EP2676737A1 - Rückzug-Sperrventil - Google Patents

Rückzug-Sperrventil Download PDF

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Publication number
EP2676737A1
EP2676737A1 EP13172419.7A EP13172419A EP2676737A1 EP 2676737 A1 EP2676737 A1 EP 2676737A1 EP 13172419 A EP13172419 A EP 13172419A EP 2676737 A1 EP2676737 A1 EP 2676737A1
Authority
EP
European Patent Office
Prior art keywords
spring
tube
edge portion
piston head
axially
Prior art date
Legal status (The legal status 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 status listed.)
Granted
Application number
EP13172419.7A
Other languages
English (en)
French (fr)
Other versions
EP2676737B1 (de
Inventor
Heiner Ophardt
Ali Mirbach
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Gotohti com Inc
Original Assignee
Gotohti com Inc
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 CA2780503A external-priority patent/CA2780503C/en
Application filed by Gotohti com Inc filed Critical Gotohti com Inc
Publication of EP2676737A1 publication Critical patent/EP2676737A1/de
Application granted granted Critical
Publication of EP2676737B1 publication Critical patent/EP2676737B1/de
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47K—SANITARY EQUIPMENT NOT OTHERWISE PROVIDED FOR; TOILET ACCESSORIES
    • A47K5/00—Holders or dispensers for soap, toothpaste, or the like
    • A47K5/06—Dispensers for soap
    • A47K5/12—Dispensers for soap for liquid or pasty soap
    • A47K5/1202—Dispensers for soap for liquid or pasty soap dispensing dosed volume
    • A47K5/1204—Dispensers for soap for liquid or pasty soap dispensing dosed volume by means of a rigid dispensing chamber and pistons
    • A47K5/1205—Dispensing from the top of the dispenser with a vertical piston
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B11/00—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
    • B05B11/0005—Components or details
    • B05B11/0062—Outlet valves actuated by the pressure of the fluid to be sprayed
    • B05B11/007—Outlet valves actuated by the pressure of the fluid to be sprayed being opened by deformation of a sealing element made of resiliently deformable material, e.g. flaps, skirts, duck-bill valves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B11/00—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
    • B05B11/01—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
    • B05B11/10—Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle
    • B05B11/1001—Piston pumps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B11/00—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
    • B05B11/01—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
    • B05B11/10—Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle
    • B05B11/1097—Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle with means for sucking back the liquid or other fluent material in the nozzle after a dispensing stroke

Definitions

  • This invention also relates generally to a piston for a pump and, more particularly, to an arrangement for a disposable variable length piston for piston pumps for dispensing flowable materials.
  • dispensers of material such as creams and for example liquid honey have the problem of stringing in which an elongate string of fluid hangs from fluid in the outlet and dangles from the outlet after dispensing an allotment of fluid. With passage of time the string may form into a droplet and drop from the outlet giving the appearance that the dispenser is leaking.
  • the present invention is particularly applicable to fluid dispensers which fluid is to be dispensed out of an outlet with the outlet forming an open end of a tubular member.
  • the tubular member has its outlet opening downwardly and fluid passing through the tubular member is drawn downwardly by the forces of gravity.
  • An object of the second aspect of the present invention is to provide a fluid dispenser in which after dispensing fluid out an outlet draws fluid back through the outlet to reduce dripping and/or stringing.
  • valve member comprising a spring member and a piston head member
  • the spring first end coupled to the tube inner wall at a first location against relative axial movement with the tube member
  • the piston-forming element having an inner head portion, an outer base portion and a variable length portion intermediate the head portion and the base portion joining the head portion and the base portion,
  • the base portion having a central axially extending hollow stem having a central passageway open at an outer end forming an outlet
  • Figure 15 is a pictorial view similar to Figure 5 but of a second embodiment of a valve piston member adapted for substitution for the valve piston member in Figure 5 and showing the valve piston member in an uncompressed condition;
  • Figure 17 is a cross-sectional end view similar to Figure 6 but of the valve piston member of Figure 15 along section line A-A' in Figure 15 ;
  • Figure 18 is a cross-sectional side view similar to Figure 2 but of a third embodiment of a piston pump adapted for substitution for the pump piston in Figure 1 and with the valve piston member in an uncompressed condition;
  • Figure 20 is a cross-sectional side view similar to Figure 2 but of a fifth embodiment of a pump piston adapted for substitution for the pump piston in Figure 1 and with the valve piston member in an uncompressed condition;
  • Figure 21 is a cross-sectional view similar to Figure 18 of a sixth embodiment of a pump piston for use in substitution of the pump piston in Figure 1 ;
  • Figure 22 is a cross-sectional view of a pump in accordance with the seventh embodiment of the invention with the pump piston in an extended position and a valve piston member in an uncompressed condition;
  • Figure 24 is a cross-sectional side view of the pump piston as in Figure 22 but with the valve piston member in a first compressed condition;
  • Figure 26 is a cross-sectional side view of an eighth embodiment of a pump piston for use in the pump shown in Figure 22 with a valve piston member in an uncompressed condition;
  • Figure 28 is a cross-sectional side view of a tenth embodiment of a pump piston for use in the pump shown in Figure 22 with a valve piston member in an uncompressed condition;
  • Figure 32 is a cross-sectional side view of a thirteenth embodiment of a pump piston for use in the pump shown in Figure 22 with a valve piston member in an uncompressed condition;
  • Figure 33 is a cross-sectional side view of a fourteenth embodiment of a pump piston for use in the pump shown in Figure 22 with a valve piston member in an uncompressed condition;
  • Figure 35 is a side view showing a portion of Figure 34 enlarged
  • Figure 36 is an enlarged side view similar to that shown in Figure 35 but showing a sixteenth embodiment of a pump piston of the present invention
  • Figure 37 is a side view the same as in an unbiased condition in Figure 36 with the pump piston in a biased condition;
  • Figure 40 is a schematic side view of a portion of a fluid dispenser in accordance with an eighteenth embodiment of the present invention having similarities to the embodiment shown in Figure 39 ;
  • Figure 42 is a perspective view of a valve piston member in accordance with a nineteenth embodiment of the present invention.
