GB2151752A

GB2151752A - Gas flow regulating assembly

Info

Publication number: GB2151752A
Application number: GB8334448A
Authority: GB
Inventors: Malcolm Campbell Oates; John James Burgess
Original assignee: Taymar Ltd
Current assignee: Coleman Taymar Ltd
Priority date: 1983-12-23
Filing date: 1983-12-23
Publication date: 1985-07-24
Also published as: GB2151752B; GB8334448D0

Abstract

A gas flow regulating assembly (10) for an L.P.G. appliance has a body (20) which has at one end an inlet connection (16) and a canister valve actuating pin (22) and at its other end a gas outlet connection (24), the inlet and outlet connections being co-axial with each other and with the canister (11) when in position, a blind bore (27) in the body (20) extending transversely of said axis and accommodating a valve (31), a first flow passage (44) extending from the inlet to the valve (31) and a diaphragm chamber (33) communicating with the open end of blind bore (27) and closed by a diaphragm (34) influenceable by an actuating member (36) to control flow of gas through the valve (31) by acting on a stem (35) thereof, a second gas flow passage (37) extending from the diaphragm chamber (37) to outlet (24). <IMAGE>

Description

SPECIFICATION Gas flow regulating assembly This invention relates to a gas flow regulating assembly for use in a L.P.G. appliance which can be attached to or have attached to it a fuel supply container in the form of a valved disposable canister.

Various regulating assemblies have been proposed previously for such appliances, but most, if not all, suffer from the disadvantages that if the appliance is jogged, tipped or tilted, liquid gas issued from the appliance jet, giving a spirt of flame which not only is wasteful of gas, but often can startle the appliance user or may cause a fire. This is a particularly severe problem with L.P.G. blow torches, which are often used in a tilted or inverted position.

A further problem with canister-type L.P.G. appliances is the problem of flame regulation. Most conventional values have a simple conical or similar restrictor valve including on/off function. Such valves do not give very good control because of manufacturing tolerances and the frictional effect of sealings or packings which make them quite difficult to turn, particularly after a period of disuse, to which many L.P.G. blowtorches, used by D.l.Y.

enthusiasts, are subject.

A known regulating assembly (U.S. Patent 3521669 Turner) overcomes the problem of regulation by using a diaphragm type regulating valve, but has the added complication of a separate oni off valve and a pre-set regulation to a predetermined outlet pressure. This patent Turner has the added disadvantage that, considering the axis of a canister connecting formation as the main axis of the assembly, the axis of the regulating valve is coincident with the main axis, at the end of the assembly remote from the connecting formation, and the gas outlet extends laterally outwards from the assembly.

In most situations, the physical dispositions of the on/off regulating valve knob and the gas outlet might be thought to be of little importance, and their inter relationship merely a matter of simple engineering variation. However, canister-type L.P.G. appliances are a particular field where such dispositions are of considerable importance in that manufacturing costs can be influenced by them and the weight and aesthetic appearance of the appliances can be considerably effected. In many instances, such as stoves and lanterns, the disposition of the connecting formation determines the disposition of the other components, because it is conventional, desirable, and sometimes essential that the canister be used upright, eg as a base for the appliance, and to prevent liquid gas flow from the appliance.Thus, the vertically arranged canister with the gas connecting assembly atop it has become a very common item in this field.

It is an object of the present invention to provide a gas flow regulating assembly for a L.P.G. canister-type appliance whereby some or all of the above described disadvantages are obviated or minimised.

The invention provides a gas flow regulating assembly for a L.P.G. canister-type appliance, comprising: a body having at one end a canister connecting formation including an internally threaded spigot and a canister valve actuation pin, and at the other end a gas outlet connecting formation co-axial with the canister connecting forma tion; a blind bore in the body extending transversely of said axis and accomodating a flow control valve; a first flow passage extending from the canister connecting formation to the blind bore adjacent its blind end; a diaphragm chamber communicating with the other end of the blind bore and closed by a diaphragm which can be acted upon by an actuating member and which can influence the flow of gas through the valve by acting on a stem thereof; and a 15. second flow passage extending from the diaphragm chamber to the gas outlet connecting formation.

