BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of truck for use with a rail car;
FIG. 2 is an exploded view of bolster end- and side frame;
FIG. 3 is a perspective view of a bolster attached to a side frame and supported by a spring group on a support shelf;
FIG. 4 is a top plan view of a spring group in spaced relation and arranged in a predetermined pattern;
FIG. 5 is a section view of a spring group supporting the bolster end of the present invention;
FIG. 6 is a perspective view of the bottom of a bolster end having a spring receptacle of the present invention;
FIG. 7 is a bottom plan view of the bolster end showing the spring pockets arranged on the spring receptacle in accordance with the present invention;
FIG. 8 is a bottom plan view of a control spring pocket; and
FIG. 9 is a perspective view of a second embodiment of a bolster end in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
An exemplary railcar wheel truck assembly 10, as shown in FIG. 1, has a first side frame 12 and a second side frame 14, which are arranged in parallel alignment. Each side frame 12, 14 has an inside, an outside, and a spring window 18 extending there between. Spring windows 18 are about at the longitudinal midpoint of each side frame 12, 14. Transversely connected bolster 16 couples first and second side frames 12 and 14 at their respective spring windows 18. Bolster 16 extends from the inside of the spring window 18 through each side frame 12, 14. First axle and wheel set 20 and second axle and wheel set 22 are positioned at the opposed ends of aligned side frames 12 and 14. Each of first and second axle and wheel set 20, 22 has an axle axis 30 generally transverse to the longitudinal axis 31 of first and second side frames 12, 14 and about parallel to bolster 16. Each of first and second wheel sets 20, 22 include wheels 24 and 26 and axle 28 with axle axis 30.
Continuing to refer to FIG. 1, bolster 16 has first end 32 and second end 34, which respectively extend through spring windows 18 of first and second side frames 12 and 14. The bolster first end 32 is slidingly connected to the first side frame 12 and supported by a spring group 36. Likewise, the second bolster end 34 is slidingly connected to the second side frame 14 at window 18. The support of the bolster 16 (FIG. 1) is most effective when the springs are vertically mounted between the side frame 12 and the bolster end 32 and held in a predetermined arrangement.
Window 18, bolster end 32, spring group 36, first friction shoe 38 and second friction shoe 40 of side frame 12 are shown in FIG. 2 in an enlarged, partially sectioned and exploded view. As bolster ends 32 and 34, and first and second side frames 12, 14 are structurally and functionally similar, only bolster end 32 at first side frame 12 will be described, but the description is also applicable to bolster end 34 and spring window 18 on second side frame 14. The spring group 36 comprises a plurality of load springs 48, and control springs 54, 56. Each one of the plurality of load springs 48 in the spring group 36 bears against the bolster 16 to hold the bolster end 32 in spaced relation to the support platform 42. Each of the control springs 54, 56 engages and bears against friction shoes 38, 40 to limit and control train car movement with respect to the side frames 12, 14.
Referring to FIG. 2, spring window 18 has lower support platform 42 with first and second upright side columns or side faces 44 and 46, respectively, extending vertically from platform 42 and a top 45 (FIG. 1). Spring group 36 is shown as a three by three matrix of load springs 48, and control springs 54 and 56. In this matrix, first inner control spring 50 and second inner control spring 52 are concentrically positioned in outer control springs 54 and 56, respectively, to provide control spring subassemblies. Load springs 48, or load spring subassemblies may include 2 or 3 individual springs concentrically arranged in a manner to meet design criteria or to provide optimum dynamic performance of suspension spring group 36.
Bolster end 32 in FIG. 2 has spring receptacle 51 on the bolster bottom 17. Spring receptacle 51 includes lugs 61 and tapered bottom surface 64 forming a bolster chamfer adjacent the innermost spring pockets 96. Friction shoe pockets 63 receive first and second friction shoes 38 and 40, respectively, for sliding operation therein and in cooperation with side faces 44. 46. The control springs 50 and 52 apply a biasing force to friction shoes 38, 40 to cause frictional contact with side frames 44, 46 to resist movement between the bolster end 32 and side frame 12.
