Patent Document

RELATED APPLICATIONS  
       [0001]    Priority is hereby claimed to U.S. Provisional Patent Application No. ______ , filed on Mar. 30, 2002, and said application is incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to an actuator/coupler device. In particular, to a device attached to a towed vehicle for releasably coupling the towed vehicle to a towing vehicle, and for actuating brakes on the towed vehicle.  
           [0004]    2. Background  
           [0005]    Devices for coupling towing and towed vehicles are well known in the art. These devices are necessary in order to assist the towing vehicle in braking situations. When the towing vehicle slows the towed vehicle tends to push or override the towing vehicle, thereby directing the momentum of the towed vehicle onto the towing vehicle during repeated stopping, which results in premature wear on the brakes of the towing vehicle. In addition, to increasing the wear on the towing vehicle brakes this effect can also make the towing vehicle difficult to control. In extreme situations this can lead to a jack-knife condition, or loss of control of the vehicles. Accordingly, a number of devices have been used over the years to not only couple a towed and towing vehicle, but also to assist in braking the towed vehicle in coordination with the towing vehicle under actual driving conditions.  
           [0006]    These devices were originally quite simple and of limited effectiveness, especially for larger more modem towed and towing vehicle combinations. In recent times, the growth of the use of towed vehicles along with the increase in the size of such vehicles has required the development of more sophisticated devices. In particular, in order to ease the strain on the brakes of the towing vehicle and to provide strong braking in emergency situations, like in a break away situation, towed vehicles utilize independent brake systems actuated in response to changes in the speed of the towing vehicle.  
           [0007]    The prior art discloses a number of methods for providing such capability. These include the use of electrical sensors to sense when the towed vehicle pushes against the towing vehicle, however, these systems proved troublesome in actual practice. Other systems utilize devices designed to sense changes in momentum between the towed and towing vehicles and apply towed vehicle brakes in response thereto.  
           [0008]    One such device is disclosed in U.S. Pat. No. 5,013,059. The device includes a housing and a telescopically attached coupler. The coupler includes a brake actuator and shock absorber combination that is activated in response to compression of the housing and coupler caused by slowing of the towing vehicle. The device includes front and rear roller shafts, which extend through holes and slots in the coupler and housing, and which support a front and rear pair of juxtaposed rollers to facilitate low friction movement of the coupler and housing relative to each other. Because of the specific arrangement of the components the device requires that the front rollers extend through slots in the coupler to engage the inner surface of the housing. For this and other reasons, the device suffers from a number of practical operational drawbacks.  
           [0009]    Thus, a need exists for an improved and simplified actuator/coupler device designed for attachment to the towed vehicle and for releasably coupling the towed vehicle to the towing vehicle, and for actuating brakes on the towed vehicle.  
         SUMMARY OF THE INVENTION  
         [0010]    An object of the present invention comprises providing an improved actuator/coupler device attached to a towed vehicle for releasably coupling the towed vehicle to a towing vehicle, and for actuating brakes on the towed vehicle.  
           [0011]    These and other objects of the present invention will become apparent to those skilled in the art upon reference to the following specification, drawings, and claims.  
           [0012]    The present invention intends to overcome the difficulties encountered heretofore. To that end, the present invention comprises an actuator/coupler device attached to a towed vehicle for releasably coupling the towed vehicle to a towing vehicle, and for actuating brakes on the towed vehicle, wherein the point of coupling is a coupler ball attached to the towing vehicle. In particular, the device comprises a generally rectangular shaped housing for attachment to the towed vehicle, and a generally hollow coupler correspondingly shaped for telescopic attachment to the housing. A roller shaft extends through a hole in the housing and extends through an elongated slot in the coupler thereby providing a point of attachment for the coupler and the housing that allows for limited movement of the coupler relative to the housing. A pair of opposing rollers secure to the roller shaft and are located inside the generally hollow interior of the coupler whereby the rollers roll on a surface within the generally hollow interior of the coupler. A brake actuator secures within the generally hollow interior of the coupler, wherein a first end of the brake actuator is secured to the roller shaft and a second end of the brake actuator is fixed to the coupler, wherein the brake actuator is in operable communication with the brakes of the towed vehicle such that the brake actuator is actuated by movement of the coupler relative to the housing. A coupler ball socket is included within the generally hollow interior of the coupler for releaseable attachment of the coupler ball attached to the towing vehicle. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a composite of several views of an actuator/coupler device, with the views labeled a-k and appearing in greater detail in FIGS.  2 - 12 .  
