Abstract:
A sulky force equalizer comprised of two actuators, connected together, and each actuator is connected to a sulky shaft. The two actuators work together in a pressurized feedback loop that captures and uses errant sulky-and-horse forces to counterbalance any imbalance of pulling forces from the horse; reduces the effort required by a horse to control, stabilize and pull the sulky; and correct any imbalance of the sulky shaft positions. The sulky force equalizer also operates in force analysis mode to test forces in the actuators.

Description:
CROSS-REFERENCE TO RELATED PATENTS 
       [0001]    The present application claims the benefit of the provisional application 61/463,326 filed Feb. 16, 2011. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to a racing sulky apparatus that minimizes resistance and reduces the effort required by the horse to control and stabilize the sulky. More particularly, the invention is an apparatus that provides force equalization between sulky and horse, and a test mode that provides an analysis of the forces between the horse and sulky. 
       BACKGROUND OF THE INVENTION 
       [0003]    In harness racing, a racehorse pulls a two-wheeled cart, or sulky, having a pair of shafts. The shafts are attached to a harness saddle circling the horse&#39;s body. As the horse trots, it rolls from side to side, and this motion is transmitted to the sulky through the shafts tending to cause the sulky to fish-tail, or zig-zag, on the track, and put a strain or drag on the horse&#39;s forward moving energy. Any side-to-side motion transmitted from the horse to the sulky detracts from the forward motion of the horse. 
         [0004]    Another drag on the horse&#39;s forward motion occurs when sulky makes a turn or changes lanes. The connection between sulky and horse, the shafts, creates a barrier to the ability of the horse and sulky to negotiate a turn. When the horse enters a turn at a high rate of speed the sulky skids on the tracks and this outside force pulls on the sulky, contributing to horse-and-sulky loss of distance, time and racing position. 
         [0005]    Finally, there are a number of forces that are always trying to separate the stationary-prone sulky from the moving horse, i.e., friction, wind resistance, gravity, etc. 
         [0006]    It is desirable to reduce or eliminate these forces and movements that detract from the forward motion of horse and sulky, i.e., the side-to-side movements of the horse, skidding of the sulky, the outward pull and skidding of the sulky in a turn, and forces that try to separate the stationary-prone sulky from the moving horse. 
         [0007]    Attempts have been made to overcome the above-noted disadvantages of the conventional systems for hitching a horse to a sulky by using various ball-joint arrangements and rigid mounted bullet type connectors. U.S. Pat. No. 4,473,991 discloses a harness connector device wherein a pin secured to the harness fits into a first ball joint connected through a linking member to a second ball joint, which in turn is connected to a shaft. As a result the link member is able to move relative to the shaft and harness to permit displacement of the harness relative to the shaft tending to alleviate side-slipping of the sulky. 
         [0008]    U.S. Pat. No. 5,056,301 issued to Garland &amp; Boutilier discloses a sulky cart that has shafts with off-set forward end portions and it attempts to eliminate the rigid connection between harness and sulky. The sulky cart is releasably attached to an off-set elongated sleeve member with a connector assembly on the forward end of the sleeve member. The connector assembly contains a rotatable ball with a central aperture for sliding over a harness pin secured to and extending from a harness saddle. The harness pin is provided near its outer end with a locked locking device, so that the cart can be hitched to the saddle harness by sliding the harness pin and locking device through the central aperture in the ball. 
         [0009]    Finally, Boutilier U.S. Pat. No. 7,818,951 discloses an apparatus that connects the shafts of the sulky to a harness in a manner so as to isolate racehorse motion from the racing sulky. The apparatus includes a ball joint for a rotating attachment to the harness and a threaded end for fixed attachment to the sulky shaft. A dampening piston is provided between the ball joint and the sulky shaft to provide shock absorption and thereby isolate horse movement by dampening the running, trotting, pacing, and galloping motions of the horse from the sulky. 
