AU615106B2 - Portable heating device - Google Patents

Description

615 06 COMMONWEALTH OF AUSTRALIA The Patents Act 1952-1969 Name of Applicant(s): Address of Applicant(s): GLASS ENGINEERING PTY LTD 21 Michlin Street MOOROOKA QLD 4105 o 00 a c o 0 a 0000 i oa a Address for Service: G.R. CULLEN COMPANY, Patent Trade Mark Attorneys, Dalgety House, 79 Eagle Street, Brisbane, Qld. 4000, Australia.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: 0 0 0 0 0 a0 0 o0 a 0 a0 o 0 a 0 PORTABLE HEATING DEVICE The following statement is a full description of the invention including the best method of performing it known to us BO(Y 2 'It 4 4 2 THIS INVENTION relates to a portable heating apparatus for assisting in the cutting of glass and is particularly related to although is not limited to assisting in the cutting of laminated glass.

Large sheets of glass measuring say 4 metres x 3 metres are frequently supplied to glass merchants, window manufacturers and the like as basic stock from which smaller sheets are cut as required. The large sheets of glass are usually cut by scoring the upper and/or lower surface of the glass by a glass cutting wheel followed by tilting of the o sheet of glass of glass at its free end to break the glass eoco sheet across the score line(s). Laminated glass usually 0000 comprises two sheets of glass laminated to an intermediate o 444444 layer of a thermoplastic polymer. Although very effective as

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15 a safety glass, laminated glasses are usually very expensive compared to conventional glasses and great care must be taken to avoid wastage during cutting.

#004 0o To cut laminated glass into smaller sections, it is o generally necessary to score the upper and lower glass sheet o followed by fracturing the upper and lower glass sheet by tilting the portions of glass on each side of the score line o first in one direction and then the other.

0O Once the upper and lower glass laminates have been severed, the thermoplastic polymer intermediate layer must be cut to complete the separation process. To cut the intermediate thermoplastic polymer, a radiant heater (usually ii;-t; r4 3 a nichrome element encased in a quartz tube) is positioned over the severed region and heat is applied until the thermoplastic polymeric intermediate layer softens sufficiently to enable the respective portions of the laminated glass be drawn apart thereby severing the intermediate layer.

A disadvantage of severing laminated glass lies in a step of severing the polymeric intermediate layer. This step is extremely slow and consumes unnecessary energy due to the inherently poor thermal conductivity of glass. Radiant heat must be applied to the region of transversely fractured oa glass for a minute or more until the thermoplastic polymeric intermediate layer has softened sufficiently to enable the sheets of glass on each side of the fracture to be drawn 4 4l apart to sever the intermediate layer.

In many situations, laminated glass is cut on site before insertion into a window or other type of frame. Under these conditions, it is necessary for the heater to be portable so as to allow on-site heating and separation of the 4400 020 intermediate polymeric layer.

It is an object of the invention to at least o partially overcome the abovementioned disadvantages.

4 In one form the invention resides in a portable heating apparatus for softening or melting the polymeric intermediate layer in laminated glass, said heating apparatus comprising 1: !i ,i

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4 7- 4 a hollow elongate body having one or more outlet apertures extending longitudinally of said body and in linear alignment, pressurization means to supply pressurized fluid to the interior of said body, and heating means to heat said fluid prior to emergence from said one or more outlet apertures.

The portable heating apparatus can be used on site to soften or melt the polymeric intermediate layer in o0°ilb laminated glass after the laminated glass has been scored and S broken. Generally, upon heating, the laminated glass panes 0-0. are pulled apart until eventually the polymeric intermediate 0 0of, 00 e os S° layer breaks. The process can be facilitated by a cutter or 0000 knife to cut the polymeric intermediate layer once it has been softened enough to allow the glass panes to be separated far enough to allow a cutter to be inserted into the glass 0 oo0 ooo 0 0 pane to cut the intermediate layer.

The hollow elongate body may be of oval or 0100 oo00 substantially circular cross-section. It is preferred that the hollow elongate body is of an eccentric oval 0 00 0o0 o configuration having a narrowed portion at one end. The -o reason for this shall be explained below.

