AU673293B2 - Glass repair - Google Patents

Description

s _d 43372 GEH:MH P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: PHILIP DAVID PAYNE Name of inventor: PHILIP DAVID PAYNE Address for Service: COLLISON C0.,117 King William Street, Adelaide, S.A. 5000 Invention Title: GLASS REPAIR 00** 0 Details of Associated Provisional Appl:cations: PM2176 dated 3rd November 1993 The following statement is a full description of this invention, including the best method of performing t known to e: Name of inventor: PHILIP DAVID

PAYNE

Address for Service: COLLISON CO.,117 King William Street, Adelaide, S.A. 5000 Invention Title: GLASS REPAIR Details of Associated Provisional Applications: PM2176 dated 3rd November 1993 The following statement is a full description of this invention, including the best method of performing it known to me: This invention relates to the repair of glass, more particularly to the repair of sheet or plate glass and also to the repair of the laminated glass of automobile windscreens.

BACKGROUND OF THE INVENTION The repair of automotive windscreens is well known, particulal~y for the repair of small chips and cracks. This includes the technique of filling the chip or crack with a resin having substantially the same index of refraction of the glass being repaired, and there are various patent specifications describing various techniques and apparatus for attending to such repair.

While the main concentration has been directed to the repair of laminated glass, some attention has been directed to the repair of single sheets or plate glass, US 4,385,879 and US 4,814,185 describe the technique of applying a non-stick piece of material to the reverse side of the glass to prevent excess resin passing through the crack, In US 4, 385,879 the method and apparatus 15 described therein is only applicable to a single small hole passing through the glass, and US 4,814,185 is similarly limited to the size of hole to be repaired *too in the plate glass.

a o Australian Application No 89354/91 which corresponds to US 5,116,441 discloses a method and apparatus for repairing laminated windscreens or 20 plate glass having cracks longer than a star crack from the point of impact, By that inventlr it is possible to repair long cracks by sliding a repair bridge along the crack the specification also discloses the use of a crack opener a applied to the reverse side of the glass to open the crack so that the repair resin can enter the crack. Also with that technique the repair resin is applied In 25 two stages, one resin is applied first and then a second resin of higher viscosity is applied to the crack.

This method of repairing a long crack requiring the necessity of applying a thin resin first into the fine narrow portion of the crack, requires the removal of the injector, and applying the injector with a thicker resin to a further portion of the crack or to be applied to the first applied resin to fill the crack. However by this time tie first applied resin Is beginning to cure and thus this resin has either to be removed or else the repair is not satisfactory for thin resin is much weaker and does not have the required strength.

~OL While the prior art methods and apparatus have been relatively successful, it is an object of this invention to provide a method and apparatus which overcomes various problems associated with the known methods, Thus it is an object of this invention to provide a kit comprising various items which can be used in differing combinations to facilitate the repair of differing types of glass and differing types of damage to the glass, It is a further object of this invention to provide a method and apparatus for the repair of damage to plate glass, It is a still further object to provide a method and apparatus for the removal of the damaged portion of a plate glass sheet and the insertion of a replacement piece of glass into the plate glass sheet, BRIEF STATEMENTS OF THE INVENTION There is provided according to the invention a method of repairing a glass sheet, wherein the damage extends through the thickness of the glass sheet, the steps including applying resin and a cover strip to one side of the glass 6:9, sheet to cover the damage, applying a second cover strip to cover the damage 0 on the second side of the glass sheet, and injecting the rosin into the damaged S"area by passing a needle of a syringe under said second cover strip from the top of the damaged area to fill the damage from the bottomn while the air in the damaged area passes out around the needle of the syringe, completely filling the damaged area with the single resin, curing the resin and removing the cover strips, Also there is provided according to the invention a repair kit for use in the above method, the repair kit including a resin injector comprising a pressure bolt through which a pressure bolt is screwed; a syringe; a crack opener bridge including suction cups and a levelling screw; and an injector assembly inc,'uing a bridge, said injector and suction cups; whereby said crack opener assembly may be combined with the injector assembly and/or levelling bar to provide 'RAQ 30 support for the repair of large areas, FIELD OF INVENTION This invention describes the tools and methods used to repair large and small holes and cracks to plate and laminated glass. This includes such glass as mirrors, shower screens, glass display cabinets, and any sized household, business or shopfront windows. The process of injecting resins into bullet holes, cracks and cavities where necessary, and the method of cutting out damaged glass and replacing that particular area with a new piece to prevent having to replace the entire window are explained. The process of cutting out an insert in glass for the purpose of passing letters through are also explained.

