WO2012015753A2

WO2012015753A2 - Railroad tie trenching apparatus and methods

Info

Publication number: WO2012015753A2
Application number: PCT/US2011/045219
Authority: WO
Inventors: Dean T. Wickman; Steven L. Benck; Dennis Hanke; Andrew C. Wickman; Thomas J. Wickman
Original assignee: Rail Construction Equipment Company
Priority date: 2010-07-27
Filing date: 2011-07-25
Publication date: 2012-02-02
Also published as: WO2012015753A3

Abstract

A trenching attachment is provided. The trenching attachment includes a cutting tool and an indication structure that is operable to set a depth of the cutting tool relative to the rails of a railroad track. The indication structure and cutting tool are movable at least about a first, second, and a third axis to align the trenching attachment with a crib used to contain a railroad tie.

Description

RAILROAD TIE TRENCHING APPARATUS AND METHODS

FIELD OF THE INVENTION

[0001] This invention generally relates to railroad construction equipment and specifically to railroad construction equipment configured for the maintenance and replacement of railroad ties.

BACKGROUND OF THE INVENTION

[0002] Conventional railroads typically employ railroad ties that attach to and support the rails at an underside thereof. The ties are typically situated within a mound of soil and other materials commonly referred to as a ballast. These ties are traditionally wooden, but there is a growing use of concrete ties in the industry. In either case, over time, the ties must be replaced as a result of wear or other damage to the tie. Replacement operations can entail replacing a group of adjacent ties, or various non-adjacent ties.

[0003] Generally, it is undesirable and/or difficult to move or otherwise reposition the rails during replacement because the rails are still attached to other ties. As such, the damaged ties are removed from the ballast, leaving a cavity therein typically referred to as a "crib," by sliding the damaged tie out from under the rails. Thereafter a new tie is slid into the crib, and the rails are affixed to the new tie.

[0004] However, sliding a new tie back under the rails is a difficult task for various reasons. For example, wooden ties have a tendency to wear away via contact with the ballast. As the tie is worn away, the ballast works upward towards the rails and under the tie. As a result, the crib has a smaller depth relative to the bottom surface of the rails than the overall height of a new wooden tie.

[0005] As another example, while having the same general shape and performing the same general function as a wooden tie, concrete ties have several metal anchors (i.e.

"towers") that are set into the concrete and each have an exposed portion that extends above a top surface of the concrete tie. The towers are used in conjunction with clips to fasten each rail to the concrete tie. When fastened, each rail has a tower on either side of the rail that extends above the interface between the rail and the concrete tie. As a result, the crib depth relative to the bottom surface of the rails is less than the overall height of the concrete tie including the towers.

[0006] Unfortunately, whether inserting a new wooden or concrete tie, the crib typically must be dug out using shovels and other tools to accommodate the overall height of the new tie. As a result, the amount of material removed from each crib can vary and is generally an uncontrolled parameter. Moreover, railroad crews must be careful not to damage the rails extending across the top of the crib when digging the same out. As such, replacing ties can be costly and time consuming, and is generally an imprecise process.

[0007] In response to the above noted inefficiencies, chain cutters have been utilized to reduce the amount of time required to remove material from the crib. A typical chain cutter is generally a scaled up chain saw that can be positioned under the rails to remove material from the crib. While decreasing the time required to dig out the crib, chain cutters nonetheless must be manually positioned and thus the depth dug out using the chain cutter can vary from crib to crib and is therefore still an uncontrolled parameter.

[0008] Once the cribs are dug out and the new ties are situated within the crib, the ballast and tie are elevated to the bottom surface of the rails by rapidly shaking the tie within the ballast to loosen the soil to allow it to fill in below the tie in a process called "nipping." However, nipping can be a difficult task if the crib has been dug out too much. In some instances, where the crib has been dug too deep, nipping is not possible. Due to the highly imprecise nature of digging the cribs out, often times crew members must halt nipping operations, remove the tie from the overly deep crib, fill in material, reinsert the new tie, and finally restart the nipping process.

[0009] In view of the above, it is desirable to have an apparatus and method for digging out a crib to accommodate a new tie in a cost efficient and repeatable manner.

[0010] Embodiments of the invention provide such an apparatus and method. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.

