TOOL FOR TIGHTENING NUT ON A BOLT TO FORM A FIXED CONNECTION

Abstract

A Tool for tightening a nut on a bolt to form a fixed connection, consisting of an air-driven hydraulic pump which transfers oil pressure to a hydraulic cylinder with a piston connected to a shaft which by means of an air-driven motor (90′) is caused to screw on the threads of the bolt where the nut is connected to a second separate air-driven motor (91′) that screws the nut on the said bolt as the bolt is stretched.

Claims

1-5. (canceled)

6. A tool to tighten a nut on a bolt to form a fixed connection by first stretching the bolt with a set force with subsequent screwing on the nut for correct prestress, the tool comprising: a first motor; a bolt tensioner shaft including internal threads which connects to the bolt, wherein the bolt tensioner shaft is adapted to be rotated by the first motor; a hydraulic piston; an oil pump adapted to supply oil to the hydraulic piston, wherein the hydraulic piston is adapted to extend when an oil pressure is introduced from the oil pump to the hydraulic piston and the extension of the hydraulic piston stretches the bolt, and wherein the hydraulic piston is attached to a hydraulic tensioner shaft that is connected to the bolt tensioner shaft by a locking claw; a second motor; and a pipe that is adapted to be rotated by the second motor, wherein the pipe is swivel-connected axially to the bolt tensioner shaft for engaging the nut.

7. A tool according to claim 6, further including a gear mechanism with first and second gear wheel rotatable mounted on a static common gear shaft, wherein the first gear wheel is adapted to transfer rotational motion from the first motor to the bolt tensioner shaft, and the second gear wheel is adapted to transfer rotational motion from the second motor to the pipe.

8. A tool according to claim 7, further including a fluid pressure sensor detecting the fluid pressure delivered to the first and second motors.

9. A tool according to claim 7, further including a display, a microprocessor connected to the display, an oil pressure sensor connected to the microprocessor, wherein the pressure sensor is configured to detect the oil pressure delivered from the oil pump, and wherein the oil pressure is shown on the display.

10. A tool according to claim 9, further including a fluid pressure sensor detecting the fluid pressure delivered to the first and second motors.

11. A tool according to claim 6, wherein the first and second motors are powered by a fluid or electricity.

12. A tool according to claim 6, further including a display, a microprocessor connected to the display, an oil pressure sensor connected to the microprocessor, wherein the pressure sensor is configured to detect the oil pressure delivered from the oil pump, and wherein the oil pressure is shown on the display.

13. A tool according to claim 6, further including a fluid pressure sensor detecting the fluid pressure delivered to the first and second motors.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention will now be described in more detail and with reference to the appended in which:

[0014] FIG. 1A showing a left side view of the tool.

[0015] FIG. 1B showing the tool underneath.

[0016] FIG. 1C showing a perspective of the of the tool.

[0017] FIG. 2A showing a section view of the cylinder house including the replaceable nozzle.

[0018] FIG. 2B showing a sub assembly of the mechanism, including the replaceable nozzle.

[0019] FIG. 3A showing a detail section of the pneumatic house.

[0020] FIG. 3B showing the detailed view of the motor house.

[0021] FIG. 4 showing the schematics of the total system.

DETAILED DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1A-B-C, showing the position of; a cap 1 mounted with bolts on top of the cylinder house for hydraulics 2. cylinder house for air-supply 3 mounted at the rear part of the tool, the middle plate 4 mounted between the said cylinder houses 2, 3 and the air motor house 5 which is the lowest part of the tool and housing the motors.

[0023] The rear plate 6 bolted to the said cylinder house for hydraulics 2 thru the said cylinder house for pneumatics 3 and connects the handle 7 to the tool. Valve house 8 is placed between the said cylinder houses 2, 3, including the operational switch 10 which change the direction of rotation placed with handles on both side of the tool and the Regulator for Maximum Pressure 11 for regulating the power supply pressure where the wheel for regulating the pressure is placed on top right of the top plate 1. A stub 9 in the very bottom of the construction for direct interface towards the base material or a washer or the like.

[0024] A trigger 12 which open and close the valve regulating the power supply flow, as part of the handle 7, and a power supply coupler 13 which is the connection between the tool and the power supply, and finally a display including a microprocessor adapted to read and analyse sensor data coming from pressure sensors in the power supply system and/or sensors in the hydraulic power system.

[0025] Further in the cylinder house for hydraulics 2 a locking claw 25 is provided for enabling the replacement of the nozzle including the bolt tensioner shaft 26 which connects to the bolt and the pipe 27 which rotates the nut.

[0026] FIG. 2A-B, showing a detailed view of the said hydraulic cylinder house 2 and every part visualized with numbering.

[0027] A hydraulic piston 20 including an O-ring seal 20′, capable of moving in vertical directions, housing Springs 22 providing positive down force. A hydraulic shaft 21 is connected to the said Hydraulic Piston and is sealed both on the upper side and on the bottom side of the hydraulics with Seals 23. An upper hydraulic tensioner shaft 24 underneath and screwed into the said Hydraulic Piston connects the upper hydraulic system to a locking claw 25.

[0028] This said locking claw connects the said upper hydraulic tensioner shaft 24 with a replaceable bolt tensioner shaft 26. Said bolt tensioner shaft has an inner thread 26′ which enables the Shaft 26 to be screwed onto a bolt and transfers the force from the tool to the said bolt. A standard sized pipe 27 with standard hexagonal interface 27′ for the nut is swivel connected to the said shaft 26.

[0029] FIG. 3A-B, showing a detailed view of the pneumatic cylinder house 3, the motor house 5 and every part visualized with numbering.

[0030] An air-driven piston 31 activating a Piston 33 which activates an Oil Pump 34′ capable of increasing or decreasing the hydraulic pressure acting on the said hydraulic piston. A Return Spring 32 pushing the said air-driven piston back to the showed start position when no air pressure is acting on the said piston.

[0031] A Communicator Pin 36 for controlling the air flow acting on the said air-driven piston. An Inlet Valve 80′ of check valve type, securing the flow. And with a Valve Plug 81 mounted to the top of the air supply cylinder house 3. And a flow turn pin 84 for directing the air flow.

[0032] FIG. 4, showing a function and connection diagram for the tool where the operator first adjust the force wanted to stretch the bolts using the wheel 11 on the maximum pressure regulator (83′), and placing the tool on the bolt and activate the operational switch in a first position which activates the Air Motor 90′ to screw the tension rod 24 onto the bolt threads at the same time as a fitted pipe 27 enters the nut and turn it to enter the same bolt threads.

[0033] Then by actuating a Valve 12′ via the trigger 12, the internal air-driven hydraulic pump 34′ and start pressing oil into the hydraulic cylinder where a piston 20 pulls the tension bar 24 and extends the bolt while the nut is simultaneously actuated by torque from the air motor 91′. When the predetermined tension for the bolt is reached, the operational switch is moved to a second position whereby the air motor 90′ goes in reverse.

[0034] The trigger 12 is released, whereby the oil pump 34′ stops and the oil pressure is released by the pressure relief valve 86′ opening when the air pressure from the valve 12′ is absent and the tool is unscrewed by the bolt and ready for the next bolt and nut.