Patent Publication Number: US-2012042491-A1

Title: Apparatus and method for installing a track on a tracked vehicle

Description:
This application claims the benefit of U.S. Provisional Application No. 61/376,084, filed Aug. 23, 2010. 
    
    
     TECHNICAL FIELD 
     This invention relates generally to an apparatus or tool and a method of use of the same for installing a continuous loop of track onto the wheels or sprockets of a tracked vehicle, which substantially reduces or eliminates need for use of pry bars and other leverage devices, come along winches, manual manipulation, and the like, providing a safer, faster method compared to known practices. 
     BACKGROUND ART 
     U.S. Provisional Application No. 61/376,084, filed Aug. 23, 2010, is incorporated herein by reference in its entirety. 
     Installing or reinstalling a track on a tracked vehicle or work machine, such as a track loader, track hoe, bulldozer, and other tracked agricultural, construction, earth moving, forestry, or mining machines, and military and police vehicles, is usually a time consuming and often dangerous task. In this latter regard, on job sites such as open air mines and quarries, machines sometimes lose a track in dangerous environments such as next to or at the base of rock faces where blasting has recently occurred, such that falling rocks is a continuous danger. Tracks are also commonly lost when traversing hill sides and the like. Thus, the ability to install or reinstall a track in an expedient manner, requiring as few personnel as possible, is advantageous, both from a productivity perspective, and a safety perspective. 
     The track is a loop of rubber or metal, and includes outwardly facing ground contacting plates or pads which can include treads for traction. The track includes inwardly facing drive lugs which cooperatively engage mating lugs on the drive sprocket or wheel drivingly rotatable for driving the track. The drive lugs on the track are either in the form of recesses or inward projections on the inner surface of the track that cooperatively receive, or are received in, mating lugs on the drive sprocket or wheel. These lugs on the track also engage or partially encircle a groove or raised element on the idler for holding the track in alignment with the drive sprocket or wheel, the idler, and any bogeys or other wheels of the vehicle or machine. 
     The process of installing or reinstalling a track, also referred to as “retracking”, involves jacking or otherwise raising and supporting the affected side of the vehicle, sometimes under the dangerous conditions mentioned above. The pressure in a track tensioning system in connection with an idler roller or wheel, usually at the front of the machine, must also be relieved and the idler retracted, usually toward the rear of the machine. The rear arc of the track will either already encircle the drive wheel, or will be placed thereabout. The bottom run of the track will then extend forwardly at a small acute angle to a fore and aft axis running between the drive wheel and idler. The front arc and top run of the track will be freestanding, but will typically sag under its weight so as to have a height and an arc radius smaller than that required for installation, that is, passage over the idler wheel. In this latter regard, the arc radius and height must exceed that of the idler, so that the lugs can pass about the outer circumferential surface of the idler. The slack must also be taken out of the track to provide the length necessary to encircle the idler. The track is then pushed or dragged sidewardly into alignment with the fore and aft drive wheel to idler axis. It may be possible to do this and take the slack out by manual manipulation. But, for larger tracks, a pry bar or bars, overhead crane, come along winch, or other tool or tools is/are often required to force the front arc of the track about the idler, which often entails tensioning the track to its largest lengthwise extent. Then, the track must be manipulated over the idler, which typically entails forcing a portion of the track at a time over the edge of the idler using tools such as pry bars, chains, or the like. In this regard, because the track is flexible or of hinged construction, those portions of the track not supported will sag, which often makes the fitting of the track about the idler a time consuming and frustrating task, resulting in lost productivity. Damage can also be caused by the use of pry bars, hammers, and other tools. Once the track is in place, the idler is tensioned and the side of the machine lowered to return the machine to operation. 
     SUMMARY OF THE INVENTION 
     What is disclosed is an apparatus or tool for installing a continuous loop of track onto the idler wheel or sprocket of a tracked vehicle, which substantially reduces or eliminates need for use of pry bars and other leverage devices, come along winches, manual manipulation, and the like, providing a safer, faster method compared to known practices such as set forth above. 
