Snap disc device
OwnerPierre P. Schwabinventor
Life of this patent
Estimating the term…
Abstract
A bowed snap-disc includes inner and outer perimeters that provide the disc with operating characteristics not found in comparably sized discs. At certain points along its circumference, the inner perimeter extends farther from the disc's center than certain other points of the disc's outer perimeter. This provides the disc with a unique combination of spring constant, compressive force, deflection and coefficient of compliance. The disc is particularly useful as a small, flat compression spring; a shaft or bar locking element; tightness indicator for a threaded fastener; or a lock washer.
Claims18
A fastener, comprising:
- a first member;
- a bar adjacent the first member and having four faces to define a substantially square cross-section;
- and
- a disc being elastically stressed due to engagement with the bar, the disc includes a curved outer edge with a minimum radial point, and an inner edge with a maximum radial point, wherein a center of gravity of the disc is at least as close to the minimum radial point as the center of gravity is close to the maximum radial point, the inner edge further includes four substantially linear edges that grip the four faces of the bar, and the curved outer edge abuts the first member, whereby the disc limits movement between the first member and the bar.
A fastener, comprising:
- a threaded member with a first surface;
- a second member with a second surface;
- a disc compressed between the first surface and second surface, such that the disc is elastically stressed to an intermediate position between an unstressed position of zero percent where a surface of the disc is bowed and a fully stressed position of a 100% where the surface is substantially flat, the disc includes an outer edge with a minimum radial point, and an inner edge with a maximum radial point, wherein a center of gravity of the disc is at least as close to the minimum radial point as the center of gravity is close to the maximum radial point;
- and
- a standoff element adjacent the disc and inhibiting the disc from deflecting completely to the fully stressed position.
A fastener, comprising:
- a disc elastically deflectable between an unstressed position of zero percent where a surface of the disc is bowed and a fully stressed position of a 100% where the surface is substantially flat, the disc has a thickness, an inner edge having a maximum radial point, and an outer edge having an effective outer diameter and a minimum radial point, wherein a center of gravity of the disc is at least as close to the minimum radial point as the center of gravity is close to the maximum radial point, the disc has a spring constant that is defined as a force needed to compress the disc to an intermediate position of 75% divided by a distance that the disc deflects upon moving from the unstressed position of zero percent to the intermediate position of 75%, wherein the disc has a coefficient of compliance greater than ten with the coefficient of compliance being defined as the thickness cubed divided by a product of the spring constant times the effective outer diameter squared, wherein the thickness is expressed in mils, the spring constant is expressed in pounds per inch, and the effective outer diameter is expressed in inches.
Dependencies are inferred from the claim text.