U.S. patent application number 10/926835 was filed with the patent office on 2006-02-02 for tactile warning system.
Invention is credited to Todd J. Seman.
Application Number | 20060024132 10/926835 |
Document ID | / |
Family ID | 35732384 |
Filed Date | 2006-02-02 |
United States Patent
Application |
20060024132 |
Kind Code |
A1 |
Seman; Todd J. |
February 2, 2006 |
Tactile warning system
Abstract
A tactile warning system (100 or 200) having an application
surface (114 or 214) and a sheet (110 or 210) formed from a
predetermined material and adhered to the application surface. The
tactile warning system includes a plurality of tactile warning
members (112 or 212) formed from a selected material different from
the predetermined material of the sheet. The plurality of tactile
warning members are disposed between the sheet and the application
surface. The plurality of tactile warning members contact the
application surface without an intermediate layer disposed
therebetween.
Inventors: |
Seman; Todd J.; (Roy,
WA) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE
SUITE 2800
SEATTLE
WA
98101-2347
US
|
Family ID: |
35732384 |
Appl. No.: |
10/926835 |
Filed: |
August 25, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60598250 |
Aug 2, 2004 |
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Current U.S.
Class: |
404/15 |
Current CPC
Class: |
A61H 3/066 20130101;
E01C 11/222 20130101 |
Class at
Publication: |
404/015 |
International
Class: |
E01F 11/00 20060101
E01F011/00 |
Claims
1. A tactile warning system for providing tactile warning
sensations to a user, the tactile warning system attachable to an
application surface comprising: (a) a plurality of tactile warning
members formed from a selected material, the tactile warning
members having a top surface and a bottom surface; and (b) a sheet
coupled to the top surface of each of the plurality of tactile
warning members, the sheet formed from an activatable material
activatable from a first state in which the sheet is resistant to
adhering to an application surface to an application state in which
the sheet is adapted to adhere to the application surface without
use of an adhesive to sandwich the plurality of tactile warning
members between the sheet and the application surface such that the
bottom surface of each of the plurality of tactile warning members
contacts the application surface.
2. The tactile warning system of claim 1, wherein the activatable
material of the sheet is a heat activated material activatable by
heating the sheet above a predetermined temperature to configure
the sheet from a solid state to at least a partially molten
state.
3. The tactile warning system of claim 2, wherein the activatable
material of the sheet is a preformed thermoplastic material.
4. The tactile warning system of claim 2, wherein the selected
material of the plurality of tactile warning members is a heat
resistant material able to withstand temperatures at least up to
the predetermined temperature without melting.
5. The tactile warning system of claim 4, wherein the selected
material of the plurality of tactile warning members is a porous
material.
6. The tactile warning system of claim 1, furthering including a
plurality of bonds coupling the plurality of tactile warning
members to the sheet while the sheet is in the first state prior to
adherence to the application surface, the plurality of bonds absent
of adhesive.
7. The tactile warning system of claim 6, wherein the plurality of
bonds each comprise a portion of the activatable material of the
sheet hardened from a liquefied state to a solid state thereby
bonding the plurality of tactile warning members to the sheet.
8. The tactile warning system of claim 1, wherein the sheet is in a
substantially flat configuration when in the first state and
wherein the sheet is adapted to be at least partially liquefied
during transition between the first state and the application state
so that the sheet conforms in shape to the application surface and
the plurality of tactile warning members when in the application
state.
9. The tactile warning system of claim 1, wherein the tactile
warning members are embedded in the sheet when the sheet is in the
first state such that a bottom surface of the sheet is
substantially flush with the bottom surfaces of the tactile warning
members.
10. A tactile warning system for providing tactile warning
sensations to a user, the tactile warning system attachable to an
application surface comprising: (a) a plurality of tactile warning
members formed from a heat resistant material, the tactile warning
members having a top surface and a bottom surface; and (b) a
preformed thermoplastic sheet coupled to the top surface of each of
the plurality of tactile warning members, the preformed
thermoplastic sheet activatable by application of heat to adhere
the preformed thermoplastic sheet to the application surface such
that the plurality of tactile warning members are sandwiched
between the preformed thermoplastic sheet and the application
surface with the bottom surface of each of the plurality of tactile
warning members contacting the application surface without an
adhesive or additional thermoplastic layer disposed
therebetween.