  • Figure 44 is a pictorial view of a piston valve member in accordance with a twenty-first embodiment of the present invention.
  • Figure 45 is a schematic side view of a portion of a fluid dispenser in accordance with a twenty-second embodiment of the present invention having similarities to the embodiment shown in Figure 40 ;
  • Figure 47 is a schematic side view of a portion of a fluid dispenser in accordance with a twenty-third embodiment of the present invention having similarities to the embodiment shown in Figure 40 .
  • FIG. 1 comprising a pump assembly 10 secured to a reservoir or container 26 having a threaded neck 34.
  • the pump assembly has a body 12, a one-way valve 14 and a pump piston 16.
  • the body 12 provides a cylindrical chamber 18 in which the pump piston 16 is axially reciprocally slidable in a cycle of operation so as to draw fluid from within the container 26 and dispense it out of an outlet 54.
  • the chamber 18 has a cylindrical chamber wall 20 disposed coaxially about a central chamber axis 22.
  • the head portion 47 includes a centrally extending head stem 30 upon which a head disc 48 is mounted.
  • the head disc 48 extends radially outwardly from the head stem 30 as a circular resilient flexible disc located at the inwardmost end of the head portion 47 and extending radially therefrom.
  • the head disc 48 is sized to circumferentially abut the inner chamber wall 20 substantially preventing fluid flow therepast inwardly in the chamber 18.
  • the head disc 48 is formed as a thin resilient disc having an elastically deformable edge portion 48a to engage the chamber wall 20.
  • the edge portion extends radially outwardly and in a direction axially outwardly of the chamber 18.
  • the edge portion is adapted to deflect radially inwardly away from the chamber wall 20 to permit fluid flow outwardly in the chamber 18 therepast.
  • the head stem 30 has a center 33 coaxial about the axis from which four elongate arms 32 extend radially outwardly and axially to provide an X shape in cross-section as in Figures 6 and 8 .
  • Each arm 32 carries at its axial end a radially outwardly extending hooking member 34 with an axially inwardly directed catching surface 35.
  • the variable length intermediate portion 45 comprises an elongate tubular member 200 disposed to bridge between the head portion 47 and the base portion 49 joining them together axially spaced apart.
  • the tubular member 200 has an inner end 202 and an outer end 204.
  • the inner end 202 of the tubular member 200 is fixedly coupled to the head portion 47 by being formed integrally therewith.
  • the outer end 204 of the tubular member 200 engages the base portion 49.
  • the tubular member 200 is coupled to the head portion 47 and the base portion 49 in a manner so as to not interfere with the engagement of the head disc 48 and a base disc 50 carried on the base portion 49 with the side wall 20 of the chamber.
  • the tubular member 200 has a wall 206 extending between the inner end 202 and the outer end 204.
  • the wall 206 has a radially inwardly directed inner wall surface 208 and a radially outwardly directed outer wall surface 210.
  • the wall 206 has the shape of a solid of revolution rotated about the central axis 22.
  • the wall extends circumferentially entirely about the central axis 22, that is, 360 degrees about the central axis 22.
  • Each of the inner end 202 and the outer end 204 is an annular ring that extends annularly 360 degrees about the central axis 22.
  • a plurality of openings 212 extend radially through the wall 206 between the inner wall surface 208 and the outer wall surface 210.
  • the openings 212 each have an axial extent.
  • the openings 212 are spaced circumferentially about the tubular member 200 with each openings 212 spaced circumferentially from its adjacent openings 212 by an axially extending web 213.
  • the openings 212 are identical and evenly spaced circumferentially by identical webs 213.
  • Each opening 212 is shown to be defined between an inner end surface 501, an outer end surface 503 and two side surfaces 505 and 507.
  • Each opening 212 is axially elongate and has an axial extent between the inner end surface 501 and the outer end surface 503.
  • Each opening has a circumferential extent between the side surfaces 505 and 507.
