Abstract:
A vehicle controllable and smooth ride system with sprung weight comparable to or less than the unsprung weight is provided by a cantilevered connection between the front and rear unsprung weight and near horizontal arrangement of suspension devices in the sprung weight of the vehicle so verticle motion of the front and rear unsprung weight is transmitted to the sprung weight while the entire sprung weight is applied to each front and rear unsprung weight motions.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention is directed to a suspension system for vehicles having comparable or heavier unsprung weight than sprung weight, wherein the vertical motion of the front and rear unsprung weight is transmitted to the sprung weight while the sprung weight is applied to both front and rear unsprung weight motion. 
     2. Description of the Prior Art 
     It is almost universally known in vehicle suspension systems that the sprung weight of a vehicle is always much heavier than the unsprung weight in order to curb the violent vertical pitching of the sprung weight relative to the lighter unsprung weight. The normal terminology in speaking of sprung and unsprung weight is to assign to unsprung weight the total of tires, wheels, axles and the spring means supported by the tires (hereinafter called tires), and to assign to the sprung weight the term body such as the engine, transmission, frame, any cargo and all people in the body (hereinafter called body). 
     To have a controllable and smooth riding vehicle, the body has to be considerably heavier than the tires, and there must be some suspension components connected between the body and the tires. An example of current weight distribution with the body being heavier than the tire is well understood. When such a vehicle hits a bump or obstacle the tires move upward compressing the suspension components or shocks, and energy is created. The suspension components want to return the tires so as to recover its normal shape and the energy will thus be dissipated through the lighter of the objects containing it which is to push the lighter tires down to the road. 
     When a vehicle does not have enough body weight to control the tire weight, a rough ride for the occupant will occur and poor vehicle control will result. For example, as the tires move upward some of the energy will be discharged through the lighter body then the remaining compressed energy will give the body an extra jolt. 
     If a vehicle has more tire weight than body weight there is an almost hopeless suspension problem. What happens is the tire weight controls the body weight instead of the normal situation where the body weight controls the tires. The problem is overcome in a suspension system for vehicles having comparable or heavier tire weight than body weight, although the system is not to be limited in that way, by the vertical motion of the front and rear tires being transmitted to the body while the body weight is substantially all applied to both the front and rear tire motion. 
     BRIEF DESCRIPTION OF THE INVENTION 
     There is a distinct problem with vehicle suspensions when the weight of the vehicle tires is equal to or greater than the body weight, as pointed out above when the heavier tires control the vertical motion response of the lighter body. 
     An important object of the invention is to employ cantilever means for energy transfer between the tires and body so that the cantilever means transfers the body weight of the entire vehicle to resist the motion of the front and rear tires, instead of utilizing just part of the body weight to control each tire. 
     A further object of the invention is to arrive at a workable vehicle in which the tires are heavier than the body by locating the energy transfer components above a system of cantilever means operating between the tires and body and to direct the thrust reaction of the energy components to a near horizontal plane. 
     A still further object of the invention is to be able to apply the entire body weight to the motion of either the front or rear tires so that the body weight is heavier than the weight of either front or rear tires. Other objects of the invention are achieved by an improved direction of reaction of energy transfer means, such as gas shocks, or an air shock, and it can also be achieved with the use of leaf or coil springs, air bags or coil-over shocks. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is disclosed in a preferred embodiment in the following drawing views, as follows: 
     FIG. 1 is a side elevation of a vehicle assembly having a frame and body mounted on the front and rear wheels, tires and axle in a four wheel drive arrangement; 
     FIG. 2 is a plan view of the vehicle of FIG. 1 taken along the line 2--2 in FIG. 1, with the body outlined in a schematic rendering; 
     FIG. 3 is a side elevation of the construction of a full length main frame together with the suspension system for the axles; 
     FIG. 4 is a side elevational view of the frame and suspension system illustrating the range of motion of the wheels, tires, axles, cantilevers and gas shocks; and 
     FIG. 5 is a side view of the frame and suspension system of another embodiment. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The vehicle 9 of FIG. 1 is currently recognized as a Bigfoot 4×4 having the suspension assembly above referred to in which there are large front tires 10, large nonsteerable rear tires 11, a front drive axle 12, a rear drive axle 13, torque drive shafts 14 and 15 suitably geared into a transfer case 16. The upper end of the case 16 is fitted with a transmission drive fitting 17. The transmission and engine assemblies are not shown to better disclose the important construction of the vehicle 9. 
