Patent Publication Number: US-7594707-B2

Title: Snap-in bearing rack and pinion system

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention pertains to the art of refrigerators, and more particularly, to a support arrangement having a rack and pinion stabilizing system for a pull-out freezer drawer. 
   2. Description of the Related Art 
   Pull-out drawers in a refrigerator cabinet, and in particular bottom mount freezers in which the freezer compartment is located at the bottom of the refrigerator while the fresh food compartment is located at the top of the refrigerator, are often used to increase versatility of storing a wide range of food items, and for increasing the accessibility of items stored in the lower portion of the refrigerator cabinet. These bottom mounted freezer drawers are typically mounted on slides or glides fastened to the sidewalls of the inner liner of the refrigerator cabinet and telescopically extend horizontally toward the opening of the refrigerator. Unfortunately, these slides can extend at different rates when the large drawer is opened and closed, particularly when the horizontal force (i.e. the consumer pushing or pulling the drawer) is not centered. The effect of the different rates of extension can create a “wobble” or “racking” as the drawer is extended or inserted. This drawer rack or wobble typically can occur when the velocity of the drawer and slide assembly varies with position along the face of the drawer as it is extended or inserted. 
   Rack and pinion stabilizing assemblies have been provided to help insure that both slide assemblies move at the same speed as the drawer is extended or inserted. One problem with rack and pinion stabilizing assemblies is aligning the gear wheels on the sides of the drawer with the associated rack gears during assembly of the drawer to the cabinet or mounting structure. 
   SUMMARY OF THE INVENTION 
   The invention relates to a rack and pinion stabilizing system for a pull-out apparatus having spaced mounting brackets including first and second slide assemblies positioned to movably support the pull-out apparatus and having a rack gear associated with each of the first and second slide assemblies and a snap-on pinion gear assembly. The snap-on pinion gear assembly includes a shaft, first and second pinion gears on opposite ends of the shaft, and first and second bearing brackets rotatably supporting the shaft. Each bearing bracket includes at least one latch surface arranged to engage a mounting bracket to attach the pinion gear assembly to the pull-out apparatus with each pinion gear engaging a rack gear. 
   The rack gear can be part of a C-shaped channel connected to each of the first and second slide assemblies. The mounting brackets can include sides and a recess to receive the shaft and further can include at least one strike surface to engage the latch surface. The bearing brackets can include a journal to rotatably support the shaft, and can have a first member extending generally perpendicular to the journal and a second member extending generally perpendicular to the journal and generally parallel to the first member. The first member and the second member can be arranged to engage a mounting bracket. The first members can include two latch surfaces and the mounting brackets can include two strike surfaces. 
   The bearing bracket second members can include a rib extending generally perpendicular to the journal and toward the first member and the mounting brackets can include a slot extending generally perpendicularly from the recess to receive the rib to locate the bearing bracket with the latch surfaces aligned with the strike surfaces. The first member can be flexible to allow the latch surfaces to slide on the side of the mounting bracket and engage the strike surfaces as bearing brackets are mounted to the mounting brackets. The latch surfaces can have a ramp extending upwardly from the surface of the first members and a lock surface extending generally perpendicular from the surface of the first members to the distal end of the ramps. The strike surfaces can comprise an opening in the mounting brackets arranged to receive the latch surface with the lock surface engaging the edge of the opening. 
   In another aspect the invention relates to a rack and pinion stabilizing system for a cabinet drawer including first and second slide assemblies mounted in the cabinet, a rack gear connected to each of the first and second slide assemblies, and spaced mounting brackets connected to the drawer having opposite sides and a bottom edge. Each mounting bracket can include a recess in the bottom edge, a slot extending from the recess generally perpendicular to the bottom edge, and two strike surface openings in the mounting brackets adjacent the slot. The rack and pinion stabilizing system can also include a snap-on pinion gear assembly having a shaft, first and second pinion gears mounted on opposite ends of the shaft and first and second bearing brackets. The bearing brackets can include a journal arranged to rotatably support the shaft, a first member extending generally perpendicular to the journal, a second member extending generally perpendicular to the journal and generally parallel to the first member. The first and second members can be arranged to engage the opposite sides of the mounting bracket and the first members can have two latch surfaces each including a ramp extending upwardly from the surface of the first member and a lock surface arranged to engage the two strike surface openings in the mounting bracket. The second members can have a rib extending generally perpendicular to the journal and arranged to engage the slot to locate the bearing bracket with the latch surfaces aligned with the strike surface openings. 
