Patent Publication Number: US-8968160-B2

Title: Treadmill belt support assembly

Description:
RELATED APPLICATIONS 
     This application claims the benefit of priority of U.S. Provisional Application Ser. No. 60/944,235 filed Jun. 15, 2007, the disclosure of which is incorporated herein by reference in its entirety as if fully set forth herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Exercise treadmills have conventionally used an endless running belt that is supported on a pair of rollers, front and back, with the running belt serving no purpose other than a platform for rotation on the rollers. One of the two rollers is typically driven or otherwise interconnected to a drive mechanism that is movable in order to enable maintenance of the belt system. 
     SUMMARY OF THE INVENTION 
     The present invention relates to belts and drive systems used in treadmills and similar devices. More particularly the present invention relates to an apparatus and method for maintaining a drive belt for a pulley of a driven roller of a treadmill under tension and for enabling ready removal and replacement of the drive belt. In accordance with the invention there is provided an apparatus and method for mounting a drive belt in a treadmill, the apparatus comprising a rotational drive mechanism mounted on a frame, the drive mechanism being interconnected via the drive belt to an axle of one of a pair of rollers around which are wound a treadmill belt wherein the rollers are mounted on the frame so as to create a selectable tension or force in the treadmill belt wherein the axle of the one of the pair of rollers is mounted and the interconnection of the drive belt are adapted to transmit at least a portion of the tension or force in the treadmill belt to the drive belt. 
     In accordance with the invention there is provided, a treadmill comprising: 
     a pair of rollers mounted on a frame; 
     an endless running belt wound around the rollers under a selected tension; 
     at least one of the rollers having a roller pulley for receiving a drive belt; 
     a drive mechanism comprising a driven rotor having a drive pulley; 
     the drive belt being wound around the roller pulley and the drive pulley at a drive tension created by the selected tension in the running belt. 
     The drive mechanism is preferably fixedly mounted to the frame, the drive tension in the drive belt being created by the selected tension in the running belt pulling against the fixedly mounted drive mechanism through the drive pulley. 
     At least one of the drive pulley and the roller pulley is preferably adapted to enable the drive belt to be readily manually released from being wound around the drive pulley or the roller pulley upon relaxation of tension in the roller belt to a selected degree. 
     The at least one roller having the roller pulley is preferably movable toward the fixedly mounted drive mechanism upon relaxation of the selected tension in the roller belt a distance sufficient to enable the drive belt to be readily manually released from being wound around the drive pulley. 
     The roller pulley is typically mounted on an axle that is slidably mounted within a slot mechanism for back and forth travel within a slot, the slot mechanism having a rearward stop edge or surface fixedly located relative to the drive pulley in a position that is selected to limit travel of the axle away from the drive pulley to a degree that limits the tension in the drive belt to a selected maximum. 
     The roller pulley is typically mounted on an axle that is slidably mounted within a slot mechanism for back and forth travel within a slot, the slot mechanism having a release aperture for removal of the axle from the slot on relaxation of the tension in the roller belt to a selected degree. 
     The treadmill can further comprise a mechanism for selectively adjusting the selected tension in the roller belt. 
     The mechanism for selectively adjusting the selected tension in the roller belt  16  typically comprises a separation adjustment device  80  fixedly interconnected to the frame  20  and adjustably engageable with one of the rollers to enable the rollers to be adjustably moved toward F and away TD from each other. 
     In another aspect of the invention there is provided a treadmill comprising: 
     a pair of rollers mounted on a frame; 
     an endless running belt wound around the rollers; 
     at least one of the rollers having a roller pulley for receiving a drive belt; 
     a drive mechanism comprising a driven rotor having a drive pulley, the drive belt being wound around the roller pulley and the drive pulley; 
     the drive mechanism being fixedly mounted to the frame; the running belt being maintained under a selected tension that acts through the roller pulley to maintain the drive pulley under tension. 
     In such an embodiment, the rollers are preferably adjustably movable toward and away from each other to enable the tension in the running belt to be selectively adjusted. 
     In such an embodiment the treadmill preferably further comprises a separation adjustment device  80  fixedly interconnected to the frame  20  and adjustably engageable with one of the rollers to enable the rollers to be adjustably moved toward F and away TD from each other. 
