Patent Publication Number: US-8113172-B2

Title: Adjustable advance distributor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a non-provisional of U.S. Provisional Patent Application No. 61/099,164, which was filed on Sep. 22, 2008, claims priority to that application under 35 U.S.C. §119(e) and incorporates by reference that application in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to distributors used to control ignition timing in motor vehicles. More particularly, the present invention relates to modular and adjustable distributor assemblies used to control ignition timing in motor vehicles. 
     2. Description of the Related Art 
     Conventionally, ignition timing in an engine is adjusted by loosening a clamp nut of a distributor. Once the distributor clamp nut is loosened, the distributor housing can be rotated until an appropriate timing mark was properly located relative to the timing pointer on the engine. Once the distributor housing was properly oriented, the clamp nut would be tightened. Conventional timing adjustment could take considerable time because the distributor often moved in an unpredictable manner during tightening of the clamp nut. 
     In addition, distributors of varying makes and models of engines often differ one from the next. Thus, a distributor manufacturer often had to produce several varieties of distributors to meet consumer demand. 
     SUMMARY OF THE INVENTION 
     For these reasons, a modular and adjustable distributor assembly is desired. The distributor preferably allows a user to quickly and easily adjust the timing of the vehicle. In some configurations, the adjustable advance distributor can be adjusted without the use of mechanical tools of any type. In such embodiments, the timing can be adjusted through finger-adjustable control members. An upper housing of the distributor can be split into two separate components that are connected together by an adjustable mechanism. The adjustable mechanism allows the ignition advance to be adjusted by turning a knob. The knob forms a portion of an adjustment mechanism that connects the two separate components together. Thus, because the knob can be easily turned while the engine is running, the adjustable advance distributor can be used to make changes to the ignition timing without the use of a timing light or the like. Preferably, the housing comprises scaled degree markings for easy viewing of changes, which provides an added level of adjustment control to the user. 
     In some configurations, the adjustable advance distributor comprises a modular construction that allows a manufacturer to mass produce an upper adjustable portion of the distributor while facilitating an interchange of shafts to fit various engines with minimal tooling expense. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages of the present invention will now be described with reference to the drawings of a preferred embodiment, which embodiment is intended to illustrate and not to limit the invention, and in which figures: 
         FIG. 1  is an exploded perspective view of an adjustable advance, modular distributor that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. 
         FIG. 2  is a perspective view of a distributor shaft of the distributor of  FIG. 1 . 
         FIG. 3  is an enlarged sectional view of a portion of the distributor. 
         FIG. 4  is an enlarged perspective view of a thumbwheel. 
         FIG. 5  is an enlarged partially sectioned perspective view of a portion of the distributor. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An adjustable advance distributor  100  is shown in  FIG. 1 . The distributor  100  generally comprises a drive gear  102 . The drive gear  102  is connected to a distributor shaft  104 . The distributor shaft  104  can be a hardened steel shaft having a diameter of about 0.50 inch. The distributor shaft  104  extends upward from the drive gear  102  through a shaft housing assembly  106 . The shaft housing  106  connects to a lower housing assembly  110  that contains an ignition module  112  in the illustrated configuration. The lower housing assembly  110  can comprise an anodized lower housing assembly  110 . A top plate assembly  114  overlies the lower housing assembly  110 . The top plate assembly  114  contains at least a portion of a vacuum advance assembly  116  that connects to a cam plate  120 . A timing wheel or reluctor  122  connects to the distributor shaft  104  and the distributor shaft  104  connects to a rotor assembly  124 . 
     With reference to  FIG. 1 , the drive gear  102  comprises a spiral or helical cut gear portion  130  and a lower generally cylindrical portion  132 . The illustrated drive gear  102  also comprises an axially extending bore  134  and a radially extending hole  136 . The axially extending bore  134  receives an end portion of the distributor shaft  104 . The end portion of the distributor shaft comprises a second radially extending hole  140  (see  FIG. 2 ). The second radially extending hole  140  generally aligns with the radially extending hole  136  of the drive gear. A roll pin  142  can be positioned in the radially extending hole  136  and the second radially extending hole  140 . Thus, the roll pin  142  secures the drive gear  102  onto an end portion of the distributor shaft  104 . Preferably, a thrust washer  144  is positioned along a top surface of the drive gear  102  and the distributor shaft  104  extends through the thrust washer  144 . 
     The drive gear  102  can be interchanged such that the distributor  100  can be modified depending upon the make and model of engine that the distributor will be used with. For example, General Motors and Ford use different drive gears to transfer movement to the stock distributors. The drive gear  102  can be selected to correspond to the stock drive gear pattern. In addition, in some configurations, the distributor shaft  104  can be varying lengths such that the length can be changed depending upon the application. This modular configuration enhances the number of makes and models of engines with which the distributor  100  can be used. 
