MXPA01001506A - Releasing of glazing panels - Google Patents

Abstract

Glazing panels such as vehicle windscreens (16) bonded to a supporting frame (7) are released by firstly arranging light energy delivery means adjacent the panel and subsequently transmitting light energy from the delivery means (2) through the panel (16) thereby to effect release of the panel from the frame. The light may be pulsed according to a predetermined regime and may be delivered by a discharge lamp having rapidly attenuating intensity, or quasi continuous wave pulsed laser. The mechanism of panel release may be by thermal degradation of the bonding material, cleavage of material at a surface of, or within the body of the panel, or a combination of such mechanisms.

Description

RELEASE OF GLASS PANELS FIELD OF THE INVENTION The present invention relates to the release of glazed panels from the support structures. The reference to glazed panels should be understood to mean panels, screens, or windows of glass, plastics or any other material substantially transparent to the wavelengths in the visible range of the spectrum.

BACKGROUND OF THE INVENTION Vehicle windshields typically comprise either hardened glazed panels or laminated panel structures (typically comprising an outer glass layer, an inner glass layer and an interleaved layer, interposed between the inner and outer glass layers) . The glazed panel can be colored depending on the preference to absorb specific wavelengths (particularly U.V.). For laminated windshields the interleaved layer is typically colored.

WO-A-9617737 discloses a method and apparatus for releasing attached transparent screens (typically vehicle windshields) from the supporting structures to which they are attached. The technique described uses directed laser energy to effect the release of a screen from a structure. The technique is useful in that the laser energy is directed from the laser head to the glazed panel / joint flange interface. However, there are problems in ensuring that the energy required for the release is supplied without overheating occurring in the body of the glazed panel, and also because the nature of high laser energy apparatuses there are inherent health and safety consequences. An improved technique has been designed.

BRIEF DESCRIPTION OF THE INVENTION According to a first aspect, the invention provides a method of releasing a glazed panel of a structure to which the panel is joined by the interposed bonding material, the method comprising: i) installing the medium of light energy supply adjacent to the glazed panel; and, ii) operating the light energy supply means for transmitting light energy from one side of the glazed panel to the other to effect the release of the glazed panel from the structure. According to a second aspect, the invention provides the apparatus for releasing a glazed panel of a structure to which the panel is attached by the interposed bonding material, the apparatus comprising means of supplying light energy capable of being installed adjacent to the glazing panel, and operable to transmit light energy from one side of the glazed panel to the other to effect the release of the panel from the structure. The light energy delivered is preferably of a wavelength substantially in the range of 300nm-1500nm (more preferably in the range of 400nm-700nm). The delivered light energy is desirably pulsed according to a predetermined rate, preferably in such a way that the duration of the pulse event (T activated) is less than the interval between pulses (T deactivated). Desirably, a simple impulse event of delivered light energy is of sufficient energy to effect the separation of the glazed panel from the structure together with a length of the joining material. The apparatus preferably includes a pulse generating network (which may include an array of capacitors and inductors) to cause the apparatus to produce a light impulse event. The apparatus preferably further comprises a firing network for initiating the operation of the pulse generator network. The control means is preferably provided to control one or more parameters of the apparatus, which preferably include the minimum allowable time that elapses between the subsequent light impulse event. Therefore, the control means is preferably linked to the firing network and / or to the pulse generating network. HE it provides beneficially a safety device to cut off the current in order to reduce the accidental start of a light impulse event. Preferred features of the activation feature of the safety device for cutting current are described herein and in the appended claims. It is preferred that the medium be provided to selectively adjust the intensity of the light supplied. This is important in view of the different degree to which various colored glazed panels absorb light energy in the contemplated wavelength range. It is preferred that the apparatus include different preset parameter settings which can be switched depending on the dye of the glazed panel to be disengaged. The light energy can be absorbed at the interface of the bonding material / panel either by the same bonding material, or by an absorption layer comprising the panel (such as the porous glass layer commonly found in the glazed panels of the vehicles) or by a suitable "" light absorbing coating provided at the interface. The light energy supply means can be tracked around the periphery of the glazed panel, preferably at a predetermined rate depending on the power of the light energy supply means and the pulse rate. The tracking means (preferably motorized tracking means) can be provided for this purpose. Alternatively, the light energy supply means may be hand-held and placed in the glaze manually by an operator. Therefore, the supply means can have a manual trigger to initiate a light pulse when the supply head is placed for the satisfaction of the operators. The apparatus preferably includes a safety device for cutting the current that requires at least two input devices to be operated before the light energy is supplied from the supply means. One of the input devices comprising the device for cutting the current may include the manual (main) trigger. The apparatus preferably includes a supply head (desirably carrying a light-emitting device) from which the light energy is supplied, the supply head advantageously including at least two input devices comprising the safety device "to cut the current, both input devices in the supply head require the drive in order to allow the light energy to be supplied from the supply means.The input devices comprising the safety device to cut the current preferably comprise input devices electrical (such as switching means) After driving, the input devices comprising the device for cutting the current are preferably reset to a non-driving state.