BRIEF SUMMARY OF THE INVENTION

[0011] In view of the above, embodiments of the present invention provide a trenching attachment that overcomes existing problems in the art. More particularly, embodiments of the present invention provide a trenching attachment that has an indication surface used to accurately align the trenching attachment with the bottom surface of a rail of a railroad track to remove material from cribs at a uniform and repeatable depth to increase the efficiency and decrease the cost of tie replacing operations. Still more particularly, embodiments of the present invention provide a trenching attachment that incorporates multiple axes of adjustment to align the trenching attachment with cribs having various orientations relative to the ground.

[0012] In one aspect, a trenching attachment for a piece of heavy construction equipment is provided. An embodiment of the trenching attachment according to this aspect includes an articulation arrangement for connecting the attachment to an arm of the heavy construction equipment and for positioning the attachment relative to the heavy construction equipment. The trenching attachment also includes a cutting tool extending from the articulation arrangement. An indication structure is mounted to the cutting tool. The indication structure is operably mounted to provide an indication of depth of the cutting tool relative to one or more rails of a railroad.

[0013] In certain embodiments, the indication structure includes a generally flat indication surface configured to contact a generally flat bottom surface of the one or more rails of the railroad. The indication surface is parallel to a cutting plane of the cutting tool. The indication surface is also parallel to a top surface of the cutting tool.

[0014] In certain embodiments, the indication surface is provided by a top surface of the indication structure. In certain other embodiments, the indication surface is provided by an indication block mounted to a frame of the indication structure.

[0015] In certain embodiments, the indication structure includes an indication surface at a top portion thereof. The indication surface is elevated above the cutting tool at a constant height along a length of the indication surface.

[0016] In certain embodiments, the trenching attachment further includes a sensor operably mounted to the indication structure to detect a contact between the indication structure and a bottom surface of one or more rails of the railroad.

[0017] In another aspect, a trenching attachment for a piece of heavy construction equipment is provided. An embodiment of the trenching attachment according to this aspect includes a base. A mount is connected to the base and rotatable relative to the base about a first axis and rotatable relative to a connecting structure of the heavy construction equipment about a second axis. The trenching attachment also includes a pivot structure connected to the base and rotatable relative to the base about a third axis. A cutting tool is mounted to the pivot structure and extends outwardly therefrom. An indication structure is fixedly mounted to the cutting tool such that rotation of the mount about the first and second axes and rotation of the pivot structure about the third axis causes a like respective rotation in the indication structure.

[0018] In certain embodiments, the indication structure includes a body and a plurality of supports connecting the body to the cutting tool. The indication structure includes an indicator block mounted on a top surface of the body. The indicator block provides an indication surface adapted to provide an indication of depth of the cutting tool relative to one or more rails of a railroad. In certain embodiments, the indicator block is mounted to the top surface of the body between a pair of angle bars that are mounted in an opposed space relation. In certain other embodiments, a top surface of the body provides an indication surface adapted to provide an indication of depth of the cutting tool relative to one or more rails of a railroad.

[0019] In certain embodiments, the indication structure includes a straight portion and a lead in portion. The lead in portion extends from an end of the straight portion at a non zero angle such that the lead in portion is not parallel with the straight portion. The indication structure provides an indication surface. The indication surface extends along the straight portion and the lead in portion. The indication surface extending along the lead in portion is positioned below the indication surface extending along the straight portion.

[0020] In certain embodiments, an end of the lead in portion defines a terminal end of the indication structure. The terminal end is adjacent an end of the cutting tool. In certain other embodiments, an end of the lead in portion defines a terminal end of the indication structure. The terminal end extends beyond an end of the cutting tool.

[0021] In yet another aspect, a method for replacing a railroad tie of a railroad using a trenching attachment for a piece of heavy construction equipment is provided. The method includes the steps of removing an existing railroad tie. The method also includes the step of positioning a cutting tool adjacent a trench previously occupied by the existing railroad tie. The method also includes the step of inserting the cutting tool into the trench and simultaneously locating the cutting tool at a fixed distance from a bottom surface of one or more rails of the railroad by contacting the bottom surface of the one or more rails with an indication structure mounted to the cutting tool.

[0022] In certain embodiments, the method further includes the step of removing material from a bottom of the trench using the cutting tool. In certain embodiments, the step of removing includes removing material such that the trench has a generally constant depth measured from the bottom surface of the one or more rails of the railroad.

