Abstract:
A speed limited wheel includes a wheel main body defining a cavity, a urethane wheel outer overmolded to the cavity, a brake hub and a plurality of brake elements. The brake hub is disposed in the cavity and includes a cylindrical flange. The wheel main body is rotatable relative to the brake hub about a wheel rotational axis. The plurality of brake elements is disposed in the cavity and is circumferentially surrounded by the cylindrical flange of the brake hub. Each brake element is pivotally mounted to the wheel main body for pivoting between a first position spaced apart from a cylindrical flange of the brake hub and a second position engaging the cylindrical flange of the brake hub for generating friction to reduce a rotational speed of the wheel. The speed limited wheel may be a caster.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 62/082,183 filed 20 Nov. 2015, which application is herein expressly incorporated by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to wheels such as casters and wheels for skateboards, roller skates, in-line skates and the like. The casters may be used for material handling carts, industrial carts, various vehicles, medical transportation devices, chairs and other items conventionally including casters. The present disclosure more particularly relates to speed limited wheels for such applications. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0004]    Various devices are provided with wheels for increased mobility. For example, material handling carts, industrial carts, various vehicles, medical transportation devices, chairs are conventionally provided with wheels in the form of casters. Skateboards, roller skates, in-line skates and the like are also conventionally provided with a plurality of wheels. It is generally desirable to reduce the rolling friction of these wheels for the ease of use and to improve overall performance. In some circumstances, however, it may be desirable to limit or dampen the rotation speed of such wheels. 
         [0005]    While known wheels, including casters, may have proven to be suitable for their intended purposes, a continuous need for improvement exists. 
       SUMMARY 
       [0006]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0007]    According to a particular aspect, the present teachings provide a speed limited wheel including a first member, a second member and a plurality of brake elements. The first member is rotationally supported on an axle by at least one bearing for rotation about a rotational axis. The first member is able to rotate relative to the second member. The plurality of brake elements are pivotally mounted to the first member for pivoting between a first position spaced apart from a cooperating surface of the second member and a second position engaging the cooperating surface of the second member for generating friction to reduce a rotational speed of the wheel. 
         [0008]    According to another particular aspect, the present teachings provide a speed limited wheel, a wheel main body defining a cavity, a urethane wheel outer overmolded to the cavity, a brake hub and a plurality of brake elements. The brake hub is disposed in the cavity and includes a cylindrical flange. The wheel main body is rotatable relative to the brake hub about a wheel rotational axis. The plurality of brake elements is disposed in the cavity and is circumferentially surrounded by the cylindrical flange of the brake hub. Each brake element is pivotally mounted to the wheel main body for pivoting between a first position spaced apart from the cylindrical flange of the and a second position engaging the cylindrical flange of the brake hub for generating friction to reduce a rotational speed of the wheel. 
         [0009]    According to yet another particular aspect, the present teachings provide a method of reducing a rotational speed of a wheel having a wheel main body defining a cavity. The method includes disposing a brake hub in the cavity. The brake hub includes a cylindrical flange. The wheel main body is rotatable relative to the brake hub about a wheel rotational axis. The method additionally includes pivotally mounting a plurality of brake elements to the wheel main body. The method further includes pivoting each brake element between a first position spaced apart from the cylindrical flange of the second member brake hub and a second position engaging the cylindrical flange of the brake hub generating friction to reduce a rotational speed of the wheel. 
         [0010]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0012]      FIG. 1A  is a perspective view of a speed limited wheel constructed in accordance with the present teachings. 
           [0013]      FIG. 1B  is a partially exploded view of the speed limited wheel of  FIG. 1A . 
           [0014]      FIG. 1C  is a front view of the speed limited wheel of  FIG. 1A . 
           [0015]      FIG. 1D  is a sectional view taken along the line  1 D- 1 D of  FIG. 1C . 
           [0016]      FIG. 1E  is a side view of the speed limited wheel of  FIG. 1A . 
