AU4061202A - A stack of removable lenses - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S): Bart Wilson AND Seth Wilson AND Stephen S. Wilson ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

INVENTION TITLE: A stack of removable lenses The following statement is a full description of this invention, including the best method of performing it known to me/us:- BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention pertains to the following areas of technology: Apparel Guards and Protectors; for wearer's head FROM' :RI CHRRD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06: 18PM 1 and face; eye shields Such as goggles having a lens-cover plate; 2 and windshield covers.

3 2. Descrip tion of the Prior Art: 4 Face shields are employed in environments where contamination of the eyes may occur. It is well known in the art 6 that flexible transparent lenses affixed by numerous methods are 7 overlaid on the face shield for protection. The lease. are easily 8 removed and discarded when visibility is reduced from the 9 accumulation of dirt or other contaminants. In motor sports for instance, multiple layers of transparent lenses are overlaid on 11 the face shield, each being sequentially removed as they become 12 contaminated, because they reduce the visibility of the operator.

13 The drawback of the lenses in the prior art is that each 14 transparent lens applied over the face shield is itself a hindrance to good visibility due to its optical index of 16 refraction. Most comon materials used as plastics have optical 17 indexes of refraction ranging from 1.47 to 1.498. The Index 18 mismatch between the removable lens and air (air has an optical 19 index of 1.00) causes a reflection of 4% of the light that would normally come to the operator' a eyes. This reflection effect is 21 additive for each additional surface to air interface. Then for FROrt :RICHARD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06: 19PM PG 1 each removable lens having two surfaces, the reflections are 8%.

2 Thus a stack of seven lenses would reflect 42% of the light away 3 from the operator thereby reducing the brightness of the objects 4 viewed. A second optical phenomenon occurs simultaneously that also reduces visibility. The reflections are hi-directional and 6 thus make the lens stack appear as a semi-permeable mirror to the 7 operator. This mirror effect further reduces visibility, because 8 the light that passes through the lens stack reflects off of the 9 operator's face and then reflects off of the lens stack into the operator's eyes. The effect to the operator is that he sees his 11 own image on the inside of the stack nearly as brightly as the 12 objects viewed on the outside. This significantly reduces 13 visibility.

14 Another drawback to this stacking arrangement is that moisture exhaled by the operator's breath can cloud or fog-up the 16 lenses also reducing visibility. The air spaces between each lens 17 allows the moisture to enter this area.

18 19 SU1IOIRY OF THE INVENTION An object of the present invention is to provide a series of 21 easily removable optically clear lens stacks that do not cause FROrt RICHARD SLEHOFER FAX NO. 818-597-8294 May. 09 2002 06: 19PM P7 1 reflection to the operator's eyes. The prior art discloses 2 reflective lens stacks that do cause reflections to the 3 operator's eyes. An example of this type of prior art of 4 reflective lens stacks is disclosed in U.S. Patent No. 5,592,698 issued on Jan. 14, 1997 to Woods.

6 Refraction is the change in the direction in which waves 7 travel when they pass from one kind of matter into another. Waves 8 are refracted (bent) when they pass at an angle from one medium 9 into another in which the velocity of light is different. The amount that a ray of a certain wavelength bends in passing from 11 one medium to another is indicated by the index of refraction 12 between the two mediums for that wavelength. The index of 13 refraction indicates the amount that a light ray bends as it 14 passes out of one substance and into another. When light passes from air to a denser substance, such as Mylar film, it slows 16 down. If the light ray enters the Mylar film at any angle except 17 a right angle, the slowing down causes the light ray to bend at 18 the point of entry. This bending is called refraction. The ratio 19 of the speed of light in air to its speed in the Mylar film is the Mylar film's index of refraction.

21 The present invention includes a series of alternating FROMt :RICHARD SLEHOFER FAX NO. :819-597-8294 May. 09 2002 06:20PM P8 1 optically clear films whose indexes of refraction are matched to 2 within .2 and which will nearly eliminate all reflections to the 3 operator's eyes. The layers Of film are adhesively laminated to 4 one another and are compliant so there is no air between the layers. The film layers can be large and generally rectangular in 6 shape with a tab extending from each of the film layers. The tabs 7 can be staggered so that the user can remove the top most layer 8 and then the next succeeding layer. This embodiment of the 9 present invention can be applied to race car windshields, windows, visors or direct view displays such as ATM machines that 11 are subject to contaminating environments. Accordingly, the 12 present invention is an adhesively laminated multi-layered clear 13 film adapted to be used on a racer's face shield, or on the 14 windshield of a race car to keep the vieving area clean during the course of a race.