[0023] Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:

[0025] FIG. 1 is a side partial cross-section of a pair of rails of a railroad track mounted to a concrete railroad tie;

[0026] FIG. 2 is a partial side cross-section of a ballast with a tie removed therefrom;

[0027] FIG. 3 is a perspective view of an exemplary embodiment of a trenching attachment according to teachings of the present invention;

[0028] FIG. 4 is an exploded perspective view of the trenching attachment of FIG. 3;

[0029] FIG. 5 is a side view of an indication structure of the trenching attachment of FIG. 3;

[0030] FIG. 6 is a front cross-sectional view of the indication structure of FIG. 5;

[0031] FIG. 7 is a partial side view of the indication structure of FIG. 5 mounted to a cutting tool;

[0032] FIG. 8 is a partial side view of the trenching attachment 40 aligned with a crib; [0033] FIG. 9 is a partial perspective view of the trenching attachment 40 aligned with a crib;

[0034] FIG. 10 is a partial side view of the trenching attachment 40 partially disposed within the crib;

[0035] FIG. 11 is a partial side view of the trenching attachment 40 aligned adjacent to the crib; and

[0036] FIG. 12 is a partial side view of a crib with a new concrete tie disposed therein.

[0037] While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

[0038] Turning now to the drawings, there is illustrated in FIG. 1 a typical concrete railroad tie 12 supported in a ballast 10. The concrete railroad tie 12 uses a plurality of towers 14 and a plurality of clips 16 to affix a pair of rails 18 to the concrete railroad tie 12. Typically, each rail 18 has a tower 14 situated on either side thereof. Each tower 14 incorporates a clip 16 used to affix the rail 18 to the concrete railroad tie 12. While the following description will discuss embodiments of the invention in the context of a concrete railroad tie, it is recognized that the advantages and benefits of embodiments of the invention equally apply to operations involving wooden railroad ties.

[0039] Turning now to FIG. 2, to install a concrete railroad tie 12, the concrete tie 12 must be slid along direction 26 into a crib 28 where a tie was previously situated. The previous tie may have been a wooden tie or a concrete railroad tie. In either event, the crib 28 has a depth measured from a bottom surface 38 of the crib 28 to a bottom surface 20 of the rails 18 as illustrated by dimension 32. The concrete railroad tie 12 to be placed within the crib 28 also has overall height measured from a bottom surface 22 of the concrete tie 12 to a top surface 24 of the towers 14 as illustrated by dimension 30. Generally, the overall height of the tie 12 (dimension 30) is greater than the overall depth (dimension 32) of the crib 28. As such, to slide the concrete railroad tie 12 along direction 26 into the crib 28, the overall depth of the crib 28 must be increased to compensate for the additional height of the towers 14 as illustrated by dimension 36. As noted above, the rails 18 typically cannot be moved to compensate or the additional height of the towers 14. As such, digging out the crib 28 is generally necessitated.

[0040] With reference now to FIG. 3, an exemplary embodiment of a trenching attachment 40 is illustrated for performing the digging operations discussed above. The trenching attachment 40 includes an articulation arrangement that has a base 42 , a mount 44, and a pivot structure 46. The mount 44 is attached to the base 42. The mount 44 is designed such that the trenching attachment 40 may be attached to numerous pieces of railway construction equipment. Typically, the mount 44 is used to attach the trenching apparatus 40 to an arm of an excavator or similar piece of heavy equipment. However, the trenching attachment 40 is not limited in its use to such equipment. Indeed, the mount 44 can be designed to incorporate the trenching attachment 40 to various other pieces of equipment.

[0041] A pivot structure 46 is mounted to the base 42 and is moveable relative thereto. The pivot structure 46 carries a cutting tool 48. An indication structure 50 is mounted to the cutting tool 48. As will be discussed in greater detail below, movement of the pivot structure 46 relative to the base 42 results in the adjustment of the cutting tool 48 and indication structure 50 relative to the base 42.

[0042] The indication structure 50 provides an indication surface 52. The indication surface 52 abuts against the bottom surface 20 of the rails 18 to place the cutting tool 48 at an appropriate depth within the crib 28 to quickly and precisely achieve the desired crib depth for receipt of a new railroad tie 12 (see FIG. 2).

