drilling device with feed disengagement at the end of retraction

Abstract

Drilling device comprising a housing containing: - a motor; - a drilling spindle movable in rotation and / or translation along a longitudinal axis; - a transmission comprising: - a first pinion linked in rotation with said spindle and movable in translation along said spindle along said longitudinal axis; - a second pinion linked to said spindle by a helical connection along said longitudinal axis; - a third pinion, meshing with said first pinion, and capable of being driven in rotation by said motor; - a fourth pinion, meshing with said second pinion, movable between: - a engaged position in which it is linked in rotation with said third gear, the drive in rotation of said third pinion by said motor inducing a deployment of said spindle over a predetermined deployment stroke;- a fixed position in which it is rotationally bound with said housing and is free to rotate with respect to said third pinion, a rotation of said third pinion by said motor inducing a retraction of said spindle following a predetermined retraction stroke, said fourth pinion being able to take an intermediate position in which it is free to rotate with respect to said housing and said third pinion in such a way that it does not exert appreciably any torque on said second pinion so that a rotational drive of said third pinion by said motor induces a rotation of said second pinion at the same rotational frequency as that of said spindle. Fig. 1;

Description

Title of the invention: Drilling device with feed disengagement at the end of retraction 1. Scope of the invention

[0001] The field of the invention is that of drilling devices. 2. Prior art

[0002] Drilling devices, also called drills, are commonly used in various industrial sectors, such as aeronautics, to perform various tasks. In this sector, drills with automatic feed are commonly used; that is, drills in which the drilling spindle (or output spindle), which carries a cutting tool, is driven simultaneously in translation and rotation about its longitudinal axis.

[0003] Patent documents FR-A1-2 881 366 and FR-A1-2 918 592 describe such drills, for example.

[0004] With reference to [Fig. 1], a drill of this type classically comprises:

[0005] - a grooved and threaded output pin 10;

[0006] - a pneumatic motor (not shown) equipped with a rotor R and connected to a valve compressed air supply;

[0007] - a transmission T capable of transforming a rotational movement of the rotor R into a rotational and / or translational movement of the output spindle 10 along the same axis, i.e. its longitudinal axis.

[0008] This transmission T comprises:

[0009] - a first pinion 11 coaxial with the spindle 10 and provided with internal splines cooperating with the external grooves of spindle 10;

[0010] - a second pinion 12 coaxial with the spindle 10 and provided with an internal thread cooperating with the thread of spindle 10;

[0011] - a third pinion 13 with an axis parallel to the spindle 10, meshing with the first pinion 11 following a first transmission ratio and driven in rotation by the drill motor via a pair of bevel gears 15 and / or one or more epicyclic gear trains (not shown);

[0012] - a fourth pinion 14 with an axis parallel to the spindle 10, meshing with the second pinion 12 following a second transmission ratio different from the first ratio.

[0013] The fourth pinion 14 includes first ogive-shaped dog clutches 140 capable of cooperating with complementaryly shaped clutch housings 130 provided on the third pinion 13 such that when the dog clutches 140 are housed in the clutch housings 130, the fourth pinion 14 and The third pinion 13 are rotationally linked. As will be described in more detail later, the ogive shape of the first dogs makes them suitable for disengaging the rotational link when the fourth and third pinions have started to move away from each other.

[0014] The fourth pinion 14 also includes second dogs 141 of complementary shape to locking dogs 17 fixed relative to the casing C of the drill.

[0015] The fourth pinion 14 is fixed in translation to the rod 160 of the piston 161 and free to rotate relative to it. This rod 160 is movable in translation along the axis of rotation of the fourth pinion in a chamber 162 of a monostable cylinder 16 so as to be able to:

[0016] - an engaged position in which the first dogs 140 are housed in the clutch housings 130 and the second dogs 141 do not cooperate with the locking dogs 17, so that the fourth pinion 14 is rotationally linked with the third pinion 13 and is rotationally mobile relative to the housing C, and

[0017] - a fixed position in which the first 140 dog clutches do not cooperate with the clutch housings 130 and the second dogs 141 cooperate with the locking dogs 17 so that the fourth pinion 14 is fixed in rotation relative to the housing C and mobile in rotation relative to the third pinion 13.

[0018] To move the fourth pinion 14 from its engaged position to its immobilized position, the side of the chamber 162 of the cylinder 16, facing the fourth pinion 14, is supplied with compressed air. The fourth pinion 14 then moves away from the third pinion 13 against the effect of the spring 163.

[0019] To move the fourth pinion 14 from its immobilized position to its engaged position, the chamber 162 of the cylinder 16 is opened to the air by means of a distributor (not shown) so as to bring the fourth pinion 14 closer to the third pinion 13 under the effect of the spring 163.

[0020] The spindle 10 is provided with a deployment end stop 18 capable of bearing against a fixed deployment end stop in translation (here the first pinion 11) relative to the housing, and a retraction end stop 19 capable of bearing against a retraction end stop (here the second pinion) fixed relative to the housing.

[0021] This type of drill can also be used to make holes with or without a countersink at the hole entry. Such a countersink is designed to receive a rivet with a countersunk head, the surface of which must be flush with the drilled surface. This requires precise control of the drilled depth.

[0022] When starting the drill to perform a drilling operation with or without countersinking, the end stop for retraction 19 is in contact with the end stop for retraction (i.e. the second pinion 12) so that the spindle 10 is completely retracted.

[0023] The fourth pinion 14 is in the engaged position in which it is rotationally linked with the third pinion 13.

[0024] The motor is supplied in the direction of operation (i.e., drilling) such that the third pinion 13 is driven in rotation. The fourth pinion 14, which is rotationally linked with the third pinion 13, rotates at the same speed.

[0025] The first pinion 11 is driven in rotation by the third pinion 13 so that the spindle 10 is driven in rotation about its longitudinal axis.

[0026] The second pinion 12 is driven in rotation by the fourth pinion 14.

[0027] The reduction ratio between the first 11 and the third pinion 12 is different of the reduction ratio between the second pinion 12 and the fourth pinion 14. Thus, given the helical connection between the second pinion 12 and the spindle 10, the spindle 10 is driven in translation along its axis and extends out of the housing until the end-of-deployment stop 18 is against the end-of-deployment stop (i.e. of the first pinion 11).

