Patent Abstract:
A debris eradicating brake head for use in a side frame mounted braking system in a railway vehicle. The brake head being mounted on an end of a brake beam and including a brake shoe carrier associated with the brake head, a brake shoe secured to a face portion of the brake shoe carrier, and a brake head extension extending from a side portion of the brake shoe carrier for associating the brake head within a unit guide in a side frame of the railway vehicle. The brake head extension including at least one of a first and a second tapered surface configured for breaking up and pushing debris out of the unit guide in the side frame. Eradication of debris within the side frame increases the braking efficiency of the railway vehicle as it reduces the amount of force necessary for applying the brake shoes to the wheels.

Full Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present disclosure is directed to a brake head for beam securement of a railway braking system within a unit guide in a side frame, and more particularly, to a brake head having a brake head extension which is configured to eradicate debris which becomes trapped within the unit guide and reduces braking efficiency, and still more particularly, to a debris eradicating brake head for use with a truck mounted braking system which eliminates or reduces debris within the unit guide to yield more efficient braking. 
     Description of Related Art 
     Truck mounted braking systems are well-known in the railway industry and typically comprise a series of force transmitting members, levers and linkages which function to move a group of brake shoes against the wheels of a railway vehicle to effect stoppage of the railway vehicle. Examples of truck-mounted brake mechanisms include the TMX® or UBX® systems, owned by WABTEC Holding Corp., the assignee of the present invention. In these systems, two brake beams are provided per truck to provide the braking force to the two axles of the truck. The two brake beams are activated by at least one brake cylinder that is in fluid communication with a source of compressed air, such as an air reservoir mounted on the body of the railway vehicle. 
     In general, each brake beam includes a compression beam having its terminal ends coupled to the ends of a V-shaped tension beam. A brake head is provided at the opposing terminal ends of the compression beam and/or the V-shaped tension beam. Each brake head includes a brake shoe carrier adapted to receive a removable brake shoe. The brake mechanism is coupled to the truck of the railway vehicle at end portions of the brake heads. In operation, the brake beam having the compression beam and the V-shaped tension beam is suspended by brake head extension members which extend into and move within units guides located in the side frames of the railway truck bogie to allow movements of the braking system with the truck. 
     Any truck mounted brake system that uses unit guides for beam securement is susceptible to debris buildup such as snow, ice, ballast, etc. The unit guide is open so as to allow the brake beam to move back and forth freely. By design, there is nothing to stop the accumulation of debris in the unit guide. This accumulation of debris can be detrimental to braking efficiency. There is a need to design a brake head having an extension member which eliminates debris buildup and yields more efficient braking. 
     SUMMARY OF THE INVENTION 
     In accordance with an embodiment of the present disclosure, a debris eradicating brake head, mounted on an end of a brake beam, is provided for a railway vehicle. According to one embodiment, the debris eradicating brake head can be used with a truck mounted braking system for mounting the braking system in the side frame of the railway vehicle. The brake head includes a brake shoe carrier associated with the brake head, a brake shoe secured to a face portion of the brake shoe carrier, and a brake head extension extending from a side portion of the brake shoe carrier for associating the brake head with the railway vehicle. The brake head extension includes at least a first tapered surface configured to eradicate debris which may become trapped at the location where the brake head extension is associated with the railway vehicle, such as within a unit guide in the side frame of the railway vehicle. 
     The brake head extension can include a second tapered surface and the first and second tapered surfaces can be adjacently disposed with respect to each other. According to one embodiment, the first and second tapered surfaces are configured such that they cooperate together to form a concentrated point contact which applies a force to any debris located within a path of movement of the brake head extension. According to another embodiment, the first and second tapered surfaces cooperate together to form a line contact force configured to apply an amplified force to any debris located within a path of movement of the brake head extension and direct the debris away from the direction of motion of the brake head extension. 
