Abstract:
A tool for and method to facilitate the replacement of wheels on track-and-wheel vehicles and equipment by lifting the track from the road-wheels in a quick, safe and efficient manner. A tool with an elongated section and two forked ends, each fork having a long prong and a short prong, the long prongs of both ends not being on the same side of the tool. In operation, one forked end is placed in notches in the lower track, and the other forked end is placed in notches in the upper track. The vehicle is then driven in a direction so that the tool acts as a wedge lifting the upper track off of the road wheel.

Description:
RELATED APPLICATION 
     This is a continuation-in-part application of U.S. patent application Ser. No. 08/259,040 filed Jun. 13, 1994 and now abandoned. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to lifting tracks and/or wheels on vehicular track-and-wheel systems to facilitate the removal and replacement of failed or damaged wheels. 
     BACKGROUND 
     The present invention has particular utility with track-and-wheel driven vehicles used for general civil engineering or general military purposes. When a wheel fails or is damaged, it must be replaced. Currently, lifts are used to lift the wheel off of the ground and lower track. The upper track is lifted off of the top of the wheel using a chain that is attached to a manual winch which is hung over any suitable edge or corner that can be found on the vehicle above the track-and-wheel system. 
     Under ideal weather conditions on dry pavement, the old process requires three to four people, and approximately 45 minutes to one hour, on average, to complete. In unfavorable weather conditions and on more difficult terrain, the old process could require 5 persons and 3 to 5 hours. The number of personnel and time required using the old systems and methods are a tremendous disadvantage. This is especially true where time and personnel are critical, such as in battle or wartime conditions where loss of equipment and time delays cost lives. 
     Even under ideal conditions, the current method is not safe. The winch is simply hooked over any available comer and the risk of slippage of the chain or the winch is high. Additionally, the personnel must manually operate the equipment. Consequently, at least one person is placed at risk of potentially severe personal injury using the old method. 
     The present tool and method has tremendous advantages over the old systems and methods. First of all, the present invention performs the same task as the old methods in approximately 15 minutes and only requires two persons. The tool also costs less to manufacture, weighs less, can be stored and used more easily, does not require that the personnel be near the equipment during the lifting operation and has a greatly reduced potential for slippage. 
     SUMMARY OF THE INVENTION 
     A tool for and a method to facilitate the replacement of wheels on track-and-wheel vehicles and equipment by lifting the track from the road-wheels in a quick, safe and efficient manner. A tool having an elongated section, two forked ends each having a long prong and a short prong, where the long prongs of both ends are on opposite sides of the tool. To use the tool, one forked end is placed in notches in the lower track; the other forked end is placed in notches in the upper track and the vehicle is driven in a direction so that the tool acts as a wedge lifting the upper track off of the top of the road wheel. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an illustration of a track-lifting tool. 
     FIG. 2a is an illustration of an alternative construction of the invention. 
     FIG. 2b is an illustration of another alternative embodiment. 
     FIG. 2c is an illustration of the alternative embodiment of FIG. 2b in more detail. 
     FIG. 3 is an illustration of an earth-moving vehicle with a track-and-wheel system. 
     FIG. 4a is an illustration of a section of track as viewed from the top down with the top track removed showing a position on the track where the lower prongs can be placed in the sprocket guide-hole notches in the outer track and the position where the road wheel lift is placed. 
     FIG. 4b is an illustration of a section of the track as viewed from the top showing the position where the top prongs of the tool can be placed to prepare for the lifting operation. 
     FIG. 5a is an illustration of the proper placement of the tool on the track-and-wheel system. 
     FIG. 5b is an illustration of how the tool is placed on the track-and-wheel system from the perspective of the vehicle looking out. 
     FIG. 6 is an illustration of a track-and-wheel system lifted by the tool from the perspective of the vehicle looking out. 
     FIG. 7 is an illustration of a lifted track and wheel hub with the damaged wheel removed. 
     FIG. 8 is an illustration of a lifted track and replaced wheel. 
     FIG. 9 is an illustration of a repaired track-and-wheel system ready for operation. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The tool 1 shown in FIG. 1 is comprised of an elongated section 2 and two end sections 4 and 6. When positioned in an upright position as illustrated, the Tool 1 has two opposing sides 8 and 10 relative to an axis 12. 
     An embodiment of the Tool 1 shown in FIG. 1, is of particular utility for track-and-wheel systems such as those found on military tanks and similar military and commercial vehicles shown in FIG. 3. 
     For a track-and-wheel system, the Tool 1 can be used to lift and separate the track 24 from the top of the wheel 22. For this purpose, the end sections 4 and 6 are forked, with each fork having two prongs of unequal length 14, 16, 18 and 20. Each end 4 and 6 has a long prong 14 and 16 and a relatively shorter prong 18 and 20. The long prong 14, on one end 4, is on the opposite side 8 of the long prong 16, of the other end 6. 
     The dimensions of Tool 1 are determined by the equipment on which the tool is intended to be used. For example, the earth mover shown in FIG. 3 has a road-wheel 22 and track 24 drive system. The size and weight of the wheels and tracks for different track-and-wheel systems vary widely depending on the vehicle or equipment on which the system is used. For this reason, the actual dimensions of components of the invention vary with the variety of sizes and weights in track-and-wheel system equipment and vehicles. 
