Basketball backboard with shatter-resistant properties

A shatter-resistant basketball backboard is provided, which comprises a tempered glass basketball backboard having a front surface and back surface; and a plastic film adhered to the rear surface of the backboard. In preferred embodiments, the plastic film is comprised of at least one plastic layer and an adhesive layer. The plastic film can have a release liner adjacent to the adhesive layer, and a scratch resistant coating adjacent to the plastic layer. Ultraviolet resistance properties can also reside in the film or adhesive. The plastic film can be made of polyethylene terephthalate, polycarbonate or like materials. Plastic film can be applied either in an OEM or retrofit installation.

FIELD OF THE INVENTION 
The present invention generally relates to basketball goals and more 
specifically to an improved shatter-resistant tempered glass backboard 
with a transparent plastic film adhered thereto. 
BACKGROUND 
The shattering of glass basketball goals during play has become a serious 
impediment to the safety of the participants. Current glass backboards 
typically are one-half (1/2) to three-eighth (3/8) inch tempered glass. 
When subjected to appropriate forces, such as during a player's dunk or 
other force applied to the rim, the tempered glass is stressed beyond its 
elastic limit and shatters into a myriad of small glass pieces. Typically, 
these pieces are roughly oblong, and approximately one-half (1/2) to one 
(1) inch long. These glass projectiles rain down on the players on the 
court, creating a possibility for skin lacerations and serious eye injury. 
Also, the shower of glass pieces can ricochet towards participants 
positioned courtside, such as cheerleaders, ball boys, cameramen and 
spectators. The danger to the safety of people at the game cannot be 
ignored by sports arena owners and operators. 
In addition to the safety issues, the shattering of a glass backboard 
creates clean-up problems. Maintenance personal must carefully locate and 
remove thousands of glass particles that have fallen to the floor and slid 
under objects. Missing just a single piece can cause great damage if a 
player subsequently falls on the glass fragment. Also, even if some 
portions of the shattered glass do not fall to the floor during breakage, 
they likely will during replacement operations. 
Finally, the shattering of backboard can also have a significant effect on 
the tempo of the game. The time necessary to clean-up and replace a 
backboard can cause a long delay in the game, possibly affecting the 
momentum experienced by one or both teams. Also, there is a feeling of 
machismo associated with the shattering of a glass backboard, allowing the 
team inflicting such damage to gain a perceived or real emotional 
advantage. Such events and passion can influence the outcome of a sporting 
event. 
Recent attempts to address the above problems focus upon decreasing the 
stresses imparted to the glass backboard during play. Such attempts 
primarily address the mounting of a basketball rim to a basketball goal. 
See, e.g., U.S. Pat. Nos. 4,588,188 and 5,037,092. While these latest 
attempts may reduce the incidence of backboard shatter for new 
installations, backboards continue to shatter all too frequently. None of 
these solutions seek to restrain the glass particles from dismantling from 
the backboard unit once the inevitable breakage occurs. Also, apparently 
no prior art solutions have targeted broken glass retention systems which 
can be applied to existing installations in a retro-fit manner to decrease 
their hazardous potential. 
Thus there is a need in the art for an improved glass backboard goal that 
minimizes the ill effects of the shattering of tempered glass. 
SUMMARY OF THE INVENTION 
A shatter-resistant basketball backboard is provided, which comprises a 
tempered glass basketball backboard having a front surface and back 
surface; and a plastic film adhered to the rear surface of the backboard. 
In a preferred embodiment, the plastic film is comprised of at least one 
plastic layer and a mounting adhesive layer. The plastic film can have a 
release liner adjacent to the adhesive layer, and a scratch-resistant 
coating adjacent to the plastic layer. Ultraviolet resistance properties 
can also reside in the film or adhesive. The plastic film can be made of 
polyethylene terephthalate, polycarbonate or like materials. Plastic film 
can be applied either in an OEM or retrofit installation. 
These and other aspects of the present invention as disclosed herein will 
become apparent to those skilled in the art after a reading of the 
following description of the preferred embodiments when considered with 
the drawings.

The drawings are for the purpose of describing a preferred embodiment of 
the invention and are not intended to limit the present invention. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is an exploded view of a basketball backboard illustrating an 
embodiment of this invention. The backboard 10 comprises a one-half (1/2) 
to three-eighth (3/8) inch tempered glass section, a mounting frame 14 and 
a goal assembly 16 (shown in dashed lines). Mounting slots 18 allow 
attachment of the backboard to the support structure stand (not shown). 
