Abstract:
A shock absorber that combines both the suspension function and the shock absorbing function in one unit. It has an elongated shock body filled with hydraulic fluid and a piston mounted on a piston rod that reciprocally travels within the shock body. The shock body is telescopically received in a bypass cylinder body having a greater diameter that produces an annular chamber between the outer surface of the shock body and the inner surface of the bypass cylinder body. A coil spring is mounted on the outside surface of the bypass cylinder body to provide a suspension function by the shock absorber. A plurality of bypass tubes are associated with longitudinally spaced ports in the shock body. Adjuster rods are telescopically received inside the respective bypass tubes for controlling whether the individual ports are closed, partially open, or fully open. These adjuster rods would be manipulated externally of the shock absorber assembly.

Description:
This application claims the priority of U.S. Provisional Patent Application Ser. No. 60/555,837 filed Mar. 23, 2004. 

   BACKGROUND OF THE INVENTION 
   Many types of suspensions and supports include a spring and a damping device to help isolate that supported from the support structure or surface. For example, automotive vehicles commonly use separate springs and simple shock absorbers to support the vehicle frame on the axle assemblies. Simple shock absorbers are typically oil-filled cylinders within which a vented piston is mounted. The piston is connected to a shaft which extends out of one end of the cylinder. The outer end of the shaft is mounted to one point on the vehicle and the other end of the cylinder is mounted to another point on the vehicle in parallel with the suspension spring. Thus, simple shock absorbers only provide damping and not support. 
   Another type of shock absorber, which is the type commonly used with motorcycles, off-road vehicles, competition automotive vehicles and off-road bicycles, combines both the suspension function and the shock absorbing function in one unit. This second type of shock absorber commonly uses a spring unit to provide the suspension function coupled with a damping unit to provide the damping function. Conventional shock absorber designs commonly incorporate an external coil spring, an internal air spring, or an internal bladder to provide the suspension function. 
   Typical shock absorbers (also referred to as shocks) provide two kinds of damping: compression damping (“CD”), and rebound damping (“RD”). One refers to damping force created during “inward” travel of the shaft (shortening of the shock), the other refers to force created during “outward” travel of the shaft (lengthening of the shock). Generally, but not always—depending on linkage connecting shock to vehicle, RD applies during outward motion and CD applies during inward motion. Some shocks are externally adjustable by the user to provide for RD and/or CD adjustment. 
   Piston-type shock absorbers can be designed to provide the same amount of damping on both the compression stroke and the rebound stroke. Alternatively, the fluid passageways through the vented, damping piston can be designed so that the restriction to fluid flow through the damping piston during the compression stroke is different from the restriction to fluid flow during the rebound stroke. In this case the damping during the entire compression stroke is different from the damping during the entire stroke. 
   Another type of damping is called position-sensitive damping. Position-sensitive damping is typically achieved by the combination of conventional vented piston damping, with the oil flowing through the damping system, plus damping provided by the passage of oil around the damping piston through a bypass chamber or channel, which permits oil to bypass the piston during part of the piston stroke. The bypass channel permits lesser damping over the portion of the stroke during which some fluid flows around the piston through the bypass channel. Therefore, the shock can have different damping characteristics along different segments of the stroke. This is beneficial to the user because a single set of shocks can provide a smooth damping for less aggressive riding and firm damping for aggressive riding without making any adjustments during the ride. For example, the shocks can provide reduced damping in the mid-stroke zone, where the shock is most active in, for example, trail riding or other less aggressive riding. If the rider starts riding more aggressively, or hits a large bump, causing the shock to compress deeper into the stroke, the bypass damping then becomes available and the shock also relies on the conventional piston damping. This type of shock absorber has been available for many years. 
