DE2609852A1 - PNEUMATIC DEVICE FOR TESTING THE AIR TIGHTNESS OF CONTAINERS - Google Patents

Description

PATENT LAWYERS

RUFF and BElER STUTTGART

D i ρ I.-C h e m. Dr. Shout Dipl.-Ing. J. B e i e r

Neckarstrasse 5O D-7OOO Stuttgart 1 Tel .: C071O 227O51 * Telex O7-23412 erub d

March 9, 1976 JB / Bo

Applicant: Giovanni ABBATIELLO, Pontinia, Italy

962

963

Pneumatic device for testing the airtightness of containers

The present invention relates to a pneumatic device for testing the airtightness of containers of each Shape and size and for sorting out defective containers, of which several units are arranged on a rotor to form an automatic machine with a continuous repeat cycle.

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They are machines for testing cylindrical containers has become known to sort out a damaged container using the air flowing out of it.

The container is inserted into a bell and, together with the bell itself, is hermetically sealed by an elastic pad locked. When the container loses air, the escaped air remains within the between the outside of the Container and the inside of the bell formed Eaumes and causes a pressure increase there. This pressure sends through a membrane sends an electrical signal to an electronic device, which receives this signal, in response to a selection device to operate, which separates the damaged container from the usable.

These machines, which operate as described, consist of mechanical means for picking up and inserting the container into the bell, mechanical means to ensure the air exclusion and electronic means to determine the pressure controlling the container selector.

The device according to the present invention is based on the equilibrium of two pressures acting on a membrane, with the surface of the membrane on one side through the pressure of the air supplied to the tested container and pressed on the other side by the pressure of the air, which corresponds to that of the container to be tested and which is directed into an inserted storage space.

When the pressure inside a damaged container drops, the air pressure in the storage space pushes the membrane,

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until an electrical contact arranged thereon is closed, whereby the controller to sort out the defective Behältas is triggered from the device.

According to the invention, the following main parts are in combination intended:

a pneumatic piston which is retracted by a spring and which provides the means for pressing the container to be tested against an elastic pad,

a storage space, which is the means for generating the counterpressure of the air on the membrane to create the equilibrium conditions forms,

a housing containing a membrane with an electrical contact which contains the means for detecting the loss of air forms in a container.

These means are connected to an electro-pneumatic circuit, which includes the following parts:

a supply valve for advancing the piston,

an outlet valve to return the piston to bring the usable container into the transport channel,

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3) ■,

an electric exhaust valve to return the piston for sorting out the damaged container into a reject channel,

a supply valve for supplying the compressed air for the test into the container and into the storage space,

a supply valve for forwarding the air pressure in the storage space to the membrane,

an interrogation microswitch to operate the electrical outlet valve.

These valves and the microswitch, operated by suitable ones Cams determine the cycle of the various processes.

The container, which is subjected to the tests with the aid of the device according to the invention, is by the thrust of the Piston hermetically sealed against an elastic cushion, and then the compressed air for the test is the container and fed to the storage space. The air in the container pushes the membrane against a flat surface with the atmosphere cooperating housing. At this stage the container is separated from the storage chamber, and the cooperative The membrane brought by the pressure of the storage space is balanced by the effect of the two pressures.

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When the container loses air, that moves from the pressure of the storage space printed membrane until the electrical Contact is closed so that if the contact of the position microswitch is also closed, the solenoid valve is actuated, the release of the air from the cylinder allows a .Return of the piston and the defective container drops into the reject channel.

However, if the tested container does not leak air, the conditions described above do not arise and the container is further held by the piston, which - together with a star wheel device - that of the star wheel device accommodated container by the cam, which actuates the cylinder exhaust valve, releases, the star wheel device introduces the container into the! conveying channel.

Thus, the device according to the present invention enables the formation of a completely pneumatic machine, which has the following advantages:

The combination of the piston and the Spei ehe space allows it is to omit all mechanical means in machines according to the state of the art, the electronic means of control the reject device and the equipment necessary to test each type of container, thereby creating a machine which is much easier and cheaper.

