Abstract: An apparatus for inserting dowel bars into a concrete slab in association with a slip forming machine of a type having a frame with a mold attached thereto for shaping uncured concrete into a continuous concrete slab. The mold having a front and rear pan portion with a space therein completely across the mold. A dowel bar inserter having individual fork assemblies is disposed above this space in the pan for pushing the dowel bars down into the formed concrete slab, preferably all at one time. The dowel bar inserter is adjustable and removable. If removed, the forward and rear pan portions of the mold can be bolted together instead of being spaced apart. The front pan portion is greater than three feet long. The rear pan portion is greater than two feet long and the front pan portion is preferably longer than the rear pan portion.

Abstract: A method and apparatus for inserting dowel bars into a concrete slab is used in association with a slip forming machine of a type having a frame with a pan attached thereto for shaping uncured concrete into a continuous concrete slab. A plurality of openings are exposed through the pan and are spaced across the pan. Dowel bar retainers are disposed in each respective one of the openings for holding a dowel bar in readiness to be inserted into the concrete slab. A dowel bar inserter is disposed above each of the dowel bar retainers for pushing a dowel bar disposed in a respective one of the dowel bar retainers through a respective one of the openings and into the concrete slab. Apparatus is provided for automatically and independently actuating each one of the dowel bar inserters at a predetermined place in a concrete slab whereby respective ones of the dowel bars disposed in respective ones of the dowel bar inserters can be positioned in the concrete in a predetermined pattern across the concrete slab.

Abstract: An improved method and apparatus of inserting dowel bars into a newly formed concrete road surface at locations for at least partially forming transverse joints therein includes a slip forming machine for laying a strip of newly formed concrete. A dowel bar placement pan subframe is operably connected to the frame of the machine and extends generally transversely to the direction of forward movement of the frame. The subframe has a plurality of parallel slots disposed therein along the length thereof. A trolley is provided for traveling back and forth across the subframe and has a mechanism therein for storing a plurality of dowel bars therein and permitting the stored dowel bars to roll downwardly one behind the other. A dowel bar stopping device is provided for stopping the lowermost one of the dowel bars at a predetermined position with respect to the trolley.

Abstract: An apparatus for automatically slip forming concrete having a movable frame for moving in a first direction over concrete to be formed into a desired shape. The movable frame has a longitudinal centerline generally aligned with or parallel to the first direction. A crown forming structure is attached to the frame for selectively producing a desired crown on the concrete being so formed. The crown forming structure includes a left segment pivotally attached on an inner portion thereof, along an axis generally near to and aligned with or parallel to the longitudinal centerline of the movable frame. The crown forming structure also includes a right segment pivotally attached on an inner portion thereof, along an axis generally near to and aligned with or parallel to the longitudinal centerline of the movable frame. A transition adjusting device is provided for selectively raising and lowering said inner ends of the right and left segments for controlling the crown forming structure.

Abstract: An apparatus for continuously forming and positioning a keyway joint is removably coupled to the front end of a slip-form paving machine. A supply roll of key strip stock is mounted on the apparatus and the strip is guided to successive arrangements of forming rollers for shaping the strip into a desired form. An automatic punch mechanism is provided for pucnhing holes in the strip liner and an automatic tie bar mechanism is also associated with the apparatus for automatically placing tie bars into these holes. Because it is difficult to assure that such tie bars are properly placed in the holes and since an improperly positioned tie bar can cause serious damage to the keyway and pavement already laid, a mechanism is provided for shutting down the paving machine if such tie bars are not properly placed.