Device for conveying and gripping preforms in thermal conditioning unit and gripper capable of cooperating with gripping device

Abstract

The invention relates to a gripping device (26) for gripping preforms (4) of containers (2) made of thermoplastic material in a thermal conditioning unit, comprising at least:-a support (32) comprising a hole having a vertical axis A; -a mandrel having an axis of rotation B, the first end of the mandrel being mounted in the bore of the support (32), pivotally connected with sliding relative to the support (32), the vertical axis A of the support (32) and the axis of rotation B of the mandrel thus being coaxial; -rotating means mounted on opposite free ends of the mandrel and comprising at least:-a rotating means nose (46) detachably fixed to the free end of the mandrel, the rotating means nose (46) for receiving a neck (10) of a preform (4); an ejector (48) fixed to the support (32) by a removable fixing means, the mandrel and the rotary device nose (46) extending coaxially with the ejector (48) such that a free end of the rotary device nose (46) protrudes from the ejector (48), the ejector has a substantially tubular shape and comprises, at one of the ends, at least one ejection surface for ejecting the preform (4); characterised in that the removable securing means comprise at least one jaw (70) secured to the ejector (48) and / or to the support (32), each jaw (70) comprising a male or female means capable of cooperating with a complementary female or male means secured to the support or correspondingly to the ejector (48), and at least one resilient means, the resilient means are able to hold the male or female means of the jaw (70) in a locked position in the female or male means of the support or in the respective ejector (48).

Description

Technical Field

[0001] The invention relates to a device for transporting and gripping tubular preforms while the preforms are rotated about their main axis, more particularly in a thermal conditioning unit, as well as a gripper suitable for being fixed to a robot arm and cooperating with a gripping device according to the invention, and a method for assembling and / or disassembling at least one rotating device nose of a gripping device according to the invention.

[0002] The invention relates to the field of producing hollow bodies made of thermoplastic material, for which purpose a preform is first produced by injection molding and then formed into a container in a container production plant. Background Art

[0003] To this end, the container manufacturing plant comprises a thermal conditioning unit, also called an oven, in which the preforms are thermally conditioned, and a blow moulding unit to obtain the final container, in which the preforms are formed by a blow moulding operation or by a stretch blow moulding operation.

[0004] "Hollow body" refers to a preform of a container, or even a final container, or possibly an intermediate container, that is to say any type of hollow body comprising a body from which an open tubular neck extends.

[0005] In the following the term preform will preferably be used in a non-limiting manner.

[0006] The preform is generally in the form of a tubular cylinder which is closed at one of its axial ends and which is extended at its other end by a neck which is also tubular.

[0007] The neck extends axially from a main annular flange arranged at the junction of the neck and the body of the preform to an annular lip, also called rim, which delimits the axial opening of the neck.

[0008] During the blowing operation, it is required that the body of the preform undergoes plastic deformation in order to form the final container. In order to be able to carry out this blowing operation, it is necessary to bring the body of the preform to a temperature above the glass transition temperature of the material. To this end, the preform is thermally conditioned by circulating it in the oven by means of a conveyor device along a heating path. The oven comprises a heating device, for example constituted by an infrared lamp or a laser diode, in front of which the preform moves by means of a conveyor device.

[0009] During its movement in the oven, the preform is advantageously rotated about its main axis in order to homogenize the heating.

[0010] The preforms are usually held on the transport device by means of gripping mechanisms.

[0011] The preforms are transferred or loaded to the inlet of the oven by transferring the preforms from a preform supply device to a transport device.

[0012] The operation consisting of gripping the preform with a gripping device is called "threading".

[0013] In the same way, the operation consisting of unloading the heated preforms from the gripping device at the exit from the oven is called "unwinding".

[0014] Traditionally, the gripping device grips the preform by the inner surface of the neck using gripping means. The gripping device is then driven by a vertical downward movement along the main axis of the preform relative to the conveying device so as to allow the gripping device to be inserted into the neck. To this end, the conveying device circulates above the transfer device.

[0015] Instead, the gripping device is separated from the preform due to the bearing of the ejection surface on the edge of the preform and the raising of the gripping device along the main axis of the preform relative to the conveying device, so as to allow the gripping device to be separated from the neck.

[0016] The trajectory of the preform carried by the transfer mechanism is usually tangential to the trajectory of the conveyor at one point or at most two trajectories overlap at a short distance. This overlapping area at one point or at a short distance is subsequently called "threading area".

[0017] In order to perform the threading operation, the gripping member must be synchronized with the conveying member so that the gripping member is precisely actuated to face the threading area.

[0018] Likewise, in order to perform the wire withdrawal operation, the gripping member must be synchronized with the conveying member so that the gripping member is precisely actuated to face the wire withdrawal area.

