Browse Prior Art Database

Vacuum Pressure Switch

IP.com Disclosure Number: IPCOM000090829D
Original Publication Date: 1969-Jul-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Anderson, TH: AUTHOR

Abstract

The diaphragm switch is used as a vacuum or pressure actuated device for sensing documents in a document transport. Although not hermetically sealed. the diaphragm is subjected to a minimum fluid flow which is exerted on the side of the diaphragm opposite the contact points. In each environment, a light weight plastic hall or other shaped element transmits a localized force to the diaphragm to assure adequate deformation at the correct location for good electrical contact.

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Vacuum Pressure Switch

The diaphragm switch is used as a vacuum or pressure actuated device for sensing documents in a document transport. Although not hermetically sealed. the diaphragm is subjected to a minimum fluid flow which is exerted on the side of the diaphragm opposite the contact points. In each environment, a light weight plastic hall or other shaped element transmits a localized force to the diaphragm to assure adequate deformation at the correct location for good electrical contact.

The device in drawing A functions to open a switch upon the occurrence of an increase in vacuum. Compressively retained between housings 10 and 11 is circuit board 12, apertured electrically insulating spacer 13, and a copper clad etched elastic diaphragm 14. Plastic ball 15 is positioned and biased by spring 16 to normally bias the conductive lower surface of diaphragm 14 into contact with the conductive upper surface of board 12. The spherical surface of bail 15 aces through disk 17, carried by diaphragm 14, to localize pressure exerted on diaphragm 14 to the contact area of board 12 to maintain adequate electrical contact. Adjusting screw 18 affords regulation of the biasing force exerted by spring 16. The lower surface of diaphragm 14 communicates with the atmosphere through air bleed 27 and dust filter 28.

Shown with a document transport, vacuum Pv is applied at conduit 20 with branch 21 which communicates with surface 22 of document supporting bed 23. Normally, with...