AU2008291083B2

AU2008291083B2 - Gas-fired heat-shrinking torch and associated kit

Info

Publication number: AU2008291083B2
Application number: AU2008291083A
Authority: AU
Inventors: William Berselli
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-08-31
Filing date: 2008-08-20
Publication date: 2012-12-06
Anticipated expiration: 2028-08-20
Also published as: AU2008291083A1; WO2009027291A1; WO2009027291A4; ITMO20070274A1; EP2191199B1; EP2191199A1

Abstract

A combustible gas-fired heat-shrinking torch (1) for heat-sealing, for example, sheets of tar strips and the like for waterproofing civil roofing, comprising means for dispensing at least one combustible gas which are provided with at least one discharge port (2) for the combustible gas and at least one flexible tubular element (3) which can be associated with at least one tank for supplying the combustible gas. The torch (1) comprises means (4) for mixing the combustible gas with at least one oxidizer taken within the group that includes air, oxygen and the like for the combustion of the combustible gas dispensed by the discharge port (2).

Description

GAS-FIRED HEAT-SHRINKING TORCH AND ASSOCIATED KIT Technical Field The present invention relates to a gas-fired heat-shrinking torch for heat-sealing, for example, sheets of tar strip, polyethylene hoods and the 5 like for waterproofing civil roofing and to the associated kit. Background Art Known types of gas-fired torch generally have a flexible duct, which can be connected at its ends respectively to a combustible gas tank and a port for the discharge of the combustible gas, for example of the type of a io nozzle, which is provided with a handle for directionality of such torch. The tank is, for example, of the type of an ordinary cylinder of natural gas, LPG, or the like. Further, at the handle there are means for controlling the flow of gas which can be operated manually by the operator and are such as to allow or 15 interrupt the flow of gas from the tank to the discharge port. The combustible gas in output from the discharge port is ignited by the operator, for example, by placing a flame at the discharge port of such gas, and the torch thus provided is used for heat-shrinking operations for heat-sealing, for example, sheets of tar strip and the like for waterproofing 20 civil roofing. These types of torch are not free from drawbacks, which include the fact that they are not safe to use for the operator. These types of torch are in fact not provided with safety systems which ensure, when necessary, the shutdown of such torch and/or the 25 stopping of the escape of oxidizing gas from the discharge port. Another drawback is that the ignition of the torch is generally performed manually, for example by means of a lighter, requiring a high degree of attention in the operator and in any case not ensuring their safe use. 30 Further, these types of torch have a low combustion efficiency due to 2 the poor mixing between the combustible gas and the oxidizer, which for example is the air that surrounds the flame. Another drawback of known types of torch is that they have a high degree of noise and further such torches, by operating at a high pressure of 5 the combustible gas, form long and concentrated flames which force the operator to have a high degree of manual skill in heat-shrinking operations. Disclosure of the Invention The present disclosure relates to addressing the above-mentioned drawbacks of the background art, by providing a gas-fired heat-shrinking 10 torch that preferably allows operation at high combustion efficiencies. Within this disclosure, an object of an embodiment is to provide a torch which is easy and safe to use in any operating condition. An object of the torch according to another embodiment is to have safety systems which make its use safe according to applicable statutory 15 provisions regarding workplace safety. An object of another embodiment is to provide a torch which is simple, relatively easy to provide in practice, safe in use, effective in operation, and of relatively low costs. In an aspect there is provided a combustible gas-fired heat-shrinking 20 torch for heat-sealing, which comprises means for dispensing at least one combustible gas which are provided with at least one discharge port for said combustible gas and at least one flexible tubular element which can be associated with at least one tank for supplying said combustible gas, wherein said torch further comprises means for mixing said combustible gas 25 with at least one oxidizer taken within the group that includes air, oxygen and the like for the combustion of said combustible gas dispensed by said discharge port, and a first means for controlling the flow of combustible gas which are directly interposed between said discharge port and said tank in order to adjust said flow, wherein said first flow control means comprise at 30 least one electric valve and at least one one-way valve, said electric valve 2A In another aspect there is provided a heat-shrinking kit for heat sealing, comprising at least one combustible gas torch as defined in one or more of the preceding claims, and means for igniting said combustible gas, said ignition means comprising at least one controlled sparking element 5 which can face the discharge port of said torch, characterized in that said controlled sparking element comprises at least two electrodes which are mutually side-by-side and at least one pair of photocells, such as to convert the signal of proximity of said torch to said ignition means into an electrical signal between the two electrodes for the ignition, by sparking, of said io combustible gas dispensed by said torch. Brief description of the drawings Further characteristics