FR3117053A1 - drilling device with spindle uncoupling and braking means - Google Patents

Abstract

The present invention relates to a pneumatic drilling device comprising: an output pin; a pneumatic motor fitted with a rotor; a transmission capable of transforming a rotational movement of said rotor into a rotational and/or translational movement of said output spindle along the same axis; means for controlling the stopping of said motor, According to the invention, said device comprises: means for coupling in movement of said output spindle and of said rotor, said coupling means being able to assume: an uncoupled state in which said spindle and said rotor are not in mesh; a coupled state in which said spindle and said rotor are not engaged, control means for stopping said motor, and/or braking means to oppose the rotation and/or translation of said spindle, said device comprising means for actuating said coupling means capable of placing said coupling means in their uncoupled state upon activation of said stop control means of said motor, and/or means for activating said means braking capable of activating said braking means to oppose the rotation and/or translation of said spindle upon activation of said stopping control means of said motor.

Description

drilling device with spindle uncoupling and braking means

1. Field of the invention

The field of the invention is that of pneumatic tools such as, for example, drills.

2. Prior Art

Drills are commonly used especially in various industrial sectors, including aeronautics, to work towards the completion of various tasks.

Use is made in this sector in particular of so-called automatic feed drills, that is to say drills whose drilling spindle (or output spindle), which carries a cutting tool, is driven simultaneously in translation and in rotation according to its longitudinal axis.

Documents FR-A1-2 881 366 and FR-A1-2 918 592 describe, for example, such a drill.

These tools typically include

• a threaded spline output pin;
• a pneumatic motor fitted with a rotor;
• a transmission capable of transforming a rotational movement of said rotor into a rotational and/or translational movement of said output spindle along the same axis.

This type of drill can also be used to make a countersink at the entrance of the hole. This countersink is intended to receive a countersunk rivet whose surface must be flush with the pierced surface. This presupposes a mastery of the pierced depth.

To precisely stop the advance of the drill, this type of drill is equipped with an advance stop, which causes the reversal of the direction of the advance when the required countersink depth is reached. Reversing the feed causes the drill to retract and the spindle to return to its position at the start of the drilling cycle. This is described in document FR-A1-3 089 440.

This type of drill therefore comprises a second stop which aims to stop the retraction of the spindle when the latter reaches a retracted position corresponding to the start of the drilling cycle.

This stop comprises a conical ring placed on the threaded spline spindle. The positioning of this ring on the spindle is such that when the spindle reaches its position for the start of the drilling cycle, this ring activates a stop command for the drill. This command shuts off power to the air motor. This type of solution is well known in the state of the art and will not be detailed here.

The pneumatic motors ordinarily used in this type of drill are vane motors whose rotation frequency is moderate, around 20,000 rpm and whose vanes induce internal friction.

The applicant has innovated by introducing the use of turbines in this type of drill. These turbines offer greater power and a smaller footprint than vane motors. This has greatly improved the productivity of the drills.

These turbines also have a very high rotation frequency, of the order of 60,000 rpm, and do not present any internal friction.

However, these last points generate a disadvantage that we will detail here.

At the end of a drilling operation comprising the phases of drilling, countersinking then retraction of the spindle, it is logically sought to have the motor stop which is brief so that the spindle can always stop in the same position corresponding to the start of a drilling cycle.

However, due to its significantly higher rotation frequency than a vane motor, a turbine contains a significantly greater quantity of kinetic energy after drilling than a vane motor. In addition, it has much lower internal friction than a vane motor. This results in a significantly longer turbine downtime than that of a vane motor.

The result of this is that after stopping the compressed air supply to the turbine, the spindle can continue to rotate and move forward as long as the turbine has not stopped rotating.

The spindle can thus, after having been retracted, re-advance in the direction of drilling to finally stop in a longitudinal position further extended than its position at the start of the drilling cycle. A part of the useful drilling stroke of the drill along which the cutting tool placed at the end of the spindle can be moved is thus trimmed. In other words, when the spindle is not stopped after retraction in the position it occupied at the start of the drilling cycle, the possible drilling depth for the following cycle is lower.

