Abstract:
A railcar moving or positioning system incorporating relatively simple mechanical bogey frame side member sensing systems mounted on each dog carriage of a railcar indexing system is disclosed. Each sensing system is used to control the operation of a dog mounted on the same carriage. A mechanical follower device is employed to sense the underside of an encountered bogey frame side member. Deflection of the follower is used to operate a hydraulic valve which, in turn, is used as a control cylinder to raise or lower an adjacent dog member.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     I. Field of the Invention  
         [0002]     The present invention relates generally to trackside railway car handling equipment for positioning railway cars along a track for loading or unloading operations. More particularly, the present invention relates to train indexer systems that include dogs that engage the bogey frames of railcars and, specifically, to indexer systems that include mechanical systems for sensing the presence of bogey frames in conjunction with the operation of the dogs.  
         [0003]     II. Related Art  
         [0004]     Freight-hauling railway cars need to be precisely positioned proximate freight or cargo handling equipment during loading and unloading operations. Freight in the form of bulk cargo such as grain is typically loaded or unloaded with reference to stationary freight handling equipment such as chutes and conveyor equipment situated at fixed locations above or in pits beneath a specific portion of the track. Railcars for transporting grain or other such finely divided dry bulk agricultural commodities may be covered and designed with a plurality of spaced bottom discharge hopper bins or chutes accessing the main cargo storage volume. The chutes are closed by capstan-operated rack and pinion bottom closure gate systems.  
         [0005]     In the loading and discharge operations, a connected engine roughly positions one end of a string of cars to be loaded or unloaded beneath or above the appropriate equipment at the desired fixed location. Because locomotives are not well suited for precisely positioning individual cars or even strings of cars along a railroad track, positioning devices known as train movers or positioners are located at fixed stations along the track. The positioning devices are generally in the form of “indexers”, or “progressors”. Indexers generally employ a pair of spaced “dogs”, which operate together. The dogs are heavy car-engaging members mounted on movable dog carriages which are operated along built-in auxiliary carriage tracks or guideways. In the case of systems designed to operate by pushing against railway car truck bogey frames, the guideways are located one on the outside of each of the track rails in juxtaposed parallel relation thereto to engage and simultaneously push against the spaced sides of a bogey frame, axle or other portion of a railcar to urge the car and others attached to it in a desired direction for a limited distance. The system then retracts and finds the next bogey frame or axle, etc. to repeat the process. The system can be stopped at any point in a cycle when the desired position is reached for loading or unloading a car.  
         [0006]     Progressors designed to operate against bogey frames also have built-in guideways on the outside of each of the spaced rails with dogs that operate along each of the guideways. The systems are also spaced along the track and, rather than operating simultaneously against both sides of a bogey frame to move a car or string of cars, the dogs of a progressor are operated alternately, sequentially to “hand off” the car or string of cars alternating between dogs on opposed sides of the track.  
         [0007]     Using either type system an entire string of connected cars may be advanced and loaded or unloaded, one car at a time. As with the indexer system, the progressor can be stopped at any point in the operating cycle when the desired position is reached.  
         [0008]     The positioning devices of the present invention are indexer systems that utilize dogs that operate against the wheel truck bogey frames of the cars. The proper operation of these devices depends on the ability of the system to detect the presence of bogey frames and operate corresponding dogs accordingly. Many techniques have been employed to detect the presence of or locate wheel truck bogey frames. These include optical or mechanical devices that sense the presence of train wheels, mechanical devices that are linked to operate the dogs directly upon detection of the presence of a wheel truck bogey frame, techniques that include using the deflection of raised dogs striking carriage bogey frames from behind to sense those frames. Using the “dog” method, the first of two spaced opposed dogs encountering the bogey frame is pushed down from behind and the second dog which is also in the pushing posture engages the bogey frame as the dog carriage continues to move.  