In one embodiment, the delivered light energy comprises a plurality of wavelengths, more preferably in the visible range of the spectrum. In one embodiment, it is preferred that the light energy be non-coherent. Preferably, the light energy is rapidly attenuated with the distance such that a few centimeters (preferably less than 10 cm, more preferably less than 5 cm) of the power supply means the density of the light energy significantly decreases from its power. maximum value (falling preferably to 50% of its maximum value or below). The pulse rate is controlled, preferably in such a way that a subsequent light pulse event is inhibited in the circumstances in which a preceding light pulse occurs within a predetermined period of time. This prevents the appliance from being operated very quickly (which can cause overheating of the glazed panel and / or gas discharge tubes). If the trigger (or other actuator) is held by the operator permanently operated, the control of the apparatus provides that a series of pulse events start at a predetermined time interval (typically greater than the minimum allowed time interval). The predetermined time interval is established by the control means and is dependent on the established discharge energy level. Typically the predetermined time interval for the "continuous" drive is substantially in the range of 0.5-5s (most preferably l-3s). The greater the set impulse discharge energy, the greater the minimum allowable interval and also the set level of the predetermined time interval for the "continuous" drive. Desirably, the pulse rate is controlled in such a way that a next light pulse event is inhibited if the time elapsing after a preceding light pulse event is greater than a predetermined time. This ensures that the device is not accidentally left in an operable condition after use for a series of impulse events. The device, for example, can be reverted to a "standby" mode.

The energy supplied is preferably in the range of 100 Joules 10,000 Joules per pulse (more - preferably in the range of 500-1500 Joules per pulse). The duration of the pulse (T activated) is preferably in the range of Iμs-lOOms, more preferably 1 ms-2 ms. In a preferred embodiment, the energy supply means comprises the electric gas discharge apparatus. Desirably, the operation of the gas discharge apparatus is controlled to limit the pulse rate and / or duration of the light pulse. The operation of the gas discharge apparatus is preferably controlled by: i) charging an array of capacitors; ii) initiate a trip pulse to discharge the array of capacitors; and, iii) downloading the array of capacitors through an inductor to the gas discharge apparatus. According to the above, for this preferred embodiment, the apparatus according to the invention includes energy supply means comprising the electrical gas discharge apparatus. The electric gas discharge apparatus is controlled to limit the pulse rate of the supplied light. The apparatus preferably includes a pulse generating network having an arrangement of capacitors and inductors in which the capacitor is discharged through the inductor to cause the electric gas discharge apparatus to produce a light pulse. The apparatus preferably further comprises a trigger network for initiating the discharge of the capacitor from the pulse generating network. The control means is preferably provided to control one or more parameters of the apparatus that include the minimum allowable time that elapses between the subsequent discharge pulses of the electrical gas discharge device. The electrical gas discharge apparatus preferably comprises an electric gas discharge tube. - The electric gas discharge apparatus desirably comprises a reflector (preferably a parabolic reflector) installed to direct the emitted light in a predetermined direction. The reflector preferably includes a reflective coating of a thermostable material, which preferably comprises a silver material. The apparatus preferably includes a window through which the emitted light is directed to pass through the glazed panel. The window can be omitted from the apparatus, and it has been found that omitting the window is beneficially useful for cooling the light emitting devices (discharge tubes). Desirably, the apparatus includes a longitudinal guide arrangement (preferably "quick release" releasably) to be located against a peripheral edge of the glazed panel. The longitudinal guide helps the operator to manually position the appliance correctly with respect to the joint flange that secures the glazed panel. The apparatus may comprise focusing means installed to focus the light energy at a predetermined location. In one embodiment, the tracking and pulsing orientation of the light energy supply means may be coordinated in such a manner that subsequent light pulses spatially overlap the relevant portion of the glazed panel. The operation performed in this way ensures a good separation of the panel from the structure at the interface of the bonding material / inner layer of the panel. It has been found that for glazed panels (particularly those that include a colored interleaved layer), the operation of the light energy supply means in pulsed mode provides benefits, because