Patent Publication Number: US-2012031522-A1

Title: Motorcycle Fork Oil Changer and Method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     This invention pertains to motorcycle maintenance. More particularly, this invention pertains to an apparatus useful in removing and replacing motorcycle fork oil in a motorcycle fork tube. 
     2. Description of the Related Art 
     In several designs of modern-day motorcycles, a motorcycle fork is provided which is pivotally secured in relation to the motorcycle&#39;s frame to connect the motorcycle&#39;s front wheel and axle to its frame. The motorcycle fork typically incorporates a front suspension system and a front wheel brake, and allows the motorcycle to be steered via handlebars fixed in relation to the fork. A common form of motorcycle fork commercially available is a telescopic fork. The telescopic fork typically includes a pair of fork tubes, with one fork tube slidably received within the other fork tube such that the fork tubes are telescopically extendable. The telescopic fork contains several suspension components internally and is designed to compress and extend to adjust for inconsistencies in the riding surface during normal operation of the motorcycle. More specifically, a the telescopically extendable fork tubes contains springs, fork oil, and air, thereby creating a shock absorber for adjusting shock imparted to the front wheel of the motorcycle. 
     In normal operation of a motorcycle, dust and other fouling gradually accumulates in the fork oil, thereby degrading the performance of the fork. Thus, it is recommended that the fork oil be periodically changed as part of normal maintenance of the motorcycle. In several telescopic fork designs, a small, threaded drain hole is provided in the outer fork tube with a threaded bolt removably received therein, such that removal of the threaded bolt from the drain hole allows fork oil to drain from within the fork tubes. However, absent suitable means to collect the fork oil as it drains from the drain hole, the draining fork oil can often spill onto the exterior of the fork and nearby surfaces, making draining of the fork oil a messy operation. Moreover, the drain hole is typically too small to allow efficient replacement of drained fork oil into the fork tubes through the drain hole. Thus, complete disassembly and reassembly of the motorcycle fork, a complicated and difficult process, is required to allow replacement of the fork oil into the fork tubes. 
     In light of the above, an apparatus allowing for faster, cleaner, and more convenient changing of motorcycle fork oil is desired. 
     BRIEF SUMMARY OF THE INVENTION 
     A motorcycle fork oil changer useful in draining and replacing the fork oil in a motorcycle fork and an associated method for draining and replacing the fork oil in a motorcycle fork are disclosed. The motorcycle fork oil changer includes a nozzle defining a through opening. The nozzle is adapted to be releasably secured to a motorcycle fork adjacent a drain hole in the motorcycle fork such that the drain hole is placed in at least liquid-tight, fluid communication with the through opening. A plurality of conduits are provided to allow the through opening of the nozzle to be selectively placed in fluid communication with at least one fluid reservoir to facilitate movement of fluid between the reservoir and the motorcycle fork through the drain hole. A valve is provided to regulate fluid flow along the conduits, thus allowing the valve to regulate fluid flow between the fluid reservoir and the drain hole. 
