WO1983002753A1 - Heated gas blower device - Google Patents

Heated gas blower device Download PDF

Info

Publication number
WO1983002753A1
WO1983002753A1 PCT/GB1983/000042 GB8300042W WO8302753A1 WO 1983002753 A1 WO1983002753 A1 WO 1983002753A1 GB 8300042 W GB8300042 W GB 8300042W WO 8302753 A1 WO8302753 A1 WO 8302753A1
Authority
WO
WIPO (PCT)
Prior art keywords
nozzle
shield
flow
blower
mounting portion
Prior art date
Application number
PCT/GB1983/000042
Other languages
French (fr)
Inventor
Electronics Limited Skilten
Original Assignee
Skarsten, Stephen, Randolph
Bowskill, Robert
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Skarsten, Stephen, Randolph, Bowskill, Robert filed Critical Skarsten, Stephen, Randolph
Priority to JP83500798A priority Critical patent/JPS59500208A/en
Publication of WO1983002753A1 publication Critical patent/WO1983002753A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B44—DECORATIVE ARTS
    • B44D—PAINTING OR ARTISTIC DRAWING, NOT OTHERWISE PROVIDED FOR; PRESERVING PAINTINGS; SURFACE TREATMENT TO OBTAIN SPECIAL ARTISTIC SURFACE EFFECTS OR FINISHES
    • B44D3/00—Accessories or implements for use in connection with painting or artistic drawing, not otherwise provided for; Methods or devices for colour determination, selection, or synthesis, e.g. use of colour tables
    • B44D3/16—Implements or apparatus for removing dry paint from surfaces, e.g. by scraping, by burning
    • B44D3/166—Implements or apparatus for removing dry paint from surfaces, e.g. by scraping, by burning by heating, e.g. by burning
    • B44D3/168—Implements or apparatus for removing dry paint from surfaces, e.g. by scraping, by burning by heating, e.g. by burning by electrically heating

Definitions

  • This invention relates to heated gas blower devices and in one example to hand-held devices suitable for tasks such as paint stripping.
  • Hot air guns have been produced with an electrically powered blower and an electrical heating element. Such guns have been suggested for use in paint stripping and are indeed effective. A problem that is encountered, however, is that because of the high air temperatures that need to be achieved for correct functioning of the gun, the nozzle - usually of metal to give the required mechanical strength - becomes hot enough to cause serious burns if touched accidently by the operator either during or immediately after use.
  • the present invention consists ⁇ n a heated gas blower device comprising a nozzle; blower means for establishing a flow of gas through the nozzle; a heater for heating the flow of gas; a shield at least partially surrounding the nozzle; and means for directing a subsidiary flow of relatively cool gas from the blower means outwardly of the device between the nozzle and the shield to effect cooling of the shield.
  • said means for directing a subsidiary flow comprises a flow divider disposed between the blower means and the heater.
  • the shield completely surrounds the nozzle.
  • the shield and the nozzle comprise respective coaxial cylinders having substantially aligned free ends.
  • the shield is formed of metal and the nozzle of heat insulating material.
  • the free ends of the shield serves to support the free end of the nozzle.
  • Figure 1 is a sectional view, in partly diagrammatic form, of a device according to the invention.
  • Figure 2 is an end view of the device shown in Figure 1, and
  • Figure 3 is a section on line 3-3 of Figure 1.
  • a hot air gun 10 comprising a body 12 moulded in two halves (suitably divided in the plane of Figure l) from suitable plastics material.
  • the body includes a hollow pistol grip 14 within which are located an electrical connector 16 for the connection of an external mains lead and a power on/off switch 18.
  • a blower shown schematically at 20 In the main cavity 19 of the housing there is supported a blower shown schematically at 20, the blower being located by means of locating lugs (not shown) formed integrally with the body halves.
  • the blower is of conventional form with a driven impeller 22 and an electric motor 24 supplied via the switch 18. Adjacent the impeller, the body is formed with air inlet apertures 26.
  • the body 12 tapers to an annular nose portion 28 which includes on its interior surface integral bearing rings 30 and 32. On its exterior surface, the nose portion 28 is formed with a stepped portion 33 which is of reduced diameter.
  • a cylindrical nozzle 34 of relatively thin heat-insulating material is located within the nose portion 28 and is held as a force fit against the two bearing rings 30 and 32.
  • a cylindrical metal shield 38 which is coaxial with and of the same length as the nozzle 34 is mounted upon stepped portion 33.
  • the nozzle 34 is formed of a mica-based material and the shield 58 of aluminium.
  • Each bearing ring is formed with a series of circumferentially spaced notches 40 (seen also in Figure 5) which serve to provide, with the annular gap between the rings, a series of channels 42 extending from the body cavity 19 to the annular gap 44 between the nozzle 54 and shield 58.
  • the nozzle 34 Towards its free end, the nozzle 34 has riveted to it a series of flanges 46 formed from light guage metal sheet. Each of these flanges engages the inner cylindrical surface of the shield 58 and thereby serves to support the relatively thin nozzle within the mechanically stronger shield. At the free end the nozzle carries - again suitably by riveting - a baffle ring 48.
  • baffle plates 50 which lie in orthogonal diametric planes of the nozzle. These plates terminate short of the free end of the nozzle and, near that end, carry electrical heating elements shown schematically at 52. These elements are connected by leads (not shown) to the switch 18. Beyond the plates 50, the end of the nozzle 54 is covered by a protective wire grill 54.
  • the blower 20 will in use serve to establish a flow of air towards the nozzle 54 of, for example, approximately 500 litres/minute. Most of this flow will pass axially through the nozzle to be heated by the element 52 to a temperature of, typically, 600°C. Because of the notches 40, however, a small portion of the flow will be divided from the main flow and directed along the channels 42 and through annular gap 44 between the nozzle and the shield. This air of course by-passes the heating element and will be effective to cool the shield 58. At the free ends of the nozzle and shield, the relatively cool air will pass to the atmosphere, being directed away from the area to which heat is intended to be applied by means of the baffle ring 48.
  • the shield is kept at a reduced temperature and, whilst still hot, will be less likely to cause injury. Because the nozzle is protected by the surrounding shield and supported at its free end through flanges 46, it does not need to be mechanically strong and can be made economically from relatively thin material. Since only a minor portion of the air flow is diverted for cooling purposes, the flow rate of heated'air that can be achieved with a given blower is not significantly reduced.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

