Abstract:
A flange bearing comprises a housing having a body with a reinforcing member encased therein. The housing provides strength and resistance to stress fracturing without the use of heavy materials, such as cast iron, or the use of ribs and recesses which can harbor contaminates. The bearing is preferably lightweight and easily cleaned. Also, a leveler constructed in accordance with the present invention provides similar advantages.

Description:
RELATED CASES  
       [0001]    This application is a continuation of copending application Ser. No. 08/655,040, filed May 26, 1996.  
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates generally to assembly lines and conveyor systems, and, in particular, to a flange bearing for supporting a rotatable shaft.  
           [0003]    In manufacturing, assembly lines and conveyor systems commonly utilize flange bearings to support cylindrical shafts upon which manufactured products are transported. The bearings are mounted to a support structure which forms a track or bed along which the products are conveyed. Each shaft is received in a bearing insert of a housing for the flange bearing. The flange bearing might comprise a square housing mounted using four bolts, one at each corner. Alternatively, the flange bearing might comprise an eye-shaped housing utilizing two bolts for mounting.  
           [0004]    Cast iron was the common material used for manufacturing early flange bearing housings which were mounted by either two or four bolts. A solid body was formed which easily withstood the stresses imparted by the heavy and/or cyclic loads from the shaft supported therein. Further, the cast iron housing was usually either metal-plated or painted to resist corrosion from exposure to water, cleaning chemicals, spilled products or other contaminates, especially in the food processing industry. However, the housing exterior would eventually deteriorate or become unsightly, especially since stringent cleaning was required to meet sanitation specifications in the aforementioned industry.  
           [0005]    A more recent type of flange bearing comprises an injection-molded plastic housing. In particular, if the housing is injection molded in the form of solid plastic, the housing would disadvantageously shrink and deform unpredictably upon cooling. In order to provide an injection-molded housing of the equivalent strength of cast iron with repeatable dimensional stability, it is necessary to increase the overall geometry slightly for strength and incorporate a ribbed structure for dimensional stability. the result is an “engineered plastic” housing providing the desired positional geometry incorporating ribs and cavities. In an engineered plastic housing, the ribs provide strengthening to resist stress fractures of the housing from the shaft loading, while maintaining the desired shape during the molding process.  
           [0006]    In addition, the cavities of the engineered plastic housing are more difficult and time consuming to clean satisfactorily than a solid body housing. Plugs created to fill the cavities, thereby making cleaning easier, tend to settle after time and during temperature changes so that the outer surface of the housing body is no longer flush, and the same cleaning difficulties remain. Plugs are often made of a different material than the housing and consequently expand and contract at a different rate than the housing causing undesirable cracks, crevices and uneven surfaces.  
           [0007]    In view of the foregoing, a need exists for an improved bearing housing that overcomes the problems mentioned.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention overcomes the aforenoted disadvantages by providing a housing having a lightweight, substantially solid body including an encased reinforcing member. This member provides additional strength and aids in transmitting loads from a shaft supported by the housing radially outwardly to fasteners which are used to mount the housing. The body does not have recesses formed on its mounting surface which could harbor contaminates, and therefore thorough cleaning of the housing is made easy.  
           [0009]    The reinforcing member is preferably a loop formed from a band of metal which surrounds the bolt holes and shaft opening of the housing. Ends of the metallic band may be fastened using a screw engaged through holes on the band ends. Alternatively, the band ends may be spot-welded together, or the band may be formed in a continuous loop. In another embodiment, the reinforcing member may comprise one or more substantially straight metallic strips encased within the body material.  
           [0010]    An important feature of the present invention is the use of the reinforcing member to provide additional strength to a lightweight body. Stress fractures from heavy and/or cyclic loading from a shaft supported by the housing are less likely to occur as a result of the presence of the reinforcing member in the body. The member may be suspended within the housing material and helps provide transmission of the loading radially outwardly from the shaft to the fasteners.  
           [0011]    Another important feature of the present invention is the formation of a substantially solid body which does not include recesses or cavities for the accumulation of dirt, grease or other contaminates. Thus, cleaning the housing to meet sanitation specifications is readily accomplished.  
           [0012]    In one preferred embodiment, the housing comprises a generally parallelogram shaped flange bearing. Two bolts in holes in narrow portions of a housing body mount the bearing to a conveyor structure. A rotatable shaft is supported in a bearing insert received in an opening in the housing body. A cover is optionally placed over one end of the shaft to protect passersby and to warn of the moving part contained therein. Alternatively, the housing may comprise a substantially square flange bearing having four bolts for mounting.  