Furthermore, when an operator handles such a tool, and he inadvertently activates the start-up trigger when the tool is not positioned at the place where it must be implemented to make a hole , the cutting tool attached to the end of the spindle continues to rotate for a while before stopping. During this phase of driving the cutting tool in motion before the machine stops completely, the operator may inadvertently approach his hand and injure himself or another operator in the vicinity. The operator can still bring the rotating cutting tool into contact with an element located in his environment (aircraft fuselage, workbench, workstation, etc.) and damage him and/or the tool.

Turbine drills can therefore be further improved.

3. Objects of the invention

The aim of the invention is in particular to provide an effective solution to at least some of these various problems.

In particular, according to at least one embodiment, an objective of the invention is to improve the reliability of pneumatic drills, in particular turbine drills.

In particular, the invention aims, according to at least one embodiment, to improve the safety of pneumatic drills, in particular turbine drills.

Another object of the invention is, according to at least one embodiment, to provide a technique making it possible to quickly stop the movement of a drill spindle after the stop command of the drill motor.

Another object of the invention is, according to at least one embodiment, to provide a technique making it possible to gradually and smoothly stop the movement of a drill spindle after the command to stop the drill motor.

Another objective of the invention is, according to at least one embodiment, to provide a technique which is simple in design and/or reliable and/or inexpensive.

4. Presentation of the invention

For this, the invention proposes a pneumatic drilling device comprising:

• an output pin;
• a pneumatic motor fitted with a rotor;
• a transmission capable of transforming a rotational movement of said rotor into a rotational and/or translational movement of said output spindle along the same axis;
• means for controlling the stopping of said motor.

According to the invention, said device comprises:

• means for coupling in motion said output spindle and said rotor, said coupling means being able to take:
• an uncoupled state in which said spindle and said rotor are not engaged;
• a coupled state in which said spindle and said rotor are not engaged,

and or

• braking means to oppose the rotation and/or translation of said spindle,

said device comprising means for actuating said coupling means suitable for placing said coupling means in their uncoupled state upon activation of said stop control means of said motor and/or means for activating said means braking capable of activating said braking means to oppose the rotation and/or translation of said spindle upon activation of said stopping control means of said motor.

Thus, the invention consists in uncoupling the output pin from the rotor of the motor as soon as the stopping of the motor is commanded. Thus, the rotor of the motor can continue to rotate, after it has been ordered to stop, under the effect of its inertia until it comes to a complete stop, without causing the spindle to move, which is uncoupled from the rotor as soon as the motor stops. is ordered.

Alternatively or in addition, the invention consists in braking the rotation and/or the translation of the spindle as soon as the stopping of the motor is commanded.

The inertia of the spindle being quite low, the implementation of the invention makes it possible to lead to its almost immediate stop, or at the very least very quickly, after the motor stop command is actuated.

The invention thus makes it possible in particular, by reducing the period of immobilization of the spindle after the engine stop is commanded:

• to stop the spindle as close as possible to the start position of the drilling cycle.
• improve safety by preventing a cutting tool attached to the spindle from continuing to rotate for a moment when the tool is accidentally activated.

The coupling between the spindle and the rotor can be indirect, neither the clutch nor the brake being in this case in contact with the spindle.

According to one possible characteristic, a device according to the invention comprises said coupling means and said braking means, and in which said means for activating said braking means are capable of activating said braking means to oppose the rotation and/or translation of said spindle when said coupling means are in their uncoupled state.

This implementation makes it possible to combine the advantages inherent in the means of uncoupling and braking to immobilize the spindle very quickly at the end of the drilling.

According to a possible variant, said coupling means comprise a clutch capable of assuming two states:

• a disengaged state in which said spindle and said rotor are not engaged;
• an engaged state in which said spindle and said rotor are engaged;

said actuating means being capable of causing said clutch to pass from one state to the other.

Such a clutch makes it possible to obtain sometimes a coupling sometimes a discoupling in a simple and effective way.

According to a possible variant, a device according to the invention comprises means for supplying said engine with compressed gas, said means for supplying said engine and said actuating means acting simultaneously to:

• energizing said motor and placing said clutch in its engaged state, and
• stopping the supply of said motor and placing said clutch in its disengaged state.

