WO1996015371A1 - Pump piston - Google Patents

Pump piston Download PDF

Info

Publication number
WO1996015371A1
WO1996015371A1 PCT/AU1995/000752 AU9500752W WO9615371A1 WO 1996015371 A1 WO1996015371 A1 WO 1996015371A1 AU 9500752 W AU9500752 W AU 9500752W WO 9615371 A1 WO9615371 A1 WO 9615371A1
Authority
WO
WIPO (PCT)
Prior art keywords
side wall
pump piston
cup
shaped body
lip
Prior art date
Application number
PCT/AU1995/000752
Other languages
French (fr)
Inventor
Klaus Zimmer-Vorhaus
Original Assignee
Zimmer Vorhaus Klaus
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AUPM9355A external-priority patent/AUPM935594A0/en
Priority claimed from AUPN0574A external-priority patent/AUPN057495A0/en
Application filed by Zimmer Vorhaus Klaus filed Critical Zimmer Vorhaus Klaus
Priority to AU38359/95A priority Critical patent/AU3835995A/en
Publication of WO1996015371A1 publication Critical patent/WO1996015371A1/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
    • F04B53/14—Pistons, piston-rods or piston-rod connections

Definitions

  • the present invention relates to pistons for pumps and in particular to a piston for a water pump.
  • Pump pistons reciprocate along a cylinder, and require sealing between the walls of the cylinder and the side walls of the piston.
  • This sealing normally takes the form of piston rings located around the outer wall of the piston.
  • the present invention seeks to provide a piston with an integral sealing means.
  • the invention comprises a pump piston, adapted to pump liquids in a cylinder, comprising: a cup-shaped body made from a flexible material having a side wall extending from a base terminating in a lip at the free end; wherein said side wall is so configured that the side wall expands during the discharge stroke, to seal against the cylinder.
  • the invention comprises a pump piston, adapted to pump liquids, comprising
  • cup-shaped body made from a flexible material having a side wall extending from a base terminating in a lip at the free end;
  • Figure 1 illustrates a prospective view of a piston in accordance with one embodiment of the present invention
  • Figure 2 illustrates a half sectional view of the piston illustrated in figure 1 ;
  • Figure 3 illustrates a part sectional view of the side wall of the piston illustrated in figure 1 ;
  • Figure 4 illustrates a side view of the piston illustrated in figure 1 ;
  • Figure 5 illustrates a plan view of the embodiment illustrated in above figures showing an exaggerated movement of the sealing arms
  • Figure 6 illustrates the same sectional view as that of figure 3, but shown during the pumping stroke;
  • Figure 7 illustrates a further embodiment of the present invention;
  • Figure 8 illustrates cross sectional view of another embodiment of the present invention;
  • Figure 9 illustrates a perspective view of another embodiment of the present invention
  • Figure 10 illustrates a plan view of the piston shown in figure 9;
  • FIG 11 illustrates a double acting piston according to another embodiment of the present invention
  • figure 12 illustrates schematically an apparatus for cutting the spiral cuts
  • figure 13 illustrates a further view of the apparatus shown in figure 12.
  • a pump piston (1 ) as shown in figures 1 to 6, comprises a cup-shaped body (2) having a side wall (3) from a base (4).
  • a central bore (5) extends through the base (4) to receive the drive rod (not shown) to reciprocate the piston in the cylinder.
  • Located around the lip (6) of the side wall (3) are three cuts ( 7,8 & 9 ), which extend completely through the side wall (3).
  • Each cut (7, 8 & 9) spirals from the lip (6) to adjacent the base (4), as shown in figures 2 and 4, and as shown in figure 3 the cuts (7, 8 & 9) are angled outwardly and away from the lip (6), at any suitable angle not necessary the angle, shown in figures 3 & 6.
  • the cuts (7, 8 & 9) form sealing fingers (10, 11 & 12) which as shown in figures 5 & 6 pivot radially outwardly from the piston (1) during the pump discharge stroke, as a result of the axial vector (13) and the radial vector (14) of the fluid pressure.
  • the cut surface (15) of finger (10) slides on the cut surface (16) of the side wall (3) forming a seal.
  • Cut 7a-7b extends approximately 160° around the piston (1), with the lowest point 7b being approximately 45° behind the top cut 8a of the next cut 8a-8b. This pattern being repeated around the piston (1 ), preferably angle of the cuts is
  • the invention is suitable for a double acting piston (17) shown in figure 7 where the construction of the fingers is the same as the other embodiment.
  • a further embodiment is shown in figure 8, in which the piston (18) has the side wall (19) tapering to the lip (6).
  • the material of construction is chosen to have a suitable flexibility to allow the side wall to expand outwardly during the pump stroke to seal against the wall of the cylinder.
  • a variation of the piston in figure 8, is shown in figures 9 & 10, in which vertical cuts (20) are made at a number of positions around the side walls (19). Theses cuts (20) are substantially tangential to the inner surface (21) of the side Walls (19).
  • the thus formed fingers (22) slide radially outwardly across each other and seal against the cylinder and themselves.
  • a double acting cylinder (23) is shown in figure 11 , which is constructed n the same manner as that of figures 9 &10.
  • FIG 12 and 13 An apparatus to make the spiral cuts of the pistons illustrated in figures 1 to 7 is shown in figure 12 and 13.
  • the apparatus comprises a cutter blade holder (23) having a number of blades (24).
  • a piston centring pin (25) is located in the center of the blades.
  • the piston blank (26) is slid over the centring pin (25) which mates in the central bore (5) of the piston blank (26).
  • the piston blank (26) is rotated in the direction of arrow 27, and the blades (24) cut the spiral cuts (7, 8 & 9).

