Drilling device comprising a sliding gear actuated by a bistable element

Abstract

The invention relates to a drilling device comprising a sliding gear that can move between an engaged position and an immobilized position, the device comprising holding means for holding the fourth gear in its engaged position and in its immobilized position, and first movement means for moving the fourth gear from its engaged position to its immobilized position, and vice versa, the holding means and the first movement means comprising a bistable elastic element capable of assuming two stable states, namely: - an engagement state in which it holds the fourth gear in its engaged position, and - an immobilization state in which it holds the fourth gear in its immobilized position.

Description

[0001] Title: Sliding pinion drilling device actuated by a bistable element

[0002] 1. Scope of the invention

[0003] The field of the invention is that of drilling devices.

[0004] 2. Prior art

[0005] Drilling devices, also called drills, are commonly used in various industrial sectors, such as aerospace, to perform a variety of tasks. In this sector, drills with automatic feed are frequently used; these are drills whose drilling spindle (or output spindle), which carries a cutting tool, can be driven simultaneously in translation and rotation along its longitudinal axis.

[0006] Patent documents FR-A1-2 881 366 and FR-A1-2 918 592 describe such drills, for example.

[0007] With reference to Figure 1, a drill of this type typically includes:

[0008] - a 10mm grooved and threaded output spindle;

[0009] - a pneumatic motor (not shown), connected to a compressed air supply valve, or an electric motor, equipped in both cases with an R rotor;

[0010] - 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.

[0011] This T transmission includes:

[0012] - a first pinion 11 coaxial with the spindle 10 and equipped with internal splines cooperating with the external splines of the spindle 10;

[0013] - a second pinion 12 coaxial with the spindle 10 and equipped with an internal tapping cooperating with the thread of the spindle 10;

[0014] - a third pinion 13 with an axis parallel to the spindle 10, meshing with the first pinion 11 according to 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 and / or spur gears (not shown);

[0015] - a fourth pinion 14 with an axis parallel to the spindle 10, meshing with the second pinion 12 according to a second transmission ratio different from the first ratio.

[0016] The fourth pinion 14 includes first dog clutches 140 with a pointed shape, capable of cooperating with complementary clutch housings 130 formed 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. As will be described in more detail later, the pointed shape of the first dog clutches enables them to disengage the rotational link when the fourth and third pinions begin to separate.

[0017] More specifically, the separation of the third and fourth gears is used to trigger the power supply to a cylinder which completes the movement of the fourth gear towards its immobilized position.

[0018] From the stage where the third and fourth pinions are still stuck together, the shape of the ogives allows, under the increase of a torque between the third and fourth pinions, to exert a force between the third and fourth pinions tending to separate them.

[0019] This torque occurs when the spindle reaches the end of its extension and the motor continues to exert a driving torque on the third gear. At this point, the spindle can no longer advance, and the first and second gears are locked in rotation relative to each other. Since the reduction ratios between the first and third gears, and between the second and fourth gears, are different, the third and fourth gears tend to rotate at different speeds. This is how the torque between these third and fourth gears is created.

[0020] The fourth pinion 14 also includes second dog clutches 141 with a shape complementary to the locking dog clutches 17 fixed relative to the drill housing C. These dog clutches do not have a shape capable of disengaging the fourth pinion from the housing.

[0021] 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 within a chamber 162 of a monostable cylinder 16 so as to be able to:

[0022] - 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

[0023] - a stationary position in which the first dogs 140 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 stationary in rotation relative to the housing C and movable in rotation relative to the third pinion 13. To move the fourth pinion 14 from its engaged position to its stationary 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.

[0024] 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.

[0025] The spindle 10 is equipped 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.

[0026] When starting the drill to perform a drilling operation with or without countersinking, the end stop retraction 19 is in contact with the end stop retraction (i.e. the second pinion 12) so that the spindle 10 is completely retracted.

[0027] The fourth pinion 14 is in the engaged position in which it is rotationally linked with the third pinion 13.

[0028] 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 to the third pinion 13, rotates at the same speed.

[0029] The first pinion 11 is driven in rotation by the third pinion 13 so that the spindle 10 is driven in rotation along its longitudinal axis.

[0030] The second pinion 12 is driven in rotation by the fourth pinion 14.

[0031] The reduction ratio between the first 11 and the third pinion 12 is different from 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).

[0032] When the deployment end stop 18 is against the deployment end stop, the deployment of the spindle 10 is halted, forcing the second gear 12 to rotate at the same speed as the spindle 10 and the first gear 11. The third 13 and fourth 14 gears therefore tend to rotate at different speeds due to the difference in reduction ratios mentioned above. Consequently, given the ogive shape of the first dog clutches 140 of the fourth gear 14, these dog clutches 140 tend to disengage from the clutch housings 130 of the third gear 13, causing the fourth gear 14 to move away from the third gear 13 towards its stationary position.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] The retraction of the spindle 10 occurs until the end-of-retraction stop 19 is in contact with the end-of-retraction stop.

[0037] 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 vented to the air and the motor supply valve to be closed.

[0038] The chamber 162 is no longer pressurized, so 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.

[0039] The drilling device is now ready to perform another drilling operation. These drilling devices are very efficient. However, whether the drill motor is pneumatic or electric, a pneumatic actuator is used to move the fourth pinion into its locked position after the spindle has fully extended.

[0040] This therefore systematically implies the need to supply the drill with compressed air, which limits the use of such a drill in places with a compressed air supply infrastructure.

[0041] When a drill has a pneumatic motor, it makes sense that it must be used in locations equipped with a compressed air supply infrastructure. The fact that the actuator used to move the fourth gear is pneumatic does not, in itself, pose a problem.

[0042] On the other hand, when the drill motor is electric, the fact that the actuator used to move the fourth pinion is pneumatic implies having both a compressed air supply infrastructure and an electricity supply infrastructure.

[0043] These self-feeding drills of the prior art can thus be improved, in particular to not require a pneumatic actuator to ensure the movement of the fourth pinion.

[0044] 3. Objectives of the invention

[0045] The invention aims in particular to provide an effective solution to at least some of these different problems.

[0046] In particular, according to at least one embodiment, an objective of the invention is to optimize automatic feed drills.

[0047] In particular, the invention aims, according to at least one embodiment, to provide such a drill in which the movement of the fourth pinion does not require a supply of compressed air.

[0048] Another objective of the invention is, according to at least one embodiment, to provide such a drill which can operate entirely electrically without requiring pneumatic power.

[0049] 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.

[0050] 4. Presentation of the invention

[0051] To this end, the invention proposes a drilling device comprising a housing containing:

[0052] - a motor comprising a rotor capable of rotating in a direction of operation; - a transmission;

[0053] - a drilling spindle capable of being driven in rotation or in rotation and translation about a longitudinal axis of said spindle via said motor and said transmission; said transmission comprising:

[0054] - a first pinion linked in rotation with said spindle and mounted movable in translation along said spindle along said longitudinal axis of said spindle;

[0055] - a second pinion linked to said spindle by a helical connection along said longitudinal axis of said spindle;

[0056] - a third pinion, meshing with said first pinion, guided in rotation relative to said casing and capable of being driven in rotation by said motor;

[0057] - a fourth pinion, guided in rotation and translation relative to said housing, meshing with said second pinion, said fourth pinion being movable between:

[0058] - a engaged position in which it is linked in rotation with said third gear by first 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;

[0059] - a fixed position in which it is rotationally linked with said housing by second means of connection and is free in rotation 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.

[0060] According to the invention, such a device comprises means for retaining said fourth pinion in its engaged position and in its immobilized position, and first means for moving said fourth pinion from its engaged position to its immobilized position, and vice versa, said retaining means and said first means of movement comprising a bistable elastic element capable of taking two stable states, namely:

[0061] - a clutch state in which it maintains said fourth pinion in its engaged position, and - an immobilization state in which it maintains said fourth pinion in its immobilized position.

[0062] Thus, according to this aspect, the invention consists of implementing a bistable element to maintain the fourth gear in its engaged position and in its immobilized position, and to move it in its immobilized position. According to the invention, maintaining the fourth gear and moving it are thus achieved without the use of pneumatic means.

[0063] The invention can thus make it possible to produce a drilling device which does not need to be connected to a pneumatic power source to operate, and which can operate entirely with an electrical power supply.

[0064] According to one possible feature, a device according to the invention comprises a sliding shaft carrying said fourth pinion and linked in translation to said fourth pinion along its axis of rotation, said bistable elastic element comprising at least one longitudinal element having two ends, one of said ends being articulated at at least a first articulation point on said housing and the other of said ends being articulated at at least a second articulation point on said sliding shaft, said at least one longitudinal element being compressible in a direction collinear with a line passing through said two ends and having a predetermined stiffness, said sliding shaft being movable relative to said housing between positions corresponding to said engaged and immobilized positions of said fourth pinion, said second articulation point of said sliding shaft occupying, in said engaged and immobilized states,positions substantially symmetrical with respect to a median plane perpendicular to said sliding shaft and passing through said first articulation point of said housing, the distance between said ends of said at least one longitudinal element in a relaxed state being greater than the distance between said first and second articulation points when said second articulation point of said sliding shaft is in said median plane.

[0065] According to one possible characteristic, said at least one elongated element belongs to the group comprising

[0066] - a metal blade whose compressibility results from its buckling;

[0067] - a component incorporating a spring whose compressibility results from the compression of said spring. According to one possible characteristic, said bistable elastic element comprises a bistable elastic washer.

[0068] According to one possible characteristic, the first means of transportation include:

[0069] - a first end-of-deployment stop attached to said spindle and intended to bear against a second end-of-deployment stop linked to said casing, said first and second end-of-deployment stops delimiting the end of said deployment stroke of said spindle;

[0070] - said first linkage means which include pins integral with said fourth pinion and adapted to cooperate with clutch housings of said third pinion in said engaged position to link said third and fourth pinions in rotation, said pins and clutch housings being configured to induce a displacement of said fourth pinion in the direction of said immobilized position when said first end-of-deployment stop is against said second end-of-deployment stop and said rotor rotates in said direction of operation, said displacement occurring over a stroke inducing said second articulation point of said sliding shaft to pass said median plane and the passage of said bistable elastic element into said immobilized state

[0071] According to one possible characteristic, said first means of moving said fourth pinion from said engaged position to said immobilized position comprise an actuator capable of transmitting said fourth pinion a displacement force capable of bringing said second articulation point of said sliding shaft beyond said median plane and of moving said bistable elastic element from said engaged state to said immobilized state, said actuator being able to take at least:

[0072] - a neutral state in which it does not transmit said displacement force to said fourth pinion, said neutral state being maintained when said spindle is moved over said predetermined extension stroke and over said predetermined retraction stroke, and

[0073] - a state of displacement in which it transmits to said fourth pinion said displacement force, said state of displacement being taken, at the end of a retraction of said spindle over the whole of said predetermined retraction stroke, under the effect of a rotation of said rotor in said working direction.