the absorption of energy in the body of the glass is minimized. screen or panel (particularly in the interleaved layer of laminated glazed panels). In a preferred embodiment the apparatus comprises: (i) a light energy supply head including an electrically operable light emitting element; (ii) a remote base unit of the supply head, the base unit including the electric power supply for the light emitting element of the supply head; Y, (iii) flexible electrical cable extending from the base unit and the supply head that allows the connection of the supply head to the base unit. The invention will now be described in specific embodiments by way of example only and with reference to the accompanying drawings in which: BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a diagrammatic representation showing the operation of light pulses of the light energy and the effect on the temperature of the porous glass and the glazed panel; Figure 2 is a representation similar to that shown in Figure 1 showing the continuous wave laser radiation of the prior art and the effect on the temperature of the porous glass and the glazed panel; Figure 3 is a schematic representation of a first embodiment of the light energy supply means according to the invention; Figure 4 is a perspective view of a preferred embodiment of the apparatus according to the invention; Figure 5 is a perspective view of the light energy supply head of the apparatus of Figure 4; Figure 6 is a perspective assembly view of the head of Figure 5; Figure 7 is a diagram of the system of an apparatus including the light energy supply means of the previous figures; Figure 8 is a block diagram of the pulse generating network of the system shown in Figure 7; Figure 9 is a block diagram of the firing network of the system shown in Figure 7.

DETAILED DESCRIPTION OF THE INVENTION In the application shown, the apparatus 1 is used to release a vehicle glazing panel (windshield 16) from a support structure 7 to which it is joined by a dark colored polyurethane union flange 8, interleaved , which extends around the entire periphery of the panel 16 in contact with the structure 7. The windshield panel 16 comprises an outer glass layer 9, an inner glass layer 10 and intermediate therebetween, an interleaved layer 11 comprising a colored laminated material which is transparent at some wavelengths of visible light but opaque to other radiations and also to ultra violet (UV) radiation. The purpose of the interleaved layer 11 is to provide structural strength to the windshield 16 such that in case of impact, the screen remains intact, and also provides a U.V. Immediately adjacent to the joining flange 8, the periphery of the inner layer 10 of the windshield panel 16 is provided with a bonded porous glass layer 12 which is typically dark in color (more typically in black). The purpose of the porous glass layer is to inhibit the passage of ultraviolet radiation through the screen to collide on the polyurethane bonding flange 8 which is typically degradable after exposure to UV radiation. Although described in the specific embodiments in relation to a laminated windshield, the invention is equally suitable for use in relation to other glazed panels joined in a similar manner such as the "hardened" glazed pendants of vehicles, et c. Figures 1 and 2 compare pulses of light according to the pulse rate of the present invention (which will be described in detail hereinafter), with the continuous wave laser operation known from the prior art system described in WO -A-9617737, and the associated effect on the temperature of the porous glass layer 12 in relation to the integrity threshold of the glazed panel (particularly the exfoliation in the interleaved layer 11 of the panel for a laminated windshield panel). The use of continuous wave laser radiation results in excess heat formation within the panel body 16, (particularly in the interleaved layer 11 for the laminated screens). This has the effect that increased power is required as would be the case where significant heat formation does not occur within the panel 16 body., it has been found that the formation of heat within the body of the panel 16 results in the fracture of the glass in the body of the glazed panel (or in the interleaved layer 11 for the laminated screens). This increases the absorption of energy within the body of the panel 16 which leads to a "chain event" in which increasingly increasing amounts of energy supplied are absorbed within the body of the panel 16. This results in less energy reaching the porous glass layer interface 12 / joining flange 8, consequently reducing the effectiveness of the separation. This over-absorption within the body of the glazed panel can also occur for non-laminated windshields such as glazed "hardened glass" windshield panels (particularly where they are clogged). An additional problem with a laser system as described in the prior art is that the use of powerful laser devices in widely unsupervised situations presents serious health and safety consequences. In addition, laser systems and apparatus tend to be relatively expensive. The use of the light pulse operation allows a burst of energy to be supplied to the interface between the porous glass layer 12 / bonding flange 8 in a sufficiently short time to ensure that sufficient energy is absorbed for the release at the interface of the bonding flange. 