Patent Publication Number: US-2013237384-A1

Title: Collapsible treadmill

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a treadmill, and more particularly, to a collapsible treadmill. 
     2. Description of the Related Art 
     To allow convenient storage of a treadmill, the commercially available treadmill is collapsible. For example, referring to  FIGS. 1-2 , a conventional collapsible treadmill  10  disclosed in U.S. Pat. No. 5,674,453 is composed of a support structure  11  put on the ground, two upright members  12  extending toward a top end thereof from the support structure  11 , and a tread base  14  pivotably attached to respective inner sides of the two upright members  12  via two base axes separately. The tread base  14  includes a first section  14 A and a second section  14 B located reversely relative to the first section  14 A. 
     When it is intended to collapse the tread base  14 , apply an upward force to the second section  14 B to turn the first section  14 A on the two base axes  13 . In other words, the tread base  14  is moved upward to a collapsed position from an operational position. The treadmill  10  can though function as collapsing the tread base  14 , but it still has the following drawbacks. 
     1. Where the tread base  14  is pivoted must be close to an end portion  14 C and there is none of any connecting member between the tread base  14  and the support structure  11 . When the tread base  14  is turned upward, an inertial force can be generated and applied to the upright members  12  and the support structure  11 , so the support structure is subject to shake. 
     2. When a user is jogging or running on the tread base  14 , the whole weight of the user and the tread base is supported by the two base axes  13  to easily result in fatigue and deformation of the two base axes  13  to further affect the long-term rotational and folding smoothness of the tread base  14 . 
     Although Taiwan Pat. No. 1234471 disclosed an improvement on the aforesaid prior art, the improved structure has numerous components and it is complicated to assemble them, so the product cost is higher to be unfavorable to commercial competition, thus needing further improvement. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a collapsible treadmill, which platform is highly stable and which folding structure is simple and practicable. 
     The foregoing objective of the present invention is attained by the collapsible treadmill composed of a chassis, two support members, a standing post, a main frame, a folding device, and two limiters. The chassis includes two lateral bars spaced from each other and each having a first end portion and a second end portion reversely located relative to the first end portion. Each of the support members is mounted close to the first end portion of one of the two lateral bars and does not contact the ground. The standing post is connected to the chassis, extending toward the top end of the treadmill. The main frame includes two lateral frames, a frame body, and an endless belt. The two lateral frames are spaced from each other and each have a first section and a second section arranged reversely relative to the first section. The frame body is formed of at least one fastening bar fixedly connected between the two lateral frames. The endless belt is provided with two (front and rear) ends put inside the frame body for rotation along a closed path. The folding device includes a lifting frame having two first lateral frames spaced from each other and two second lateral frames spaced from each other. A rear end of the lifting frame is pivotably attached to the main frame. The lifting frame has two active pivot members formed at a front end thereof and contacting against the two support members separately. Respective front ends of two linking-up members are connected with the active pivot members separately. Respective rear ends of the two linking-up members are connected with the two lateral bars separately. The two limiters are mounted inside the chassis and define a limited space with the support members for limiting the space within which the active pivot members can act. 
     Therefore, the platform of the present invention can be preferably stable and the folding structure of the same can be simple and practicable because the lifting frame is mounted to the support members via the two active pivot members, the two linking-up members are mounted to the chassis, and the limiters have anti-run function. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the conventional treadmill under operational status. 
         FIG. 2  is a side view of the conventional treadmill under collapsed status. 
         FIG. 3  is a perspective view of a first preferred embodiment of the present invention. 
         FIG. 4  is an exploded view of the first preferred embodiment of the present invention, in which the instrument unit is not shown. 
         FIG. 5  is a side view of the first preferred embodiment of the present invention, in which the instrument unit is not shown and one lateral bar of the main frame is hidden. 
         FIG. 6  is similar to  FIG. 5 , illustrating that the treadmill is partially collapsed. 
