US 7,111,408 B2Granted

Folding rule

AssigneeCooper Brands, Inc.

InventorsJames M. Critelli, Edgar T. Gilliam

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Abstract

A folding rule includes a plurality of segments having length indicating indicia thereon, including a plurality of intermediate segments having a length to thickness ratio in the range of 40:1 to 60:1; the segments pivotally connected together and pivotally moveable between a collapsed configuration wherein the segments are stacked and an extended configuration wherein the segments are linearly aligned along a measurement axis, wherein at least one intermediate segment rotates by approximately 180° with respect to an adjacent intermediate segment to move between the collapsed configuration and the extended configuration; the segments formed of a generally homogenous electrically non-conductive mixture of wood and plastic. The intermediate segments may be substantially identical except for the length indicating indicia thereon, and at least the intermediate segments may be hydrophobic and be formed of a generally homogenous mixture of wood and ABS plastic. A method of forming such folding rules is also disclosed.

Claims18

Dependent claims

A folding rule, comprising:

a plurality of hydrophobic segments having length indicating indicia thereon, including a first end segment and second end segment and a plurality of intermediate segments, the hydrophobic segments formed of a generally homogenous electrically non-conductive mixture of wood and ABS plastic;
the intermediate segments having a length to thickness ratio in the range of 40:1 to 60:1 and each of the intermediate segments comprising a first hole disposed toward a first end thereof and a second hole disposed toward a second opposite end thereof;
the intermediate segments pivotally connected together at respective pivot joints via a plurality of posts each extending through the first hole of a first intermediate segment of the joint and the second hole of an adjacent intermediate segment of the joint;
wherein the intermediate segments forming each pivot joint are biased toward one another;
at least the intermediate segments pivotally moveable between a collapsed configuration wherein the intermediate segments are stacked and an extended configuration wherein the intermediate segments are linearly aligned along a measurement axis, wherein at least one intermediate segment rotates by approximately 180° with respect to an adjacent intermediate segment to move between the collapsed configuration and the extended configuration;
the intermediate segments each further comprising a plurality of protrusions extending normal to the measurement axis and disposed proximate the first hole and a plurality of recesses extending normal to the measurement axis and disposed proximate the second hole;
wherein the protrusions and the recesses are complementarily formed.

4 more elements

Dependencies are inferred from the claim text.