  • the valve body or base portion 49 has a base stem 46 that carries the base disc 50, locating disc 66, locating webs 67 and an engagement flange 62.
  • the base disc 50 is a circular resilient flexible disc located on the stem 46 spaced axially outwardly from the head disc 48.
  • the base disc 50 extends radially outwardly from the stem 46 to circumferentially engage the chamber wall 20 substantially preventing fluid flow therebetween outwardly in the chamber 18.
  • the base disc 50 is preferably formed as thin resilient disc, in effect, having an elastically deformable edge portion 30a to engage the chamber wall 20.
  • the stem 46 has a central passageway 52 extending along the axis 22 from an inner inlet end 58 located on the stem 46 between the head disc 48 and the base disc 50 to the outlet 54 at the outer end of the base portion 49.
  • the passageway 52 permits fluid communication through the base portion 49 past the base disc 50, between the inlet end 58 and the outlet 54.
  • Locating discs 66 and locating webs 67 best seen in Figure 7 are provided to engage the chamber wall 20 so as to assist in maintaining the base portion 49 axially centered within the chamber 18 when sliding axially in and out of the chamber 18.
  • the stem 46 comprises a tubular member and can be seen to have the passageway 52 extend therethrough between the outlet 54 and the inlet end 58 with the inlet end 58 open to the chamber 18 between the head disc 48 and the base disc 50.
  • Each of the base portion 49 and the head portion 47 is circular in any in cross-section normal the axis 22 therethrough.
  • Each of the base portion 49 and the head portion 47 is adapted to be slidably received in chamber 18 coaxially within the chamber 18.
  • the passageway 52 has its side wall 52a formed to provide an axially outwardly directed catch surface 290 which forms a hook member in axial opposition to the axially inwardly directed catching surface 35 to be engaged by the hooking member 34 of the head stem 30 and limit inward axial movement of the head portion 47 relative the base portion 49.
  • the catch surface 290 is provided as an axially outwardly directed shoulder between an inner portion of the passageway 52 of a first diameter and an outer portion of a larger diameter.
  • the engagement flange 62 is provided on the stem 46 for engagement as by an actuator, not shown, to move the base portion 49 inwardly and outwardly.
  • the engagement flange 62 may also serve the function of a stopping disc to limit axial inward movement of the pump piston 16 by engagement with the outer end 23 of the body 12.
  • the stem 46 is shown to extend outwardly from the engagement flange 62 to the discharge outlet 54 as a relatively narrow hollow tube 138 with the passageway 52 coaxially therethrough.
  • the one-way valve 14 comprises a unitary piece of resilient material having a resilient, flexible, annular rim 132 for engagement with the side wall of the chamber 18.
  • the one-way valve 14 is integrally formed with a shouldering button 134 which is secured in a snap-fit inside an opening 136 in a central upper end of the chamber 18.
  • annular inner compartment 111 is formed inside the chamber 18 between the one-way valve 14 and the head disc 48 and an annular outer compartment 112 is formed inside the chamber 18 between the head disc 48 and the base disc 50.
  • the volume of the annular outer compartment 112 varies with variance of the axial length of the variable length intermediate portion 45 of the pump piston 16.
  • the body 12 carries an outer cylindrical portion 40 carrying threads 130 to cooperate with threads formed on the threaded neck 34 of the container 26.
  • the pump assembly 10 is preferably orientated such that such that the outlet 54 is directed downwardly, however, this is not necessary.
  • the tubular member 200 has an inherent resiliency by reason of being formed from a suitable resilient material, preferably plastic material.
  • the inherent resiliency of the tubular member 200 biases the tubular member 200 to adopt an unbiased configuration of a maximum axial length measured along the central axis.
  • the tubular member 200 is subjected to axially directed compression forces the tubular member 200 compresses axially such that its axial length as measured along the central axis 22 reduces and when such compressive forces are released, the tubular member 200 increases in length expanding towards the unbiased condition.
  • Figure 2 shows the pump piston 16 and its valve piston member 15 in an uncompressed condition.
  • Figure 3 shows the pump piston 16 and its valve piston member 15 in a first compressed condition in which the variable length intermediate portion 45 and its tubular member 30 are compressed to be of reduced axial length compared to Figure 2.
  • Figure 4 shows the pump piston 16 and its valve piston member 15 in a second compressed condition compressed to be of reduced axial length compared to Figure 3 .
  • the tubular member 200 is disposed about the central axis 22 bridging between the head portion 47 and the base portion 49 and acts in the manner of a spring to urge the head portion 47 and base portion 49 axially apart.
  • the inner end 202 of the tubular member 200 is fixed to the head stem 30 radially inwardly from the head disc 48 by being formed integrally therewith.
  • the base portion 49 is arranged such that the outer end 204 of the tubular member 200 engages the base stem 46 of the base portion 49 radially inwardly from the base disc 50.
  • the base portion 49 provides an axially inwardly directed surface 300 at its inner end between the inner inlet end 58 of the passageway 52 and the base disc 50 which surface 300 is to be engaged by the outer end 204 of the tubular member 200.
