Torque wrench assembly

1. A torque wrench assembly, comprising:

a torque wrench head being adapted to both tighten and loosen a fastener, the torque wrench head comprising a fastener engaging arrangement and a drive arrangement for driving the fastener engaging arrangement; and

an assembly for mounting the torque wrench assembly on a support, the torque wrench head and the mounting assembly being adapted so that the torque wrench head is capable of both tightening a fastener and loosening a fastener, wherein the torque wrench head is movably mounted on the mounting assembly so that the torque wrench head is capable of both tightening a fastener and loosening a fastener by moving the torque wrench head relative to the mounting assembly between a fastener tightening position and a fastener loosening position, wherein the torque wrench head is rotatably coupled to the mounting assembly via a rotatable coupling arrangement such that the torque wrench head is free to rotate relative to the mounting assembly in a clockwise or anticlockwise direction.

2. The torque wrench assembly as claimed in claim 1 , further comprising a locking arrangement provided between the torque wrench head and the mounting assembly, wherein the locking arrangement is adapted to lock the torque wrench head and the mounting assembly together so no relative movement is possible in at least a fastener loosening position and a fastener tightening position.

3. The torque wrench assembly as claimed in claim 1 , wherein the drive arrangement comprises a low torque high speed drive arrangement and a low speed high torque drive arrangement.

4. The torque wrench assembly as claimed in claim 3 , further comprising a ratchet arrangement operably coupled to the fastener engaging arrangement, wherein the low speed high torque drive arrangement and the high speed low torque drive arrangement are operably coupled via the ratchet arrangement.

5. The torque wrench assembly as claimed in claim 4 , wherein the ratchet arrangement is adapted so as to allow the high speed low torque drive arrangement to operate independently of the low speed high torque drive arrangement with the ratchet arrangement disengaged.

6. The torque wrench as claimed in claim 4 , wherein the ratchet arrangement is adapted so as to allow the low speed high torque drive arrangement to engage the high speed low torque drive arrangement when rotating the fastener into a final position at a predetermined torque setting.

7. The torque wrench assembly as claimed in claim 4 , wherein the high speed low torque drive arrangement comprises a motor and a worm gear assembly operably coupling the motor to the fastener engaging arrangement, the worm gear assembly comprising a worm and a worm wheel.

8. The torque wrench assembly as claimed in claim 7 , wherein the worm wheel is mechanically coupled to a pair of internal ratchet gears of the ratchet arrangement via a coupling arrangement.

9. The torque wrench assembly as claimed in claim 4 , wherein at least part of the low torque high speed drive arrangement are mounted on the fastener engaging arrangement, and wherein at least part of the ratchet arrangement is symmetrically mounted on the fastener engaging arrangement about the part of the low torque high speed drive arrangement mounted on the fastener engaging arrangement.

10. The torque wrench assembly as claimed in claim 9 , wherein at last part of the high torque low speed drive arrangement being symmetrically mounted on the fastener engaging arrangement about the part of the low torque high speed drive arrangement mounted on the fastener engaging arrangement.

11. The torque wrench assembly as claimed in claim 3 , wherein the high torque low speed drive arrangement comprises:

a lever ratchet arm having a first end rotatably mounted on the shaft of the fastener engaging arrangement; and

a cylinder and piston assembly operably coupled between a second end of or along the length of the lever ratchet arm and the torque wrench head.

12. The torque wrench assembly as claimed in claim 11 , further comprising:

a ratchet arrangement operably coupled to the fastener engaging arrangement, wherein the low speed high torque drive arrangement and the high speed low torque drive arrangement are operably coupled via the ratchet arrangement, and wherein the lever ratchet arm comprises:

an elongate lever having a first part operably coupled to the piston and a second bifurcated end, each fork of the bifurcated end having a through bore for receiving the shaft of the fastener engaging arrangement;

wherein each fork of the bifurcated end of the lever ratchet arm comprises an external ratchet gear with through bore mounted thereon and being operably couplable to a correspondingly located internal ratchet gear on the ratchet arrangement; and

wherein the interacting ratchet arrangements of the internal and external ratchet gears are adapted to allow the ratchet arrangements to slip past each other during the high speed low torque phase of the bolt tightening or loosening.