and advantages of the present invention will WO 2009/027291 PCT/EP2008/060907 3 become better apparent from the following detailed description of a preferred but not exclusive embodiment of a gas-fired heat-shrinking torch, illustrated by way of non-limiting example in the accompanying drawings, wherein: 5 Figure 1 is a partially sectional lateral elevation view of the torch according to the invention; Figure 2 is a top plan view of Figure 1; Figure 3 is a side view of the ignition means of the heat-shrinking kit, according to the invention; 10 Figure 4 is a top plan view of Figure 3; Figure 5 is a schematic view of the heat-shrinking kit according to the invention. Ways of carrying out the Invention With reference to the figures, the reference numeral 1 generally 15 designates a combustible gas-fired heat-shrinking torch for heat-sealing, for example, sheets of tar strip and the like for waterproofing civil roofings and the like. The torch I comprises means for dispensing at least one combustible gas, which is comprised in the group that includes methane gas, natural gas, 20 LPG and others. The dispensing means are provided with at least one discharge port 2 for the discharge of the combustible gas and at least one flexible tubular element 3, which can be associated with at least one tank for supplying such combustible gas. 25 The flexible tubular element 3, for example, can be connected to the combustible gas couplings provided proximate to a wall or the like, or of an ordinary gas cylinder. In particular, the torch 1 comprises means 4 for mixing the combustible gas with at least one oxidizer, for example also in gaseous 30 form, such as air, oxygen or other oxidizer, for induced combustion of the WO 2009/027291 PCT/EP2008/060907 4 combustible gas dispensed by the discharge port 2 and therefore for the heat-shrinking of the heat-sealing, for example, of sheets of tar strip and the like for waterproofing civil roofings or plastic hoods. Advantageously, the mixing means 4 are interposed directly between 5 the flexible tubular element 3 and the discharge port 2. The mixing means 4, in particular, comprise at least one tubular portion 5, which is associated by means of a first end 6 with the flexible tubular element 3 and has the second free end 7 arranged at the discharge port 2. 10 The tubular portion 5 has, for example, a taper in the central region, which is comprised between the first and second ends 6 and 7. The tubular portion 5 is for example of the type of a Venturi tube; the first and second ends 6 and 7 are in fact respectively of the converging type and of the diverging type. In particular, the discharge port 2 coincides with 15 the second end 7 of the tubular portion 5 and for example the discharge port 2 has a diffuser for the dispensed combustible gas-oxidizer mix. The diffuser, for example, is adapted to act as a flame shield, further performing the function of containing and orienting the flame for uniform heating of the surface to be heat-shrunk. 20 The tubular portion 5 is suitable for the passage of the flow of combustible gas from the tank to the discharge port 2 and for the simultaneous suction of at least one specific quantity of oxidizer in countercurrent with respect to the flow of combustible gas. The flows of gas in countercurrent are adapted to mix the combustible 25 gas with the oxidizer; the particular shape of the mixing means 4, particularly the converging-diverging shape of the tubular portion 5, in fact allows the natural mixing of the combustible gas with the oxidizer, which is drawn into the tubular portion by the flow of the combustible gas itself. The torch I comprises first means 8 for blocking the flow of 30 combustible gas, which are interposed directly between the discharge port 2 WO 2009/027291 PCT/EP2008/060907 5 and the tank for adjusting the flow-rate of such flow. Advantageously, the first flow control means 8 are arranged proximate to the flexible tubular element 3 proximate to the end thereof that is associated with the combustible gas tank. 5 The first flow control means 8 comprise at least one electric valve 9 and at least one one-way valve 10; the electric valve 9 can be activated, for example, remotely for the passage and/or control of the flow of combustible gas. The one-way valve 10 is adapted to prevent dangerous flashbacks into 10 the gas supply main and therefore into the tank. The first flow control means 8 further comprise at least one reduction unit 11 for reducing the pressure of the combustible gas, for example provided with a pressure gauge for displaying the pressure of the combustible gas that is present from the tank to the discharge port 2. 15 The torch 1 further comprises second means 12 for controlling the flow of combustible gas, which are associated at gripping means 13, for example of the type of a knob or the like, for gripping the torch 1 for manual control of the directionality of the combustible gas jet. The second flow control means 12 are suitable, for example, for immediate manual actuation 20 of the interruption and dispensing of the flow of combustible gas from the discharge port 2. The second flow control means 12, in particular, comprise at least one actuation lever 14 for a valve, not shown in the figures, for controlling the flow of combustible gas. 25 The lever 14 can move alternately between at least one active configuration, in which the flow control valve is open, and at least one release configuration, in which the flow control valve is closed to interrupt the flow of combustible gas in output from the discharge port 2. Advantageously, the gripping means 13 of the torch I have at least 30 one pair of knobs, which allow the operator to grip it with both hands during WO 2009/027291 PCT/EP2008/060907 6 heat-shrinking operations. For example, both knobs might be provided with devices for closing the flow control valve and/or the electric valve 9 for controlling the flow of gas when the operator releases at least one of such knobs. 