RAIL GRINDING MACHINE

Abstract: A railraod mounted grinding machine for maintaining the railhead profile of railroad track rails includes a plurality of grinding modules (38) mounted on an undercarriage (40). The undercarriage (40) is shiftably carried, by a track engaging platform, for side to side positioning of the grinding module (38) across the longitudinal axis of a rail (34). Each grinding module (38) is independently tiltable relative to the undercarriage (40).

Description: This invention relates to a rail grinding apparatus according to the preamble of claim 1. Railroad track rails are subject to wear by the passage of trains over the rails. In particular, depressions in the upper surface of a rail may develop such that the rail head presents an undulating, corrugated surface. Moreover, the rail may develop burrs, or otherwise lose its symmetrical profile. Maintenance of smooth running surfaces on railroad track rails is important for reasons of safety, riding comfort, protection of the track, track bed and rolling stock, noise suppression, and reduced maintenance of the track and track bed. Grinding machines for maintaining railroad track rails in smooth, properly shaped condition are known. Such grinding machines generally comprise a plurality of rotatable grinding modules carried by a locomotive or the like in close proximity to the rail head surfaces of a railroad track. The grinding modules include rotatable, abrasive grinding stones that can be lowered into a position flush with the rail surface to grind and restore the rail surface to a smooth, desired profile. The grinding modules of rail grinding machines are typically raised into storage positions on the supporting locomotive or the like when not being operated to grind rails. The modules must therefore be lowered and properly oriented along the rail head prior to conducting grinding operations. The rail contacting support mechanisms for initially positioning and orienting the grinding modules are typically larger and more expensive than the size of wheels or other rail contacting support mechanisms required to maintain the modules in proper orientation once in place. In the past, the functions of orienting the grinding modules and supporting the grinding modules once in place have been combined into a single support device. While only a small area of the support device is subjected to continuous contact with the railhead, the entire device must be discarded when the device becomes worn. In US-A-4 583 327 is disclosed a rail grinding apparatus according to the preamble of claim 1. This prior art apparatus comprises a main frame and a pair of undercarriages. Undercarriage 18 is supported by wheels while undercarriage 16 is not. An actuator supports the undercarriage from the main frame and apparently moves it between raised and lowered positions. The known system comprises no means for detecting the rails as the undercarriage is being lowered. Thus, misalignment or damage may occur when lowering the undercarriage into the lowered position. These drawbacks are also associated with the rail grinding apparatus disclosed in FR-A-2 206 409. The known rail grinding apparatus according to this document discloses an undercarriage which can be raised and lowered. Further, conically shaped recesses are provided to keep the undercarriage in a defined raised position, but no means are provided which secure a precise lowering of the undercarriage. It is therefore object of the invention, to provide a rail grinding apparatus which avoids the above mentioned drawbacks and which allows a precise and quick lowering of the undercarriage, avoiding misalignment or damage of the apparatus or the rails. This object is met by the invention according to the characterizing part of claim 1. The main advantages of the invention and preferred embodiments thereof will be described in detail in the following description taking reference to the attached drawings. Fig. 1 is a fragementary, side elevational view of a rail grinding machine in accordance with the present invention with the parts removed for clarity; Fig. 2 is a front elevational view of a rail grinding machine in accordance with the present invention with parts removed for clarity, phantom lines depicting the grinding machine undercarriages in locked and raised positions; Fig. 3 is a fragmentary, front elevational view of one of the undercarriages of the rail grinding machine in accordance with the present invention, with parts removed for clarity, phantom lines depicting the undercarriage in the raised and locked position; Fig. 4 is a fragmentary, sectional view taken along line 4-4 of Fig. 3; Fig. 5 is a fragmentary, sectional view taken along line 5-5 of Fig. 3; Fig. 6 is similar to Fig. 3 but with the undercarriage partially