     A method for operating the motorcycle fork oil changer to accomplish draining and replacing fork oil in a motorcycle fork is also disclosed. In an initial step, the nozzle of the motorcycle fork oil changer is attached to the motorcycle fork with the through opening sealed against the drain hole. Following attachment of the nozzle, a measure of pressurized gas is introduced into the motorcycle fork through the through opening. The valve of the motorcycle fork oil changer is closed to preserve the pressure within the motorcycle fork. The motorcycle fork is positioned such that the drain hole of the motorcycle fork is lower than the surface of the fork oil within the motorcycle fork. The valve is then opened to drain the fork oil from the motorcycle fork. Once at least a portion of the fork oil is drained from within the motorcycle fork, a vacuum source is placed in fluid communication with the motorcycle fork oil changer to create a vacuum within the motorcycle fork. The valve is closed to preserve the vacuum within the motorcycle fork. The motorcycle fork oil changer is then placed in fluid communication with a replacement oil source. The valve is opened, thus allowing replacement oil to be introduced to the motorcycle fork interior. Following introduction of replacement fork oil into the motorcycle fork, the motorcycle fork oil changer is disconnected from the motorcycle fork. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The above-mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which: 
         FIG. 1  is a perspective view of one embodiment of a motorcycle fork oil changer showing several features of the present invention; 
         FIG. 2  is a cross-sectional side view of the nozzle portion of the motorcycle fork oil changer of  FIG. 1 ; 
         FIG. 3  is a side elevation view showing the motorcycle fork oil changer of  FIG. 1  adjacent a telescopic motorcycle fork, with various fluid reservoirs illustrated schematically; 
         FIG. 4  is a flow diagram illustrating one embodiment of a method for draining and replacing fork oil in an motorcycle fork of the present invention; 
         FIG. 5  is a flow diagram showing in greater detail the method of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A motorcycle fork oil changer useful in draining and replacing the fork oil in a motorcycle fork and an associated method for draining and replacing the fork oil in a motorcycle fork are disclosed. The motorcycle fork oil changer, or changer, is referred to at  10  herein and in the accompanying Figures. The changer  10  provides a tool for establishing fluid communication with a plurality of fluid reservoirs  60  to allow for movement of fluid into and out from within a motorcycle fork tube through a conventional motorcycle fork drain hole in order to assist in changing the fork oil in the motorcycle fork. 
       FIG. 1  illustrates a perspective view of one embodiment of a changer  10 . As shown in  FIG. 1 , the changer  10  includes a nozzle  12  defining a through opening  14 . The nozzle  12  is adapted to be releasably secured to a motorcycle fork  70  adjacent a drain hole  72  in the motorcycle fork such that the drain hole is placed in at least liquid-tight, fluid communication with the through opening  14  (see  FIGS. 2 and 3 ). As will be described in further detail below, a plurality of conduits  16 ,  54  are provided to allow the through opening  14  of the nozzle  12  to be selectively placed in fluid communication with at least one fluid reservoir  60  to facilitate movement of fluid between the reservoir  60  and the motorcycle fork through the drain hole. A valve  20  is provided to regulate fluid flow along the conduits  16 ,  54 , thus allowing the valve  20  to regulate fluid flow between the fluid reservoir  60  and the drain hole. 
       FIG. 2  illustrates a cross-sectional view of the nozzle  12  portion of the changer  10  of  FIG. 1 . As shown in  FIG. 2 , the nozzle  12  includes a substantially rigid central tube  24  having a first end  26  and a second end  32 . A first flexible elongated conduit  16  is provided having a first end  18  secured to the first end  26  of the central tube  24 . In the illustrated embodiment, the central tube first end  26  defines an outer threaded portion  28 . The first conduit first end  18  is threaded onto the outer threaded portion  28  of the central tube first end  26  to establish a substantially liquid-tight connection between the central tube first end  26  and the first conduit first end  18 . In another embodiment, the central tube first end  26  is received within the first conduit first end  18  to create a frictional connection between the central tube first end  26  and the first conduit first end  18 . Those skilled in the art will recognize other means for securing the central tube first end  26  to the first conduit first end  18 , such as by mechanical fastening means, welds, adhesives, or by providing a central tube  24  and first conduit  16  as an integral unit, and such other securing means may be used without departing from the spirit and scope of the present invention. 
     A gasket  30  is provided to extend from the second end  32  of the central tube  24 . The gasket  30  is sized to neatly surround a conventional motorcycle fork drain hole  72  and is adapted to engage the portions of the motorcycle fork  70  surrounding the drain hole  72  to establish an at least liquid-tight seal between the drain hole  72  and the central tube  24 . In the illustrated embodiment, the gasket  30  surrounds the second end  32  of the central tube  24  and extends from the first conduit first end  18  along the outer surface of the central tube  24  and beyond the central tube second end  32  to allow abutment of the gasket  30  between the motorcycle fork tube and the central tube  24 . 
