FR3105751A1 - Tool changer - Google Patents

Abstract

A tool changer (10) comprising: a locking device (29) capable of adopting a first locked state and a second unlocked state; a controller capable of selectively adopting a first state and a second state; the control device being arranged such that: - in the first state, the input mechanical power is transmitted to the locking device (29); - in the second state, the input mechanical power is transmitted to the output port (56). Articulated arm comprising such a tool changer FIGURE OF THE ABSTRACT: Fig. 2

Description

Tool changer

FIELD OF THE INVENTION

The invention relates to the field of handling and more particularly to remotely operated handling in an aggressive environment.

BACKGROUND OF THE INVENTION

Conventionally, nuclear waste is stored in drums which are stored in secure volumes. The handling of these drums is done using a gripper attached to a terminal segment of an articulated arm which brings the drums through a conduit to the secure volume. An operator controls the gripper remotely using a cable which acts on the jaws of the gripper. Thus the operations of picking up and depositing drums are done in a secure manner.

It happens that some barrels are damaged, making it necessary to carry out cutting, nibbling or drilling operations to restore them. The limited dexterity of the pliers does not allow sufficiently precise control of the various tools necessary for repairing the barrel.

OBJECT OF THE INVENTION

The object of the invention is to facilitate the performance of remotely operated work.

To this end, provision is made for a tool changer comprising an input port for receiving input mechanical power, an output port for delivering output mechanical power, an interface intended to accommodate a tool, a locking device being able to adopt a first locked state in which the tool is secured to the interface and a second unlocked state in which the tool is detached from the interface. The tool changer also includes a controller that can selectively adopt a first state and a second state. According to the invention, the control device is arranged in such a way that in the first state, the mechanical input power is transmitted to the locking device so as to cause the locking device to change state. In the second state of the controller, the input mechanical power is transmitted to the output port.

A tool change device is thus obtained in which the actuation of the locking of the tool and the actuation of the tool come from the same source of mechanical power, which makes it possible to reduce the weight, the size and the cost of such a tool changer. The tool changer according to the invention is also particularly suitable for its implementation on an existing device such as for example a cable tele-operation gripper.

The device is particularly compact when the mechanical input power is supplied in the form of rotation.

Locking reliability is ensured when the locking device includes a cam to actuate a follower integral with a lock.

The jamming of a tool in the changer is avoided when the locking device comprises means for ejecting the tool.

Safety of use is improved when the locking device includes first means for returning to its first locked state and/or when the control device includes second means for returning the control device to its first state

The robustness of the control of the device in a disturbed radio electric environment is improved when the control device is actuated by a cable.

The tool changer is particularly effective when the control device comprises a pallet slidably mounted relative to a first housing of the tool changer.

The invention also relates to an articulated arm comprising an end segment provided with a tool changer as described above and in which the input port is connected by a flexible shaft to a motor carried by the articulated arm.

Other characteristics and advantages of the invention will become apparent on reading the following description of particular non-limiting embodiments of the invention.

Reference will be made to the following figures among which:

Figure 1 is a schematic view of an articulated arm according to the invention;

Figure 2 is a schematic sectional view of a tool changer according to the invention in a locked configuration and in a first state;

Figure 3 is an exploded schematic view of the tool changer of Figure 2;

Figure 4 is a schematic sectional view along a plane IV-IV of the tool changer of Figure 2 in a locked state;

Figure 5 is an exploded schematic view of the tool changer of Figure 2 in a locked configuration and in a second state;

Figure 6 is an exploded schematic view of the tool changer of Figure 2 in an unlocked configuration and in a second state;

Figure 7 is a schematic view of the tool changer of Figure 2 in an unlocked configuration and in a second state;

Figure 8 is a schematic sectional view along a plane IV-IV of the tool changer of Figure 2 in an unlocked state;

Figure 9 is a schematic sectional view of a tool changer according to the invention in a locked configuration and in a second state;

Figure 10 is a detail of a lock according to the invention in a locked configuration;

Figure 11 is a detail view of a lock of the invention in a first unlocking step;

Figure 12 is a detail view of a lock of the invention in a second unlocking step.

DETAILED DESCRIPTION OF THE INVENTION

Referring to Figure 1, the articulated arm according to the invention, and generally designated 1, comprises a fixed base 2 which carries a first shaft 3 rotatably mounted on the base 2. A first end 5.1 of a first arm segment 5 is articulated on a bearing with the aid of a pivot connection 6. The second end 5.2 of the first arm segment 5 receives an end segment 7 articulated at its first end 7.1 around a pivot 8. The second end 7.2 of the terminal segment 7 of the articulated arm 1 receives a tool changer 10. All the joints and bearings of the arm 1 are motorized, connected to a control unit 9 and controlled from the latter. A tool changer 10 is screwed onto the terminal segment 7 and is also connected by a ring 11 to a first end 12.1 of a first actuating cable 12. The second end 12.2 of the first cable 12 is connected to a handle 13. The tool changer 10 also comprises an input port 18 to which is connected a square end piece 14 of a first end 15.1 of a second shaft 15 of transmission flexible. The other end 15.2 of the second flexible shaft 15 is connected to an electric gear motor 16 screwed to the terminal segment 7. The gear motor 16 is connected to the control unit 9.