           [0017]      FIG. 1F  is a rear view of the speed limited wheel of  FIG. 1A . 
           [0018]      FIG. 2A  is a perspective view of a wheel main body and overmold subassembly of the speed limited wheel of  FIG. 1A . 
           [0019]      FIG. 2B  is a front view of the wheel main body and overmold subassembly of the speed limited wheel of  FIG. 2A . 
           [0020]      FIG. 2C  is a cross-sectional view of the wheel main body and overmold subassembly of the speed limited wheel of  FIG. 2A  taken along the line  2 C- 2 C of  FIG. 2B . 
           [0021]      FIG. 2D  is a rear view of the wheel main body and overmold subassembly of the speed limited wheel of  FIG. 2A . 
           [0022]      FIG. 3A  is perspective view of the wheel main body of the speed limited wheel of  FIG. 1A . 
           [0023]      FIG. 3B  is another perspective view of the wheel main body of  FIG. 3A . 
           [0024]      FIG. 3C  is a front view of the wheel main body of  FIG. 3A . 
           [0025]      FIG. 3D  is a sectional view of the wheel main body of  FIG. 3A  taken along the line  3 D- 3 D of  FIG. 3C . 
           [0026]      FIG. 3E  is a side view of the wheel main body of  FIG. 3A . 
           [0027]      FIG. 3F  is a rear view of the wheel main body of  FIG. 3A . 
           [0028]      FIG. 4A  is perspective view of a bushing/brake body of the speed limited wheel of  FIG. 1A . 
           [0029]      FIG. 4B  is another perspective view of the bushing/brake body of  FIG. 4A . 
           [0030]      FIG. 4C  is a front view of the bushing/brake body of  FIG. 3A . 
           [0031]      FIG. 4D  is a sectional view of the bushing/brake body of  FIG. 4A  taken along the line  4 D- 4 D of  FIG. 4C . 
           [0032]      FIG. 4E  is a side view of the bushing/brake body of  FIG. 3A . 
           [0033]      FIG. 4F  is a sectional view of the bushing/brake body of  FIG. 4A  taken along the line  4 F- 4 F of  FIG. 4E . 
           [0034]      FIG. 5A  is perspective view of a bushing/brake body and overmold subassembly of the speed limited wheel of  FIG. 1A . 
           [0035]      FIG. 5B  is side view of the bushing/brake body and overmold subassembly of  FIG. 5A . 
           [0036]      FIG. 5C  is a rear view of the bushing/brake body and overmold subassembly of  FIG. 5A . 
           [0037]      FIG. 5D  is a sectional view of the bushing/brake body and overmold subassembly of  FIG. 5A  taken along the line  5 D- 5 D of  FIG. 5C . 
           [0038]      FIG. 6A  is a perspective view of one of the brake elements of the speed limited wheel of  FIG. 1A . 
           [0039]      FIG. 6B  is another perspective view of the brake elements of  FIG. 6A . 
           [0040]      FIG. 6C-6H  are various other views of the brake elements of  FIG. 6A . 
           [0041]      FIG. 7A  is a perspective view of a cover of the speed limited wheel of  FIG. 1A . 
           [0042]      FIG. 7B  is another perspective view of the cover of  FIG. 7A . 
           [0043]      FIG. 7C  is a front view of the cover of  FIG. 7A . 
           [0044]      FIG. 7D  is a cross-sectional view of the cover of  FIG. 7A  taken along the line  7 D- 7 D of  FIG. 7C . 
           [0045]      FIG. 7E  is a side view of the cover of  FIG. 7A . 
           [0046]      FIG. 7F  is a rear view of the cover of  FIG. 7A . 
           [0047]      FIG. 8A  is a perspective view of a plate of the speed limited wheel of  FIG. 1A . 
           [0048]      FIG. 8B  is another perspective view of the plate of  FIG. 8A . 
           [0049]      FIG. 8C  is a front view of the plate of  FIG. 8A . 
