US 5,203,861 AGranted

Plastic sprocket wheel with replaceable teeth

OwnerGuy L. Irwin, Andre Robininventors

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Abstract

A plastic sprocket wheel includes a sprocket body having a series of circularly spaced recesses located around a body circumferential edge, there also being a body side face opening in at least one body side face which communicates with the recess edge openings so that replaceable tooth elements can be slidably inserted into an associated recess when tooth replacement such as required when one or more teeth of an operating sprocket break or are rendered unusable. The replacement mounting requires no separate fastening devices for holding replacement teeth securely to the sprocket body, friction fit being sufficient to that end. The sprocket body is of resilient material such as an acetal, a polyethylene, a polypropylene etc., and the tooth elements can be of metal or the same material as the sprocket body, or such can be a combination of materials, e.g., a strong metal tooth piece molded in a resilient or plastic material core. Further forms of tooth element/sprocket body constructions are provided for use in and to counter effects in conveyors where right and/or left turn belt runs apply significant laterally directed force to the sprocket tooth elements.

Claims27

Dependent claims

A sprocket wheel with removable/replaceable teeth, said sprocket wheel comprising

a sprocket body having opposite side faces and a circumferential edge surface extending between said side faces, there being a plurality of recesses extending radially inwardly from openings spaced around said edge surface, with each recess opening at at least one of said side faces, each recess having a part narrowed circumferentially relative to its edge surface opening and located radially inwardly of the body edge surface,
a corresponding plurality of tooth elements associated one with each respective recess, each tooth element including a tooth piece and a base piece, the base piece being receivable in its associated recess with the tooth element extending radially beyond the sprocket body edge surface, said base piece being configured complementally to the recess wherein received, the base piece having an envelope size larger than an envelope size of its associated recess, the sprocket body being made of a resilient material so that when said base piece is slidably removably inserted into its associated recess through the opening at the at least one body side face, body structure defining said recess is caused to elastically yield to admit said base piece in recess conformable occupancy and in tight frictional base piece external surface-to-recess surface interference fit, and
means associated with each base piece and recess for maintaining the base piece when inserted in the recess, registered therein with an end surface of the base piece aligned flush with said sprocket body one side face.

A sprocket wheel with removable/replaceable teeth, said sprocket wheel comprising

a sprocket body having opposed side faces and a generally circular edge profile extending between said side faces, there being a plurality of body projections circularly spaced around the body edge with recesses intervening the projections and extending radially inwardly a distance from the edge surface, each recess passing from side face-to-side face of the body between respective side face openings thereat, each recess having an envelope of a given dimension, and
a corresponding plurality of tooth elements, each tooth element including a tooth piece and a base piece, each base piece being configured complementally to and receivable in a respective one of the recesses and having an envelope dimension larger than that of its associated recess, said sprocket body being made of a resilient material so that when a larger envelope dimension base piece is slidably removably inserted into an associated smaller envelope dimension recess through one side face opening,
a projection intervened by said respective one recess and having an unoccupied next adjacent recess is caused to yield elastically diminishing the envelope dimension of any such unoccupied recess, insertion of a last base piece into a last unoccupied recess requiring insertion force sufficient to counter elastic yield imposed on body projections adjacent said last recess tending to restore it to said given envelope dimension whereby there is established with said last base piece insertion a circularly imposed compressive force transmissively acting on all base pieces for securing them tightly in their associated recesses.

Dependencies are inferred from the claim text.