The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jun. 16, 1987

Filed:

Aug. 04, 1986
Applicant:
Inventors:

William P Newton, Spencerport, NY (US);

Robert S Flight, Rochester, NY (US);

Assignee:

Caldwell Manufacturing Company, Rochester, NY (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E05F / ;
U.S. Cl.
CPC ...
16197 ; 267 74 ; 267179 ;
Abstract

A coupler connects end regions of different sizes of coiled tension springs 30 and 40 to components of block and tackle window balance systems 10. Each coupler 15, 20, or 25 has a snug fit within terminal coils 41 of the strongest spring 40 having the smallest inside diameter, and weaker spring 30 with a larger inside diameter has its terminal coils 31 necked down to fit the coupler. The coupler has a notch or opening with an abrupt edge 18, 22, or 28 axially spaced from an end of the coupler so that the notch is at least twice as long as the largest wire diameter used in the coil springs. At least one of the terminal coils of each spring is indented into the notch or opening in the coupler to a depth of more than one-half the wire diameter so that the indented coil interlocks with edge 18, 22, or 28 and keeps the spring from slipping off the coupler.


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