Claims
- 1. An improved system for installing and removing bolts and nuts from flanged joints in both a high torque phase and a low torque phase which comprises:a) a wrench body having first and second end portions with a rotatable drive head on the first end of the body for engaging and rotating the bolt or nut; b) a high-torque motor that includes a hydraulic cylinder attached to the wrench body for receiving fluid under pressure for rotating the drive head during the high-torque phase, the cylinder having an extendable pushrod operatively connected to the drive head enabling said rotation; c) a low-torque motor which is also operatively connected to the drive head and rotates the bolt or the nut during the low-torque phase of removal or installation; d) a source of pressurized hydraulic fluid; e) a plurality of flow lines for transmitting fluid between the fluid source and the high and low-torque motors, including a first pair of flowlines that communicate with the low-torque motor and a second pair of flowlines that communicate with the high-torque motor; f) a valving member that, upon reaching a pre-selected high-torque value, opens responsive to increasing fluid pressure to divert fluid flow to the high-torque motor for driving the high-torque motor during the high-torque phase; g) wherein the valving member senses fluid pressure and diverts flow to thereby define the high-torque and low-torque phases; and h) the valve member automatically opening or closing responsive to a change in fluid pressure to selectively drive the high-torque motor or the low-torque motor depending on the torque value required, wherein the valving member diverts fluid flow without the use of strain gauges, solenoid valves, or electronic pressure switches.
- 2. An improved system for installing and removing bolts and nuts from flanged joints in both a high torque phase and a low torque phase which comprises:a) a wrench body having first and second end portions with a rotatable drive head on the first end of the body for engaging and rotating the bolt or nut; b) a high-torque motor that includes a hydraulic cylinder attached to the wrench body for receiving fluid under pressure for rotating the drive head during the high-torque phase, the cylinder having an extendable pushrod operatively connected to the drive head enabling said rotation; c) a low-torque motor which is also operatively connected to the drive head and rotates the bolt or the nut during the low-torque phase of removal or installation; d) a source of pressurized hydraulic fluid; e) a plurality of flowlines for transmitting fluid between the fluid source and the high and low-torque motors, including a first pair of flowlines that communicate with the low-torque motor and a second pair of flowlines that communicate with the high-torque motor; f) a valving member that, upon reaching a pre-selected high-torque value, opens responsive to increasing fluid pressure to divert fluid flow to the high-torque motor for driving the high-torque motor during the high-torque phase; g) wherein the valving member senses fluid pressure and diverts flow to thereby define the high-torque and low-torque phases; and h) the valve member automatically opening or closing responsive to a change in fluid pressure to selectively drive the high-torque motor or the low-torque motor depending on the torque value required, wherein the valving member diverts fluid flow without the use of electricity.
- 3. An improved system for installing and removing bolts and nuts from flanged joints in both a high torque phase and a low torque phase which comprises:a) a wrench body having first and second end portions with a rotatable drive head on the first end of the body for engaging and rotating the bolt or nut; b) a high-torque motor that includes a hydraulic cylinder attached to the wrench body for receiving fluid under pressure for rotating the drive head during the high-torque phase, the cylinder having an extendable pushrod operatively connected to the drive bead enabling said rotation; c) a low-torque motor which is also operatively connected to the drive bead and rotates the bolt or the nut during the low-torque phase of removal or installation; d) a source of pressurized hydraulic fluid; e) a plurality of flowlines for transmitting fluid between the fluid source and the high and low-torque motors, including a first pair of flowlines that communicate with the low-torque motor and a second pair of flowlines that communicate with the high-torque motor; f) a valving member that, upon reaching a pre-selected high-torque value, opens responsive to increasing fluid pressure to divert fluid flow to the high-torque motor for driving the high-torque motor during the high-torque phase; g) wherein the valving member senses fluid pressure and diverts flow to thereby define the high-torque and low-torque phases; and h) the valve member automatically opening or closing responsive to a change in fluid pressure to selectively drive the high-torque motor or the low-torque motor depending on the torque value required, wherein the low-torque motor directly engages, without intermediate gears, the drive head.
Parent Case Info
This application is a continuation of U.S. Ser. No. 08/734,305, filed Oct. 21, 1996, now abandoned, which was a continuation of U.S. Ser. No. 08/600,469, filed Feb. 12, 1996, now abandoned which was a continuation of U.S. Ser. No. 08/261,430, filed Jun. 17, 1994, now abandoned.
US Referenced Citations (18)
Continuations (3)
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Number |
Date |
Country |
Parent |
08/734305 |
Oct 1996 |
US |
Child |
08/965818 |
|
US |
Parent |
08/600469 |
Feb 1996 |
US |
Child |
08/734305 |
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US |
Parent |
08/261430 |
Jun 1994 |
US |
Child |
08/600469 |
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US |