         [0009]     While such systems work quite well, the presence of auxiliary devices such as tripper rods which are used in conjunction with operating bottom discharge gates may interfere with using raised dogs as sensors. Direct connected mechanical systems are shown, for example, in U.S. Pat. Nos. 6,389,984 and 5,709,153. These also require additional mechanical linking devices. Thus, there remains a need to provide a simple mechanical truck carriage bogey frame detecting system that includes a simplified operating system for a corresponding pusher dog.  
       SUMMARY OF THE INVENTION  
       [0010]     In accordance with the present invention there is provided a railcar indexing system incorporating a relatively simple mechanical bogey frame sensing system that is mounted on each dog carriage of the indexing system and used to control the operation of a corresponding dog mounted on the same carriage. The sensing system includes a mechanical follower device mounted on a crank arm positioned to be deflected by the underside of an encountered bogey frame. The crank arm is linked through a series of devices which operate to open a normally closed hydraulic valve device which, in turn, enables a connected cylinder to raise or lower a corresponding dog member.  
         [0011]     The detailed embodiment illustrates a high dog railcar indexing system that includes right and left indexers, each of which is provided with a mechanical bogey frame detecting system in accordance with the present invention. The railcar indexing system includes a pair of trackside guideways located along, just outside of and parallel to the rails of the track. A dog carriage is mounted in and designed to operate along each such trackside guideway. A vertically pivoted pusher dog is mounted on each carriage. A bogey frame sensing system is mounted on each carriage associated with and used in the control of the operation of the corresponding pusher dog.  
         [0012]     As indicated, each bogey frame detecting system includes a crank arm-mounted follower wheel designed to encounter and be deflected by the underside of a bogey frame. The crank arm is connected through a series of devices to an operating lever that provides a force to overcome a spring and open a spring-biased, normally closed hydraulic valve device which, in turn, is connected in a line to a cylinder for operating a corresponding pusher dog. The valve is mounted in relation to and designed to be opened according to the deflection of the follower. A resilient or spring-biased linkage is provided to enable the follower to operate the spring-biased valve. The linkage includes a pair of springs mounted on a movable rod connected to move through an opening in a deflection plate such that one spring is located and maintained on either side of the deflection plate. The deflection plate is, in turn, connected to bias and flex a switch-operating resilient member.  
         [0013]     The follower crank arm is fixed to and designed to rotate a shaft member in a first direction when it is in a bogey frame seeking mode. The shaft member, in turn, operates a connected pusher member, which is also connected to a fixed end of the movable rod carrying the springs and which operates in the detecting mode to force the movable rod to move in a first direction generally parallel to its length compressing a near spring against the deflection plate and releasing a spring beyond the deflection plate. This flexes a valve opening member against a valve-operating pushbutton eventually producing sufficient force to overcome an internal valve spring. This opens the normally closed spring-biased hydraulic valve. The valve is located in a line connected to a dog-operating cylinder and when the valve is opened, this causes the cylinder to retract and raise the dog. Conversely, when the follower is released, the shaft is rotated in the opposite direction, the rod is retracted and the spring beyond the deflection plate is compressed and the spring closer to the pusher is released. A return or counter-balance spring may also be provided to counter-balance the system and aid return of the flexed switch-operating member and closing of the valve.  
         [0014]     After the right and left indexers both find corresponding bogey frame side members and have their dogs raised, both indexers are operated to push together to move the car or string of cars along the track using several serially connected hydraulic cylinders or other means. When it is desired to retract the indexers, as at the end of a stroke or to position the next car, retraction of the indexers causes the followers to move out from under the bogey frame holding them down and this allows the followers to pop up and the corresponding spring-biased hydraulic valve to close as described. This leads to a lowering of the dogs and passage of the follower under a bogey frame side member in the opposite direction does not affect the spring-biased valve.  
