Abstract:
Described is a belt used in conjunction with road wheels device and method of supporting weight of hybrid tire tracking-laying vehicles more safely and efficiently at highway speeds. The supporting device includes belts  004 , road tires  002 , track tires  003 , tensioning tires  015 , and supporting frame and axles. The road tires  002  are located outside beside the belt  004  with a larger diameter than the belt  004 . The outside road tires work to laterally guide the belt  004  and to prevent the rubber belt  004  from track-throwing. The tensioning tires  015  running inside the belt  004  along the wheel runways  027 , are guided by the belt guide horns  020 . In this proposed device, the belt  004  can remain sufficiently taut to prevent the guide horns  020  from slipping over the track tires  003  and road tires  002 . The designed hybrid belt with tires can remove debris such as mud and sand, and prevent track-throwing even during turning maneuvers.

Description:
BACKGROUND 
       [0001]    1. Field of Invention 
         [0002]    This invention relates to a hybrid combination of tracks in conjunction with road wheels for vehicles. 
         [0003]    2. Description of Prior Art 
         [0004]    Numerous types of vehicles are frequently used in terrain in which it is difficult for pneumatic tires to operate. Amphibious vehicles, military tanks, construction equipment, tractors, and recreational vehicles may be required to operate on terrains that are very soft and/or debris covered, such as sand, mud, rocks, tree branches, and building debris. Pneumatic tires are not very capable of efficient operation on the above mentioned soft and/or debris covered surfaces, as they tend to burrow into the surface rather than riding across the surface and climbing over debris. 
         [0005]    Belt vehicles have been developed for use on terrains in which pneumatic tire vehicles are impractical. For example, see U.S. Pat. Nos. 3,361,488 (Ohm et al), 3,688,858 (Jesperson), 3,734,577 (Snellman), and 3,955,855 (Massieon et al). In many types of terrain, these vehicles provide improved performance relative to the performance of a pneumatic tire vehicle. Still difficulties are encountered with existing belt vehicles. 
         [0006]    Originally, such tracks were made of a plurality of metal links or shoes pivotally attached to each other to form an belt, which is very heavy and causes serious damage to surfaces on which it runs. Metal links are also noisy, an uncomfortable ride for passengers, and require significantly more maintenance when operated at high speeds. For example, see U.S. Pat. Nos. 2,823,082 (Bauer) and 4,530,546 (Meisel, Jr.). Heavy off-road only vehicles and construction equipment that travel at low speeds may still use metal tracks. 
         [0007]    A need has developed for a low maintenance form of vehicle appropriate for both normal road use and off-road use. There is a significant need for a vehicle capable of rapid responses to armed conflicts and natural emergencies. Also, a load carrying vehicle that is both on road and off road would be useful in many areas, such as construction, agriculture, and undeveloped regions without extensive road infrastructure. Most load carrying off-road vehicles presently have very large wheels or very cumbersome tracks, which are heavy, slow moving, prone to coming off in debris, inappropriate for use on roads at normal highway speeds, and which wear excessively when used on hard surfaces. 
         [0008]    Rubber belts have become popular for construction and low soil compaction farming equipment that must travel or operate on road surfaces. With the combination of rubber technology and a tremendous amount of trial and error, various types of rubber tracks are now available. For example, see U.S. Pat. Nos. 5,279,378 (Graiwey et al) and 6,267,458 (Hansen et al). Most equipment is operated on the job site only and is transported between sites by trucks or trailers. To eliminate the inconvenience of transporting the vehicle between job sites, a vehicle that can operate on both public roads at normal speeds and off road is required. 
         [0009]    A number of hybrid steel tracks with rubber pads have been proposed where the links or shoes are made of metal that is provided with a rubber cover or insert. For example, see U.S. Pat. Nos. 2,359,586 (Sayler), 2,369,130 (Benson), 2,409,502 (Leguillon et al), 3,148,921 (Batur et al), 4,109,971 (Black et al), 4,359,248 (Kortering), and 4,588,233 (DenBensten). While these hybrid tracks reduce noise and greatly reduce road damage, they are still relatively slow moving, prone to coming off in debris, worn excessively when used on hard surfaces, and inappropriate for use on roads at normal highway speeds. Hybrid steel tracks with rubber pads are more complex than rubber tracks and require more maintenance. However, they are capable of carrying extreme loads. 
         [0010]    Rubber tracks are generally capable of higher speeds than either steel or hybrid tracks. However, no track vehicle can match the high speed at which pneumatic tire vehicles can comfortably operate. All tracked vehicles are prone to coming off in debris and wear excessively when used on hard surfaces. 
         [0011]    Some of the problems encountered in using such an endless rubber track in practice are maintaining adequate uniform tension on the rubber track as it twists to accommodate even a small amount of misalignment, keeping the rubber track lateral and aligned with each track wheel when there is even a small amount of misalignment, keeping the rubber track in lateral alignment with the track wheels when it is subjected to large lateral loads occurring during turning maneuvers or on steep inclines, as well as debris wedging between the rubber track and the track wheels affecting alignment and the ability to drive the rubber track. 
         [0012]    Throwing a track is the most dangerous and catastrophic problem that can occur during the operation of rubber tracks. As travel velocity increases the energy, the resulting danger posed by throwing a track increases with the velocity squared. At road traffic speeds, sudden maneuvers, such as sudden lane changes could result in throwing a track. An unbalanced track or slack in the rubber track and the resulting flapping set upper limits on the safe travel speed. Travel speeds are finally limited by friction heating of the rubber track. 
         [0013]    3. Description of Related Art 
         [0014]    [Note: As used herein, the term rubber relates to any elastic and primarily non-metallic materials, such as rubber, elastomer, or combinations thereof used in the manufacture of belts]. 
         [0015]    Most rubber tracks are formed around a basic carcass or belt. The carcass includes an endless belt-shaped rubber-like elastic member, a number of core bars (usually of metal) embedded therein, aligned in the longitudinal direction thereof, and extending in the traverse directions thereof. It also includes high tension strength cords embedded in the endless elastic member to surround the core bars circumferentially outward. For example, see U.S. Pat. Nos. 4,904,030 (Ono), 5,295,741 (Togashi et al), 5,511,869 (Edwards et al), and 6,241,327 (Gleasman). 
         [0016]    Some have suggested the construction of endless rubber tracks using a plurality of interconnected polymeric modules. For example, see U.S. Pat. Nos. 4,861,120 (Edwards et al) and 5,005,922 (Edwards et al). 
