Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Backgrcund cf the Inventlon
The present inventlon relates to pavement marke-s cf
the cube corner reflex reflector type which are cleaned by the
action of vehicular trafflc on the roadway contactlng the re-
~ 9~z9
1 flector, and in particular to such pavement markers which are2 suitable for use in snow areas and are, therefore, construc-
3 ted so as to protect the reflector from contact with snowplow4 blades
Pavement markers have become widely accepted as per-
6 manent installations for providing visible signals which mark
7 traffic lanes and control the flow of traffic on roadways in
8 connection with, or in place of, conventional painted traf-
g f c lines. While a large number of such markers employ re-
flectors which reflect light emanating from oncoming vehicles
11 to provide a visible $ignal to the operators of such oncoming
12 vehicles, other markers have been proposed which utilize an
13 independent light source, such as an electric lamp located
14 within the marker, to provide a signal visible from oncoming
1~ vehicles. The term "signal means" is employed herein to de-
16 note any such marker employing a reflector, a lamp or another
q light source or any arrangement which provides the desired
~8 visible signal.
L9 A snowplowable version of such a prior art pavement
æo marXer is disclosed in U. S. Patent No. 3,790,293, issued to
21 S. A. Heenan et al. on February 5, 1974, and ~. S. Patent No.
22 3,809,487, issued tc R. ~ Flanagan on May 7, 1974, both of
23 which patent;s are assigned to the assignee of the present
24 invention. In the arrangements used in those patents, a base
~ember of relatively high-strength material, such as metal,
26 includes a pair of laterally spaced apart keels which are
27 permanently affixed to the roadway surface by insertion into
28 grooves cut in the pavement, and a reflector body of synthetic
2~ resin ma~erial is affixed to the base member for selective re-
~0 moval and r~placement without destruction of the base member.
~9~329
1 The base member is providcd with inclined ramps for protect-
2 ing the reflector body from encounters with snowplow blades.
3 In these prior art snowplowable pavement markers, an
4 attempt was made to minimize the height of the pavement marker
above the roadway surface by minimizing the height of the re-
6 flector body carried by the base, thereby to minimize the im-
7 pact forces imparted to vehicle tires as they passed over the
8 pavement marker. Indeed, in these prior art snowplowable
g pavement markers the maximum height of the marker ~bove the
roadway surface had been reduced as far as possible with
11 existing reflex reflector bodies and installation techniques,
12 consistent with obtaining satisfactory visibility of the pave-
13 ment marker, but could not be reducec. below about .72 inches
14 above the pavement.
It has also been recognized in connection with these
16 prior art pavement markers that the angle between the roadway
17 surface and the inclined ramps of the base member should be
18 minimized to minimize the impact forces imparted to the pave-
L9 ment marker and to the surrounding pavement by impact of snow-
plow blades with the inclined ramps of the pavement marker.
21 While theoretically the ramp angle could ~e reduced as low as
~2 desired, the lower the angle the longer the ramp would have to
2~ be to maintain the same maximum height and, accordingly, the
24 longer the keel members and the longer the grooves or recesses
that would have to be cut in the pavement. The longer the
26 grooves, the greater the weakening of the pavement and the
27 greater the time and expense required to form the grooves.
28 Furthermore, the longer the base member, the heavier and more
29 expensive it is. Thus, these factors serve practically to
limit the ramp an~le that could be obtained with thcse prior
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1 art pavement markers to no lower than 6 degrees.
2 In addition, the prior art pavement markers were
3 monodirectional devices. While bidirectional reflector
4 bodies were available, in order to mount them in a metal
base member for protection from impact with sno~low blades,
6 it would be necessary to have inclined ramps extending from
7 the reflector b~dy in both directions. Thus, if the same
8 ramp angle and maximum height above the roadway surface
9 were to be maintained, it would be necessary virtually to
double the length of the base member, with the attendant
11 disadvantages discussed above.
12 It has been suggested in the prior art partially to
13 recess the reflector elements below the level of the roadway
14- surface as, for example, in U.S. Patent No. 2,260,498, issued
to L. M. Wise on October 28, 1941, and U.S. Patent No. 1,952,942,
16 issued to D. E. Ross on March 27, 1934. In Wise and Ross,
17 because of the nature of the glass lens used, the portion of
18 the lens disposed below the roadway would be wasted and ino~-
L9 erative. Further, the Wise pavement marker is a generally
cylindrical body embedded in the pavement, with a part-conical
21 inclined upper surface extending above the level of the roadway
22 surface at an angle in excess of 25 degrees with the roadway
23 surface, at which angle the impact forces of snowplow blades
Z4 against the pavement marker are so great that they destroy
the pavement marker and/or severely damage the surrounding
26 pavement and snowplow blade. Reduction of the an~le by increasing
27 the diameter of the Wise pavement mar~er would require unacceptable
28 increases in the size of the pavement recess and the weight of
29 the pavement marker itself. Furthermore, the cros5 sectional
~0
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outline of the l~lise pavement marker bodY is not conducive to
ready insertion into a recess which is cut or drilled in a
finished pavement.
The Ross device suffers from basically the same disad-
vantages. Also these devices, as well as those of U.S. Patents
Nos. 3,836,275 (Finch) and 2,126,224 (Shaffer et al.),
essentially try to minimize height by using small part-spheri-
cal bead-type reflectors. All have proven impractical and in-
efficient as a result of dirt build-up, since they are unacces-
sible to the wiping action of passing vehicle tires.
Accordina to the present invention there is provided
a base member for use as a component of a low-profile road marker,
said base member havinq first and second laterally spaced-apart
lonqitudinally extendinq ramD members each having a lower portion
and an upper portion and an inclined surface extending between a
lowermost end and an uppermost end to form an inclined ramp, the
lower portion of said base member defining a longitudinally ex-
tending keel portion adapted to be recessed below the road surface
with the upper portion of each said ramp member adapted to extend
above the road surface, and said base member having a support member
interconnectinq said ramp members and providing a downwardly
facing bottom surface adapted to be disposed in a complementary
recess cut in the road surface and a generally upwardly facing
suDDort surface adapted to carry signal means thereon, the signal
means' thus adaDted to be disposed between and below said ramp
members with an uPDer nortion of the siqnal means disposed
above the road surface.
According to a further aspect of the invention there
is provided a low profile road marker comprising said base member
-- 5
1(~8~Z9
in combination with a signal means disposed between and below said
ramp members and carried by said support surface.
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9l~29
The base member of the invention will best be un~erstood by
reference to the following specification taken in connection
with the accompanying drawings.
