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Title: Method and apparatus for braking a derrick winch

Patent ·
OSTI ID:5394029

This patent describes an apparatus for braking a derrick winch with a winch brake. It comprises: a control lever remotely located from the winch; a servo-control circuit connecting the lever and brake for actuating the brake in response to movement of the lever, and including: a torque motor having a shaft mechanically coupled to the control lever; a brake activating device for actuating the winch brake; a first position transducer for sensing the position of the control lever; a second position transducer for sensing the position of the winch brake; a first force transducer for measuring the force applied to the winch brake; a first comparator; a second comparator. The first comparator being connected to receive signals from the first and second position transducers and to deliver an error signal to the torque motor and to the second comparator. The second comparator being connected to receive signals from the first comparator and from the first force transducer and to deliver an error signal to the actuating device.

Assignee:
Schlumberger Technology Corp., Houston, TX
Patent Number(s):
US 4865393
Application Number:
PPN: US 7068093A
OSTI ID:
5394029
Resource Relation:
Patent File Date: 29 Jun 1987
Country of Publication:
United States
Language:
English