           [0050]      FIG. 8D  is a cross-sectional view of the plate of  FIG. 8A  taken along the line  8 D- 8 D of  FIG. 8C . 
           [0051]      FIG. 8E  is a side view of the plate of  FIG. 8A . 
           [0052]      FIG. 8F  is a rear view of the plate of  FIG. 8A . 
           [0053]      FIG. 9  is a perspective view of another speed limited wheel constructed in accordance with the present teachings, the wheel illustrated as a caster and shown operatively associated with a caster bracket. 
           [0054]      FIG. 10  is another perspective view of the caster and caster bracket of  FIG. 9 . 
           [0055]      FIG. 11  is a perspective side view of the caster of  FIG. 9 . 
           [0056]      FIG. 12  is another perspective view of the caster of  FIG. 9 . 
           [0057]      FIG. 13  is another perspective view of the caster of  FIG. 9 . 
           [0058]      FIG. 14  is a perspective view of another speed limited wheel constructed in accordance with the present teachings, the wheel illustrated as a caster and shown operatively associated with a caster bracket. 
           [0059]      FIG. 15  is another perspective view of the caster and caster bracket of  FIG. 14 . 
           [0060]      FIG. 16  is a perspective side view of the caster of  FIG. 14 . 
           [0061]      FIG. 17  is another perspective view of the caster of  FIG. 14 . 
           [0062]      FIG. 18  is a perspective view of another speed limited wheel constructed in accordance with the present teachings, the wheel illustrated as a caster and shown operatively associated with a caster bracket. 
           [0063]      FIG. 19  is another perspective view of the caster and caster bracket of  FIG. 18 . 
           [0064]      FIG. 20  is a perspective side view of the caster of  FIG. 18 . 
           [0065]      FIG. 21  is another perspective view of the caster of  FIG. 18 . 
           [0066]      FIG. 22  is another perspective view of the caster of  FIG. 18 . 
       
    
    
       [0067]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0068]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0069]    With general reference to  FIGS. 1A through 8F  of the drawings and particular reference to  FIGS. 1A and 1B  thereof, a first speed limited wheel in accordance with the teachings of the present invention is illustrated and generally identified at reference character  10 . As will become clear from the following description, the speed limited wheel  10  may be particularly adapted to dampen rotational speeds through frictional loading. In one particularly application, the speed limited wheel  10  may be used on a skateboard, for example. The skateboard may include one or more speed limited wheels  10 . The speed limited wheel  10  may also be used for conventional roller skates, in-line skates and other application in which it may be desired to limit or dampen speed. It will be appreciated (and specifically described below) that the present teachings may be incorporated into a wheel in the form of a caster. 
         [0070]    With particular reference to the exploded view of  FIG. 1B , the speed limited wheel  10  is illustrated to generally include a first member  12  and a second member  14 . The first member may be an outer member in the form of a wheel main body and overmold subassembly  12 . The second member may be an inner member in the form of a bushing/brake body and overmold subassembly  14 . Additionally, the speed limited wheel  10  may include a plurality of brake elements  16 . Further, the speed limited wheel  10  may include a pair of bearings  18 , a plate  20  and cover  22 . 
         [0071]    The wheel main body and overmold subassembly  12  is shown in more detail in  FIGS. 2A-2D . The main body  24  of the subassembly  12  is shown particularly in  FIGS. 3A-3F . The main body  24  may be injected molded of a plastic material, for example. An outer surface  12 A of the wheel main body and overmold subassembly  12  may be overmolded to the main body in any manner well known in the art. In one application, the overmold material is urethane. A rear side of the main body may define a cavity for receiving the plurality of brake elements  16  and the bushing/brake body and overmold  14 . At a radially outermost portion, the cavity has a greater width as compared to a center thereof. A front side of the wheel main body and overmold subassembly  12  is adapted to conventionally receive one of the bearings  18 . 
