Hoist apparatus

Hoist apparatus for moving a load along a cable or the like, comprising:

• a housing;
• a first sheave rotatably mounted onto said housing and drivingly interconnected with a rotative power source, the circumference of said sheave being formed into a continuous groove;
• a second sheave having a grooved circumference mounted for axial rotation coplanar with said first sheave with its circumferential groove lying opposite that of said first sheave;
• at least one peripherally grooved roller rotatably mounted on said second sheave;
• means mounting said second sheave to said housing for eccentric swinging movement toward and away from said first sheave;
• said cable being received into the groove of said second sheave lying opposite said first sheave and thence engaging the groove of said first sheave over substantially 270.degree. thereof followed by engagement with said roller before exiting from the housing;
• flexible chainlike means received over the cable in the first sheave groove;
• and
• bell crank means mounted onto said second sheave and interconnected with the ends of said chainlike means, whereby movement of said second sheave with respect to said first sheave varies the engagement force of the chainlike means with the cable.

Powered hoist apparatus for moving a load along a cable, comprising:

• a first rotatable member drivingly connected to a source of rotative power, said member having a grooved periphery for receiving the cable;
• a second rotatable member having a grooved periphery within a part of which the cable is received, said second member being located adjacent the first member in the same plane therewith and arranged for eccentric swinging movement about an axis toward and away from said first member;
• elongated pressure applying means received about said first member contacting the cable received within the first member groove having first and second end portions;
• and
• a bell crank pivotally connected to said eccentric axis and said second member for movement therewith and connected to the first and second end portions of said pressure applying means, whereby on movement of the second member away from said first member, tensile force is applied simultaneously to both said first and second end portions, increasing the retaining pressure on the cable within the peripheral groove.

Hoist apparatus for powering a load along a cable or the like, comprising:

• a housing;
• a first sheave rotatably mounted to said housing and drivingly interconnected with a rotative power source, the circumference of said sheave being formed into a continuous groove;
• a second sheave having a grooved circumference mounted for axial rotation coplanar with said first sheave and with its circumferential groove lying opposite that of said first sheave;
• means mounting said second sheave to said housing for eccentric swinging movement toward and away from said first sheave;
• said cable being received into that portion of the groove of said second sheave lying opposite said first sheave and thence engaging the groove of said first sheave before exiting from the housing;
• flexible chainlike means received over the cable in the first sheave groove;
• and
• bell crank means pivotally mounted onto said second sheave and having each of its respective ends interconnected with an end of said chainlike means, whereby movement of said second sheave with respect to said first sheave varies the engagement force of the chainlike means with the cable.