         [0017]    Terrain contacting lugs are formed integral with the exterior surface of this basic belt element. Known rubber tracks have large lugs in a variety of well-known orientations, such as those formed generally perpendicular to the track axis, at an angle to the track axis, or in a chevron or modified-chevron design. These latter specialized tracks also include interior lugs or horns for maintaining the track in alignment as it travels over the circumferences of the rubber tires. These lugs are located either in the center of the interior surface of the track (for fitting between the tires of dual wheels) or in two aligned rows near the outside edges of the track (for receiving a single tire there between). For example, see U.S. Pat. Nos. 5,447,365 (Muramastsu et al), and 5,540,489 (Muramatsu et al). 
         [0018]    Endless rubber tracks have been adapted to existing high-speed military steel track laying vehicles to improve efficiency at higher road speeds. For example, see U.S. Pat. No. 2,357,140 (Soucy et al). 
       OBJECTS AND ADVANTAGES 
       [0019]    Spring rubber or pneumatic road tires  002  slightly larger in diameter than the endless rubber belt  004  are located beside the belt to laterally guide the endless rubber belt  004  and minimize track-throwing occurrences. Spring rubber or pneumatic tires absorb rough road shocks from stones and pot holes that might break solid wheels of similar strength. The side located road tires  002  act as large guides. However, unlike existing tracks, the guide horns  020  are not prone to grabbing loose debris and wedging the debris between the rubber belt  004  and the track tires  003 . Loose debris wedged between rubber belt  004  and the track tires  003  can easily lift the rubber belt  004  off the track tires  003 . The side shoulder of the road tire  002  is protected from track friction wear by a small gap present between the road tire  002  and the endless rubber belt  004  at full road tire  002  inflation and track the outside guide horns  020 , which are designed to spread any lateral load against the tire over a large area. When the inflation of road tires  002  is sufficiently reduced, the track outside the guide horns  020  is designed to operate like a V-belt gripping both the track tires  003  and the road tires  002 . Interior 3D curvilinear belt drive teeth  033  may be used to eliminate endless rubber belt slippage on track drive wheel. The 3D curvilinear drive teeth  033  allow much larger track wheel misalignments than conventional drive horns. However, in most applications, the tight endless rubber belt  004  on the track drive tire  031  should provide more than enough traction to prevent excessive slippage of the rubber belt  004 . Slight rubber belt  004  slippage substantially reduces drive train shock forces. Eliminating the drive teeth  033  allows track drive wheels to dig through any debris that may have accumulated inside the endless rubber belt  004 . As a result, debris, such as sticks and stones, cleans itself away much easier. The road tires  002  located beside the endless rubber belt  004  also protect the rubber belt  004  by clearing material away from the track while turning in soft soils or loose debris. On smooth hard surfaces, if fully inflated, the road tires  002  would lift the endless rubber belt  004  off the surface. The endless rubber belt  004  can be lifted off hard road surfaces during high speed travel, dramatically reducing wear and rolling friction. Higher road speeds with reduced power consumption are achieved by disengaging the rubber belt  004  during high speed operation. The rubber belt  004  would then be engaged when required by brakes between the track tires  003  and road tires  002 . A tensioning idler is composed of tensioning track guides  006 , tensioning shaft  007 , and dual tensioning tires  015 . Retracting the tensioning idler in combination with the slight ground clearance provided by the road tires  002  on hard surfaces can allow the rubber belt  004  to be removed and replaced without the use of vehicle jacks. 
         [0020]    The outside road tires  002  prevent the rubber belt  004  from track-throwing even when the track tires  003  are misaligned. The optional interior 3D curvilinear drive teeth  033  and the track outside guide horns  020  are practically immune to realistic amounts of misalignment. With a pattern belt canvas, which allows for an amount of belt shear, the proposed hybrid tire rubber belt systems can be adapted to vehicles with a suspension not specifically designed for rubber belts. In such an application, a pivotable tensioning idler dynamically maintains uniform tension across the width of the rubber belt  004 . The angular misalignment between tandem solid axis  001  is further reduced by a hydraulic linkage between them, which enables the hybrid tire and rubber belt system to be used on many existing tire vehicles. 
       SUMMARY 
       [0021]    In accordance with the present invention, a belt is used in conjunction with road wheels to support weight of hybrid wheel track-laying vehicles. This is an improved design that allows a belt to be driven more efficiently and safely at highway speeds, diminishes the possibility of mud, sand, or other debris dislodging the track during turning maneuvers, and reduces belt wear when this invention is used on hard surfaces. 
     
    
     
       DRAWING FIGURES 
         [0022]      FIG. 1  is an isometric view of rubber belt assembly for dual track tires. 
           [0023]      FIG. 2  is a front view of rubber belt assembly for dual track tires showing the position of cutting plane A-A. 
           [0024]      FIG. 3  is a cross section of rubber belt assembly for dual track tires at cutting plane A-A. 
           [0025]      FIG. 4  is a side view of rubber belt assembly for dual track tires showing the position of cutting planes B 1 -B 1 , B 2 -B 2 , B 3 -B 3 , and B 4 -B 4 . 
           [0026]      FIG. 5  is an end view of rubber belt assembly for dual track tires at cutting plane B 1 -B 1 . 
           [0027]      FIG. 6  is an end view of rubber belt assembly for dual track tires at cutting plane B 2 -B 2 . 
           [0028]      FIG. 7  is an end view of rubber belt assembly for dual track tires at cutting plane B 3 -B 3 . 
           [0029]      FIG. 8  is an end view of rubber belt assembly for dual track tires at cutting plane B 4 -B 4 . 
           [0030]      FIG. 9  is a front view of rubber belt frame for dual track tires with rubber belt removed. 
           [0031]      FIG. 10  is a top view of rubber belt frame for dual track tires with rubber belt removed. 
           [0032]      FIG. 11  is a side view with dual tire rubber belt for over dual track tires showing the positions of cutting plane C 2 -C 2  and cut object C 1 -C 1 . 
           [0033]      FIG. 12  is a front view of one single rubber belt unit at cut object C 1 -C 1 . 
           [0034]      FIG. 13  is a top view of one single rubber belt unit at cut object C 1 -C 1 . 
           [0035]      FIG. 14  is a rear view of one set of rubber belt unit at cutting plane C 2 -C 2 . 
           [0036]      FIG. 15  is an isometric view of rubber belt assembly for single track tire twisted 8 degrees. 
           [0037]      FIG. 16  is a front view of rubber belt assembly for single track tire twisted 8 degrees. 
           [0038]      FIG. 17  is a top view of rubber belt assembly for single track tire side twisted 8 degrees. 