     A connector  38  is provided to secure the nozzle  12  in place against the motorcycle fork adjacent the drain hole. In the illustrated embodiment, the connector  38  includes a plate  42  having a through bore  44  defining a substantially circular inner lip  40 . An outer surface  34  of the gasket  30  defines an annular indentation  36  sized to receive the inner lip  40  of the plate  42  therein and to engage the inner lip  40  to hold the plate  42  fixed in relation to the gasket  30  such that the plate  40  extends outwardly from the gasket  30  substantially perpendicular to the central tube  24 . A first peripheral end  46  and opposite second peripheral end  48  of the plate  42  define curved portions extending rearwardly of the through bore  44  toward the central tube first end  26 . The curved portions of the first and second peripheral ends  46 ,  48  serve as hooks which are adapted to engage at least one binding (not shown) to bind the nozzle  12  in place against the motorcycle fork  70  adjacent the drain hole  72 . In this manner, the nozzle  12  is adapted to be releasably secured to the motorcycle fork  70  proximate the drain hole  72 . Those skilled in the art will recognize other configurations and devices suitable to allow the nozzle  12  to be releasably secured to the motorcycle fork  70  proximate the drain hole  72 , and such other configurations or devices may be used without departing from the spirit and scope of the present invention. 
     It will further be understood that, while the nozzle  12  of the present embodiment includes discreet gasket  30 , central tube  24 , and connector  38  components, each of these components may be integrally formed with other components of the nozzle  12 . For example, in one embodiment, the gasket  30  and the central tube  24  are provided as an integral unit. In another embodiment, the gasket  30 , central tube  24 , and connector  38  are collectively provided as an integral unit. In yet another embodiment, the gasket  30  extends along the central tube second end  32 , while a central portion of the central tube  24  defines the annular ring for receiving and engaging the plate  42  to join the plate  42  to the central tube  24 . 
     Referring to  FIG. 1 , the valve  20  is provided to be in fluid communication with a second end  22  of the first conduit  16  such that the first conduit  16  establishes at least liquid-tight fluid communication between the valve  20  and the through opening  14  of the nozzle  12 . The valve  20  includes at least a first passageway  50  and a second passageway  52  and is provided with at least two valve positions, namely, at least a first position in which fluid flow between the first and second passageways  50 ,  52  is permitted, and at least a second position in which fluid flow between the first and second passageways  50 ,  52  is substantially prevented. In the illustrated embodiment, the valve  20  is a standard, quarter-turn rotary valve of the type known to one of skill in the art. Of course, those skilled in the art will recognize other devices, such as clamps, stoppers, or the like, which may be used to regulate fluid flow within the first conduit  16  without departing from the spirit and scope of the present invention. 
     In the illustrated embodiment, the first passageway  50  of the valve  20  is received within the first conduit second end  22  to establish a frictional connection between the first passageway  50  and the first conduit second end  22  with the first passageway  50  in liquid tight fluid communication with the first conduit  16 . A second conduit  54  is provided having a first end  56  connected in liquid tight fluid communication with the second passageway  52  through a similar frictional connection. Those skilled in the art will recognize other means for securing the first conduit second end  22  to the first passageway  50  and the second conduit first end  56  to the second passageway  52 , such as by mechanical fastening means, welds, adhesives, or by providing a valve  20  which is integrally formed with either or both of the first or second conduits  16 ,  54 , and such other securing means may be used without departing from the spirit and scope of the present invention. 
     Referring to  FIGS. 1 and 3 , a second end  58  of the second conduit  54  is adapted to be removably secured in fluid communication with a plurality of reservoirs  60 , including a pressurized gas source  62 , a fork oil drain  64 , a vacuum source  66 , and a replacement fork oil source  68 . In the illustrated embodiment, the second conduit  58  is fabricated from a flexible resilient material, such as rubber, thermoplastic, or other such material, such that the second conduit second end  58  is capable of slight deformation to receive a slightly smaller sized outlet therein. In this embodiment, each of the pressurized gas source  62 , vacuum source  66 , and replacement fork oil source  68  defines an outlet (not shown) capable of being received within the second conduit second end  58  to establish a frictional connection between the outlet and the second conduit second end  58 . The fork oil drain  64  defines a receptacle capable of receiving fork oil from the second conduit second end  58  in a manner known to one of ordinary skill in the art. Additionally, in one embodiment, at least a portion of at least one of the first and second conduits  16 ,  54  is translucent, such that a user of the changer  10  is able to determine the presence of fluid inside the first and second conduits  16 ,  54 . 
