to alink member15 of thetrack part10, and of which the other end is pivotally connected to abase frame21; and a drivingpart31 to control the length of theextendable rod32 by extending or contracting theextendable rod32.

The above conventional treadmill controls its inclination of thetrack part10 by means of extending or contracting the extendable rod in the direction of30a. In this case, the load or impact of user is concentrated on the part where user put their foot apart from theother end22aof a fixed member by d1. That is, The load and/or impact is concentrated on the front part of thetrack part10, and thus the load Fa of theactuator30 will be obtained by the following equation in condition that thetrack part10 is parallel to the ground.
Fa′=F Equation 1

In general, since d2 is designed smaller than d1, the load Fa′ applied on theactuator30 is calculated by user's load F₁amplified by d1/d2. Besides, the actuator get more moment due to user's load F₁generated from exercise on the track. The conventional treadmill accordingly needs a big actuator to endure the load and it result in an unnecessary increase of manufacture costs and power consumption.

Also, it is not desirable to install a big actuator in the narrow space between atrack part10 and abase frame21, from view that a user feels safe when the distance between thebase frame21 and thetrack part10 is as short as possible. As a solution for this problem, it can be considered that theactuator30 is installed at both sides of the track part as a pair. However, if twoactuators30 are not exactly controlled with the same extended or the same contracted length, it causes to have a problem thattrack part10 is widthwise inclined even by the small amount, whereby the user feels unstable and uncomfortable.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above and/or other problems, and it is an object of the present invention to provide with an actuator for controlling an inclination of the track part of a treadmill, which is capable of stably controlling the inclination of the track part by simultaneously contracting or simultaneously extending a pair of extendable rods.

Another object of the present invention is to provide an inclination control device of a treadmill, which minimizes the load and moment on the extendable rod of the actuator for controlling the inclination of the treadmill thereby enhancing durability as well as efficiently reducing the manufacturing cost.

In order to achieve the above objects and another aspect of the present invention, the present invention provides an actuator for controlling the inclination of the track part of a treadmill comprising: a driving unit; a pinion rotatably driven by the driving unit; a belt formed to transmit the driving force from the pinion; a pair of driving pulleys engaging with the belt so as to receive the driving force from the pinion; a pair of screw rod combined with each of the driving pulley for rotating together with each of the driving pulley; and a pair of housings having female thread for engaging with each of the screw rod, whereby a pair of screw rods are simultaneously extruded from or simultaneously inserted into each of the housing by the same length.

This is intended to control a pair of extendable rods including the screw rods and the housings to be extended or contracted by the same amount based on that the driving force from the driving unit is transmitted via the belt to a pair of the driving pulleys so that a pair of the driving pulleys rotates by the same amount.

Herein, at least one idler pulley engaging the belt is additionally included thereby obtaining the higher wrapping angle of the pinion surrounded by the belt. Therefore, the friction between the pinion and the belt is increased, and the driving force can be transmitted to a driving pulley without any loss.

Periodical grooves are formed on the outer sides of the pinion, the idler pulley and the driving pulley, and also, the periodical protuberances engaged with the grooves are formed so as to thoroughly remove any slip between the belt and the pulleys due to the increase of the friction, thereby precisely controlling the screw rod's displacement.

It is effective to further comprising: a bracket for rotatably fixing the pinion, the idler pully, and the driving pulleys as one module; bracket hinges formed on both end sides the bracket to be pivotally combined with the track part of a treadmill; and housing hinges formed at each of the housings, whereby the actuator can be easily combined with a treadmill which realizes stable control of the inclination of the track part.

Meanwhile, the actuator for controlling the inclination of a treadmill can use chain or gear instead of the belt as a power transmission means in order to embody the same function.

That is, the treadmill can comprise a driving unit; a pinion rotatably driven by the driving unit; at least one pair of intermediate gear formed to transmit the driving force from the pinion; a pair of driving gears engaging with the intermediate gears so as to receive the driving force from the pinion; a pair of screw rod combined with each of the driving gear for rotating together with each of the driving gear; and a pair of housings having female thread for engaging with each of the screw rod, whereby a pair of screw rods are simultaneously extruded from or simultaneously inserted into each of the housing by the same length.

