Browse Prior Art Database

Roll Spacing Measurement Method

IP.com Disclosure Number: IPCOM000043700D
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Colby, RS: AUTHOR

Abstract

A direct method for the measurement of small distances between solid surfaces is provided by the apparatus of Fig. 1. As an example of the application, the gap spacing of the magnetic brush roller to the photoconductor drum in an electrostatic printer can be measured. Current methods typically involve use of the shim stock or "feeler gauges" which are inserted into a gap to be measured. A certain degree of operator judgment is required as to the level of force used in the insertion. In addition, measurement resolution and accuracy are limited for several reasons. First, shims or gauges of less than .001 inch are too fragile for practical use. Secondly, to cover a wide range, a large collection of gauges would be required. Finally, stacking of several gauges together produces uncertainty due to contaminated films, etc.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 58% of the total text.

Page 1 of 2

Roll Spacing Measurement Method

A direct method for the measurement of small distances between solid surfaces is provided by the apparatus of Fig. 1. As an example of the application, the gap spacing of the magnetic brush roller to the photoconductor drum in an electrostatic printer can be measured. Current methods typically involve use of the shim stock or "feeler gauges" which are inserted into a gap to be measured. A certain degree of operator judgment is required as to the level of force used in the insertion. In addition, measurement resolution and accuracy are limited for several reasons. First, shims or gauges of less than .001 inch are too fragile for practical use. Secondly, to cover a wide range, a large collection of gauges would be required. Finally, stacking of several gauges together produces uncertainty due to contaminated films, etc., between gauges. The measuring element of the apparatus described here consists of a small flexible tube 11. Air, under pressure, is supplied to the tube through a regulator 12 and control orifice
13. The outside diameter of the tube is chosen to be larger than the gap to be measured. In use, the tube is inserted into the gap between the surfaces 15 and 16, and the resulting flattening of the tube restricts air flow through it. This restriction results in a change in pressure which is measured by a pressure gauge 14. As an application of the method, a tube of .070 inch outside diameter and .015 inch wall thickness was...