Abstract:
A three-wheeled vehicle having a reversed tricycle configuration provides a means of transporting a quadraped pet, such as a dog, to accompany the pet owner while he or she jogs or runs behind the vehicle pushing and steering it.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application is a continuation-in-part of application Ser. No. 11/027,537, filed Dec. 30, 2004 now abandoned. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a three-wheeled vehicle in which a dog or other quadruped pet can be transported while the pet owner is jogging or running behind the vehicle. This invention enables an individual who enjoys jogging and/or running with their pet to have their pet accompany them when the pet is not able or disposed to do so. 
   Three-wheeled strollers designed for carrying an infant while an adult is jogging or running have long been known in the prior art. A typical example of such a “baby jogger” is taught by Jacobs, U.S. Pat. No. 5,029,891. The baby jogger vehicle has a tricycle-type wheel configuration, with one wheel in the front and two wheels in the rear. A seat to accommodate an infant in the upright seated position is positioned above the rear wheels. A handle for pushing and guiding the vehicle extends from the portion of the vehicle supported by the two rear wheels. 
   The principal problem encountered in adapting such a “baby jogger” for pets is the fact that dogs and other quadrupeds do not sit the same way humans do. In the upright seated position, humans lean back with their legs dangling in front of them. Dogs and most other quadruped animals, on the other hand, sit leaning forward on their front legs. Therefore, a pet jogger should be designed for load distribution toward the front of the vehicle, as opposed to the baby jogger which distributes the load to the rear. 
   For optimal stability of a three-wheeled vehicle, the load should be concentrated above the wider wheel base afforded by the two wheels with a connecting axle. Applying this principle to a pet jogger with forward load distribution, it follows that the optimal design is not the standard tricycle configuration, but rather a reversed tricycle configuration, with two wheels in the front and one in the rear. 
   One version of a three-wheeled vehicle primarily designed for transporting aged, infirm or disabled pets is taught by Gordon, U.S. Pat. No. 6,913,271. But Gordon ignores the different load distribution of a pet vehicle and retains the standard tricycle configuration of a baby jogger. Furthermore, the Gordon design is not adaptable to jogging or running on rugged terrain, since the platform on which the pet sits is supported directly on the axles of the front and rear wheels, thus limiting ground clearance height to the radius of the wheels. In the Gordon “Pet Buggy,” moreover, the shock of passing over curbing or other irregularities in the vehicle&#39;s path is imparted directly to the platform on which the pet sits, without any cushioning or shock-absorbing mechanism. 
   Consequently, the Gordon “Pet Buggy” does not address the need for a stable vehicle in which a pet can comfortably sit while its owner jogs or runs. This is precisely the need that the present invention is designed to address. 
   SUMMARY OF THE INVENTION 
   The present invention addresses the need for a three-wheeled vehicle designed to transport a pet over a variety of terrains with a human jogger/runner pushing and steering the vehicle from the rear. 
   It is an object of the present invention to provide a three-wheeled pet vehicle with a reversed tricycle configuration so that the forward load distribution of a sitting quadruped is stably borne by the vehicle&#39;s wider two-wheel base. 
   It is another object of the present invention to provide a three-wheeled pet vehicle with wheel diameter and ground clearance sufficient to enable a smooth ride on a variety of terrains. 
   It is a further object of the present invention to provide a two-wheeled pet vehicle with shock absorbers to soften the shock of encountering irregularities in the vehicle&#39;s path and thereby avoid agitating the pet. 
   It is yet another object of the present invention to provide a two-wheeled pet vehicle having a steering assembly connected to the two front wheels to optimize handling and control in the reversed tricycle configuration. 
   It is yet a further object of the present invention to provide a two-wheeled pet vehicle with bicycle-type wheel braking mechanisms for increased safety, particularly when stopping the vehicle on steep downhill grades. 
   It is still another object of the present invention to provide a means of restraining the pet within a seat enclosure to prevent the pet from jumping out of the vehicle. 
