PIVOT AXLE ASSEMBLY FOR ROADWORTHY RAILROAD BALLAST TAMPER APPARATUS

1 . A rail tamper apparatus, comprising:

a chassis configured for being hitched to a semi-tractor trailer for road travel, and also configured for travel on rails of a railroad track;

at least one ballast tamping unit mounted to said chassis;

a turntable unit mounted to said chassis; and

a pivoting axle assembly mounted to said chassis that is retractable relative to said chassis in a road travel position for highway travel, and is extendable from the chassis into a track travel position for operation on the rails, and including a rail wheel drive motor being extendable with said axle assembly.

2 . The apparatus of claim 1 , wherein said apparatus has a weight of less than 80,000 pounds and a width of less than or equal to 96 inches.

3 . The apparatus of claim 1 , wherein said pivoting rail wheel assembly is provided with a pivot shaft extending generally parallel to the rails, and said assembly is pivotable relative to said chassis about said shaft.

4 . The apparatus of claim 1 , wherein said pivoting rail wheel assembly is provided with powered latches connected to said chassis and constructed and arranged for maintaining said assembly in said track travel position relative to said chassis.

5 . The apparatus of claim 4 , wherein said latches are constructed and arranged for rotatably operating between an extended, rail travel position, and a retracted position.

6 . The apparatus of claim 5 , wherein said latches include a latch arm having a latch end configured for engaging a slot in said chassis.

7 . The apparatus of claim 5 , wherein said pivoting rail wheel assembly is provided with a main shaft with endcaps, and said latches are configured for engaging said endcaps in said rail travel position.

8 . The apparatus of claim 5 , further including at least one lift cylinder connected to said chassis and to said pivoting rail wheel assembly for reciprocally moving said assembly vertically relative to said chassis, said at least one lift cylinders being constructed and arranged such that extension of the assembly by said at least one cylinder past an operational position allows for disengagement of the latches for subsequent retraction of said assembly to a highway travel position.

9 . The apparatus of claim 8 , further including a pair of said lift cylinders, said lift cylinders being mounted to said rail wheel assembly outboard of a pair of rail wheels mounted to said assembly.

10 . The apparatus of claim 9 , further including bearings for said rail wheels, said bearings being located inboard of said wheels.

11 . A pivoting rail wheel assembly for use with a railway maintenance vehicle having a chassis, said assembly comprising:

a housing configured for being vertically reciprocable relative to said chassis;

a pair of rail wheels mounted to said housing;

a drive motor associated with said housing and configured for powering at least one of said rail wheels;

a pivot shaft associated with said housing and slidably connecting said housing to said chassis, said housing being pivotable about said shaft;

at least one powered latch connected to said chassis and constructed and arranged for maintaining said assembly in a track travel position relative to said chassis.

12 . The assembly of claim 11 , wherein said latches are provided with fluid power cylinders and are constructed and arranged for rotatably operating relative to said chassis between an extended, rail travel position, and a retracted position.

13 . The apparatus of claim 12 , wherein said latches include a latch arm having a latch end configured for engaging a slot in said chassis, and said main shaft is provided with endcaps, said latches are configured for engaging said endcaps in said rail travel position.

14 . The assembly of claim 12 , wherein said latches are constructed and arranged, so that when in said retracted position, said housing is movable vertically towards said chassis.

15 . The assembly of claim 11 , further including at least one derail bar disposed on said housing.

16 . The assembly of claim 11 , further including a brake assembly mounted on said housing for exerting braking force on said rail wheels.