       FIGS. 4 and 5  are a series of flow charts illustrating one embodiment of a method  100  for draining and replacing fork oil in a motorcycle fork of the present invention. Specifically,  FIG. 4  is a flow chart illustrating one embodiment of the method  100 , while  FIG. 5  is a flow chart illustrating in greater detail the steps of the method  100  shown in  FIG. 4 . In the illustrated embodiment of  FIGS. 4 and 5 , a typical design of a telescopic motorcycle fork  70  is used, in which the fork  70  includes a drain hole  72  with a threaded bolt  74  received therein. 
     Referring to  FIG. 4 , in an initial step,  102 , the nozzle  12  is attached to the motorcycle fork  70  with the through opening  14  sealed against the drain hole  72 . As shown in  FIG. 5 , the step  102  of attaching the nozzle  12  is accomplished by performing a series of inclusive steps. In an optional initial step to discourage spillage of fork oil from the motorcycle fork  70 , the fork  70  is oriented  114  such that the drain hole  72  is elevated substantially above the level of fork oil within the fork  70 . Thereafter, the threaded bolt  74  is removed from the drain hole  72 , thereby exposing  116  the drain hole  72 . Following exposure  116  of the drain hole  72 , the nozzle  12  is placed  118  against the motorcycle fork  70  with the gasket  30  surrounding and engaging the exterior of the drain hole  72  to establish the through opening  14  and the drain hole  72  in fluid communication. The connector  38  is then configured to secure the nozzle  12  in place against the motorcycle fork  70 . For example, as discussed above, in the one embodiment a plurality of flexible bindings (not shown) are provided to engage the curved portions of the first and second peripheral ends  46 ,  48  of the plate  42 , and to wrap around the exterior of the motorcycle fork  70 , thereby binding the nozzle  12  in place against the fork  70 . Thereafter, the motorcycle fork  70  is reoriented  120  such that the drain hole  72  is held below the level of the fork oil within the motorcycle fork  70 . 
     Following attachment  102  of the nozzle  12 , a measure of pressurized gas is introduced  104  into the motorcycle fork. Referring to  FIG. 5 , the valve  20  is closed  122 . The second end  58  of the second conduit  54  is connected  124  to a pressurized gas source  62 . Thereafter, the valve  20  is opened  126 , thereby allowing a measure of pressurized gas to travel through the valve  20  and the through opening  14  and to enter the interior of the motorcycle fork  70 . Thereafter, the valve  20  is closed  128 , and the pressurized gas source  62  is disconnected from the second end  58  of the second conduit  54 . 
     It will be understood that, once the pressurized gas is introduced  104  into the interior of the motorcycle fork  70  and the motorcycle fork  70  is oriented  120  such that the drain hole  72  is held below the level of the fork oil within the motorcycle fork  70 , the tendency of the gas in the interior of the motorcycle fork  70  to reach a state of pressure equilibrium with the atmosphere surrounding the motorcycle fork  70  results in increased pressure exerted on the fork oil. Specifically, the pressurized gas within the motorcycle fork  70  tends to force the fork oil from within the motorcycle fork  70  outward through the drain hole  72 . It will further be understood that, with the changer  10  installed over the drain hole  72  and the valve  20  in a closed position, the closed valve  20  prevents drainage of the fork oil through the changer  10 . Accordingly, following introduction  104  of pressurized gas into the interior of the motorcycle fork  70  and subsequent closing of the valve  128 , the pressurized gas source  62  is disconnected  130  from the second end  58  of the second conduit  54 , and the fork oil is drained  106  from the motorcycle fork  70 . As shown in  FIG. 5 , the second end  58  of the second conduit  54  is placed  132  in fluid communication with the fork oil drain  64 . The valve  20  is then opened  134  to allow at least a portion of the fork oil within the motorcycle fork  70  to be pushed outward through the drain hole  72  and changer  10 , and to allow the oil to drain into the fork oil drain  64 . In an optional step  136 , the valve  20  is again closed to arrest drainage of fork oil through the changer  10 . 