         [0072]    The bushing/brake body and overmold subassembly  14  is shown in more detail in  FIGS. 5A-5D . The main body or brake hub  26  of the bushing/brake body and overmold subassembly  14  is shown particularly in  FIGS. 4A-4F . The main body  26  may be constructed of metal such as aluminum, for example. The inner surface of the main bushing/brake body and overmold subassembly  14  may be overmolded to the main body  26  in any manner well known in the art. In one application, the overmold material may be ceramic, rubber or any other suitable material. The front side of the main body  26  defines a cavity for receiving the plurality of brake elements  16 . At a radially outermost portion, the cavity has a greater width as compared to a center thereof. Upon assembly of the speed limited wheel  10 , the bushing/brake body and overmold subassembly  14  is clamped between the inner races of the bearings  18  with suitable washers. As the inner races of the bearings  18  do not rotate relative to the axle shaft, the bushing/brake body and overmold subassembly  14  is similar held non-rotationally with respect to the axle shaft. 
         [0073]    With reference to  FIGS. 6A-6H , one of the brake elements  6  of the speed limited wheel is further illustrated. It will be understood that the remaining brake elements  16  are substantially identical. In the embodiment illustrated, the speed limited wheel  10  is shown to include three (3) brake elements  16 . Those skilled in the art will appreciate that the speed limited wheel  10  may be constructed to include a greater or lesser number of brake elements  16  within the scope of the present teachings. 
         [0074]    Each brake element  16  is shown to define a convexly curved friction surface  16 A. The brake elements  16  may be independently coupled to the wheel main body and overmold subassembly  12  such that the brake elements  16  each rotate with the wheel main body and overmold subassembly  12  about a rotational axis of the wheel main body and overmold subassembly  12  and may pivot about an axis parallel to the rotational axis of the wheel main body and overmold subassembly  12 . In the particular embodiment illustrated, each of the brake elements may have a weight of approximately 50 grams. This weight will be understood to be merely exemplary and may be modified for particular applications within the scope of the present teachings. 
         [0075]    At one end of each of the brake elements  16 , a tab  16 B is provided at an inner surface. The tab  16 B includes a hole  16 C for receiving a fastener  28 . The fastener  28  attaches the brake element  16  to the wheel main body and overmold subassembly  12 . The fastener  28  defines the pivot axis about which the brake weight  16  may pivot. At an opposite end, each of the brake elements  16  defines a slot  16 D that receives a roll pin  30 . The roll pin  30  attaches to a spring  32 . The spring  32  is associated with each of the brake elements  16 . As the rotational speed of the wheel increases, the brake elements  16  are forced radially outward to engage a cooperating surface of the bushing/brake body and overmold subassembly  14 . This engagement or rubbing produces friction that limits or dampens the rotational speed of the wheel  10 . As the wheel  10  rotates faster, the frictional force increases. The strength of the springs  32  on the brake elements  16  predetermines the wheel rotational speed at which the brake elements  16  start rubbing the bushing/brake body and overmold subassembly  14  and apply friction. The springs  32  also determine how much force is applied along with the size of the weights. 
         [0076]    The plate  20  is shown in further detail in  FIGS. 8A-8F . The plate  20  is particularly adapted to fasten to the main body  24 . The plate  20  defines three (3) screw holes  20 A which correspond with the screws  28  that secure the brake elements  16  to the wheel main body and overmold subassembly  12 . 
         [0077]    Turning to  FIGS. 7A-7F , the cover  22  is further shown. The cover  22  mounts to the wheel main body and overmold subassembly  12  for rotation therewith and covers the cavity defined by the wheel main body and overmold subassembly  12 . A plurality of fasteners  28  are used to secure the cover  22 . A rear face of the cover  22  defines a recess for accommodating one of the bearings  18 . An axle shaft (not specifically shown) passes through wheel  10  and is rotationally supported by the bearings  18 . 