           [0039]      FIG. 18  is a side view of rubber belt assembly showing the positions of cutting planes D 1 -D 1 , D 2 -D 2 , D 3 -D 3 , D 4 -D 4 , and D 5 -D 5 . 
           [0040]      FIG. 19  is an end view of rubber belt assembly for single track tire at cutting plane D 1 -D 1 . 
           [0041]      FIG. 20  is an end view of rubber belt assembly for single track tire at cutting plane D 2 -D 2 . 
           [0042]      FIG. 21  is an end view of rubber belt assembly for single track tire at cutting plane D 3 -D 3 . 
           [0043]      FIG. 22  is an end view of rubber belt assembly for single track tire at cutting plane D 4 -D 4 . 
           [0044]      FIG. 23  is an end view of rubber belt assembly for single track tire at cutting plane D 5 -D 5 . 
           [0045]      FIG. 24  is a front view of rubber belt assembly for single track tire with rubber belt removed twisted 8 degrees. 
           [0046]      FIG. 25  is a top view of rubber belt assembly for single track tire with rubber belt removed twisted 8 degrees. 
           [0047]      FIG. 26  is an isometric view of belt tooth. 
           [0048]      FIG. 27  is an isometric view of rubber belt assembly for single track tire. 
           [0049]      FIG. 28  is a front view of rubber belt assembly for single track tire. 
           [0050]      FIG. 29  is a top view of rubber belt assembly for single track tire. 
           [0051]      FIG. 30  is a side view of rubber belt assembly for single track tire showing the positions of all cutting planes E 1 -E 1 , E 2 -E 2 , E 3 -E 3 , E 4 -E 4 , and E 5 -E 5 . 
           [0052]      FIG. 31  is an end view of rubber belt assembly for single track tire at cutting plane E 1 -E 1 . 
           [0053]      FIG. 32  is an end view of rubber belt assembly for single track tire at cutting plane E 2 -E 2 . 
           [0054]      FIG. 33  is an end view of rubber belt assembly for single track tire at cutting plane E 3 -E 3 . 
           [0055]      FIG. 34  is an end view of rubber belt assembly for single track tire at cutting plane E 4 -E 4 . 
           [0056]      FIG. 35  is an end view of rubber belt assembly for single track tire at cutting plane E 5 -E 5 . 
           [0057]      FIG. 36  is a front view of rubber belt frame for single track tire with rubber belt removed. 
           [0058]      FIG. 37  is a top view of rubber belt frame for single track tire with rubber belt removed. 
           [0059]      FIG. 38  is a side view of rubber belt showing the positions of cutting plains F 1 -F 1  and F 2 -F 2 . 
           [0060]      FIG. 39  is the end view of a rubber belt unit at cutting plane F 1 -F 1  looking along the length of the rubber belt. 
           [0061]      FIG. 40  is the inside view of rubber belt unit at cutting plane F 1 -F 1 . 
           [0062]      FIG. 41  is the inside view of rubber belt bending at cutting plane F 2 -F 2 . 
       
    
    
     REFERENCE CHARACTERS IN DRAWINGS 
       [0000]    
       
           001  axle shaft 
           002  road tires 
           003  dual track tires 
           004  dual tire rubber belt 
           005  rear track frame 
           006  tensioning track guide 
           007  tensioning shaft 
           008  track hydro-pneumatic cylinder 
           009  track frame pivot joint 
           010  track frame slide joint 
           011  track frame parallelogram 
           012  track frame tensioning pivot joint 
           013  road wheel rim 
           014  dual track wheel rim 
           015  dual tensioning tires 
           016  track hydro-pneumatic push rod 
           017  gap between road tire and rubber belt 
           018  rear axle joint 
           019  front axle joint 
           020  rubber belt guide horns 
           021  rubber belt guide horns outer edge 
           022  rubber belt guide horns inner edge 
           023  rubber belt tread 
           024  belt 
           025  rubber belt guide horns front 
           026  rubber belt guide horns back 
           027  rubber belt wheel runway 
           028  rubber belt center runway 
           029  vertex of rubber belt guide horn 
           030  rubber belt guide horn gap 
           031  single drive track tire 
           032  single track tire 
           033  drive tooth 
           034  key way 
           035  track frame arm 
           036  tensioning pivot joint 
           037  track hydro-pneumatic piston 
           038  dual tensioning wheel rim 
           040  cylinder rear hinge joint 
           041  cylinder front hinge joint 
           045  single track wheel rim 
           047  single tensioning wheel rim 
           050  single tire rubber belt 
           060  rubber belt guide horn height 
           061  rubber belt tread depth 
           062  rubber belt road clearance 
           063  angle from vertical of the rubber belt guide horns outer edge  021   
           064  angle from vertical of the rubber belt guide horns inner edge  022   
           065  rubber belt tensioning guide clearance depth 
           070  axle extension 
           071  front track frame 
       
     
       DESCRIPTION 
       [0114]    During high speed road travel, the road tires are better suited for high speed operation. To reduce rubber belt  004  wear, rolling resistance and heat build up, the rubber belt  004  may be disengaged during road usage. To allow the rubber belt  004  to be disengaged for road travel, one or more of the axles shafts  001  needs to be driven. The axle shafts  001  are equipped with suspension for road and off road travel. 
         [0115]    The complete dual tire hybrid rubber belt assembly is shown in  FIGS. 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9  and  10 . The dual tire rubber belt  004  used on the dual tire hybrid rubber belt assembly is shown in  FIGS. 11 ,  12 ,  13 , and  14 . 
         [0116]      FIG. 1  shows an isometric view of the complete dual tire hybrid rubber belt assembly.  FIG. 10  is the top view of dual tire hybrid rubber belt assembly with the dual tire rubber belt  004  removed from the complete assembly shown in  FIG. 1 .  FIG. 9  is the front view of the dual tire hybrid rubber belt assembly with the dual tire rubber belt  004  removed. With the dual tire rubber belt  004  removed, the internal components are clearly visible in  FIG. 10 .  FIG. 2  shows the front view of the complete dual tire hybrid rubber belt assembly. A cutting plane A-A, is shown in  FIG. 2 . The cutting plane A-A looking inwards towards the vehicle body, is taken between the outside track tire  003  and the track frame  005 .  FIG. 3  shows the side view of the complete dual tire hybrid rubber belt assembly taken along the cutting plane A-A.  FIG. 4  shows the outside view of the complete dual tire hybrid rubber belt assembly. Cutting planes B 1 -B 1 , B 2 -B 2 , B 3 -B 3  and B 4 -B 4  are shown in  FIG. 4 . Cutting plane B 1 -B 1  is taken through the rear axle shaft  001  looking forward to the front.  FIG. 5  shows the rear view of the complete dual tire hybrid rubber belt assembly taken along the cutting plane B 1 -B 1 . Cutting plane B 2 -B 2  is taken through the front tensioning shaft  007  looking forward to the front.  FIG. 6  shows the rear view of the complete dual tire hybrid rubber belt assembly taken along the cutting plane B 2 -B 2 . Cutting plane B 3 -B 3  is taken through just in front of the front road tires  002  looking forward to the front.  FIG. 7  shows the rear view of the complete dual tire hybrid rubber belt assembly taken along the cutting plane B 3 -B 3 . Cutting plane B 4 -B 4  is taken through just in front of the rear road tires  002  looking forward to the front.  FIG. 8  shows the rear view of the complete dual tire hybrid rubber belt assembly taken along the cutting plane B 4 -B 4 . 