   U.S. Pat. No. 5,178,239 illustrates another example of a position-sensitive shock absorber. The position-sensitive damping action of the bypass channel is available during both the compression and rebound strokes. U.S. Pat. No. 6,415,895 is directed to shock absorbers, including position-sensitive shock absorbers in which the position-sensitive damping can be different during compression and rebound strokes and shock absorbers with damping adjusters which vary the damping provided during compression and rebound strokes. A further aspect is directed to a shock absorber including a cylinder with a piston moveably mounted within the cylinder. 
   It is an object of the invention to provide a novel shock absorber that provides both a suspension function and a damping function. 
   It is also an object of the invention to provide a novel shock absorber that has bypass passageways whose hydraulic fluid flow can be increased or decreased by external mechanical structure to vary the damping characteristics. 
   It is another object of the invention to provide a novel shock absorber that has bypass tubes having a kidney-shaped transverse cross section. 
   It is an additional object of the invention to provide a novel shock absorber that has unique check valves having kidney-shaped check valve pistons. 
   It is also an object of the invention to provide a novel shock absorber that has structure for increasing or decreasing the length of the external coil spring. 
   SUMMARY OF THE INVENTION 
   The problem with current products on the market is: 
   1: The only way to have an externally adjustable bypass shock is to have a separate emulsion shock to be used as a coil guide. What this does is provide a shock “guide” for the coil springs. For suspension damping a current bypass shock is used. Thus, on each corner of the car one must mount two separate shocks to have totally adjustable dampening control . . . eight shocks in total. 
   2: The other alternative is an “internal bypass shock.” Essentially this achieves the same goals as applicant&#39;s invention except it is only adjustable internally. One can use one shock per wheel, and have as much adjustability as (1) above. However, the shock has to be removed from the vehicle and disassembled to adjust the damping within the shock. This is the major drawback to this shock. It isn&#39;t practical when one wants to adjust the shocks on demand and out in the field. 
   The way to solve both problems is to have an “externally adjustable internal bypass shock.” What this achieves is not only the goal of using one shock per wheel, but also having the adjustability of using two present day separate components. Some highlights of the present invention are: 
   a) the shock absorber consists of an inner shock body with external bypass tubes and an outer threaded body to cover the bypass channels and allow a coil spring to be attached to the outside of the outer threaded body independent of the bypass channels; 
   b) the bulkhead allows each bypass channel to be attached adjacent to the shock body resulting in reduced overall diameter for the inner part of the shock; 
   c) there is an outer body consisting of a steel cylinder threaded externally for a shock adjuster to be installed for pre-loading of the springs; 
   d) check valves reside in the lower and/or upper bulkheads. These reside at the end of the bypass channel. Adjusting these check valves and/or the fluid available to them is what determines dampening characteristics. 
   The externally adjustable internal bypass shock has position-sensitive damping that can be different during compression and rebound strokes. There are adjuster rods which vary the damping provided during compression and rebound strokes. 
   The externally adjustable internal bypass shock absorber includes a cylindrical shock body within which a piston is moveably mounted for movement between the first and second ends of the cylinder. First and second bypass ports open into the cylinder exterior at axially spaced-apart positions. The bypass ports are coupled to bypass channels. The piston on the piston rod has a static position from which it initially starts traveling during compression. The distance to the first port aperture would be considered the first compression zone. Hydraulic fluid in the cylinder during this travel of the piston attempts to exit the port aperture and return to the rear of the piston through the bypass channels. The adjuster rod can be adjusted downwardly to leave the port aperture completely open, partially closed or completely closed. These changes will produce different dampening effects during Compression Zone  1  travel. 