           [0013]    A preferred method of manufacturing a reinforced housing of the present invention comprises the steps of:  
           [0014]    a) preparing a mold for the housing including desired openings for receiving one or more fasteners and a shaft;  
           [0015]    b) preparing a metallic band for insertion into a space of the mold, with the band forming a shape smaller than the mold&#39;s outer shape;  
           [0016]    c) suspending the band within the mold;  
           [0017]    d) pouring a thermosetting material into the mold to encase the band; and  
           [0018]    e) cooling the material thereby creating a substantially solid yet lightweight body reinforced by the band contained within. In this method, Step b) may comprise using a screw engaged through holes in the ends of the band which is shaped into a loop. Alternatively, Steps b) and c) may comprise suspending one or more substantially straight metallic strips in the space of the mold as the reinforcing members, instead of a loop.  
           [0019]    Further advantages and applications will become apparent to those skilled in the art from the following detailed description and the drawings referenced herein.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    [0020]FIG. 1 is a front perspective view of a preferred flange bearing embodiment having a housing constructed in accordance with the present invention;  
         [0021]    [0021]FIG. 2 is a top plan view of the housing of FIG. 1, with a reinforcing member shown in phantom;  
         [0022]    [0022]FIG. 3 a  is a top plan view of the reinforcing member;  
         [0023]    [0023]FIG. 3 b  is a top plan view of the reinforcing member comprising multiple strips;  
         [0024]    [0024]FIG. 4 is a side elevational view of the reinforcing member;  
         [0025]    [0025]FIG. 5 is a detail view of overlapped ends of the reinforcing member having holes;  
         [0026]    [0026]FIG. 6 is an alternative cross-sectional view of the reinforcing member taken along line  6 - 6  in FIG. 3 a;    
         [0027]    [0027]FIG. 7 a  is a top plan view of a bolt sleeve for the housing of FIG. 1;  
         [0028]    [0028]FIG. 7 b  is a side elevational view of the bolt sleeve;  
         [0029]    [0029]FIG. 8 is a perspective view of an alternate embodiment of the present invention; and  
         [0030]    [0030]FIG. 9 is a top plan view of the embodiment of FIG. 8 with a reinforcing member shown in phantom.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]    Most modern manufacturing facilities rely heavily upon conveyor systems which transport products through the various manufacturing procedures along a predetermined path. The manufacturing environment includes exposure of manufacturing and conveyor equipment to various fluids, dust, material debris and other contaminates. The fluids may include lubricants and/or liquid products. The material debris may be metal, plastic or food particles. Dirt or even bacteria may be present in the manufacturing facility and must be satisfactorily removed for product quality assurance, particularly in the food processing industry which maintains high sanitation standards.  
         [0032]    A preferred embodiment comprising a two bolt flange bearing  10  constructed in accordance with the present invention is shown in FIG. 1 and is used in conveyor systems to support a shaft (not shown) as will be readily understood by those of skill in the art. The shaft is preferably supported within a bearing insert  12  positioned in a housing  14  between holes  16  for mounting of the bearing  10  to a conveyor structure (not shown). The bearing insert  12  is typically a lubricated ball bearing. The shaft diameters may range from about ¾ inches to about 3 inches. Mounting bolts (not shown) received in the holes  16  of bolt sleeves  18  are generally about {fraction (5/16)} inches to about ¾ inches in diameter.  
         [0033]    A substantially flat or planar mounting surface  20  of the bearing  10  may be formed on a distal side of the housing  14 , and a non-planar surface  22  may be formed on a proximal side of a substantially solid body  24  of the housing  14 . The mounting surface  20  generally forms an eye shape or parallelogram having rounded corners, with the bolt sleeves  18  and mounting holes  16  positioned within acute corners and an opening  26  for the bearing insert  12  positioned within obtuse corners of the parallelogram. A screw and grease inlet orifice  28  are preferably provided at a side wall  30  of the housing  14  for lubrication of the bearing as required. Although a two bolt flange bearing is shown and described herein, it is understood that a four bolt and other flange bearing designs are possible in the present invention.  
