Safety system for overhead support of weighted articles

In a system for raising and lowering a weighted article between supported elevated and supported lower positions, the combination comprising:

• an overhead support means;
• a pair of pulley members supported from said support means at laterally spaced points from each other;
• means to swivel support one of said pulley members from said overhead support means;
• a fixed attachment means supported within reach of a person;
• a link chain connected at one end to the article and passing vertically upwardly over the swivel supported pulley member and then the other pulley member and extending downwardly and connected at its other end to said attachment means, said chain having a length when fully extended sufficient to permit said article to be suspended within reach of a person;
• means on said chain positioned a sufficient distance from the end of the chain connected to said attachment means for connecting the chain to said attachment means when the chain is drawn downwardly to raise the article to the elevated position;
• said means to swivel support one of the said pulley members permitting said one of said pulley members to swivel at an angle to a vertical through its point of support to said support means during normal operation of raising, lowering and supporting the article in elevated and lower positions;
• the improvement comprising said swivel supported pulley member including a housing, a pulley sheave rotatably supported in said housing, said pulley sheave being rotatably supported by a pin extending through said housing, a chain arrestor arm projecting from said housing and fixed relative to said housing and having at least a portion extending transverse of and spaced from the pulley sheave and out of the path of said chain during normal operation, said arrestor arm having stop means on said portion for engaging and stopping said chain when tension in said chain between said swivel supported pulley member and said fixed attachment means is abruptly reduced and said swivel supported pulley member swings toward the vertical and moves the arm fixed thereto and stop means into engagement with the chain, said arrestor arm being a U-shaped member also supported on said pin, said U-shaped member having means thereon for abutting said housing to retain said arrestor arm in a fixed operation position.

A safety pulley for attachment to an overhead support means and used in systems to raise and lower and suspend a weighted article by a link chain, said pulley member comprising:

• a U-shaped housing including a pair of spaced legs connected together by a cross piece;
• a pulley sheave;
• a pin extending through said housing for rotatably supporting said pulley sheave;
• swivel means carried by said cross piece for attachment to the overhead support means, said swivel means permitting said pulley member to swivel at an angle to a vertical when the link chain with tension therein passes over the pulley sheave;
• and
• a chain arrestor arm fixed relative to and projecting from said housing in a downwardly and outwardly direction and having a portion extending transverse of and spaced from the pulley sheave, said arrestor arm having stop means on said portion for engaging and stopping the link chain when tension in said chain is reduced to permit the pulley member to swivel toward a vertical position, said arrestor arm being a U-shaped member also supported on said pin, said U-shaped member including a pair of arm elements connected by a cross piece spaced radially outwardly of said pulley sheave, said cross piece containing a V-shaped guide terminating in a rectangular slot to provide said stop means, said V-shaped guide being capable of directing a link of the chain into the rectangular slot and thus resist passage of further links, and means on the free end of at least one of said arms for abutting said housing to retain said arrestor arm fixed relative to said housing when in an operating position.