Herein, the intermediate gears can be plural at one side between the pinion and the driving pulley because it is necessary to install the driving pulleys apart from the pinion in the narrow and long bracket.

On the other hand, the present invention provides with an inclination control device for a treadmill having at least one track part comprising: at least one extendable rod pivotally connected with at least one second hinge which moves together with the support member, and pivotally connected with a third hinge of the track part which is located apart from the first hinge at the track part; wherein, the inclination of the track part is controlled by the extension or the contraction of the extendable rod.

That is, the first hinge, the second hinge and the third hinge form three-link structure, thereby securely support the track part. Although the actuator is located in the front area of the track belt on which user put their feet, as the load and/or impact from a user is not concentrated on the screw rod of the actuator because three elements (i.e., the track part, the support member, and the screw rod with the housing) make up a three-link mechanism, the screw rod can be designed to be smaller diameter or to be a smaller size for obtaining the required durability, thereby realizing the small-sized actuator and saving the manufacturing cost.

It is desirable to include a traverse member to connect between a pair of the support members for obtaining stability.

Also, the second hinge is located at the traverse member so as to easily pivotally combine the extendable rod (more specifically, housing) with the traverse member, thereby achieving the lower manufacturing cost.

It is effective for each roller to be attached at the end of the support members contacted with the ground, thereby reducing friction between the support member and ground when the inclination of the track part is controlled.

When the length of the support member is assumed as L, it is desirable that the second hinge is located in 0.1 L or 0.5 L from one end of the support member contacted with ground. It means that the second hinge is formed near to ground so as to reduce the load applied on the screw rod.

The gear can be used as a means of transmitting power from the drive unit for controlling the inclination of the treadmill.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other objects and advantages of the invention will become apparent and more readily appreciated from the following description of preferred embodiments, taken in conjunction with the accompanying drawings of which:

FIGS. 1 and 2 are views illustrating an inclination control device of a conventional treadmill, in which:

FIG. 1 is a side view illustrating a structure of inclination control device of treadmill;

FIG. 2 is a side view showing the reaction force on the inclination control device ofFIG. 1 as a user exercises thereon;

FIGS.3 to7 are views illustrating an actuator for controlling an inclination of the track part of the treadmill in accordance with one embodiment of the present invention;

FIG. 3 is perspective views of part of the actuator when the extendable rod thereof is contracted.

FIG. 4 is perspective views of part of the actuator when the extendable rod thereof is extended.

FIG. 5 is a perspective view of the actuator adding a hinge bracket into the part of the actuator ofFIG. 3;

FIG. 6 is a perspective view of the actuator from another view;

FIG. 7 is a plane view ofFIG. 5;

FIG. 8 is a schematic view illustrating a structure of an actuator for controlling an inclination of the track part of the treadmill in accordance with another embodiment of the present invention;

FIGS.9 to12 are views illustrating an inclination control device using the actuator shown inFIG. 5 for a treadmill in accordance with one embodiment of the present invention;

FIG. 9 is a perspective view illustrating the treadmill when the inclination of the track part is high position;

FIG. 10 is a perspective view illustrating a structure of the treadmill when the inclination of the track part is low position;

FIG. 11 is a perspective view illustrating a structure of treadmill without a driving cover when the inclination of the track part is low position;

FIG. 12 is a side view of the treadmill shown inFIG. 10; and

FIG. 13 is a FIG. to explain the three-linked truss structure for diverging the load from walking or running of a user.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, an actuator for controlling an inclination of a treadmill according to a preferred embodiment of the present invention will be described.

As illustrated in FIGS.3 to7, theactuator130 for controlling the inclination of a treadmill in accordance with one embodiment of the present invention comprises a driving unit for generating and transmitting the driving torque; and a pair ofextendable rod140 which can be extended or contracted in its length by using the power transmitted from the driving unit.