From the application this? Means. There is another important one Advantage, namely an increase in the test angle, which in turn increases the effectiveness and therefore the performance of the device. Furthermore, the storage space gives the membrane an operational stability during the test cycle, which is prevented Vibration of the machine due to movements and

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enables precise control of the device and the sorting out of the defective container at the same time.

So there is a pneumatic device for testing the airtightness of containers of any shape and size and for Sorting out of damaged containers as well as an automatic machine with a continuous repetition cycle created, which contains a plurality of such pneumatic devices which, in combination, comprise a pneumatic piston, the one in a cylinder with a return spring for supporting and pressing the container against a resilient pad is arranged, a vibrating pressure piece which is arranged at the end of the piston rod and by a spring in its normal situation is maintained. A washer that supports the elastic pad and is pressed by a spring holds by one conical valve seat closes the air passage and absorbs the impact of the container caused by the piston thrust. There is a storage space for generating the counter pressure of the air on a membrane, on the other side of the Pressure de3 container acts, and an annular support that holds the disc with the elastic cushion and the housing of the Carries membrane and is movable along spindles, which are attached to the rotor by gears driven by a chain the chain being operated by one of the same gears to make the device of different height to adapt the container.

Further advantages and features of the invention emerge from the subclaims and the description in connection with the drawings. A preferred embodiment of the invention is shown in the drawings and will explained in more detail below. Show it:

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Pig. 1 shows a section through the machine along line I-II in Pig. 2, who uses the rotor the pneumatic device, the air distribution system of the pneumatic circuit, the unit of disks on which the control cams are attached, the valves and shows the brushes of the electric circuit

Figure 2 is a front elevation view of the machine incorporating the supply system for the containers in the various Operating devices shows

Fig. 3 is a front view of the machine which the

Shows the drive of the rotor unit carrying the working units,

4 shows a schematic, circuit diagram-like representation of the pneumatic circuit of the device for moving the piston and supplying the air for testing the containers and into the memory space,, and

and 5 & the subsequent cycle of the cams for actuation the valves of the electro-pneumatic circuit.

In Figures 1 and 2, the devices are attached at equal intervals on the circumference of a rotor 1, which by a drive operated by a motor 6 2,3,4,5 on a hollow, at the upper end of a frame 8 of the machine

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solid shaft 7 runs idle and also, the star wheel device 9 for feeding and 10 for receiving the containers which are synchronized with the various devices.

On the rotor 1 are the storage space 11, the pneumatic one Piston 12 and an annular carrier 13 attached, the one. Washer 14 with an elastic pad 15 carries the axially is arranged opposite the piston 12 and the diaphragm housing 16.

By means of an annular carrier 13 carried by a series of spindles 17 attached to the rotor 1, depending on of the height of the container to be tested 18 - by means of the Gear 19, which are screwed onto the spindles 17 and are rotatably arranged in the holes of the annular support 13, move along the axes of the rotor.

These gears 19, which are operated by a chain 20, which is controlled by one of the gears 19 itself, move the annular support 13 to its desired Location.

The pneumatic piston 12 and its return spring 21 are arranged in a cylinder 22 attached to the rotor 1. A pressure piece 24 is attached to the end of the piston rod 23 of the piston 12, which is attached to a ball seat 25 and held on its axis by a spring 26, which ensures that the edge 27 of the container 18 rests on the elastic pad 15.

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Δη the annular carrier 13 is a hollow bush 28 with attached radial holes through which the air enters the container 18 is directed. This bushing 28 carries the housing 16 of the membrane 29 and the disc 14 with the elastic pad 15.

The disc 14 is provided with a seal 30 at its inner hole provided for hermetic sealing and slides under the action of a spring 31 on a bushing 28 to allow the air through ■ gear to close, by means of its conical seat 32, which is attached to another conical seat of the stop pin 34 is present.