11. The tactile warning system of claim 10, wherein the preformed
thermoplastic sheet is activated by heating the preformed
thermoplastic sheet above a predetermined temperature to configure
the preformed thermoplastic sheet from a solid state to at least a
partially molten state.
12. The tactile warning system of claim 11, wherein the selected
material of the plurality of tactile warning members is a heat
resistant material able to withstand temperatures at least up to
the predetermined temperature without melting.
13. The tactile warning system of claim 12, wherein the selected
material of the plurality of tactile warning member is a porous
material.
14. The tactile warning system of claim 10, furthering including a
plurality of bonds coupling the plurality of tactile warning
members to the preformed thermoplastic sheet while the preformed
thermoplastic sheet is in the first state prior to adherence to the
application surface, the plurality of bonds absent of adhesive.
15. The tactile warning system of claim 14, wherein the plurality
of bonds each comprise a portion of the activatable material of the
preformed thermoplastic sheet hardened from a liquefied state to a
solid state bonding the plurality of tactile warning members to the
preformed thermoplastic sheet.
16. The tactile warning system of claim 10, wherein the preformed
thermoplastic sheet is in a substantially flat configuration when
in the first state and wherein the preformed thermoplastic sheet is
adapted to be at least partially liquefied during transition
between the first state and the application state so that the
preformed thermoplastic sheet conforms in shape to the application
surface and the plurality of tactile warning members when in the
application state.
17. The tactile warning system of claim 10, wherein the tactile
warning members are embedded in the preformed thermoplastic sheet
such that a bottom surface of the preformed thermoplastic sheet is
substantially flush with the bottom surfaces of the tactile warning
members prior to adhering of the preformed thermoplastic sheet to
the application surface.
18. A tactile warning system for providing tactile warning
sensations to a user, the tactile warning system comprising: (a) an
application surface; (b) a sheet formed from a predetermined
material and adhered to the application surface; and (c) a
plurality of tactile warning members formed from a selected
material different from the predetermined material of the sheet,
the plurality of tactile warning members disposed between the sheet
and the application surface, the plurality of tactile warning
members contacting the application surface without an intermediate
layer disposed therebetween.
19. The tactile warning system of claim 18, wherein the
predetermined material of the sheet is a preformed thermoplastic
material.
20. The tactile warning system of claim 18, wherein the selected
material of the plurality of tactile warning members is a heat
resistant material.
21. The tactile warning system of claim 18, wherein the
predetermined material of the sheet is a preformed thermoplastic
material which begins to melt at a predetermined temperature and
wherein the selected material of the plurality of tactile warning
members is a heat resistant material able to withstand temperatures
at least up to the predetermined temperature without melting.
22. The tactile warning system of claim 18, wherein the tactile
warning system is free of an adhesive layer or additional sheet
disposed between the tactile warning members and the application
surface.
23. A method of applying a tactile warning for providing tactile
warning sensations to a user to an application surface, wherein the
tactile warning system includes a sheet and a plurality of tactile
warning members, the method comprising: (a) placing a sheet and a
plurality of tactile warning members upon the application surface
such that the tactile warning members are disposed between the
sheet and the application surface and such that the plurality of
tactile warning members contact the application surface without an
intermediate layer disposed therebetween; and (b) activating the
sheet such that the sheet is transformed from a substantially
non-adhering state to an adhering state wherein the sheet adheres
to the application surface sandwiching the tactile warning members
between the application surface and the sheet.
24. The method of claim 23, wherein activating the sheet includes
heating the sheet to at or above a predetermined temperature.
25. The method of claim 24, further comprising using tactile
warning members formed from a heat resistant material able to
withstand temperatures at or above the predetermined temperature
without melting.