   After the piston has passed the first port aperture, the hydraulic fluid is then pushed outwardly through the second port aperture which is closer to the top end of the shock body. This zone is identified as Compression Zone  2 . It has a bypass channel connected to that port aperture. An adjuster rod can be moved up and down in the bypass channel to have the port completely open, partially closed or fully closed. These changes will affect the dampening effects in Compression Zone  2 . Each of the described adjuster rods can be activated by the external bypass adjuster members located externally adjacent the top end of the shock. It is to be understood that additional port apertures could be formed along the length of the shock body to produce additional compression zones. On the rebound cycle the fluid is pushed downwardly in front of the rear end of the piston and forced radially outward and upwardly through a bypass tube that extends up to the top bulkhead. The top end of the bypass tube is closed by a check valve that has an adjuster rod pushing downwardly against it. The top end of this adjuster rod has an external bypass adjuster control which allows the operation of the check valve to be varied. This will produce different dampening effects on the rebound cycle. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top plan view of the novel shock absorber; 
       FIG. 2  is a rear elevation view of the shock absorber; 
       FIG. 3  is a left end view of the shock absorber; 
       FIG. 4  is an exploded front perspective view of the shock absorber; 
       FIG. 5  is an exploded front perspective view of the top assembly; 
       FIG. 6  is an exploded front perspective view of the main body assembly; 
       FIG. 7A  is side elevation view of the top bulkhead; 
       FIG. 7B  is a bottom plan view of the top bulkhead; 
       FIG. 8A  is a side elevation view of the bottom bulkhead; 
       FIG. 8B  is a top plan view of the bottom bulkhead; 
       FIG. 9A  is a side elevation view of check valve A; 
       FIG. 9B  is a top plan view of the check valve piston illustrated in  FIG. 9A ; 
       FIG. 10A  is a side elevation view of check valve B; 
       FIG. 10B  is a top plan view of the check valve piston illustrated in  FIG. 10A ; 
       FIG. 11  is an exploded front perspective view that shows the assembly of the main seal body, the bottom cap and the wiper seal; 
       FIG. 12  is an exploded front perspective view of the coil spring and spring top collar; 
       FIG. 13  is a side elevation view of the assembly of the piston, the piston rod and the spring bottom collar; 
       FIG. 14  is a side elevation view of the shock absorber showing Compression Zone  1 ; 
       FIG. 15  is a cross sectional taken along lines  15 - 15  of  FIG. 14 ; 
       FIG. 16  is a side elevation view of the shock absorber showing Compression Zone  2 ; 
       FIG. 17  is a cross sectional view taken along lines  17 - 17  of  FIG. 16 ; 
       FIG. 18  is a side elevation view of the shock absorber during the Rebound Cycle; and 
       FIG. 19  is a cross sectional view taken along lines  19 - 19  of  FIG. 18 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The externally adjustable internal bypass shock absorber will now be described by referring to  FIGS. 1-19  of the drawings. The shock absorber is generally designated numeral  24 .  FIGS. 1-3  show the shock absorber  24  completely assembled. The invention will be more easily understood by specifically describing the individual components and assemblies. This will be done by referring to the other drawings. 
     FIG. 4  is an exploded front perspective view of shock absorber  24 . Numeral  26  identifies the top assembly (see  FIG. 5 ). Numeral  28  identifies the main body assembly (see  FIG. 6 ). The main seal body and assembly  30  is illustrated in  FIG. 11 . The coil spring  32  and its associated structure are illustrated in  FIG. 12 . The piston rod  34  and its associated structure are illustrated in  FIG. 13 . 
   The basic components of the shock absorber are clearly illustrated in  FIG. 6 . The shock body  36  is a hollow cylinder having an outer diameter D 1 . A plurality of bypass tubes or channels  38  are rigidly secured to the outer surface of shock body  36  by brazing or some other similar process. These bypass tubes have a transverse cross section that is kidney-shaped. The inner side wall surface of these bypass tubes is concave and the outer surface of the bypass tubes is convex. The concave side wall curvature mates with the outer surface of shock body  36 . Although four bypass tubes  38  are illustrated, it is to be understood that fewer can be used or more bypass tubes can be used. Outer threaded body  40  telescopes over bypass tubes  38  with the inner surface of outer threaded body  40  pressed against the outer convex side wall surface of the respective bypass tubes  38 . The space between adjacent bypass tubes form fluid passageways whose purpose will be understood later. A top bulkhead  42  is attached to the top end of shock body  36 , bypass tubes  38  and outer threaded body  40 . A bottom bulkhead  43  is attached to the bottom end of the same respective parts. 