8 / Porous glass layer 12 without damaging heat formation in the body of the glazed panel 16. Sufficient energy can be supplied for the localized release of the glazed panel in a simple burst of pulses; alternatively repeated successive bursts / bursts may be preferable, particularly with more dark colored glazed panels. Where successive bursts / bursts are used, sufficient time is provided between bursts of energy pulses (T off) to allow the absorbed heat to dissipate within the body of the glazed panel (including in interleaved layer 11). The use of unaligned light facilitates the rapid attenuation of energy with distance from the apparatus and makes the apparatus more suitable from the point of view of health and safety. Referring to Figure 3, the apparatus generally designated 1 comprises a supply head 4 which includes a high pressure inert / noble gas such as xenon or krypton. The discharge tube operates to produce a burst of light output from a range of wavelengths in the visible spectrum (approximately in the range of 400nm to 700nm). The energy supplied, by impulse, is typically in the range of 500-1500 Joules, however the energy dissipates (attenuates) quickly with the distance from the tube.

(This is an important operational aspect, as will be described immediately below). A housing / frame 3 encircles the discharge tube and includes the protection gables 5, 6 and a transmissible sale of expandable visible light. A parabolic reflector wall 8 opposite the window 7 is placed to reflect the light coming from the inverse side of the discharge tube 2 to pass through the window 7. The reflecting wall 8 is provided with a reflecting thermometry reflecting coating typically of a material which includes a silver material. When used, the optical supply head is placed as shown in Figure 3 and a trigger is operated with the ability to be manually operated to produce a simple light pulse which passes through the screen 6 and is absorbed into the layer of porous glass 12 and / or the joining flange 8. The porous glass 12 or bonding flange is rapidly heated and separated from the screen typically by either ablation of the glass, temperature carbonization of the flange 8, or other thermal mechanisms . Typically a single shot / pulse is sufficient to effect the release during a stretch of the screen that approaches the length of the discharge tube 2 (typically 5-15 cm) although multiple shots may be used (e.g. at low power to minimize the damage of porous glass, or where the screen is dark in color). In a typical system, an energy trace of 5cm * 2cm is projected onto the glazed panel. The operator then moves to an adjacent portion of the periphery of the screen before instigating an additional light pulse. The procedure is repeated around the entire periphery of the panel to effect complete release. In the preferred installation (as shown in Figures 4 to 6) the supply head 4 is connected to a base unit 40 by an electric cable 41. The base unit 40 includes the power supply and the control system 29 for the operation of the apparatus, which includes the firing network 30, the pulse generating network 31, the capacitor bank 32, the inductor 34 and the capacitor charge power supply 33. The power supply and control system is described in detail below with reference to Figures 7 to 9. The electric cable 41 includes the electrical wiring for supplying electric power to the components of the lighting head 4, which includes the flash lamp discharge tubes 2a, 2b and the cooling fans 45, 46. As shown in Figure 6, the head includes a pair of flash lamps (electric gas discharge tubes) 2a, 2b installed in parallel (but electrically connected to each other). n series) extending between the end connectors 47, 48 and passing through the openings 47, 48 in the housing 3. The condition of the flash lamps 2a, 2b in parallel ensures that the required light energy is deliverable to effect the release of the glazed panel and also improves the thermal / electrical efficiency. Typically a system that uses tubes in parallel array (electrically connected in series) can provide between 20,000 to 1 million pulse events (depending on panel dye); a single tube would allow only approximately 200-500 impulse events before failing. The electrical connection in series improves the optimal use of the capacitor because the load passes serially sequentially through the tubes connected in series. The inner walls of the housing 3 are coated in a reflective thermoreresin stent material (typically including a silver material) and define a curved reflecting surface installed to reflect the light coming from the flash lamps 2a, 2b down through the end open 48 of the housing 3. The housing 3 is received in a liner 49 projecting from a portion of the lower housing 50. The lower extent of the protruding lining 49 is fitted with a quartz window 54 secured by an open support plate 55. The window 54 allows the illumination light generated by the flash lamps 2a, 2b pass of the housing 3. The lower part of the support plate 55 is fitted with a removable "quick-fit" opening plate 56 which includes a projecting longitudinal peripheral flange 57. The flange 57 serves as a longitudinal guide, which it is located against the peripheral edge of the glazed panel and that it helps to place the head in the correct position with respect to the connecting flange 8. The upper portion of the housing 3 is secured to a casting 51 which at the opposite ends sit cooling fans 45, 46 in the respective angled conduits 52, 53 to direct the cooling air in order to cool the tubes of the flash lamp 2a, 2b. The cooling of the tubes of the flash lamp is important in order to maximize the life of the tube. Typically the flash lamp tubes (for other applications) are cooled with water. Water cooling would be impractical for the apparatus of the present invention because the lighting head needs to be relatively light in weight and maneuverable for operator handling. Electric cable 41 would be too complicated if it were necessary to bring cooling water to the head and the head would be unmanageable if a water cooling jacket filled with cooling water were incorporated in the head design. In addition, it is likely that the cooling water present in the head absorbs a portion of the useful light energy emitted by the tubes of the flash lamp 2a, 2b. It is considered important the installation of cooling fans, parallel lamp tubes, and reflector, innovative and inventive aspects of the design both individually and jointly. A casting 58 is secured to the casting 53, extending upward therefrom. The casting 58 includes a hollow flange 59 to which the flexible cable 41 is secured and includes an upper saddle edge 60. A molded shell cover 61 is pivotably secured to one end (pivot assembly 62) to the casting which extends upwards 58. The cover 61 includes the spaced vents 68, 69 which allow the fans 45, 46 to draw air into the interior of the apparatus. When manual pressure is applied downwardly to the cover 61, a slight pivotal "closing" movement of the lid occurs relative to the casting 58 (against a tilt spring - not shown) resulting in a clutch of a formation interior provided in the cover 61 with a limit switch 63 carried by the casting 58. As a result, the limit switch is closed. The control system 29 is configured to inhibit activation of the flash lamp unless the limit switch 63 is closed. In this manner, the limit switch arrangement 63 and the pivot cover 61 act as a control device. safety to cut off the current that prevents activation of the flash lamp unless the predetermined conditions are satisfied (in this case unless sufficient pressure is applied to the cover 61). Even with the device for cutting off the bypassed current, an external switch 66 on the cover 61 must be operated before the control system 29 initiates the activation sequence of the flash lamp. Therefore, the arrangement of the device for cutting the current requires at least two input signals to be passed to the control system 29 before a flash lamp pulse can be triggered. Other devices designed to cut off the current could, for example, comprise a pressure or other sensor installed in the head to detect contact with the glazed panel, and / or a second confirmatory switch capable of being manually operated 67 provided in the frame (Both switches need to be operated to start the activation sequence of the flash lamp). It has been found that significantly improved results are achieved where the supplied light is in the visible range of the spectrum, and the light is pulsed according to a regime in which a series of discrete pulses of light is transmitted, the pulse duration (T activated) being substantially in the range of lμs up to 100 ms (more preferably in the range lms- 2ms) and the pulse repetition frequency being substantially in the range of 0.1 Hz-10 Hz (more preferably in the range of 0.3 Hz-1 Hz). It has been found that the use of the pulse rate described herein and the lower wavelengths of light (in the visible spectrum) provide significantly improved results in which a greater proportion of energy delivered at the interface of the optical layer is concentrated. porous glass 12 / bonding flange 8, and excess heat formation (and associated glass fracture) in the interleaved layer 11 is prevented or at least improved. The supply head 4 is used to supply light energy of a side to side of the glazed panel in order to concentrate the energy in the porous glass layer 12. The separation of the panel 6 from the structure 7 is effected as a result of the absorption of energy at the interface of the porous glass layer 12 / flange of bonding 8 resulting in rapid heating and either the crack or degradation of the porous glass material 12 comprising the panel 6, or the degradation of the material comprising the joint flange 8 (or the degradation of a primer coating applied to the glazed panel prior to installation in contact with the joint flange). The release mechanism may comprise a combination of the described mechanisms. Referring to Figure 7, the tubes 2a, 2b are controlled to produce high intensity pulses for a predetermined pulse rate by means of the control unit 29 operating for the appropriate programmed instructions in conjunction with the manual trigger. The control unit 29 