Cmi Limited

Cmi Corporations

Don W Smith

George W Swisher, Jr

Gary L Westphall

A paving machine having a medially located dowel bar feeder positioned in front of a dowel bar inserter. The machine has a screw or paddle for spreading the concrete and a front strike-off to allocate a proper amount of unconsolidated concrete beneath the machine. Next in line, internal vibrators are mounted to the machine to perform a preliminary consolidation of the concrete, followed by a screed to meter out a correct volume of consolidated concrete for a finished concrete slab. To the rear of the screed, the dowel bar feeder drops dowel bars in a predetermined pattern on the top surface of the consolidated concrete. The dowel bar inserted is mounted to the paving machine behind the dowel bar feeder and includes a plurality of vibrating forks which descend to engage the dropped dowel bars and insert the dowels into the unhardened concrete. In operation, the dowel bars are dropped and the paving machine is driven forward until the forks are over the dropped dowel bars. The paving machine is then stopped and the forks are lowered to insert the dowel bars into the concrete. A finishing machine is operated behind the paving machine to insert center bars and to produce a final consolidated and smoothed grade in the concrete. The paving machine may be adapted to insert dowel bars for transverse joints in a straight or a skewed pattern. In the case of the straight pattern, all the dowel bars for each transverse joint are dropped at the same time. For the skewed pattern, the dowel bars for each transverse joint are dropped one at a time.

Paving machine with drop-then-stop dowel bar insertion

A paving machine having a medially located dowel bar feeder positioned in front of a dowel bar inserter. The machine has a screw or paddle for spreading the concrete and a front strike-off to allocate a proper amount of unconsolidated concrete beneath the machine. Next in line, internal vibrators are mounted to the machine to perform a preliminary consolidation of the concrete, followed by a screed to meter out a correct volume of consolidated concrete for a finished concrete slab. To the rear of the screed, the dowel bar feeder drops dowel bars in a predetermined pattern on the top surface of the consolidated concrete. The dowel bar inserter is mounted to the paving machine behind the dowel bar feeder and is adapted to travel between a forward position and a rear position and includes a plurality of vibrating forks which descend to engage the dropped dowel bars and insert the dowels into the unhardened concrete. Behind the dowel bar inserter, the machine includes a center bar inserter, a tube vibrator, a tamping bar, an extrusion pan and a float pan. The paving machine may be adapted to insert dowel bars for transverse joints in a straight or a skewed pattern. In the case of the straight pattern, all the dowel bars for each transverse joint are dropped at the same time. For the skewed pattern, the dowel bars for each transverse joint are dropped one at a time.

Paving machine with midline dowel bar insertion

A center bar inserter having a frame for supporting a plurality of forks for pivotal movement about a horizontal axis is provided. Insertion of a center bar is preformed by simultaneously extending the forks into the concrete slab while the forks pivot about a horizontal axis. A pair of vibrating sleds are secured to the float pan reward of the center bar inserter for repairing the surface of the concrete slab disturbed by the insertion of the center bar.

Center bar inserter

An improved material transfer mechanism comprising a selectively variable speed hydraulic power assembly having an output connected to and powering a material conveyor. A double acting hydraulic ram positions a swash plate control lever that determines the rotational speed of the output shaft, and a hydraulic porting valve assembly is disposed to actuate the hydraulic ram, the hydraulic porting valve assembly comprising a pivotally supported valve body having an internally disposed fluid control means, the fluid control means being variably displaced in the valve body by the actuation of a pressure controlling mechanism for the purpose of selectively determining and establishing fluid communication of a source of hydraulic pressure fluid to alternate ends of the hydraulic ram with the hydraulic porting valve assembly to selectively control the hydraulic ram. The valve body is biased in a first pivotal direction and is movable in a second pivotal direction by a feed back linkage cable interconnecting the valve body and the swash plate control lever. A sensor mechanism detects the material transferred by the material conveyor and responsively positions the pressure controlling mechanism independently to the position of the valve body.

Growing community of inventors

Edmond, OK, United States of America

Don W Smith