WO1989003492A1

WO1989003492A1 - Improvements to valves in gas bottles

Info

Publication number: WO1989003492A1
Application number: PCT/SE1988/000516
Authority: WO
Inventors: John Larsson; Erik T. Eriksson
Original assignee: Gce Gas Control Equipment Ab
Priority date: 1987-10-08
Filing date: 1988-10-07
Publication date: 1989-04-20
Also published as: NL8820742A; GB2217436B; SE8703888D0; NL192889C; SE8703888L; GB2217436A; GB8912535D0; SE459115B; DE3890870C2; EP0419466A1; NL192889B

Abstract

An arrangement fo realizing a lower opening torque than closing torque in valves for gas bottles. A so-callled box nut is disposed in the valve housing. Between the wheel spindle (8) and the box nut (11), there is disposed an inner sleeve-shaped member (12) provided with inner and outer threads. The inner threads being disposed to be in mesh with the threads on the wheel spindle (8) and the outer threads in mesh with the threads of the box nut (11). During the first phase of the rotational movement of the wheel, the wheel spindle (8) turns in the inner threads in the inner sleeve-shaped member (12), whereafter the wheel spindle (8) together with the inner sleeve-shaped member (12) turns in the box nut (11). The ratio between the pitch of the inner and the outer threads in the inner sleeve-shaped member (12) is such that the opening torque lies in the interval of 30-70 % of the closing torque.

Description

IMPROVEMENTS TO VALUES IN GAS BOTTLES

TECHNICAL FIELD

The present invention relates to an arrangement for realizing a lower opening torque than closing torque in a valve for gas bottles, comprising a valve housing which includes valve seat, valve cone and valve spindle, being disposed to be influenced by a wheel spindle associated with the valve wheel, and journalled by means of threads in an outer sleeve-like member, a so-called box nut disposed in the valve housing, there being provided, between the wheel spindle and box nut of the valve, an inner sleeve-shaped member which is both interiorly and exteriorly threaded, the inner threads being arranged to mesh with the threads on the wheel spindle and the outer threads with the threads of the box nut; recesses being provided in the upper portion of the inner sleeve-shaped member, and a dog device being radially disposed in the wheel spindle and, together with the wheel spindle is rotatably disposed between the abutments formed in the above-mentioned recesses, the wheel spindle turning, during the first phase of the turning movement of the wheel, in the interior threads in the inner sleeve-shaped member on rotation of the dog device between the abutments, and, during the remainder of the turning movement, the wheel spindle and inner sleeve-shaped member turn in the box nut. In the operation of valves which are connected to gas bottles, it is not an uncommon occurrence - and this in particular at gas filling stations - that the valve on closure is tightened too hard. It may then become difficult to open the valve. This has probed to be a problem, in particular when gas bottles are used in medical contexts. Medical care staff or patients are often unable to open the bottle valve. The object of the present invention is, therefore, to realize an arrangement which facilitates opening of the valve. In this instance, the arrangement is substantially characterized in that the ratio between the pitch of the inner and outer threads in the inner, sleeve-shaped member 12 is such that the opening torque lies in the interval of 30-70% of the closing torque. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The nature of the present invention and its aspects will be more readily understood from the following brief description of the accompanying Drawings, and discussion relating thereto.

In the accompanying Drawings:

Fig. 1 is a cross section through a gas bottle valve;

Fig. 2 shows the upper portion of a valve fitted with the arrangement according to the present invention; and

Fig. 3 is a cross section taken through the upper portion according to Fig. 2. DESCRIPTION OF PREFERRED EMBODIMENT

Referring to the Drawings, Fig. 1 shows an example of a valve for gas bottles. The valve consists of a valve housing 1 with a connection 2 to the gas bottle and a connection 3 to a consumption conduit. In the housing 1, there is disposed a valve seat 4 and a valve cone 5 cooperating therewith and provided with a gasket 6 of a plastic material such as, for example, teflon (R) and is connected to a valve spindle 7. This is interconnected to a wheel spindle 8 which is operated by means of a wheel 9. The wheel spindle 8 is journalled, by means of threads 10, in a so-called box nut 11 which is screwed into the valve housing 1.

Fig. 2 shows a bottle valve which has been supplemented with the arrangement of the present invention. The Figure shows, partly in cross section, the upper portion of the valve. At the bottom in the Figure, the upper portion of the valve spindle 7 and the valve housing 1 are shown. The so-called box nut 11 is screwed into the valve housing and consists of a sleeve-shaped member which is also provided with interior threads 14. An inner sleeve-shaped member 12 is disposed in the box nut and is provided with interior and exterior threads 13 and 14, respectively. The threaded wheel spindle 8 is disposed in this sleeve-shaped member 12. A recess 16 is disposed in the circumferencial surface of the upper portion of the sleeve-shaped member 12. Furthermore, a dog device 15, for example a pin-shaped device, is disposed in the wheel spindle 8 and is rotatably disposed in the recess 16. As a result of this arrangement, the wheel spindle 8 may, thus, be turned through a certain angle in the inner sleeve-shaped member 12. The Figure shows a device 17 disposed on the wheel spindle, to which the wheel or knob is fixedly screwed. A connecting piece is provided between the wheel spindle and the valve spindle 7, in the illustrated embodiment being in the form of a ball-shaped device 18.

