Tear-off lens system and method for goggles

This invention provides a stack of tear-off lenses for rapid and easy mounting over a main goggle lens. The invention overcomes the previously discussed disadvantages of excessive mounting time and effort. A method of manufacturing the stack is also provided. In addition, a goggle incorporating the stack of tear-off lenses, as well as a kit for adapting a goggle for tear-off lenses, including the tear-off lens stack and a retaining post member, are disclosed.

FIELD OF THE INVENTION 
The present invention relates to protective eyewear and, more particularly, 
to transparencies for goggles which may be readily removed from the lenses 
thereof. 
BACKGROUND OF THE INVENTION 
Motorcyclists who use their bikes in off-road activities often find that 
dirt and debris accumulate on the lens surface of the goggle. This 
substantially reduces visibility and makes safe operation difficult. 
Accumulation of debris on the lens surface is a particular problem in 
activities such as motocrosses and hill climbs. The decreased visibility 
due to debris, together with the high speed of these events, can produce 
dangerous operating conditions. 
One known solution to this problem, as disclosed in U.S. Pat. No. 
4,428,081, is provided by a goggle in which a webbing of transparent 
material is fed over the goggle lens by means of rollers mounted at the 
opposite side edges of the goggle frame. When the segment of transparent 
webbing overlying the lens becomes dirty, the wearer pulls a cord to cause 
a fresh segment of the transparent webbing to be pulled across the lens. 
This solution requires an auxiliary mechanical feed mechanism, resulting 
in additional weight and complexity. 
One solution that avoids the need for additional mechanic systems, as 
disclosed in U.S. Pat. No. 3,945,044, is tear-off transparent lenses. 
These tear-off lenses comprise individual, thin pieces of transparent 
plastic material that have the general shape of the goggle lens and which 
have tabs around their peripheral edges. A plurality of the transparent 
lenses may be overlaid on the goggle lens by inserting tabs between the 
lens and the flexible lens frame. When vision is obscured due to 
accumulation of debris, the wearer can reach up with one hand and tear 
away the outer tear-off lens. The dirty transparency is discarded and the 
wearer has a clear view through the lens and remaining unsoiled 
transparencies. 
One principal drawback of the foregoing arrangement is that the 
transparencies are attached to the lens only by the tabs. In addition, the 
lenses must be individually mounted. 
U.S. Pat. No. 4,455,689 discloses another type of removable transparency. 
In this patent, a specially configured bracket is inserted through the 
strap slot on one side of the goggle frame. A plurality of transparencies 
are then individually installed over the lens. Peripheral tabs on the 
lens-shaped portion of each transparency are inserted between the lens and 
the goggle frame. A retaining pin extending from the bracket is forced 
through a small hole formed in the inner region of an elongated member 
which extends from one end of the transparency. The elongated member of 
the transparency is folded back on itself so that the retaining pin 
extends through a large opening in the outer end of the elongated member. 
Successive transparencies are similarly mounted. The elongated member of 
the outermost transparency is not folded but is left free to be grasped 
with one hand so that the soiled transparency can be torn away from the 
goggle frame. The elongated member of the outermost transparency that has 
just been exposed will then automatically extend. 
One disadvantage with this type of configuration is that the transparencies 
must be individually mounted over the lens. The considerable time and 
effort required to individually position and mount the transparencies can 
pose a significant drawback if the transparencies have to be mounted just 
prior to, or during, a race. In addition, individual transparencies are 
prone to damage due to scratching, for example, and can easily become 
soiled. 
Another type of goggle having a tear off lens, identified as being marketed 
under the trademark Oakley, is discussed at Column 1, lines 63 et seq. of 
U.S. Pat. No. 4,455,689. In this goggle, an attachment element with a 
small round head projects outwardly from the goggle lens adjacent to one 
side thereof. A plurality of transparencies, each of which has an 
elongated member which extends beyond the left side edge thereof when 
viewed from the wearer's perspective, are individually mounted over the 
lens. The elongated members have a large circular hole adjacent to their 
outer end and a small hole which tightly fits over the rounded portion of 
the attachment element. Each of the transparencies has insertion tabs 
around the peripheral side edges thereof. The transparencies are mounted 
individually in a manner similar to that described with respect to the 
goggle disclosed in U.S. Pat. No. 4,455,689, by inserting the tabs between 
the lens and the lens frame and folding over the elongated portion. 
