WO2020065424A1

WO2020065424A1 - Tool changing device for a robot with the mechanical coupling elements being pneumatic fittings

Info

Publication number: WO2020065424A1
Application number: PCT/IB2019/057405
Authority: WO
Inventors: Giuseppe Bellandi
Original assignee: GIMATIC S.r.l.
Priority date: 2018-09-27
Filing date: 2019-09-03
Publication date: 2020-04-02

Abstract

A tool changing device, preferably for collaborative robots, comprising a first plate constrainable to a robot and provided with at least one first supplying or suctioning duct to supply or suction a working fluid, and a second plate constrainable to a tool to be moved, able to be removably fastened to the first plate and provided with at least one second supplying or suctioning duct to supply or suction the working fluid to/from the tool, is described. The tool changing device is further provided with mechanical plate- coupling elements able to be locked on the other plate, and with respective locking means and pneumatic fittings to fluidically connect the at least one first duct to the at least one second duct. Advantageously, the mechanical coupling elements are the pneumatic fittings or, conversely, the pneumatic fittings are the mechanical coupling elements.

Description

TOOL CHANGING DEVICE FOR A ROBOT WITH THE MECHANICAL COUPLING ELEMENTS BEING PNEUMATIC FITTINGS

DESCRIPTION

Field of the invention

The present invention refers to a tool changing device that can be fastened to a corresponding robot, preferably a so-named collaborative robot.

State of the art

Recently, in the industrial context, there was a growing need to use so- named "collaborative robots," i.e. robots that can work in close contact with the operators without risking injuring them.

In fact, as is known, industrial robots work very quickly and can cause injuries to an operator in the event of collision with the latter: thus, for safety reasons, spaces adjacent to operating robots are usually forbidden to operators.

Collaborative robots work at a lower speed with respect to a typical industrial robot and have safety systems that rely on position sensors that control the stopping of the robot whenever the presence of an operator is detected at a certain distance, thus preventing the possibility of possible accident.

These characteristics allow a greater cooperation between robots and operators, which is essential in contexts in which it can be necessary for human operators and robots to carry out joint activities or which, in any case, must operate next to each other.

Collaborative robots can be equipped with tools that allow to carry out different tasks (gripping tools, cutting tools, etc.). Tool changing devices that can be fastened to the end portion of the arm of the robot were designed in order to use more tools interchangeably on a same robot.

A typical tool changing device comprises a plate intended to be fastened to the robot (generally by means of screws), and for this reason identified as robot side plate, and a second plate, on which the tools necessary to carry out the work are installed and for this reason named tool side plate; the tool changing devices also comprise mechanical coupling elements between the first and the second plates and, in case of pneumatic tools, a plurality of supplying or suctioning ducts to supply or suction the working fluid of the tool.

While the first plate is generally permanently constrained to the robot, the second plate is intended to be reversibly mounted/unmounted on/from the first plate to allow to quickly replace the tools.

For this reason, mechanical coupling elements are provided between the first and the second plates which can comprise threaded elements or mushroom-shaped mechanical coupling pins with an upper portion of greater diameter with respect to the lower portion extending from the plate.

Generally, the mechanical coupling pins are on the tool side plate and engage in corresponding seats obtained in the robot side plate; in order to ensure that the first and the second plates are constrained to each other while the robot is moving, the first plate has locking means for the mechanical coupling pins of the second plate. The locking means comprise a ring nut that is able to restrain the mechanical coupling pins and to maintain them sandwich- like interposed between the two plates. This way, the ring nut, together with the first plate, remains constrained to the second plate because prevented from making movements away therefrom.

The ring nut is rotated manually by the operator between a first angular unlocking position, at which the ring nut does not engage the lower portions of the mechanical coupling pins and the second plate can be mounted or unmounted on/from the first plate, and a second angular locking position, at which the ring nut engages the lower portions of the mechanical coupling pins and the first plate is constrained to the second plate.

In practice, when there is a need to replace the tools, the operator preventively prepares the second plate with the tools required, rotates the ring nut of the device in the unlocking direction, changes the tool, thus allowing to unmount the second plate with the tools that are no longer necessary, mounts the second plate previously prearranged with the tools required and, by turning the ring nut to the locking position, constrains the second plate to the first one and thus to the robot: this way, the tool replacement operation is easy and quick.

The tool changing device is usually also connected to the electric, pneumatic or hydraulic supply lines in order to allow the movement and functionality of the tools.

In particular, the pneumatic compressed air supply lines, generally controlled by taps upstream, are inserted in the first plate of the tool changing device radially from the outside and supply ducts which extend radially and axially inside the first plate and which open on the lower face, i.e. the one intended to come into contact with the second plate of the tool changing device, at the pneumatic fittings of the second plate.

In fact, the second plate is provided, on its upper surface, i.e. the one that goes in abutment against the lower face of the first plate, with as many ducts and pneumatic fittings that connect to the ducts of the first plate, when the second plate is mounted on the first plate, thus conferring continuity to the pneumatic lines.

In other words, the second tool side plate is provided both with mechanical coupling pins and with pneumatic fittings for the fluidic connection, which are distinct from the mechanical coupling pins.

Thus, in practice, the operator must mount the second tool side plate on the first robot side plate so that both the mechanical coupling elements, i.e. the pins, and the pneumatic fittings are properly inserted in the respective seats so as to allow the proper operations of the tool changing device.

