EP2663801B1

EP2663801B1 - Connecting device for cylinders of various shapes and sizes

Info

Publication number: EP2663801B1
Application number: EP12705416.1A
Authority: EP
Inventors: Massimo Tonati; Antonello Mucci
Original assignee: TOF Srl
Current assignee: TOF Srl
Priority date: 2011-01-14
Filing date: 2012-01-12
Publication date: 2018-12-12
Anticipated expiration: 2032-01-12
Also published as: ITMI20110029A1; EP2663801A1; IT1404666B1; WO2012095810A1

Description

The present invention relates to a device for connecting a pressure reducer, suitable for mounting on cylinders provided with connection and closing means of various shapes and sizes. There exist on the market cylinders filled with pressurized gas, provided with connection means of various shapes and sizes, in particular small cylinders filled with liquefied carbon dioxide, in which said connection means comprise an external thread and an annular flat surface coaxial with said thread. Said closing means normally comprise a needle valve, also coaxial with said thread.
A device that is connected with said cylinder, a pressure reducer, must be provided with an internal thread and with a corresponding annular flat surface coaxial with said internal thread. Connection with the cylinder takes place by screwing and the seal is obtained by a gasket interposed between said corresponding annular flat surfaces.
To act on said closing means, the connection element will be provided with a pin, also coaxial with the thread, which, after screwing, will press on the needle to open the valve.
Such a device is known from DE10 2007 005 864 A1 . Although various cylinders provided with the connection and closing means described exist on the market, said means differ, albeit slightly, in shape and size. Therefore, a specific connection element must be used for each of said cylinders. The use of gaskets of different height, as a function of the gap to be filled, does not solve the problem. In fact, if a hard gasket is used, the vibrations that are triggered during passage of the gas can cause unscrewing, while by using a soft gasket optimum clamping is obtained, but the gasket is subject to significant wear and must therefore be changed after two or three cylinder replacements. It must also be taken into account that said devices are often used by unqualified people, who might not fully understand the problems of safety linked to the use of devices subjected to relatively high pressures.
The present invention solves the problem posed by proposing a device, in conformity with claim 1, suitable for mounting on cylinders provided with connection and closing means, wherein:

said connection means comprise an external thread and a first annular flat surface coaxial with said external thread;
said closing means comprise a needle valve, also coaxial with said external thread;

In particular, the device according to the invention is characterized in that, after clamping has taken place, the surface of the gasket that comes into contact with said first annular flat surface of said cylinder, said second annular flat surface of the housing and said first annular flat surface of said cylinder lie on the same plane.
In this way, after clamping has taken place, contact is produced between rigid surfaces, in general made of brass or another metal, which effectively prevents unscrewing.
The advantage deriving from the use of a device according to the invention naturally consists in the possibility of being able to use the various types of cylinder available on the market, without having to necessarily be in possession of specific connection elements.
In the description of an example of application, specific reference will be made to a pressure reducer, as this is the device that is applied directly to the cylinder in the majority of cases. However, the technical solutions that will be described can also be applied to devices of different type, such as fixed metal or flexible pipes of the type used for high pressure pipes, to connect cylinder and reducer, or universal adapters.
The invention will now be described, by way of non-limiting example, according to a preferred embodiment, with reference to the accompanying figures, wherein:

Figs. 1 (a, b) show a pressure reducer adapted to be applied to cylinders provided with connection and closing means of various shapes and sizes;
Figs. 2, 3, 4 (a, b, c) show the connection sequence of said pressure reducer respectively with a first, a second and a third cylinder.