It would therefore be desirable to provide transparencies which can be 
rapidly mounted on the goggle lens and to minimize the breakage loss 
associated with individual loose transparencies. 
SUMMARY OF THE INVENTION 
In accordance with one aspect of the invention, a stack or book of flexible 
tear-off lenses, adhesively secured together, is provided that can be 
rapidly and easily mounted over a main goggle lens. The invention 
overcomes the previously discussed disadvantages of excessive positioning 
and mounting time. As used herein, "main goggle lens" means the lens of a 
goggle that is mounted in the goggle, either removably or permanently, and 
is intended for continued use, alone or in conjunction with disposable 
tear-off lenses. Since the main lens can become scratched or otherwise 
damaged after long periods of use, or to change the lens color, these 
lenses can be removed from the goggle frame and replaced. 
In accordance with the invention, the stack of tear-off lenses includes a 
plurality of flexible transparent lenses that are adhesively bonded 
together in registry with each other, each having adhesive along upper and 
lower peripheral portions of each of the lenses. Each of the lenses is 
manually, serially removable from the lens stack. 
Each of the lenses in the stack has a central lens portion, which usually 
corresponds to the general shape of the main goggle lens, and a securing 
tab at one end of the tear-off lenses. The securing tabs of the stack are 
insertable into an opening or slot located in the goggle to facilitate 
attaching the stack to the frame. 
The tear-off lenses each further include an elongated removal tab, usually 
located at the end opposite the end having the securing tab. The elongated 
removal tabs extend beyond the frame and preferably have suitable 
structure, such as a first small diameter opening and an outwardly spaced 
second opening of larger diameter to allow fastening the removal tabs in a 
manner allowing for rapid and easy individual sequential removal of the 
tear-off lenses. The removal tabs are sufficiently flexible to enable 
folding thereof for securing the lens sheets to a post retaining member 
mounted on the goggle. 
A transverse crease, which may be a line of perforation, can be included 
between the removal tab and the central lens portion to facilitate 
adherence of the tear-off lens to the goggle lens. The elongated removal 
tab may have first and second apertures for mounting the tab over a 
retaining post member which can be located on the goggle. The bottom 
tear-off lens of the stack includes adhesive for removably securing the 
tear-off lens stack to the main goggle lens. 
The tearable lenses of the invention are of a desired shape, usually 
configured to generally correspond to the shape of the permanent goggle 
lens. The stack of tear-off lenses comprises a plurality of adhesively 
bonded transparent plastic sheets which have adhesive at the upper and 
lower peripheral portions thereof. The bonding strength of the adhesive is 
sufficient to provide adhesion of the tear-off lenses while enabling 
manual, serial separation and removal of the lenses from the stack. 
Preferably, during fabrication of the tear-off lens stack, a layer of 
protective material, such as wax paper, for example, is applied over the 
adhesive of the bottom tear-off lens for protecting the adhesive until the 
time of intended use. If desired, the bottom lens in the tear-off lens 
stack could perform the function of the protective material, in which case 
the bottom adhesive layer could be omitted. 
In accordance with another aspect of the invention, a goggle comprising a 
frame with a main goggle lens, together with a stack of tear-off lenses, 
as previously described, mounted thereover is provided. The goggle further 
includes a vertical opening or slot in the goggle at one side thereof into 
which a side peripheral portion or securing tab on each lens of the 
tear-off lens stack is insertable when in position over the main goggle 
lens for assisting in maintaining the tear-off lens stack in the mounted 
position. The goggle also includes a retaining post member at a side of 
the goggle opposite the side where the slot is located, for retaining the 
removal tabs in a desired position for facilitating removal. 