BRIEF DESCRIPTION OF DRAWINGS •In order to more fully describe the invention reference is made to the accompanying drawings in which:- 15 FIG 1 is an exploded view of the primary injector; FIG 2 is a view of the syringe; FIG 3 is an exploded view of a crack opener assembly;

S

FIG 4 is an exploded view of a secondary injector assembly; FIG 5 are views in plan and exploded elevation of the primary injector assembly; FIG 6 are views showing the filling of the injectors and syringe with resin; L L FIG 7 shows the repair of a bullet hole in plate glass; FIG 8(a) is an enlarged view of portion of FIG 7 and FIG 8(b) is a further enlarged view of portion of FIG 8(a); FIG 9 is an illustration of a large hole in plate glass; FIG 10 is an illustration of the repair of the glass in FIG 9; FIG'S 11 and 11 show the application of the invention to the provision of a mail insert in plate glass; FIG'S 12(a) and 12(b) illustrate a levelling bar as used in FIG 10; and FIG 13 illustrates an edge crack opener, DESCRIPTION OF THE PREFERRED EMBODIMENT The components and items of the invention will now be described in some detail before the procedure and method of use of the kit is described.

FIG 1 shows the primary injector which comprises resin bolt 1.1 which is screwed into the sleeve 1.2. The resin bolt 1.1 is hollow to receive the 15 pressure bolt 1,3 which is screwed Into the sleeve 1.2 so that by rotation of the pressure bolt the pressure bolt can be moved down the resin bolt, The pressure bolt 1.3 has a pair of grooves 1,5 to receive sealing rings 1,4, A further seal 1,6 is positioned at the end opening 1.7. As later described In more detail, resin is placed in the resin bolt, the bolt applied to the glass, and on screwing the pressure bolt, resin is forced into the crack in the glass. The seal 1,6 prevents contact of the resin bolt with the glass and also prevents escape of the resin beneath the pressure bolt. The seals 1,4 prevent leakage of the resin along the pressure bolt, and also when the pressure bolt is withdrawn while the resin bolt is in contact with the glass, a suction is created on the crack in the glass, A syringe is illustrated In FIG 2, the syringe having a barrel and a plunger 2.1, the plunger at its inner end having a rubber seal thereon to seal on the inner surface of the barrel. A tip 2.3 is formed at the end of the barrel which receives a rubber sleeve 2.4, the rubber sleeve being used when the syringe 6 is used for very long cracks by sliding along the glass. Also the rubber sleeve 2.3 can be removed and replaced with a needle, the use of which will be later described.

In order to open cracks so that the resin can be inserted in the crack, there Is shown in FIG 3 a crack opener which comprises a levelling bolt 3.1 which is screwed into a bridge 3.2. Plastic suction cups are screwed into the bridge from the opposite side thereof, the figure showing the assembly in exploded view and in plan view. When the crack opener is used, it is positioned on the opposite side of the glass, the suction locating the bridge in position so that when the bolt 3.1 is screwed onto the glass at the area of the crack, rotation of the bolt will apply pressure to the glass and thus slightly deflect the glass to open the crack on the side of the glass opposite to the crack opener.