Brief Description of the Drawings
FIGURE 1 is an exploded front perspective view of a
bidirectional pavement marker including a base member and a
reflector assembly, constructed in accordance with an embo-
dying the features of a first embodiment of the present in-
vention;
FIG~ 2 i8 a reduced top plan view of the base member
of the pavement marker of FIG~ l;
FIG 3 is an end elevational view of the base member
of FIG~ 2~ as viewed from the right-hand end thereof;
FIG~ 4 i8 a fragmentary view in vertical section taken
along the line 4-4 in FIGc 2;
FIG~ 5 is a side elevati~nal view of the base member
of FIG~ 4r shown installed in place on the pavement of a road-
way;
FIG~ 6 is a view in vertical section taken along the
line 6-6 in FIGo 2~ with a reflector assembly positioned on
the base members;
FIG~ 7 i~ a fragmentary view, similar to FIG~ 6, of
an alternative form of base member;
FIG~ 8 is an enlarged top plan view of the reflector
assembly of FIG~ l;
FIG~ 9 is an enlarged fragmentay view in vertical
section taken along ~he line 9-9 in FIGc 8;
FIG~ 10 is an end elevational view of the reflector
,
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1 assembly of FIG. l;
2 FIG. 11 is an enlarged fragmentary side elevational
3 view of a portion of the base member shown in FIG. 5;
4 FIG. 12 is a side elevational view of a cutting appa-
ratus for cutting in the pavement the recesses for receiving
6 the pavement marker of FIG. 1, with a portion of the blade
7 assembly broken away;
8 FIG. 13 is an enlarged, fragmentary end elevational
g view in partial vertical section o the apparatus of FIG. 12,
as viewed from the right hand end thereof;
11 FIG. 14 is a top plan view of a monodirectional pave-
12 ment marker constructed.in accordance with and embodying the
13 features of a second embodiment of the present invention;
14 FIG. 15 is a side elevational view of the pavement
marker of FIG. 14, as viewed from the left~hand side thereof
16 FIG. 16 is a fragmentary side elevational view of a
17 cutting apparatus for cutting in the pavement the recesses
18 for mounting the pavement marker of FIG. 14;
L9 FIG. 17 is an end elevational view of the apparatus
~o of FIG. 16, as viewed from the right-hand end thereof;
21 FIG. 18 is a fragmentary side elevational view of an
~2 alternative form of cutting apparatus for cutting in the pave-
23 ment the recess for mounting the pavement marker of FIG. 14;
24 and
FIG. 19 is an end elevational view of the apparatus
26 of FIG. 18, as viewed from the right-hand end thereof.
7 Description of the Preferred Embodiments
28 Referring no~ to FIGS. 1 through 6 and 11 of the
29
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1 drawings, there is illustrated a snowplowable pavement marker,
2 generally designated by the numeral 30. In use, the pavement
3 marker 30 is embedded in the pavement 20 of a roadway so as
~ to project above the roadway surface 21 and be visible from
oncoming vehicles traveling in either direction along the road-
6 way surface, while being protected from snowplow blades 25 in-
7 clined at an acute angle A to the direction of travel D. The
8 pavement marker 30 includes a base member, generally designated
g by the numeral 40, which is formed of a relatively high-strength
material, such as metal, and supports thereon a reflector assem-
11 bly, generally designated by the numeral 70. The base member 40
12 is preferably cast as an integral unit, and includes a pair of
13 parallel, elongated, laterally spaced apart keel members 41 and
14 45, the keel member 41 having parallel substantially vertically
extending inner and outer side surfaces 42 and 43, and the ke~l
16 member 45 having parallel substantially vertically extending
17 inner and outer side surfaces 46 and 47.
18 ~ach of the keel members 41 and 45 lS provided with a
substantially identical irregular bottom surface, generally
~0 designated by the numeral 44, which interconnects the side
21 surfaces 42 and A3 and the side surfaces 46 and 47 along the
22 bottoms of the keel members 41 and 45. More particularly,
~3 each of the irregular bottom surfaces 44 includes a flat
24 horizontal bottom portion 48 disposed centrally of the keel
mem~er and a pair of downwardly sloping and slightly arcuate
26 end portions 49 lying substantially along a common imaginary
27 circle C and respectively extending downwardly from the oppo-
28 site ends of the keel member toward the bottom portion 48,
29
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.
2g
1 each of the end portions 49 being interconnected ~7ith the
2 adjacent end of the flat bottom portion 48 by a plurality of
3 substantially right-angular step portions 50. The step por-
4 tions 5~ define a plurality of tooth-like points 51, all of
which lie along the imaginary circle C and function to re-
6 tard slipping or shifting of the base member 40 with respect
7 to the pavement.
8 Each of the keel members 41 and 45 is also provided
g with a pair of inclined upper surfaces 52 and 53 which res-
pectively rise from adjacent to the opposite ends of the
11 keel member to uppermost portions which join a flat top sur-
12 face 54 and interconnect the side surfaces 42, 43 and 46, 47
13 at radiused corners to prevent stress concentrations when the
! 14 base member ~0 is struck by a plow blade. The lower ends of
the inclined surfaces 52 and 53 respectively ~oin short in-
16 clined surfaces 49b which slope downwardly from the inclined
17 surfaces 52 and 53 toward the adjacent ends of the base mem-
18 ber 40 and are respectively connected to the end portions 49
~9 by short vertical end surfaces 49a. The base member 40 has
B 20 a kasal plane P which is substantially parallel to the top
21 surfaces 54 and intersects the short inclined surfaces 49b
22 slightly above their lines of intersection with the inclined
23 upper surfaces 52 and 53.
