This application claims priority to European Patent Application No. 03079185.9 filed Dec. 24, 2003, and which is incorporated herein by reference.
Not Applicable.
The present invention relates to a tap, especially a tap for a gas or liquefied gas cylinder, comprising a fixed tap structure including a tap body, an actuating wheel rotatable about an axis of rotation with respect to the fixed tap structure to open or close the tap, and a means for indicating the open or closed position of the tap, said means comprising a movable element for covering or exposing a signaling means, said signaling means indicating by its visibility or invisibility the open or closed condition of the tap.
Taps provided with a means or a device permitting an operator to see the closed or open condition of the tap on the exterior thereof are known in the state of the art. For example, in a known prior art tap a fixed ring or band is provided on the exterior surface of the tap body. This ring is normally masked by the actuating wheel of the tap and it has color different from the tap body and the actuating wheel. This simple system functions only with a tap having an upwardly and downwardly movable actuating wheel and stem assembly in view of the fact that the ring can only be uncovered or exposed by actuating wheel movement in axial direction relative to the tap body. Further, for a tap of very small opening movement, the actuating wheel moves only a very limited axial distance relative to the tap body and the ring indicating the open position of the tap would be only very slightly uncovered and therefore not be clearly discernible below the actuating wheel.
Known in the art are also taps having actuating wheels provided with windows through which marks can be seen on fixed tap structure indicating the open or closed position of the tap. However, these devices are limited to taps whose actuating wheel is only movable a fraction of a turn, such as a quarter turn, for opening and closing the tap.
Finally, in the prior art taps are known having relatively complex and cumbersome systems for indicating the open or closed condition of the tap.
The object of the present invention is to avoid these disadvantages and to provide a tap having a simple means or device for indicating the open or closed condition of the tap, which is easily visible on the exterior of the tap, and which can be used on a tap having an upwardly and downwardly movable stem, on a tap having a rotating stem (not movable upwardly and downwardly) and also on a tap having an actuating wheel rotatable only a fraction of a turn or multiple turns for opening or closing the tap.
According to the invention the movable element of the indicating means is a skirt coupled, on one side, to the actuating wheel so as to be entrained in rotation therewith and coupled, on another side, to the fixed tap structure by a means causing, under the effect of rotational movement of the skirt in one or the other direction, an axial displacement thereof along the axis of rotation with respect to the actuating wheel and with respect to the fixed tap structure so as to cover or expose the signaling means.
Accordingly, the movable skirt of the means for indicating the open or closed position of the tap effects an upward or downward movement relative to the fixed tap structure in response to the rotational movement of the actuating wheel of the tap to uncover or cover the signaling means even if the actuating wheel or the tap stem does not move upwardly or downwardly. The coupling between the movable skirt and the fixed tap structure can be designed by selection of an appropriate angle of inclination or pitch angle of the engagement means between these two parts so as to produce a sufficient axial movement of the skirt to uncover or expose a large signaling surface of substantial height or width so as to be easily visible or discernible on the exterior of the tap. Similarly, for taps having a stem without axial movement or small axial movement and also for taps having a quarter turn actuating wheel for opening or closing the tap, a large signaling surface having a substantial height can be exposed.
According to a preferred embodiment of the invention the device or means for indicating the open or closed condition of the tap comprises an annular support member separate from the tap body (but being a part of the fixed tap structure) and mounted normally stationary with respect thereto, and the movable skirt surrounds the annular support member and is provided with an internal single or multiple threaded screw thread engaged with a correspondingly internally threaded portion of the support member. In this embodiment the signaling means is provided on the annular support member on a lower portion thereof to be exposed by the axial movement of the skirt when the actuating wheel of the tap is rotated in a direction to open the tap. At least the lower portion of the annular support member provided with the signaling means (or forming the signaling means) or the entirety of this member may be distinguished from the adjacent surfaces of the tap body and the actuating wheel by at least one of the conditions comprising a different surface finish, a different color, and a different material.
The annular support member is fixed to the tap body by a friction fit, namely a press fit, and it is moreover provided with a central polygonal or star-shaped opening having for example 24 angles or facets arranged in zigzag or in accordion-type fashion, engaged on an end portion of polygonal shape, for example square- or hexagonal shape, of a gland ring of the tap. The annular support member may have one or more rupture initiation areas to permit opening or closing of the tap in case of jamming of the skirt between the actuating wheel and the annular support member, by application of a sufficient force to the actuating wheel causing breakage of the support member at the rupture initiation areas. In addition, the retention force of the press fit engagement of the annular support member on the tap body and the design of the polygonal shape of the opening in the support member can be selected to permit the support member to be rotated about the tap body and the gland ring by application of a sufficient force to the actuating wheel to overcome the retention force of the press fit and deform the polygonal opening in case the support member is fabricated from a high strength material tending to resist breakage at the rupture initiation areas.
To couple the movable skirt to the actuating wheel for rotating therewith it is provided at its upper extremity with a flange provided with a plurality of projection portions or lobes spaced from one another in circumferential direction and received in recesses of corresponding shape formed in the interior of a cavity of the actuating wheel. The lower extremity of the skirt is visible below the actuating wheel at least in the position thereof covering the indicating means.
Preferably, in the tap closed position the movable skirt is in a lower position covering the lower extremity of the annular support member or the signaling means provided at its lower extremity or adjacent thereto and by rotational movement of the actuating wheel in a direction to open the tap the movable skirt is caused to be displaced axially upwardly to thereby uncover the lower end portion or extremity of the annular support member or its signaling means for indicating the condition of the tap so as to be easily visible, even from a remote location, on the exterior of the tap to thereby indicate the open position of the tap.
