Abstract:
An axle assembly for an in-line skate for retaining a wheel and a pair of bearings in a chassis of the in-line skate. The axle assembly has an elongated spacer hub, for supporting a bearing at each end portion thereof; an elongated male coupler, for bearing on a first side wall of the in-line skate chassis; and an elongated female coupler, for bearing on an opposing second side wall of the in-line skate chassis. The male and female couplers are insertable inwardly through axle bores of the chassis then through opposite ends of the spacer hub to obtain an assembled condition in which the wheel and pair of bearings are retained in the chassis. The male and female couplers are provided with means for interlocking with each other when in the assembled condition, to prevent outwardly movement of the couplers.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/465,033, filed Apr. 25, 2003. 

   FIELD OF THE INVENTION 
   The present invention relates to in-line skates. In particular, it relates to an axle assembly for in-line skates to facilitate replacement of bearings and wheels of the skates. 
   BACKGROUND OF THE INVENTION 
   In-line skating is a popular activity enjoyed by many, both young and old. It is preferred by many as a means for exercising, as it is less demanding of knees and other parts of the body than running or jogging. In-line skating is also done competitively by in-line skating enthusiasts. 
   A plurality of wheels on an in-line skate are typically supported on a chassis of the skate through a pair of bearings disposed at each end of an axle. Various skating surfaces on which skating is carried out, for example asphalt and concrete, can cause rapid wear to contact surfaces of the wheels, which are typically formed of a polymer material. Also, debris found on skating surfaces, such as sand, cinders, slag, or the like can enter the bearings and cause rapid wear of the balls, rollers, or races of the bearings. Therefore, it is advantageous when using in-line skates to have available spare wheels and bearings for replacement, in the event a wheel or bearing becomes worn and unusable. 
   For convenience or to save time, especially when in competition, it is preferred to have an axle assembly which can be quickly disassembled and reassembled. Also, it is preferred to be able to disassemble and assemble the axle assembly without the use of tools such as wrenches, pliers, screw drivers, or the like. 
   Another consideration in an axle assembly is the amount of extension of any axle retaining component beyond the end of the axle, as often, especially in competition, when leaning into a curve the skates are at an angle which places ends of the axles close to the skating surface. An axle assembly having a bulky retaining component or retaining component extending too far beyond the chassis of the skate, could cause a fall if contact is made with the skating surface. 
   Examples of axle assemblies, as just described, are found in U.S. Pat. No. 5,601,342 and U.S. Pat. No. 5,630,652 wherein an axle extends beyond a chassis of the skate and a bulky bolt lever or actuator/cap is used to retain the axle. 
   Another axle assembly, such as that found in U.S. Pat. No. 5,271,633, requires the use of a screw driver in order to disassemble the axle assembly, and a good locking means is not provided to keep the axle assembly from disconnecting during use of the skates. 
   The axle assembly found in U.S. Pat. No. 5,891,115 requires the use of an allen wrench in a drive recess of the axle, in order to assemble the axle assembly. 
   OBJECTS OF THE INVENTION 
   It is an object of the present invention to provide a durable axle assembly for an in-line skate which reliably retains a wheel and bearings in a chassis of an in-line skate. 
   It is another object of the present invention to provide an axle assembly which can be disassembled and assembled without the use of hand tools. 
   It is still another object of the present invention to provide an axle assembly which does not extend beyond the chassis of the skate an amount that would prevent the skater from inclining the skate to the skating surface as may be done when rounding a curve. 
   It is still another object of the invention to provide an axle assembly which is easily useable and with components configured so as to prevent mis-assembly of the axle assembly. 