FIG 4 shows an example of the secondary injector assembly which can be used for sliding along cracks in laminated glass. The injector 4.1 is screwed Into the oridge 4 3 at one end and a levelling bolt 4.2 is screwed into the ".bridge 4.3 at the other end. The bridge 4,3 is supported on a suction cup which is pressed onto the glass to secure the assembly to the glass. To allow the assembly to slide along the glass, a lubricant can be used under the i" suction cup. The bridge has a slot 4,4 on its undersurface so that the bridge 4.3 can be positioned over another bridge to form the primary injector assembly as described in FIG Thus FIG 5 shows the primary injector assembly which is formed by two bridges 5,1 (corresponding to bridge 4,3 above described) and 5.2 positioned "i at right angles to each other and fastened to each other by a fastener such as a plastic bolt 5.3, Bridge 5,1 has the levelling bolt 5,4 screwed into one end while the injector 5,5 Is screwed into the other end thereof, Bridge 5.2 has a suction cup 5,6 at each end to hold the assembly against the glass. This assembly is used mainly for the repair of small stone damage and at the point of cracks, AgaIn lubricant can be applied to the suction cups for sliding of the assembly along the crack, The two injectors are shown in FIG 6 and the method of filling same with resin.

The injector 6,1 is faced upwards and the resin 6,3 is dripped in from the bottle 6.4. To fill the syringe 6.2, the rubber sleeve 6,6 is placed on the tip 6,7 and the tip 6,5 of the resin bottle is pushed into the sleeve 6.6, The resin bottle 6.4 is squeezed in 6,8 while the plunger 6,9 is withdrawn to suck the LI -I resin into the syringe. The rubber sleeve 6.6 can be left on when used to repair long cracks. However when the needle 6.10 is to be used, as later described in respect of FIG'S 7, 8 and 10, in the repair of large holes the sleeve 6.6 is removed and the needle 6.10 placed on the tip 6.7.

FIG 7 is a face on view of the repairing of a bullet hole, A bullet usually forms small hole 7.7 on the entry side with a larger area 7.9 of glass knocked out on the exit side. The primary injector assembly 7,3 is placed in position with the levelling bolt 7,5 securing the glass plate and holds in position a plastic tab flat over the damaged area 7.9 on the exit side of the hole, The empty injector 7,4 is positioned against the glass to level the assembly 7.3 while the suction cups 7,6 hold the assembly in position. The syringe is shown in position and the needle 7.10 Is inserted down into the cavity behind the plastic tab, FIG 8(a) and 8(b) are side views of FIG 7 to enlarged scales showing that a small plastic tab 8,2 is positioned over the entry hole to prevent the resin escaping from that hole. The empty injector 8.7 is positioned against the glass, while the levelling bolt 8,6 holds the glass disc 8.5 over the plastic tab 8,4 to hold it in place. The needle 8.3 is inserted between the glass 8.1 and the tab 8.4 to allow the resin to fill the cavity 8.9. The tab 8,4 returns back flush against the ".glass surface 8,1 when the needle is withdrawn.

0*'o :i.Soo 20 The invention can also be used to repair a plate glass window that has a large hole, and FIG'S 9 and 10 illustrate the method of doing so. A piece of glass that is to replace the damaged area 9.4 is placed against the area to be I repaired and a border 9.1 is marked around it on the window, The glass 9.4 is then cut along it just inside this marked line 9,2 with a glass cutter, Lines 9,3 .25 are also cut towards the corners to assist in the removal of the damaged glass.

In FIG 10 the broken glass has been removed and the new piece 10.1 positioned in place, Metal levelling bars 10.6 are held in position on the reverse side with crack openers 10.7 to ensure the glass is flush. The cavity 10.2 that has yet to be filled with resin is visible, Tape or tabs are placed behind the cavity to prevent the escape of the resin, Tabs 10,3 are placed over the front of the cavity, one at a time and the cavity Is filled with resin behind that tab by a syringe filled with resin. The needle 10,5 is inserted Into the cavity behind the tab and the resin squeezed Into the area, The resin runs down into the cavity and fills from the bottom thus forcing the air out, When the cavity behind that tab is filled, the next tab is positioned and the process is d repeated until the whole peripheral cavity is filled.

FIG 11 illustrates the method of providing a mail insert in a glass sheet or panel. The area to be cut is marked by line 11.3 and then cut out. Double sided tape 11,5 is placed on the reverse side of fascias 11.1 each of which has a cut out portion 11.4 which fascias are then placed in position on opposite sides of the glass 11.7 to cover the slot 11.3 formed in the glass 11.7.

