TUBE CATCHER FOR A HOT FORMING MACHINE AND HOT FORMING MACHINE

Abstract

The present disclosure provides a tube catcher for a hot forming machine comprising a foot for mounting the tube catcher in the hot forming machine, an upper contact surface for catching a glass tube as it falls into the hot forming machine, and a damping element, which is arranged below the upper contact surface in such a way that it allows the upper contact surface to elastically recede in the direction of the falling direction of the glass tube. This minimizes damage to glass tubes on impact and permits a high production speed. For this purpose, the damping element includes a compressible chamber that can be filled with a gas.

Claims

1. A tube catcher for a hot forming machine, comprising: a foot for mounting the tube catcher in the hot forming machine; an upper contact surface for catching a glass tube as the glass tube falls along a falling direction into the hot forming machine; and a damping element arranged below the upper contact surface in such a way that it allows the upper contact surface to elastically recede in the direction of the falling direction of the glass tube, wherein the damping element comprises a compressible chamber which can be filled with a gas.

2. The tube catcher of claim 1, further comprising a pressure control device connected to the compressible chamber.

3. The tube catcher of claim 1, further comprising an outlet channel connected to the compressible chamber.

4. The tube catcher of claim 1, further comprising a fixing device adapted to fix the upper contact surface in a compressed state of the chamber.

5. The tube catcher of claim 4, wherein the fixing device comprises a magnet.

6. The tube catcher of claim 1, wherein, when the chamber is in a compressed state, the upper contact surface is fixed in the hot forming machine such that it is further movable at least in the direction of the falling direction of the glass tube.

7. A method for catching a glass tube in a hot forming machine, comprising the steps of: arranging an upper contact surface and a damping element arranged below the upper contact surface in such a way that it allows the upper contact surface to elastically recede in the direction of the falling direction of the glass tube, below the glass tube; filling a compressible chamber in the damping element with a gas; and dropping the glass tube.

8. The method of claim 7, wherein the filling step comprises adjusting a predetermined pressure in the chamber, which is determined from the weight of the glass tube.

9. The method of claim 7, further comprising the steps of: catching the glass tube on the upper contact surface; and after the catching step, causing gas to flow out of the chamber.

10. The method of claim 7, further comprising the steps of: catching the glass tube on the upper contact surface; and after the catching step, fixing the upper contact surface in a compressed state of the chamber.

11. The method according to claim 10, wherein the fixing step is carried out with a magnet.

12. The method according to claim 7, further comprising the step of catching the glass tube on the upper contact surface, and wherein, when the chamber is in a compressed state, the upper contact surface is moved further at least in the direction of the falling direction of the glass tube after the glass tube has been caught on the upper contact surface, wherein the glass tube is fixed beforehand by a holding chuck.

13. A hot forming machine with a tube catcher according to claim 1.

14. The hot forming machine of claim 13, further comprising: a rotatably arranged preloading rim with a plurality of radially symmetrically arranged loading positions for respectively holding a vertically standing glass tube; an individually openable holding device for the glass tube held in the respective loading position is in the preloading rim for each of the loading positions; and an actuating device associated with the tube catcher is arranged in the hot forming machine, wherein the actuating device opens the holding device of that loading position, whose respectively held glass tube, in a given angular position of the preloading rim, is aligned with the upper contact surface of the tube catcher.

15. The hot forming machine of claim 14, wherein the respective holding device comprises a holding plate pivotable under an opening and the actuating device comprises a slider whose movement pivots the holding plate away under the opening.

16. The hot forming machine of claim 13, wherein the preloading rim has a number of preloading positions for respectively holding a further glass tube, wherein the number corresponds to the number of loading positions, and each loading position being has a corresponding preloading position, and the machine further comprises a pushing device that pushes a glass tube held in a preloading position at a given angular position of the preloading rim into the loading position assigned to this preloading position, and the pushing device is upstream of the actuating device in the direction of rotation of the preloading rim.

17. The hot forming machine of claim 16, further comprising a second actuating device adapted to close the holding device at a given angular position of the preloading rim, wherein the second actuating device is between the first actuating device and the pushing device in the direction of rotation of the preloading rim.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Embodiments of the present disclosure are explained in more detail using drawings in which:

[0033] FIG. 1 shows a schematic view of parts of a hot forming machine.

[0034] FIGS. 2a -2d show a chronological sequence of the catching process of the tube catcher.

[0035] FIG. 3 shows a schematic diagram of the vertical position of the tube catcher during the catching process, plotted against time in comparison with the state of the art.

[0036] FIG. 4 shows a schematic view of parts of the lower preloading rim of the hot forming machine from below.