   It is still a further object of the present invention to provide one or more support bars to enable the pet to prop itself up on its front paws and thus assume a semi-standing posture. 
   The foregoing and other beneficial and useful objects are achieved by a three-wheeled vehicle for transporting a quadruped pet, such as a dog, while the pet owner is jogging or running and pushing the vehicle from behind. The vehicle comprises three wheels, an undercarriage, a pet enclosure, and a steering assembly. 
   The three wheels are arranged in a reversed tricycle configuration, that is, with two front wheels in the forward part of the vehicle and one rear wheel in the back of the vehicle. The two front wheels are rotatably attached on either end of a front wheel axle, while the rear wheel is rotatably attached to a shorter rear wheel axle. All three wheels are of the type typically found on bicycle, with metal spokes supporting rim-mounted air-inflated tires. All three wheels have the same diameter, preferably sixteen inches (16″), large enough to allow a relatively smooth ride on rugged terrain. 
   The undercarriage comprises two forward uprights, a carriage frame and a rear wheel fork. The two forward uprights are erect tubular members, fabricated of durable plastic or metal, which are attached to the front wheel axle just inside the front wheels. The forward uprights slant obliquely upward from the front wheel axle at an acute angle of about 70° to the horizontal plane. At the bottom of each forward upright, just above the point of attachment to the front wheel axle, is a shock-absorber, preferably a coiled steel spring shock-absorber of the type typically installed on mountain bikes. 
   The upper end of each forward upright is rigidly attached to the forward end of the carriage frame. The carriage frame is a truncated A-frame structure, fabricated of durable tubular plastic or metal. The carriage frame has an open end, a closed end and a mid-frame bar. The carriage-frame is rigidly attached to the forward uprights at the open end in the front of the vehicle and rigidly attached to the rear wheel fork at the closed end at the rear of the vehicle. 
   The rear wheel fork comprises two fork prongs that extend perpendicularly or at an obtuse angle downward from the closed end of the carriage frame and connects to either end of the rear wheel axle. At the bottom of each fork prong, just above the point of attachment to the rear wheel axle, is a shock-absorber, preferably a coiled steel spring shock-absorber of the type typically installed on mountain bikes. 
   The pet enclosure comprises a pet platform, a platform rod, a back panel, a panel rod, two enclosure uprights, and one or more support bars. The pet platform is a square, rectangular or trapezoidal sheet of flexible material, such as woven natural or synthetic fiber. The pet platform is tautly stretched between the mid-frame bar of the carriage frame and the platform rod, with the latter being a solid metal rod secured at either end to the forward uprights. 
   The back panel is a square, rectangular or trapezoidal sheet of the same flexible material as the pet platform. The back panel is tautly stretched between the mid-frame bar of the carriage frame and the panel rod. The panel rod is a solid metal rod secured at either end to the enclosure uprights, which are tubular metal or durable plastic attached at the bases to either end of the mid-frame bar. 
   Alternately, the pet platform and the back panel can be one integral sheet of flexible material stretched tautly between the platform rod and the panel rod and wrapping around the mid-frame bar of the carriage frame. Also alternately, the enclosure uprights can be rotably attached to the mid-frame bar with a locking mechanism so to allow the back panel to be tilted forward or backward and locked in various positions to accommodate different sized pets. 
   Preferably, the back panel and/or the pet platform has a pet harness comprising one or more flexible straps designed to be attached to a pet and/or to a pet collar in order to restrict the pet&#39;s movement within the pet enclosure. 
   One or more support bars comprise arcuate tubular metal or durable plastic bars that are attached to the two forward uprights and wrap around the front of the vehicle. Preferably, the support bars extend around both sides of the pet platform and also extend back to meet or attach to the enclosure uprights, thereby forming a complete enclosure around all sides of the pet platform. Optionally, the support bars can be wrapped with the same flexible material used for the pet platform and the back panel. 