The driving unit has anactuator motor131 generating rotating force; atransmission132 for reducing the rotating speed of aactuator motor131; apinion133 rotatably combined with thetransmission132; abelt137 to transmit rotating power via thepinion133; driving

pulleys

135,136 rotatably installed by the power transmitted from the pinion via thebelt137, anidler pulley134 rotatably installed for changing the path of thebelt137 between thepinion133 and driving

pullys

135,136 so as to increase the wrapping angle of thepinion133; thebelt137 transmitting the driving force from thepinion133 to the driving

pulley

135,136; abracket138 rotatably fixing thepinion133,idler pulley134, and driving

pulleys

135,136 for forming them as one module; a pair of protuberances138aat both end sides of thebracket138 to be pivotally combined with thetrack part110 of the treadmill100; and a fixingplate139 on a low side of thebracket138 for fixing thetransmission132.

In order to prevent the slip between thebelt137 and pulleys (includingpinion133,idler pulley134 and a pair of drivingpulleys135,136), although not shown in the Figures, it is effective that grooves are periodically formed at outside of the

pulleys

133,134,135,136, and that protuberances for engaging with the grooves respectively are periodically formed at one side or at both sides of thebelt137. A commercially used V-groove type belt having protuberances on its one side can be applied thereto through twisting the belt by 180 between thepinion133 and theidler pulley134 and between theidler pulley134 and the drivingpulley135.

Also, as shown in FIGS.3 to5 and7, by the installation of theidler pulley134 in thebracket138 for changing the path of thebelt137, the wrapping angle of thepinion133 is increased more than 180° so that precise control of the rotation angle of the driving

pulleys

135,136 can be realized by the increase of the driving friction therebetween.

A pair of theextendable rod140 rotates together with each of the driving

pulleys

135,136 fixed to the upper end thereof. Eachextendable rod140 includes ascrew rod142 having thread on its whole length, and ahousing141 having female thread for engaging with the thread of thescrew rod142, and thus, eachextendable rod140 can become longer when thescrew rod142 is extruded from thehousing141 by relative rotation therebetween, and become shorter when the screw rod is inserted into thehousing141.

Herein, a hinge hole141aas a housing hinge is formed at the low end of therespective housing141 for being pivotally combined with each of second hinges141aof thetrack part110. In order for the driving

pulleys

135,136 and thebracket138 integrally move together, thebracket138 is fastened bynuts142b. That is, groove is formed between thenut142band the driving

pulleys

135,136 in the direction of circumference and thebracket138 is inserted within the groove142a.

The drawing notation of132ais a bearing installation part supporting rotation of a rotating axis132bto connect thetransmission132 and apinion133, and the drawing notation of139ais a bolt to fix the fixingplate139 to thebracket138.

Hereinafter, operation principle of theactuator130 in accordance with one embodiment of the present invention is explained.

When theactuator motor131 rotates in order to drive the contractedextendable rod140 to be extended as illustrated inFIG. 5, the driving torque is transmitted from theactuator motor131 to thepinion133, and thepinion133 is driven to rotate counterclockwise. Accordingly, anidler pulley134 connected by thebelt137 with thepinion133 is driven to rotate clockwise, and simultaneously, a pair of driving

pulleys

135,136 is driven to rotate counterclockwise. As one end141aof thehousing141 is fixed to other component such as asupport member151 or atraverse member153, thehousing141 is restricted not to rotate any longer. Thus, as the driving

pulley

135,136 are driven rotate counterclockwise, a pair of thescrew rods142 accordingly rotate together with the

pulleys

135,136 at the same angle, and thus, a pair ofscrew rods142 is to be upwardly (142c) extruded from thehousing141 by the same length each other, whereby the length d of the extendable rod become longer as shown inFIG. 5.

Similarly, when theactuator motor131 rotates in order to drive the extendedextendable rod140 to be contracted as illustrated inFIG. 3, the driving torque is transmitted from theactuator motor131 to thepinion133, and thepinion133 is driven to rotate clockwise. Accordingly, anidler pulley134 connected by thebelt137 with thepinion133 is driven to rotate counterclockwise, and simultaneously, a pair of driving

pulleys

135,136 is driven to rotate clockwise. As one end141aof thehousing141 is fixed to other component such as asupport member151 or atraverse member153, thehousing141 is restricted not to rotate any longer. Thus, as the driving

pulley

135,136 are driven rotate clockwise, a pair of thescrew rods142 accordingly rotate together with the

pulleys

135,136 at the same angle, and thus, a pair ofscrew rods142 is to be downwardly (142d) extruded from thehousing141 by the same length each other, whereby the length d of the extendable rod become shorter as shown inFIG. 3

In the above manner, theactuator130 can precisely control the length of a pair of the extendable rod simultaneously.