26. The method of claim 23, further including transforming the
sheet from a first configuration to a conformed configuration
wherein the sheet is configured in a shape of the tactile warning
members and application surface.
27. The method of claim 23, further including heating the tactile
warning members and pressing them into the sheet to bond the
tactile warning members to the sheet.
28. The method of claim 23, further including coupling the tactile
warning members to the sheet prior to placing the sheet upon the
application surface.
29. The method of claim 28, wherein the tactile warning members are
coupled to the sheet by heating the tactile warning members and
engaging them with the sheet to partially melt the sheet, resulting
in the adherence of the tactile warning members to the sheet once
the sheet cools.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application hereby claims the benefit of U.S.
Provisional Patent Application No. 60/598,250, filed on Aug. 2,
2004, entitled Tactile Warning System, the disclosure of which is
hereby expressly incorporated by reference, and the priority from
the filing date of which is hereby claimed under 35 U.S.C. .sctn.
119(e).
FIELD OF THE INVENTION
[0002] The present invention relates generally to tactile warning
systems for indicating to sight impaired individuals the presence
of a hazard and/or an obstacle.
BACKGROUND OF THE INVENTION
[0003] It is well known that persons with little or no usable
vision depend upon environmental cues for safe and independent
travel. A few examples of environmental cues are ambient sounds,
buzzers, physical elements that may be sensed by a cane, such as a
curb, and surface/floor texture changes that may be felt by a
person's foot or cane. For instance, a sight impaired individual
may use the edge of a curb of a raised sidewalk to help
differentiate between a safe path provided by the raised sidewalk
and a hazardous path provided by a roadway.
[0004] However, it has been found that transitions, which provide
means for transitioning between safe pedestrian paths and obstacles
and/or hazards, a few examples of transitions being curb ramps,
vehicle drop-offs, and depressed corners providing means for
transitioning between an elevated surface and a lower surface,
although accommodating access to wheelchair bound individuals and
others, provide a hazard to sight impaired individuals. Moreover,
since the edge of the safe pedestrian path and the obstacle and/or
hazard is eliminated by the transition, the ability of the sight
impaired individual to differentiate between the safe pedestrian
path and the obstacle and/or hazard is also eliminated. Therefore,
a sight impaired individual may accidentally walk onto/into the
obstacle or hazard, such as a roadway, since there is no raised
curb to mark and separate the safe pedestrian route when there is a
ramp providing a gradual transition from the elevated surface to
the lower surface.
[0005] Because of the inherent danger caused by transitions, the
Americans with Disabilities Act Accessibility Guidelines (ADAAG)
require that tactile warning systems be installed onto pavement or
ground surfaces at certain hazardous junctures. The tactile warning
systems provide a contrasting texture that signals a hazardous
condition to the pedestrian, and thereby informs the pedestrian to
exercise care. In particular, the current regulation requires that
the tactile warning system consist of truncated domes having a
nominal diameter of 0.9 inches, protruding from the ground surface
to a height of 0.2 inches, and having a center-to-center spacing of
2.35 inches. In addition, the tactile warning system should be of
contrasting color to effectively warn whose who have greatly
impaired vision.
[0006] In many cases, the tactile warning systems must be
retrofitted onto existing ground surfaces. Several previously
developed systems are in use for applying a tactile warning system
onto existing ground surfaces. Although somewhat effective, these
previously developed tactile warning systems are not without their
problems. In the previously developed tactile warning systems, a
sheet having truncated domes is adhered to an existing ground
surface via an adhesive layer. The sheet and truncated domes are
integrally formed together, i.e., the sheet is homogenous with the
truncated domes. The sheet and truncated dome are made from either
a preformed thermoplastic material, plastic, or rubber material.
The adhesive layer is either a heat activated adhesive sheet or a
liquid applied adhesive.