       Frame Construction 
       [0117]    The complete dual tire hybrid rubber belt assembly shown in  FIGS. 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9  and  10  is assembled as follows. 
         [0118]    As shown in  FIG. 10 , the rear axle joint  018  is mounted on the rear axle shaft extension  070  and the front joint  019  shown in  FIG. 3  is mounted on the front axle shaft extension  070  so that they are aligned to each other. As shown in  FIG. 3 , the track frame pivot joint  009  is attached to the rear axle joint  018 . The track frame slide joint  010  is attached to the front axle joint  019 . The track frame  005  is fixed at the track frame pivot joint  009  so that it goes through the track frame slide joint  010  with the key-way  034  facing upwards. A key is placed on the key-way  034  to prevent the track frame  005  from twisting. 
         [0119]    As shown in  FIG. 3 , the track frame arm  035  is attached to top of rear track frame  005  between the track frame pivot joint  009  and the track frame sliding joint  010 . The hydro-pneumatic cylinder  008  is attached to the track frame arm  035  by cylinder rear hinge joint  040 . The front of the hydro-pneumatic piston  037  is attached to the hydro-pneumatic push rod  016  by the cylinder front hinge joint  041 . The hydro-pneumatic push rod  016  is connected to the tensioning shaft  007  by the tensioning pivot joint  036 . The front track frame  071  is bolted onto the rear track frame  005  in front of the front axle extension  070 . The hydro-pneumatic push rod  037  is connected to the front track frame  071  by the track parallelogram  011 . 
         [0120]    As shown in  FIG. 5 , the rear dual track wheel rims  014  are mounted on the rear axle shaft extension  070  both sides of the rear track frame  005 . The rear dual track wheel rims  014  are mounted by either bolted directly onto the rear axle shaft extension  070  or bolted to a brake assembly which is in turn bolted onto the rear axle shaft extension  070 . 
         [0121]    The front dual track wheel rims  014  are mounted on the front axle shaft extension  070  both sides of the rear track frame  005  which is aligned with the rear dual track wheel rims  014 . The front dual track wheel rims  014  are mounted by either bolted directly onto the front axle shaft extension  070  or bolted to a brake assembly which is in turn bolted onto the front axle shaft extension  070 . The front dual track tires  003  are mounted onto the front dual track wheel rims  014 . The rear dual track tires  003  are mounted onto the rear dual track wheel rims  014 . 
         [0122]    As shown in  FIG. 5 , the inside rear road wheel rim  013  is bolted onto the rear axle shaft  001 . The rear axle extension  070  is bolted through the inside rear road wheel rim  013  onto the rear axle shaft  001 . The inside front road wheel rim  013  is bolted onto the front axle shaft  001  and is aligned with the inside rear road wheel rim  013 . The front axle extension  070  is bolted through the inside front road wheel rim  013  onto the front axle shaft  001 . The outside rear road wheel rim  013  is bolted onto the rear axle shaft extension  070 . The outside front road wheel rim  013  is bolted onto the front axle shaft extension  070  and is aligned with the outside rear road wheel rim  013 . The front and rear road wheel rims  013  are located on both sides of the front and dual track tires  003 . The road tires  002  are mounted on all road wheel rims  013 . 
         [0123]    As shown in  FIG. 6 , the tensioning wheel rims  038  are mounted on the tensioning shaft  007  so that they are aligned with the front and rear dual track tires  003 . The tensioning tires  015  are mounted onto the tensioning wheel rims  038 . The tensioning guide  006  are mounted on the tensioning shaft  007 , outside of the tensioning tires  015 . The idle guides  006  align with the dual tire rubber belt  004  so that the dual tire rubber belt  004  runs between them. 
       Track Construction 
       [0124]      FIG. 11  shows the dual tire rubber belt  004 . Cutting planes C 1 -C 1  and C 2 -C 2  are shown on  FIG. 11 . The cutting plane C 1 -C 1  cuts around one single rubber belt unit.  FIG. 12  shows the front view of a single rubber belt unit taken along the cutting plane C 1 -C 1 .  FIG. 13  shows the top view of a single rubber belt unit taken along the cutting plane C 1 -C 1 . Cutting plane C 2 -C 2  is taken at the edge where the dual tire rubber belt  004  bends around the tensioning tires  015  looking forward to the front.  FIG. 14  shows the rear view of the dual tire rubber belt  004  taken along the cutting plane C 2 -C 2 . 
         [0125]    The dual tire rubber belt  004  is constructed as continuous belt with repeated patterned units. The length of the unrepeated patterned unit is called a rubber belt unit. The backbone of the rubber belt  004  is a belt  024 . The belt  024  includes an endless belt-shaped rubber-like elastic member, a canvas radially aligned high tension strength cords, and may include a number of core bars embedded therein and aligned laterally across the belt side to side. The radial canvas allows some shear motion within the rubber belt without buckling. The rubber belt tread  023 , shown below the rubber belt  004  in  FIG. 12 , is attached outside the backbone of the rubber belt  004 . The rubber belt tread  023  is made of abrasion resistance rubber suitable for road and off road usage with a raised tread pattern. The rubber belt tread  023  has a tread depth  061  as shown in  FIG. 6 . The raised pattern of the rubber belt tread  023  is chosen as a compromise of specific needs. Some of the many specific needs include a deep open self cleaning pattern for soft soils and a dense wear resistance pattern for high speed road usage. The rubber belt tread  023  protects the backbone of the rubber belt  004  from damage and grips the travel surface. 