         [0014]    [0014]FIG. 2 is a side view of the device, and shows in detail item d in FIG. 1.  
         [0015]    [0015]FIG. 3 is a cross section view of the device taken along the line U-U shown in FIG. 2, and shows in detail item h in FIG. 1.  
         [0016]    [0016]FIG. 4 is a cross section view of the device taken along the line R-R shown in FIG. 2, and shows in detail item i in FIG. 1.  
         [0017]    [0017]FIG. 5 is a cross section view of the device taken along the line Q-Q shown in FIG. 2, and shows in detail item j in FIG. 1.  
         [0018]    [0018]FIG. 6 is a cross section view of the device taken along the line T-T shown in FIG. 2, and shows in detail item k in FIG. 1.  
         [0019]    [0019]FIG. 7 is a cross section view of the device taken along the line N-N shown in FIG. 2, and shows in detail item b in FIG. 1.  
         [0020]    [0020]FIG. 8 is a bottom view of the device, and shows in detail item e in FIG. 1.  
         [0021]    [0021]FIG. 9 is a cross section view of the device taken along the line L-L shown in FIG. 8; and shows in detail item f in FIG. 1.  
         [0022]    [0022]FIG. 10 is a top view of the device, and shows in detail item c in FIG. 1.  
         [0023]    [0023]FIG. 11 is a rear end view of the device, and shows in detail item a in FIG. 1.  
         [0024]    [0024]FIG. 12 is a front end view of the device, and shows in detail item g in FIG. 1.  
         [0025]    [0025]FIG. 13 is a perspective view of the device.  
         [0026]    [0026]FIG. 14 is a perspective view of a coupler of the device.  
         [0027]    [0027]FIG. 15 is a perspective view of the internal components of the coupler.  
         [0028]    [0028]FIG. 16 is a rear view of a master cylinder assembly of the device.  
         [0029]    [0029]FIG. 17 is a top view of the master cylinder.  
         [0030]    [0030]FIG. 18 is a side cross sectional view of the master cylinder.  
         [0031]    [0031]FIG. 19 is a bottom view of the master cylinder.  
         [0032]    [0032]FIG. 20 is an enlarged side cross sectional view of a valve cavity of the master cylinder.  
         [0033]    [0033]FIG. 21 is a portion of the device depicted in FIG. 2, enlarged to show a safety latch and trailer hitch of the device. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0034]    In the Figures, an actuator/coupler device  10  is shown. In particular reference to FIGS.  13 - 15  the device includes a generally hollow  3 -sided housing  12  that telescopically houses a coupler  14 . Forward and rear coupler shafts  16 ,  20  secure the coupler  14  and housing  12 . As shown in FIG. 13, the forward and rear coupler shafts  16 ,  20  secure through forward and rear housing holes  25 ,  27  in the housing  12 . The holes  25 ,  27  fix the movement of the shafts  16 ,  20  relative to the housing  12 . As shown in FIG. 14, the shafts  16 ,  20  pass through forward and rear coupler slots  24 ,  26  in the coupler  14 . In this manner, the elongated forward and rear coupler slots  24 ,  26  allow for limited lateral movement of the coupler  14  relative to the housing  12 .  
         [0035]    [0035]FIG. 15 shows the internal components of the device  10  located within the coupler  14 .  