  • an annular groove 301 is provided in the surface 300 open axially inwardly within which groove 301 the outer end 204 of the tubular member 200 is seated. Engagement between the annular groove 301 and the outer end 204 of the tubular member 200 assists in maintaining the tubular member 200 coaxially disposed about the central axis 22.
  • the groove 301 preferably has an outer side surface which is directed radially inwardly to engage the outer surface 210 of the wall of the tubular member 200.
  • the variable length intermediate portion 45 has an axial length defined as a length measured along the central axis 22 as between the head disc 48 and the base disc 50. This axial length is measured along the axis 22 between a center 218 on the head portion 47 and a center 220 of the base disc 50.
  • the axial length is indicated as L on Figure 2 and is variable between a maximum length and a minimum length due to the ability of the elongate members 200 to deflect.
  • the pump assembly 10 is shown in Figures 12 , 13 and 14 in use in a cycle of operation of the pump.
  • Figures 11 and 14 show the pump piston 16 within the chamber 18 of the body 12 in an uncompressed condition (also sometimes referred to herein as an expanded condition) as seen in Figure 2 in which the variable length intermediate portion 45 is in its maximum length.
  • an uncompressed condition also sometimes referred to herein as an expanded condition
  • resistance to movement of the head portion 47 and particularly its head disc 48 within the chamber 18 will give rise to tension forces being applied across the tubular member 200.
  • the response of the tubular member 200 to such tension force will depend upon the nature and resiliency of the tubular member 200 and the amount of the tension force.
  • Figures 12 and 13 show the pump piston 16 received in the chamber 18 of the body 12 with the variable length intermediate portion 45 in a first compressed condition as seen in Figure 3 .
  • the base portion 49 inwardly in the chamber 18 resistance to inward movement of the head portion 47 and notably resistance to movement of the head disc 48 inwardly in the chamber 18 results in compressive forces being applied to the variable length intermediate portion 45 between the base portion 49 and the head portion 47.
  • Such compressive forces cause the tubular member 200 to deform to reduce the axial length of the variable length intermediate portion 45 to a reduced length compressed condition as seen in Figures 12 and 13 .
  • variable length intermediate portion 45 In operation of the pump, the relative tension forces and compression forces which may be applied through the variable length intermediate portion 45 between the base portion 49 and the head portion 47 will cause the variable length intermediate portion 45 to adopt configurations between an expanded condition and a compressed condition.
  • the relative resistance of the head portion 47 to sliding within the chamber 18 is affected by many factors including the friction to movement of the head portion 47 within the chamber 18, inwardly and outwardly, the nature of the fluid in the reservoir having regard to, for example, its viscosity and temperature, the speed with which the base portion 49 is moved and various other factors which will be apparent to a person skilled in the art.
  • a person skilled in the art by simple experimentation can determine suitable configurations for the intermediate member 45 so as to provide for the axial length of the variable length portion to vary between a suitable minimum length and a suitable maximum length in cyclical movement of the pump piston 16 in a cycle of operation.
  • the outer wall surface 210 of the wall 206 of the tubular member 200 as seen in side view in Figure 2 in the uncompressed condition is convex, that is, the outer wall surface 210 bows radially outwardly.
  • the openings 212 are provided through the wall 206 such that the openings change in relative shape with axial deflection of the tubular member 200.
  • Each opening 212 provides a passage through which fluid may flow through the wall 206.
  • each opening 12 provides a minimum cross-sectional area for fluid flow therebetween.
  • the cross-sectional area of the passage through openings 212 for fluid flow therethrough preferably increases as the tubular member 200 is deflected axially from the expanded condition to the compressed condition by reason of the circumferential extent of each opening between the side surfaces 505 and 507 increasing as the wall 206 bows out and the outer wall surface 210 increases in convexity. While not necessary, having the cross-sectional area of the passage through each opening increase as the tubular member 200 is compressed is advantageous since during operation of the pump, a larger volumetric fluid flow through the tubular member 200 is required when the tubular member 200 is compressed.
  • Figure 6 shows a cross-sectional end view through the pump piston 16 in the uncompressed condition of Figure 2 in which the openings 212 are shown in end cross-section disposed between the webs 213.
  • Figure 10 shows a similar cross-sectional end view as in Figure 6 , however, with the pump piston 16 in a compressed condition of Figure 3 in which the tubular member 200 is axially compressed compared to Figure 2 .
  • each opening 212 has been increased by reason that side surfaces 505 and 507 defining each opening 212 are circumferentially farther apart in Figure 10 than in Figure 6 .
  • the cross-sectional area for fluid flow through each opening is a function of the circumferential extent of the opening. Generally, in the first embodiment with an increase in circumferential extent, the cross-sectional area of the opening increases.
  • the pump assembly operates in a cycle of operation in which the pump piston 16 is reciprocally moved relative the body 12 inwardly in a retraction stroke and outwardly in a withdrawal stroke.
  • the withdrawal of the pump piston 16 causes the one-way valve 14 to open with fluid to flow past annular rim 132 which is deflected radially inwardly into the inner compartment 111 in the chamber 18.