         [0034]    For protection against contaminates contributing to bearing failure, covers and seals (not shown) may optionally be placed at the bearing insert  12 , over the end of the shaft as will be understood by those of skill in the art. Brightly colored covers also provide visual warning that a moving part is contained within. These seals may include a back shaft seal positioned between the distal surface  20  of the housing  14  and the mounting wall of the conveyor structure, as well as an O-ring and front shaft seal positioned between the open or closed cover and a proximal surface  31  of the housing  14 .  
         [0035]    [0035]FIG. 2 shows the housing  14  with a reinforcing member  32  illustrated in phantom. The member  32  is preferably encased within the material of the body  24  in the present invention and preferably comprises a loop formed by a metallic strip or band. The material of the housing body  24  is preferably urethane, although other pourable, thermosetting materials may alternatively be used to form the housing body  24 . In the preferred embodiment, the urethane is poured or pumped into a female cavity within which is suspended the reinforcing member  32 .  
         [0036]    The housing  14  for the two bolt flange bearing  10  is preferably of standard dimensions, and for supporting a shaft of either 1{fraction (3/16)} or 1¼ inches in diameter the housing  14  measures approximately 5.56 inches at the widest part and 3.31 inches perpendicular to the widest part. The distance between centers of the holes  16  is about 4.59 inches, and the bearing insert opening  26  is about 2.44 inches in diameter. The distance between the mounting and proximal surfaces  20 ,  22  of the housing  14  is about 0.89 inches.  
         [0037]    The loop of the metallic band  32  generally conforms to a parallelogram shape, as shown in FIG. 3, and is somewhat smaller than the shape of the bearing&#39;s mounting surface  20 . The metallic band  32  is preferably positioned to circumscribe the mounting holes  16  and bearing insert opening  26 . The loop  32  preferably measures about 5.21 inches at its widest part and about 2.86 inches measured perpendicular to the widest part. The radius of curvature at about the bearing insert position is about 1.40 inches, and the radius of curvature at about the mounting holes  16  is about 0.279 inches. The reinforcing member  32  is preferably 300 series stainless steel, 16 or 20 gage.  
         [0038]    The metallic band  32  may be formed as a continuous loop, or the loop may be created by fastening together ends  34  of the band  32 . FIGS. 4 and 5 show side views of the band  32 , with the latter showing holes  36  provided near the band ends  34  for receiving a fastener. In this embodiment, an overlap of about one inch is provided at the band ends  34  and a screw (not shown) is received through the holes  36  of each end  34  while the band  32  is suspended within the housing mold and the poured urethane cools and sets during the manufacturing of the housing  14 . Alternatively, the ends  34  of the band  32  may be welded together as will be easily understood by those of skill in the art.  
         [0039]    In another preferred embodiment, the metallic band  32  includes a longitudinal central portion  38  having an arcuate cross-section, shown in FIG. 6. The curvature is such that an inner surface  40  of the central portion  38 , toward the bearing insert  12 , is concave, and an outer surface  42 , toward the side walls  30  of the housing  14 , is convex. The band  32  has a total width of about ⅝ inches, and the central portion  38  has a radius of curvature of approximately 0.13 inches such that the band  32  measures about {fraction (3/16)} inches from an innermost point to an outermost point of the central portion  38  of the band  32 .  
         [0040]    The load capacity of the two bolt flange bearing housing  14  is preferably up to about 1,710 lbs. The housing load capacity for a four bolt flange bearing constructed in accordance with the present invention is preferably up to about 3,640 lbs. The central portion  38  is preferably curved as described (FIG. 6) to assist the transmission of the loads radially outward from the shaft to the mounting bolts. However, flat bands not having a curved central portion  38 , as shown in FIGS.  2 - 4 , may alternatively be used without loss of the advantages of the present invention. Further, in alternate embodiments, one or more substantially straight metallic bars or strips may be used as reinforcing members for the housing body. The strip(s) are preferably positioned along the longest portion(s) of the housing body  24 . Thus, the reinforcing member  32  of the present invention is not limited to a loop shape but may comprise element(s) not conforming to the general outer shape of the housing body  24 .  
         [0041]    [0041]FIGS. 7 a  and  7   b  show the sleeve  18  which is received in the housing  14  and forms the hole  16  for the mounting bolt (not shown). The sleeve  18  is substantially cylindrical and may have an exterior grooved portion  44 . The outer diameter at ends  46  of the sleeve  18  is about 0.63 inches, and the outer diameter at the grooved portion  44  is about 0.56 inches. The inner diameter of the sleeve  18  is about 0.44 inches and the sleeve length is about 0.75 inches.  