         [0010]    Thus, at best, the prior art devices are force isolation devices that attempt to alleviate side-slipping of the sulky by a ball-joint arrangement, or devices that attempt to eliminate the effects of too rigid a relationship between harness and sulky, or devices that use a sulky cart with shafts having off-set forward end portions and dissipate the energy from unwanted movements of the horse and sulky. 
         [0011]    A need exists for a device doesn&#39;t simply dissipate or isolate unwanted forces but uses the unwanted sulky-horse forces to greatly reduce the unwanted forces. The device corrects any imbalance of the shaft positions and allows the horse to pull the sulky in the forward direction alone. 
         [0012]    Therefore, an object of the present invention is a device for connecting the shafts of a sulky to a harness saddle and having the device capture the forces of unwanted sulky movements, redirecting and converting those forces to equalize any imbalance of the sulky shaft positions and allow the horse to pull the sulky evenly in the forward direction alone. Other objects and advantages of the present invention will become apparent from the following description and accompanying drawings of a preferred embodiment thereof and from the manufacture and use of the invention. 
       SUMMARY 
       [0013]    To achieve the objects of the present invention there is provided a device for connecting a sulky shaft to a harness which device comprises two double-action, actuating, tandem cylinders connected together. Each cylinder contains a piston connected to a piston rod, and the rod slides through the head of the cylinder. The piston divides the inside of the cylinder into two sealed, variable-volume chambers, and an upper and lower chamber. Each chamber has a port through which fluid enters and leaves the chamber. Tubing connects the ports of the bottom chambers, and separate tubing connects the ports of the upper chambers. Pressure in the chambers operate the piston and rod assembly as a liquid or gas enters a chamber through the ports, moving the piston forward and backward in a pressurized feedback loop that equalizes pressure in all four chambers. 
         [0014]    It is an object of the invention to use the unwanted sulky-and-horse forces to greatly reduce those unwanted forces, correct any imbalance of the sulky shaft position, and allow the horse to pull the sulky in the forward direction alone. 
         [0015]    It is an object of the invention to correct any lead-lag position of the sulky shaft tips, which occurs when the force of a lead shaft is greater than the lag shaft. The sulky force equalizer uses the connected tandem actuators to correct the lead-lag imbalance, shifting fluid pressure between the actuators, allowing chamber pressures to equalize, and correcting the lead-lag position of the sulky shaft tips. 
         [0016]    It is an object of the invention to equalize any force imbalance the horse exerts on the sulky&#39;s parallel shafts. 
         [0017]    It is another object of the invention to maintain a balanced sulky pulling force for the horse. The equalizer allows the sulky shafts to pivot freely as it tracks behind the horse and enhances the controllability of the sulky 
         [0018]    It is an object of the present invention to capture the separation forces of the sulky and horse movements, converting that force into fluid pressure, redirecting and using that converted force to equalize any imbalance of the sulky shaft positions, and let the horse pull the sulky evenly in the forward direction alone. 
         [0019]    It is an object of the present invention to provide a device for a racing sulky that reduces sulky resistance to the horse&#39;s forward motion. 
         [0020]    It is another object of the present invention to create a pressure sensing feedback loop that senses force differentials, captures those force differentials, and distributes the forces to correct any imbalance of the sulky shaft position, eliminating force differentials that hinder the forward motion of the horse. 
         [0021]    An object of the present invention is to maintain evenly distributed forces between the parallel sulky shafts as a horse propels the sulky forward, and greatly reduce sulky fish-tailing, skidding, and yaw wagging movement. 
         [0022]    Another object of the present invention is to provide an ergonomic connection between the racehorse and sulky by providing a resilient connection that allows the racehorse an area of free mobility within the confines of the harness and the sulky connection. 
         [0023]    Another ergonomic object of the present invention is the reduced amount of vibration transmitted from the sulky to the racehorse. The invention absorbs shock and vibration as it converts and equalizes the pulling force. 