A hot air blower has a relatively thin heat insulating nozzle (34) mounted coaxially within a metallic shield (38). A blower (20) directs a flow of air to the nozzle where it is heated by an electrical heater (52). A portion of the flow from the blower is directed through channels (42) to pass between the nozzle and the shield to keep the shield relatively cool. The blower is suitable in one example for paint stripping.

Description

HEATED GAS BLOWER DEVICE
This invention relates to heated gas blower devices and in one example to hand-held devices suitable for tasks such as paint stripping.
Hot air guns have been produced with an electrically powered blower and an electrical heating element. Such guns have been suggested for use in paint stripping and are indeed effective. A problem that is encountered, however, is that because of the high air temperatures that need to be achieved for correct functioning of the gun, the nozzle - usually of metal to give the required mechanical strength - becomes hot enough to cause serious burns if touched accidently by the operator either during or immediately after use.
It is one object of this invention to provide an improved device in which the risk of injury to the operator is considerably reduced.
Accordingly, the present invention consists άn a heated gas blower device comprising a nozzle; blower means for establishing a flow of gas through the nozzle; a heater for heating the flow of gas; a shield at least partially surrounding the nozzle; and means for directing a subsidiary flow of relatively cool gas from the blower means outwardly of the device between the nozzle and the shield to effect cooling of the shield.
Advantageously, said means for directing a subsidiary flow comprises a flow divider disposed between the blower means and the heater. Preferably, the shield completely surrounds the nozzle.
Suitably, the shield and the nozzle comprise respective coaxial cylinders having substantially aligned free ends.
Advantageously, the shield is formed of metal and the nozzle of heat insulating material.
In one form of the invention, the free ends of the shield serves to support the free end of the nozzle.
The invention will now be described by way of example with reference to the accompanying drawing in which:-
Figure 1 is a sectional view, in partly diagrammatic form, of a device according to the invention,
Figure 2 is an end view of the device shown in Figure 1, and
Figure 3 is a section on line 3-3 of Figure 1.
There is shown in the drawing a hot air gun 10 comprising a body 12 moulded in two halves (suitably divided in the plane of Figure l) from suitable plastics material. The body includes a hollow pistol grip 14 within which are located an electrical connector 16 for the connection of an external mains lead and a power on/off switch 18. In the main cavity 19 of the housing there is supported a blower shown schematically at 20, the blower being located by means of locating lugs (not shown) formed integrally with the body halves. The blower is of conventional form with a driven impeller 22 and an electric motor 24 supplied via the switch 18. Adjacent the impeller, the body is formed with air inlet apertures 26. Towards the right, as seen in the drawing, the body 12 tapers to an annular nose portion 28 which includes on its interior surface integral bearing rings 30 and 32. On its exterior surface, the nose portion 28 is formed with a stepped portion 33 which is of reduced diameter.
A cylindrical nozzle 34 of relatively thin heat-insulating material is located within the nose portion 28 and is held as a force fit against the two bearing rings 30 and 32. A cylindrical metal shield 38 which is coaxial with and of the same length as the nozzle 34 is mounted upon stepped portion 33. In this example, the nozzle 34 is formed of a mica-based material and the shield 58 of aluminium. Each bearing ring is formed with a series of circumferentially spaced notches 40 (seen also in Figure 5) which serve to provide, with the annular gap between the rings, a series of channels 42 extending from the body cavity 19 to the annular gap 44 between the nozzle 54 and shield 58.
Towards its free end, the nozzle 34 has riveted to it a series of flanges 46 formed from light guage metal sheet. Each of these flanges engages the inner cylindrical surface of the shield 58 and thereby serves to support the relatively thin nozzle within the mechanically stronger shield. At the free end the nozzle carries - again suitably by riveting - a baffle ring 48.
