Abstract:
A conveyor roller having a spring loaded telescoping tubular axle with tapered hexagonal shaped ends allowing quick replacement in the side frame openings of a conveyor when the openings are worn to an oversize. The tapered hex ends also provide for a tight fit between hex ends and hex holes in the frame to lessen relative motion (rattling) between the two surfaces that causes wear and noise. The roller can be installed from either side of the conveyor because the axle is collapsible from either end.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS STATEMENT 
     REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to rollers for roller conveyors and more specifically to a conveyor roller with a telescoping shaft having tapered ends. 
     2. Description of Related Art 
     A conveyor roller generally is rotatably mounted on a shaft, which, in turn, is mounted in openings located in laterally spaced side frame members of the conveyor. 
     The shaft is generally loosely positioned in the mounting aperture and vibration and loading conditions of the roller causes the shaft to bounce, causing noise and wear on both the shaft and the aperture. Over time, the wear from shaft vibration results in enlargement of the mounting aperture, creating an even looser fit between the shaft and the frame and generating even more noise. Eventually, the shaft vibration causes the frame to cut through the roller shaft, resulting in the roller dropping out of the frame. 
     It would accordingly be desirable to modify the mounting of a roller shaft in a conveyor frame to minimize the vibration of the shaft in the frame and thereby lessen the noise which is produced and the wear which occurs on both the shaft and the frame. 
     It also is desirable to be able to replace rollers easily when they become worn. It further is desirable to be able to assemble the roller axles by hand immediately prior to being placed into the roller assembly. This eliminates the use of tools required for crimping, drilling, pinning, or staking of the axle. 
     BRIEF SUMMARY AND OBJECTS OF THE INVENTION 
     According to this invention, the mounting of a conveyor roller to the conveyor frame members is improved by the use of a roller shaft which is telescoping and has tapered ends. The roller shaft preferably is of two-piece telescoping tubular construction with a spring positioned inside the telescoping tubular members urging the members away from each other. The tubular construction of the shaft or axle provides added strength in the middle of the span compared to a solid hex axle and keeps the axle aligned with the bearings without being distorted out of alignment when subjected to a load. 
     The ends of the shaft are tapered outwardly and engage the mounting holes in the conveyor frame to eliminate play between the shaft and the mounting holes. The tapered ends allow replacement rollers to be placed into mounting holes that have been enlarged by wear and still seat firmly. 
     The tapered ends of the shaft and the mounting holes are shaped to prevent rotation of the shaft. Preferably they are both hexagonally shaped, but can be square or round with one or more flats. 
     Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings which are merely illustrative of the invention. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     In the drawings, wherein like numbers refer to like parts wherever they occur: 
     FIG. 1 is a partial vertical sectional view showing a roller and bearing assemblies in section and a telescoping axle in detail; and 
     FIG. 2 is a partial vertical sectional view of a modification of the invention showing a roller and bearing assemblies in section and a telescoping axle in detail. 
    
    
     DETAILED DESCRIPTION OF INVENTION 
     The following detailed description illustrates the invention by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what I presently believe is the best mode of carrying out the invention. As various changes could be made in the constructions without departing from the scope of the invention, it is intended that all matter contained in the description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     FIG. 1 shows a conveyor roller assembly  10  mounted between conveyor frame members  11 , 11   a . The roller assembly  10  comprises a cylindrical roller tube  12  rotatably mounted on a shaft or axle assembly  13  by bearing assemblies  14 . The frame members have openings  15 , 15   a  therein to mount the roller assemblies  10 . 
     The shaft assembly  13  is the essential feature of this invention and includes a larger tubular axle member  20  which accepts a telescoping smaller tubular member  21  in a snug sliding fit at their inboard ends  20   a , 21   a . A large shaft end adaptor  22  is press fitted into the outboard end  20   b  of the larger shaft tube member  20 . A small end adaptor  23  is press fitted into the outboard end  21   b  of the smaller shaft tube member  21 . 
     The large end adaptor  22  includes a shank area  24  which is press fit into the outboard end of the large axle tube  20 , an enlarged shoulder  25  which engages the outboard end  20   b , and a hexagonal end portion or spindle  26 . The end portion  26  has a straight portion  27  which connects to the shoulder  25  and an outwardly tapered end portion  28  which is designed to non-rotatably engage the frame opening  15   a  which also is hexagonal in shape. 
     The small end adaptor  23  includes a shank area  33  which is press fitted into the outboard end of the small axle tube  21 , an enlarged shoulder  34  which engages the outboard end  21   b , and a hexagonal end portion or spindle  35 . The end portion  35  has a straight portion  36  which connects to the shoulder  34  and an outwardly tapered end portion  37  which is designed to non-rotatably engage the frame opening  15  which also is hexagonal in shape. 
     While the adaptors  22 , 23  are called large end and small end, respectively, the only difference is that the large end adaptor shank  24  is larger in diameter to fit the larger outer tube  20 . The small end adaptor shank  33  is smaller in diameter than the shank  24  to fit the inside diameter of the smaller inner tubular axle member  21 . The adaptors  22 , 23  are made from powdered metal. 
     The bearing assemblies  14  each include an antifriction bearing  46  in the form of a single row ball bearing which has an outer race or ring  47 , and an inner race or ring  48  which define a raceway  49  which receives rolling elements  50  in the form of balls. The bearing assemblies  14  also include an inner collar  51  having a depending flange  51   a  and a sleeve or outer collar  52 . The antifriction bearing  46  is retained between the inner collar  51  and the sleeve  52  and the bearing assemblies  14  are press fitted into the ends of the roller tube  12 . The collars  51 , 52  are polymeric materials. The inner collars  51  have hexagonal inner surfaces which mate with the hexagonal axle areas  27 , 35  to rotatably lock the inner races  48  to the axle  13 . 
     A plug  40  is pressed into the inboard end  21   a  of the inner tubular member  21 . The plug  40  has a reduced body portion  41  which engages the inner surface of the tubular member  21  and a head  42 . The head  42  has an internal shoulder  43  which engages the tubular end  21   a , an annular surface  44  whose outer diameter is slightly less than the outer diameter of the inner tubular member  21 , so that it is freely movable through the outer tubular member  20 , and an external surface  45  within the outer tubular member  20 . 
     The large end adaptor shank  24  has an internal surface  53  in the outer tubular member  20  which is aligned with and opposed to the plug external surface  45 . Positioned between and engaging the surfaces  45 , 53  is a resilient means such as the shown helical spring  54 . The spring  54  urges the outer tubular axle member  20  and the inner tubular axle member  21  apart, thus facilitating engagement of the end adaptors  22 , 23  into the frame openings  15   a , 15  respectively. 
     Another form of the invention is shown in FIG.  2 . In this form, the outer and inner axle tubes  20 , 21  have their ends  55 , 56  respectively swaged from round to hex shape. The end  55  has a transitional area  57  from the axle diameter to a bearing seat area  58 , and then a tapered hexagonal area  59  to the end of the axle. The inner tube end  56  has a similar transitional area  57   a , a bearing seat  58   a , and a tapered. hexagonal end  59   a.    
     The use of the tapered hex ends on the spindles combined with the frame hexagonally shaped openings provide a tight fit between the hex ends and the frame, and thus less relative motion between the rollers and the frame to reduce wear and noise. Also, the rollers can be installed from either side of the conveyor frame because the axle is collapsible from either end. 
     This invention is intended to cover all changes and modifications of the examples of the invention herein chosen for purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.