The mounting frame 14 typically includes a "U" shaped injection molded 
neoprene gasket (not shown) along the perimeter of the glass 12, 
protecting the glass from the frame 14. 
The goal assembly 16 is attached to the glass 12 and mounting frame 14 
through a goal anchor assembly 22. The goal anchor assembly is mounted 
through holes 24 in the glass and secures the goal to the glass 12 and 
mounting frame 14. The goal assembly 16 can be a breakaway type to release 
the rim portion thereof when excessive force is applied thereto. In 
typical backboards, a target area (not shown) and edge border (not shown) 
are applied by conventional technologies, e.g., screen printing, to the 
front of the glass surface. 
The drawing of the backboard 10 and related elements is intended to 
represent a conventional glass backboard being sold and used today. This 
invention can be practiced on a wide variety of backboard configurations 
and mounting hardware. 
A plastic film 30, 50 also is shown in FIG. 1. In a retro-fit installation, 
the plastic film 30, 50 is cut to size, to approximately fill the exposed 
glass surface area of the rear surface of the backboard 10. In a preferred 
embodiment, the goal anchor assembly 22 is first removed from the 
backboard 10 prior to application of the plastic film 30, 50. The film 30, 
50 is then properly applied to the back surface of the glass 12, as 
discussed below. Access holes 34 are then created in the film, so that the 
goal anchor assembly 22 can be reattached. 
FIG. 2 illustrates a cross section of the plastic film 30 in a preferred 
embodiment, after mounting has occurred on the glass 12. The glass 12 
(shown of undetermined width in FIG. 2) typically is a one-half (1/2) to 
three-eighth (3/8) inch optically clear tempered glass. The back surface 
13 of the glass is on the rear of the backboard, and usually is not 
contacted by the ball or other playing object. The plastic film 30 in this 
embodiment is comprised of a film-to-glass mounting adhesive layer 32, a 
first plastic layer 34, a film-to-film adhesive layer 36, and a second 
plastic layer 38. 
FIG. 3 illustrates an alternative embodiment for the plastic film 50 bonded 
to tempered glass 12. As with the previous embodiment, a film-to-glass 
mounting adhesive 52 bonds a plastic layer 54 to the rear surface 13 of 
the glass 12. 
The plastic layers 34, 38 and 54 typically are comprised of a polymerized 
ethylene resin (P.E.T. or polyethylene terephthalate). Alternatively a 
polycarbonate film could be used. In the embodiment shown in FIG. 2, both 
plastic layers 34 and 38 are approximately 4 mils (approximately 100 
microns) thick. Also, in a preferred embodiment, the outer plastic layer, 
38, 54 has a scratch resistant coating 56 applied to the outer surface. 
This coating protects the film during normal cleaning and maintenance. 
Also, in a preferred embodiment, the film includes ultraviolet (UV) light 
protectors or inhibitors, either applied as an external coating, or 
applied within the film or adhesives. 
The film-to-glass bonding adhesive 32 and 52, in a preferred embodiment, 
already is applied to the plastic layer 34, 54 when the plastic film is 
obtained from a film supplier. The adhesive 32, 52 is exposed by removing 
a release liner (not shown) prior to application to the glass 12. The 
adhesive must have sufficient bonding strength so that the majority of the 
glass particles will remain bonded to the film 30, 50 after breakage. 
Also, the adhesive must be substantially optically clear to not distort 
the existing clarity of the glass 12. In a preferred embodiment, the 
adhesive is selected from the following group: acrylic copolymer pressure 
sensitive adhesive; an acrylic-vinyl acetate pressure sensitive adhesive; 
or a vinyl ether polymer pressure sensitive acetate adhesive. Adhesive 
density typically is approximately fourteen (14) pounds per ream. After 
application, the adhesive layer typically consumes no more than 1 mil of 
thickness. 
The film-to-film laminating adhesive 36 shown in FIG. 2 also must be 
substantially optically clear, and can be formed from the following: 
acrylic copolymer pressure sensitive adhesive; an acrylic-vinyl acetate 
pressure sensitive adhesive; or a vinyl ether polymer pressure sensitive 
acetate adhesive. Laminating adhesive density typically is seven (7) 
pounds per ream. 