[0007] During application of the heat activated adhesive sheet
tactile warning system, the surface receiving the tactile warning
system is prepared by cleaning and preheating the surface with a
propane heat gun. The heat activated adhesive sheet is applied to
the heated surface. The heat activated adhesive layer is then
heated with the propane heat gun until the adhesive layer becomes
molten. Once the heat activated adhesive layer is molten, the
homogeneous sheet of preformed thermoplastic material is carefully
positioned on the heat activated adhesive layer. A specialty roller
having channels to receive the truncated domes is rolled over the
preformed thermoplastic material to aid the adherence of the
thermoplastic material to the ground surface. The thermoplastic
tactile warning system cannot be heated by the propane heat gun
since the truncated domes would melt and spread out, thus losing
their shape.
[0008] Although effective, this system is not without its problems.
First, the thermoplastic material, even when properly applied by
adhesives, has been found susceptible to delaminating due to
adhesive failure, thereby presenting a tripping hazard. Second, the
system requires a two-part system, wherein an adhesive layer must
first be applied to the ground surface, heated, and the sheet
applied upon the adhesive layer as accurately as possible. A
special roller is then used to press the sheet onto the adhesive
layer, the roller having channels to permit the truncated domes to
pass through the channels as the roller is moved across the sheet.
This process is cumbersome, prone to error, especially in the
accurate placement of the sheet upon the adhesive layer.
[0009] When the sheet is not perfectly placed on the adhesive, two
problems occur. First, some of the adhesive is exposed, producing
an unsightly installation and causing a tripping hazard. Second, a
portion of the sheet may not be in contact with the adhesive layer,
permitting an edge of the sheet to roll up or catch a pedestrian's
foot, creating a tripping hazard. Further, it has been found that
the above described tactile warning system does not conform well to
the surface it is applied to, leading to air pockets and/or
permitting water and ice to make its way under the tactile warning
system, leading to its deterioration and/or delamination and
creating an unaesthetic appearance. Further, the two layers (i.e.,
the sheet and the adhesive layer) increase the overall height of
the tactile warning system, increasing the tripping hazard of the
installation.
[0010] The tactile warning systems utilizing liquid adhesives
encounter the same problems mentioned above. Further, the adhesive
application process these systems utilize is messy, labor
intensive, and results in the release of volatile organic compounds
(VOCs) to the atmosphere, and often requires more extensive surface
preparation than for the heat activated adhesive layer systems
described above.
[0011] Thus, there exists a need for a tactile warning system that
is easy to install, does not require the use of an adhesive,
resists delamination, does not present a tripping hazard, has a low
profile, conforms well to the contours of the application surface,
is durable, is cost effective to manufacture, and wherein
installation does not result in the release of VOCs to the
environment.
SUMMARY OF THE INVENTION
[0012] One embodiment of a tactile warning system for providing
tactile warning sensations to a user, the tactile warning system
attachable to an application surface and formed in accordance with
the present invention is disclosed. The tactile warning system
includes a top layer having a plurality of tactile warning members
attached thereto. The top layer with attached tactile warning
members form a single unit adherable to an application surface. The
top layer is formed from a heat activated material adapted to be
heated to a selected temperature at which the top layer becomes at
least partially molten, resulting in the covering of the tactile
warning members and adhering of the top layer to the application
surface, sandwiching the tactile warning members between the top
layer and the application surface. The top layer may be a preformed
thermoplastic material and the tactile warning members may be
shaped as truncated domes. The tactile warning members may be
formed from a heat resistant material, such as a ceramic material.
The tactile warning members may be adhered to the top layer prior
to installation, such as by heating the tactile warning members and
engaging them with the top layer to partially melt the top layer,
resulting in the adherence of the tactile warning members to the
top layer. The tactile warning system may be applied without the
application of an adhesive or other intermediate layer disposed
between the application surface and the tactile warning
members.
[0013] Another embodiment of a tactile warning system for providing
tactile warning sensations to a user, the tactile warning system
attachable to an application surface and formed in accordance with
the present invention is disclosed. The tactile warning system
includes a plurality of tactile warning members formed from a
selected material, the tactile warning members having a top surface
and a bottom surface. The tactile warning system also includes a
sheet coupled to the top surface of each of the plurality of
tactile warning members. The sheet is formed from an activatable
material activatable from a first state in which the sheet is
resistant to adhering to an application surface to an application
state. In the application state, the sheet is adapted to adhere to
the application surface without use of an adhesive to sandwich the
plurality of tactile warning members between the sheet and the
application surface such that the bottom surface of each of the
plurality of tactile warning members contacts the application
surface.