Within the nozzle 54 there are located a pair of intersecting baffle plates 50 which lie in orthogonal diametric planes of the nozzle. These plates terminate short of the free end of the nozzle and, near that end, carry electrical heating elements shown schematically at 52. These elements are connected by leads (not shown) to the switch 18. Beyond the plates 50, the end of the nozzle 54 is covered by a protective wire grill 54.
The operation of the described device can now be understood. The blower 20 will in use serve to establish a flow of air towards the nozzle 54 of, for example, approximately 500 litres/minute. Most of this flow will pass axially through the nozzle to be heated by the element 52 to a temperature of, typically, 600°C. Because of the notches 40, however, a small portion of the flow will be divided from the main flow and directed along the channels 42 and through annular gap 44 between the nozzle and the shield. This air of course by-passes the heating element and will be effective to cool the shield 58. At the free ends of the nozzle and shield, the relatively cool air will pass to the atmosphere, being directed away from the area to which heat is intended to be applied by means of the baffle ring 48. It will be appreciated that because of the cooling air flow through annular gap 44, the shield is kept at a reduced temperature and, whilst still hot, will be less likely to cause injury. Because the nozzle is protected by the surrounding shield and supported at its free end through flanges 46, it does not need to be mechanically strong and can be made economically from relatively thin material. Since only a minor portion of the air flow is diverted for cooling purposes, the flow rate of heated'air that can be achieved with a given blower is not significantly reduced.
It should be understood that this invention has been described by way of example only and numerous modifications are possible without departing from the scope of the invention. The shield and nozzle can take forms other than the described arrangement of coaxial circular cylinders and can be produced from materials other than those specifically mentioned. Further, the illustrated arrangement of notches cut into the body nose portion to divide the air flow could be replaced by other alternatives involving baffles or the like. Whilst, for simplicity, a heated air blower has been described, it is possible with suitable supply lines to produce jets of heated nitrogen or other gases with blower devices according to this invention.

Claims

1. A heated gas blower device comprising a nozzle; blower means for establishing a flow of gas through the nozzle; a heater for heating the flow of gas; a shield at least partially surrounding the nozzle and means for directing a subsidiary flow of relatively cool gas from the blower means outwardly of the device between the nozzle and the shield to effect cooling of the shield.
2. A device according to Claim 1, wherein said means for directing a subsidiary flow comprises a flow divider disposed between the blower means and the heater.
5. A device according to Claim 1, wherein the shield completely surrounds the nozzle.
4. A device according to Claim 5, wherein the shield and the nozzle comprise respective coaxial cylinders.
5« A device according to Claim 4, further comprising a body with an annular mounting portion, the inward end of the nozzle being received within the mounting portion and the mounting portion being received within the inward end of the shield.
6. A device according to Claim 5, wherein said flow divider comprises aperture means formed in said annular mounting portion.
7. A device according to Claim 6, wherein said aperture means comprises a series of cirσumferentially spaced channels each extending axially through the mounting portion.
8. A device according to Claim 4, wherein the free ends of the nozzle is supported from the free end of the shield.
9. A device according to Claim 8, wherein the shield is formed . of metal and the nozzle of heat insulating material.
10. A device according to Claim 1, further comprising handle means enabling the device to be hand held.
PCT/GB1983/000042 1982-02-12 1983-02-11 Heated gas blower device WO1983002753A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP83500798A JPS59500208A (en) 1982-02-12 1983-02-11 heated gas blower

