Abstract:
A walk-behind rail condition monitoring apparatus is provided, including a frame; at least one handle on the frame; a processor mounted to the frame; a couplant tank mounted to the frame; and a rail capture unit mounted to the frame. The rail capture unit is constructed and arranged for retaining an ultrasonic sensing wheel and including a plurality of rotating guides for maintaining alignment of the monitor on a railroad rail.

Description:
RELATED APPLICATION 
       [0001]    This application claims 35 USC 119(e) priority from U.S. Provisional Application Ser. No. 62/137,051 filed Mar. 23, 2015. 
     
    
     BACKGROUND 
       [0002]    The present invention relates generally to railroad rail condition monitoring systems, and more specifically, to an improved, compact rail condition monitor constructed and arranged for monitoring a single rail as an operator walks behind the unit. 
         [0003]    Monitoring of the condition of railroad rails to monitor cracks, defective couplings and the like using ultrasonic technology is known in the art. In one embodiment, a conventional utility truck is provided with retractable rail travel wheels, and has an operator workstation, where an operator monitors data obtained by an ultrasonic sensing unit in contact with the rail. Such systems are disclosed in commonly-assigned, copending US Patent Publication Nos. 2013/0231873-A1 and 2014/0069193-A1, both of which are incorporated by reference. 
         [0004]    There is a need by railroads for a smaller scale rail condition monitoring system for use in rail yards, for short distances, and in other locations where a large vehicle is too expensive, impractical or otherwise unsuitable. Walk-behind rail maintenance systems are available. Also, conventional systems require the operator to wear components on his body in a backpack, which is heavy and in some cases difficult to access. Thus, there is a need for an improved walk-behind rail condition monitoring apparatus that is more ergonomically suitable to the operator. 
       SUMMARY 
       [0005]    The above-listed needs are met or exceeded by the present walk-behind rail condition monitoring apparatus, which features many system components integrated into a single housing that easily pushed along the rail by an operator. A six-point rail engagement provides greater stability and accuracy. The multi-point engagement includes pairs of biased rollers which ride on each side of the rail head, and which are constructed and arranged to pivot clear of the rail head if an obstruction is encountered. Such obstructions include but are not limited to switches or rail crossings. During operation, the rollers provide increased stability for the apparatus, and facilitate the maintenance of operational alignment of the apparatus as the operator walks along the track. Also, the present configuration is more adaptable to varying cross-sections of rail and variations in real head geometry due to wear. The rollers are optionally retractable by the operator. 
         [0006]    Another feature of the present monitoring apparatus is an enhanced, on-board DSP (Digital Signal Processor) technology which incorporates software for both A-Scan (oscilloscope display) and B-Scan (colored icons represent rail condition and alert the operator of flaws) technology. Further, the processor is equipped with GPS capability. Included in the processor software are liquid acoustic couplant flow control functions that control a couplant flow pump to adjust the couplant flow patterns in view of operating and/or environmental conditions. The operator can control the couplant flow output through a Graphic User Interface (GUI) on the processor. When the operator pauses in monitoring, the unit features a retractable blade stand to hold the apparatus upright on the rail, or alternately, on the ground. As is known in the art, the couplant is sprayed upon the rail near the ultrasonic transducer for accurate ultrasonic data retrieval. 
         [0007]    Other features include a storage area on an upper surface of the couplant tank for storing an ethernet cable, an adjustable push handle to accommodate a variety of operators, a detachable side handle that mounts left or right for more convenient pushing while the operator walks alongside the unit, a retract lever for disengaging the multi-point rail capture system, a quick connect tool-less battery coupling. 
         [0008]    More specifically, a walk-behind rail condition monitoring apparatus is provided, including a frame; at least one handle on the frame; a processor mounted to the frame; a couplant tank mounted to the frame; and a rail capture unit mounted to the frame. The rail capture unit is constructed and arranged for retaining an ultrasonic sensing wheel and including a plurality of rotating guides for maintaining alignment of the monitor on a railroad rail. 