         [0024]    Still another ergonomic object of the present invention is noise reduction at the connection point of the sulky and harness. The disclosed device absorbs shock and vibration and balances the force applied by the horse to the sulky, resulting in a significant noise reduction at the sulky and harness connection point. 
         [0025]    Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of an embodiment of the invention in conjunction with the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  shows an illustration of a racing sulky and horse (seen by dotted line) showing the attachment of the shafts of the sulky to the harness saddle on the horse in accordance with an embodiment of the invention (seen in solid line); 
           [0027]      FIG. 2  shows a close-up illustration of the actuator assembly of the embodiment; 
           [0028]      FIG. 3  shows an exploded view of the actuator, the cross-connected tubing, and the clevis carriage assembly of the disclosed embodiment; 
           [0029]      FIG. 4   a  shows an exploded internal view of clevis carriage bearing assembly; 
           [0030]      FIG. 4  shows an exploded view clevis carriage and carriage guide track; 
           [0031]      FIG. 5  shows an exploded view of actuator components; 
           [0032]      FIG. 6A  shows an exploded cutaway view of the actuators with an even amount of force applied to the clevis carriage by the horse; 
           [0033]      FIG. 6B  shows an exploded cut-away view of actuators with a greater amount of force applied to the left clevis carriage by the horse; and 
           [0034]      FIG. 6C  shows an exploded cutaway view of the actuators with a greater amount of force being applied to the right clevis carriage by the horse. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    One representative form of a racing sulky configured to embody the concepts of the invention is seen in  FIG. 1 . The connecting device, a sulky force equalizer  30 , is mounted in this embodiment as a saddle mount actuator. However, the actuator can be mounted a number of ways, including in a nose mounted actuator or an actuator rear mounted and it would operate the same way. 
         [0036]    In  FIG. 1  the sulky and horse are seen in dotted lines and an embodiment of the present invention is seen in solid line  30 , attached to the shafts of the sulky. As noted, the saddle mount sulky force equalizer is the connecting device between the racehorse and sulky. 
         [0037]      FIG. 2  shows the sulky force equalizer  202  connected to the shafts of the sulky, and configured in a test mode. The test mode is set by adjusting the left and right pressure equalization ball valves  14   a, b . Additionally, in the test mode, pressure gauge tubing  40  and  42  are connected to pressure gauges  43 . The sulky force equalizer can be configured with or without the pressure gauges, i.e., in a test mode or in a racing mode. In the racing mode the force equalizer does not use the pressure gauges  43  or tubing  40  and  42 . 
         [0038]    In the  FIG. 2  embodiment left, right actuator assemblies  10   a, b  are connected to the left and right clevis carriages  23   a, b , and the clevis carriages  23   a, b  move along left and right clevis guide tracks  25   a, b . Additionally, shaft adaptors  19   a, b  attach the clevis guide tracks  25   a, b  to the sulky shafts, and also attach the sulky shafts to the left and right actuator assemblies  10   a, b.    
         [0039]      FIG. 3  is an exploded view of the sulky force equalizer in a racing mode  101 . In the racing mode the sulky force equalizer consists of the following three major components: clevis carriages  23   a, b , clevis guide tracks  25   a , b, and tandem actuators  10   a, b.    
         [0040]    Replacing the prior art rigid type shaft hitch, the clevis guide tracks  25   a, b  are attached to the tips of the sulky shafts by the shaft adapters  19   a, b , the adapters are screwed into the clevis guide track receivers  28   a, b , and the head portion of the adapters  19   a, b  are inserted and secured into the sulky shafts. The clevis guide tracks  25   a, b  have an upper rail and a lower rail which allows the clevis carriages  23   a, b  to freely travel forward and backward, creating a resilient connection, able to respond to the motions of the horse. 