5 The torch I comprises safety means for closing the electric valve 9 and consequently blocking the flow of combustible gas from the tank to the discharge port 2. The safety means comprise at least one timer, which is not shown in the figures, which is adapted to send an electric signal for closing the 10 electric valve 9 at a presettable time limit of inactivity of the torch 1. Advantageously, there is a heat-shrinking kit for heat-sealing, for example, sheets of tar strip and the like for a waterproofing civil roofings or others, which has at least one torch I, as described above, and at least means 15 for igniting the combustible gas. 15 The ignition means 15 comprise at least one controlled-sparking element 16, which can face the discharge port 2 of the torch 1. The sparking element 16 comprises at least two electrodes 17 which are mutually side-by-side and at least one pair of photocells 18, such as to convert the signal of proximity of the torch 1 to the ignition means 15 into 20 an electrical signal between the two electrodes 17 for igniting by sparking the combustible gas dispensed by the torch 1. The heat-shrinking kit further comprises at least one sensor 19, which is comprised within the group of odor sensors, sensors for detecting the quantity of gas in the air and the like, to be arranged proximate to the area of 25 use of the torch 1. The sensor 19 is adapted to send a signal for closing the electric valve 9 to control the flow of combustible gas from the tank to the discharge port 2. The kit finally comprises means 20 for supporting the torch 1 and the 30 flexible tubular element 3, which are of the type of a horizontally swinging WO 2009/027291 PCT/EP2008/060907 7 arn or other type for lifting from the ground the torch 1 and, in particular, the flexible tubular element 3, which for example is covered at least partially with a self-extinguishing or fire-resistant sheath. The horizontally swinging arm is, for example, provided with a stand 5 for supporting the means 13 for gripping the torch 1, which can have a sensor for detecting the proximity of the torch 1 such as to send a signal for closing the electric valve 9 and consequently controlling the flow of combustible gas from the tank to the discharge port 2. The operation of the present invention is as follows. 10 The flexible tubular element 3 with the torch I in operating and inactive conditions is supported by the horizontally swinging arm, so as to avoid occasional cutting and at the same time the overheating thereof if the torch 1 is used inappropriately by the operator. The tightness of the torch 1 from the tank to the discharge port 2 is 15 controlled by means of the pressure gauge, since each pressure drop measured with the flow control valve closed corresponds to an unwanted leak of combustible gas. Once these checks have been performed, the operator acts on the lever 14 and moves it from the release configuration to the working 20 configuration for the passage of the flow of combustible gas allowed by the simultaneous opening of the flow control valve and of the electric valve 9. Combustion of the gas occurs by arranging the discharge port 2 proximate to the ignition means 15: the photocells 18 provide the electrical signal to the electrodes 17, which produce the spark to ignite the 25 combustible gas which is pre-mixed with the oxidizer, which is generally air. The operator performs the heat-shrinking operations by gripping the torch 1 with both hands; if the operator is forced to release the grip of at least one handle, release of the lever 14 and/or of the closure device, if 30 provided, would close the flow control valve and therefore would interrupt WO 2009/027291 PCT/EP2008/060907 8 the flow of combustible gas. Further, in a preferred embodiment, the extraction of the torch 1 from the stand activates the timer and opens the electric valve 9 for the passage of the flow of combustible gas from the tank to the flow control valve. 5 Vice versa, placing the torch I on the stand deactivates the timer and closes the electric valve 9, which remains closed, even if electric power is not available. If the operator inadvertently leaves the torch I in inactive condition and not positioned in the stand, the timer, after the preset limit time has 10 elapsed, closes the electric valve 9 and prevents leaks of combustible gas or accumulation thereof in the flexible tubular element 3. In case of uncontrolled leaks of combustible gas or accumulation of an excessive quantity of such gas in the environment that surrounds the torch 1, the sensor 19 closes remotely the electric valve 9 and thus interrupts 15 the dispensing of such combustible gas. In practice it has been shown that the invention achieves the proposed aim and objects and in particular the fact is stressed that the gas-fired heat shrinking torch allows to have high combustion efficiencies by way of the forced mixing between the combustible gas and the oxidizer. 20 Further, the torch according to the invention as devised is easy and safe to use in any operating condition. The torch according to the invention in fact has safety systems, which in addition to making its use suitable according to applicable statutory provisions in terms of workplace safety, determine its automatic shutdown 25 in case of prolonged nonuse and limit its leaks of unburned gas. The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. All the details may further be replaced with other technically 30 equivalent elements.

