Abstract: A pavement marker comprising a base member and a signal device for sending a light signal to a driver of an oncoming vehicle further includes a longitudinally extending tire directing hood member that directs tire contact away from the upper edge, upper portion, and upper generally corner portions of the signal device front face, while allowing tire contact with the lower portion of the signal device front face. The signal device front face is at a predetermined recess depth in said pavement marker, and is at a predetermined angle with respect to the roadway surface. The marker can be either a snowplowable marker or a sun country marker. The signal device optionally can be mounted on a base member by a mechanical interlock. Optional drainage channels can be provided in the base member to allow drainage of fluid from in front of the lower portion of the signal device.

Abstract: A method for tooling a pattern of retroreflective microcubes, which pattern can be subdivided into smaller increments within which there are straight line tooling paths, none of which pass through an otherwise solid part of the incremental pattern. The tooling paths within the various increments need not be parallel to a common plane. Various adaptions of the method enable the tooling of a number of specific microcube shapes and for modifying such optical properties of the microcubes as entrance angularity, incidence angularity, orientation angularity, observation angularity, percent active aperture and retroreflectance. Specific techniques govern the pre-selection of cube parameters such as cube axis cant, cube apex decentration, and cube boundary proportions, which parameters can be adjusted independently of each other. Designs tooled by the method can have 100% active aperture at near zero degrees entrance angle.

Abstract: A heated kettle for melting and mixing a thermoplastic resin into a homogeneous mixture has a helically-formed agitator which rotates about a central shaft in close proximity to the internal wall of the kettle. Fixed to the shaft at approximately the center of the kettle is a cluster of radially extending paddles. The paddles and agitator have opposite pitch when the agitator and paddles are rotated, the resin circulates along the wall of the kettle and thence through a central region of the kettle. The circulation action serves to thoroughly melt and mix the resin into a homogeneous liquid mass.

Abstract: A method for producing a pelletized pavement marking mixture includes selecting an appropriate thermoplastic binder that is a solid at ambient temperatures and heating the appropriate thermoplastic binder in a reaction vessel to a temperature sufficient to form a liquid thermoplastic binder; forming a heated pavement marking mixture by adding a plasticizer and a filler to the liquid thermoplastic binder in the reaction vessel; forming a substantially homogeneous pavement marking mixture by blending the heated pavement marking mixture for period sufficient to substantially evenly distribute the plasticizer and the filler within the liquid thermoplastic resin while maintaining the heated pavement mixture at an elevated temperature; extruding the substantially homogeneous pavement marking mixture from the reaction vessel to form an extruded substantially homogeneous pavement marking mixture; and pelletizing the extruded substantially homogeneous pavement marking mixture.

Abstract: A method for marking roadway surface includes selecting an appropriate thermoplastic binder that is a solid at ambient temperatures and mixing the appropriate thermoplastic binder in a mixing vessel with a plasticizer and a filler to form a substantially evenly blended homogeneous pavement marking mixture by blending the pavement marking mixture for period sufficient to substantially evenly distribute the plasticizer and the filler with the thermoplastic resin; transferring the substantially evenly blended pavement marking mixture from the mixing vessel to a compression pelletizer; and pelletizing the substantially evenly blended pavement marking mixture by compression. A pavement marking mixture consists of pellets, each of which consists of a substantially evenly blended blend of a thermoplastic binder, a plasticizer, and a filler. The pavement marking mixture is heated to melting and applied to the roadway surface.

Abstract: Cellular retroreflective sheeting comprises a first film of thermoplastic material which has been formed to define arrays of minute cube-corner reflective elements on one face thereof. The reflective elements are covered with a second thin thermoplastic film and the two films together pass over a patterned roller where a series of sonic welding heads rapidly bond the films together forming small cells of retroreflective cube-corner elements in the pattern of the roller. Because the heat generated in the welding process is localized to the pattern of the roller, cell walls may be formed having narrow thickness yet good bonding of the films is achieved. Further, residual heat does not appreciably transfer to adjacent retroreflective elements, therefore, distortion of adjacent elements is minimized and a sheeting construction is achieved having superior brilliance and durability as well as maximum retroreflective capability over a wide angular range of incident light.

Abstract: A retroreflector construction comprises a first transparent layer of a relatively high refractive index having on its rear surface one or more cube corner retroreflector elements; a second thin transparent layer of relatively low refractive index in substantially uninterrupted contact with the rear surface of the first layer; and a third metallic reflective layer in substantially uninterrupted contact with the rear surface of the second layer. The ratio of the indices of refraction of the two transparent layers is sufficient to allow TIR at their interface for at least some of the cube faces. The third, metallic layer assures face reflection when TIR fails. The construction provides greater retroreflectance than would be achieved with a single metallized transparent layer, and provides retroreflectance over a broader range of entrance angles and orientation angles than would be achieved with a single non-metallized (air-backed) transparent layer.