In accordance with another aspect of the invention, a method of making a 
stack of tear-off goggle lenses of the type previously described is 
provided. The method includes: applying adhesive material over bottom 
portions of each of a plurality of flexible transparent lens webs 
corresponding to the upper and lower peripheral adhesively bonded together 
portions of the lens stack; bonding together the webs with the adhesive 
material while the webs are in registry to form a laminated web stack; and 
forming the webs, such as by cutting or stamping, for example, to form the 
tear-off lenses in the desired shape and size. In accordance with one 
embodiment of the method, the forming occurs after the bonding of the 
webs. In accordance with another embodiment, the method further includes 
applying a layer of protective material over the adhesive of the bottom 
web for protecting the adhesive material thereat. The adhesive material 
may be applied to the web as two linear strips and the webs can be bonded 
together to form a stack preform. Thereafter, the stack preform is formed 
to produce the stack of tear-off lenses of desired shape and size. 
In accordance with a preferred embodiment of the invention, the adhesive 
that is utilized to bond the tear-off lenses together is a two-sided 
adhesive tape. Most preferably, one side of the tape has greater bonding 
strength than the other side. This allows the side of the tape with the 
greater bonding strength to be adhered directly to the bottom surface of 
each of the tear-off lenses so that between an outermost lens and the next 
lens in the stack, the adhesive tape remains adhered to the outermost lens 
when it is removed from the stack. 
In accordance with still another aspect of the present invention, a kit for 
adapting a goggle for tear-off lenses is provided. The kit includes a 
retaining post member adapted for mounting on the frame of the goggle. The 
retaining post member can include a base portion, a cylindrical extension 
portion and an enlarged head portion. The kit also includes a stack of 
tear-off lenses as previously described, each tear-off lens including a 
securing tab at one end of the lens and an elongated removal tab at the 
opposite end of the lens, the securing tab being insertable into the 
goggle for securing the stack to the frame in conjunction with adhesively 
securing the stack to the main lens of the goggle, the elongated tab being 
securable to the post member when it is mounted on the goggle frame. 
The stack of tear-off lenses provides for rapid mounting of a plurality of 
the lenses over the main lens of a goggle. This avoids the prior art 
disadvantage of the substantial time and effort required for individually 
positioning and mounting the tear-off lenses. Moreover, the tear-off lens 
stack of the present invention avoids scratching and soiling that can 
occur with known individual tearoff lenses.

DETAILED DESCRIPTION 
Referring to the drawings generally, where like reference numerals refer to 
like parts, and in particular to FIG. 1, there is illustrated a stack or 
book of tear-off lenses 10, which in this embodiment includes five 
tear-off lenses 12a-12e, and adhesive 14 located along upper and lower 
peripheral portions of the bottom of each lens 12. Greater or fewer 
tear-off lenses can make up a stack or book of lenses, as desired. 
Stack 10 can also includes a layer of protective material 16, which in this 
case is wax paper, under bottom lens 12e and the adhesive thereon for 
protecting the adhesive on the bottom of lens 12e until stack 10 is ready 
for use, whereupon protective mater can be easily removed, such as by 
peeling it from bottom lens 12e. 
Preferably, and as illustrated in FIG. 1, adhesive 14 on the bottom side of 
the upper and lower peripheral portions of each of lenses 12, comprises a 
two-sided tape on each of the upper and lower portions. Most preferably, 
the side of the tape that is adhered to the bottom surface of lenses 12 
has a greater bonding strength than the other side of the tape. This 
allows the adhesive tape to remain on the topmost lens as it is being 
removed from the lens stack during use. Transparent polyester is a 
suitable material for the tape substrate or carrier, preferably having a 
thickness of about 0.5 mil. Adhesive 14 should permit manual separation of 
the lenses from the top to the bottom of stack 10. Suitable adhesives for 
use in accordance with the invention are known in the art and include 
adhesives such as acrylic resin-based adhesives, for example. 