[0074] According to one possible characteristic, said actuator includes a movable lever capable of taking:

[0075] - said neutral state in which said spindle does not transmit force to said lever and said lever does not transmit said displacement force to said fourth pinion so that said fourth pinion is held in said engaged position by said bistable elastic element in engagement state, said neutral state being maintained when said spindle is moved on said predetermined deployment stroke and on said predetermined retraction stroke;

[0076] - said state of displacement, taken at the end of a deployment of said spindle over the entirety of said predetermined deployment stroke, under the effect of a rotation of said rotor in said working direction, in which said lever transmits said displacement force to said fourth pinion so as to bring said second articulation point of said sliding shaft beyond said median plane and to make said bistable elastic element pass from said engaged state to said immobilized state, said device comprising a first end-of-deployment stop integral with said spindle and intended to bear against a second end-of-deployment stop linked to said housing, said first and second end-of-deployment stops delimiting the end of said deployment stroke of said spindle, said device comprising an elastic return element against the effect of which said first pinion is mounted to move in translation along said spindle,a rotation of said spindle in said working direction when said first end-of-deployment stop is against said second end-of-deployment stop, inducing a translational drive along said spindle of said first pinion by said second pinion, said first pinion acting on said lever to place it in its moving state.

[0077] According to one possible feature, a device according to the invention includes second means for moving said fourth pinion from said immobilized position to said engaged position.

[0078] According to one possible feature, said second means of movement include a first end stop of retraction integral with said spindle, and a fork linked in translation with said fourth pinion, said first end stop of retraction being configured to act on said fork on a final portion of said retraction stroke so as to drive said fork in translation and to bring said second articulation point of said sliding shaft beyond said median plane to bring said bistable elastic element into said engaged state and move said fourth pinion towards said engaged position.

[0079] According to one possible characteristic, said second means of movement comprise: means for reversing the direction of rotation of said rotor capable of rotating said rotor in a direction opposite to said working direction; a sliding shaft carrying said fourth pinion and linked in translation to said fourth pinion along its axis of rotation; a unidirectional clutch configured to: not link said third pinion and said sliding shaft in rotation when said rotor rotates in said working direction, and link said third pinion and said sliding shaft in rotation when said rotor rotates in said direction opposite to said working direction;a cam shaped to induce, during a rotation of said rotor in said direction opposite to said working direction, a displacement of said sliding shaft and of said fourth pinion from said immobilized position to said engaged position, and to bring said second articulation point of said sliding shaft to pass said median plane and to make said bistable elastic element pass into said engaged state, said cam being annular and coaxial with said sliding shaft, said cam having a ramp whose development is parallel to the axis of rotation of said sliding shaft, said ramp being in contact with a lug rotationally fixed to said sliding shaft along the axis of rotation of said sliding shaft, said lug being at least partially translationally fixed to said sliding shaft along the axis of translation of said sliding shaft.;

[0080] In this way, a rotation of said rotor in the opposite direction of said working direction induces a displacement of said lug on said cam, said displacement causing said second articulation point of said sliding shaft to pass said median plane and to cause said bistable elastic element to pass into said engaged state and a displacement of said sliding shaft and of said fourth pinion from said immobilized position to said engaged position.

[0081] According to one possible feature, said ramp of said annular cam comprises a projecting end in the direction of the engaged position of said fourth pinion and a recessed end receiving said lug when said fourth pinion is in the immobilized position, said device comprising means for immobilizing the sliding shaft in rotation when said fourth pinion is in the engaged position such that the trajectory of said lug during the passage of the fourth pinion from its engaged position to its immobilized position is parallel to the axis of said sliding shaft.

[0082] 5. Description of the figures

[0083] Other features and advantages of the invention will become apparent from the following description of particular embodiments, given by way of simple illustration and not limitation, and the accompanying drawings, among which:

[0084] [Fig 1] Figure 1 illustrates a partial longitudinal cross-sectional view of a drill according to the prior art;

[0085] [Fig 2] Figure 2(a) illustrates a partial longitudinal view of a drill according to a first embodiment of the invention implementing a magnet whose fourth pinion is in the engaged position, Figure 2(b) illustrates a detailed side view of the cam system of this drill, and Figure 2(c) illustrates a cross-sectional view along the axis AA of Figure 2(a); [Fig 3] Figure 3(a) illustrates a partial longitudinal view of a drill according to a first embodiment of the invention implementing a magnet whose fourth pinion is in the immobilized position, Figure 3(b) illustrates a detailed side view of the cam system of this drill, and Figure 3(c) illustrates a cross-sectional view along the axis BB of Figure 3(a);

[0086] [Fig 4] Figure 4 illustrates a partial perspective view of the cam system of the drill in Figures 2 and 3;

[0087] [Fig 5] [Fig 6] Figures 5 and 6 illustrate partial longitudinal section views of a drill according to a first embodiment of the invention implementing a fork;

[0088] [Fig 7] Figure 7 illustrates a partial longitudinal view of a drill according to a second embodiment of the invention implementing a bistable elastic element whose fourth pinion is in the engaged position;

[0089] [Fig 8] Figure 8 illustrates a partial longitudinal view of a drill according to a second embodiment of the invention implementing a bistable elastic element whose fourth pinion is in an intermediate position between its engaged and immobilized positions; [Fig 9] Figure 9 illustrates a partial longitudinal view of a drill according to a second embodiment of the invention implementing a bistable elastic element whose fourth pinion is in the immobilized position;

[0090] [Fig 10] Figure 10 illustrates a perspective view of a bistable elastic washer of a drill according to the second embodiment of the invention.

[0091] 6. Description of specific embodiments

[0092] 6.1. First embodiment: magnetic device

[0093] 6.1.1. Architecture

[0094] In relation to figures 2 to 6, an example of the realization of a drill according to the invention comprising a magnet is presented.

[0095] Actuation button

[0096] The drill typically includes a start button (not shown).

[0097] Such a start button does not require sustained pressure from the operator as a trigger requires.

[0098] The operator presses the start button once to initiate a drilling operation. The drilling operation then proceeds until the drill stops automatically. An emergency stop button is also available for early shutdown if necessary.

[0099] Ordering methods

[0100] The drill also conventionally includes control means 300, such as a controller internal or external to the drill housing, comprising electronic and logic components, which allow the operation of the drill to be controlled. Such a controller is conventional in itself, except that it is configured and programmed to allow the control of a drill according to the invention.

[0101] Motorized spindle drive transmission

[0102] Such a drill typically includes a housing 20. It preferably also includes means for attaching the housing 20 to drilling grids. Such drilling grids are known in themselves and are therefore not described in further detail here.

[0103] The housing 20 contains a spindle 10 which can be extended outside the housing 20. This spindle 10 is designed to carry, at one of its ends, a cutting tool such as a drill bit (not shown). This drill bit is coaxial with the spindle 10 and rotationally connected to it.

[0104] The spindle 10 includes longitudinal grooves 101 and is threaded 102 along its entire length.

[0105] Pin 10 is equipped with:

[0106] - a first end-of-deployment stop 18 capable of bearing against a second fixed end-of-deployment stop in translation relative to the housing 20 along the axis of the spindle 10; in this case, the second end-of-deployment stop is constituted here by a ball bearing 37, which will be described in more detail later, and

[0107] - a first end stop for retraction 19 capable of bearing against a second end stop for retraction fixed in translation relative to the housing 20 along the axis of the spindle, in this case the second end stop for retraction is constituted here by the end of a second pinion 12 which will be described in more detail later.

[0108] The first 18 and second 37 deployment end stops define a predetermined deployment stroke of the pin 10.

[0109] The first 19 and second 12 retraction end stops define a predetermined retraction stroke of the spindle 10.

[0110] The drill bit is intended to be secured to the spindle 10 on the side of the first end stop of retraction 19.

[0111] The drill includes an electric motor (not shown) equipped with an R rotor.

[0112] The drill includes a transmission T. This transmission T is interposed between the rotor R of the motor and the spindle 10. It is capable of transforming a rotational movement of the rotor in the working direction (i.e. drilling direction) into a rotational movement or into a combined rotational and translational movement of the output spindle 10 along the same axis, i.e. its longitudinal axis X.

[0113] This T transmission includes:

[0114] - a first pinion 11 coaxial with the spindle 10 and equipped with internal splines cooperating with the external longitudinal grooves of the spindle 10 (the first pinion 11 and the spindle 10 are thus linked by a linear connection along the longitudinal axis of the spindle 10);

[0115] - the second pinion 12 coaxial with the spindle 10 and equipped with an internal thread cooperating with the thread 102 of the spindle 10 (the second pinion 12 and the spindle 10 are thus linked by a helical connection along the longitudinal axis of the spindle 10); - a third pinion 13 with an axis parallel to the spindle 10, guided in rotation relative to the housing 20, meshing with the first pinion 11 according to a first transmission ratio and driven in rotation by the drill motor directly or via any type of gear(s), in particular here a spur pinion 15;

[0116] - a fourth pinion 14 with an axis parallel to the spindle 10, guided in rotation and translation relative to the housing 20, meshing with the second pinion 12 according to a second transmission ratio different from the first ratio.

[0117] Optional vibrator

[0118] Optionally, the drill includes a vibratory feeder. A vibratory feeder is a mechanical device that, when used on a drilling machine, adds an alternating component to the spindle's feed motion. This component causes the drill bit's cutting edges, connected 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.

[0119] The vibrator is a roller bearing with corrugations on one of its tracks. As the tracks rotate relative to each other, the thickness of the vibrator varies between minimum and maximum values, several times per revolution.

[0120] This is achieved in the following way.

[0121] The assembly consisting of the spindle 10, the first pinion 11 and the second pinion 12, is guided in rotation relative to the housing 20 by means of a bearing 30 and a bearing 31. A ball thrust bearing 32 essentially prevents friction between the first 11 and second 12 pinions.

[0122] The vibrator comprises a first track 33, without surface undulations, bearing against the bearing 30. It also comprises rollers 34 that bear against the first track 33. The vibrator further comprises a second track 35 having surface undulations. This track 35 bears against the first pinion 11 and the rollers 34.

[0123] It is possible to not use a vibrating device. Otherwise, it is designed to be deactivated during the milling operation.

[0124] The drill includes a ball bearing 37, which acts as a second end-of-extension stop. This ball bearing 37 is mounted on a ring 39 fixed relative to the housing 20. This ring 39 has, oriented towards the bearing 30, a surface 390 against which one end of a compression spring 40, called the countersinking finalization spring, can bear. This spring 40 is, for example, one or more Belleville washers. The other end of the spring 40 is housed in a ring 41 which bears against the bearing 30.

[0125] 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.

[0126] Reversible rotational linkage of the third and fourth gears

[0127] The fourth pinion 14 includes pins 140 capable of cooperating with clutch housings 130 of essentially complementary shape provided on the third pinion 13 in such a way that when the pins 140 are housed in the clutch housings 130, the fourth pinion 14 and the third pinion 13 are rotationally linked. The pins 140 and the clutch housings 130 thus constitute means of rotationally linking the third 13 and the fourth 14 pinions.