16 BRIEF DESCRIPTION OF fT DEM(INGS 17 FIG. 1 is a perspective view of an off-road wearer'helmet 18 showing one embodiment of the present invention affixed to the 19 face shield of the helmet.

FROM :RICHFRD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06:20PM P9 1 FIG. 2 is a front elevational view of the helmet shown in 2 FIG. I showing the tab portion without any adhesive for allowing 3 the wearer of the helmet to easily grasp the tab and peel-off the 4 soiled top layer of the present invention.

FIG. 3 is a partial sectional view taken along line 3--3 in 6 FIG. 2. This view shows the tension post extending outwardly from 7 the face shield with the left-side end tab portion of the present 8 invention.

9 FIG. 4 is a front elevational view illustrating the present invention before it is affixed to the face shield of the helmet.

11 FIG. 5. is a top view of the stackable lenses illustrating 12 seven layers of lens held together by an adhesive applied between 13 each lens with the thicknesses of the layers of each lens and 14 applied adhesive highly exaggerated to clearly show the relationship between the lenses and the adhesive and also to show 16 the end portions that do not have any adhesive between each lens 17 layer for forming the removable tab portions at both ends of the 18 present invention.

19 FIG. 6 illustrates a 60" wide roll of film, which will be FROM :RICHRD SLEHOFER FFX NO. :818-597-8294 May. 09 2002 06:21PM 1 used to cut out the optical stacks that are illustrated in FIG.

2 4. The gray stripes illustrate the clear adhesive, and the clear 3 stripes illustrate the clear film without adhesive. It is to be 4 understood that the gray stripes are for illustration purposes only, because the adhesive is clear.

6 FIG. 7 is an exploded perspective view illustrating seven 7 sheets of film layer and seven layers of clear adhesive 8 interposed between each sheet of film layer. This embodiment is 9 used for windshields, windows and the like.

FIG. 8 is a view of the laminated sheets illustrated in FIG.

11 7 having a rectangular shape with a series of six tabs for 12 removing each top layer of the lenses successively as the 13 uppermost exposed lens layer becomes soiled or otherwise 14 contaminated.

FROM :RICHARD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06:21PM P11 1 Detailed Description of the Invention 2 The present invention will now be discussed in detail. As 3 stated above, FIG. 4 is a front elevational view illustrating the 4 present invention 10 before it is affixed to the face shield of the helmet 50. The top view in FIG. 5 illustrates 7 layers of 6 lenses 15 adhesively affixed to each successive lens. The 7 adhesive layer is numbered 20. The material used to form the 8 lenses is preferably a clear polyester. The lens layers are 9 fabricated from sheets of plastic film sold under the registered trademark Mylar owned by the DuPont Company. The several 11 trademark registrations for the mark Mylar list several types of 12 products sold under that mark, and include polyester film. The 13 type of Mylar used in the present invention is made from the 14 clear polymer polyethylene terephalate, commonly referred to as PET, which is the most important polyester. PET is thermoplastic- 16 -that is, it softens and melts at high temperatures. Uses of PET 17 film include magnetic tapes and shrink wrap. The adhesive 20 used 18 to laminate the lenses together sequentially is a clear optical 19 low tack material. The thickness of each lens will range from mil to 7 mil (1 mil is The preferred thickness will be 2 21 mil. Even after the adhesive material is applied to a 2 mil 22 thickness lens, the thickness of the 2 mil thickness lenses will 23 still be 2 mil.

FROM :RICHARD SLEHOFER FX NO. :818-597-8294 May. 09 2002 06:21PM P12 1 The adhesive has nominal thickness. As illustrated in FIG. 2 after the seven layers of film and the six layers of adhesive are 3 laminated together, the overall thickness of the end product is 4 15 mils. The term "wetting" can be used to describe the relationship between the laminated film layers. When viewing 6 through the laminated layers, it appears to be one single piece 7 of plastic film. No reflections are evident. The end tab portions 8 without the adhesive exhibit reflections are not a hindrance to 9 the user, because these end portions are folded back over the posts as illustrated in FIG. 3, and do not affect the visibility 11 of the user.

12 The adhesive material 20 will be a water-based acrylic 13 optically clear adhesive or an oil based clear adhesive, with the 14 water based adhesive being the preferred embodiment. After the seven layers are laminated or otherwise bonded together with the 16 adhesive layers, the thickness of each adhesive layer is 17 negligible even though the adhesive layers are illustrated in 18 FIGS. 4 and 5 as distinct layers. FIG. 5. is a top view of the 19 stackable lenses illustrating seven layers of lens held together by an adhesive applied between each lens with the thicknesses of 21 the layers of lenses and applied adhesive highly exaggerated to 22 clearly show the relationship between the lenses and the adhesive FROM :RICHRRD SLEHOFER FAX NO. :618-597-8294 May. 09 2002 06:22PM P123 1 and also to show the end portions that do not have any adhesive 2 between each lens layer for forming the removable tab portions 3 at both ends of the present invention.