disengaged with the rail and guide roller assembly included, phantom lines depicting the undercarriage in the rail engaging position; Fig. 7 is a fragmentary, side elevational view taken from the perspective of the line 7-7 of Fig. 6; Fig. 8 is similar to Fig. 7, but with the guide roller in the raised position; Fig. 9 is a sectional view taken along the line 9-9 of Fig. 1 with a grinding module shown in tilted configuration, phantom lines depicting the grinding module in an alternative tilted position; Fig. 10 is a sectional view taken along the line 10-10 of Fig. 9; Fig. 11 is similar to Fig. 10, but with the grinding module in the raised position; Fig. 12a is a schematic diagram of a grinding stone in grinding contact with the rail; Fig. 12b is similar to 12a, but with the grinding stone tilted from the horizontal; Fig. 12c is similar to Fig. 12b, but with the grinding stone shifted laterally; Fig. 12d is a schematic diagram of a grinding stone in tilted, grinding contact with a rail in the presence of an obstruction; and Fig. 13 is a schematic, plan view of a grinding stone in grinding contact with a rail. A rail grinding machine 20 in accordance with the present invention broadly includes main frame 22 supported by rail engaging wheels 24, operator cab 26, equipment compartment 28, and a plurality of grinding assemblies 30. The rail engaging wheels 24 support the rail grinding machine 20 on railroad track 32. The track 32 comprises a pair of rails 34 stretching across ties 36 of railroad bed 37. Each grinding assembly 30 broadly includes a plurality of grinding modules 38 individually mounted on a grinding assembly undercarriage 40. Each grinding assembly undercarriage 40 includes a grinding module support frame 42 attached to the rail grinding machine main frame 22 by fore and aft telescoping struts 44, 46. Each grinding module 38 is suspended from support frame 42 by fore and aft brackets 48 and 50. Referring in particular to Figs. 1, 3 and 6, fore and aft struts 44, 46 each include outer slide tube 52 pivotally coupled to main frame 22 by pivot pin 54, and an inner slide rod 56 slidably received within outer slide tube 52. The inner slide rod 56 includes lowermost base plate 58 attached to support frame 42 by bolts 60. Extensible boot 61 extends between outer slide tube 52 and the base plate 58 of inner slide rod 56. Spreader piston and cylinder assemblies 62 extend between brackets 64 depending from the main frame 22 and the outer slide tube 52 of each fore and aft strut 44, 46. Each grinding module support frame 42 includes fore and aft U-shaped support members 66, 68 interconnected by uppermost, gauge side and field side frame members 70, 72. Side to side braces 74, 76, 78 extend between the gauge side and the field side frame members 70, 72. A pair of fore and aft, horizontal slide rods 80, 82 extend between gauge side and field side frame members 70, 72 for slidable support of each grinding module 38. Fore and aft undercarriage elevation piston and cylinder assemblies 84 extend between brackets 86 depending from main frame 22 and the fore and aft U-shaped frame members 66, 68. Each grinding module 38 includes grinding motor 90 supported on grinding module base plate 92, grinding shaft 94, and grinding stone 96. The grinding shaft 94 defines a center grinding axis 97 for each grinding module. Grinding stones 96 are annular grinding wheels each having lowermost grinding surface 98, inner stone diameter 100, and outer stone diameter 102. Shiftable, fore and aft, grinding module support rods 104, 106 extend upwardly from base plate 92 of each grinding module 38. A grinding module top brace 108 extends between each fore and aft, vertical, grinding module support rod 104, 106. The vertical, grinding module support rods 104, 106 are received within fore and aft, vertical, grinding module support sleeves 110, 112. Gauge side shroud 114 extends between sleeves 110, 112. The fore and aft grinding module support sleeves 110, 112 are pivotally connected to respective fore and aft brackets 48, 50 by pivot supports 116, 118. A grinding module elevation piston and cylinder assembly 120 extends between the forward pivot support 116 and top brace 108 of each grinding module 38. Referring to Fig. 9, each grinding module forward bracket 48 includes a tilt cylinder supporting brace 120a. A grinding module tilting piston and cylinder assembly 122 extends between the brace 120a and the forward pivot support 116 of each respective grinding module. Again referring to Fig. 9, each of the fore and aft brackets 48, 50 are attached to a slide tube 124 carried by a respective fore or aft horizontal support rod 80, 82. As best seen in Figs. 10 and 11, a horizontal brace 125 extends between the slide tubes 124 of each pair of grinding module fore and aft support