   SUMMARY OF THE INVENTION 
   The present invention is an axle assembly for an in-line skate, for retaining a wheel and a pair of bearings in a chassis of the in-line skate. The axle assembly has an elongated spacer hub, for supporting a bearing at each end portion thereof. The axle assembly also has a male coupler, for bearing on a first side wall of the in-line skate chassis, and a female coupler, for bearing on an opposing second side wall of the in-line skate chassis. The male and female couplers are insertable inwardly through axle bores of the chassis then into opposite ends of the spacer hub to be in an assembled condition in which the wheels and the pair of bearings are retained in the chassis. Each coupler is provided with means for engaging each other, when the couplers are in the assembled condition, so as to prevent outwardly movement of the couplers. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will become more readily apparent from the following description of a preferred embodiment thereof shown, by way of example only, in the accompanying drawings, wherein: 
       FIG. 1  is a side view of a prior art in-line skate; 
       FIG. 2  is an end view of a portion of the prior art in-line skate of  FIG. 1 ; 
       FIG. 3  is an end view of an in-line skate having an axle assembly of the present invention; 
       FIGS. 4   a–e  are a side view, end views, and sectional views of a spacer hub of the present invention; 
       FIGS. 5   a–d  are a side view, top view, head end view, and engaging end view of a male coupler of the present invention; 
       FIGS. 6   a–d  are a side view, top view, head end view, and engaging end view of a female coupler of the present invention; 
       FIG. 7  is an end view of an in-line skate having an axle assembly of the present invention as arranged for initiation of an assembly process, with a chassis, a wheel, and bearings of the in-line skate shown in section; 
       FIG. 8  is an end view of an in-line skate having an axle assembly of the present invention as arranged following a step of the assembly process for inserting the couplers, with a chassis, a wheel, and bearings of the in-line skate shown in section; and 
       FIG. 9  is an end view of an in-line skate having an axle assembly of the present invention as arranged following a step of the assembly process for engaging the couplers, with a chassis, a wheel, and bearings of the in-line skate shown in section. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention is an axle assembly which could be used by an original equipment manufacturer on new in-line skates, or by owners of in-line skates that wish to improve the performance of their skates by substituting axle assemblies of the present invention for original axle assemblies. The axle assembly of the present invention is configured so as to be useable in most brands of in-line skates. 
     FIGS. 1 and 2  show a side and an end view respectively of conventional in-line skates, having known axle assemblies requiring an allen wrench for disassembling and assembling. The axial assembly of the present invention is configured for use on an in-line skate of this type. 
   In  FIG. 1 , a skate boot  1 , including a sole portion  2 , is attached to an in-line skate chassis  3  having a plurality of wheels  4 . Each wheel is attached to the chassis with use of an axle assembly  5 . The arrangement of a wheel  4  and axle assembly  5  on chassis  3  is better viewed in  FIG. 2 . Referring to  FIG. 2 , chassis  3  includes opposing sidewalls  6  and  7  projecting vertically downward from the body of the chassis. Each sidewall has an axle bore  8  arranged so that the bores of the two sidewalls are in alignment with a central axis  9 . 
   Each wheel, which is typically molded of a polymer material, has bearing cavities  10  molded therein, at both sides of the wheel  4 , which are centered, when assembled, on central axis  9 . Bearings  11  are inserted in the cavities  10  so as to enable nearly frictionless rotation of the wheels on the skate chassis. 
   In mounting the wheels to an in-line skate, as shown in  FIG. 2 , each wheel and pair of bearings is first assembled and then slid into the gap between the side walls  6  and  7  of the chassis  3 , so as to align the centers of the bearings with the centers of the axle bores. Then, each portion of the axle assembly  5  is inserted through one of the sidewalls ( 6 ,  7 ) and one of the pair of bearings  11 . The axle is secured in that arrangement by using allen wrenches to thread an external thread of one portion into an internal thread of the other portion. The prior in-line skate of  FIGS. 1 and 2  is only one example of many axle assemblies which are available. However, the chassis, arranged with the opposing sidewalls and axle bores, are found on many brands of in-line skates. 
   As discussed above, the present axle assembly is configured to replace most axle assemblies as known and described in  FIG. 2 , without the need for modification to the chassis  3 , wheel  4  or bearings  11 . 
     FIG. 3  shows an axle assembly  13  of the present invention in place on a conventional in-line skate. In  FIG. 3 , wheel  4  having bearings  11 , is mounted to chassis  3  having sidewalls  6  and  7  with axle bores  8 . In the present invention, axle assembly  13 , is made up of a spacer hub  14 , a male coupler  15 , and a female coupler  16 , which, when assembled, reliably holds the wheel  4  and bearings  11  in place on chassis  3 . Details of each of the components, spacer hub  14  and couplers  15 ,  16  are shown in detail in  FIGS. 4   a–e ,  5   a–d , and  6   a–d , and described below. 