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8204118 1982-02-12
GB8204118820212 1982-02-12

Publications (1)

Publication Number Publication Date
WO1983002753A1 true WO1983002753A1 (en) 1983-08-18

Family

ID=10528289

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1983/000042 WO1983002753A1 (en) 1982-02-12 1983-02-11 Heated gas blower device

Country Status (3)

Country Link
EP (1) EP0101482A1 (en)
JP (1) JPS59500208A (en)
WO (1) WO1983002753A1 (en)

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0125109A2 (en) * 1983-05-05 1984-11-14 Black & Decker Inc. Guard for a hot air gun
EP0159134A1 (en) * 1984-03-15 1985-10-23 Allan James Wiseman Surface stripping aid
US5909535A (en) * 1998-04-23 1999-06-01 Seelye Acquisition, Inc. Hot air welding torch with concentric tubular members providing cooling air flow
US6370326B2 (en) * 2000-06-01 2002-04-09 Chuan-Hsin Cheng Safety hot air blowing gun
US6763183B1 (en) * 2003-06-09 2004-07-13 Yeu Chyuan Industrial Co., Ltd. Cooling and isolating structure for external casing of hot air blowing gun
US7039301B1 (en) * 1999-10-04 2006-05-02 Excel Dryer, Inc. Method and apparatus for hand drying
GB2501175A (en) * 2012-03-30 2013-10-16 Dyson Technology Ltd A hand held blower with an insulating chamber
USD715995S1 (en) 2013-09-26 2014-10-21 Dyson Technology Limited Hair dryer
USD715996S1 (en) 2013-09-26 2014-10-21 Dyson Technology Limited Hair dryer
USD716492S1 (en) 2013-09-26 2014-10-28 Dyson Technology Limited Hair dryer
US9144286B2 (en) 2012-03-30 2015-09-29 Dyson Technology Limited Hand held appliance
US9173468B2 (en) 2012-03-30 2015-11-03 Dyson Technology Limited Hand held appliance
US9282800B2 (en) 2012-03-30 2016-03-15 Dyson Technology Limited Hand held appliance
US9282799B2 (en) 2012-07-04 2016-03-15 Dyson Technology Limited Attachment for a hand held appliance
US9414662B2 (en) 2013-07-05 2016-08-16 Dyson Technology Limited Hand held appliance
US9420865B2 (en) 2013-07-05 2016-08-23 Dyson Technology Limited Hand held appliance
US9420864B2 (en) 2013-07-05 2016-08-23 Dyson Technology Limited Hand held appliance
US9526310B2 (en) 2012-07-04 2016-12-27 Dyson Technology Limited Attachment for a hand held appliance
US9596916B2 (en) 2013-07-05 2017-03-21 Dyson Technologies Limited Hand held appliance
US9675157B2 (en) 2012-03-30 2017-06-13 Dyson Technology Limited Hand held appliance
US9681726B2 (en) 2013-07-05 2017-06-20 Dyson Technology Limited Hand held appliance
US9687058B2 (en) 2013-09-26 2017-06-27 Dyson Technology Limited Hand held appliance
USD791407S1 (en) 2015-01-12 2017-07-04 Dyson Technology Limited Hair appliance
US9808067B2 (en) 2013-07-24 2017-11-07 Dyson Technology Limited Attachment for a handheld appliance
US9808066B2 (en) 2013-07-05 2017-11-07 Dyson Technology Limited Hand held appliance
US9808065B2 (en) 2013-07-05 2017-11-07 Dyson Technology Limited Hand held appliance
US10016040B2 (en) 2012-03-30 2018-07-10 Dyson Technology Limited Hand held appliance
US10194728B2 (en) 2015-01-21 2019-02-05 Dyson Technology Limited Attachment for a hand held appliance
US10213001B2 (en) 2015-01-21 2019-02-26 Dyson Technology Limited Attachment for a hand held appliance
US10278471B2 (en) 2013-09-27 2019-05-07 Dyson Technology Limited Hand held appliance

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3094606A (en) * 1958-10-29 1963-06-18 Edwin W Ferris Electric paint removing device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3094606A (en) * 1958-10-29 1963-06-18 Edwin W Ferris Electric paint removing device