[0014] Still another embodiment of a tactile warning system
attachable to an application surface and formed in accordance with
the present invention is disclosed. The tactile warning system
includes a plurality of tactile warning members formed from a heat
resistant material, the tactile warning members having a top
surface and a bottom surface. The tactile warning system also
includes a preformed thermoplastic sheet coupled to the top surface
of each of the plurality of tactile warning members. The preformed
thermoplastic sheet is activatible by application of heat to adhere
the preformed thermoplastic sheet to the application surface such
that the plurality of tactile warning members are sandwiched
between the preformed thermoplastic sheet and the application
surface. The bottom surface of each of the plurality of tactile
warning members contacts the application surface without an
adhesive or additional thermoplastic layer disposed
therebetween.
[0015] A still yet another embodiment of a tactile warning system
formed in accordance with the present invention is disclosed. The
tactile warning system includes an application surface and a sheet
formed from a predetermined material and adhered to the application
surface. The tactile warning system further includes a plurality of
tactile warning members formed from a selected material different
from the predetermined material of the sheet. The plurality of
tactile warning members are disposed between the sheet and the
application surface, the plurality of tactile warning members
contacting the application surface without an intermediate layer
disposed therebetween.
[0016] One method performed in accordance with the present
invention of applying a tactile warning system to an application
surface, wherein the tactile warning system includes a sheet and a
plurality of tactile warning members, is disclosed. The method
includes placing a sheet and a plurality of tactile warning members
upon the application surface such that the tactile warning members
are disposed between the sheet and the application surface and such
that the plurality of tactile warning members contact the
application surface without an intermediate layer disposed
therebetween. The method further includes activating the sheet such
that the sheet is transformed from a substantially non-adhering
state to an adhering state wherein the sheet adheres to the
application surface sandwiching the tactile warning members between
the application surface and the sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The foregoing aspects and many of the attendant advantages
of this invention will become better understood by reference to the
following detailed description, when taken in conjunction with the
accompanying drawings, wherein:
[0018] FIG. 1 is a perspective view of one embodiment of a tactile
warning system formed in accordance with the present invention
depicting the tactile warning system prior to application to a
sidewalk ramp;
[0019] FIG. 2 is a perspective view of the tactile warning system
of FIG. 1 depicting the tactile warning system after application to
a sidewalk ramp;
[0020] FIG. 3 is a cross-sectional view of one embodiment of a
tactile warning system formed in accordance with the present
invention prior to adherence of the tactile warning system to an
application surface;
[0021] FIG. 4 is a cross-sectional view of the tactile warning
system of FIG. 3 as adhered to the application surface;
[0022] FIG. 5 is a perspective view of the tactile warning system
of FIG. 4;
[0023] FIG. 6 is a cross-sectional view of an alternate embodiment
of a tactile warning system formed in accordance with the present
invention depicting the tactile warning system prior to application
to an application surface; and
[0024] FIG. 7 is a cross-sectional view of the tactile warning
system of FIG. 6 depicting the tactile warning system after
application to the application surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Referring to FIGS. 1-5, one embodiment of a tactile warning
system 100 formed in accordance with the present invention is
disclosed. Turning to FIG. 2, the tactile warning system 100
provides a textural change to warn sight impaired individuals of a
hazard or obstacle in the vicinity of the sight impaired
individual. Moreover, the tactile warning system 100 provides a
contrasting texture that signals a potentially hazardous condition
to the pedestrian, and thereby informs the pedestrian to exercise
care.