         [0015]     A system is also provided to lock down the followers in a non-detecting mode and maintain the dogs in a down position when the indexer is fully retracted. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     In the drawings wherein like reference characters are used to designate like parts throughout the same;  
         [0017]      FIG. 1   a  is a broken plan view of a high dog railcar indexer system using bogey frame sensing in accordance with the invention shown with a single railcar wheel truck assembly;  
         [0018]      FIG. 1   b  is a side elevational view of the railcar indexer system of  FIG. 1   a;    
         [0019]      FIG. 2  is an enlarged fragmentary perspective view of a railcar indexing system similar to that illustrated in  FIGS. 1   a  and  1   b;    
         [0020]      FIG. 3  is a greatly enlarged fragmentary side view of a portion of the system of  FIG. 2 ;  
         [0021]      FIG. 4  is an inside fragmentary perspective view of an indexer of the indexing system of  FIG. 2 ; and  
         [0022]      FIG. 5  is an exploded perspective view of a bogey frame detecting and dog operating system in accordance with the invention with parts removed for clarity;  
         [0023]      FIG. 6  shows the view of  FIG. 5  as assembled;  
         [0024]      FIG. 7  shows a fragment of an indexer hydraulic schematic for operating an indexer in accordance with the invention; and  
         [0025]      FIG. 8  is a simplified sectional view of a typical indexer cylinder in accordance with the invention. 
     
    
     DETAILED DESCRIPTION  
       [0026]     The following detailed description of the present invention describes the invention with reference to railcar indexing system employing a pair of spaced pusher dogs that operate in unison against opposite sides of a bogey frame. The carriages then retract and the dogs drop or are pushed down until the followers find the next wheel truck bogey frame and the process is the repeated. The system may be stopped anywhere the operator desires so that loading or unloading operations may be performed. It will be appreciated that the system described is intended to be an example of the inventive concept and is not to be considered as a limitation on the scope of the invention.  
         [0027]      FIGS. 1   a  and  1   b  are fragmentary plan and side views that depict a high dog railcar indexer, generally at  10 , including a railcar wheel truck assembly  11  situated on a railroad track having rails  12  and  14 , the truck assembly having spaced bogey frame side members  16  and  18 , respectively, which extend beyond the spaced rails. The truck carriage further includes four wheels as at  20 . A pair of spaced trackside guideways are shown at  22  and  24  situated just outside and extending along parallel to the track rails  12  and  14 , together with a pair of dog carriages  26  and  28 , respectively, carrying high pusher dogs  30  and  32 , best seen in  FIG. 2 , which are shown in the raised position addressing the spaced bogey frame sides  16  and  18 , respectively, contacting them above the level of an axle  34 . A bogey frame sensing system in accordance with the invention is shown generally  36  in  FIGS. 2 and 3  and the system at  36  being used to control dog  32 . The dog carriages  26  and  28  are operated by reciprocating, serially connected or tandem hydraulic cylinder devices, generally,  37  and  38  ( FIG. 1 ), which may consist of four cylinders, and operate in series to move the carriages along the corresponding guideways. The bogey frame detecting and dog-operating system of the invention is shown in greater detail in  FIGS. 3-7 .  
         [0028]      FIG. 3  is a greatly enlarged fragmentary side view of a portion of the railway indexing system of  FIG. 2  showing bogey frame side member  18  having an underside  40  with which the bogey frame detecting system of the invention interacts. Although only a single bogey frame detecting system will be described, it will be noted, as seen in  FIG. 1 , that identical opposed systems are employed in left and right indexers adjacent the spaced rails of the track. The details of bogey frame detecting and dog operating system  36  will next be described in greater detail.  
         [0029]     An important aspect of the system is a system designed to mechanically detect the presence and passage of the underside of a railcar wheel truck bogey frame side member rather than detecting the passage of a wheel or other portion of the car. The system is also one used to control raising and lowering of a corresponding dog based on the operation of the bogey frame detection system of the invention. The detection system utilizes a spring-biased lever-operated concept to flex a resilient member which, in turn, depresses a valve opening pushbutton during the interval that a follower is held down under the underside of a bogey frame side member, thereby opening a normally closed hydraulic valve which, in turn, causes a hydraulic cylinder to raise a corresponding dog.  