brackets 48, 50. A grinding module horizontal positioning piston and cylinder assembly 126 extends between each horizontal brace 125 and gauge side frame member 70. Grinding assembly supporting rail engaging wheel assemblies 128 are carried by each fore and aft U-shaped frame member 66, 68. Each wheel assembly 128 includes rail engaging wheel 130 rotatably attached to a respective U-shaped frame member 66, 68 by pillow blocks 132, and guide roller assembly 134. Wheels 130 include rail top engaging surface 136 and side rail engaging flange 138. The rail top engaging surface 136 of each wheel 130 is of a standard width, comparable to the width of the rail head. Each guide roller assembly 134 includes a set down roller 139 rotatably supported by opposed gauge side and field side bearing plates 140, 142. The bearing plates 140, 142 are pivotally mounted to support brackets 144, 146 that extend downwardly from each U-shaped frame member 66, 68. A guide roller assembly piston and cylinder assembly 148 extends between the field side bearing plate 142 of each guide roller assembly 134 and a respective stanchion 149 carried by each fore and aft U-shaped frame member 66, 68. Referring to Fig. 4, an upright securing flange 150 extends upwardly from each brace 74, 78. Securing flange receiving clevises 152 extend downwardly from main frame 42. Locking pins 154 are attached to locking pin actuating piston and cylinder assemblies 156 for shifting between securing flange engaging and securing flange clearing positions. In operation, grinding assemblies 30 of rail grinding machine 20, when not in use, are transported in raised, noncontacting relationship with the rails 34 of track 32, as depicted by phantom lines in Fig. 2 and Fig. 3. In particular, securing flanges 150 of grinding assembly undercarriage support frame 42 are secured within flange receiving clevises 152 of main frame 22 by locking pins 154, and the fore and aft struts 44, 46 are fully retracted. To commence guiding operations, locking pins 154 are shifted to their securing flange clearing position, as depicted in Fig. 1. The spreading piston and cylinder assemblies 62 are fully extended so as to tilt the individual grinding assemblies 30 inwardly towards the gauge side of rails 34. The grinding assemblies 30 are lowered towards railroad track 36 by extending the undercarriage elevation piston and cylinder assemblies 84. Prior to lowering the grinding assemblies 30 towards the track 36, the guide roller assemblies 134 are pivoted downwardly by extending the guide roller piston and cylinder assemblies 148. Accordingly, the set down rollers 139 are the first members of the grinding assemblies 30 to come into contact with rails 34. Referring in particular to Fig. 6, it will be appreciated that the width of the guide rollers 139 ensures engagement of the guide rollers 139 with the rails 34, regardless of where the grinding assembly 30 is positioned by the spreader cylinders 62. Contact of the guide rollers 139 with the rails 34 generally positions the grinding assemblies 30 in elevation. Once the guide rollers 139 have contacted the rail 34, the spreader piston and cylinder assemblies 62 can be retracted so as to shift the grinding assemblies 30 outwardly in a direction towards the field side of the rail 34. The rail engaging flange 138 of each wheel 130 will accordingly be brought into contact with the gauge side of rail 34. The guide roller piston and cylinder assemblies 148 can thereafter be retracted such that the weight of the grinding assembly 30 is borne by wheels 130. It will be understood, however, that an upward biasing force is exerted by the elevation piston and cylinder assemblies 86, 88 such that the entire weight of the grinding assembly 30 is not necessarily borne by the wheels 130. The spreader piston and cylinder assemblies 62 provide a constant biasing pressure to maintain the wheels 130 in engagement with rail 34. The top surface of rail 34 is ground by placing the grinding stone 96 directly over the rail 34, as depicted in Fig. 12a. The grinding axis of rotation 95 is centered along the longitudinal axis of rail 34. Referring to Fig. 13, the rail 34 is contained between the inner diameter 100 of grinding stone 96, and grinding contact between the stone 96 and rail 34 is along a diameteral line d of the grinding stone 96. As the grinding stone 96 is rotated as indicated by arrows R of Fig. 13, and is moved along the rail 34 in the direction of arrow A of Fig 13, the fine scratches S left on the rail 34 by the grinding action of the stone 96 are oriented perpendicular to the longitudinal axis of the rail 34. As depicted in Fig. 9, each grinding module 38 can be pivoted around pivot point P to position the grinding stone 96 at various tilt angles relative to the railhead. As