     The first tapered surface can be tapered at an angle of approximately 30-80 degrees, approximately 60-80 degrees, or approximately 70 degrees with respect to a transverse plane extending through the brake head extension. The second tapered surface can be tapered at an angle of approximately 30-80 degrees, approximately 60-80 degrees, or approximately 70 degrees with respect to a transverse plane extending through the brake shoe carrier. 
     The brake head extension is configured to cooperate with a unit guide located within a side frame of the braking system for the railway vehicle for mounting the braking system within the railway vehicle and the tapered surface is configured for removing any debris which becomes trapped within the unit guide. 
     In accordance with another embodiment of the present disclosure, a debris eradicating brake head is provided for use with a railway braking system. The railway braking system includes a pair of brake beams mounted at each end of the brake system. Each of the brake beams have a brake head attached to each end thereof, each of the brake heads carry a brake shoe thereon, which are positioned for engagement with a respective railway vehicle during a brake application. Each of the brake heads comprise a brake head extension configured for cooperating with a respective unit guide in a side frame of the railway vehicle for movably mounting the brake beams in the braking system. The brake head extensions include at least a first taper configured to push out any accumulated debris trapped within the unit guide. 
     The brake heads include a brake shoe carrier for holding a brake shoe on a front face of the brake head. The brake head extension extends in an outward direction and which is generally perpendicular with respect to a side portion of the brake shoe carrier. 
     According to one embodiment, the brake head extension can include a second tapered surface. The first and second tapered surfaces can be adjacently disposed with respect to each other. The first and second tapered surfaces cooperate together to form a concentrated point contact configured to apply a force to any debris located within a path of movement of the brake head extension. The first and second tapered surfaces can also cooperate together to form a line contact force configured to apply an amplified force to any debris located within a path of movement of the brake head extension. These first and second tapered surfaces are configured to direct debris away from the direction of motion of the brake head extension. 
     According to one embodiment, the at least one of the first tapered surface and the second tapered surface can be tapered at an angle of approximately 30-80 degrees, approximately 60-80 degrees, or approximately 70 degrees with respect to a transverse plane extending through the brake head extension. 
     According to another embodiment of the present disclosure, a method of improving braking efficiency of a truck mounted braking system is provided. The railway braking system includes a pair of brake beams mounted at each end of the brake system. Each of the brake beams have a brake head attached to each end thereof, and each of the brake heads carry a brake shoe thereon. These brake shoes are positioned for engagement with a respective railway vehicle wheel during a brake application. Each of the brake heads comprise a brake head extension configured for cooperating with a respective unit guide in a side frame of the railway vehicle for movably mounting the brake beams in the braking system. The method comprises providing at least a first taper and a second taper on the brake head extensions. These first and second tapers are configured to break up and push out any accumulated debris trapped within the unit guide which improves the application of force applied by the brake shoes during braking of the railway vehicle. 
     The first and second tapers can be adjacently disposed with respect to each other to form a concentrated point contact for eradicating any accumulated debris trapped within the unit guide located within a path of movement of the brake head extension in the unit guide. At least one of the first and second tapered surfaces can be tapered at an angle of approximately 30-80 degrees, approximately 60-80 degrees, or 70 degrees with respect to a transverse plane extending through the brake head extension. 
     These and other features and characteristics of the device for eradicating debris from unit guides within truck side frames for increasing the braking efficiency of truck-mounted braking systems, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention. As used in the specification and the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING(S) 
         FIG. 1  is a top view of a truck mounted brake assembly in accordance with the prior art; 
         FIG. 2  is a perspective view of a brake beam of a truck mounted brake assembly of  FIG. 1  showing a current brake head design in accordance with the prior art; 
         FIG. 3  is a perspective view of a brake beam of a truck mounted brake assembly showing the brake head in accordance with an embodiment of the present disclosure; 
         FIGS. 4A and 4B  show front and side perspective views of the brake head of  FIG. 3  in accordance with the prior art; 
         FIGS. 5A and 5B  show front and side perspective views of the brake head of  FIG. 3  in accordance with an embodiment of the present invention; and 
         FIG. 6  shows a partial perspective view of the brake beam of  FIGS. 5A and 5B  cooperating with a unit guide in accordance with an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal”, and derivatives thereof, shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting. 