2~ Each o~ the inclined upper surfaces 52 has an inner
Z5 edge 52a which is inclined with respect to the ka~l plane P
26 at a first acute angle X (see FIG. 11), and an outer edge 52b
27 which is inclined with respect to the bas~l plane P at a sec-
28 ond acute angle Y. In like manner, each of the inclined upper
29
, ~
_ ~ _
.. . _
1~9~
1 surfaces 53 has an inner edge 53a which is inclined with res-
B 2 pect to the ~* plane P at the angle X, and an outer edge
3 53b which is inclined with respect to the^bas~1 plane P at
4 the angle Y. Thus, each of the inclined upper surfaces 52
and 53 is slightly sloped downwardly and laterally outwardly
6 Of the base member 40.
7 More particularly, the inner edges 52a of the inclined
8 upper surfaces 52 intersect the top surfaces 54 a sliyht dis-
g tance forwardly of the points where the outer edges 52b inter-
sect the top surfaces 54, the base member 40 being oriented
11 with the longitudinal axis thereof extending parallel to the
12 direction of travel D, so that the lines of intersection 54a
13 between the inclined upper surfaces ~2 and the top surfaces
14 54 are each disposed at an acute angle with respect to the
direction of travel D. In like manner, the inner edges 53a
16 of the inclined upper surfaces 53 intersect the top surfaces
17 54 a slight distance forwardly of the points where the outer
18 edges 53b intersect the top surfaces 54, so that the lines of
L9 intersection 54b between the inclined upper surfaces 53 and
the top surfaces 54 are each disposed at the angle Z with
21 respect to the direction of travel D. The angle Z is prefer-
22 ably greater than or e~ual to the plow blaae angle A, being
23 generally in the range of between 60 degrees and 75 degrees,
24 although it could be slightly less than the angle A. The
short inclined surfaces 49b of the keel member 41 are res-
26 pectively coplanar with the short inclined surfaces 49b of
27 the keel member 45 and are preferably inclined at an angle
28 of approximately 15 degrees with respect to the basa~ plane
29 P-
: 3~ The portions of the inner side surfaces 42 ~nd 46 of
G /,
1~89~3Z9
¦3 1 the keel membèrs 41 and 45 above the b~sal plane P extend in-
2 wardly to form thickened portions 55 extending from approxi-
3 mately midway between the ends of the inclined surfaces 52
4 to approximately mid~Jay between the ends of the inclined sur-
face 53, each of the thickened portions 55 having sloping
6 shoulder portions 55a and a recessed inner side wall portion
7 56 centrally thereof. Extending laterally outwardly from the
8 keel members 41 and 45 are longitudinally spaced apart support
g tabs 57 and 58, the tabs 57 and 58 all having bottom surfaces
59 which are coplanar and lie substantially in the b s~l plane
11 P
12 Interconnecting the thickened portions 55 of the keel
13 members 41 and 45 is a web-like support member, generally des-
14 ignated by t~e numeral 60, which is substantially rectangular
in plan outline. The support member 60 has a flat planar top
16 surface 61 which lies substantially in the b~a-l plane P and
17 an arcuate part-cylindrical convex bottom surface 62 which is
18 connected at the opposite ends thereof to the top surface 61
L9 ~Y short end surfaces 66. Recessed in the top surface 61 cen-
trally thereof and parallel thereto is a support surface 63
21 which lies below the b~s~l plane P and extends transversely
22 substantially all the way across the support member 60, and
23 which is longitudinally substantially coextensive with the
24 recessed side portions 56 of the keel members 41 and 45.
Substantially vertically extending end walls 64 extend down-
26 wardly from the top surface 61 at the opposite ends of the
27 support surface 63, the end walls 64 and the recessed inner
28 side wall portions 56 of the keel members 41 and 45 all
29 belng connected to the support surface 63 by a peripheral
channel or ~roove 65 which extends all the way around the
J 2_
1~)898Z9
support surface 63 and is generally arcuate in transverse
cross section (see FIG. 4).
Referring now also to FIGS. 8-10 of the drawings,
the reflector assembly 70 is dimensioned to fit between the
end walls 64 and the recessed inner side wall portions 56 to
be supported upon the support surface 63. The reflector
assembly 70 preferably may be generally of the type disc o~ed
in U.S. Patent No. 3,332,327, issued to S. A. Heenan on
July 25, 1967. In the preferred form, the pavement marker 70
will be provided with a glass overlay to render it highly
abrasion resistant. Alternatively, the reflector assembly 70
may be of the type disclosed in detail in copending Canadian
Application Serial No. 277303.
The reflector assembly 70 includes a body or shell 71
o~ light-transmitting synthetic resin which, in use, is filled
or "potted" with a relatively rigid filler material to form a
solid core 72 which is contiguous with the inner surface 73 of
the shell 71 and serves to reinforce the shell 71 and provide
a solid, rugged structure capable of withstanding forces ap-
plied to the reflector assembly 70 when the outer surface 74of the shell 71 is struck by vehicular traffic during service.
The reflector assembly 70 i~ provided with a generally hori-
zontal base 75 for cooperatively engaging the surface on which
the reflector assembly 70 is to be~1nstalled. The shell 71 in-
cludes a generally horizontal top wall 76 which is raisedvertically above the base 75 and i8 lnterconnected therewith by
opposed inclined front and rear walls 77 and 78 and opposed sub-
~tantially vertically extending side walls 79.
Each of the inclined walls 77 and 78 is provided with
a re~lector system~ generally designated by the n~meral 80,
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and including a generally planar obverse light-receiving face
81 on the outer surface of the shell 71 and a reverse light-
receiving face 82 on the inner surface of the shell 71.
The reflecting system 80 employed is a triple mirror reflex
reflector system in principle, ~he reverse face 82 containing
a plurality of light-reflecting elements 85, each having three
substantially square planar surfaces arranged mutually at right
angles and meeting at a common point remote from the obverse
face 81, thus forming a cube corner, the axis of which is
arranged to be generally in alignment with light rays refracted
from the obverse face 81. The reverse face 82, including at
least the light-reflecting element~ 85, i8 preferably coated
with a light-reflecting material, such as by metallizing.
Extending between the end walls 79 along the bottom edges of
the obverse faces 81 are two parallel gutters 86. Integral
with each of the front walls 77 adjacent to the opposite ends
thereof and extending upwardly therefrom substantially normal
thereto from the gutters 86 partway to the upper end~ of the
obver~e faces 81 are parallel pairs of shoulder flangers 87.
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1 Extending upwardly from the gutters 86 at points spaced a
2 predetermined slight distance inwardly from the opposite
3 ends thereof are two lugs 88. Overlying each of the ob-
4 verse faces 81 is a flat glass layer 90 which extends sub-
stantially the entire length of the obverse face 81 bet-
6 ween the inner surfaces of the shoulder flanges 87, and
7 up~.~ardly from the lugs 88 to the t~p surface 74 of the
8 shell 71, each of the glass layers 90 preferably being
g secured to the associated obverse face 81 by a sui~able
adnesive. The glass layers 90 serve to provide additional
11 protection against abrasion of the obverse faces 81 of the
12 reflecting systems 80~ -
13 Fixedly secured to and compietely covering the base
14 75 is a pad 91 of an adhesive, impact-absorbing material,
the bottom surface of which may be ccvered with a suitable
16 release liner 92. In assembly of the reflector assembly 70
17 with the base member 40 of the pavem~nt marker 30, the re-
L8 lease liner 92 is removed and the pad 91 is placed upon the
19 support surface 63 of the base member 40 with the obverse
~o faces 81 of the reflector systems 80 respectively facing
21 toward the opposite ends of the pavement marker 30, i~e.,
op~os ~æd
: B ~2 facing the~directionsof oncoming vehicles. It will be un-
23 derstood that the reflector assembly 70 may be assembled
24 with the base member 40 either before or after the base
member 40 is installed on the pavement. Significantly,
26 the adhesive attachment of the reflector assembly 70 to
27 the base member 40 permits later removal and replacement
28 of the reflector assembly 70 in the event it becomes
29
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1(~89~29
damaged, worn or the like, without removlng the base member
40 from the pavement.
It is a significant feature in reducing the overall
height of the marker of the present invention that when the
reflector assembly 70 is mounted in place upon the support
surface 63, substantially the entire obverse face 81 of
the reflect ~ system 80 lies above the plane P,bUt the lower-
most ones of the reflector elements 85 lie below the plane P,
but even so are operative to reflect incident light even
adjacent to the lower edge of the obverse face 81, by reason
of downward refraction of the incident light by the front face.
