Patent Publication Number: US-11642912-B2

Title: Omni-directional wheel for pool vacuum head

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/687,300, titled “Omni-Directional Wheel for Pool Vacuum Head,” filed Nov. 18, 2019, which is a continuation of U.S. patent application Ser. No. 15/002,619, now U.S. Pat. No. 10,479,135, titled “Omni-Directional Wheel for Pool Vacuum Head,” filed Jan. 21, 2016, the contents of which are incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     Manual pool vacuums are known in the art. These apparatus typically include an operational head having a substantially planar bottom. Wheels on opposing sides of the head are installed to preserve the planar bottom just over the pool&#39;s surface. A hose typically installed centrally on the head connects to a pool filtration system. The pump of the filtration system draws water and debris toward the vacuum, under the vacuum head, through the hose and into the filter where debris is trapped. Since the bottom of the head is in close proximity to the pool surface, a Venturi effect is created, increasing suction at the vacuum head and making it more difficult to move along the pool&#39;s surface. 
     To operate the vacuum, the head is moved along the pool&#39;s surface using a long extendable pole connected to the vacuum head. The wheels are normally oriented on the head for back-and-forth motion. This is because users can exert back-and-forth pressure on the pole more easily than other directions. Although the customary back-and-forth motion is more efficient than other directions due to posture and the user&#39;s orientation to the vacuum head, users occasionally desire to sweep the vacuum head side-to-side in the event a portion of the pool&#39;s surface or errant debris is missed during a first pass. This side-to-side action, already difficult due to viscosity and suction, is made even more difficult because the wheels travel only in two directions. 
     Omni-directional wheels are also known in the art. Omni-directional wheels have small rollers around their circumference which are perpendicular to the axis of rotation, allowing them to be driven forward, backward, and side-to-side. State of the art omni-directional wheels are typically expensive to produce, having multiple different moving parts, and difficult to assemble, requiring fasteners or other mechanisms to hold them together. For these reasons they are disfavored for use in pool vacuums and other applications where cost and ease of use are at a premium. 
     It is therefore an object of the invention is to provide an omni-directional wheel for a pool vacuum head that rolls from side-to-side and diagonally in addition to back and forth. Another object of the invention is to provide an omni-directional wheel for a pool vacuum head that is simple and inexpensive to mold, and easy to assemble and install. Another object of the invention is to provide an omni-directional wheel that can be readily used on an existing pool vacuum head without changing the head&#39;s basic structure or theory of operation. These and other Objects are more fully discussed in the following summary, description and claims. 
     SUMMARY 
     An omni-directional wheel includes at least two substantially identical interlocking frames. Each frame has a hub which is rotatable around a common axis allowing the frames to rotate together. Lower supports extend radially around the hub, and upper supports are coupled to the hub. The upper supports extend radially around the common axis, and the upper supports and the lower supports are in a circumferentially staggered relationship around the common axis. 
     Rollers are retained by the lower supports and retained by the upper supports. To allow omni-directional movement, the rollers are oriented normal to the common axis and held in a staggered relationship around the wheel and present convex rolling faces. Optimally, the omni-directional wheel has two frames for holding the rollers, and the two frames are substantially identical. For mounting the omni-directional wheel on a pool vacuum head, the hubs each have a central hole. 
     While the lower supports are staggered around the hub and the upper supports staggered around the common axis, the lower supports and the upper supports are also preferably staggered along the common axis. To allow such a configuration, a plurality of risers is employed, connecting the upper supports to the hub. When the omni-directional wheel is assembled, the risers of each frame are interlocked. Preferably the risers are interlocked in a way that the risers releasably lock into the hub. Additionally, the lower supports and the upper supports are configured to releasably lock together to hold the wheel together. 
     In order to lock the rollers in position, each of the rollers comprises a spindle engaging channels formed in one of the plurality of lower supports and one of the plurality of upper supports. To hold the rollers on the lower supports and the upper supports, each lower support has a lower support head, and each upper support has an upper support head, with the lower support heads and the upper support heads distal from the hubs. The lower support heads and the upper support heads include the channels that hold the spindles extending from each of the rollers. 
     To lock the frames together, the risers each have a first post, and the hubs each have a first bore. The first posts and the first bores releasably lock together. For added resiliency in holding the rollers on the omni-directional wheel, the upper support heads each comprises a second post and the lower support heads each comprise a second bore, wherein the second posts and the second bores are releasably locked together. With the spindles locked in the channels on the lower support heads and the upper support heads, the rollers preferably extend radially farther from the common axis than the lower supports and the upper supports. 
     The frames may be characterized as a pair of essentially identical interlocking disc frames that form the omni-directional wheel and define its periphery or circumference. Each of the interlocking disc frames has a central hub defining a central axis for rotating the omni-directional wheel about the central axis, and rollers coupled or retained around the periphery or circumference of the wheel. Each of the rollers is oriented to roll about peripheral axes that are normal to the central axis. The rollers are preferably coupled to each of the interlocking disc frames in a staggered relationship around the periphery of the omni-directional wheel, allowing the wheel to move in multiple directions. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG.  1    illustrates a perspective view of an assembled omni-directional wheel for pool vacuum heads; 
         FIG.  2    illustrates an inside plan view of a frame for the wheel; 
         FIG.  3    illustrates a perspective view of the frame holding rollers; 
         FIG.  4    illustrates an exploded view of the wheel; 
         FIG.  5    illustrates a pool vacuum head bearing several wheels. 
     