The axis of the blind bore is preferably at right angles to the aforesaid axis but it can be at other angles thereto.

The actuating member can have a knob attached thereto and can be threadedly connected so that rotation thereof moves its position axially which influences the valve stem and allows it to move from a closed to a fully open position and vice versa with a regulated band of positions therebetween.

The invention will be described further, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a sketch of a cross-sectional elevation through a preferred assembly of the invention: Figures 2 to 4 are schematic elevations illustrating the assembly of Fig. 1 in position on a lantern, a stove and a blow torch respectively.

A preferred embodiment of gas regulator assembly 10 of the invention is suitable for use with a L.P.G. canister 11 having a valved outlet 12 which consists of a threaded boss 13 having a central valve 14 which can be opened by a pusher pin or the like, and a surrounding annular rim 15. The assembly 10 comprises a body 20 made of brass and having at its lower end (as illustrated) a canister connecting formation in the form of an internally threaded spigot 16. The outer surface of the spigot 16 has an annular channel 17 which accommodates and locates a resilient sealing washer 18. To the lower face 19 of the body 20 is attached a support 21, better seen in Fig. 4, which is part of a blowtorch. For use with a lantern or stove (Figs. 2 and 3), the support 21.can be omitted.The boss 13 of the canister engages spigot 16 and a pin 22 of the body 20 enters a passage in boss 13 and opens valve 14 thereof. The boss 13 seals with an 0-ring 23 in the spigot 16 upon final tightening. A secondary seal and a supporting connection is generated by the engagement of the rim 15 of the canister 11 compressing washer 18 against support 21 during final screwing connection of the canister 11 to the assembly 10.

The other, upper, end of the body 20 is provided with a gas outlet connector formation in the form of a threaded socket 24 coaxial with spigot 16. The common axis of these two components can be looked upon as a main axis of the body 20. Socket 24 receives a threaded connector nipple 25 which secures a gas flow pipe 26 to the outlet.

Centrally of the body 20 is a blind bore 27 whose axis intersects the main axis and lies at right angles. thereto. The bore 27 has a plain section 28 adjacent its closed end 29 and a threaded section 30 remote therefrom. A first gas flow passage 44 extends from the canister connection formation to the closed end 29 of the blind bore 27, which accommodates a tire valve 31 located by a threaded bridge 32.

The open end of bore 27 communicates with a chamber 33 which is outwardly closed by a flexible diaphragm 34, which can act on a stem 35 of valve 31 by a member 36. A second gas flow passage 37 extends from chamber 33 to socket 24. The diaphragm 34 is secured by an annulus 38 which has an inner left hand thread 39 which is engaged by a complementary thread on an actuating member 40 in the form of a cup. Member 40 acts on the diaphragm 34 by means of a member 41 and a compression spring 42 within the cup. An operating knob 43 is secured to member 40.

In an "off" position the member 40 is at is outer most position.and the internally spring loaded valve stem 35 prevents gas flow through the valve 31 in bore 27. As the knob 43 is turned in an anticlockwise direction, member 40 moves to the left and spring 42 influences the diaphragm to move to the left, depressing stem 35 and opening the valve 31. The more the knob is turned, the greater the degree of opening.

The diaphragm and its associated parts, particularly spring 42, have a regulating effect on gas flow in that at any particular setting of knob 43 and member 40, the diaphragm and valve member 35 are biassed into engagement (via member 36). If due to extra gas flow, eg liquid gas entering bore 27 or a pressure rise in the canister 15. due to termperature rise, the pressure in chamber 33 rises, it displaces diaphragm 34 to the right, thus at least partially closing valve 31 until the pressure in chamber 33 re-attains its present value. Conversely, pressure drop in chamber 33 causes movement of diaphragm 34 to the left and a greater degree of opening of valve 31 to raise the pressure.