  • head disc 48 remains substantially undeflected and assists in creating a vacuum in the inner compartment 111 to deflect rim 132 and draw fluid past rim 132.
  • the head disc 48 substantially prevents flow inwardly therepast in the withdrawal stroke and, on the other hand, deforms to permit flow outwardly therepast in the retraction stroke.
  • the head disc 48 shown facilitates this by being formed as a thin resilient disc, in effect, having an elastically deformable edge portion near chamber wall 20.
  • head disc 48 When not deformed, head disc 48 abuts the chamber wall 20 to form a substantially fluid impermeable seal.
  • Head disc 48 When deformed, as by its edge portion 48a being bent away from wall 20, fluid may flow outwardly past the head disc, Head disc 48 is deformed when the pressure differential across it, that is, when the pressure on the upstream side is greater in the inner compartment 111 than the pressure on the downstream side in the outer compartment 112 by an amount greater than the maximum pressure differential which the edge portion of the head disc can withstand without deflecting.
  • this pressure differential is sufficiently large, the edge portion of the head disc deforms and fluid flows outwardly therepast.
  • the pressure differential reduces to less than a given pressure differential, the head disc 48 returns to its original inherent shape substantially forming a seal with the wall 20.
  • Figures 11 to 14 show different conditions the variable length intermediate portion 45 assumes in a cycle of operation.
  • the base portion 49 is moved in a retraction stroke from an extended position as seen in Figure 11 to a retracted position as seen in Figure 13 .
  • a withdrawal stroke the base portion 49 is moved from the retracted position of Figure 13 to the extended position shown in Figure 11 .
  • Figure 11 illustrates the pump piston 16 with the base portion 49 in the extended position and the pump piston 16 and its valve piston member 15 and its variable length intermediate portion 45 in an uncompressed condition.
  • the outer compartment 112 formed in the chamber 18 between the head disc 48 and base disc 49 is at a maximum volume.
  • the base portion 49 is moved inwardly in a retraction stroke to assume the condition of Figure 12 in which the pump piston 16, its valve piston member 15 and its variable length intermediate portion 45 are a compressed condition.
  • variable length intermediate portion 45 On the base portion 49 moving inwardly in the chamber 18 from the position of Figure 11 , while the length of the variable length intermediate portion 45 is greater than its minimum length, resistance to movement of the head portion 47 and its head disc 48 inwardly in the chamber 18 is sufficient that the length of the variable length intermediate portion 45 decreases toward its minimum length as shown in Figure 12 before the head portion 47 is moved inwardly in the chamber 18.
  • compressive forces will be applied to the variable length intermediate portion 45 which forces will reduce the length of the variable length intermediate portion 45 until the compressive forces transferred by the variable length intermediate portion 45 are greater than the resistance to movement of the head portion 47 inwardly in the chamber.
  • the compressive forces may be developed such that the variable length intermediate portion substantially decreases to its minimum length before the head portion 47 is substantially moved inwardly.
  • tension forces will act on the variable length intermediate portion 45 expanding the variable length portion 45 until such time as the tension forces which are transferred by the variable length intermediate portion 45 from the base portion 49 the head portion 47 are greater than the resistance of the head portion for movement outwardly in the chamber.
  • the tension forces may be developed such that the variable length intermediate portion 45 substantially increases to its maximum length before the head portion 47 is substantially moved outwardly.
  • variable length intermediate portion 45 is maintained in the expanded condition with the variable length intermediate portion 45 at its maximum length and tension forces caused by movement of the base portion 49 are transferred via the variable length intermediate portion 45 to the head portion 47.
  • the volume of the inner compartment 111 reduces and hence fluid is discharged from the inner compartment 111 past the head disc 48, through the tubular member 200 via the openings 212 through the passageway 52 out the outlet 54 since fluid within the chamber 18 is prevented from passing inwardly past the one way valve 14 and is prevented from passing outwardly past the base disc 50.
  • pressure is created within the inner compartment 111 which closes the one-way valve 14. Fluid within the inner compartment 111 becomes compressed by movement of the head disc 48 inwardly.
  • the relative nature of the head disc 48 and the base disc 50 and the engagement of each with the chamber wall 20 are preferably selected such that vacuum created within the outer compartment 112 will drawback fluid from the passageway 52 rather than deflect the head disc 48 to draw liquid from the inner compartment 111 past the head disc 48 into the outer compartment 112, or, deflect the base disc 50 to draw atmospheric air between the base disc 50 and the chamber wall 20.
  • the drawback pump assembly 10 in accordance with the present invention may be used in manually operated dispensers such as those in which, for example, the pump piston 16 is moved manually as by a user engaging an actuator such as a lever which urges the pump piston 16 either outwardly or inwardly.
  • the drawback pump can also be used in automated systems in which a user will activate an automated mechanism to move the pump piston 16 in a cycle of operation.
  • a preferred arrangement for operation of the drawback pump assembly 10 in accordance with the present invention is for the pump assembly to assume a position between the condition shown in Figure 14 and the condition shown in Figure 11 as a rest position between cycles of operation.
