Abstract:
A leaf spring assembly for a vehicle having a frame and an axle. The leaf spring assembly includes a first leaf spring and a trailing arm having first and second ends. The first end of the trailing arm adapted to be coupled to the frame to form a trailing arm attachment point. The first leaf spring is disposed beneath the trailing arm and includes a width defining a lateral direction and first and second ends defining a longitudinal direction. The first end of the first leaf spring being concentrically wound with the first end of the trailing arm and adapted to be attached to the frame.
Abstract:
The present invention is directed to a driveline configuration for a heavy-duty truck having multiple drive axles. The driveline configuration reduces the torsional vibrations associated with second order torsional excitation produced by the driveline's universal joints in both nominal and off-design conditions. The forward drive axle (101) and rearward drive axle (102) are oriented such that the interaxle drive shaft (110) utilizes a parallel shaft geometry with small joint operating angles. A double cardan joint (115) connects the main drive shaft (107) to the forward drive axle.
Abstract:
A steering system for steering a vehicle, including a subframe disposed at the rear end of the vehicle for supporting the vehicle, the subframe being pivotably connected to the vehicle, a pair of axles attached in tandem to the subframe, the axles having wheels disposed thereon and a pivot restricting mechanism for partially restricting the pivotable movement of the tandem axle with respect to the vehicle. The pivot restricting mechanism exerts a torsional force on the subframe so as to bias the subframe in such a manner as to align the subframe in an aligned position where the wheels are aligned with the vehicle. The pivot point of the subframe is offset in the direction of one of the axles from the midpoint of the axles with respect to one another.
Abstract:
A pneumatic suspension system for a vehicle providing minimum pneumatic spring stiffness to minimize frame beaming in the vehicle frame. In one embodiment of the invention, the pneumatic suspension system has a first pneumatic spring connected to a first axle and to the frame. A second pneumatic spring is connected to the second axle and to the frame. The first and second pneumatic springs contain pneumatic fluid. A conduit containing pneumatic fluid is in fluid communication with the first and second pneumatic springs. The conduit allows the fluid to move between the first and second pneumatic springs. The pneumatic fluid in the conduit has a fluid resonant frequency. The first and second pneumatic springs and the conduit define a system having a variable stiffness dependent upon an input vibration frequency. The input vibration frequency is a predetermined fraction of the fluid resonant frequency. The pneumatic conduit is sized so the predetermined fraction of the fluid resonant frequency corresponds to the frame beaming frequency, thereby providing minimum stiffness of the system at the frame beaming frequency.
Abstract:
A pneumatically damped vehicle suspension system. The suspension system provides damping which is load-dependent, i.e., the amount of damping varies in approximate proportion to the load supported by the suspension system, thereby maintaining a nearly constant fraction of critical damping over the normal range of operating loads. The damping provided by the system is also frequency-dependent, a characteristic not achievable with hydraulic dampers. Two independent damping circuits provide maximum damping at the suspension's two resonant frequencies, or modes of vibration--the bounce mode and the axlehop mode. Relatively little damping is provided at other frequencies, resulting in improved isolation of road inputs.
Abstract:
A vehicle suspension system with load-controlled damping for a vehicle having a leveling valve actuated by changes in the distance between the axles and the frame and connected to air springs and to a damper to provide load control of the damper. The damper has two cylinders, an inner one filled with oil and in which a piston moves, and an outer one with an annular space between them mostly filled with oil. A jounce metering valve passes oil from below the piston into the annular space upon downward movement of the piston, the resistance to the fluid flow being varied by pressure applied by the leveling valve in accordance with vehicle load. A high-speed-jounce blow-off valve passes oil in the same manner in larger amount when actuated by high-velocity downward movement of the piston, the actuation speed depending on the pressure applied by the leveling valve. Similarly a rebound metering valve sends oil through the piston upon its upward movement, and there is a high-speed-rebound blow-off valve for sending additional oil therethrough, and the resistance of the pressure and the actuation velocity of the latter depend on the pressure applied by the leveling valve, which depends on the frame-supported load.
Abstract:
A gearshift linkage for a cab-over-engine type truck having a shift lever extending up through the cab floor enables the forward tilting of the cab on the frame, about the cab pivot axis, without disengagement of the shift linkage and without dislocation of the shift lever from the cab. In the preferred embodiment, a conventional shifter control unit is secured to the cab just below the floor, with the shift lever extending up from the control unit. The control unit is equipped to accept side-to-side movement of the shift lever and translate it into rotation of a control unit output shaft, and to accept forward and rearward movement of the shift lever and translate it into generally forward and rearward movement of the output shaft. The control unit output shaft is connected through a first universal joint to a control shaft which extends forwardly and downwardly from the cab, being connected at its other end to a specially configured universal joint. The special universal joint is at the forward end of a transmission linkage shaft which extends back to the transmission and mounted to the truck frame for both axial sliding movement and rotational movement. The specially configured universal joint is at the apex of a sharply acute angle between the control shaft and the transmission linkage shaft, and is located as close as possible to the cab pivot axis, about which the cab tilts forward on the frame. When the cab is tilted forward on its axis, all of the shift linkage remains connected. The offset of the special joint from the cab pivot axis causes the control shaft to undergo some translation relative to the shifter control unit, causing the shift lever to undergo minor changes of position not detrimental to the operation or to the shift linkage.
Abstract:
An improved cab for a cab-over-engine configured tractor has a driver's seat mounted to a floor of the cab wherein the floor is substantially flat. The tractor includes a frame for supporting the cab. An engine is mounted to the frame substantially beneath the cab, yet rearward of the floor so that the floor may be substantially flat. Auxiliary devices such as the radiator, radiator fan, and alternator are mounted to the frame remote from the engine and powered by a drive train that extends from the auxiliary devices to the engine.