Abstract:
A device for regulating the pressure and/or flow of pressurized gas, comprising a body with a gas inlet, a gas outlet and a gas passage connecting the outlet with the inlet, a pressure reducer and a flow selector arranged downstream of the pressure reducer, a hand-wheel rotatably mounted on the body and cooperating with the flow selector for adjusting the flow, and a pressure indicator located at the center of the hand-wheel. The device comprises also a shaft rigidly fixed to the body and rotatably bearing the hand-wheel, the shaft supporting the pressure reducer and comprising a gas channel fluidly connected to the gas passage in the body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present invention is the US national stage under 35 U.S.C. §371 of International Application No. PCT/EP2015/054472, which was filed on Mar. 4, 2015, and which claims the priority of application LU 92395 filed on Mar. 7, 2014, the content of which (text, drawings and claims) are incorporated here by reference in its entirety. 
     
    
     FIELD 
       [0002]    The invention is directed to the field of taps for pressurized gas storage tanks like gas cylinders. Such taps can comprise several functions like a shut-off function, a pressure reducing function and/or a flow selector function. 
       BACKGROUND 
       [0003]    Prior art patent document published EP 2 791 409 A1 discloses a gas cylinder tap with a pressure reducer and a flow selector. The flow selector is operated by means of a hand-wheel that rotates a disk with calibrated holes arranged along a circle in order to bring a specific hole of a calibrated section in front of a gas passage fluidly connected to the gas outlet of the tap. A pressure indicator is housed in the hand-wheel and is mounted on the tap so as not to rotate with the wheel. Indeed, the pressure indicator is supported by a thin shaft that extends through a larger shaft of the hand-wheel and also through the piston of the pressure reducer. The piston comprises a closure element that cooperates with a seat in the tap body. The thin shaft holding the pressure indicator extends through the piston until the closure element so as to be constantly in fluidic connection with the high pressure directly upstream of the seat. The pressure indicator provides therefore information of the pressure in the gas cylinder. This arrangement is however rather bulky in the longitudinal direction of the tap. Also, the pressure indicator is mechanically linked to the piston of the pressure reducer. This means that the pressure indicator is likely to disturb the functioning of the pressure reducer. Indeed, the frictional forces between the shaft and the guiding surfaces in the shaft of the hand-wheel will interfere with the forces acting on the piston for the regulation of the pressure. In addition, the presence of dust or particles between the pressure indicator housing and the internal surface of the hand-wheel might even increase that negative interference. 
         [0004]    Prior art patent document published U.S. Pat. No. 6,283,146 B1 discloses also a gas cylinder tap with a pressure reducer and a pressure indicator housed in a hand-wheel. Similarly to the above discussed teaching, the pressure indicator does not turn together with the hand-wheel. This tap does not however comprise any flow selector. The hand-wheel adjusts the pre-setting of the pressure reducer. The pressure indicator is held by a sophisticated arrangement comprising a pressure gauge guide that is longitudinally held in place by means of bolts screwed in a rotatable sleeve of the hand-wheel and engaging in a groove of the guide. This latter is engaged with a non-rotating spring retainer of the pressure reducer, and this in a sliding but non-rotating manner. The pressure indicator is in fluidic connection with the reduced pressure, contrary to the previous document where the pressure indicator is connected to the high pressure in the inlet. 
       SUMMARY 
       [0005]    The invention has for technical problem to provide a more compact and/or more simple tap construction with an adjustment hand-wheel housing a pressure indicator. 
         [0006]    The invention is directed to a device for regulating the pressure and/or flow of pressurized gas, comprising: a body with a gas inlet, a gas outlet and a gas passage connecting the outlet with the inlet; a pressure reducer and, preferably, a flow selector arranged downstream of the pressure reducer; a hand-wheel rotatably mounted on the body and cooperating with the pressure reducer and/or the flow selector for adjusting the pressure and/or flow; a pressure indicator located at the center of the hand wheel; wherein the device further comprises: a shaft rigidly extending from the body and rotatably bearing the hand wheel, the shaft supporting the pressure indicator. 
         [0007]    According to various embodiments of the invention, the shaft is rigidly fixed to the body, for example by screwing. 
         [0008]    According to various embodiments of the invention, the shaft comprises a gas channel fluidly connected to the gas passage in the body. 
         [0009]    According to various embodiments of the invention, one end of the shaft comprises a support for the pressure indicator, the other end of the shaft being fixed to the body in a rigid and gas-tight fashion, the other end, in various instances, comprising an external thread mating with an internal thread in the body. 
         [0010]    According to various embodiments of the invention, the support extends perpendicularly to the shaft, the support being, in various instances, integrally formed with the shaft and/or comprising means configured to rotatably engage with a tightening tool. The means can comprise an outer contour of the support, with several faces for engaging a polygonal nut. It can also comprise at least two parallel holes on the support for engagement with parallel pins on a specific tool. 