     The roller pulley is preferably mounted on an axle that is slidably mounted within a slot mechanism for back and forth travel within a slot, the slot mechanism having a rearward stop edge or surface fixedly located relative to the drive pulley in a position that is selected to limit travel of the axle away from the drive pulley to a degree that limits the tension in the drive belt to a selected maximum. 
     The roller pulley is typically mounted on an axle that is slidably mounted within a slot mechanism for back and forth travel within a slot, the slot mechanism having a release aperture for removal of the axle from the slot on relaxation of the tension in the roller belt to a selected degree. 
     In such an embodiment the treadmill preferably further comprises a mechanism for selectively adjusting the selected tension in the roller belt. 
     Further in accordance with the invention there is provided a treadmill comprising: 
     a pair of rollers mounted on a frame; 
     an endless running belt wound around the rollers under a selected tension; 
     at least one of the rollers having a roller pulley for receiving a drive belt; 
     a drive mechanism comprising a driven rotor having a drive pulley, the drive belt being wound around the roller pulley and the drive pulley; 
     the drive mechanism being fixedly mounted to the frame; 
     at least one of the drive pulley and the roller pulley being adapted to enable the drive belt to be readily manually released from being wound around the drive pulley or the roller pulley upon relaxation of the selected tension in the roller belt to a selected degree. 
     The roller pulley is mounted on an axle that is slidably mounted within a slot mechanism for back and forth travel within a slot, the slot mechanism having a release aperture for removal of the axle from the slot on relaxation of the tension in the roller belt to a selected degree. 
     The roller pulley is mounted on an axle that is slidably mounted within a slot mechanism for back and forth travel within a slot, the slot mechanism having a rearward stop edge or surface fixedly located relative to the drive pulley in a position that is selected to limit travel of the axle away from the drive pulley to a degree that limits the tension in the drive belt to a selected maximum. 
     The treadmill typically further comprises a mechanism for selectively adjusting the selected tension in the roller belt. 
     The mechanism for selectively adjusting the selected tension in the roller belt  16  preferably further comprises a separation adjustment device  80  fixedly interconnected to the frame  20  and adjustably engageable with one of the rollers to enable the rollers to be adjustably moved toward F and away TD from each other. 
     In another aspect of the invention there is provided, a treadmill comprising: 
     a pair of rollers mounted on a frame; 
     an endless running belt wound around the rollers under tension; 
     at least one of the rollers having a roller pulley for receiving a drive belt; 
     a drive mechanism comprising a driven rotor having a drive pulley, the drive belt being wound around the roller pulley and the drive pulley; 
     the drive mechanism being fixedly mounted to the frame; 
     the roller pulley being mounted for back and forth travel toward and away from the drive mechanism. 
     In such an embodiment the roller pulley preferably includes an axle that is slidably mounted within a slot mechanism for back and forth travel within a slot, the slot mechanism having a release aperture for removal of the axle from the slot on relaxation of the tension in the roller belt to a selected degree. 
     In such an embodiment the tension in the running belt creates tension in the drive belt and wherein the roller pulley is includes an axle that is slidably mounted within a slot mechanism for back and forth travel within a slot, the slot mechanism having a rearward stop edge or surface fixedly located relative to the drive pulley in a position that is selected to limit travel of the axle away from the drive pulley to a degree that limits the tension in the drive belt to a selected maximum. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and further advantages of the invention may be better understood by referring to the following description in conjunction with the accompanying drawings in which: 
         FIG. 1  is a front left perspective view of a treadmill in accordance with the invention; 
         FIG. 2  is a right side Perspective view of the drive motor and front roller pulley of the treadmill of  FIG. 1 , showing the interconnection of the two via a drive belt and pulleys of  FIG. 1 ; 
         FIG. 3  is a front perspective view showing the same components shown in  FIG. 2 ; 
         FIG. 4  is a side view of the assembly shown in  FIG. 2 ; 
         FIG. 4A  is a schematic side view of the treadmill of  FIG. 1  showing the relationship of the rollers, running belt, motor and belt pulleys and drive belt components of the  FIG. 1  treadmill; 
         FIG. 5  is a left side perspective view of the rear roller adjustment mechanism of the treadmill of  FIG. 1 ; 
         FIG. 6  is a top left side view of the rear roller adjustment mechanism shown in  FIG. 5 ; 
         FIG. 7  is a left side view of the rear roller adjustment mechanism shown in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