A first drawback of the tool changing devices described above resides in the fact that they must be made with dimensions such as to allow to distinctly and separately accommodate both the mechanical coupling elements and the pneumatic fittings of the fluidic connection on the surfaces of the two plates. For this reason, the tool changing devices according to the known art usually have great volumes (bulkiness) and a considerable weight which can make the operations of the robot less efficient and safe.

Whenever the tool changing device is also provided with electric connections, a further drawback lies in the fact that the electric power supply lines extend outwardly and around the tool changing device: the presence of these lines limits the space in which the operator can work and can cause problems in case of impact.

Summary of the Invention

Object of the present invention is to provide a tool changing device for robots that allows to overcome the drawbacks of known solutions, and which is particularly compact, simple to implement and use, and safe for operators.

The present invention thus concerns a tool changing device according to claim 1.

In particular, the tool changing device comprises a first plate constrainable to a robot, preferably a collaborative robot, and a second plate constrainable to one or more tools to be moved and able to be removably fastened to the first plate; in practice, the second plate can be mounted and unmounted on/from the first plate to facilitate the interchangeability between the tools.

The first and the second plates are respectively provided with at least one duct and at least one second supplying or suctioning duct to supply or suction the working fluid to/from the tool fastened to the second plate.

The tool changing device further comprises mechanical plate-coupling elements able to be locked on the other plate and respective locking means which, in fact, allow to lock a plate to the other without a risk of being separated when the robot is in movement.

Moreover, at least one pneumatic fitting allows to put the at least one first duct of the first plate in fluidic communication with the at least one second duct of the second plate so that, when the two plates are mechanically coupled with each other, the working fluid can pass from the first plate to the second plate, or vice-versa. Advantageously, the mechanical coupling elements are also pneumatic fittings that fluidically connect the at least first duct of the first plate to the at least one second duct of the second plate and, consequently, the pneumatic fittings are also the mechanical coupling elements for coupling a plate with the other.

In fact, unlike the tool changing devices according to the known art, the tool changing device described herein does not have distinct and spatially separate components working as mechanical coupling elements or as pneumatic fittings, but has a single component, i.e. the mechanical coupling elements working to mechanically couple the two plates and to pneumatically connect the at least one first duct and the at least one second duct.

This allows to implement tool changing devices of smaller volume and weight with respect to the devices of the known art, i.e. with limited bulkiness and structurally simpler than the known solutions which require a greater volume to accommodate both the mechanical coupling elements and the pneumatic fittings distinct from the mechanical coupling elements.

The solution thus allows to achieve a tool changing device that is more compact, easy to use and which allows to make the work of the robot more efficient.

The tool changing device is effective and simultaneously simple to achieve and comfortable to use because it is based on the concept of using the mechanical coupling elements also as pneumatic fittings, and to use the locking means so that to achieve both the mechanical coupling and the pneumatic coupling.

Preferably, the locking means comprise a single first ring nut shared by all the locking elements, and not individual locking means for each locking element. The first ring nut is movable between a locking position, in which all the mechanical coupling elements are contemporaneously locked and the two plates are joined, and an unlocking position, in which all the mechanical coupling elements are contemporaneously free and the two plates are separable.

Preferably, the locking means with which the tool changing device is equipped, are movable between an unlocking position, at which the locking means are separated from the mechanical coupling elements and thus the first plate and the second plate are separable from each other, and a locking position, at which the locking means are in abutment against the mechanical coupling elements, thus constraining the first plate and the second plate to each other so that they cannot be separated while the robot is moving.

Preferably, the mechanical coupling elements working as pneumatic fittings are on the second plate and are inserted in corresponding accommodating seats obtained in the first plate; optionally, however, their arrangement can be inverted, i.e. the mechanical coupling elements working as pneumatic fittings can be arranged on the first plate and the corresponding seats on the second plate; optionally still, the first plate can be provided both with mechanical coupling elements and accommodating seats to which the respective accommodating seats and mechanical coupling elements on the second plate correspond.

In the preferred embodiments, the mechanical coupling elements comprise a portion that can be inserted into the corresponding accommodating seat and a portion instead intended to remain outside the accommodating seat; against the latter a corresponding portion of the locking means can abut so as to obtain an undercut and prevent the mechanical coupling elements from accidentally slipping out of the respective accommodating seats, with the consequent separation of the two plates.

Preferably, the mechanical coupling elements are mushroom-shaped pins provided with a first portion cantileverly extending directly from the second plate like a stem, and with a head wider than the first portion. The head of the pin can be sealingly inserted and removed in/from the corresponding accommodating seat, and the first portion can be engaged by the locking means that abut against it in the locking position. The tool changing device can also be equipped with one, two or more pins and corresponding accommodating seats and in a number at least equal to the number of the first ducts provided on the first plate.

The pins are hollow to allow the fluid to pass from the first ducts to the second ducts, or vice-versa, and are sealed to prevent the outflow of air at the pins working as pneumatic fittings; for this reason, preferably, the head of the pin and the first portion of the pin inserted in the second plate are provided with at least one gasket, or with at least one equivalent sealing element.

In the preferred embodiments, the locking means comprise a first ring nut fastened to the first plate and provided with a knob: the first ring nut can be rotated with respect to the first plate between an unlocking position at which the first ring nut does not engage the first portion of the pins, i.e. is separated therefrom, and the second plate can be separated from the first plate, and a locking position at which the first ring nut is in abutment against the first portion of the pins and is interposed between the second plate and the head of the pins, thereby obtaining an undercut so as to lock the second plate to the first plate.