Adhesive silicon 11.6 is placed on the glass edge forming the lower edge of the opening of the cavity between the two fascias 11.1 to secure the cover 11.2 which is placed through the opening to leave the cavity covered, FIG'S 12(a) and 12(b) shows the use of the metal levelling bar 12.2 held in position by crack openers 12,3, which are used in this example to support the levelling bar. The levelling bar is used to ensure that the glass 12.5 is flush on each side of the crack 12,1. The figure also shows that the bolt 12.4 holding the levelling bar in position, and tape may be positioned over the crack before placement of the levelling bar to prevent escape of resin, Where cracks may run parallel to and/or close to the edge of the glass, an edge crack opening is used as shown in FIG 13, This comprises bar 13.1 and two suction cups 13,2, one positioned cbntrally of the bar and the other at one end. A pressure bolt 13,3 Is threaded into the other end of the bolt.

20 It has been found that metal studs 13.4 can be inserted centrally In all the suction cups to assist in spreading the centre of the cups and thus secure the cups to prevent them from pulling out too easily. While these are shown in FIG 13 only, it is to be realised that all suction cups in all embodiments may have such studs, Preferably all of the cups are pressure sensitive so that if excess pressure Is applied, the cups will pull out and so prevent more damage to the glass, Also according to the invention it is possible to treat scratches in gloqs, The glass and scratch is cleaned and then the glass and scratch is sprayed or rubbed on as a cream with a resin, The resin is then rubbed off with a cloth and in doing so the scratch is not visible or easily seen. The resin has the effect of providing a shiny gloss finish to the surface of the crack by removing the grey abraded surface in the crack itself, Thus the crack is not readily visible to the eye, BULLET HOLES AND STAR BREAKS When a projectile such as a bullet hits the surface of the glass, it often creates a hole shaped a little like the side view of a "megaphone". The actual hole will consist of a small entry from the impact side, and a much larger surface area of glass knocked out and missing from the exit side.

Both sides of the glass to be repaired are cleaned with an evaporative glass cleaning fluid. A probe is then used to scratch out any visible dirt and loose glass still remaining within the damaged area.

Resin is placed around the outer small hole and a plastic tab is placed over that and cured. This will help to secure the area and prevent any resin leakage during the following repair.

On the opposite side, the primary injector bridge assembled with an empty resin injector and a nylon levelling bolt is placed in position just below the damage. The suction cups that form part of the assembly are based to secure it to the glass surface, A small glass disc is placed over the damage with a plastic film tab larger than the damaged area placed between them, to prevent the glass disc adhering to the repaired surface. The plastic tab is positioned about 1-2 cm above the 0:66 visible damage boundary while the glass disc is positioned slightly lower than S 20 the visible boundary of the damage leaving an uncovered lip at the top of the tab.

The plastic bolt is screwed toward the glass disc and holds it in position while the empty injector is screwed toward the main glass surface to level and stabilise the assembly.

A syringe is prepared by placing an appropriate amount of medium viscosity resin into the syringe and fitting the needle to the syringe. The needle is placed at the top of the tab and carefully Inserted down between the lip and the glass, and into the damaged chamber, The piston part of the syringe is then pushed, expelling the resin into the empty damaged chamber.

The resin filling the damaged area can be clearly seen, and the air is forced out around the needle where it is inserted. When the chamber is completely filled, the needle is withdrawn. When the needle is completely withdrawn, the resin is cured by way of holding a UV lamp over the area for tine long enough to start it curing.

The lamp may be held in position by way of affixing a c cup to the end of a short piece of string secured from each end of the ,isuction cups are pressed to the glass sun'ace and will hold the lar ,v i e syringe is cleaned and put away.

After about five minutes, the primary injector assembly is carefully removed, along with the glass disc but leaving the plastic film tab in place. The curing process is aided a little by removing any obstacles that may prevent the UV rays penetrating the repaired area.