According to a possible variant, said clutch comprises a group of first discs linked in rotation to said rotor and a group of second discs linked in rotation to said output spindle, said actuating means placing said clutch in its engaged state by compressing said first and second discs against each other to link in movement by friction said rotor and said output spindle.

According to a possible variant, said actuating means comprise a piston mounted movable in translation in a chamber capable of being supplied with compressed gas by said supply means of said motor, said piston being movable in said chamber between at least:

• a clutch position in which it acts on said coupling means to place them in their coupled state or on said clutch to place it in its engaged state;
• a disengaged position in which it does not act on said coupling means to place them in their uncoupled state or on said clutch to lace it in its disengaged state.

According to a possible variant, said piston:

• acts, in its clutch position, on said discs to place said clutch in its engaged state by compressing said discs against each other;
• does not act, in its disengaged position, on said discs to place said clutch in its disengaged state.

According to a possible variant, said braking means are able to oppose rotation and/or translation of said output spindle when said clutch is in its disengaged state or when said piston is in its disengaged position.

According to a possible variant, said braking means comprise a brake disc against which at least one of said second discs linked in rotation to said output spindle comes into contact when said clutch is in its disengaged state.

In this case, said brake disc is preferably mounted floating between the casing of said device and the second disc opposite which it is located.

Said second disc located opposite said brake disc preferably has a higher hardness than that of the other discs.

According to a possible variant, a device according to the invention comprises elastic return means tending to return said coupling means to their uncoupled state or said clutch to its disengaged state or said piston to its disengaged position.

According to a possible variant, said transmission comprises means for transforming a rotational movement of said rotor into a rotational and/or translational movement of said output spindle along the same axis, said coupling means being arranged between said rotor and said transformation means, said output pin being disposed downstream of said transformation means.

According to a possible variant, said pneumatic motor is a turbine.

The invention also relates to a method for controlling a drilling device comprising:

• an output pin;
• a pneumatic motor fitted with a rotor;
• a transmission capable of transforming a rotational movement of said rotor into a rotational and/or translational movement of said output spindle along the same axis.

According to the invention, such a method comprising simultaneous steps of stopping the supply of said motor with compressed gas and of uncoupling in motion of said spindle and of said rotor,

and/or a step of braking the movement of said output spindle simultaneously with said step of stopping the supply of said motor with compressed gas.

5. Description of figures

Other characteristics and advantages of the invention will appear on reading the following description of particular embodiments, given by way of simple illustrative and non-limiting example, and the appended drawings, among which:

there illustrates a perspective view of an example of a drill according to the invention;

there illustrates a longitudinal sectional view of the drill of the ;

there shows a detail view of the at the coupling means;

there illustrates an exploded view of the coupling means;

there illustrates a perspective view of a clutch bell of a drill according to the invention;

there illustrates another perspective view of a clutch bell of a drill according to the invention;

there illustrates a perspective view of a first disc of a clutch of a drill according to the invention;

there illustrates a perspective view of a second disc of a clutch of a drill according to the invention;

there illustrates a perspective view of a plate of a clutch of a drill according to the invention;

there illustrates a perspective view of a shaft of a clutch of a drill according to the invention;

there illustrates the diagram of an example of a self-holding system for a drill according to the invention;

there illustrates a method according to the invention.

6. Description of particular embodiments

6.1. Architecture

An example of an embodiment of a drill according to the invention is presented in relation to FIGS. 1 to 11.

This is a drill with automatic feed, that is to say a drill whose drill spindle is capable of being driven in rotation and in translation simultaneously along its longitudinal axis. The invention can however be implemented for any other type of drill.

As shown, the drill 1 comprises a casing 10 housing a pneumatic motor 11 comprising a rotor 110.

In this embodiment, motor 11 is a turbine. It could, however, be a vane motor.

The housing 10 includes a connection inlet 12 to a compressed air supply line (not shown) to supply the motor.

The casing 10 also houses a drilling pin 13 (also called output pin) at the end of which fastening means (not shown) make it possible to attach a cutting tool such as a drill bit (not shown) to it. Such means are known per se to those skilled in the art and are therefore not described in more detail here.