   In another aspect the invention relates to a method for assembling a drawer and a rack and pinion stabilizing system in a cabinet including providing a cabinet having first and second slide assemblies including first and second rack gears and first and second spaced drawer mounting brackets, attaching at least a drawer element to the first and second drawer mounting brackets, providing a pinion gear assembly comprising: a shaft; first and second bearing brackets rotatably supporting the shaft; and first and second pinion gears at the opposite ends of the shaft, and assembling the pinion gear assembly to the drawer element by connecting the first and second bearing brackets to the first and second mounting brackets with the first and second pinion gears engaging the first and second rack gears. 
   In another aspect the invention relates to a method of assembling a freezer drawer having a rack and pinion stabilizing system in a refrigerator freezer cabinet drawer cavity including mounting rack gears to first and second slide assemblies, attaching mounting brackets to the first and second slide assemblies, mounting the first and second slide assemblies including the rack gears and mounting brackets to opposite side walls of the drawer cavity, attaching an insulated drawer front to the mounting brackets, providing a pinion gear assembly having a shaft, first and second bearing brackets rotatably supporting the shaft, and first and second pinion gears at the opposite ends of the shaft, extending the insulated drawer front to a fully extended position, and assembling the pinion gear assembly to the mounting brackets by connecting the first and second bearing brackets to respective mounting brackets with the first and second pinion gears engaging the rack gears. 
   The method can further include the step of assembling a container to the mounting brackets after the step of assembling the pinion gear assembly to the mounting brackets. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partial exploded view of a bottom mount freezer style refrigerator incorporating the freezer drawer support assembly of the invention; 
       FIG. 2  is a perspective view of the drawer slide and bracket assembly with the snap-on pinion gear assembly attached to drawer mounting brackets removed from a refrigerator; 
       FIG. 3  is a partial exploded view of portions of the drawer slide and bracket assembly; 
       FIG. 4A  is a perspective view of one side of the bearing bracket showing latch surfaces; 
       FIG. 4B  is a perspective view of the opposite side of the bearing bracket showing a rib for locating a bearing bracket on a drawer mounting bracket; 
       FIG. 5A  is an partial exploded view of the snap-on pinion gear assembly; 
       FIG. 5B  is a partial perspective view of the snap-on pinion gear assembly; 
       FIG. 6  is a partial perspective view of the drawer slide and bracket assembly showing a pinion gear engaging a rack gear; 
       FIG. 7A  is a partial perspective view of the a drawer slide and bracket assembly installed in a freezer compartment with the snap-on pinion gear assembly in position to be attached to the drawer mounting brackets; 
       FIG. 7B  is a partial perspective view of the drawer slide and bracket assembly installed in a freezer compartment with the snap-on pinion gear assembly attached to the drawer mounting brackets; 
       FIG. 8A  is a partial perspective view of the drawer slide and bracket assembly installed in a freezer compartment with the snap-on gear assembly in position to be attached to the drawer mounting brackets; 
       FIG. 8B  is a partial perspective view of the drawer slide and bracket assembly installed in a freezer compartment with the snap-on pinion gear assembly attached to the drawer mounting brackets; 
       FIG. 9  is a partial elevation view of the drawer slide and bracket assembly installed in a freezer compartment with a pinion gear engaging a rack gear. 
   

   DESCRIPTION OF THE INVENTION 
   While the invention will be described in terms of freezer drawers and baskets, other drawers such as fresh food compartment drawers, drawers or baskets of other appliances, for example dishwashers, or furniture drawers, for example a file cabinet drawer, may be provided with a rack and pinion stabilizing system of the present invention. In the embodiment of a freezer drawer the slide assemblies of the present invention, described in more detail below, are attached to or supported by the side walls of the refrigerator. Drawer glides or slide assemblies are generally known. Any suitable drawer glide may be adapted to be operable with the present invention. Therefore, for purposes of the disclosing the invention, and for purposes of simplicity, only the relevant components and/or components of the drawer slide will be referenced herein. 