         [0036]    These components include a pair of opposing forward rollers  18 , and a pair of opposing rear rollers  22 . The respective roller shafts  16 ,  20 , along with forward and rear bushings  28 ,  30  hold and align the forward and rear rollers  18  within the coupler  14  and housing  12 . A dampener/shock absorber  32  is affixed between the opposing pair of forward rollers  18  and through the forward roller shaft  16 . The opposite end of the dampener  32  is secured to the coupler  14  through a dampener shaft  34  that secures to a central portion of the coupler  14 . An inner L-shaped plate  46  rigidly secures inside the coupler  14 . A brake piston rod assembly  36  secures on one end to the inner plate  46 , while the other end of the brake piston assembly  36  operationally integrates into a master cylinder assembly  40  and is secured to the rear roller shaft  20  between the rear rollers  22 . The master cylinder assembly  40  includes a throughboar  120  (see FIG. 18) for receipt of the rear roller shaft  20 , and also is retained on either side with grooved slots  60  in the outer side walls of the master cylinder assembly  40  that align with a protruding ribs  61  on either side of the inner side walls of the coupler  14  (see FIG. 11). This arrangement allows for lateral movement of the master cylinder assembly  40  relative to the coupler  14 , but prevents any substantial vertical movement thereof.  
         [0037]    The device  10  attaches at its forward end to a towing vehicle (not shown) with trailer hitch  42  incorporated into the forward end of the coupler  14 . The trailer hitch  42  is operationally secured in place to a coupler ball  63  (see FIG. 21) attached to the towing vehicle with a double pivot spring loaded wedge or slide lock  44 . The rearward end of the housing  10  secures to a towed vehicle (not shown).  
         [0038]    In operation, the device  10  operates the brakes (not shown) of the towed vehicle in response to decelerations of the towing vehicle. Such decelerations of the towing vehicle cause the towed vehicle to compress housing  12  relative to the coupler  14  of the device  10 . Because the rear roller shaft  20  is fixed to the housing  12  with regard to lateral movement, this compression forces the rear roller shaft  20  and rear pair of rollers  30  forward in the rear slot  26  of the coupler  14 . The rear rollers  30  ride on an upper inside surface of the coupler  14 . The forward movement of the rear roller  30  moves the master cylinder assembly  40  forward by virtue of the fact that the rear roller shaft  20  is affixed through throughbore  120  in the rearward end of the master cylinder assembly  40 , this movement results in the compression of a brake piston  124  (see FIG. 18) contained within the master cylinder assembly  40  thereby actuating, via a hydraulic connection  110  to the master cylinder assembly  40 , the brakes of the towed vehicle. An actuator spring  48  of the brake piston rod assembly  36  that surrounds a piston rod  52  provides sufficient biasing force to counteract emergency actuation of the brake piston  124 , which is described in detail hereinbelow. The actuator spring  48  is held in place on one end by a washer  62  and by a safety clip  50  on the other end that rigidly attaches to the piston rod  52 .  
         [0039]    The device  10  also includes a dampener  32  that operates in a manner similar to that described with regard to the brake system. In particular, movement of the towing vehicle relative to the towed vehicle in either direction will result in corresponding movement of the housing  12  relative to the coupler  14 . Because the front roller shaft  16  is fixed relative to lateral movement to the housing  12 , movement of the housing  12  relative to the coupler  14  will also result in movement of the front pair of rollers  18 . The front rollers  18  move on the upper surface of the inner plate  46 , which is rigidly affixed to the coupler  14 . This movement of the front rollers  18  will translate to the dampener  32 , which on its other end is rigidly fixed by the dampener shaft  34  to the coupler  14 . The dampener  32  thereby acts in response to movement of the coupler in both directions to return the front pair of rollers  18 , as well as the housing  12  and coupler  14 , to a neutral position.  
         [0040]    As mentioned briefly hereinabove, the device  10  also includes a safety mechanism that will allow the brakes of the towed vehicle to apply in the event that the towed vehicle breaks away from the towing vehicle. In particular, a safety cable (not shown) attaches on one end to the towing vehicle. The other end attaches through an eyelet  58  of the spring clip  50 . The safety cable wraps around a safety cable ring  54  and returns for connection to the towing vehicle. The safety cable ring  54  captures the safety cable between the ring  54  and the inside of the coupler  14 . The safety cable wraps around the rounded center portion of the ring  54 , which avoids sharp bends in the safety cable that might tend to weaken or damage the safety cable. In the event of a breakaway, the safety cable is pulled tight around the safety cable ring  54  thereby removing the slack and compressing the spring  48  by pulling the spring clip  50  rearward and away from the inner plate  46 . This moves the piston rod  52  rearward toward the master cylinder assembly  40  thereby compressing the brake piston  124  and applying the towed vehicle brakes. A safety catch  38  captures the piston rod  52  to retain it in position to maintain brake pressure until the safety catch  38  is manually released. The spring  48  biases the piston rod  52  back to its neutral position upon release of the safety catch  38 . The forward end of the piston rod  52  contains friction grooves to facilitate capture by the safety catch  38 . In other words, the piston  52  passes through holes in the safety catch  38 , inner plate  46 , and spring clip  50  which is rigidly attached to the piston rod  52 . This allows the piston rod  52  to compress under the influence of the safety cable to actuator the brake piston  124 . Also, a spring  56  surrounding the piston rod  52  and located between the inner plate  46  and safety catch  38  biases the safety catch  38  after release of the safety catch  38 .  