     With reference to the accompanying figures,  FIG. 1  shows a treadmill  10  having a front end  12 , a rearward end  14  and an endless belt  16  on which a user stands. At the front end  12  of the treadmill a motor  26  is stationarily mounted by bolts or similar means  18  to the frame  20  of the treadmill, i.e. the motor and its housing do not pivot or slide or otherwise move on or relative to the frame  20 . The frame  20  is a rigid structure on which all of the operating components of the treadmill  10  are mounted. The frame typically comprises an assembly of rigid struts, linkages and the like that are rigidly interconnected to each other by bolts, welding or other conventional means. The frame  20  is typically comprised of a rigid, dimensionally stable metal material. As shown in  FIGS. 2 ,  3  the forward end of the belt  16  is wrapped under tension around a front end roller  22  and a rear end roller  24 . The running belt has a small degree of ability to stretch under tension. As mounted around the front  22  and rear  24  rollers, the running belt is formed as an endless belt  16  that remains and is maintained laterally in position on the rollers when the rollers are distanced away from each other to a sufficient extent as to create a tension T in the belt  16  thus causing the belt  16  to be frictionally engaged with the rollers  22  and  24  such that the belt  16  does not move laterally/radially along the rollers  22 ,  24 . The tension T between the axles of the front  22  and rear  24  rollers ranges between about 100 and about 1000 pounds in the mounted positions of the rollers as shown in the Figures. Typically the rollers  22 ,  24  are mounted such that the tension T between the axles is between about 500 and about 900 pounds, and most typically between about 600 and about 800 pounds. The tension T is adjustable and selectable and is selected to be at least great enough to create a tension T 2  in drive belt  46  sufficient to enable belt  46  to frictionally engage pulleys  42 ,  44  and enable pulley  42  and motor  26  to rotatably drive roller  22  when frictionally engaged with the roller belt  16 . 
     In practice, the treadmill  10 ,  FIG. 4A  includes a support platform  200  that is mounted via mounting mechanism  202  on the frame  20 . The platform  200  typically comprises a planar sheet or board comprised of dimensionally stable material such as wood or plastic. The support platform  200  lies beneath the undersurface of the vertically upper running portion  16   a  of the running belt  16  on the user of the device physically stands or runs with their feet. The belt  16  rotates 300 together with the rotating rollers  22 ,  24  due to the tension in the belt and its frictional engagement with the outside surfaces of the rollers  22 ,  24 . The undersurface of the upper running portion of the belt  16   a  slides over the top surface  200   a  of the platform  200  as the belt  16  rotates 300 together with the rollers  22 ,  24 . When a user stands on the main upper surface area  16   b  of the running belt,  FIG. 1 , the user&#39;s weight is upwardly supported by the support platform  200  via its mounting on the frame  20 , the weight of the user causing the undersurface of the upper portion  16   b  of the running belt to frictionally engage the top surface  200   a  of the support platform. The frame  20  is typically mounted on the floor  400 ,  FIGS. 1 ,  2 . The front end of the apparatus  10  typically includes a rotatable wheel that enables rollable movement of the apparatus  10  along the floor  400  the wheel being interconnected to the frame  20  via a spring loaded leg or similar shock absorbing or cushioning mechanism  410  for cushioned mounting of the apparatus  10  on a stable floor  400  or other fixed stable surface. The leg  410  is interconnected to the rigid frame  20 . Similarly, the support platform  200  is typically mounted to the frame  20  through or to a spring or other shock absorbing or cushioning member  202  so that when a user runs on the top surface  16   a  of the belt  16 , the downward and other forces exerted on the belt  16  by the user are better absorbed or cushioned by the frame  20  through the cushioning mechanism  202 . 
     The axle  34  of the front roller  22  is mounted to and projects outwardly from the axis of roller  22  on both ends of roller  22  such that the roller  22  does not move radially or axially relative to the axle  34 , i.e. the axle  34  and roller  22  are mounted to each other such that the roller  22  does rotate around the axis of the roller  22  when the axle is mounted within the slot  32 . On one end of the roller  22 , the right hand side end as shown in the figures, axle  34  is mounted in a generally horizontally oriented slot  32  that extends from front to back of the apparatus  10 . The front to back or rearward to frontward extending slot  32  is provided in a bracket  30  that itself is rigidly or stationarily mounted in a vertically upright orientation on the frame  20 . The axle  34  extends through the slot  32  and abuts a rearward edge  38  of the slot that is positioned in a preselected position so as to create a preselected direct distance D 1  and/or a preselected lateral distance D between the axis  34  of roller  22  and roller pulley  44  and the rotor  40  of a driven motor pulley  42 . The distance D or D 1  is preselected together with the radius or diameter of pulleys  42  and  44  and the length of belt  46  so as to create a preselected tension T 2  in the drive belt  46 . 
