Patent Publication Number: US-6663476-B1

Title: Portable multi-purpose rail grinding machine

Description:
This invention relates in general to a multi-purpose rail grinding machine for grinding field welds, switch points, and frogs, and more particularly to a hydraulically powered portable rail grinding machine having an ergonomic friendly frame to facilitate ergonomic operation. 
     BACKGROUND OF THE INVENTION 
     During the maintenance process of keeping railroad tracks in good operating condition, it is necessary that track or rail sections be replaced from time to time, switch points be ground to maintain proper operation of switches, and frogs repaired to maintain their proper operation. This maintenance process usually involves some form of welding such as to join two sections of rail together or to build up worn away material on switches and frogs. Following the welding processes, it is necessary to grind the welds or welded areas to match existing rail profiles or frog contours. 
     Heretofore, it has been common practice for maintenance workers to carry out the grinding operations by the use of hand-held grinders. These grinding operations entail back-breaking work because of the posture positions a worker must endure to position the grinding stone of the grinder at the proper angle to perform the necessary grinding tasks. Accordingly, such grinding tasks often lead to back injuries and lost time or accidents. 
     It is also common practice that two to three different types of grinders be made available for performing the various grinding tasks in repairing track wherein each of the grinders is used for a specific grinding task. For example, one such grinder, made and sold by Matweld, Inc. of Paducah, Ky., serves to grind the top of a rail where it is needed to finish grind field welds or rail ends. Another grinder made and sold by Matweld, Inc. is a hand-operated grinder for use on field welds, frogs, and switch points which requires the operator to endure posture positions that cause bending of the back to position the grinder on the rail. 
     Another such type of grinder offered by Matweld, Inc. for grinding the tops of frogs and rail requires the operator to bend over and position the grinder at the grinding site. Matweld also offers a profile grinder that allows the operator to be in an upright position but is only useful for finish grinding of the field welds along the top and sides of the rail. 
     Matweld, Inc. also provides a heavy-duty frog and switch grinder that rolls along both rails but is not capable of being manipulated easily for handling all types of grinding operations. 
     A frog/profile grinder that is designed for grinding frogs and finish grinding of field welds which allows the operator to be in an upright position is also sold by Matweld, Inc. 
     SUMMARY OF THE INVENTION 
     The portable multi-purpose rail grinding machine of the invention eliminates the need for stocking multiple grinders, and allows the operator to always be in a good ergonomic upright work position, while serving to grind field welds, switch points, and frogs. The machine of the invention includes a multi-positionable grinding head and adjustable rail guide assembly for grinding rail profiles, switch points, and frogs. The portable grinding machine includes adjustable handlebars for the operator that not only are adjustable during the setup for various welding operations but also for the purpose of facilitating compact storage of the grinder. An on-off control lever having an optional safety device for preventing accidental starting of the grinding motor is mounted on one of the handlebars for facilitating operation by the operator. The grinding head is adjustable for positioning the disk-shaped grinding stone in horizontal, vertical, or in-between positions to handle the various grinding tasks needed to grind field welds, switch points and frogs. An adjustable rail guide assembly is provided for facilitating the different grinding operations and includes a hook-shaped guide for hooking over and sliding along the rail as the machine is moved relative to the rail. The rail guide assembly also includes a flanged wheel for riding on the rail that may be selectively used for certain grinding operations. 
     It is therefore an object of the present invention to provide a new and improved multi-purpose rail grinding machine for grinding field welds, switches, and frogs that includes an ergonomic work frame for allowing friendly ergonomic operation by a worker in a substantially upright position. 
     Another object of the present invention is in the provision of a multi-purpose rail grinding machine for grinding field welds, switch points, and frogs, which includes a grinder head that is adjustable to position a disk-shaped grinding stone in horizontal, vertical, or in-between orientations, while the operator maintains an upstanding posture to facilitate ergonomic operation of the machine. 
     Another object of the present invention is to provide a portable multi-purpose rail grinding machine for grinding field welds, switch points, and frogs having multiple rail guiding members for guiding movement of the machine along a rail during various grinding operations. 
