Patent · US Expired

Back incline indicator

US4958145A · kind A · utility

17Cited by
7References
5Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 5, 1989
Grant dateSep 18, 1990
Priority date
Expiry dateMay 5, 2009

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S482/909
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A back incline indicator (10) employs a mercury switch (44) and a beeper (72) to indicate to a user (24) whenever the back of the user (24) is bent beyond an acceptable limit, .lambda.crit. The mercury switch (44) and beeper (72) are attached to a casing (38) including a plate (28A) that is parallel to the back of the user (24). The casing (38) is connected by a connector (14) to the shirt collar of the user (24). The mercury switch (44) is set to an angle .theta. from the plate (28A). The value of .theta. determines how much the user's back may be bent before .lambda.crit is reached. The value of .theta. may be set to different amounts as the desired value of .lambda.crit may vary with different uses of the back incline indicator (10).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.