WO2008107011A1

WO2008107011A1 - Pneumatic rotary tool including means for controlling the inversion of the engine rotation direction, and pneumatic assistance means for said control

Info

Publication number: WO2008107011A1
Application number: PCT/EP2007/051287
Authority: WO
Inventors: Emmanuel Thery
Original assignee: Georges Renault
Priority date: 2007-02-09
Filing date: 2007-02-09
Publication date: 2008-09-12
Also published as: EP2114622B1; EP2114622A1

Abstract

The invention relates to a pneumatic rotary tool, such as a screwing tool, comprising an engine and at least one member (603) for controlling the engine rotation direction, said engine being supplied with air by a main supply duct (6022) that communicates with said control member (603), characterised in that it comprises at least one piston (605) for actuating said control member (603) driven by manual mobile actuation means (604) movable between two positions each corresponding to a rotation direction of said engine, the tool including at least one bypass (6023), (6061), (6062) of said supply duct (6022) for inducing, depending on the position of said actuation member (604), a movement of said piston (605) resulting in a movement of said control member (603) in order to reverse the rotation direction of said engine.

Description

Pneumatic rotary tool comprising means for reversing the direction of rotation of the motor and means for pneumatically assisting said control.

1. Field of the invention

The field of the invention is that of industrial equipment. More specifically, the invention relates to pneumatic rotary tools comprising a motor powered by an air supply duct for rotating the motor.

The invention is particularly applicable to screwdrivers, these being provided for screwing or unscrewing, which generally involves the implementation of pneumatic means for reversing the direction of rotation of the rotor of the screwdriver.

2. Prior Art

A pneumatic motor for a screwdriver according to the prior art is described with reference to FIGS. 1, 2 and 3.

As it appears in these figures, a pneumatic motor conventionally comprises: a body 1; a front cheek 2 and a rear cheek 3 between which is mounted the body 1; a rotor 4 carrying pallets 41 and rotatably mounted on the front and rear cheeks 2, 3 respectively through bearings 21 and 31.

The body has at its base an extension l i inside which is mounted a spool 5 can be moved axially and / or actuated in rotation by a lever.

The extension 11 has an air intake orifice 111 which communicates with an air inlet duct 101 formed in the handle 10 of the tool (an exhaust duct 102 also being provided in the handle 10). .

The actuation of the spool 5 makes it possible to reverse the direction of rotation of the rotor and / or to regulate the speed of the latter. The operation is as follows.

When the drawer is in the position shown in Figure 1, the air admitted into the conduit 101 passes through the orifice 111, then into the orifice 12 (the orifice 13 being obstructed by the drawer) which communicates with the chamber 121 (extending from the side of the back cheek 3) appearing in the sectional view of FIG. 3.

At the launch of the engine, a portion of the air goes to the rear cheek 3 and the front cheek 2, which have recesses 32 for conveying air to the base of the vanes 41 so as to radially slide them to the outside of the rotor and to bring the latter into engagement with the air injected into the chamber 121.

The exhaust of the air (once the engine is launched, that is to say after a rotation of the rotor of about 90 °) is effected by the chamber 131 (FIG. 4) and by the orifice 13 ( then via the duct 102 of the handle), a complementary exhaust being effected by the orifices 14 formed in the walls of the body 1, so as to compensate for the compression of the air between the pallets when they move on the portion of the body that tends to decrease the volume between two pallets.

The reversal of the direction of rotation of the rotor is obtained by axially moving the spool 5 so as to place the orifice 13 in communication with the inlet 111, the air then circulating firstly in the chamber 131 and then escaping. by the chamber 121 (in addition to the complementary exhaust through the orifices 14).

Furthermore, with reference to FIG. 2, the angular position of the spool 5 makes it possible to modify the air passage section in the orifice 12 (or in the orifice 13 as a function of the axial position of the spool) and, by therefore, to vary the speed of rotation of the rotor.

3. Disadvantages of prior art

A disadvantage of this technique is the implementation of the spool whose axial displacement reverses the direction of rotation of the rotor. Indeed, the manipulation of such a drawer is by the thumb and the index, this to provide the user with a convenient and intuitive drawer layout.

This arrangement therefore involves traversing longitudinally the upper part of the handle of the tool from one side to the other. In practice, this manipulation proves difficult, in particular because of the resistance to axial displacement that the drawer opposes to the user.

This resistance is due to the mounting through the drawer which involves many friction.

However, it is relatively complex and / or expensive to remove these friction, several parts of the tool being involved in the generation of friction and to be adjusted between them to be able to remove all or part of the friction.

