U.S. Utility Patent 4,528,431 (US4528431A)

JavaScript disabled or not supported

It appears you have prevented JavaScript from running in your web browser or are using a web browser that does not support JavaScript. Admiral Shark's Keyboards presently requires JavaScript for quality-of-life features like switching between light/dark mode, navigating via title or image and copying search query links, and is necessary for the keyboard matrix simulators, keyboard property modals, interactable slideshows and image size optimisation. Please consider enabling JavaScript or using a web browser that supports it for a fully-featured and correctly working experience. If you have suggestions for reducing JavaScript dependency, feel free to let me know.

Provided by the ASK Keyboard Patents database

Patent diagrams of IBM's rocking switch actuator for a low force membrane contact switch at rest (left) and pressed (right)

A patent chart illustrating the force curve for IBM's rocking switch actuator for a low force membrane contact switch

Applied 3rd October 1983

Published 9th July 1985

Expired 3rd October 2003

More informaion

Name	Rocking switch actuator for a low force membrane contact switch
Inventors	Edwin T. Coleman, III
Assignees	Maxi Switch
Description	An invention of a buckling spring actuator for use with a membrane assembly to make a membrane keyswitch now typically known as "IBM membrane buckling springs". Compared to the previous capacitive design from 1977 (US4118611A), the use of membrane technology approximately halves its production costs. It was used for many Model M family keyboards.

Go back to Keyboard Patents