         [0009]    In another embodiment, a walk-behind rail condition monitoring apparatus, is provided, including a frame; at least one handle on the frame; a processor mounted to the frame, the processor having a GUI display, is programmed for providing both A-Scan and B-Scan data, and has GPS. A couplant tank is mounted to the frame; and a rail capture unit is mounted to the frame, is constructed and arranged for retaining an ultrasonic sensing wheel and including a plurality of rotating guides for maintaining alignment of the monitor on a railroad rail. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a rear perspective view of the present walk-behind rail condition monitoring apparatus; 
           [0011]      FIG. 2  is a rear view of the apparatus of  FIG. 1 ; 
           [0012]      FIG. 3  is a side elevation of the apparatus of  FIG. 1 ; 
           [0013]      FIG. 4  is a fragmentary front view of the apparatus of  FIG. 1 , showing the rail capture assembly; 
           [0014]      FIG. 5  is a side view of the present rail capture assembly showing the retractable guide wheels in operational and retracted positions; 
           [0015]      FIG. 6  is a front view of the assembly of  FIG. 5 ; 
           [0016]      FIG. 7  is a side view of the present rail capture assembly in an operational position; 
           [0017]      FIG. 8  is a side view of the assembly of  FIG. 7  with the guide wheels shown moving from the operational position to the retracted position; 
           [0018]      FIG. 9  is a schematic of the present GUI of the couplant flow control system; and 
           [0019]      FIG. 10  is a schematic flow chart of the control system operated by the GUI of  FIG. 9 . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Referring now to  FIGS. 1-3 , the present walk-behind rail condition monitoring apparatus is generally designated  10 , including a generally rectangular frame  12  made of a pair of laterally spaced sidewalls  14  and a rear wall  16 . Attached to the frame  12  at an upper end  18  is a processor support bracket  20  accommodating a computer laptop-type processor  22 . While other computers are considered suitable, a preferred unit is a Panasonic CF-H2 Toughbook touch screen with integrated GPS. The bracket  20  is constructed and arranged to permit the operator to adjust the position and angular orientation of the processor  22  relative to the frame  12 . As is known in the art, the processor  22 , also referred to as a Digital Signal Processor (DSP) includes a Graphical User Interface (GUI) display  24 , which preferably incorporates a touch screen. 
         [0021]    Also located on the processor support bracket  20  is a laterally slidable push handle  26  that permits the operator to walk beside the apparatus on either side as it rides on a rail  28  of a railroad track. As is known in the art, the rail  28  includes a head  30 , a web  31  and a flared foot  32 . The handle  26  is lockable in either of a right or left push position. 
         [0022]    Defined by the side and rear walls  14 ,  16  is a chamber  34  (shown hidden) accommodating a couplant tank  36  (also hidden). As is known in the art, the couplant is typically water, but in cold weather, additives, such as windshield washer fluid, are incorporated to prevent freezing A pump (not shown) on the frame  12  is in communication with the couplant tank  36  and distributes couplant to the rail  28  via a spray nozzle (explained below) to enhance ultrasonic data transmission. A hand held transducer  38 , also called a handset is provided for an operator to perform hand testing. 
         [0023]    Referring now to  FIGS. 3-8 , opposite the upper end  18  of the frame  12  is a lower end  40 , having four prongs  42 . An axle  44  is mounted transversely between each opposed pair of prongs, and rotatably accommodates a guide wheel  46 , two of which are provided. Also attached to the prongs  42  at the same point as the axles  44  is a rail capture assembly, generally designated  50 . A sensor bracket  52  includes a pair of laterally spaced plates  54  each connected at front and rear ends  56 ,  58  to the axles  44 . The plates  54  define a space  60  in which an ultrasonic sensor wheel  62  is rotatably retained so that a membrane  64  of the wheel is in contact with the rail head  30 . Such sensor wheels are well known in the art, and in the preferred embodiment, the wheel  62  is an XL9/11 Lite model with 11 sensing channels and a direct encoder. As is also known in the art, the sensor wheel  62  transmits sensed data on rail condition to the processor  22 . The transmission is through a cable (not shown) or wirelessly. Software in the processor  22  is configured to receive the sensed signals from the wheel  62  and to display both A-Scan and B-Scan rail condition data, the latter including real-time analysis expressed as color coded rail condition indicating icons as described in commonly-assigned US Publication No. 2013/0231873-A1 which is incorporated by reference. 
         [0024]    Another feature of the present apparatus  10  is that while the sensor wheel  62  is provided with eleven sensors and sensor channels, as known in the art, the processor  22  is provided with a 12 th  sensing channel for operator monitoring of rail condition using the handset probe  38  separate from the sensor wheel  62 . The probe  38  is also connected to the processor  22 . 
