# US 2014/0196798 A1 · Diaphragm check valves and methods of manufacture thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196798 A1 - Document ID: US20140196798A1 - Status: Published application - Kind: A1 - Application number: 14/153,662 - Filed: 2014-01-13 - Published: 2014-07-17 - Earliest claimed: 2013-01-11 - Assignees: MiniPumps, LLC - Inventors: Yu-Chong Tai; Po-Ying Li; Fukang Jiang; Changlin Pang; Natasha Yvette Bouey; Man Ting Chou; Atoosa Lotfi - Web page: https://patentgrep.com/patent/US20140196798A1 ## CPC - F16K 15/147: {the closure elements having specially formed slits or being of an elongated easily collapsible form} - B29C 70/766: {on the end part of a tubular article} - F16K 15/145: {the closure elements being shaped as a solids of revolution, e.g. cylindrical or conical} - F16K 99/0057: {the fluid being the circulating fluid itself, e.g. check valves} - B29C 39/10: incorporating preformed parts or layers, e.g. casting around inserts or for coating articles {(coating a surface by casting in general B05D1/30, B29C39/126 takes precedence)} - B29C 41/20: incorporating preformed parts or layers, e.g. moulding inserts or for coating articles - B29C 45/14598: {Coating tubular articles} - B29L 2031/753: {Medical equipment; Accessories therefor (bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008)} - B29L 2031/756: {Microarticles, nanoarticles} - F16K 15/144: {the closure elements being fixed along all or a part of their periphery} - F16K 2099/0078: {using moulding or stamping} - Y10T 137/0497: Fluid actuated or retarded - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Microscale valves for use in, e.g., micropump devices, may be formed of a slitted diaphragm bonded to the interior of a valve tube. A bump in the diaphragm and/or a backward-leakage stopper may increase the breakdown pressure of the valve. A push-rod may be used to pre-load the valve membrane to thereby increase the cracking pressure. ## Claims ### Claim 1 An in-line check valve comprising: a tube defining a lumen for flow of fluid therethrough; and affixed to an interior surface of the tube and spanning a cross-section thereof, an elastic diaphragm comprising a slit or opening therethrough, wherein the valve is configured (i) to open upon application of at least a cracking pressure on a first side of the diaphragm so as to permit fluid to pass through the slit or opening from the first side to a second side of the diaphragm, and (ii) to prevent backflow of fluid from the second side to the first side until at least a breakdown pressure is reached on the second side. ### Claim 2 (depends on 1) The check valve of claim 1, wherein a diameter of the tube is less than 1 mm. ### Claim 3 (depends on 1) The check valve of claim 1, wherein a largest dimension of the valve is less than 1 mm. ### Claim 4 (depends on 1) The check valve of claim 1, wherein the diaphragm comprises therethrough a slit configured to flex and open upon application of at least the cracking pressure on the first side of the diaphragm. ### Claim 5 (depends on 4) The check valve of claim 4, wherein the diaphragm comprises a bump on the second side, the slit being co-located with the bump. ### Claim 6 (depends on 4) The check valve of claim 4, further comprising a backward-leakage stopper abutting the diaphragm at the first side thereof. ### Claim 7 (depends on 6) The check valve of claim 6, wherein the stopper comprises a stopper tube fitted to an interior of the tube. ### Claim 8 (depends on 7) The check valve of claim 7, wherein the stopper tube has a lumen therethrough. ### Claim 9 (depends on 8) The check valve of claim 8, wherein the lumen is sized to impose a specified restriction on a rate of fluid flow therethrough. ### Claim 10 (depends on 8) The check valve of claim 8, wherein the lumen is centered at the slit. ### Claim 11 (depends on 8) The check valve of claim 8, wherein the lumen is offset from the slit. ### Claim 12 (depends on 8) The check valve of claim 8, wherein the stopper tube has multiple lumina therethrough. ### Claim 13 (depends on 6) The check valve of claim 6, wherein the stopper extends beyond and surrounds an inlet end of the rigid tube. ### Claim 14 (depends on 1) The check valve of claim 1, further comprising a pre-load member urged against the first side of the diaphragm so as to flex the diaphragm and occlude the slit or opening in a closed state of the valve. ### Claim 15 (depends on 14) The check valve of claim 14, wherein the cracking pressure depends at least in part on an axial position of the pre-load member. ### Claim 16 (depends on 1) The check valve of claim 1, wherein the diaphragm extends into a skirt secured to the interior of the rigid tube. ### Claim 17 (depends on 16) The check valve of claim 16, wherein the rigid tube includes holes through a side wall thereof in regions adjacent the skirt. ### Claim 18 (depends on 17) The check valve of claim 17, wherein the skirt is secured to the rigid tube by epoxy extending through the holes. ### Claim 19 A method for fabricating an inline valve structure using a stack mold fixture comprising (i) at least one pin having a first tier with a first diameter and a second tier with a second diameter that is smaller than the first diameter, and (ii) at least one spacer extending in height beyond the pin, the method comprising: placing a valve tube having an inner diameter matching the first diameter over the at least one pin, and filling liquid elastomer precursor into an interior space of the valve tube; forcing liquid elastomer precursor from the interior space of the valve tube, thereby forcing a surface of the liquid elastomer to a height of the at least one spacer; curing the elastomer precursor, thereby creating in the valve tube a diaphragm having a thickness equal to the distance by which the at least one spacer extends in height beyond the pin; and, following curing, removing the valve tube and diaphragm from the stack mold. ### Claim 20 (depends on 19) The method of claim 19, wherein curing the elastomer precursor further causes creation of a skirt extending from the diaphragm and having a distance equal to half a difference between the first and second diameters. ### Claim 21 (depends on 19) The method of claim 19, wherein forcing liquid elastomer precursor from the interior space of the valve tube and thereby forcing a surface of the liquid elastomer to a height of the at least one spacer comprises placing a flat member on the at least one spacer. ### Claim 22 (depends on 21) The method of claim 21, further comprising coating the flat member, prior to placement on the spacer, with an adhesion-inhibiting coating. ### Claim 23 (depends on 22) The method of claim 22, wherein the adhesion-inhibiting coating comprises at least one of parylene or gold. ### Claim 24 (depends on 21) The method of claim 21, further comprising etching a recess into the flat member prior to placement on the spacer, curing the elastomer precursor thereby causing creation, in the diaphragm, of a bump complementary to the recess. ### Claim 25 (depends on 21) The method of claim 21, wherein the stack mold fixture further comprises first and second bracket members, the method further comprising securing the at least one pin and the flat member between the first and second bracket members. ### Claim 26 (depends on 19) The method of claim 19, wherein the first tier of the at least one pin includes at least one exit flow channel, liquid elastomer precursor being forced from the interior space at least partially therethrough. ### Claim 27 (depends on 19) The method of claim 19, further comprising removing the liquid elastomer precursor forced from the interior space prior to curing. ### Claim 28 (depends on 19) The method of claim 19, further comprising creating a slit or opening in the valve diaphragm. ### Claim 29 (depends on 19) The method of claim 19, wherein the first tier of the pin rests on a support surface, the method further comprising placing an O-ring on the support surface around the pin and placing the valve tube on top of the O-ring. ### Claim 30 (depends on 19) The method of claim 19, wherein the stack mold fixture comprises multiple pins, the method comprising creating multiple valve structures simultaneously.