4 The individual stackable lenses package, illustrated in FIG.

6 5 for use with racing helmets, can be fabricated :from a roll of 7 film as illustrated in FIG. 6. The film in FIG. 6 includes seven 2 layers of clear polyester film, and having the water-based 9 acrylic adhesive laminating the seven film layers to one another.

Keep in mind that each layer of the lenses can be easily peeled 11 away as the top layer exposing the next clean lens. 'Each 12 succeeding lens layer can be removed as the top lens becomes 13 contaminated with dirt and grime during racing conditions.

14 Referring back now to FIG. 3. As previously stated, FIG. 3 illustrates the tension post 60 extending outwardly from the face 16 shield 55 with the left side end tab portion 25 of the Present 17 invention illustrated. The face shield 55 has a left tension post 18 60 and a right tension post 65. The present invention 10 has the 19 following dimensions: 18"1 in length; 2 1-0 in height; and abo6ut mails in thickness (1 mil is .0011"). The present invention is 21 symmetrical about it vertical medial axis and about its 22 horizontal nmdial axis. The left end has a removable tab portion FROM :RICHARD SLEHOFER FAX NO. :818-.597-8294 FR~r :RCHRD SEHOER FX M. :18-97-294May. 09 2002 06:22PM P14 1 2 3 4 6 7 8 9 11 12 13 14 16 17 18 19 21 22 23 25, and the right end has a removable tab portion 35. The left portion has a finger hole 39, and the right portion has a finger 29. The area 1o indicates where the adhesive 20 is applied to the layers of the lens 15. The bilateral demarcation lines 31 and 41 indicate where the adhesive stops on either side. The idemiarcation lines 31 and 41 also indicate where the tab portions begin. The present invention has a pair of bilateral keyhole-shaped slots 27 and 37 for demountablY engaging the two helmet posts 60 and SS respectively. The curved distance between the two helmet posts and 65 is the same as the distance between the centers of the pair of slots 27 and 37. The user secures the lenses to the face shield by positioning the slots adjacent the helmet posts and passing the posts through the slots. It is preferable that the remainder of the tab portion outboard from the slot be folded back upon itself so that the finger hole is also passed through the helmet post. This is illustrated in FIG. 3. The proper installation of the present invention on the helmet requires the user to position the bottom lens of the stack through the post hole by passing the post through the slot, then folding bacdk the remainder of the tab portion 25 so that the post passes through the finger hole 29. This is done for each lens working from the bottom up until the tab portion 25 of the top lens extends unfolded as illustrated in FIG. 2. In this manner, the helmet

L

FRO4 :RICHARD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06:23PM P 1 wearer can easily put his index finger through the finger hole 29 2 in the topmost lens layer and peel off to remove the topmost lens 3 layer. The clean layer below the removed layer is then exposed 4 and the removal tab portion on the exposed layer will spring back to the unfolded position to expose the finger hole so that the 6 helmet wearer can easily remove that layer after it becomes 7 soiled and contaminated. The plastic material forming the lenses 8 is resilient and will spring back to its unfolded position and 9 extend outwardly from the face shield. The thicknesses of the layered lenses and folded tab portions illustrated in FIG. 3 are 11 highly exaggerated to clearly show the folding relationship. In 12 actual practice seven lenses and seven tab portions with be 13 stacked into the space between the end of the post and the outer 14 surface of the face shield. Remember that there is no adhesive between the tab portions. This allows the removal tab portions to 16 fan out. They do not stick to one another.

17 The present invention as shown in the Drawing Figures has 18 removal tab portions at both ends. This allows a right or left- 19 handed person to easily remove the topmost layer. It also allows the driver to pull the tab with either hand depending on the 21 circumstances of the race. It is to be understood that the FROM :RICNARD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06:23PM P16 1 present invention includes a laminated lenses with only a left 2 tab portion 25, or only a right tab portion 35, or both a left 3 and a right tab portion.