   With initial reference to  FIGS. 1 and 2 , a refrigerator incorporating the invention is generally indicated at  10 . Refrigerator  10  can include a cabinet  12  to which a fresh food compartment door  14  can be attached. Refrigerator  10  constitutes a bottom mount freezer style refrigerator wherein the fresh food compartment door  14  seals off an upper fresh food compartment within cabinet  12 . In a manner well known in the art fresh food compartment door  14  can be pivotally mounted to cabinet  12  about a vertical axis through hinges (not shown). Refrigerator  10  also includes a lower, or bottom mount, freezer compartment  16  having a drawer opening  15  forming a drawer cavity. Freezer compartment  16  can be closed by a freezer drawer  18 . Freezer drawer  18  can have a handle  20  to facilitate extending and inserting freezer drawer  18 . In accordance with the invention freezer drawer  18  can be adapted to slide towards and away from cabinet  12  through the use of a slide assembly generally indicated at  22  in order to selectively access or close the freezer compartment  16 . Slide assembly  22  can include a three section, full extension slide that is well known in the art. Slide assembly  22  can include an inner section  24 , a middle section  26  and an outer section  28  that can be slideably mounted together with ball bearings (not shown) movably supporting the three sections, again as well know to those skilled in the art. Slide assembly  22  can be plated metal. While a three section, full extension slide assembly is illustrated in this application those skilled in the art should understand that other slide arrangements can be used with a rack and pinion stabilizing system according to the invention. Freezer drawer  18  can have an insulated drawer front  30  and spaced mounting brackets  32 . Drawer front  30  can be attached to mounting brackets  32  as will be described in greater detail below. Mounting brackets  32  can have one or more basket hooks  34  (see  FIGS. 1 ,  2  and  6 ) to support a basket  36  between mounting brackets  32 . Those skilled in the art will understand that basket  36  can be a wire basket as shown or can be a metal or plastic bin arranged to hang from one or more basket hooks such as basket hooks  34 . Rack and pinion stabilizing system  40  can include a pinion gear assembly  42  and rack gears  44 . Rack gears  44  can be part of the bottom surface of generally C-shaped channel  46  that can be attached to each slide assembly  22  as will be described in greater detail below. Pinion gear assembly  42  can include a shaft  48 , first and second bearing brackets  50  and first and second pinion gears  52  that will be described in greater detail below. Mounting brackets  32  can be formed of powder coated steel and shaft  48  can be formed of powder coated steel or stainless steel. C-shaped channel  46  and rack gears  44  can be formed of polystyrene material including, but not limited to HIPS or ABS plastic material. 
   As shown in  FIGS. 3 and 5A , pinion gear assembly  42  can include a shaft  48  supported by a bearing bracket  50  and having a pinion gear  52  at each end of the shaft. Shaft  48  can have opposed flattened portions  49  on each end and pinion gears  52  can have a corresponding opening  53  to receive the flattened portion  49  at the end of shaft  48 . Bearing bracket  50  can have a journal  51  that can rotatably support shaft  48 . Pinion gear assembly  42  can be assembled by pressing a pinion gear  52  on one end of a shaft  48 , sliding two bearing brackets  50  on the shaft  48  by inserting the shaft  48  into the respective journals  51  and pressing a pinion gear  52  on the opposite end of the shaft  48 . Those skilled in the art will understand that pinion gears  52  can be attached to shaft  48  using other well known assembly techniques for a wheel and shaft including other shapes to prevent pinion gear  52  from rotating relative to shaft  48 , for example D-shaped surfaces or splined surfaces, a pin to pin the pinion gear to shaft  48  or the use of suitable adhesives or spin welding to attach pinion gears  52  to shaft  48 . Pinion gears  52  and bearing brackets  50  can be formed of acetal plastic material. 
   Turning to  FIGS. 4A and 4B  bearing bracket  50  can be seen in greater detail. As noted above, bearing bracket  50  can include a journal  51  that can be arranged to rotatably support shaft  48 . As shown in  FIG. 4A , bearing bracket  50  can have a first member  54  extending generally perpendicular to journal  51  and a second member  56  that can also extend generally perpendicular to journal  51  spaced axially along journal  51 . The space between the first member  54  and second member  56  can receive and engage opposite surfaces  33  of mounting bracket  32 . First member  51  of a bearing bracket  50  can have at least one latch surface  58  spaced from journal  51 . In the embodiment illustrated in  FIGS. 4A and 4B  bearing bracket  50  includes two latch surfaces  58 . Latch surfaces  58  can be generally rectangular and can include a ramp  60  and a lock surface  62  on surface  55  of first member  54  that can engage strike  64  that can be formed in mounting brackets  32  (see  FIGS. 3 and 8A ). As illustrated, strike  64  can be a rectangular opening  65  in mounting bracket  32  shaped to receive a latch surface  58  that can include an edge  66  that can engage lock surface  62  to secure bearing bracket  50  to mounting bracket  32 . First member  54  can be flexible to allow first member  54  to deflect away from second member  56  as bearing bracket  50  is assembled to mounting bracket  32 . 