In an embodiment, the tool changing device is further provided with a second ring nut to open and close the first ducts of the first plate, the second ring nut being provided with holes and rotatable between an open position, at which the holes are aligned with the first ducts, thereby allowing the fluid passage, and a closed position at which the second ring nut intercepts the first ducts and stops the fluid passage.

In practice, the second ring nut works as a tap that allows to open or close the air passage through the first ducts of the first plate; this way, the operators can control the air passage through the tool changing device directly, by rotating the second ring nut in the desired direction.

Preferably, the second ring nut also comprises at least one a niche and more preferably still comprises a number of niches equal to the number of the first ducts of the first plate. A gasket, in which the holes described above that allow the fluid to pass through the first ducts of the first plate are obtained, is housed in each niche.

Preferably, the gaskets constitute the portion of the second ring nut that intercepts the first ducts of the first plate when the second ring nut is rotated to the closed position.

Optionally, blind channels are provided in the first plate of the tool changing device; each blind channel allows to put a hole of the gaskets in fluidic communication with the outer environment when the second ring nut is rotated to the closed position, thus allowing to rebalance the pressure that remained in the hole of the gaskets with that of the outer environment.

Preferably, the second ring nut is provided with a knob that allows to rotate the second ring nut between the closed and open positions and also with a safety pin cantileverly extending towards the knob of the first ring nut to enter into contact therewith at determined angular positions of the two ring nuts.

When the second ring nut is rotated to open the fluid passage through the first ducts of the first plate, such safety pin is intended to abut against the knob of the first ring nut so that to make it rotate to the locking position earlier with respect to the rotation of the second ring nut to the open position.

Similarly, by rotating the first ring nut to the unlocking position, it abuts against the safety pin of the second ring nut, making the latter rotate to the closed position before the two plates are unlocked, so that the separation of the second plate from the first cannot occur if the fluid passage through the pins was not closed beforehand. This prevents the accidental operation of the tools.

In a further embodiment, the tool changing device comprises a single control knob to control the first ring nut and the second ring nut that allows to contemporaneously move the two ring nuts in the same direction and preferably one before the other as described above. In other words, the knob allows to contemporaneously rotate the two ring nuts by maintaining them angularly staggered of the same angle.

In practice, this last knob is movable by an operator between a first position, at which it maintains the first ring nut in the unlocking position and the second ring nut in the locked position, and a second position at which it maintains the first ring nut in the locking position and the second ring nut in the open position. This embodiment has the advantage of facilitating the manual operations of the operator who must operate only one knob instead of two distinct knobs.

Preferably, the tool changing device comprises a sensor, preferably an inductive proximity sensor, that detects the position of the first ring nut and sends a corresponding signal to an external control unit so that the robot, to which the tool changing device is fastened, is prevented from operating if the first ring nut is not rotated to the locking position.

Optionally, the sensor can be of optical type or magnetic type.

Preferably, the first and the second plates respectively comprise at least one first through opening and at least one second through opening.

More preferably still, the first and the second plates are provided with a single through opening each and allow to obtain a single central through opening, practically a central channel, when the tool changing device is assembled, i.e. when the second plate is fastened to the first plate.

Optionally, the tools mounted on the tool changing device can be moved by means of electric power; for this reason, a further embodiment of the tool changing device comprises an electrically connecting device provided with a first connector that can be mounted on the first plate and a second connector that can be mounted on the second plate.

The first connector and the second connector each support at least one electric power line and can be functionally coupled with each other to electrically connect the electric power lines to each other and can be separated from each other to electrically disconnect the electric lines from each other.

In practice, like for the first and second plates, also the first and second connectors can be reversibly coupled with each other.

Preferably, the first connector can be installed in the first through opening of the first plate and the second connector can be installed in the second through opening of the second plate so that, when the second plate is mounted on the first plate, the second connector also functionally couples with the first connector. Thus, advantageously, the electric lines pass through the central through opening of the tool changing device fully assembled and are not instead positioned outside it, thus preventing an operator from being able bump into them and to detach them.

In a second aspect, the present invention concerns a method for functionally connecting a pneumatic tool to a manipulator/robot.

The method provides to equip the robot with a tool changing device having the characteristics mentioned above, i.e. comprising:

a first plate constrainable to the robot and provided with at least one first supplying or suctioning duct to supply or suction a working fluid;

a second plate constrainable to a tool to be moved, able to be removably fastened to the first plate and provided with at least one second supplying or suctioning duct to supply or suction the working fluid to/from the tool;

mechanical plate-coupling elements able to be locked on the other plate, and respective locking means;

- pneumatic fittings to fluidically connect the at least one first duct to the at least one second duct;

and further provides to mechanically couple one plate to the other and to fluidically connect the at least one first duct of the first plate with the at least one second duct of the second plate.

Advantageously, the mechanical coupling elements are configured as pneumatic fittings, i.e. have a dual function, and the step B) is obtained by operating the locking means directly thereon.