Continuing to refer to FIG. 2, the load springs 48 are cylindrical shaped having an axis 74 and a height 76. The load springs 48 are arranged in a predetermined spaced pattern to bear against the support platform 42 and support the bolster 16 at bolster end 32. The control springs 54, 56 are positioned in the middle row to extend into the shoe pockets 63. Each load spring 48 has a top 62, bottom 67, and a cavity 65 opening to the top 62.
Referring now to FIG. 3, the bolster end 32 is shown having a sliding attachment to side frame 12. This sliding attachment allows the bolster end 32 to move vertically within the spring window 18. Spring group 36 supports the bolster end 32. Spring group 36 is on the spring support 42 and bears against the spring receptacle 51 on bolster end 32. In normal operation of a freight railcar, spring group 36 biases bolster 16 and, thus, the freight railcar supported by bolster 16 at center plate 66 (FIG. 1). The biasing force controls or accommodates the oscillations or bouncing of the railcar, maintains railcar stability during traversal of the rail tracks and dampens any perturbations from various indeterminate influences, as noted above.
Referring now to FIG. 4 The springs 48, 54, 56 in spring group 36 are preferably positioned in spaced, parallel relation to the other springs 48, 54, 56 in an array 49 as shown in FIG. 4. Each one of the plurality of springs in spring group 36 has an axis 74 and a cavity diameter 78 and an outside spring radius 80. In the preferred arrangement 49, the axis 74 of each load spring 48 is parallel to the axis 74 of the other load springs 48 and vertically oriented. The load springs 48 are separated from the control springs 54, 56.
Referring now to FIG. 5, a side cut away view of the bolster end 32 sectioned at a line through each control spring 54, 56 is shown. The spring group 36 sits on the support platform 42 and extends upward to the individual spring tops 62 on and bearing against the spring receptacle 51. The load springs 48 springingly support the bolster end 32 in spaced relation to the support platform 42. The spring guides 106 extend downward from the spring receptacle 51 intermediate the adjacent springs. Each spring top 62 is adapted to fit in a spring pocket 96 (FIG. 7). The control springs 54, 56 are adapted to interface with the friction shoes 38, 40 by an opening 105 in the spring pocket 96. The opening 105 extends through the bolster bottom 51 and into the shoe pockets 63.
Referring to FIG. 6, the spring receptacle 51 has a plurality of spring pockets 96 shown in outline. A first spring pocket 96a comprises a first spring locator 100a positioned on a center point 84a located at the center of first spring pocket 96a. The spring locator 100a is adapted to slidingly fit into the spring cavity 65 (FIG. 2) of the respective load spring 48. The spring locator 100a has a base 102 on the spring receptacle 51. The spring locator has a tip 104 spaced from the spring receptacle 51 to position the spring locator 100 hanging downward from the spring receptacle to receive the spring top 62 (FIG. 2). The spring receptacle 51 is configured for seven similar load spring pockets 96 having three outboard spring pockets 96a, 96b, and 96c adjacent to bolster end 32 and three inboard spring pockets 96d, 96e, 96f and a center spring pocket 96g. The spring receptacle is also adapted for two control spring pockets 96h, 96i. Control spring pockets 96h and 96i extend into the respective shoe pocket 63. First spring guide 106a has a pyramid shape and is positioned intermediate spring pocket 96h and adjacent load spring pockets 96a, 96b and 96g. First spring guide 106a has a plurality of chamfers 108, the chamfers are adapted to each face an adjacent spring pocket 96a, 96b, 96g, 96h. Similarly, second spring guide 106b is positioned intermediate adjacent spring pockets 96e, 96f, 96g, and 96h. Second spring guide 106b is inboard from first spring guide 106a and adapted to a crescent moon shape having the concave surface 107 facing the control spring pocket 96h. Second spring guide 106b also has convex side 109 facing adjacent spring pockets 96f, and 96g.