Tools etc are cleaned up while the repair is curing The plastic film tab is then 15 peeled off. A razor blade is used to scrape and slice off any excess resin that may have worked its way beyond the damage boundary, leaving a filled and flat surface, **Soo In the event of an area having been unavoidably scraped with the razor blade, a polish is used to take out or reduce any dull appearance in the resin.

The tab that was originally placed on the outside of the glass is then removed and again, any excess resin is removed with the razor blade and finished off with polish if necessary.

In similar circumstances, when a projectile hits the surface of laminated glass, a star shaped crack is often formed. It consists of an impact point and fine cracks (or legs) running off in different directions.

The area is cleaned and any dirt and loose glass is scraped out. In most cases, it is necessary to drill a fine hole almost to the laminate layer at the centre of the impact point. A needle is inserted and tapped to create a tiny round shaped cavity at the base of the outer layer of glass which we call a "bullseye". The hole and bullseye allows a better penetration of resin.

The primary injector is prepared with an appropriate amount of thin viscosity resin and a rubber seal at the tip. The assembly is positioned on the glass and basing the suction cups, with the injector being positioned directly over the drilled hole. The plastic levelling bolt is screwed toward the glass till it touches. The injector is then screwed toward the glass till it touches. Then both are screwed further till an appropriate and even pressure is placed upon the damage.

The Pressure Bolt Is unscrewed to create a vacuum and draw out any air trapped within the damaged area. Then the Pressure Bolt is screwed into the injector to create enough pressure for the resin to penetrate the area and fill it, When it is filled, it is allowed to cure by way of the suns UV's or using the UV lamp. The Injector is then removed and a little resin is placed on the surface and covered with a tab and finally cured.

While the resin is curing, the tools are dismantled, cleaned and placed back in 15 the tool kit, By this time, the repair is cured. The tab is removed and any excess resin is scraped off with a razor blade. Any dull appearance left in the repair is polished out with a polish.

In some cases, the legs are too long to be treated in the above way, So a fine hole is drilled at tile "po'-it" (or tip) of each leg and a "bullseye" is tapped using a needle and tapper, The Primary Injector Assembly is prepared with a levelling bolt and injector fillcI with an appropriate quantity of thin viscosity resin, and firmly placed in position with the Injector over the "bullseye".

*oo* The injector and levelling bolt are both firmly based, and the "Pressure Bolt" is screwed down, the resin penetrates the crack and runs back toward the 25 impact point, The entire assembly can be "slid" along the crack if the resin does not quite reach the impact point. Pressure must be reduced when sliding so the crack is not closed. Lubricated suction cups make it easier to slide the injector along.

Sometimes a "crack opener" with well lubricated suction cups Is placed on the opposite side of the glass and slide along to help open up the crack a little to allow the resin to flow in easily.

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12 When the cracks are filled, they are then cured, A few minutes later, the pressure is removed and the Injector assembly is removed, Resin is placed along each crack and covered with tabs to seal the area. When all legs are filled and cured, then It is time to concentrate on the actual impact point. This procedure is the same as for the little "star break previously mentioned,

CRACKS

Cracks usually run either from the edge of the glass to a point, from an impact point to a point or edge, or a combination of all these, In any case, the procedure Is similar, It is an advantage to start the repair at the bottom anci work the resin up hill. It helps prevent air bubbles forming within the crack.

Plastic tape is placed along the entire distance of the opposite side of the crack. This prevents resin flowing out and being wasted. Metal levelling bars are placed along and across the crack and held in po"-tion with crack S.openers. The suction cups are pressed against the glass and the plastic bolt in the centre secures the metal bar, These bolts are screwed against the bar to pull the glass together and making It flush.

Starting at the base, a syringe filled with a low viscosity resin is placed over the opening of the crack, The piston is depressed forcing the resin into the crack. As the r6(sin fills and travels along the crack, the Injector or syringe is 20 slid along to keep up with the flow, Pressure is maintained on the piston to create a constant and even flow. The rubber seal at the tip of the syringe helps prevent resin wastage, Tabs are placed over the filled crack to ensure Its stability.

