Method of airtight bonding of two membranes

• US 6,484,383 B1
• Filed: 03/30/1999
• Issued: 11/26/2002
• Est. Priority Date: 03/30/1998
• Status: Expired due to Term

• Current Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius Medical Care AG)
• Inventors: Herklotz, Martin
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): Musser, Barbara J
• Application Number:
  US09/281,195
• Time in Patent Office: 1,337 Days
• Field of Search: 156/580, 156/583.3, 156/295, 156/285, 156/87, 156/382, 261/DIG.37, 73/16.6, 73/16.7, 417/395
• US Class Current: 29/446
• CPC Class Codes: G01L 9/0044 Constructional details of non-semiconductive diaphragms
• CPC Class Codes: Y10S 261/37 Modern pumps diaphragm
• CPC Class Codes: Y10T 29/49863 with prestressing of part

Abstract

A method for airtight joining of two membranes. An airtight and complete bonding of the two membranes is achieved by first producing a curvature in one of the membranes, then placing the convexly curved side of a membrane onto the membrane to be joined to it in an airtight manner, next joining the two membranes until the edge areas of the membranes are in contact, and finally applying a pressing force that seals the edge areas of the membranes in an airtight manner.

Claims

1. A method of airtight joining first and second flexible membranes comprising the steps of:

a) producing a curvature in a first membrane by increasing the pressure on the first membrane;

b) contacting the convex surface of the first membrane with a second membrane;

c) pressing the convex surface of the first membrane into the second membrane to produce a concave surface in the second membrane;

d) joining the first and second membranes, at least in part by increasing the curvature of the first membrane, until the edges of the first and second membranes come into contact; and

e) pressing together the first and second membranes to seal the edge area of the first membrane to the edge area of the second membrane and form an airtight seal between the two membranes.

2. The method according to claim 1, wherein the first membrane borders a first chamber containing a working fluid and the second membrane borders a second chamber to accommodate a fluid to be-pumped, and wherein the curvature in the first membrane is produced by increasing the pressure on the working fluid.

3. The method of claim 2, wherein the first chamber is part of a metering pump.

4. The method of claim 2, wherein the second chamber is filled with fluid before the first and second membranes are joined.

5. The method of claim 4, wherein at least a portion of the fluid is emptied from the second chamber when the first and second membranes are joined.

6. The method of claim 1, wherein a guide is provided for positioning the first and second membranes.

7. The method of claim 2, wherein the first and second chambers are provided in first and second housings respectively.

8. The method of claim 7, wherein a tension device is provided on the first and second housings for maintaining the airtight seal after the first and second membranes have been joined.

9. The method of claim 1, wherein the curvature of the first membrane causes complete deflection in the second membrane during the joining of the two membranes.

10. The method of claim 8, wherein the tension device prevents the admission of air between the first and second membranes.

11. The method of claim 2, wherein the working fluid is an oil.

12. The method of claim 2, wherein the fluid to be pumped is a dialysis fluid.

13. The method of claim 2, wherein the second chamber is filled with a gas before the first and second membranes are joined.

14. The method of claim 13, wherein at least a portion of the gas is emptied from the second chamber when the first and second membranes are joined.