[0128] The clutch housings 130 each extend along a portion of a circle whose center lies on the axis of rotation of the third pinion 13. They thus form sort of "beans".

[0129] In this embodiment, the pins 140 are cylindrical. In variants, the shape of the pins 140 and the clutch housings 130 may be chosen such that as soon as the fourth pinion 14 tends to rotate relative to the third pinion 13, the pins

[0130] The pins 140 tend to move out of the clutch housings 130, causing the fourth pinion 14 to move away from the third pinion 13 along its axis of rotation. The pins 140 are therefore not cylindrical but ogive-shaped. This principle, known to those skilled in the art, is described, for example, in patent documents FR 2 881 366 and FR 2 918 592.

[0131] Rotational immobilization of the fourth pinion

[0132] The fourth pinion 14 also includes first locking dogs

[0133] 141 of complementary shape of second locking dogs 17 fixed in relation to the casing 20 of the drill.

[0134] Movement of the fourth gear between its engaged and disengaged positions

[0135] The device includes a sliding shaft 42. This sliding shaft 4 is housed in the casing 20 and extends parallel to the spindle 10.

[0136] The sliding shaft 42 comprises a first portion 420 and a second portion 421 fitted one inside the other and linked in rotation and translation along the longitudinal axis of the sliding shaft 42. The sliding shaft 42 is movable in rotation and translation relative to the housing 20 along its longitudinal axis. For this purpose, it is guided by means of a bearing 422 relative to the housing 20 and is guided by means of bearings 423 relative to the third pinion 13, which is itself guided in rotation relative to the housing 20 by means of a bearing 424.

[0137] The fourth pinion 14 is mounted to rotate freely on the sliding shaft 420 by being placed between the first 420 and second 421 potions in such a way that it is linked in translation to the sliding shaft 42 along the axis of rotation of the latter.

[0138] Thus, the fourth pinion 14, and the sliding shaft 42, can take:

[0139] - an engaged position (illustrated in Figure 2) in which the pins 140 are housed in the clutch housings 130 and the first locking dogs 141 do not cooperate with the second 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 20, and

[0140] - a stationary position (illustrated in figure 3) in which the pins 140 do not cooperate with the clutch housings 130 and the first locking dogs 141 cooperate with the second locking dogs 17 so that the fourth pinion 14 is stationary in rotation relative to the housing 20 and is not rotationally bound with the third pinion 13.

[0141] The third pinion 13 is guided in rotation and linked in translation relative to the housing 20 by means of the bearing 424.

[0142] The sliding shaft 42 is guided in rotation and translation relative to the third pinion 13 by means of the bearings 423.

[0143] The sliding shaft 42 has a grooved portion along its longitudinal axis on which is mounted a unidirectional clutch 43 which is also linked to the third pinion 13.

[0144] The one-way clutch 43 is configured such that:

[0145] - the third pinion 13 is not rotationally bound to the sliding shaft 42 when the motor rotor R rotates in the direction of operation, and

[0146] - the third pinion 13 is linked in rotation with the sliding shaft 42 when the rotor R of the motor rotates in the opposite direction to the working direction.

[0147] Maintaining the fourth pinion in a stationary position

[0148] The drill includes means for retaining the fourth pinion 14 in its engaged position. These retaining means include a magnetic attraction element exerting a force on the fourth pinion 14, when it is in its engaged position, to maintain it in that engaged position.

[0149] This magnetic attraction element includes a permanent magnet 44 coaxial with the sliding shaft 42 and located at one of its ends.

[0150] The end of the sliding shaft 42 oriented towards the side of the magnet 44 carries a washer 45 capable of bearing against the magnet 44 when the fourth pinion 14 is in the engaged position.

[0151] In the preferred embodiment described herein, the magnet 44 therefore acts indirectly on the fourth pinion 14 via the washer 45 and the sliding shaft 42. In an alternative, the magnet 44 could act directly on the fourth pinion 14.

[0152] This magnet 44 may be an electromagnet, although this is not mandatory.

[0153] Thus, the magnet can be deactivated at any point during the drilling or deployment stroke without having to change the position of the first deployment end stop and thereby causing premature spindle retraction. This can be useful if the drilling thickness varies from one hole to the next. For each hole, the actual drilling depth can be programmed, rather than the depth corresponding to the deepest hole to be drilled. This can prevent the drill bit from overextending beyond the drilling surface and thus reduce the drilling cycle time.

[0154] Movement of the fourth gear from its engaged position to its stationary position

[0155] The drill includes means for moving the fourth pinion 14 from its engaged position to its stationary position. These means of movement include a first elastic return element exerting on the fourth pinion 14 a force tending to move it from its engaged position to its stationary position, and when it is in its stationary position, a force maintaining the fourth pinion 14 in its stationary position.

[0156] This elastic return element comprises, in this embodiment, a compression spring 46 arranged around the magnet 44 and bearing on one side against a calibration stop 47 and on the other side against the washer 45. The calibration stop 47 can be moved in translation relative to the housing 20 by acting on an adjustment knob 470 in order to calibrate the spring 46.

[0157] Deactivation of the means for holding the fourth pinion in its immobilized position by energizing the electromagnet

[0158] The drill includes means for deactivating the holding effect of the holding means, i.e. the magnet 44, of the fourth pinion 14 in the engaged position.

[0159] When the magnet 44 is an electromagnet, these deactivation means may include means for supplying electricity to the electromagnet 44 in such a way as to cancel the magnetic attraction it generates. In this case, the drill control means are configured to control the deactivation means so that they supply power to the magnet 44 when it is desired to trigger the retraction of the spindle 10. A spindle position sensor 10 could, for example, be used in this case to detect when the spindle extension corresponds to the desired drilling depth. Monitoring the evolution of the motor current over time could also make it possible to detect, during the drilling of a through hole, the moment when the drill bit breaks through, in order to trigger retraction.Monitoring the evolution of the motor current over time can also be used when it is desired to initiate retraction after a total deployment of the spindle 10, i.e. when the first 18 and second 37 end-of-deployment stops are in contact, to detect the moment when these stops come into contact with each other.

[0160] Deactivation of the means for holding the fourth pinion in its immobilized position by lever

[0161] Alternatively, the means for deactivating the holding effect of the holding means of the fourth pinion 14 in the engaged position include a lever 48 capable of transmitting to the fourth pinion 14 a repulsive force greater than the magnetic attraction force transmitted to the fourth pinion 14 by the magnetic attraction element 44.

[0162] This lever 48 is mounted to rotate freely relative to the housing 20 on an axis 49 orthogonal to the axis of the spindle 10. One end of the lever 48 is in contact with the ring 41. The second end of the lever 48, opposite to the first end, is housed in a slot 500 formed by a pusher 50.

[0163] The pusher 50 is free to move in translation within the housing 20 along the axis of the sliding shaft 42, with which it is coaxial. The pusher 50 includes a housing 501 for the washer 45, which is mounted thereon for translational movement, and includes a bearing surface 502 against which the face of the washer 45, facing the magnet 44, can bear. As will be described in more detail later, the pusher 50 is capable of pushing the washer 45 a short distance sufficient to disengage the washer from the magnet, and then the spring 46 completes the movement of the sliding shaft in its stationary position.

[0164] Lever 48 is likely to take:

[0165] - a neutral state in which the spindle 10 does not transmit any force to the lever 48 and the lever 48 does not transmit the repulsive force to the fourth pinion 14 so that the fourth pinion 14 is held in the engaged position by the magnet 44. The neutral state is maintained when the spindle 10 is moved over the predetermined deployment stroke and over the predetermined retraction stroke.

[0166] - a state of repulsion, taken at the end of a deployment of the spindle 10 over the entire predetermined deployment stroke, under the effect of a rotation of the rotor R in the direction of work, in which the lever 48 transmits the repulsion force to the fourth pinion 14 so as to counter the magnetic attraction force transmitted by the magnet 44 to the fourth pinion 14.

[0167] The first pinion 11 is mounted to move in translation along the spindle 10 against the effect of the spring 40. A rotation of the spindle 10 in the working direction, when the first end-of-deployment stop 18 is in contact with the second end-of-deployment stop 37, induces a translational drive, along the spindle 10, of the first pinion 11 by the second pinion 12, the first pinion 11 acting via the ring 41 on the lever 48 to place it in its repulsive state.

[0168] This lever 48 constitutes an actuator that could potentially be replaced by an electric actuator performing the same function. Means of moving the fourth pinion from the stationary position to the engaged position - Cam

[0169] The drill includes means for moving the fourth pinion 14 from the stationary position to the engaged position.

[0170] These means of movement include in this embodiment a cam system 51.

[0171] These means of transport include:

[0172] - the control means 300 configured to reverse the direction of rotation of the motor so that the rotor R rotates in the opposite direction to the working direction when the first end stop of retraction 19 comes into contact with the second end stop of retraction, i.e. the second pinion 12;

[0173] - the wandering tree 42;

[0174] - the unidirectional clutch 43, the third pinion 13 and the rotor R;

[0175] - a cam 510 shaped to induce, during a rotation of the rotor R in the opposite direction to the working direction, a displacement of the sliding shaft 42 and of the fourth pinion 14 from the immobilized position to the engaged position.

[0176] The cam 510 is annular and coaxial with the sliding shaft 42. It is fixed relative to the housing 20 and is located on the side of the sliding shaft 42 opposite to that where the washer 45 is located.

[0177] The cam 510 has a ramp 5100 whose development is parallel to the axis of rotation of the sliding shaft 42. It thus has a projecting end 5101 in the direction of the fourth pinion 14 and a recessed end 5102 in the opposite direction.

[0178] The ramp 5100 is in contact with a lug 52 which is rotationally linked to the sliding shaft 42 along the axis of rotation of the sliding shaft 42.

[0179] The cam 512 has, at the junction between the projecting end 5101 and the recessed end 5102, a housing 5104 for the lug 52. This housing 5104 is recessed relative to the recessed end 5102 and has a ramp 5105 which rises progressively up to the recessed end 5102 of the cam 510.

[0180] These means of movement also include a ring 53 coaxial with the sliding shaft 42.

[0181] This ring 53 is movable in translation and rotation along the axis of rotation of the sliding shaft 42 relative to the sliding shaft 42. The lug 52 is:

[0182] - linked in translation and rotation to ring 53,

[0183] - rotationally linked to the sliding shaft 42, and

[0184] - partially linked in translation relative to the sliding shaft 42 along its axis of rotation.

[0185] As will become clearer later, the lug is partially translationally bound to the sliding shaft 42 in that it is not directly and rigidly bound to it throughout the entire translational stroke of the lug. However, the lug is indirectly and elastically bound to the sliding shaft in translation due to the use of a spring 54 described below. In an alternative, the lug could be directly and / or rigidly bound to the sliding shaft in translation.