     The lower end of the shaft housing assembly  106  may comprise a recess that accommodates a sleeve bearing  146  while an upper end of the shaft housing assembly  106  may comprise a recess that accommodates a ball bearing  150 . The ball bearing  150  can be a sealed roller bearing in some embodiments. The sleeve bearing  146  can be a bronze bushing in some embodiments. In some configurations, the sleeve bearing  146  and the ball bearing  150  are simply press fit into the shaft housing assembly  106 . Together, the sleeve bearing  146  and the ball bearing  150  journal the distributor shaft  104  within the shaft housing assembly  106 . 
     In the illustrated embodiment, the shaft housing assembly  106  also comprises a smaller diameter hole  152  and a larger diameter hole  154 . Both of the smaller diameter hole  152  and the larger diameter hole  154  extend part way through the shaft housing assembly  106 . In the illustrated configuration, both of the holes  152 ,  154  extend into a central bore that contains the distributor shaft  104 . In the illustrated embodiment, the two holes  152 ,  154  are positioned between the sleeve bearing  146  and the ball bearing  150 . 
     With reference to  FIG. 5 , the lower housing assembly  110  comprises a lower housing member  156 . As shown in  FIG. 3 , the lower housing member  156  comprises a boss  160  on a lower portion of the lower housing member  156 . The boss  160  includes an encircling flange  162  and a mounting face  164 . The mounting face  164  receives an end portion of the shaft housing assembly  106 . The shaft housing assembly  106  can be secured to the lower housing member  156  in any suitable manner. In the illustrated configuration, the lower housing member  156  comprises multiple holes  166  that receive threaded fasteners  170 . The threaded fasteners  170  (e.g., socket head capscrews) thread into threaded bores formed in the upper portion of the shaft housing assembly  106 . The assembly described directly above facilitates the usage of a single lower housing member  156  with differing shaft housing assemblies  106  depending upon the application. 
     The lower housing member  156  defines at least a portion of a recess  172 . The recess  172  houses the ignition module  112 . The ignition module  112  preferably is secured within the recess in any suitable position and in any suitable manner. In the illustrated configuration, as shown in  FIG. 1 , threaded members  174  (e.g., button head capscrews) secure the ignition module  112  within the lower housing member  156 . 
     The illustrated lower housing member  156  also comprises an adjusting mechanism passage  176 . The adjusting mechanism passage  176  extends through a sidewall  180  of the lower housing member  156 . In the illustrated embodiment, the adjusting mechanism passage  176  also extends through an adjusting mechanism passage member  182 . The member  182  can have any suitable configuration. In the illustrated configuration, the member  182  is generally cubic in shape with the passage  176  extending through the member  182 . The member  182  can have a portion on each side of the sidewall  180 . Other configurations are possible. 
     The member  182  comprises a blind hole  184 . The blind hole  184  receives a detent spring  186 . A ball  190  presses against the detent spring  186  and the spring  186  presses the ball  190  outward against a back surface of a thumbwheel  192 . With reference to  FIG. 4 , the back surface of the thumbwheel  192  preferably comprises a surface with alternating steps and recesses  193  into which the ball  190  can be biased. Thus, the thumbwheel  192  in combination with the ball  190  and the spring  186  provide force feedback to indicate how much the thumbwheel  192  is being turned. Moreover, the thumbwheel  192 , ball  190 , spring  186  combination helps improve the control a user has over the amount of adjustment made to timing. In some embodiments, the thumbwheel and force feedback arrangement enables advance or retard adjustments in ½ degree increments. 
     The thumbwheel  192  is secured in axial position relative to the passage  176  with a snap ring  194 . Other configurations are possible. Preferably, the thumbwheel  192  comprises a threaded bore  196 . An adjusting rod  200  threads into the threaded bore at one end and couples to a slider block  202  at the other end. Thus, as the thumbwheel  192  rotates relative to the passage  176 , the adjusting rod  200  moves axially in and out of the thumbwheel  192 . As the adjusting rod  200  moves axially in and out of the thumbwheel  192 , the slider block  202  changes position. 
     To further support the distributor shaft  104 , a center bushing  204  can be positioned within a center of the lower housing member  156 . Thus, the distributor shaft  104  extends through a central hole formed in the lower housing member  156  and also extends within the center bushing  204  in the illustrated configuration. 
     A top plate  210 , which forms a portion of the top plate assembly  114 , overlies the lower housing member  156  such that the top plate  210  substantially closes off the recess  172  defined within the lower housing member  156 . The top plate  210  can comprise a circumferential step or recess  212  that results in the top plate  210  having a portion that is received within the sidewall  180  of the lower housing member  156 . The top plate  210  preferably is capable of rotation relative to the lower housing member  156 . 