[0019] Such gripping devices are known. This is particularly the case with European patent EP0935572, which describes a device for conveying and gripping preforms.

[0020] The gripping device includes:

[0021] - a support having a vertical axis;

[0022] - a spindle of the shaft, the spindle being mounted on a sliding pivot relative to a support having a vertical axis coaxial with the axis of the spindle;

[0023] - a rotating device, which is mounted on one end of the mandrel and comprises:

[0024] a rotating device nose removably fixed to one of the ends of the mandrel and capable of gripping the preform;

[0025] An ejector at least partially surrounding the nose of the rotary device, fixed by means of fixing means on a support having a vertical axis and capable of ejecting the preforms.

[0026] The same installation must be suitable for making different container models, and in particular containers of different capacities. A given preform model may be suitable for several container models, but not all. Therefore, the oven must be able to heat different preform models.

[0027] Preforms are not only distinguished by the shape (and size) of their bodies: they sometimes have necks of different diameters.

[0028] It is therefore easy to see that each carousel nose then needs to be replaced by another carousel nose whose diameter is adapted to the new type of preform to be heated.

[0029] The swivel nose is usually fixed to the mandrel by a bayonet. The bayonet is usually in the form of a groove made in the mandrel, in which the pin of the swivel nose engages. In order to disassemble the swivel nose, the pin must be disengaged from the bayonet.

[0030] However, the ejector must be removed beforehand because it blocks access to the portion of the swivel nose that secures the swivel nose to the mandrel.

[0031] However, the overall sequence of operations required to disassemble the ejector is still quite long.

[0032] In fact, whether or not the disassembly of the ejector is automated, there remains a need to simplify it. This is the object of the present invention. Summary of the invention

[0033] The present invention, according to a first object, proposes a gripping device for gripping preforms of containers made of thermoplastic material in a thermal conditioning unit, the gripping device comprising at least:

[0034] - a support comprising a hole having a vertical axis;

[0035] - a spindle having an axis of rotation, a first end of the spindle being mounted in a hole of the support with a sliding pivot connection relative to the support, the vertical axis of the support and the axis of rotation of the spindle thus being coaxial;

[0036] - a rotating device mounted on the opposite free end of the mandrel and comprising at least:

[0037] - a spinner nose, which is removably fixed to the free end of the mandrel, the spinner nose being intended to receive the neck of the preform;

[0038] - an ejector fixed to the support by removable fixing means, the mandrel and the spinner nose extending coaxially with the ejector so that the free end of the spinner nose projects from the ejector, the ejector having a substantially tubular shape and comprising, at one of the ends, at least one ejection surface for ejecting the preforms;

[0039] The gripping device according to the invention is characterized in that the removable fixing means comprise at least one claw fixed to the ejector and / or the support, each claw comprising a male or female device capable of cooperating with a complementary female or male device fixed to the support or, respectively, to the ejector, and at least one elastic device capable of keeping the male or female device of the claw in a locked position in the female or male device of the support or, respectively, of the ejector.

[0040] According to another aspect of the invention, each jaw pivots about an articulation axis orthogonal to the spindle having the axis of rotation.

[0041] According to another aspect of the invention, the claw extends in a groove implemented in the peripheral wall of the ejector or the support when the claw is in the locked position and all or part of the claw protrudes from the groove in the unlocked position.

[0042] According to another aspect of the present invention, the two jaws are diametrically opposed.

[0043] According to another aspect of the invention, each claw comprises a first part and a second part extending on both sides of the articulation axis, the first part comprising a male or female device capable of cooperating with a complementary female or male device fixed to a support or an ejector, and the second part comprising an actuation surface, so that by applying pressure and / or releasing pressure on the actuation surface, each claw moves from its unlocked position to its locked position, and vice versa.

[0044] According to another aspect of the present invention, the elastic return device is an annular washer or an annular helical spring or a torsion spring.

[0045] According to another aspect of the invention, a portion of the elastic return means is supported in a groove embodied in the peripheral wall of the ejector or of the support.

[0046] According to the second object, the present invention proposes a clamp capable of and intended to be fixed to a robot arm and to cooperate with a gripping device.

[0047] The clamp according to the invention is characterized in that it comprises at least two main branches which are movable relative to each other and fixed to at least one movable part of the actuator, each main branch comprising a first gripping part capable of clamping the nose of the rotating device and a second gripping part capable of cooperating with the claw of the fixing device of the gripping device to move the claw from its locked position to an unlocked position.

[0048] According to another aspect of the invention, the gripping member of each main branch comprises a secondary branch extending from said main branch towards a second main branch, the free end of the secondary branch being able to bear on the swivel nose in order to clamp it.