[0028] When the deployment end stop 18 is against the deployment end stop, the deployment of the spindle 10 is stopped, so that the second pinion 12 is forced to rotate at the same speed as that of the spindle 10 and that of the first pinion 11. The third 13 and the fourth 14 pinions therefore tend to rotate at different speeds due to the difference in reduction ratios mentioned above. Thus, given the ogive shape of the first dog clutches 140 of the fourth pinion 14, these dog clutches 140 tend to disengage from the clutch housings 130 of the third pinion 13, so that the fourth pinion 14 moves away from the third pinion 13 towards its stationary position.

[0029] This relative distance of the fourth pinion 14 from the third pinion 13 actuates the distributor (not shown) which supplies the side oriented towards the fourth pinion 14 of the chamber 162 of the cylinder 16. As a result, the cylinder 16 drives, against the effect of the spring 163, the fourth pinion 14 into its immobilized position in which it is fixed in rotation relative to the housing without being linked in rotation to the third pinion 13.

[0030] Given that the fourth pinion 14 is prevented from rotating, the second pinion 12 is also prevented from rotating relative to the housing. Thus, the spindle 10, which continues to be driven in rotation by the third 13 and the first 11 pinions, moves in translation along its axis in the direction of a retraction inside the housing.

[0031] The pitch of the threaded area of ​​the spindle 10 and the difference between the reduction ratios mentioned above result in the following: when the fourth pinion 14 is locked, the spindle 10 retracts at an appropriate speed, and when the fourth pinion 14 is engaged with the third pinion 13, the feed per revolution of the spindle 10 conforms to an appropriate value. This transmission principle is known in the prior art and will not be described in further detail.

[0032] The retraction of the spindle 10 is done until the end retraction stop 19 is in contact with the end retraction stop.

[0033] When the end stop of retraction 19 is in contact with the end stop of retraction, it acts on a distributor allowing the chamber of the cylinder 16 to be opened to the air and the motor supply valve to be closed.

[0034] The chamber 162 is no longer pressurized so that the piston 161 moves under the effect of the spring 163. The piston 161 thus drives the fourth pinion 14 into its engaged position in which the first dogs 140 are housed in the clutch housings 130 so that the fourth pinion 14 is again linked in rotation with the third pinion 13.

[0035] Even when the motor power supply is cut off, the motor rotor can continue to rotate in the direction of rotation due to its inertia. This is particularly true for high-speed motors, for example, those operating at around 60,000 rpm, and those with low internal friction. Thus, since the fourth gear 14 is in its engaged position with the third gear 13, the spindle 10 is again driven in rotation and translation along its axis in the unfolding direction.

[0036] Thus, when the kinetic energy of the motor rotor is totally consumed and the rotor finally stops rotating, the end stop 19 is no longer in contact with the end stop and the spindle 10 is slightly deployed outside the housing.

[0037] At the end of a drilling operation including the drilling phases, possibly countersinking and then spindle retraction, it is logically desired that at the moment when the motor rotor stops turning, the spindle is still in the same position corresponding to the start of a drilling cycle, i.e. the position defined by the retraction end stop against the retraction end stop.

[0038] However, given that at the end of retraction, the fourth pinion 14 is in engaged position with the third pinion 13 and that the motor rotor continues to rotate, after its supply is cut off, under the effect of the kinetic energy which it has accumulated during retraction, the spindle 10 tends to move forward and deploy a little outside the housing after retraction.

[0039] Thus, when the rotor stops rotating, the spindle can be in a partially deployed longitudinal position rather than in the position defined by the retraction end stop.

[0040] As a result, the remaining deployment stroke, which the spindle can travel in the next drilling cycle, is not total and can vary from one drilling cycle to another.

[0041] This can have a negative impact on the accuracy of drilling, in particular on the accuracy of its depth and where applicable on the quality of the countersinking.

[0042] There is therefore a need to improve this type of drill. 3. Objectives of the invention

[0043] The invention aims in particular to provide an effective solution to at least some of these different problems.

[0044] In particular, according to at least one embodiment, an objective of the invention is to make automatic feed drills more reliable.

[0045] In particular, the invention aims, according to at least one embodiment, to provide such a drill in which the spindle deployment stroke at the beginning of drilling operations is repeatable.

[0046] Another objective of the invention is, according to at least one embodiment, to provide such a drill whose drilling spindle stops at the end of retraction, in the same position.

[0047] Another objective of the invention is to provide, in at least one embodiment, such a technique which is simple and / or robust and / or economical. 4. Presentation of the invention

[0048] To this end, the invention proposes a drilling device comprising a housing containing:

[0049] - a motor comprising a rotor capable of rotating in a direction of work;

[0050] - a transmission;

[0051] - a drilling spindle capable of being driven in rotation and / or translation along a longitudinal axis of said spindle via said motor and said transmission;

[0052] said transmission comprising:

[0053] - a first pinion linked in rotation with said spindle and mounted movable in translation along said spindle along said longitudinal axis of said spindle;

[0054] - a second pinion linked to said spindle by a helical connection along said axis longitudinal of said spindle;

[0055] - a third pinion, meshing with said first pinion, and capable of being driven in rotation by said motor;

[0056] - a fourth pinion, meshing with said second pinion, said fourth pinion being mobile between:

[0057] - an engaged position in which it is rotationally linked with said third gearing by means of connection, the rotational drive of said third pinion by said motor in said working direction inducing a deployment of said spindle over a predetermined deployment stroke;

[0058] - an immobilized position in which it is rotationally bound with said housing and it is free to rotate with respect to said third pinion, a rotation of said third pinion by said motor in said working direction inducing a retraction of said spindle following a predetermined retraction stroke,

[0059] According to the invention, said fourth pinion is capable of taking an intermediate position in which it is free to rotate with respect to said housing and said third pinion in such a way that it does not exert substantially no torque on said second pinion so that a rotational drive of said third pinion by said motor induces a rotation of said second pinion at the same rotational frequency as that of said spindle.