     The vehicle 9 has a body shell 18 fitted over a roll cage 19 that is an integrated unit in which the major component is a main frame 20. In this view of FIG. 1, the unsprung weight is attributed to the large tires 10 and 11, the drive axles 12 and 13, the drive shafts 14 and 15, and certain axle alignment rods seen at 21 and 22 at the front axle 12, and similar rods 23 and 24 for the rear axle 13. 
     FIG. 2 is a plan view seen along line 2--2 in FIG. 1, with the sprung body 18 shown only in fragmentary outline so as not to obscure the components making up the unsprung weight. Thus the front steerable tires 10 have enlarged rims 25 and steerable knuckle means 26. The drive axle 12 has the differential housing 27. The before noted longitudinal main frame 20 furnishes the structure for connecting the front axle alignment rods 21 and 22 which extend from the main frame 20 (See FIG. 3) to the axle 12. The main frame 20 also furnishes the structure for connecting the rear axle alignment rods 23 and 24 which extend to the rear axle 13. The rear axle has the usual differential housing 28. The rear axle is connected to wheel rims 29 for the rear tires 11. 
     FIG. 2 has disclosed the transfer case 16 which houses a suitable gear train to deliver power to the drive shafts 14 and 15 (See FIG. 1). The engine and transmission are not shown, but with the transfer case 16 are parts of the body weight, as will appear presently. 
     A feature of the invention is seen in FIG. 3 which includes the integrated roll cage 19 or superstructure which with the main frame 20 is a principal part extending from front to rear. The main frame 20 is centrally braced by a substructure including struts 35 extending from a focal bracket 34 angularly upward and forward and rearward to join in the main frame 20. Other struts 36 make up the further substructure supporting the bracket 34 from the main frame 20. The struts 35 support brackets 29 to which the previously described alignment rods 22 and 24 are connected, while the alignment rods 21 and 23 are connected to bracket 34. 
     FIG. 4 is a side view of the system for operatively connecting the axles 12 and 13 to the main frame 20. This drawing shows the suspension compressed in solid lines and extended with dot-dash lines. It is clearly shown that the entire body weight of main frame 20 and any and all components placed thereon is supported upon both axles 12 and 13. Also, both axles 12 and 13 are restrained from spreading apart to increase the wheel span by alignment rods 21 and 23 anchored at the focal bracket 34. Furthermore, the axles 12 and 13 are retained in operative positions by rods 22 and 24 so the torque drive shafts 14 and 15 are properly kept in operative positions. To make the sprung body weight and unsprung tire weight work together, the energy transfer components in the suspension means is placed above the cantilevered  front and rear end portions 20F and 20R respectively of the main frame 20. 
     It is pointed out that the side elevation views of FIGS. 1, 3, 4 and 5 show only the near side components, as the opposite side components are obscured. FIG. 2, therefore, shows both side components so that when describing the side elevational views, a complete system of components is intended to be included. As one example, the shocks 46 are mounted in pairs at each cantilever 42, 43, and shocks 55 are also mounted in pairs at each cantilever 51, 52. The suspension does not require two shocks per cantilever or any combinations of shocks. Furthermore, the lateral stability of the axle 12 is maintained by the angular position of rods 21, 22 and the axle 13 is also maintained laterally stable by the angular relations of the rods 23, 24. 