controls the operation of a trigger network 30 for driving a pulse generating network 31 in order to supply current to the tops 2a, 2b (in accordance with the arrangement of the above-mentioned "device for cutting off the current"). ) to produce a light pulse that has the desired characteristics. An additional feature of the apparatus is that a so-called "slow supply circuit" is used to supply a substantially continuous leakage / trickle current to the flash lamps 2a or 2b when the apparatus is on or in "standby" mode. " This prevents capacitor overload and prolongs the life of the flash lamp. The "slow supply circuits" are known from the gas discharge apparatus in general. A unique feature of the present installation is that the slow charge / leakage current is used as a safety feature because the current drained by the lamps 2a, 2b is continuously monitored (by the control unit 29), the supply being cut off current to lamps 2a, 2b if the current is not drained (due to failure or breakage of the lamp). Referring to Figure 8, the pulse generating network 31 includes a bank of capacitors 32 charged at a preset voltage by an energy supply 33. The capacitor bank 32 remains charged until a trigger pulse of the trigger network initiates the discharge into the discharge tube 2, when the charge stored in the capacitor bank 32 is discharged through the inductor 34 and a secondary trigger transformer 35, to the tube 2. The discharge time constant (and therefore the duration and "profile" of the light pulse) is determined by the values of the inductor 34 and the capacitor bank 32. For an operating system, a pulse duration of lms-2ms has been found suitable. For present purposes, the pulse duration must be understood to be in the time interval between the power of light that reaches half of its maximum value and that subsequently falls to half its maximum value. The required pulse duration varies depending on the optical properties of the glazed panel to be released. For example, different glaze dyes require the supply of different energy levels to effect the release, and therefore, different power levels. The capacitor bank 32 and the inductor 34 can therefore be reset to the appropriate values depending on the glazed panel to be released in order to modify the "profile" and the power of the sent pulse. The controls capable of being selected manually or automatically in the base unit 40 allow to modify the energy output and / or pulse duration of the flash tubes 2a, 2b according to the dye of the glazed object panel. The apparatus can be provided with pre-set settings with the ability to be selected by the operator (or automatically) appropriate for common glaze dyes or other known variables. To adjust the optical power of the apparatus, the load power supply of the capacitor can be varied. The pulse repetition frequency (corresponding to the length of the interval between pulses (T deactivated)) is important to ensure that the period between successive pulses is sufficient to allow the absorbed heat in the thickness of the screen to dissipate before it is supplied. more energy. In addition, the overheating of the lamp tubes 2a, 2b is improved by this means and increases the life of the lamp. The control unit 29 is activated to control the manual trigger in order to inhibit the firing network 30 from initiating the discharge until the required period of time has elapsed. The minimum interval between the typically controlled trip is in the range of 0.3Hz-1Hz. A maximum interval between triggering is also established by the control system, typically in the range of 10-20 seconds or greater. If the operator does not fire the lamp tubes until after the previous shot has passed from the maximum interval, the control system automatically discharges the array of capacitors to ground and switches the power supply to a standby mode; therefore, the power supply to the base unit 40 must be set to an "active" mode before the apparatus is operated. The time out feature of maximum time delay ensures that the apparatus can not be left in an operational mode accidentally after use. This is an important security feature when using this mode. The energy delivered by light pulse is selected according to the dye or other qualities of the glazed panel but typically varies between 500-1500 Joules per pulse. Since no non-laser light is used, the energy is rapidly attenuated with the distance from the optical head 4 and is therefore sufficient to effect the disengagement of the glazed panel but is less susceptible to misuse of the non-operating operator. authorized or accidental. This is an important security feature when using this mode. In one embodiment, the supply head 4 can be carried by a motorized tracking system (not shown) installed to track the head 4 around the entire periphery of the glazed panel 6 to effect the complete release of the panel 6 from the structure 7. operation of the tracking system 4 and the supply of light energy by the head 4 are coordinated (by the control means not shown) in such a way that the tracking speed around the structure is maintained at a predetermined rate. For optimal performance it is preferred that the subsequent pulses of light are spatially superimposed.