[0186] For this purpose, the lug 52 is mounted in a groove 423 made at the end of the sliding shaft 42 opposite to that at which the washer 45 is located.

[0187] An elastic element, such as a compression spring 54, is arranged between the ring 53 and a shoulder of the sliding shaft 42 in such a way that a rotation of the rotor R in the opposite direction to the working direction tends to move the ring 53 towards the sliding shaft 42 and to compress the elastic element 54 between the ring 53 and the shoulder of the sliding shaft 42 if the pins 140 of the fourth pinion 14 do not extend into the clutch housings 131 of the third pinion 13 during the movement of the lug 52 against the cam 510. This will be explained in more detail later with the description of the operation of the drill.

[0188] The drill includes means for preventing the rotation of the sliding shaft 42 when the fourth gear 14 is engaged. These means are configured such that the path of the lug 52, during the transition of the fourth gear 14 from its engaged to its locked position, is parallel to the axis of the sliding shaft 42. This will be explained in more detail later with the description of the drill's operation.

[0189] This implementation ensures synchronization of the lug 52 to position the lug 52 in line with, i.e., in line with, the longitudinal axis of the sliding shaft, the housing 5104 of the cam 510 when the fourth gear 14 is in the engaged position, following a rotation of the rotor R in the opposite direction to the working direction, which has moved the fourth gear 14 from its stationary position to its engaged position. These stationary means comprise the following elements.

[0190] The ring 53 and the lug 52 are housed in a bell 56 fixed relative to the housing 20 and comprising a light 560 in which the lug 52 can move when it moves along the cam 510.

[0191] This light 560 includes a lateral bearing surface 561 against which the lug 52 comes to rest, or near which the lug 52 comes, when it passes beyond the projecting end 5101 of the cam 510 towards the hollow end 5102 under the effect of a rotation of the rotor R in the opposite direction to the working direction, as will be explained in more detail later.

[0192] When the fourth pinion 14 is in the engaged position, the lug 52 is in the axis of the housing 5104 of the cam 510 between the lateral bearing surface 561 of the slot 560 and the junction surface 5103 which extends between the protruding end 5101 of the cam 510 and the recessed end 5102 of the cam 510. The sliding shaft 42 is thus immobilized in rotation.

[0193] When the fourth pinion 14 is in the immobilized position, the lug 52 is in the housing 5104 of the cam 512.

[0194] 6.1.2. Operation

[0195] This type of drill can also be used to drill holes with or without a countersink at the hole entrance. i. Drill stopped before starting

[0196] Before starting the drill to perform a drilling operation, the drill is, if necessary, fixed on a drilling grid, in a centering hole located in the axis of the hole to be drilled.

[0197] As long as the start button is not activated by the operator, the spindle 10 is fully retracted so that the first end stop of retraction 19 is in contact with the second pinion 12, which constitutes the second end stop of retraction.

[0198] The fourth pinion 14 is in its engaged position in which it is held in position by the magnet 44 insofar as the washer 45 is in contact with the magnet 44, which exerts on it a magnetic attraction force against the compression spring 46.

[0199] The lug 52 is located in the axis of the housing 5104 of the hollow end 5102 of the cam 510, and is away from it, between the lateral bearing surface 561 of the opening 560 and the junction surface 5103 between the protruding end 5101 of the cam 510 and the hollow end 5102 of the cam 510 (cf. position A).

[0200] Lever 48 is in its neutral position. ii. Drilling operation ii.1. Spindle deployment

[0201] To start the drill, an operator presses the start button to begin the drilling operation.

[0202] The motor starts so that the rotor R is driven to rotate in the working direction, i.e. drilling direction.

[0203] The pinion 15 located at the end of the rotor R drives the third pinion 13 in rotation.

[0204] The fourth pinion 14, which is rotationally linked with the third pinion 13, is driven in rotation.

[0205] The first pinion 11 is driven in rotation by the third pinion 13 so that the spindle 10 is driven in rotation along its longitudinal axis.

[0206] The second pinion 12 is driven in rotation by the fourth pinion 14.

[0207] The reduction ratio between the first 11 and the third pinion 12 is different from 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 20 until the first end-of-deployment stop 18 is in contact with the ball bearing 37 which constitutes the second end-of-deployment stop.

[0208] During drilling operation, the following parts are stacked together to generate the alternating feed component (vibrating feed): the outer ring of the bearing 30, itself linked to the housing 20 of the drilling device; the first track 33 of the vibrator; the rollers 34 of the vibrator; the second track 35 of the vibrator; the first pinion 11 generating the rotation of the spindle 10; the second pinion 12 generating the feed 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.

[0209] During drilling, 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, 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, thus inducing the alternating feed component at the level of the drill lips.

[0210] During this period, the drill bit is driven along a helical trajectory with an appropriate cutting speed and vibrating feed rate, thus performing the expected drilling. ii.2. End of spindle deployment: passage of the fourth gear into the immobilized position

[0211] During the final milling action, the first end stop 18 comes into contact with the second end stop, i.e., in this variant, the ball bearing 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 milling surface to be finished without waviness.

[0212] 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 thread in the direction of the first deployment end stop 18. To allow this movement, the countersink finishing spring 40 compresses, giving the countersink time to be completed.

[0213] When the milling end-setting spring 40 can no longer be compressed, the second pinion 12 stops moving axially.

[0214] The stiffness of the countersink finishing spring 40 is, however, sufficiently strong so that it does not collapse during the drilling action and does not disrupt the generation of the reciprocating feed component.

[0215] When the spring 40 is compressed, the ring 41 acts on the lever 48 and moves the lever 48 from its neutral state to its repulsive state by pivoting it around the axis 49. During this movement, the lever 48 exerts a force on the movable pusher 50 and translates it in the direction of the fourth pinion 14. The pusher 50 drives the washer 45 in the same direction, which tends to move away from the magnet 44. When the repulsive force transmitted by the lever 48 to the washer 45, combined with the force exerted by the spring 46 on the washer 45, becomes greater than the magnetic attraction force exerted by the magnet 44 on the washer 45, the compression spring 46 moves the washer 45, the sliding shaft 42, and the fourth pinion 14 to its immobilized position and holds the fourth pinion 14 in this position.

[0216] As an alternative to using lever 48, the washer 45 is detached from magnet 44 by control means 300 which control the supply of electricity to magnet 44 to inhibit the magnetic attraction force it produces:

[0217] - either to the detection by the control means of the arrival of the first end-of-deployment stop 18 on the second end-of-deployment stop 37 by increasing the consumption of the electric motor;

[0218] -either before the first 18 and second 37 deployment end stops are in contact but after drilling a certain depth measured by the angle of rotation traveled by the rotor R of the motor since the start of the drill.

[0219] During the movement of the fourth pinion 14 from its engaged position to its immobilized position, the lug 52 moves translationally along the axis of the sliding shaft 42 until it engages in the housing 5104 of the cam 510, being guided there, if necessary, by the ramp 5105 (see position B). ii.3. Spindle retraction

[0220] Given that the fourth pinion 14 is in its immobilized position, the fourth pinion 14 is immobilized in rotation, and the second pinion 12 is also immobilized in rotation.

[0221] Thus, the spindle 10, which continues 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 20. ii.4. End of spindle retraction: passage of the fourth pinion into the engaged position

[0222] The retraction of the spindle 10 takes place until the first end-of-retraction stop 19 comes into contact with the second pinion 12, which constitutes the second end-of-retraction stop.

[0223] The control means 300 detect that the spindle is thus completely retracted, for example by following the evolution over time of the motor current.

[0224] When the control means 300 detect that the spindle 10 is fully retracted, they drive the motor so that the rotor R rotates in the opposite direction to the working direction.

[0225] The sliding shaft 42 is then driven in rotation by the third pinion 13 and by the unidirectional clutch 43.

[0226] The lug 52 is then driven in rotation by the sliding shaft 42. It comes out of the housing 5104 of the cam 510 and then slides against the ramp 5100 of the cam 510 towards its protruding end 5101 and translates towards the washer 45. The movement of the lug 52 along the cam 510 induces a movement of the ring 53 towards the fourth pinion 14.

[0227] If the pins 140 of the fourth pinion 14 extend into the clutch housings 130 of the third pinion 13, then the lug 52, by moving towards the washer 45, pushes the ring 53 and the spring 54, which move the fourth pinion 14 into its engaged position against the effect of the spring 46. The fourth pinion 14 is then held in this engaged position by the magnet 44 with which the washer 45 is in contact. The washer 45 comes into contact with the magnet 44 slightly before the lug 52 passes beyond the protruding end 5101 of the cam 510.Thus, at the end of the movement of the fourth pinion 14 towards its engaged position, the lug 52 passes beyond the protruding end 5101 of the cam 510, then moves slightly towards the cam 512, under the effect of the release of the spring 54 and the movement of the ring 53 towards the cam 510, so that it is located on the axis of the housing 5104 of the cam 510 between the bearing surface 561 of the slot 560 and the connecting surface 5103 between the protruding end 5101 and the recessed end 5102 of the cam 510, while remaining away from the housing 5104 (position A). The lug 52 is thus prevented from rotating between these two surfaces 561, 5103, so that the sliding shaft 42 is prevented from rotating.

[0228] If the pins 140 of the fourth pinion 14 do not extend into the clutch housings 130 of the third pinion 13, then the pins 140 will bear against the third pinion 13 outside the clutch housings 131 and the ring 53 will compress the spring 54 against the shoulder of the sliding shaft 42. The probability of this situation occurring is very low given the implementation of the "bean-shaped" clutch housings 130 which maximizes the chances that the pins 140 will always be opposite the corresponding clutch housings 130.

[0229] Meanwhile, the third pinion 13 continues its rotation. The fourth pinion 14 is driven at a different frequency than the third pinion 13 due to the difference in the number of teeth between the first 11 and second 12 pinions, so that the pins 140 synchronize with the clutch housings 131 of the third pinion 13. When the pins 140 are synchronized with the clutch housings 131, i.e., they are aligned, the spring 54 relaxes and pushes the sliding shaft 42, which completes its movement until its washer 45 comes into contact with the magnet 44. The fourth pinion 14 is then held in its engaged position by the magnet 44. The washer 45 makes contact with the magnet 44 slightly before the lug 52 passes beyond the protruding end 5101 of the cam. 510.Thus, at the end of the movement of the fourth pinion 14 towards its engaged position, the lug 52 passes beyond the protruding end 5101 of the cam 510, then moves slightly towards the cam 512 under the effect of the release of the spring 54 and the movement of the ring 53 towards the cam 510, so that the lug 52 is located on the axis of the housing 5104 of the cam 510 between the bearing surface 561 of the slot 560 and the connecting surface 5103 between the protruding end 5101 and the recessed end 5102 of the cam 510, while remaining away from the housing 5104 (position A). The lug 52 is thus prevented from rotating between these two surfaces 561, 5103 and the sliding shaft 42 is prevented from rotating.