[0049] According to another aspect of the invention, the free end of each secondary branch is provided with an end piece made of elastomer.

[0050] According to another aspect of the invention, an end piece is detachably fixed to the free end of each secondary branch.

[0051] According to another aspect of the invention, the second gripping member of each main branch comprises a pusher capable of actuating the jaws of the fixing means of the gripping device.

[0052] According to another aspect of the invention, the second gripping member of each main branch comprises at least one ejector block to which the pusher is fixed, the ejector block being able to clamp the ejector.

[0053] According to another aspect of the invention, the pusher is fixed to the ejector block so that the pusher actuates the jaws while the ejector block grips the ejector.

[0054] According to another aspect of the invention, the pusher comprises a rod extending parallel to the secondary branch and movable parallel to the secondary branch, the free end of the pusher comprising a surface capable of bearing on a corresponding claw of the fixing means of the gripping device.

[0055] According to another aspect of the invention, the rod extends through a hole formed in the main branch, and a resilient device is positioned between the main branch and the discharge block to dampen the movement of the pusher.

[0056] According to another aspect of the invention, the elastic means comprises a helical spring extending around the rod, a first end of the helical spring bearing on the main branch and an opposite end of the helical spring bearing on the ejection block.

[0057] According to another aspect of the invention, the second gripping member comprises two guides extending parallel to the rod, on either side of the rod, fixed to the main branch, and along which the ejection block can slide.

[0058] According to a third object, the invention proposes a disassembly method for disassembling at least one rotating device nose of a gripping device according to the invention, comprising at least the following operations:

[0059] - clamping the nose of the swivel device of the gripping device to prevent the nose of the swivel device from rotating and translating along its axis of rotation;

[0060] - actuating the claw of the gripping device in order to move the claw from its locked position to its unlocked position;

[0061] - Simultaneous extraction of the rotating device nose and ejector of the gripper;

[0062] - Arrange the swivel nose and ejector in the storage area.

[0063] According to another aspect of the present invention, a method for installing at least one rotating device nose of a gripping device comprises at least the following operations:

[0064] - simultaneously clamping the swivel nose and the ejector mounted on said swivel nose and positioned in the storage area;

[0065] - Positioning the rotating device nose and the ejector on the support of the gripping device;

[0066] - actuating the claws of the gripping device to move them from their unlocked position to their locked position;

[0067] - Release the swivel nose and ejector. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Other features and advantages of the present invention will become apparent upon reading the following detailed description, and for understanding of the same, reference should be made to the accompanying drawings which are briefly described below.

[0069] [ Figure 1 ] is a schematic overall view of a container production plant seen from above;

[0070] [ Figure 2 ]yes[ Figure 1 ] represents a detailed view of a circular shape of a preform;

[0071] [ Figure 3 ] is a general view of the rotating device;

[0072] [ Figure 4 ] is a perspective view of the nose of the rotary device and the ejector;

[0073] [ Figure 5 ] is a view of the nose of the rotating device;

[0074] [ Figure 6 ] is a view of the ejector with its claws in the unlocked position;

[0075] [ Figure 7 ] is a view of the ejector with its claws in the locked position;

[0076] [ Figure 8 ] is a view of the clamp in the open position;

[0077] [ Fig. 9 ] is a view of the fixture in an intermediate position;

[0078] [ Fig.10 ] is a view of the clamp in position to clamp the nose of the swivel of the ejector. DETAILED DESCRIPTION

[0079] In the following description, elements having the same structure or similar function will be denoted by the same reference numerals.

[0080] The longitudinal, vertical and transverse orientations of the trihedrons (L, V, T) shown in the reference figures will be used but are not limited to.

[0081] Conventionally, the longitudinal direction and the transverse direction are determined in a fixed manner relative to the moulding device, so that the occupied open or closed position has no influence on the orientation.

[0082] On a non-limiting basis, the terms "front" and "rear" will also be used with respect to a longitudinal orientation, and the terms "upper" and "lower" with respect to a vertical orientation, and finally "left" or "right" and "inner" or "outer" with respect to a transverse orientation.

[0083] exist[ Figure 1 ] schematically shows an apparatus 1 for mass production of containers 2 made of thermoplastic material from preforms 4.

[0084] In the following description, the preforms 4 and the containers 2 move along a circulation path from upstream to downstream in the production device. The preforms 4 move in rows along the heating path by a conveying device, which will be described in detail later.

[0085] In a non-limiting manner, the container 2 is here a bottle. The thermoplastic material is formed here, for example, from polyethylene terephthalate, denoted hereinafter by its acronym "PET".