[0037] FIG. 5 shows a cutout of FIG. 4 with closed holding devices.

[0038] FIG. 6 shows a cutout of FIG. 4 with open holding devices.

[0039] FIGS. 7a-c show a chronological sequence of the pushing process from a preloading position to a loading position in lateral view.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0040] Identical parts have the same reference signs in all drawings.

[0041] FIG. 1 shows in a schematic view the basic structure of a hot forming machine 1, which is used for the production of glass containers from a glass tube 2, which is fed vertically aligned from above. The glass containers to be produced, for example glass vials, cartridges or syringes, are used to store pharmaceutical active ingredients. The hot forming machine 1 comprises a so-called mother machine 10, which serves in particular for hot forming of the supplied glass tube 2 at an end opposite the later bottom or open end of the glass container, in particular for forming a neck with a neck opening.

[0042] Glass tubes 2 are fed at feed position 15 from a preloading rim not shown in FIG. 1. They fall down by opening a holding device in the preloading rim, are caught by a tube catcher to be described below and are then held in holding chucks at a suitable machining height, which are distributed over the circumference of a rotary table 12. The turntable 12 is designed in the form of a turnable rim with holding chucks and is mounted on the associated column 11 so that it can rotate. The turntable 12 is rotated or swiveled step by step around the assigned column 11. The glass tubes 2 held on the holding chucks are guided step by step past gas burners 17 and various processing stations 20-22, at which the processing and hot forming of the glass containers takes place during a respective standstill time.

[0043] After passing through the processing stations 20-22, the glass containers are inspected non-tactile at least in the area of the neck and the neck opening with the aid of an inspection system 30 and their properties are documented. The inspection system 30 can, for example, be a video camera with image evaluation software, with which geometric dimensions of the glass containers are evaluated on the basis of the images recorded by the video camera, for example the geometric dimensions in the case of glass vials. Finally, the glass containers are transferred to a downstream processing machine at position 16.

[0044] FIGS. 2a-d show a time sequence of the catching of the glass tube 2 by a tube catcher 40 after dropping from the preloading rim, as described above. FIGS. 2a-d show a view from the radial direction of FIG. 1, where the tube catcher 40 is shown in section. For reasons of clarity, only FIG. 2a is provided with reference signs, since the FIGS. 2b-d show the same tube catcher 40 only at other times of the catching process. First, the structure of the tube catcher 40 is explained and then the chronological sequence of the catching process is described.

[0045] The tube catcher 40 has a foot 42, with which it is fixed in the hot forming machine 1, as will be described further with regard to FIG. 4. At foot 42, concentrically to the glass tube 2, an upwardly open cylinder pot 44 is arranged. A cylindrical sleeve 46, which is also cylindrical and closed at the top, is placed on the cylinder pot 44 and dimensioned flush with the outer wall of the cylinder pot 44. The lid of the sleeve 46, which is closed at the top, forms a flat contact surface 48, on which the glass tube 2 hits when falling down from the preloading rim. The contact surface 48 itself is made of a material or coated with a material which is particularly optimized with regard to its abrasion resistance, in the example POM.

[0046] A piston 50 is concentrically arranged inside the cylinder bowl 44. Although it is cylindrical, its outer diameter is slightly smaller than the inner diameter of the cylinder bowl 44. Instead, the piston 50 is guided through a piston rod 52 which pushes through the bottom of the cylinder pot 44 so that it can only move in the vertical direction. At foot 42, the piston rod 52 leads into a cylindrical chamber 54, where it is connected to a concentrically arranged circular disc 56, the diameter of which corresponds to the diameter of chamber 54. The piston rod 52 can thus be moved in the axial direction until the disc 56 touches one of the axial boundary surfaces of chamber 54. Two air supply lines 58, 60 are arranged at foot 42, of which the first air supply line 58 leads into the area of the lid of chamber 54, the other into the center of the bottom of chamber 54. The air supply lines 58, 60 can be supplied with compressed air from outside the foot 42. Due to the described geometry, the air supply line 58 opens above the disc 56 into the chamber 54, so that the disc 56, and thus the piston 50, is pressed downwards by the pressure of the air supply line 58 until the disc 56 hits the bottom of the chamber 54. Conversely, by applying pressure to the air supply line 60, which opens into the bottom of chamber 54, the disc 56 and thus the piston 50 is pressed upwards until the disc 56 touches the cover of chamber 54.

