Abstract:
A hub ring employed in mounting a rotating shaft of an electrical device, for example an electric motor, to a supporting bracket reduces or eliminates the transmission of vibration from the shaft to the supporting bracket and is provided with an integral locking mechanism that automatically secures the hub ring to the supporting bracket when the hub ring is positioned on the bracket without the need for separate attachment parts and/or fasteners.

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention pertains to a hub ring employed in mounting a rotating shaft of an electrical device, for example an electric motor, to a supporting bracket. In particular, the present invention pertains to a hub ring that reduces or eliminates the transmission of vibration from the shaft to the supporting bracket and is provided with an integral locking mechanism that automatically secures the hub ring to the supporting bracket when the hub ring is positioned on the bracket without the need for separate attachment parts and/or fasteners. 
     (2) Description of the Related Art 
     Hub rings have long been employed in the prior art in mounting electrical devices such as electric motors to supporting brackets. Vibration damping hub rings are generally comprised of an inner, annular damper constructed of a resilient material such as rubber and an outer, annular ring constructed of a more rigid material such as plastic or metal. Hub rings are usually employed in pairs with the annular dampers of the hub rings being mounted over bearings or bushings mounted on the opposite ends of the motor shaft and the outer rigid rings of the hub rings being mounted on support brackets. 
     FIG. 1 shows one example of a prior art hub ring  12  mounted on a support bracket  14 . The support bracket  14  is one of a pair of support brackets  14 ,  16  that support an electric motor  18  by supporting opposite ends of the motor shaft  22 . In the example shown, each support bracket  14 ,  16  is constructed from a flat piece of metal that is stamped or in some other equivalent manner formed with a base portion  24  and an arm portion  26 . As shown in FIG. 1, the arm portion  26  of each bracket is bent at a right angle relative to the base portion  24 . When the base portion of each bracket is attached to a support surface, for example that of an electric appliance, each arm portion positions an arcuate support surface  28  of each arm at a vertical height above the base portion that is sufficient to support the electric motor  18  above each base portion. Although only one support surface  28  of the two bracket arms  26  is visible in FIG. 1, they are both configured in the same manner. At the opposite ends of the support surface  28  each arm is formed with a pair of outwardly projecting catches  32 . Each of the catches  32  has a latch surface  34  on its underside. 
     The support brackets  14  shown in FIG. 1 are only one example of support brackets that have been employed in supporting electrical devices such as motors. There are many other types of support brackets that are used for the same purpose, however most have the common features of an arcuate support surface and a pair of latch surfaces at opposite ends of the support surface. 
     The support surface  28  of the bracket  14  to the right in FIG. 1 is shown supporting a prior art hub ring  12  attached to the bracket. FIG. 2 shows the prior art hub ring  12  removed from the support bracket. The hub ring  12  is basically comprised of an outer annular ring  36  constructed of metal, plastic or other similar rigid material and an inner annular damper  38  constructed of rubber or other similar resilient material. The outer ring  36  has a cylindrical peripheral surface with an annular groove  42  formed into the surface forming a pair of annular rims  44  at axially opposite sides of the groove. The groove  42  has an axial dimension or width that is sized to receive the support surface  28  of the bracket in a tight fit, preventing any axial movement of the hub ring  12  relative to the bracket  14  when the hub ring is mounted on the bracket. The annular damper  38  is molded, glued or secured to the interior surface of the outer ring  36  in some other equivalent manner. In the embodiment of the hub ring shown in FIG. 2, the damper is formed with four radially inwardly projecting surfaces  46  that are dimensioned to fit in tight friction engagement around the exterior of a bearing or bushing mounted on the shaft  22  of the motor  18 . Alternatively, the interior surface  48  of the damper could be dimensioned to fit in tight friction engagement around the bearing or bushing supporting the motor shaft  22 . 
     Referring back to FIG. 1, the prior art hub ring  12  is shown mounted on the right side support bracket  14  with the damper  38  engaging around a bearing  52  mounted on the motor shaft  22 . The hub ring  12  is positioned on the support bracket  14  with the support surface  28  of the bracket engaging in the annular groove  42  of the ring. In the example shown in FIG. 1, the hub ring  12  is securely held on the bracket support surface  28  by a pair of curved straps  54  constructed of a rigid material such as metal, plastic or other similar rigid material. Each of the straps are the same and are formed with an elongated slot  56  adjacent one end and a fastener hole  58  adjacent the opposite end. In securing the hub ring  12  to the support bracket  14 , the straps  54  are positioned on the bracket as shown to the right in FIG. 1 with the pair of arm catches  32  extending through the slots  56  of the brackets and with the fastener holes  58  of the brackets aligned at the top of the hub ring  12 . A screw  62  and nut  64  fastener is then attached through the aligned holes  58  of the straps and is tightened down, thereby securing the hub ring  12  to the support bracket  14 . This attachment process is repeated for a hub ring mounted on the motor shaft  22  at the opposite end or left hand end of the motor shown in FIG.  1 . 
