Patent Publication Number: US-2005137062-A1

Title: Treadmill

Description:
The invention relates to a treadmill comprising a subframe supported against the floor or a corresponding support surface, a frame supported on the subframe for rolls and a belt section running in an endless loop around the rolls, and means arranged between the subframe and frame to vertically shift the location of one end of the frame relative to the subframe, whereby support arms are arranged to the frame with first ends articulated to the frame and second ends arranged slidably into slide bars arranged to the subframe.  
      Solutions of this type are today well known in treadmills adjustable in their running angle. An example of a prior art solution is the solution described in U.S. patent publication 6,325,745. In this known solution, the slide bars are made up of elements having a substantially C-shaped cross-section. Substantially rectangular sliding elements compatible with the shape of the slide bars are arranged to these slide bars having a substantially C-shaped cross-section. The sliding elements are fastened to the ends of a shaft inside a tubular part by means of two sleeve-like parts. Parts made of plastic, acting as stopping elements, equipped with threaded openings, compatible with the shape of the slide bar, and fastened to the slide bar with screws are also arranged to the back ends of the slide bar.  
      A drawback with the known solutions is their complexity that increases costs, both the actual costs arisen from the number of components and the costs arisen from the complexity of the assembly. A further drawback is the costs related to maintenance, because a complex structure requires in many cases a lot of maintenance, and in addition, it should be noted that a complex structure with a great deal of different parts also requires a large spare parts inventory, which for its part increased the costs.  
      It is an object of the invention to provide a simple solution to eliminate the drawbacks of the prior art. This is achieved by the treadmill of the invention. The treadmill of the invention is characterized in that the slide bars are formed of flat components fastened to the subframe, and that sliding elements are arranged at second ends of the support arms and equipped with slots compatible with the flat components, whereby the slide bars are arranged to push into the slots, thus enabling the sliding of the sliding elements along the slide bars when the location of one end of the frame is shifted vertically relative to the subframe.  
      An advantage of the invention is above all its simplicity, whereby the number of required components is essentially reduced in comparison with the prior-art solutions. Due to the simple structure, both the direct costs related to the number of components and the indirect costs related to maintenance requirements or difficulties in assembly, for instance, decrease overall in comparison with the prior art. 
    
    
      The invention will next be described in greater detail by means of a preferred embodiment shown in the attached drawing, in which  
       FIG. 1  is a general perspective view of the frame structure of the treadmill of the invention,  
       FIG. 2  is a general exploded view of the essential parts of the treadmill of the invention, and  
       FIG. 3  shows a sliding element from different directions. 
    
    
       FIG. 1  is a general perspective view of the frame structure of the treadmill of the invention. In  FIG. 1 , reference number  1  indicates a subframe supported against the floor or a corresponding support surface. The subframe  1  is made up of longitudinal profile components  2  of the treadmill and crosswise components connecting the profile components  2 ,  3 . In  FIG. 1 , reference number  4  indicates a frame supported on the subframe  1 . The frame  4  is made up of longitudinal profile components  5 ,  6  of the treadmill and crosswise components connecting the profile components  5 ,  6 . The frame  4  supports for instance rolls and a belt section running in an endless loop around them. The rolls and the belt section and other details related to the structure in question, such as the power source used to run the belt section, are not shown in the figures, because they are known to a person skilled in the art.  
      The subframe  1  and frame  4  are connected to each other with means so that the location of one end of the frame  4  can be vertically shifted relative to the subframe  1 ; in other words, one end of the frame can be lifted or lowered to change the angle position, or running angle, of the treadmill. The above-mentioned means include a support arm structure and a unit comprising a power source and power transmission means. Essential parts of the support arm structure are support arms  7 ,  8 , first ends of which are articulated to the longitudinal profile components  5 ,  6  of the frame and second ends of which are arranged slidably to slide bars  9 ,  10  arranged to the longitudinal profile components  2 ,  3  of the subframe  1 .  
      According to the essential idea of the invention, the slide bars  9 ,  10  are formed of flat elements fastened to the subframe  1 . Sliding elements  11 ,  12  are arranged at the ends of the support arms  7 ,  8  and equipped with slots  13  compatible with the flat components. The slide bars  9 ,  10  are arranged to push into the slots  13  to thus allow the sliding of the sliding elements  13  along the slide bars  9 ,  10  when the location of one end of the frame  4  is shifted vertically relative to the subframe  1 , i.e. when the size of the running angle of the treadmill is changed. When the structure is assembled, the slide bars  9 ,  10  formed by the flat components are thus in the slots  13  as shown in  FIG. 2 , whereby the sliding elements  11 ,  12  can slide along the slide bars when the running angle is adjusted. The above-mentioned structural entity according to the essential idea of the invention is shown as a general exploded view in  FIG. 2 . The structure of the sliding element is shown particularly clearly in  FIG. 3 .  
      The sliding elements  11 ,  12  can preferably be made into sleeves that are substantially round in cross-section and fastened directly to the ends of a pipe  14  connecting the ends of the support arms  7 ,  8 . The pipe  14  can preferably be made of a pipe that is substantially round in cross-section, whereby the pipe also serves as a shaft to the sleeve acting as a sliding element  11 ,  12 . An advantage of this application over the prior art is that, in the solution of the invention, a separate intermediate shaft is not needed, nor are any separate sleeves used in the joint. Thus, the number of components can be reduced and costs lowered essentially in comparison with the prior art.  
      The second ends of the flat components serving as slide bars  9 ,  10 , the back ends in the example of the figures, can preferably be equipped with stopping elements  15  that are arranged to prevent the sliding element  11 ,  12  from sliding past the end of the slide bar  9 ,  10  when the running angle of the treadmill is changed. These stopping elements  15  can preferably be screw elements, such as bolts, that are tightened to the slide bars. The use of different studs and corresponding solutions as the stopping elements is also possible.  
      The above application example is in no way intended to limit the invention, and the invention can be modified freely within the scope of the claims. Thus, it is clear that the treadmill of the invention need not necessarily be exactly as shown in the figures, and solutions of other type are also possible. For instance, the design and arrangement of the support arms and other structural details shown in  FIG. 1  can naturally be altered as required. The shapes of the profile components and crosswise components can naturally be freely varied as required.