Casing 10 houses a transmission T whose input E is connected to rotor 110 of motor 11 and whose output S is connected to pin 13.

This transmission T conventionally comprises a set of components capable of transforming a rotational movement of the rotor 110 of the motor 11 into a combined movement of rotation and translation of the drill spindle 13 along its longitudinal axis. For this, the pin is partly threaded and has longitudinal grooves cooperating respectively with a threaded nut for driving in translation 130 and with a grooved ring for driving in rotation 131. The frequency of rotation of the spindle 13 and its speed d advance are proportional to the rotational frequency of the rotor 110.

In the example shown, the axis of the rotor 110 and that of the spindle 13 are orthogonal. Alternatively, they could be parallel.

The drill includes means 15 for coupling the output spindle 13 with the rotor 110. These coupling means 15 can take:

• an uncoupled state in which spindle 13 and rotor 110 are not engaged (not linked in motion);
• a coupled state in which pin 13 and rotor 110 are engaged (linked in motion).

The drill further comprises means for actuating the coupling means capable of placing the coupling means 15 in their uncoupled state when a stop command for the motor 11 is engaged.

In this embodiment, the coupling means 15 comprise a clutch 150 whose structure will now be described.

The clutch 150 comprises a shaft 151, one end 152 of which is provided to be linked in rotation, directly or indirectly, with the shaft 111 of the rotor 110 of the turbine. This shaft 151 has longitudinal splines 153.

The clutch 15 comprises first circular discs 154 having in their center a hole 155 whose outline comprises splines 156 of complementary shape to the splines 153 of the shaft.

The clutch 150 comprises second circular discs 157 having in their center a hole 158 allowing the passage of the shaft 151. A second disc 157 is interposed between each pair of first discs 154 or vice versa. The second discs 157 are extended in their plane by lugs 159 forming a projection at their periphery.

The clutch 150 includes a bell 160 defining a housing 161 for the discs. The inner diameter of the bell is slightly larger than that of the discs so that it can accommodate them without them being blocked in translation along the axis of the bell. The peripheral contour of the bell 160 has longitudinal openings 162 which extend from the bottom 163 of the bell along its axis. These openings 162 have a shape complementary to those of the lugs 159 of the second discs 157.

The bottom 163 of the bell 160 is extended at its center by a shaft portion 164 which stretches in the opposite direction of the interior housing delimited by the bell. This shaft portion 164 is connected to input E of transmission T.

The clutch 150 comprises a plate 165 provided to close the bell 160 at the level of the opening 166 allowing the discs 154, 157 and the shaft 151 to be introduced therein. This plate 165 has, like the second discs 157, a shape circular and is extended in its plane by lugs 167 forming a projection at its periphery. These lugs 167 are also of complementary shape to the openings 162 of the bell 160.

The plate 165 is extended in its center by a shaft portion 168 which stretches on the side opposite to that facing the bell. This shaft portion is crossed by a central hole 169 allowing the passage of the shaft 151.

A bearing 16 is mounted against a shoulder formed in a housing of the casing 10 of the drill and is held there in translation by a circlip placed at the periphery of its outer ring.

The bell 160 is introduced into the casing 10 of the drill by inserting the shaft portion 164 into the inner ring of the bearing 16 until it comes into abutment against a shoulder provided for this purpose on the shaft portion 164.

A bearing 17 is inserted into an inner bore 170 provided for this purpose in the shaft portion 164 of the bell 160.

The first 154 and second 157 discs are inserted into the bell 160, being inserted therein, taking care to make the lugs 159 of the second discs 157 cooperate with the openings 162 of the bell 160.

The plate 165 is positioned to close the bell 160 by making its lugs 167 cooperate with the openings 162 of the bell 160.

A casing portion 100, to which a preferably removable static brake disc 18 is attached, is mounted on the casing 10 in such a way that its surface 101 facing the disc 18 is placed opposite the plate 165.

This housing portion 100 includes a bore 102 which extends from the side opposite the surface 101 to a shoulder. The bore 102 has at its periphery a groove 103 housing a seal 104.

A bearing 19 is inserted into a bore provided for this purpose in a piston 20 and is held there at its outer ring by a circlip.

