Apparatus for injecting fluids

• US 5,055,013 A
• Filed: 07/10/1990
• Issued: 10/08/1991
• Est. Priority Date: 07/15/1989
• Status: Expired due to Term

• Current Assignee: Fresenius AG (Fresenius SE & Co. KGaA)
• Original Assignee: Fresenius AG (Fresenius SE & Co. KGaA)
• Inventors: Faeser, Ulrich
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Szczecina, Jr., Eugene L.
• Application Number:
  US07/551,215
• Time in Patent Office: 455 Days
• Field of Search: 417/474, 417/475, 417/478, 417/479, 604/153, 128/DIG. 12
• US Class Current: 417/474
• CPC Class Codes: A61M 5/14228 with linear peristaltic action, i.e. comprising at least three pressurising members or a helical member
• CPC Class Codes: F04B 43/082 the tubular flexible member being pressed against a wall by a number of elements, each having an alternating movement in a direction perpendicular to the axes of the tubular member and each having its own driving mechanism

Abstract

The invention relates to an apparatus for injecting fluid in which as delivery conduit portion a simple hose segment having the same diameter throughout is used which is subjected to the action of a total of three pump rams, thereby forming delivery chambers (9-11) by compression of the hose segment, one of the pump rams (14) performing in the completely closed state the function of an outlet valve whilst having a delivery function until complete closure of the corresponding hose cross-section. As a result, in a very simple technical manner a considerable uniformization of the delivery flow is achieved.

Claims

1. Apparatus for injecting fluid comprising:

a housing having an accommodation space and a pressure plate;

an elastic delivery conduit portion which is arranged in the accommodation space, said elastic delivery conduit portion having an inlet connectable to a feed conduit and an outlet connectable to a discharge conduit, said conduit portion having formed therein a first conveying chamber, a second conveying chamber and a third conveying chamber;

delivery means, said delivery means having an inlet valve downstream of said inlet seen in the conveying direction, an outlet valve upstream of the outlet, and at least a first pump ram and a second pump ram for cyclically enlarging and diminishing the size of the conveying chambers, the first pump ram being disposed between the inlet valve and the outlet valve and the second pump ram being disposed between the outlet valve and the outlet;

wherein said elastic delivery conduit portion is formed as hose segment which in an uninfluenced state has a substantially constant diameter throughout;

wherein the conveying chambers are formed by compression of the elastic delivery conduit portion by means of the pump rams and the outlet valve and by subsequent expansion due to the restoring forces inherent in the elastic delivery conduit portion up to the original cross-section; and

wherein the outlet valve is a further pump ram which has a delivery function up to complete closure of the cross-section of the corresponding elastic delivery conduit portion wherein the pump rams have only two different allowable movement velocities V1 and V2.

2. Apparatus according to claim 1, wherein the first velocity V1 is associated with the inlet valve.

3. Apparatus according to claim 1, wherein the first pump ram is operative to close with second velocity V2 and to open with first velocity V1.

4. Apparatus according to claim 1, wherein the outlet valve and the second pump ram open and close with second velocity V2.

5. Apparatus according to claim 1, wherein first velocity V1 is associated with the inlet valve and is greater than second velocity V2.

6. Apparatus according to claim 1, wherein the second pump ram and the outlet valve are constructed as pump rams having the same length whereas the first pump ram has a length of three times the length of said second pump ram.

7. Apparatus for injecting fluid comprising:

a housing having an accommodation space and a pressure plate;

an elastic delivery conduit portion which is arranged in the accommodation space, said elastic delivery conduit portion having an inlet connectable to a feed conduit and an outlet connectable to a discharge conduit, said conduit portion having formed therein a first conveying chamber, a second conveying chamber and a third conveying chamber;

delivery means, said delivery means having an inlet valve downstream of said inlet seen in the conveying direction, an outlet valve upstream of the outlet, and at least a first pump ram and a second pump ram for cyclically enlarging and diminishing the size of the conveying chambers, the first pump ram being disposed between the inlet valve and the outlet valve and the second pump ram being disposed between the outlet valve and the outlet;

wherein said elastic delivery conduit portion is formed as hose segment which in an uninfluenced state has a substantially constant diameter throughout;

wherein the conveying chambers are formed by compression of the elastic delivery conduit portion by means of the pump rams and the outlet valve and by subsequent expansion due to the restoring forces inherent in the elastic delivery conduit portion up to the original cross-section;

wherein the outlet valve is a further pump ram which has a delivery function up to complete closure of the cross-section of the corresponding elastic delivery conduit portion; and

wherein the second pump ram and the outlet valve are constructed as pump rams having the same length whereas the first pump ram has a length of three times the length of said second pump ram.