Machine grooved joint on hollow concrete cylinders
OwnerJohn C. Rossboroughinventor
Life of this patent
Estimating the term…
Abstract
A bell and spigot joint of reinforced concrete manhole risers, or pipes, or abutting joints therein are improved by precasting the same, free or pre-cast grooves in the exterior faces intended for seating sealing rings. After pre-casting and curing in the kiln, the hardened, cured surfaces are machined to form a sealing ring groove proximate the ends thereof, for example around the spigot of a bell and spigot joint. The inside of the bell is also machined to hone the same to a smooth finish. The grooving apparatus is precisely centered on the axis of the member to produce a groove of uniform radius relative thereto.
Claims7
The method of machining an annular groove around the exterior surface of the spigot end of a reinforced concrete manhole riser by means of a circular track frame mounted across said spigot end, a carriage mounted to move around the circular track, a linear track extending radially on said carriage, a cutter head movable along said linear track and a rotary cutter depending from said head, said method comprising the steps of
- precisely centering said circular track frame relative to the longitudinal axis of said riser,
- power moving said carriage around said circular track frame at a controlled velocity,
- power rotating said rotating cutter of said cutter to rotate in a horizontal plane on a vertical axis;
- and power moving said cutter head along said linear track to a position thereon to form an annular groove in said spigot end said groove having an inner wall at a predetermined, uniform radial distance from said axis as said carriage travels in a circular path around said axis.
The method of machining an annular groove around the spigot end of a manhole riser, by means of a rotary cutter head movable radially on the linear track of a carriage, the carriage being movable in a circular path around a frame, supported across said spigot end, said method comprising the steps of
- power rotating the cutter of said cutter head
- power moving said cutter head and cutter inwardly on said linear track to form a part of a groove in said spigot end to a predetermined depth and
- power moving said cutter head, cutter and track on said carriage in a circular path around said spigot end at a uniform radial distance from the central longitudinal axis of said riser to complete said groove around said spigot end.
Dependencies are inferred from the claim text.