Continuing to refer to FIG. 6, spring receptacle 51 has similarly positioned third spring guide 106c and fourth spring guide 106d surrounding control spring pocket 96i. Referring to FIG. 4 and FIG. 6 together, each spring guide, referred to in general as 106, is outside the respective adjacent spring pocket 96i, 96h to protect the control spring 54, 56 from interference by a load spring 48 (FIG. 4). Each spring guide 106 has a chamfer facing the adjacent spring pocket. As shown referring to first control spring pocket 96h the arcuate ridge shaped spring guide 106b has a concave wall comprising a chamfer 107 partially concentric with the perimeter 97 of control spring pocket 96h and a convex surface 108 extending from a position adjacent the center spring pocket 96g to a position adjacent the inboard spring pocket 96f to provide a chamfer portion or gradient facing each adjacent load spring pocket 96g, 96f.
Referring to FIG. 7, a bottom elevation view of the spring receptacle 51 shows the preferred layout 49 of the spring pockets 96 having seven load springs 48 (FIG. 2) and two control springs 54, 56 (FIG. 2). The spring pockets 96 are shown in outline having a perimeter 97 to illustrate the non-overlapping array 49 layout. Spring locators 104 are positioned at the center point 84 of each load spring pocket except pocket 96b. Load spring pocket 96b is surrounded by spring guide 106a and 106c and lug 61. As shown on spring pocket 96d, the spring pocket has a pocket radius 111 having a length larger than the outside spring radius 80. (FIG. 4). Furthermore, the base 114 of spring guide 106d is spaced from center point 84 by chamfer radius 112. Chamfer radius 112 is larger than outside spring radius 80.
Referring to FIG. 8, control spring pocket 96i is shown in detail. It should be understood, control spring pocket 96h is similarly configured in mirrored relation to control spring pocket 96i. Third spring guide 106c has a first chamfer 108a facing control spring pocket 96i, a second chamfer portion 108b facing load spring pocket 96g, a third chamfer portion 108c facing load spring pocket 96b and fourth chamfer portion 108d facing load spring pocket 96c. Spring guide 106 has a base 114 and a tip 112. Each chamfer portion extends from the base 114 toward the tip 112. The junction of the base 114 and the chamfer 108 is outside the adjacent spring pocket 96. Fourth spring guide 106d has an arcuate shape having a concave side 107 adjacent the control spring pocket 96i and a convex side 109. The convex side 109 extends from a position facing center spring pocket 96g to a point adjacent spring pocket 96c. The convex side 109 has a sloping shape coming up from the base 114 and away from the adjacent spring pockets 96d and 96g. Fourth spring guide 106d has a base 114 from which the concave 107 and convex 109 sides depend. Fourth spring guide 106d has a concave chamfer portion 108e surrounding control spring pocket 96i, second convex chamfer portion 108f adjacent center load spring pocket 96g and third chamfer portion 108g facing load spring pocket 96f. Fourth chamfer portion 108h faces load spring pocket 96d.
Referring to FIG. 9 the spring receptacle 51 is shown having control spring 54 typically positioned in spring pocket 96i. An alternate configuration of spring guides 206 is shown as a second embodiment of the present invention. The spring guide 206 mass is calculated to allow bolster end 32 to flex. As should be understood, a large spring guide will stiffen the bolster end 32 making it more likely to break under load rather than flex. The spring guides 206 are spaced from the control spring 54 to allow non-impeded compression and extension of control spring 54. Spring guides 206 have chamfers 208 facing adjacent spring pockets 96.