         [0041]    The remaining Figures show detailed views of the device including cross sectional views designed to better show the orientation of the various components of the device  10 , including those components discussed hereinabove. One of the components of the device  10  shown in the remaining Figures but not already discussed in detail comprises the trailer hitch  42  and safety latch  44  (shown best in FIG. 21). In particular, the forward portion of the coupler  14  includes a curved underside portion  64  designed to receive the coupler ball  63  located on the back of the towing vehicle (see FIGS. 2, 11,  12 ). Insertion of the coupler ball  63  into the socket formed by the curved underside portion  64  initially moves a latch  66  into a substantially vertical position. A lower portion  68  of the latch  66  is curved in the shape of the coupler ball  63  and is designed to fit around the under side of the coupler ball  63  upon complete insertion of the coupler ball  63  and securement of the safety latch  44 . The latch  66  pivots about a shaft  70  between a position that allows for insertion and a position that allows for removal of the coupler ball  63 . An upper portion of the safety latch  44  includes a double pivoting latch cap  72  that consist of a latch top  74  and an extendable wedge plate  76 . The latch top  74  pivots about a top shaft  78 , and the extendable wedge plate  76  pivots about a wedge shaft  80  located toward the center of the latch top  74 . Moving the latch cap  72  downward into the locking position moves the extendable wedge plate  76  into contact with an upper edge  82  of the latch  66  and rotates the latch  66  in a counterclockwise direction to the position shown in FIG. 21. The extendable wedge plate  76  includes a wedge end  80  designed to move over the upper edge  82  of the latch  66 . This, in turn, rotates the curved lower portion  68  of the latch  66  into contact with the lower portion of coupler ball  63  to prevent removal of the coupler ball  63  from the trailer hitch  42  of the coupler  14 . Furthermore, with the wedge end  80  in place next to the upper edge  88  of the latch  66 , the latch  66  is prevented from moving in a clockwise manner that would release the coupler ball  63 .  
         [0042]    Continued downward movement of the latch cap  72  places the latch top  74  flush with the upper surface of the coupler  14 . The center portion of the latch top  74  includes a lock plate  83  that is biased by a spring  104  to extend the leading edge of the lock plate  83  into a position to allow it to secure under a lip  90  in the coupler, when the latch cap  72  is in the locked position. With the edge of the lock plate  83  secured under the lop  90  of the housing  14 , the latch cap  72  is in the locked position. To further secure the latch top  74 , the underside of the forward edge of the lock plate  83  includes a centrally located wedged shape portion  94  that fits between the lip  90  and a hook  92  located in the top center of the extendable wedge plate  76 . This helps prevent the leading edge of the lock plate  83  from slipping out from under the lip  90  in the top of the coupler  14  when the latch plate  72  is in the locked position. The lock plate  83  is secured to the latch top  74  by two opposing channels  84  (see FIG. 11), and by a rivet  96  in the latch top  74 . In addition, a safety pin  100  is inserted through hole  102  in the coupler  14  to further secure the latch  66  from movement when the latch  66  is in the locked position.  
         [0043]    To facilitate insertion and removal of the lock plate  83  from under the lip  90  in the coupler  14 , the latch plate  83  includes a rib  104  that extends upward from the lock plate  83  and includes an open area  106  between the two opposing channels  84 . Pressure applied to the rib  104  will allow for compressing the lock plate  83  against a spring  104  located around the rivet  96 . The spring  104  biases the lock plate  83  so that the leading edge protrudes. Compressing the spring  104  will allow for inserting and removing the lock plate  83 . Also, if necessary a tool like a screw driver can be inserted in the open area  106  to move the lock plate  83 . The latch cap  72  is gently biased by a spring  98  to raise the latch cap  72  into the position shown in the Figures upon release of the lock plate  83  from under the lip  90  in the coupler  14 .  
