| 摘要 |
A door-closing hinge comprising an upper barrel with a wing secured to the door and an aligned lower barrel with a wing secured to the door frame. A bolt rotatable in the lower barrel has a non-circular upper end fitting in a non-circular opening in the upper barrel and a lower stem portion of smaller diameter which extends to the lower end of the lower barrel and has in its lower end a central conical depression engaged by a pivot pin in the lower end of the lower barrel. At the upper end of the lower barrel there is a ball bearing between a threaded collar screwed into the upper end of the lower barrel and a washer on the bolt. A sleeve surrounding the bolt has inner pins slidably received in helical grooves in the bolt and outer pins slidably received in longitudinal grooves in the inner surface of the lower barrel so that when the door is swung from closed position toward open position the sleeve is moved upwardly against the force of a spring which tends to return the door to closed position. The lower barrel is filled with oil which acts hydraulically to control the rate of closing.
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