Browse Prior Art Database

Pneumatic Transducer

IP.com Disclosure Number: IPCOM000074779D
Original Publication Date: 1971-Jun-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Schaffer, RR: AUTHOR [+2]

Abstract

The sensing of documents, ribbon material, or similar objects in an unclean environment, such as in printing machines, can be conveniently accomplished by this low cost pneumatic transducer which by virtue of its unique design is self-cleansing, requires no critical adjustments with respect to the object being sensed, and is suitable for either low or high-speed sensing.

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Pneumatic Transducer

The sensing of documents, ribbon material, or similar objects in an unclean environment, such as in printing machines, can be conveniently accomplished by this low cost pneumatic transducer which by virtue of its unique design is self- cleansing, requires no critical adjustments with respect to the object being sensed, and is suitable for either low or high-speed sensing.

In drawing A, a primary air stream of pressure p1 flows in the direction indicated, out of orifice 1 and passes by a pressure-sensitive switch and finally flows out of orifice 2. A secondary air stream of pressure p2 flows out of orifice 3, in the direction indicated. Orifices 2 and 3, for a particular embodiment, are separated by a gap distance of less than half an inch. A disc 4 with an opening 4a is utilized to improve the aerodynamics in the gap. The two air streams flowing out of orifices 2 and 3, respectively, are separated when an object to be sensed is interposed in the air gap between the two orifices. In the absence of an object in this air gap, the secondary air stream, having a pressure greater than the primary stream impacts orifice 2 with sufficient force that results in the closing of orifice 2. As a result, the pressure in the enclosure between orifices 1 and 2 builds up to close the pressure sensitive switch. The presence of an object in the gap intercepts the secondary air stream and results in the lowering of the pressure in the enclosure causing the press...