     The dimensions of the elongated section 2 of the tool are determined by the diameter of the road-wheel 22, and the load which the tool must bear during the lifting motion described below. The greater the diameter of the road-wheel 22, the longer and thicker the elongated section 2 must be. The heavier the load, the thicker the elongated section 2 must be. 
     The dimensions of the forked ends 4 and 6 are determined by the dimensions of the track, the load, and the dimensions of the road-wheel. The spacing 26 between the long and short prongs 14 &amp; 18 and 16 &amp; 20, on either end, 4 or 6 respectively, of Tool 1 is determined by the shape of the linking elements 28 of the track 24 shown in FIG. 4. The difference 30 in the length of the prongs 14 &amp; 18 and 16 &amp; 20 on either end of Tool 1 is determined by the dimensions (including the diameter) of the road-wheel and the shape (including the thickness) of the linking elements 28 of the track 24 in FIGS. 4a and 4b. The shape of the prongs 14 and 18 is determined by the shape of the sprocket guide-holes or notches 32 in the track 24 shown in FIGS. 4a and 4b. Sprockets 34 which drive the track are shown in FIG. 3. 
     Using this information, a reasonably skilled tool-maker can calculate and determine the proper materials and dimensions of the tool for a particular track-and-wheel system. For a M9 (ACE) track-and-wheel earth moving vehicle, for example, suitable dimensions for the tool are: long prong length of approximately 2 inches, short prong length of 1 inch, prong thickness of approximately 3/4 inches, prong spacing of approximately 4.4 inches, and with an elongated section made of approximately 1-1/2 inch pipe with wall thickness of approximately 1/4 inches of sufficient length so that the overall length of the tool will be approximately 48 inches. The pipe may be constructed of seamless or drawn over mandrel steel. 
     METHOD OF OPERATION 
     Operation of the Tool is illustrated in FIGS. 5a &amp; 5b, 6, 7, 8 and 9. After it has been determined that a road-wheel must be removed from a track-and-wheel system, the operator should: 
     1. loosen lug-nuts 40 on the road-wheel; 
     2. on the outside portion 23 of the track 24, place the long prong 14 of one end 4 of the Tool 1 in a notch in the track 24 near the top of the wheel 22 in position 31 as shown in FIGS. 5a and 4b; 
     3. place the long prong 16 of the other end 6 of the Tool 1 in a notch in a position 29 at a different vertical position to the left or right on the track below the wheel 22 as shown in FIGS. 5a and 4a; 
     4. place the bottom of a conventional wheel lift 21 near position 27 on the inside (or vehicle) side 25 of the track 24 so that it has an angular orientation similar to the orientation of Tool 1 on the outside of the track as shown in FIG. 4a and in FIG. 5b. If a vertical lift is used, place the lift directly below the hub after the track is raised in step 5; 
     5. drive the vehicle slowly in direction 42 shown in FIGS. 5a and 5b until the track-and-wheel are lifted and Tool 1 is in position to allow removal of the damaged road-wheel from the hub 38 as shown in FIG. 6; 
     6. place the vehicle in &#34;neutral&#34; or &#34;park&#34; and, using stops, blocks and/or brakes for safety; 
     7. install the road-wheels on the hub 38 as shown in FIG. 8; 
     8. drive the vehicle slowly in direction 44 shown in FIGS. 8 opposite the direction shown in FIGS. 5a and 5b. Positions 27 and 29 (See FIG. 4a) are intended to illustrate that the positions are both to one side of the center of the wheels. The actual positions can both be either to the left or the right along the path of the track. Additionally the amount to the right or left depends on the dimensions of the wheel and track and the heights to which the wheel and track are to be raised. 
     ALTERNATIVE EMBODIMENTS 
     The elongated section or component, and/or the forked-end sections or components of the invention can be made of circular pipes, or other shaped material, and fittings to improve the absorption of the load imposed on the components during lifting. In one alternative embodiment shown in FIG. 2a, the elongated section of Tool 111 is comprised of pipe with both ends threaded and the functional ends are formed pieces which are threaded to mate with the elongated section. 
     In another alternative embodiment shown in FIG. 2b, steel pipe forming the elongated section 102 may be attached to forked end components or sections 104 and 106 made of solid steel cut to the particular dimensions required by the particular track-and-wheel system. The elongated section and end sections may be attached in any conventional way, such as welding. Preferably as shown in FIG. 2c, the end sections 104 and 106 have a shank 108 which extends into the elongated section 102. The elongated section 102 and shanks 108 of the end sections have a hole drilled or otherwise formed therein. The holes in the section 102 can then be aligned with the holes in the shanks 108 so that pins 112 can be inserted to hold the end sections 104 and 106 securely in the elongated section 102. The holes are positioned so that the end of the elongated section 102 bears the load transmitted through the end sections 104 and 106 rather than on the pins 112. 
     Currently, track-and-wheel vehicles are equipped with a &#34;cheater pipe&#34; which is used as a lever arm to loosen the lug-nuts 40 of the wheels as described in step 1 of the method described above. Another advantage of the embodiments shown in FIGS. 2a and 2b is that they can also replace the &#34;cheater pipe&#34; by disassembling the elongated section from the functional ends and using it as the &#34;cheater pipe.&#34; 
     Using this information, a reasonably skilled tool-maker can calculate and determine the proper materials and dimensions of the tool for a particular track-and-wheel system. 
     The disclosure and description of the invention provided above and in the drawings, are illustrative and explanatory thereof, and variations in the size, shape and materials as well as details of the illustrated construction are possible without departing from the spirit of the invention.