         [0041]    In the disclosed embodiment, clevis carriages  23   a, b  are constructed of a two piece steel housing (see  FIG. 4   a ) the inner housing  7 , and outer housing  31 . Enclosed within the inner and outer housing is a bank of three roller bearings  24 . The roller bearings  24  travel forward and backward within the clevis guide track, and three multipurpose bolts  30  serve as bearing axles, actuator rod connections and device assembly bolts. The clevises  21   a, b  are welded onto the inner carriage housing (see  FIG. 3 ). 
         [0042]    The carriage housing and clevises  21   a, b  travel on the exterior portion of the clevis guide track and the devises  21   a, b  attach to the coupler on each side of the horses harness. Thus, clevis carriage  23  is free-to-respond to forces from the horse, sulky and actuator pistons. 
         [0043]    In the disclosed embodiment, industry standard miniature pneumatic actuators with stainless steel cylinders are used for the tandem actuators  10   a, b . The tandem actuators  10   a, b  are mounted on the sulky shafts. Actuator rods  16   a, b  extend out of the actuators and attach to the clevis carriage  23   a, b . The mounting hardware used to attach the actuators to the sulky shaft are foot brackets  11   a, b  that connect to a post which extends perpendicular from the sulky shaft. Foot brackets  11   a, b  connect the actuator cylinders  10   a, b  to the sulky shafts and allows the sulky force equalizer to adjust the position of the sulky shafts. 
         [0044]    Within the tandem actuators are fluid pistons  130   a, b . The fluid pistons respond directly and proportionally to the position of the clevis carriage  23   a, b  through connecting rods  16   a, b . Left and right connectors  20   a, b  attach the connecting rods  16   a, b  to each clevis carriage  23   a, b.    
         [0045]    Clevises  21   a, b  are attached to the left and right sides of the horse. The devises  21   a, b  are also connected to the left and right clevis carriages  23   a, b  and the clevis carriages  23   a, b  move on the left and right bearings  24   a , b, along the left and right clevis guide tracks  25   a, b . The clevis carriages  23   a, b  move in the clevis travel direction  22 , forwards and backwards, to the left and right travel limiting bumpers  26   a, b.    
         [0046]    The clevis carriages  23   a, b  are also connected to left and right rod connectors  20   a, b . The rod connectors  20   a, b  are connected to the left and right connecting rods  16   a, b  which connect to pistons within the left and right actuators  10   a, b . As pistons within actuators  10   a, b  move forward or backward fluid is pumped into upper tubing  15  or lower tubing  17 , depending on the movement of the pistons. 
         [0047]    The clevis guide tracks  25   a, b , of this embodiment, are approximately six inches in length and allow the clevis carriages  23   a, b  to travel approximately five inches. These lengths will vary depending on the measured forces exerted by a particular horse and sulky combination. 
         [0048]      FIG. 3  also shows the left and right test gauge connections  13   a, b  where tubing is placed when the force actuator is set in the test mode. 
         [0049]      FIG. 4  shows an exploded view of clevis guide tracks  25   a, b  and clevis carriage  23   a, b , showing the forward and rearward clevis carriage travel in dotted lines. The left and right clevis carriages  23   a, b  consist of roller bearings  24  which internally travel within the clevis guide track  25   a, b  and allow the clevis carriages  23   a, b  and devises  21   a, b  to freely travel on the upper portion of the clevis guide tracks  25   a, b . Clevis carriages  23   a, b  move along clevis guide tracks  25   a, b , traveling forward to front stop  31 , up to the bumper  26 , and rearward to rear travel stop  30 . 
         [0050]    Left and right clevis shaft adapters  19   a, b  attach the clevis guide tracks to the sulky shafts, and also attach the sulky shafts to the actuators  10   a, b . Thus, providing another attachment point of the sulky force equalizer to the sulky shafts, an attachment point where force from the sulky force equalizer maintains even sulky shaft tips with the pulling horse. 
         [0051]      FIG. 4   a  is a exploded internal view of clevis carriage  23   a, b , showing the inner half of split housing  7  and the outer half of split housing  31  with a bank of roller bearings  24 . Each roller bearing  24  has a dual purpose bolt  30  which enables assembling the carriage housing  23  and provides axles for roller bearing motion. 