[0060] Thus, the invention provides a technical solution to ensure that, after the spindle has been retracted, it cannot be advanced again as long as the motor rotor continues to rotate due to the dissipation of the kinetic energy it has accumulated.

[0061] The invention thus makes it possible to guarantee that, at the end of the spindle retraction phase of each drilling cycle, the spindle is systematically stopped in translation in the same position.

[0062] As a result, at the beginning of each drilling cycle, the available spindle deployment stroke is always the same.

[0063] This improves the quality of the drilling in terms of depth and, where applicable, in terms of the execution of the countersink.

[0064] According to one possible feature, a drilling device according to the invention includes means for maintaining said fourth pinion in said intermediate position at the end of said retraction stroke of said spindle.

[0065] According to one possible feature, a drilling device according to the invention comprises:

[0066] - an end-of-deployment stop carried by said pin and capable of coming into support against a deployment end stop, said deployment end stop being fixed axially with respect to said casing;

[0067] - a retraction end stop carried by said spindle and capable of coming into support against a retraction end stop, said retraction end stop being fixed axially with respect to said casing;

[0068] - a first cylinder comprising a rod adapted to axially displace said fourth pinion between the aforementioned engaged and immobilized positions,

[0069] - control means for said first cylinder configured to:

[0070] - moving said rod in a first direction inducing a displacement of said fourth pinion of said engaged position towards said immobilized position when said end-of-deployment stop touches said end-of-deployment stop;

[0071] - moving said rod in a second direction inducing a displacement of said fourth pinion of said immobilized position towards said engaged position when said end of retraction stop touches said end of retraction stop.

[0072] According to one possible feature, said first cylinder is a single-acting cylinder comprising a chamber in which said first rod is able to slide against the effect of elastic return means, said control means being able to:

[0073] - supply compressed air to said chamber of said cylinder to induce said movement in the said first direction, the said control means of the said first cylinder acting on the said distribution means to trigger the said supply when the said end-of-deployment stop touches the said end-of-deployment stop;

[0074] - vent said chamber to the open air when said retraction end stop touches said end stop for retraction, so as to induce said movement in said second direction under the effect of a release of said elastic return means of said first cylinder.

[0075] According to one possible feature, said means for retaining said fourth pinion in said intermediate position comprise:

[0076] - a shoulder formed on said rod of said first cylinder, said shoulder separating two zones of said stem:

[0077] - a first zone having a first diameter extending from the side of said piston said first cylinder;

[0078] - a second zone having a second diameter extending on the side of said fourth pinion, the said second diameter being smaller than the said first diameter;

[0079] -a latch that can occupy:

[0080] - a blocking position in which said shoulder can come into contact with said latch when said rod is moved in said second direction, the fourth pinion occupying said intermediate position when said shoulder is in contact with said latch;

[0081] - a through position in which said shoulder can freely pass through said latch when said rod is moved in said second direction.

[0082] According to one possible characteristic, said latch is:

[0083] - linked in rotation at one of its ends around an axis parallel to said rod of said first cylinder and fixed in said casing;

[0084] - connected at its other end to a second single-acting cylinder, said device including control means for said second cylinder configured to activate said second cylinder in order to move said latch to either the blocking or passing position.

[0085] According to one possible feature, said fourth pinion includes first dogs and said housing includes second dogs, said first and second dogs being configured to link said fourth pinion and said housing in rotation in said immobilized position, said second dogs being mounted to rotate freely about the axis of rotation of said fourth pinion over a predetermined angular range against the effect of third elastic return means.

[0086] The invention also covers a method of drilling an element during a drilling operation using a drilling device according to any of the above variants, said method comprising a step of positioning and holding said fourth pinion in said intermediate position in which it is free to rotate vis-à-vis said housing and said third pinion in such a way that it does not exert substantially no torque on said second pinion so that a rotational drive of said third pinion by said motor induces a rotation of said second pinion at the same rotational frequency as that of said spindle.

[0087] According to one possible embodiment, a method according to the invention comprises, following contact of said end-of-deployment stop with said end-of-deployment stop:

[0088] - a step of retracting said spindle until said end stop retraction is in contact with said retraction end stop;

[0089] - a step of stopping the supply of said motor;

[0090] - said step of moving and holding said fourth pinion in said intermediate position;

[0091] - a residual rotation stage of said rotor, under the effect of its kinetic energy, until the said rotor is immobilized after the said kinetic energy has been absorbed, the said rotor driving in rotation, during the said residual rotation stage, the said third pinion, and the said fourth pinion exerting during this rotation substantially no torque on the said second pinion so that the said spindle is immobile in translation.

[0092] According to one possible embodiment, a method according to the invention comprises:

[0093] - a step of starting said drilling device in order to carry out said drilling operation

[0094] - a step of positioning said fourth pinion in said engaged position at the end of the said device start-up stage and prior to the execution of the said drilling operation. 5. Description of the figures

[0095] Other features and advantages of the invention will become apparent from the following description of particular embodiments, given by way of simple illustrative and non-limiting example, and the accompanying drawings, among which:

[0096] [Fig-1] [Fig. 1] illustrates a partial longitudinal cross-sectional view of a drill according to the prior art;

[0097] [Fig.2] [Fig.2] illustrates a partial perspective view of the inside of a drill according to a first embodiment of the invention;

[0098] [Fig.3] [Fig.3] illustrates a longitudinal and partial cross-sectional view of the drill of [Fig.2] whose spindle is totally retracted with the fourth pinion in an intermediate position;

[0099] [Fig.4] [Fig.4] illustrates a partial longitudinal cross-sectional view of the drill of [Fig.2] whose spindle is being deployed and the fourth pinion in the engaged position;

[0100] [Fig.5] [Fig.5] illustrates a partial longitudinal cross-sectional view of the drill of [Fig.2] with the spindle fully extended and the fourth pinion in the immobilized position;

[0101] [Fig.6] [Fig.6] illustrates a partial longitudinal cross-sectional view of the drill of [Fig.2] whose spindle is being retracted and the fourth pinion in the immobilized position;

