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US4160544A Expired / Lapsed US ⏱️ 0.0 years remaining

Small diameter, single cone coil spring for use in a box spring assembly

Assignee: L&P Property Management Co
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Filing: 1978-02-13
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Granted: 1979-07-10
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Expires: 1998-02-13
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Abstract

Abstract An improved single cone coil spring and an improved box spring assembly made from the improved single cone coil springs. The box spring assembly comprises a base frame, a series of the improved small diameter single cone coil springs and a welded wire grid, the coil springs being connected at their bottom ends to the base frame and connected at their top ends to the welded wire grid. The coil springs are established in a plurality of rows and columns throughout the box spring assembly, at least one transverse wire and at least one longitudinal wire of the wire grid span all coil springs within each row and column, respectively. Further, a supplemental transverse wire is positioned between adjacent coil spring rows, and is of a length equal to at least one of the coil springs' transverse wires adjacent thereto. All crossover points of all the grid's transverse and longitudinal wires are welded to establish the welded wire grid. The improved single cone coil springs are all of the same diameter, that diameter being less than three and one-half inches in the top loop of the coil springs. The coil spring columns are separated one from the other, and the coil spring rows are separated one from the other, by a distance at least as great as the diameter of the coil springs.

Inventors

  • 👤 Larry Higgins

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 11:08
CPC Classifications
A; A47; A47C; A47C23/00; A47C23/04; A47C23/043

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 121 words
A small diameter single cone coil spring for use in a box spring, said single cone coil spring comprising a single strand of round cross section wire formed into a top loop and at least three additional helically wound loops of decreasing diameter, the end of said top loop being wrapped around the next adjacent loop to form a knot in said coil, the improvement wherein said top loop of said spring has a diameter of less than 31/2 inches so that said spring has increased firmness relative to otherwise identical springs having top loops of substantially greater diameter, and so that said spring exhibits a substantially straight line deflection curve over a major portion of its possible range of deflection.
Claim 2
Dependent Claim 121 words
A small diameter single cone coil spring for use in a box spring, said single cone coil spring comprising a single strand of round cross section wire formed into a top loop and at least three additional helically wound loops of decreasing diameter, the end of said top loop being wrapped around the next adjacent loop to form a knot in said coil, the improvement wherein said top loop of said spring has a diameter of less than 31/2 inches so that said spring has increased firmness relative to otherwise identical springs having top loops of substantially greater diameter, and so that said spring exhibits a substantially straight line deflection curve over a major portion of its possible range of deflection.
Claim 3
Dependent Claim 30 words
The coil spring of claim 1 wherein said top loop diameter is maintained to an accuracy of plus or minus 0.015 inch through an arcuate section of at least 300°.
Claim 4
Dependent Claim 22 words
The coil of claim 1 wherein said single strand of wire has a nominal diameter maintained to an accuracy of 0.0005 inch.

References Cited (Backward Citations)

US3270354A Cited
US3577574A Cited
US3767180A Cited
US3774248A Cited
US3916463A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-07-09 1983-01-08 1983-07-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-07-09 1987-01-08 1987-07-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-07-09 1991-01-08 1991-07-10 $7700.00 Window Closed / Lapsed

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