   The arch of each support bar extends several inches forward of the platform rod, thus allowing the pet to lean forward in a semi-upright posture rather than sitting continuously. If more than one support bar is used, the arch of the higher support bars extends further forward than the arch of the lower support bars, thus enabling the pet to progressively assume a more upright posture by ascending stepwise with its front paws from the lower to the higher support bars. 
   Preferably, a retractable cover, made of flexible impervious fabric, is attached to the enclosure uprights above the back panel. When opened, the retractable cover extends above the pet platform in order to protect the pet from the elements. 
   The steering assembly comprises a horizontal handle bar, two steering bars, and one or more hand brakes. The handle bar is tubular metal with two handles, one at each end. Attached to one of both of the handles are hand brakes of the type typically installed on bicycles. When the hand brake is squeezed, it pulls on a cable which extends along the steering bars to control caliper or disc brakes on both front wheels. 
   The steering bars extend from the handle bar to the mid-frame bar of the carriage frame, to which they are rotatably attached. From the mid-frame bar, the steering bars extend further to the front wheel axle, to which their distal ends are rigidly attached between the forward upright and the wheel on either end of the axle. 
   In this configuration, the steering assembly enables the jogger/runner to control the movements of the vehicle in all directions by pushing it forward, pulling it back, applying the brakes, and/or applying a turning torque to the handle bar. The connection of the handle bar to the front wheels through the two steering bars optimizes the handling of the vehicle by transmitting the turning torque directly to the front wheels, which control the direction of the vehicle&#39;s movement. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front perspective view of the preferred embodiment of the present invention. 
       FIG. 2  is a side perspective view of the preferred embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1 , the vehicle  10  comprises three wheels  11 , an undercarriage  12 , a pet enclosure  13 , and a steering assembly  14 . The three wheels  11  are arranged in a reversed tricycle configuration, that is, with two front wheels  15  in the forward part of the vehicle  10  and one rear wheel  16  in the back of the vehicle  10 . The two front wheels  15  are rotatably attached on either end of a front wheel axle  17 , while the rear wheel  16  is rotatably attached to a shorter rear wheel axle  18 . All three wheels  11  are of the type typically found on bicycle, with metal spokes supporting rim-mounted air-inflated tires. All three wheels  11  have the same diameter, preferably sixteen inches (16″), large enough to allow a relatively smooth ride on rugged terrain. 
   Referring to  FIGS. 1 and 2 , the undercarriage  12  comprises two forward uprights  19 , a carriage frame  20  and a rear wheel fork  21 . The two forward uprights  19  are erect tubular members, fabricated of durable plastic or metal, which are attached to the front wheel axle  17  just inside the front wheels  15 . The forward uprights  19  slant obliquely upward from the front wheel axle  17  at an acute angle of approximately 70° to the horizontal plane. At the bottom of each forward upright  19 , just above the point of attachment to the front wheel axle  17 , is a shock-absorber  22 , preferably a coiled steel spring shock-absorber of the type typically installed on mountain bikes. 
   The upper end of each forward upright  19  is rigidly attached to the forward end of the carriage frame  20 . The carriage frame  20  is a truncated A-frame structure, fabricated of durable tubular plastic or metal. The carriage frame  20  has an open end  23 , a closed end  24  and a mid-frame bar  25 . The carriage-frame  20  is rigidly attached to the forward uprights  19  at the open end  23  in the front of the vehicle and rigidly attached to the rear wheel fork  21  at the closed end  24  at the rear of the vehicle. 
   The rear wheel fork  21  comprises two fork prongs  26  that extend perpendicularly or at an obtuse angle downward from the closed  24  end of the carriage frame  20  and connects to either end of the rear wheel axle  18 . At the bottom of each fork prong  26 , just above the point of attachment to the rear wheel axle  18 , is a shock-absorber  22 , preferably a coiled steel spring shock-absorber of the type typically installed on mountain bikes. 