         [0126]    The dual track tires  003  run inside the dual tire rubber belt  004  along the rubber belt wheel runways  027 . The rubber belt  004  is driven from the rear dual track tires  003  and perhaps also from the front dual track tires  003 . The dual track tires  003  are prevented from spinning within the dual rubber belt  004  by static friction. The inside surface of the rubber belt  004  may have a shallow rib pattern to increase grip between the dual track tires  003  and the rubber belt  004 . The shallow rib pattern is designed to reduce the dual track tires  003  from hydroplaning on the inner surface of the rubber belt  004 . Rows of rubber belt guide horns  020 , shown above the rubber belt  004  in  FIG. 12 , are attached inside the backbone of the rubber belt  004 . Each track tire  003  runs along the rubber belt wheel runway  027  between two rows of rubber belt guide horns  020 . In the center between the two rows of rubber belt guide horns  020  the rubber belt center runway  028  is unused. This rubber belt center runway  028  is not filled with rubber belt guide horns  020  because they are not needed and they would unnecessarily increase the rubber belt  004  weight. The track tires  003  are guided by the rubber belt guide horn inner edges  022 . The guide horn inner edges  022  viewed from the end form a spline shape which allows the track tires  003  to pivot through a small angle without being pushed away from the rubber belt  004 . 
         [0127]    In  FIG. 19 , the angle of the track tires  031  pivot equals the axle shaft  001  pivot, which occurs as the vehicle travels over uneven terrain. Increasing the allowed track tire  031  pivot angle will increase the angle  064  of the guide horn inner edge  022  from vertical. The angle  064  is shown in  FIG. 39 . When large lateral forces are applied to the rubber belt  004 , a large angle  064  of the guide horn inner edge  022  from vertical will cause the single track tires  031  to lifting off rubber belt  004  rather than laterally retaining them. As a result, only a few degrees of track tire  031  pivot are allowable. 
         [0128]    The road tires  002  are located outside rubber belt  004  as shown in  FIG. 5  and  FIG. 8 . When the road tires  002  are fully inflated, the tires side walls will not swell outwards significantly under the vehicle&#39;s weight. As a result when the road tires  002  are fully inflated there is a small gap  017  between the rubber belt guide horns  020  and the side walls of the road tires  002 . The inflated road tires  002  also lifts the rubber belt  004  off the flat hard road surfaces creating a clearance  062  between the rubber belt  004  and the road surface. The small gap  017  between the rubber belt guide horns  020  and the side walls of the road tires  002  allows the rubber belt  004  to be disengaged traveling on flat hard road surfaces. When the road tires  002  are partially deflated, they will settle and lower the rubber belt  004  until it comes in contact with the ground surface. As the partially deflated road tires  002  settle under the vehicle weight, the bottom side walls of the road tires  002  will swell outwards eliminating the gap  017  between the road tires  002  and the rubber belt  004 . The rubber belt guide horns outer edge  021  spreads the lateral load against the road tire  002  over a large side wall area. As shown in  FIG. 12 , the angle  064  of the guide horns inner edge  022  from vertical is designed to maximize the surface area in contact with road tires  002 , provide lateral retention of the rubber belt  004 , and direct the rubber belt  004  away from the road ties as the rubber belt  004  is pushed upwards towards the axle. In most situations a small angle  064  of the guide horns inner edge  022  from vertical, approximately 10 degrees is a good compromise. 
         [0129]    The road tire  002  and the track tire  003  together form a V-belt pulley for the outer rubber belt guide horns  020 . The larger diameter road tires  002  acts as a very deep pulley guide sidewall. When there is an excessive amount of debris between the dual track tires  003  and the rubber belt  004  or the rubber belt  004  is excessively twisted, the rubber belt guide horns  020  may slip off the dual track tires  003 . Even in these extreme cases, the rubber belt  004  is prevented from being thrown by the larger diameter road tires  002 . The larger diameter road tires form large flanges as shown in  FIG. 5  and  FIG. 8 , which confines the rubber belt  004 . Without the road tires  002  functioning as large flanges, the rubber belt  004  would be thrown when the rubber belt  004  is lifted away from the dual track tires  003 . With road tires  002  functioning as large flanges, the rubber belt  004  needs to lift away from the track tires  003  by the guide horn height  060  plus the tread depth  061  plus the track road clearance  062 . The road tires  002  also provide a greater surface area to resist rubber lateral forces of the rubber belt  004  on the dual track tires  003  by the amount of the tread depth  061 . A further benefit of the road tires  002  located on both sides of the rubber belt  004  is that the rubber belt  004  will be guided between the road tires  002  as they push against the guide horns outer edges  021 . As a result, the rubber belt  004  can have less tension than the equivalent ground pressure without a concern of the rubber belt  004  climbing off the dual track tires  003 . 
         [0130]    On soft soils or in loose debris, the road tires  002  sink down so that the rubber belt  004  comes in solid contact with the soft surface. As a result, the road tires  002  only sink into the soft surface by a small amount before the weight of the vehicle is supported by the high flotation rubber belt  004 . Without the additional flotation provided by the rubber belt  004 , the road tires  002  would sink beyond the point where they can climb out from the hole created by sinking. Also without the additional traction provided by the rubber belt  004 , the road tires  002  would spin and dig deep holes in soft surfaces. The continuous rubber belt  004  can also bridge over loose debris such as boulders and fallen tree branches. The relatively smooth road tires  002  have a larger diameter than the rubber belt  004  and as a result the road tires  002  will push loose debris away from the guide horns  020 . Debris should be kept away from the guide horns  020 , which can grab debris in the guide horn gaps  030 . The depressions the road tires  002  create on both sides of the rubber belt  004  act as gutters for the rubber belt  004  to dump debris. 
         [0131]    The shock to both the road tires  002  and the dual track tires  003  from stones and pot holes can be extreme. In order to withstand the shock, the road tires  002  are assumed to be standard pneumatic tires, but they may be spring rubber. Similarly, the dual track tires  003  are assumed to be standard pneumatic or spring rubber tires. In either case, the road tires  002  and the dual track tires  003  are able to safely absorb shocks that might break a similar strength solid wheels. 
         [0132]    The reduced footprint of only the road tires  002  on hard surfaces greatly reduces the turning force required to skid steer the hybrid rubber belt vehicle. The road tires  002  also push loose debris away from the rubber belt  004  as the vehicle turns. This is particularly important at the front and rear dual track tires  003 . Debris entering the rubber belt  004  at the front or rear dual track tires  003  is pinched in between the guide horn gaps  030  as the rubber belt wraps around the dual track tires  003 . By the road tires pushing loose debris away from the rubber belt  004 , the danger of debris wedged between the guide horns  020  and lifting the rubber belt off the dual track tires  003  is avoided. 