Claims (44)

1. CLAIMS Having described the invention as an antecedent, the content of the following claims is claimed as property: 1. A method of releasing a glazed panel from a structure to which the panel is joined by interleaved joining material, characterized in that the method It comprises: i) installing the Light energy supply means adjacent to the glazed panel; and, ii) operating the light energy supply means for transmitting light energy from one side of the glazed panel to the other to effect the release of the glazed panel from the structure.
2. 2. A method according to the claim 1, characterized in that the light energy delivered is of a wavelength substantially in the range of 30 Onm-150 Onm.
3. 3. A method according to claim 2, characterized in that the delivered light energy is of a wavelength substantially in the range of 400nm-700nm.
4. 4. A method according to any of the preceding claims, characterized in that the delivered light energy comprises a plurality of wavelengths.
5. A method according to any of the preceding claims, characterized in that the light energy is significantly attenuated with the distance such that a few centimeters away from the energy supply means the energy density significantly decreases from its maximum value.
6. 6. A method according to claim 5, characterized in that at a distance substantially in the range of 5 cm or less from the supply means the light energy density is 50% of the maximum value, or less.
7. 7. A method according to any of the preceding claims, characterized in that the light energy is non-coherent.
8. A method according to any of the preceding claims, characterized in that the supplied light energy is pulsed according to a predetermined rate.
9. 9. A method according to the claim 8, characterized in that the pulse duration (T activated) of a light pulse event is substantially in the range of lμs-lOOms.
10. 10. A method according to the claim 9, characterized in that the pulse duration of a light pulse event is substantially in the range of Ims - 2ms.
11. A method according to any one of the preceding claims, characterized in that the pulse rate is controlled to inhibit a next light pulse event in the time that elapses after a previous light pulse event is less than a predetermined time.
12. A method according to any one of the preceding claims, characterized in that the pulse rate is controlled to inhibit a subsequent light pulse event if the time that elapses after a previous light pulse event is greater than a predetermined time.
13. A method according to any one of the preceding claims, characterized in that the pulse duration (T activated) is less than the minimum permissible pulse interval (T deactivated).
14. A method according to any of claims 8 to 13, characterized in that a single light energy pulse supplied is of sufficient energy to effect separation of the screen from the structure along a length of the joining material.
15. A method according to any of the preceding claims, characterized in that the light energy supply means is hand held and capable of being placed in relation to the glaze manually by an operator.
16. 16. A method according to any of the preceding claims, characterized in that the energy supply means comprises an electrical gas discharge device.
17. 17. A method according to claim 16, characterized in that the operation of the electrical apparatus is controlled to limit the pulse rate and / or duration of the light pulse.
18. 18. A method according to claim 17, characterized in that the gas discharge apparatus is controlled by: i) charging an array of capacitors; ii) initiate a trip pulse to discharge the array of capacitors; and, iii) downloading the array of capacitors through an inductor to the gas discharge apparatus.
19. 19. A method according to the claim 17 or claim 18, characterized in that the gas discharge light emitting device is supplied with a slow charge / leakage current at different times during a pulse event.
20. 20. A method according to the claim 19, characterized in that the slow charge leakage current is monitored to provide an indication of the operability of the gas discharge light emitting device.
21. 21. The apparatus for releasing a glazed panel from a structure to which the panel is attached by sandwiching material, the apparatus comprising means of supplying light energy which are installed adjacent to the glazing panel, and operable to transmit light energy from one side to the other of the glazed panel to effect the release of the panel from the structure.