[0230] The retraction stop can be performed after a predetermined angle of rotation of the lug relative to the cam. This angle can be measured by the motor's angle sensor, taking into account the reduction ratio between the motor and the sliding shaft, and is considered by the drill's control means. In the illustrated embodiment, the cam is actually a double cam with two ramps, each extending through 180°, and the lug is a double lug, each end of which acts on a different cam. Therefore, half a turn of the double lug relative to the cam may be sufficient to move the fourth gear from its stationary position to its engaged position. However, a full turn may be required depending on the reliability of the reset.

[0231] Lever 48 is also in its neutral state.

[0232] The drill is then in the state it was in before it was started so that a new drilling cycle can be started by pressing the start button.

[0233] 6.1.3. Variant: fork

[0234] In a variant illustrated in figures 5 and 6, the means of moving the fourth pinion 14 from its immobilized position to its engaged position do not include the cam system described above.

[0235] Alternatively, they include a 60 range.

[0236] This fork 60 is crossed at one of its ends by the spindle 10. At the other of its ends, the fork 60 is linked in translation to the sliding shaft 42. The fork 60 is also crossed by a rotating stop shaft 67.

[0237] The fork 60 is movable in translation between:

[0238] - an engaged position, illustrated in figure 5, in which the fourth pinion 14 is in the engaged position, and - an immobilized position, illustrated in figure 6, in which the fourth pinion 14 is in its immobilized position.

[0239] The device includes a lock 62. This lock 62 includes at one end a hook 620 and at the other end a cam 621.

[0240] The hook 620 is likely to cooperate with an attachment point 64 linked to the fork 60.

[0241] The lock 62 is mounted to rotate freely around an axis 63 linked to the housing 20 between:

[0242] - a release position, illustrated in Figure 5, in which the hook 620 does not cooperate with the attachment point 64, so that it does not hold the fork 60 in its immobilized position, and

[0243] - a locking position, illustrated in figure 6, in which the hook 620 cooperates with the hooking point 64 so that it holds the fork 60 in its immobilized position.

[0244] The fork 60 carries a spring blade 65, which tends to keep the lock 62 in its locked position.

[0245] A compression spring 66 is interposed between the first end stop of retraction 19 and the fork 60.

[0246] The first end stop of retraction 19 includes a conical portion 190 oriented towards the side of the lock 62.

[0247] The 620 hook includes a 6200 ramp designed to act on the 64 attachment point.

[0248] Throughout the deployment of the spindle 10 out of the housing 20, the fourth pinion 14 is held in its engaged position by the magnet 44. The fork 60 is in its engaged position, in which it is held by the magnet 44, and in which the hook 620 does not cooperate with the hook point 64, which is in contact with the ramp 6200.

[0249] During the movement of the fourth pinion 14 from its engaged position to its immobilized position under the effect of the release of the spring 46, the fork 60 is progressively driven in translation by the sliding shaft 42 towards the first end stop of retraction 19. During this movement, the hook point 64 slides against the ramp 6200 of the lock 62, which induces a rotation of the lock 62 around the axis 63 allowing the progressive passage of the hook point 64 into the hook 620.

[0250] When the fourth pinion 14 is in its immobilized position, the fork 60 is in its immobilized position and the lock 62 is in its locked position in which it is held by the spring blade 65. The hook point 64 is then trapped in the hook 620 so that the fork 60 is held in its immobilized position.

[0251] Given that the fourth pinion 14 is in its immobilized position, the spindle 10 retracts.

[0252] During the final portion of the spindle 10's retraction stroke, the first end stop compresses the spring 66. Then, the conical portion 190 of the first end stop 19 gradually acts on the cam 621 of the lock 62, causing the lock 62 to rotate around the axis 63. This rotation of the lock 62 induces a gradual movement of the lock 62 from its locked position to its released position. When the lock 62 reaches its released position, the hook 620 releases the engagement point 64, so that the fork 60 is driven in translation along the spindle 10 by the release of the compression spring 66. The fork 60 then drives the sliding shaft 42 in translation, so that the fourth pinion 14 gradually moves from its stationary position to its engaged position.

[0253] If, during the movement of the fourth pinion 14 from its stationary position to its engaged position, the pins 140 of the fourth pinion 14 extend into the continuation of the clutch housings 130 of the third pinion 13, then the fork 60 moves the sliding shaft 42 and the fourth pinion 14 into its engaged position under the effect of the release of the spring 66. The fourth pinion 14 is then held in this engaged position by the magnet 44.

[0254] If, during the movement of the fourth gear 14 from its stationary position to its engaged position, the pins 140 of the fourth gear 14 do not extend into the clutch housings 130 of the third gear 13, then the pins 140 will bear against the third gear 13 outside the clutch housings 131, and the spring 66 will partially relax. Then, as in the case of the cam system, when the pins 140 synchronize with the clutch housings 131, the spring 66 fully relaxes the fork 60, which moves the sliding shaft 42 until the fourth gear 14 is in its engaged position, where it is held by the magnet 44.

[0255] In this variant, no second retraction end stop is implemented. The retraction end position of the spindle 10 corresponds to its position when the fourth pinion 14 leaves its immobilized position.

[0256] 6.2. Second embodiment: device with a bistable element 6.2.1. Architecture

[0257] In relation to figures 7 to 10, an example of an embodiment of a drill according to the invention comprising a bistable element is presented.

[0258] Figures 2 (a), 2 (b), 3 (a), 3 (b) and 4 of the preceding embodiment are also to be taken into consideration with regard to the displacement and positioning of the lug 52 relative to the cam 510.

[0259] Actuation button

[0260] The drill typically includes a start button (not shown).

[0261] Such a start button does not require sustained pressure from the operator as a trigger requires.

[0262] The operator presses the start button once to initiate a drilling operation. The drilling operation then proceeds until the drill stops automatically. An emergency stop button is also available for early shutdown if necessary.

[0263] Ordering methods

[0264] The drill also conventionally includes control means 300, such as a controller internal or external to the drill housing, comprising electronic and logic components, which allow the operation of the drill to be controlled. Such a controller is conventional in itself, except that it is configured and programmed to allow the control of a drill according to the invention.

[0265] Motorized spindle drive transmission

[0266] Such a drill typically includes a housing 20. It preferably also includes means for attaching the housing 20 to drilling grids. Such drilling grids are known in themselves and are therefore not described in further detail here.

[0267] The housing 20 contains a spindle 10 that can be extended outside the housing 20. This spindle 10 is designed to carry, at one of its ends, a cutting tool such as a drill bit. This drill bit is coaxial with the spindle 10 and rotationally connected to it.

[0268] The spindle 10 includes longitudinal grooves 101 and is threaded 102 along its entire length.

[0269] The spindle 10 is equipped with: - a first end-of-deployment stop 18 capable of bearing against a second fixed end-of-deployment stop in translation relative to the housing 20 along the axis of the spindle 10; in this case, the second end-of-deployment stop is constituted by a first pinion 11, and

[0270] - of a first end stop for retraction 19 capable of bearing against a second end stop for retraction fixed in translation relative to the housing 20 along the axis of the spindle 10, in this case the second end stop for retraction is constituted by the end of a second pinion 12.

[0271] The first 18 and second 11 deployment end stops define a predetermined deployment stroke of the pin 10.

[0272] The first 19 and second 12 retraction end stops define a predetermined retraction stroke of the spindle 10.

[0273] The drill bit is intended to be secured to the spindle 10 on the side of the first end stop of retraction 19.

[0274] The drill includes an electric motor (not shown) equipped with an R rotor.

[0275] The drill includes a transmission T. This transmission T is interposed between the rotor R of the motor and the spindle 10. It is capable of transforming a rotational movement of the rotor R in the working direction (i.e. drilling direction) into a rotational movement or into a combined rotational and translational movement of the output spindle 10 along the same axis, i.e. its longitudinal axis X.

[0276] This T transmission includes:

[0277] - the first pinion 11 coaxial with the spindle 10 and equipped with internal splines cooperating with the external longitudinal grooves of the spindle 10 (the first pinion 11 and the spindle 10 are thus linked by a linear connection along the longitudinal axis of the spindle 10);

[0278] - the second pinion 12 coaxial to the spindle 10 and equipped with an internal tapping cooperating with the thread 102 of the spindle 10 (the second pinion 12 and the spindle 10 are thus linked by a helical connection along the longitudinal axis of the spindle 10);

[0279] - a third pinion 13 with an axis parallel to the spindle 10, guided in rotation relative to the housing, meshing with the first pinion 11 according to a first transmission ratio and driven in rotation by the drill motor directly or via any type of gear(s), in particular here a pair of bevel gears 150;

[0280] - a fourth pinion 14 with an axis parallel to the spindle 10, guided in rotation and translation relative to the housing, meshing with the second pinion 12 according to a second transmission ratio different from the first ratio.

[0281] Optional vibrator

[0282] In the figures, the drill is shown in its variant without a vibrator. However, as in the first embodiment with a magnet, the drill can optionally include a vibrator.

[0283] The drill can also include, as in the first magnetic embodiment, a ball bearing stop playing in particular the role of a second end-of-deployment stop.

[0284] Such a vibrating and ball bearing are not described here in more detail because their structures may be identical to those described in relation to the first magnetic embodiment.

[0285] The assembly consisting of the spindle 10, the first pinion 11 and the second pinion 12 is guided in rotation relative to the housing 20 by means of a bearing 30 and a bearing 31. A ball thrust bearing 32 essentially prevents friction between the first 11 and second 12 pinions.

[0286] A track 33, without surface undulation, comes to rest against the bearing 30. Rollers 34 come to rest against the first track 33.

[0287] A spring 36 is arranged between the bearing 31 and the second pinion 12 to tend to press the first pinion 11, the second pinion 12, the rollers 34 and the track 33 against each other and against the bearing 30.

[0288] Reversible rotational linkage of the third and fourth gears

[0289] The fourth pinion 14 includes pins 140 capable of cooperating with complementaryly shaped clutch housings 130 provided on the third pinion 13 in such a way that when the pins 140 are housed in the clutch housings 130, the fourth pinion 14 and the third pinion 13 are rotationally linked. The pins 140 and the clutch housings 130 thus constitute means of rotationally linking the third 13 and the fourth 14 pinions.

[0290] The clutch housings 130 each extend along a portion of a circle whose center lies on the axis of rotation of the third pinion 13. They thus form sort of "beans".

[0291] The shape of the first pins 140 and the clutch housings 130 is chosen such that as soon as the fourth pinion 14 tends to rotate relative to the third pinion 13, the pins 140 tend to move out of the clutch housings 130, causing the fourth pinion 14 to move away, along its axis of rotation, from the third pinion 13. The pins

[0292] 140 are thus presented, for example, in the form of ogives. 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.

[0293] Rotational immobilization of the fourth pinion

[0294] The fourth pinion 14 also includes first locking dogs

[0295] 141 of complementary shape of second locking dogs 17 fixed in relation to the casing 20 of the drill.

