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US 2025/0052554 A1Published application
Tape Measure with Variable Preformed Stressed Spiral Spring Retraction System
AssigneeMilwaukee Electric Tool Corporation
InventorsOluwatosin T. Kolade, Shih-Chi Chou
Life of this patent
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Abstract
A tool, such as a tape measure, including a spring-based retraction system is shown. The spring-based retraction system is driven by a spiral spring, that has a variable preformed stress profile along the length of the spring.
Claims13
A system for forming a variably stressed spiral spring for a tape measure, the system comprising:
- a supply of a ribbon material;
- a smoothing station including a pair of calendaring rollers;
- an end roller;
- a heating station positioned between the smoothing station and the end roller;
- a storage device;
- and
- a stressing station positioned between the end roller and the storage device, the stressing station configured to form different levels of preformed stress in different portions of the ribbon material as the material passes through the stressing station;
- wherein the storage device includes an arbor configured to store the ribbon material when wound to form a spiral spring.
5 more elements
A system for forming a variably stressed spring for a tape measure comprising:
- a metal sheet of spring material;
- a smoothing station;
- a stressing station;
- a heating station positioned between the smoothing station and the stressing station, the stressing station configured to deform the metal sheet of spring material such that different free coil diameters are formed along a length of the metal sheet of spring material;
- and
- a storage device configured to store the metal sheet of spring material when wound to form a spiral spring;
- wherein the spiral spring includes a first section having a first free coil diameter and wherein the first free coil diameter is substantially constant across the first section;
- wherein the spiral spring includes a second section having a plurality of segments, each of the plurality of segments having a different free coil diameter such that free coil diameter varies along a length of the second section.
5 more elements
Dependencies are inferred from the claim text.