         [0078]    Turning to  FIGS. 9-13 , another speed limited wheel in accordance with the present teachings is illustrated and identified at reference character  100 . The speed limited wheel is specifically embodied as a caster. It will be understood that the components of the caster  100  and the speed limited wheel  10  of  FIG. 1A  are substantively identical construction and function to the extent not otherwise detailed herein. Like reference characters will be used in the drawings to identify like components. As compared to the wheel  10 , the caster  100  provides an arrangement for dual-direction braking. 
         [0079]    In  FIGS. 9 and 10 , the caster  100  is shown operatively associated with a caster bracket  102 . The caster bracket  102  may function to couple the caster with a chair, other article of furniture, or the like. It will be understood that the caster bracket  102  may be conventional in construction and operation. 
         [0080]    The caster  100  is illustrated to include a plurality of brake elements  16 . In the embodiment illustrated, the caster  100  is shown to include two (2) brake elements  16 . Those skilled in the art will appreciate that the caster  100  may be alternatively constructed to include a greater or lesser number of brake elements  16  within the scope of the present teachings. For purposes of providing dual direction braking, the brake elements  16  pivot in opposite directions for frictionally engaging the main body  24  of the subassembly  14 . As shown in  FIG. 12 , for example, the upper illustrated brake element  16  pivots counterclockwise for frictional engagement and the lower illustrated brake element  16  pivots clockwise for frictional engagement. 
         [0081]    As the rotational speed of the caster  100  increases, the brake elements  16  are forced radially outward to engage the cooperating surface of the bushing/brake body and overmold subassembly  14 . This engagement or rubbing produces friction that limits or dampens the rotational speed of the caster  100 . As the caster rotates faster, the frictional force increases. As before, the strength of the springs on the brake elements  16  predetermines the caster rotational speed at which the brake elements  16  start rubbing the bushing/brake body and overmold subassembly  14  and apply friction. The springs also determine how much force is applied along with the size of the weights. 
         [0082]    With reference now to  FIGS. 14-17 , another speed limited wheel in accordance with the present teachings is illustrated and identified at reference character  200 . The speed limited wheel is again embodied as a caster  200 . It will be understood that the components of the caster  200  is substantively identical to the embodiments  10  and  100  described above to the extent not otherwise detailed herein. Again, like reference characters will be used to identify like elements. The caster  200  primarily differs from the prior described embodiments in that the amount of pressure applied to the internal hub may be adjusted to provide braking at different rotational speeds. As illustrated, a plurality of holes in the stationary and cam plate  20  are provided for selectively receiving each of fasteners  28 . With reference to  FIGS. 17, 21 and 22 , the fasteners  28  are shown engaging the clockwise-most hold of each plurality of holes. Engagement of the fasteners  28  with the middle hole of each plurality of holes functions to increase the amount of frictional braking. In the same regard, engagement of the fasteners  28  with the counterclockwise-most hole of each plurality of holes still further increases the amount of frictional braking. 
         [0083]    Turning finally to  FIGS. 18-22 , another speed limited wheel in accordance with the present teachings is illustrated. The speed limited wheel is again embodied as a caster and identified at reference character  200 . It will be understood that the components of the caster  100  are substantively identical to the components of the previously described embodiments to the extent not otherwise detailed herein. Again, like reference characters will be used to identify like elements. The caster primarily differs from the prior described embodiments in that the brake elements  16  may be locked against the internal hub to prevent rotation. 
         [0084]    As illustrated, the caster  300  includes a lock device  302 . The lock device  302  may include a manually controlled key  304 . The key  304  may be rotated in a first direction (e.g., clockwise) to lock the brake elements  16  against the inner hub and a second direction (e.g., counterclockwise) to unlock the brake elements  16 . The pinholes in the plate  20  show the attachment points for the springs  32 . Clockwise rotation of the key  304  puts more tension on the springs  32  for locking the brake elements  304 . 
         [0085]    The foregoing description of the embodiment(s) has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. One or more example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.