[0102] [Fig.7] [Fig.7] illustrates a partial longitudinal cross-sectional view of the drill of [Fig.2] whose spindle is close to full retraction and the fourth pinion in an intermediate position;

[0103] [Fig.8] [Fig.9] Figures 8 and 9 illustrate cross-sectional and partial views of the drill of [Fig.2] whose latch is in the unlocked position;

[0104] [Fig. 10] [Fig. 11] Figures 10 and 11 illustrate cross-sectional and partial views of the drill of [Fig.2] whose distributor is in a state of open air;

[0105] [Fig. 12] [Fig. 13] Figures 12 and 13 illustrate cross-sectional views of the drill of [Fig.2] with the latch in the locked position;

[0106] [Fig. 14] [Fig. 15] Figures 14 and 15 illustrate cross-sectional views of the drill of [Fig.2] whose distributor is in a state of open air;

[0107] [Fig. 16] [Fig. 16] illustrates a partial longitudinal cross-sectional view of the inside of a drill according to a second embodiment of the invention equipped with a vibrator;

[0108] [Fig. 17] [Fig. 17] illustrates a detailed view of [Fig. 16];

[0109] [Fig. 18] [Fig. 18] illustrates a flowchart of the operation of a device according to the invention.

[0110] 6. Description of particular embodiments 6.1. Architecture

[0111] An example of the embodiment of a drill according to the invention is presented in relation to figures 2 to 15.

[0112] As shown in these figures, such a drill typically comprises a housing 20 outside of which a spindle 10 can be deployed. This spindle is adapted to carry a drill bit at its end near the retraction stop. This drill bit is coaxial with the spindle and rotationally fixed to it.

[0113] The pin 10 includes longitudinal grooves 101 and is threaded 102 along its entire length.

[0114] Pin 10 is equipped with: - of a deployment end stop 18 capable of bearing against a fixed deployment end stop in translation relative to the housing along the spindle axis, in this case said stop is constituted by the end of the first pinion 11 for the devices shown in figures 2 to 15, and - of a retraction end stop 19 capable of bearing against a fixed retraction end stop in translation relative to the housing along the axis of the spindle, in this case said stop is constituted by the end of the second pinion 12 for the devices shown in figures 2 to 15.

[0115] The drill includes a motor (not shown) equipped with a rotor R. This could, for example, be a pneumatic (vane) motor, a pneumatic turbine, or an electric motor. In this embodiment, the motor is a pneumatic turbine connected to a compressed air supply valve.

[0116] The drill includes a transmission. This transmission is interposed between the motor rotor and the spindle. It is capable of transforming a rotational movement of the rotor in the working direction (i.e., drilling direction) into a rotational and / or translational movement of the output spindle 10 along the same axis, i.e., its longitudinal axis X.

[0117] This transmission includes:

[0118] - a first pinion 11 coaxial with the spindle 10 and provided with internal splines cooperating with the external longitudinal grooves of the spindle 10 (the first pinion and the spindle are thus linked by a linear connection along the longitudinal axis of the spindle);

[0119] - a second pinion 12 coaxial with the spindle 10 and provided with an internal thread cooperating with the thread 102 of the spindle 10 (the second pinion and the spindle are thus linked by a helical connection along the longitudinal axis of the spindle);

[0120] - a third pinion 13 with an axis parallel to the spindle 10, meshing with the first pinion 11 following a first transmission ratio and driven in rotation by the drill motor directly or via a pair of bevel gears 15 and / or one or more epicyclic gear trains (not shown);

[0121] - a fourth pinion 14 with an axis parallel to the spindle 10, meshing with the second pinion 12 following a second transmission ratio different from the first ratio.

[0122] In this embodiment, the first pinion 11 acts as a deployment end stop and the second pinion 12 acts as a retraction end stop.

[0123] The fourth pinion 14 comprises first dog clutches 140, shaped like ogives, capable of cooperating with clutch housings 130 of complementary shape arranged opposite each other on the third pinion 13 in such a way that when the dog clutches 140 are housed in the clutch housings 130, the fourth pinion 14 and the third pinion 13 are rotationally linked. The first dog clutches and the clutch housings thus constitute means of linking the rotation of the third and fourth pinions.

[0124] The shape of the first dogs 140 and the clutch housings 130 is chosen in such a way that as soon as the fourth pinion tends to rotate relative to the third pinion, the first dogs 140 tend to move out of the clutch housings 130, inducing that the fourth pinion 14 tends to move away, along its axis of rotation, from the third pinion 13. This principle, known in itself to a person skilled in the art, is described for example in patent documents FR 2 881 366 and FR 2 918 592.

[0125] The fourth pinion 14 also includes second dogs 141 of complementary shape to locking dogs 17 fixed relative to the drill housing.

[0126] In one embodiment, the locking dogs 17 are mounted to rotate freely relative to the housing along the axis of rotation of the fourth pinion 14 over a predetermined angular range against the effect of elastic return means. These elastic return means here take the form of elastomer springs 170 housed in grooves 171 in ring portions formed in the housing, against one end of which fingers integral with the locking dogs 17 bear.

[0127] The fourth pinion 14 is fixed in translation to the rod 160 of a piston 161 of a first monostable (i.e., single-acting) cylinder 16, and free in rotation relative to this rod. This piston 161 is movable in translation along the axis of rotation of the fourth pinion in a chamber 162 such that the fourth pinion 14 can assume:

[0128] - an engaged position in which the first 140 dog clutches are housed in the clutch housings 130 and second dog clutches 141 do not cooperate with the locking dogs 17 so that the fourth pinion 14 is rotationally linked with the third pinion 130 and is free to rotate relative to the housing, and

[0129] - a stationary position in which the first 140 dog clutches do not cooperate with the clutch housings 130 and the second dogs 141 cooperate with the locking dogs 17 so that the fourth pinion 14 is immobile in rotation relative to the housing and is not linked in rotation with the third pinion 13.