[0043] The trenching apparatus 40 provides generally three axes of adjustment for the cutting tool 48 and indication structure 50. More particularly, the base 42 is adjustable relative to the mount 44 about axis 54. The pivot structure 46 is adjustable relative to the base 42 about axis 56. The mount 44 is adjustable relative to the structure receiving the mount 44 (e.g. the arm of an excavator) about axis 58. These axes of adjustment 54, 56, 58 allow the cutting tool 48 to be positioned relative to cribs of various orientations 28 (see FIG. 2).

[0044] Turning now to FIG. 4, the base 42 has a top plate 70, a bottom plate 72, and a vertical member 74 extending therebetween. A hub structure 76 providing a bore 78 extends from a top surface 80 of the top plate 70. The bore 78 is configured to receive a pin 64 used to hingedly connect the mount 44 to the base 42.

[0045] The bottom plate 72 is spaced apart from the top plate 70 such that an opening 82 exists therebetween. Each of the top and bottom plates 70, 72 also have an aperture 84 extending therethrough. The apertures 84 are aligned and configured to receive a pin 96 used to fix the pivot structure 46 relative to the base 42 within the opening 82.

[0046] The base 42 also provides a connection point 86 for a first actuator 110 connected between the base 42 and the mount 44. The first actuator 110 is operable to rotate the base 42 relative to the mount 44 about axis 54. Similarly, the base 42 provides a second connection point 88 for a second actuator 112 connected between the base 42 and pivot structure 46. The second actuator 112 is operable to move the pivot structure 46 relative to the base 42 about axis 56.

[0047] To rotate the trenching attachment 40 about axis 54, the first actuator 110 lengthens or shortens to rotate the cutting tool 48 and indication structure 50 relative to the mount 44. Similarly, to rotate the cutting tool 48 and indication structure 50 relative to the axis 56, the second actuator 112 lengthens or shortens. Additionally, and depending upon the particular piece of equipment carrying the trenching attachment 40, the entire trenching attachment 40 can also rotate relative to the axis 58 of the mount 44. Accordingly, the trenching attachment 40 can accommodate cribs 28 with various orientations relative to the surface the vehicle the attachment is carried by is situated on.

[0048] The mount 44 has a pair of upper mounting flanges extending upwardly away from a base plate 92. The upper mounting flanges 90 have apertures 91 extending therethrough such that the mount 44 is attachable to an arm or similar structure of a piece of construction equipment. Due to the varying pieces of equipment that can incorporate the trenching attachment 40, the mount 44 can take on various forms to accommodate mounting of the trenching attachment 40, and is therefore not limited to the illustrated structure.

[0049] The mount 44 also has a pair of lower mounting flanges 94 extending downwardly away from the base plate 92. The lower mounting flanges 94 surround the hub 76 on either side thereof. A pin 64 slides through the lower mounting flanges 94 and the bore 78 of the hub 76 to hingedly connect the mount 44 relative to the base 42. [0050] The pivot structure 46 has a housing 98. The housing 98 is configured to receive a motor 106 therein. The motor 106 has a drive shaft 108 that extends through the housing 98 to a drive sprocket 134. The drive sprocket 134 is operable to drive a chain cutter 136 of the cutting tool 48.

[0051] An adjustable mount 100 extends away from the housing 98 of the pivot structure 46. The adjustable mount 100 has a plurality of mounting locations 114 to mount the second actuator 112 thereto. The particular mounting location 114 used for the second actuator 112 defines a starting position of the pivot structure 46 about axis 56. The adjustable mount 100 has a bore 106 passing therethrough for receipt of the pin 96 to connect the pivot structure 46 to the base 42. Once connected, lengthening and shortening the second actuator 112 will rotate the pivot structure 46 about axis 56 relative to the base 42.

[0052] A mounting plate 102 extends away from the housing 96 of the pivot structure 46. The mounting plate 102 has a plurality of apertures 104 to mount the cutting tool 48 to the pivot structure 46. The mounting plate 102 mounts with a mounting portion 138 of a support bar 120 of the cutting tool 48. The support bar 120 has a plurality of apertures 140 that are alignable with the apertures 104 of the mounting plate 102. The support bar also includes a keying feature 142 to ensure that the support bar 120 is mounted to the mounting plate 102 in the appropriate position.

