GB2397374A

GB2397374A - Blow Torch

Info

Publication number: GB2397374A
Application number: GB0400327A
Authority: GB
Inventors: Philip William Robinson
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-01-08
Filing date: 2004-01-08
Publication date: 2004-07-21
Anticipated expiration: 2024-01-08
Also published as: GB2397374B; GB0300324D0; GB0400327D0

Abstract

A blow torch 10 for welding, soldering or cutting comprises a head 12 directly connected to a gas canister 14 and has a valve 44 to control the release of gas from the canister 14 and a connector 19 coupled to an oxygen supply 24 via a flexible tube 20. The gas may be propane or butane. The head may have interchangeable nozzles 16, 18 for different applications. Tube 20 may have a non return valve and flashback arrestor 22. The oxygen supply 24 maybe a container 26 having two flexible bladders 28, 30. Bladder 28 may be filled with oxygen at a low pressure and bladder 30 may be filled with ambient air using a pump which may be manually or electrically operated. To achieve a hotter flame, oxygen in bladder 28 is pressurised by pumping air into bladder 30 so that more oxygen is supplied to the head 12 which therefore increases the rate at which gas from the canister 14 can be burned. Oxygen in bladder 28 may be replenished though a valve 34 and tubing 36 either by high pressure oxygen 38 or by an electrically operated oxygen generator 42.

Description

- - 1

BLOW TORCH

The present invention relates to a blow torch.

Blow torches are known which comprise a burner tube that forms parts of a head fitted directly to an aerosol like canister containing a liquefied gas, such as butane or propane. Such blow torches, which will herein be termed gas canister blow torches, have a variety of uses ranging from 0 soldering to cooking. While the flame of gas canister blow torches is sufficiently hot for soldering or caramelizing sugar, it is not hot enough to perform such tasks as welding or metal cutting.

Torches that can be used for welding or cutting through metal have a head connected by way of flexible tubes and pressure regulators to two separate high pressure gas cylinders, one storing a combustible gas, such as acetylene, and the other oxygen. Such welding equipment is not only cumbersome but it is also not readily available to the occasional user because of its cost and because of the precautions that need to be taken to ensure safe storage of the pressurized gas cylinders.

According to the present invention, there is provided a gas canister blow torch which comprises a gas canister, a head fitted directly to the gas canister and incorporating a valve for controlling the release of gas from the canister and a burner tube for burning the gas released from the canister in ambient air, wherein the head is additionally connectable by way of a flexible tube to an oxygen supply so as to enable the burner tube to produce a hotter flame by burning the gas released from the canister in a gas containing a higher concentration of oxygen than the ambient air.

À À À . À :: À À - 2 It has previously been proposed in US 3732060 to connected a head to two canisters one containing fuel and the other a chemical oxygen generator. However, carrying two canisters is unwieldy and does not allow the blow torch to be manoeuvred easily. Hence in another embodiment of the latter patent it is proposed to connect the head by two flexible hoses to bottle containing a fuel and an oxygen generator. It not previously been proposed however to connect a gas canister blow torch by a flexible tube to a separate oxygen supply.

In the modified gas canister blow torch of the invention, the user is given the option to increase the flame temperature by burning the gas from the canister in oxygen or in oxygen-enriched air instead of ambient air but the convenience and portability of a gas canister blow torch is not compromised.

The oxygen is preferably stored and supplied at a pressure that is less than 7 psi above atmospheric.

Oxygen delivered to the head of the blow torch at a pressure of typically 5 psi is sufficient to achieve a flame hot enough to meet all the needs of occasional users. The storage of the oxygen at low pressure offers the important advantage of improved safety. In particular, no special precautions need to be taken in the storing and handling of the oxygen containers because they would not pose a serious danger even if punctured. Because of the low pressure of the oxygen supply, it must of necessity have a large volume and this precludes its direct attachment to the head of the blow torch.

In GB Patent Application No. 0300322.5, there is described an oxygen container which is particularly suited for supplying oxygen to the blow torch head in the present invention. The oxygen container comprises two air-tight 1 t e r À 8 8 e compartments that are separated from one another by at least one flexible wall. The first compartment can be filled with oxygen and the second is filled with air and serves to pressurise the first compartment.