[0047] A further air supply line 62 is arranged in the axis of the piston 50, which opens out below the sleeve 46 and can be supplied with compressed air laterally through an opening 64 in the wall of the cylinder pot 44. The corresponding pneumatic equipment such as pumps, hoses and valves are not shown in the drawings. However, they are available and can be controlled as required by control electronics. In particular, the supply line 62 can be supplied with compressed air in an adjustable manner so that a defined pressure can be set in the chamber 66 formed above the piston 50 and delimited above and radially by the sleeve 46. The space between the outer diameter of the piston 50 and the inner diameter of the cylinder pot 44 forms outlet channels 67, 68 through which compressed air can escape from chamber 66. The adjustment of a certain pressure in chamber 66 therefore requires a constant supply of air through the air supply line 62, and in other design examples not shown, the outlet ducts 67, 68 may be more complex, e.g. several outlet ducts with different diameters or with varying cross-sections depending on the axial position (e.g. by a conical design of piston 50 and inside of cylinder bowl 44 or by further outlet channels which do not extend over the entire height), so that a progressive damping characteristic is achieved.

[0048] A magnet 69 is arranged at the outlet of the air supply line 62, which is designed as a permanent magnet and whose strength is selected such that the pressure of the air cushion in the chamber 66 is sufficient to release the magnetic connection as required. The inside of the cover of the sleeve 46 is ferromagnetic above the magnet 69, so that when the chamber 66 is compressed it sticks to the magnet 69 at a sufficiently small distance. In addition, a chuck 70 is arranged above the tube catcher 40 in the hot forming machine 1 as already described for FIG. 1, which is also controlled by the control electronics as required in order to grip and hold the glass tube by means of the clamping jaws 72, 74 of the chuck 70.

[0049] After only the construction of the tube catcher 40 and the holding chuck 70 arranged above it has been described, the sequence of the catching process is explained in the following using FIGS. 2a-d. In a first phase, shown in FIG. 2a, air is supplied through the air supply line 60 so that the piston 50 is fixed in an upper position. Air with a defined air volume is also supplied through the air supply line 60, so that a specified pressure is set in chamber 66. This pressure is determined by the tube weight of the glass tube 2 and can be adjusted to different tube weights. In the FIG. 2a phase, the pressure in chamber 66 is sufficient to release the cover from magnet 69 and the jaws 70, 72 are open. The glass tube 2 falls down in the direction of the contact surface 48.

[0050] In the following only changes of the control variables are described for the FIGS. 2b-d. Control variables not described remain unchanged.

[0051] In FIG. 2b, the glass tube 2 hits the contact surface 48, which is compressed by the elasticity of the air in the chamber 66, so that the fall of the glass tube 2 is gently slowed down by the elastic receding of the contact surface 48. At this point, the air supply through the air supply duct 60 is also terminated, so that the pressure in chamber 66 drops even further and chamber 66 is further compressed, as the remaining air escapes through the outlet ducts 67, 68. The final state of compression is shown in FIG. 2c when the cover of the sleeve 46 hits the top of the piston 50. The compression of chamber 66 is then at maximum. The magnet 69 fixes the cover of the sleeve 46 with the contact surface 48 on the piston 50.

[0052] In the state shown in FIG. 2c, the glass tube 2 has a defined vertical position. The next step is to close the clamping jaws 70, 72 so that the glass tube 2 is gripped for further processing in the hot forming machine 1. The air supply to the air supply line 60 is then terminated and air is led into the air supply line 58 instead. This causes the piston 50 to sink, initially under the influence of gravity, then also downwards due to the pressure existing above the disc 56 in chamber 54. Since the magnet 69 fixes the cover, the piston 50 also moves the sleeve 46 and thus the contact surface 48 downwards. Since the glass tube 2 is held by the holding chuck 70, the contact surface 48 moves away from the glass tube 2 in the falling direction of the glass tube 2. The glass tube 2 is then moved radially in the hot forming machine to the other processing stations in the manner described for FIG. 1. The air supply to the air supply lines 60, 62 is reactivated as before, so that chamber 66 expands again. The tube catcher 50 is now ready to catch the next tube.

[0053] FIG. 3 shows the vertical position of the glass tube 2 during the collection process described above compared to the prior art, applied against time. The solid line shows the vertical position of the glass tube 2 in prior art catching processes, e.g. by a contact surface and a damper made of a rubber-like material. This material bounces back so that the vertical position oscillates around the end position with gradually decreasing amplitude. In contrast, the dashed line shows the course of the vertical position after the catching process described in FIGS. 2a-d. This runs strictly monotonously and asymptotically up to a resting position, which is also reached much earlier than in the prior art.

