Precise load positioner
AssigneeColumbus McKinnon Corporation
InventorsKenneth D. Schreyer, Alton H. Cooper
Life of this patent
Estimating the term…
Abstract
A device for precisely positioning a hoist suspended load which operates by temporarily releasing the hoist brake for a predetermined limited time period without actuating the hoist motor so that the load is lowered through a small incremental distance by the influence of its own weight. A control signal may be generated by a delay timer, a repeat cycle timer, a digital timing device or a device for detecting the degree of movement of the load carried by the hoist.
Claims11
A precise positioner control system for targeting the lowering of a load which is suspended at an elevated position by means of a hoist of the type having a motor for driving the load lift wheel of the hoist and a brake co-acting with the lift wheel drive system such that when the hoist motor is actuated the brake is automatically released to permit the motor to drive the hoist and lift the load carried thereby, and when the motor is deactuated the brake is automatically engaged to prevent the load from lowering with respect to the hoist;
- said precise positioner control system being characterized by having:
- manual control means manually operable only when said motor is deenergized for releasing said brake so as to permit the load carried by the hoist to descend in response to gravity forces, and automatic control means adapted to be pre-set so as to be automatically operable to reset said brake following a manually uncontrollable interval of predetermined extent subsequent to manually controlled release of said brake, so as to terminate said brake release function as the load arrives precisely at the operator's preselected lower target elevation, and wherein said automatic control means incorporates power supply switching means arranged so that upon operator-continuance of operation of said manual control means said auotmatic control means functions repetitively so as to permit lowering of said load successively throughout a series of automatically controlled periods of time until operation of said manual control means is discontinued.
A precise positioner control system for targeting the lowering of a load which is suspended at an elevated position by means of a hoist of the type having a motor for driving the load lift wheel of the hoist and a brake co-acting with the lift wheel drive system such that when the hoist motor is actuated the brake is automatically released to permit the motor to drive the hoist and lift the load carried thereby, and when the motor is deactuated the brake is automatically engaged to prevent the load from lowering with respect to the hoist;
- said precise positioner control system being characterized by having:
- manual control means manually operable only when said motor is deenergized for releasing said brake so as to permit the load carried by the hoist to descend in response to gravity forces, and automatic control means adapted to be pre-set so as to be automatically operable to reset said brake following a manually uncontrollable interval of predetermined extent subsequent to manually controlled release of said brake, so as to terminate said brake release function as the load arrives precisely at the operator's preselected lower target elevation, and wherein said automatic control means incorporates power supply switching means arranged so that upon operator-continuance of operation of said manual control means said automatic control means functions repetitively so as to permit lowering of said load throughout a series of successively automatically controlled minute distances of load travel until operation of said manual control means is discontinued.
Dependencies are inferred from the claim text.