   Referring again to  FIG. 3  and  FIGS. 7A and 8A , first member  54  and second member  56  can be axially spaced along journal  51  to engage opposite side surfaces  33  of mounting bracket  32 . As a bearing bracket  50  is assembled to a mounting bracket  32  the ramp surface  60  can engage the bottom edge  68  of mounting bracket  32  bending first member  54  away from second member  56  to allow bearing bracket  50  to slide onto mounting bracket  50 . Second member  56  can have a rib  70  extending generally perpendicular to journal  51  forming a ramp extending toward first member  54 . Mounting bracket  32  can have a slot  72  extending generally perpendicular to recess  74  that can be formed in the bottom edge  68  of mounting bracket  32  that can be sized to receive rib  70 . Recess  74  can be semi-circular to receive the upper surface  76  of journal  51  to locate pinion gear assembly along mounting bracket  32 . As a bearing bracket  50  is slid into position on mounting bracket  32  rib  70  can engage slot  72  to guide bearing bracket onto mounting bracket  32  with upper surface  76  of journal  51  aligned in recess  74  and with latch surfaces  58  aligned with strikes  64 . As noted above when ramp surfaces  60  engage bottom edge  68  first member  54  can deflect to allow ramp surfaces  60  to slide along slide wall  33  until the ramp surface drops into strike surface  64  opening  65 . When bearing bracket  50  is fully slid on mounting bracket  32  ramp surface  60  can be received in strike surface  64  opening  65  with lock surface  62  engaging the edge  66  of the strike surface  64  locking bearing bracket  50  on mounting bracket  32 . With two latch surfaces  58  engaging two strike surfaces, rib  70  engaging slot  72  and upper surface  76  of journal  51  engaging recess  74  bearing bracket is held securely in position on mounting bracket  32  and can thereby hold pinion gear  52  rotatably in position adjacent the bottom edge  68  of mounting bracket  32 .  FIGS. 7A and 8A  illustrate pinion gear assembly  42  prior to assembly near mounting bracket  32  and  FIGS. 7B and 8B  illustrate pinion gear assembly  42  assembled to the mounting bracket  32  as described above. In the event it is desired to remove drawer  18  for cleaning or for service or for any reason, pinion gear assembly  42  can be detached from mounting brackets  32 , without removing the freezer drawer  18 , by flexing the first members  54  away from the side wall  33  of mounting bracket  32  sufficiently to withdraw latch surfaces  58  from strike openings  64  and sliding bearing bracket  50  downward off mounting brackets  32 . For example, a screwdriver blade or similar instrument can be inserted between first member  54  and mounting bracket  32  to flex first member  54  sufficiently to allow latch  58  to slide out of strike  64  and down the surface  33  or mounting bracket  32 . An advantage of the rack and pinion stabilizing system according to the invention is that the pinion gear assembly  42  can be removed and replaced without removing the drawer/door. In competitive designs the drawer must be removed in order to replace the pinion gear assembly, or even to “reset” the rack and pinion stabilizing system in the case that teeth become misaligned side to side. 
   Referring now to  FIGS. 2 ,  6 ,  7 B and  9  when pinion gear assembly  42  is snapped into position on mounting brackets  32 , pinion gears  52  engage downward facing rack gears  44  on each side of drawer  18 . When pinion gears  52  are engaged with rack gears  44  as drawer  18  is moved in or out, pinion gears  52  rotate along rack gears  44 . As described above, pinion gears  52  are connected by shaft  48 , and since the shaft  48  has flattened portions  49  and pinion gears  52  have mating surfaces  53  that engage flattened portions  49 , each pinion gear  52  must rotate at the same speed providing equal linear motion along the respective rack gears  44 . Thus, slide assemblies  22  can only move linearly with each side of drawer  18  moving the same amount as pinion gears  52  rotate and move along rack gears  44 . Accordingly, drawer motion is stabilized against rack and wobble as the drawer is extended from and inserted into the freezer compartment  16  of the refrigerator  10 . As noted above, use of a rack and pinion stabilizer for a drawer or other pull-out apparatus can assure that the drawer or pull-out apparatus moves uniformly as it is pulled out or pushed in, even if the force is not applied evenly to the drawer or apparatus thus assuring the drawer or apparatus remains in alignment. 
