Land vehicles – Wheeled – Running gear
Reexamination Certificate
2000-02-04
2001-11-06
English, Peter C. (Department: 3619)
Land vehicles
Wheeled
Running gear
C280S124116
Reexamination Certificate
active
06311995
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to vehicle suspensions and, more specifically, to farm vehicle suspensions which enable a farm vehicle to negotiate very rough and uneven ground.
2. Description of the Prior Art
Off road vehicles, and in particular farm vehicles, have to negotiate very rough and uneven terrain. Farming vehicles often transport heavy loads such as fertilizer, seeds, and liquids for spreading or spraying, often times carrying heavy weights high above the vehicle's center of gravity. In order to maintain vehicle stability with these heavy loads, it is important that all four wheels contact the ground continuously while the vehicle frame, and thus, the load maintain level travel.
Suspension systems utilizing a trailing arm portion to absorb vehicle motion forces are commonly known. For example, U.S. Pat. No. 2,510,424 to Shook is directed to a suspension comprising two trailing arms hinged at one end to a substantially U-shaped laterally tiltable member. The trailing arms are hinged at the other end to a housing located at the inner sides of the wheels. There are separate axles journaled in a housing. The housing is pivotally attached to the center of a crossbar. The trailing arms connect to the U-shaped member at a level well above the connection to the axle. This high angle of attachment imposes greater sheer stress on the pin connecting the trailing arm to the U-shaped member than would a trailing arm positioned in a plane substantially parallel to level ground.
U.S. Pat. No. 3,426,862 to Wilfert relates to a drive axle for vehicles, the relevant part comprising two trailing arms rotatably connected at one end by pins to a transversely disposed tubular shaped housing. The housing is rigidly connected in a cross-like manner with another tubularly shaped housing part that is pivotal about the vehicle longitudinal axis. The second tubular shaped housing supports the drive axle and the trailing arms are secured at the other end to the wheel carriers. Guide links above and below the driving half shafts are used as cross-guide members, while the axle gear is rigidly or elastically mounted to the frame. These joints where the two housings connect are more likely to weaken and/or fail than would a one-piece unit.
What is needed is a suspension system that minimizes stress on the connecting points, while allowing all four vehicle wheels to independently maintain contact with the ground and simultaneously keep the vehicle frame level, thereby permitting increased weight loads to remain stable while traversing uneven terrain.
SUMMARY OF THE INVENTION
The present invention is directed to a vehicle suspension apparatus that satisfies the need to provide substantially stress free connecting points, allow all vehicle wheels to independently maintain contact with the ground throughout all types of terrain, and at the same time continuously maintain a level frame, thus leading to increased vehicle load stability.
In one form, the present invention has a first and second leading arm, each leading arm having a first end opposed to a second end, a pivot pin having a first end which is opposed to a second end and a walking beam having first and second ends. The walking beam is pivotally attached to the pivot pin first end at a location between the walking beam first and second ends. The pivot pin second end is fixedly attached to a cross-member which is fixedly attached to a vehicle frame.
The first leading arm first end is pivotally attached to the walking beam first end and the first leading arm second end is fixedly attached to an axle. The second leading arm first end is pivotally attached to the walking beam second end and the second leading arm second end is fixedly attached to an axle. The horizontal plane of the first and second leading arms are substantially parallel to level ground and a plurality of shock assemblies are fixedly attached between the axle and the vehicle frame.
In another form, the plurality of shock assemblies are omitted.
In yet another form, the present invention comprises a first and second leading arm, each leading arm having a first end opposed to a second end, a first and second trailing arm, each trailing arm having a first end opposed to a second end, a first walking beam having first and second ends, a second walking beam having first and second ends, and one or more pivot pins. The pivot pins are fixedly attached to a cross-member which is fixedly attached to a vehicle frame in a manner such that a first extending end of the pivot pin extends outward from a first side of the cross-member and a second extending end of the pivot pin extends outward from an opposing side of the cross-member.
The first walking beam is pivotally attached to the pivot pin first extending end at a location between the first walking beam first and second ends, and the second walking beam is pivotally attached to the pivot pin second extending end at a location between the second walking beam first and second ends.
The first leading arm first end is pivotally attached to the first walking beam first end and the first leading arm second end is fixedly attached to an axle. The second leading arm first end is pivotally attached to the first walking beam second end and the second leading arm second end is fixedly attached to an axle. The first trailing arm first end is pivotally attached to the second walking beam first end and the first trailing arm second end is fixedly attached to an axle. The second trailing arm first end is pivotally attached to the second walking beam second end and the second trailing arm second end is fixedly attached to an axle.
The horizontal plane of the leading and trailing arms are substantially parallel to level ground and a plurality of shock assemblies are fixedly attached between the axle and the vehicle frame.
In another form of the invention, the shock assemblies are omitted.
An advantage of the present invention is that by maintaining the leading and trailing arms substantially parallel to level ground, sheering forces at the pivotal attachment points are substantially reduced.
Another advantage of the present invention is that by having independent leading and trailing arms, the vehicle wheels independently maintain continuous contact with the ground throughout all types of terrain, while continuously maintaining the vehicle frame in a level position, thus increasing the stability of the vehicle. In farming usage, where heavy loads are maintained well above the vehicle center of gravity, vehicles utilizing the present invention are substantially less likely to overturn when traversing rough terrain.
Still another advantage of the present invention is that the optional shock assemblies in combination with the independent leading and trailing arms allow for even further load stability.
The combination of the ability of the leading and trailing arms to react independently to rough terrain, the rotation of the walking beam when the leading and trailing arms reach the travel limit of their ability to pivot, and the wear pads and bushings allow for load stability heretofore unachievable in the prior art. The synergy of the combination of these features provides a smoother ride for the operator and increased load capacity in the design of farm vehicles. The optional addition of shock assemblies allows for an even smoother ride.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying figures which illustrate, by way of example, the principles of the invention.
All references cited in the preceding sections are incorporated by reference as if fully set forth herein.
REFERENCES:
patent: 2510424 (1950-06-01), Shook
patent: 3273912 (1966-09-01), Crockett
patent: 3292943 (1966-12-01), Crockett
patent: 3311186 (1967-03-01), Kamlukin
patent: 3414290 (1968-12-01), Wilfert et al.
patent: 3420543 (1969-01-01), Strifler et al.
patent: 3426862 (1969-02-01), Wilfert
pate
English Peter C.
GVM, Inc.
Maria Carmen Santa
McNees Wallace & Nurick LLC
Smolow Mitchell A.
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