     FIG. 3 shows a variation in the prior art mechanism for attaching a hub ring to a support bracket where the pair of curved straps are replaced by a single strap  66  having an inverted U-shape. The single strap  66  is constructed of metal, plastic or other similar resilient material. It is formed with a pair of elongated slots  68  adjacent its opposite distal ends and with a U-shaped bend  72  at its center. The center U-shaped bend  72  gives the single strap a resiliency in addition to the resiliency of the material from which the strap is constructed. In securing the hub ring  12  to a support bracket  14  employing the single strap  66 , one of the elongated slots  68  is first attached over one of the arm catches  32  of the support bracket and the strap  66  is stretched over the top of the hub ring  12 . Stretching the strap  66  causes the U-shaped bend  72  to open slightly enabling the elongated slot  68  on the opposite end of the strap to pass over the other arm catch  32  and engage with the latch surface  34  of the catch, thereby attaching the single strap  66  onto the support bracket securing the hub ring to the support bracket. In a variation of this attaching mechanism, a screw and nut fastener  74  can be provided through the U-shaped bend  72 . The fastener  74  can be tightened down to constrict the single strap  66  over the top of the hub ring  12  to further secure the hub ring to the support bracket  14 . 
     FIG. 4 shows a still further variation of a hub ring  76  that is similar to the previously described prior art hub rings except that it is provided with an integral attachment mechanism. The hub ring shown in FIG. 4 is usually constructed of resilient plastic and includes a center ring  78  dimensioned to fit in tight friction engagement around a bearing or bushing  82  mounted on the motor shaft  84 . An outer ring  86  surrounds the center ring  78  and is connected to the center ring by a plurality of curved, resilient spring members  88 . The hub ring  76  is held to the support bracket  14  by integrally formed flexible attaching straps  92  that have slotted openings (not shown) near their distal ends. The attaching straps  92  are shown in their operative position in FIG. 4 securing the hub ring  76  to the support bracket  14 . In at rest or free positions of the attaching straps  92  the resiliency of the straps moves them to positions that are spaced radially outward from the arm catches  32  of the support bracket. In attaching the hub ring  76  to the support bracket  14 , the hub ring is first positioned on the support surface  28  of the bracket and one of the straps  92  is positioned over one arm catch  32  with the one strap engaging the latch surface  34  of the arm catch. The hub ring  76  is then rotated slightly causing the engaged strap  92  to stretch and the free strap  92  is stretched until its elongated slot (not shown) can be passed over the opposite arm catch  32  of the support bracket engaging the free strap with the opposite latch surface  34 . 
     The prior art hub ring attachment mechanisms described above are disadvantaged in that they are difficult to secure to the support bracket  14 . The hub ring shown in FIG. 1 is attached by first positioning the hub ring on the support bracket  14  and then holding the two curved straps  54  over the opposite sides of the hub ring while the bolt  62  is inserted through the aligned holes  58  of the straps. The nut  64  is then threaded on the bolt  62  and tightened down to secure the hub ring  12  to the support bracket. Thus, the attachment mechanism shown in FIG. 1 has the drawback of having multiple parts which makes the installation and removal of the attachment mechanism difficult and time consuming, especially in environments having limited space, for example in the interior of a household appliance. 
     Despite the benefits over the multiple part attachment mechanism of FIG. 1, the inverted U-shaped strap  66  attachment mechanism of FIG. 3 is still separate from the hub ring  12 , thereby still requiring its own installation time. If the fastener  74  is used to further secure the single strap  66  to the support bracket  14  the installation and removal of the strap is made more difficult and time consuming, especially in environments having limited space. 
     The integral attachment mechanism or straps  92  of the hub ring  76  of FIG. 4 eliminate some of the problems associated with using separate attachment mechanisms from the hub ring, however its attachment to the support bracket  14  is still difficult. Each strap  92  must be stretched during installation and removal, thus requiring more time. In addition, because the straps  92  flex away from the hub ring in their at rest or free positions, one strap must be held over one arm catch  32  while the other strap is stretched and positioned over the opposite arm catch making installation difficult. 
