US 4,428,522 A · Step driver

Abstract

Apparatus for placing steps in a concrete pipe or riser immediately after the pipe has been cast but before it is cured. A movable carriage is mounted upon a support column that is arranged to move a step driving mechanism vertically along the inner wall of the riser before the riser is removed from the casting jacket. The position of the carriage is automatically indexed to sequentially place the driving mechanism at the desired vertically spaced step locations. The drive mechanism is actuated at each location to drive a bifurcated member horizontally into the wall of the riser. In one embodiment of the invention the bifurcated member is a step that is automatically gravity loaded into the mechanism from an overhead supply magazine. In this embodiment of the invention the step is embedded in the riser and is set in place during curing. In another embodiment of the invention, the bifurcated member is a hole forming tool for accurately placing a pair of step receiving holes in the riser wall into which the steps are subsequently locked in place.

Claims12

Dependent claims

Apparatus for driving steps into a precast riser section that is supported in an upright position within a jacket that includes

a stationary support column for movably supporting a carriage for movement back and forth over a vertical path of travel between a raised home position and a fully extended lowermost position,
means for positioning a precast riser in an upright position adjacent to the stationary column whereby the column is located on the outside of the riser,
an elongated bracket suspended from the carriage that is arranged to pass downwardly into the riser as the carriage is lowered from the home position toward the lowermost position,
a slide means mounted in the distal end of the bracket for moving a bifurcated member into the riser wall, and
control means for sequentially indexing the carriage to position the slide means at predetermined step locations and reciprocating the slide means to drive the bifurcated member into the wall at each step location.

2 more elements

In a machine for fabricating concrete pipe wherein the pipe is cast in an upright position within a jacket seated upon a worktable at a first station and the work table is moved to bring the pipe into a second station, the improvement comprising,

a support column mounted adjacent the table,
a carriage movably supported upon the column so as to move vertically along a path of travel towards and away from the table,
a magazine depending from the carriage for movement therewith, said magazine being positioned on the carriage to pass downwardly into a pipe seated on the table in the second station adjacent to the inside wall thereof,
said magazine having a chamber for storing a plurality of steps in a stack-like configuration over a slide means operatively mounted in the distal end of the magazine whereby steps stored therein are gravity loaded into said slide means,
indexing means for sequentially positioning the carriage to locate the slide means at spaced apart step locations, and
drive means for moving the slide mechanism toward the riser wall at each step location to embed a step seated therein into said wall and then return the slide means to a step loading position.

3 more elements

Dependencies are inferred from the claim text.

Step driver

Life of this patent

Step driver

Life of this patent

Abstract

Claims12