     A still further object of the present invention is to provide a multi-purpose portable rail grinding machine for allowing an operator to manipulate the machine while in an upright standing position for any of the grinding operations and which thereby eliminates the need to have a number of different types of grinders that only perform the required grinding task and wherein the machine of the invention is light-weight and versatile. 
    
    
     Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts. 
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the rail grinding machine of the invention in association with rail or track and illustrating an operator in an upright position operating the machine and also illustrating the hook-shaped rail guide member of the adjustable rail guide assembly in engagement with the rail and also showing the grinding stone in its horizontally disposed position; 
     FIG. 2 is a perspective view of a part of the machine of the invention looking down from above and where the flanged wheel guide is on the track, and partially illustrating the position of the operator, and also showing the grinding stone in its horizontally disposed position; 
     FIG. 3 is a perspective view of the machine of the invention with the grinding stone positioned vertically and the operator standing upright to operate the machine; 
     FIG. 4 is a generally side elevational view but partially perspective of the machine of the invention with the adjustable rail guide assembly cut off and illustrating the adjustability of the handlebars between different elevations and positions; 
     FIG. 5 is a front elevational view of the machine of the invention with some parts omitted for purposes of clarity to illustrate some of the various positions the grinding stone can be adjusted, where the grinding stone is shown in solid and in horizontal position, and in phantom in angular and vertical positions; 
     FIG. 6 is a fragmentary perspective view of the underside of the machine of the invention to illustrate the use of the wrench carried by the machine for changing the stone and/or servicing the grinder; 
     FIG. 7 is a perspective view of the machine of the invention illustrating the positioning of the handlebars for facilitating compact storage of the grinder; 
     FIG. 8 is a transverse sectional view taken through a rail and showing the guide assembly of the machine of the invention and particularly the hook-shaped member in engagement with the rail head; 
     FIG. 9 is a view similar to FIG. 8 but showing the flanged roller of the guide assembly in riding engagement with the rail; and 
     FIG. 10 is a fragmentary perspective view of a modified frame having upper and lower receivers for the rail guide assembly. 
    
    
     DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and particularly to FIGS. 1 to  4 , the portable upstanding multi-purpose grinding machine of the invention, generally designated by the numeral  10 , includes a frame  12  having a grinding head or grinder  14  adjustably mounted thereon, a handlebar assembly  16  adjustably carried by the frame, and a rail guide assembly  18  adjustably carried by the frame. Thus, the machine can be set up for the various grinding tasks, including grinding field welds, switch points, and frogs. 
     The rail guide assembly  18  is at one end of the machine and serves to guide the frame as it moves along a rail, while manipulation of the machine by an operator  20  is accomplished by gripping the handlebar assembly  16  at the other end of the machine as the operator manually positions the grinder  14  in grinding position and moves the machine along a rail  22 . 
     The frame  12  includes an L-shaped tubular bar having a horizontally extending portion  24  and a substantially vertically extending portion  26  extending downwardly from one end of the horizontal portion. Actually the vertical portion  26  extends downwardly and slightly away from the horizontal portion and is therefore at a slight angle to the horizontal portion. At the free end of the horizontal portion  24 , a tubular socket  28  is suitably secured to the horizontal portion by welding or other suitable means and extends at right angles to the horizontal portion. Accordingly, the tubular socket  28  extends substantially vertically when the machine is disposed so that the horizontal portion  24  is in substantially parallel relation to the ground. 
     The tubular socket  28  is split and expandable to adjustably receive the round tubular vertical bar  30  of the handlebar assembly  16 , as illustrated in FIG.  4 . It will be appreciated the handlebars would be turned about 180 degrees and elevated to a comfortable handling position when operating the machine. Flanges are provided on the split edges of the tubular socket  28 . A locking assembly  32  includes a handle  33  to which a threaded stud is suitably secured and extends through a hole in one flange and is threadedly received in a tapped hole in the other flange. Thus, tightening of the socket  28  by actuation of the handle  33  locks the tubular bar  30  of the handlebars in a selected position. Similarly, loosening of the socket by actuation of the handle allows adjustment of the handlebars. 