   The pet enclosure  13  comprises a pet platform  27 , a platform rod  28 , a back panel  29 , a panel rod  30 , two enclosure uprights  31 , and one or more support bars  32 . The pet platform  27  is a square, rectangular or trapezoidal sheet of flexible material, such as woven natural or synthetic fiber. The pet platform  27  is tautly stretched between the mid-frame bar  25  of the carriage frame  20  and the platform rod  28 , with the latter being a solid metal rod secured at either end to the forward uprights  19 . 
   The back panel  29  is a square, rectangular or trapezoidal sheet of the same flexible material as the pet platform  27 . The back panel  29  is tautly stretched between the mid-frame bar  25  of the carriage frame  20  and the panel rod  30 . The panel rod  30  is a solid metal rod secured at either end to the enclosure uprights  31 , which are tubular metal or durable plastic attached at the bases to either end of the mid-frame bar  25 . 
   Alternately, the pet platform  27  and the back panel  29  can be one integral sheet of flexible material stretched tautly between the platform rod  28  and the panel rod  30  and wrapping around the mid-frame bar  25  of the carriage frame  20 . Also alternately, the enclosure uprights  31  can be rotably attached to the mid-frame bar  25  with a locking mechanism (not shown) so to allow the back panel  29  to be tilted forward or backward and locked in various positions to accommodate different sized pets. 
   Preferably, the back panel  29  and/or the pet platform  27  have a pet harness  33  comprising one or more flexible straps designed to be attached to a pet and/or to a pet collar in order to restrict the pet&#39;s movement within the pet enclosure  13 . 
   One or more support bars  32  comprise arcuate tubular metal or durable plastic bars that are attached to the two forward uprights  19  and wrap around the front of the vehicle  10 . Preferably, the support bars  32  extend around both sides of the pet platform  27  and also extend back to meet or attach to the enclosure uprights  31 , thereby forming a complete enclosure around all sides of the pet platform  27 . Optionally, the support bars  32  can be wrapped with the same flexible material used for the pet platform  27  and the back panel  29 . 
   The arch of each support bar  32  extends several inches forward of the platform rod  28 , thus allowing the pet to lean forward in a semi-upright posture rather than sitting continuously. If more than one support bar  32  is used, the arch of the higher support bars  32  extends further forward than the arch of the lower support bars  32 , thus enabling the pet to progressively assume a more upright posture by ascending stepwise with its front paws from the lower to the higher support bars  32 . 
   Preferably, a retractable cover  34 , made of flexible impervious fabric, is attached to the enclosure uprights  31  above the back panel  29 . When opened, the retractable cover  34  extends above the pet platform  27  in order to protect the pet from the elements. 
   The steering assembly  14  comprises a horizontal handle bar  35 , two steering bars  36 , and one or more hand brakes  37 . The handle bar  35  is tubular metal with two handles  38 , one at each end. Attached to one or both of the handles  38  are hand brakes  37  of the type typically installed on bicycles. When the hand brake  37  is squeezed, it pulls on a cable (not shown) which extends along the steering bars  36  to control caliper or disc brakes (not shown) on both front wheels  15 . 
   The steering bars  36  extend from the handle bar  35  to the mid-frame bar  25  of the carriage frame  20 , to which they are rotatably attached. From the mid-frame bar  25 , the steering bars  26  extend further to the front wheel axle  17 , to which their distal ends are rigidly attached between the forward upright  19  and the front wheel  15  on either end of the front wheel axle  17 . 
   In this configuration, the steering assembly  14  enables the jogger/runner to control the movements of the vehicle  10  in all directions by pushing it forward, pulling it back, applying the brakes  37 , and/or applying a turning torque to the handle bar  35 . The connection of the handle bar  35  to the front wheels  15  through the two steering bars  36  optimizes the handling of the vehicle  10  by transmitting the turning torque directly to the front wheels  15 , which control the direction of the vehicle&#39;s movement. 
   While this invention has been described with reference to a specific embodiment, the description is not to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications, or embodiments that fall within the true scope of this invention.