     Referring to the drawings in which like reference characters refer to like parts throughout the several views thereof, the present disclosure is generally directed to a device for correcting uneven brake shoe wear on truck-mounted brakes of a railway vehicle. 
     Reference is now made to  FIG. 1 , which shows a truck-mounted brake assembly, generally indicated as  10 , which is commonly used in the art. The brake mechanism  10 , as described herein, is intended for connection to a truck of a railway vehicle (not shown), as will be readily apparent to those skilled in the railway vehicle art. Examples of truck mounted braking systems include the TMX® or UBX® designs, owned by WABTEC Holding Corp., the assignee of the present invention. The brake mechanism  10  is adapted for use in railway vehicles adapted for passenger and/or cargo transit. However, this use is intended to be non-limiting and the brake mechanism  10  has applications in railway vehicles generally. 
     With continuing reference to  FIGS. 1 and 2 , the brake mechanism  10  includes a pair of brake beams, generally indicated as  12 , which are substantially identical. Each of the brake beams  12  include a compression beam  14 , a generally V-shaped tension beam  16  and a strut  26 . The terminal ends of the compression beam  14  are coupled to the corresponding terminal ends of the tension beam  16 . At a location substantially midway between their opposite ends, the compression beam  14  and the tension beam  16  of the respective brake beams  12  are spaced apart sufficiently to allow connection of the strut  26  therebetween. 
     A brake head  18  is provided at the opposing terminal ends of the compression beam  14  and/or the tension beam  16 . Each brake head  18  includes a brake shoe carrier  20  adapted to receive a removable brake shoe  22 . The brake mechanism  10  is coupled to the truck of the railway vehicle (not shown) at end portions or brake head extensions  24  extending from a side portion  25  (see  FIG. 2 ) of the brake heads  18 . The brake head extensions  24  cooperate with unit guides located within the truck side frames. In operation, the compression beam  14  and the tension beam  16  hang from the side frames of the truck. 
     With continuing reference to  FIGS. 1 and 2 , the brake mechanism  10  further includes a pair of force transmitting levers  44 ,  46  pivotally connected by pins  48  to the strut member  26  of the respective brake beam  12 . The force transmitting members  44 ,  46  are interconnected by a rod  27  and a slack adjuster  28 . As shown in  FIG. 1 , the rod  27  also connects a brake cylinder  29  to one end  44   a  of the force transmitting lever  44  for transferring the braking force exerted by the brake cylinder to the brake beam  12 . The automatic slack adjuster  28  is attached to the opposing end  44   b  of the force transmitting lever  44  to automatically extend and move the brake heads  18  closer to the wheels of the railway vehicle in order to compensate for wear of the brake shoes  22 . 
     Reference is now made to  FIGS. 3 and 6 , which show a brake beam, generally indicated as  112 , in accordance with the invention, for use within railway braking systems, such as a truck mounted braking system, including a brake head  118  in accordance with an embodiment of the present disclosure. The railway braking system includes a pair of brake beams  112 , which are substantially identical, only one of which is shown in  FIG. 3 , mounted at each end of the braking system. Each of the brake beams  112  include a compression beam  114 , a generally V-shaped tension beam  116  and a strut  126 . The terminal ends of the compression beam  114  are coupled to the corresponding terminal ends of the tension beam  116 . At a location substantially midway between their opposite ends, the compression beam  114  and the tension beam  116  of the respective brake beams  112  are spaced apart sufficiently to allow connection of the strut  126  therebetween. The brake head  118  is attached to each end of the brake beam  112 . The brake head  118  includes a brake shoe carrier  120  configured to receive a removable brake shoe thereon (not shown), which can be changed as needed, when the brake shoe becomes worn. 
