Tekscan, Inc.

Jay Winters

Boris Oreper

Robert M Podoloff

Michael H Benjamin

Charles Malacaria

Mark Lowe

Robert F Golden

Anthony Coviello

Charles McWilliams

This invention relates to apparatus for detecting the contact or nip width between two contacting surfaces. The apparatus includes first and second insulating substrates each of which has a pattern of conductive material formed on a facing inner surface thereof, which substrates are adapted to be fitted between the contacting surfaces. For a first embodiment, the pattern of conductive material on one substrate includes a pair of conductive terminals spaced by a distance greater than the contact width to be measured and the conductive pattern on the other substrate includes a conductor which extends over at least a distance greater than the maximum width W to be measured. A resistance path is provided between the conductive terminals having a resistance R0 which is higher than that of the conductor and material is provided in the space between the conductor and the resistance path which material substantially permits current flow therethrough between the conductor and the resistance path in areas where the contacting surfaces are not in contact and which has a resistance less than R0 permitting current flow therethrough in areas where the contact surfaces are in contact. Circuitry is also provided for applying current to one of the terminals and for utilizing the difference in current flow between the terminals to determine contact width. For a second embodiment, the conductive pattern on one substrate includes N substantially parallel and evenly spaced conductive columns and the pattern on the other substrate is a plurality of substantially parallel and evenly spaced rows. The columns are divided into M groups, where M is an integer which is at least 2, and each of the rows is at an angle &thgr; to a line perpendicular to the columns when extending across alternate ones of the groups and at an angle &minus;&thgr; when extending across the remaining groups. The number of columns in each group is selected to achieve a desired resolution, and &thgr; is selected so that the distance in the direction of the columns between the ends of a row for each group is substantially equal to the spacing between adjacent rows.

Contact width sensors

A force and pressure sensor is provided having two sets of parallel electrodes which are positioned facing one another and arranged so that electrodes of one set cross the electrodes of the second set at an angle to create a plurality of electrode intersections. Pressure-sensitive resistive material lies between the electrodes at each intersection. An adhesive layer is applied to at least one of the electrode sets in areas between electrode intersections to secure the first and second electrode sets in facing relationship, the adhesive layer preferably being applied in a pattern which provides passages where the adhesive layer does not exist to allow air to escape from interior areas of the electrode set. The thickness of the adhesive layer may be adjusted to permit preloading or to provide a threshold level for the sensor. In order to permit electrodes of the electrode set to be trimmed around their periphery, electrical contact to each electrode of the electrode sets is made intermediate the ends of the electrodes. This is accomplished by providing an insulating layer over the rear of each electrode set having holes therein at the desired intersection points and having a plurality of connecting conductors on the back of the insulating sheet, one for each electrode, which make contact with the corresponding electrode through the hole in the insulating sheet.

Flexible tactile sensor for measuring foot pressure distributions and

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Andover, MA, United States of America

Jay Winters