The oxygen container can be periodically replenished from a conventional high pressure oxygen cylinder but it is alternatively possible to produce oxygen at low pressure on demand to fill the oxygen container by pumping ambient air lo through a molecular sieve.

Conveniently, the tube connecting the head to the oxygen supply include a non-return valve to act as a flashback arrestor.

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which the single figure is a schematic representation of a welding system including a blow torch of the invention.

The illustrated welding system includes a blow torch 10 consisting of a head 12 fitted directly to a gas canister 14 filled with a suitable gas such as propane or butane. The head 12 of the blow 10 torch can have interchangeable burner tubes or nozzles 16 and 18 to provide flames of different shape and intensity suited to different applications.

The blow torch 10 differs from conventional gas canister blow torches in that it is provided with a connector 19 for a flexible tube 20 to enable oxygen from a low pressure oxygen supply 24 to be supplied to the head 12.

The tube 20 incorporates a non-return valve and flashback arrestor 22.

The illustrated oxygen supply 24 is an oxygen container comprising an outer housing 26 containing two flexible bladders 28 and 30. The bladder 28 is filled with oxygen and : I: tel: À À À À 1 1 is connected to the non-return valve 22 whereas the bladder is filled with ambient air using a suitable pump which may be manually or electrically operated.

To enable the oxygen supply stored in the bladder 28 to be replenished as it becomes depleted, the bladder 28 is connected through a valve 34 and suitable tubing 36 either to a high pressure oxygen 38 fitted with a pressure regulator 40 or to an electrically operated oxygen generator lo 42 producing oxygen on demand such as by pumping ambient air through a molecular sieve.

The blow torch 12 can be used in a conventional manner to burn the gas released from the canister 14 in ambient air. This will produce a flame that is suitable, for example, for soldering.

To achieve a hotter flame, the head 12 is fed with oxygen from the oxygen container 24. The oxygen in the bladder 28 is pressurized by pumping air into the bladder 30 and in this way oxygen at a supply pressure of approximately psi is supplied to the head 12. The oxygen supply enables the blow torch 10 to achieve a hotter flame in that the rate at which gas from the canister i4 can be burned is increased. The head 12 is fitted in the usual manner with a valve 44 to control the release of the combustible gas and this valve 44 can be set higher when the head 12 is connected to burn that gas in oxygen rather than ambient air.

As oxygen is drawn from the bladder 28, the pressure in the bladder drop and the bladder 28 collapses. To maintain the pressure, more air is pumped into the bladder 28 and in this way the bladder 28 can be totally depleted of oxygen 3s without the pressure of the oxygen supply at the head 12 dropping.

c t lel 111 e Àe When the oxygen container 24 is empty of oxygen, it is refilled by venting the bladder 30 to atmosphere and supplying oxygen to the bladder 28 from the oxygen cylinder 38 or the oxygen generator. Once the bladder 28 is full at the pressure of the regular 40 or the output pressure of the generator 42, the valve 34 is again closed and the container 24 is once again ready for use with the blow torch 10.

It has previously been proposed in US 3732060 to connected a head to two canisters one containing fuel and the other a chemical oxygen generator

Claims

|: t. À 1 À À - 6 - CLAIMS

1. A gas canister blow torch which comprises a gas canister, a head fitted directly to the gas canister and incorporating a valve for controlling the release of gas from the canister and a burner tube for burning the gas released from the canister in ambient air, wherein the head is additionally connectible by way of a flexible tube to an oxygen supply so as to enable the burner tube to produce a lo hotter flame by burning the gas released from the canister in a gas containing a higher concentration of oxygen than the ambient air.

2. A welding system comprising a gas canister blow torch as claimed in claim 1 in combination with means for storing and supplying oxygen to the blow torch at a pressure of less than 7 psi above atmospheric.

3. A welding system as claimed in claim 2, wherein the means for storing the oxygen is a container comprising two air-tight compartments that are separated from one another by at least one flexible wall, wherein the first compartment is filled with oxygen and the second is filled with air and serves to pressurize the first compartment.

4. A welding system as claimed in claim 2 or 3, wherein the tube connecting the head to the oxygen supply include a non-return valve to act as a flashback arrestor.

5. A welding system constructed substantially as herein described with reference to and as illustrated in the accompanying drawing.