[0130] The fourth pinion 14 can also assume an intermediate position. In this intermediate position, it is interposed between the third pinion 13 and the locking dogs 17. The first dogs 140 of the fourth pinion 14 are then located outside the clutch housings 130 of the third pinion 13, so that the fourth pinion 14 is not rotationally bound to the third pinion 13. Furthermore, the second dogs 141 do not cooperate with the locking dogs 17 of the housing, so that the fourth pinion 14 is also not rotationally bound to the housing. In other words, in this intermediate position, the fourth pinion 14 is free to rotate relative to the third pinion 13 and the housing.

[0131] To move the fourth pinion 14 from its engaged position to its immobilized position, the side facing the fourth pinion 14 of the chamber 162 of the cylinder 16 is supplied with compressed air so as to move the fourth pinion 14 away from the third pinion 13 against the effect of the spring 163. To do this, the drill includes a distributor (not shown) equipped with a spool, this distributor being connected to a source of compressed air (not shown), and being able to take a supply state in which it is able to supply compressed air to the chamber 162 of the cylinder 16 to induce this movement of the fourth pinion 14.

[0132] The drill includes a mechanism for acting on the distributor to place it in its supply state for chamber 16 when, due to the translational blocking of the spindle 10 by the arrival of the end-of-deployment stop 18 bearing against the end-of-deployment stop 11, the fourth pinion 14 rotates relative to the third pinion 13 and moves away from the third pinion 13 towards its immobilized position. This mechanism transforms such a movement of the fourth pinion 14 into a movement of the distributor spool, placing it in a position in which the distributor is in its supply state and consequently supplies compressed air to chamber 162 of the cylinder 16. A mechanism of this type is known to those skilled in the art and is, for example, described in patent documents FR 2 881 366 and FR 2 918 592.

[0133] To move the fourth pinion 14 from its stationary position to its engaged position, the distributor spool is moved so as to put the distributor in a venting state in which it is able to vent the chamber 162 of the jack 16 so as to bring the fourth pinion 14 closer to the third pinion 13 under the effect of the spring 163.

[0134] The rod 160 of the cylinder 16 includes a first end connected to the piston 161. Starting from the piston 161, the rod 160 includes a first section having a first diameter 1600 extended by a second section having a second diameter 1601. The first diameter is larger than the second diameter. A shoulder 1602 is provided between the sections with larger diameters 1600 and smaller diameters 1601.

[0135] The drill includes a locking element. This locking element is in the form of a latch 23 shaped like a portion of a ring. This latch 23 is mounted to rotate freely about an axis 24 parallel to the axis of the spindle 10 between:

[0136] - a passing position in which it is away from the rod 160 of the cylinder 16 so well that the shoulder 1602 can freely pass the latch 23 when the rod 161 of the cylinder 16 moves the fourth pinion towards its engaged position;

[0137] - a locking position in which it is supported against the rod 160 of the cylinder 16 if although the shoulder 1602 can come into contact with the latch 23 when the rod 161 of the cylinder 16 moves the fourth pinion to its engaged position.

[0138] A spring acts on the latch 23 to tend to maintain it in its locking position.

[0139] The drill includes a second monostable (i.e. single-acting) cylinder 25 equipped with a rod 250 which, when it is deployed against the effect of the spring, acts on the latch 23 to move it into its passing position.

[0140] The shoulder 1602 is located along the rod 160 of the first cylinder 16 in such a way that when the latch 23 is in its locking position, bearing against the small diameter portion 1601 of the rod 160 and abutting against the shoulder 1602, the fourth pinion 14 is in the intermediate position.

[0141] The drill includes means for actuating the distributor adapted to place it in its venting state from chamber 162 of the first cylinder 16. These actuating means include: - an actuator 21 comprising a finger 22 movable in a chamber 23 against the effect of a spring 24, and - an actuation element 26 of the finger 22 of the actuator 21.

[0142] This actuating element 26 has the form of a sleeve that is mounted to rotate freely around the distal end of the spindle, i.e., the end intended to be connected to a cutting tool. It is also mounted to translate freely along the distal end of the spindle. Elastic return means, such as spring washers 27, are interposed between the actuating element 26 and the second pinion 12. These washers 27 tend to oppose the approach of the actuating element 26 to the second pinion 12. The actuating element 26 has On its outer peripheral contour there is a hollow portion 260 of small diameter and a projecting portion 261 of large diameter. These portions define a cam profile capable of acting on the finger 22 of the actuator 21 to move it from one of its positions to another.

[0143] The actuating element 26 is mounted to move in translation along the spindle 10 between:

[0144] - an inactive position in which it is held away from the second pinion 12, supported against a stop 200 formed in the housing, such that the end of the finger 22 is in the hollow portion 260 so that the finger 22 is in its supply position in which the distributor is in its compressed air supply state to the chamber 162 of the cylinder 16, and

[0145] - a venting position in which it is brought closer to the second pinion 12, against the effect of the spring washers 27, in such a way that the end of the finger 22 is against the protruding portion 261 so that the finger 22 is in its venting position in which the distributor is in its venting state of the chamber 162 of the cylinder 16. This venting position of the actuating element 26 is reached when the retracted spindle 10 compresses the spring washers 27 between the second pinion 12 and the actuating element 26 via the end-of-retraction stop 19.

[0146] As long as the retraction end stop 19 is not bearing against the retraction end stop 12 via the actuating element 26, the spring washers 27 act on the actuating element 26 to move it away from the second pinion 12 and hold it in its inactive position in which the end of the finger 22 is against the hollow portion 260, so that the distributor is in its supply state for the chamber 162 of the cylinder 16. At the end of the retraction of the spindle 10, the retraction end stop 19 bears against the actuating element 26 and moves it translationally along the spindle 10 towards the second pinion 12 against the effect of the spring washers 27. When the retraction end stop 19, the actuating element 26, and the second pinion 12 are in contact with each other, the retraction is complete and the actuating element 26 is in its open-air position.The rod of the finger 22 rests against the projecting portion 261 of the actuating element 26 so that the distributor is in its state of venting the chamber 162 of the cylinder 16 to the atmosphere.

[0147] The drill includes an operating trigger. This operating trigger is movable between: - a relaxed position; - an initial position allowing the latch 23 to move into its forward position; - a motor supply position to perform a drilling cycle.