     Looking at FIG. 3, the front suspension assembly 40 comprises an anchor bracket 41 fixed to the adjacent front frame portion 20F, a cantilever means 42 is pivoted at one end on bracket 41 and a secondary cantilever means 43 is carried by the cantilever means 42. The outer end of the cantilever 42 is pivotally connected to a motion transfer strut 44 extending from a pivot connection on axle 12. The outer end of the secondary cantilever means 43 is connected to the piston rod 45 of a gas shock absorber unit 46 having its base end 47 fixed to a structural part of the roll cage 19. 
     The rear suspension assembly 49 is similar to the front assembly in that there is a fixed bracket 50 on the rear portion 20R of the main frame 20 to pivotally support one end of a primary cantilever means 51 and also a secondary cantilever means 52 fixed to the primary cantilever means 51. The outer end of the primary cantilever means 51 is pivotally connected to a motion transfer strut 53 the lower end of which is pivotally connected to the axle part 13. The secondary cantilever means 52 is pivotally connected to the piston rod 54 of a gas shock absorber unit 55. That gas shock absorber unit 55 has its base end 56 connected to the adjacent portion of the roll cage 19 which is an integral part of the main frame 20. 
     The just described suspension assemblies 40 and 49 are angularly positioned at a near horizontal angle relative to the motion transfer struts 44 and 53. Furthermore, the total static body weight of the vehicle as defined above is heavier than the static tire weight of either of the front or rear tires 10 or 11. However, as pointed out before, the total static weight of the front and rear tires is heavier than the static body weight. Static weight is a common term of art meaning the weight at rest. When the front tires 10 react to a bump and move vertically, the motion transfer struts 44 at the front of the body cause the cantilever means 42 to swing about the anchor bracket 41 in an arc that is greater than the arc followed by the secondary cantilever means 43. This relative difference in arcuate displacement reduces the stroke or linear motion of the piston rod 45 in the gas shock absorber 46. The resulting push exerted by the front gas shock absorber 46 in the front suspension assembly 40 is transmitted into the frame 20 through roll cage 19 with the result that the reaction to the front shock absorber 46 is that the entire weight of the body is caused to resist the vertical motion that has caused the shock 46 to push on the body thus making substantially all of the weight of the body available to oppose the vertical motion of the front tire. Since the combined front and rear tire system is about 60% of the total vehicle weight, the body weight is more than the weight of either of the front or rear tire systems. 
     When the same bump that the front tires 10 have passed over is confronted by the rear tires 11, the same reaction of the rear suspension assembly 49 takes place. The result is that the body weight is made to be heavier than the rear tire 11. The overall reaction is that the suspension systems 40 or 49 act to apply the body weight to whichever wheel is displaced. 
     The embodiment seen in FIG. 5 differs from the one seen in FIG. 3 in that the suspension means 60 and 61 are now angularly directed oppositely to those seen in FIG. 3. The operational effect of the FIG. 5 embodiment is substantially like that of the first embodiment. It is noted that the body 62 has a modified frame structure to accommodate the change in the near horizontal position of the suspension means 60 and 61. That change alters the way the body 62 responds. While FIG. 5 discloses a different embodiment for the arrangement of suspension means, it is understood that other combinations can be employed. However, in any arrangement of FIGS. 3 and 5, the tires are opposed by the reactions of the suspension means 61 or 60 as the vehicle encounters an obstruction. 
     The view of FIG. 4 is intended to illustrate the travel of the tires 10 and 11 from the dotted line down positions 10A and 11A to the elevated or raised full line positions 10B and 11B. There is, however, a slight change in the wheelbase dimension of the axles 12 and 13. 
     It should now be recognized that this vehicle having total tire weight greater than the total body weight, there results a controllable suspension system in which body weight can be made to impose a greater weight upon either of the front or the rear tires upon a change in the vertical position of the front or rear tires. In other words by employing vertical motion transfer struts 44 and 53 to actuate cantilever means associated with generally horizontal suspension units 40 and 49 in response to change of positions encountered by the tire assemblies 10 and 11, the body weight can be made relatively heavier than the tire weight so that a more normal ride is produced.