         FIG. 7  is similar to  FIG. 5 , illustrating that the treadmill is fully collapsed. 
         FIG. 8  is another side view of the first preferred embodiment of the present invention, illustrating that the platform is being lifted. 
         FIG. 9  is similar to  FIG. 8 , illustrating that the platform is lifted. 
         FIG. 10  is a side view of a second preferred embodiment of the present invention. 
         FIG. 11  is similar to  FIG. 10 , illustrating that the treadmill is partially collapsed. 
         FIG. 12  is similar to  FIG. 10 , illustrating that the treadmill is fully collapsed. 
         FIG. 13  is another side view of the second preferred embodiment of the present invention, illustrating that the platform is being lifted. 
         FIG. 14  is similar to  FIG. 13 , illustrating that the platform is lifted. 
         FIG. 15  is a side view of a third preferred embodiment of the present invention, illustrating that the front ends of the linking-up members are acentrically connected with the active pivot members. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     First of all, note that the relative positions, like “top” and “bottom”, set forth in the following paragraphs are defined based on the user&#39;s operational orientation and identical or similar elements in different preferred embodiments are indicated by the same reference numerals. 
     Referring to  FIGS. 3-4 , a collapsible treadmill  2  constructed according to a first preferred embodiment of the present invention is composed of a chassis  20  placed on a support surface (e.g. ground), a set of standing posts  30  mounted to a front end of the chassis  20  and extending toward a top end of the collapsible treadmill  2 , a main frame  40  connected with a platform  50 , and a folding device  60  connected between the chassis  20  and the main frame  40 . The detailed descriptions and operations of these elements as well as their interrelations are recited in the respective paragraphs as follows. 
     The chassis  20  includes two lateral bars  21  spaced from each other, two connection bars  22  fixedly connected between the two lateral bars  21 , and two support members  23  mounted to two lateral ends of the two connection bars  22  and close to the front end of the chassis  20 . The chassis  20  further includes conventional components at a rear end thereof, such as a pair of rollers  25 , a hydraulic cylinder  26 , and a retractable bar assembly  27 . A receiving space is formed inside the chassis  20 . 
     The standing post  30  includes a set of instrument units  32  mounted to a top end thereof. 
     The main frame  40  includes a front section extending into the receiving space of the chassis  20  and connected with a platform  50 . The main frame  40  includes two lateral frames  41 , each of which is formed of a first section  411  and a second  412  arranged reversely relative to and spaced from the first section  411 , a frame body formed of three fastening bars  42  fixedly connected between the two lateral frames  41 , and an endless belt having a front end and a rear end, which are placed inside the frame body, and being rotatable along a closed path. 
     In practice, in the first preferred embodiment, an electric motor (not shown) is installed onto a front end of the main frame  40  for driving rotation of the endless belt  44   
     The folding device  60  further includes a linear actuator  61 , a lifting frame  63 , two active pivot members  65 , two linking-up members  67 , and two limiters  70 . The linear actuator  61  is mounted onto the main frame  40  and has a lifting pipe  611 , the length of which is retractable. The lifting frame  63  is formed of two first lateral frames  631  spaced from each other, two second lateral frames  63  spaced from each other, and two fastening bars  633  fixedly connected between the second lateral frames  632 . The fastening bars  633  are connected with the lifting pipe  611  to enable the lifting frame  63  to be hauled by the lifting pipe  611  for elevation-angle lifting motion. The lifting frame  63  has a rear end pivotably attached to the main frame  40  and a front end thereof contacting against the support member  23  via two active pivot members  65 . In this embodiment, each of the two active pivot members  65  is, but not limited to, a wheel and a pivotal center on which the active pivot members  65  and the lifting frame  63  are connected protrudes from a front end surface of the first section of the main frame  40 . 