It is also possible that the actuator for controlling the inclination of the treadmill of the present invention can drive as a manner of transmitting power from a motor to a screw rod of the extendable rod using plural gears as shownFIG. 8.

Hereinafter, details of another embodiment of the present invention including plural gears will be explained.

As illustrated inFIG. 8, an actuator230 for controlling the inclination by using gears for transmitting the driving torque comprises a driving unit generating the driving torque, and a pair ofextendable rods140 of which length are contracted and extended by the driving torque transmitted from the driving unit. Herein, in order to clarify this embodiment, an explanation of the detailed structure described above on theextendable rod140 is omitted as it is identical or similar to the foregoing embodiment.

The driving unit includes The driving unit has anactuator motor131 generating rotating force; apinion gear233 rotatably driven by theactuator motor131;

intermediate gears

234,234′,234″ engaging thepinion gear233; a pair of driving

gears

235,236 fixed to rotate together with ascrew rod142 engaging the intermediate gears234-234″ and abracket138 formed for rotatably fix the

gears

233,234,234′,234″,235,236 as one module.

In case that thepinion gear233 is located in the center ofbracket138, it is possible to arrange intermediate gear126 symmetrically. However, in the case that thepinion gear233 is not located in the center ofbracket138, such is not possible. For example, as shown inFIG. 8, when thepinion gear233 is placed left from the center, oneintermediate gear234 is installed between thepinion gear233 andleft driving gear135, while three

gears

234,234′,234″ are installed between thepinion gear233 andright driving gear136. That is, it is not needed to set up the same number of left and right gear and it is enough to balance the number of the teeth of gears to be engaged each other. When the number of left and right gears is different, a moving direction of left andright screw rods142 can be matched by means of balancing the number of intermediate gear. That is, when the number of one side ofintermediate gear234 is odd, that of the other side of intermediate gears234-234″ should be odd, and when the number of one side ofintermediate gear234 is even, that of the other side of intermediate gears234-234″ should be even.

Hereinafter, operation principle of the actuator230 in accordance with another embodiment of the present invention is explained.

In order to control the length of theextendable rod140, as aactuator motor131 is driven to rotate, apinion gear233 also rotates interlocked with theactuator motor131. Thus, one or several

intermediate gears

233,233′,233″ engaged with thepinion gear233 also rotate in the opposite direction, and the driving

pulleys

235,236 engaged withintermediate gears234 is also driven rotate. According to the rotation of the driving gears235,236, a pair of thescrew rod142 fixed to the driving gears235,236 respectively move up and down by being extruded from or being inserted into thehousing141 so that the length ofextendable rod140 can be contracted or extended.

Furthermore, the mechanism of power transmission in accordance with one embodiment of the present invention is not limited to the above described belt system as well as the gear system. The scope of the present invention includes a power transmission by driving the driving means such as driving

pulleys

135,136 with a chain system, and also includes the construction of which extendable rod comprises a rack gear engaging driving gears235,236.

On the other hand, the present invention provides with an inclination control device of treadmill using the above actuator for controlling the inclination of a treadmill. Hereinafter, details of an inclination control device of a treadmill in accordance with one embodiment referring to FIGS.9 to13.

FIG. 9 is a perspective view illustrating the treadmill when the inclination of the track part is high position, andFIG. 10 is a perspective view illustrating the structure of treadmill without the driving cover shown inFIG. 9. Thetreadmill101 with the inclination control device in accordance with one embodiment of the present invention comprises atrack part110 on which user run or walk; atrack driving unit120 for driving thetrack belt112 to rotate endlessly of thetrack part110; an inclination control device to control the inclination of thetrack part110 by including theactuator130, theextendable rod140 and afront support150 to uphold thetrack part110 with controlling the inclination thereof; arear support160 to uphold a rear part of thetrack part110; and a column part170 vertically protruded from thetrack part110.