List of the figures

Further characteristics and advantages of the invention will become clearer in the following detailed description of three preferred, but not exclusive, embodiments illustrated by way of example and without limitations, with the aid of the accompanying figures, in which:

- figure 1 is a perspective view of a first embodiment of a tool changing device according to the present invention;

- figure 2 is a plan view, from the bottom, of the tool changing device shown in figure 1 ;

- figure 2A is a sectional view considered on the plane A-A of figure 2;

- figure 3 is a perspective view of a detail of the tool changing device shown in figure 1 in a first configuration of use, unlocked;

- figure 4 is a perspective view of a detail of the tool changing device shown in figure 1 in a second configuration of use, locked;

- figure 5 is a plan and partially sectional view of a component of the tool changing device shown in figure 1 , in a first configuration of use, unlocked;

- figure 6 is a plan and partially sectional view of a component of the tool changing device shown in figure 1 in a second configuration of use, locked;

- figure 7 is a perspective view of a second embodiment of a tool changing device according to the present invention;

- figure 8 is an isometric view of a component of the tool changing device shown in figure 7;

- figure 9 is a cross-sectional view of the tool changing device shown in figure 7;

- figure 10 is a perspective and partially exploded view of a detail of the tool changing device shown in figure 7;

- figure 11 is a plan view, from the bottom, of the tool changing device shown in figure 7 in a third configuration of use;

- figure 11 A is a sectional view considered on the plane A-A of figure 11 ;

- figure 12 is a plan view, from the bottom, of the tool changing device shown in figure 7 in a first configuration of use;

- figure 12A is a sectional front view considered on the plane B-B of figure 12; - figure 13 is a plan view from the bottom of the tool changing device shown in figure 7 in a first configuration of use;

- figure 14 is a plan view from the bottom of the tool changing device shown in figure 7 in a second configuration of use;

- figure 15 is a plan view from the bottom of the tool changing device shown in figure 7 in a third configuration of use;

- figure 16 is a perspective view of a third embodiment of a tool changing device according to the present invention.

- figure 17 is an isometric, partially sectional, view of a fourth embodiment of the tool changing device according to the present invention.

Detailed description of the invention

Figures 1 -6 show a first embodiment of the tool changing device 1 according to the present invention, intended to be mounted on robots and manipulators, preferably collaborative robots, and which can be equipped with one or more tools, for example grippers or suction pads, to allow to grab and move objects.

For simplicity, the robot and possible tools are not shown in figure 1 and in the figures that will be described below. Explicit reference will be made to the collaborative robots henceforth, taking care to consider that the tool changing device can be installed on robots in general.

In particular, with reference to figure 1 , the tool changing device 1 comprises a first plate 2 directly constrainable to the collaborative robot and for this defined as robot side plate, and a second plate 4 on which the tools can be mounted, and for this identified as tool side plate.

The second plate 4 can be reversibly fastened to the first plate 2, i.e. can be mounted or unmounted on/from it so that to be able to equip the collaborative robot with the tools required in a quick and fast way: in figure 1 , for example, the tool changing device 1 is shown with the second plate 2 separated from the first plate 4.

The tool changing device 1 can be connected to electric lines and/or to external supplying or suctioning lines to supply or suction a working fluid, so as to allow the operations of the tools. For example, it is possible to equip the tool changing device 1 with a support for suction pads and, by means of the external suctioning line, to ensure a safe grip on the piece to be moved by sucking air, i.e. by means of pneumatic vacuum, or it is possible to fasten pneumatic grippers to it and to adjust their opening and closing by means of compressed air.

In order to make the description simpler, reference will henceforth only be made to the use of compressed air, but a technician of the sector will certainly also be able to extend what is described for vacuums.

The first plate 2 has a first upper face 10 at which the first plate 2 is constrained to the collaborative robot and a second lower face 11 visible in figures 5 and 6 and intended to abut against the second plate 4 when it is mounted thereon. The first plate 2 has quadrilateral shape with four roundish or lobed angles and, in the center, a first through opening 13.

Returning to figure 1 , at the angles on the upper face 10 of the first plate 2, there are first pneumatic joints 14, which allow to connect the tool changing device 1 to an external compressed air supply line by means of first flexible tubes 12.

In this first embodiment, the air flow is adjusted by means of taps upstream of the device itself (not shown in the figure).

Remaining on figure 1 , it can be noted that, similarly to the first plate 2, also the second plate 4 has a first upper face 16 intended to abut against the lower face 11 of the first plate 2, and a second lower face 17, shown in figure 2, on which there are second pneumatic joints 15 connected to second tubes 18. The second plate 4 also has a quadrilateral shape with roundish or lobed angles and a second through opening 19 at the center. Thus, the lower face 11 of the first plate 2 and the upper face 16 of the second plate 4 constitute the mounting interface of the second plate 4 to the first plate 2, at which the fluidic connection between the first plate 2 and the second plate 4 occurs. In fact, since the tools are fastened to the second plate 4 and the external lines are engaged in the pneumatic joints 14 of the first plate 2, the tool changing device 1 must comprise ducts and pneumatic fittings that allow to bring compressed air to the pneumatic tools so as to allow them to operate.

Figure 2A shows the plates 2 and 4 functionally coupled: the first plate 2 and the second plate 4 are provided, respectively, with first ducts 3 and with second ducts 5 which open at the first pneumatic joints 14 and at the second pneumatic joints 15; such pneumatic joints 14, 15 are fastened to the plates 2, 4 by means of a first thread 20 and a second thread 21 , respectively.

At the end opposite the first and second pneumatic joints 14, 15, the first ducts 3 and the second ducts 5 respectively end at seats 31 and corresponding pins 6 that will now be described in detail.