[0054] FIG. 4 finally shows a lower preloading rim 76 of a hot forming machine 1. The preloading rim 76 according to FIG. 4 has a 20-fold radial symmetry, i.e. it is designed for a hot forming machine with twenty processing positions, in contrast to the hot forming machine 1 according to FIG. 1, which has sixteen processing positions. On the shown preloading rim 76 a preloading position and a loading position for a glass tube 2 are defined in each of the twenty positions, which will be explained in more detail referring FIGS. 7a-c. In the loading position, the vertical glass tube 2 is aligned with one of the twenty openings 78, each of which is part of one of the twenty individually operated holding devices 80. FIG. 4 shows the preloading rim 76 from below; the function of the holding devices 80 and their actuation is explained in FIGS. 5 and 6.

[0055] In FIG. 4 the holding devices 80 are all open so that the openings 78 are visible. The preloading rim 76 is designed for counterclockwise rotation (seen from below in FIG. 4). A given opening 78 and holding device 80 first passes a non-rotating actuating device 82 which is fixed in the hot forming machine 1 and closes the respective holding device 80, as described referring to FIG. 5. After a few steps, the respective holding device 80 then reaches a position in which a pushing device 84 is arranged, which pushes a glass tube 2 from a pre-loading position inwards into the loading position, so that the glass tube 2 stands vertically above the holding device 80 in the now closed opening 78.

[0056] Only a few cycles later, after the preloading rim has been moved three positions further, does the respective holding device 80 reach a position in which a further actuating device 86 is arranged, which opens the respective holding device 80, as described for FIG. 6. The glass tube 2 then falls through the opening 78 in the manner already described for FIG. 2 onto the tube catcher 40, orin other design examplesonto another tube catcher as known from the prior art.

[0057] FIGS. 5 and 6 each show a cutout of the FIG. 4, FIG. 5 in the area of the actuating device 86, FIG. 6 in the area of the actuating device 82. As can be seen in FIGS. 5 and 6, each holding device 80 comprises a holding plate 88, each of which is pivotally mounted about one axis 90, respectively. The retaining plate 88 has a circular opening which is aligned with the respective opening 78 in the open position of the retaining plate 88 in FIG. 6. In the closed position of the support plate 88 shown in FIG. 5, the support plate 88 closes the opening 78. Each of the actuating devices 82, 86 comprises a pneumatically actuated slider 92, 94 which are each arranged to push against the support plate 88 on different sides and thus move it into the open or closed position.

[0058] Finally, the FIGS. 7a-c show in a lateral view the process of pushing the glass tube 2 from the preloading position into the loading position, as explained above. FIGS. 7a-c show a schematic side view of the upper part of the hot forming machine 1. In FIG. 7a the glass tube 2 is inclined in a radially outward preloading position. In FIG. 7b, the preloading rim reaches the position in which the pushing device 84 is arranged in a given cycle. This has a slider 96, which is exactly radially aligned inwards andalso pneumatically actuatedpushes the glass tube 4 onto the holding device 80 into a loading position, as shown in FIG. 7c. At a later time in a later rotation cycle, the holding device 80 is then opened, as described above.

[0059] In versions of the present disclosure, hot forming machine 1 described for FIG. 1 and FIGS. 4-7c may also be equipped with a prior art tube catcher which is not designed in accordance with the version according to FIG. 2.

LIST OF REFERENCE SIGNS

[0060] 1 Hot forming machine

[0061] 2 Glass tube or semi-finished intermediate product

[0062] 5 Vial

[0063] 6 Cylindrical side wall

[0064] 7 Shoulder

[0065] 8 Neck

[0066] 9 Roller edge

[0067] 10 Mother machine

[0068] 11 Pillar with drive

[0069] 12 Turntable

[0070] 15 Feed section

[0071] 16 Transfer section

[0072] 17 Gas burner

[0073] 18 Burner flame

[0074] 20 First hot forming section

[0075] 21 Second hot forming section

[0076] 22 Third hot forming section

[0077] 30 Non-tactile inspection system, e.g. video camera

[0078] 40 Tube catcher

[0079] 42 Foot

[0080] 44 Cylinder pot

[0081] 46 Sleeve

[0082] 48 Contact surface

[0083] 50 Piston

[0084] 52 Piston rod

[0085] 54 Chamber

[0086] 56 Disc

[0087] 58, 60, 62 Air supply line

[0088] 64 Opening

[0089] 66 Chamber

[0090] 67, 68 Outlet channel

[0091] 69 Magnet

[0092] 70 Holding chuck

[0093] 72, 74 Clamping jaws

[0094] 76 Lower preloading rim

[0095] 78 Opening

[0096] 80 Holding device

[0097] 82 Actuating device

[0098] 84 Pushing device

[0099] 86 Actuating device

[0100] 88 Holder plate

[0101] 90 Axis

[0102] 92, 94, 96 Slider