Browse Prior Art Database

MULTICOLOR LAMINATE PRESSURE FEELER GAUGE

IP.com Disclosure Number: IPCOM000007889D
Original Publication Date: 1996-Nov-01
Included in the Prior Art Database: 2002-May-02
Document File: 3 page(s) / 182K

Publishing Venue

Motorola

Related People

Ronald Scott Lipton: AUTHOR [+4]

Abstract

There are many mechanical measurement tech- niques that can be used to measure mechanical force in a single dimension. Unfortunately, all of the meth- ods involve the securing of a large area to perform this measurement. At worst, an evasive method ohen needs to be employed to perform this test. The tools that measure this type of force are also expensive and do not justi@ purchase for low or single use.

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Technical Developments

MULTICOLOR LAMINATE PRESSURE FEELER GAUGE

by Ronald Scott Lipton, Harry Fuerhaupter, Kenneth Storts and Brian Black

would be made visible depending upon the force applied to the film. There are several methods of achieving this mechanism, but the advantages for each method are the same:

The method allows measurement in areas which are dithcult to access.

The measurement is quantifiable without the use of extra equipment.

INTRODUCTION

  There are many mechanical measurement tech- niques that can be used to measure mechanical force in a single dimension. Unfortunately, all of the meth- ods involve the securing of a large area to perform this measurement. At worst, an evasive method ohen needs to be employed to perform this test. The tools that measure this type of force are also expensive and do not justi@ purchase for low or single use.

  As an example, the force applied to an elec- tronic tixture during certain automatic assembly oper- ations requires periodic calibration. The contact area where force is applied is small and often difficult to access. Typical force gauges would not be able to access the area for measurement. A custom-made force gauge would be too expensive to justify the use of the equipment.

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KNOWN TECHNOLOGY SOLUTIONS

  One known solution to this problem is the use of a pressure-sensitive film. This film changes color when a specific pressure is applied to it. The color- changing mechanism is accomplished by means of microsphere ink capsules laminated between two thin polymer films. When enough pressure is applied to break the microspheres, the ink escapes and stains the polymer film. In order to get a quantifiable meas- urement from the marks lefi by the ink, a colorime- ter is used. This instrument measures the color den- sity of the ink markings and compares them to a programmed calibration curve in order to determine the applied force. The extra equipment needed to interpret the ink markings increases the cost of per- forming the measurement.

The film is less expensive than using equipment when few measurements are needed.

The film serves as a permanent record of the measurement.

The film could be stamped to any desired size.

The color/force calibration chart could be printed on the back of the force gauge.

The force gauge would be easy to use (no calibra- tion by user).

  There are three major methods ofaccomplishing a multicolor force measurement. First, it is possible to use microsphere ink capsules which have differ- ent pressure tolerances. For instance, a set of microsphere ink capsules laminated between two thin polymer films could have the following pres- sure tolerances and ink colors:

Ink Color

Yellow Red

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Microsphere Pressure Tolerance UD to 10 osi up to 20 psi up to 30 psi

  When the applied force is great enough t...