  • the dispenser may be arranged such that the base portion 49 is biased to assume as a rest position between cycles of operation, the extended position seen in Figure 11 .
  • a person would manually operate a lever to move the dispenser from the position of Figure 11 to the position of Figure 13 .
  • a spring will return the lever and base portion 48 to the position of Figure 11 .
  • fluid is dispensed from the outlet 54.
  • a rest position between cycles may preferably be at some point in between the position of Figure 14 and the position of Figure 11 .
  • valve piston member 15 consisting of the piston head portion 47 and intermediate portion 45 as being formed from a unitary piece of plastic preferably by injection molding. It is to be appreciated that a similar structure could be formed with each of the head portion 47, base portion 49 and intermediate portion 45 being separately formed. Also the variable length intermediate portion 45 could be formed together with either or both of the head portion 47 and the base portion 49 as a unitary piece of plastic.
  • the tubular member 200 has an inherent unbiased condition when molded.
  • An assembled pump piston 16 will have an inherent unbiased condition as seen in Figure 2 which it will assume when no axial forces are applied to it.
  • the inherent unbiased condition of the pump piston 16 depends on the inherent unbiased condition of the head portion 47, the base portion 49 and the intermediate portion 45. In the preferred embodiment, effectively only the tubular member 200 is axially deformable.
  • the tubular member 200 is axially compressible from the inherent unbiased condition to assume conditions in which its axial length is reduced compared to the inherent unbiased condition. When deformed to a reduced length condition and released, the tubular member returns to its inherent unbiased condition.
  • the tubular member can also be axially expandable from the inherent unbiased condition to a stretched position in which its axial length is increased compared to the inherent unbiased condition. For example, if the wall of the tubular member is in the inherent unbiased condition, not straight but bowed, then on applying axial tension forces, the wall may be deformed against its bias to become straight increasing the axial length.
  • the tubular member 200 cannot be stretched and has its maximum axial length as the inherent unbiased condition.
  • having the tubular member 200 compressed has the advantage that the inherent bias of the tubular member 200 will assist in ensuring that the outer end 204 of the tubular member 200 is maintained and urged into engagement with the groove 301.
  • the tubular member 200 is selected so as to provide the head portion 47 and its head disc 48 maintained coaxially arranged within the chamber.
  • Figure 1 illustrates a four-piece pump having as the four pieces, the body 12, the one-way valve 14 and the two-piece pump piston 16, and in which the chamber 18 in the body 12 has a constant diameter.
  • the invention of the present application is also adaptable for use with two piece pumps having a stepped chamber. Such pumps have been disclosed in U.S. Patent 5,676,277 to Ophardt, issued October 14, 1997 , the disclosure of which is incorporated herein by reference.
  • FIG. 15 to 17 showing a second embodiment in which a valve piston member 15 comprising a head portion 47 and a variable length intermediate tubular portion 45 is adapted for use with a base portion 49 identical to that shown, for example, in Figure 1 with the first embodiment.
  • the only difference over the first embodiment of Figures 1 to 14 is the configuration of the openings 212.
  • each of the side surfaces 507 and 509 which define the openings 212 therebetween converges at a common inner point 501 and at a common outer point 503.
  • Figure 15 illustrates a condition in which the axial length of the tubular member 200 is greater than the axial length of the tubular member 200 in Figure 16 .
  • each of the side surfaces 503 and 507 abut each other so as to close the openings 212 to prevent fluid flow therethrough.
  • the concavity of the outer surface 210 of the tubular member 200 increases and the side surfaces 505 and 507 come to have the circumferential extent to which they are spaced increase such that the openings 212 become of increased cross-sectional area.
  • a passage is formed through each opening 212 of a given cross-sectional area
  • Figure 15 the cross-sectional through any passage is reduced to zero as best seen in Figure 17 in cross-section.
  • the second embodiment illustrated in Figures 15 to 17 may be manufactured in a number of ways.
  • the wall of the tubular member 200 could be made initially without any openings 212 therethrough, and thereafter axially extending slits may be cut through the wall at each place where an opening 212 is desired.
  • Each slit that is cut preferably would extend in a flat plane which includes a central axis 22 and extends radially outwardly therefrom through the wall. Where the slits are cut in an unbiased condition of the tubular member 200, the openings 212 would be closed.
  • Adopting the pump piston 16 with an arrangement in which the pump piston 16 is in an unbiased condition when the tubular member 200 is in an unbiased condition or a stretched condition would result in the openings being closed when the pump piston is in the unbiased condition.
  • Figure 18 shows a fourth embodiment of a piston pump in accordance with the present invention.
  • the fourth embodiment of Figure 18 is substantially identical to the first embodiment of Figure 2 with a first exception that the head stem 30 of the valve piston member 15 of the first embodiment has been removed and is replaced by a hooking member 34 carried on the annular outer end 204 of the tubular member 200.
  • the hooking member 34 is arrow head shaped and has axially inwardly directed catching surfaces 35 which extend both radially outwardly on an outer prong 160 and radially inwardly on an inner prong 161.