22. 22. The apparatus according to the claim 21, characterized in that it is controllable to supply the light energy in the form of a light pulse.
23. 23. The apparatus according to claim 21, characterized in that the apparatus includes control means for adjusting and / or limiting: the repetition rate of pulses of events of successive pulses of light; and / or, the duration of a light impulse event; and / or, the intensity of the light supplied.
24. 24. The apparatus that includes the control means for controlling one or more parameters of the apparatus characterized in that it includes the minimum allowable time that elapses between the subsequent discharge pulses of the electric gas discharge device.
25. 25. The apparatus according to any of the preceding claims 21 to 24, characterized in that the supply means includes a manual trigger to initiate a light pulse when the supply head is positioned for the satisfaction of the operators.
26. 26. The apparatus according to any of claims 21 to 25, characterized in that the apparatus includes a safety device for cutting the current that requires at least two input devices to be operated before the light energy is supplied from the supply means. .
27. The apparatus according to claim 26, characterized in that it includes a supply head from which the light energy is supplied, the supply head including at least two input devices comprising the safety device to cut off the current, requiring separate devices the input drive in order to allow the light energy to be supplied from the supply means.
28. The apparatus according to claim 26 or 27, characterized in that the input devices comprise electrical input devices (such as switching means).
29. 29. The apparatus according to any of claims 26 to 28, characterized in that after the drive the input devices comprising the device for cutting the current are restored to a non-driving state.
30. 30. The apparatus according to any of claims 21 to 29, characterized in that the means for selectively adjusting the intensity of the light supplied is provided.
31. 31. The apparatus according to any of claims 21 to 30, characterized in that the apparatus includes different preset settings which can be switched to alter one or more parameters of the delivered light energy, dependent on the dye of the glazed panel to be disconnected or other factors .
32. 32. The apparatus according to claim 31, characterized in that it includes adjustable parameters of light energy: intensity of light; and / or, pulse duration; and / or, impulse interval.
33. 33. The apparatus according to any of claims 21 to 32, characterized in that the light energy supply means comprises the electrical gas discharge device.
34. 34. The apparatus according to the claim 33, characterized in that the electric gas discharge device includes a light emitting discharge tube.
35. 35. The apparatus according to the claim 34, characterized in that the electric gas discharge apparatus includes a pair of light emitting discharge tubes installed in a side-by-side relationship.
36. 36. The apparatus according to any of claims 21 to 35, characterized in that it further comprises cooling means for cooling a light emitting element of the light energy supply means.
37. 37. The apparatus according to claim 36, characterized in that the cooling means comprises air cooling means such as an electrically operated fan.
38. 38. The apparatus according to any of the preceding indications 33 to 37, characterized in that it includes a pulse generating network having an array of capacitors and inductors in which the capacitor is discharged through the inductor to cause the electric discharge apparatus of gas produces a light impulse.
39. 39. The apparatus according to claim 38, characterized in that it includes a trigger network for initiating the discharge of the capacitor from the pulse generating network.
40. 40. The apparatus according to any of claims 21 to 39, characterized in that the apparatus includes a reflector installed to direct the emitted light in a predetermined direction.
41. 41. The apparatus according to any of claims 21 to 40, characterized in that the apparatus comprises a window through which the emitted light is directed to pass through the glazed panel.
42. 42. The apparatus according to any of claims 21 to 41, characterized in that the apparatus comprises a longitudinal guide installed to be located against a peripheral edge of the glazed panel.
43. 43. The apparatus according to any of claims 21 to 42, characterized in that the apparatus comprises: (i) a light energy supply head including an electrically operable light emitting element; (ii) a remote base unit from the supply head, the base unit including the electric power supply for the light emitting element of the supply head; Y, (iii) a flexible electrical cable that extends from the base unit and the supply head that allows the connection of the supply head to the base unit
44. 44. The apparatus according to claim 44, characterized in that the light emitting element of the supply head comprises an electrical gas discharge light emitting device, the base unit including an electrical power arrangement having a capacitor to be discharged through the device electric discharge of light emitter in the head by means of the electric cable.