Hinge with pin retaining means

Claim 1

A HINGE COMPRISING A PAIR OF HINGE LEAVES HAVING INTERFITTING KNUCKLES WITH AN ALIGNED BORE EXTENDING THERETHROUGH, A HINGE PIN SEATED IN SAID BORE TO PROVIDE A PIVOTAL CONNECTION BETWEEN SAID HINGE LEAVES, THE LOWERMOST OF SAID KNUCKLES HAVING A COUNTERBORE IN THE END THEREOF, A HINGE TIP SECURED WITHIN SAID COUNTERBORE, SAID HINGE TIP AND SAID COUNTERBORE DEFINING AN ANNULAR CAVITY IN SAID LOWERMOST KNUCKLE, AN ELONGATED ANNULAR COLLAR OF RESILIENTLY DEFORMABLE PLASTIC MATERIAL OF HIGH TENSILE STRENGTH LOOSELY RECEIVED IN SAID ANNULAR CAVITY, SAID COLLAR BEING SPACED FROM THE WALL OF SAID COUNTERBORE TO PROVIDE AN ANNULAR RECESS, THE UPPER END OF SAID COLLAR HAVING AN INNER DIAMETER GREATER THAN THE DIAMETER OF THE PIN SO AS TO FREELY RECEIVE THE PIN THEREIN AND AN INTERNAL RIB POSITIONED BELOW SAID UPPER END OF THE COLLAR OF NORMALLY LESSER DIAMETER THAN THAT OF THE PIN, SAID COLLAR BEING RADIALLY MOVABLE IN THE CAVITY SO AS TO BE AUTOMATICALLY ALIGNED BY THE PIN AS IT PASSES THERETHROUGH, SAID COLLAR BEING EXPANDABLE RADIALLY OUTWARDLY TO PERMIT INSERTION AND WITHDRAWAL OF SAID PIN AND ENGAGING SAID PIN TO APPLY A CONTRACTILE FORCE TO LIMIT THE MOVEMENT THEREOF.