The piston 20 is inserted into the bore 102 of the casing portion 100, until the inner race of the bearing 19 comes into abutment against a shoulder provided for this purpose on the shaft portion 168 of the plate 165, in interposing between it and the shoulder a compression spring 21.

A circlip is placed at the inner ring of bearing 19. Piston 20 and plate 165 are thus connected in translation along the axis of piston 20.

The piston 20 includes an inner bore 200 formed opposite the bore housing the bearing 19. The peripheral contour of this bore 200 includes a groove 201 housing a seal 202.

A second casing portion 106, having a guide position 107, is attached against the other casing portion 100 by introducing its guide portion 107 into the bore 200 of the piston 20. The piston 20 is thus guided in translation between the first 100 and second 106 housing portions which form a chamber 105. The chamber 105 inside which the piston 20 is mounted movable in translation forms with it a cylinder.

The shaft 151 is inserted inside the central hole 169 of the plate 165 and the holes 155, 158 of the first 154 and second 157 discs, taking care to make the splines 156 of the first 154 discs cooperate with that of the shaft 151 , until its end is housed in the inner ring of bearing 17.

The shaft 151 is thus guided in rotation like the bell 160.

A channel 22 is made between the first 100 and second 106 housing portions to supply the chamber 105 of the actuator.

The clutch 150 is likely to assume two states:

• a disengaged state in which pin 160 and rotor 110 are not engaged;
• an engaged state in which pin 160 and rotor 110 are engaged.

In the engaged state, the first 154 and second 157 discs of the clutch 150 are compressed against each other so that the shaft 151 and the bell 160 are connected in rotation. The bell 160 being connected in movement with the spindle 13 by the transmission T, the rotor 110 and the spindle 13 are engaged.

In the disengaged state, the first 154 and second 157 discs of the clutch 150 are not compressed against each other so that the shaft 151 and the bell 160 are not connected in rotation. The bell 160 being linked in movement with the spindle 13 by the transmission T, the rotor 110 and the spindle 13 are not engaged.

The piston 20 is movable in the chamber 105 between at least:

• a clutch position in which it acts on the clutch 150 to place it in its engaged state (the coupling means 15 are then in their coupled state);
• a disengaged position in which it does not act on the clutch 150 to place it in its disengaged state (the coupling means 15 are then in their uncoupled state).

Compression spring 21 tends to act on piston 20 along arrow B to return clutch 150 to its disengaged state.

When pressurized air is injected into the channel 22, the piston 20 translates along the arrow B. It causes in its movement the plate 165 which compresses the discs 154, 157 to place the clutch 150 in its being engaged .

In the engaged state, the plate 165 is moved away from the surface of the brake disc 18 so that the brake is deactivated.

In the disengaged state, the plate 165 is pressed along the arrow A against the brake disc 18 under the effect of the spring. In braking action, the brake disc 18 is compressed between the plate 165 and a surface 101 of the housing part 106. The brake is then activated and acts to slow the rotation of the bell 160, and therefore the movement of the spindle 13 connected to it in motion.

The drill includes means for controlling the stopping and starting of the motor 11.

Such a start-up command may correspond to the actuation of a trigger to place it in the start-up position. Such a stop command for motor 11 may correspond to the actuation of a trigger to place it in the stop position.

In this embodiment, the engine starting and stopping control means are such as those described in relation to the .

These control means comprise in this embodiment a pneumatic control system called self-maintaining 23. Such a system is designed such that a leak in the motor supply circuit induces a stoppage of the latter.

We present in relation to the an example of a self-holding system 23.

In this example, this system 23 comprises a pipe 230 permanently connected, via the connection inlet 12, to a compressed air supply network 230 so that it is permanently supplied with a constant flow of compressed air. . The input is connected to a channel 233 which is connected via a channel 234 to the input of a start button 231, and via a channel 236 to the input of a distributor 235. The output of the distributor 235 is connected to the motor 15 and to the dispenser drawer via a power supply loop 237. The output of the start button 231 is connected to the input of an emergency stop button 232 by a channel 238 and to the valve spool 235 via channels 239, 240. The output of the start button 231 is also connected via channels 239, 241 and 22 to the cylinder chamber 105, and via channels 239, 241 and 242 to the entry of a distributor 243 end of drilling. The end-of-drilling distributor 243 is designed to be actuated by a conical stop 244 integral with the drilling spindle 13. The end-of-boring distributor 243 acts like the emergency stop button 232 to cause the closing of the distributor. motor supply 235, and thus cut off the motor supply.

