Integrated roller for a treadmill, method for making and a special-purpose extrusion tool

Abstract

An integrated roller for a treadmill is comprised of rollers, the said rollers are of integrated structure with the outer end and the inner end integrated, the outer diameter surface of the said inner end and the inner hole surface of the said outer end form close fit or clearance fit, and the tip of the inner end extends inward along the inner diameter direction for a distance to form a plateau shape. The making method thereof comprises an extrusion and an inverted extrusion by a mold. This utility model features material saving, simple structure and less process steps in making and makes up the drawback of prior art rollers of high raw materials consumption, complicated structure and complicated making process. This invention is used for treadmill rollers.

1 . An integrated roller for a treadmill comprised of rollers, which is characterized in that the said rollers are of integrated structure with the outer end ( 41 ) and the inner end ( 42 ) integrated, the outer diameter surface of the said inner end ( 421 ) and the inner hole surface of the said outer end ( 411 ) form close fit or clearance fit, and the tip of the inner end ( 422 ) extends inward along the inner diameter direction for a distance to form a plateau shape. 
   
   
       2 . An integrated roller for a treadmill according to  claim 1 , which is characterized in that the said clearance is 0-6 mm. 
   
   
       3 . An integrated roller for a treadmill according to  claim 1 , which is characterized in that inside the said clearance is configured with solid glue ( 11 ) or iron ring. 
   
   
       4 . An integrated roller for a treadmill according to  claim 1  or  3 , which is characterized in that the said roller is of cylindrical or arcuate shape. 
   
   
       5 . A method for making an integrated roller for a treadmill according to  claim 1 , which is characterized in that the said method comprises the following several steps:
 a. Firstly prepare raw blank, place the blank on a lower fixed plate ( 6 ) of a horizontal oil hydraulic press, then compact the blank using an upper compaction plate ( 7 ), and then carry out a first-time extrusion to the blank using a female mold ( 8 ), in this way, a steel tube with round end is extruded into a tube with arcuate end, and after the completion of this step, the second step is followed.   b. The second step is to place the blank that has gone through the first-time extrusion on a lower fixed plate ( 6 ) of a horizontal oil hydraulic press, compact with an upper compaction plate ( 7 ), then carry out inverted extrusion to the steel tube that has gone through the first-time molding ( 9 ) using a male mold ( 10 ) with different outer diameter so that the outer diameter surface of the inner end ( 421 ) and the inner hole surface of the outer end ( 422 ) form close fit or clearance fit, in this way, a half finished product shape is formed, and after the completion of this step, the half finished product is further processed to have a plateau ( 44 ) for bearing ( 5 ) placing to finish the production of a finished product in this invention.   
   
   
       6 . A method for making an integrated roller for a treadmill according to  claim 5 , which is characterized in that the said processing is by the method of lathe machining or mold extrusion. 
   
   
       7 . A special-purpose mold to realize a making method for an integrated roller of a treadmill according to  claim 5  or  6 , which is characterized in that such mold includes a male mold ( 10 ) and a female mold ( 8 ), the said female mold ( 8 ) has a tapering hole ( 81 ) configured inside the front end body, the front end of the hole ( 81 ) is horizontal, the middle is arc transition section, and the rear end is horizontal, the said male mold ( 10 ) has a boss ( 101 ) with tapering fillet configured on the front end, at the same time, the boss ( 101 ) and the support are in tapering fillet transition connection.