   In  FIGS. 4   a–e , various views of the spacer hub  14  are shown.  FIG. 4   a  is a side view,  FIGS. 4   b  and  4   c  are opposing end views, and  FIGS. 4   d  and  4   e  are sectional views of sections A—A and B—B (indicated in  FIG. 4   b ) respectively. The various portions of the spacer hub  14  are locking chamber  17 , and coupler shaft receiving cylinders  18  and  19 . Each coupler shaft receiving cylinder  18  and  19  extends from an end of the coupler to the locking chamber  17 . Preferably, locking chamber  17  is cylindrical in shape and each coupler shaft receiving cylinder is generally cylindrical in shape, except for opposing locking arm entry grooves  20  extending lengthwise in sidewalls of the cylinders, along the entire length of the cylinders. The diameter of each of the coupler shaft receiving cylinders  18  and  19  is preferably the same and is less than the diameter of the locking chamber  17 , in order to form locking shoulders  21 , the function of which is described below. 
   An external surface of the spacer hub  14  has bearing support surfaces  22  at each end and spacing shoulders  23  which are formed at both ends of a central portion  24  of the spacer hub. Central portion  24  has a diameter which is greater than a diameter of the bearing support surfaces  22 . An inner race of each bearing  11  bears on the bearing support surface of the spacer hub when the axle assembly is in place. The spacer hub  14  has nearly a mirror image symmetry about a central plane which is parallel to the ends of the spacer hub, with the exception that the opposing locking arm entry grooves are rotated 90° about central axis  25 , as best seen by comparing  FIG. 4   b  with  FIG. 4   c . Because of such symmetry, the spacer hub cannot be inserted incorrectly during assembly. In assembling the axle assembly, the spacing hub is first placed through a bore in wheel  4 , and then each bearing  11  is slid over the bearing support surface  22  and into bearing cavity  10 . The assembled spacing hub, wheel, and bearings are then slid between the chassis sidewalls  6  and  7  (see  FIG. 3 ) until the central axis  25  of the spacer hub is in alignment with a central axis of the aligned axle bores  8  in the chassis side walls  6  and  7 . 
     FIGS. 5   a–d  and  6   a–d  show male coupler  15  and female coupler  16  of the present axle assembly. In  FIGS. 5   a–d , male coupler  15  has head  26 , chassis shoulder  27 , shaft  28 , and locking arms  29 . Chassis shoulder  27  is dimensioned to enable it to be pressed by hand into one of the axle bores  8  of the chassis side walls  6  and  7 . Head  26  limits entry of the chassis shoulder into the axle bore and also functions as a means for rotating the coupler into an engaged condition, as described below. Head  26  includes wings  30  which can be grasped between the thumb and index finger of the user to perform the engaging step. The wings have dimensions to provide adequate leverage, when rotating the coupler, but are not oversized, so as to reduce the chance of the wings contacting the skating surface during use, as discussed above. Coupler shaft  28  is dimensioned to slide freely into the coupler shaft receiving cylinder  18  or  19  of the spacer hub  14  during assembly. A clearance of about 0.001–0.004 inch is preferred between surfaces of the coupler shaft and the coupler shaft receiving cylinder. At an end of the male coupler, which is opposite the end having head  26 , are disposed opposing locking arms  29 . The opposing locking arms  29  extend laterally outward from the coupler and engage portions of the female coupler  16  when the axle assembly is fully assembled. The locking arms preferably are symmetric about axis  31  of the coupler. A dimension w, indicated in  FIG. 5   a , is arranged to be greater than a diameter of the coupler shaft receiving cylinders  18  and  19 , but lesser than the diameter of the locking chamber  17  of the spacer hub  14 . The dimension w,  FIG. 5   a , and a dimension t,  FIG. 5   d  are selected to provide a sliding fit, without use of tools, into locking arm entry grooves  20 . A clearance of about 0.003 to 0.008 inch between the locking arms  29  and the locking arm entry grooves  20  is preferred. 