     As shown in  FIG. 6 , the brake head  118  is positioned for engagement with a respective railway vehicle wheel  150  during a brake application. The brake head  118  includes a brake head extension  124  extending from a side portion  125  of the brake shoe carrier  120  (see  FIGS. 5A  and  5 B). The brake head extension  124  is configured for cooperating with a respective unit guide  160  in a side frame  155  of the railway vehicle for movably mounting the brake beam  112  in the braking system. Each braking system includes a pair of brake beams  112 , each end of which includes brake heads  118  and brake head extension members  124  configured to cooperate with respective unit guides  160  in the side frames  155  for mounting the braking system in the truck, generally indicated as  200 , of the railway vehicle. These unit guides  160  are susceptible to debris buildup such as snow, ice, ballast, etc. As shown in  FIG. 6 , the unit guide  160  is open so as to allow the brake beam  112  to move back and forth freely. By design, there is nothing to stop the accumulation of debris in the unit guide  160 . This accumulation of debris can be detrimental to braking efficiency. 
     With continuing reference to  FIGS. 3 and 6 , and with further reference to  FIGS. 5A and 5B , the brake head extension  124  includes at least a first tapered surface  130 . A second tapered surface  132  can also be provided on the brake head extension  124 . The first and second tapered surfaces  130  and  132  are adjacently disposed with respect to each other. As shown in  FIGS. 4A and 4B , in the prior art designs, the brake head extension  24  extending from a side portion  25  of the brake shoe carrier  20 , typically included a flat end guide  30  having a plane P 1  which was perpendicular to the unit guide and formed an approximate angle α of approximately 90 degrees with respect to a transverse plane P 2  extending through the brake head extension  18 . This particular design resulted in a very distributed force contact being applied to any accumulated debris that became trapped in the unit guides. 
     Referring back to  FIGS. 5A and 5B , the tapered surfaces  130 ,  132  change this normally distributed force into a concentrated point C or line contact force L. This concentrated point C or line contact L applied a concentrated or amplified force to any debris located within a path of movement of the brake head extension  124 . The first tapered surface  130  acts to break up the debris and the second tapered surface  132  causes the debris to be directed outward away from the path of force application. According to one example, the series of tapers function like a snow plow moving through the unit guide  160  to direct debris away from the direction of motion of the brake head extension  124 . The amplification of brake force coming from the brake head extension  124  results in more effective removal of debris, allowing less brake force being applied to the wheels to be lost. 
     According to one embodiment, at least the first tapered surface  130  can be tapered along a vertical plane P 3  at an angle β of approximately 30-80 degrees with respect to a transverse plane P 4  extending through the brake head extension  124 . According to another embodiment, this angle β can be approximately 60-80 degrees or approximately 70 degrees. It can be appreciated that angle β can be varied in order to optimize the performance of the brake head extension  124  depending upon certain environmental conditions in order to effectively eradicate debris trapped within the unit guide  160 . Second tapered surface  132  can also be tapered along a horizontal plane at an angle of approximately 30-80 degrees or approximately 70 degrees with respect to the transverse plane P 4  extending through the brake head extension. As viewed in  FIGS. 5A and 5B , this second tapered surface  132  would extend into the page. It can also be appreciated that tapered surfaces  130 ,  132  can be tapered at approximately the same angle with respect to each other or at different angles in order to optimize the performance of the brake head extension  124 . 
     While various embodiments of the device for eradicating debris within unit guides of truck side frames for increasing braking efficiency of a railway vehicle were provided in the foregoing description, those skilled in the art may make modifications and alterations to these embodiments without departing from the scope and spirit of the invention. For example, it is to be understood that this disclosure contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment. Accordingly, the foregoing description is intended to be illustrative rather than restrictive. The invention described hereinabove is defined by the appended claims and all changes to the invention that fall within the meaning and the range of equivalency of the claims are to be embraced within their scope.

Technology Classification (CPC): 5