9 In practice, the materials used, as well as the shapes and dimensions, may be any according to requirements without thereby abandoning the scope of the protection of the appended claims. The disclosures in Italian Patent Application No. M02007A000274 5 from which this application claims priority are incorporated herein by reference. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such 1o reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs. It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any 15 other country. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the 20 presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

1. A combustible gas-fired heat-shrinking torch for heat-sealing, comprising means for dispensing at least one combustible gas which are provided with at least one discharge port for said combustible gas and at 5 least one flexible tubular element which can be associated with at least one tank for supplying said combustible gas, said torch further comprising means for mixing said combustible gas with at least one oxidizer taken within the group that includes air, oxygen and the like for the combustion of said combustible gas dispensed by said discharge port and first means for io controlling the flow of combustible gas which are directly interposed between said discharge port and said tank in order to adjust said flow, wherein said first flow control means comprise at least one electric valve and at least one one-way valve, said electric valve being activatable remotely for the passage and/or control of said flow of combustible gas. 15

2. The torch according to claim 1, wherein said mixing means are interposed directly between said flexible tubular element and said discharge port. 20

3. The torch according to one or more of the preceding claims, wherein said mixing means comprise at least one tubular portion which is associated by means of a first end with the flexible tubular element and with the second free end arranged at said discharge port, said tubular portion having at least one taper in the region comprised between said first end and 25 said second end.

4. The torch according to one or more of the preceding claims, wherein said tubular portion is of the type of a Venturi Tube, said first and second ends being respectively of the converging and diverging type, said 30 discharge port and said second end coinciding and said tubular portion 11 being suitable for the passage of said combustible gas from said tank to said discharge port and for the simultaneous suction of at least one specific quantity of said oxidizer in the countercurrent for the mixing of said combustible gas and of said oxidizer. 5

5. The torch according to claim 1 and to one or more of the preceding claims, wherein said first flow control means are arranged proximate to said flexible tubular element at the end of said flexible tubular element that is associated with said tank. 10

6. The torch according to one or more of the preceding claims, the torch comprising a second means for controlling the flow of said gas which are associated at means for gripping said torch for manually actuating the interruption and dispensing of the flow of combustible gas from said is discharge port.

7. The torch according to one or more of the preceding claims, wherein said second flow control means comprise at least one actuation lever, which is associated with at least one valve for controlling the flow of 20 combustible gas, said lever being movable alternately between at least one active configuration, in which said flow control valve is open, and at least one release configuration, in which said flow control valve is closed so as to interrupt the flow of combustible gas in output from said discharge port. 25

8. The torch according to one or more of the preceding claims, the torch comprising a safety means for closing said electric valve and controlling said flow of combustible gas from said tank to said discharge port.

9. The torch according to one or more of the preceding claims, 30 wherein said safety means comprise at least one timer which is adapted to 12 send a signal for closing said electric valve at a presettable maximum time of inactivity of said torch.

10. A heat-shrinking kit for heat-sealing, comprising at least one 5 combustible gas torch as defined in one or more of the preceding claims, and means for igniting said combustible gas, said ignition means comprising at least one controlled sparking element which can face the discharge port of said torch, characterized in that said controlled sparking element comprises at least two electrodes which are mutually side-by-side and at least one pair io of photocells, such as to convert the signal of proximity of said torch to said ignition means into an electrical signal between the two electrodes for the ignition, by sparking, of said combustible gas dispensed by said torch.

11. The kit according to claim 10, the kit comprising at least one is sensor, which is comprised within the group of odor sensors, sensors for detecting the quantity of gas in the air, and the like, which is arranged proximate to the area of use of said torch, said sensor being adapted to send a signal for closing said electric valve to control the flow of combustible gas from said tank to said discharge port. 20

12. The kit according to either claim 10 or 11, the kit comprising means for supporting said torch.

13. A combustible gas-fired heat shrinking torch substantially as 25 herein described with reference to the accompanying drawings.

14. A heat shrinking kit substantially as herein described with reference to the accompanying drawings.