If the reflecti~e area were projected parallel to the nominal
refracted ray, the lower edge of such projection would intersect
the front face substantially at the plane P.
15Furthermore, the vertical distance between the top
surface 74 of the shell 71 and the bottom surface of the pad
; 91 is such that when the reflector assembly 70 is mounted in
place upon the support surface 63 of the base member 40, the
reflector assembly 70 is at all points therof below the inclined
upper surfaces 52 and 53 and the top ~urfaces 54 of the base
member 40 a predetermined distance sufficient to prevent con-
tact of the reflector assembly 70 by the corners of angled
plow blades. In other words, when the reflector assembly 70 is
mounted in place and the plane P is disposed horizontally, a
vertical line extending upwardly from any point on the reflector
a~sembly 70 will lntersect a plane parallel to
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10898Z9
1 the inclined surfaces 52 or 53 or the top surface 54 a finite
2 vertical distance above that point on the reflector assembly 70
3 ~see FIG. 6).
4 Referring to FIG. 7 of the drawings, there is illus-
trated an alternative form of base member, generally desig-
6 nated by the numeral 120, which is substantially identical
to the base member 40 except for the arrangement of the top
8 surface of the support member 60. More particularly, in
g t,he base member 120, the support member 60 is provided at
the opposite ends thereof with two short coplanar flat top
11 surfaces 121 respectiyely connecting concave cylindrical
12 surfaces 122 which are substantially concentric with the
13 bottom cylindrical surface 62, and are interconnected at
14 the bottom edges thereof by a planar'support surface 123
parallel to the top surfaces 121. The support surface 123
16 is sufficiently recessed below the top surfaces 121 so as
17 to be able to accommodate the reflector assembly 70 therein
18 in essentially the same manner as was described above ~ith
L9 respect to the base member 40. This alternative arrange-
ment, while still precluding entry of the plow blade,
21 facilitates the entry of vehicle tires onto the arcuate
22 surfaces 122 so that the wiping action of the tires will
23 be effected further down on the glass layers 90 than is
24 possible with the base member 40, thereby achieving a
more complete wiping of the glass layers 90.
26 , In installation of the pavement marker 30 on the
27
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` ' ~0
', ' ' ' ~'
1(~89~329
1 pavement 20, the base member 40 must be embedded in the
2 pavement so that the roadway surface 21 will lie substan-
3 tially in the basaL plane P of the base member 40. This
4 necessitates that the bottom portions of the keel members
41 and 45 and the support member 60 respectively be re-
6 cessed below the roadway surface 21 in corresponding
7 grooves or recesses in the pavement 20. It is a signifi-
8 cant feature of the present invention that the pavement
g marker 30, and particularly the base member 40 thereof,
has been constructed greatly to facilitate the installa-
11 tion of the pavement marker 30 on the pavement 20 so that
12 the support surface 63 lies below the roadway surface 21,
13 all without enlarging the overall length of the pavement
14 marker 30, thereby to minimize the maximum height of the
pavement marker 30 above the roadway surface 21 while main-
16 taining an adequately low angle between the inclined up~er
17 surfaces 52 and 53 and the roadway surface 21.
18 More particularly, as was described above, the bot-
~ tom surfaces 44 of the keel members 41 and 45 are generally
zO arcuate in overall outline, and the bottom surface 62 of
21 the support member 60 is arcuate in outline, thereby per-
~2 mitting the keel members 41 and 45 and the support member
23 60 to be respectively received in complementary arcuate
24 grooves or recesses 95, 96 and 97 in the pavement 20. Such
arcuate grooves can be conveniently cut with circular cut-
26 ting blades suitable for cutting concrete or the li~e. Cir-
27 cular blade concrete cutting machines are ~nown in the prior
28 art and, indeed, are routinely used to form the arcuate keel
29
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1 recesses for installing the snowplowable pavement markers
2 disclosed in the aforementioned U. S. Patents Nos. 3,790,293
~ and 3,809,487.
4 However, such prior art cutting machines have been
provided with only two laterally spaced apart coaxial circu-
lar saw blades of equal diameter for forming the keel reces-
7 ses, which recesses are relatively narrow, typically no wi-
8 der than the groove cut by a single saw blade. Such prior
g art machines are not capable of cutting a wide arcuate groove10 in the pavement, nor are they capable of cutting different
11 size grooves without changing blades. Thus, were such prior
12 art machines utilized to install the pavement marker of the
13 present invention, it would be necessary either to use sep-
14 arate machines, or to perform several cutting or machining
operations, one utilizing the prior art machine to cut the
16 keel grooves or recesses, and a separate machining operation
17 or perhaps a series of such operations to form the wide shal-
18 low groove necessary to accommodate the support member 60 of
L9 the pavement marXer 30. Such a multi-step procedure would
be unacceptably time-consuming and expensive, as well as
21 hazardous
22 Accordingly, referring now to FIGS. 12 and 13 of the
23 drawings, there is provided in the present invention a no~el
Z4 cutting apparatus permitting easy installation of the mar~er
30. The cutting apparatus is generally designated by the
26 numeral 100, and is capable of simultaneously cutting the
27 recesses 95, 96 and 97 in a single operation. The cutting
28 apparatus 100 includes a generally rectangular frame 101,
29
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1 having rotatably secured thereto adjacent to a rear end
2 thereof a transversely extending a~le 102 coupled at the
3 opposite ends thereof to a pair of support wheels 103 for
4 rolling the cutting apparatus 100 along the roadway sur-
face 21. It will be understood that additional pairs of
6 support wheels could be mounted on the frame 100, as nee-
7 ded or desired. Carried by the frame 101 adjacent to the
8 front end thereof is a transversely extending rotatably
9 mounted horizontal axle or shaft 104 having fixedly se-
cured thereto at laterally spaced apart points thereon two
11 pairs of relatively large side-by-side circular cutting
12 blades 105 and 106, dimensioned and positioned for respect-
13 ively cutting the keel recesses 95 and 96 in the pavement
14 20. Fixedly secured to the shaft 104 between the cutting
blades 105 and 106 are a plurality of smaller diameter co-
16 axial circular cutting blades 107 arranged closely together
17 and equidistantly spaced apart by spacers 108 so as to cut
18 a substantially continuous arcuate recess 97 in the pave-
ment 20 between the recesses 95 and 96 for accommodating
the support member 60 of the pavement marker 30~ The cutt-
21 lng blades 105-107, the spacers 108 and the washers 109 are
æ2 all securely held in place on the shaft 104 for rotation
23 therewith by nuts lO9A. If desired, the shaft 104 could be
z4 mounted for movement away from the pavement 20 when not
cutting, to facilitate movement of the apparatus 100 along
1~ b~sic
{J 26 the pavement 20 between~cutting operations. The cutting
27 machine may be of the type manufactured by Clipper Manufac-
28 turing Company, Model C-600-K.