   Top bulkhead  42  is illustrated in  FIGS. 7A and 7B . Top bulkhead  42  houses the rebound check valves  45  and directs fluid back into the shock body  36 . Top bulkhead  42  is bonded to the top end of shock body  36  and bypass tubes  38 . The top bulkhead  42  also directs fluid from in between bypass tubes  38  out into the reservoir  47  via the manifold  48 .  FIG. 7B  shows the bottom of top bulkhead  42 . It has a plurality of outlets  55  that communicates with manifold  48  and reservoir  47 . 
   Bottom bulkhead  43  uses the compression check valves  50  and directs fluid from the bypass tubes  38  back into shock body  36 . Bottom bulkhead  43  also directs fluid inside the shock body, outside the bypass tubes  38  and into the top bulkhead  42  for direction to reservoir  47 . Bypass tubes allow fluid to flow around the piston  52  (from above to below). These bypass tubes  38  direct the fluid to the check valves and this fluid forces them open or closed depending on the direction of travel of the piston. Piston rod  34  and piston  52  move dynamically within shock body  36 . As the piston  52  travels up or down port holes in the shock body  36  allow oil to bypass the piston via the bypass tubes  38 . 
   Bottom bulkhead  43  is illustrated in  FIGS. 8A and 8B .  FIG. 8B  is a top view of bottom bulkhead  43 . It shows a plurality of compression check valve guides  56  for receiving compression valves  50 . The specific structure of compression valves  50  is illustrated in  FIGS. 10A and 10B . They have a check valve piston  59  separated from a check valve stop  60  by a plurality of springs  61 . 
   Rebound check valve  45  is illustrated in  FIGS. 9A and 9B . It has a check valve piston  63  separated from a check valve stop  66  by coil springs  64 . A threaded stud  68  functions just like the adjuster rods  70 . When the bypass adjuster  76  is turned, this moves the check valve stop  68  up or down allowing the check valve to let more or less fluid bypass the piston  52 . The check valve springs  61  and  64  keep the respective check valves closed during rebound or compression and open during rebound or compression depending which direction the valve is placed. The check valve stops  60  and  66  can be stationery or the position can be moved to determine how much the respective check valve pistons are allowed to open. This also determines damping characteristics of a particular zone within the shock. 
     FIG. 5  shows the top assembly  26  that is attached to the top end of the main body assembly  28 . Reservoir  47  is a hollow cylindrical metal tube within which a piston  72  is telescopically received. The internal chamber formed between the bottom end of manifold  48  and the top end of reservoir piston  72  is the reservoir for extra oil to be stored. Between the bottom end of reservoir piston  72  and the bottom end cap  73  is formed a second chamber that would be filled with pressurized gas. The function of the reservoir is to store extra oil. This allows displacement of oil as piston rod  34  is compressed in and out of the shock body  36 . The top  75  of the shock houses the bypass adjusters  76  and is secured to the top end of the main body assembly  28  by bolts  77 . The top  75  of the shock is bolted to the vehicle. Bolts  77  threads into tap holes in the top bulkhead  42 . 
   There is an adjuster block  79  connected to the bottom end of each of the adjuster rods  70 . The adjuster blocks are moved up and down to close off or open the port apertures in shock body  36  that allow fluid to flow downwardly through the bypass tubes  38  to the check valves  50 . The location of these adjuster blocks  79  determines the damping characteristics of the particular position of the piston within shock body  36 . The dynamic part of the check valve assemblies  50  is the check valve piston  59 . It is spring loaded and when fluid is forced down via the bypass tubes, the check valve piston will move downwardly opening a hole in the bottom bulkhead  43 . This allows fluid to travel back down beneath the piston  52 . The top ends of adjuster rods  70  have external threads that thread into the bypass adjusters  76 . When the bypass adjuster  76  is turned for adjustment, it moves the adjuster rod up or down. Spring loaded ball plungers  83  are threaded into the top  75  of the shock and extend into the bypass adjusters  76 . There is a corresponding detent in the bypass adjuster. After adjustment this ball plunger keeps the bypass adjuster from rotating. Manifold seals  84  seal the manifold  48  to the top bulkhead  42 . Manifold  48  channels oil from inside the threaded shock body into reservoir  47 . 