     The tension in belt  46  is created by the pull or tension T in belt  16  which pulls the axle  34  in the backward direction T shown in  FIG. 4  causing the axle to be pulled against the rearwardmost edge  38  of slot  32  in which the axle  34  is slidably mounted. The length of belt  46 , distances D and/or D 1 , the diameters of pulleys  42 ,  44  and the position of the stop edge  38  of slot  32  are all preselected to create and maintain a predetermined degree/amount of tension in belt  46  within a predetermined range that is appropriate for the type of belt  46  employed. The absolute value of the range of desired tension in belt  46  depends and varies depending on the construction of belt  46  itself, e.g. depending on the materials of which belt is made, its width, thickness, length, configuration and the like. Typically for commercially available motor drive belts the predetermined amount of tension created in belt  46  is between about 60 and about 200 pounds. 
     Axle  34  is disengageable or removable from slot  32  by reducing or eliminating or relieving the tension T in running belt  16  to the point where, as a result of removal/elimination/release of the backward pulling force T,  FIG. 4 , the center of axle  34  can be slid in the forward direction F into horizontal alignment with vertical/removal slot  31  at which point axle  34  can be lifted in an upward direction U out of slot  32  entirely. Upon release or elimination of tension T in belt  16 , the tension T 2  in belt  46  is also released, eliminated or relieved due to the fact that there is no longer a backward force/tension T causing the axle  34  to be pulled backwardly away from fixed rotor  40 .Rotor  40  of motor  26  is held in a fixed/stationary position by virtue of the fixed bolting of motor  26  to the frame  20  by bolt, weld, screw or other means. 
     Once the tension T 2  in belt  46  is released/eliminated, and axle  34  is removed from slot  32  by upward U movement of the axle  34  through slot  31 , the drive belt  46  can be unwound/removed from engagement around pulley  44  by pulling the drive belt  46  in the lateral direction L,  FIG. 4  off and past the lateral most extension point of axle  34 . Drive belt  46  is fully removable by similarly laterally pulling the belt  46  from engagement around motor pulley  42 . Once fully removed from pulleys  44  and  42 , a new drive belt can be readily and quickly manually placed around both pulleys  42  and  44  while the axle  34  is still disengaged/removed from slot  32 . Once a new drive belt is wound around pulleys  42 ,  44 , the roller axle  34  can be reinserted into slot  32  through slot  31  and the tension T in running belt  16  re-established as described below to re-establish tension T 2  in the new belt  46 . 
     With reference to  FIGS. 6-8 , the degree of tension T in running belt  16  is controllably variable by the user by operation of rear separation adjustment device  80 . Typically two such mechanisms are mounted to the rear portion of the frame, equidistant from the center of the belt  16  on the left and right rear sides of the frame.  FIGS. 7 ,  8  illustrate a left rear side separation adjustment device  80 , the right side mechanism not being shown. As shown, the roller separation adjustment device  80  is comprised of a bolt  70  having a threaded portion  72  that is screwably engaged with a complementary threaded portion  74  of the aperture  75  of a nut  76  that is press fit within a flanged abutment mechanism  78 . As shown in  FIGS. 6 ,  7 , the bolt  70  extends through an aperture  92  that extends radially through the rear axle  90  of rear treadmill belt roller  24 , the exterior diameter of the nut  76  being mounted within the radial aperture through the axle  90  and the flange mechanism  78  having a first flange portion  79  that is arranged to abut against the outside surface of the rear axle and a second flange portion  77  that is arranged to abut against a frame portion (not shown) for purposes of enabling the bolt  70 ,  72  and nut  74 ,  76  to better engage against the outside radial/circumferential surface of the rear axle  90 . When the bolt  70  is turned/rotated about its axis in a preselected direction, e.g. clockwise C,  FIG. 7 , the screwably engaged nut  76  will translate in the rearward TD direction and eventually with a sufficient degree of rotation C, the nut  76  will push the front face of flange portion  79  against the outside radial surface of axle  90  thus moving axle  90  and roller  24  in the rearward TD direction and creating a tension T,  FIG. 1 , in belt  16  to/of a degree that is selected by the user depending on the degree to which bolt  70  is rotated C around its axis. 