  • two hook members are provided as firstly an annular axially inwardly extending resilient finger member 164 with a distal end which extends radially inwardly to provide an axially outwardly directed catch surface to engage the catching surface 35 of the outer prong 160 and secondly an annular axially inwardly extending resilient finger member 166 with a distal end which extends radially outwardly to provide an axially outwardly directed catch surface to engage the catching surface 35 of the inner prong 161.
  • Engagement between the hooking member 34 and the finger members 164 and 166 couples the tubular portion 200 of the valve piston member 15 to the base portion 49 in a snap fit relation against axial removal.
  • the hooking member 34 has angled camming surfaces on each radially inward and radially outward side outwardly of the catching surfaces to urge the fingers 164 and 166 radially apart in insertion. While two fingers 164 and 166 are shown only one is necessary.
  • the tubular member 200 is symmetrical about the central axis 22 such that with axial compression and expansion of the resilient tubular member 200, the tubular member has an inherent bias to maintain itself coaxially disposed about the central axis 22 which, particularly with the embodiment of Figure 18 , can avoid the need for other coaxial locating devices such as the head stem which in the other embodiments serves to assist in coaxially locating the head portion 47 coaxially slidable relative to the base portion 49.
  • Figure 19 shows a fourth embodiment of a pump assembly 10 in cross-section which uses a pump piston 16 with a valve piston member 15 with a head portion 47 as in the second embodiment in Figures 15 to 17 in which the openings 212 through the tubular members 200 close.
  • the outer end 204 of the tubular member 200 carries a hooking member 34 adapted to engage in a hook member carried on the base portion 49 at an inner end of the base portion annularly about the inner opening of the base passageway 52.
  • valve piston member 15 and its head portion 47 continue to include a cross shaped head stem 30 similar to that shown in the first embodiment, however, which head stem 30 does not carry the hooking members 34.
  • the pump piston 16 is illustrated as being within body 12 attached to a bottle 26 similar to that shown in Figure 1 attached to a bottle 26.
  • a removable closure cap 170 is provided which engages the body 12 in a snap-fit relation as by a radially inwardly extending hook ring on the cap 170 engaging a radially outwardly extending hook ring about an outer end 23 of the chamber wall 20.
  • the cap 170 engages the engagement flange 62 to stop the base portion 49 from movement outwardly.
  • the cap 170 has a center post 171 which extends into the passageway 52 of the base stem 46 to engage an outer end of the head stem 30 in a position that maintains the tubular portion 200 with its opening 212 closed preventing fluid flow outwardly. Fluid flow outwardly can also be prevented by the center post 171 preventing flow out the outlet 54.
  • the openings 212 of the tubular member 200 could be formed as by injection molding at the time of forming the tubular member 200. These openings 212 are to be closed on applying the cap 170 by the tubular member 200 being stretched by engagement of the center post 171 to have the axial length of the tubular member 200 increased from the inherent unbiased condition.
  • the tubular member 200 could have the openings 212 open to provide fluid flow when the piston 16 is in an unbiased inherent condition.
  • the cap urges the head stem 30 inwardly to increase the length of the tubular portion 200 and close the openings 212.
  • FIG. 20 shows a fifth embodiment of the present invention.
  • the fifth embodiment of Figure 20 is identical to the first embodiment of Figure 1 with the exception that the head stem 30 shown in the first embodiment to have an X-shape in cross-section is replaced by a tubular head stem 30 in the embodiment of Figure 20 .
  • the tubular head stem 30 is formed with a cylindrical wall 150 and provides a head stem passageway 152 coaxial therethrough, closed at an inner end 151 and open at an outer end 153.
  • a hooking member 34 is provided to extend radially outwardly from the exterior surface of the tubular head stem 30 and provide an axially inwardly directed catching surface 35 for engaging with the catch surface 290 on the base portion 49.
  • One or more apertures 154 are provided through the wall 150 of the tubular head stem 30 to permit fluid flow from within the chamber 18 into the head stem passageway 152 through the tubular head stem 30 and hence into the base stem passageway 52 of the stem of the base portion to the outlet 54.
  • Figure 21 shows a sixth embodiment of a piston pump in accordance with the present invention.
  • the embodiment of Figure 21 is substantially the same as the embodiment illustrated in Figure 18 with the exception that the wall 206 of the tubular member 200 when compressed assumes an hourglass shape as seen in side in which the outer surface 210 of the wall is convex.
  • the extent to which the outer surface 210 is convex increases as the axial length of the tubular member 200 decreases.
  • the openings 212 through the tubular member 200 are to be provided such that they provide for flow as desired through the wall when the tubular member 200 is compressed.
  • the openings 212 can have configurations which, when uncompressed, the openings are closed and, when compressed, the openings are open with increased cross-sectional area.
  • a maximum reduction in the axial length of the tubular member 200 can be a configuration in which the inner surface 208 of the webs 213 on opposite sides of the tubular member 200 engage, or in versions in which a head stem 30 is provided, the inner surfaces 208 of the webs 213 engage the head stem.
