Abstract: The safety valve comprises a body and an obturator movable in the body between a closed position (FIG. 2) and an open position (FIG. 3). It also comprises means for displacing the obturator in order to displace it towards its closed position when the pressure of the fluid is lower than a threshold value, and the displacement means comprise: a piston for driving the obturator towards its open position, the piston being in contact with the pressurised fluid when the obturator is in the open position, and means for returning the obturator towards its closed position. Application, for example, to pneumatic machining machines.

Abstract: A pneumatic processing machine includes a pneumatic motor, a circuit for connecting the motor to a source of compressed air, a tool holder spindle, and a drive mechanism. The mechanism includes a selection element which can be moved to select a first method of driving the spindle and a second method of driving the spindle. A device for controlling the operation of the machine controls the carrying-out of a driving cycle which includes at least one phase for driving the spindle according to the first driving method, then a phase for driving the spindle according to the second driving method, then the stopping of the supply of air to the motor. A supply valve of the circuit is controlled mechanically by the selection element to interrupt the supply of compressed air to the motor at the end of the driving cycle.

Abstract: The tool comprises firstly a cutter support for being driven in rotation about a first axis of rotation that is to coincide with the axis of the orifice, and a cutter rotatably mounted on the cutter support to rotate about a second axis of rotation parallel to the first axis of rotation and spaced apart therefrom by a non-zero offset distance. A front segment of the cutter support has maximum radial extent relative to the first axis of rotation that is less than or equal to the radius of the orifice to enable the front segment to penetrate into the orifice during drilling. The tool is particularly applicable to drilling machines used in the aviation industry.

Abstract: A pneumatic machine tool includes a telescopic spindle having a drive shaft driven in rotation by a pneumatic motor. A hollow shaft is slidingly mounted on the drive shaft. A tool holder is associated with the hollow shaft and is driven in translation by a control device. The control device includes a carriage driven in translation by an endless screw via a nut carried by the carriage. The endless screw is driven in rotation by an electric motor. The character is provided with a force sensor designed to measure the thrust exerted on the tool holder and connected to a central processing unit in which is stored an algorithm for processing the signal delivered by the sensor and for monitoring the advance of the tool carried by the spindle.

Abstract: This pneumatic machine tool includes a driving shaft (14) driven in rotation by pneumatic drive means (12), a driven tool-carrier shaft (16), a gear mechanism (18) disposed between the driving shaft and the driven shaft to drive the latter, a set of sensors (22) for measuring operating parameters of the machine tool, and a central control unit (20) in which are stored algorithms for controlling machining as a function of data received from the sensors, the gear mechanism including means (24, 26, 28, 30) for changing the gear ratio. The gear mechanism includes primary and secondary sets (24, 26) of toothed wheels with different demultiplication ratios, each adapted to rotate freely relative to the driving shaft (14). The speed changing means include a positive clutch (28) constrained to rotate with the driving shaft (14) and axially mobile relative thereto between two end positions in which the positive clutch (28) is engaged with respective sets of toothed wheels (24, 26).

Abstract: This pneumatic machine tool comprises a telescopic spindle (18) having a drive shaft (28) driven in rotation by a pneumatic motor (14) and on which is slidingly mounted a hollow shaft (36) with which a tool holder (30) is associated and which is driven in translation by control means (24) comprising a carriage (38) driven in translation by an endless screw (42) via a nut (40) carried by the carriage (38), the said endless screw being driven in rotation by an electric motor, and is characterized in that the carriage is provided with a force sensor (52; 55) designed to measure the thrust exerted on the tool holder (30) and connected to a central processing unit in which is stored an algorithm for processing the signal delivered by the sensor and for monitoring the advance of the tool carried by the spindle.

Abstract: This pneumatic machining machine comprises a toolholder spindle (14), pneumatic drive means ensuring the drive of the spindle (14) and a central unit (16) which stores programs for controlling the drive means for the execution of machining cycles as a function of the type of tool held by the spindle (14), said spindle (14) being equipped with means (20) for coding the type of tool which it carries, and the machine being provided with means (28) for reading the coding means, which are connected to the central unit (16) in order to supply the latter with information relating to the tool fitted to the spindle. The coding means (20) are arranged in the form of a set of grooves forming an optical code, and the reading means (28) comprise sets of optical fibers for detecting the presence of the grooves.

Abstract: A telescopic spindle for a machine tool. The spindle has a sleeve at its rear end and the end of the spindle can slide inside the sleeve over a "compensation" stroke C1, the sleeve being capable of entering inside the body of the machine to travel over a stroke C2, so that the total stroke of the spindle is equal to C1+C2. This serves to reduce the total amount of space taken up by the machine tool.