Pressure-operated friction locking apparatus for slidably adjustable truck trailer coupling

In an adjustable coupling apparatus for adjustably coupling a trailer to a truck in which said apparatus includes first and second elongate and slidably engaging members for affording such adjustability, and incorporating a releasable locking mechanism for selectively restraining said members against relative slidable movement, the improvement in said locking mechanism comprising:

• friction shoe means mounted on the first member for transverse movement with respect thereto into frictional contact with the second member;
• fluid pressure actuator means for selectively displacing said friction shoe means in said transverse movement, said actuator means having a pressurized condition in which it forces said friction shoe means into said frictional contact with the second member so as to frictionally lock said members against said relative slidable movement, and having an unpressurized condition relieving said friction shoe means from said frictional contact with the second member so as to allow said relative slidable movement of said members;
• fluid control means connected to said actuator means for selectively causing said actuator means to assume either said pressurized condition or said unpressurized condition;
• and
• a pressure actuated safety pin mechanism including a shear pin means mounted on said members for movement between a locking condition preventing relative slidable movement of said members and an unlocking condition allowing relative slidable movement of said members, and a pressure-operated pin actuating means coupled to said shear pin means, said pin actuating means being responsive to said fluid control means for disposing said shear pin means in its locking condition when said actuator means for said friction shoe means is in its pressurized condition, and for causing said shear pin means to assume its unlocking condition when said actuator means for said friction shoe means is caused to assume said unpressurized condition.

In an extendable reach-type truck trailer tongue apparatus having inner and outer rigid tubular tongue members of mating rectangular cross section that are telescopically engaged for adjusting the tongue length, and having a releasable locking mechanism for selectively locking said members at a selected length and for releasing said members to permit telescoping to another selected tongue length, the improved locking mechanism in combination therewith comprising:

• friction shoe means mounted on the inner tongue member for transverse and outward movement with respect thereto into frictional contact with an interior wall surface of the outer tongue member;
• fluid pressure actuator means supported by said inner tongue member for selectively moving said friction shoe means between an unlocked condition in which said friction shoe means is released from said frictional contact so as to permit telescoping of said members and a locked condition in which said shoe means is forced outwardly into said frictional contact with the interior wall surface of the outer tongue member so that a force in reaction thereto causes an exterior wall surface portion of said inner member which lies generally opposite said shoe means to be present against a corresponding and contacting portion of the interior wall surface of said outer tongue member to frictionally bind said members against both longitudinal telescoping and transverse play;
• and
• fluid control means for causing said fluid pressure means to selectively dispose said friction shoe means in either said locked or unlocked condition.

A pressure-operated, releasable, friction locking mechanism in combination with first and second rigid, elongated and lengthwise slidably engaged members that adjustably couple a truck and trailer, wherein said first member has a pair of transversely angulated walls forming an interior corner that joins adjacent, generally flat surfaces of said first member, and wherein said second member has a pair of transversely angulated walls forming an exterior corner that joins adjacent, generally flat surfaces of said second member and is mated to said interior corner of said first member walls so that said adjacent, generally flat surfaces of said first member walls and said second member walls are disposed in proximate and opposing relation, said first and second members being relatively sized so that a free space gap exists between opposing surfaces of said first and second members, and wherein said locking mechanism comprises:

• friction shoe means and fluid pressure actuator means therefore sandwiched between said opposing surfaces of said walls of said members so that said friction shoe means is displaceable by said fluid pressure actuator means relative to said opposing walls surfaces of said members for selectively causing a released condition in which said members are relatively slidable and a locked condition in which said shoe means is forced transversely and outwardly with respect to one of said members into frictional contact with said adjacent, generally flat surfaces of the other of said members so as to cause reactionary forces on said members that frictionally bind said members against both relative sliding movement and transversely play;
• and
• fluid control means for causing said fluid pressure means to selectively dispose said friction shoe means in either said locked condition or released condition.