         [0133]    The top inside view of the rubber belt  004  is shown in  FIG. 13  and  FIG. 14 . The front and back of each guide horn  020  forms an angled shape. In prior art designs, the front and back surfaces  025  and  026  of the rubber belt guide horns  020  may be perpendicular to the rubber belt  004  side. In this design, the front and back surfaces  025  and  026  of the guide horns  020  may be twisted in parallel as shown in  FIG. 13  and  FIG. 14 . When the front and back surfaces  025  and  026  of the guide horns  020  are twisted in parallel, there is smaller straight through guide horn gap  030  in between the guide horns  020 . The smaller straight through rubber belt guide horn gap  030  provides greater lateral support to the rubber belt  004  and makes it more difficult for debris to enter. Also if the rubber belt is forced to bend in a sharper angle than the wedge shape of the guide horns  020  was designed for, the twisted front and back surfaces of the guide horns  020  allow the rubber belt guide horns  020  to displace each other sideways rather than preventing the sharp bend angle. The guide horns  020  fit together end to end as shown in  FIG. 14 . 
       Tensioning Idlers Construction 
       [0134]    The dual tensioning tires  015  run inside the dual tire rubber belt  004  along the wheel runways  027 . Each tensioning tire  015  runs along the wheel run way  027  between two rows of guide horns  020 . The dual tensioning tires  015  are guided by the rubber belt guide horn inner edges  022 . The guide horn inner edges  022  viewed from the end form a spline shape which allows the tensioning tires  015  to pivot through a small angle without being pushed away from the rubber belt  004 . The pivot angle of the dual tensioning tires  015  is dependent on the twisting amount of the rubber belt  004 . The tensioning pivot joint  036  prevents the rubber belt  004  from lifting off one side of the dual tensioning tires  015  as the rubber belt  004  twists. The twisting of the rubber belt  004  is caused by the difference in pivot angles between the front and rear axle shafts  001 . 
         [0135]    The tensioning track guides  006  are located outside rubber belt  004  as shown in  FIG. 6  and  FIG. 7 . The outer guide horns  020  are held by the tensioning track guide  006  on the outside and the tensioning tire  015  on the inside. Together the tensioning track guide  006  and the tensioning tire  015  form a V-belt pulley for the outer guide horns  020 . The amount of the tensioning track guides  006  extend beyond the rubber belt tread  023  is the rubber belt tensioning guide clearance depth  065 . The guide horns outer edge  021  spreads the lateral load against the tensioning track guides  006  over a large area. The side wall slope of the tensioning track guides  006  is designed to maximize the surface area in contact with the guide horns outer edge  021 . This provides lateral retention of the rubber belt  004 , and centers the rubber belt  004  between the tensioning track guides  006  by the rubber belt  004  tension. 
         [0136]    The continuous rubber belt  004  can also bridge over loose debris such as boulders and fallen tree branches. The smooth tensioning track guides  006  have a larger diameter than the rubber belt  004  surrounding the dual tensioning tires  015  and as a result they will push loose debris away from the guide horns  020 . Debris should be kept away from the guide horns  020  because the guide horns can grab debris in the rubber belt guide horn gaps  030 . The depressions the tensioning track guides  006  create on both sides of the rubber belt  004  act as gutters for the rubber belt  004  to dump debris. 
         [0137]    The shock to both the tensioning track guides  006  and the dual tensioning tires  015  from stones can be extreme. To withstand shock from stones, the tensioning track guides  006  are assumed to be standard pneumatic or spring rubber tires. Similarly the dual tensioning tires  015  are assumed to be standard pneumatic or spring rubber tires. In either case the tensioning track guides  006  and the dual tensioning tires  015  are able to safely absorb shocks that might break a similar strength solid wheels. 
         [0138]    The tensioning track guides  006  also push loose debris away from the rubber belt  004  as the vehicle turns. This is particularly important at the front and rear. Debris entering the rubber belt  004  at the front dual tensioning tires  015  is pinched in between the guide horn gaps  030  as the rubber belt  004  wraps around the dual tensioning tires  015 . By the tensioning track guides  006  pushing loose debris away from the rubber belt  004 , the danger of debris wedged between the guide horns  020  and lifting the rubber belt  004  off the dual tensioning tires  015  is avoided. 
       Frame Operation 
       [0139]    The suspension used by the hybrid rubber belt vehicle is not limited to track laying vehicle suspension. Track laying vehicle suspension has the advantage of not introducing axle shaft  001  vertical misalignment while traveling over rough terrine. Hybrid rubber belt vehicles with typical wheeled vehicle suspension such as solid axle, wishbone, McPherson strut and variations of these suspension types will sustain axle shaft  001  vertical misalignment while traveling over rough terrine. The hybrid rubber belt assembly is designed to accommodate a small amounts of axle shaft  001  vertical misalignment. 
         [0140]    Typical wheeled vehicle suspension will cause the axle shafts  001  to tilt inwards as the road tires  002  and dual track tires  003  rise over bumps. Similarly the axle shafts  001  will tilt outwards as the road tires  002  and dual track tires  003  fall into depressions. The geometry of the suspension will cause the rubber belt  004  to twist. For the rubber belt  004  to accommodate twisting without buckling, the radial canvas embedded into the belt  024  allows an amount of lateral and longitudinal shear. 
         [0141]    Separately raising the front axle shaft  001  or lowering the rear axle shaft  001  will cause top rear of the rubber belt  004  to twist outwards and the bottom rear of the rubber belt  004  to twist inwards. As the hybrid rubber belt vehicle travels forward, the rubber belt  004  needs to move inward along the top between the rear and front dual track tires  003  and moves outward along the bottom between the front and rear dual track tires  003 . The outer edge of the rubber belt  004  also tightens as the front and rear axle shafts  001  move up and down separately. Some of the slackness along the inside edge of the rubber belt  004  will be taken up by the tensioning shaft  007  pivoting outwards on the tensioning pivot joint  036 . The elastomer construction of the rubber belt&#39;s belt prevents the pivoting of the tensioning shaft  007  from taking up the inside edge slackness around the full length of the rubber belt  004 . As a result the rubber belt  004  is forced to fit tightly around the outer dual track tire  003 . 