[0026] In the illustrated embodiment, the tactile warning system
100 is shown as applied to a ramp 102 of a sidewalk 104. Normally,
the raised height of the sidewalk 104 relative to the height of the
adjacent roadway 106 provides a curb edge 108 which indicates to a
sight impaired individual the presence of the roadway 106. However,
it has been found that transitions, such as curb ramps 102, vehicle
drop-offs, depressed corners, and the like, although accommodating
access to wheelchair bound individuals, provide a hazard to sight
impaired individuals since the curb edge 108 of the sidewalk 104 is
eliminated, thereby also eliminating the ability of the sight
impaired individual to detect the transition between the sidewalk
104 and the roadway 106. Therefore, a sight impaired individual may
accidentally walk onto the roadway 106 since there is no curb edge
108 to mark and separate the sidewalk 104 from the roadway 106 when
there is a ramp 102 transitioning from the sidewalk 104 height to
the surface of the roadway 106. The illustrated embodiment of the
tactile warning system 100 provides a contrasting texture that
signals to a sight impaired user of the ramp 102 the presence of
the roadway 106.
[0027] Turning to FIGS. 1 and 3, the components of the tactile
warning system 100 will be described in more detail. The tactile
warning system 100 includes a sheet or top layer 110 and a
plurality of tactile warning members 112. The top layer 110 is
preferably made of a heat activated material, such that when the
heat activated material is heated above a predetermined activation
temperature, one suitable example being 400.degree. F., the heat
activated material is able to bond to an application surface 114, a
few suitable examples being an asphalt, brick, or concrete surface
of a sidewalk, platform, walkway, pedestrian path, floor, bike
path, etc. One example of a suitable heat activated material is a
preformed thermoplastic, skid resistant, night time visible,
pavement marking material manufactured by Zumar Industries, Inc.,
of Tacoma, Wash., sold under the HOTTAPE trademark, part number
896278. The material is preferably 75 to 90 mils in thickness,
however it should be apparent to those skilled in the art that
other thicknesses, either thinner or thicker, are suitable for use
with and are within the spirit and scope of the present invention.
Preferably, the top layer 110 should be of a color which contrasts
with the application surface 114 to effectively warn those who have
some vision, but who's vision is greatly impaired.
[0028] In the illustrated embodiment, the tactile warning members
112 are formed from a heat resistant material able to withstand
temperatures greater than the predetermined activation temperature
of the top layer 110 such that when the top layer 110 is heated,
the tactile warning members 112 are able to substantially retain
their shape without deforming. In one embodiment, the tactile
warning members 112 are formed from a porous material, such as a
ceramic material, although it should be apparent to those skilled
in the art that other materials are suitable for use with and are
within the spirit and scope of the present invention. The tactile
warning members 112 of the illustrated embodiment are formed as
truncated domes 104 having a nominal diameter of 0.9 inches and a
height of about 0.2 inches. The tactile warning members 112 are
coupled to the top layer 110 in a grid pattern having a
center-to-center spacing of about 2.35 inches.
[0029] Although the tactile warning members 112 of the illustrated
embodiment are described as having a specific shape and being
formed from a specific material, it should be apparent to those
skilled in the art that other shapes and materials are suitable for
use with and are within the spirit and scope of the present
invention. Further, although the tactile warning members 112 are
illustrated and described as being attached to the top layer 110 in
a grid pattern having a specific center-to-center spacing, it
should be apparent to those skilled in the art that other placement
patterns and spacings are suitable for use with and are within the
spirit and scope of the present invention.
[0030] Preferably, the tactile warning members 112 are coupled to
the top layer 110 by heating the tactile warning members 112 to a
temperature exceeding that of the predetermined activation
temperature of the top layer 110. The tactile warning members 112
are then pressed into the top layer 110 such that the top layer 110
melts at the points of contact with the tactile warning members
112, then cools, forming bonds adhering the tactile warning members
112 to the top layer 110 without the need of adhesives or
fasteners.
[0031] In light of the above description of the components of the
tactile warning system 100, the installation of the tactile warning
system 100 will now be described. The first step in installation is
the preparation of the application surface 114. The application
surface 114 should be clean, dry, and above 32.degree. F.