[0086] exist[ Figure 2] is shown an example of such a preform 4. The preform 4 has a main axis "X" shown vertically in the figure. The preform has a cylindrical body 6 with a tubular wall which is closed at one of its axial ends by a bottom 8 and which is open at its other end by a neck 10 which is also tubular. The neck 10 is delimited downwardly by a collar 12 and upwardly by an upper edge called edge 14.

[0087] The neck 10 generally has its final shape, whereas the body 6 of the preform 4 is intended to undergo relatively significant deformation during the forming step in order to form the final container 2 .

[0088] like[ Figure 1 ] as shown, the container manufacturing equipment includes at least one heat adjustment unit 16, a molding unit 18 and a manipulator 20.

[0089] The heat conditioning unit 16, also called an oven, makes it possible to heat the successive preforms 4 to a reference temperature. The reference temperature is chosen so that the body 6 of each preform 4 at the outlet of the heat conditioning unit 16 is in a ductile state, allowing the body 6 of the heated preform to be deformed so as to form the container 2 in the forming unit 18. The reference temperature is between the glass transition temperature and the crystallization temperature of the plastic material of the preform 4. In the case of PET, the reference temperature is, for example, close to 110°. The value of the reference temperature may vary depending on the product with which the container 2 is to be filled or on the filling technology of the container. Thus, for example, the reference temperature is different for hot-filled or carbonated products.

[0090] according to[ Figure 1 ], the heat conditioning unit 16 is a vortex furnace, in which the preforms 4 are conveyed to be exposed to a plurality of heating radiation sources 22.

[0091] To this end, the thermal conditioning unit 16 comprises a conveying device 24 for conveying the preforms 4 through the thermal conditioning unit 16 along a heating path extending between an inlet and an outlet of the thermal conditioning unit 16 .

[0092] like Figure 1 and Figure 3 As shown, the conveying device 24 comprises a series of gripping devices, each of which is capable of supporting one preform 4 , mounted on chains and moving along a heating path in the thermal conditioning unit 16 .

[0093] In another embodiment not shown, the conveying device 24 comprises, for example, a series of gripping devices 26, each capable of supporting a preform, mounted on shuttles of the linear motor type circulating on a closed magnetic circuit. The movement of each of these shuttles is controlled independently of the others by a control unit (not shown in the figure).

[0094] Each gripping device 26 is capable of receiving a preform 4, for example by fitting the neck 10 to a rotating device 27, as shown in [ Figure 3 When the preform 4 is supported by the rotating devices 27, each rotating device 27 can, for example, rotate relative to the chain around a rotation axis A coinciding with the main axis X of the preform 4.

[0095] The oven also comprises a heating chamber comprising two side walls facing each other and at least one of these walls being a wall supporting a plurality of radiation sources 22 arranged one above the other and next to one another facing the preforms.

[0096] In other words, the thermal conditioning unit 16 comprises a plurality of radiation sources 22 distributed along the heating path and according to a height distribution substantially corresponding to the height of the preforms, so that the entire height of the body 6 of each preform is exposed to the radiation sources 22 on the path of the preforms in the thermal conditioning unit 16. The rotating device 27 allows the body 6 of the preform to be uniformly exposed to the radiation sources 22 by rotating the preform around its main axis X. In this particular embodiment, the radiation sources 22 are distributed only on one side of this heating path and a reflective wall 23 is arranged on the other side of the heating path to reflect the heat towards the preforms.

[0097] In another embodiment not shown, the radiation sources 22 may be distributed on both sides of the heating path without departing from the scope of the present invention.

[0098] It should also be noted that, where appropriate, the radiation sources 22 are arranged so as not to subject the neck 10 to the heat emitted by the radiation sources 22. In fact, as previously described, only the body 6 of the preform is deformed to produce the container 2. Therefore, the neck 10 cannot be deformed during the forming process and cannot be heated. In order to prevent heating of the neck 10, the oven 16 may include ventilation means arranged directly opposite the neck to discharge heat that may be absorbed by the neck.

[0099] Each radiation source 22 is formed by an incandescent lamp emitting infrared radiation.

[0100] In another embodiment, each radiation source 22 is a laser diode that emits infrared radiation.

[0101] In other words, each radiation source 22 is a laser emitting in the infrared (eg, a laser diode) and is organized by juxtaposition and / or superposition to form one or more matrices.

[0102] In another embodiment, each radiation source 22 is a microwave generator.

[0103] Then, once the preform 4 has been heat-conditioned in the heat-conditioning unit 16 , it is transferred to the forming unit 18 to be formed there.

[0104] The forming unit 18 for forming the container 2 from the preform 4 comprises a forming wheel 28, which rotates to move a plurality of forming stations from an inlet to an outlet, and successive containers 4 are formed from the preform 4 and then removed from the outlet, as shown in [ Figure 1 ] As shown. The rotation axis of the forming wheel 28 is, for example, substantially parallel to the main axis X of the preform 4 when it is transported by the forming wheel 28.