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Details Of Reciprocating Pumps (AREA)
  • Reciprocating Pumps (AREA)

Abstract

A pump piston (1) comprises a cup-shaped body (2). The piston (1) is reciprocated in a cylinder to pump liquids. The side wall (3) of the piston (1) is configured to allow the side wall (3) to expand during the pump discharge stroke to seal against the cylinder. The side wall (3) could be tapered from the base (4) to the free end (6), or have spiral cuts (7, 8, 9) from the free end (6) to adjacent the base (4), which are angled radially outwardly and away from the free end (6), or vertical cuts (20) which are substantially tangential to the inner surface of the cup-shaped body (2).

Description

Pump Piston
The present invention relates to pistons for pumps and in particular to a piston for a water pump.
Pump pistons reciprocate along a cylinder, and require sealing between the walls of the cylinder and the side walls of the piston. This sealing normally takes the form of piston rings located around the outer wall of the piston. The present invention seeks to provide a piston with an integral sealing means.
In one broad form the invention comprises a pump piston, adapted to pump liquids in a cylinder, comprising: a cup-shaped body made from a flexible material having a side wall extending from a base terminating in a lip at the free end; wherein said side wall is so configured that the side wall expands during the discharge stroke, to seal against the cylinder.
In another form the invention comprises a pump piston, adapted to pump liquids, comprising
a cup-shaped body made from a flexible material having a side wall extending from a base terminating in a lip at the free end; and
at least one cut extending through the material of the side wall, and beginning at the lip of the side wall and spiralling around the side wall towards the base of the cup-shaped body, forming a sealing means which during the discharge stroke, moves radially outwardly to seal against the cylinder.
The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 illustrates a prospective view of a piston in accordance with one embodiment of the present invention;
Figure 2 illustrates a half sectional view of the piston illustrated in figure 1 ;
Figure 3 illustrates a part sectional view of the side wall of the piston illustrated in figure 1 ; Figure 4 illustrates a side view of the piston illustrated in figure 1 ;
Figure 5 illustrates a plan view of the embodiment illustrated in above figures showing an exaggerated movement of the sealing arms;
Figure 6 illustrates the same sectional view as that of figure 3, but shown during the pumping stroke; Figure 7 illustrates a further embodiment of the present invention; Figure 8 illustrates cross sectional view of another embodiment of the present invention;
Figure 9 illustrates a perspective view of another embodiment of the present invention; Figure 10 illustrates a plan view of the piston shown in figure 9;
Figure 11 illustrates a double acting piston according to another embodiment of the present invention; figure 12 illustrates schematically an apparatus for cutting the spiral cuts; and figure 13 illustrates a further view of the apparatus shown in figure 12. A pump piston (1 ), as shown in figures 1 to 6, comprises a cup-shaped body (2) having a side wall (3) from a base (4). A central bore (5) extends through the base (4) to receive the drive rod (not shown) to reciprocate the piston in the cylinder. Located around the lip (6) of the side wall (3) are three cuts ( 7,8 & 9 ), which extend completely through the side wall (3). Each cut (7, 8 & 9) spirals from the lip (6) to adjacent the base (4), as shown in figures 2 and 4, and as shown in figure 3 the cuts (7, 8 & 9) are angled outwardly and away from the lip (6), at any suitable angle not necessary the angle, shown in figures 3 & 6. In use, the cuts (7, 8 & 9) form sealing fingers (10, 11 & 12) which as shown in figures 5 & 6 pivot radially outwardly from the piston (1) during the pump discharge stroke, as a result of the axial vector (13) and the radial vector (14) of the fluid pressure. The cut surface (15) of finger (10) slides on the cut surface (16) of the side wall (3) forming a seal.
As shown in figures 1 & 5 the fingers overlap each other which assists in the flexibility of the fingers and hence their sealing action. Cut 7a-7b extends approximately 160° around the piston (1), with the lowest point 7b being approximately 45° behind the top cut 8a of the next cut 8a-8b. This pattern being repeated around the piston (1 ), preferably angle of the cuts is
approximately 5°. However any suitable stagger or overlap, depending on the material of construction can be used.
The invention is suitable for a double acting piston (17) shown in figure 7 where the construction of the fingers is the same as the other embodiment. A further embodiment is shown in figure 8, in which the piston (18) has the side wall (19) tapering to the lip (6). The material of construction is chosen to have a suitable flexibility to allow the side wall to expand outwardly during the pump stroke to seal against the wall of the cylinder. A variation of the piston in figure 8, is shown in figures 9 & 10, in which vertical cuts (20) are made at a number of positions around the side walls (19). Theses cuts (20) are substantially tangential to the inner surface (21) of the side Walls (19). Thus during the pumping or discharge stroke the thus formed fingers (22) slide radially outwardly across each other and seal against the cylinder and themselves.
A double acting cylinder (23) is shown in figure 11 , which is constructed n the same manner as that of figures 9 &10.
Depending on the material of construction , which for example can be of any suitable plastics such as high density polypropylene, there can be any number of cuts, from one, two etc. upwards, to effect sealing , provided that the fingers exhibit the required degree of flexibility.
An apparatus to make the spiral cuts of the pistons illustrated in figures 1 to 7 is shown in figure 12 and 13. The apparatus comprises a cutter blade holder (23) having a number of blades (24). A piston centring pin (25) is located in the center of the blades. The piston blank (26) is slid over the centring pin (25) which mates in the central bore (5) of the piston blank (26). The piston blank (26) is rotated in the direction of arrow 27, and the blades (24) cut the spiral cuts (7, 8 & 9).
It should be obvious to people skilled in the art that modifications and alterations can be made to the before described embodiments without departing from the scope and spirit of the present invention