         [0011]    According to various embodiments of the invention, the shaft extends through the hand-wheel and the pressure indicator is located at the center and inside the hand-wheel. 
         [0012]    According to various embodiments of the invention, it comprises a sleeve rotatably mounted on the shaft, the hand-wheel being attached to the sleeve. 
         [0013]    According to various embodiments of the invention, the sleeve comprises, or is attached to, a shoulder portion distant from the hand-wheel; the sleeve being supported by the shaft and surrounded by a bearing portion of the body between the hand-wheel and the shoulder portion. 
         [0014]    According to various embodiments of the invention, the bearing portion of the body is a separate portion that is mounted on the rest of the body, the portion being, in various instances, generally flat and/or circular. 
         [0015]    According to various embodiments of the invention, the sleeve, the hand-wheel and the bearing portion are configured so that they can be assembled together in a pre-assembly, the shaft inserted through the sleeve can then be fixed to the body and the pre-assembly be fixed to the body. 
         [0016]    According to various embodiments of the invention, the shoulder portion comprises a disk with passages of different sections forming the flow selector. 
         [0017]    According to various embodiments of the invention, the bearing portion of the body comprises the gas outlet, the outlet, in various instances, extending transversally, preferably at least essentially perpendicularly, to the longitudinal direction of the shaft. 
         [0018]    According to various embodiments of the invention, the disk is in rotatable contact with a contact surface of the bearing portion of the body, the surface comprising a hole with a passage in the portion interconnecting the gas outlet with the hole. 
         [0019]    According to various embodiments of the invention, the hand-wheel is generally cup-shaped, the pressure indicator being housed in the cavity of the cup. 
         [0020]    According to various embodiments of the invention, the body extends essentially along a longitudinal axis of a threaded portion forming the gas inlet and to engage in a gas cylinder neck, the device comprising a pressure reducer that is disposed laterally with regard to the longitudinal axis. 
         [0021]    According to various embodiments of the invention, the pressure reduced comprises a movable element that regulates a restricted flow passage, the element being movable in translation along an axis that is transversal, in various instances, essentially perpendicular, to the longitudinal axis of the body. 
         [0022]    According to various embodiments of the invention, the device comprises a flow selector fluidly downstream of the pressure reducer, between the gas outlet and the pressure reducer. 
         [0023]    According to various embodiments of the invention, the gas channel of the shaft is fluidly connected to the gas passage upstream of the pressure reducer. 
         [0024]    The invention is particularly interesting in that it provides a simple and cost effective construction for mounting a hand-wheel with a pressure indicator at its center on the body of regulating device for pressurized gas. 
     
    
     
       DRAWINGS 
         [0025]    The unique FIGURE is a sectional view of a device for regulating the pressure and the flow of pressurized gas, in accordance with various embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    The unique FIGURE a sectional view of a device for gas cylinder with a pressure reducer and a flow selector. The view shows however only the portion of the device that comprises the flow selector, a hand-wheel for adjusting the selector and a pressure indicator housed in the hand-wheel. 
         [0027]    The device  2  comprises a body  4  with a gas inlet  6 , a gas outlet  8  and a gas passage  10   1 ,  10   2  and  10   3  connecting with the outlet with the inlet. The device comprises a pressure reducer  12  which is schematically represented in the FIGURE. A pressure reducer is well-known as such by the skilled person and does need to be further detailed. The exit of the pressure reducer  12  is fluidly connected through the gas passage portion  10   3  with a flow selector  14 . A gas passage portion  10   4  connects the inlet  6  directly with a pressure indicator  20  mounted on a shaft  16 . The shaft comprises a gas channel  18  extending through the shaft along its longitudinal axis for connecting the pressure indicator with the gas passage at a portion that is upstream of the pressure reducer  12 . This means that the pressure indicator informs of the pressure at the inlet, i.e. in the gas cylinder. 
         [0028]    The valve body  4  comprises a main portion  4   1  and a bearing portion  4   2 . The shaft  16  is rigidly mounted on the main portion  4   1 , e.g. by means of a threaded engagement and a gas tight engagement. To provide a stable and rigid mounting, the shaft can comprise a free end portion  16   1  with a reduced diameter that engages into a corresponding bore in the main body  4   1  and a male thread  16   2  portion that is distant from the free end  16   1 . 
         [0029]    A sleeve  24  extends along a portion of the external surface of the shaft  16  so as to be supported by the shaft. The sleeve  24  comprises a disk-shaped shoulder portion  32  that is located in a flow selection chamber  28  downstream of the pressure reducer  12 . This chamber  28  is formed in a cavity of the main body  4   1  that is closed by the bearing portion  4   2  of the body in a gas tight fashion by means of the joint  30 . The disk  32  comprises a series of calibrated holes or apertures  32   1  to  32   n  where n is an integer greater than 1. These holes or apertures preferably have different flow sections and are configured to be positioned in a selective manner in front of a hole  34  in the bearing portion  4   2  of the body, thereby limiting the flow of gas to the outlet  8 . Alternatively or in a complementary manner, the number and position of the holes or apertures can be organized such that several of them are in front of the hole  34 , the flow section and gas flow being varied with the number of holes or apertures in front of the hole  34 . 
