Articulated torque arm construction

Claim 2

A torque arm unit comprising a first arm and a second arm pivotally connected to said first arm at a central pivot point, said first arm including a yoke portion having two opposed end portions pivotally connected to a torque transmitting body at body pivot points, said second arm including a yoke portion having two opposed end portions pivotally connected to a torque receiving body at body pivot points, each of said body pivot points including a thrust bearing means which has thrust bearing contact surfaces and which is arranged to receive and transmit thrust loads in at least one direction, and said first and second arms each including a prestressing means biasing said thrust bearing contact surfaces of said thrust bearing means together to prevent separation of the thrust bearing contact surfaces arranged to receive and transmit thrust loads in one direction when the thrust load is imposed in the opposite direction.

Claim 3

A torQue arm unit as defined in claim 1, wherein said prestressing means includes a stressed rod member extending between said end portions of said yoke portion.

Claim 4

A torque arm unit as defined in claim 1, wherein said thrust bearing contact surfaces of each of said body pivot points includes a radial end face of a self-aligning ball bushing.

Claim 5

A torque arm unit as defined in claim 3, wherein said central pivot point includes a thrust bearing means which has thrust bearing contact surfaces and which is arranged to receive and transmit thrust loads in at least one direction, said thrust bearing contact surfaces including a radial end face of a self-aligning ball bushing.

Claim 6

A torque arm unit as defined in claim 1, wherein said yoke portion of each arm is a U-shaped member, and each arm includes a substantially U-shaped reinforcing member welded to said yoke portion, said reinforcing member being substantially coplanar with said yoke member to resist deflection of said end portions.

Claim 7

A torque arm unit comprising a first arm and a second arm pivotally connected to said first arm at a central pivot point, said first arm including a portion pivotally connected to a torque transmitting body, said second arm including a portion pivotally connected to a torque receiving body, said central pivot point including a thrust bearing means which has thrust bearing contact surfaces and which is arranged to receive and transmit loads in one direction, said thrust bearing contact surfaces including a radial end face of a self-aligning ball bushing.

Claim 8

A torque arm unit comprising a first arm and a second arm pivotally connected to said first arm at a central pivot point, said first arm including a portion pivotally connected to a torque transmitting body, said second arm including a portion pivotally connected to a torque receiving body, said central pivot point including a thrust bearing means which has thrust bearing contact surfaces and which is arranged to receive and transmit loads in one direction, said thrust bearing contact surfaces including a radial end face of a self-aligning ball bushing.

Claim 9

A torque arm unit comprising a first arm and a second arm pivotally connected to said first arm at a central pivot point said first arm including a yoke portion having two opposed end portions each of which is pivotally connected to a torque transmitting body at body pivot points, said second arm including a yoke portion having two opposed end portions each of which is pivotally connected to a torque receiving body at body pivot points, one of the body pivot points of said first arm and one of the body pivot points of said second arm including thrust bearing means arranged to receive and transmit thrust loads in a first direction, the other body pivot points of said first and second arms including thrust bearing means arranged to receive and transmit thrust loads in a second direction opposite said first direction, each of said body pivot points including a self-aligning ball bushing to permit relative rotational movement of said arms at said body pivot points, and one end face of each of said ball bushings being a contact surface of said thrust bearing means.

Claim 10

A torque arm unit comprising a first arm and a second arm pivotally connected to said first arm at a central pivot point said first arm including a yoke portion having two opposed end portions each of which is pivotally connected to a torque transmitting body at body pivot points, said second arm including a yoke portion having two opposed end portions each of which is pivotally connected to a torque receiving body at body pivot points, one of the body pivot points of said first arm and one of the body pivot points of said second arm including thrust bearing means arranged to receive and transmit thrust loads in a first direction, the other body pivot points of said first and second arms including thrust bearing means arranged to receive and transmit thrust loads in a second direction opposite said first direction, each of said body pivot points including a self-aligning ball bushing to permit relative rotational movement of said arms at said body pivot points, and one end face of each of said ball bushings being a contact surface of said thrust bearing means.