Suitable suppliers of pressure sensitive adhesives and scratch resistant 
coatings include National Starch & Chemical Corp., Ashland Chemical Co., 
and Morton International, Inc. 
Plastic film 30, 50 of the type used herein can be obtained from many 
suppliers of safety and security film, such as Clear Defense Incorporated, 
121 E. Main St., Martinsville, Va., Model Numbers, CD 225 Clear and CD 125 
Clear. Preferred properties for each are as follows: 
TABLE 
______________________________________ 
FILM PROPERTIES 
CD 125 CD 225 
CLEAR CLEAR 
______________________________________ 
PHYSICAL PROPERTIES 
Number of Film Layers 
1 2 
Laminate Thickness (including 
0.005 (120) 
0.009 (225) 
adhesive) 
inches (microns) 
Tensile Strength - PSI 
28,000 28,000 
Break Strength - lbs/inch 
110 225 
Peel Strength - lbs/inch 
9 8 
SOLAR PROPERTIES 
Solar Transmittance - % 
82 82 
Solar Reflectance - % 
10 10 
Solar Absorptance - % 
8 8 
Visible Light Transmittance - % 
93 93 
U-Factor 1.02-1.13 1.02-1.13 
Shading Coefficient 0.94 0.94 
Ultraviolet Light Transmitted - % 
0-10 0-8 
Total Solar Energy Rejected - % 
17 17 
______________________________________ 
The above property parameters are well known in the art, and the 
information provided herein can be used by those skilled in the art to 
select proper film to practice this invention. The tensile and break 
strength values above were measured in accordance with the following 
standards: ASTM D 882-75 (American Society for Testing Materials); ASTM 
1004-76; ASTM D 1938-67. The lbs/inch values above is per linear inch of 
width. All solar data has been measured in accordance with AIMCAL 
standards (Association of Industrial Metalizers, Coaters and Laminators). 
FIG. 4 illustrates the rear view of a tempered glass section 60, which is 
intended to be used in a backboard assembly 10. Mounting hardware has not 
been added. At this stage of production, the glass section 60 can be 
approximately 71.5 inches in width W, and 41.5 inches in height, H. A 
rectangular target area 62 is applied directly on the glass 60, through 
conventional techniques, e.g., ceramic screen printing or the like. An 
outer edge border 64 surrounds the perimeter of the front of the glass, 
and will be partially covered up when the mounting frame (not shown) is 
installed. Through holes 66 accept the goal anchor assembly. In an 
original equipment manufacturer (OEM) installation, the plastic film 30 or 
50 is applied directly to the rear surface of the glass section 60, in the 
manner described below. The film is cut to fill up the entire rear surface 
area, and then applied to the glass. Holes in the film are then made to 
allow access through holes 66 for the goal anchor assembly. If additional 
holes (not shown) are provided in the corner of the glass for the mounting 
frame, like holes can be made into the film to accommodate them. 
FIG. 5A shows a front view of a basketball goal 70 with tempered glass 72, 
mounting frame 74, holes 76 and a target area 78. For this type of 
backboard, a rear horizontal member 80 may extend above the height of a 
front horizontal support member 82. In another embodiment, an additional 
section(s) of plastic film 90, 91 is applied to the front surface of the 
glass 72 for additional protection in this area of the backboard. The 
plastic film may be comprised of one or more layers of plastic, such as 
that shown by Elements 30 or 50. The mounting slots 18 and related 
structure are partially visible through the glass 72 in FIG. 5A. 
FIGS. 5A and 5B depict a plastic film strip 91 that can be applied on the 
bottom portion of the glass 72, below or at or above the bottom portion of 
the ceramic screen printed border 81. Plastic film 90 is shown in FIGS. 5A 
and 5C and can also be applied to the front surface of the glass 72 for 
added protection. 
The method of applying plastic film 30, 50, 90, 91 to tempered glass makes 
use of tools, commonly available to the plastic film industry. Tools that 
can be used include the following: 
TABLE 
______________________________________ 
APPLICATION TOOLS 
______________________________________ 
6" Scraper 
Pro Handle/12" Cleaning Squeegee 
Lint-free Paper Towels 
6" Pro (Power) Squeegee 
Stainless Olfa Cutting Knife 
5 Way Cutting Guide 
Square PVC Bumper 
Polly 11 Pressure Sprayer 
Drop Cloth (if Backboard is lowered to gym floor for 
installation of system) 
11/8" Open Face Wrench 
Adjustable 1/2" Wrench 
______________________________________ 
The method of applying plastic film 30, 50, 90 to tempered glass for an 
existing installation can involve the following steps: 
General 
Preferably the glass should be room temperature. 