When the start button 231 is pressed, the motor 11 and the channel 22 are simultaneously supplied with compressed air so that:

• the clutch 150 is in the engaged state,
• the brake is off,
• the rotor 11 rotates,
• spindle 13 is driven by a combined movement of rotation and translation.

When the conical stop 244 actuates the end-of-drilling distributor 243, a leak is created in the supply circuit of the motor 11 and of the jack so that;

• motor 11 is no longer powered,
• the piston returns to its disengaged position under the effect of the spring so that the clutch 150 goes into its disengaged state,
• the plate 165 comes into contact with the brake disc 18 so that the brake is activated.

6.2. Functioning

When the start button 231 is pressed, both the inlet and the distributor drawer 235 are supplied with compressed air so that the motor 11 is powered. The supply loop 237 induces that the supply to the motor 11 is self-maintained. The motor and the channel 22 are thus simultaneously supplied with compressed air so that:

• the piston 20 is in its clutch position, against the effect of the spring, in which it compresses the discs 154, 157 against each other;
• the clutch 150 is in the engaged state,
• the brake is deactivated (the plate 165 is located away from the brake disc 18),
• the rotor 110 rotates,
• spindle 13 is driven by a combined movement of rotation and translation by motor 11, clutch 150 and transmission T.

When, at the end of drilling, the stopper 244 secured to pin 13 actuates the end-of-drilling distributor 243, the control of the distributor is exposed to the open air, this causing it to close, so that:

• motor 11 is no longer powered and its rotor 110 continues to rotate under the effect of the kinetic energy it has accumulated,
• the cylinder is simultaneously no longer supplied so that the piston 20 moves under the effect of the spring into its disengaged position, thus placing the clutch 150 in its disengaged state, and activating the brake to stop the rotation of the bell 160, transmission T and pin 13.

The rotor 110 continues to turn a little under the effect of its inertia. Spindle 13, which is uncoupled from rotor 110 by clutch 150, is no longer driven in motion while rotor 110 continues to rotate. The spindle is almost immediately stopped by the brake. The kinetic energy of the spindle and transmission is absorbed by the brake causing the spindle to stop.

The brake is optional. The fact of implementing it makes it possible to accelerate the stopping of the spindle after the actuation of the command to stop the motor. When the brake is not applied, the spindle may continue to move after the motor stop command has been actuated for a little longer. However, the fact that it is uncoupled from the rotor means that it stops much more quickly than in a prior art drill without uncoupling means.

Alternatively, only the brake can be implemented without the uncoupling means being.

6.3. Process

The invention also relates to a method for controlling a drilling device comprising:

• an output pin;
• a pneumatic motor fitted with a rotor;
• a transmission capable of transforming a rotational movement of said rotor into a rotational and/or translational movement of said output spindle along the same axis.

Such a method comprises at least the following simultaneous steps:

• a step 24 of stopping the supply of the motor 11 with compressed gas, and
• a step 25 of uncoupling in movement of the spindle 13 and the rotor 11.

Such a method may further comprise a step 26 of braking the movement of the output spindle simultaneously with the step of stopping the supply of compressed gas to the motor.

Alternatively, the method may include the step 26 of braking the movement of the output spindle simultaneously with the step of stopping the supply of compressed gas to the motor without implementing the uncoupling step 25.

6.4. Variant

The clutch and/or the brake can be placed anywhere in the kinematic chain between the output of the turbine and the spindle. They can for example be integrated at other levels in the transmission, in particular downstream of the first reduction stage of the turbine with the benefit of rotating the clutch at a lower rotation frequency.

The clutch will preferably be placed in the kinematic chain between the output of the turbine and the spindle at a place where it will be able to withstand the torque to which it will be subjected.

