Cable reeling system

• US 5,495,157 A
• Filed: 01/26/1994
• Issued: 02/27/1996
• Est. Priority Date: 07/27/1991
• Status: Expired due to Fees

• Current Assignee: Metool Products Ltd.
• Original Assignee: Metool Products Ltd.
• Inventors: Dade, Malcolm J., Richards, Marcus
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Masih, Karen
• Application Number:
  US08/185,956
• Time in Patent Office: 762 Days
• Field of Search: 318/6, 318/561, 318/432, 318/560, 242/193, 242/250, 242/225, 242/186, 242/75.44, 242/86.51, 242/390, 242/225
• US Class Current: 318/432
• CPC Class Codes: B65H 75/4484 Electronic arrangements or adaptations for controlling the winding or unwinding process, e.g. with sensors
• CPC Class Codes: B65H 75/4486 Electric motors
• CPC Class Codes: H02G 11/02 using take-up reel or drum

Abstract

A cable reel system for use in conjunction with a mobile installation movable relative to a fixed base station and being connected to the fixed base station via a cable, the system comprising a reel on which the cable is stored, the reel being connected by a motor shaft to an AC motor which drives the reel via reduction means to pay-out cable whilst the mobile installation moves away from the base station and to reel-in cable whilst the mobile installation moves towards the base station, the reel system further comprising sensing means located adjacent said motor shaft and operable to provide a signal representative of the position of the motor shaft, and a controller, which receives the signal and calculates a torque demand signal, the controller further continually varying a stator current of the motor in response to cable paying-out or reeling-in operating conditions pertaining at a given instant by using the torque demand signal to calculate and supply phase currents to the motor to provide a required torque at the motor shaft for maintaining tension of the cable extending between the mobile installation and the fixed base station within a predetermined range of values.

Claims

1. A cable reel system for use in conjunction with a mobile installation relative to a fixed base station and being connected to the fixed base station via a cable, the system comprising a reel on which the cable is stored, the reel being connected by a motor shaft to an AC motor which drives the reel via reduction means to pay-out cable whilst the mobile installation moves away from the base station and to reel-in cable whilst the mobile installation moves towards the base station, the reel system further comprising sensing means located adjacent said motor shaft and operable to provide a signal representative of the position of the motor shaft, and a controller, which receives said signal and calculates a torque demand signal, the controller further continually varying a stator current of the motor in response to cable paying-out or reeling-in operating conditions pertaining at a given instant by using said torque demand signal to calculate and supply phase currents to the motor to provide a required torque at the motor shaft for maintaining tension of the cable extending between the mobile installation and said fixed base station within a predetermined range of values.

2. A reel system as in claim 1, wherein said signal is compared with a reference signal by the controller to calculate the torque demand signal.

3. A reel system as in claim 1 or 2, wherein the controller provides the stator current of the motor such that said required torque at the motor shaft is constant.

4. A reel system as in claim 1 or 2, wherein the reel is mounted on a mobile installation and is connected to a base station via a cable mounted on the reel.

5. A reel system as in claim 1 or 2, wherein the reel is mounted on a base _station and connected to a mobile installation via a cable mounted on the reel.

6. A reel system as in claim 4, wherein the controller selects a system correction factor in response to the direction of movement of the reel.

7. A reel system as in claim 4, wherein said required torque is varied as a function of the amount of cable on the reel.

8. A reel system as in claim 3 wherein the reel is mounted on the mobile installation.

9. A reel system as in claim 3 wherein the reel is mounted on the base station.

10. A reel system as in claim 5 wherein the controller selects a system correction factor in response to the direction of movement of the reel.

11. A reel system as defined in claim 5 wherein said required torque is varied as a function of the amount of cable on the reel.

12. A reel system as defined in claim 6 wherein said required torque is varied as a function of the amount of cable on the reel.