Split-beam suspension system

In a trailing arm suspension for a vehicle, said suspension having a trailing arm adapted to support an axle carrying ground-engaging wheels, and further having a bracket adapted to be mounted to a vehicle frame and an air spring adapted to be mounted to the frame, the improvement wherein:

• the trailing arm has a front portion, an axle mount, and a rear portion, the front portion having a terminal end pivotably connected to the bracket, the axle mount being adapted to be connected to the axle and the rear portion having an air spring support connected to and supporting the air spring;
• the front portion further having a shank extending rearwardly from the terminal end, said shank having a bend so that part of the shank extends rearwardly and then laterally inwardly toward the axle mount, thereby partially defining an open space adjacent to the trailing arm;
• each of said terminal end, axle mount, and air spring support having a load bearing center, said centers laying in a single vertical plane;
• whereby the trailing arm can be mounted to the frame for pivotal movement thereof about a horizontal axis relative to the frame and accommodate equipment mounted on the vehicle within the open space while being substantially free of a torsional moment about a longitudinal axis of the trailing arm.

A trailing arm for a trailing arm suspension in a vehicle, said suspension being adapted to support an axle carrying ground-engaging wheels, and having a bracket mounted to a vehicle frame on each side of said vehicle, and an air spring suspended from the frame on each side of the vehicle, rearwardly of the respective bracket, the trailing arm comprising:

• a beam and a beam extension, one of said beam and said beam extension having means to support the axle;
• said beam having a first end and a second end with a shank extending therebetween, said shank having a bend so that the shank extends rearwardly from the first end and then laterally toward the second end, thereby partially defining an open space adjacent to the trailing arm to accommodate equipment mounted on the vehicle within the open space when the trailing arm is mounted to the vehicle;
• said beam being symmetrical about a transverse plane extending through the beam ends, the first end being adapted to be pivotably connected to the bracket for movement about an axis lying substantially in the transverse plane, the second end having a first connection surface;
• said beam extension being adapted to support the air spring and having an inner end, the inner end having a second connection surface for being rigidly attached to the first connection surface to form a trailing arm having a predetermined angular configuration, said second surface being shaped to interface with the first connection surface in a number of different relative angular relationships and being secured to the beam at the said first and second connection surfaces while extending generally rearwardly,
• whereby the beam can be selectively adapted to form a trailing arm on each side of the vehicle, said trailing arm having the same predetermined angular configuration on each side of the vehicle, when the first connection surface is rigidly mounted to the second connection surface, the beam first end is mounted to one of said brackets and the beam extension supports the respective air spring.

A trailing arm for a trailing arm suspension in a vehicle, said suspension being adapted to support an axle carrying ground-engaging wheels, and having a bracket mounted to a vehicle frame on each side of said vehicle, and an air spring suspended from the frame on each side of the vehicle, rearwardly of the respective bracket, the trailing arm comprising:

• a beam and a beam extension;
• an axle bracket mounted to the beam for supporting the axle;
• said beam having a first end and a second end, the first end being adapted to be pivotably connected to the bracket, the second end having a first connection surface;
• said beam extension being elongated and having an inner end and an outer end, the inner end having a second connection surface for being rigidly attached to the first connection surface to form a trailing arm having a predetermined angular configuration, said second connection surface being shaped to interface with the first connection surface in a number of different relative angular relationships while maintaining the outer end generally rearwardly of the inner end when the trailing arm is mounted to a vehicle, said outer end being adapted to support the air spring and further being laterally offset from said inner end,
• and said beam extension being symmetrical about a transverse plane extending through the ends of the beam extension,
• whereby the beam extension can be selectively adapted to form a trailing arm on each side of the vehicle, said trailing arm having the same predetermined angular configuration on each side of the vehicle, when the first connection surface is rigidly mounted to the second connection surface, the beam first end is mounted to one of said brackets and the beam extension supports the respective air spring.

In a trailing arm for a suspension for a vehicle having a frame with a bracket mounted thereto, said suspension comprising:

• the trailing arm having a forward portion and a rearward portion;
• said forward portion adapted to be pivotably mounted to the bracket for vertical swinging movement relative to the frame and said rearward portion adapted to support an air spring between the trailing arm and the frame for cushioning the swinging movement of the trailing arm;
• means for mounting an axle carrying ground-engaging wheels to the trailing arm;
• and
• a transverse beam mounted to the trailing arm to resist roll in the suspension, the improvement wherein:
• the trailing arm has a distal end at the rear portion, a U-shaped slot opening through the distal end, said slot being adapted to receive the transverse beam, and a plate secured to the distal end of the trailing arm to cover the open end of the slot.