Abstract: A roadway marker comprises shell molded of suitable plastic and having an internal honeycomb configuration. A base plate extends over the lower surface of the shell covering the honeycomb arrangement and defining a plurality of chambers internal to the shell. The plate is provided with a plurality of apertures, each opening to a chamber. When the marker is installed, adhesive material flows through the apertures and into the chambers. Before the adhesive sets, it forms mushroomed-shaped configurations over the top inside surface of the plate. The mushroomed configurations create a strong mechanical bond between the plate and the associated roadway surface. The large lower surface area of the plate also enhances bonding of the marker to the roadway.

Abstract: A pavement marking eradicator (10) for removing pavement marking from pavement. The eradicator has a grinding apparatus (13) having a safety skirt (31) to which is mounted a collector (39) of a vacuum system (14). The vacuum system also has a cyclone (36) for collecting and filtering debris created by the grinding apparatus during operation.

Abstract: A low-profile housing and lens assembly system for use in a pavement marker. The housing is generally shell like and has a recess for accommodating a retroreflective lens element. The housing is provided with means defining a flat base for providing improved adhesion of the marker to the pavement.

Abstract: A photoluminescent retroreflective sheeting for use in structures when a power outage occurs. Guidance systems are made from this sheeting to mark exits and escape routes as well as possible hazards and safety devices. The novel sheeting includes photoluminescent properties that glow in the dark as well as retroreflective properties that retroreflect light incident upon the same sheet such that only one sheet has to be used rather than individual sheets with separate properties.

Abstract: A potted shell style pavement marker reinforced with fiberglass in the form of a mat of fiberglass strands located near the bottom of the marker or in the form of chopped fiberglass strands distributed throughout the fill material. The mat provides support against torsional or bending stresses near the bottom of the marker. The chopped strands in the fill material provide three-dimensional support throughout the height and depth of the fill in the interior of the housing. Both means of support are expected to reduce the number of cracks that develop in the fill, to prevent the expansion of any cracks which do develop, to prevent premature disintegration of the marker, and to increase average marker life. The supporting mat and the chopped fiberglass strands can be used together in a single marker.

Abstract: A low-profile housing and lens assembly system for use in a pavement marker. The housing is generally shell like and has a recess for accommodating a retroreflective lens element. The housing is provided with means defining a flat base for providing improved adhesion of the marker to the pavement.

Abstract: A retroreflective unitary laminate material having an acrylic layer on which a sign legend is printed and which is covered by an ultraviolet absorbent overlay that has poor affinity for paint and low surface tension thus protecting the printed sign from deterioration due to weathering and enabling the sign to be readily cleansed without damaging the printed signs, and minimizing water beading on the sign front face.

Abstract: A low-profile snowplowable pavement marker is disclosed including a base member and a retroreflector. The base member has two arcuate-bottom keel members interconnected by a support member. The upper surfaces of the keel members define inclined ramps. The spacing of inner surfaces of the ramps allows retroreflectance of oncoming light while accommodating larger plow blade angles encountered in higher speed plowing. The support member has a central planar support surface for carrying the retroreflector and upwardly facing curved top surfaces providing relief in the base member between the ramps and in front of the retroreflector to allow tires of approaching vehicles to wipe the lens assembly. The housing of the retroreflector is molded from long-glass-fiber-reinforced composite thermoplastic material with a recess for accommodating a retroreflective lens element of a different thermoplastic material.

Abstract: A one-way snowplowable pavement marker having an auxiliary ramp at the front of a body portion connecting the spaced first and second primary ramps for supporting a snowplow blade tip when the tip is at angle up to 60.degree. from a line perpendicular to the direction of travel to protect a reflector in the marker. A cast-in-place shelf is formed behind the reflector for supporting the blade tip before and after it leaves the auxiliary ramp to prevent the reflector from being contacted by the snowplow blade.

Abstract: A retroreflective unitary laminate material having an acrylic layer on which a sign legend is printed and which is covered by an ultraviolet absorbent overlay that has poor affinity for paint and low surface tension thus protecting the printed sign from deterioration due to weathering and enabling the sign to be readily cleansed without damaging the printed signs, and minimizing water beading on the sign front face.

Abstract: An optically precise endless embossing belt for making retroreflection materials having projections with 90.degree. corners is provided by the instant invention.

Abstract: A pavement marker base is provided having a generally planar bottom support surface with an array of downwardly facing open chambers molded therein. Deformations are formed on the bottom surfaces of at least some of the walls dividing the chambers, and also preferably in the peripheral support surface of the marker base to provide additional downwardly facing surface area to mate with an adhesive material used to adhere the marker base to a roadway surface. These deformations may be characterized by a variety of surface shapes, such as arcs, rectangular notches, and dovetails. In the preferred embodiment, chamber walls include outwardly directed lips to engage the adhesive material. In another embodiment of the invention, a wire mesh covers at least some of the bottom surface of the marker base, and is imbedded within the bottom surface of the chamber walls and peripheral support surface. The mesh engages with the adhesive to provide a strong means of anchorage.