[0148] The drill includes control means 300 comprising pneumatic logic components, in particular the distributor, which conventionally allow control of the operation of the pneumatic functions of the drill.

[0149] In this embodiment, these control means are designed to: - when the trigger is in the initialization position, actuate the second cylinder 25 so as to place and maintain, as long as the trigger is pressed by an operator, the locking element 26 in its unlocked position, to allow the fourth pinion to move from its intermediate position to its engaged position; - When the trigger is in the motor power position, command the opening of the motor power valve, which remains open after the trigger is released until the end of the drilling cycle or the activation of an emergency stop, so as to: - rotate the third 13 and fourth 14 pinions relative to each other to allow the first dogs 140 of the fourth pinion 14 to synchronize with the clutch housings 130 of the third pinion 13 and to gradually come into contact with them; - to move the spindle to perform a drilling cycle.

[0150] The engine starts after the fourth pinion has made contact with the third pinion, so that the synchronization of the first dogs 140 with the clutch housings 130 occurs at a moderate rotational speed of the third pinion, thus avoiding shocks that could damage the first dogs and the clutch housings. This time offset is achieved by two means: - The trigger is pressed in two stages, i.e., initial position followed by motor power-up position. The motor's power supply valve is therefore opened after the fourth gear is released. - a small-section pneumatic conduit between the trigger and the motor's supply valve opening control. This small cross-section induces a pressure drop on the airflow controlling the valve opening and therefore a slight delay in opening.

[0151] The trigger is held in the motor power position for a short time to start the drilling cycle which continues to run until its completion after the operator releases the trigger which returns to the released position. 6.2. Operation

[0152] This type of drill can also be used to make holes with or without countersinking at the hole entry.

[0153] The logic diagram placed in [Fig.18] illustrates the operation of the device as described below.

[0154] 6.2.1. Drill stopped before starting: fourth gear in position intermediate

[0155] Before the drill starts to perform drilling, the spindle 10 is fully retracted so that the end-of-retraction stop 19 is in contact with the actuating element 26 and compresses the elastic washers 27 between it and the second pinion 12 which constitutes the end-of-retraction stop.

[0156] The actuation element 26 is in its open position in which the finger 22 is in its open position.

[0157] The distributor is in its state of venting chamber 162 of the first cylinder 16.

[0158] The spring 163 acts on the piston 161 in such a way as to tend to bring the fourth pinion 14 closer to the third pinion 13.

[0159] The control means do not supply the second cylinder 25 in such a way that the spring maintains the locking element 23 in its locking position in which it is supported against the small diameter area 1601 of the rod of the cylinder 16 and against the shoulder 1602.

[0160] The fourth pinion 14 is thus held in an intermediate position. 6.2.2. Starting the drill

[0161] i. Initialization phase: transition of the fourth pinion from the intermediate position to the engaged position

[0162] To start the drill, an operator activates the trigger so as to place it momentarily in the initialization position and then in its motor power supply position.

[0163] The control means actuate a second cylinder 25 to place the locking element 23 in its open position, against the effect of the spring. This has the effect of moving the locking element 23 away from the rod 160 of the cylinder 16 such that it extends beyond the large diameter area 1600.

[0164] This releases the movement of the piston 161 which, under the effect of the spring 163, tends to move the fourth pinion 14 from its intermediate position to its engaged position.

[0165] Then after a short period of time the engine starts, causing the fourth pinion to finalize its movement into its clutch position in which it is rotationally linked with the third pinion.

[0166] The operator releases the trigger, which returns to its released position.

[0167] When the operator releases the trigger, the control means cut off the power supply to the second cylinder 25 so that the locking element 23 comes supported against the large diameter area 1600 of the rod 160 of the first cylinder 16 under the effect of the spring, while the motor supply valve remains in the open position. ii. Drilling phase

[0168] The fourth pinion 14, which is rotationally linked with the third pinion 13 and the motor rotates at its nominal rotational frequency.

[0169] The first pinion 11 is driven in rotation by the third pinion 13 so that the spindle 10 is driven in rotation about its longitudinal axis.

[0170] The second pinion 12 is driven in rotation by the fourth pinion 14.

[0171] The reduction ratio between the first 11 and the third pinion 12 is different of the reduction ratio between the second pinion 12 and the fourth pinion 14. Thus, taking into account the helical connection between the second pinion 2 and the spindle, the spindle is driven in translation along its axis and extends out of the housing until the end-of-deployment stop 18 is in contact with the first pinion 11 which constitutes the end-of-deployment stop.

[0172] During this period the drill is driven along a helical trajectory with an adequate cutting speed and feed rate, thus achieving the expected drilling.

[0173] iii. End of spindle deployment: pinion moving into the immobilized position

[0174] When the end-of-deployment stop 18 is against the end-of-deployment stop, the deployment of the spindle 10 is stopped. The third 13 and fourth 14 pinions therefore tend to rotate at different speeds. Thus, given the ogive shape of the first dog clutches 140 of the fourth pinion 14, these dog clutches 140 tend to disengage from the clutch housings 130 of the third pinion 13, so that the fourth pinion 14 moves away from the third pinion 13 towards its immobilized position.

[0175] This relative distance of the fourth pinion 14 from the third pinion 13 causes the distributor to switch to its supply state for the chamber 162 of the cylinder 16, such that the side of the chamber 162 of the cylinder 16 facing the fourth pinion 14 is supplied with compressed air. As a result, the piston 162 of the cylinder 16, against the effect of the spring 163, drives the fourth pinion 14 into its immobilized position, in which its second dogs 141 cooperate with the locking dogs 17. The fourth pinion 14 is then rotationally immobile relative to the housing and is not rotationally bound to the third pinion 13.

[0176] During this movement, the locking element 23 (i.e., the latch), which is held against the rod 160 of the first cylinder by the spring, slides first against the large-diameter area 1600 and then against the small-diameter area 1601 of the rod 160. Thus, when the fourth pinion 14 is in the immobilized position, The locking element 23 is supported against the small diameter area 1601 of the rod 160 while being away from the shoulder 1602.

