초록 ▼

A screed with a trussed beam having a cross-section in the geometrical shape of an equilateral triangle used to support tools for working plastic concrete. The beam is supported between spaced apart, wheeled carriages riding forms bounding the plastic concrete. The beam is oriented such that the cro

A screed with a trussed beam having a cross-section in the geometrical shape of an equilateral triangle used to support tools for working plastic concrete. The beam is supported between spaced apart, wheeled carriages riding forms bounding the plastic concrete. The beam is oriented such that the cross-sectional triangle is inverted with the wide base at the screed top and the apex at the bottom. The inverted triangular truss beam has sufficient space to suspend working tools substantially within the peripheral edges of the beam. The screed uses upstanding integral outriggers so that the pitch at the center of the screed can be adjusted exteriorly to the pour site.

대표청구항 ▼

A screed with a trussed beam having a cross-section in the geometrical shape of an equilateral triangle used to support tools for working plastic concrete. The beam is supported between spaced apart, wheeled carriages riding forms bounding the plastic concrete. The beam is oriented such that the cro

A screed with a trussed beam having a cross-section in the geometrical shape of an equilateral triangle used to support tools for working plastic concrete. The beam is supported between spaced apart, wheeled carriages riding forms bounding the plastic concrete. The beam is oriented such that the cross-sectional triangle is inverted with the wide base at the screed top and the apex at the bottom. The inverted triangular truss beam has sufficient space to suspend working tools substantially within the peripheral edges of the beam. The screed uses upstanding integral outriggers so that the pitch at the center of the screed can be adjusted exteriorly to the pour site. port. 6. The apparatus as set forth in claim 1, further comprising: a deflection bar mounted beneath said platform for engaging the normally vertically upstanding leg member of the pavement marker upon which the protective covering is mounted so as to deflect the normally vertically upstanding leg member of the pavement marker to a substantially horizontal position at which said at least one toothed implement can engage the protective covering of the pavement marker so as to remove the protective covering from the pavement marker. 7. The apparatus as set forth in claim 3, further comprising: a at least one wheel assembly rotatably mounted upon said platform for rollably supporting said platform upon the roadway surface upon which the plurality of pavement markers, from which the protective coverings are to be removed, are disposed. 8. The apparatus as set forth in claim 7, wherein: said at least one wheel assembly rotatably mounted upon said platform comprises a pair of laterally spaced wheel assemblies mounted upon said forward base end of said platform, and a single steerable wheel assembly mounted upon said rear apex end of said platform. 9. The apparatus as set forth in claim 3, further comprising: trailer hitch means mounted upon said forward base end of said platform for attaching said platform to the roadwork vehicle. 10. In combination, apparatus, adapted to be attached to a roadwork vehicle so as to be movable along with the roadwork vehicle as the roadwork vehicle moves over a roadway surface, for automatically removing protective coverings from the normally vertically upstanding leg members of flexible pavement markers fixedly secured upon a roadway surface, comprising: a roadwork vehicle; a platform attached to said roadwork vehicle; at least one toothed implement mounted beneath said platform so as to be located at a predetermined position above the roadway surface so as not to be engaged with the roadway surface and yet be engageable with the protective coverings of the pavement markers fixedly mounted upon the roadway surface so as to remove the protective coverings from the pavement markers as said roadwork vehicle moves over a roadway surface; an exhaust port defined within said platform through which removed pavement marker protective covering debris can be exhausted; and a suction blower mounted upon said platform and fluidly connected to said exhaust port so as to exhaust pavement marker protective covering debris removed by said at least one toothed implement. 11. The combination as set forth in claim 10, wherein: a drive motor, having a drive output shaft, is mounted upon said platform; a drive sprocket is mounted upon said drive output shaft of said drive motor; a driven sprocket is rotatably mounted upon said platform; and said at least one toothed implement comprises a plurality of toothed implements fixedly mounted upon a drive chain operatively engaged with said drive and driven sprockets. 12. The combination as set forth in claim 11, wherein: said platform has a configuration which is substantially that of an isosceles triangle wherein the base portion of said isosceles triangle is located at the forward end of said platform as considered in the direction of movement of said apparatus along the roadway surface, and the side portions of said isosceles triangle converge toward the rear apex end of said platform; said plurality of toothed implements, said drive and driven sprockets, and said drive chain are disposed beneath said forward end of said platform; and said exhaust port is defined within said rear end of said platform. 13. The combination as set forth in claim 12, further comprising: brush means dependently supported from said platform in a substantially peripheral array around said platform for engaging the roadway surface so as to effectively form a substantially sealed region beneath said platform whereby removed pavement marker protective c