         [0025]    Referring now to  FIGS. 4-8 , a feature of the present rail capture assembly  50  is at least one and preferably two rail guides  66  on each side of the rail  28 . Each rail guide  66  includes a roller  68  arranged to rotatably contact a side edge  70  of the rail head  30 . Each roller  68  is secured to a pivot arm  72  secured at an end opposite the roller to a pivot point  74  on the corresponding bracket plate  54 . The rail guides  66  are constructed and arranged to pivot out of engagement with the rail upon contact with an obstruction  67  on the rail, such as a switch, rail coupling or the like. As such, the guides  66  are biased to an operational position “P” and are pivotably to a retracted position “R”. Upon passing the obstacle, a biasing force on the pivot arms  72  provided by a corresponding spring (not shown) causes them to reengage the rail head  30 . As such, the present rail capture assembly  50  includes six contact points, the two guide wheels  46  and the four rollers  68 . 
         [0026]    As seen in  FIG. 8 , the pivot arms  72  are connected together for common movement by a bar  76 , which in turn is connected to a lever  78 . Operator actuation of the lever causes the rollers to move from the operational position “P” to the retracted position “R”, such as when the apparatus  10  is moved from one rail to another, or during shipping of the apparatus to another work location. 
         [0027]    Referring now to  FIGS. 9 and 10 , another feature of the present apparatus  10  is that the operator can adjust the flow of liquid couplant from the GUI on the processor  22 . The couplant flow rate and on/off interval is adjustable based on several variables, user presets, including speed of the apparatus, and/or environmental conditions such as ambient temperature. In the present apparatus  10 , the preferred spray nozzle flow rate for applying couplant to the rail  28 , via a nozzle  99 , which is located in front of the ultrasonic sensor wheel  64 , near the top of the rail  28 . The couplant tank  36  holds approximately 5 quarts of liquid couplant. The preferred testing speed, referring to the speed at which the operator moves the apparatus  10  along the rail  28 , is in the general range of 2.5 to 3.0 miles per hour. The couplant spray pump motor is preferably rated at 24 Volts DC and will run off a motor control circuit which is integrated in the DSP  22  and is powered by a battery  82  (shown hidden) which is preferably a 4 hour continuous run Lithium Manganese battery. 
         [0028]    The processor  22  is programmed to provide multiple flow rates (typically five) and on/off interval settings selectable by the user from the GUI on the display  24 . The default values are to be downloaded from the GUI via configuration file or job download. Couplant pump motor speed and on/off intervals are controlled by pulse width modulation driven from a FPGA on a One-Pass I/O board. The user selected flow rate is downloaded from the GUI and will be passed to the FPGA on the I/O board from the DSP  22 . 
         [0029]    In addition to the selectable flow rate control on the GUI, there are “AUTO”  84 , “ON”  86 , and “OFF” buttons  88 . The ON and OFF buttons  86 ,  88  are used to manually apply couplant at the selected flow rate and flow interval pattern. The AUTO button  84  will engage the user selected flow rate (1 of 5) and flow interval pattern, and the detection of forward motion by monitoring an encoder associated with the sensor wheel  62  to start the pump. When in the AUTO mode of operation, and the OFF button  88  is actuated, the AUTO mode is to be exited. When the forward or reverse motion of the apparatus  10  reaches a specified minimum velocity, the pump motor will be turned off 
         [0030]    Referring now to  FIG. 10 , the processor  22  is programmed so that a speed sensor  90  and a direction sensor  92  sense motion of the sensor wheel  62 , then transmit sensed signals to the processor  22  for display on the GUI interface unit  24 . The operator inputs on the GUI/display  24  the mode selection at  94 , then an appropriate flow rate is determined at  96 , so that ultimately the pump motor  98  is controlled for the appropriate distribution of couplant. 
         [0031]    Referring again to  FIGS. 1-3 , the frame  12  also features a retractable blade stand  100  that is retractable or extendable by the operator. The stand  100  is configured for holding the apparatus  10  upright on the rail  28  when the apparatus is not moving. 
         [0032]    While a particular embodiment of the present walk-behind rail condition monitoring apparatus has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.