     What is needed to overcome the disadvantages of prior art hub ring attachment mechanisms is a hub ring attachment mechanism that does not require separate component parts and is automatically attached to the support bracket as the hub ring is positioned on the support bracket 
     SUMMARY OF THE INVENTION 
     The hub ring of the present invention overcomes disadvantages associated with prior art hub rings by providing a hub ring with an integral locking mechanism. The integral locking mechanism automatically locks the hub ring on the support bracket when it is properly positioned on the support surface of the support bracket. There is no need for additional attachment parts, fasteners or tools. In addition, the hub ring of the invention can be easily removed from its attachment to the support bracket by using only a prying tool, for example a small flat tip screwdriver. In the preferred embodiment of the invention the hub ring and its integral locking mechanism are constructed of a rigid but resilient plastic, thereby reducing its cost of manufacture. The hub ring of the invention is basically comprised of an annular ring having a pair of resilient, flexible arms and having three flanges that project radially outwardly from the ring where the ring, arms and flanges are all formed as a single monolithic piece. 
     The annular ring has a cylindrical exterior surface and an interior surface that surrounds a center opening of the ring. The exterior surface of the ring has an axial width between first and second circular end faces of the ring. A resilient vibration damper of the types employed in prior art hub rings is molded or otherwise secured to the interior surface of the ring. 
     A center positioning flange of the plurality of flanges extends radially outwardly from the exterior surface of the ring adjacent the ring first end face. A pair of side positioning flanges of the plurality of flanges project radially outwardly from the exterior surface of the ring adjacent the second end face of the ring. The center flange and the pair of side positioning flanges are spaced axially from each other forming a gap between the flanges at the bottom of the ring exterior surface. The gap is dimensioned sufficiently wide to receive the support bracket in the gap with the support surface of the bracket engaging the bottom of the ring exterior surface. The plurality of flanges engage against opposite first and second surfaces of the bracket on opposite sides of the bracket support surface, thereby securely positioning the hub ring on the support surface of the bracket. 
     The pair of resilient, flexible arms project radially outwardly from the exterior surface of the ring adjacent the first end face of the ring. The pair of arms are positioned on the ring exterior surface slightly above the pair of side positioning flanges. The arms make up a part of the locking mechanism of the hub ring. The resilient flexibility of the arms enables them to flex axially between first and second positions of the arms relative to the ring. Each arm projects radially from the ring exterior surface to a distal end of the arm and each arm has a wedge shaped barb at its distal end. Each barb has a cam surface that slides along a side of the support bracket when the hub ring is moved toward the support surface of the bracket causing the resilient arm of each locking mechanism to resiliently flex from a first, at rest position of the arm relative to the ring to a second, axially displaced position of each arm relative to the ring. Each barb also has a locking surface that passes over and engages against the latch surface of each arm catch of the support bracket when the hub ring is positioned with its exterior surface on the support surface of the support bracket. When the locking surface of the barb passes over the latch surface of the support bracket the resiliency of each arm causes each arm to flex from its second axially displaced position relative to the ring back to its first position relative to the ring, thereby positioning the locking surface of each barb beneath the latch surface of the support bracket catch arms automatically locking the hub ring to the support bracket. Each arm of the locking mechanisms is provided with a rib extending across a surface of the arm adjacent the barb. The rib engages against a side surface of the support bracket with the hub ring attached to the support bracket and maintains a small spacing between each resilient arm and the surface of the support bracket engaged by the rib. The spacing is sufficient to enable insertion of a prying tool between the resilient arm and the support bracket where the prying tool can be used to flex the arm from its first position to its second position relative to the ring, thereby enabling the ring to be removed from the support bracket. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects and features of the present invention are revealed in the following detailed description of the preferred embodiment of the invention and in the drawing figures wherein 
     FIG. 1 shows a pair of prior art support brackets, a pair of prior art curved attachment straps and an electric motor mounted by a prior art hub ring to one of the support brackets by a pair of attachment straps; 
     FIG. 2 shows the prior art hub ring of FIG. 1 removed from the support bracket; 
     FIG. 3 shows prior art single strap hub ring attachment mechanisms; 
     FIG. 4 shows a further embodiment of a prior art hub ring attachment mechanism; 
     FIG. 5 is a perspective view of the hub ring of the invention; 
     FIG. 6 is an end elevation view of the hub ring of FIG. 5; 
     FIG. 7 is a side elevation view of the hub ring of FIG. 5 and a portion of a support bracket to which the hub ring is secure; and 
     FIG. 8 is a top plan view of the hub ring of FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 5 through 8 show the hub ring  102  of the invention with its integral locking mechanism. In the preferred embodiment of the invention the hub ring and its integral locking mechanism are constructed of a rigid but resilient plastic, thereby reducing its manufacturing cost. The hub ring  102  is basically comprised of an annular ring  104  having a pair of resilient, flexible arms  106  and having three flanges  108 ,  112  that project radially outwardly from the ring with the ring  104 , arms,  106  and flanges  108 ,  112  all being formed as a single monolithic piece. 