     The slider block  202  preferably comprises a generally vertical aperture  214 . The aperture  214  receives a dowel pin  216 . The dowel pin  216  extends upward from the slider block  202  into a hole  218  formed in the top plate  210 . As the slider block  202  translates, the top plate  210  rotates. Thus, movement of the thumbwheel  192  causes movement of the adjusting rod  200 , movement of the adjusting rod  200  causes movement of the dowel pin  216  and movement of the dowel pin  216  causes rotation of the top plate  210 . 
     In some configurations, an opening  218  can be provided in the bottom of the lower housing member  156 . The opening can receive a shoulder bolt or the like. The shoulder bolt can extended upward into a slotted opening  219  in the bottom of the top plate member  210 . Thus, the shoulder bolt in combination with the slotted opening  219  can be used to limit the range of relative movement between the top plate member  210  and the lower housing member  156 . Other configurations are possible, which can include inverting the components or provided a molded in component to limit the range of relative movement. 
     The top plate  210  comprises a central opening  220 . The central opening receives a center bushing  222 . The center bushing  222  preferably comprises a circumferential flange that rests against a recessed surface of the top plate  210 . Other configurations are possible. The distributor shaft  104  extends through an interior of the center bushing  222  while a cam plate  224  and a cam plate washer  226  are mounted on an outside of the center bushing  222 . 
     The cam plate  224  comprises a hole  230 . The hole  230  connects with a vacuum advance mechanism  232 . As is known, the vacuum advance mechanism comprises a spring-loaded diaphragm that fits inside a metal housing  234 . The diaphragm is connected to a vacuum actuator arm  236 , which connects with the hole  230 . Accordingly, movement of the diaphragm within the metal housing  234  causes movement of the actuator arm  236 , which causes corresponding movement of the cam plate  226 . In the illustrated configuration, a bracket  238  carries the vacuum advance mechanism  232  and the bracket  238  can be secured to the top plate  210  with threaded fasteners or the like but any suitable manner can be used. 
     A sensor (not shown) can be mounted to the cam plate  226 . The sensor detects movement of the reluctor  122 . Movement of the cam plate  226  caused by the vacuum advance mechanism  232  can cause related movement of the sensor (not shown). In addition, movement of the top plate  210  relative to the lower housing member  156  also results in related movement of the sensor. Accordingly, because the sensor senses movement of the reluctor  122 , the movement of the sensor caused by the vacuum advance mechanism  232  and the movement between the top plate and the lower housing member change the timing of movement of the reluctor  122  sensed by the sensor. 
     Wires from the sensor can extend through an enlarged opening  238  in the top plate  210 . The wires, thus, can couple the sensor to the ignition module  112  while providing sufficient clearance to accommodate the relative movement between the top plate  210  and the lower housing member  156 . 
     The cam plate  224  rests on a flange of the center bushing  222  and a snap ring  240  secures the cam plate  224  in axial position relative to the center bushing  222 . An outer groove in the center bushing  222  receives the snap ring  240 . In the illustrated configuration, a washer is positioned between the snap ring  240  and an upper surface of the cam plate  224 . In addition, a center bushing shim  244  can be positioned on an upper surface of the center bushing  222 . 
     Just above the center bushing  222 , the reluctor  122  is mounted to the distributor shaft  104 . The reluctor  122  can be held in position with a snap ring  246  or the like. The rotor assembly  124 , which comprises a rotor  248  and a rotor contact  250 , also is secured to the distributor shaft  104  in any suitable manner. 
     With reference to  FIG. 1 , markings  260  are shown on an upper portion of the lower housing member  156  and a lower portion of the top plate  210 . These markings  260  can have any suitable form. In one configuration, the markings  260  on the lower housing member  156  define a graduated scale while the markings  260  on the top plate  210  define a single line. By observing movement of the line relative to the graduated scale, a user can visually observe the type (quality) and the amount (quantity) of movement they induce by rotation of the thumbwheel. Thus, controlled adjustments can be made and observed without the need for a timing light or mechanical tools. Moreover, the illustrated configuration enables timing adjustment without loosening an adjusting nut of a distributor, which is at the connection between the distributor and the associated engine. 
     Although the present invention has been described in terms of a certain embodiment, other embodiments apparent to those of ordinary skill in the art also are within the scope of this invention. Thus, various changes and modifications may be made without departing from the spirit and scope of the invention. For instance, various components may be repositioned as desired. Moreover, not all of the features, aspects and advantages are necessarily required to practice the present invention. Accordingly, the scope of the present invention is intended to be defined only by the claims that follow.