     At the lower end of the frame of vertical portion  26 , a square tubular socket or receiver  36  is secured by welding or otherwise and disposed in a horizontal position substantially parallel to the horizontal portion  24  of the frame  12 . The tubular socket  36  includes a portion extending forwardly of the vertical portion for adjustably receiving the square tubular bar  38  of the rail guide assembly  18 . The bar  38  is telescopically received in the socket  36  and locked in place selectively by a hand-operable set screw  40 . 
     The tubular socket  36  also extends rearwardly of the vertical portion  26  of the frame and includes a grinder mounting plate  42  suitably secured thereto such as by welding or the like. The mounting plate  42  extends substantially at right angles to the axis of the socket  36 . 
     A second grinder mounting plate  44  is carried by the frame and includes an upper arm  46  and a lower arm  48 . The upper arm  46  extends parallel to the split tubular socket  28  and the round tubular bar  30  of the handlebar assembly  16 , while the lower arm  48  extends at an angle to the upper arm for adjustably supporting the grinder head  14 . 
     Accordingly, the grinder plate  42  and the grinder plate  44  are spaced apart to receive therebetween the grinder head  14 , and as explained below, to permit the adjustment of the grinder head to vary the position of the grinding stone. 
     The grinding head  14  includes a hydraulic motor  50  having an output shaft  52  on which a disk-shaped grinding stone  54  is mounted and locked in place by a nut  56 . A shroud and frame member  58  suitably secured to or integral with the housing for the hydraulic motor  50  not only shrouds a large part of the grinding stone but also provides support for the hydraulic motor and is disposed between the mounting plates  42  and  44 . As seen particularly in FIG. 6, a safety plate  59  covers a substantial part of the outer side of the grinding stone  54  and further includes a bumper  61  for guarding against inadvertent engagement of the grinding stone flange and shaft with a rail. Suitable pins are provided on the shroud for being rotatably received in holes in the mounting plates  42  and  44  and are threaded to receive nuts  60  which when tightened, as explained further below, will lock the grinder head in a desired grinding position. The mounting plates  42  and  44  include portions that are offset from the frame to facilitate the operation of the adjusting means for the grinding head. Thus, loosening or tightening of the nuts  60  by the open-end wrench  62  or other suitable wrench allows adjustment of the grinding head and the stone to a desired position on the frame. 
     The wrench  62  has different sized sockets at each end, one of which fits on the nut  56  of the grinder shaft and the other of which fits on the other nuts on the machine including the adjusting nuts  60  for adjusting the position of the stone  54 . The open-end wrench  62  is normally carried on the grinder mounting plate  44  in a suitable fashion, as shown in FIGS. 1,  2 ,  4 ,  5  and  7 . However, any suitable wrench may be used. 
     Control of the machine by an operator is accomplished by gripping the handlebar assembly  16 . At the upper end of the handlebar assembly tubular bar  30 , a U-shaped bar  64  includes handles  66  and  68  that are gripped and engaged by the hands of the operator  20 , as shown particularly in FIG. 1, for manipulating the grinding machine. Inasmuch as the handlebar assembly is adjustably mounted on the frame of the grinding machine, it may be raised or lowered relative to the frame to position it ergonomically friendly to an operator. Moreover, the handlebar assembly may be rotatably adjusted in the frame socket  28  to ergonomically fit the operator for a particular grinding task, and to facilitate compact storage, as shown in FIG. 7, wherein the handlebar assembly is rotated so that the handles  66  and  68  extend substantially perpendicular to the frame  12  and are moved downwardly. 
     To turn the hydraulic motor of the grinder on and off, a trigger assembly  70  is provided on the handle  68  having a pivotally mounted lever  71  that may be selectively depressed to power the grinder or released to shut down the grinder. Actuation of the trigger lever drives a shielded push-pull cable  72  that extends from the trigger assembly to a hydraulic control valve  74  on the hydraulic motor. An optional safety mechanism is available on the trigger assembly actuable by the operator prior to squeezing the trigger, thereby preventing accidental operation of the motor. Hydraulic lines  76  extend from the valve  74  and are suitably connected to a hydraulic power source that is usually available to railroad maintenance crews. Thus, releasing the optional A safety mechanism and squeezing the trigger lever actuates the control valve to turn on the grinder. 
