CA1089829A - Low profile road marker and base member therefor - Google Patents

Abstract

SNOWPLOWABLE PAVEMENT MARKER AND METHOD
AND APPARATUS FOR INSTALLING SAME
ABSTRACT OF THE DISCLOSURE
A low-profile snowplowable pavement marker includes a metal base member having two arcuate-bottom keel members inter-connected by an arcuate-bottom support member, the upper sur-faces of the keel members respectively defining inclined ramps each having an inner edge and an outer edge respectively rising at different angles from a basal plane at one end of the base member toward the other end thereof to corresponding coplanar top surfaces, the support member having a support surface lying below the basal plane for supporting thereon a cube corner reflex reflector assembly partially recessed below the basal plane. The keel members and the support member are respectively secured in complementary arcuate recesses with the basal plane substantially coplanar with the roadway surface, the recesses being cut in the pavement with circular blade cutting apparatus without moving the cutting apparatus along the pavement. A
bidirectional marker is shown as well as cutting apparatus for cutting the three recesses therefor simultaneously. A mono-directional pavement marker is shown, with two forms of cutting apparatus for respectively cutting the keel recesses either simultaneously or sequentially with the support member recess.

Description

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 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 l~t~

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 1(~8~Z9 in combination with a signal means disposed between and below said ramp members and carried by said support surface.

` G

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 , ~ -7-1(~89829 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 C _ ~ _ 9~Z9 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, ~0 ~, ' . ~ _ .

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 , ~

_ ~ _ .. . _ 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 : 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 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, 1~89829 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.

9~29 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 - ~_ 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 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 ~, '29 ` ' ~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 /~
C ' - ~

1(~8~3~29 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, ~ /~

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.

~o :, . - .

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 C
_~.

1~9~329 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-.

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~

~ 2G -.. , .

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 - ~ _ ' ' 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 . ~S

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 _ ~ _ '.
... . .

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 .

. .

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~-.~

,. ~

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 C ~ ~2 -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 ~ .

9~2~

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-9~29 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~ .

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-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 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 f ~ _ ~ _ ~ . .' 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~

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

Claims (13)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A base member for use as a component of a low-profile road marker, said base member having first and second laterally spaced-apart longitudinally extending ramp 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 extending 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 further having a support member interconnect-ing 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 support surface adapted to carry signal means thereon, the signal means thus adapted to be disposed between and below said ramp members with an upper portion of the signal means disposed above the road surface.

2. A base member as claimed in claim 1, wherein the base member has a downwardly facing surface defining a plane adapted to engage the road surface with said support surface below said plane.

3. A base member as claimed in claim 1, wherein the keel portion includes first and second parallel keels and said support member interconnects said keels as well as said ramp members, said first and second keels being generally arcuate in outline along the bottoms thereof and adapted to be disposed in comple-mentary arcuate recesses in the road surface.

4. A base member as claimed in claim 3, wherein the bottoms of said first and second keels are adapted to extend farther below the road surface than does the bottom surface of said support member.

5. A base member as claimed in claim 1, wherein the support surface is adapted to be recessed below the road surface and is thus adapted to carry the signal means with a lower portion thereof disposed below the roadway surface.

6. A base member as claimed in claim 1, wherein the bottom surface is generally arcuate in outline.

7. A base member as claimed in claim 1, wherein the bottom surface is convex.

8. A base member as claimed in claim 1, wherein the support surface is substantially flat.

9. A base member as claimed in claim 1, wherein each ramp has an inner side edge and an outer side edge, said inner side edges of said ramps being inclined at a first acute angle with respect to the road surface and the outer side edges of said ramps are inclined at a second acute angle which is greater than said first angle.

10. A base member as claimed in claim 9, wherein the inner and outer side edges of said ramps terminate at the same vertical distance above the road surface.

11. A low-Profile road marker comprising a base member as claimed in claim 1 in combination with a signal means disposed between and below said ramp members and carried by said support surface.

12. A road marker as claimed in claim 11, wherein said signal means has a lower portion adapted to be disposed below the road surface and an upper portion adapted to be disposed above the road surface, wherein both the upper portion of the signal means and at least a part of the lower portion thereof are operable to reflect light incident upon the upper portion of the signal means from an oncoming vehicle back toward said vehicle, and wherein said ramps are so configured and arranged to provide adequate space therebetween to allow vehicle tires to wipe the upper portion of the signal means.

13. A road marker as claimed in claim 11, wherein said signal means comprises a cube corner reflex reflector having an inclined front surface which, in situ, is disposed at an angle to the road surface of between 15° and 60°.