U.S. patent application number 11/906949 was filed with the patent office on 2009-02-12 for recessed snowplowable pavement marker.
Invention is credited to Harry E. Lowe.
Application Number | 20090041541 11/906949 |
Document ID | / |
Family ID | 40346706 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090041541 |
Kind Code |
A1 |
Lowe; Harry E. |
February 12, 2009 |
Recessed snowplowable pavement marker
Abstract
A recessed snowplowable reflective pavement marker is mounted in
a shallow elongated groove in a highway surface to expose the
marker to headlights of oncoming motor vehicles. The marker has a
plastic housing with a pocket for holding the reflector and two
sidewalls that support positioning tabs to overlie the uncut
pavement. These tabs maintain markers at a fixed depth below the
pavement. Two other upstanding sidewalls extend laterally in the
groove and terminate at the lower edge of the reflective area of
the reflector. These sidewalls prevent adhesive from entering the
reflector pocket. The function of the positioning tabs and lateral
sidewalls plus the requirement that headlights need only illuminate
this reflective area and not the reflector's non reflective base
serve to reduce groove depth by 50% less than prior art. This
lightweight plastic housing and shallower groove reduce
installation costs and enhance marker safety and performance.
Inventors: |
Lowe; Harry E.; (Schaumburg,
IL) |
Correspondence
Address: |
Charles F. Lind
2210 E. Sherwood Road
Arlington Hts.
IL
60004
US
|
Family ID: |
40346706 |
Appl. No.: |
11/906949 |
Filed: |
October 3, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60849201 |
Oct 3, 2006 |
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Current U.S.
Class: |
404/14 |
Current CPC
Class: |
E01F 9/553 20160201 |
Class at
Publication: |
404/14 |
International
Class: |
E01F 9/06 20060101
E01F009/06 |
Claims
1. A recessed pavement marker component, comprising a unitary
housing having an upwardly facing pocket defined by a base and
opposed pairs of upstanding side walls; positioning tabs projected
outwardly of the pocket from the upper portion of one pair of the
side walls; and anchor means projected outwardly of the pocket from
the lower portions of the transverse pair of side walls, whereby a
reflector can be secured in the housing pocket to define the
recessed marker, whereby said marker can be positioned in
appropriate grooves in the pavement until the positioning tabs
overlie the uncut pavement surface and adhesive in the groove sets
to securely hold the housing in the pavement via the anchor
means.
2. A recessed pavement marker according to claim 1, further
including the anchor means comprising a plurality of separate
spaced apart transversely arranged projections from both of the
transverse side walls.
3. A recessed pavement marker according to claim 1, further
comprising each positioning tab being connected via a narrow neck
to the top of its side wall, to easily break away when the housing
is set in place as located and without dislocation of the
marker.
4. A recessed pavement marker according to claim 3, further
including the anchor means comprising a plurality of separate
spaced apart generally parallel transversely arranged projections
from both transverse side walls, whereupon the reflector will lie
completely below the level of the uncut pavement surface.
Description
RELATED APPLICATION
[0001] Provisional Application 60/849,201, filed Oct. 3, 2006 in
the name of the same inventor and entitled RECESSED SNOWPLOWABLE
PAVEMENT MARKER, disclosed the subject matter as in this currently
filed application.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to snowplowable pavement
markers for use in providing lane delineation, etc. Pavement
markers must withstand damage from the vehicle traffic, snowplows,
and sundry environmental factors. Two types of snowplowable
pavement markers are generally being used now: raised markers and
recessed markers.
[0003] A typical raised marker utilizes a heavy iron casting
embedded within a pavement cutout. The casting has raised laterally
spaced inclined longitudinal rails, and a reflector held between
and at a lower height than the rails. Both the rails and reflector
as mounted protrude slightly above the pavement surface. Raised
markers have been used extensively in snow-belt States, as the
rails effectively guide the snowplow up and over the reflector.
However, many raised marker castings are now being dislodged from
the pavement, which then potentially become heavy projectiles
capable of causing both vehicle damage and personal injury. In
fact, some States have already demanded increased inspection of
raised markers and/or their removal.