Lenses 12 of stack 10, each of which is manually serially removable 
therefrom from the top to bottom of stack 10, includes a central lens 
viewing portion 18 that usually generally corresponds to the shape of the 
main goggle lens. A securing and orientation tab portion 20 is provided at 
one end of stack 10 and an elongated removal tab 22 having a first opening 
24 and a second opening 26 are located at the opposite end. The diameter 
of the first opening is less than that of the second opening to facilitate 
use of stack 10 as hereinafter described. An additional third opening 28 
may also be provided to facilitate gripping removal tab 22 when it is 
desired to remove the outermost lens from stack 10. 
The upper and lower peripheral portions of the adhesive 14 each taper 
towards a point 23 or other area of reduced size compared with the width 
of the adhesive near the middle locations along the lenses 12. This taper 
results in less adhesive where the lens 12 is first separated by action of 
the tab 22 and aids in peeling off the lens 12 without displacing the 
lower lenses before they are to be removed. A corresponding taper 25 at 
the opposite side of the adhesive also serves to minimize or prevent 
dislodging of the remaining lenses 12 as the topmost lens is removed. 
As illustrated in FIG. 1, ech lens 12a-e includes a transverse crease 29 
extending across lenses 12a-e, located between viewing portion 18 and 
removal tab 22. Crease 29 can be formed by any suitable method and can be 
a line of perforation, for example. In the illustrated embodiment, crease 
29 facilitates the mounting and adherence of stack 10 to goggle 30 of 
FIGS. 2-6 as main goggle lens 36 is recessed within goggle frame 32 and 
the elongated removal tab 22 must curve upwardly and outwardly, as seen in 
FIG. 3, without forcing the lens 12a-e away from the surface of the main 
lens 36. 
A goggle 30 having stack 10 of tearable lenses 12 mounted thereon is shown 
in FIGS. 2-4. Goggle 30 includes a flexible frame 32, including foam-lined 
air vents 34, a main goggle lens 36, a foam liner or flange 38, an elastic 
headband 40 (partially illustrated) and a retaining post member 42, 
secured to frame 32. The general construction of frame 32, lens 36, 
foam-lined air vents 34 and foam liner 38 is disclosed in U.S. Pat. No. 
3,945,044 to McGee, assigned to the assignee of the present application, 
the disclosure of which is hereby incorporated by reference. Frame 32 has 
an interior groove which mounts main goggle lens 36 therein. The sides of 
the lens 36 extend into the groove to form an opening or vertical slot 44 
between the lens 36 and the frame 32. Since frame 32 and main goggle lens 
36 are somewhat flexible, slot 44 can conform to the initial thickness of 
stack 10 and the reduced thickness as lenses 12 are removed therefrom. 
Stack sheets 10 of tearable lenses 12 are easily attached to the goggle 
frame by removing protective material 16, inserting tab 20 into slot 44 
located at the right-hand portion of the frame, which first serves to 
orient the stack so that the user correctly places the stack on the main 
lens, and then serves to help secure the stack, and subsequently attaching 
removal tabs 22 to retaining post member 42. Referring to FIG. 7, post 
member 42 is designed to be easily attached to goggle frame 32 by 
inserting post member end 45 into slot opening 46 provided in frame 32, 
which also allows headband 40 to be secured to frame 32. End 45 of post 
member 42, with a portion of the sidewall thereof, defines a z-shaped snap 
lock retaining portion 47 together with the interior of a complementary 
shaped portion of slot 46. While this type of post member is known per se, 
in another embodiment, the post hold down member can comprise a flat base 
with a glue-on adhesive surface which is secured to the main lens 36. This 
post would be a generic form usable with a wide variety of goggles of 
different manufacturers. 
Referring to FIGS. 5-6, attachment of removal tabs 22a-e entails placing 
the smaller innermost first hole 24 over rounded head 48 of retaining post 
member 42. Hole 24 is slightly smaller in diameter than rounded head 48, 
but can be easily fitted thereover due to the flexibility of the plastic 
material employed for lens 12. Since hole 24 is smaller than head 48, tab 
22 is secured behind head 48 on neck portion 50. 