   Main seal body and assembly  30  is illustrated in  FIG. 11 . It is the housing for the main shock seal. This housing is sandwiched between the shock bottom aluminum cap  88  and the bottom bulkhead  43 . It contains outer o-rings to center itself within bottom bulkhead  43 . Wiper seal  89  surrounds piston rod  34 . Bolts  90  secure bottom cap  88  and main seal body and assembly  30  to bottom bulkhead  43 . 
     FIG. 13  shows piston  52  mounted on one end of piston rod  34 . Spring bottom collar  92  is mounted on the other end of piston rod  34 . Attached thereto is piston rod end  93 . Spring bottom collar  92  serves as a bottom stop for coil spring  32 . It also keeps the coil spring concentric about the shock assembly. Piston rod end  93  bolts to the particular vehicle using the shock. 
     FIG. 12  shows a spring guide  96  that helps guide the spring  32  up and down the outer threaded body  40 . It also serves as a stop if one so chooses to use a secondary spring set up. The front end of coil spring  32  is captured in spring top collar  94 . Spring top collar  94  is threaded internally and threads onto the outer threaded body  40 . The movement of spring top collar up or down adjusts the pre-load on the coil spring. 
   The manner in which the externally adjustable internal bypass shock absorber functions will be discussed by referring to  FIGS. 14-19 .  FIGS. 14-17  relates to the compression stroke.  FIGS. 18 and 19  relate to the rebound cycle. 
     FIGS. 14-15  relates to the action that takes place in Compression Zone  1 . When piston rod  34  is traveling upwardly through shock body  36 , piston  52  compresses the fluid in the interior chamber of shock body  36 . Piston  52  has a plurality of bore holes that allow some hydraulic fluid to pass through them on this compression stroke. This provides a damping effect. Part way up the interior of shock body  36  there is a port hole  100  that is a distance L 2  from the top bulkhead  42 . The lower end of adjuster rod  70  is not covering port  100  and this allows some of the hydraulic fluid to travel rearwardly through bypass tube  38  against check valves  50  causing check valve piston  5   a  to be depressed and allowing the hydraulic fluid back into the interior chamber behind piston  52 . This also provides a damping function for Compression Zone  1 .  FIGS. 16 and 17  show the piston  52  traveling further along the interior chamber. A second port hole  101  is located a predetermined distance L 1  from top bulkhead  42 . At this point piston  52  has already passed port aperture  100  and therefore the fluid in front of it is forced through port  101  and down bypass tube  38  against check valves  50  causing check valve piston  59  to be depressed and allowing the hydraulic fluid to enter back into the interior chamber behind piston  52 . 
   The Rebound Cycle is illustrated in  FIGS. 18-19 . As piston  52  travels rearwardly, hydraulic fluid is pushed rearwardly toward bottom bulkhead  43  and radially outward and upward through bypass tube  38 . This fluid then compresses check valve  45  which allows the fluid to enter back into the interior chamber. Adjustment of the various bypass adjusters can vary the damping effects in the different Compression Zones and different Rebound Zones. 
   Although this invention has been described in connection with specific forms and embodiments thereof, it will be appreciated that various modifications other than those discussed above may be resorted to without departing from the spirit or scope of the invention. For example, equivalent elements may be substituted for those specifically shown and described, certain features may be used independently of other features, and the number and configuration of various vehicle components described above may be altered, all without departing from the spirit or scope of the invention as defined in the appended Claims.