[0105] Each blow-moulding station comprises a mould 30 forming a mould cavity having the shape of the container 2 to be formed and arranged to receive a preform 4 so that the body 6 of the preform extends into the mould cavity.

[0106] The container manufacturing device also comprises a manipulator 20 provided with a robot arm 21 equipped at one of its ends with a disassembly fixture of the rotary device 27. The assembly of the robot arm 21 and the fixture is movable at least partially above the oven in order to ensure the disassembly of the rotary device 27. The fixture will be described in more detail later in the description.

[0107] like[ Figure 3 ], the gripping device 26 comprises a support member 32 also referred to as a chain link, although in Figure 3 , but is actually integrated into a chain comprising a plurality of such chain links.

[0108] In this embodiment, the link 32, preferably of metal (for example steel), comprises two superposed branches 34, 36 projecting laterally from a core 38. The branches 34, 36 are pierced by coaxial holes 40 which together define a main axis.

[0109] The gripping device 26 further comprises:

[0110] - a spindle 42 with an axis of rotation, mounted in the hole 40 of the link 32, with a sliding pivot connection relative to the link 32. Thus, the main axis of the hole 40 and the axis of rotation of the spindle 42 are coaxial;

[0111] - a pinion 44 which rotates integrally with one of the free ends of the spindle 42. The pinion 44 is advantageously formed on a sleeve 45 in the form of a coil, tightly fitted onto the spindle 42;

[0112] - A rotating device 27 is mounted on the other end of the spindle and comprises at least:

[0113] - a swivel nose 46 which is removably fixed to the mandrel, in this case via a bayonet (not shown in the figures). The swivel nose is intended to receive the neck 10 of the preform 4;

[0114] - an ejector 48 is fixed to the support 32 by removable fixing means which will be described in detail later in the description. This ejector 48 has a substantially cylindrical shape and comprises at one of its ends at least one so-called preform ejection surface;

[0115] The spindle and swivel nose 46 extend coaxially with the ejector 48 such that the free end of the swivel nose 46 protrudes from the ejector 48 .

[0116] According to an alternative embodiment not shown in the figures, the support 32 can be a linear motor which also includes at least one hole and in which the spindle, the rotating device and the pinion are mounted as sliding pivots, without exceeding the scope of the invention.

[0117] like Figures 3 to 5 As shown, the swivel 27 includes a swivel nose 46 and an ejector 48 .

[0118] The rotating device 27 is a mobile device for ensuring the gripping of the preform 4 by its neck 10 and is mounted on the link 32 with two degrees of freedom: translation along the main axis A and rotation about it.

[0119] In this embodiment, the spinner nose 46 comprises a radially expandable head 50 inserted by force inside the neck 10 of the preform 4 , a radiator 52 and a shaft 54 ​​.

[0120] like[ Figure 5 ] As shown in the figure, the cylindrical head 50 has a vertical axis "A", and the outer diameter of the head is slightly smaller than the inner diameter of the neck 10, so that when the head 50 is assembled into the neck 10, a radial sliding gap is left between the head 50 and the neck 10.

[0121] The head 50 comprises rings 56 in the form of annular sectors. Each ring 56 is received to slide radially in a radial groove of the head 50 between the following positions:

[0122] - a retracted position towards the head axis "A", allowing vertical sliding of the rotary device relative to the neck 10;

[0123] - a radially expanded position in which the ring can be tightened against the internal cylindrical face of the neck 10 so as to retain the preform 4 by friction.

[0124] The ring 56 is elastically restrained towards its expanded position by an elastic collar which is inserted radially between the bottom of the groove implemented in the head and the ring 56 .

[0125] The head 50 is delimited vertically downwardly by a section of larger diameter which delimits an annular shoulder surface which turns upward and forms a locating surface [N] against which the edge 14 is received while being stopped vertically when the head 50 is assembled in the neck 10 .

[0126] The radiator 52 is arranged below the head 50 and comprises a blade 58 of substantially cylindrical shape with a main vertical axis A, coaxial with the axis A of the head and having a diameter equal to the diameter of a section having a greater diameter than the head.

[0127] The shaft 54 ​​is fixed at one of its ends to the assembly of radiator and head, while the other end of the shaft 54 ​​is removably fixed to a spindle, in this case by a bayonet (not shown in the figures).

[0128] The head, radiator, shaft and mandrel are coaxial.

[0129] like Figure 6 and Figure 7 As shown, the ejector 48 comprises:

[0130] a substantially cylindrical base 60 with axis A, comprising a central hole [S], a platform 62 pierced with a central bore 64 and defining a discharge surface 66,

[0131] A series of feet 68 , here four in number, connecting the base 60 to the platform 62 and defining hollows between them.