As shown for example in figure 1 , the second plate 4 can be fastened to the first plate 2 by means of the mechanical coupling elements which are configured as mushroom-shaped pins 6, positioned on the angles of the upper face 16 of the second plate 4, in the embodiments described herein. Such pins 6 have a first portion 7 extending directly from the second plate 4, like a stem, and a head 27 of a greater diameter with respect to the first portion 7.

By looking at figure 2A, it is possible to see that the pin 6 is fastened on the second plate 4 by means of a third thread 22, that is coaxial to the second ducts 5 and hollow.

The pins 6 are inserted with the head 27 in corresponding seats 31 obtained, as shown in figures 5 and 6, on the lower face 11 of the first plate 2 so as to allow a mechanical coupling between the two plates 2 and 4. In order to ensure that the second plate 4 remains stably fastened to the first plate 2 and that it does not separate therefrom while the collaborative robot is operating, the tool changing device 1 further comprises locking means 8 that allow to lock the second plate 4 on the first plate 2.

Such locking means 8 will be described in depth below, now let's focus on figure 2A, which shows a pin 6 of the second plate 4 inserted in the seat 31 of the first plate 2 so that to implement the mechanical, and simultaneously pneumatic, coupling between the two plates.

As set forth previously, the pins 6 are hollow and are positioned on the second plate 4 in a coaxial way with respect to the second ducts 5 so that, when they couple with the corresponding seats 31 of the first plate 2, they constitute a mechanical coupling means, but also a pneumatic fitting of fluidic connection between the first ducts 3 of the first plate 2 and the second ducts 5 of the second plate 4.

In other words, the pneumatic fitting 6 simultaneously allows to couple the first plate 2 with the second plate 4 both from a mechanical point of view and from a fluidic point of view, because it allows the compressed air to pass from the first plate 2 to the second plate 4, or the suctioning to create the vacuum.

In practice, the pins 6 are also pneumatic fittings, unlike the tool changing devices according to the known art in which the mechanical coupling and pneumatic coupling functions are carried out by distinct elements.

In fact, the pneumatic fitting 6, inserted in the corresponding seat 31 by means of the head 27, defines a central channel 28, which allows the compressed air to pass from the first plate 2 to the second plate 4 in the direction shown by the arrow in figure 2A.

In order to ensure an adequate pneumatic seal, the tool changing device 1 is provided with a first gasket 23 of the O-ring type, or a similar sealing element, positioned between the pin 6 and the second plate 4, and with a second gasket 34 placed on the head 27 of the pin 6 and which is interposed between the surface of the first plate 2 delimiting the seat 31 and the head 27 itself.

As set forth previously, the tool changing device 1 comprises locking means 8 that allow to lock the second plate 2 to the first plate 1.

In the first embodiment described herein, the locking means 8 comprise, as shown in figures 5 and 6, a first ring nut 24 fastened to the first plate 2, a knob 25 combined therewith by means of a pivot 26 and a spring 57, or equivalent resilient element, positioned between the first ring nut 24 and the knob 25.

The first ring nut 24 is coaxial with respect to the first plate 2 and with respect to the two joined plates 2 and 4, and can be rotated with respect to it between:

an unlocking position, at which the pins 6 of the second plate 4 can be freely inserted and removed in/from the respective seats 31 of the first plate 2, and the second plate 4 can thus be mounted/unmounted on/from the first plate 2, and

a locking position, at which the pins 6 of the second plate 4 are locked in the seats 31 , without being able to come out, and the second plate 4 is locked to the first plate 2 and cannot be separated therefrom.

The first ring nut 24 is thus shared by all the pins 6, in the sense that the first ring nut 24 is used to lock and unlock all the pins 6 contemporaneously.

The first ring nut 24 is provided with hooked ends 30 that allow to lock the second plate 4 to the first plate 2, going into abutment, as shown in figure 4, against the first portion 7 of the pins 6, thus obtaining an undercut: this way, the first ring nut 24 in the locking position is sandwich-like interposed between the upper surface 16 of the second plate 4 and the head 27 of the pin 6, thus preventing the two plates 2 and 4 from separating.

Figure 6 shows the partially overlapping position that the hooked ends 30 take with respect to the accommodating seats 31 of the pins 6 when the ring nut 24 is rotated by an operator to the locking position, in the direction shown by the respective arrow.

As can instead be appreciated in figure 3, when the ring nut 24 is in the unlocking position, the hooked end 30 does not abut against the first portion 7 of the pins 6 and the two plates 2 and 4 can be separated from each other.

In fact, as can be seen in figure 5, when the first ring nut 24 is in the unlocking position, i.e. when the operator rotates the knob 25 in the direction shown by the respective arrow, the hooked ends 30 are in misaligned position with respect to the seats 31 of the pins 6, thus allowing their respective insertion or removal from the seats 31 themselves.

In substance, the locking of the second plate 4 on the first plate 2 is carried out by obtaining an undercut at the first portion 7 of the pins 6; the pins 6 thus constitute the lockable portion of the second plate 4.

In order to ensure that the collaborative robot can become operative only if the first ring nut 24 is rotated in the locking position, i.e. only if the second plate 4 is constrained to the first plate 2, the tool changing device 1 is provided with detecting means to detect the position of the first ring nut 24 and which comprise an inductive proximity sensor 9 visible in figures 5 and 6.