Preferably, the application surface 114 is free of longitudinal
seams or joints, deterioration, loosely exposed aggregate, soil
saturation areas, joint- or seal-crack filled areas, surface
sealing compounds, or areas subject to repeated standing water. A
broom or air sweeper may be used to clean the application surface
114. The application surface 114 should be substantially free of
loose particles, dust, and dirt. Markings, such as paint,
thermoplastic, and preformed thermoplastic markings, may remain on
the application surface 114 if the markings are in good condition.
Loose, flaking, cracked, or adhesive-applied markings should be
removed from the application surface 114.
[0032] Moisture should be removed from the application surface 114.
One suitable method of moisture removal is through application of
heat by a torch. Concrete application surfaces should be moisture
free for 24 hours prior to application for best results. Oil and
grease residue should be removed prior to application. New
concrete, such as concrete less than three moths old, should be
sandblasted to remove curing compounds. Chip seal surfaces should
be cured and stable.
[0033] Next, the application surface 114 should be marked to
clearly delineated, such as by the use of chalk or spray paint, the
location wherein the tactile warning system 100 is to be placed
upon the application surface 114. Application of large segments of
the tactile warning system 100 should be avoided, with a large
tactile warning system 100 installation divided into more
manageable installation sizes, such as segments less than or equal
to about 2 feet by 4 feet.
[0034] The application surface 114 is then heated for application
of the tactile warning system 100. A torch may be used to heat the
application surface 114. The torch is preferably adjusted such that
the flame is blue with an orange or yellow tip. The torch is
adjusted to provide the maximum heat available. A circular motion
may used to heat the application surface 114, including heating the
application surface 114 about 6 inches outward of where the tactile
warning system 100 is to be applied.
[0035] After the application surface 114 is heated, the tactile
warning system 100 is set down upon the application surface 114
with the reflective material 116, such as exposed glass compounds,
facing upward. The installer should discontinue squeezing the torch
handle and utilize the pre-set pilot valve of the torch to heat the
tactile warning system 100 while holding the torch nozzle
approximately 6 inches above the tactile warning system 100. If the
tactile warning system 100 is splattering with the introduction of
the torch, the torch nozzle may be too close to the tactile warning
system 100 or the pilot valve may need to be adjusted to lower the
intensity of the flame.
[0036] The torch nozzle should be held about 6 inches over the top
layer 110 so that the flame is fully extended and heat evenly
applied as the installer moves the torch in a continuous, circular
motion across the tactile warning system 100. The top layer 110
will begin to soften and change shape from the top layer's 110
initially flat profile (shown in FIGS. 1 and 3) to conform to the
application surface 114 to which it is applied, and also conform to
the shape of the tactile warning members 112 disposed between the
top layer 110 and the application surface 114 as shown in FIGS. 2,
4, and 5. As best shown in FIG. 4, the top layer 110 adheres
directly to the application surface 114, sandwiching the tactile
warning members 112 between the top layer 110 and the application
surface 114 without an adhesive layer or second layer of
thermoplastic material being disposed therebetween.
[0037] During heating, the top layer 110 may bubble and discharge.
The top layer 110 of the tactile warning system 100 may change
color, turning slightly darker or pale yellow if white. If the top
layer 110 changes color, the installer should quickly move the
torch to another section to avoid burning or unnecessarily
scorching the top layer 110 by overheating. A soft, "chewing-gum"
consistency indicates proper heating when initially probed with a
putty knife. The top layer 110 should return to its original color
upon cooling and scorch marks will be removed by traffic.
[0038] Turning to FIGS. 4 and 5, during a preferred installation,
the entire tactile warning system 100 is evenly heated. After the
top layer 110 has melted and heat-fused to the application surface
114, the installer may retrace the perimeter of the tactile warning
system 100 and extend the heat to the application surface 114
adjacent to the perimeter of the tactile warning system 100 to
ensure all edges have been sufficiently bonded. For best
retro-reflective properties and skid resistance, the reflective
material 116 should be embedded between 50-60% into the top layer
110. While the tactile warning system 100 is hot, the edges of the
top layer 110 may be feathered with a putty knife or beveled with
the torch.