Corresponding reference numerals will be used throughout the several figures of the drawings.
The tap according to the invention will now be described in greater detail. As shown in
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As best shown in
The
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It will be understood that during rotation of the actuating wheel 14 the movable skirt 32 will rotate with the wheel 14 and due to the threaded engagement between the elements 32 and 34, the external element or skirt 32 will move vertically while the internal element 34 remains stationary. The pitch angle of the threaded engagement between the two elements 32 and 34 is selected to be sufficiently high so as to uncover a substantial portion of the support member 34 at the lower extremity 34a thereof. An axial motion or substantial axial motion of the actuating wheel 14 is not necessary for exposing the lower portion 34a of the support member 34. If the axial displacement of the actuating wheel is small or if its rotation is only a fraction of a turn, such as a quarter turn, the pitch angle of the threaded portions 36 and 38 is selected sufficiently high to ensure uncovering of a substantial portion of the lower extremity 34a of the support member 34. It is also possible to provide multiple threaded screw threads to increase the axial displacement of the skirt 32.
As mentioned hereinbefore, the indicating device according to the invention can also be used in combination with a tap having an upwardly and downwardly movable stem, namely a tap provided with an actuating wheel that moves axially with respect to the body when the wheel is rotated for opening or closing the tap. Such a tap is shown schematically in
During the lifetime of the tap the skirt 32 may possibly get stuck between the internal support member 34 and the actuating wheel 14. In this case the tap may be opened or closed by exertion of a larger actuation force on the actuating wheel 14 causing breakage of the predetermined rupture areas 50 of the annular support member 34. If the support member 34 is fabricated from a strong material tending to resist breakage of the predetermined rupture areas 50 the larger force applied to the actuating wheel 14 may cause rotation of the support member 34 about the tap body 12 and about the polygonal end portion of the gland ring 34 by deformation of the polygonal opening 46 of the annular support member 34. Of course, this force must also overcome the retention force of the press-fitted engagement of the annular support member 34 on the tap body 12. The frictional engagement is accordingly a relatively weak frictional engagement but which is sufficient to normally retain the annular support member 34 against rotation in combination with the engagement of the polygonal opening 46 on the polygonal end portion of the gland ring 24.
It is to be understood that instead of the threaded portions 36 and 38 of the external and internal elements 32 and 34 it is also possible to provide any other means causing a vertical or axial movement of the external element 32 with respect to the internal element 34 when the external element 32 is rotated about the axis A of the tap 10.
For example, instead of the threaded portions 36 and 38 the external portion 32 may also be provided with pins (not shown) spaced circumferentially from one another and extending inwardly from the internal cylindrical surface of the skirt 32 to be received in helical grooves (not shown) of the internal element 34. Alternatively, the pins may be provided on the internal support element 34 and received in helical grooves of the skirt 32.
In another embodiment, the internal element or the support member 34 may be eliminated and the movable skirt 32 may be mounted directly on the tap body 12 and coupled thereto by any appropriate means, such as a threaded engagement, for causing vertical or axial displacement of the skirt 32 when it is rotated by means of the actuating wheel 14 about the axis A of the tap 10. In this case a portion of the body 12 of the tap 10 to be uncovered or masked by the skirt 32 serves as the signaling means or the signaling surface to indicate the position of the tap 10. This portion of the tap body 12 may be colored, for example in red, or may have another surface finish, for example a bright appearance to distinguish it from the adjacent surfaces of the tap 10 and the skirt 32, or may be provided with a colored band or other means, applied to the external surface of the tap body 12.
Further, by an appropriate design of the means causing the external element 32 to move vertically when rotated by means of the actuating wheel 14, for example by an appropriate form of the threaded portions 36 and 38, such as a right hand thread or a left hand thread, the device for indicating the position of the tap 10 may be formed to mask the indicating portion of the tap body 12 or of the member 34 in the closed position of the tap and to expose the indicating portion in the open position of the tap, as described hereinbefore, or contrarily, namely to mask the indicating portion in the open position and to expose it in the closed position of the tap.
From the preceding description it will be understood that the mechanism of the invention permits one to see the open or closed position of the tap 10 on the exterior thereof even when the stem 16 and the actuating wheel 14 do not move vertically or axially along the axis A for opening or closing the tap 10. The same functioning is also insured for a tap whose actuating stem 16′ is threaded into the gland ring 24′ or into the tap body and carries the sealing member 20 adapted to tightly engage the tap seat 22 (
Finally, the signaling portion or surface 34a of the internal element 34 does not need to extend down to the lower extremity of the element 34, but the internal element 34 may be provided at its lower extremity with a small circumferential external stop (not shown) on which the external portion 32 comes to seat in closed or open position of the tap, so as to mask the signaling portion or surface 34a provided above the circumferential stop. Also, the external element 32 may have one or a plurality of windows (not shown) spaced circumferentially and/or axially from one another and adapted to be aligned with one or more signaling surfaces (not shown) arranged in a similar manner on the internal element 34 or on the tap body 12.
A spring (not shown) may be provided between the actuating wheel 14 and the support member 34 to eliminate any backlash between these elements and to serve to safely retain the parts in position.
According to a still further embodiment, the skirt can be totally retractable into the interior of the actuating wheel in one of the two positions (open or closed) of the tap and extended partly from the interior of the wheel in the other position of the tap. In this case the signaling means may be provided on the tap body or may be provided on the portion of the skirt to be extended from within the actuating wheel in one of the two positions of the tap.
Other variations or modifications may be made by the skilled person to the preferred embodiments described hereinbefore and shown in the drawings without leaving the scope of the invention as defined by the annexed claims.
Number | Date | Country | Kind |
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03079185.9 | Dec 2003 | EP | regional |