Abstract: The present invention provides a speed governor (5) suitable for use in a fluid driven down-hole tool (3). The speed governor comprises an actuator (7) operatively coupled to a motive fluid flow control valve (6). The actuator is and arranged so as to be activatable, directly or indirectly, in response to the running speed of the tool (3), for opening of the control valve (6) with increasing rotational speed of the motor (3) above a predetermined speed limit thereby to limit the rotational speed of the downhole tool (3).

Abstract: The present invention provides an active downhole cutting tool guide device 14 for use in a hole 17 with sides between which a hole-cutting tool 15 mounted on a drill string and provided with said device may be disposed. The guide device 14 comprises at least one elongate longitudinally extending hole-side engagement member 20 mounted on a body 19 disposable, in use of the device, in-line with the drill string, so as to be movable relative to said body 19 between a retracted position and a radially outwardly displaced position for hole-side engagement. Each engagement member 20 has pressurized-fluid operable actuator mechanism 24 formed and arranged for driving said hole-side engagement member 20 between its retracted and hole-side engagement positions. The guide device 14 includes pressurized fluid supply mechanism 28, 18 formed and arranged for controlling the supply of pressurized fluid to the actuator mechanism 24, for operation thereof.

Abstract: A turbine (4) suitable for use in down-hole drilling and the like, and comprising a tubular casing (11) enclosing a chamber (18) having rotatably mounted therein a rotor (19). The rotor (19) comprises at least one turbine wheel blade arrays (30a) with an annular array of angularly distributed blades (30), and a generally axially extending inner drive fluid passage (14) generally radially inwardly of said rotor (19). The casing (11) also has respective generally axially extending outer drive fluid passage (16) associated with said at least one turbine wheel blade array (30a), and one of the inner and the outer drive fluid passages (14, 16) constitute a drive fluid supply passage and is provided with outlet nozzles (17) formed and arranged for directing at least one jet of drive fluid onto the blade drive fluid receiving faces (31) for imparting rotary drive to said rotor (19).

Abstract: The present invention provides a speed governor (5) suitable for use in a fluid driven down-hole tool (3). The speed governor comprises an actuator (7) operatively coupled to a motive fluid flow control valve (6). The actuator is and arranged so as to be activatable, directly or indirectly, in response to the running speed of the tool (3), for opening of the control valve (6) with increasing rotational speed of the motor (3) above a predetermined speed limit thereby to limit the rotational speed of the downhole tool (3).

Abstract: The present invention provides a down-hole tool guide apparatus 6 suitable for use in controlling movement of a down-hole apparatus 1 provided with a pressurised working fluid supply in a borehole P. The apparatus comprises: a body 7 having a chamber 13 in which is slidably mounted a piston 14. A high pressure end 13a of the chamber 13 is connected 36 to the pressurised working fluid supply 10 for supplying pressurised working fluid to a high pressure side 32 of said piston 14. A low pressure end 13b of the chamber 13 is connected with the outside of the guide apparatus 6 and is provided with a spring 16 for applying a biasing force to the low pressure side 17 of the piston 14 corresponding to a predetermined threshold pressure of the pressurised fluid supply at the high pressure side of the piston 14. The body 7 mounts at least one shoe 25 having an engagement face 26.

Abstract: The present invention provides an active downhole cutting tool guide device 14 for use in a hole 17 with sides between which a hole-cutting tool 15 mounted on a drill string and provided with said device may be disposed. The guide device 14 comprises at least one elongate longitudinally extending hole-side engagement member 20 mounted on a body 19 disposable, in use of the device, in-line with the drill string, so as to be movable relative to said body 19 between a retracted position and a radially outwardly displaced position for hole-side engagement. Each engagement member 20 has pressurized-fluid operable actuator means 24 formed and arranged for driving said hole-side engagement member 20 between its retracted and hole-side engagement positions. The guide device 14 includes pressurized fluid supply means 28, 18 formed and arranged for controlling the supply of pressurized fluid to the actuator means 28, 18 for operation thereof.

Abstract: The present invention provides an active downhole cutting tool guide device 14 for use in a hole 17 with sides between which a hole-cutting tool 15 mounted on a drill string and provided with said device may be disposed. The guide device 14 comprises at least one elongate longitudinally extending hole-side engagement member 20 mounted on a body 19 disposable, in use of the device, in-line with the drill string, so as to be movable relative to said body 19 between a retracted position and a radially outwardly displaced position for hole-side engagement. Each engagement member 20 has pressurised-fluid operable actuator means 24 formed and arranged for driving said hole-side engagement member 20 between its retracted and hole-aide engagement positions. The guide device 14 includes preasurised fluid supply means 28,18 formmed and arranged for controlling the supply of pressurised fluid to the actuator means 28,18 for operation thereof.

Abstract: The present invention relates to a wing motor of the type suitable for use in down-hole drilling applications. The motor comprises a generally tubular casing 1, 2 and a rotor 4 mounted for rotation within the casing 1, 2 with a chamber 18 therebetween. The casing 1, 2 is provided with angularly spaced apart inlets and outlets 19, 20 for ingress of pressurized working fluid from an inlet conduit 19a in the casing 1, 2 into the chamber 18 and egress of the fluid to an outlet conduit 20a separated from inlet conduit 19a by a wall 21. The casing 1, 2 has a generally radially extending wall 3 extending more or less into contact with the rotor 4 at an angular position between the outlet 20 and the inlet 19.