With the present invention it Is possible to repair a long crack from one end to the other without having to change resins to one of differing viscosity, or even remove the injector from the glass being repaired, It has been found that by the invention the resin will penetrate even the finest crack, and as the resin has the desired tensile strength, a strong repair is achieved without having to remove the injector during the repair to place a stronger resin In it and attempting to put it back on some time later,

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In most cases, a hole is drilled at the point and an injector assembly is positioned. The procedure for filling the tip is the same as that explained above for the legs of a very large star break, During progress along the crack, plastic tabs are placed over the filled crack to ensure that resin does not flow out of the crack, The resin within the crack cures as the repair progresses. After the entire crack is filled and tabbed, the tools are removed and cleaned. The plastic tabs are then removed and any excess resin is sliced off, When repairing laminated glass, there Is no need to place tape on the opposite sid? of the glass. However, the process for repair is very similar and a little slower, The crack is usually always tighter because it is held together with the laminate In between the two sheets of glass.

A resin filled "Secondary Injector" and levelling bolt are screwed into the injector bridge with a lubricated suction cup. This is placed on the glass and 15 with the suction cup based, the Injector Is placed over the crack and screwed in toward the crack. The levelling bolt is also based to the glass surface to help stabilise the assembly. The pressure bolt Is screwed In to force the resin to penetrate the crack, The assembly is slid along the crack as it fills.

When approaching the joint, a tiny hole is drilled at the point an a "bullseye" 20 Is tapped using the needle anC tapper. The "Primary Injector" Is prepared with very thin resin and placed at the point, The Injector and levelling bolt are Sbased firmly against the glass surface, The pressure bolt Is screwed in to force the resin to penetrate the crack and run back to meet the first placed resin, As before, tabs are placed over the repair and cured, When the crack is all filled, the injectors are removed and the UV lamp is placed in position where necessary. The tools are cleaned and the tabs removed after the resin is cured, The excess resin is scraped off and the glass cleaned, VERY LARGE HOLES In rare cases, a large projectile such as a large rock or brick is thrown right through the plate glass creating a large hole with legs.

_C A rectangular or square piece of glass slightly larger than the damaged area is measured and cut. This is placed on the glass over the damaged area and the boundary carefully marked onto the damaged glass surface. Plastic tape is then placed on the reverse side of the glass along the marked lines, A diamond coated cutting wheel is used to cut along each of the four marked lines, The damaged glass in the centre is removed and the piece of new glass is put into position. Levelling bars are placed across the back and secured with the abovementioned crack openers.

After sealing the back with plastic tape over and along the cavity around the insert, the front is checked to ensure it is flush, A fine "Bead" of thin resin is placed along just above and below the bottom horizontal cavity. The long tabs are placed over to cover the two beads of resin along the cavity. They over-lap a little to ensure a good seal, The resin is cured to ensure the tabs stay In place, A syringe is prepared with a medium viscosity resin e 15 The syringe Is positioned vertically facing down at the top of the tab. The tip of too, does the syringe needle Is inserted between the tab and the glass. The resin in the e0rs syringe is forced into and fills the cavity, The syringe and needle is withdrawn "and re-inserted in the same manner along the bottom till the entire length is filled, Any air bubbles trapped are sucked out by pulling on the syringe piston 20 to create a suction, The UV lamp is secured in place to cure the resin, A small tab is then placed vertically over the lower side cavity and again using :a thin "bead" of resin either side of the cavity and cured to secure It, The syringe needle is inserted into the cavity at the top of the tab and the resin begins to fill up, ihe side. As the resin runs down into the cavity and fills it, the air is forced up and out. Whln the resin reaches the top, the syringe is withdrawn.

A bead of r( sin Is vlaced either side of the cavity. Another small tab Is placed just above and square with the lower tab and secured in the same way as before, This Is cured before Inserting the syringe again, These steps are followed all the way up the side.