Thetrack part110 includes amain bracket111 to cover the bottom side of thetrack part110; a footplate (not shown) installed in the main bracket to uphold the load of user; a support frame (not shown) installed in the main bracket to support the footplate; atrack belt112 installed to cover the upper and lower sides of the footplate for endlessly rotating; aside cover113 to cover both sides of upper part of themain bracket111; a plate114 fixed to the upper side of the front part of themain bracket111 and having ahinge hole114ato be pivotally combined with each of the protuberance138aof thebracket138 of the actuator shown inFIG. 4; afirst hinge plate115 located at the lower side of themain bracket111 to pivotally combined with the end of thesupport member151; a fixingplate116 located at the upper side of themain bracket111 for easily combining the column part170.

Thetrack driving unit120 includes atrack driving motor121 generating the rotating power driving thetrack belt112 of thetrack part110, aconnection belt122 transmitting power of thetrack driving motor121, a drivingroller123 connected with the connection belt for being driven to rotate by thetrack driving motor121, anidler roller124 located at the rear part of thetrack part110, and adriver unit cover125 for preventing the undesirable dusts or particles from entering into thetrack driving motor121.

Thefront support150 includes a pair ofsupport members151 pivotally connected to each of thefirst bracket115 located at both sides of the lower part oftrack part110, aroller152 rotatably combined with the end of each of thesupport member151 so that the end of thesupport member151 can smoothly slide against the ground. And thesupport member151 includes atraverse member153 to connect the bothsupport members151 each other. Herein, afirst hinge151ais formed at the pivotally connected point between thesupport member151 and thefirst bracket115 of thetrack part110.

Therear support160 has contact portions made of rubber material for preventing the unexpected slide between therear support160 and the contact portion.

The column part170 includes acolumn171 upwardly stretching from thetrack part110 by combining with the fixingplate116, a handle attached to the other end ofcolumn171, and acontrol panel173 combined with the end of the handle for inputting the exercise program and displaying exercise information.

The inclination control device includes theactuator130 for simultaneously controlling the length of theextendable rod140 by the same amount, theexpandable rod140 as described above, and afront support150 for upholding the front part oftrack part110.

Theactuator130 is structured as illustrated inFIG. 3 orFIG. 7 and above mentioned. How to install theactuator130 in a treadmill is as follow.

As illustrated inFIG. 13, an inclination control device of treadmill of the present invention can efficiently prevent its

members

110,151,141 from being concentrated by load from a user due to three-link truss structure of which three hinges151a,141a,138aare formed as rotatable.

Also, by supporting both sides of thetrack part110 with two extendable rods, an inclination of thetrack part110 in the width direction can be prevented thereby preventing the fluctuation or unbalance thereof in the width direction.

Comprised as above mentioned, the operation mechanism of the inclination control device of the treadmill can be easily understandable referring to that of the foregoing actuator inFIG. 3 andFIG. 4. A difference of rotating direction of theactuator motor131 makes a pair ofscrew rods141 be extruded from thehousing141 by the same length so that the inclination of thetrack part110 can be precisely controlled.FIG. 12 illustrates the situation when the length d ofextendable rod140 gets shortest, and thus, the downward inclination of thetrack part110 is realized within the range between −10° and 0°

Referring toFIG. 12, in case that the load Fp due to a user's exercise thereon is applied on the front part B oftrack part110 as indicated inFIG. 12, the reaction force Fa on theextendable rod140 and the reaction force Fs on thesupport member151 can be calculated as following equations 2 and 3.
Fs=Fp×(L2/L1) EQUATION 2
Fa=Fp×(L4/L3) EQUATION 3

Therefore, different from the reaction force for the inclination control device of a conventional treadmill (see equation 1), the reaction force Fa on theextendable rod140 in the axial direction thereof is came to be reduced rather than be increased. Furthermore, any moment is not applied on the extendable rod, since both ends of theextendable rod140 are formed as the rotatable hinges138a,141a. In view that a member came to be broken due to the repeated bending fatigue loads, theactuator130 can have almost permanent life span because any moment is not applied on theextendable rod140. As the moment and the reaction force Fa of theextendable rod140 are minimized, it is possible to design the extendable rod to have a minimized diameter, thereby also realizing the smaller capacity of the actuator motor as well as the reduced weight of the extendable rod140 (i.e., thehousing141 and the screw rod142) Accordingly, energy consumption required to drive and to manufacture theactuator130 can be also reduced.