     According to a preferred aspect of the invention, the apparatus includes a pair of track grippers configured and operable for gripping at least the edges of the portion of the track to be installed or reinstalled over the idler wheel or sprocket, and shaping that portion of the track into an arc of appropriate size for passage laterally over the idler wheel or sprocket, hereinafter also referred to by just the term “idler”. 
     Each gripper preferably forms or is formable in a rigid, generally arcuate or angular shape suitable for gripping the opposite edges of the track portion for forming and holding it in the required size arc. The gripper is also sufficiently robust to be capable of being pulled or carried while holding the edge of the track in the arc shape, and for taking slack out of or tensioning the track as required and moving the track laterally over and onto the idler, which entails passage of the lugs over the idler also. This de-slacking or tensioning and movement can be accomplished manually for some lighter tracks, such as the rubber track or belt of a compact track loader or bulldozer, and heavier tracks will require powered assistance, such as from a crane, or the bucket, blade or fork of a work machine or vehicle, or the tracked vehicle or machine itself. 
     As non-limiting structural examples, the grippers can comprise rigid structures of tubular or solid metal such as steel or aluminum, such as weldments; castings; or extruded shapes curved or bent to the desired arc shape and size. As another non-limiting example, the grippers can comprise assemblies, such as angularly related segments hingedly or pivotally connected together in end to end relation so as to be relatively movable into the desired arc shape, and fastened or restrained in that shape, for instance, by threaded fasteners, pins, turnbuckles, hydraulic cylinders, or other suitable apparatus. With regard to the term “arc shape” this is to be interpreted as including a series of straight segments in end to end, angularly related pattern, forming a generally angularly arced shape, as well as a smoothly curved shape. 
     According to another preferred aspect of the invention, each of the grippers includes either a single, continuous gripping element, or a plurality of individual or discrete gripping elements or cleats, positioned and oriented to extend in an inward direction toward the other gripper, and configured for cooperatively engaging the edge of the track for gripping and holding or supporting the track portion in the arc shape, and for de-slacking or tensioning and carrying it laterally into position on the idler. As non-limiting examples, the single continuous gripping element can comprise a flange or lip formed in the arc shape and size, and the individual gripping elements can comprise plates, tabs, pins, bolts, and/or prongs, arranged in an arcuate or angularly related pattern. As one option, if sufficient clearance is available, the gripping elements can comprise removable pins which extend across the space between the grippers. As another option, the gripping element or elements can be in the form of inwardly facing grooves configured for cooperatively receiving the edge of the track, and can optionally be configured for holding it using a clamping action. 
     The invention additionally includes arms that support and hold the grippers in a generally parallel, spaced apart relation such that the gripping element or elements of the respective grippers are in opposing relation and are spaced a distance apart corresponding about to the width of the track, so as to be capable of capturing or bounding the portion of the track to be installed onto the idler, and positioning the gripping element or elements for supporting and holding the track in the arc shape. In this latter regard, the arms can be adjustable for different width tracks, or non-adjustable but capable of being opened and closed or assembled for positioning about a track of a particular width. 
     As a non-limiting example of adjustable arms, a sidewardly telescoping assembly can be used wherein two arms, each carrying a gripper are relatively telescoping sidewardly, that is, inwardly or outwardly, one relative to the other, or both relative to a center or main member. As another example, the arms can be relatively movable via a scissors or pivotal connection. In either instance, the arms can be fixed or retained in a set position via suitable apparatus such as a pinned connection, turnbuckle or hydraulic cylinder, these latter apparatus being usable also for adjustably moving the arms. 
     According to another preferred aspect of the invention, the grippers can be removably mounted or attached to the ends of the arms, for breaking down or compacting the apparatus for transport and storage, and to allow interchanging different size grippers for use with different size tracks or idlers. Thus, as an example, a larger radius gripper for use with a larger radius idler can be interchanged with a smaller radius gripper for use with a smaller radius idler, and/or a medium size gripper, or a gripper for a different style or type of track, e.g., a rubber track or steel track. As a non-limiting example, this removable attachment can be achieved with removable pins or bolts, or hooks. Thus, for example, an apparatus having telescopically or pivotally adjustable arms can be provided in combination with multiple sets of interchangeable grippers of different sizes for use with a variety of different track configurations and sizes. 