4. Objectives of the invention

The invention particularly aims to overcome the disadvantages of the prior art.

More precisely, the object of the invention is to propose a technique of inversion of the direction of motor rotation for a pneumatic rotary tool such as a screwdriver which allows manipulation without effort, or practically, by the user. The invention also aims to provide such a technique that allows intuitive manipulation by the user.

The invention also aims to provide such a technique that is simple in design and easy to implement.

5. DISCLOSURE OF THE INVENTION These objectives, as well as others which will appear later, are achieved by means of the invention which relates to a pneumatic rotary tool such as a screwdriver, comprising an engine and at least one a control member of the direction of rotation of said motor, said motor being supplied with air by a main supply conduit communicating with said control member, characterized in that it comprises at least one actuating piston of said member control device controlled by manual operating means movable between two positions each corresponding to a direction of rotation of said motor, the tool comprising at least one bypass of said supply duct capable of driving, depending on the position of said body actuation, a displacement of said piston likely to cause a displacement of said control member causing a reversal of the direction of rotation of said motor.

Thus, thanks to the invention, the manipulation allowing the reversal of the direction of rotation of the motor is facilitated by pneumatic assistance due to the implementation of the derivation of the supply duct. In this way, the user acts without effort, or almost, on the manual actuating means, the pneumatic assistance taking over the action initiated by the user.

Advantageously, said one or more pistons are slidably mounted in a slide having a communication orifice with said bypass, the communication between said bypass and said orifice being released or obstructed by a movable part coupled to said actuating means.

A relatively simple conception design is thus obtained by the implementation of a triggering means (the mobile part) of the pneumatic assistance that is easy to couple to the manual actuating means. Indeed, the adjustment of this part allowing it to be moved with a minimum of friction can be easily obtained.

Preferably, said actuating means comprise two actuators driving one a direction of rotation of said motor and the other the opposite direction of rotation. The implementation of two actuators makes it possible to contribute to the simplicity of handling of the tool, by allowing the user to clearly identify, by the relative positions of the actuators, the action to be performed to cause the reversal of the direction. motor rotation.

According to an advantageous solution, said control member is rotatable between two positions each corresponding to a direction of rotation of said motor, said one or more pistons being movable in a plane perpendicular to the axis of rotation of said control member, said control member preferably having two fins extending radially, a piston cooperating with each fin. It is thus possible to obtain the reversal of the motor rotation direction with a rotation of the control member over a limited stroke also involving a displacement on a limited stroke of the pistons.

The tool therefore involves reduced displacements of the moving parts involved in the reversal of the direction of motor rotation, allowing a simple and reactive operation.

Preferably, said actuators are movable in directions substantially parallel to the axis of rotation of said control member.

It is thus possible ergonomically to arrange the corresponding actuating means, for example at the front of the handle or at a rear part of the tool.

In addition, actuating means operable in a direction parallel to the axis of rotation allow manipulation thereof with one hand (the one holding the tool).

According to a preferred embodiment, said movable part comprises a slide slidably mounted in a chamber into which said orifice opens on the one hand and said bypass on the other hand, said slider carrying a shutter intended to allow / block the passage of air from said bypass to said orifice through said chamber.

In this case, said actuators are preferably coupled together so that the passage of one of said sliders in a position allowing said air passage causes the passage of the other slider in a position prohibiting said passage of air.

According to a preferred solution, the tool integrates a single piece in which are provided: - said main supply duct; said one or more leads; said slides; said one or more chambers.

In this way, the structural parts linked to the moving elements are grouped together in a single piece, enabling the direction of motor rotation to be reversed.

Such a part thus contributes to the simplicity of manufacture and / or assembly of the tool.

It is noted that such a piece can easily be manufactured by various conceivable techniques.

According to a preferred embodiment, said actuators are coupled to each other by a toggle system.

In this way, the manipulation of the tool (to reverse the direction of motor rotation) becomes particularly simple and intuitive. Indeed, the actuation of one of the actuators automatically drives, via the rocker system, an action on the other actuator. Meanwhile, pressing one of the actuators, it becomes obvious to the user that the reversal of the direction of rotation is obtained by pressing the other actuator. 6. List of figures

Other characteristics and advantages of the invention will emerge more clearly on reading the following description of a preferred embodiment of the invention, given by way of illustrative and nonlimiting example, and the appended drawings among which: - Figures 1 to 3 are views of a pneumatic tool with reversal of the direction of motor rotation according to the prior art;

- Figures 4 to 5 are partial perspective views of a tool according to the invention, respectively in a position of unscrewing and in a screwing position; Figure 6 is a partial view in a vertical longitudinal section of a tool according to the invention; - Figure 7 is a partial view in a horizontal longitudinal section of a tool according to the invention; FIG. 8 is a view of a tool according to the invention according to section BB indicated in FIG. 7. DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

7.1. Recall of the principle of invention

As indicated above, the principle of the invention lies in the fact of proposing a pneumatic rotary tool whose reversing control of the motor rotation direction is pneumatically assisted.