With reference to Fig. 1, the reference numeral (1) indicates a pressure reducer device adapted to be applied to cylinders provided with connection and closing means of various shapes and sizes.
Said device (1) comprises a housing (2) which accommodates therein a mechanism (3), of known type, which is operated by rotating a knob (4) and has the function of regulating the pressure of the gas drawn up from a cylinder (5) onto which said housing (2) is screwed through a thread (6) obtained in the part thereof that connects with said cylinder (5).
The figures show the upper part of the cylinder (5) which is provided with connection means for connection with the pressure reducer device and with closing means. Said connection means comprise a first annular flat surface (5a) and a thread (5b), while said closing means comprise a needle valve (5c). The housing (2) is provided, on the bottom of the thread (6), with a second annular flat surface (6a) against which said first annular flat surface (5a) abuts.
A gauge (8) is connected on the side of said housing (2) to measure the delivery pressure.
A lever (9) is also provided, to facilitate assembly and disassembly operations, said lever (9) being made by a U-bent rod, with ends (9a), bent at right angles, which fit into suitable seats (10) obtained on the housing (2). The lever (9) and the seats (10) are made so that the lever (9) can rotate at an angle of about 90°, so that when the lever (9) is at rest, it is positioned parallel to the axis of the device (1), and when it is used for screwing and unscrewing the device (1) on the cylinder (5), it is rotated upward by about 90° and can therefore be easily grasped to carry out the operation.
The cylinder (5) is provided, in the part that fits into the thread (6) of the housing (2), with said needle valve (5c), which is opened by a pin (11), accommodated in the housing (2), which, when the cylinder (5) is screwed into the thread (6), presses against said needle valve (5c).
The seal between the cylinder (5) and the housing (2) is obtained by an annular gasket (12) that fits into a specific seat (13) obtained in the housing (2). When the upper end of the cylinder (5) is screwed into the thread (6) obtained in the housing (2), the first annular flat surface (5a) abuts against the corresponding second annular flat surface (6a) obtained in the housing (2), deforming the gasket (12). After clamping has taken place, the first annular flat surface (5a) of the cylinder (5) is in contact with the corresponding second annular surface (6a) of the housing (2) and with the gasket (12).
After clamping has taken place, the surface of the gasket (12) which comes into contact with said first annular flat surface (5a) of said cylinder (5), said second annular flat surface (6a) of the housing (2) and said annular flat surface (5a) of said cylinder (5) are located on the same plane.
As clamping is obtained by said contact between the flat surfaces (5a) and (6a), the force with which the gasket (12) presses against the first annular flat surface (5a) of the cylinder (5) and the bottom of the seat (13) obtained in the housing (2), depends on the extent to which said gasket (12) is compressed during clamping and on its stiffness. Said parameters must therefore be selected so that said force is sufficient to guarantee the seal, taking account of the pressure of the gas.
The gasket (12) must have sufficient flexibility to be able to completely enter the seat (13), without being subjected to permanent deformation, and sufficiently stiff to produce, as a consequence of the deformation imparted, the force required to obtain the seal.
Said gasket (12) can be made of an elastomer, for example of polyurethane type, with Shore hardness of between 70 and 100. If necessary, the gasket (12) can be given the necessary flexibility by a configuration that makes it particularly flexible, for example by providing one or more grooves (12a).
Fig. 2 shows the situation of Fig. 1 in greater detail.
Fig. 2a shows the cylinder (5) and the housing (2) of the reducer (1) still decoupled.
Fig. 2b shows the cylinder (5), partially screwed into the thread (6), in the instant in which contact takes place between the first annular flat surface (5a) of the cylinder (5) and the corresponding surface of the gasket (12). In this situation, as the gasket (12), has still not been clamped between the first annular flat surface (5a) of the cylinder (5) and the bottom of its seat (13), obtained in the housing (2), it does not exert any seal, said seal being reached fully when, continuing to screw the cylinder (5) into the thread (6), the gasket (12) is deformed and exerts, through reaction, the pressure required to obtain an effective seal.
Fig. 2c shows the cylinder (5) screwed fully into the thread (6). In these conditions, the first annular flat surface (5a) of the cylinder (5) is clamped against the corresponding second annular flat surface (6a) of the housing (2), contact between said two flat surfaces (5a) and (6a) exerting an effective locking action. Simultaneously, the pin (11) presses against the needle of the valve (5c), opening it, and the gasket (12) is deformed until it enters its seat (13) completely. The elastic deformation of the gasket (12) generates, through reaction, the force required for the gasket (12), to obtain the seal between the cylinder (5) and the housing (2).
Figures. 3 (a, b, c) show the same sequence as Figs. 2 (a, b, c), but referring to a second cylinder (15), the upper end of which, although having a different shape to that of the first cylinder (5), again has an annular flat surface (15a), a thread (15b), suitable to be screwed into the thread (6) of the housing (2), and a needle valve (15c), the needle of said valve (15c) being in a position such that the pin (11) can open it when the cylinder (15) is screwed into the thread (6).
Figs. 4 (a, b, c) show the same sequence as Figs. 2 (a, b, c) and 3 (a, b, c), but referring to a third cylinder (25), the upper end of which, although having a different shape to that of the cylinders (5) and (15), again has an annular flat surface (25a), a thread (25b), suitable to be screwed into the thread (6) of the housing (2), and a needle valve (25c), the needle of said valve (25c) being in a position such that the pin (11) can open it when the cylinder (25) is screwed into the thread (6).
The examples shown in the figures indicate the three shapes for the upper ends of the cylinders (5, 15, 25) which are currently effectively present on the market. As shown by the figures, therefore, a single device can effectively be applied in all possible cases. However, cases could occur in which the threads of the cylinders are not compatible with the thread (6) present on the housing (2) and/or the position of the needle of the valve of the cylinder is such that the pin (11) present on the housing (2) is not of the length necessary to obtain correct opening. To make the device (1) according to the invention suitable to be used in all possible combinations, it will be sufficient to fit, between the thread (6) and the thread of the cylinder, a ring (not shown) externally threaded so as to be screwed into the thread (6) of the housing (2), and internally threaded so as to be screwed into the thread the cylinder. It is possible to proceed in the same manner with the pin (11) which can be replaced by another pin (not shown) of suitable length to obtain correct opening of the needle valve of the cylinder.
As is clear from the foregoing description, the device according to the invention is suitable to be applied to cylinders with connection ends of different sizes, said adjustment being obtainable also by adding and/or replacing parts. However, in the specific case of reducers for cylinders of small sizes, the variety of cylinders currently existing on the market ensures that a single reducer, without adding and/or replacing parts, is sufficient for all possible combinations.
The invention has been described purely by way of non-limiting example, according to a preferred embodiment. Those skilled in the art may find numerous other variants, all falling within the scope of protection of the claims below.