Thus, whatever, the pressure condition caused by the canister the output gas pressure remains constant at a value which is effectively set by the position of knob 43. Because the threads at 39 serve no sealing function (indeed, the interior of member 40 is vented to atmosphere via a port 45) there is little resistance to turning of knob 43, once the valve has been initially opened, so that a user can regulate gas flow very easily. This feature is particularly important in the case of the blow torch illustrated in Fig. 4, wherein a user gripping the canister at its upper end by one hand can manipulate the control knob 43 with the thumb and first finger of the same hand, leaving his other hand free, eg to support or locate a workpiece.

With the blowtorch of Fig. 4 supported generally horizontally by the support 21 and bottom rim 46 resting on a surface, the burner 47 is directed upwardly and forms a convenient fixed flame in which a workpiece can be manipulated, eg as in glass blowing. Here the one-handed adjustability is also of great value as a user will normally require one hand to support his workpiece.

Claims

1. A gas flow regulating assembly for a L.P.G.

canister-type appliance, comprising: a body having at one end a canister connecting formation including an internally threaded spigot and a canister valve actuation pin, and at the other end a gas outlet connecting formation co-axial with the canister connecting formation, a blind bore in the body extending transversely of said axis and accommodating a flow control valve; a first flow passage extending from the canister connecting formation to the blind bore adjacent its blind end; a diaphragm chamber communicating with the other end of the blind bore and closed by a diaphragm which can be acted upon by an actuating member and which can influence the flow of gas through the valve by acting on a stem thereof; and a second flow passage extending from the diaphragm chamber to the gas outlet connecting formation.

2. An assembly as claimed in claim 1 wherein the axis of the blind bore is at right angles to the aforesaid axis.

3. An assembly as claimed in claim 1 or 2 wherein the actuating member has a knob attached thereto.

4. An assembly as claimed in claim 1, 2 or 3 wherein the actuating member is threadedly connected so that rotation thereof moves its position axially which influences the valve stem and allows it to move from the closed to a fully open position and vice versa with a regulated band of positions therebetween.

5. A gas flow regulating assembly substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Amendments to the claims have been filed, and have the following effect: (a) Claims 1, 3 & 4 above have been deleted or textually amended.

(b) New or textually amended claims have been filed as follows: (c) Claims 5 above have been re-numbered as Claim 3 and their appendancies corrected.

1. A gas flow regulating assembly for a L.P.G.

canistertype appliance, comprising: a body having at one end a canister connecting formation including an internally threaded spigot and a canister valve actuation pin, and at the other end a gas outlet connecting formation co-axial with the canister connecting formation, a blind bore in the body extending transversely of said axis and accommodating a flow control valve comprising a valve seat, a stem carrying a valve closure member and a clo sure spring biassing the valve closure member towards a closed position in a direction towards the diaphragm; a first flow passage extending from the canister connecting formation to the blind bore adjacent its blind end a second flow passage extending from a diaphragm chamber to the gas outlet connecting formation; said diaphragm chamber communicating with the other end of the blind bore and being closed by a diaphragm which has a regulating spring on its side remote from the chamber, a threadedly engaged rotatable actuating member being provided which is the sole control member of the assembly and rotation of which causes axial movement to influence the regulating spring to adjust the axial position of the centre of the diaphragm between a regulating position wherein a valve member of the valve has been displaced against the action of its internal spring to open and allow flow of gas to the diaphragm chamber wherein the gas pressure in the diaphragm, and thus the pressure of gas flowing from the outlet is regulated by movement of the diaphragm in response to the pressure in the diaphragm chamber and its external spring acting on opposite sides of the diaphragm, and a closed position wherein the diaphragm is withdrawn from the fire valve sufficiently to allow the valve to close completely under the influence of its own spring to prevent the flow of gas to the diaphragm chamber.