     According to another aspect of the invention, the apparatus can be suspended by an overhead structure, such as, but not limited to, a crane or gantry, for instance, as commonly found on equipment service vehicles and in repair shops. It can also be suspended from an element of the tracked machine or vehicle itself or another vehicle or machine, such as from a bucket or blade thereof, or a structural support thereof such as a cylinder or arm carrying the bucket or blade. In one embodiment, the apparatus of the invention will be suspended from a service truck crane positionable next to the track and movable in a manner for taking the necessary slack out of or tensioning the track and moving it laterally toward and over the idler. 
     As an aspect of the method of the invention, the side of the tracked vehicle or machine on which the track is to be installed or reinstalled, will have to be elevated. This can be done, if possible, using a crane, or with a jack or jacks, or an inflatable bag or bags. The vehicle or machine can then be supported on timbers, stands, cribbing, or an inflated bag or bags during the installation. As another aspect, the pressure in the idler support will be relieved, and the idler retracted. As another aspect of the method of the invention, the apparatus will be fitted and installed about the end of the track. This will entail selection of grippers sufficiently large to form the end of the track in a large enough arc shape to partially encircle the idler with sufficient margin for passage of the lugs over the circumference of the idler. The apparatus, thus installed on the track, will then be used to take the slack out of or tension the track as required for passage over the idler. As a next or in the same step, the track can then be carried by the apparatus laterally into position about the idler. Here, the apparatus can be supported on a stand, movable over the ground or other surface below the apparatus, such as on wheels or skids, or on a dolly, or it can be supported on or from suitable support structure such as a crane, truck, fork, bucket or blade of another vehicle, or even a bucket, arm, or blade of the tracked vehicle or machine itself. For example in this latter regard, if the tracked machine is a track hoe, the stick or arm supporting the bucket of the hoe can be used for supporting the apparatus of the invention, and manipulated as required for installing the track. Once the track is installed, the apparatus can be removed, the idler extended, and the vehicle or machine lowered to ready it for operation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of apparatus of the invention; 
         FIG. 2  is a top view of apparatus of the invention; 
         FIG. 3  is a perspective view of a representative tracked vehicle with which the invention can be used; 
         FIG. 4  is a perspective view of a tracked vehicle with which the invention can be used, showing a track of the vehicle off; 
         FIG. 5  is an end view of a representative tracked vehicle; 
         FIG. 6  is a simple five schematic view of a tracked vehicle with a track off; 
         FIG. 7  is a simple find and view of a tracked vehicle showing steps of a method of the invention for retracking; 
         FIG. 8  is a simplified schematic side view showing steps of the invention; 
         FIG. 9  is a simplified top view of a tracked vehicle being retracked using the invention; 
         FIG. 10  is a simplified side view of a tracked vehicle being retracked using the invention; 
         FIG. 11  is another simplified top view of a tracked vehicle being retracked using the invention; 
         FIG. 12  is another simplified side view of a tracked vehicle being retracked using the invention; 
         FIG. 13  is a simplified perspective view of a typical tracked vehicle with which the invention can be used; 
         FIG. 14  is a simplified perspective view of another typical tracked vehicle with which the invention can be used; 
         FIG. 15  is a simplified top view of a tracked vehicle being retracked using the invention; 
         FIG. 16  is a fragmentary top view of a tracked vehicle being retracked using the invention; 
         FIG. 17  is another fragmentary top view of a tracked vehicle being retracked using the invention; 
         FIG. 18  is another fragmentary top view of a vehicle being retracked using the invention; 
         FIG. 19  is another fragmentary top view of a vehicle being retracked using the invention; 
         FIG. 20  is a side view showing apparatus of the invention on a tracked vehicle; 
         FIG. 21  is a fragmentary side view of apparatus of the invention; and 
         FIG. 22  is a fragmentary perspective view of apparatus of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 through 21 , embodiments of preferred apparatus and steps of preferred methods of the invention are shown. In  FIGS. 1 and 2 , a preferred apparatus  30  includes a pair of track grippers  32  and  34  configured and operable for gripping at least the edges of the portion of the track to be installed or reinstalled over the idler wheel or sprocket of a tracked work machine or vehicle. Each gripper  32 ,  34  as an overall arc shape adapted for shaping that portion of the track gripped thereby into an arc of appropriate size for passage laterally over the idler wheel or sprocket, hereinafter also referred to by just the term “idler”, as will be discussed hereinbelow. 