     Once at least a portion of the fork oil is drained  106  from within the motorcycle fork  70 , a vacuum is created  108  within the motorcycle fork  70 . In the embodiment of  FIG. 5 , the second conduit second end  58  is connected  138  to the vacuum source  66 . The vacuum source  66  is configured to apply a low-pressure differential to the interior of the changer  10 , thereby creating  140  a low-pressure vacuum within the motorcycle fork  70 . In an embodiment of the method invention in which the valve  20  is closed  136  following drainage of the fork oil into the fork oil drain  64 , the valve is re-opened  142  to allow the vacuum source  66  to be placed in fluid communication with the motorcycle fork interior, thus allowing the vacuum source  66  to subsequently apply  144  the low-pressure differential to create the low-pressure vacuum within the motorcycle fork  70 . Once the low-pressure vacuum is created  140  within the motorcycle fork  70 , the valve  20  is again closed  146  to substantially maintain the low-pressure vacuum and to discourage equalization of pressure between the interior and exterior of the motorcycle fork  70 . 
     Following closure of the valve  20  to secure the low-pressure vacuum within the motorcycle fork  70 , replacement oil is introduced  110  to the motorcycle fork interior. The second conduit second end  58  is removed from the vacuum source  66  and connected  148  to a replacement fork oil source  68 . The replacement fork oil source  68  is configured to provide a measure of replacement fork oil to the second conduit sufficient to refill the fork oil within the motorcycle fork  70  to a level acceptable for operation of the fork. Upon connection  148  of the replacement fork oil source  68 , the valve  20  is opened  150 , thus allowing the low-pressure vacuum inside the motorcycle fork  70  to draw replacement fork oil from the replacement fork oil source  68  through the changer  10  and into the motorcycle fork  70 . It will be understood that the amount of fork oil provided to the motorcycle fork  70  by the replacement fork oil source  68  is dependent upon the amount of fork oil drained from the fork during the drainage step  106 , the strength of the low-pressure vacuum created  108  within the fork, and the amount of fork oil specified for use in the specific motorcycle fork  70 . For example, in one embodiment, the replacement fork oil source  68  is configured to hold a pre-determined amount of replacement fork oil determined to be sufficient to return the fork oil level in the motorcycle fork  70  to within a predetermined range of levels deemed acceptable for an intended use of the motorcycle fork  70 . In another embodiment, the replacement fork oil source  68  holds an amount of replacement fork oil excessive to the needs of the fork oil changing process. In this embodiment, the amount of replacement fork oil drawn into the motorcycle fork  70  is controlled by adjusting the strength of the low-pressure vacuum provided by the vacuum source  66 . Alternatively, the amount of replacement fork oil drawn into the motorcycle fork  70  is limited by closing the valve  20  once a sufficient amount of replacement fork oil is drawn. Following introduction  110  of replacement fork oil into the motorcycle fork  70 , the changer  10  is disconnected  112  from the motorcycle fork  70 . If no additional maintenance or repair is to be performed on the motorcycle fork  70  which requires the threaded bolt  74  to be removed, the threaded bolt  74  is replaced within the drain hole  72  in order to return the motorcycle fork  70  to proper working order. 
     From the foregoing description, it will be recognized by those skilled in the art that a motorcycle fork oil changer and an associated method for draining and replacing the fork oil in a motorcycle fork has been provided. The motorcycle fork oil changer and associated method are useful to provide a clean and convenient apparatus and method for draining and replacing the fork oil in a motorcycle fork. While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant&#39;s general inventive concept.