Referring to Figures 2 to 10, the tool changer 10 comprises a first housing 40 substantially parallelepipedic on the upper face 40.1 of which a first internally splined sleeve 20 is mounted for rotation about an input axis O _y using of a first ball bearing 21. The first end 20.1 of the splined sleeve 20 opens outwards from the first casing 40. The splined sleeve 20 is integral with a cam support 23 and comprises a first set of internal splines 24 .

The cam support 23 comprises a cam 25. The cam 25 accommodates rollers 26 carried by a proximal end 27.1 of a lock 27 slidably mounted in a first bore 41 of the first casing 40.

A first helical traction spring 28 extends between the cam support 23 and an attachment point 42 of the first casing 40 to exert a force tending to cause rotation of the cam support 23 in a clockwise direction according to the representation of the figures. 4 and 8.

The splined sleeve 20, the cam support 23 and the lock 27 constitute a locking device 29 of the tool changer 10.

As visible in Figure 10, the lock 27 comprises a first protrusion 27.3 whose section is substantially in the shape of a semicircle. The first protrusion 27.3 projects from a lower face 27.4 of the lock 27.

The first casing 40 also defines a first tapered housing 43 open on the lower face 40.2 and into which the first bore 41 opens. The lower face 40.2 also comprises a second bore 44 and a second tapered housing 45.

The locking device 29 can selectively adopt a first locked state and a second unlocked state. In the first locked state - shown in Figures 2 to 5 - a distal end 27.2 of the lock 27 extends into the first tapered housing 43. In the unlocked state - shown in Figures 6 to 8 - a distal end 27.2 of the lock 27 extends into the first tapered housing 43.

The tool changer 10 also comprises a pallet 50 mounted to slide relative to the first casing 40 in a direction substantially parallel to the first axis Oy. The pallet 50 is, here, guided on a surface using a bronze bearing 51 The pallet 50 receives a third shaft 52 mounted for rotation relative to the pallet 50 around the axis Oy via a second ball bearing 52.1. A fourth upper end 53 of the third shaft 52 comprises a second set of external splines 54. The second lower end 55 of the third shaft 52 includes a third set of outer splines 56. The fourth upper end 53 of the third shaft 52 also has a square recess 22 to cooperate with the square end piece 14.

A second helical compression spring 58 extends between the first casing 40 and the pallet 50 to exert a return force on the pallet, here a downward vertical force according to the representation of figures 2, 3 and 5.

The pallet 50 also includes an eyelet 57 through which passes one end 17.1 of a second cable 17 provided with a crimp 17.2. The pallet 50 can adopt a first state shown in Figure 5 in which the second set of grooves 54 comes into engagement with the first set of grooves 24. In this first state, the first pallet 50 can also adopt a second state shown in Figure 3 , wherein the second set of splines 54 is disengaged from the first set of splines 24 and the third set of splines 56 projects from an underside 40.2 of the first casing 40 through a second bore 44. The second spring 58 helical exerts a force to return the pallet 50 to its second state. Thus, pulling on the second cable 17 brings the pallet 50 from a second state (FIG. 3) to a first state (FIG. 5).

The pallet 50, the third shaft 52, the second cable 17, the bearing 51 and the spring 58 constitute a control device for the tool changer 10.

As visible in Figures 3 and 5, the tool 70 comprises a second housing 71 substantially parallelepipedic. A first truncated cone 72 provided in its upper part with a third bore 73 projects from the upper face 71.1 of the second casing 71. A centering pin 74 also projects from the upper face 71.1 of the second casing 71. The tool 70 also includes a second sleeve 75 provided with a fourth set of internal splines 75.1. The second sleeve 75 is rotatably mounted relative to the second casing 71 using a third ball bearing 76. The lower part 75.2 of the second sleeve 75 comprises a first toothing 77 outside. A fifth shaft 78 projects from a lower face 71.2 of the second casing 71. The fifth shaft 78 is rotatably mounted around an axis substantially parallel to the axis Oy via a fourth ball bearing 79. The upper end 78.1 of the fifth shaft 78 comprises a toothed wheel 80. A toothed belt 81 connects the first toothing 77 and the toothed wheel 80.

As visible in FIG. 10, the third bore 73 comprises a second protrusion 73.1 whose section is substantially in the shape of a semicircle. The second protrusion 73.1 projects from an underside 73.2 of the third bore 73.