29
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1 ~lso mounted on the frame 101 is a suitable drive
2 mechanism, generally diagrammatically represented by the
3 numeral 110, which may be any suitable type of electric
4 or gasoline-powered motor or the like, coupled by suit-
able means such as a belt or chain to the shaft 104 for
6 rotatably driving same and thus rotatably driving the
7 cutting blades 105-107.
8 The cutting apparatus 100 also includes a limit
g assembly, generally designated by the numeral 115, which
comprises a pivot arm 114 pivotally mounted at one end
~1 thereof on a shaft 113 carried by the frame 101, the dis-
1~ tal end of the pivot arm 114 carrying a shaft 117 on which
13 is pivotally mounted a guide wheel 1~6 adapted for engage-
14 ment with the roadway surface 21. Secured to the frame 101
is an internally threaded nut member 119 with which is
16 threadedly engaged a handled setscrew 11~, the end of which
17 bears against the pivot arm 114.
18 In operation, the cutting apparatus 100 is disposed
~g upon the roadway surface 21 and loc~ed in an operating po-
sition, with the cutting blades 105-107 positioned for cut-
21 ting the recesses 95-g7 in the desired location on the pave-
~2 ment 20. It will be understood that, initially, the cutting
23 blades 105-106 are substantially tangent to the roadway sur-
24 face 21, whereby the frame 101 is in-lined upwardly and the
setscrew 118 is out of engagement with the pivot arm 114.
26 When the cutting blades 105-107 are driven, they serve to
27 cut the arcuate recesses 105-107 in the pavement 20 in a
28 well-known manner, the recesses 95 and 96 being deeper than
29
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1 the recess 97 because of the different diameters of the
2 cutting blades. The setscrew 118 is set so that it will
3 engage the pivot arm 114 and thereby stop the downward
4 movement of the frame 101 and the cutting blades 105-107
when the recesses 95-97 have reached their predetermined
6 desired depths. Thus, the cutting apparatus 100 permits
q accurate simultaneous cutting of the recesses 95-97 with-
8 out movement of the apparatus 100 from its operating po-
g sition.
The recesses 95-~7 are then cleaned and a suitable
11 epoxy adhesive material is deposited therein, the adhesive
12 material being such that it adheres to both the material
i3 f the pavement 20 as well as the material of the keel mem-
14 bers 41 and 45 and support member 60. The keel members 41
and 45 and t~e support member 60 are then respectively in-
16 serted into the recesses 95-97 and adhesively secured
17 therein at a depth such that the roadway surface 21 lies
B L8 substantially in the La3al plane P, insertion of the base
19 member 40 to a greater depth being prevented by engagement
of the support flanges 57 and 58 with the roadway surface
21 21.
22 It will be appreciated that when thus secured in
23 place, the pavement marker 30 is disposed so that the top
24 surface 61 of the support member 60 is substantially copla-
nar with the roadway surface 21, whereby the obverse faces
26 81 of the reflector system 80 extend above the roadway sur-
27 face 21 so as to be clearly visible between the keels 41
28 and 45 from oncoming vehicles approaching in either direc-
29
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lQ89t329
1 tion along the roadway. However, the lower portion of the
2 reflector assembly 70 is recessed below the roadway surface
~ 21 so as to minimize the overall height of the pavement
4 marker 30, thereby minimizing the impact force imparted to
vehicle tires and snowplow blades which contact the pavement
6 marker 30.
7 The angle X at which the inner edges 52a and S3a of
8 the inclined upper surfaces 52 and 53 are inclined to the
g roadway surface is preferably approximately 6.5 degrees,
while the angle Y at which the outer edges 52b and 53b are
11 inclined is approximately 6 degrees, the inclined upper
12 surfaces 52 and 53 forming inclined ramps which serve to
13 deflect oncolning snowplow blades upwardly out of contact
14 with the reflector assembly 70, which is at all points
disposed below the inclined upper surfaces 52 and 53 and
16 the top surfaces 54. Thus, the inclined upper surfaces 52
17 and 53 slope slightly downwardly toward the outer sides of
18 the base me~ber 40 and respectively intersect the top sur-
L9 faces 54 at oblique horizontal intersection lines 54a and
54b. Therefore, it can be seen that the lengths of the
21 top surfaces 54, measured longitudinally of the base mem-
22 ber 40, are greater along the inner edges thereof than
23 along the outer edges thereof~ More particularly, in the
24 preferred eT~lbodiment of the inventicn the length of the
top surfaces 54 along the inner edges thereof is substan-
2~ tially equal to ,58 times the lateral distance therebetween.
27 This lengthening of the inner edges of the top sur-
Z8 faces 54 is a significant feature of the present invention,
2~
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lQ89~3Z9
1 a~d it can be seen that the inclination of the inner edges
2 52a and 53a of the inclined upper surfaces 52 and 53 at a
3 slightly greater angle than the outer edges 52b and 53b
4 thereof, permits this lengthening of the inner edges of
the top surfaces 54 without any increase in the overall
6 length of the base member 40, and without any increase in
7 the inclination of the outer edges 52b and 53b. The pur-
8 pose of this configuration is to prevent angled plow blades
g from dropping between the top surfaces 54 and damaging the
reflector assembly 70. It has been found that for the vast
11 majority of snowplow blades the angle A that the blade
12 makes with the direction of travel is approximately 60 de-
13 grees. Referring to FIG. 2 of the drawings, the trailing
14 end 26 of the plow blade 25 must arrive at the top surface
54 of the keel member 41 before the leading end 27 of the
16 blade 25 leaves the top surface 54 of the keel member 45,
17 otherwise the blade 25 could move below the top surfaces
18 54 of the base member 40 and may contact the reflector as-
L~ sembly 70. Thus, the inside edges of the top surfaces 54
must have a length substantially equal to the lateral dis-
21 tance therebetween times the cotangent of the blade angle
22 A. Therefore, for a 60 degree blade angle A, the length of
23 the inside edges of the top sur~aces 54 must be substantially
24 equal to at least about .58 times the lateral distance there-
between.
26 It can be seen that as the plow blade 25 approaches
27 the pavement marker 30 in the direction D in ~IG. 2, it
28 will first c~ntact the outer edge 53b of the inclined upper
29
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1~898Z9
1 surface 53 of the keel member 45. It has been recognized
2 that an angled plow blade will ride along that outer edge
3 53b and will not contact the inner edge 53a, even when
4 the angle of inclination of the inner edge 53a is as much
5 as 1/2 degree higher than that of the outer edge 53b.