    
    
     DESCRIPTION 
     Referring to  FIG.  1   , an omni-directional wheel  10  for a pool vacuum head  12  ( FIG.  5   ) is constructed as a typical omni-directional wheel (i.e., a wheel rotating about an axis with rollers around the perimeter rotating normal to that axis). The wheel  10  includes a first frame  14  or disc frame  14  and a second frame  16  or second disc frame  16  ( FIG.  4   ). Although referred to as different structures for illustration and clarity, the first frame  14  and the second frame  16  are virtually identical and therefore are interchangeable when constructing the wheel  10 . When referring to sub-structures of the first frame  14 , it is to be understood that the second frame  16  has the same sub-structures. 
     Still referring to  FIG.  1   , the first frame  14  includes a central hub  18  rotating around a central or common axis  20  ( FIG.  4   ); i.e., an axis common to the first frame  14  and second frame  16 , and perpendicular to the pool vacuum head&#39;s  12  conventional back-and-forth direction of travel. Multiple lower supports  22 , four in the illustrated embodiment, extend from the central hub  18 . A series of rollers  28  are mounted on the lower supports  22 , allowing the pool vacuum head  12  to roll from side-to-side as well as back-and-forth. The first frame  14  also has upper supports  26  that extend over the rollers&#39;  28  rolling faces  50 . The rolling faces  50  of the rollers  28  preferably textured to provide a gripping surface. 
     Referring to  FIG.  2   , The first frame  14  (and by extension, the second frame  16 ) includes risers  24  extending from the central huh  18  along the common axis  20 . The risers  24  are preferably in a uniform alternating arrangement with the lower supports  22  around the central hub  18 . The uniform alternating nature of the lower supports  22  and the risers  24  allow the first frame  14  to interlock with the second frame  16  in the process of forming a completed wheel  10   
     The upper supports  26  project from the risers  24  to cover the rollers  28 . Distal from the hub  18 , the lower supports  22  each terminate in a lower support head  34  and the upper supports  26  each terminate in an upper support head  36 . In the illustrated embodiment, the lower support heads  34  and the upper support heads  36  are enlarged to support the rollers  28 . Also in the illustrated embodiment, the rollers  28  have spindles  40  that engage the lower support heads  34  and the upper support heads  36  in channels  38  provided formed on either side of each lower support head  34  and upper support head  36 . 
     Still referring to  FIG.  2   , as discussed the lower supports  22  and lower support heads  34  are in a uniform alternating arrangement with the risers  24  and the upper supports  26  and upper support heads  36  that extend from the risers  24 . The arrangement allows the first frame  14  to interlock with the second frame  16  such that the spindles  40  are locked in complementary channels. 
     For locking the first frame  14  and the second frame  16  together, each riser  24  comprises a first post  42  and the hub  18  comprises first bores  44  sized complimentary to first posts  42  to releasably lock the first posts  42  therein. Likewise, the upper support heads  36  comprise second posts  46  and the lower support heads  34  comprise second bores  48  sized complimentary to the second posts  46  to releasably lock the second posts  46  therein. 
     Referring to  FIG.  3   , the first frame  14  is shown with the rollers  28  installed and ready for union with the second frame  16 . Preferably, the risers  24  are disposed at a height such that the upper supports  26  conform to the rolling faces  50  of the rollers  28  while allowing sufficient space to remove the rollers  28  from under the upper supports  26 . Because rollers are of uniform size, and because the first frame  14  and the second frame  16  are virtually identical and complimentary, the wheel  10  can be manufactured easily and inexpensively using only two molds. 
     Referring to  FIG.  4   , the first frame  14  and the second frame  16  are shown in the process of forming the wheel. Although rollers  28  are not shown on the second frame  16  for clarity and purposes of illustration, they would be installed in the same manner as shown on the first frame  14 . The lower supports  22  and the upper supports  28  are uniformly alternating. Because the risers  24  are all of uniform height, when the second frame  16  is brought against the first frame  14 , the rollers  28  are locked in the channels  38 . The wheel  10  is held together since the first posts  42 , first bores  44 , second posts  46  and second bores  48  of the first frame  14  engage those of the second frame  16 . 
     Referring to  FIG.  5   , with the first frame  14  and the second frame  16  assembled with all of the rollers  28 , multiple wheels  10  are ready for installation on a conventional pool vacuum head  12 . Since the rollers are installed on peripheral axes  30  also defined as axis normal to the common axis  20 , they rotate perpendicular to the common axis  20 . The omni-directional nature of the wheels  10  allows the pool vacuum head to roll in a conventional back-and-forth motion, and/or a side-to-side motion as illustrated. 
     The structure of the wheel  10  having been shown and described, its method of use will now be discussed. 
     A plurality of rollers  28  are initially installed on the lower supports  22  of the first frame  14  so that the spindles  40  rest in the channels  38  of the lower support heads  34 , able to rotate freely under the upper supports  26 . A complimentary second frame  16  including rollers  28  similarly installed is interlocked with the first frame  14  thereby creating the wheel  10 . A plurality of wheels  10  are installed in lieu of conventional wheels (not shown) on a pool vacuum head  12 . A user can then vacuum a pool surface (not shown), by rolling the pool vacuum head  12  in any desired direction on the surface. 
     The foregoing description of the preferred embodiment of the Invention is sufficient in detail to enable one skilled in the art to make and use the invention. It is understood, however, that the detail of the preferred embodiment presented is not intended to limit the scope of the invention, in as much as equivalents thereof and other modifications which come within the scope of the invention as defined by the claims will become apparent to those skilled in the art upon reading this specification.