In addition, by letting the second hinge141afar apart from thetrack part110, as the reaction force on theextendable rod140 in the axial direction thereof can surprisingly be reduced, when the length of thesupport member151 is assumed to be L5, it is more desirable that the length of L3 is longer than 0.5*L5.

As above explained, The present invention provides with an actuator for inclination controlling of treadmill, which comprises: a motor, a pinion rotating with power of the motor, a belt for transmitting power from the motor, a pair of driving pulleys rotatably engaged with the belt, a pair of the screw rod combined with the driving pulley on its one end, a female screw engaging a screw thread of the screw rod, a housing attached to the screw rod by the female screw so that it facilitates inclination control of a track of the treadmill.

In order to maintain the track part stable during a user's exercise on the track part, a pair of the extendable rod including the screw rod and the housing can be contracted or extended by the same length so that the treadmill can be easily and precisely controlled.

In addition, as the present invention provides with an inclination control device of treadmill using the actuator supporting both sides of track part with a pair of the extendable rods, a user can run or walk on thetrack part110 without an inclination in the width direction which causes a user feel to unstable and unsafe.

The present invention also can save manufacturing cost and enhance durability surprisingly because the load can be effectively diverged and the moment on the extendable rod is removed by constructing one or a pair of three-linked truss structure of which hinges are all rotatable relative to the near members. Also, the actuator according to the present invention can save power consumption for driving and manufacturing cost.

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 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.

On the other hand, although theactuator130 usingbelt137 for transmitting the driving toque is described above as one embodiment of the present invention, any actuator capable of simultaneously controlling a pair of theextendable rod140 is within the scope of the present invention. Also, the inclination control device having a pair of theextendable rod140 for achieving threehinges138a,141a,151 for three-linked truss structure is described above as one embodiment of the present invention, an inclination control device only having oneextendable rod140 is also within the scope of the present invention.

Claims

1. An actuator for controlling the inclination of the track part of a treadmill comprising:

a motor;

a pinion rotatably driven by the motor;

a belt formed to transmit the driving force from the pinion;

a pair of driving pulleys engaging with the belt so as to receive the driving force from the pinion;

a pair of screw rod combined with each of the driving pulley for rotating together with each of the driving pulley; and

a pair of housings having female thread for engaging with each of the screw rod;

wherein a pair of screw rods are simultaneously extruded from or simultaneously inserted into each of the housing by the same length.

2. The actuator for controlling the inclination of the track part of a treadmill as claimed inclaim 1 further comprising:

at least one idler pulley engaging with the belt;

wherein the belt is engaged with the pinion, the idler pulley, and the driving pulleys for transmitting the driving force from the pinion to the driving pulleys.

3. The actuator for controlling the inclination of the track part of a treadmill as claimed inclaim 1, wherein the pinion, the idler pulley, and the driving pulleys has at least one groove on their sides so as to engage with the protuberances periodically formed on the belt.

4. The actuator for controlling the inclination of the track part of a treadmill as claimed inclaim 2 further comprising:

a bracket for rotatably fixing the pinion, the idler pulley and the driving pulleys; and

bracket hinges formed at the both sides of the bracket;

housing hinges formed at each of the housings.

5. An inclination control device for a treadmill having at least one track part comprising:

at least one support member pivotally connected with at least one first hinge at the track part for extending from the track part to the ground; and

at least one extendable rod pivotally connected with at least one second hinge which moves together with the support member, and pivotally connected with at least one third hinge of the track part which is located apart from the first hinge at the track part;

wherein, the inclination of the track part is controlled by the extension or the contraction of the extendable rod.

6. The inclination control device for a treadmill as claimed in claim5, wherein the support members are formed as a pair for pivotally being connected with a pair of the first hinges at the track part, and the extendable rods are formed as a pair for pivotally being connected with a pair of the third hinges at the track part.