     As shown,  FIGS. 5-7 , the rear axle  90  of the rear roller  24  is vertically supported on the frame  20  via the bolt  70 ,  72  (left side only shown) that is engaged within the axle receiving aperture  92 , the bolt  70 ,  72  being mounted at is distal end  70  and proximal end  72  on the components shown which are affixed to the frame  20 . 
     Similarly, any tension T,  FIGS. 1 ,  8  that may exist in belt  16  may be lessened, relieved or eliminated completely by rotating bolt  70  in the opposite direction CC to a selected degree to cause nut  76  to move in the forward direction F. If tension T exists in belt  16 , axle  90  and roller  24  will move forwardly F together with forward movement F of nut  76  under the force of tension T. The tension T in belt  16  can be completely relieved/eliminated by turning bolt  70  to a degree sufficient to move nut  76  and associated flange element  78  forwardly F enough such that the running belt  16  is no longer stretched between the front and rear rollers and is in a relaxed state. 
     Once the running belt  16  is in a relaxed state and no longer under tension T,  FIGS. 4 ,  5 , the tension T 2  in belt  46  is also relaxed or eliminated and the axle  34  of the front roller and pulley  44  can then be slid forwardly F,  FIG. 3 , through slot  32  into alignment with slot  31  to remove axle  34  from slot  32  entirely to enable replacement of drive belt  46  as described above. 
     In the embodiments described, the adjustment bolt  70  is screwably engaged with nut  76  as a mechanism for forcibly moving the rear roller  24  backward and forward. Other mechanisms can alternatively be used. For example, the interior surface of aperture  92  of axle  90  could be provided with a complementary set of teeth to engage directly with the screw teeth  73  provided on the surface of bolt  70 . Elastic pull mechanisms (not shown) attached to the frame could alternatively be provided to pull the axle  90  of the rear roller  24  rearwardly TD. A push screw mechanism, as opposed to the pull screw  70  mechanism, could alternatively be provided. Pneumatic or hydraulic actuators/cylinders connected between the frame and the axle of one or the other of the rollers could also be employed. Any mechanism that enables controllable movement of the axle one roller  22 ,  24  relative to the other can be employed, i.e. that enables controlled variation of the front to back orthogonal distance between the axes of the two rollers when mounted in substantially parallel relationship to each other. 
     Rotation and driving of the shaft of the motor  26  by conventional means (e.g. electricity, fuel, spring or the like mechanism) rotates the pulley  42  which is fixedly attached to the shaft of the motor  26 . Drive belt  46  is wound around the outside circumferential edge of pulley  42  under tension as described below. Thus as pulley  42  is drivably rotated around rotor  40 , drive belt  46  is drivably rotated together with the drivably rotated pulley  42 . As shown, drive belt  46 ,  FIGS. 3-5  is also wound around roller pulley  44  under tension as described below. Pulley  44  is fixedly attached to axle  34  of roller  22 . The driven rotation of belt  46  in turn drivably rotates front roller  22 . The driven rotation of roller  22  by belt  46  through pulleys,  42 ,  44  and axle  34  in turn drivably rotates running belt  16  which is also tension mounted on and around the outer circumferential surface of roller  22 . 
     Motor  26  is controllably drivable at predeterminable and user selectable speeds at and for predeterminable and user selectable intervals of time by interconnection to programmed or programmable electronic control mechanisms such as computers, microprocessors and the like. Such electronic controls have user interfaces that are typically mounted on an upright display device  13 , the electronic controls being readily manually programmable by a user standing on the belt  16 . The electronic controls are typically interconnected to conventional electrical energy feed control devices such as a variable resistor, rheostat, potentiometer or the like that are in turn interconnected to the motor  26  to controllably drive the motor. Other motor speed controls mechanisms such as meshed gears, controllable transmission systems and the like can similarly be employed to enable the user to selectively control the timing and speed of the driven rotation of motor  26  and thus in turn the speed of rotation of the rollers  22 ,  24  and in turn the speed of rotation of the running belt  16 .