         [0142]    When each front dual track tire  003  applies inward lateral force against the guide horns inner edge  022  of each inside row of guide horns  020 , the top of the rubber belt  004  is forced inwards. When the slightly looser inside edge of the rubber belt  004  rides up the inside front track tire  003 , the rubber belt  004  will be held in place by its outer edge which is tightly fitted around the outer front track tire  003 . The top of the rubber belt  004  is forced inwards by each dual tensioning tire  015  which applies inward lateral force against the guide horns inner edge  022  of each inside row of guide horns  020 . The outside tensioning guide  006  applies lateral force against the guide horns outer edge  021  along the outside edge of the rubber belt  004 . Furthermore the rubber belt  004  is prevented from slipping outwards and off from the front dual track tires  003  by the outside front road tire  002  which applies lateral force against the guide horns outer edge  021  along the outside edge of the rubber belt  004 . 
         [0143]    The bottom of the rubber belt  004  is forced inwards by each rear dual track tire  003  applying inward lateral force against the rubber belt guide horns inner edge  022  of each inside row of rubber belt guide horns  020 . When the slightly looser inside edge of the rubber belt rides down the inside rear track tire  003 , the rubber belt  004  will be held in place by its outer edge which is tightly fitted around the outer rear track tire  003 . Furthermore the rubber belt  004  is prevented from slipping outwards and off from the dual track tires  003  by the outside rear road tire  002  which applies lateral force against the rubber belt guide horns outer edge  021  of the row of rubber belt guide horns  020  along the outside edge of the rubber belt  004 . 
         [0144]    Separately lowering the front axle shaft  001  or raising the rear axle shaft  001  will cause top rear of the rubber belt  004  to twist inwards and the bottom rear of the rubber belt  004  to twist outwards. As the hybrid rubber belt vehicle travels forward, the rubber belt  004  needs to move outward along the top between the rear and front dual track tires  003  and needs to move inward along the bottom between the front and rear dual track tires  003 . The outer edge of the rubber belt  004  also tightens as the front and rear axle shafts  001  move up and down separately. Some of the slackness along the inside edge of the rubber belt  004  will be taken up by the tensioning shaft  007  pivoting outwards on the tensioning pivot joint  036 . The elastomer construction of the rubber belt&#39;s belt prevents the pivoting of the tensioning shaft  007  from taking up the inside edge slackness around the full length of the rubber belt  004 . As a result the rubber belt  004  is forced to fit tightly around the outer track tire  003 . 
         [0145]    When each front dual track tire  003  applies outwards lateral force against the guide horns inner edge  022  of each outside row of guide horns  020 , the top of the rubber belt  004  is forced outwards. When the slightly looser inside edge of the rubber belt  004  rides up the inside front track tire  003 , the rubber belt  004  is held in place by its outer edge which is tightly fitted around the outer front track tire  003 . The top of the rubber belt  004  is forced outwards by each dual tensioning tire  015  which applies outward lateral force against the guide horns inner edges  022  of each inside row of guide horns  020 . The inside tensioning guide  006  applies lateral force against the track guide horns outer edge  021  of the row of guide horns  020  along the inside edge of the rubber belt  004 . Furthermore the rubber belt  004  is prevented from slipping inwards and off the front dual track tires  003  by the inside front road tire  002  which applies lateral force against the guide horns outer edge  021  along the inside edge of the rubber belt  004 . 
         [0146]    The bottom of the rubber belt  004  is forced outwards by each rear dual track tire  003  applying inward lateral force against the guide horns inner edge  022  of each outside row of guide horns  020 . When the slightly looser inside edge of the rubber belt  004  rides down the inside rear track tire  003 , the rubber belt  004  is held in place by its outer edge which is tightly fitted around the outer rear track tire  003 . Furthermore the rubber belt  004  is prevented from slipping inwards and off the rear dual track tires  003  by the inside rear road tire  002  which applies lateral force against the rubber belt guide horns outer edge  021  along the inside edge of the rubber belt  004 . 
         [0147]    In an outward rear skid turn, the rubber belt  004  is forced inwards on the rear and forced outwards on the front. The outside rear road tire  002  clears debris away from rear dual track tires  003 . The inside rear road tire  002  provides extra protection preventing the rubber belt  004  from slipping off the rear dual track tires  003  and sliding inwards. The inside front road tire  002  clears debris away from the front dual track tires  003 . The outside front road tire  002  provides extra protection preventing the rubber belt  004  from slipping off the front dual track tires  003  and sliding outwards. 
         [0148]    Similarly in an inward rear skid turn, the rubber belt  004  is forced outwards on the rear and forced inwards on the front. The inside rear road tire  002  clears debris away from rear dual track tires  003 . The outside rear road tire  002  provides extra protection preventing the rubber belt  004  from slipping off the rear dual track tires  003  and sliding outwards. The outside front road tire  002  clears debris away from the front dual track tires  003 . The inside front road tire  002  provides extra protection preventing the rubber belt  004  from slipping off the front dual track tires  003  and sliding inwards. 
         [0149]    Near constant tensioning is maintained in the rubber belt  004  by the hydro-pneumatic cylinder  008  which applies a nearly constant extension force. The hydro-pneumatic cylinder  008  applies longitudinally outward force to the tensioning shaft  007 . The constant force applied by the dual tensioning tires  015  maintains a constant rubber belt  004  tension. The rubber belt  004  length is shortened by twisting. A longer rubber belt  004  length is required when the rubber belt  004  is supporting the vehicle&#39;s weight on boulders, tree limbs or other hard debris. As the vehicle craws over the hard debris, the vehicle&#39;s weight forces the rubber belt  004  upwards. When the rubber belt  004  is not directly supported by the dual track tires  003 , the rubber belt  004  is allowed to bend upwards. This upwards bending of the rubber belt  004  results in a longer rubber belt  004  length required when the vehicle craws over hard debris. When sticky debris accumulates around the dual track tires  003  or in the rubber belt wheel runway  027 , the effective track tire  003  size increases. Changing track tire  003  size also requires rubber belt  004  length to change. The hydro-pneumatic cylinder  008  dynamically extends and retracts to accommodate changes in the required length of the rubber belt  004 . 
         [0150]    Optionally the rubber belt  004  may be disengaged during on road usage to reduce rubber belt  004  wear, heat and noise. Disengaging the rubber belt  004  during high speed travel greatly reduces any chance of throwing a high velocity rubber belt with a destructive amount of kinetic energy. In order to be able to disengage the rubber belt, the dual track wheel rims  014  are bolted to a brake assembly which is in turn bolted onto the rear axle shaft extension  070 . Also the road tires  002  need to be inflated such that there is a clearance between the rubber belt  004  and the road surface. The rubber belt  004  is disengaged from the road tires  002  by releasing the brakes of the brake assembly to which dual track wheel rims  014  are bolted. With the rubber belt  004  disengaged, the rubber belt  004  is able to freely rotate or cease to rotate as the hybrid rubber belt vehicle travels on roads. The rubber belt  004  is re-engaged with the road tires  002  by applying the brakes of the brake assembly to which dual track wheel rims  014  are bolted. 