The hollow elongate body can be of any suitable length to allow the apparatus to be placed along a score line of the laminated glass. It is preferred that the hollow elongate body is of sufficient length to allow the apparatus

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Y to extend along the entire width of the score line. However, if the laminated glass is of excessive width, the apparatus can be used to initially melt a portion of the intermediate polymeric layer and then be moved to the remaining portion of the laminated glass to melt the remaining portion of the intermediate polymeric layer. The length of the hollow elongate portion may be adjustable. The adjustment can be in the form of a number of telescopic tube sections or alternately of separate sections which can be attached to o0I each other.

0 Oi D o000 The hollow elongate body may be divided into a 0000 00 number of compartments by a web or other partition which 0 000004 0 0 extends longitudinally of said body. Preferably, the hollow 0000 lif elongate body is divided into an upper and lower compartment by a single web. The upper compartment is preferably of a larger dimension than the lower compartment and the lower S 0 0 compartment is preferably in the region of the tapered portion of the hollow elongate body. The upper and lower 4 4 compartments are preferably in fluid communication with each other. The fluid communication may be in the form of a 0 00 o00 series of apertures extending along the length of the web 0 0 60 separating the upper and lower compartments. Alternately, the fluid communication may be in the form of a single slot extending along the length of the web.

The pressurization means preferably comprises a tangential or radial fan which may be an electric or other i i! i 6 type of driven fan. The fan may be located spaced from the tubular body and coupled thereto through suitable fluid conduit. Preferably, the pressurization means is connected directly to one end of the hollow elongate body and may supply air or other pressurized fluid to the upper compartment.

The heating means is provided to heat the fluid prior to exit from the one or more apertures. The heating means is preferably located in the lower compartment.

110 Alternately, the heating means may be located in the upper compartment or adjacent to the blower. The heating means may comprise an elongate heater element which may extend o throughout the length of the lower compartment.

The portable heating apparatus may be provided with carry handles which may be located adjacent each end of the tubular body. The carry handles may also space the hollow elongate body slightly above the surface of the glass to be heated to allow heated fluid to pass through the fluid exit o slot without restriction.

The one or more outlet apertures may comprise a 0 9 no single slot or a plurality of longitudinally spaced 0 apertures. The apertures may be tapered to further pressurize the air as it flows through the aperture.

The apparatus may further be provided with control means which controls the pressurization means and heating means either individually or in combination. It is preferred

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*4 7 that both the pressurized means and heating means are electrically operated and are controlled by a switch or like control member.

The apparatus may be operated by a mains power supply or if necessary a portable power generator.

In use, pressurized air is supplied by the pressurization means to the upper compartment. The pressurized air can subsequently pass through the apertures or slots in the web to the lower housing where it is heated o 00 by the fluid heater. Subsequently, the heated fluid passes 0 through the outlet aperture(s) as a narrow strip of heated 0 air. The one or more outlet apertures can be positioned 000000 above a score line of the laminated glass to melt the 0 intermediate polymeric layer. An advantage in having the hollow elongate body as a tapered oval configuration with the outlet aperture(s) at the tapered portion, is that this S0 4 results in a maximum heating of the pressurised air flowing around the heating means and also guides the subsequently heated air through the outlet aperture(s).

In order that the invention may be more clearly o4 understood reference is now made to a preferred embodiment of the invention in which figure 1 is a perspective view of a j portable heating apparatus according to an embodiment of the 0 invention.

The embodiment is directed to a portable heating apparatus 80 comprising a hollow elongate body 81 of

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i 8 convenient length, the interior of the body being divided into an upper and lower compartment 83, 82 by a web 84 extending longitudinally of the body 81. Upper compartment 83 is in fluid communication with lower compartment 82 by means of spaced apertures 85 located along web 84.

Lower compartment 82 has a fluid outlet slot 86 extending longitudinally of the lowest portion of tubular body 81. A heating means in the form of an electric heating element 87 is located within lower compartment 82 and also extends longitudinally therealong. Heating means 87 may be o mounted within lower compartment 82 by ceramic brackets.

At each end of hollow elongate body 81 are support brackets 88 with insulated carrying handles 89.

The lower edge 90 of bracket 88 provides a means for supporting the portable apparatus 80 above a surface such as laminated glass. If required, adjustment means (not shown) may be associated with the support brackets 88 to 0 0 and the surface of the glass upon which apparatus 80 is supported.