         [0052]      FIG. 5  shows the last major component of the saddle mount actuator, the left and right tandem actuators  10   a, b , which are attached to the sulky shafts and the clevis carriages  23   a, b . The attachment to the sulky shaft is obtained by wrap around right and left foot brackets  11   a, b  that mount the cylinder portion of the actuators  10   a, b  to the left and right sulky shafts. Left and right rods  16   a, b  of the actuators  10   a, b  connect to the clevis carriages  23   a, b  and a left and right rod connectors  20   a, b . Brackets  11   a, b  attach the actuators to the sulky shafts. 
         [0053]    Left rod  16   a  connects left fluid piston  21   a  and left clevis carriage  23   a , right rod  16   b  connects right fluid piston  21   b , and right clevis carriage  23   b . Actuators  10   a, b  are hollow cylinders which contain left and right slide pistons  130   a, b . The right fluid piston  130   b  separate fluid chambers  140   b  and  145   b  on the right shaft and left fluid piston  130   a  separates fluid chambers  140   a  and  145   a  on the left shaft. 
         [0054]    Upper tubing  17  allows pressure equalization between fluid chambers  145   a  and  145   b , lower tubing  15  allows pressure equalization between fluid chambers  140   a  and  145   b . The upper and lower tubing allows fluid to shift sides and maintain equal chamber pressure, keeping the sulky shaft tips even with the horse. 
       Detailed Description of the Tandem Acting Actuator 
       [0055]      FIGS. 6   a, b  and  c  show the operation of the sulky force equalizer in several phases, as the application of force differs while being propelled forward by the horse. The figures are cutaway views of the interior portion of the actuators fully assembled and attached to the clevis bearing assembly. 
         [0056]    A trotting horse with a sulky force equalizer connected between the sulky and horse follows the following approximate sequence: 
         [0057]    (1) Suspension Phase  FIG. 6   a    
         [0058]    (2) Left Stance Phase  FIG. 6   b    
         [0059]    (3) Suspension Phase  FIG. 6   a    
         [0060]    (4) Right Stance Phase  FIG. 6   c    
         [0061]    (5) Cycle complete, repeat starting at (1) or (2) 
         [0062]    Thus, a complete cycle starts at (1) or (2), cycles down to the end at (4) and (5), and the cycle repeats. Additionally, there are errant forces trying to separate the stationary-prone sulky from the moving horse, i.e., friction, wind resistance, gravity, etc. The purpose for the resilient connection between clevis carriages  23  and the harness of the horse is to capture the side-to-side movements of the horse, as well as the errant separating-type forces between the sulky and horse, and uses those forces to generate pressure in actuator chambers  140  and  145 . 
         [0063]    The left and right rolls of the horse and stray errant forces provide the energy to operate the sulky force equalizer. The sulky force equalizer compresses in one actuator on one side of the horse and causes the actuator on the other side to expand alternating from side to side (approximately three times a second), as described in the following description. 
         [0064]      FIG. 6   a  is an exploded cutaway view of the actuators showing an equal amount of pulling force applied to clevis carriages  23   a  and  23   b . This position usually occurs during the suspension phase as the horse trots, an equal pressure in chambers  140   a  and  140   b ,  145   a  and  145   b , and allows the horse to pull the sulky with a balanced force on both shafts while maintaining parallel sulky shaft tips perpendicular with the horses harness. 
         [0065]      FIG. 6   b  is an exploded cutaway view of the sulky force equalizer actuators  10   a, b  with the pistons and clevis positions showing a greater of pulling force applied to the left side of the force equalizer. This greater amount of force usually occurs during the left stance phase as the horse trots. 