Claims

Claims
1. A pump piston, adapted to pump liquids in a cylinder, comprising: a cup-shaped body made from a flexible material having a side wall extending from a base terminating in a lip at the free end; wherein said side wall is so configured that the side wall expands during the discharge stroke, to seal against the cylinder.
2. A pump piston comprising :
a cup-shaped body made from a flexible material having a side wall extending from a base terminating in a lip at the free end; and
at least one cut extending through the material of the side wall, and beginning at the lip of the side wall and spiralling around the side wall towards the base of the cup-shaped body, forming a sealing means which during the discharge stroke, moves radially outwardly to seal against the cylinder.
3. A pump piston according to claim 2, wherein the at least one cut is angled radially outwardly and away from the free end of the cup-shaped body.
4. A pump piston according to claim 3, wherein the at least one cut is angled radially outwardly and away from the free end of the cup-shaped body at an angle of approximately 5°.
5. A pump piston according to any one of claims 2 to 4, wherein there is a plurality of cuts which are staggered around the side wall forming fingers overlap the adjacent finger.
6. A pump piston according to claim 5, wherein there are three cuts.
7. A pump piston, adapted to pump liquids in a cylinder, comprising
a cup-shaped body made from a flexible material having a side wall extending from a base terminating in a lip at the free end; wherein said side wall tapers from the base to the lip, so that the side wall expands during the discharge stroke, to seal against the cylinder.
8. A pump piston according to claim 7, further comprising a plurality of axially cuts, around the periphery of the cup-shaped body, extending from the lip to adjacent the base, and being substantially tangential to the inner surface of the side wall.
9. A pump piston according to any one of the previous claims wherein the material of construction is high density polypropylene.
10. A pump piston according to any one of the preceding claims wherein the piston is double acting.
11. A pump piston substantially as herein before described with reference to figures 1 to 6, figure 7, figure 8, figures 9 and 10, or figure 11 of the
accompanying drawings.
PCT/AU1995/000752 1994-11-11 1995-11-13 Pump piston WO1996015371A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU38359/95A AU3835995A (en) 1994-11-11 1995-11-13 Pump piston