In use, the spring guides 106 help with installation of the springs 48, 54, and 56. The springs 48, 54, 56 are pre-compressed and inserted in the spring window 18 between the bolster 16 and the side frame 12, 14. The spring guides help installer urge the spring top 62 into the respective spring pockets 96. During use, the spring pocket 96 is the predetermined location for the top 62. The spring pockets 96 on the spring receptacle 51 retain the top 62 of the springs 48, 54, 56 to hold the spring group 36 in a symmetrical or desired arrangement as shown in FIGS. 2,3,4 and 5. The springs 46, 54,56 will compress and extend as the bolster ends 32, 34 move with respect to the side frames 12, 14. The bolster 16 is attached to the rail car (not shown) at plate 66 (FIG. 1). The railcar weight at either an unloaded or a fully laden weight causes spring compression. However, for any particular railcar, the railcar weight is a variable with a broad range extending from an empty-car, vehicle tare weight to a loaded-to-capacity railcar, and perhaps loaded above the rated, vehicle weight. As the railcar traverses the track on wheels 24, 26 (FIG. 1), it experiences dynamic compressive forces on the springs 48, and it is susceptible to all the above-cited track flaws as well as countless others, which could contribute to undamped oscillations causing excitation of the springs 48. Springs 48, 54, 56 are held in parallel, spaced relation to provide the requisite damping and support to the railcar and wheel-truck assembly 10 for its safe operation. However, though the super elevated curves partially alleviate some railcar operational problems, other significant operational problems for railcar operation remain or are created as a result of operating through these curves causing unloaded springs that may be urged by vibrations or jolts to the wheels 24, 26 (FIG. 1) to move with respect to each other on the bolster end 32 and the spring support shelf 42. The spring receptacle 51 is adapted to receive and retain each spring top 62 in a respective spring pocket 96. The spring pocket 96 represents the respective spring's location in the spring array 49 (FIG. 4). The spring locator 100 slidingly mates in cavity 65 and the spring guides 106 bear against the top 62 at the outer edge 75 (FIG. 4) to urge the spring top 62 to stay in the spring pocket 96. The spring top 62 in the spring pocket 96 helps the springs 46, 54,56 maintain the spaced, parallel, relation to optimize support performance and to minimize wear and damage due to misaligned springs. It should be understood, the second end 34 of the bolster 16 is similarly configured as the first end 32.
First bolster end 32 has at least one load spring 48 and at least one control spring 54 between the first spring receptacle and the first side frame. The control spring 54 has a top 62 (FIG. 3) in a load pocket 96 (FIG. 7) having spring guides 106 spaced at predetermined angles around a perimeter 97 of the first control spring pocket and intermediate the adjacent load spring pocket 96. The second bolster end 34 has a similar configuration having at least one load spring between the second end 34 at second spring receptacle 51 and the second side frame 14. The load spring 48 has a top 62 in a load spring pocket 96 on the spring receptacle 51 on the second end 34. The spring guides 106 are spaced at predetermined angles around a perimeter of the second spring pocket 96. Additional spring pockets 96 with or without spring locators 106 may be configured on each spring receptacle 51. First spring receptacle 51 on bolster end 32 is configurable with control spring pockets 96h, 96i for receiving control springs 54, 56. control spring pockets 96h, 96i extend into the shoe pocket 63 through opening 105 for interface with friction shoes 38, 44. Friction shoes 38, 40 prevent extreme movement between the bolster 16 and the side frame 14. The control spring pockets 96h, 96i each have a plurality of spring guides 106 located outside the respective perimeter 97 to help with installation and to prevent the control spring from jumping out of the spring pocket. As should be understood, the movement of the rail car with respect to the side frames 12, 14 causes a loading and unloading of the spring group 36 which may cause the individual springs 48, 54 and 56 to move with respect to each other. The spring pockets 96 (FIG. 6, 7, 8) and associated spring guides 106 urge the spring tops 62 to stay in spring pockets 96 (FIG. 6) on the spring receptacle 51 to keep the springs in spaced and preferably parallel relation to each other in a vertical position on the support platform 42.
Each of the spring pockets is defined by a desired pocket perimeter and a centerpoint. If a spring locator is in the pocket, it is positioned on the centerpoint. The spring locator comprising a projection extending downward from the spring receptacle adapted to slidingly fit in the cavity of the respective load spring in the spring pocket,
Although the invention has been described above in connection with particular embodiments and examples, it will be appreciated by those skilled in the art that the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein.
Patent Application
20080017065
