Patent Publication Number: US-7717829-B2

Title: Engaging mechanism for a folding apparatus of a treadmill

Description:
BACKGROUND OF THE INVENTION 
   1. Fields of the Invention 
   The invention relates to an engaging mechanism for a folding apparatus of a treadmill, and more particularly, to an engaging mechanism that prevents the folding apparatus from an unexpected false action. 
   2. Description of the Related Art 
   In the application Ser. Nos. 11/900,042 and 11/866,999, the inventor of the invention has developed a folding apparatus of a treadmill that permits an easy folding of the platform frame in an upright position and even an easy folding of a handrail assembly. In this way, a complete folding is achieved. It is apparent that the inventor has made every effort to enhance the practicality and convenience of the product in the actual use. However, the inventor still found that it is likely to create a certain extent of sway on the platform frame and the handrail assembly due to the existence of the folding apparatus, thereby causing users to have little psychological anxiety and misgivings when the platform frame of the treadmill is moved in a horizontal operational position and the user wants to employ the lifting motor and the slope adjusting support to adjust the exercise slope. 
   In fact, any treadmill having a folding apparatus for providing an auxiliary force creates a varying degree of sway when the mechanism for adjusting the exercise slope is operated. The slight sway won&#39;t harm the operators. In order to eliminate the misgiving of the operator in use, a further solution is developed again. 
   SUMMARY OF THE INVENTION 
   It is a primary object of the invention to eliminate the above-mentioned drawbacks and to provide an engaging mechanism for a folding apparatus of a treadmill that avoids the above-mentioned swaying phenomenon so as to enhance the structural stability in using the treadmill. In this way, the operator does not have additional mental burden and apprehensiveness. 
   According the invention, an engaging mechanism applies a proper engaging force to a positioning plate fixed at the bottom of the internal side of the handrail assembly such that an unexpected false pushing action caused by the driving behavior of a slope adjusting support by the lifting motor is prevented when the platform frame of the treadmill is moved in a horizontal operational position. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a preferred embodiment of the invention; 
       FIG. 2  is a side view of  FIG. 1 ; 
       FIG. 3  is a bottom view of  FIG. 1 ; 
       FIG. 4  is a side view of the operation of the structure of  FIG. 3 ; 
       FIG. 5  is a schematic drawing of the structure of  FIG. 1  in a folded position; 
       FIG. 6  is a schematic drawing of another embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The present invention will now be described in more detail hereinafter with reference to the accompanying drawings that show various embodiments of the invention. 
   Referring to  FIGS. 1 ,  2  and  3  in which a preferred embodiment of the invention is illustrated, a platform frame  10  includes a transmission motor  11  at one side thereof for driving a continuous moving belt (not shown) into rotation by use of a transmission belt  12 , a front roller  13 , and a rear roller  14 . Meanwhile, a lifting motor  15  is employed to move an adjusting support  16  upward and downward for adjusting the supporting angle of the platform frame  10 . Moreover, two connection pins  17 ,  18  are disposed at both sides of the platform frame  10 , respectively, for pivotally coupling a handrail assembly  19  and a rear support  20 , respectively. 
   Moreover, a slide pusher  22 , to which a pneumatic cylinder  21  applies a pushing force, is interposed between a first and a second strengthening bar  101 ,  102 . The other end of the slide pusher  22  is pivotally connected to the rear support  20 . Besides, a coupling rod  23  is interposed between the rear support  20  and the handrail assembly  19 . As a result, the handrail assembly  19  can be folded up by the coupling rod  23  in cooperation with a crossbar  24 . Thus, a folding apparatus of a treadmill is created by the above-mentioned components. 
   Referring to  FIGS. 3 through 5 , an engaging mechanism  30  is disposed at the bottom of a strengthening bar  103  of the platform frame  10 . The engaging mechanism  30  applies a proper engaging force to a positioning plate  25  fixed at the bottom of the internal side of the handrail assembly  19  when the platform frame  10  is brought in a horizontal application position. 
   The engaging mechanism  30  consists of an operating lever  31 , an elongated coupling lock piece  32 , a quadruple connecting mechanism  33 , two protruding studs  34  and two elastic elements  35 . An external member  341  of the protruding studs  34  is engaged into a first insertion hole  251  of the positioning plate  25  in place (see  FIG. 3 ) when the platform frame  10  is brought in a horizontal application position. The quadruple connecting mechanism  33  consists of four connecting rods which are pivotally coupled together. When the coupling lock piece  32  is pulled by the operating lever  31 , a pivot joint  331  of the quadruple connecting mechanism  33  is pulled in such a way that the quadruple connecting mechanism  33  is brought into a contracting shape distortion state. The protruding studs  34  are attached to a pulled portion at an opposing end of the quadruple connecting mechanism  33 . Therefore, the protruding studs  34  are laterally shifted toward the internal side of the platform frame  10  due to the contracting deformation of the quadruple connecting mechanism  33 . In this way, the external member  341  can be disengaged from the first insertion hole  251  of the positioning plate  25  (see  FIG. 4 ). Accordingly, the platform frame  10  may be lifted upwards in a folded position (see  FIG. 5 ). 
   Likewise, the quadruple connecting mechanism  33  is returned back to the original position under the influence of the resilience of the elastic elements  35  when the platform frame  10  is lowered from the upright folded position to the horizontal application position. In this way, the external members  341  of the protruding studs  34  are engaged into the first insertion holes  251  of the positioning plates  25  again and automatically returned in the state as shown in  FIG. 3 . As a result, any adverse effect of the above-mentioned can be avoided when the operator employs the lifting motor  15  and the adjusting support  16  to adjust the exercise slope. 
   As shown in  FIG. 6 , a second insertion hole  252  is formed in the positioning plate  25 . The external member  341  of the protruding stud  34  can also be automatically engaged into the second insertion hole  252  when the platform frame  10  is brought into the upright folded position. In this way, an unexpected rollover of the platform frame can be prevented, thereby greatly enhancing the operation safety. 
   Many changes and modifications in the above-described embodiments of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.