Locking system for release arm of fifth wheel
Method and apparatus for locking the release arm of a conventional fifth wheel as is commonly used on highway truck-tractors. The locking system is designed to operate independently of and without interference with any release mechanism that is used on conventional fifth wheels in use at this time. The device includes a sliding shaft with a lock plate on its end which slides transversely across the path of movement of the release arm of the fifth wheel so that when the shaft is in the retracted position the release arm is prevented by the lock plate from being manually moved.
1 . An improved truck fifth wheel of the type that includes a top plate having a rear opening formed by opposing first and second divergent legs terminating in an elongated medial slot for receiving a king pin of a trailer, a pivotally mounted lock jaw having unlocked and locked positions, the lock jaw having a recess for receiving the king pin therein, a slidable lock bar for securing the lock jaw in the locked position, a release handle attached to an upper end of a release arm, and the release arm attached to the lock bar for sliding the lock bar back and forth, wherein the improvement comprises:
a) a shaft having a lock plate on a free end thereof extending from a means for moving the shaft mounted on said top plate for reciprocal movement across said top plate between a retracted position and an extended position to secure said release arm in a closed position when said shaft is in said retracted position.
2 . The fifth wheel of claim 1 , wherein said shaft is disposed in front of said lock jaw to permit interference-free operation of said lock jaw.
3 . The fifth wheel of claim 2 , wherein the means for moving the shaft further comprises a linear actuator to reciprocate said shaft.
4 . The fifth wheel of claim 2 , wherein the means for moving the shaft further comprises a pneumatic cylinder to reciprocate said shaft.
5 . The fifth wheel of claim 1 , wherein the means for moving said shaft is mounted on said top plate so that said lock plate intersects with the path of movement of said release arm.
6 . A fifth wheel, comprising:
a) a top plate having a rear opening formed by opposing first and second divergent legs terminating in an elongated medial slot for receiving a king pin of a trailer;
b) a pivotally mounted lock jaw having unlocked and locked positions, said lock jaw having a recess for receiving the king pin therein,
c) a slidable lock bar for securing said lock jaw in the locked position and a release arm for sliding said lock bar back and forth; and
d) a shaft having a lock plate on a free end thereof extending from a means for moving the shaft mounted on said top plate for reciprocal movement across said top plate between a retracted position and an extended position to secure said release arm in a closed position when said shaft is in said retracted position.
7 . The fifth wheel of claim 6 , wherein said shaft is disposed in front of said lock jaw to permit interference-free operation of said lock jaw.
8 . The fifth wheel of claim 7 , wherein the means for moving the shaft further comprises a linear actuator to reciprocate said shaft.
9 . The fifth wheel of claim 7 , wherein the means for moving the shaft further comprises a pneumatic cylinder to reciprocate said shaft.
10 . The fifth wheel of claim 6 , wherein the means for moving said shaft is mounted on said top plate so that said lock plate intersects with the path of movement of said release arm.
11 . A method for making a fifth wheel, comprising the steps of:
a) providing a top plate having a rear opening formed by opposing first and second divergent legs terminating in an elongated medial slot for receiving a king pin of a trailer;
b) pivotally mounting a lock jaw on said top plate having unlocked and locked positions, said lock jaw having a recess for receiving the king pin therein;
c) providing a slidable lock bar for securing said lock jaw in the locked position and a release handle for sliding said lock bar back and forth; and
d) mounting a shaft having a lock plate on a free end thereof extending from a means for moving the shaft mounted on said top plate for reciprocal movement across said top plate between a retracted position and an extended position to secure said release arm in a closed position when said shaft is in said retracted position.
12 . The method of claim 11 , further comprising the step of disposing said shaft in front of said lock jaw to permit interference-free operation of said lock jaw.
13 . The method of claim 12 , wherein the means for moving the shaft further comprises a linear actuator to reciprocate said shaft.
14 . The method of claim 12 , wherein the means for moving the shaft further comprises a pneumatic cylinder to reciprocate said shaft.
15 . The method of claim 11 , further comprising the step of mounting the means for moving the shaft on said top plate so that said lock plate intersects with the path of movement of said release arm.