Liquid supply apparatus

• US 20050209562A1
• Filed: 02/06/2003
• Published: 09/22/2005
• Est. Priority Date: 02/08/2002
• Status: Active Grant

• Current Assignee: E-WHA Fresenius Kabi Inc.
• Original Assignee: E-WHA Fresenius Kabi Inc.
• Inventors: Kim, Yong-Nyun
• Granted Patent: US 7,475,797 B2
• Time in Patent Office: Days
• US Class Current: 604/141
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/14526 the piston being actuated by fluid pressure
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28
• CPC Class Codes: A61M 5/31513 Piston constructions to improve sealing or sliding

Abstract

A liquid supply apparatus is provided. The liquid supply apparatus has a cylinder, a piston and a gas supply apparatus. The cylinder is provided with a head portion with outlet. The cylinder has a rear end opened. The piston is inserted into the cylinder. The piston moves along the longitudinal direction of the cylinder so as to supply liquid contained in the cylinder. The gas supply apparatus generates and supplies gas to push the piston. The piston has a pair of sealing ring. The sealing ring has a base attached to a body of the piston and a outer wing connected to the base. The gas supply apparatus has a gas pressure regulator.

Claims

1. A liquid supply apparatus, comprising:

an elongated cylinder including a head portion with an opening, and an open rear portion;

a piston which is inserted into the cylinder and hermetically divides an inner space of the cylinder into a liquid compartment on the side of the head portion and a gas compartment on the side of the rear portion; and

a gas supply apparatus constructed to supply the gas compartment with gas and connected to the rear portion of the cylinder,

whereby the piston is moved toward the head portion when the gas is supplied to the gas compartment.

2. The liquid supply apparatus as claimed in claim 1, wherein the piston comprises a body and a sealing ring which surrounds the body and is in contact with an inner surface of the cylinder, and the sealing ring comprises an inner base fixed to the body and an outer wing which is connected to the base and is in contact with the inner surface of the cylinder.

3. The liquid supply apparatus as claimed in claim 2, wherein the outer wing is inclined with respect to a wall of the cylinder.

4. The liquid supply apparatus as claimed in claim 2 or 3, wherein the piston comprises at least two sealing rings, and the outer wing of one of the sealing rings on a side of the liquid compartment extends toward the liquid compartment and the outer wing of the other sealing ring on a side of the gas compartment extends toward the gas compartment.

5. The liquid supply apparatus as claimed in claim 2 or 3, wherein the body is provided with an annular groove, and the base of the sealing ring is fitted into the groove.

6. The liquid supply apparatus as claimed in claim 4, wherein a sealing ring on a side of the liquid compartment and a sealing ring on a side of the gas compartment are sealing rings with a substantially identical dimension, and a radius of the bottom of the groove in the piston body into which the sealing ring on the side of the gas compartment is fitted is larger than that of the bottom of the groove into which the sealing ring on the side of the liquid compartment is fitted.

7. The liquid supply apparatus as claimed in claim 2 or 3, wherein the outer wing is configured such that a tip thereof does not extend beyond a distal end of the base.

8. The liquid supply apparatus as claimed in claim 1, wherein the head portion of the cylinder includes a truncated conical projection extending into the cylinder, the projection is formed with an opening, and the piston is provided with a truncated conical recess for accommodating the projection.

9. The liquid supply apparatus as claimed in claim 1, wherein the gas supply apparatus comprises an outer wall and a partition connected to the outer wall so as to define a gas supply chamber by the outer wall and the partition, the gas compartment of the cylinder and the gas supply chamber are divided by the partition, and the partition is provided with a through-hole through which the gas supply chamber and the gas compartment communicate with each other.

10. The liquid supply apparatus as claimed in claim 9, wherein the outer wall and the rear portion of the cylinder are fitted into or around and coupled with each other, and an annular groove is provided in one of fitted contact surfaces thereof, whereby upon coupling of the outer wall and the rear portion of the cylinder using an adhesive, a surplus of the adhesive is received by the annular groove.