7. The inclination control device for a treadmill as claimed inclaim 6, wherein a pair of the support members include a traverse member which connects the support members each other, and the second hinges are formed as a pair at the support members or at the traverse member for pivotally being connected with a pair of the extendable rods.

8. The inclination control device for a treadmill as claimed inclaim 7, wherein a pair of the extendable rods include a pair of housings having a housing hinge respectively for being pivotally connected with each of the second hinge, and having female thread; and a pair of screw rods engaging respectively with the female thread of each of the housing so as to be extruded from or inserted into each of the housing by relative rotation therebetween;

and, further comprising:

a pair of driving pulleys combined with each of the screw rod for rotating together with the screw rod;

a belt engaging with the driving pulleys;

a pinion engaging with the belt for transmitting a driving force via the belt to the driving pulleys;

a motor for making the pinion rotate; and

a bracket for rotatably fixing the pinion, and the driving pulleys, and having a pair of bracket hinges on its both sides to be pivotally combined with each of the third hinges;

wherein one of the first hinges, one of the second hinges, and one of the third hinges form hinges of three-link structure.

9. The inclination control device for a treadmill as claimed inclaim 8, wherein the screw rods integrally rotate with each of the driving pulley respectively.

10. The inclination control device for a treadmill as claimed inclaim 8, further comprising:

at least one idler pulley rotatably fixed to the bracket for engaging with the belt;

11. The inclination control device for a treadmill as claimed inclaim 10, wherein the pinion, the idler pulley, and the driving pulleys have at least one groove on their sides so as to engage with the protuberances periodically formed on one side of the belt.

12. The inclination control device for a treadmill as claimed inclaim 8, further comprising a roller formed at the end of each of the support member which is contact with the ground.

13. The inclination control device for a treadmill as claimed inclaim 8, wherein the second hinges are formed within the range between 0.1 L to 0.5 L from one end contacted with the ground, when the length of the support member is L.

14. The inclination control device for a treadmill as claimed inclaim 8, wherein a pair of the extendable rods include a pair of housings having a housing hinge respectively for pivotally connecting with each of the second hinge, and having female thread; and a pair of screw rods engaging respectively with the female thread of each of the housing so as to be extruded from or inserted into each of the housing by relative rotation therebetween;

and, further comprising:

a pair of driving gears combined with each of the screw rod for rotating together with the screw rod;

at least one pair of intermediate gears engaging with the driving gears;

a pinion gear engaging with the intermediate gears for transmitting a driving force via the intermediate gears to the driving gears;

a motor for making the pinion gear rotate; and

a bracket for rotatably fixing the pinion gear, the intermediate gears and the driving gears, and having bracket hinges on its both sides for being pivotally connected with each of the third hinges;

15. An inclination control device for a treadmill having at least one track part, comprising:

a pair of support members pivotally connected with a pair of first hinges at the track part for extending from the track part to the ground;

a pair of housings having a housing hinge respectively for being pivotally connected with a pair of second hinges at the support members, and having female thread;

a pair of screw rod engaging respectively with the female thread of each of the housing so as to be extruded from or inserted into by relative rotation therebetween;

a belt engaging with the driving pulleys;

a motor for letting pinion rotate; and

a bracket for rotatably fixing the pinion and the driving pulleys, and having a pair of bracket hinges on its both sides to be pivotally combined with a pair of the third hinges at the track part;

wherein the third hinges are apart from the first hinges respectively, and wherein one of the first hinges, one of the second hinges and one of the third hinges form a three-linked structure.

16. The inclination control device for a treadmill as claimed inclaim 15, wherein the screw rods are integrally rotate with each of the driving pulley respectively.

17. The inclination control device for a treadmill as claimed inclaim 15, further comprising:

18. The inclination control device for a treadmill as claimed inclaim 17, wherein the pinion, the idler pulley, and the driving pulleys have at least one groove on their sides so as to engage with the protuberances periodically formed on one side of the belt.

19. The inclination control device for a treadmill as claimed inclaim 15, further comprising a roller formed at the end of each of the support member which is contact with the ground.

20. The inclination control device for a treadmill as claimed inclaim 15, wherein the second hinges are formed within the range between 0.1 L to 0.5 L from one end contacted with the ground, when the length of the support member is L.