The valve of Fig. 2 is shown in the closed position. To open the valve, the wheel 17 is actuated in the direction of the arrow 20. On commencement of the turning movement, the dog pin abuts against the one abutment in the recess 16 in the sleeve-shaped member 12 (see position A, in Fig. 3). As a result, the wheel spindle 8 will, during the first phase of the opening movement, turn in the inner threads on the member 12. When the wheel spindle 8 turns, the ball 18 will lightly release from the valve spindle 7. The spindle 7 is then urged upwardly by the gas pressure in the bottle, the valve cone being lifted a certain distance (a few tenths of a millimetre) from the valve seat. This is made possible in that a certain clearance 19 is provided between the valve spindle 8 and the inner sleeve-shaped member 12. Once the wheel has been turned so far that the dog pin 15 has reached the second abutment in the recess 16 (position B in Fig. 3), the dog pin will, on continued rotation, entrain the inner sleeve-shaped member 12. This will then turn in the threads 14 between the inner and outer sleeve-shaped members. On this rotation, the wheel spindle 8 and the inner sleeve-shaped member 12 will move upwardly. Because the lower portion of the member 12 connects to the upper portion of the valve spindle 7, this spindle and the valve cone will also move upwardly, the valve then opening fully. The outer or exterior threads 14 on the inner sleeve-shaped member 12 which are in mesh with the threads on the box nut n are of higher pitch than the inner threads 13 which are in mesh with the threads on the wheel spindle. The torque in the inner threads 13 is considerably less than the torque in the outer threads 14. During the first phase of the opening movement, i.e. when the dog pin 15 moves between the abutments in the recess 16, the torque will, therefore, be less than during the continued opening movement, i.e. when the dog pin 15 entrains the inner sleeve-shaped member 12. By way of example, it might be mentioned that if a diameter is selected for the inner thread of 8 mm and a thread pitch of 1 mm, and for the outer thread a diameter of 14 mm and a thread pitch of 1.5 mm, the ratio between the torques will be approximately 1:2. By variation of the pitch of the inner and outer threads in the inner sleeve-shaped member 12, it is possible to cause the opening torque to lie in the range of between 30 and 70 per cent of the closing torque. However, the inner thread should not be given an excessively high pitch, since there would then be the risk that the wheel spindle would unthread because of vibrations on, for example, transport of the gas bottles. Such dimensioning that the opening torque constitutes substantially 50 per cent of the closing torque is probably most preferable. Furthermore, the recess in which the dog pin rotates may embrace an angle in the range of between 90° and 120°. Preferably, this angle should lie in the interval of between 100° and 110°.

Thus, on closure of the valve, the wheel is turned in the opposite direction. The dog pin 15 is then turned in the recess 16 until it reaches the abutment. During this rotation, the wheel spindle moves in the inner sleeve-shaped member 12. On continued rotation, the dog pin 15 entrains the inner sleeve 12 so that the wheel spindle 8 and the inner sleeve 12 rotate in the box nut 11. After a certain turning of the wheel, the gasket 6 of the cone 5 will reach the valve seat 4 and the valve will be closed.

With reference to the arrangement as described in the foregoing and shown on the Drawings, it has, thus, become possible, using simple and few details, to realize a valve for gas bottles which possesses a considerably lower opening torque than closing torque therefore. The present invention should not be considered as restricted to that described above and shown on the Drawings, many modifications being conceivable without departing from the spirit and scope of the appended Claims.

Claims

WHAT WE CLAIM AND DESIRE TO SECURE BY LETTERS PATENT IS:

1. An arrangement for realizing a lower opening torque than closing torque in valves for gas bottles, comprising a valve housing (1) which includes valve seat, valve cone and valve spindle (7), which is disposed to be actuated by a wheel spindle (8) associated with the valve wheel, which, by means of threads, is journalled in an outer sleeve-shaped member (11), a so-called box nut, there being disposed between the wheel spindle (8) and the box nut (11), an inner sleeve-shaped member (12) which is both interiorly and exteriorly threaded, the inner threads being arranged to mesh with the threads on the wheel spindle (8) and the outer threads with the threads of the box nut (11), a recess (16) being disposed in the upper portion of the circumferential surface of the inner sleeve-sh-aped member (12), a dog device (15) being radially disposed in the wheel spindle (8) and, together with the wheel spindle (8) being rotably disposed between the abutments formed in said recess (16), the wheel spindle (8), during the first phase of the turning movement of the wheel, turning in the inner threads in the inner sleeve-shaped member (12) as long as the dog device (15) moves between the abutments, whereafter the wheel spindle (8), together with the inner sleeve-shaped member (12), turns in the box nut (11), characterized in that the ratio between the pitch of the inner and outer threads in the inner sleeve-shaped member (12) is such that the opening torque lies in the interval of 30-70% of the closing torque.

2. The arrangement as claimed in Claim 1, characterized in that the ratio between the thread pitches is such that the opening torque is largely 50% of the closing torque.