4 The windshield embodiment 100 illustrated in FIGS. 7 and 8 will now be discussed in detail. An optical stack of removable 6 lenses for affixing to an optical window such as a racing car 7 windshield is disclosed in FIG. 8. The embodiment 100 has a 8 plurality of seven generally rectangular superposed removable 9 lenses 105 adhesively affixed to one another. The outer perimeter is continuous. Each of the removable lens 105 is held to each 11 successive lens with a clear uninterrupted adhesive layer 110 12 interposed between each of the removable lens. The perimeter has 13 at least one generally straight edge portion 115. In the 14 embodiment illustrated in FIG. 8, the perimeter is rectangular and has four straight edge portions, one for each side. It is to 16 be understood that the invention could be practiced with only one 17 generally straight edge portion. The area adjacent to the 18 straight edge portion 115 has a banded portion 120 that does not 19 have any adhesive affixed to any of the layers of film to assist in allowing each said film layer 105 to be peeled off 21 successively along the straight edge portion. A plurality of 22 staggered tabs 125 are affixed to the film layers one-at-a-tie.

FROM :RICHARD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06:24PM P17 1 The tabs 125 extend from the straight edge portions 120 to assist 2 the user in removing the uppermost soiled and. grimy film layer, 3 and to successively remove each next clean layer as the top 4 exposed layer becomes contaminated.

The adhesive layer can be foreshortened so as to expose 6 successively a portion of the lens layers without optical wetting 7 to create a grasping tab.

8 The stack of removable lenses as illustrated in FIGS. 7 and 9 8 can have an optically clear adhesive as the bottom last layer to aid in mounting the stack of lenses to the windshield. The 11 stack is affixed to the windshield in much the same way that 12 tinted window plastic film is affixed to a window. The windshield 13 is sprayed with water and the bottom adhesive layer with the 14 stack is then applied to the windshield. Air bubbles and the like are eliminated with a squeegee appliance. The bottom layer 16 becomes "wetted" to the windshield.

17 The stack of removable lenses 100 can be applied to any type 18 of optical window such as windshield, window, face shield, or a 19 video display. It is common at an ATM terminal to have a video display for the customer. The surface of the display can b:e lpt 14 FROM :RICHARD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06:24PM P18 1 clear by using the present invention.

2 While the present invention has been shown and described herein in what is conceived to be the best mode contemplated, it is recognized that departures may be made therefrom within the scope of the invention which is therefore not to be limited to the details disclosed herein, but is to be afforded the full scope of the invention.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise.", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the commongeneral knowledge in Australia.

Claims (6)

1. 2. The optical stack of removable lenses as recited in Claim 1 further comprising: a second removable tab portion opposite the end of said removal tab portion. FROM :RIC[jPRD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06:25PM
2. 3. The stack of removable lenses as recited in claim 1 further comprising: slots for mounting said optical stack of removable lenses to a face shield.
3. 4. The stack of removable lenses as recited in claim 1 further comprising: means for mounting said optical stack of removable lenses to a face shield. The optical stack of removable lenses as recited in claim 1 wherein: said removable lenses and said clear adhesive layers have an index of refraction between 1.40 and 1.52. FROM :RI.CARD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06:25PM P21 1 6. An optical stack of removable lenses for affixing to an 2 optical window comprising: 3 a plurality of generally rectangular superposed removable 4 lenses adhesively affixed to one another and forming a continuous perimeter; 6 each said removable lens being held to each successive lens 7 with a clear uninterrupted adhesive layer interposed between each 8 said removable lens; 9 said perimeter having a generally straight edge portion; the area adjacent said straight edge portion having a banded 11 portion that does not have any adhesive affixed to any of the 12 layers of film to assist in allowing each said film layer to be 13 peeled off successively along said straight edge portion; and 14 a plurality of staggered tabs affixed to each said film layer and extending from said straight edge portion to assist the 16 user in removing said uppermost soiled film layer, and 17 successively removing each said next clean layer as said top 18 exposed layer becomes contaminated. FROM :RICViARD SLEHOFER FAX NO. :818-597-8294 May. 09 2002 06:26PM P22 19
4. 7. The stack of removable lenses as recited in claim 6 21 wherein: 22 the adhesive layer is foreshortened as to expose a portion 23 of the lens layers without optical wetting, creating a grasping 24 tab. 26
5. 8. The stack of removable lenses as recited in claim 6 27 wherein; 28 an optically clear adhesive is the last layer to aid in 29 mounting to a face shield.
6. 9. The stack of removable lenses as recited in claim 6 31 wherein: 32 the optical window to which said stack of removable lenses 33 is mounted includes a windshield, window, face shield, or a video 34 display. The steps, features, compositions and compounds disclosed herein or referred to or indicated in the specification and/or claims of this application, individually or collectively, and any and all combinations of any two or more of said steps or features. DATED this TENTH day of MAY 2002 Bart Wilson AND Seth Wilson AND Stephen S. Wilson by DAVIES COLLISON CAVE Patent Attorneys for the applicant(s)