US 4,852,719 AGranted

Modular screw conveyor

AssigneeLaitram, L.L.C.

InventorJames M. Lapeyre

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Abstract

A screw conveyor composed of a plurality of modules mated end to end and of identical integrally molded construction. Each module is molded of a suitable plastic material and has integrally formed therewith a cylindrical body, a coaxially disposed tube within the body, and a web helically disposed between the coaxial tube and the cylindircal body. The module includes ends mateable with corresponding ends of like modules to provide a screw conveyor of intended length and which is rotatable as a single unitary structure. Each module may have a sheave integrally molded thereon for mating with a V-belt drive. Alternatively, the modules can be of open form each having a helical web molded on a central tube preferably having a non-circular and adapted for end to end mating with like modules to provide a screw conveyor of desired length. This open type of screw conveyor can be readily retrofitted to systems having conventional metal conveyor screws.

Claims15

Dependent claims

A screw conveyor composed of a plurality of like modules mated end-to-end, each of said plurality of modules being integrally molded and each of said plurality of modules comprising:

a central tube having first and second ends and an opening extending therethrough between said first and second ends, said opening having a non-circular cross section;
a helical web disposed around the outer surface of said central tube and integrally formed thereto, said helical web having a predetermined length and first and second ends extending axially outwardly of said first and second ends of said central tube, respectively, by a predetermined length;
said first and second ends of said central tube having means for sealingly engaging adjacent ones of said plurality of like modules as mated end-to-end to form said screw conveyor to provide helical screw conveying surfaces disposed around an effectively continuous central tube;
said first and second ends of said helical web having means for confronting corresponding means on adjacent ones of said plurality of like modules as mated end-to-end to form said screw conveyor to provide helical screw conveying surfaces disposed around an effectively continuous central tube;
a tensile member extending through said openings of said effectively continuous central tube of said plurality of like modules mated end-to-end to form said screw conveyor, said tensile member having a non-circular cross section corresponding to said non-circular cross section of said opening of said central tube;
and
means for securing ends of said tensile member with respect to end ones of said plurality of like modules to maintain said plurality of like modules mated end-to-end in compressive mated engagement.

4 more elements

A plastic screw conveyor, comprising:

a plurality of integrally molded like modules mated end-to-end to form said plastic screw conveyor, each of said integrally molded modules including
a central tube having a non-circular aperture extending therethrough and first and second ends, said non-circular aperture having a cross section,
a helical web having a length about one percent less than one helical pitch length disposed around the outer surface of said central tube and integrally molded therewith, said helical web having first and second ends extending axially outwardly of said first and second ends of said central tube, respectively, by a predetermined length,
each one of said first and second ends of said central tube having means for sealingly engaging adjacent ones of said plurality of integrally molded like modules as mated end-to-end to form said plastic screw conveyor to provide a helical screw conveying surface disposed around an effectively continuous central tube,
said first and second ends of said helical web having means for confronting corresponding means on adjacent ones of said plurality of integrally molded like modules as mated end-to-end to form said plastic screw conveyor to provide a helical screw conveying surface disposed around an effectively continuous central tube,
said plastic screw conveyor having a length determined by the number of integrally molded like modules mated end-to-end constituting said plurality of integrally molded like modules;
a drive shaft extending substantially the length of said screw conveyor through each of said non-circular apertures of said plurality of integrally molded like modules as mated end-to-end to form said plastic screw conveyor, said drive shaft having a non-circular cross-section corresponding to said cross section of said non-circular aperture, said non-circular cross section of said drive shaft cooperating with each of said non-circular apertures of said plurality of integrally molded like modules such that rotation of said drive shaft causes uniform rotation of said plurality of integrally molded like modules;
and
fastening means located at each end of said shaft to maintain said plurality of integrally molded like modules as mated end-to-end to form said plastic screw conveyor, and to allow limited axial movement of said plurality of integrally molded like modules on said drive shaft resulting from expansion and contraction of said plurality of integrally molded like modules due to changes in temperature.

6 more elements

Dependencies are inferred from the claim text.