     Each gripper  32 ,  34  comprises a rigid structure of tubular or solid metal such as steel or aluminum, and can be a weldment, castings, or extruded shape curved or bent to the desired arc shape and size. With regard to the term “arc shape” this is to be interpreted as including a series of straight segments in end to end, angularly related pattern, forming a generally arced or curved shape, as well as a smoothly curved shape. 
     Each of the grippers  32 ,  34  includes a single, continuous gripping element  36  positioned and oriented to extend in an inward direction toward the other gripper  32 ,  34  and configured for cooperatively engaging the edge of the track for gripping and holding or supporting the track portion in the arc shape, and for carrying it laterally into position on the idler. Here, as a non-limiting example, the single continuous gripping element  36  can comprise a flange or lip formed in the arc shape and size. 
     Apparatus  30  is configured to allow interchanging ability of different grippers having characteristics adapted for use with particular track types and/or sizes, such as illustrated by alternative grippers  36 A in  FIG. 1  having a smaller arc radius. Grippers having larger radius arcs can also be provided as desired or required for a particular application. The invention additionally includes adjustable support arms  38 ,  40  that support and hold the grippers  32 ,  34  in a generally parallel, spaced apart relation such that the gripping elements of the respective grippers  32 ,  34  are in opposing relation and are spaced a distance apart corresponding to the width of the track to be installed, so as to be capable of capturing or bounding the portion of the track to be installed onto an idler, as will be explained. In this latter regard, the arms can be adjustable for different width tracks, or non-adjustable but capable of being opened and closed or assembled for positioning about a track of a particular width. 
     For attachment to support arms  38 ,  40 , each gripper  32 ,  34  includes a receiver  42 , configured to cooperatively receive and connect to a gripper end  44  of arm  38  or  40  by a suitable attachment, such as pins  46  receivable through mating holes  48 . Arms  38 ,  40  additionally include base ends  50  telescopingly receivable in receivers  52  of a main receiver member  54 , in parallel relation, and can be held in place therein in any suitable manner, such as using additional pins  46  selectably receivable in holes  48 , for setting a width of apparatus  30 , as denoted by arrows W. Additional holes  48  can also be provided in gripper ends  44  of arms  38 ,  40  to allow adjusting the length of that portion of apparatus  30 , if desired, as denoted by arrows L. Gripper ends  44  can be of different lengths or other configurations, as illustrated, for compensating for the offset locations of receivers  52 , as required. As additional features, apparatus  30  can include lifting elements, such as a swivel ring  56  on member  54 , and other eyelets or lifting rings, hooks or the like, as desired or required for a particular application. As other examples, the support arms of the apparatus can be relatively movable via a scissors or pivotal connection or action, as desired. In either instance, the arms can be fixed or retained in a set position via suitable apparatus such as a pinned connection, turnbuckle or hydraulic cylinder, these latter apparatus being usable also for adjustably moving the arms. 
     According to another aspect of the invention, by virtue of the pinned connections, grippers  32 ,  34 , and support arms  38 ,  40 , can be removed, for breaking down or compacting apparatus  30  for transport and storage, and to allow interchanging different size grippers, e.g., grippers  36 A, for use with different size tracks or idlers. Thus, as an example, a larger radius gripper for use with a larger radius idler can be interchanged with a smaller radius gripper for use with a smaller radius idler, and/or a medium size gripper, or a gripper for a different style or type of track, e.g., a rubber track or steel track. 