   Referring to  FIG. 2 , a drawer slide and bracket assembly  38  according to the invention can be assembled as follows. A C-shaped channel  46  including rack gear  44  can be attached to a slide assembly  22  by, for example, riveting a C-shaped channel  46  to outer section  28  of slide assembly  22  to hold C-shaped channel  46  in position on slide assembly  22 . A mounting bracket  32  can be attached to slide assembly  22  by, for example, riveting a mounting bracket  32  to inner section  24  thus forming a drawer slide and bracket assembly  38 . In  FIG. 2  a pair of drawer slide and bracket assemblies are illustrated with a pinion gear assembly  42  attached. Those skilled in the art will understand that suitable fixtures can be used when a C-shaped channel  46  is attached to outer section  28  and when a mounting bracket  32  is attached to inner section  24  to assure that the elements of drawer slide and bracket assembly  38 , slide assembly  22 , C-shaped channel  46  and mounting bracket  32 , will be correctly positioned relative to one another. To assure that the drawer slide and bracket assemblies  38  are correctly positioned in freezer compartment  16  a fixture, not shown, can be positioned in freezer compartment  16  that can be used to locate and pre-drill holes, not shown, in the side walls  17  of freezer compartment for mounting drawer slide and bracket assemblies  38  on the side walls  17  of the freezer compartment  16 . If desired, side walls  17  can be reinforced where fasteners will attach the drawer slide and bracket assembly  38  to the side walls  17 . For example, a metal plate, not shown, can be positioned in the insulation space adjacent side walls  17  to reinforce the portion of side walls  17  to which the drawer slide and bracket assembly will be attached. A metal plate can not only provide a secure mounting for the fasteners used to attach the drawer slide and mounting bracket  38 , but can also function to spread the load of a filled freezer drawer  18  over a larger area of the side wall  17  of freezer compartment  16  than only where fasteners (not shown) attach the drawer slide and bracket assembly  38  to a side wall  17 . Those skilled in the art will understand that suitable fasteners such as threaded fasteners or other well known suitable fasteners can be used to attach a drawer slide and bracket assemblies  38  to the side walls  17  of the freezer compartment  16 . 
   Following attachment of drawer slide and bracket assemblies  38  in a freezer compartment, freezer drawer  18  can be assembled by attaching a drawer front  30  to mounting brackets  32 . Mounting brackets  32  can include mounting flanges  31  that can have two or more holes  35  (see  FIG. 2 ) to receive fasteners to secure at least one drawer element, drawer front  30 , to mounting brackets  32 . Drawer front  30  can have a surface, not shown, to engage mounting flanges  31  to properly position drawer front on mounting flanges  31  while fasteners (not shown) are driven into the inner surface (not shown) of drawer front  30  to attach each mounting flange  31  to drawer front  30  as is well known to those skilled in the art. If desired, drawer front  30  can have reinforced sections where mounting flanges  31  are attached to the drawer front by suitable fasteners. Drawer front  30  can have handle  20  attached to drawer front  30  prior to drawer front  30  being attached to mounting flanges  31 , although, if desired drawer handle  20  can be assembled after assembly of the freezer drawer  18  is complete. 
   After freezer drawer front  30  is attached to mounting brackets  32  forming freezer drawer  18 , freezer drawer  18  can be fully withdrawn so that the drawer slide and bracket assembly  38  is fully extended as illustrated in  FIG. 2 . With freezer drawer  18  fully extended and properly aligned for movement parallel to slides  22 , pinion gear assembly  42  can be attached to mounting brackets  32  as described above by positioning pinion gear assembly  42  in the position shown in  FIGS. 7A and 8A , and then sliding the bearing brackets  50  upward into engagement with mounting brackets  32  until the bearing brackets  52  snap into the position illustrated in  FIGS. 7B ,  8 B and  9  with pinion gears  52  engaging rack gears  44  and latch surfaces  58  engaging strikes  64 . Assembling pinion gear assembly  42  to freezer drawer  18  in the fully extended position assures that the rack and pinion stabilizing system is properly aligned and that the freezer drawer  18  will close and seal properly to cabinet  12 . As is well known in the art freezer drawer  18  can have suitable seals (not shown) on the surface of freezer drawer  18  that contact cabinet  12  at drawer opening  15  to help assure sealing of the freezer compartment when the freezer drawer  18  is closed. With the pinion gear assembly  42  attached, basket  36  can be assembled to freezer drawer  18  by inserting basket  36  between mounting brackets  32  until basket  36  engages mounting hooks  34  to support the basket in drawer  18 . Thus, the rack and pinion stabilizer according to the invention can be easily assembled to a drawer or other pull-out apparatus with the drawer or pull-out apparatus properly aligned. As freezer drawer  18  is opened and closed pinion gears  52  connected by shaft  48  have equal rotational and linear motion along the respective rack gears  44 . Accordingly, drawer motion is stabilized against rack and wobble as it is extended from and inserted into the freezer compartment  16  of the refrigerator cabinet  12 . This system allows the drawer to be extended and inserted with a consistent and correct orientation to assure an effective seal to prevent air from permeating into or out of freezer drawer making it difficult to regulate temperatures, humidity and other factors within the drawer. 
   While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.