When the inductive proximity sensor 9 detects the presence of the first ring nut 24, as shown in figure 6, it sends a signal to an external control unit that allows the collaborative robot to start operating; instead, when the inductive proximity sensor 9 does not detect the presence of the first ring nut 24, as shown in figure 5, it prevents the robot from moving by means of the external control unit.

By comparing figures 5 and 6, in order to prevent the first ring nut 24 in the locking position from accidentally rotating to the unlocking position without the intervention of an operator, the knob 25 is provided with a tooth 67 that is inserted, when the first ring nut 24 is in the locking position, in a corresponding opening 68 obtained in the first plate 2; in addition, the spring 57 counters the positioning of the knob 25 in the unlocking position so that the force exerted by an operator is necessary for rotating the knob 25 with respect to the pivot 26, thus moving the tooth 67 away from the opening 68 and bringing it to the unlocking position, thus allowing the separation of the two plates 2 and 4.

Figures 7-15 show a second embodiment 1 ' of the present invention that is different from the first described previously in that it comprises a second ring nut 29 to close the first supplying/suctioning ducts 3 provided in the first plate 2. The second ring nut 29 works as a tap of the working fluid ducts 3. The second ring nut 29 is positioned on the first plate 2, above the first ring nut 24 that intercepts the first portions 7 of the pins 6, i.e. is in a position more proximal to the upper surface 10 of the first plate 2, and is ring-shaped so as to not intercept the first through opening 13 of the first plate 2.

As shown in figure 9, the second ring nut 29 is provided with niches, or compartments 32, extending along an arc of a circle, thus assuming a slot-like shape.

A gasket 33, provided with a hole 35, is positioned in each niche 32 and, in this embodiment, the number of niches 32 and thus also the number of gaskets 33 and holes 35 corresponds to the number of first ducts 3 of the first plate 2.

The second ring nut 29 is positioned coaxially with respect to the first plate 2 and with respect to the plates 2 and 4 joined, and can be rotated with respect to it between:

- a first open position at which the holes 35 are aligned with the first compressed air ducts 3, which thus remain open to make the air flow to the seats 31 that accommodate the pins 6;

- a second closed position, at which the holes 35 are misaligned with respect to the first ducts 3, which thus remain closed to prevent the air from being supplied to the seats 31 of the pins 6.

In other words, unlike the first embodiment described previously, the opening and closing of the pneumatic air, and in general of the working fluid, that passes through the tool changing device to reach the tools fastened thereto, does not only occur by means of taps upstream of the device, but is obtained by rotating the second ring nut 29.

This way, during the tool exchanging operations, the operators can close or open the compressed air passage by acting directly on the tool changing device T provided with the second ring nut 29, without having to intervene on the taps upstream thereof.

Figure 10 shows a detail of the second ring nut 29 wherein the gasket 33 is separated from the niche 32 that accommodates it when the tool changing device is properly mounted.

Figures 11 and 12 shown the tool changing device 1 ' equipped with the first ring nut 24 and the second ring nut 29, respectively in the locking and open position of the first ducts 3, and in the unlocking and closed position of the first ducts 3.

From the comparison of figures 11A and 12A, it is possible to see that, when the tool changing device 1 ' is in the locking and open position of the first ducts 3 (figures 11 and 11 A), the first ring nut 24 intercepts the first portion 7 of the pins 6 and the second ring nut 29 is rotated so that the holes 35 are aligned with respect to the first duct 3, thus allowing the passage of compressed air; when the tool changing device 1 ' is in the unlocking and closed position of the first ducts 3 (figures 12 and 12A), the second ring nut 29 does not intercept the first portion 7 of the pins 6 and the second ring nut 29 is rotated so that the gasket 33 intercepts the respective first duct 3, thus preventing the passage of compressed air.

In order to allow the compressed air that remained in the volume delimited by the gasket and constituting the hole 35 to be vented, the first plate 2 is provided with blind channels 38 that put the hole 35 in fluidic communication with the outer environment when the second ring nut 29 is rotated to the closed position, as shown in figure 12A.

Operatively, the operator must open the passage of compressed air through the first ducts 3 after having locked the second plate 4 to the first plate 2 and, vice-versa, unlock it after having closed the respective first pneumatic ducts 3 to prevent quick depressurization of the tools and possible accidents for the operators.

In order to prevent these problems, the second ring nut 29 is provided with a safety pin 36 best visible in figures 7 and 8 and fastened in proximity of the knob 37 so that to protrude towards the knob 25 of the first ring nut 24, by intercepting it, i.e. to: - abut against it and push the first ring nut 24 to rotate together with the second ring nut 29 during the rotation towards the locking position of the pins 6; and

- to allow the first ring nut 24 to drive the second ring nut 29 to rotate during the rotation towards the unlocking position of the pins 6, thus obtaining the closing of the ducts 3 before the pins 6 are released by the first ring nut 24.

As shown in figures 13 and 15, the first ring nut 24 and the second ring nut 29 are slightly cantilevered angularly one with respect to the other due to the presence of the safety pin 36; this way, by rotating the second ring nut 29 in the direction shown by the respective arrow shown in figure 15 to open the first ducts 3, the safety pin 36 abuts against the first ring nut 24, thus determining the locking of the second plate 4 to the first plate 2 before the second ring nut 29 opens the first ducts 3.

Similarly, by rotating the first ring nut 24 to the unlocking position, as shown by the respective arrow in figure 13, the displacement of the second ring nut 29 to the closed position of the first channels 3 before the unlocking of the second plate 2 is determined due to the presence of the safety pin 36.

