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Pneumatic Latch Circuit

IP.com Disclosure Number: IPCOM000093691D
Original Publication Date: 1966-Jan-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 3 page(s) / 55K

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Norwood, RE: AUTHOR


This circuit employs diaphragm-type elements interconnected to provide a continuous fluid pressure selectively in either of two outlets.

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Pneumatic Latch Circuit

This circuit employs diaphragm-type elements interconnected to provide a continuous fluid pressure selectively in either of two outlets.

The fluid logic devices A...H have flexible diaphragms. The latter are sealable against respective transverse ridges 2 upon supply of pressure fluid to corresponding control chambers 3. Latch L has flexible diaphragm 4 that is sealable selectively against transverse ridges 5 or 6 in chambers 7 and 8, respectively.

Assume control ports a, b, c and d are vented by suitable devices, not shown, that chokes 9 and 10 are of equal flow capacity, and that diaphragm 4 of L is seated against ridge 5 as shown. Then, pressure fluid from source Ps flows via 10 over ridges 2 of A and B to chamber 8. From here, fluid flows at a restricted rate via choke 11 to atmosphere. Also, fluid flows at a substantially unrestricted rate to chamber 3 of F for sealing its diaphragm 1 to cut off outlet 12 from vent port 13. Hence, pressure fluid from Ps flows over 2 of E to 12. Meanwhile, pressure fluid from Ps flows via 9 and over ridges 2 of C and D to chamber 7 of L, causing pressure in 7 to equal that in Ps. However, since this pressure acts over somewhat less than half the total effective area of diaphragm 4, it is insufficient to unseat 4 from 5. Also pressure fluid from Ps supplied via 9 seals diaphragm 1 of G against its ridge 2. With 4 sealed against 5, chamber 3 of H is vented via choke 16, thus causing outlet 14 to be vented via port 15.

To vent outlet 12 and provide in outlet 14 a pressure substantially equal to Ps, control fluid at sufficient pressure is supplied via port a or b to the corresponding chamber 3 of A or B, to seal the corresponding diaphragm 1 and thus cut off flow of pressure fluid to 8. Chamber 8 then vents at the rate controlled by choke 11, causing diaphragm 4 to snap leftward and seal against 6, exposing the entire right-hand face of 4 to full supply pressure. Pressure fluid now vents at the rate controlled by 16, but sufficient pressure is effective on diaphragm 1 of H to seal it and thus cut off 14 from vent 15. As pressure fluid is...