Claims (15)

Pneumatic drilling device comprising:

• an output pin;
• a pneumatic motor provided with a rotor;
• a transmission capable of transforming a rotational movement of said rotor into a rotational and/or translational movement of said output spindle along the same axis;
• means for controlling the stopping of said motor,

characterized in that said device comprises:

• means for coupling in motion said output spindle and said rotor, said coupling means being able to take:
• an uncoupled state in which said spindle and said rotor are not engaged;
• a coupled state in which said spindle and said rotor are not engaged,
• means for controlling the stopping of said motor,

and or

• braking means to oppose the rotation and/or translation of said spindle,

said device comprising means for actuating said coupling means capable of placing said coupling means in their uncoupled state upon activation of said stopping control means of said motor, and/or means for activating said braking means capable of activating said braking means to oppose the rotation and/or translation of said spindle upon activation of said stopping control means of said motor. Device according to claim 1 comprising said coupling means and said braking means, and in which said means for activating said braking means are capable of activating said braking means to oppose the rotation and/or translation of said pin when said coupling means are in their uncoupled state. Device according to Claim 1 or 2, in which the said coupling means comprise a clutch capable of assuming two states:

• a disengaged state in which said spindle and said rotor are not engaged;
• an engaged state in which said spindle and said rotor are engaged;

said actuating means being capable of causing said clutch to pass from one state to the other. Device according to claim 3 comprising means for supplying said engine with compressed gas, said means for supplying said engine and said actuating means acting simultaneously to:

• energizing said motor and placing said clutch in its engaged state, and
• stopping the supply of said motor and placing said clutch in its disengaged state.

Apparatus according to claim 3 or 4 wherein said clutch comprises a group of first discs rotatably linked to said rotor and a group of second discs rotatably linked to said output spindle, said actuating means placing said clutch in its engaged state by compressing said first and second discs together to frictionally link said rotor and said output spindle. Device according to any one of Claims 1 to 5, in which the said actuating means comprise a piston mounted movable in translation in a chamber capable of being supplied with compressed gas by the said supply means of the said motor, the said piston being movable in said room enters at least:

• a clutch position in which it acts on said coupling means to place them in their coupled state or on said clutch to place it in its engaged state;
• a disengaged position in which it does not act on said coupling means to place them in their uncoupled state or on said clutch to lace it in its disengaged state.

Device according to claims 5 and 6 wherein said piston:

• acts, in its clutch position, on said discs to place said clutch in its engaged state by compressing said discs against each other;
• does not act, in its disengaged position, on said discs to place said clutch in its disengaged state.

Device according to any one of Claims 3 to 7, in which the said braking means are able to oppose a rotation and/or a translation of the said output spindle when the said clutch is in its disengaged state or when the said piston is in its disengaged position. Device according to Claim 2 and any one of Claims 5 or 7, in which the said braking means comprise a brake disc against which at least one of the said second discs rotatably linked to the said output spindle comes into contact when the said clutch is in its disengaged state. Device according to Claim 9, in which the said brake disc is mounted floating between the casing of the said device and the second disc facing which it is located. Device according to Claim 10, in which the said second disc located opposite the said brake disc has a greater hardness than that of the other discs. Device according to any one of claims 1 to 11 comprising elastic return means tending to return said coupling means to their uncoupled state or said clutch to its disengaged state or said piston to its disengaged position. Device according to any one of Claims 1 to 12, in which the said transmission comprises means for transforming a rotational movement of the said rotor into a rotational and/or translational movement of the said output spindle along the same axis, the said means coupling being disposed between said rotor and said transformation means, said output pin being disposed downstream of said transformation means. Device according to any of claims 1 to 13 wherein said air motor is a turbine. Method for controlling a drilling device comprising:

• an output pin;
• a pneumatic motor provided with a rotor;
• a transmission capable of transforming a rotational movement of said rotor into a rotational and/or translational movement of said output spindle along the same axis;

said method comprising simultaneous steps of stopping the supply of said motor with compressed gas and of uncoupling in motion of said spindle and of said rotor,
and/or a step of braking the movement of said output spindle simultaneously with said step of stopping the supply of said motor with compressed gas.