The present invention relates to a chuck for handling a glass tube loaded therein.

Special forming machines are used in the serial production of glass containers made from a tube for medical use (vials, bottles, cartridges and syringes).

These are products with a certain complexity, and in order to meet increasingly strict quality requirements, they require a very precise forming process.

In particular, for syringes, there are provided devices, stations or in-line assemblies, which act on the glass tube, cutting it and forming it in order to produce the tip and the flange, which are present on the body of the syringe.

This all takes place semi-automatically, as this production allows particularly high hourly production rates.

It must also be observed that handling of the single glass tube, at least 1.5 m in length, from which a certain number of syringes all without any marks on their body and completely identical to one another in shape must be produced, is particularly delicate.

Therefore, there are produced heads or crowns carrying a series of chucks or grippers that receive the single glass tube and handle it in first place to proceed with forming of the tip.

This assembly of chucks or grippers must operate in complete synchronism with one another to carry the tube or at least a portion thereof to be handled by means of specific extensions or fingers provided by the chuck.

Likewise, the lengths that have been provided at one end thereof with a tip must then be treated in order to create a flange at the other end in accordance with the established standards.

In general, these chucks are suitable for the specific operation they must carry out and are controlled by toothed crowns or gears and chains that are somewhat noisy and are subject to stretching, undesirable and damaging for operating precision.

Moreover, the fingers of the chuck are connected to levers and joints with multiple fulcrums for the transmission of motion that makes them difficult to adjust, and are subject to wear in the pivot points between the parts. These lever mechanisms are also directly controlled by levers operatively connected to reaction springs on which it is not possible to act. For example, in order to replace a spring the whole chuck must be disassembled.

An example of these grippers or jaws for handling glass tubes is shown in the document EP 2189425.

EP 895967 by the same applicant relates to a machining head for glass processing machines having high precision and robustness.

EP2189425 relates to a fixing clamp comprising feed channels for glass tubes, moving clamping jaws and related moving actuator with lever operation.

The general object of the present invention is to produce a chuck for handling a glass tube loaded therein which is capable of solving the aforesaid problems of the prior art in a manner that is very simple, inexpensive and particularly functional.

Another object of the present invention is to produce a chuck for handling a glass tube loaded therein which has a particularly simple structure and is easy to adjust even when installed.

Another object of the present invention is to produce a chuck for handling a glass tube loaded therein which has no articulated lever assemblies for controlling the fingers of the chuck.

One more object of the present invention is to identify a chuck for handling a glass tube loaded therein that can be used with the glass tube or semi-finished glass product fed both vertically and horizontally without any problems.

The aforesaid objects are achieved by a chuck for handling a glass tube loaded therein produced according to the independent claim 1 and the subclaims that follow.

The structural and functional features of the present invention and its advantages in relation to the current state of the art will be even clearer and more apparent from an examination of the following description, which refers to the accompanying schematic drawings, which show an example of embodiment of the invention. In the drawings:

- Fig. 1 is an elevation view in longitudinal section of a chuck for handling a glass tube loaded therein provided with a control lever for moving the fingers in a position of maximum aperture between the fingers;

- Fig. 2 is a view similar to the view of Fig. 1 in which the chuck provides that the movement of the lever controls the movement of the fingers to a position of minimum aperture between the fingers;

- Fig. 3 shows a sectional view of the chuck similar to the previous views in which it is shown how the fingers are engaged on a glass tube inserted therein;

- Fig. 4 shows an enlarged side elevation view of only the lower part with fingers closed on a glass tube;

- Fig. 5 shows an enlarged side elevation sectional view of the same part of the chuck of Fig. 4;

- Fig. 6 shows a perspective view of part of the chuck of Fig. 5 according to the arrows VI-VI from the bottom upwards;

- Fig. 7 shows a sectional view of a further embodiment of a chuck according to the invention in which it is shown how the fingers are engaged on a glass tube inserted therein;

- Figs. 8 and 9 are perspective side elevation views of the chuck of Fig. 7; - Fig. 10 is an enlarged section of part of the chuck shown in Fig. 8 along the line X-X;

- Fig. 11 is a sectional plan view of the chuck of Fig. 7 along the line XI-XI of Fig. 9.

In the following description, for illustration of the figures identical reference numbers are used to indicate components with the same function. Moreover, for clarity of illustration, some reference numbers may not have been repeated in all the figures.

Indications such as "vertical" and "horizontal", "upper" and "lower" (in the absence of other indications) must be interpreted with reference to the assembly (or operating) conditions and referring to normal terminology in use in current language, where "vertical" indicates a direction substantially parallel to the direction of the gravitational force vector "g" and horizontal indicates a direction perpendicular thereto.

With reference to the figures, provided by way of non-limiting example, there is shown an embodiment of a chuck for handling a glass tube loaded therein, which is used in machines for forming syringes from glass tube that produce the body of the single syringe in series at high speed.