shown in Fig. 12b, pivoting of the grinding module 38 around pivot point P, without shifting of the pivot point laterally in relation to the longitudinal axis of rail 34, shifts the line of grinding contact between the stone 96 and rail 34 from the center, diameteral line d of the grinding stone to a point outboard of the diameteral line d. While tilting of the grinding module 38 to the orientation depicted in Fig. 12b enables shaping of the railhead, the resultant shifting of the line of contact between the grinding stone 96 and the rail 34 away from the diameteral line d of stone 96 causes uneven wear of the stone 96. Moreover, orientiation of the grinding stone 96 as depicted in Fig. 12b causes the scratches S left by the grinding operation to be transverse to the desired orientation perpendicular to the rail longitudinal axis. The grinding module 38, together with pivot point P, cart be shifted laterally relative to the longitudinal axis of rail 34 by the extension and retraction of piston and cylinder assembly 126. More particularly, extension of respective horizontal positioning piston and cylinder assemblies 126 shifts the associated undercarriage 40 towards the field side of rail 34, and retraction sof the piston and cylinder assembly 126 shifts the undercarriage towards the gauge side of rail 34. Moreover, elevation of each individual grinding module 38 relative to the undercarriage 40 can be adjusted by the extension and retraction of respective module elevation piston and cylinder assemblies 120. Accordingly, the pivot point P can be shifted away from the center of rail 34, as depicted in Fig. 12c, and the grinding stone 96 can be lowered into contact with the rail 34 along a diameteral line d of the grinding stone 96. Referring to Fig. 12d, rail 34 is depicted in close proximity to an obstruction W. The obstruction could be a wooden support W placed along the rail at a highway crossing or the like. The presence of the obstruction W interferes with the placement of the grinding stone 96 relative to the rail 34. The capability to laterally shift the undercarriage 40 from side to side relative to the longitudinal axis of rail 34 provides a distinct advantage when grinding the rail 34 in the presence of an obstruction. In particular, referring to Fig. 12d, pivot point P can be shifted laterally away from the obstruction W thereby allowing the grinding stone 96 to be tilted to a greater tilt angle while still avoiding the obstruction, than would otherwise be attainable. Although the grinding contact with the stone 96 with the rail 34 is, in the instance depicted in Fig. 12d, moved away from the diameteral line d of the grinding stone 96, the amount of grinding required to be done in the presence of an obstruction is typically minimal.

Claims: Rail grinding apparatus for grinding rails of a railroad track, said apparatus including a main frame (22) supported by said rails (34) for movement along said railroad track (32) and an undercarriage (40) operably carried by said main frame (22) and shiftable between a raised rail clearing position and a lowered rail engaging position, said undercarriage (40) including rail engaging wheels (130) positionable for supporting said undercarriage (40) in said rail engaging position, said apparatus characterized in further having sensing means (139) operably carried by said undercarriage (40) for detecting the position of said rails (34) as said undercarriage (40) is lowered from said rail clearing position to said rail engaging position, said apparatus also having undercarriage wheel positioning means (62) operably coupled to said sensing means (139) for positioning said undercarriage wheels (130) in abutting relationship with said rails (34) when said sensing means (139) detects the position of said rails (34). The apparatus of claim 1, wherein said undercarriage wheel positioning means (62) comprises means for shifting said undercarriage wheels (130) transversely of said rail axis. The apparatus of claim 2, including means (148) for retracting said sensing means (139) retractable from said rail (34) when said undercarriage wheels (130) engage such rails (34). The apparatus of claim 3, wherein said sensing means includes a roller (139) for engaging said rails (34) in an abutting relationship, said roller (139) being generally wider than said rails (34) whereby said roller (139) may engage said rail (34) over a range of lateral roller positions. The apparatus of claim 4, wherein said sensing means includes a roller bracket (140, 142) pivotably coupled to said undercarriage (40), said roller (139) being rotably mounted in said roller bracket (140, 142).

Inventors: VIEAU, ROBERT G.
Applicants: LORAM MAINTENANCE OF WAY, INC.
Application year: 1988
Main classification: E01B31
IPC codes: E01B31