[0177] In the variant in which the locking dogs 17 are mobile against the effect of the elastomer springs 170, the cooperation of the second dogs 141 with the locking dogs 17 is dampened.

[0178] Given that the fourth pinion 14 is prevented from rotating, the second pinion 12 is also prevented from rotating. Thus, the spindle, continuing to be driven in rotation by the third pinion 13 and the first pinion 11, moves in translation along its axis in the direction of retraction inside the housing.

[0179] iv. End of spindle retraction: passage of the fourth pinion into the intermediate position

[0180] The retraction of the spindle 10 takes place until the end-of-retraction stop 19 moves the actuating element 26 into its venting position in the open air by compressing against each other the end-of-stroke stop 19, the actuating element 26 and the second pinion 12 which constitutes the end-of-retraction stop.

[0181] The spindle 10 is then completely retracted and the actuating element 26 places the finger 22 in its venting position, in which the distributor is in its venting state of the chamber 162 of the cylinder 16, while the control means cut off the power supply to the motor.

[0182] The chamber 162 of the first cylinder 16 empties while the piston 161 moves in the chamber 162 under the effect of the spring 163 inducing a displacement of the fourth pinion 14 from its immobilized position towards its engaged position.

[0183] During this movement of the piston 162, the shoulder 1602 comes against the locking element 23, thus locking the fourth pinion 14 in its intermediate position in which it is free to rotate with respect to the third pinion 13 and the housing.

[0184] Even when the motor power supply is cut off, the motor rotor can continue to rotate in the direction of rotation due to its inertia. This is particularly true for high-speed motors, for example, those operating at around 60,000 rpm, and those with low internal friction. However, since the fourth pinion 14 is in its intermediate position where it is free to rotate, the rotation of the third pinion 13, due to the dissipation of the rotor's kinetic energy, induces a rotation of the spindle 10 but no translational movement of the spindle itself.

[0185] In this way, the invention makes it possible to guarantee that at the end of the retraction phase of a drilling cycle, and the complete shutdown of the motor after the dissipation of its kinetic energy, the spindle is systematically fully retracted so that at The drilling cycle starts when the available spindle extension stroke is complete. Thus, at the start of each drilling cycle, the available spindle extension stroke is complete.

[0186] The drill is then in the state it was in before it started so that a new cycle can be started by activating the trigger. 6.3. Terminology

[0187] The means for maintaining the fourth pinion 14 in the intermediate position at the end of the spindle retraction stroke include in particular the shoulder 1602, the locking element 23 (or latch) and the spring which tends to hold it against the rod 160 of the first cylinder 16.

[0188] The means for driving the fourth pinion 14 in the intermediate position include in particular the spring 163 which acts on the piston 161.

[0189] The means for maintaining the fourth pinion 14 in the engaged position include in particular the spring 163 which acts on the piston 161.

[0190] The means for maintaining the fourth pinion 14 in the immobilized position include in particular the first cylinder 16 and its supply distributor. 6.4. Integration of a vibrant

[0191] An example of the embodiment of a drill according to the invention equipped with a vibrator is presented in relation to Figures 16 and 17. 6.4.1. Vibrating Function

[0192] The vibrator is a mechanical device which, when used on a drilling device, adds an alternating component to the feed motion of the spindle. This component allows the cutting edges of the drill bit attached to the spindle to emerge from the material several times per revolution, thus fragmenting the chips. This makes it easier to extract the chips from the hole during drilling and reduces the risk of clogging or damage to the hole wall.

[0193] Some drilling operations require finishing with a countersink in the same operation. This countersink is designed to hold the conical head of a rivet, and perfect alignment must exist between the cones of the rivet and the countersink to ensure a perfect seal of the drilled structure. It is therefore important that the surface of the countersink be free of any ripples that would result from the reciprocating feed component. The vibratory feed must also be deactivated at the end of the countersinking process to obtain a perfect taper. 6.4.2. Composition of the vibrating

[0194] The vibrator is presented as a roller stop, one of whose tracks has undulations, so when the tracks rotate relative to each other, the thickness of the vibrator varies between minimum and maximum values, several times per revolution.

[0195] This is achieved by the design shown [Fig.16].

[0196] The first pinion 11 is guided in rotation relative to the housing 20 by means of a bearing 30. The second pinion 12 is guided in rotation relative to the housing 20 by a bearing 31. The first 11 and second 12 pinions are guided in rotation relative to each other by means of a ball thrust bearing 32.

[0197] The vibrator includes a first track 33, without surface undulation, bearing against the bearing 30. It also includes rollers 34 which bear against the first track 33. The vibrator further includes a second track 35 having surface undulations.

[0198] The drill includes a ball bearing 37 which acts as the end-of-extension stop. This ball bearing 37 is mounted on a ring 39 fixed relative to the housing 20. This ring 39 includes, oriented towards the bearing 30, a surface 390 against which one end of a compression spring 40, called the countersinking finalization spring, bears. The other end of the spring 40 is housed in a ring 41 which bears against the bearing 30.

[0199] A spring 36 is arranged between the bearing 31 and the second pinion 12 to tend to press the elements constituting the vibrating against each other and against the bearing 30. 6.4.3. Operation of the vibrating mechanism i. In drilling action

[0200] During drilling, the stacking of the following parts is used to generate the reciprocating feed component (vibrating feed), from left to right in [Fig.16]: - the outer ring of the bearing 30, itself linked to the housing 20 of the drilling device. - the first track 33 of the vibrant - the 34 rollers of the vibrating - the second track 35 of the vibrant - the first pinion 11 generating the rotation of the spindle 10 - the second pinion 12 generating the rotation of the spindle 10, this pinion 12 is separated from the first pinion 11 by a row of balls 320 acting as a stop. - the return spring 36

[0201] During drilling action, due to the rotation of the first pinion 11 relative to the housing 20, the tracks 33, 35 of the vibrator rotate relative to each other, this inducing an alternating axial movement of the first pinion 11. This movement is transmitted to the second pinion 12 and then to the spindle 10, which induces the alternating feed component at the level of the drill lips. ii. In the final stages of the countersinking

[0202] During the finalization of the countersink, the end-of-deployment stop 18 comes into contact with the end-of-deployment stop, i.e., in this embodiment, the ball stop 37. The axial movement of the spindle 10 is interrupted while the spindle 10 continues to rotate through an angle of approximately one revolution. This allows the countersink surface to be finished without waviness.

