Patent · US Expired

Indicating device

US5311834A · kind A · utility

7Cited by
4References
42Claims
0Family size

Inventor

Key dates

Filing dateOct 30, 1991
Grant dateMay 17, 1994
Priority date
Expiry dateOct 30, 2011

Classification

  • Technology area (CPC A)Human Necessities
  • CPC primaryA63F2009/0004
  • WIPO fieldFurniture, games
  • WIPO sectorOther fields

Abstract

A numerical device (10) for recording and display of individual numbers, symbols and other indicia. The display can incorporate an infinite number of indicia in rows, columns and the like to represent thousands, hundreds, tens, and single digits and the like. The normal length of each column would be up to a maximum of ten numbers. The numerals are encapsulated in a plastic containment housing (12) having chambers which contain a fluid. By depressing a particular number at a particular location, the fluid is displaced from that location and the contrasting color at the rear of the liquid containment area becomes visible after the opaque liquid has been displaced from that particular location. Each column of numbers, e.g., tens, hundreds etc. would be separately contained on, or adjacent to, one common fluid access compartment. Adjacent numeral chambers are joined by a connecting tube (32). The device (10) would normally be overcovered with an overlay membrane-(54) of paper or the like. A common use for the product is a book mark on the covers of books. The user presses the prospective numbers according to the number of pages that the reader is currently located at and each pressure…

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