6 Thus, by increasing the angle of inclination X of the in-
7 ner edges 53a to approximately 6.5 degrees, it has been
8 possible to lengthen the inner edges of the top surfaces
9 54 by approximately 1/2 inch, without increasing the rate
10 at which the plow blade is displaced upward by the in-
11 clined upper surfaces 52 or 53. To be more specific, the
12 vertical angle of inclination X of th~ inner edges 52a
13 and 53a can be increased until the horizontal lines of
14 intersection 54a and 54b thereof with the top surfaces 54
form an angle Z with the longitudinal axis of the pavement
16 marker 30 which is e~ual to the angle A that the plow
17 blade makes with that longitudinal axis. Accordingly, it
18 can be seen that this construction permits an effective
lengthening of the top surfaces 54 without either increas-
20 ing the angle of inclination of the parts of the inclined
21 upper surfaces 52 and 53 which contact the plow blade, or
~2 increasing the overall length of the base member 40. The
23 total savings in length is the lateral width of the top
24 surface 54 at the point of intersection with the outer
25 edge 52b or 53b multiplied by 2 cot Z.
< 26 In addition to effectively protecting the reflec-
27 tor assembly 70 from contact with snowplow blades, the
28 shallowness of the pavement marker 30 and the distance
29
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1 between the keel members 41 and 45 is such as to permit
2 the relatively flexible tires of oncoming vehicles to
3 contact the glass layers 90 on the reflector assembly
4 70 thereby to provide a wiping action for cleaning the
~ front faces of the glass layers 90, while the glass
6 layers 90 protect the obverse faces 81 from abrasion.
7 These advantages are accomplished, and a bidirectional
8 pavement marker is provided, all with a total pavement
g marker length which is substantially the same as that
f the monodirectional pavement markers disclosed in
11 the aforementioned prior art Patents Nos. 3,790,293
12 and 3,809,487, and with an overall height above the
13 roadway surface 21 about 40-45~ less than that of the
14 pavement markers of those patents.
In a constructional model of the pavement marker
16 30, the base member 40 is preferably an integral metal
17 casting, the dimensions of which are such that when in-
L8 stalled in place on the pavement in the position illus-
L9 strated in FIG. 6, the maximum height of the pave~ent
~0 marker 30 above the roadway surface :'1 is approximately
21 .41 inches and the overall length of the base member 40
~2 is approximately 9.25 inches. The low angle of 6 de-
23 grees of the outer edges of the ramps to the ba~al
24 plane P, together with the lower height, materially
reduces impact of snowplow blades against the base mem-
26 ber 40, thus relieving the "jolt" felt by the driver of
27 a plow, and minimizing the impact forces on the under-
28 lying roadway surface, and reducing the area of un-
~9 plowed road surface caused by the raising of the plow blade.
It also serves to reduce the impact forces transmittcd to
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the tires of vehlcles whlch pass over the marker. The inner
edges 52a and 53a of the inclined upper surfaces 52 and 53 are
inclined at an angle of approximately 6.5 degrees with respect
to the plane P, and the inclined surfaces 49b are inclined at
an angle of approximately 15 degrees with respect to the basal
plane P and extend therebelow so ~hat oncoming snowplow blades
will not strike the leading edges of the keel members 41 and
45. The vertical distance between the plane P and the support
s~rface 63 is approximately c16 inches, so that the total
vertical distance between the support surface 63 and the top
surfaces 54 is approximately .57 inches. The total height of
the reflector assembly 70 is approximatley .44 inches.
Referring now also to FIGSo 14 and 15 of the
drawings, there is illustrated a monodirectional snowplowable
pavement marker, generally designated by the numeral 130, which
is suitable for use in snow areas and includes a base member
140 having supported thereon the reflector assembly 70~ By
"monodirectional" it i9 meant that the marker will be plowed
in one direction only, and not necessarily that the reflector
as~embly is capable of reflecting light in only one direction.
The base member 140 is similar in shape to the base members of
the monodirectional pavement markers disclosed in the afore-
mentioned U. S. Patents Nos, 3,790,293 and 3,809,487. However,
the base member 140 of the present invention has been sig-
nificantly improved so that the overall height of the pavementmarker 130 ab~ve the roadway surface 21 when the pavement
marker is ins~alled is substantially less than the overall
height of the prior art pavement markers, and the angles of the
.
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9~29
1 inclined ramps which protect the reflector assembly 70
2 are substantially less than the angles of the ramps in
3 the prior art pavement markers, and yet the overall
4 length of the base member 140 is less than that of the
prior base members.
6 The base member 140 is preferably cast as an
7 integral unit of a relatively high-strength material,
8 such as metal, and includes a pair of parallel, elonga-
9 ted, laterally spaced apart keel members 141 and 145,
the keel member 141 having parallel substantially verti-
11 cally extending inner and outer side surfaces 142 and
12 143, and the keel member 145 having parallel substantial-
13 ly vertically extending inner and outer side surfaces 146
14 and 147,
Each of the keel members 141 and 145 is provided
16 with a substantially identical irreguLar bottom surface,
17 generally designated by the numeral 144, which intercon-
L8 nects the side surfaces 142 and 143 and the side surfaces
L9 146 and 147 along the bottoms of the keel members 141 and
zO 145. More particularly, each of the irregular bottom sur-
21 faces 144 includes a flat horizontal bottom portion 148
~2 ~isposed centra~ly of the keel member and a pair of down-
z3 wardly sloping and slightly arcuate end portions 149 lying
24 substantially along a common imaginary circle Cl and res-
pectively extending downwardly from the opposite ends of
26 the keel member toward the bottom portion 148, each of the
27 end portions 149 being interconnected with the adjacent
28 end of the flat bottom portion 148 by a plurality of su~-
29
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9t3Z9
1 stantially right-angular step portions 150. The step
2 portions 150 define a plurality of tooth-like points
~ 151, all of which lie along the circle Cl and serve
4 the same function as the points 51 described above in
connection with FIGS. 1-6.
6 Intersectin~ the inclined portions 149 at the
7 front ends of the keel members 141 and 145 are vertical
8 front end surfaces 149a the upper ends of which inter-
g sect short inclined upper surfaces 149b which rise rear-
wardly to a ~asa~ plane Pl at an angle of about 15 de-
11 grees thereto, at which point they respectively intersect
12 inclined uppersurfaces 152 which rise rearwardly above
13 the tops of the keel members 141 and 145 to uppermost
14 portions where they intersect top surfaces 154 which are
parallel to the ba5al plane Pl and spaced approximately
16 .40 inches thereabove, the top surfaces 154 terminating
17 in inclined rear surfaces 158.
~8 Each of the inclined upper surfaces 152 has an
L9 inner edge 152a which is inclined with respect to the
~asa~-plane Pl at a first acute angl~ of approximately
~1 4-5 degrees, and an outer edge 152b which is inclined
22 with respect to the basal plane Pl at a second acute
23 angle of approximately 4 degrees. Thus, each of the
24 inclined upper surfaces 152 is slightly slope~ downward-
ly and laterally outwardly of the base member 140.