     Each of the two linking-up members  67  has a front end connected coaxially with one of the active pivot members  65  and a rear end connected with one of the lateral bars  21 . Each of the two limiters  70  includes a combination portion  701  and a stop portion  702 . Each of the stop portions is located on one of the active pivot members  65 , extending forwardly and downwardly toward a front end of the treadmill slantingways. 
     Referring to  FIGS. 5-7 , when it is intended to collapse the main frame  40  or the platform  50 , the two active pivot members  65  can function as respective folding points. The two active pivot members  65  are connected with the lifting frame  63  and hauled by the linking-up members  67  to the chassis  20 , so the two active pivot members  65  will be confined within the support members  23  of the chassis  20  separately to be movable within the very small range. When the main frame  40  or the platform  50  pivots on the two active pivot members  65 , the two active pivot members  65  may be pulled upward by an inertial force; meanwhile, stopped by the two limiters  70 , the two active pivot members  65  can be prevented from disengagement from the support members  23  separately. Thus, the platform  50  can be successfully collapsed. 
     Referring to  FIGS. 8-9 , when it is intended for the main frame  40  or the platform  50  to lift the elevation angle, the linear actuator  61  can apply an upward force to the lifting frame  53  in such a way that the two active pivot members  65  are forced to contact against the support members  23  and the counterforce will lift the front end of the main frame  40  or the platform  50 . 
     Referring to  FIG. 10 , a second preferred embodiment of the present invention is different from the first preferred embodiment of the present invention as recited thereinafter. A spacer  80  is further mounted to a front section of the chassis  20  and a limiting member  85  includes an upper end connected with the main frame  40 . The limiting member  85  is provided with an elongated slot  86  formed on a lower section thereof and having an upper limit  861  and a lower limit  862  for limited movement of the limiting member  85  along the elongated shot  86  between the upper and lower limits  861  and  862 . When it is intended to collapse the main frame  40  or the platform  50 , the two active pivot members  65  function as respective folding points. Connected with the lifting frame  63 , the two active pivot members  65  are also hauled to the chassis  20 , so the two active pivot members  65  are confined inside the support member  23  to be movable within the support member  23 . Referring to  FIGS. 11-12 , when the main frame  40  or the platform  50  pivots on the two active pivot members  65 ; the two active pivot members  65  may though be pulled upward but the lower limit is confined by the spacer  80  to prevent the two active pivot members  65  from disengaging from the support member  23  to successfully complete the folding operation. In other words, the limiters  70  of the first embodiment have the anti-run function identical to that of the limiting member  85  of the second embodiment, so if the present invention is actually manufactured, the set of the limiters and the active pivoting members or the set of the limiting member and the spacer can be selectively adopted. 
     Referring to  FIGS. 13-14 , when it is intended to lift the elevation angle of the main frame  40  or the platform  50 , the linear actuator  61  applies a downward force to the lifting frame  63  and the two active pivot members  65  are forced to contact against the support member  23 , so the counterforce will lift the front end of the main frame  40  or of the platform  50 . 
     Referring to  FIG. 15 , in a third preferred embodiment of the present invention, the relationship of connection between the linking-up member  67  and the active pivoting member  65  is interchangeable as recited thereinafter. The front ends of the linking-up members  67  can be acentrically connected with the active pivoting members separately in such a way that the active pivoting members  65  are movable forwardly and backwardly for a small distance and thus the platform  50  can be successfully collapsed likewise. 
     In conclusion, the new-type lifting frame  63  of the folding device  60  of the present invention works with the two active pivoting members  65  and the two linking-up members  67 , which are mounted to the chassis  20 , in coordination with the anti-run function of the limiter  70  or the spacer  80  and the limiting member  85 , so the platform  50  is structurally very firm and the folding device  60  thereof is structurally simple and practicable. 
     Although the present invention has been described with respect to specific preferred embodiments thereof, it is in no way limited to the specifics of the illustrated structures but changes and modifications may be made within the scope of the appended claims.