[0296] Movement of the fourth gear between its engaged and disengaged positions

[0297] The device includes a sliding shaft 42. This sliding shaft 42 is housed in the casing 20 and extends parallel to the spindle 10.

[0298] The sliding shaft 42 is free to rotate and translate relative to the housing 20 along its longitudinal axis. It is guided by two bearings 420 and 421. Bearing 420 guides the sliding shaft 42 relative to the housing 20, while bearing 421 guides the sliding shaft 42 within the third pinion 13, which is itself guided in rotation within the housing by means of bearings 422.

[0299] The fourth pinion 14 is mounted to rotate freely on the sliding shaft 42 and is linked in translation to the sliding shaft 42 along the latter's axis of rotation in such a way that the fourth pinion 14, and the sliding shaft 42, can take:

[0300] - an engaged position (illustrated in Figure 7) in which the pins 140 are housed in the clutch housings 130 and the first locking dogs 141 do not cooperate with the second 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 20, and

[0301] - a stationary position (illustrated in figure 9) in which the pins 140 do not cooperate with the clutch housings 130 and the first locking dogs 141 cooperate with the second locking dogs 17 so that the fourth pinion 14 is stationary in rotation relative to the housing 20 and is not rotationally bound with the third pinion 13.

[0302] The third pinion 13 is guided in rotation and linked in translation relative to the housing 20 by means of the bearings 424.

[0303] The sliding shaft 42 is guided in rotation and translation on the one hand relative to the housing 20 and on the other hand relative to the third pinion 13 respectively by means of the bearings 420 and 421.

[0304] The sliding shaft 42 has a grooved portion along its longitudinal axis on which is mounted a unidirectional clutch 43 which is also linked to the third pinion 13.

[0305] The one-way clutch 43 is configured such that:

[0306] - the third pinion 13 is not rotationally bound to the sliding shaft 42 when the motor rotor R rotates in the direction of operation, and

[0307] - the third pinion 13 is linked in rotation with the sliding shaft 42 when the rotor R of the motor rotates in the opposite direction to the working direction.

[0308] Movement and holding of the fourth pinion in a stationary position

[0309] The drill includes means for holding the fourth pinion 14 in its engaged position and in its immobilized position, and means for moving the fourth pinion 14 from its engaged position to its immobilized position, and vice versa.

[0310] These means of support and movement include a bistable elastic element 70 capable (illustrated in figure 7) of taking two stable states, namely:

[0311] - a clutch state in which it holds the fourth pinion 14 in its engaged position, and

[0312] - a state of immobilization (illustrated in figure 9) in which it maintains the fourth pinion 14 in its immobilized position.

[0313] This bistable elastic element 70 comprises at least one long element having two ends. One end is articulated at at least one first articulation point 700 on the housing 20. The other end is articulated at at least one second articulation point 701 on the sliding shaft 42. The at least one long element is compressible in a direction collinear with a line passing through its two ends and has a predetermined stiffness. The sliding shaft 42 is movable relative to the housing 20 between positions corresponding to the engaged and locked positions of the fourth pinion 14. The second articulation point 701 on the sliding shaft 42 occupies, in the engaged and locked states, substantially symmetrical positions with respect to a median plane PM perpendicular to the sliding shaft 42 and passing through the first articulation point 700 on the housing 20.The distance between the ends of at least one long element taken in a relaxed state being greater than the distance between the first 700 and second 701 articulation points when the second articulation point 701 to the sliding shaft 42 is in the median plane PM.

[0314] Between its two stable states, the bistable element 70 can assume a median state, illustrated in Figure 8, in which the second articulation point 701 lies in the median plane. Between the median state and the engaged state, the bistable element 70 tends to move the fourth pinion 14 towards its engaged position. Between the median state and the disengaged state, the bistable element 70 tends to move the fourth pinion 14 towards its disengaged position.

[0315] At least one elongated element preferentially belongs to the group comprising:

[0316] - a metal blade whose compressibility results from its buckling;

[0317] - a component incorporating a spring whose compressibility results from the compression of said spring.

[0318] In this embodiment, the bistable elastic element comprises a bistable elastic washer 70.

[0319] More specifically, this bistable elastic washer 70 is connected to the housing 20 by a plurality of first articulation points 700. For this, the outer circular peripheral contour 702 of the bistable elastic washer 70 is housed in a groove 200 fixed relative to the housing 20.

[0320] In addition, the bistable elastic washer 70 is connected to the sliding shaft 42 by a plurality of second articulation points 701. For this purpose, it includes a central circular hole 703 whose contour is housed in a groove 423 formed at a first end of the sliding shaft 42.

[0321] When the first end-of-deployment stop 18 is against the second end-of-deployment stop 11 and the rotor R is rotating in the direction of travel, the third 13 and fourth pinions 14 rotate relative to each other. This causes the ogive-shaped pins 140 and the clutch housings 131 to move the fourth pinion 14 towards the immobilized position over a stroke that causes the second pivot points 701 of the bistable washer 70 on the sliding shaft 42 to pass the median plane PM, and the bistable spring washer 70 to transition from its engaged to its immobilized state. For this to occur, the length of the ogives must be greater than half the stroke of the sliding shaft between the engaged and immobilized positions.

[0322] Due to its stiffness, the bistable elastic washer 70 participates, beyond the passage of the median plane PM through the second articulation points 701, in moving the fourth pinion 14 towards its immobilized position.

[0323] When the fourth pinion 14 is in its immobilized position, it is supported against the housing in such a way that the bistable elastic washer 70 exerts on the sliding shaft 42 an elastic restoring force tending to maintain it, and the fourth pinion 14, in the immobilized position.

[0324] Movement of the fourth gear from its engaged position to its stationary position

[0325] The means for moving the fourth pinion 14 from its engaged position to its immobilized position include here not only the ogive pins 141 and the clutch housings 131 but also the bistable elastic washer 70.

[0326] However, alternatively, the pins may be cylindrical rather than ogival as in the first magnetic embodiment, and the means for moving the fourth pinion 14 from its engaged position to its immobilized position may include an actuator capable of transmitting to the fourth pinion 14 a displacement force sufficient to bring the second articulation points 701 on the sliding shaft 42 beyond the median plane PM and to move the bistable elastic element 70 from its engaged state to its immobilized state. Such an actuator may have at least:

[0327] - a neutral state in which it does not transmit the displacement force to the fourth pinion 14, the neutral state being maintained when the spindle 10 is moved over the predetermined deployment stroke and over the predetermined retraction stroke, and

[0328] - a state of displacement in which it transmits the displacement force to the fourth pinion 14, the state of displacement being taken, at the end of a deployment of the spindle 10 over the entire predetermined deployment stroke, under the effect of a rotation of the rotor R in the direction of work.

[0329] As in the previous embodiment, using the magnet, this actuator can include the lever (not shown here) which will have a first end connected in rotation to the housing 20 along an axis orthogonal to the spindle 10, and a second end capable of acting, directly or indirectly on the fourth pinion 14 to move it from its engaged position to its immobilized position over a sufficient stroke to bring the second articulation points 701 to the sliding shaft 42 to pass the median plane PM and to move the bistable elastic element 70 from its engaged state to its immobilized state.

[0330] In this lever-operated variant, the first pinion 11 is mounted to move linearly along the spindle 10 against the effect of a spring. A rotation of the spindle 10 in the working direction, when the first end-of-extension stop 18 is against the second end-of-extension stop 11, induces a linear drive along the spindle 10 of the first pinion 11 by the second pinion 12, the first pinion 11 acting on the lever to place it in its moving position.

[0331] Means of moving the fourth pinion from the stationary position to the engaged position - Cam

[0332] The drill includes means for moving the fourth pinion 14 from the stationary position to the engaged position.

[0333] These means of transport include in this embodiment a cam system.

[0334] These means of transport include:

[0335] - the control means configured to reverse the direction of rotation of the motor so that the rotor R rotates in the opposite direction to the working direction when the first end stop of retraction 19 comes into contact with the second end stop of retraction 12;

[0336] - the wandering tree 42;

[0337] - the unidirectional clutch 43, the third pinion 13 and the rotor R;

[0338] - a cam 510 shaped to bring, during a rotation of the rotor R in the opposite direction to the working direction, the second articulation points 701 of the bistable washer 70 to the sliding shaft 42 to pass the median plane PM, to move the bistable washer 70 into its engaged state, and to move the sliding shaft 42 and the fourth pinion 14 from the immobilized position to the engaged position.

[0339] The cam 510 is annular and coaxial with the sliding shaft 42. It is fixed relative to the housing 20 and is located on the side of the sliding shaft 42 where the bistable washer 70 is located.

[0340] The cam 510 has a ramp 5100 whose development is parallel to the axis of rotation of the sliding shaft 42. It thus has a projecting end 5101 in the direction of the fourth pinion 14 and a recessed end 5102 in the opposite direction.

[0341] The 5100 ramp is in contact with a lug 52.

[0342] The cam 512 has, at the junction between the projecting end 5101 and the recessed end 5102, a housing 5104 for the lug 52. This housing 5104 is recessed relative to the recessed end 5102 and has a ramp 5105 which rises progressively up to the recessed end 5102 of the cam 510.

[0343] The ergot 52 is:

[0344] - rotationally linked to the sliding shaft 42, and

[0345] - partially linked in translation to the wandering tree 42.

[0346] For this purpose, the lug 52 is mounted in a housing 521 provided for this purpose in the sliding shaft 42, perpendicular to its axis. A compression spring 520 is interposed between the lug 52 and the bottom of the housing 521. This spring 520 tends to compress between the lug 52 and the bottom of the housing 521 when the lug 52 moves inside the housing 521 towards the third pinion 13.

[0347] As will become clearer later, the lug is partially translationally bound to the sliding shaft 42 in that it is not rigidly bound to it throughout the entire translational stroke of the lug. However, the lug is elastically and indirectly bound to the sliding shaft due to the spring 520. In an alternative, the lug could be directly and / or rigidly bound to the sliding shaft.

[0348] Rotating the rotor R in the opposite direction to its working direction causes the lug 52 to move along the cam 510. As it slides along the ramp 5100 of the cam 510, the lug 52 follows a helical path around the axis of the sliding shaft 42 and moves the sliding shaft 42 translationally towards the engaged position of the fourth gear 14. This movement causes the second pivot points 701 of the sliding shaft 42 to pass the median plane PM and the bistable elastic element 70 to enter the engaged position. This results in the sliding shaft 42 and the fourth gear 14 moving from the stationary position to the engaged position.

[0349] During this movement of the sliding shaft 42, the second articulation points 701 of the bistable washer 70 with the sliding shaft 42 pass the median plane PM. From the point of passing this plane, the bistable washer 70, due to its stiffness, contributes to the movement of the sliding shaft 42 to position the fourth pinion 14 in its engaged position.