A chuck of this kind is suitable to receive the single glass tube and to retain it during processing of the part which extends outside the chuck whether for forming the tip or for forming the flange.

The chuck shown in the figures, indicated as a whole with 11, comprises an outer structure 12 fixed to the machine frame (not shown), inside which there is provided a rotating part carrying gripping fingers 13, which in the example are three in number for each chuck.

In the example illustrated, the single chuck 11 is arranged vertically relative to the floor surface or ground and receives therein a glass tube 14 of a certain length (usually around 1.5 m). As will be illustrated, this is only one application of the chuck of the invention, as this length, provided with tip shaped end, can also be arranged horizontally, parallel to the floor surface or ground. In this case the chuck receives therein a length of glass tube cut to size to produce a syringe body and previously provided with a tip shaped end portion. On the other end of the length of glass tube, projecting from the chuck, the flange of the syringe body must be produced.

Moreover, a pair of sealed bearings 15, the inner ring of which rotatably supports a first hollow outer body 16, is arranged in the central part of the outer structure 12 of the chuck. These bearings 15 are arranged in a cartridge constrained to the load bearing structure of the chuck.

A second inner body 17, also hollow and essentially tubular, which receives the glass tube 14, is in turn arranged coaxially inside the first tubular hollow outer body 16 according to the axis X of the chuck 11.

The first hollow outer body 16 carries integral therewith, in the top part opposite the part in which the fingers 13 are arranged, a rotor 18 that collaborates with a stator 19 of a direct motorization assembly 20 of the chuck 11. The stator 19 is integral with the outer load bearing structure 12.

Therefore, the stator part of the control servomotor 20 of each of the series of chucks 11 is provided in the upper part constrained to the outer load bearing structure 12 of the machine body. The rotor part of the servomotor of each chuck is instead constrained to the first hollow outer body 16 of the chuck, which is fixed.

The first hollow outer body 16 is provided at a free lower end thereof with an extension 21 enlarged outwards in which there are provided three oriented seats or holes 22 for housing and sliding of the fingers 13, arranged at 120° from one another. The fingers 13 have a circular or oval section, just as the sliding seats. These seats 22 are inclined converging towards the axis X of the chuck 11 by an angle of around 45° so that the ends of the fingers 13, when the fingers 13 are translated inside the seats 22, contact, or do not contact, the glass tube 14.

The seats 22 act as oriented slides in each of which the single finger 13 can translate between a lowered position for gripping the glass tube 14 and a raised position for releasing the glass tube 14.

Consequently, each chuck or gripper 11 is provided with three fingers 13 which can be moved to engage on or disengage from the glass tube 14 and are actuated by means of a control lever 23 external to the chuck and arranged above in a rotating crown of chucks of the machine (not shown). Operation of this control lever 23 determines raising of the fingers 13 or of the second inner body 17 carrying the enlarged extension 21 in which the fingers 13 are positioned, which translates relative to the first hollow outer body 16.

The second inner body 17 carrying the enlarged extension 21 is thus movable axially relative to the load bearing structure 12 and to the first inner body 16. It must be noted that the second inner body 17 is constrained by means of grub screws or lock screws 24 to an annular crown 25 external to both the bodies 16, 17, to which the fingers 13 are constrained in an articulated manner. More precisely, as is also highlighted in Figs. 4, 5 and 6, the annular crown 25 is provided at the top with three pairs of forks 26, arranged at 120° from one another, in outward facing openings 27 of which a pin 28 is positioned. The pin 28 is provided with a through hole 29 in which a cotter pin 30 is positioned, which constrains the finger 13 to said pin 28. Rounded opposite ends of the pin 28 act as sliders inside the outward facing openings 27 of the pairs of forks 26, allowing adaptation of the position of the fingers 13 when the second inner body 17 moves relative to the first outer body 16.

Above the annular crown 25 on respective columns 31 there are provided, for each of the three forks 26, pairs of springs 32 that abut against an upper annular crown 33, integral with the first hollow outer body 16 below the central part of the outer structure 12 in which the pair of bearings 15 is arranged. The series of six springs normally maintain the enlarged extension 21 of the second hollow inner body 17, carrying the fingers 13, normally lowered creating the gripping force of said fingers on the glass tube.

In this way the springs 32 act to maintain the fingers 13, thrust downward engaging on the glass tube 14, idle.

The second hollow inner body 17 thus acts as element for controlling the movement of the fingers 13 between a position engaged on the glass tube 14 and a position disengaged from the glass tube.

The axial movement of the second inner body 17 relative to the first hollow outer body 16 is allowed due to the fact that the grub screws or lock screws 24 of the second inner body 17 to the annular crown 25 pass through axial slots 34 made in the first hollow outer body 16, which can only rotate but cannot move axially.