[0053] The support bar 120 also has a race 122 disposed between top and bottom plates 124, 126 of the support bar 120. The race 122 carries and guides the chain cutter 136. The support bar 120 further includes a notch 132 at a distal end thereof for receipt of an idler sprocket 130. The idler sprocket 130 guides the chain cutter 136 as it is driven by the drive sprocket 134 and motor 106.

[0054] The indication structure 50 mounts to the top plate 124 of the support bar 120. As will be discussed in greater detail below, the indication structure 50 provides an indication surface 52 used to dig the appropriate depth of a crib 28 (see FIG. 2) that will accommodate the overall height of a new railroad tie (see FIGS. 1 and 2). The indication structure 50 mounts to the support bar 120 at a plurality of mounting locations 144 schematically illustrated. The indication structure 50 may be mechanically affixed to the support bar 120 in a variety of ways including but not limited to welding, brazing, fastening, and other similar methods and/or processes. [0055] Turning now to FIG. 5, the indication structure 50 has a straight portion 150 and a lead in portion 152. The lead in portion 152 extends away from the straight portion 150 at an angle a as illustrated. The lead in portion 152 assists with guiding the trenching attachment 40 under the rails 18 (see FIG. 2). While it is generally advantageous to utilize the lead in portion 152, it is recognized that the same can be omitted in other embodiments. In embodiments omitting the lead in portion 152, the straight portion 150 can be longer than the spacing between the rails to ensure the appropriate depth is maintained during cutting.

[0056] The indication structure 50 has a body 156 supported by a plurality of supports 154 that mount at the mounting locations 144 (see FIG. 4) of the support bar 120. As illustrated in FIG. 5, the body 156 generally supports the indication surface 52. In some embodiments, the indication surface 52 can be part of the body 156, and in other embodiments can be formed from a separate component attached to the body 156, as described below.

[0057] Turning now to FIG. 6, the indication surface 52 is illustrated as provided by an indicator block 170. The indicator block 170 is situated on the body 156. The indication surface 52 is a top surface of the indication block 170. The indicator block 170 is fixed to the body 156 using a pair of angle bars 174. As illustrated, the indicator block 170 has at least one bore 172 passing therethrough to fasten the indicator block 170 to the angle bars 174. As such, the indicator block 170 is generally removable from a remainder of the indication structure 50.

[0058] Accordingly, different indicator blocks 170 of different sizes and materials can be used depending upon the particular application. Additionally, as the indication surface 52 is worn away due to the frictional contact between the indicator block 170 and the bottom surface 20 of the rails 18 (see FIG. 2), the indicator block 170 can be replaced. In one embodiment, the indicator block 170 can be formed from ultra high molecular weight polyethylene, but other materials, e.g. other plastics, metals, or composite materials, are contemplated.

[0059] A single or a plurality of sensors 176 can also be attached to the indication block 170. The sensors 176 can be connected to a processor 178 used to alert an operator when the indication block 170 is in sufficient contact with the bottom surface 20 of the rails 18 (see FIG. 2). In one embodiment, the sensors 176 can be strain gauges, however other sensors are indeed contemplated, e.g. hall effect and touch sensors. Indeed, any sensor 176 that can detect a contact between the indication surface 52 of the indicator block 170 and the bottom surface 20 of the rails 18 is sufficient (see FIG. 2). Further, the sensors 176 and the processor 178 can be omitted entirely in other embodiments.

[0060] Still referring to FIG. 6, each support 154 mounts to the body 156 using a pair of angle bars 180. Each support 154 has a neck 182 that is affixed to the angle bars 180. The neck 182 can be affixed to the angle bars 180 in a variety of ways including but not limited to welding, brazing, fasteners, or similar structures and/or by similar processes. Further, the angle bars 180 may be omitted entirely such that the neck 182 of each support 154 mounts directly to the body 156 via welding or brazing.

[0061] Each support 154 also has a flange 184 extending away from the neck 182. A dampener 186 is mounted to the flange 184. The dampener 186 provides a mounting surface 188 to affix the indication structure 50 to the top plate 124 of the support bar 120 at the mounting locations 144 (see FIG. 4). The dampener 188 is operable to dampen the mechanical vibrations caused by the cutting tool 136 (see FIG. 4) during operation.