This procedure is the same for filling both sides and the procedure for filling the bottom Is the same as the top. When all the cavities arm filled and cured, the UV lamp Is removed, the tape and tools on the opposite side are removed, the tabs are removed, any excess resin sliced and scraped off. Finally, any patches of scraped resin can be polished to improve its clarity, LETTER BOX INSERTS TO GLASS With a paint pen two parallel horizontal lines are marked on the glass to be cut. The size is determined by the size of material being planned to pass through it, A diamond cutting wheel is used to cut along the two marked lines.

When cut right through, three vertical inserts are cut, one at each end and one in the centre, A gentle force is then applied from the other side to push the centre piece out.

Any rough areas are tidied up with the same cutting tool. A polished metal fascia with a "slot" cut out slightly smaller than the hole cut in the glass is prepared with an appropriate double sided tape, The fascia is placed in position on the glass and covers any rough or unsightly parts of the cut glass behind it, 15 An Identical metal fascia Is similarly prepared and placed c the opposite side goe of the glass exactly behind the first fascia, Silicon is then placed into the cavity between the two plates to completely conceal the glass between them.

A polished "right angled" piece of metal is inserted to cover the silicon in the bottom, leaving a neat and tidy finish, Thus It will be seen that the Invention provides a versatile kit which can be used in a variety of situations depending on the type of repair to be carried out. The bridge portion of the crack opener can be added as a cross piece on o the Injection assembly to provide greater support for the larger area to be repaired. Also these crack opener bridges are used to support the long levelling bridge for supporting and positioning the replacement piece of glass when a damaged portiun has been removed.

Also as the injection assembly can be slid along a crack or join between two pieces of glass, by the application of lubricant to the suction cups, the repair is not limited to a short crack to be repaired, by the invention is capable of repairing a crack of indefinite length, Thus it will be seen that according to the invention there is provided a method of repairing glass sheets which is effective and simple in its ooeration.

16 Whatever type of repair is being carried out, there is no necessity of changing resins during repairs. For each repair a selected resin is chosen, and this selected resin is used throughout that repair.

Although various forms of the invention have been described in some detail it is to be realised that the invention is not limited to the specific details described, but can include variations and modifications falling with the spirit and scope of the invention.

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Claims (4)

1. 2. A method of repairing a glass sheet as defined in claim 1 wherein the damage to the glass sheet is extensive, the said method including the steps of removing the damaged area, cutting and positioning a replacement piece of 15 glass by positioning support means on one side of the glass sheet to ensure S.that the replacement piece of glass is flush with the sheet of glass, said piece of glass being dimensioned to provide a gap between the piece of glass and the sheet of glass, positioning a first cover strip on one side of the glass to a. ::cover said gap, positioning a second cover strip on the other side of the glass 20 to cover said gap, injecting said single resin into the gap by a needle inserted under one of said sealing tape or tabs, removing the displaced air by means of the needle position, curing the resin, and removing the cover strips. i 3. A method of repairing a glass sheet as defined in claim 2 including the go steps of positioning at least two pairs of crack openers having suction cups to adhere to the glass sheet adjacent the gap, each said pair of crack openers supporting a levelling bar extending across the inserted piece of glass to ensure that the piece of glass is flush with the glass sheet, c:~ LCC_ 18
2. 4. A repair kit for repairing damage to a glass sheet when used in the method of repairing a glass sheet as defined In any one of the preceding claims, said repair kit including a resin injector comprising a pressure bolt through which a pressure bolt is screwed; a syringe; a crack opener bridge including suction cups and a levelling screw; and an injector assembly including a bridge, said injector and suction cups; whereby said crack opener assembly may be combined with the injector assembly/and or levelling bar to provide support for the repair of large areas.
3. 5. A method of repairing a glass sheet substantially as hereinbefore described with reference to the accompanying drawings. DATED this 22nd day of August 1996 PHILIP DAVID PAYNE By his Patent Attorneys COLLISON CO o 9 9* 9 .6 9 ABSTRACT A kit is described for repairing laminated glass and plate glass sheets. The invention also describes methods of repairing large and small holes in glass sheets. Large holes in plate glass can be repaired by removing the damaged area and inserting a replacement piece of glass to be joined by a resin having the same refractive index as the glass sheet. 9e
4. 9.B 9** 9oi 0o 90 9 9 9