         [0151]    To change either the front or rear outside road tire  002 , the vehicle is lifted on jacks so that the outside road tire  002  to be removed is no longer bearing the vehicle&#39;s weight. The outside road wheel rim  013  together with the mounted road tire  002  are unbolted from axle extension  070 . After the outside road tire  002  and outside road wheel rim  013  have been removed, the road tire  002  is taken off and a replacement road tire  002  is put on the road wheel rim  013 . The outside road tire  002  and outside road wheel rim  013  are bolted onto the axle extension  070 . Finally the vehicle is lowered and jacks are removed. 
         [0152]    To change the rubber belt  004  without breaking the endless belt, the vehicle is jacked so that neither the outside road tires  002  nor the rubber belt is bearing the vehicle&#39;s weight. Both front and rear outside road wheel rims  013  together with the mounted road tires are unbolted from the axle extensions  070 . After the outside road tires  002  with road wheel rims  013  have been removed the hydro-pneumatic cylinder  008  is retracted. With the hydro-pneumatic cylinder  008  retracted, the rubber belt  004  can be slipped over the dual tensioning tires  015  and idle guides  006 . The rubber belt  004  is also slipped over the dual track tires  003  and removed. A replacement rubber belt  004  is similarly put on by slipping it over the dual track tires  003 , the dual tensioning tires  015  and idle guides  006 . The outside road tires  002  and outside road wheel rims  013  are bolted onto the axle extensions  070 . Finally the vehicle is lowered and jacks are removed. 
         [0153]    To change either the front or rear inside road tire  002  or remove the track assembly, the vehicle is jacked so that neither the road tires  002  nor the rubber belt  004  is bearing the vehicle&#39;s weight. If there is sufficient clearance in the gap  017  between road tire  002  and rubber belt  004 , a suitable wrench can be inserted. The front and rear axle extensions  070  can be unbolted with a suitable wrench. The front and rear axles  001  and the complete assembly attached to the axle extensions  070  can be removed in one step. The complete assembly attached to the axle extensions  070  consists of the track frame, tensioning idlers, track tires  003 , outer road ties  002  and rubber belt  004 . Otherwise, the rubber belt  004  is removed as described previously. After the rubber belt  004  has been removed, the gap between the inside track tire  003  and the inside road tire  002  will be more than sufficient to insert a suitable wrench. If there are no means of lifting the complete assembly attached to the axle extensions  070 , the assembly can be first disassembled. With a means of lifting, the complete assembly is attached to the axle extensions  070 . The front and rear axle extensions  070  can be unbolted from the front and rear axles  001  and the complete assembly attached to the axle extensions  070  can be removed. Otherwise the assembly needs to be disassembled and removed one piece at a time until the complete assembly attached to the axle extensions  070  has been removed. 
         [0154]    To disassemble the complete assembly attached to the axle extensions  070 , the rubber belt  004  is removed as described previously. The hydro-pneumatic cylinder  008  can be disconnected at the front  041  and rear  040  hinge joints which allows the hydro-pneumatic cylinder  008  to be removed. The front track frame  071  is unbolted from the rear track frame  005  and the attached tensioning idler assembly is removed. The rear track frame  005  is disconnected from the rear axle extension  070  by separating the track frame pivot joint  009  from the rear axle joint  018 . The rear track frame  005  is slid forward in the track frame slide joint  010  until the rear track frame  005  clears the rear dual track tires  003 . The rear axle extension  070  is unbolted from the rear axle  001  allowing the rear axle extension  070  and the attached dual rear track tires  003  to be removed. The rear track frame  005  is slid backwards and out of the track frame slide joint  010 . The front axle extension  070  is unbolted from the front axle  001  and rear axle extension  070  and the attached dual front track tires  003  are removed. 
         [0155]    At this point the track assembly has been completely removed leaving only the inside road tires  002  and road wheel rims  013  bolted onto the axle shafts  001 . At this point either front or rear inside road tire can be replaced or the track assembly may be left removed reducing the total vehicle width. To replace either the front or rear inside road tire  002 , the inside road wheel rim  013  together with the mounted road tire are unbolted from the axle  001 . After the inside road tire  002  and inside road wheel rim  013  have been removed, the road tire  002  is taken off and a replacement road tire  002  is put on the road wheel rim  013 . The inside road tire  002  and outside road wheel rim  013  are bolted onto the axle  001 . Process of reattaching the track assembly is performed by reversal of the removal steps. 
       CONCLUSION, RAMIFICATIONS, AND SCOPE 
       [0156]    Although the invention has been described and demonstrated with reference to specific preferred embodiments, it should be understood by those who are skilled in the art that some modification in form and detail may be made therein without deviating from the spirit and scope of the invention as defined in the following claims. 
         [0157]    Many other variations are possible. For example these variations include track laying systems where the drive wheels do not support the vehicle&#39;s weight as it travels over terrain. Other variations include implementations where the tensioning wheels also support the vehicle&#39;s weight as it travels over terrain. 
         [0158]    The first variation embodiment where drive wheels do not support the vehicle&#39;s weight is quite popular and is used by a wide variety of vehicles including most military track laying vehicles. In this embodiment track and road wheels support the vehicle weight as it travels over terrain. Track wheel axles are connected to a frame or vehicle body by suspension elements. These suspension elements insure the track wheel axles remain parallel or nearly so through the suspension travel, with each other, with the drive wheel axle and with the tensioning axle. Each track wheel axle has one or more track wheels attached. Prior art track laying systems do not include road wheels which are mounted beside and in proximity to the track. This invention further includes larger diameter road wheels attached on the track wheel axles on either one side or both sides of the track. These road wheels are a greater radius than the combined radius of track wheels and the track thickness. These road wheels are located in close proximity beside the track and support the vehicle&#39;s weight on hard ground and roads, such that the track is unloaded or lightly loaded. 
         [0159]    The advantages provided by the road wheels included in this invention are increased protection from debris entering the track during turning, reduced track wear and heat generation hard ground and roads, bearing greater side loading forces without requiring large track guide wedges, reduced force required to turn, this is particularly true when turning on hard surfaces, the track confined between guides and road wheels greatly reduces the possibility of de-tracking of band tracks, reduced track angular momentum and kinetic energy when the vehicle is traveling at high speeds on roads and the track rotation is decoupled from road wheel rotation. 
         [0160]    Thus the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.