     Referring also to  FIGS. 3-12 , a representative tracked work machine  58  is shown, including with a track  60  on one side untracked in  FIGS. 4 through 6 , and track  60  being reinstalled according to steps of a method of the invention in  FIGS. 7 through 12 . Here, machine  58  is a depicted as a compact track loader having tracks  60  on opposite sides of the machine. Tracks  60  can be of rubber or steel construction, and encircle idlers  62  on the front end of the machine and drive wheels  64  on the rear end, with several bogey wheels  66  disposed between a lower idler  62  and drive wheel  64 . In operation, with tracks  60  properly installed as illustrated in  FIG. 3 , drive wheel  64  will be rotated in the well known manner to move track  60  about idlers  62  for propelling machine  58  in one direction the other and for maneuvering and turning the machine.  FIGS. 4 through 6  show one of tracks  60  off of idlers  62 , which can happen for a variety of reasons, such as, but not limited to, due to wear and looseness of the track, or operation on a surface or under conditions where large lateral forces are exerted to remove the track. 
     In  FIG. 7 , as an initial step of the method of the invention, the affected side of machine  58  is raised. This can be accomplished using a jack or jacks, crane, inflatable air bags or the like. To maintain the side of the machine in the raised position, cribbing or timbers  68  are used. This is to enable sliding or moving the affected track  60  laterally toward machine  58 , and to take required slack out of it (if any) or tension it to enable installing or fitting it about idlers  62 , including any lugs on the track or idler as denoted by arrows X. This installation is accomplished using the apparatus  30  just discussed. 
     As another initial step, the idlers  62  are retracted, so as to be lowered and/or moved rearwardly, as illustrated by arrows RT in  FIG. 8 . This provides the clearance for installing track  60 . 
     With the side of the machine raised, apparatus  30  is now fitted about the end of track  60 . To do this, main receiver member  54  is positioned just in front of track  60 . This can be done manually, or using a crane of other lifting device (not shown). Grippers  32  and  34  will be selected so as to have the appropriate arc radius for installing track  60  about idlers  62 , which will be a radius marginally larger than the outer circumference of the idlers, as illustrated by the relative size of gripper element  36  and idler  62  in  FIG. 10 . 
     With the end of track  60  supported and shaped by gripping elements  36 , apparatus  30  is moved or manipulated, to install the track about idlers  62 . This is possible because the end of track  60  is captured or retained by grippers  32 ,  34 . This step involves moving or pulling apparatus  30  forwardly, as denoted by arrows F, to take necessary slack out of or tension the track, and laterally, as denoted by arrow L, into a forward position over idlers  62 , as illustrated in  FIGS. 9 through 12 . This can be performed manually, or using a lifting device, such as a crane, lever, or pry bar or bars. 
     With track  60  properly installed, idlers  62  are extended, as denoted by arrow E in  FIG. 12 , and machine  58  lowered to return to operation. 
     Referring also to  FIG. 13 , another work machine is shown which is a bulldozer  70  having heavy steel tracks  72 , which can be reinstalled using the apparatus and method of the invention, such as an apparatus  30 . 
     Referring also to  FIGS. 14 through 17 , a representative tracked excavator  74  is shown, including in  FIGS. 15 through 17  having a large track  76  reinstalled about a front idler  62  using apparatus  30  according to the invention. In particular, in  FIG. 15 , the side of excavator  74  is raised as before, idler  62  is retracted, and apparatus  30  is suspended from a crane  78  of a service truck  80 , to allow sizing and fitting grippers  32  and  34  about the end of the track  76 , as denoted by arrows Y, in the above described manner. In  FIG. 16 , grippers  32  and  34  support track  76  from crane  78 . Going to  FIG. 17 , apparatus  30  is moved by crane  78  forwardly and laterally, and upwardly or downwardly, to remove any slack or tension the track as required and install track  76  on the idler, as denoted by arrows F and L. The idler can now be extended, and the excavator lowered for operation. 
       FIGS. 18 and 19  illustrate that the present invention allows some work machines such as excavator  74  to be self-retracking. Here, the bucket  82  of the excavator  74  can be used to lift the side of the excavator, for securing with timbers or the like as before. A jack, air bag or the like could alternatively be used. Idler  62  is retracted as before. Apparatus  30  is suspended from the excavator bucket  82  for fitting about the end of track  76 . The stick  84  supporting the bucket and the bucket itself can then be manipulated to move apparatus  30  and track  76  forwardly, laterally, and upwardly and downwardly as required, as denoted by arrows F and L into position on the idler. The idler is then extended as before and the machine lowered for operation. 