7.2. Architectural Example of a Tool According to the Invention

With reference to FIG. 6, a pneumatic rotary tool such as a screwdriver comprises, in the present embodiment: a housing 601 in which the motor (not shown) of the tool is rotatably mounted; a handle 602; a control member of the direction of rotation of the motor, hereinafter referred to as inverter 603; manual actuating means 604 intended to occupy two distinct positions: a first position corresponding to a direction of engine rotation, another position corresponding to a direction of engine rotation opposite to that of the first position.

In addition, the handle 602 has a cavity 6021 intended to be connected, in the lower part of the handle, to an air supply circuit, and communicating with: a main supply conduit 6022, supplying the motor of the tool through the inverter 603; a bypass 6023 intended to conduct a flow of air to pistons (described in more detail below) capable of acting on the inverter as a function of the position of the manual actuating means 604. The inverter 603 is described in greater detail with reference to FIGS. 4, 5 and 8. As illustrated by these figures, the inverter 603 is rotatably mounted in the housing of the tool, and has orifices 6031 for diffusing air into the engine. .

The inverter 603 is capable of pivoting over a determined range, so as to place the orifices 6031 opposite the chambers of the motor corresponding to a direction of rotation such that the unscrewing in a first position of the orifices 6031 (in this case, this position being that illustrated in Figure 4), or facing the motor chambers corresponding to a direction of rotation such as the screwing in a second position of the orifices 6031 (in this case, this position being that illustrated in Figure 5) . For this, the inverter 603 is mounted in a secondary housing 6032 (mounted inside the tool housing 601 and integral therewith), the secondary housing having two notches 60321.

In addition, the inverter 603 carries two radial fins 6033 protruding through the notches 60321, each fin being capable of being angularly deflected over the angular range determined by the corresponding indentation.

As it is clear, the indentations extend symmetrically with respect to the median plane of the tool.

Furthermore, the tool comprises two actuating pistons 605 slidably mounted, each in a slide 6051 and capable of causing pivoting of the inverter 603 from a screwing position to a unscrewing position or vice versa.

The pistons 605 are movable in a plane perpendicular to the axis of rotation of the inverter and are positioned to cooperate each with a fin 6033 of the inverter. The operation is as follows: when a piston 605 comes out of its slide, it exerts a thrust on the corresponding vane 6033, which causes a rotation of the inverter 603. The pushed vane moves in its notch until abut against the upper edge of the latter. Simultaneously, the other fin also moves into its notch by exerting a thrust on the corresponding piston 605 which therefore enters its slide.

The actuation of the pistons is described below with reference to FIGS. 7 and 8.

According to the present embodiment, the actuating means comprise two actuators 6041 interconnected by a flip-flop piece 6042 comprising: two arms 60421, each coupled to an actuation 6041; a leg 60422, centered between the arms 60421, and pivotally mounted by its free end on the housing 601 of the tool. It is understood that in this way: an actuator 6041 controls a direction of motor rotation, the other actuator controlling the opposite direction of rotation; moving one of the actuators in one direction causes movement in an opposite direction of the other actuator. In addition, as shown in FIG. 8, it is noted that the actuators are manipulated in a direction parallel to the longitudinal axis of the housing of the tool (or in other words, in a direction parallel to the axis rotation of the inverter, and therefore of the engine).

The actuators 6041 are each formed by a slide slidably mounted in a chamber 6043 in communication with the shunt 6023 via conduits 6061, 6062.

These ducts 6061, 6062 thus constitute extensions of the branch 6023, the ducts 6061 extending longitudinally through a piece 606, and the ducts 6062, extending transversely in the room 606 to from ducts 6061 to join rooms 6043 in which they open.

It will be noted that the chambers 6043 and the slides 6051 communicate in pairs through an orifice 6052; the actuators 6041 each have two sealing portions 60411 (forming a sealed sliding connection with the corresponding chamber 6043) connected by a connecting portion 60412 (here having a frustoconical shape but may also have a cylindrical shape according to a possible variant).