[0350] When the fourth pinion 14 is in the engaged position, the wing is in contact with the third pinion 13 which acts as a stop in such a way that the bistable washer 70 exerts on the sliding shaft 42 an elastic restoring force tending to maintain the fourth pinion 14 in its engaged position.

[0351] The device includes means for immobilizing the sliding shaft 42 in rotation when the fourth pinion 14 is in the engaged position such that the trajectory of the lug 52 during the passage of the fourth pinion 14 from its engaged position to its immobilized position is parallel to the axis of the sliding shaft 42.

[0352] This design ensures synchronization of the lug 52, positioning it in line with the longitudinal axis of the sliding shaft and the housing 5104 of the cam 510 when the fourth gear 14 is engaged after the rotor R has rotated in the opposite direction to the direction of rotation that brought the fourth gear 14 into its engaged position. This design prevents the lug from directly striking the cam and the gear from returning to its stationary position.

[0353] These immobilization methods include the following elements.

[0354] In addition, the lug 52 is housed in a bell 56 fixed relative to the housing 20 and comprising a light 560 in which the lug 52 can move when it moves along the cam 510.

[0355] This light 560 includes a lateral support surface 561 against which the lug 52 comes to rest or near which the lug 52 comes when it passes beyond the projecting end 5101 of the cam 510 towards the hollow end 5102 under the effect of a rotation of the rotor R in the opposite direction to the working direction, as will be explained in more detail later.

[0356] When the fourth pinion 14 is in the engaged position, the lug 52 is located on the axis of the cam 5104 housing between the lateral bearing surface 561 of the slot 560 and the junction surface 5103 between the protruding end 5101 of the cam 510 and the recessed end 5102 of the cam 510, while being away from the housing 5104 (position A). The sliding shaft 42 is thus prevented from rotating.

[0357] When the fourth pinion 14 is in the immobilized position, the lug 52 is in the housing 5104 of the cam 510.

[0358] 6.2.2. Operation

[0359] This type of drill can also be used to drill holes with or without a countersink at the hole entrance. i. Drill stopped before starting

[0360] Before starting the drill to perform a drilling operation, the drill is, if necessary, fixed on a drilling grid, in a centering hole located in the axis of the hole to be drilled.

[0361] As long as the start button is not activated by the operator, the spindle 10 is fully retracted so that the first end stop of retraction 19 is in contact with the second pinion 12 which constitutes the second end stop of retraction.

[0362] The fourth pinion 14 is in its engaged position in which it is held in position as long as the bistable washer 70 is in its engaged state.

[0363] The lug 52 is located on the axis of the housing 5104 of the recessed end 5102 of the cam 510, and is offset from it, between the lateral bearing surface 561 of the slot 560 and the junction surface 5103 between the protruding end 5101 of the cam 510 and the recessed end 5102 of the cam 510 (position A). ii. Drilling operation ii.1. Spindle deployment

[0364] To start the drill, an operator presses the start button to initiate a drilling operation.

[0365] The motor starts so that the rotor R is driven to rotate in the working direction, i.e. drilling direction.

[0366] The conical couple 15 is driven in rotation by the rotor R and drives in rotation the third pinion 13.

[0367] The fourth pinion 14, which is rotationally linked with the third pinion 13, is driven in rotation. 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.

[0368] The second pinion 12 is driven in rotation by the fourth pinion 14.

[0369] The reduction ratio between the first 11 and the third pinion 12 is different from 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 20 until the first end-of-deployment stop 18 is in contact with the first pinion 11 which constitutes the second end-of-deployment stop.

[0370] During this period, the drill bit is driven along a helical trajectory with an appropriate cutting speed and feed rate, thus achieving the expected drilling.

[0371] 11.2. End of spindle deployment: passage of the fourth pinion into the immobilized position

[0372] When the first end-of-deployment stop 18 is against the second end-of-deployment stop 11, the deployment of the spindle 10 is stopped. The third 13 and fourth 14 gears therefore tend to rotate at different speeds. Thus, given the ogive shape of the pins 140 of the fourth gear 14, these pins 140 tend to come out of the clutch housings 130 of the third gear 13, so that the fourth gear 14 moves away from the third gear 13 towards its stationary position.

[0373] The second articulation points 701 of the bistable washer 70 with the sliding shaft 42 extend beyond the median plane PM so that the bistable washer 70 participates in moving the fourth pinion 14 into its immobilized position and then in maintaining it in its immobilized state.

[0374] During the movement of the fourth pinion 14 from its engaged position to its immobilized position, the lug 52 moves in translation along the axis of the sliding shaft 42 until it comes to rest in the housing 5104 of the cam 510 and is guided there if necessary by the ramp 5105 (position B).

[0375] In addition to or as an alternative to the ogive pins 140, the lever could allow the passage of the fourth pinion 14 into its immobilized position and the passage of the bistable washer 70 into its immobilized state.

[0376] 11.3. Pin retraction

[0377] When the fourth pinion 14 is in its immobilized position, the fourth pinion 14 is immobilized in rotation and the second pinion 12 is also immobilized in rotation.

[0378] Thus, spindle 10, which continues to be driven in rotation by the third pinion

[0379] 13 and the first pinion 11, moves in translation along its axis in the direction of a retraction inside the housing 20. ii.4. End of spindle retraction: passage of the fourth pinion into the engaged position

[0380] The retraction of the spindle 10 takes place until the first end-of-retraction stop 19 comes into contact with the second pinion 12, which constitutes the second end-of-retraction stop.

[0381] The control means detect that the pin 10 is thus completely retracted, for example by following the evolution over time of the motor current.

[0382] When the control means detect that the spindle 10 is fully retracted, they drive the motor so that the rotor R rotates in the opposite direction to the working direction.

[0383] The sliding shaft 42 is then driven in rotation by the third pinion 13 and by the unidirectional clutch 43.

[0384] The lug 52 is then rotated by the sliding shaft 42. It exits the housing 5104 of the cam 510 and then slides against the ramp 5100 of the cam from the recessed end 5102 to the projecting end 5101. The movement of the lug 52 along the ramp 5100 of the cam 510 induces a sliding of the sliding shaft 42 and the fourth pinion 14 towards the engaged position.

[0385] During this movement, the second articulation points 701 of the bistable washer 70 to the sliding shaft 42 pass the median plane PM beyond which the bistable washer 70 exerts on the sliding shaft 42 a force tending to move it, and the fourth pinion 14, towards the engaged position.

[0386] If the pins 140 of the fourth pinion 14 extend into the clutch housings 130 of the third pinion 13, then the fourth pinion 14 moves into its engaged position. The fourth pinion 14 is then held in this engaged position by the bistable washer 70. The fourth pinion 14 is in its engaged position slightly before the lug 52 passes beyond the projecting end 5101 of the cam 510. Thus, at the end of the movement of the fourth pinion 14 towards its engaged position, the lug 52 passes beyond the projecting end 5101 of the cam 510, then moves slightly towards the housing 5104 of the cam 512 under the effect of the release of the spring 520, so that it is in axis, i.e.extending from the housing 5104 of the cam 510 between the bearing surface 561 of the slot 560 and the connecting surface 5103 between the protruding end 5101 and the recessed end 5102 of the cam 510, while remaining away from the housing 5104 of the cam (position A). The lug 52 is thus prevented from rotating between these two surfaces 5103, 561 so that the sliding shaft 42 is prevented from rotating.

[0387] If the pins 140 of the fourth pinion 14 do not extend into the clutch housings 130 of the third pinion 13, then the pins 140 come to rest against the third pinion 13 outside the clutch housings 130 and the lug 52 compresses the spring 520 in the housing 521 of the sliding shaft 42. The probability of this situation occurring is very low given the implementation of the "bean-shaped" clutch housings 130 which maximizes the chances that the pins 140 are always opposite the corresponding clutch housings 130.

[0388] Meanwhile, the third pinion 13 continues its rotation. The fourth pinion 14 is driven at a different frequency than the third pinion 13 due to the difference in the number of teeth between the first and second pinions 11 and 12. As a result, the pins 140 gradually synchronize with the clutch housings 130 of the third pinion 13. When the pins 140 are synchronized with the clutch housings 130, i.e., they are aligned, the spring 520 relaxes and acts on the bistable washer 70 in such a way that its second points of articulation 701 with the sliding shaft 42 extend beyond the median plane PM. The bistable washer gradually reaches its engaged position by pushing the sliding shaft 42, which completes its movement until the fourth pinion 14 is in its engaged position. The fourth pinion is then held in its engaged position by the bistable washer 70.The fourth pinion 14 is in its engaged position a little before the lug 52 passes beyond the protruding end 5101 of the cam 510. Thus, at the end of the movement of the fourth pinion 14 towards its engaged position, the lug 52 passes beyond the protruding end 5101 of the cam 510 and then moves slightly towards the cam 512 under the effect of the release of the spring 520, so that it is in the axis of the housing 5104 of the cam 510 between the bearing surface 561 of the slot 560 and the connecting surface 5103 between the protruding end 5101 and the recessed end 5102 of the cam 510, while remaining away from the housing 5104 of the cam 510 (position A). The lug 52 is thus blocked in rotation between these two surfaces 561, 5103 and the sliding shaft 42 is immobilized in rotation.

[0389] The bistable washer 70 is in its immobilized state. The retraction can be stopped after a predetermined angle of rotation of the lug relative to the cam. This angle can be measured by the motor's angle sensor, taking into account the reduction ratio between the motor and the sliding shaft, and is considered by the drill's control means. In the illustrated embodiment, the cam is actually a double cam with two ramps, each extending through 180°, and the lug is a double lug, each end of which acts on a different cam. Therefore, half a turn of the double lug relative to the cam may be sufficient to move the fourth gear from its immobilized position to its engaged position. However, a full turn may be required depending on the reliability of the reset.

[0390] The drill is then in the state it was in before it was started so that a new drilling cycle can be started by pressing the start button.

[0391] 6.2.3. Variant: fork

[0392] In one variant, the means of moving the fourth pinion 14 from its stationary position to its engaged position do not include the cam system described above.

[0393] Alternatively, they include a 60 range.

[0394] Reference is made below to figures 5 and 6, which illustrate the fork system in the context of the magnet embodiment, insofar as the fork system can be implemented in the same way in the bistable washer embodiment.

[0395] This fork 60 is crossed at one of its ends by the spindle 10. At the other of its ends, the fork 60 is linked in translation to the sliding shaft 42. The fork 60 is also crossed by a rotating stop shaft 67.

[0396] The fork 60 is movable in translation between:

[0397] - an engaged position, illustrated in Figure 5, in which the fourth pinion 14 is in the engaged position, and

[0398] - a stationary position, illustrated in figure 6, in which the fourth pinion 14 is in its stationary position.

[0399] The device includes a lock 62. This lock 62 includes at one end a hook 620 and at the other end a cam 621.

[0400] The hook 620 is likely to cooperate with an attachment point 64 linked to the fork 60.