26 More particularly, the inner edges 152a of the
27 inclined upper surfaces 152 respectively intersect the
28 top surfaces 154 a slight distance forwardly of the
29
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1~89~329
1 points where the outer edges 152b intersect the top sur-
2 faces 154, the base member 140 being oriented in use with
3 the longitudinal axis thereof extending parallel to the
4 direction of vehicle travel, so that the lines of inter-
section 154a between the inclined upper surfaces 152 and
6 the top surfaces 154 are each disposed at an acute angle
7 with respect to the direction of travel. This angle is
8 preferably greater than or equal to the plow blade angle
g ~. for the same reasons as were set forth above with res-
pect to FIGS, 1-6
11 The inner surfaces 142 and 146 of the keel members
12 141 and 145 above the basal plane Pl respectively extend
13 inwardly to form thickened portions 155 from approximately
14 midway between the ends of the inclined uppersurfaces 152
to the rear ends of the keel members 141 and 145, each of
16 the thickened portions 155 having sloping shoulder portions
17 155a and a recessed inner side wall portion 156 adjacent to
18 the rear en~ thereof.
Interconnecting the thickened portions 155 of the
~0 keel members 141 and 145 adjacent to the rear ends thereof
21 is a support member, generally designated by the numeral
~2 160, which is substantially rectangular in plan outline.
23 The support member 160 has a flat planar upper surface 161
24 which lies substantially in the ba_al plane Pl and an ar-
cuate part-cylindrical convex bottom surface 162 which is
26 connected at the front ends thereof to the upper surface
27 161 by a rounded end surface 166. Recessed in the upper
28 surface 161 centrally thereof and parallel thereto is a
29
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support surface 163 which lies below the plane Pl and extends
transversley all the way across the support member 160 and is
longitudinally substantially coextensive with the recessed
inner side wall portions 156 of the keel members 141 and 145.
Substantially vertically extending end walls 164 extend down-
wardly from the upper surface 161 at the opposite ends of the
support surface 163, the end walls 164 and the recessed inner
side wall portions 156 of the keel members 141 and 145 all being
connected to the support surface 163 by a peripheral channel
or groove (not shown) like the channel 65 in the base member 40,
which extends all the way around the support ~urface 163 and is
arcuate in transverse cross section.
The rear end of the upper surface 161 and the lower
ends of the rear surfaces 158 of the keels are joined to the
rear end of the arcuate bottom surface 162 of the support
member 160 by a rounded surface 167.
The reflector assembly 70 is mounted on the support
surface 163 in exactly the same manner as was described above
with respect to the support surface 63 of the pave~ent marker
30, with substantially all portions of the reflector assembly
70 below the upper edges of the lugs 88 being disposed below the
plane Pl an~ all portions of the reflector assembly 70 above
the upper edges of the lugs 88, including substantially the
entire obverse faces 81, being di~posed above the plane Pl.
Again, the lowermost ones of the reflex light reflect-
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B 1 ing elements 85 lie below the basal plane Pl. Further-
2 more, the vertical distance between the top surface of
3 the reflector assembly 70 and the bottom surface of the
4 pad 91 is such that when the reflector assembly 70 is
mounted in place upon the support surface 163 of the
- 6 base member 140, the reflector assembly 70 at all points
7 thereof is spaced a predetermined distance vertically
8 below a plane parallel to the top surfaces 154 and the
g inclined uppex surfaces 152 of the base member 140 to
prevent plow blade corners from contacting the reflector
11 assembly 70.
12 As was explained above with respect to the bidir-
13. ectional pavement marker 30, the faet that the inner edges
14 152a of the .inclined upper surfaces 152 are inclined to
the ~asal plane Pl at a greater angle than are the outer
16 edges 152b,~the top surfaces 154 can effectively be leng-
17 thened without increasing.the overall length of the base
18 member 140 and without changing the angle of the outside
edges 152b which contact the oncoming plow blade. As was
~0 also explained above, the angles between the longitudinal
21 axis of the base member 140 and the lines of intersection
22 154a can be as little as the angle A of the plow blade
. 23 with the direction of travel.
24 It will be noted that the pavement marker 130 has
all the advantages of the pavement marker 30 in terms of
2G ease of installation, by reason of the arcuate outlines
27 of the bottom surfaces of the keel members 141 and 145 and
28 the support member 160. Thus, in installation of the pave-
29 ment marker 13Q, the keel members 141 and 145 and the sup-
_ ~ _
f~ .
9829
port member 160 are respectively received and adhesively
secured in complementary arcuate recesses 195, 196 and
197 which are cut in the pavement 20 with circular cutting
members, the pavement marker 130 being inserted in the recesses
195-197 to a depth such that the roadway surface 21 lies sub-
stantially in the plane Pl. It will be appreciated that one
of the two obverse faces 81 of the reflector assembly 70 will
extend above the roadway surface 21 and will be visible between
the keel members 141 and 145 to oncoming vehicles approaching
from the forward end of the pavement marker 130.
Indeed, the pavement marker 130.has a significant
additional advantage over the pavement mar~er 30, in that
- outer edges 152b of the inclined ramp surfaces 152 intersect
the roadway surface 21 at an angle of only about four degrees,
i.e., one-third less than the ramp angle of the pavement marker
30, and about one-third lower than the ramp angle of the prior
ca~tings, thereby significantly reducing the impact and
acceleration forces imparted to the pavement marker 130, the
surrounding pavement 20 and snowplow blades when such blades
impact the inclined ramp surfaces of the pavement marker 130.
; It will be understood that the reflector assembly 70 is pro-
tected by the inclined ramp surfaces 152, and the glass layers
90 of the reflector assembly 70 are expoged to the wiping action
of vehicle tires, all in the same manner as was described above
with respect to the pavement marker 30.
However, because the ~upport member 160 is not cen-
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829
1 tered longitudinally with respect to the keel ~embers 141
2 and 145, the arcuate recesses 195-197 cannot be simulta-
3 neously formed by the use of the cutting apparatus 100.
4 Therefore, referring to FIGS. 16 and 17 of the drawings,
there is provided an alternative form of cutting appara-
6 tus, generally designated by the numeral 200, for simul-
7 taneously cutting the recesses 195-197 in the pavement 20.
8 The cutting apparatus 200 is generally identical to the
g cutting apparatus 100 except for the mounting of the cutt-
ing blades, therefore only that mounting portion of the
11 cutting apparatus 200 will be described in detail.