[0132] The hole [S] and the central bore 64 are nested about a common axis.

[0133] The seat 60 also comprises at least one fixing means, also called claw 70 , which makes it possible to fix the ejector 48 to the support 32 .

[0134] exist Figure 6 and Figure 7 In the embodiment shown in FIG. 2 , the jaws 70 are two in number and are diametrically opposed.

[0135] Each jaw 70 extends in a slot 72 embodied in the base 60 and pivots about an articulation axis 74 which is orthogonal to the axis 74 of the base 60 .

[0136] Each of the claws 70 includes a first portion 76 and a second portion 78 extending on both sides of the hinge axis 74 .

[0137] The first portion 76 is arranged below the articulation axis 74 and comprises a male or female part able to cooperate with a complementary female or male complementary part (not shown in the figures) fixed to the support 32 or to the ejector.

[0138] The second portion 78 is arranged above the articulation axis 74 and comprises a so-called actuation surface, so that by exerting pressure on the actuation surface and / or releasing pressure, each claw 70 is moved from its unlocked position (eg, Figure 6 ]) to its locked position (as shown in [ Figure 7 ]) and vice versa.

[0139] The base 60 also comprises an annular groove 80, implemented both in the wall of the base 60 and in one of the parts of the jaw 70. This groove 80 makes it possible to accommodate elastic return means (not shown in the figures) which ensure the position of the jaw when it is free from the clamp and vice versa.

[0140] In order to modify the rotary device, in particular in the event of a change in the model of preform 4 , the rotary device can be disassembled manually by an operator or automatically by a manipulator 20 equipped with a fixture allowing the rotary device to be disassembled.

[0141] like Figure 1 As schematically shown in FIG. 1 , the manipulator 20 includes a mechanical arm 21 and a clamp ( Figure 1 ), which is used to clamp the swivel, that is, to simultaneously clamp the assembly of the ejector 48 and the swivel nose 46.

[0142] like Figures 8 to 10 As shown, the clamp is positioned above the rotating device in order to remove it from the support 32 and vice versa in order to reassemble it on the support 32 .

[0143] The fixture includes a base 82 having a rectangular parallelepiped shape, the base including an axis C located at the center of its upper surface. The robot arm 21 is fixed at the upper surface of the base 82. The base 82 includes at least one actuator (not shown in the figure), and the movable part 84 of the actuator is retracted from the side of the rectangular parallelepiped. The actuator can be pneumatic, such as a cylinder, or electric, such as a brushless motor.

[0144] Two so-called main branches 86 are movably mounted, in particular translatably relative to each other. Each main branch 86 is oriented vertically and parallel to the axis A of the base 82. Each main branch 86 is fixed at one of its ends to the mobile part 84 of the actuator.

[0145] Each main branch 86 comprises, at the other end, a first gripping member 88 capable of clamping the swivel nose 46. The first gripping member comprises a secondary branch 90 extending from the first main branch 86 towards the second main branch 86. Each secondary branch 90 is orthogonal to the axis C of the base 82. Each secondary branch 90 comprises an adjustment device so that the first gripping member 88 can be positioned vertically relative to the main branch 86 so that each secondary branch 90 is opposite to the swivel nose 46 to be clamped. The free end of the secondary branch 90 is provided with an end piece 92, in particular a deformable material, to clamp the swivel nose 46 at the radiator. The end piece 92 is detachably mounted relative to the secondary branch 90 so as to be removed in case of wear of the secondary branch.

[0146] The second capture member 94 is located on the main branch 86 and opposite the portion fixed to the actuator.

[0147] The second gripping members 94 are capable of cooperating with the fixing means of the ejector 48 to move the claws 70 from their locked position to their unlocked position. Each second gripping member 94 comprises a pusher 96 forming a radial projection towards the axis A, which is intended to cooperate with the fixing means of the ejector 48, in particular with a so-called actuating surface of the fixing means, so that, when pressure is applied to the actuating surface and / or released, each claw 70 moves from its unlocked position to its locked position and vice versa.

[0148] refer to Figures 8 to 10 The pusher 96 comprises a rod extending parallel to the secondary branch 90 and movable parallel to the latter, the free end of which comprises a surface capable of bearing on the claw 70 of the fixing device.

[0149] The second gripping member 94 also comprises at least one so-called ejector block 98. This ejector block 98 is able to grip the ejector 48 and to hold it in a certain position before locking or unlocking it. To achieve this grip, the ejector block 98 has a shape complementary to the outer surface of the ejector. The ejector block 98 is fixed to a rod 100 extending through a hole implemented in the main branch 86, with elastic means 102 positioned between the main branch 86 and the ejector block 98 to dampen the movement of the pusher 96 during the movement of the branch.