0 0 oUv A pressurization means in the form of an electric 0 00, 0air blower 91 is located at one end of hollow elongate body 81 and in fluid communication with upper compartment 83. The electric air blower may be a tangential or radial fan.

Pressurized fluid such as air supplied by air blower 91 enters lower compartment 82 via apertures 85 and is heated by

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9 heating element 87 before issuing from the outlet slot 86 as a narrow strip of heated air.

A control switch 92 is provided to control the function of the air blower 91 or electric heating element 87 either individually or in combination.

In use, the portable heating apparatus is located above the break line of the laminated glass with the fluid outlet slot being closely spaced above the break. The apparatus is then turned on to supply a narrow strip of heated air into the break to soften and/or melt the intermediate polymeric layer.

A particular advantage of the portable apparatus is its ease of use with laminated glass cutting apparatus or in association with "free hand" cutting of laminated glass.

The portable heating apparatus of the invention permits on-site trimming or adjustment of pre-cut laminated glass panels where the on-site use of a laminated glass cutting apparatus is not possible or is inconvenient.

4 4 The apparatus replaces the use of flammable liquids for severing of the polymeric intermediate layer.

In an alternative embodiment of the apparatus, the heating means may comprise a plurality of spaced gas burner nozzles or the like, preferably with a radiant gauze to control gas flames and to permit even infra red radiation along the length of the apparatus. The pressurization means may comprise a source of pressurized fuel gas such as propane, butane, LPG or the like. Heated gaseous combustion products issue from the elongate outlet slot as a narrow curtain to heat the polymeric intermediate layer together with radiant energy from the radiant gauze directed onto a predetermined area of the glass.

It will be appreciated that various other changes or modifications may be made to the embodiment described without departing from the spirit and scope of the invention r o as defined in the appended claims.

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Claims (11)

1. A portable heating apparatus for softening or melting the polymeric intermediate layer in laminated glass, said heating apparatus comprising a hollow elongate body having one or more outlet apertures extending longitudinally of said body and in linear alignment, pressurization means to supply pressurized fluid to the interior of said body, and a heating means to heat said fluid prior to emergence from said one or more outlet apertures.

2. The apparatus as claimed in claim 1, wherein said hollow elongate body is divided into first and second compartments by a web extending longitudinally of said body, said first and second compartments being in fluid communication with each other.

3. The apparatus as claimed in claim 2, wherein said first and second compartments are in fluid communication with each other by one or more apertures in said web.

4. The apparatus as claimed in claim 3, wherein said one or more apertures are spaced longitudinally of said web. The apparatus as claimed in any one of claims 2 to 4, wherein said pressurization means supplies pressurized gas to the first compartment and said one or more outlet apertures are located in an outer wall of said second 1100 #100 I I.i 11 i

6. precedi a fluil body.

7. fluid b

8. p r eed within

9. heatinq longitu precedi said or from a

11. preced functii either

12. whereir from si area o a I o I a I I co 0 o 0 o 00 ar 0~ compartment. MIS *a0 4'~ A; -vU 12 6. The apparatus as claimed in any one of the preceding claims, wherein said pressurization means comprises a fluid blower located at one end of said hollow elongate body. 7. The apparatus as claimed in claim 6, wherein saia fluid blower comprises a tangential or radial fan. i'o7 8. The apparatus as claimed in any one ofA the- -e-eed4g G-a-M- wherein said heating means is located within said second compartment. 9. The apparatus as claimed in claim 8, wherein said heating means comprises an elongate heating element extending fit* longitudinally of the second compartment. The apparatus as claimed in any one of the Jif preceding claims wherein spacing means is provided to space said one or more outlet apertures at a predetermined distance from a surface of a laminated glass sheet. 11. The apparatus as claimed in any one of the preceding claims including a control means to control the function of the pressurization means and the heating means either individually or in combination. 00 12. The apparatus as claimed in any preceding claim wherein said heating means is adapted to direct radiant heat from said one or more outlet apertures onto a predetermined

71-4 area of a laminated glass sheet. 13 13. A portable heating apparatus substantially as hereinbefore described with reference to the accompanying drawing. DATED this EIGHTEENTH day of SEPTEMBER 1989. GLASS ENGINEERING PTY LTD By Their Patent Attorneys G R CULLEN CO .0