The chuck of the present invention is identical to the description above when it is used as element for gripping and handling a length of semi-finished glass provided with tip that must be provided at the other end with the customary flange required of syringes.

A chuck of this kind can also operate in a horizontal arrangement without problems of any sort, gripping the part of length of glass tube provided with tip.

The advantages of the new solution of chuck according to the present invention are numerous.

A first advantage is that a chuck of this kind is operated by a respective servomotor individually, and therefore there is no interference or disturbance caused by gears or chains for controlling its rotation.

This is both in its arrangement for producing the tip part of the syringe and for producing the lower flange part transverse to the body of the glass tube.

The provision of a servomotor for controlling each single chuck gives the advantage of uniform rotation, without vibrations caused either by the rotation transmission chain, which is used conventionally, or by a series of gears, more or less with the same effect.

Moreover, a considerable reduction is obtained in the number of parts required to produce the movement of the fingers due to elimination of a series of double fulcrums for transmitting motion to the fingers, which until now was implemented by a series of lever mechanisms articulated to one another.

Further, the arrangement of an annular crown provided with forks for transmitting motion to the fingers also allows the elimination of the series of articulated levers of the prior art.

The arrangement of springs along the perimeter of the annular crown outside the hollow bodies of the chuck allows easy maintenance. In fact, with an arrangement of this kind, replacement thereof is made simpler, as it no longer requires maintenance at the workbench, but can take place with the chuck assembled on the machine.

Moreover, it is possible to calibrate the gripping force due to a micrometric preload system and/or to replace them by operating and rotating the columns 31 to regulate the load of the springs 32.

Figs. 7-11 show views of a further embodiment of a chuck according to the invention, showing how the fingers are engaged on a glass tube inserted therein, just as in the previous embodiment.

In this further example, the same elements are indicated with the same reference numbers.

Also in this second example of chuck, it comprises an outer structure 12 fixed to the machine frame inside which there is provided a rotating part carrying gripping fingers 113, which in the example are three in number for each chuck and which are of a different shape relative to those shown in Figs. 1- 6.

Also in this case, the first hollow outer body 16 is provided, at a lower free end thereof, with an extension 121 enlarged outwards in which there are provided three oriented seats or holes 122 for housing and sliding of the fingers 113, arranged at 120° from one another. These seats 122 are inclined converging towards the axis X of the chuck 11 by an angle of around 45° so that the ends of the fingers 113, when the fingers 113 are translated inside the seats 122, contact, or do not contact, the glass tube 14.

It must be noted how these fingers 113 have a different shape in quadrilateral section relative to the previous ones of circular or oval shape.

Nonetheless, also in this case the seats 122 act as oriented slides in each of which the single finger 113 can translate between a lowered position for gripping the glass tube 14 and a raised position for releasing the glass tube 14.

Likewise, the three fingers 113 can be moved and are actuated by means of the aforesaid control lever 23 external to the chuck and arranged above in a rotating crown of chucks of the machine (not shown). Operation of this control lever 23 determines raising of the fingers 113, i.e., of the second inner body 17 carrying the enlarged extension 121 in which the fingers 113 are positioned, which translates relative to the first hollow outer body 16.

Also in this case an annular crown 125 is provided, external to both the bodies 16, 17, to which the fingers 113 are constrained in an articulated manner. More precisely, as can also be seen from the figures, in particular from Figs. 10 and 11, the annular crown 125 is provided at the top with three pairs of forks 126, arranged at 120° from one another, in pairs of outward facing openings 127 of which a pin 128 is positioned.

In this case, the pin 128 passes through a hole 40 of the single finger 113 and is provided in its end areas with rollers 38 for sliding inside the outward facing openings 127 of the pairs of forks 126. The rollers 38 are held in position by two Seeger rings 39 positioned at opposite ends of the pin 128 and of the rollers 38 and collaborating with screws 40 screwed into the pin 128 on opposite sides.

Above the annular crown 125 there is provided resting on its upper surface a helical spring 41 that abuts against an upper annular crown 33, integral with the first hollow outer body 16 below the central part of the outer structure 12 in which the pair of bearings 15 is arranged.

This spring 41, coaxial to the chuck, normally maintains the enlarged extension 121 of the second hollow inner body 17, carrying the fingers 113, normally lowered creating the gripping force of said fingers on the glass tube.

In this way, the spring 41 acts to maintain the fingers 113, thrust downwards engaging on glass tube 14, idle.

A further difference relative to the previous embodiment is the shape in section of the fingers 113, which being quadrilateral is better guided in its movement to engage on and disengage from the glass tube.

This embodiment also has the same advantages as those described above. In this way the objects mentioned in the introduction of the description are achieved.

The scope of protection of the present invention is defined by the appended claims.