Patent ID: 6267702
Filing Date: 2001-07-31
Classification: A62B,B66D

Abstract:
A pulley with an automatic emergency brake comprising:a disk with a peripheral race to support and guide a rope having a pull leg and a load leg for lifting and lowering loads, while the disk is rotating on a shaft thereof;a yoke for supporting the shaft;an upper coupling device fitted with the yoke;a double walled rocker arm having corners forming a triangle shape with a hypotenuse slantwise located at a top thereof and with two acute angles, which include a greater angle corner and a smaller angle corner the greater angle corner is located on the pull leg and the smaller angle corner is located on the load leg of the rope, and a substantially right angle corner, the rocker arm having two outer walls fixed to the pulley yoke by transverse pins that are off centered with respect to the shaft of the disk in a direction of the pull rope;a transverse axled snatch block located at the substantially right angle corner of the triangle shape on the rocker arm on which the pull leg of the rope slides;an adjustable counterweight mounted at the smaller acute angle corner of the triangle shape on the rocker arm;a bushing fitted on a transverse pin mounted on the pulley yoke;a transverse axle pin located at the greater acute angle corner of the triangle shape on the rocker arm;a grip wedge mounted on the transverse axle pin for slipping between the rope in the race of the pulley disk and the bushing for compressing and blocking the rope in the race or for leaving a blocking position and releasing the rope,wherein by pulling the pull leg of the rope and by pushing the snatch block, the rocker arm will rotate and remove the grip wedge, while by slackening the pull leg of the rope, the counterweight will cause the rocker arm to rotate, apply the grip wedge and thus block the rope.