The housing 16 fastened to the socket 28 consists of two elements which hermetically seal the membrane 29. The element 35 cooperating with the storage space 11 has a flat surface 37 ₅ which is in contact with the membrane 29, whereas the other element 36 connected to the container 18 is provided with a concave surface 38 which, when the membrane 29 is elastically deformed, this keeps within the limits of its mechanical strength when the membrane is pressed by the pressure of the storage space 11.

The supply valves 40, 41, 42, 43 of the device are arranged on a disk 44 fastened to the hub 45 of the rotor 1, whereas the actuating cams 46, 47, 48, 49 ₅ 50 are arranged on another disk 51, which is fixed with a sleeve 52 attached to the end of the hollow shaft 7 is connected.

By a spacer 531 on the disc 44 for the Valves that rotate with the rotor 1 is attached, another disk 54 is attached, which is an interrogation microswitch 55 and so causes the disks 44 and 54 to rotate relative to the stationary disk 51.

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The sleeve 52 supports axially the rotor 1 and connecting supply conduits 56 and 57 _an d _e i _n the protective tube 58 for the electrical wires. A ring 59 moving with the rotor 1 distributes the compressed air to the various devices that make up the machine.

In this ring 59 two holes 60 and 61 are closed for each supplying device is provided which cooperate with two chambers or recesses 62 and 63 which are within the Hole are provided, are separated by sealing rings 64- and with the holes 65 and 66 of the sleeve 52 have connection.

The devices are supplied by lines 56 and 57, of which line 56 is used to actuate piston 12, whereas line 57 is provided for testing containers 18. The electrical wires running through the protective tube 58 are connected to two plates 67 and 68 which are fastened to an insulating part or an insulating plate 69 inserted into the hub of the sleeve 52. These plates 67 and 68, of which one (67) is centrally located, while the other (68) is annular, allow the passage of the current to the electrical circuit through two contact brushes 70, which are attached to another, with the disc ^ M- rotating insulating plate 71 are arranged.

The sequence of action of the cams 46,47,48,4-9,50 to control the supply valves 40,41,42,43 and the microswitch 55 according to the diagram in Fig. 5 "and 5a is in described below.

The containers 18 are received by a star wheel device 9 from a supply channel 72 and corresponding to the individual devices fed to the machine.

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When this position is reached, the cam 46 opens the supply valve 40 of the cylinder 22 and causes the piston 12 to move forward, as a result of which the pivoted Pressure piece 24 of the container 18 is pressed from its bottom part against the elastic pad 15 until it is with his opposite edge 27 is pressed against this. The disk 14 presses the spring under the impact of the container 18 31, which absorbs the shock and - by making the conical seat 32 moved away - keeps the passage for the supply of air into the container 18 open. After closing the valve 40, the opens again in the next cycle, the Compressed air for the test through the operated by the cam 47 Supply valve 42 is blown into the tank 18, taking at the same time the storage space 11 is also supplied. The membrane remains under the pressure of the air of the container 18, which as Outlet, the line cooperating with the storage space 11, is pressed against the flat surface of the element 35.

Then the cam 48 opens the valve 43, which the storage space 11 connects to the membrane 29, while the valve 42 is still for a short time to fill the volume of the line Time remains open. Then the container 18 after closing the valve 42 for the entire test duration of the one with the Membrane 29 cooperating storage space 11 separately.

When these conditions are met, if the container 18 is defective, the internal pressure of the container will decrease by the loss of air and the pressure of the storage space 11 presses the membrane 29 until the contact 39 is closed. When the query microswitch 55 is closed by the cam 49 is and when the contact 39 of the membrane 29 is closed,

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the circuit is closed with the solenoid valve 74- that the Lets air out of the cylinder 22, causes the piston to return and drops the container 18 into the reject channel 75.