         [0066]    A detailed description of the internal and external component movements during fluid displacement is as follows: clevis carriage  23   a  and piston  130   a  are pulled forward by the horse, the sulky and shafts are attempting to separate or lose distance with the forward moving horse, as this movement occurs a compression of fluid in chamber  140   a  is displaced into chamber  140   b . As the higher pressure fluid enters chamber  140   b , piston  130   b  and clevis carriage  23   b  move rearward increasing the distance between the clevis carriage and the sulky shaft tip, forcibly pushing (by means of the harness connection) the right sulky shaft forward, gaining distance with the forward moving horse, and as the left shaft loses distance and the right shaft gains distance with the forward moving horse the fluid pressures in chambers  140   a  and  140   b ,  145   a  and  145   b  equalize allowing the horse to pull the sulky forward with an equal amount of force on each parallel shaft. 
         [0067]      FIG. 6   c  is an exploded cutaway view of the force equalizer actuators  10   a, b  with the pistons and clevis positions showing a greater amount of pulling force being applied to the right side of the force equalizer. This greater amount of force usually occurs during the right stance phase as the horse trots. 
         [0068]    A detailed description of the internal and external components movements during fluid displacement is as follows. The horse pulls clevis carriage  23   b  and fluid piston  130   b  forward. The sulky and shafts attempt to separate or lose distance with the horse, and as this movement occurs a compression of fluid in chamber  140   b  displaces into chamber  140   a , the piston  130   a  and clevis carriage  23   a  move rearward increasing the distance between clevis  23   a  and the sulky shaft tip, forcibly pushing (by means of the harness connection) the left shaft forward gaining distance with the forward moving horse. As the right shaft loses distance and the left shaft gains distance with the forward moving horse, the fluid pressures in chambers  140   a  and  140   b ,  145   a  and  145   b  equalize allowing the horse to pull the sulky forward with an equal amount of force on each parallel shaft. 
         [0069]    Thus, as the horse is in motion around the track, forces between the left and right sulky shafts alternate and the left or right pressure and the fluid flow described above repeats. During this process the sulky force equalizer captures the leftward or rightward force of the horse, converts those forces, redirects the forces and uses those captured forces to equalize the racehorse&#39;s pull on the sulky. 
       Force Analysis Mode 
       [0070]    The sulky force equalizer is also capable of operating in a force analyzer mode. The primary mode of operation for the sulky force equalizer is the racing mode, accomplished when valves  14   a  and  14   b  are in the open position, and the pulling force applied by the horse equalizes between the two parallel shafts of the sulky, enabling a smoother forward motion. Testing to confirm this equalization of force can be monitored with the pressure gauges  43 . To operate the force analyzer to determine the pulling force applied by the horse to the sulkies parallel shafts individually, valves  14   a  and  14   b  are placed in the closed position, and this eliminates any crossover of fluid pressure. 
         [0071]    As noted, the force analysis mode requires additional components that would normally not be installed for use during the race mode. These components would include the pressure gauge tubing  40  and  42 , and pressure gauges  43 . Once these components are in place, the test mode is set by closing the left and right ball valves  14   a, b ; this position allows a force test to determine the amount of force being applied to each individual parallel shaft. This will verify the actual imbalances of pulling forces by the horse, proving the need for a force-equalizing device, the sulky force equalizer, and also confirming the operation of the sulky force equalizer. Further analysis could include sulky design and performance testing, accessing track conditions, optimizing track designs, driver performance, as well as other test situations. 
         [0072]    The force analysis mode can be configured test pressure in the tandem acting actuators four chambers  140   a, b  and  145   a, b . A positive force can be monitored by connecting pressure gauges  43  to the fluid chambers  140   a, b , and a negative force can be monitored by connecting pressure gauges  43  to chambers  145   a, b.    
         [0073]    Having described preferred embodiments of the invention, it will be understood to those skilled in the art that variations and modifications thereof fall within the spirit and scope of the invention. Those of skill in the art may effect alterations, modifications and variations to particular embodiments without departing from the scope of the invention, which is defined by the appended claims.