[0004] Recessed markets are mounted below the pavement surface, in
long narrow grooves that allow vehicle headlight rays to impact the
reflector. These deep grooves tend to collect debris, rain, and
snow which obscures the reflective marker surfaces and reduces or
precludes reflectivity. Moreover, deep grooves can errantly steer
the wheels of motorcycles and small cars. Deep grooves also take
longer to clean out than more shallow grooves.
OBJECTS AND FEATURES OF THE INVENTION
[0005] General objects of this invention are to provide a recessed
marker that overcomes problems found in the prior art markers,
including: being more economically and accurately installed and
less costly to maintain; having improved reflectivity for good
visibility; and being of lightweight construction for minimizing
damage should the marker become dislodged from the pavement.
[0006] Detailed features of the invention include: (1) reducing the
groove depth by aligning the bottom groove face generally with the
lower edge of the marker reflective surface, thereby minimizing the
groove depth. The prior art groove is significantly deeper because
it must account for the non-reflective height of the reflector
structure and the thickness of reflector adhesive. (2) reducing
marker and tire wear/damage because of a lower reflector profile.
(3) increasing the groove width to provide easier marker
installation and to increase water drainage from the groove.
[0007] Another general object of the invention is to allow for the
.use of multiple or tandem reflectors spaced longitudinally apart
in a single shallow depth groove, for-improving reflective
efficiency.
SUMMARY OF THE INVENTION
[0008] The housing is made from strong lightweight plastic, such as
polycarbonate (PC) or acrylonnitrile-butadiene-styrene (ABS),
having an upwardly open pocket defined by a base and interconnected
side walls that receive and hold the reflector. The two lateral
side walls cross the groove and protrude from the base to terminate
at the lower edge of the reflective area of the reflector. The
other side walls rise upwardly beyond the top of the reflector.
Positioning tabs project laterally off of these side walls operable
to overlie the uncut roadway pavement adjacent the groove and
thereby accurately position the marker so that the top of the
reflector will be at a desired clearance below the uncut pavement
surface and the lower reflective edge will be generally aligned
with the bottom face of the shallow groove.
[0009] Thus, after adhesive has been admitted into the secondary
groove, the marker can be positioned in the groove, whereupon tab
contact with the uncut pavement surfaces will accurately and
consistently locate the marker reflector below the uncut pavement
surface and the marker will be firmly held thereat when the
adhesive sets. The use of positioning tabs, lateral side walls, and
a slightly deepened secondary groove allows the longitudinal
shallow groove depth to be approximately 50 percent less than that
of typical prior art grooves.
[0010] The invention can be enhanced even further from a cost
benefit/reflectivity standpoint by installing tandem markers, each
spaced two or three feet apart in the same longitudinal groove.
[0011] Generally, any reflector might be located approximately
three/five feet from the ends of the shallow groove, which for a
single reflector might therefore be approximately six/ten feet in
length; while tandem reflectors might be positioned in longer
grooves, with possibly three/four feet between the groove ends and
the nearest reflector and with two/three feet separation between
adjacent reflectors.
[0012] The inventive marker can be modified to accommodate recessed
reflectors of different sizes and/or configurations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and other objects, features or advantages of the
invention will be more fully understood and appreciated after
considering the following description of the invention, which
includes the accompanying drawings, wherein:
[0014] FIG. 1 is a perspective view, part broken away and in
section, of the roadway pavement having the line of sight shallow
and secondary installation grooves cut therein, the marker with its
positioning tabs and reflector in place, and the adhesive holding
the marker in the pavement;
[0015] FIG. 2 is an exploded perspective view of the pavement and
line of sight shallow and secondary grooves cut therein, and the
marker housing and reflector components in exploded
association;
[0016] FIG. 3 is a cross-sectional side view of a prior art marker
installed in a conventionally cut pavement groove;
[0017] FIG. 4 is a cross-sectional side view of the subject marker
installed in the proposed cut and adhesive filled pavement
groove;
[0018] FIG. 5 is a sectional view taken from line-5-5 in FIG.