11. The liquid supply apparatus as claimed in claim 9, wherein the outer wall comprises an insertion portion tightly fitted into the cylinder and bonded to an inner surface of the cylinder using an adhesive, an exposed portion exposed outside of the cylinder, and a stepped portion connected to an outer wall of the exposed portion radially outward from an outer wall of the insertion portion, and an edge between the insertion portion and the stepped portion is provided with an annular groove.

12. The liquid supply apparatus as claimed in claim 9, wherein the partition of the gas supply apparatus is provided with a bore through which the gas compartment and the outside of the cylinder communicate with each other, and the gas supply apparatus further comprises a pressure regulator provided in the bore.

13. The liquid supply apparatus as claimed in claim 12, wherein the bore is cylindrical and connected to the gas compartment through a connection passage formed in the bottom of the bore, and

the pressure regulator comprises:

a sealing ring which surrounds the connection passage, is fixed to the bottom, and has an end protruding from the bottom,

an opening/closing member including a contact wall with a contact surface which selectively comes into contact with or is separated from the end of the sealing ring, an inner wall axially extending from a central portion of the contact wall, and a conical slant wall protruding from an end of the inner wall to a side opposite to the connection passage, thereby moving in an axial direction of the bore, and

an elastic member for urging the opening/closing member toward the sealing ring.

14. The liquid supply apparatus as claimed in claim 13, wherein a protruding tube surrounding the connection passage and axially protruding from the bottom is provided in the bore, and the inner wall of the opening/closing member surrounds the protruding tube.

15. The liquid supply apparatus as claimed in claim 14, wherein a guide structure for linear movement of the opening/closing member is provided between the protruding tube or the connection passage and the inner wall of the opening/closing member.

16. The liquid supply apparatus as claimed in claim 13, wherein the opening/closing member further comprises an axially extending outer wall, and a guide structure for linear movement of the opening/closing member is provided between the outer wall and the bore.

17. The liquid supply apparatus as claimed in claim 13, wherein a stroke of the opening/closing member is limited to no more than 2 mm.

18. The liquid supply apparatus as claimed in any one of claims 13 to 17, wherein the sealing ring is fixed by being fitted into a groove formed in the bottom, and a tip of a portion of the sealing ring protruding from the groove is rounded.

19. The liquid supply apparatus as claimed in claim 9, wherein the partition of the gas supply apparatus is provided with a passage through which the gas compartment and the outside of the cylinder communicate with each other, a one-way valve is provided in the passage, and the one-way valve allows gas to flow into the cylinder but prevents gas from flowing out.

20. The liquid supply apparatus as claimed in claim 9, wherein the gas supply chamber comprises a first chamber for containing a liquid material and a second chamber for containing a solid material which generates gas through a reaction with the liquid material, and a breakable separation structure is provided between the first and second chambers.

21. The liquid supply apparatus as claimed in claim 20, wherein an elastic member for urging the solid material toward the separation structure is provided in the first chamber.

22. The liquid supply apparatus as claimed in claim 20, wherein the separation structure comprises a first partition which surrounds a passage between the first and second chambers and is provided with an annular groove, and a second partition of which a rim is fitted into the annular groove of the first partition.

23. The liquid supply apparatus as claimed in claim 22, wherein a sealing ring is provided between the first and second partitions.

24. The liquid supply apparatus as claimed in any one of claims 20 to 23, wherein the outer wall further comprises a cover as a separate member, and the first chamber is defined in the cover.

25. The liquid supply apparatus as claimed in claim 24, wherein the cover comprises a peripheral wall fitted around the outer wall, and an annular groove is provided in one of fitted contact surfaces thereof, whereby upon coupling of the cover and the outer wall using an adhesive, an adhesive receiving space for collecting and receiving a surplus of the adhesive is provided.

26. The liquid supply apparatus as claimed in claim 24, wherein the cover comprises a peripheral wall and an inner sidewall extending parallel to and spaced apart from the peripheral wall at an outer periphery of the cover, whereby an end of a sheet for filtering gas is placed between the peripheral wall and the inner sidewall.