[0150] The elastic means 102 consist of a helical spring extending around the rod 100 and bearing with its first end on the main branch 86 and with its opposite end on the discharge block 98 .

[0151] like Figures 8 to 10 As shown, the pusher 96 is fixed to the ejection block 98 in such a way that the pusher simultaneously actuates the jaws 70 when the ejector has been clamped by the ejection block 98 .

[0152] Advantageously, but not shown in the figures, the second gripping member 94 comprises two guides extending parallel to the rod 100, on either side of the rod 100, which are fixed to the main branch 86 and along which the ejection block 98 can slide. These guides make it possible to improve the quality of the movement of the ejection block 98.

[0153] Thanks to the above-described fixture, we will be able to automatically replace the swivel and in particular the ejector and the swivel nose 46 according to the process that will be described below.

[0154] In this respect, the invention also relates to a method for automatically changing a rotating device.

[0155] like Figure 1 and 8 As shown, the mechanical arm 21 of the fixed clamp as described above is positioned at the rotating device to be disassembled. Then, the clamp is in an open position, that is, the main branch 86, the first gripping member, and the second gripping member are in a spaced apart position, so as not to contact the rotating device to be clamped.

[0156] The clamp then grips the rotating device nose 46 of the gripping device 26 to prevent it from rotating and translating along its axis of rotation, and actuates the claws 70 of the fixing device of the gripping device 26 to move the claws from their locked position to their unlocked position. Fig.10 The clamp is shown in the clamping position. The main branch 86 has moved so that the first gripping member 88 engages with the swivel nose 46 and the pusher 96 unlocks the claws 70 of the ejector fixture.

[0157] Advantageously and as [ Fig. 9 ], the clamp can be in an intermediate position. The main branch 86 has been moved so that the second gripping member 94, that is, the ejector block 98, is in contact with the ejector to fix the ejector. On the other hand, the first gripping member has not yet come into contact with the rotating device nose 46, and the pusher 96 has not yet unlocked the claw 70 of the fixture of the ejector 48.

[0158] When clamping the ejector, the movement, in particular the translation, of the main branch 86 allows three successive steps: clamping the ejector 48 by the ejection block 98, clamping the swivel nose 46 by the end piece 92 of the secondary branch 90, and unlocking the claws 70 of the fixing device fixing the ejector to the support 32.

[0159] Finally, the gripper simultaneously extracts the swivel nose 46 and the ejector from the gripper 26 and places them in a storage area.

[0160] Advantageously, the method comprises carrying out various additional steps:

[0161] - simultaneously clamping the swivel nose 46 and the ejector 48 mounted on said swivel nose and positioned in the storage area;

[0162] - Positioning the rotating device nose and the ejector on the support 32 of the gripping device 26;

[0163] - actuating the claw 70 of the gripping device 26 to move the card from its unlocked position to its locked position;

[0164] - Release the swivel nose and ejector.

[0165] Finally, the swivel nose and ejector assembly is moved at the storage area.

Claims

1. A gripping device (26) for gripping a preform (4) of a container (2) made of thermoplastic material in a thermal conditioning unit, the gripping device comprising at least: - a support (32) comprising a hole having a vertical axis (A); - a spindle having an axis of rotation (B), a first end of which is mounted in a hole in the support (32) with a sliding pivot connection relative to the support (32), the vertical axis (A) of the support (32) and the axis of rotation (B) of the spindle thus being coaxial; - a rotating device mounted on the opposite free end of the mandrel and comprising at least: - a spinner nose (46) fixed in a removable manner to the free end of the mandrel, the spinner nose (46) being intended to receive the neck (10) of the preform (4); - an ejector (48) fixed to the support (32) by removable fixing means, the mandrel and the spinner nose (46) extending coaxially with the ejector (48) so that the free end of the spinner nose (46) projects from the ejector (48), the ejector having a substantially tubular shape and comprising at least one ejection surface for ejecting the preforms (4) at one of the ends; Characterized in that the removable fixing device comprises at least one claw (70) fixed to the ejector (48) and / or the support (32), each claw (70) comprising a male device or a female device capable of cooperating with a complementary female device or a male device fixed to the support or respectively fixed to the ejector (48), and at least one elastic device capable of keeping the male device or the female device of the claw (70) in a locked position in the female device or the male device of the support or respectively the ejector (48).

2. The gripping device (26) according to claim 1, characterized in that Each jaw (70) pivots about an articulation axis (74) orthogonal to a spindle having an axis of rotation (B).