Cited By (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0125109A2 (en) * 1983-05-05 1984-11-14 Black & Decker Inc. Guard for a hot air gun
EP0125109A3 (en) * 1983-05-05 1986-07-16 Black & Decker Inc. Guard for a hot air gun
EP0159134A1 (en) * 1984-03-15 1985-10-23 Allan James Wiseman Surface stripping aid
US5909535A (en) * 1998-04-23 1999-06-01 Seelye Acquisition, Inc. Hot air welding torch with concentric tubular members providing cooling air flow
US7039301B1 (en) * 1999-10-04 2006-05-02 Excel Dryer, Inc. Method and apparatus for hand drying
US6370326B2 (en) * 2000-06-01 2002-04-09 Chuan-Hsin Cheng Safety hot air blowing gun
US6763183B1 (en) * 2003-06-09 2004-07-13 Yeu Chyuan Industrial Co., Ltd. Cooling and isolating structure for external casing of hot air blowing gun
US10610000B2 (en) 2012-03-30 2020-04-07 Dyson Technology Limited Hand held appliance
US10016040B2 (en) 2012-03-30 2018-07-10 Dyson Technology Limited Hand held appliance
US10687595B2 (en) 2012-03-30 2020-06-23 Dyson Technology Limited Hand held appliance
US9675157B2 (en) 2012-03-30 2017-06-13 Dyson Technology Limited Hand held appliance
GB2501175A (en) * 2012-03-30 2013-10-16 Dyson Technology Ltd A hand held blower with an insulating chamber
US9144286B2 (en) 2012-03-30 2015-09-29 Dyson Technology Limited Hand held appliance
US9173468B2 (en) 2012-03-30 2015-11-03 Dyson Technology Limited Hand held appliance
US9282800B2 (en) 2012-03-30 2016-03-15 Dyson Technology Limited Hand held appliance
GB2501175B (en) * 2012-03-30 2014-04-23 Dyson Technology Ltd A hand held appliance
US10117491B2 (en) 2012-03-30 2018-11-06 Dyson Technology Limited Hand held appliance
US9282799B2 (en) 2012-07-04 2016-03-15 Dyson Technology Limited Attachment for a hand held appliance
US10010150B2 (en) 2012-07-04 2018-07-03 Dyson Technology Limited Attachment for a hand held appliance
US9526310B2 (en) 2012-07-04 2016-12-27 Dyson Technology Limited Attachment for a hand held appliance
US10575617B2 (en) 2012-07-04 2020-03-03 Dyson Technology Limited Attachment for a hand held appliance
US9808065B2 (en) 2013-07-05 2017-11-07 Dyson Technology Limited Hand held appliance
US9420864B2 (en) 2013-07-05 2016-08-23 Dyson Technology Limited Hand held appliance
US9414662B2 (en) 2013-07-05 2016-08-16 Dyson Technology Limited Hand held appliance
US9420865B2 (en) 2013-07-05 2016-08-23 Dyson Technology Limited Hand held appliance
US9681726B2 (en) 2013-07-05 2017-06-20 Dyson Technology Limited Hand held appliance
US9808066B2 (en) 2013-07-05 2017-11-07 Dyson Technology Limited Hand held appliance
US9596916B2 (en) 2013-07-05 2017-03-21 Dyson Technologies Limited Hand held appliance
US9808067B2 (en) 2013-07-24 2017-11-07 Dyson Technology Limited Attachment for a handheld appliance
US9687058B2 (en) 2013-09-26 2017-06-27 Dyson Technology Limited Hand held appliance
USD716492S1 (en) 2013-09-26 2014-10-28 Dyson Technology Limited Hair dryer
USD715996S1 (en) 2013-09-26 2014-10-21 Dyson Technology Limited Hair dryer
USD715995S1 (en) 2013-09-26 2014-10-21 Dyson Technology Limited Hair dryer
US10278471B2 (en) 2013-09-27 2019-05-07 Dyson Technology Limited Hand held appliance
USD791407S1 (en) 2015-01-12 2017-07-04 Dyson Technology Limited Hair appliance
US10194728B2 (en) 2015-01-21 2019-02-05 Dyson Technology Limited Attachment for a hand held appliance
US10213001B2 (en) 2015-01-21 2019-02-26 Dyson Technology Limited Attachment for a hand held appliance

Also Published As

Publication number Publication date
EP0101482A1 (en) 1984-02-29
JPS59500208A (en) 1984-02-16

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