     The annular ring  104  has a cylindrical exterior surface  114  and an interior surface  116  that surrounds a center opening  118  of the ring having a center axis  122 . The ring  104  is shown in FIGS. 5 through 8 with its vibration damper removed to show the details of the interior or the ring. The exterior surface  114  of the ring has an axial width between a first circular end face  124  of the ring and a second circular end face  126  of the ring. Referring to FIG. 5, the interior surface  116  of the ring has an axial width that is smaller than that of the exterior surface  114 . This gives the ring a cross-section having a general trapezoidal configuration. The interior surface of the ring is also provided with a plurality of protrusions  128  that project radially inwardly from the ring interior surface adjacent the top of the ring. A resilient vibration damper (not shown) of the types employed in prior art hub rings discussed earlier is molded or otherwise secured to the ring interior surface  116 . The vibration damper extends between the two end faces  124 ,  126  of the ring over the interior surface  116  and the plurality of protrusions  128 . Together, the plurality of protrusions  128  and the trapezoidal cross-section configuration of the ring secure the vibration damper to the interior surface  116  of the ring preventing circumferential movement of the damper relative to the ring and preventing axial movement of the damper relative to the ring. 
     A center positioning flange  108  of the plurality of flanges extends radially outwardly from the ring exterior surface  114  at the bottom of the ring. As seen in FIG. 7, the center flange  108  is positioned adjacent the first end face  124  of the ring and has an outer surface  130  that is in the same plane as the ring first end face  124 . The opposite side of the center flange  108  is formed with a tapered surface  132  adjacent the distal end of the flange and a flat surface  134  adjacent the connection of the flange to the ring. 
     A pair of side positioning flanges  112  of the plurality of flanges project radially outwardly from the ring exterior surface  114 . As seen in FIG. 7 the pair of side positioning flanges  112  extend from the ring adjacent the second end surface  126  of the ring. Each side positioning flange has a flat surface  136  that opposes the center flange flat surface  134  and the pair of arms  106 . Each side flange extends radially from the ring to outer edges  138  of each of the flanges positioned slightly outside of the circumference of the ring exterior surface  114  as seen in FIG.  6 . The center flange flat surface  134  and the side flange flat surfaces  136  are spaced axially from each other forming a gap  142  between the flanges at the bottom of the ring exterior surface. As seen in FIG. 7, the gap  142  is dimensioned sufficiently wide to receive the width of the support bracket  114  with the support surface  28  of the bracket engaging the exterior surface  114  of the hub ring and with a first side surface  144  of the bracket engaging against the center flange flat surface  134  and a second side surface  146  of the bracket engaging against the flat surfaces  136  of the side positioning flanges  112 . 
     The pair of resilient, flexible arms  106  project radially outwardly from the ring exterior surface  114  adjacent the first end face  124  of the ring. As seen in FIG. 6, the arms are positioned on the ring exterior surface slightly above the pair of side positioning flanges  112 . The arms make up a part of the locking mechanism of the hub ring. The resilient flexibility of the arms enables them to flex axially between first and second positions of the arms relative to the hub ring. In FIGS. 5 through 8 the arms are shown in their first, at rest positions relative to the ring  104 . When the arms are moved to their second positions relative to the ring they flex or bend axially away from the pair of side positioning flanges  112 . Each arm projects radially from the ring exterior surface  114  to a distal end of the arm and each arm has a wedge shaped barb  152  at its distal end. Each barb  152  has a tapered surface  154  that faces toward the pair of side positioning flanges  112 . The tapered surfaces  154  of the barbs slid along the first surface  144  of the bracket when the hub ring  12  is being positioned on the support surface  28  of the bracket causing the resilient arms to resiliently flex from their first, at rest positions of the arms relative to the annular ring  104  to their second, axially displaced positions of the arms relative to the ring. Each barb also has a locking surface  156  that is angled relative to its tapered surface  154 . Each locking surface  156  is positioned on the arm to pass over and engage against the latch surface  34  of each support bracket arm catch  32  when the hub ring is being positioned on the support surface  28  of the bracket. Each arm of the locking mechanisms is also provided with a rib  158  that extends across a surface of the arm from the ring exterior surface  114  to the barb  152  of the arm. The rib  158  functions in reinforcing the arm and also functions as an axial spacer as will be explained. 