Claim 11

A torque arm unit comprising a first arm and a second arm, said arms being pivotally connected to each other by a bearing at a central pivot point, said arms each including a U-shaped yoke portion having opposed end portions, the two opposed end portions of said first arm each being pivotally connected to a torque transmitting body at a body pivot point, the two opposed end portions of said second arm each being pivotally connected to a torque receiving body at a body pivot point, one of the body pivot points of said first arm and one of the body pivot points of said second arm including thrust bearing means arranged to receive and transmit thrust loads in a first direction, the other body pivot points of said first and second arms including thrust bearing means arranged to receive and transmit thrust loads in a second direction opposite said first direction, and a substantially flat U-shaped reinforcing portion adjacent each of said yoke portions, each of said reinforcing portions being substantially flat and being substantially coplanar with a plane defined by the central pivot point and the body pivot points of its associated yoke portion to resist separation of the bearing contact surfaces of the thrust bearing means arranged to receive and transmit thrust loads in one direction when the thrust load is in a direction opposite said one direction.

Claim 12

A torque arm unit comprising a first arm and a second arm, said arms being pivotally connected to each other by a bearing at a central pivot point, said arms each including a U-shaped yoke portion having opposed end portions, the two opposed end portions of said first arm each being pivotally connected to a torque transmitting body at a body pivot point, the two opposed end portions of said second arm each being pivotally connected to a torque receiving body at a body pivot point, one of the body pivot points of said first arm and one of the body pivot points of said second arm including thrust bearing means arranged to receive and transmit thrust loads in a first direction, the other body pivot points of said first and second arms including thrust bearing means arranged to receive and transmit thrust loads in a second direction opposite said first direction, and a substantially flat U-shaped reinforcing portion adjacent each of said yoke portions, each of said reinforcing portions being substantially flat and being substantially coplanar with a plane defined by the central pivot point and the body pivot points of its associated yoke portion to resist separation of the bearing contact surfaces of the thrust bearing means arranged to receive and transmit thrust loads in one direction when the thrust load is in a direction opposite said one direction.

Claim 13

A torque arm unit as set forth in claim 8, wherein one of said arms includes bearing support means adjacent said central pivot point comprising two spaced-apart and substantially flat projecting ear potions extending from the yoke portion of said one arm and arranged in a plane substantially perpendicular to the plane of the reinforcing portion of said one arm, and said reinforcing portion of said one arm includes three sections, one of said sections interspaces said two projecting ears and is adjacent a surface of each ear, another of said sections is adjacent the other surface of one of said ears, and the other of said sections is adjacent the other surface of the other of said ears.

Claim 14

A torque arm unit as set forth in claim 9, wherein the other of said arms includes bearing support means adjacent said central pivot point comprising a substantially flat projecting ear portion extending from the yoke portion of said other arm and arranged in a plane substantially perpendicular to the plane of the reinforcing portion of said other arm, said ear portion of said other arm is received within the space between said ear portions of said one arm, and said reinforcing portion of said other arm includes two sections, one of said sections is adjacent one surface of said ear portion of said other arm, and the other of said sections is adjacent the other surface of said ear portion of said other arm.

Claim 15

A tunneling machine comprising a support frame and a movable frame carried on said support frame by a plurality of articulated torque arm units, each of said units including a first arm and a second arm pivotally connected to said first arm at a central pivot point, said first arm including a yoke portion having two opposed end portions pivotally connected to a torque transmitting body at body pivot points, said second arm including a yoke portion having two opposed end portions pivotally connected to a torque receiving body at body pivot points, each of said body pivot points including a thrust bearing means which has thrust bearing contact surfaces and which is arranged to receive and transmit thrust loads in at least one direction, and said first and second arms each including a prestressing means biasing said thrust bearing contact surfaces of said thrust bearing means together to prevent separation of the thrust bearing contact surfaces arranged to receive and transmit thrust loads in one direction when the thrust load is imposed in the opposite direction.

Claim 16

A tunneling machine comprising a support frame and a movable frame carried on said support frame by a plurality of articulated torque arm units, each of said units including a first arm and a second arm pivotally connected to said first arm at a central pivot point, said first arm including a yoke portion having two opposed end portions pivotally connected to a torque transmitting body at body pivot points, said second arm including a yoke portion having two opposed end portions pivotally connected to a torque receiving body at body pivot points, each of said body pivot points including a thrust bearing means which has thrust bearing contact surfaces and which is arranged to receive and transmit thrust loads in at least one direction, and said first and second arms each including a prestressing means biasing said thrust bearing contact surfaces of said thrust bearing means together to prevent separation of the thrust bearing contact surfaces arranged to receive and transmit thrust loads in one direction when the thrust load is imposed in the opposite direction.

Claim 17

A tunneling machine as defined in claim 11, wherein said prestressing means includes a stressed rod member operatively interconnecting said end portions of said yoke portion.