3. The gripping device (26) according to any one of the preceding claims, characterized in that When the claw (70) is in the locked position, the claw (70) extends in a groove (72) implemented in the peripheral wall of the ejector (48) or the support (32), and in the unlocked position, all or part of the claw (70) protrudes from the groove (72).

4. The gripping device (26) according to any one of the preceding claims, characterized in that The two claws (70) are diametrically opposed.

5. The gripping device (26) according to any one of the preceding claims, characterized in that Each claw (70) comprises a first portion (76) and a second portion (78) extending on both sides of the hinge axis (74), the first portion (76) comprising a male device or a female device capable of cooperating with a complementary female device or a male device fixed to the support member (32) or the ejector (48), and the second portion (78) comprising an actuating surface so that by applying pressure and / or releasing pressure on the actuating surface, each claw (70) moves from its unlocked position to its locked position, and vice versa.

6. The gripping device (26) according to any one of the preceding claims, characterized in that The elastic return device is an annular washer or an annular helical spring or a torsion spring.

7. The gripping device (26) according to claim 6, characterized in that A portion of the elastic return device is supported in a groove (80) formed in the peripheral wall of the ejector (48) or of the support element (32).

8. A clamp capable of being and used to be fixed to a robot arm (21) and to cooperate with a gripping device (26) according to any one of claims 1 to 7, characterized in that: The clamp comprises at least two main branches (86) which are movable relative to each other and fixed to at least one movable part of the actuator, each main branch (86) comprising a first gripping part (88) and a second gripping part (94), the first gripping part being capable of clamping the nose (46) of the rotating device, and the second gripping part being capable of cooperating with the claw (70) of the fixing device of the gripping device (26) to move the claw (70) from its locked position to an unlocked position.

9. The clamp according to claim 8, characterized in that The gripping member of each main branch (86) comprises a secondary branch (90) extending from said main branch (86) towards the second main branch (86), the free end of the secondary branch (90) being able to bear on the swivel nose (46) to clamp the swivel nose.

10. The clamp according to claim 9, characterized in that The free end of each secondary branch (90) is provided with an end piece (92) made of elastomer.

11. The clamp according to claim 10, characterized in that An end piece (92) is removably fixed to the free end of each secondary branch (90).

12. The clamp according to any one of claims 8 to 11, characterized in that The second gripping member (94) of each main branch (86) comprises a pusher (96) capable of actuating the jaws (70) of the fixing means of the gripping device (26).

13. The clamp according to any one of claims 8 to 12, characterized in that The second gripping member (94) of each main branch (86) comprises at least one ejector block (98) to which the pusher (96) is fixed, the ejector block (98) being capable of clamping the ejector (48).

14. The clamp according to any one of claims 12 to 13, characterized in that The pusher (96) is fixed to the ejector block (98) so that the pusher (96) actuates the jaws while the ejector block (98) grips the ejector.

15. The clamp according to any one of claims 12 to 14, characterized in that The pusher (96) comprises a rod (100) extending parallel to the secondary branch (90) and movable parallel thereto, the free end of the pusher (96) comprising a surface capable of bearing on a corresponding claw (70) of a fixing device of the gripping device (26).

16. The clamp according to any one of claims 12 to 15, characterized in that A rod (100) extends through a hole formed in the main branch (86), and a resilient device (102) is positioned between the main branch (86) and the ejection block (98) to dampen the movement of the pusher (96).

17. The clamp according to claim 16, characterized in that The elastic means (102) comprises a helical spring extending around the rod (100), a first end of the helical spring bearing on the main branch (86) and an opposite end of the helical spring bearing on the ejection block (98).

18. The clamp according to any one of claims 15 to 17, characterized in that The second gripping member (94) comprises two guides extending parallel to the rod (100), on either side of the rod (100), fixed to the main branch (86), and along which the ejection block (98) can slide.

19. A disassembly method for disassembling at least one swivel device nose (46) of a gripping device (26) according to any one of claims 1 to 7, comprising at least the following operations: - clamping the swivel nose (46) of the gripping device (26) to prevent the swivel nose from rotating and translating along its axis of rotation; - actuating a claw (70) of the gripping device (26) in order to move the claw from its locked position to its unlocked position; - Simultaneously extracting the rotating device nose and the ejector of the gripping device (26); - Arrange the swivel nose and ejector in the storage area.

20. A method for installing at least one swivel device nose (46) of a gripping device (26) according to any one of claims 1 to 7, comprising at least the following operations: - simultaneously gripping the swivel nose and the ejector (48) mounted on said swivel nose and positioned in the storage area; - Positioning the rotating device nose and the ejector on the support (32) of the gripping device (26); - actuating the claws (70) of the gripping device (26) to move them from their unlocked position to their locked position; - Release the swivel nose (46) and the ejector (48).

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