         [0030]    The hole  34  in the bearing portion  4   2  of the body  4  is in direct fluid communication with the gas passage  10   3  that fluidly connects the outlet  8  with the hole  34 . Sealing means like an O-ring can be placed in a housing formed in the hole  34  so as to provide a gas tight connection with the disk  32 . Similarly, sealing means like an O-ring  26  is placed between the internal surface of the sleeve  24  and the external surface of the shaft  24 . For instance, an O-ring  26  is placed in a circular groove on the external surface of the shaft, the O-ring contacting the internal surface of the sleeve  24 . 
         [0031]    The bearing portion  4   2  of the body  4  comprises a bore surrounding the sleeve  24 . An O-ring  27  is placed in a circular groove in the surface of the bore and contacts the external surface of the sleeve. This provides a gas-tight assembly of the chamber  28 . 
         [0032]    A hand-wheel  22  is attached to the sleeve  24 , more particularly at the portion the sleeve  24  that is distant from the disk-shaped shoulder  32  and that extends from the bearing portion  4   2  of the body  4 . To that end, the sleeve  24  can comprise a shoulder portion receiving the bottom portion  22   1  of the hand-wheel, this latter being secured against that shoulder portion by means of a nut or ring to be crimped. Means preventing a relative rotation between the hand-wheel and the sleeve are of course foreseen (but not visible in the sectional view). 
         [0033]    The hand-wheel  22  is, in various instances, cup-shaped with a bottom wall  22   1 , a generally flared circular wall  22   2  and an external rim  22   3 . The hand-wheel  22  forms thereby a cavity  22   4  that houses the pressure indicator  20 . This latter is supported by a front surface or wall  16   3  of the shaft  16 . The pressure indicator can be a mechanical one with a Bourdon tube as illustrated or any other indicator, like for example a digital one. The pressure indicator  20  is, in various instances, completely housed in the cavity  22   4  of the hand-wheel  22 . This latter can comprise a transparent cover  22   5  extending over the cavity  22   4  and protecting the pressure indicator. 
         [0034]    Upon manipulation in rotation the hand-wheel transmits its rotational movement to the sleeve  24  and to the disk  32  for selecting the desired flow rate of gas whereas the pressure indicator remains stationary and indicates the inlet pressure, i.e. the pressure in the storage tank. 
         [0035]    The above detailed construction is particularly interesting with regard to its assembly. The sleeve  24  can indeed be inserted into the bearing portion  4   2  of the body  4  and the hand-wheel  22  can then be mounted on the sleeve  24 , thereby providing a pre-assembly. The shaft  16  can be inserted into the sleeve of that pre-assembly. The pre-assembly with protruding free end of the shaft can be brought close to the main body  4   1 , in the direction of the corresponding bore of the main body. The free end of the shaft  16  serves therefore as guiding means and can then be fastened to the body, for instance by screwing. Afterwards, the bearing portion  4   2  of the body  4  can be secured to the main body  4   1 , e.g. by screwing means (not visible in the presented sectional view). 
         [0036]    In the above construction, in various instances, the body comprises a threaded port at the inlet  6  for engagement in the neck of a gas cylinder. The body  4  can therefore extend essentially longitudinally along the axis of that threaded port. This axis can correspond or be parallel essentially to the schematic representation of the gas passages  10   1  and  10   4 . As is visible in the FIGURE, the flow selector  14  is then arranged laterally with regard that longitudinal axis. The axis of the shaft  16  is indeed inclined at an angle comprised between 30° and 60° with the longitudinal axis. The pressure reducer  12  that is only schematically represented can be arranged also laterally, in various instances, at a place around the longitudinal axis that is not yet occupied by the flow selector  14 . The pressure reducer  12  can comprise a movable element, like a piston, that controls the position of a shut-off device and delimits a low pressure chamber downstream of the device. This element can be arranged so as to be movable in translation along a direction that is transversal or even generally perpendicular to the longitudinal axis of the regulating device. This provides the advantage that the shaft can easily be fluidly connected with the inlet, e.g. with an essentially central passage  10   4  the can be concentric with the longitudinal axis of the regulating device. 
         [0037]    The above construction of the hand-wheel has been specifically described in connection with a flow selector. It can however be also applied for the pre-setting and adjustment of a pressure reducer. Indeed, the shoulder portion attached or formed with the sleeve could indeed modify the pre-tension of the spring of a pressure reducer, for example via a threaded engagement.