[0039] The tactile warning system 100 should be inspected after
installation. After the tactile warning system 100 has cooled, a
putty knife may be used to remove a portion of the top layer 110 to
test the adherence of the tactile warning system 100 to the
application surface 114. Edges should be rounded and thoroughly
bonded. If properly installed on asphalt, the top layer 110 should
not pry off without removing some asphalt as evidenced by asphalt
being embedded on the underside of the removed portion of the top
layer 110. If the top layer 110 pries off without any asphalt
embedded on its underside, replace the removed portion of the top
layer 110 and reheat that portion of the top layer 110. If
installed on concrete, the top layer 110 is bonded properly when it
pulls away from itself, leaving a residual film on the application
surface 114. If the top layer 110 does not pull away from the
application surface 114 without any residual film on the
application surface 114, reposition the tactile warning system 100
and reheat that portion of the top layer 110. Typically, the
tactile warning system 100 may be used about 15 minutes after
installation.
[0040] As should be apparent to those skilled in the art, the
illustrated embodiment of the present invention provides a tactile
warning system 100 that does not require the use of an adhesive,
providing for simplified installation, reduced costs, less mess, a
lower profile due to the elimination of an adhesive layer or other
such layer, such as a thermoplastic base layer, does not require
the use of a primer, can be applied even in low temperature
conditions, is retro-reflective, does not result in the release of
VOCs, and does not require special or heavy equipment.
[0041] Referring to FIGS. 6 and 7, an alternate embodiment of a
tactile warning system 200 formed in accordance with the present
invention is depicted. The tactile warning system 200 of FIGS. 6
and 7 is substantially similar to the embodiment described and
illustrated with reference to FIG. 1-5. Therefore, for the sake of
brevity, this detailed description will focus only upon those
aspects of the embodiment of FIGS. 6 and 7 which depart from the
above described embodiment.
[0042] In the alternate embodiment of FIGS. 6 and 7, the method of
attaching the tactile warning members 212 to the top layer 210 has
been modified. More specifically, both the top layer 210 and the
tactile warning members 212 are heated to allow the embedding of
the tactile warning members 212 into the top layer 210 such that
the bottom surfaces of the tactile warning members 212 are
substantially flush with the bottom surface of the top layer 210.
Among other things, this configuration allows for greater ease in
handling and shipping the tactile warning system 200 and reduces
the potential that the tactile warning members 212 are damaged or
dislodged during shipping and handling. The tactile warning system
200 is applied to the application surface 214 in the same manner as
the above described embodiment.
[0043] Although the illustrated embodiments are described and
illustrated as using a heat activated top layer, it should be
apparent to those skilled in the art that other materials here now
know or to be developed which may be activated by other means are
suitable for use with the present invention, such as infrared,
sound, chemical, or pressure activated materials.
[0044] Although the illustrated embodiments are described and
illustrated as using a top layer that exhibits retro-reflective
properties while also being skid resistant, it should be apparent
to those skilled in the art that the top layer may exhibit only one
of these properties, both of these properties, or neither of these
properties without departing from the spirit and scope of the
present invention.
[0045] Although the illustrated embodiments are described and
illustrated as being applied to a ramp to indicate to a sight
impaired user the proximity of a potential hazard, it should be
apparent to those skilled in the art that the tactile warning
system may also be used any time tactile sensations are desired to
be provided to a user whether sight impaired or not. For instance,
the tactile warning systems may used to provide tactile sensations
to individuals to provide positive guidance directing the user
along a selected path through tactile sensations. For instance, the
edges of a path may be lined with the tactile warning system to
provide tactile guidance to a user to permit them to follow the
path through tactile sensations alone. In another example, the
tactile warning systems are used to provide tactile sensations to
users indicating the edge of a passenger loading platform, such as
a train, subway, or other passenger vehicle loading platform.
[0046] While the preferred embodiment of the invention has been
illustrated and described, it will be appreciated that various
changes can be made therein without departing from the spirit and
scope of the invention.
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