Although illustrated as incorporating a dampener 186, it is recognized that in other embodiments the indication structure 50 can be provided without the same, and the flange 184 can mount directly to the top plate of the support bar 120 (see FIG. 4).

[0062] The base 156 incorporates a pair of shrouds 190 on either side thereof. The shrouds 190 generally protect the remainder of the indication structure 50 from flying debris during cutting operations. It will be recognized that the shrouds 190 can be a variety of shapes and sizes. It will be further recognized that the shrouds 190 can be omitted entirely in other embodiments.

[0063] Turning now to FIG. 7, the cutting chain 136 generally defines a bottom cutting surface 202. The indication surface 52 of the straight portion 150 is disposed above the cutting surface 202 by a distance H. The distance H is such that when the indication surface 52 of the straight portion 150 abuts against a bottom surface 20 of the rails 18, the crib 28 will be dug out to such a depth equal to a distance H.

[0064] In one embodiment, the distance H is such that the trenching attachment 40 (see FIG. 3) will dig out the crib 28 (see FIG. 2) deep enough to provide for the overall height of the concrete railroad tie 12 and an additional amount of clearance. It will be recognized that the desired dimensions of a particular crib 28 are governed by the dimensions of the tie to be situated therein. As such, the distance H between the indication surface 52 and cutting surface 202 can be varied by using varying sizes of indication structures 50 or using indicator blocks 170 (see FIG. 6) of differing dimensions with the indication structure 50. Additionally, the mounts 154 can be adjustable such the distance H can be varied by increasing or decreasing the height of the mounts.

[0065] Having discussed the structural attributes of one embodiment of the trenching attachment 40, the following discusses various modes of operation and use of the same.

[0066] With reference now to FIG. 8, the trenching attachment 40 is generally aligned with a crib 28. Once generally aligned, the trenching attachment 40 is moved along direction 204 to bring the indication surface 52 into contact with the bottom surface of the rails 20 to locate the cutting tool 48 at the appropriate depth within the crib 28. To align the trenching attachment 40 relative to the crib 28, an operator positions it adjacent to the crib 28 by adjusting the position of the trenching attachment 40 via the axes 54, 56, 58 (see FIG. 3) as well as any additional adjustment axes of the equipment that the trenching attachment 40 is connected to.

[0067] For example, and with reference to FIG. 9, the trenching attachment 40 is illustrated aligned with a crib 28 that has a bottom surface at an angle a relative to a generally flat portion of ground 206. Such a scenario is often the case when the ballast 10 has an incline 208 to allow clearance for drainage systems and the like. To align the trenching attachment 40 with the illustrated crib 28, an operator can rotate the trenching attachment 40 about axis 54 in either of directions 210 or 212. Likewise, the operator can also adjust the trenching attachment 40 about axis 56 by rotating the same in directions 214 or 216 about axis 56. Furthermore, the operator can also adjust the trenching attachment 40 about axis 58 by rotating the same in directions 218 or 220.

[0068] Turning now to FIG. 10, once aligned the trenching attachment is moved into the crib 28 such that the indication surface 52 of the straight portion 150 is in contact with the bottom surface 20 of each rail 18. When these surfaces are in contact, the cutting surface 202 (see FIG. 7) is at the appropriate depth as set by the distance H between the indication surface 52 and cutting surface 202 (see FIG. 7). The trenching attachment 40 then moves within the crib and generally transverse to the rails 18 to dig out the crib to achieve the appropriate depth.

[0069] With reference now to FIG. 11, once the appropriate depth is achieved, the trenching attachment 40 is removed from the crib 28 along direction 210. As illustrated in FIG. 11, the crib 28 thereafter has a depth Ff generally equivalent to the distance H between the indication surface 52 and the cutting surface 202.

[0070] A new concrete tie 12 may then be positioned within the crib 28 without the danger of the towers 14 of the new concrete tie 12 interfering with the rails 18 during positioning of the concrete tie 12. Once in position as illustrated in FIG. 12, the concrete railroad tie 12 may be elevated to fasten the same to the rails 18 by nipping or other similar processes.

[0071] As described herein, embodiments of the trenching attachment 40 provide an attachment that can quickly and repeatedly set an appropriate crib depth for receipt of a new railroad tie without the need to manually dig out the crib 28. As such, the trenching attachment 40 facilitates faster and more precise placement of railroad ties 12 on existing and new lines of railroad track.