         [0042]    Referring to FIG. 8, levelers are used for various machinery and have problems similar to those mentioned above for the flange bearing  10 . Levelers are used on the bottom ends of the legs of a machine to adjust or level the machine height. However, adequate cleaning and disinfecting is greatly complicated by the presence of recesses, cavities, apertures and the like in the leveler housing.  
         [0043]    In another embodiment of the present invention, FIG. 8 shows a leveler  50  comprising a somewhat teardrop shaped foot or housing  52  for supporting a machine (not shown) at an adjustable height. A threaded steel stem or shaft  54  is preferably received in an opening  56  in a broad portion  58  of a housing body  59 , and a narrow portion  60  of the body  59  preferably has a hole  62  to receive a bolt (not shown) for mounting the foot  52  to the floor or other surface. The hole  62  is preferably offset a distance away from the shaft opening  56  in order to accommodate a drill or other tool used for securing the bolt to the floor. The shaft  54  is received in a leg of the machine, and the machine height is adjusted by rotation of the shaft  54 .  
         [0044]    The top plan view of FIG. 9 shows the teardrop shaped housing  52  having a reinforcing member  64  in phantom. It is understood, however, by those skilled in the art that other shapes for the leveler housing  52  are available and may be used in the present invention. The reinforcing member  64  preferably comprises a metallic band forming a loop which generally conforms to the outer shape of the housing  52 . The use of the reinforcing member  64  adds strength to resist upward pulling loads applied to the housing  52  which preferably has a smooth underside without cavities (not shown).  
         [0045]    The housing  52  preferably measures about 5.5 inches at the widest part, and a distance of about 2.75 inches separates the lag hole  62  for receiving the bolt and the shaft opening. The narrow portion  60  of the housing  52  is about 0.73 inches thick, and the broad portion  58  of the housing  52  is about 1.10 inches thick.  
         [0046]    The shaft  54  is preferably about 7.25 inches long and may have a diameter of about ¾ inches to about 1¼ inches. The shaft  54  may optionally be zinc-plated. Wrench flats (not shown) are typically provided at about 1¼ inches from the distal end of the shaft  54  which is received in the housing opening  56 , to facilitate the leveler height adjustment by rotating the shaft  54  at the flats.  
         [0047]    The metallic band  64  preferably forms a loop having a maximum diameter of at least 3⅝ inches. The band  64  preferably has a width no greater than about 0.7 inches. The band  64  may be flat or have a curved central portion as described herein. The band  64  may comprise fastened loop ends or be continuously formed. Alternatively, the reinforcing member  64  may comprise one or a plurality of substantially straight metallic strips for assisting the load transmission from the shaft  54  to the bolt. The member  64  is preferably suspended within a poured urethane material. Preferably, the load capacity of the leveler housing  52  is up to about 7,200 lbs.  
         [0048]    A preferred method of manufacturing a housing  14 ,  52  constructed in accordance with the present invention comprises the steps of:  
         [0049]    a) preparing a mold for the housing  14 ,  52  including desired openings for receiving one or more fasteners and a shaft  54 ;  
         [0050]    b) preparing a metallic band  32 ,  64  for insertion into a space in the mold, the band  32 ,  64  forming a shape smaller than the mold&#39;s cavity;  
         [0051]    c) suspending the band  32 ,  64  within the mold;  
         [0052]    d) introducing a thermosetting material into the mold to encase the band  32 ,  64 ; and  
         [0053]    e) cooling the material thereby creating a substantially solid yet lightweight body  24 ,  59  reinforced by the band  32 ,  64  contained within. In this method, Step b) preferably comprises using a screw engaged through holes  36  in ends  34  of the band  32 ,  64  to secure the band  32 ,  64  in a loop shape. Although, other methods of securing the band ends  34  may also be used as known to those of ordinary skill in the art. Steps b) and c) may alternatively comprise suspending one or more substantially straight metallic strips in the mold as the reinforcing members, instead of a loop. As will be readily understood by those of skill in the art, Step d) may be accomplished by a variety of methods including, but not limited to, pouring or pumping the thermosetting material into the mold.  
         [0054]    The embodiments illustrated and described above are provided merely as examples of the present invention. Other changes and modifications can be made from the embodiments presented herein by those skilled in the art without departure from the spirit and scope of the invention, as defined by the appended claims.