     Referring also to  FIGS. 20 ,  21  and  22 , another embodiment of an apparatus  86  for installing a track, such as track  76  about an idler  62  of any of a variety of tracked work machines or vehicles according to the invention is shown. Apparatus  86  differs from apparatus  30  primarily in the provision of adjustable size grippers  88 , supported on adjustable arms  38  and  40  adjustably carried on and movable relative to a main receiver member  54 , and fixable in a selected spaced apart width using a pin  46 , in the above described manner. 
     Each gripper  88  consists of several gripper segments  90 , here numbering  5 , joined together in end to end relation by hinge joints  92  to allow relative hinged movement thereabout. A middle gripper segment  90  is fixed to arm  38  or  40 . Each gripper segment  90  includes a gripping element segment, which is preferably a flat plate or strip of suitable metal such as steel or aluminum, projecting sidewardly therefrom and adapted for cooperatively engaging a portion of track  76  for forming it into the required arc shape and size for installing about idler  62 , essentially in a manner equivalent to that described above. 
     Here, it should be noted that the arc shape is actually comprised of the angularly related segments  90  and thus is considered to be equivalent to and representative of an actual arc shape for the purposes of the invention. 
     Adjacent ones of gripper segments  90  are additionally connected together by adjusting members which here can comprise, as non-limiting examples, turnbuckles  96  or hydraulic cylinders  98 . Turnbuckles  96  and cylinders  98  are connected to the respective gripper segments  90  by pivot joints  100 , each comprising a clevis  102  on the ends of the respective segments  90 , pivotally connected to the end of the turnbuckle or cylinder by a pin  46  received through holes  48  in the respective members. As a result, shortening the turnbuckle or cylinder between adjacent segments  90  will increase the angle therebetween and thus the radius or size of the arc, and lengthening them will decrease the radius or size. 
     Here, it should be noted that as an advantage of the use of angularly related segments  90 , a wide variety of sizes can be achieved. As another advantage, for a track consisting of angularly related or hingedly connected tread plates, the flat gripping elements can make better surface to surface contact with those plates, so as to possibly provide better gripping and holding strength. Good holding strength can also be achieved with rubber tracks. When adjusting turnbuckles  96 , an appropriate tool such as a wrench can be used. Pressurized hydraulic fluid for cylinders  98  can be provided by connection to the machine or vehicle being retracked, if available, or connection to a system of a service truck or portable hydraulic system, which enables operation remotely and with less manual effort. 
     Apparatus  86  can be supported in any of the above described manners, e.g., by a service truck or crane, gantry, or bucket or other suitable movable member of a vehicle or machine, for installation of a track such as track  76  in any of the above described manners. The side of the vehicle or machine can be raised and supported using a crane, or with a jack or jacks, or an inflatable bag or bags. The vehicle or machine can also be supported on timbers, stands, cribbing, or an inflated bag or bags during the installation. 
     It should be apparent that the apparatus of the invention shall be of sufficient size and robustness for shaping, supporting and holding the track to be installed. This will entail selection of grippers sufficiently large to form the end of the track in a large enough arc shape to partially encircle the idler with sufficient margin for passage of the lugs over the circumference of the idler. The grippers and apparatus must also be robust enough to extend or tension the track, and to move it laterally. This can be supplemented by additional support apparatus below apparatus  30  or  86 , such as wheels, skids, a fork or forks, or a bucket or blade of another vehicle. 
     In light of all the foregoing, it should thus be apparent to those skilled in the art that there has been shown and described a novel apparatus and method for installing a track on a tracked vehicle. However, it should also be apparent that, within the principles and scope of the invention, many changes are possible and contemplated, including in the details, materials, and arrangements of parts which have been described and illustrated to explain the nature of the invention. Thus, while the foregoing description and discussion addresses certain preferred embodiments or elements of the invention, it should further be understood that concepts of the invention, as based upon the foregoing description and discussion, may be readily incorporated into or employed in other embodiments and constructions without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown, and all changes, modifications, variations, and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is limited only by the claims which follow.