Apparatus and method for producing and uniformly applying foamed bituminous binders to road surfaces

Apparatus for coating a road surface with 100% bituminous binder material, the apparatus being of the type which includes a vehicle which travels over the road surface and in which a source of bituminous binder material in a fluid state is carried by the vehicle and in which a source of pressurized gas is carried by the vehicle, the vehicle having a forwardly and rearwardly extending longitudinal axis, the improvement comprising:

• a first substantially horizontal fluid conduit carried by the vehicle, the first horizontal fluid conduit being transverse to the longitudinal axis of the vehicle and being positioned in spaced relationship above the road surface, a second substantially horizontal fluid conduit carried by the vehicle, the second horizontal fluid conduit being transverse to the longitudinal axis of the vehicle and being positioned in spaced relationship above the road surface,
• means joining the first fluid conduit to the source of bituminous binder material for fluid flow from the source of bituminous binder material to the first fluid conduit,
• means joining the second fluid conduit to the source of pressurized gas for fluid flow from the source of pressuried gas to the second fluid conduit,
• a plurality of mixer housings positioned adjacent the road surface, Docket 268
• a plurality of first fluid connector members, there being one first fluid connector member joining each of the mixer housings to the first fluid conduit for fluid flow between the first fluid conduit and the respective mixer housing, a plurality of second fluid connector members, there being one second fluid connector member joining each mixer housing to the second fluid conduit for fluid flow between the respective mixer housing and the second fluid conduit,
• a plurality of director caps, each director cap having an upper part and a lower part, the upper part of each director cap being adjustably attached to one of the mixer housings in communication therewith as the director cap extends from the mixer housing, each director cap being provided with a throat portion having a downwardly directed outlet passage with gradually decreasing dimensions,
• a plurality of tubes, there being a tube fixedly positioned within each mixer housing and extending into the director cap which is adjustably attached thereto, the tube having an end portion within the throat portion of the director cap which is adjustably attached to the respective mixer housing, each tube being connected to the respective second fluid connector member for fluid flow from the second connector member and to the tube,
• a plurality of nozzle members, there being one nozzle member adjustably attached to each director cap and at the lower part of each director cap, each nozzle member having a discharge opening which is directed downwardly and in alignment with the outlet passage of the throat portion of its respective director cap,
• a plurality of securing members, there being one securing member attached to each mixer housing and engageable with the director cap which is adjustably attached to the mixer housing, each securing member being engageable with its respective director cap to retain the respective director cap in the adjusted position thereof with respect to the mixer housing,
• wherein bituminous binder material flows into the mixer housing from the first fluid conduit and wherein pressurized gas flows into the mixer housing from the second fluid conduit, the bituminous material and the gas being mixed within the mixer housing to form a foam, the foam flowing downwardly through the throat portion of the director cap and through the nozzle member and to the road surface,
• the director cap being adjustable with respect to the mixer housing to adjust the position of the throat portion of the director cap with respect to the tube to adjust the characteristics of foam flowing from the nozzle member.