13. The torque wrench assembly as claimed in claim 12 , wherein the ratchet arrangement comprises a plurality of interoperable ratchet teeth on at least one pair of internal and external ratchet gears, the interoperable ratchet teeth are on mutually opposing surfaces of the internal and external ratchet gears, each tooth has a lower landing, a ramp and an upper landing, the upright portion between an edge of the upper landing and the lower landing of two adjacent teeth provide the surface of action during the low speed high torque phase of fastener tightening or loosening.

14. The torque wrench assembly as claimed in claim 13 , wherein the full stroke of the piston of the cylinder and piston assembly from a fully extended position to a fully withdrawn position and back to a fully extended position causes the interoperable ratchet teeth on at least one external ratchet gear to move from a position where the surface of action of correspondingly located teeth on mutually opposing surfaces of the internal and external ratchet gears are in abutment to where these surfaces are pulled apart and the ramps of the teeth on the external ratchet gear slide up along the ramps of the teeth on the internal ratchet gear until the upper lands of internal and external ratchet gears pass each other causing the upper lands of the external ratchet gears to drop onto the and lower lands of the internal ratchet gears wherein the piston is in the fully withdrawn position and wherein extension of the piston causes the surfaces of action to engage and drive the internal ratchet gear through a rotation causing the fastener to be rotated through an angular rotation thereby applying a make up or break out torque to the fastener.

15. The torque wrench assembly as claimed in claim 12 , wherein the high speed low torque drive arrangement comprises a motor and a worm gear assembly operably coupling the motor to the fastener engaging arrangement, the worm gear assembly comprising a worm and a worm wheel, and wherein the internal ratchet gears, the external ratchet gears and the bifurcated end of the lever ratchet arm are symmetrically mounted on the fastener engaging arrangement about the worm wheel.

16. The torque wrench assembly as claimed in claim 11 , wherein the high speed low torque drive arrangement comprises a motor and a worm gear assembly operably coupling the motor to the fastener engaging arrangement, the worm gear assembly comprising a worm and a worm wheel, and wherein the axis of rotation of a rotational coupling arrangement coupling the torque wrench head to the mounting assembly intersects the axis of rotation of the worm, and wherein the axis of rotation of the rotational coupling arrangement coupling the torque wrench head to the mounting assembly intersects the axis of stroke of the piston of the cylinder and piston assembly.

17. The torque wrench assembly as claimed in claim 11 , wherein the high speed low torque drive arrangement comprises a motor and a worm gear assembly operably coupling the motor to the fastener engaging arrangement, the worm gear assembly comprising a worm and a worm wheel, wherein the torque wrench head has a main body formed for receiving the fastener engaging arrangement, the cylinder and piston assembly and the worm, wherein the main body of the torque wrench head has a first collar for receiving the fastener engaging arrangement and a second collar for receiving the cylinder and piston assembly, and wherein the collars are arranged so that the axis of rotation of the fastener engaging arrangement and the axis of the stroke of the cylinder are perpendicular.

18. The torque wrench assembly as claimed in claim 17 , wherein the collar for receiving the fastener engaging arrangement has a support frame for locating and retaining the worm thereon.

19. The torque wrench assembly as claimed in claim 11 , further comprising a system for measuring and recording torque applied to a fastener comprising the cylinder and piston assembly having a position detector for detecting the travel position of a piston rod or piston and the cylinder and piston assembly having a pressure sensor for measuring the fluid pressure acting on the piston.

20. The torque wrench assembly as claimed in claim 1 , wherein the mounting assembly is for mounting the torque wrench assembly on a flange of the support, the mounting assembly comprising a multi-part collar, wherein the collar is formed for enclosing the external surface of the flange with a releasable locking arrangement for securely locking the collar in position.

21. The torque wrench assembly as claimed in claim 20 , wherein the collar has locating arrangements for locating the collar on the flange, wherein the flange has a plurality of fixed locating arrangements, and wherein the locating arrangements of the collar are formed for engagement with the fixed locating arrangements of the flange.

22. The torque wrench assembly as claim in claim 20 , wherein the mounting assembly comprises a reaction arm for coupling the mounting assembly to the collar.

23. The torque wrench assembly as claimed in claim 1 , the torque wrench assembly has a control system for controlling fastener make up and break out, the control system comprising a sensor arrangement for detecting a predetermined fluid pressure, and a fluid circuit for controlling the low speed high torque drive arrangement and the high speed low torque drive arrangement which are operable on the one fluid circuit, and wherein the control system is operable for monitoring fluid pressure from the sensor arrangement and operable for switching the fluid circuit between the high speed low torque drive arrangement and the low speed high torque drive arrangement.