US 4,022,556 A · Concrete slab extruder having a free flight auger

Abstract

A machine is provided for forming hollow cored concrete slabs in which the hollow core may be produced with shapes other than circular in cross section. The machine may produce a noncircular cross sectioned core by utilizing a novel auger assembly construction which employs an open spiral auger, in the form of a corkscrew, which is supported by an initial core forming member which constitutes a surface of revolution and which conforms substantially to the internal surface of the spiral auger member so as to permit the auger to move over the surface thereof and thus continuously wipe clean the surface and prevent any build up on the initial core forming member. The rotating auger is utilized to compress and form concrete material firstly over the initial core forming member and secondly over the final trowel member, in a manner such that the final slab product will have a core with a cross sectional shape approximating that of the final trowel member. Such cross sectional core shape may be of almost of any desired configuration, and the present invention further contemplates the use of interchangeable final trowel members.

Claims8

Dependent claims

A machine for forming hollow cored articles, comprising:

a frame;
at least one rotatable auger of open spiral configuration having an internal surface conforming to an envelope produced by a surface of revolution;
means supporting the at least one auger for rotation about its central longitudinal axis in a stationary position relative to the frame;
a power source mounted on the frame for rotating the at least one auger;
an initial non-rotatable core forming member associated with the at least one auger and having a predetermined cross section with an outer surface conforming substantially to the internal surface of the rotatable auger and having a major portion encompassed thereby;
a final core forming trowel member secured in axial alignment to the initial core forming member and establishing the final cross sectional configuration of the core;
means surrounding at least the final trowel member to establish the outer surfaces of the article being formed;
feed chamber means surrounding said rotatable auger for confining said material whereby the auger moves the material toward the final trowel member and means surrounding the latter member;
and
means mounting the initial core forming member and final trowel member on the frame.

7 more elements

A machine for forming hollow cored concrete slabs on a longitudinally extending surface, said machine comprising:

a main frame having a power source, longitudinal side members and cross support members wherein said main frame further comprises wheel means adapted to engage tracks disposed longitudinally on both sides of said surface;
a hopper in communication with a feed chamber and disposed on the frame;
a plurality of spaced parallel auger assemblies each having (1) a rotatable auger of open spiral configuration having an internal surface conforming to an envelope produced by a surface of revolution, (2) means supporting the auger for rotation about its central longitudinal axis in a stationary position relative to the frame, (3) an initial non-rotatable core forming member associated with the auger and having a predetermined cross section with an outer surface conforming substantially to the internal surface of the auger and having a major portion encompassed thereby, and (4) a final non-rotatable core forming trowel member secured in axial alignment to the initial core forming member and establishing the final cross sectional configuration of the core;
a core forming area defined by top, side and bottom members mounted on said frame, the core forming area surrounding said rotatable augers for confining the molding material while each auger moves the material over its final core forming trowel member, each of the auger assemblies having the rotatable auger operatively connected to the power source.

1 more element

Dependencies are inferred from the claim text.

Concrete slab extruder having a free flight auger

Life of this patent

Concrete slab extruder having a free flight auger

Life of this patent

Abstract

Claims8