Claims

Pressure reducer (1) suitable for mounting on cylinders (5, 15, 25) provided with connection and closing means, wherein:
said connection means comprise an external thread (5b, 15b, 25b) and a first annular flat surface (5a, 15a, 25a) coaxial with said external thread (5b, 15b, 25b);

said closing means comprise a needle valve (5c, 15c, 25c), also coaxial with said external thread (5b, 15b, 25b);

said pressure reducer is contained in a housing (2) provided with an internal thread (6) and an second annular flat surface (6a), coaxial with said internal thread (6), the connection with said cylinders (5, 15, 25) taking place by screwing and said needle valve (5c, 15c, 25c) being opened by the pressure exerted by a pin (11), present on said housing (2), wherein the pressure reducer comprises an annular gasket (12) and a specific seat (13) of said housing (2) into which it fits to obtain the seal, the pressure reducer (1) being configured so that after clamping has taken place, said second annular flat surface (6a) of said housing (2) is in contact with said first annular flat surface (5a, 15a, 25a) of said cylinder (5, 15, 25),) and the surface of the annular gasket (12) comes into contact with said first annular flat surface (5a,15a,25a) of said cylinder (5,15,25), and said second annular flat surface (6a) of the housing (2) and said first annular flat surface (5a, 15a,25a) of said cylinder (5,15,25) lie on the same plane,

said annular gasket (12) being deformed due to said clamping and exerting, through spring reaction on the bottom of said seat (13) and on said first annular flat surface (5a, 15a, 25a) of said cylinder (5, 15, 25), the force required to obtain, between said cylinder (5, 15, 25) and the housing (2) of the device (1) pressure-seal of the gas drawn up, wherein the gasket has sufficient flexibility-to completely enter the seat when clamping takes place without being subjected to permanent deformation, and is sufficiently stiff to produce, as a consequence of the deformation imparted, the force required to obtain the seal.
The pressure reducer according to claim 1, characterized in that one or more grooves (12a) are provided on the side of said gasket (12), said one or more grooves being suitable to provide said gasket (12) with the flexibility to develop the force required to obtain the seal.
The pressure reducer according to claim 1 or 2, characterized in that said gasket (12) is made of an elastomer having a Shore hardness of between 70 and 100.
The pressure reducer according to at least one of claims 1 to 3, characterized in that said gasket (12) is made with a polyurethane elastomer.
The pressure reducer according to at least one of claims 1 to 4, characterized in that it comprises a ring fitted between the thread (6) of the housing (2) and the external thread (5b, 5 15b, 25b) of the cylinder, said ring being externally threaded so as to be screwed into the thread (6) of the housing (2), and internally threaded so as to be screwed into the external thread (5b, 5 15b, 25b) of the cylinder.
The pressure reducer according to at least one of claims 1 to 5, characterized in that the pin (11) is replaceable by another pin (11), of suitable length to obtain correct opening of the needle valve of the cylinder.
The pressure reducer according to claim 1, characterized in that it comprises a lever (9) to facilitate assembly and disassembly operations, said lever (9) being made by a U-bent rod, with ends (9a), bent at right angles, which are inserted in suitable seats (10) obtained on the housing (2), said lever (9) and said seats (10) being made so that the lever (9) can rotate at an angle of about 90°, so that when the lever (9) is at rest, it is positioned parallel to the axis of the pressure reducer (1), and when it is used for screwing and unscrewing the device (1) of the cylinder (5, 15, 25), it is rotated upward by about 90° and can therefore be easily grasped to carry out the operation.