If, on the other hand, the tested container 18 is not defective, since the equilibrium conditions on the membrane remain unchanged, the contact of the interrogation microswitch 55 ₅ closes while the contact 39 of the membrane 29 is open; the solenoid valve 74- is not operated so that the piston continues to hold the container 18.

In accordance with the star wheel device 10, the operating cam 50 is provided for the exhaust valve 41, which the Releases air from the cylinder 22 and thus enables the container 18 to be released by the piston 12, the container, which is received by the star wheel device 10, is introduced into the conveying channel 76 '.

This last-mentioned process thus concludes the test cycle, which is automatically repeated for each device.

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Claims (1)

A 15 962/3 - 13 - Expectations Pneumatic device for testing the airtightness of containers of all shapes and sizes and for sorting out from defective containers, of which several units are arranged on a rotor, to an automatic machine with a continuous repetition cycle, characterized by a pneumatic piston (12), which in a cylinder (22) with a return spring (21) for supporting and pressing a container (18) against an elastic one Pad (15) is arranged, an articulated pressure piece (24), which is at the end of the rod (23) of the piston (12) is arranged and held in its normal position by a spring (26), a washer (14 ·), which the elastic Pad (15) which is pressed by a spring (31) and the air passage through a conical valve seat (33) keeps closed, with the disk damping the impact of the container resulting from the thrust of the piston, a Storage space (11) for generating the counter pressure of the air on a membrane (29), on the other side of which the pressure of the Container (18) acts, and an annular support (13) that holds the disc with the elastic cushion and a housing (16) carries the membrane, the carrier being movable along spindles (17) attached to the - ^ otor (1) by gears (19) are attached, which are operated by a chain (20) driven by one of the same gears, in order to adapt the device to the different heights of the containers (18). 609840/0308 A 15 962/3 - 14 - Device according to. Claim 1, characterized in that the Membrane (29) is designed and arranged in such a way that when the pressure within a damaged container (18) decreases , they are blocked under the action of the pressure of the storage space (11) and a contact (39) of an electrical circuit closes so that a solenoid valve (74) from an interrogation position microswitch (55) is actuated, and thus initiates the outflow of air from the cylinder, so that the Piston (12) returns and the container runs into a reject channel (75). Pneumatic device according to Claims 1 and 2, characterized in that the two elements of the housing (16) hermetically sealed membrane (29) under the pressure of the air of the container on the flat surface (37) of a Element (35) remains pressed and, in contrast, moves under the pressure of the air of the storage space (11), until it hits the concave surface of the other element, so that this causes the elastic deformation of the membrane keeps within the limits of its mechanical strength. Pneumatic device according to one of Claims 1 to 3, characterized in that the disk carrying the elastic pad (15) is designed so that it moves when it is present one through the piston (12). the pushed container (18) moves along the axis of the bushing that creates the shock compresses receiving spring and its conical seat from the conical seat of the stop pin separates to the Allow air to flow into the container. 609840/030 8 A 15 962/3 - 15 - 5 Pneumatic device according to one of Claims 1 to 4, characterized in that the ring-shaped bearing the disc for the elastic cushion (15) and the housing for the membrane Carrier (13) - depending on the height of the container to be tested. (18) - by means of gears (19) along the on the eotor (1) attached spindles (17) is adjustable, · whereby the gears are operated by a chain, which in turn is operated by one of the same gears that are attached to the spindles (17), the gears in the Holes of the carrier (13) are arranged to be axially immovable, but freely rotatable. 6. Pneumatic device according to one of claims 1 to 5> characterized in that the pressure piece (24) by the arrangement of a hemispherical end of the piston rod (23) in a hemispherical seat provided in the pressure piece (24) itself can be designed to be pivotable. 7- device according to one of claims 1 to 6, characterized in that that the unit for supplying the pneumatic devices is formed by three discs, of which the the operating cam for the valves and the query microswitch (55) supporting is fixed, whereas the Valves and disks carrying the interrogation microswitch rotate together with the eotor. 609840/0308 Blank page