         [0030]     As seen in the  FIGS. 3-7 , the bogey frame detection and dog-operating system of the invention includes a follower wheel  50  attached to a shaft  52  which, in turn, is mounted in a lever or crank arm  54 , which is fixed to rotate an operating rod or shaft  56 . A spacer sleeve member is provided at  58 . The shaft  56  is, in turn, supported and mounted to rotate in sleeve  60  and openings in spaced parallel support gusset members  62  and  64 , which are mounted on a carriage platform member  66  ( FIG. 4 ). A combination spring-mounting rod  68  and pusher device  70  with extension  72  is provided, and is attached via an operating arm  74  fixed using a clevis-type mount to rotate with operating shaft  56 . The rod  68  is adapted to carry a pair of compression springs  76  and  78 , which are carried and maintained on either side of a deflection plate  80  having an opening  82  through which a free end of rod  68  is mounted. A washer  84  is fixed to the free end of rod  68  to retain the spring  76 . A normally closed, spring-biased valve device  86  (see  FIG. 7 ) is mounted in fixed relation to the carriage frame and is equipped with a resilient depressible operating pushbutton as at  88  which operates against an internal spring  89  ( FIG. 7 ). Deflection plate  76  is fixed to a resilient flexing member  90 , the underside of which is utilized to operate the pushbutton  88  of valve  86 . A hold-down plate or “flag” lever  92  is also fixed to operating rod  56  and a return or release spring  94  for flag lever  92  is provided mounted in a hollow cylinder  96  fixed to the member  90 .  
         [0031]     A further counter-balance spring for counter-balancing the member  90  is shown at  98  and is mounted between an end of member  90  and a flange member  100  fixed to gusset  64  to counter-balance the major portion of the member  90  and associated parts, which are offset with respect to shaft  56 .  
         [0032]     The dog  32  is operated to be raised and lowered by a cylinder  102  having a rod  104  mounted between a clevis  96  attached to the dog  32  as by rod eye  108  and a heavy retaining gusset member  110  fixed to the carriage frame member  111 . A stop  112  is provided to address and receive the pusher face  114  of the dog  32  when it is in the down or dropped position as shown in  FIG. 4 .  
         [0033]     The fully rearward or return position of an indexer of the invention is shown best in the fragmentary perspective view of  FIG. 4  in which dogs and followers both are in a hold-down mode. As seen in the  FIG. 1 , the guideway is further provided with a fixed heavy vertical gusset member  120  on which is mounted a hold-down roller  122  which is designed to rotate flag member  92  and hold it down at the end of a return stroke of the indexer. A further fixed heavy gusset member  124  is provided spaced from member  120  and carries a knock-down plate  126  fixed thereto. The knock-down plate further carries a proximity sensor  126  which senses the proximity of a fixed member  128  when the indexer is fully retracted. Detection of the member  128  by the proximity switch disables raising of the dog  32 . In this position, as shown in  FIG. 4 , by operation of flag member  92 , follower roller  50  is held in a down position in the opposite direction of that which occurs upon encountering a bogey frame side member when the indexer is advanced. Thus, valve  86  remains closed.  
         [0034]      FIG. 6  depicts the parts of the exploded view of  FIG. 5  in an assembled condition with the dog in the raised position and the follower wheel  50  and arm  54  also in the fully upright position. This configuration would occur as the carriage begins its retraction part of the cycle and the follower  50  comes out from under a bogey frame, but the dog  32  has not yet dropped or been pushed down.  
         [0035]      FIG. 7  depicts a fragmentary schematic view of a portion of a hydraulic system utilized to operate an indexer in accordance with the present invention. The view includes a pair of hydraulic lines  140  and  142  connected to a carriage-moving cylinder  144  through respective solenoid valves  146  and  148 . A second, serially connected carriage-moving cylinder is shown at  150  and additional serially connected cylinders for moving the carriage back and forth are not illustrated. A typical system will have four serially connected cylinders which add up to a total stroke for the left or right indexer of about 65 feet. This is sufficient distance to accommodate any normal inter-bogey frame interval. A by-pass hydraulic line is shown at  152  which is connected by a hydraulic valve  86  to operate dog cylinder  102 . An additional solenoid valve is shown at  154  and check valves are depicted at  156  and  158 .  