         [0044]    FIGS.  16 - 20  show in detail the master cylinder assembly  40 , which is generally of a conventional design. In particular, FIG. 16 shows a rear view of the master cylinder assembly  40  that includes a hydraulic line port  110  for connecting a hydraulic line between the brakes of the towed vehicle and the master cylinder assembly  40 . The rear of the master cylinder assembly  40  also includes a valve cavity  112  for attachment of a solenoid (not shown) the purpose of which is described in detail hereinbelow. The master cylinder assembly  40  includes a fill cap  114  and a diaphragm  116  to allow for operational sealing and filling of a brake fluid reservoir  118 . Alternatively, a standard fill cap with a relief valve can be used. Hydraulic fluid is transmitted to a hydraulic cylinder  122  through a plurality of ports (not shown). The hydraulic cylinder  122  also includes a hydraulic piston  124  (see FIG. 18) that is an extension of piston rod  52 . The master cylinder assembly  40  includes the throughbore  120  for mounting to the rear roller shaft  20 .  
         [0045]    In operation, the hydraulic cylinder  122  also includes a spring (not shown) at an end opposite to the hydraulic piston  124  that acts to return the hydraulic piston  124  to a neutral position after actuating the brakes. A circular cup (not shown) surrounds the outside of the hydraulic piston  124  to help create pressure during actuation. The master cylinder assembly  40  includes a centrally located port (not shown) to allow for fluid communication between the reservoir  118  and the hydraulic cylinder  122 . With the hydraulic piston  124  in a neutral position the central port is uncovered to allow the hydraulic cylinder  122  to fill with fluid. Upon forward movement of the master cylinder assembly  40  the hydraulic piston  124  is captured between the circular cup and moves forward until it covers the central port and cuts off the flow of fluid between the reservoir  118  and the hydraulic cylinder  122 . This allows for compression of the hydraulic fluid in the hydraulic cylinder  122  thereby creating pressure to actuator the brakes of the towed vehicle. After braking, the spring provides a biasing force to return the hydraulic piston  122  to its neutral position, and ports (not shown) at the piston end of the hydraulic cylinder  122  allow for fluid to backfill into the hydraulic cylinder  122  to further assist in retraction of the hydraulic piston  120 .  
         [0046]    The master cylinder assembly  40  includes a solenoid (not shown) that attaches to the valve cavity  112 . The solenoid provides control over fluid communication through a backup port  126  between the reservoir  118  and the hydraulic cylinder  122 . The need for fluid communication through the backup part  126  arises when the towing vehicle backs up with the towed vehicle attached. Movement of the coupler  14  relative to the housing  12 , created by slowing of the towing vehicle, results in application of the towed vehicle brakes, however, the same relative movement results if the towing vehicle backs up. In this situation the towed vehicle brakes would be undesirably actuated. To avoid this situation a solenoid is attached to the master cylinder assembly  40  at the valve cavity  112 . The solenoid is normally in the closed position, which will prevent fluid communication between the reservoir  118  and the hydraulic cylinder  122  via the back up port  126 . The solenoid is electrically connected to the towing vehicle to open and allow fluid communication via the back up port  126  when the towing vehicle is placed in a reverse gear. This avoids application of the towed vehicle brakes by allowing the hydraulic fluid to flow unrestricted between the reservoir  118  and the hydraulic cylinder  124 , thereby preventing any pressure build up in the hydraulic cylinder  122 .  
         [0047]    The foregoing description and drawings comprise illustrative embodiments of the present inventions. The foregoing embodiments and the methods described herein may vary based on the ability, experience, and preference of those skilled in the art. Merely listing the steps of the method in a certain order does not constitute any limitation on the order of the steps of the method. The foregoing description and drawings merely explain and illustrate the invention, and the invention is not limited thereto, except insofar as the claims are so limited. Those skilled in the art that have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.

Technology Category: 7