Apply the film in a relatively clean environment. It is not desirable to 
allow dust or other particles to be trapped between the mounting adhesive 
and glass. 
Site Preparation 
Use a lint free (preferably cotton twill or calico) drop cloth to extend 
four feet out in front of the backboard and four feet behind the backboard 
(assuming that the backboard will be lowered to the gym floor to install 
the system) 
Installers should wear only cotton "lint free" clothes and a cap or hair 
net (if installers have long hair) to reduce lint or hair from being drawn 
to the film adhesive by static electricity as the release liner is removed 
from the mounting adhesive side of the film. 
Slip Solution 
Prepare an aqueous slip solution, preferably of distilled water, mixed with 
a gentle shampoo (preferably Johnson and Johnson's baby shampoo-yellow 
colored, not pink) as follows: 
On cool to average room temperature glass surfaces, use 3/4 teaspoon of 
shampoo to a pint of distilled water 
On hot glass surfaces (85 degrees Fahrenheit or above), use 1 teaspoon of 
shampoo to a pint of distilled water 
On cold glass surfaces (45 degrees Fahrenheit or below), use less than 1/2 
teaspoon of shampoo to a pint of distilled water 
The slip solution is considered a contaminant in the final installation. 
Therefore, careful attention should be paid to the above instructions to 
ensure proper adhesion and clarity. 
Removing Goal Assembly 
Use appropriate tools (e.g., the 1/2" adjustable wrench and the 1-1/8" open 
face wrench) to remove both the goal and the assembly unit (including the 
polycarbonate support plates, if any, on both the front and backside of 
the backboard). 
Be sure that the entire goal assembly unit is removed so that the installer 
of the film can have access to the back and front glass surface 
surrounding the goal area of the glass surface. 
Cleaning the Glass 
Spray the back surface of the glass backboard thoroughly with the slip 
solution and clean the surface with a suitable scraper (e.g., 6" Scraper) 
to clean the surface in the following pattern as shown in FIG. 6. First 
scrape horizontally in the 101 direction shown in 101, followed by the 
103, 105, 107 and 109 directions. 
After the back of the glass backboard is "razor" cleaned, spray the surface 
again and use the cleaning squeegee to remove any debris left behind by 
the razor cleaning. Wipe around the edges with "lint-free" paper towels. 
Do not wipe the glass surface with paper towels. 
For an embodiment incorporating plastic film on the front side of the 
backboard, spray the front of the glass backboard and clean it with the 
squeegee. Use the same pattern as shown in FIG. 6. While the film will 
only cover the goal mounting area, the entire front of the backboard 
should be cleaned with the cleaning squeegee. Next, wipe around the edges 
with the "lint-free" paper towels. 
Application of the Film 
Installation on the back surface of the backboard (preferably, should be 
done first before applying film to front surface if front surface 
application is planned): 
Spray the back surface of the backboard, starting at the bottom right 
corner and continue with a sweeping motion pattern from right to left 
until the entire board is covered with the slip solution. 
When using plastic film incorporating a release liner, the release liner 
must be "peeled" from the adhesive side of the film and the adhesive must 
be sprayed simultaneously with the slip solution to avoid static 
electricity pulling dust into the adhesive. 
Re-wet the glass surface again, thoroughly. 
Re-wet the adhesive side again. 
Then, apply the film to the back surface of the backboard. 
Squeegeeing 
Spray the entire surface of the film with the slip solution. 
Position film and squeegee (e.g., 6" pro (power) squeegee) in the 
directions as shown in FIG. 7 using two hands and squeegeeing relatively 
hard upward 111 to tack the top first. 
Then from the middle, proceed to tack horizontally 113 across the top. 
After tacking the top, start the downward 115 strokes. Such actions should 
remove substantially all of the moisture from the slip solution, so that a 
proper bond can form between the film and glass. 
When doing the vertical squeegeeing 111 and 115, the strokes should overlap 
by 50% and the strokes should be not longer than 6"-8". Use the square PVC 
Bumper, wrapped in a paper towel (to protect the film and to absorb the 
moisture pushed to edges), to "bump" all the film edges. 