After securing tab 22e to retaining post 42, the remaining portion of tab 
22e is folded back on itself so that, and as illustrated in FIG. 6, larger 
hole 26 is placed over head 48 onto neck portion 50. 
As shown in FIG. 4, remaining securing tabs 22a-d of the stack are 
similarly mounted onto retaining post member 42. Topmost tab 22a of the 
stack only has innermost hole 24 mounted onto retaining post member 42. 
The remaining portion of tab 22a is left free to extend beyond the goggle 
frame so that the wearer can easily grasp it to remove the lens sheet. 
Upon removal of lens 12a, removal tab 22b of immediately underlying lens 
12b automatically unfolds to extend beyond goggle frame 32. During riding, 
for example, a motorcyclist wearing the goggle can easily grasp the 
elongated member of the outermost transparency, pull it free of the post 
member and peel off the outer tear-off lens with one quick motion. When 
the outer elongated member is pulled free of the retaining post member, 
the elongated member of the immediately underlying transparency 
automatically unfolds, and is ready for grasping by the cyclist when it is 
time once again to remove another tear-off lens. 
The stack of tearable lenses can be made by bonding together a plurality of 
adhesively coated plastic webs. As shown in FIGS. 8 and 9, webs 60a-e of 
transparent flexible plastic lens material are taken from rolls 62a-e and 
are contacted with adhesive tape 64a-e from adhesive tape rolls 66a-e. The 
tape rolls provide a two-sided adhesive tape 64a-e on the surface of webs 
60a-e whereby the side of the tape with the greater bonding strength is 
adhered to the surface of each web that is the bottom surface in the 
finished tear-off lens stack. Web 60e and adhesive tape 64e has adhered 
thereto a protective material 68 which is a web of wax paper from roll 70. 
Coated webs 60a-e are passed through compression rollers 72, 72' to 
provide a laminated preform 74 as shown in FIG. 10. Preform 74 is cut to 
desired shape and size in cutter 78 to yield stacks 10. The crease line 29 
can be created by a series of perforation holes formed by cutter 78. 
Conveyor 79 is utilized to transport the product as required. 
FIG. 11 illustrates the outline of the cuts 80 to be made by cutter 78 to 
preform 74 (not showing wax paper sheet 68). FIG. 12 illustrates the 
resulting lens stack 10 with the bottom tear-off lens facing upwardly and 
the protective wax paper sheet removed. 
It is to be understood that the process for making the tear-off lens stack 
in accordance with the invention can be accomplished in a variety of ways. 
For example, the shape of the individual lenses could be cut or formed, 
individually or as a web, prior to application of the adhesive and 
subsequent bonding together of the individual lens material layers. Also, 
adhesive material could be applied directly to the lens material without 
using adhesive tape, such as by spraying, rolling or brushing, for 
example. 
A wide variety of transparent plastic materials may be employed for webs 
60, as desired, and materials such as polyesters are particularly 
suitable. The thickness of the tear-off lens material may also vary as 
desired. Thicknesses of about 3 to 7 mils (1 mil=0.001/inch) are suitable 
with a preferred thickness being about 4 mils. 
The width of adhesive tape 14 may be varied to suit the specific geometry 
of the permanent lens of the protective eye goggle and can also depend on 
the bonding strength of the adhesive. The total surface area covered by 
the tape should be sufficient to assure adequate adhesion of the members 
of the stack for the particular tear-off lens and goggle configuration 
utilized. 
The stack of tearable lenses may be supplied to the user in the form of a 
kit. The kit includes a stack of tearable lenses 10 (as illustrated in 
FIG. 1, for example) and post retaining member 42, such as illustrated in 
FIG. 7, or the alternate embodiment previously described in which a 
generic form of post has a glue-on adhesive base secured to the main lens. 
Such a kit could be adaptable for use with a wide variety of goggles 
produced by different manufacturers. 
While illustrative embodiments of the invention are shown in the drawings 
and are described in detail herein, the invention is susceptible of 
embodiment in many different forms. It should be understood that the 
present disclosure is to be considered as an exemplification of the 
principles of the invention and is not intended to limit the invention to 
the embodiments illustrated.