[0072] All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0073] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non- claimed element as essential to the practice of the invention. [0074] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

WHAT IS CLAIMED IS:

1. A trenching attachment for a piece of heavy construction equipment, the attachment comprising:

an articulation arrangement for connecting the attachment to an arm of the heavy construction equipment and for positioning the attachment relative to the heavy construction equipment;

a cutting tool extending from the articulation arrangement; and an indication structure mounted to the cutting tool, the indication structure operably mounted to provide an indication of depth of the cutting tool relative to one or more rails of a railroad.

2. The trenching attachment of claim 1, wherein the indication structure includes a generally flat indication surface configured to contact a generally flat bottom surface of the one or more rails of the railroad.

3. The trenching attachment of claim 2, wherein the indication surface is parallel to a cutting plane of the cutting tool.

4. The trenching attachment of claim 2, wherein the indication surface is parallel to a top surface of the cutting tool.

5. The trenching attachment of claim 2, wherein the indication surface is provided by a top surface of the indication structure.

6. The trenching attachment of claim 2, wherein the indication surface is provided by an indication block mounted to a frame of the indication structure.

7. The trenching attachment of claim 1, wherein the indication structure includes an indication surface at a top portion thereof, the indication surface elevated above the cutting tool at a constant height along a length of the indication surface.

8. The trenching attachment of claim 1, further comprising a sensor operably mounted to the indication structure to detect a contact between the indication structure and a bottom surface of one or more rails of the railroad.

9. A trenching attachment for a piece of heavy construction equipment, the attachment comprising:

a base;

a mount connected to the base and rotatable relative to the base about a first axis and rotatable relative to a connecting structure of the heavy construction equipment about a second axis;

a pivot structure connected to the base and rotatable relative to the base about a third axis;

a cutting tool mounted to the pivot structure and extending outwardly therefrom; and

an indication structure fixedly mounted to the cutting tool such that rotation of the mount about the first and second axes and rotation of the pivot structure about the third axis causes a like respective rotation in the indication structure.

10. The trenching attachment of claim 9, wherein the indication structure includes a body and a plurality of supports connecting the body to the cutting tool.

11. The trenching attachment of claim 10, wherein the indication structure includes an indicator block mounted on a top surface of the body, the indicator block providing an indication surface adapted to provide an indication of depth of the cutting tool relative to one or more rails of a railroad.

12. The trenching attachment of claim 11 , wherein the indicator block is mounted to the top surface of the body between a pair of angle bars that are mounted in an opposed spaced relation.

13. The trenching attachment of claim 10, wherein a top surface of the body provides an indication surface adapted to provide an indication of depth of the cutting tool relative to one or more rails of a railroad.

14. The trenching attachment of claim 9, wherein the indication structure includes a straight portion and a lead in portion, the lead in portion extending from an end of the straight portion at a non-zero angle such that the lead in portion is not parallel with the straight portion.

15. The trenching attachment of claim 14, wherein the indication structure provides an indication surface, the indication surface extending along the straight portion and the lead in portion, and wherein the indication surface extending along the lead in portion is positioned below the indication surface extending along the straight portion.

16. The trenching attachment of claim 15, wherein an end of the lead in portion defines a terminal end of the indication structure, the terminal end adjacent an end of the cutting tool.

17. The trenching attachment of claim 15, wherein an end of the lead in portion defines a terminal end of the indication structure, the terminal end extending beyond an end of the cutting tool.

18. A method for replacing a railroad tie of a railroad using a trenching attachment for a piece of heavy construction equipment, the method comprising the steps of:

removing an existing railroad tie;

positioning a cutting tool adjacent a trench previously occupied by the existing railroad tie; and

inserting the cutting tool into the trench and simultaneously locating the cutting tool at a fixed distance from a bottom surface of one or more rails of the railroad by contacting the bottom surface of the one or more rails with an indication structure mounted to the cutting tool.

19. The method of claim 18 further comprising the step of removing material from a bottom of the trench using the cutting tool.

20. The method of claim 19, wherein the step of removing includes removing material such that the trench has a generally constant depth measured from the bottom surface of the one or more rails of the railroad.