Re-wet the film surface using the slip solution and repeat above 
squeegeeing steps. 
"Tuck" or "tack" the edges of the film behind the steel frame of the 
backboard. 
Any debris or foreign particles caught between film and glass should be 
removed before completing the first squeegeeing. Thoroughly wet any film 
lifted from the glass as well as the glass before re-applying the film 
back onto the glass. Insure that you squeegee the slip solution back past 
the water-line left from the initial lifting of the film before continuing 
to do the final squeegee. 
Miscellaneous 
Because of the aggressive mounting adhesive on the film, it will grab if 
insufficient slip solution is sprayed on the glass, causing adhesive drag 
smear marks. 
Tap water contains certain amounts of minerals and salts which have been 
found to contaminate the bond between the film and the glass surface. 
Application of the Reinforcement Panels on the Front Surface (if 
applicable) 
Spray the front surface of the backboard and clean it again with the slip 
solution and cleaning squeegee. 
Select the proper film strip for the desired size, e.g., 
11/2".times.691/4inch strip for bottom section of backboard (Element 91 of 
FIGS. 5A and 5B). 
Remove the release liner, using the same technique as described earlier, 
and apply the film: 
Install the strip of film along the bottom of the front surface, lining-up 
the top of the film strip with the top of the target ceramic screen 
printed outline of the board and "tuck" and "tack" the bottom of the film 
about 1/4" behind the steel frame (see diagram below): 
Provide a second (if desired) plastic film (e.g., 51/2".times.10") (element 
90 of FIGS. 5A and 5C). 
Remove the release liner and apply the film panel, using the same 
techniques as outlined above. 
Install the panel 90 in the middle of the board directly over the two holes 
in the backboard provided for the goal installation (see, e.g., element 90 
of FIGS. 5A and 5C) and then 
Position the bottom of the panel 90 against the top of the film strip 91 
applied in the prior step, leaving a 1/8" light line between the two 
pieces. The two pieces of film 90 and 91 preferably should not touch. 
Final Installation Steps 
Take the PVC Square Bumper and wrap in a paper towel and bump all the edges 
of the film again. 
If any rough edges are discovered, or edges which are too tight against the 
frame (edges puckered up), use the 5 Way Cutting Guide and the Stainless 
Olfa Cutting Knife to trim such edges so the film can lay smooth and flat 
against the glass. 
Using a suitable knife, e.g., the Olfa Cutting Knife, cut the film on the 
back and front of the backboard where it overlays the two holes in the 
backboard (same holes provided for installing the goal). The cut should be 
smooth and angled back away from the hole so the film will not touch the 
bolts used in installing the goal (otherwise the film may finger if the 
bolts come into contact with the edge of the film around the holes). 
Perform one final bumping around the holes with the PVC Square Bumper, 
wrapped in a paper tower. 
Wait approximately two (2) hours after all the above steps have been 
completed and re-install the Basketball Goal Assembly unit, including the 
acrylic support plates on the front. 
With practice, the above steps can be accomplished in quicker time and with 
greater acumen. However, the above steps arc not so complicated as to 
necessarily require skilled craftsman, and it is contemplated that 
installations can be performed by maintenance or other suitable personnel 
already employed at the area or other establishment housing the backboard. 
For OEM installations, the above procedures can also apply, eliminating the 
steps involved with removal of existing hardware and other non-essential 
steps. Also, the film can be applied all the way to the edges of the 
glass, since the frame has yet to be installed on the glass backboard. 
The term "shatter-resistant" as used herein refers to the functioning of 
the plastic film in assisting in the retention of glass in the backboard 
after breakage. Thus, the film helps avoid a shattering or showering of 
the glass particles after breaks. 
While the discussion above pertains primarily to a basketball backboard, it 
should be understood that the broken glass retention properties of the 
plastic film described above can also prove beneficial when the film is 
mounted on other recreational glass surfaces. Such recreational glass 
surfaces include partitions used along the perimeter of hockey rinks, as 
well as the glass used in slot machines, pinball machines, video games, 
and other surfaces where glass is preferred but a breakage is possible or 
imminent. 
The above description of the preferred embodiments thus detail many ways in 
which the present invention can provide its intended purposes. While 
several preferred embodiments are described in detail hereinabove, it is 
apparent that various changes might be made without departing from the 
scope of the invention, which is set forth in the accompanying claims.