     In attaching the hub ring  76  of the invention to the support bracket  14  of the prior art, the hub ring is first positioned manually above the support bracket with the gap  142  between the center flange  108  and side positioning flanges  112  positioned directly above the support surface  28  of the bracket. The hub ring is then moved downwardly toward the support surface. As the hub ring is moved downwardly the outer edges  138  of the side positioning flanges  112  will first come into contact with and slide over the bracket second surface  146  due to their being positioned slightly outside of the circumference of the ring exterior surface  114 . As the hub ring is continued to be moved downwardly the tapered surfaces  154  of the pair of barbs  152  will next come into engagement with the support bracket  14  sliding over the first surface  144  of the bracket. If the hub ring  76  is held manually with its center axis  122  parallel to the support bracket support surface  28  and with its center axis  122  perpendicular with the bracket first  144  and second  146  surfaces, the tapered surfaces  154  of the barbs will cause the resilient arms  106  to flex relative to the annular ring  104  from their first positions to their second positions as the tapered surfaces  154  pass over the bracket first surface  144 . However, it may be difficult for the installer to continue to hold the hub ring  76  in its orientation with its center axis  122  parallel to the bracket support surface  28  and the hub ring may rotate slightly in a clockwise rotation relative to the support bracket  14  as viewed in FIG.  7 . The slight rotation of the hub ring will be corrected though as the hub ring  76  is continued to be moved downwardly toward the bracket support surface  28  and the tapered surface  132  of the center flange  108  comes into contact with the first surface  144  of the bracket adjacent the bottom of the bracket support surface  28 . The tapered surface  132  of the center flange will move the hub ring  76  to the orientation relative to the support bracket  14  shown in FIG. 7 as the tapered surface passes over the bracket first surface  144 . As the hub ring is continued to be moved downwardly the exterior surface  114  of the ring will eventually seat on the support surface  28  of the support bracket and the locking surfaces  156  of the barbs  152  will pass over the latch surfaces  34  of the bracket arm catches  32  causing the resilient arms  106  to snap back to their first positions relative to the annular ring  104 , thereby automatically locking the hub ring  76  on the support bracket  14 . FIG. 7 shows the hub ring  76  locked on the support bracket  14  with the center flange flat surface  134  engaging the bracket first surface  144  and the side flange flat surfaces  136  engaging the bracket second surface  146 , with the locking surfaces  156  of the pair of barbs  152  engaging beneath the latch surfaces  34  of the support bracket arm catches  32  and with the pair of ribs  158  engaging against the first surface  144  of the support bracket. The engagement of all of these surfaces of the hub ring  76  with the respective surfaces of the support bracket  14  securely holds the hub ring against movement on the support bracket. 
     Referring to FIG. 7, it can be seen that the engagement of the resilient arm ribs  158  against the bracket first surface  144  produces a small spacing  162  between the resilient arms  106  and the bracket first surface. The spacing  162  is sufficiently large to enable the insertion of a flat prying tool into the spacing to flex the resilient arms  106  away from the bracket first surface  144 . The arms  106  can be flexed away from the bracket first surface to the extent that the locking surfaces  156  of the barbs  152  will pass from beneath the latch surfaces  34  of the bracket arm catches  32  enabling the hub ring  76  to be easily removed from its locked position on the support bracket  14  by pulling the hub ring upwardly. In removing the hub ring one of the barbs  152  is first removed from its engagement with the arm catch latch surface  34  and is then moved upwardly slightly so that the barb engages against the bracket first surface  144  above the latch surface  34 , and then the other barb  152  is moved in a similar manner in unlocking the hub ring from the support bracket. 
     Thus, the integral locking mechanism of the hub ring automatically locks the hub ring on the support bracket when it is properly positioned on the support surface of the support bracket. There is no need for additional attachment parts, fasteners or tools. In addition, the hub ring is easily removed from its attachment to the support bracket by using only a prying tool, for example a small flat tipped screwdriver. The hub ring and its integral locking mechanism are constructed of a rigid but resilient plastic, reducing its manufacturing costs. 
     While the present invention has been described by reference to a specific embodiment, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention defined in the following claims.