   With reference to  FIGS. 6   a–d , female coupler  16  has head  32 , chassis shoulder  33 , shaft.  34 , and locking arms  35 . As in the male coupler, the head  32 , chassis shoulder  33 , and shaft  34  perform the same functions and are dimensioned as discussed above in describing the male coupler. Because of the near mirror image symmetry of the spacing hub  14 , as discussed above, the selected end of the spacer hub, into which either the male or the female coupler is inserted, is interchangeable, so the user cannot make a mistake in that regard when assembling the axle assembly. In addition to the above-described components of the female coupler, the female coupler also includes means for interlocking with the locking arms  29  of the male coupler. Included in the interlocking means of the female coupler  16  are interlocking grooves  36  into which the locking arms  29  of the male coupler slide, and interlocking groove extensions  37  into which the locking arms  29  of the male coupler rotate when the couplers are interlocked. The interlocking grooves  36  and interlocking groove extensions  37  communicate with each other and also with interlocking cavity  38 . Although only one of the interlocking grooves  36  and groove extensions  37  can be seen in  FIG. 6   d , another interlocking groove and groove extension is present on an opposing side of the female coupler. The pair of interlocking grooves and groove extensions are symmetric about a central axis  39 . The communicating components of the male and female couplers are dimensioned so as to enable the locking arms  29  of the male coupler to freely enter the interlocking grooves  36  and interlocking groove extensions  37  of the female coupler during an assembly process, which is described below. The female coupler  16  also has wings  40  on head  32  for use in rotating the female coupler about its central axis  39  for interlocking the male and female couplers. 
   Referring to  FIGS. 7 ,  8 , and  9 , the assembly process is described.  FIG. 7  shows the wheel  4 , bearings  11 , spacer hub  14 , and chassis side walls  6  and  7  in section, in a vertical plane which includes a central axis  25  of the spacer hub. As mentioned above, the wheel  4 , bearings  11 , and spacer hub  14  are first assembled and are then slid between the opposing chassis side walls  6  and  7 , so that spacer hub axis  25  is aligned with a central axis of the aligned axle bores  8  of the sidewalls  6  and  7  of the chassis. 
   Following that initial step, a second step, the beginning of which is depicted in  FIG. 7 , is to slide the male and female couplers  15 ,  16  into the spacer hub  14 . The procedure for the male coupler is identical to the female coupler and includes passing the coupler through the axle bore  8  and through the coupler shaft receiving cylinder  18  or  19 . As mentioned above, it does not matter which coupler is inserted into a selected end of the spacer hub. During the insertion, when the locking arms reach the outer end of the spacer hub, it may be necessary to rotate the coupler about its central axis, in order to line up the locking arms with the locking arm entry grooves  20 . The locking arms, locking arm entry grooves, and coupler shaft receiving cylinders are dimensioned so that the central axes of the spacing hub  14  and couplers  15  and  16  are forced into alignment when the above-described assembly step is carried out. 
   Following alignment of the locking arms and locking arm entry grooves, the coupler is slid all the way into the hub until the head of the coupler stops against an outside surface of the chassis side wall  6  or  7 .  FIG. 8  shows the axle assembly following such step, when both the male and female couplers are inserted. The locking arms  29  of the male coupler  15  are nested in the interlocking grooves  36  of the female coupler, as shown at indicator  41  of  FIG. 8 . Although nested, the couplers are not interlocked, at this point. During the insertion step the male and female couplers must be maintained in the rotational alignment established by the locking arm entry grooves  20  of the spacer hub  14  in order that the interlocking means are in alignment for nesting. If such rotational alignment is lost, a slight rotation of one of the couplers easily brings the components into alignment. 
   In a last step of the assembly process, as depicted in  FIG. 9 , one or both of the couplers are rotated about its central axis, so as to interlock the locking arms  29  of the male coupler in the interlocking groove extension  37  of the female coupler  16 , as depicted at  42  of  FIG. 9 . Such interlocking prevents movement of the couplers outwardly in opposing axial directions. Thus the entire axle, bearings and wheel assembly is securely held in place. 
   As an added measure to more positively maintain the interlocking arrangement, the couplers can be magnetized to provide a magnetic attraction between interlocking ends of the couplers. 
   The components of the present invention are preferably fabricated of steel or stainless steel, however lighter weight materials such as aluminum, magnesium or titanium are possible in practice of the invention. 
   Fabrication of the components of the axle assembly can be carried out by machining, casting, powdered metallurgical or other fabricating methods. 
   While specific materials, dimensional data, etc. have been set forth for purposes of describing the invention, various modifications can be resorted to, in light of the above teachings, without departing from Applicant&#39;s novel contributions; therefore in determining the scope of the present invention, reference shall be made to the appended claims.