It is understood that the connecting portion 60412 defines with the corresponding chamber 6043 a space in which air from the branch 6023 and 6061 conduits, 6062 is likely to flow.

In the configuration illustrated in FIGS. 7 and 8 according to which the actuator 6041 on the right of FIG. 7 is actuated (that is to say engaged towards the inside of the tool, as opposed to the outgoing position of the left actuator), the right actuator is slid to the bottom of its chamber 6043 so that the gap between the connecting portion 60412 and the chamber 6043 communicates the conduit 6061 and the orifice 6052. The The air coming from the bypass can thus pass into the slide 6051 of the piston 605 (on the right of FIG. 8), which causes the piston 605 to exit its slide, which then acts as described above on the corresponding blade of the piston. inverter.

It is noted that the chambers 6043 each have at their end an exhaust port 60431 ensuring the mobility of the actuation in the chamber, without compression or vacuum of air.

Meanwhile, the latch 6042 being in a position in which the right actuator is pushed towards the inside of the tool and allows the passage of air from the bypass to the slide of the right piston, the actuator of left is pulled by the rocker towards the outside of the tool in a position in which the passage of air towards the slide of the left piston is blocked.

Indeed, the connecting portion 60412 of the left-hand actuator is brought into a position in which a sealing portion 60411 is placed between the duct 6061 on the left and the orifice 6052. This sealing portion therefore forms a shutter of air passage between conduit 6061 and port 6052.

The right piston 605 pushing the right fin 6033 of the inverter, the latter rotates and the left wing 6033 pushes the piston 605 left in its slide. Note that the movable members (pistons and actuators) cooperating directly or indirectly with the inverter are mounted in one and the same part 606, in which are provided: the main supply conduit 6022; branch 6023 and conduits 6061 and 6062; the chambers 6043 of the actuators;

the 6051 slides of the pistons.

In addition, this part 606 also forms the secondary casing 6032 of the inverter 603.

Claims

1. Pneumatic rotary tool such as a screwdriver, comprising a motor and at least one control member (603) of the direction of rotation of said motor, said motor being supplied with air by a main supply duct (6022) communicating with said control member (603), characterized in that it comprises at least one actuating piston (605) of said control member (603) controlled by mobile manual actuating means (604) between two corresponding positions each having a direction of rotation of said motor, the tool comprising at least one branch (6023), (6061), (6062) of said supply line (6022) capable of driving, depending on the position of said member actuation (604), a displacement of said piston (605) likely to cause a displacement of said control member (603) causing a reversal of the direction of rotation of said motor.

The pneumatic rotary tool according to claim 1, characterized in that said one or more pistons (605) are slidably mounted in a slider (6051) having a communication port (6052) with said shunt (6023), (6061), ( 6062), the communication between said bypass and said port being released or obstructed by a movable portion (6041) coupled to said actuating means (604).

3. pneumatic rotary tool according to one of claims 1 and 2, characterized in that said actuating means comprises two actuators (6041) driving one a direction of rotation of said motor and the other the opposite direction of rotation.

4. Pneumatic rotary tool according to any one of claims 1 to 3, characterized in that said control member (603) is rotatable between two positions each corresponding to a direction of rotation of said motor, said piston or pistons (605). ) being movable in a plane perpendicular to the axis of rotation of said control member (603).

5. Pneumatic rotary tool according to claim 4, characterized in that said control member (603) has two wings (6033) extending radially, a piston (605) cooperating with each fin (6033).

6. pneumatic rotary tool according to one of claims 4 and 5, characterized in that said actuators (6041) are movable in directions substantially parallel to the axis of rotation of said control member (603).

7. Pneumatic rotary tool according to any one of claims 2 to 6, characterized in that said movable portion comprises a slide slidably mounted in a chamber (6043) into which opens said orifice (6052) on the one hand and said bypass (6023), (6061), (6062) on the other hand, said shutter carrying a shutter (60411) for allowing / blocking the passage of air from said shunt to said orifice through said chamber.

8. Pneumatic rotary tool according to claims 3 and 7, characterized in that said actuators are coupled together so that the passage of one of said sliders in a position allowing said passage of air causes the passage of the other slider in a position prohibiting said passage of air.

9. pneumatic rotary tool according to one of the two claims 7 and 8, characterized in that it incorporates a one-piece piece (606) in which are provided: said main supply duct (6022); said one or more leads (6023), (6061), (6062); said slides (6051); said at least one chamber (6043).

Pneumatic rotary tool according to one of claims 3 to

9, characterized in that said actuators (6041) are coupled to each other by a flip-flop system (6042).