     The square tubular bar  38  of the rail guide assembly  18  has mounted thereon and suitably secured thereto, such as by welding, a hook-shaped guide member  80  and a flanged wheel guide member  82 . The hook-shaped guide member includes a laterally extending bar  84  secured at one end as by welding or otherwise to the end of the tubular bar  38 . A hook-shaped portion  86  shaped to fit over the head of the rail  22  is provided at the other end of the bar  84 , as shown particularly in FIG. 8. A pin  88  is suitably secured to the bar  84  as by welding or otherwise and extends downwardly and in spaced relation to the hook-shaped portion  86  so as to fit over the opposite side of the rail head and coact with the hook-shaped portion  86  in guiding the forward end of the machine along a rail, as seen in FIG.  8 . Spacing between the hook portion  86  and the pin  88  is such that the hook-shaped guide member may be tilted on or off the rail when placing it on the rail in guiding relation with the rail or removing it from the rail. When the hook-shaped member is on the rail, it will be appreciated that the operator can slide the machine along the rail knowing that the forward end of the machine is guided by the hook-shaped guide member. 
     The flange wheel guide member  82  includes a wheel  90  having a cylindrical hub  92  and opposed radially extending removable wheel flanges  94  and  96 . While not shown, one or the other of the flanges may be suitably removed for purposes of facilitating the guiding of the wheel. The wheel  90  is rotatably carried on a shaft  98  that is supported on a U-shaped carrier  100  that is in turn suitably secured at one end such as by welding or the like to the tubular bar  38  of the rail guide assembly  18 . 
     It will be appreciated that by loosening and tightening the set screw  40 , the tubular bar  38  may be selectively telescopically moved to position the hook-shaped guide member  80  or the wheel guide member  90  closer to or farther away from the frame  12 . Further, with the set screw  40  loosened, the tubular bar with the guide members can be completely removed from the tubular socket  36  and rotated to dispose either the hook-shaped guide member  80  or the wheel guide member  82  into operative position for serving to guide and position the front end of the machine when involved in a grinding operation. 
     As above noted, the hook-shaped guide member is shown in guiding operation in FIG. 8, while the wheel guide member is shown in guiding operation in FIG.  9 . 
     Referring to FIG. 10, a modified frame  12 A for the machine of the invention is shown which includes a second or upper receiver  36 A for the rail guide assembly  18 . The receiver  36 A extends substantially parallel to and is spaced above the receiver  36 . The upper receiver  36 A is supported at its outer free end by a tubular bar  110  extending upward from the lower receiver  36 , and it is suitably connected at its inner end to the frame portion  26 . The connections of the upper receiver  36 A and support bar  110  are by welding or other suitable means. A hand operable set screw  40   a  is provided on the upper receiver  36 A to adjustably lock the rail guide assembly in the receiver. It will be appreciated that any number of receivers may be provided to enhance the ergonomic use of the machine. Thus, in the embodiment of FIG. 10, the rail guide assembly may be mounted in either receiver as desired by the user to conduct any particular grinding task. 
     It can now be appreciated that depending on whether the grinding machine of the invention is to be used to grind a field weld, switch points, or a frog, it will first be set up for a particular grinding operation by adjusting the disposition of the grinding stone, choosing the appropriate guiding member, and adjusting the position of the handlebar assembly to the comfort of the operator for carrying out a chosen grinding operation. 
     In operation, to primarily use the machine of the invention for thermite weld profile blending or removal of weld material at welded abutting rail sections, the grinding stone is adjusted to the horizontal position and the hook-shaped guide member is used and placed in operative position with a rail head, as seen in FIG.  1 . 
     For switch undercutting and rollover removal, the stone is adjusted to the 45 degree position, and the wheel guide member with both flanges is used and placed in riding relation on a rail. 
     For rollover grinding and grinding of frog points or switch points, the grinding stone is adjusted to its vertical position, as seen in FIG. 3, and the wheel guide member with one flange removed is placed into guiding relation on a rail. Straight rollover grinding can also be accomplished with both flanges on the wheel guide member. 
     It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.