         [0036]     A simplified sectional view of a typical indexer cylinder as at  150  is shown in  FIG. 8  and includes a rod  160  having hydraulic connections at  162  and  164  and cylinder connections at  166  and  168 . An internal by-pass line shown at  170 , which provides fluid to extend the next cylinder, as shown in  FIG. 7 , and also fluid to retract the dog cylinder  102  and thereby raise the dog  32 . Adequate under and over pressure protection is provided in the hydraulic system in a well known manner and the operational description assumes pressures and volumes within operating limits.  
         [0037]     In operation, the left and right indexer systems coordinate the operation of the carriages  26  and  28  and the respective dogs  30  and  32  to operate in unison against a bogey frame. Thus, the operation of the system starts with indexers fully retracted with the dogs down and the sensing follower wheels in a locked down position as shown in the fragmentary view of  FIG. 4 . Owing to the amount of fluid which must be pumped to operate the system in the hunting mode, i.e., looking for a bogey frame to push, although both left and right indexers are activated, normally one will lead moving its carriage forward. Using the illustrated indexer example of the detailed embodiment will proceed until the follower  50  encounters the underside of a bogey frame side member and crank arm member  54  is pivoted to the left, as shown in  FIGS. 2 and 3 . Rotation of the follower crank arm as at  54  rotates the operating rod  56  in a counterclockwise direction based on  FIGS. 2, 3  and  6 , which pivots arm  74  and causes the pusher  70  and rod  68  to be displaced to the left thereby compressing spring  78  and releasing the compression on spring  76 . Spring  78  thus pushes against plate  80  which, in turn, causes a downward flexure of member  90  depressing pushbutton valve operator  88  eventually with sufficient force to overcome the biasing of spring  89  and open the valve  86  as shown best in the fragmentary hydraulic schematic of  FIG. 7 .  
         [0038]     The depression of pushbutton  88  is resisted by and must overcome the resistance of spring  89  and, nominally, about 100 pounds force is necessary to open valve  86  and maintain it in the open position. The opening of valve  86  allows hydraulic fluid to flow to and retract cylinder  102  which, in turn, causes the connected dog  32  to be raised into pushing position. After the first raised dog is in position against the corresponding bogey frame side member, the other indexer of the pair will perform the same sequence until both indexer dogs are in pushing position against the corresponding bogey frame side members. Further extension of the serially-connected carriage-moving cylinders will propel the bogey frame and connected car or cars along the tracks as desired. By using the balanced force of both right and left indexers against a bogey frame, a total force of 40 tons or more is available to advance the cars.  
         [0039]     At the end of the total stroke or when it is desired to reverse the system, the serially-connected carriage-moving cylinders are caused to retract which, in turn, causes the follower wheel as at  50  to move out from under the bogey frame member  16  and thereby resume its upright position releasing the deflection on member  90  as aided by counter-balance spring  98 , thereby releasing pushbutton  88  and closing valve  86 . This enables the corresponding cylinder  102  to extend and allows the dogs as at  32  to drop. When the system is fully retracted, it resumes the initial position as previously described. The system can then be re-extended to encounter the next desired bogey frame. Of course, the system may be stopped at any time when a car of interest is properly positioned for loading or unloading.  
         [0040]     While the above-described detailed embodiment describes a railcar indexer system which operates to move the cars in a single direction, it will be appreciated that each carriage could also carry a pair of oppositely disposed dogs in a well known manner to achieve a reversing system using the wheel truck bogey frame side member detecting system of the present invention. A system could also be built to be operated in the manner of a progressor, also in a well known manner, which would be familiar to those skilled in the art.  
         [0041]     This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.