Bellows pump having adjustable stop cam for varying the stroke

• US 4,655,690 A
• Filed: 11/21/1985
• Issued: 04/07/1987
• Est. Priority Date: 07/21/1983
• Status: Expired due to Term

• Current Assignee: Lang Apparatebau GmbH (Ecolab, Inc.)
• Original Assignee: Lang Apparatebau GmbH (Ecolab, Inc.)
• Inventors: Scheurl, Robert, Strasser, Hans-Erwin, Boedecker, Kay
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Neils, Paul F.
• Application Number:
  US06/800,365
• Time in Patent Office: 502 Days
• Field of Search: 417/63, 417/53, 417/472, 92/43, 92/44, 92/47, 92/98 D, 92/13.2, 92/13.4, 92/134, 222/309
• US Class Current: 417/53
• CPC Class Codes: F04B 13/00 Pumps specially modified to deliver fixed or variable measured quantities
• CPC Class Codes: F04B 43/0063 bell-shaped flexible members

Abstract

A bellows pump with the improvement of an adjustable index for uniformly controlling the amount of fluid displaced in each expansion and compression cycle.

Claims

1. In a mechanically operated bellows pump having a pump body with intake and exit conduits and a flowingly connected central conduit, a bellows circular in cross-section and operatively connected to said central conduit, means for expanding and compressing said bellows, means for connectively positioning one end of said bellows above said central conduit, and valve means for controlling the flow of fluids entering said intake conduit and leaving said exit conduit, so that when said bellows is expanded it sucks fluid in through said intake conduit and holds said fluid within the bellows itself and when said bellows is compressed it forces said fluid out of said exit conduit,

the improvement comprising means for uniformly controlling the amount of fluid displaced by said pump in each expansion and compression cycle, said means comprising at least one adjustable stop cam mounted on said pump body and at least one associated counter-cam connected to the moveable end of said bellows, so that the length of the compression stroke of said bellows is determined by the point at which each said stop cam and counter-cam interacts;

said stop cams being an index means comprising at least two sets of ascending steps positioned on said pump body in a concentric notional circle lying outside the periphery of said bellows, each said set being equidistantly spaced from each other about said notional circle, so that each said counter-cam can always interact with only one said step at a time;

the moveable end of said bellows being surmounted by an actuation cap which fixedly connects said at least one counter-cam with said moveable end; and

wherein a turning lock in the form of a casing is associated with said actuation cap and can only be released by complete removal.

2. The improved pump of claim 1 wherein said at least one counter-cam is integral with said actuation cap.

3. The improved pump of claim 1 wherein said at least one counter-cam is moveable with relation to said at least one stop cam by revolving said at least one counter-cam about the central axis of said bellows.

4. The improved pump of claim 1 wherein the expansion stroke of said bellows is limited by a resilient stop ring which interacts with said at least one counter-cam when the bellows is expanded to a given extent, and which stop ring is fixedly connected to said pump body.

5. The improved pump of claim 4 wherein said pump is surrounded by an annular casing in the region of said at least one stop cam, said at least one counter-cam and said resilient stop ring, so that said resilient stop ring is held in place and fixedly connected to said pump body.

6. The improved pump of claim 1 wherein said valve means are spring-loaded valves.

7. The improved pump of claim 6 wherein said bellows are made of a flexible plastic.

8. The improved pump of claim 7 wherein said plastic is a polytetrafluoroethylene.

9. A method for metering liquid chemical preparations employing a mechanically operated bellows pump having a pump body with intake and exit conduits and a flowingly connected central conduit, a bellows circular in cross-section and operatively connected to said central conduit, means for expanding and compressing said bellows, means for connectively positioning one end of said bellows above said central conduit, and valve means for controlling the flow of fluids entering said intake conduit and leaving said exit conduit, so that when said bellows is expanded it sucks fluid in through said intake conduit and holds said fluid within the bellows itself and when said bellows is compressed it forces said fluid out of said exit conduit, means for uniformly controlling the amount of fluid displaced by said pump in each expansion and compression cycle, said means comprising at least one adjustable stop cam mounted on said pump body and at least one associated counter-cam connected to the moveable end of said bellows, so that the length of the compression stroke of said bellows is determined by the point at which each said stop cam and counter-cam interacts;

said stop cams being an index means comprising at least two sets of ascending steps positioned on said pump body in a concentric notional circle lying outside the periphery of said bellows, each said set being equidistantly spaced from each other about said notional circle, so that each said counter-cam can always interact with only one said step at a time;

the moveable end of said bellows being surmounted by an actuation cap which fixedly connects said at least one counter-cam with said moveable end; and

wherein a turning lock in the form of a casing is associated with said actuation cap and can only be released by complete removal, said method comprising;

setting said index means to a desired volume to be metered;

locking said turning lock so that said volume cannot be altered without releasing said turning lock; and

compressing and releasing said bellows to discharge and meter said liquid chemical.