[0401] The lock 62 is mounted to rotate freely around an axis 63 attached to the housing between: - a release position, illustrated in Figure 5, in which the hook 620 does not cooperate with the hooking point 64 so that it does not hold the fork 60 in its immobilized position, and

[0402] - a locking position, illustrated in figure 6, in which the hook 620 cooperates with the hooking point 64 so that it holds the fork 60 in its immobilized position.

[0403] The fork 60 carries a spring blade 65, which tends to keep the lock 62 in its locked position.

[0404] A compression spring 66 is interposed between the first end stop of retraction 19 and the fork 60.

[0405] The first end stop of retraction 19 includes a conical portion 190 oriented towards the side of the lock 62.

[0406] The 620 hook includes a 6200 ramp designed to act on the 64 attachment point.

[0407] Throughout the deployment of the spindle 10 out of the housing 20, the fourth pinion 14 is held in its engaged position by the bistable washer 70, which is in its engaged state. The fork 60 is in its engaged position, held by the bistable washer 70, and in which the hook 620 does not cooperate with the engagement point 64, which is bearing against the ramp 6200.

[0408] During the movement of the fourth pinion 14 from its engaged position to its immobilized position under the effect on the one hand of a relative rotation of the third 13 and fourth 14 pinions and on the other hand of the passage of the bistable washer 70 from its engaged state to its immobilized state, the fork 60 is progressively driven in translation by the sliding shaft 42 towards the first end stop of retraction 19. During this movement, the hook point 64 slides against the ramp 6200 of the lock 62, which induces a rotation of the lock 62 around the axis 63 allowing the progressive passage of the hook point 64 in the hook 620.

[0409] When the fourth pinion 14 is in its immobilized position, in which it is held by the bistable washer 70, the fork 60 is in its immobilized position and the lock 62 is in its locked position in which it is held by the spring blade 65. The hook point 64 is then trapped in the hook 620 so that the fork 60 is held in its immobilized position.

[0410] Given that the fourth pinion 14 is in its immobilized position, the spindle

[0411] 10 retracts. On a final portion of the retraction stroke of the spindle 10, the first end stop compresses the spring 66, then the conical portion 190 of the first end stop 19 acts progressively on the cam 621 of the lock 62 so that the lock 62 rotates around the axis 63. This rotation of the lock 62 induces a progressive displacement of the lock 62 from its locking position to its release position. When the lock 62 reaches its release position, the hook 620 releases the hook point 64 so that the fork 60 is driven in translation along the spindle 10 under the effect of the release of the compression spring 66. The fork 60 then drives the sliding shaft 42 in translation by exerting a displacement force on it causing the second articulation points 701 of the bistable washer 70 with the sliding shaft 42 to pass the median plane PM.The bistable washer 70 thus gradually moves from its immobilized state to its engaged state and the fourth pinion 14 gradually moves from its immobilized position to its engaged position.

[0412] If, during the movement of the fourth pinion 14 from its stationary position to its engaged position, the pins 140 of the fourth pinion 14 extend into the clutch housings 130 of the third pinion 13, then the fork 60, under the effect of the spring 66's release, and the bistable washer 70 move the sliding shaft 42 and the fourth pinion 14 into its engaged position. The fourth pinion 14 is then held in this engaged position by the bistable washer 70.

[0413] If, during the movement of the fourth pinion 14 from its immobilized position to its engaged position, the pins 140 of the fourth pinion 14 do not extend into the clutch housings 130 of the third pinion 13, then the pins 140 come to rest against the third pinion 13 outside the clutch housings 130 and the spring 66 partially relaxes and exerts a force on the fork 60 and on the sliding shaft 42 tending to press the end of the pins 140 against the third pinion 13. The lock 60 is then in its release position in which the hooking point 64 is not trapped in the hook 620.Then, as in the case of the cam system, when the pins 140 synchronize with the clutch housings 130, the spring 66 continues to unwind, moving the fork 60 translationally towards and the sliding shaft 42 towards their engaged positions, so that the second articulation points 701 of the bistable washer 70 with the sliding shaft 42 gradually pass the median plane PM. The bistable washer 70 then pushes the sliding shaft until the fourth pin 14 is in its engaged position, where it is held by the bistable washer 70.

[0414] In this variant, no second retraction end stop is implemented. The retraction end position of spindle 10 corresponds to its position when the fourth pinion 14 leaves its immobilized position. 6.3. Variants

[0415] The two embodiments described above, as well as their variants, are wholly or partially combinable. Thus, variants of the magnetic embodiment can be implemented in the bistable washer embodiment, and vice versa.

Claims

DEMANDS 1. 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 or in rotation and translation about 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, guided in rotation relative to said casing and capable of being driven in rotation by said motor; - a fourth pinion, guided in rotation and translation relative to said housing, 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 first 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; - a stationary position in which it is rotationally connected to said housing by second connecting means 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 along a predetermined retraction stroke, characterized in that said device comprises means for maintaining said fourth pinion in its engaged position and in its stationary position, and first means for moving said fourth pinion from its engaged position to its immobilized position, and conversely, said means of support and said first means of movement comprising a bistable elastic element capable of taking two stable states, namely: - a clutch state in which it maintains said fourth pinion in its engaged position, and - a state of immobilization in which it maintains said fourth pinion in its immobilized position.

2. Device according to claim 1 comprising a sliding shaft carrying said fourth pinion and linked in translation to said fourth pinion about its axis of rotation, said bistable elastic element comprising at least one longitudinal element having two ends, one of said ends being articulated at at least a first articulation point on said housing and the other of said ends being articulated at at least a second articulation point on said sliding shaft, said at least one longitudinal element being compressible in a direction collinear with a line passing through said two ends and having a predetermined stiffness, said sliding shaft being movable relative to said housing between positions corresponding to said engaged and immobilized positions of said fourth pinion, said second articulation point of said sliding shaft occupying, in said engaged and immobilized states,positions substantially symmetrical with respect to a median plane perpendicular to said sliding shaft and passing through said first articulation point of said housing, the distance between said ends of said at least one longitudinal element in a relaxed state being greater than the distance between said first and second articulation points when said second articulation point of said sliding shaft is in said median plane.

3. Device according to claim 2 in which said at least one elongated element belongs to the group comprising: - a metal blade whose compressibility results from its buckling; - a component incorporating a spring whose compressibility results from the compression of said spring.

4. Device according to claim 2 or 3 in which said bistable elastic element comprises a bistable elastic washer.

5. Device according to any one of claims 2 to 4, wherein said first means of movement comprise: - a first end-of-deployment stop attached to said spindle and intended to bear against a second end-of-deployment stop linked to said casing, said first and second end-of-deployment stops delimiting the end of said deployment stroke of said spindle; - said first means of connection which include pins integral with said fourth pinion and suitable to cooperate with clutch housings of said third pinion in said engaged position to link in rotation said third and fourth pinions, said pins and clutch housings being shaped to induce a displacement of said fourth pinion in the direction of said immobilized position when said first end-of-deployment stop is in contact with said second end-of-deployment stop and said rotor rotates in said working direction, said displacement taking place over a stroke inducing said second articulation point of said sliding shaft to pass said median plane and the passage of said bistable elastic element into said immobilized state.

6. A device according to any one of claims 2 to 4, wherein said first means for moving said fourth pinion from said engaged position to said immobilized position comprise an actuator capable of transmitting said fourth pinion a displacement force capable of bringing said second articulation point of said sliding shaft beyond said median plane and of moving said bistable elastic element from said engaged state to said immobilized state, said actuator being able to take at least: - a neutral state in which it does not transmit said displacement force to said fourth pinion, said neutral state being maintained when said spindle is moved over said predetermined extension stroke and over said predetermined retraction stroke, and - a state of displacement in which it transmits to said fourth pinion said displacement force, said state of displacement being taken, following a retraction of said spindle over the entire predetermined retraction stroke, under the effect of a rotation of said rotor in said working direction.

7. Device according to claim 6, wherein said actuator comprises a movable lever capable of taking: - said neutral state in which said spindle does not transmit force to said lever and said lever does not transmit said displacement force to said fourth pinion so that said fourth pinion is held in said engaged position by said bistable elastic element in engagement state, said neutral state being maintained when said spindle is moved on said predetermined deployment stroke and on said predetermined retraction stroke; - said state of displacement, taken at the end of a deployment of said spindle over the entirety of said predetermined deployment stroke, under the effect of a rotation of said rotor in said working direction, in which said lever transmits said displacement force to said fourth pinion so as to bring said second articulation point of said sliding shaft beyond said median plane and to make said bistable elastic element pass from said engaged state to said immobilized state, said device comprising a first end-of-deployment stop integral with said spindle and intended to bear against a second end-of-deployment stop linked to said housing, said first and second end-of-deployment stops delimiting the end of said deployment stroke of said spindle, said device comprising an elastic return element against the effect of which said first pinion is mounted to move in translation along said spindle,a rotation of said spindle in said working direction when said first end-of-deployment stop is against said second end-of-deployment stop, inducing a translational drive along said spindle of said first pinion by said second pinion, said first pinion acting on said lever to place it in its moving state.

8. Device according to any one of claims 1 to 7 comprising second means for moving said fourth pinion from said immobilized position to said engaged position.

9. Device according to claim 8 in which said second means of movement comprise a first end stop of retraction integral with said spindle, and a fork linked in translation with said fourth pinion, said first end stop of retraction being configured to act on said fork on a final portion of said retraction stroke so as to drive said fork in translation and to bring said second articulation point of said sliding shaft beyond said median plane to bring said bistable elastic element into said engaged state and move said fourth pinion towards said engaged position.

10. Device according to claim 8 in which said second means of movement comprise: means for reversing the direction of rotation of said rotor capable of rotating said rotor in a direction opposite to said working direction; a sliding shaft carrying said fourth pinion and linked in translation to said fourth pinion along its axis of rotation; a unidirectional clutch configured to: not link said third pinion and said sliding shaft in rotation when said rotor rotates in said working direction, and link said third pinion and said sliding shaft in rotation when said rotor rotates in said direction opposite to said working direction;a cam shaped to induce, during a rotation of said rotor in said direction opposite to said working direction, a displacement of said sliding shaft and of said fourth pinion from said immobilized position to said engaged position, and to bring said second articulation point of said sliding shaft to pass said median plane and to make said bistable elastic element pass into said engaged state, said cam being annular and coaxial with said sliding shaft, said cam having a ramp whose development is parallel to the axis of rotation of said sliding shaft, said ramp being in contact with a lug fixed in rotation to said sliding shaft along the axis of rotation of said sliding shaft; said lug being at least partially linked in translation to said sliding shaft along the translation axis of said sliding shaft.

11. Device according to claim 10 in which said ramp of said annular cam includes a projecting end in the direction of the engaged position of said fourth pinion and a hollow end receiving said lug when said fourth pinion is in immobilized position, said device including means for immobilizing in rotation said sliding shaft when said fourth pinion is in engaged position such that the trajectory of said lug during the passage of the fourth pinion from its engaged position to its immobilized position is parallel to the axis of said sliding shaft.

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