This way, the improper use of the tool changing device by the operators is prevented.

Finally, as shown in figure 14, it is possible to rotate the two ring nuts 24,

29 independently of each other if the movement of one does not intercept that of the other by means of the safety pin 36: for example, when the first ring nut 24 is in the locking position, it is possible to open or close the first ducts 3, and thus to adjust the passage of compressed air, without affecting the rotation of the first ring nut 24 itself.

This is not possible, for example, in the third embodiment of the tool changing device 1 " shown in figure 16: in this case, a single knob 40 adjusts the rotation of both ring nuts 24 and 29 so that to only allow the movements shown in figures 13 and 15, without the possibility to move them separately as shown in figure 14. This certainly makes the work of operators easier and safer, who, by rotating a single knob 40, unlock the second plate 4 from the first plate 2, thus first closing the passage of the compressed air and opening the passage of the working fluid, by first locking the second plate 4 to the first plate 2.

Thus, in the light of the characteristics described above, it is clear that, by implementing the tool changing devices 1 , T, 1 " provided with mechanical coupling elements, i.e. pins 6 that also work as pneumatic fittings between the two plates 2, 4, the volume of the tool changing device 1 , T, 1 " is smaller with respect to the volume of a tool changing device according to the known art and provided with an equal number of mechanical coupling elements that are structurally and functionally distinct from the pneumatic fittings.

The tool changing devices 1 , T, 1 " are in fact more compact and lighter than the devices according to the known art and allow to overcome the problems of bulkiness and weight described previously.

Figure 17 shows a fourth embodiment T" provided with an electrically connected device 50 that comprises a first connector 51 that can be fastened to the robot side plate 2 in the first through opening 13 and a second connector 52 that can be fastened to the tool side plate 4 in the second though opening 19. The first connector 51 and the second connector 52 can be fastened to the respective plates 2 and 4 of the tool changing device by means of screws 53. First electric lines converge at the first connector 51 , and second electric lines (not shown in the figures), which must each be connected to a corresponding first electric line, converge at the second connector 52. For this reason, the second connector 52 is provided with connecting plugs 56 each connected to a second electric line, and the first connector 51 is provided with corresponding connecting plugs 58.

When the tool side plate 4 is fastened to the robot side plate 2, the two connectors 51 and 52 are functionally coupled; i.e. the plugs 56 and 58 are electrically connected to give continuity to the respective electric lines and when the tool side plate 4 is separated from the robot side plate 2, the connectors 51 , 52 also separate.

When the second plate 4 is mounted on the first plate 2, the through opening 13 and the through opening 19 form a single central through opening 41.

The device 50 advantageously allows the electric lines to be positioned through such central opening 41 (visible in figure 2) and, by using collaborative robots provided with electric lines that directly come out of the wrist of the robot on which the tool changing device T" is fastened, it is also possible to arrange the electric lines directly at the center of the robot and of the tool changing device 1 for the electric power supply of the tools.

In other words, this solution allows not to have cumbersome and dangerous electric cables surrounding the tool changing device and the robot, to the advantage of the safety of the people working near the tool itself.

Claims

1. A tool changing device (1

comprising:

a first plate (2) constrainable to a robot and provided with at least one first supplying or suctioning duct (3) to supply or suction a working fluid;

a second plate (4) constrainable to a tool to be moved, able to be removably fastened to the first plate (2) and provided with at least one second supplying or suctioning duct (5) to supply or suction the working fluid to/from the tool;

mechanical plate-coupling elements (6) able to be locked on the other plate, and respective locking means (8);

pneumatic fittings to fluidically connect the at least one first duct (3) to the at least one second duct (5),

characterized in that the mechanical coupling elements (6) are the pneumatic fittings or, conversely, the pneumatic fittings are the mechanical coupling elements (6).

2. Tool changing device (1 ,T,1”, T”) according to claim 1 , wherein the locking means (8) are movable between an unlocking position at which said locking means (8) are separated from the mechanical coupling elements (6) and the first plate (2) and the second plate (4) can be separated, and a locking position at which the locking means (8) are in abutment against the mechanical coupling elements (6) and the first plate (2) and the second plate (4) are constrained to each other and cannot be separated.

3. Tool changing device (1 ,1’, 1”, T”) according to claim 1 or claim 2, wherein the locking means (8) comprise a single ring nut (24) movable between a locking position of all mechanical coupling elements (6) contemporaneously and an unlocking position of all mechanical coupling elements (6) contemporaneously.

4. Tool changing device (1 ,T,T',T”) according to any one of claims 1 -3, comprising accommodating seats (31 ) to accommodate the mechanical coupling elements (6) and wherein the mechanical coupling elements (6) comprise a portion (27) that can be inserted into the corresponding accommodating seat (31 ) to obtain the pneumatic coupling and a portion (7) intended to remain outside the accommodating seat (31 ) against which a corresponding portion (30) of the locking means (8) can abut so as to obtain an undercut and prevent the mechanical coupling elements (6) from accidentally slipping out of the respective accommodating seats (31 ).

5. Tool changing device (1 ,1’,1”,T”) according to claim 4, wherein the mechanical coupling elements (6) are mushroom-shaped pins provided with a first portion (7) cantileverly extending directly from the second plate (2) and with a head (27) wider than the first portion (7), and wherein the head (27) can be sealingly inserted into the corresponding accommodating seat (31 ) and the first portion (7) can be engaged by the locking means (8) that abut against it in the locking position.