In operation, and according to a first step, when a user wishes to couple a tool 70 to the tool changer 10, he presents the tool changer 10 so that the first truncated cone 72 substantially faces the first housing 43 (figure 3). Then, and according to a second step, the user acts on the handle 13 to exert tension on the first cable 12 and to move the pallet 50 from its second state (FIG. 3) to its first state (FIG. 5). When the pallet 50 is in its first state (FIG. 5), the first set of splines 24 cooperates with the second set of splines 54 and a rotation of the geared motor 16 in a first direction S1 causes the locking device 29 to pass from its first locked state to its second unlocked state (third step - Figure 6). The tool changer 10 is then brought closer to the tool 70 until the first truncated cone 72 is engaged in the first frustoconical housing 43 (fourth stage). The relative movement of the tool changer 10 relative to the tool 70 guided by the sliding of the outer surface of the first truncated cone 72 on the inner surface of the first frustoconical housing 43 and also by the sliding of the outer surface of the centering 74 on the inner surface of the second tapered housing 45. The torque exerted by the geared motor 16 on the locking device 29 is maintained during this movement to oppose the helical return spring 28 and maintain the locking device 29 in its second unlocked state. Once the tool 70 is engaged in the tool changer 10 (FIG. 7), the geared motor 16 is controlled to perform a rotation in a second direction S2 opposite to the first direction S1 to return the locking device 29 to its first unlocked state. (fifth stage – figure 9). In this configuration, the lock 27 extends into the third bore 73 and holds the tool changer 10 and the tool 70 in position. According to a sixth step, the user acts on the handle 13 and, under the effect of the second spring 58, the pallet 50 slides to pass into its second state (FIG. 2). In this second state of the pallet 50, the third set of splines 56 of the third shaft 52 cooperates with the fourth set of splines 75.1 of the second sleeve 75 and a rotation of the geared motor 16 is transmitted by the toothed belt 81 to the fifth shaft 78.

When the user wishes to change tools, he acts on the handle 13 to cause the pallet 50 to pass from its second state represented in FIG. 2 to its first state represented in FIG. the second direction S2 so as to release the lock 27 from the third bore 73. In this first state of the pallet 50, no mechanical power is transmitted to the tool During the translation of the lock 27, the first protrusion 27.3 comes in contact with the second protrusion 73.1 and exerts a pushing force on the tool 70 in order to detach the tool 70 from the first tapered housing 43.

Thus, it is possible to implement different types of tools at the end of a single articulated arm without the need to manually intervene directly on the end of the articulated arm. In the case of interventions of the articulated arm in an environment that justifies decontamination of the end of the arm before an operator can intervene on it, the operational gains (control, costs, delays) are significant.

Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

Especially,

-although here the control device comprises a ring 11 for connection to a control cable, the invention also applies to other types of control ports such as for example a toothed wheel or an electric actuator;

- although here the proximal end of the lock is provided with rollers, the invention also applies to other types of followers linked to the lock such as, for example, a bronze or Teflon follower;

- although here the cam support is returned to position using a helical spring, the invention also applies to other types of first return means such as Belleville washers, an elastomer block , a permanent magnet, a leaf spring or a distribution of mass using gravity;

- although here the pallet is returned to position using a helical spring, the invention also applies to other types of second return means such as Belleville washers, an elastomer block, a permanent magnet, a leaf spring or a distribution of mass using gravity;

- although here the lock comprises a protrusion, the invention also applies to other means of ejection of the tool such as for example compressed air, a controlled pusher or a cam;

- although here the tool changer comprises a first frustoconical housing, the invention also applies to other types of interface intended to accommodate a tool such as for example a frustoconical or cylindrical projection, a chuck;

- although here the input power is supplied in the form of a rotation, the invention also applies to other types of input port suitable for receiving mechanical power, such as a port for receiving mechanical power in the form of back and forth motion;

- although here the lower end of the third shaft comprises a third set of external splines, the invention also applies to other types of output port for delivering mechanical power such as internal splines a bayonet, for example, dogs, a friction clutch disc;

- although here the third shaft 52 comprises a square footprint, the invention also applies to other types of input port to receive one mechanical power such as for example a splined shaft, a flat, a flange, a joint gimbal.

Claims (9)

Tool changer (10) comprising:
an input port (22) for receiving input mechanical power;
an output port (56) for delivering output mechanical power,
an interface (43) intended to receive a tool (70);
a locking device (29) capable of adopting a first locked state in which the tool (70) is fixed to the interface (43) and a second unlocked state in which the tool (70) is separated from the interface ( 43);
a controller capable of selectively adopting a first state and a second state;
the control device being arranged so that:
- in the first state, the input mechanical power is transmitted to the locking device (29) so as to cause the locking device (29) to change state;
- in the second state, the input mechanical power is transmitted to the output port (56). A tool changer (10) according to claim 1, wherein the input mechanical power is provided in the form of rotation. Tool changer (10) according to claim 2, in which the locking device (29) comprises a cam (25) for actuating a follower (26) integral with a lock (27). Tool changer (10) according to any one of the preceding claims, in which the locking device (29) comprises means (27.3) for ejecting the tool (70). A tool changer (10) according to any preceding claim, wherein the locking device (29) includes first biasing means (28) to its first locked state. A tool changer (10) according to any preceding claim, wherein the control device is operated by a cable (17). A tool changer (10) according to any preceding claim, wherein the controller includes second means for biasing (58) the controller to its second state. A tool changer (10) according to any preceding claim, wherein the control device comprises a pallet (50) slidably mounted relative to a first housing (40) of the tool changer (10). Articulated arm (1) comprising an end segment (7) provided with a tool changer (10) according to any one of the preceding claims, in which the entry port (14) is connected by a flexible shaft (15 ) to a motor (16) carried by the articulated arm (1).