[0203] Meanwhile, the second pinion 12 continues to rotate. With the spindle 10 axially stationary, the second pinion 12 moves under the action of the spindle 10's threads in the direction of the deployment end stop 18. To allow this movement, the countersink finishing spring 40 compresses, giving the countersink time to be completed. When the countersink finishing spring 40 can no longer compress, the second pinion 12 stops moving axially and begins to rotate at the same speed as the first pinion 11, triggering the retraction of the spindle 10 as explained above.

[0204] The stiffness of the countersink finishing spring 40 is also sufficiently strong so that it does not collapse during the drilling action and does not disrupt the generation of the reciprocating feed component.

Claims

1. Demands Drilling device comprising a housing containing: - a motor comprising a rotor capable of rotating in a working direction; - a transmission; - a drilling spindle capable of being driven in rotation and / or translation along a longitudinal axis of said spindle via said motor and said transmission; said transmission comprising: - a first pinion linked in rotation with said spindle and mounted movable in translation along said spindle along said longitudinal axis of said spindle; - a second pinion linked to said spindle by a helical connection along said longitudinal axis of said spindle; - a third pinion, meshing with said first pinion, and capable of being driven in rotation by said motor; - a fourth pinion, meshing with said second pinion, said fourth pinion being movable between: - a engaged position in which it is linked in rotation with said third gear by means of linkage, the rotational drive of said third pinion by said motor in said working direction inducing a deployment of said spindle over a predetermined deployment stroke; - a stationary position in which it is rotationally bound to said housing and is free to rotate with respect to said third pinion, a rotation of said third pinion by said motor in said working direction inducing a retraction of said spindle following a predetermined retraction stroke, characterized in that said fourth pinion is capable of assuming an intermediate position in which it is free to rotate with respect to said housing and said third pinion in such a way that it exerts substantially no torque on said second pinion, so that a rotational drive of said third pinion by said motor induces a rotation of said second pinion at the same rotational frequency as that of said spindle, said device comprising: - means of maintaining said fourth pinion in said intermediate position at the end of said retraction stroke of said spindle. - a deployment end stop carried by said spindle and capable of bearing against a deployment end stop, said deployment end stop being fixed axially with respect to said housing; - a retraction end stop carried by said spindle and capable of bearing against a retraction end stop, said retraction end stop being fixed axially with respect to said housing; - a first cylinder comprising a rod capable of axially displacing said fourth pinion between said engaged and immobilized positions, - control means for said first cylinder configured for: - move said rod in a first direction inducing a displacement of said fourth pinion from said engaged position to said immobilized position when said end-of-deployment stop touches said end-of-deployment stop; - moving said rod in a second direction inducing a displacement of said fourth pinion from said immobilized position to said engaged position when said end-of-retraction stop touches said end-of-retraction stop, said means of retaining said fourth pinion in said intermediate position include: - a shoulder formed on said rod of said first cylinder, said shoulder separating two zones of said rod: - a first zone having a first diameter extending from the side of said piston of said first cylinder; - a second zone having a second diameter extending from the side of said fourth pinion, said second diameter being smaller than said first diameter; -a latch that can occupy: - a locking position in which said shoulder can come into contact with said latch when said rod is moved in said second direction, the fourth pinion occupying said intermediate position when said shoulder is in contact with said latch; - a passing position in which said shoulder can freely pass through said latch when said rod is moved in said second direction, said latch being: - rotationally bound at one of its ends around an axis parallel to said rod of said first cylinder and fixed in said housing; - connected at the other of its ends to a second single-acting cylinder, said device comprising control means for said second cylinder configured to activate said second cylinder in order to move said latch to one or the other of the blocking or passing positions.

2. A drilling device according to claim 1, wherein said first cylinder is a single-acting cylinder comprising a chamber in which said first rod is able to slide against the effect of elastic return means, said control means being able to: - supply compressed air to said chamber of said cylinder to induce said displacement in said first direction, said control means of said first cylinder acting on said distribution means to trigger said supply when said end-of-deployment stop touches said end-of-deployment stop; - vent said chamber to the air when said end-of-retraction stop touches said end-of-retraction stop, so as to induce said displacement in said second direction under the effect of a release of said elastic return means of said first cylinder.

3. Device according to any one of claims 1 or 2 wherein said fourth pinion comprises first dogs and said housing comprises second dogs, said first and second dogs being configured to link said fourth pinion and said housing in rotation in said immobilized position, said second dogs being mounted movable in rotation about the axis of rotation of said fourth pinion over a predetermined angular range against the effect of third elastic return means.

4. A method for drilling an element during a drilling operation using a drilling device according to any one of claims 1 to 3, said method comprising a step of positioning and holding said fourth pinion in said intermediate position in which it is free to rotate with respect to said housing and said third pinion in such a way that it does not exert appreciably any torque on said second pinion so that a rotational drive of said third pinion by said motor induces a rotation of said second pinion at the same rotational frequency as that of said spindle, said method comprising: - a step of starting said drilling device in order to carry out said drilling operation, - a step of positioning said fourth pinion in said engaged position at the end of said starting step of the device and prior to carrying out said drilling operation, said positioning step comprising a step of activating said second cylinder by said control means to move said latch into its passing position.

5. The method according to claim 4 comprises, following contact of said deployment end stop with said deployment end stop: - a step of retracting said spindle until said retraction end stop is in contact with said retraction end stop; - a step of stopping the supply of said motor; - said step of moving and holding said fourth pinion in said intermediate position; - a step of residual rotation of said rotor, under the effect of its kinetic energy, until said rotor is immobilized after said kinetic energy is absorbed, said rotor driving said third pinion in rotation during said residual rotation step, and said fourth pinion exerting substantially no torque on said second pinion during this rotation so that said spindle is stationary in translation.

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