6. Tool changing device (1 ,1’,1”,T”) according to claim 5, wherein the mechanical coupling pins (6) functioning as a pneumatic fitting are located on the second plate (4) and the accommodating seats (31 ) are obtained in the first plate (2).

7. Tool changing device (1 ,1’,1”,T”) according to claim 6, wherein the pins (6) are hollow and coaxial with respect to the second ducts (5) of the second plate (4).

8. Tool changing device (1 ,1’,1”,T”) according to claim 6 or claim 7, wherein the locking means (8) comprise a first ring nut (24) fastened to the first plate (2) and provided with a knob (25), wherein the first ring nut (24) can be rotated with respect to the first plate (2) between an unlocking position at which the first ring nut (24) does not engage the first portion (7) of the pins (6) and the second plate (4) can be separated from the first plate (2), and a locking position at which the first ring nut (24) is in abutment against the first portion (7) of the pins (6) and is interposed between the second plate (4) and the head (27) of the pins (6), thereby obtaining an undercut so as to lock the second plate (4) to the first plate (2).

9. Tool changing device (T,1”,T”) according to claim 8, comprising a second ring nut (29) to open and close the first ducts (3) of the first plate (2), the second ring nut being provided with holes (35) and rotatable between an open position at which the holes (35) are aligned with the first ducts (3) thereby allowing the fluid passage, and a closed position at which the second ring nut (29) intercepts the first ducts (3) and stops the fluid passage.

10. Tool changing device (T,1”,T”) according to claim 9, wherein the second ring nut (29) comprises niches (32) and gaskets (33) housed in the niches (32), wherein the holes (35) are obtained on the gaskets (33), and wherein the gaskets (33) intercept the first ducts (3) in the closed position of the second ring nut (29).

11. Tool changing device (T,1”,T”) according to claim 9 or claim 10, wherein the second ring nut (29) is provided with a knob (37) for manual activation and a safety pin (36) intended to abut against the knob (25) of the first ring nut (24) so as to turn the first ring nut (24) itself to the locking position before the second ring nut (29) causes the first ducts (3) of the first plate (2) to open.

12. Tool changing device (T,1”,T”) according to claim 11 , wherein the first ring nut (24) abuts against the safety pin (36) so as to turn the second ring nut (29) to the open position before the first ring nut (24) causes the second plate (4) to be unlocked from the first plate (2).

13. Tool changing device (1”, 1”’) according to claim 9 or claim 10, comprising a single knob (40) to control both the first ring nut (24) and the second ring nut (29) and movable by an operator between a first position at which it holds the first ring nut (24) in the unlocking position and the second ring nut (29) in the closed position, and a second position at which it holds the first ring nut (24) in the locking position and the second ring nut (29) in the open position.

14. Tool changing device (T, 1”,1’”) according to any one of preceding claims 9-13, comprising blind channels (38) for fluid communication between the holes (35) of the second ring nut (29) rotated to the closed position and the external environment.

15. Tool changing device (1 , T, 1”,1’”) according to any one of preceding claims 8-14, comprising a sensor (9) that detects the position of the first ring nut (24) and sends a corresponding signal to an external control unit.

16. Tool changing device (1 , T, 1”,1’”) according to any one of preceding claims 1 -15, wherein the first plate (2) and the second plate (4) each comprises at least one first through opening (13) and at least one second through opening (19), respectively, which together form at least one central opening (41 ).

17. Tool changing device (T”) according to any one of preceding claims 1 -16, comprising an electrically connecting device (50) provided with a first connector (51 ) that can be mounted on the first plate (2) and a second connector (52) that can be mounted on the second plate (4), wherein the first connector (51 ) and the second connector (52) each support at least one electric power line and can be functionally coupled to electrically connect said corresponding electric power lines to each other and can be separated to electrically disconnect said electric power lines from each other.

18. Tool changing device (T”) according to any one of preceding claims 1 -17, comprising an electrically connecting device (50) provided with a first connector (51 ) that can be mounted on the first plate (2) and a second connector (52) that can be mounted on the second plate (4), wherein the connectors (51 , 52) support corresponding electric power lines and can be connected/disconnected together with the first plate (2) and the second plate (4), and wherein the first plate (2) comprises a first through opening (13) and the first connector (51 ) can be installed in said through opening (13) and/or wherein the second plate (4) comprises a second through opening (19) and the second connector (52) can be installed in said second through opening (19).

19. Tool changing device (T”) according to claim 18, wherein the first through opening (13) and the second through opening (19) constitute a central through opening (41 ) and wherein the electric power lines connected by means of the electrically connecting device (50) pass through the first and the second plates (2, 4) of the tool changing device along said central through opening (41 ).

20. A method of functionally connecting a pneumatic tool to a robot, comprising the steps of:

A) providing the robot with a tool changing device (1 , 1’, 1”, 1’”) equipped with:

a first plate (2) constrainable to the robot and provided with at least one first supplying or suctioning duct (3) to supply or suction a working fluid;

pneumatic fittings to fluidically connect the at least one first duct (3) to the at least one second duct (5);

B) coupling one plate to the other and fluidically connecting the at least one first duct (3) of the first plate (2) with the at least one second duct (5) of the second plate (4);

characterized in that the mechanical coupling elements (6) are designed as pneumatic fittings and in that, by step B) is achieved by operating the locking means directly on them.