Collapsible treadmill

Abstract

A collapsible treadmill is composed of a chassis having two support members in no contact with the ground; a main frame having an endless belt rotatable along a closed path; a folding device having a lifting frame, the lifting frame having two first lateral frames spaced from each other and two second lateral frames spaced from each other, the lifting frame having a rear end pivotably attached to the main frame and two active pivoting members formed at a front end thereof and contacting against the support members; two linking-up members having front ends connected with the active pivoting members and rear ends connected with the chassis; and two limiters mounted to the chassis and defining a limited space with the support members for limiting the space within which the active pivot members can act.

What is claimed is: 
     
         1 . A collapsible treadmill comprising:
 a chassis having two lateral bars and two support members, the two lateral bars being spaced from each other and each having a first end portion and a second end portion arranged reversely relative to the first end portion, the two support members being mounted close to the first end portions of the two lateral bars respectively and having no contact with the ground;   a standing post connected to the chassis and extending toward a top end of the treadmill;   a main frame having two lateral frames, a frame body, and an endless belt, the two lateral frames being spaced from each other and each having a first section and a second section arranged reversely relative to the first section, the frame body being formed of at least one fastening bar fixedly connected between the two lateral frames, the endless belt having a front end and a rear end, which are placed inside the frame body, for rotation along a closed path; and   a folding device having a lifting frame, two linking-up members, and two limiters, the lifting frame having two first lateral frames spaced from each other and two second lateral frames spaced from each other, the lifting frame having a rear end pivotably attached to the main frame, two active pivoting members being mounted to a front end of the lifting frame and contacting against the support members, each of the two linking-up members having a front end connected with one of the active pivoting members, each of the two linking-up members having a rear end connected with one of the lateral bars, the two limiters being mounted inside the chassis and defining a limited space with the support members for limiting the space within which the active pivoting members can act.   
     
     
         2 . The collapsible treadmill as defined in  claim 1 , wherein the chassis comprises two connection bars fixedly connected between the two lateral bars; the two support members are mounted to two lateral ends of the connection bars respectively and close to a front end of the chassis. 
     
     
         3 . The collapsible treadmill as defined in  claim 1 , wherein each of the two linking-up members comprises a front end coaxially connected with one of the active pivoting members and a rear end thereof connected with the two lateral bars of the chassis. 
     
     
         4 . The collapsible treadmill as defined in  claim 1 , wherein each of the two linking-up members comprises a front end acentrically connected with the two active pivoting members and a rear end thereof connected with the two lateral bars of the chassis, the active pivoting members being movable forwardly and backwardly inside the support members respectively when the platform is being collapsed. 
     
     
         5 . The collapsible treadmill as defined in  claim 1 , wherein each of the limiters comprises a spacer and a limiting member, the limiting member having an upper end connected with the main frame, an elongated slot formed on a lower section of the limiting member, the elongated slot having an upper limit and a lower limit for limited movement of the spacer between the upper limit and the lower limit. 
     
     
         6 . The collapsible treadmill as defined in  claim 1 , wherein each of the limiters comprises a combination portion and a stop portion located above the active pivoting member. 
     
     
         7 . The collapsible treadmill as defined in  claim 6 , wherein each of the stop portions of the limiters is inclined forwardly and downwardly toward a front end of the treadmill. 
     
     
         8 . The collapsible treadmill as defined in  claim 1 , wherein a pivotal center on which the active pivot members and the lifting frame are connected protrudes from a front end surface of the first section of the main frame. 
     
     
         9 . The collapsible treadmill as defined in  claim 8 , wherein each of the active pivoting members is a wheel. 
     
     
         10 . The collapsible treadmill as defined in  claim 1 , wherein the folding device comprises a linear actuator mounted onto the main frame and having a lifting pipe, the length of which is retractable, the lifting pipe being connected with the lifting frame, the lifting frame being adapted for being hauled by the linear actuator for elevation-angle lifting motion.