4;
[0019] FIG. 6A is a plan view of a single inventive marker shown
mounted in the cut pavement groove;
[0020] FIG. 6B is a schematic illustration of the groove and
pavement profiles illustrated in FIG. 6A:
[0021] FIGS. 7A and 7B are illustrations similar to FIGS. 6A and
6B, except of a tandem or two marker setup;
[0022] FIGS. 8A and 8B are illustrations similar to FIGS. 6A and
6B, except of a tandem or three marker setup;
[0023] FIG. 9 is a schematic illustration of a vehicle approaching
tandem markers with illuminating and reflecting light rays
included;
[0024] FIG. 10 is a chart illustrating the reflectivity of
inventive markers as a vehicle approaches.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The invention provides that a traditional line of sight
groove 10 would be cut in the pavement 12, but to a shallower depth
to where the marker 14 is to be located, where then a short
secondary deeper groove 16 would be cut sufficient to mount the
marker 14 therein while yet having marker top clearance 18 below
the adjacent uncut pavement surface 19. The marker 14 will comprise
a housing 20 having laterally extended tabs 22 sized to rest on the
adjacent uncut pavement surface 19 when the marker is positioned in
the secondary groove 16 while yet having the marker top clearance
18 below the uncut pavement surface. This positioned marker will
also preferably have the lower reflective edge 24 of the reflector
face 26 generally lined up with the bottom face 28 of the shallow
line of sight groove 10.
[0026] Further, after a suitable adhesive or epoxy 30 is in the
secondary groove 16, the marker need only be pressed into it until
the positioning tabs 22 rest on the adjacent uncut pavement surface
19, whereupon the marker will be accurately located relative to the
pavement and securely held therein when the adhesive or epoxy
sets.
[0027] The prior art and inventive recessed markers are in part
compared in FIGS. 3 and 4. Thus, a line of sight groove 10 is cut
in the pavement for both markers, starting at zero depth at both
line of sight groove ends (shown in FIGS. 6B. 7B and 8B) and
extending progressively to a deepest medial portion, such as where
the markers might be secured by an effective adhesive or epoxy.
[0028] However, the line of sight groove depths 31 are clearly
different for the prior art and present markers, as the prior art
marker 14PA sits on and is held by adhesive to the bottom face 29
of its groove (see FIG. 3) while the depth of the present marker 14
is determined when the positioning tabs 22 rest on the adjacent
uncut pavement surface (see FIGS. 4 and 5).
[0029] The reflector housing 20 might be of unitary construction
with a defined upwardly facing pocket 32 defined by a base 34 and
opposed pairs of upstanding side walls 36 and 38. The positioning
tabs 22 project outwardly of the pocket from the upper portion of
the side walls 36. The tabs further might be narrow as a neck at
the top of its side wall, to easily break away without dislocation
of the marker. Also, the anchor means or tabs 42 project outwardly
away from the lower portions of the side walls 38 and away from
pocket 32. The anchor means might be comprised as many separate
spaced apart projections off of the housing or projecting flanges
across the entire width of side walls 38.
[0030] The invention further provides that the secondary groove 16
is cut to the width and depth needed to have the reflector housing
20 fit therein, and yet be spaced from the secondary groove
pavement surface 40. Adhesive such as epoxy can be admitted into
the secondary groove, so that after the housing is pressed into the
adhesive, the adhesive can flow around the anchor tabs so that as
soon as the adhesive sets, the housing and its reflector will be
firmly secured relative to the pavement.
[0031] The sizing and arrangement of these components including the
tabs 22 and reflector mounting relative thereto will preferably
provide that the recessed marker can be positioned in the secondary
groove so that the bottom face 28 of the line of sight cut groove
10 will generally line up with the lower edge 24 of the reflective
surface 26 on the held reflector 14.
[0032] Generally, the top of the reflector should be recessed
approximately 0.12 inches below the uncut pavement surface. The
vertical height of the reflective surface might be approximately
0.25-0.30 inches. The height of the adhesive fill 30 in the
secondary groove 16 should be possibly 0.05-0.15 inches below the
top of transverse side walls 38.
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