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
AUPM9355 1994-11-11
AUPM9355A AUPM935594A0 (en) 1994-11-11 1994-11-11 Pump piston
AUPN0574 1995-01-16
AUPN0574A AUPN057495A0 (en) 1995-01-16 1995-01-16 Pump piston

Publications (1)

Publication Number Publication Date
WO1996015371A1 true WO1996015371A1 (en) 1996-05-23

Family

ID=25644812

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1995/000752 WO1996015371A1 (en) 1994-11-11 1995-11-13 Pump piston

Country Status (3)

Country Link
CN (1) CN1140484A (en)
CA (1) CA2180939A1 (en)
WO (1) WO1996015371A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE819966A (en) * 1973-09-28 1975-01-16 HIGH-PRESSURE HYDRAULIC MACHINES PISTONS IMPROVEMENTS
US3897072A (en) * 1973-02-12 1975-07-29 Crane Packing Co Slit ring with connecting membrane
GB2137697A (en) * 1983-03-16 1984-10-10 Loctite Corp Dripless syringe
US4540352A (en) * 1982-09-11 1985-09-10 Erich Becker Pendular piston pump having a cup-shaped sealing element
EP0171892A2 (en) * 1984-06-18 1986-02-19 Trw Inc. Reciprocating pump piston
GB2183747A (en) * 1985-12-04 1987-06-10 Teves Gmbh Alfred Piston and cylinder assembly including a seal arrangement

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3897072A (en) * 1973-02-12 1975-07-29 Crane Packing Co Slit ring with connecting membrane
BE819966A (en) * 1973-09-28 1975-01-16 HIGH-PRESSURE HYDRAULIC MACHINES PISTONS IMPROVEMENTS
US4540352A (en) * 1982-09-11 1985-09-10 Erich Becker Pendular piston pump having a cup-shaped sealing element
GB2137697A (en) * 1983-03-16 1984-10-10 Loctite Corp Dripless syringe
EP0171892A2 (en) * 1984-06-18 1986-02-19 Trw Inc. Reciprocating pump piston
GB2183747A (en) * 1985-12-04 1987-06-10 Teves Gmbh Alfred Piston and cylinder assembly including a seal arrangement

Also Published As

Publication number Publication date
CN1140484A (en) 1997-01-15
CA2180939A1 (en) 1996-05-23

Similar Documents

Publication Publication Date Title
FI100059B (en) Wavy sight plate and methods of making it
DE19510828C2 (en) Diaphragm pump with a shaped membrane
EP1317626B1 (en) Method and device for conveying media
US4497496A (en) Hydrodynamic slitted seal and method of manufacture thereof
EP1431515A3 (en) Turbine engine shroud segment and assembly with circumferential seal on a planar segment surface
EP0604740A1 (en) Diaphragm pump
RU2004134357A (en) REFINER PLATES WITH KNIVES IN THE FORM OF THE LOGARITHMIC SPIRAL
JPH11201087A (en) Centrifugal or half axial flow type pump impeller used in pump for transporting sewage
US4381184A (en) Extruder apparatus
WO1996015371A1 (en) Pump piston
WO1997042412A1 (en) Pseudo static peristaltic pump
US7896730B2 (en) Variable length, variable diameter separation chamber for a food processor having configurable cutting perforations
WO2007045288A1 (en) Rotor for a rotary machine and a rotary machine
DE2341013C2 (en) Radial piston pump
EP3480424B1 (en) Positive-displacement pump
EP1315272A3 (en) Canned pump with temperature sensor
DE19834536C2 (en) Device, microsystem and method for transporting and / or segregating liquids
RU93004927A (en) METHOD OF MANUFACTURING ASSEMBLED PRODUCTS AND DEVICE FOR ITS IMPLEMENTATION
EP3303844B1 (en) Impeller for a centrifugal pump and centrifugal pump
US4300843A (en) Streaming vibrator with an uninterrupted rolling area and an unloaded blade
EP3287593B1 (en) Rotary vane pump
GB1562402A (en) Tower packing element
EP1358006B1 (en) Dividing device
DE194957T1 (en) DEVICE TO REDUCE LEAF TIP LOSS IN COMPRESSORS.
US2345176A (en) Piston ring means

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 95191556.8

Country of ref document: CN

AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU IS JP KE KG KP KR KZ LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TT UA UG US UZ VN

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): KE LS MW SD SZ UG AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG

ENP Entry into the national phase

Ref document number: 1996 669525

Country of ref document: US

Date of ref document: 19960710

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 2180939

Country of ref document: CA

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642