12 More particularly, the cutting apparatus 200
B 13 includes a pair of~ ~ ts or axles 204 which are rota-
1*. tably mounted on the frame 101 adiacent to the front
end thereof, and each has fixedly secured thereto a
16 relatively large diameter circular cutting blade 205 and 206,
17 dimensioned and positioned for respectively cutting the keel
18 recesses 195 and 196 in the pavement 20. Fixedly secured to
19 the frame 101 adjacent to the front end thereof and extend-
: 20 ing downwardly therefrom at an acute angle thereto are a pair
21 Of support arms 208 respectively disposed just inside the
d ~ ~j C,
~2 large diameter cutting blades 205~ Extending between the sup-
23 port arms 20~ adjacent to the distal ends thereof and rotatably
24 carried thereby is a horizontal shaft or axis 209 having fixed-
ly secured thereto a plurality of smaller diameter circular
26 blades 207 arranged closely toqether in side-by-side relation-
27 ship so as to cut a substantially continuous arcuate recess
28 197 in the pavement 20 between the recesses 195 and 196, for
29
9~Z9
1 accommodating the support member 160 of the pavement marker
2 130. It will be understood that the drive mechanism mounted
3 on the frame 101 must be coupled to both of the shafts 204
and 209, by any suitable means, for simultaneously rotatably
driving the cutting blades 205-207. It will also be appre-
6 ciated that the relati~e speeds of rotation of the cutting
q blades 205-207 could be varied by suitable gearing, all in
8 a well-known manner.
g Referring now to FIGS. 18 and 19 of the drawings,
there is illustrated still another form of cutting apparatus,
11 generally designated by the numeral 300, for cutting the re-
12 cesses 195-197 in the pavement 20. The cutting apparatus
13' 300 is essentially the same as the c~-tting apparatuses 100
14 and 200, except for the mounting arrangement for the small
15 " diameter cutting blades, wherefore only this different mount-
16 ,ing arrangement will be described in detail.
17 ' More particularly, the cutting apparatus 300 includes
18 a horizontal shaft or axle 304 rotatably mounted on the frame
L9 101 adjacent to the front end thereo and having fixedly se-
~0 cured thereto at laterally spaced-apart points thereon, two
21 relatively large diameter circular cutting blades 305 and 306,
22 dimensioned and positioned for respectively cutting the keel
23 recesses 195 and 196 in the pavement 20. ~espectively pivot-
24 ally mounted on the shaft 304 outboard of the cutting blades
305 and 306 are two support arms 308 which project forwardly
26 beyond the peripheries of the lar~e cutting blades 305 and
27 306. Extending between the support arms 308 and rotatably
2B carried thereby forwardly beyond the peripheries of the large
29
f ~ _ ~ _
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9~3Z~
cutting ~lades 305 and 306 is a horizontal shaft 309 having
fixedly secured thereto a plurality of smaller diameter cir-
cular cutting blades 307 which are arranged closely together in
side-by-side relationship so as to cut a substantially con-
tinuous arcuate recess 197 in the pavement 20 between therecesses 195 and 196 for accommodating the support member 160
of the pavement marker 130. The support arms 308 may be piv-
oted about the axis of the shaft 304 either by manual means
or by suitable drive mechanism carried by the frame 101. It
will be understood that the shafts 304 and 309 are rotatably
driven in generallly the same manner as was described above
with respect to the cutting apparatus 200.
In operation, the shaft 304 moves with the frame 101
in the same manner as in the cutting apparatuses 100 and 200,
but the shaft 309 is independently movable upwardly and down-
wardly about the axis of the shaft 304 between a retracted
position wherein the attached cutting blades 307 are out of
engagement with the pavement 20 (FIG. 18), and a cutting
po~ltion wherein the attached blades are di4po~ed below the
blades 305 and 306 for cutting engagement with the pavement 20.
When the keel recesses 195 and 196 are being cut by the cutting
blades 305 and 306, the shaft 309 will be disposed in its
retracted position. After the cutting of the keel recesses 195
and 196 has been completed, the frame 101 is lifted and the
support arms 308 are pivoted downwardly about the axis of the
shaft 309 to move blades 307 into cutting position for cutting
recess 197 at the proper horizontal distance from recesses
; l9S and 196 for accommodating the support
~ -36~
29
1 member recess 197 by the cutting blades 307. Thus, the keel re-
2 cesses and the support member recess are formed sequentially, but
3 without having to move the cutting apparatus 300 from its operat-
4 ing position on the pavement 20. The order of cutting of the keel
recesses and the support member recess could be reversed.
6 Neither FIG. 18 nor FIG. 19 shows the parts of apparatus
7 300 in strictly realistic fashion. Thus, when blades 305 and
8 306 are at the lowermost positions thereof, having completed
9 the cutting of recesses 195 and 196, blades 307 have not yet
started to cut recess 197 and blades 305 and 306 are retracted
11 from recesses 195 and 196 prior to the commencement of the
12 cutting action of blades 307.
13 Both of the cutting apparatuses 200 and 300 provide quick
14 and efficient cutting of the recesses 195-197 without the nece-
ssity of moving the cutting apparatus from its operating position
16 on the roadway, and provide accurate and reproducible positioning
17 of the recesses 195-197 with respect to one another.
18 While, for convenience of illustration, the pavement markers
19 30 and 130 have been illustrated with the bidirectional reflector
assembly 70 mounted thereon, it will be appreciated that a mono-
21 directional reflector assembly could also be used, and it will be
22 understood that mono or bidirectional signal means could be used
23 in either of the mono or bidirectional castings.
24 While the inclined ramps 152 of the pavement markers 30
and 130 have been disclosed with the inner and outer edges thereof
26 at different angles of inclination, it will be appreciated that
27 coplanar ramps could also be used.
28 From the foregoing, it can be seen that there has been
29 provided a novel and improved bidirectional snowplowable pave-
ment marker which includes a base member having protecting
31 inclined ramps and a reflector assembly carried by the base
32 member between and below the ramps and protected thereby from
33 impact with snowplow blades, while affording high nighttime
r~
1(~89829
1 visibility from oncoming vehicles and permitting the reflec-
2 tor to be exposed to the wiping action of vehicle tires.
3 More particularly, there has been provided a pave-
4 ment marker of the character described, which has a very low
height above the roadway surface, and low-angled protective
6 ramps on the base member, while nevertheless maintaining an
7 overall length which is no greater than the overall length
8 of similar prior art monodirectional markers.
g In addition, there has been provided a pavement mar-
ker of the character described wherein the reflector asse~bly
11 is carried by a support surface on the base member which is,
12 in use, recessed below the roadway surface, the support mem-
13 ber being constructed so as to facilitate installation there-
14 of on the paJement.
There has also been provided improved apparatus and
16 methods for installing the pavement markers of the present
17 invention on the roadway by simultaneously cutting in the
L8 pavement arcuate recesses for respectively receivin~ the
1~ keel members and the support member of the pavement marker.
There has also been provided an alternative form of
21 method and apparatus for sequentially cutting the recesses
22 for the monodirectional pavement marker without the necessi-
23 ty of moving the cutting apparatus along the roadway.
24 While there have been described what are at present
considered to be the preferred embodiments of the invention,
26 it will be understood that various modifications may be made
27 therein, and it is intended to cover in the appended claims
æs all such modifications as fall within the true spirit and
29 scope of the invention.
~ r