  • a limit on reduction of the axial length of the tubular portion 200 can be a position in which the outer surface 210 of the webs 213 extend radially outwardly to engage the wall 20 of the chamber 18.
  • FIG. 1 illustrates the openings 212 through the wall 206 of the tubular member 200 as being identical openings evenly spaced circumferentially about the central axis 22. This is not necessary. Some openings 212 may be larger than other openings 212, however, a preferred configuration would be with openings 212 of comparable size symmetrically arranged relative to the central axis 22 to assist in maintaining the tubular member 200 coaxial about the central axis 22 with deflection.
  • FIG. 22 shows a seventh embodiment of a piston pump assembly 10 in accordance with the present invention.
  • the embodiment of Figure 22 has many similarities to the embodiment illustrated in Figure 1 and similar reference numerals are used to refer to similar elements.
  • the pump piston 16 continues to be formed from two elements, namely, the valve piston member 15 and the valve body 17.
  • the valve body 17 is modified over that shown in Figure 1 so as to have the central passageway 52 through the valve body 17 enlarged so as to provide a valve piston chamber 19 opening axially inwardly through the inlet end 58 and ending at an axially inwardly directed chamber shoulder 218.
  • valve piston member 15 in Figure 22 is identical to that shown in Figure 5 , however, of reduced relative size compared to that shown in Figure 1 such that the head portion 47 and its head disc 48 are coaxially slidable within the valve piston chamber 19 with an edge portion of the head disc 48 to engage an inner cylindrical chamber wall 220 of the valve piston chamber 19 of the valve body 17 in Figure 22 in the same manner that in Figure 1 the edge portion of the head disc 48 engages the chamber wall 20 of the chamber 18 in the body 12.
  • the outer end 204 of the tubular member 200 forming the intermediate portion 45 engages the chamber shoulder 218 of the valve body 17.
  • valve piston member 15 in the embodiment of Figure 22 is substantially the same as is the case in the embodiment of Figure 1 with, however, the notable exception that the edge portion of the head disc 48 engages the chamber wall 220 of the valve body 17 rather than the chamber wall 20 of the body 12.
  • a helical coil spring 222 is provided coaxially within the chamber 18 and adapted to bias the valve body 17 axially outwardly from the chamber 18 as by having an axial outer end 224 of the spring 222 engage the valve body 17 at an axially inwardly directed shoulder 226 on the valve body 17 radially outwardly of the opening to the valve piston chamber 19.
  • An inner end 228 of the spring 222 is shown to engage a central non-deflecting portion of the one-way inlet valve 14.
  • reference P1 identifies a pressure of fluid in the passageway 52 on an axial upstream side of the head disc 48 of the head portion 47 in the inner compartment 111 and reference P2 is a pressure of the fluid in the passageway 52 on an axial downstream side of the head disc 48 of the head portion 47 in the outer compartment 112.
  • a pressure differential across the head disc 48 of the head portion 47 is measured as the upstream pressure P1 minus the downstream pressure P2.
  • the tubular member 200 of the intermediate portion 45 acts as a spring member which is deflectable from an unbiased position as shown in Figure 23 to biased positions such as shown in Figures 24 and 25 with the tubular member 200 being resilient and having an inherent bias to assume the unbiased position in Figure 23 in which the tubular member 200 extends an axial distance equal to an unbiased length.
  • the tubular member 200 is deflectable from the unbiased position of Figure 23 to biased positions such as shown in Figures 24 and 25 in which the length of the tubular member 200 is different than the unbiased length in Figure 23 .
  • the tubular member 200 is deflectable from the unbiased position shown in Figure 23 to a first biased position shown in Figure 24 when the pressure differential across the head disc 48 is equal to a first pressure level.
  • the peripheral circumferential edge portion 48a of the head disc 48 on the head portion 47 is elastically deformable between an unbiased condition and biased condition wherein in the unbiased condition, the edge portion engages the chamber wall 220 of the valve piston chamber 19 to prevent fluid flow therepast and in biased positions, the edge portion elastically deflects away from the chamber wall 220 to permit fluid flow therepast.
  • the edge portion of the head disc 48 assumes it unbiased condition when the pressure differential across the head disc 48 is less than or equal to the first pressure level.
  • the edge portion of the head disc 48 assumes biased conditions to permit fluid flow therepast when the pressure differential exceeds the first pressure level.
  • Figure 23 illustrates a condition in which the pressure differential is less than the first pressure level.
  • Figure 24 illustrates a condition in which the pressure differential is equal to the first pressure level and, as can be seen, the spring-forming tubular member 200 has been moved from an unbiased position as seen in Figure 23 to assume a biased condition in Figure 24 . In Figure 24 , however, the edge portion 48a of the head disc 48 continues to engage the chamber wall 220 to prevent fluid flow therebetween.
  • Figure 25 illustrates a condition in which the pressure differential exceeds the first pressure level.
  • the edge portion 48a of the head disc 48 has been deflected radially inwardly from the chamber wall 220 permitting fluid flow outwardly therepast.
  • fluid may flow outwardly past the head disc 48 through the openings 212 of the tubular member 200 and out through the passageway 52 between the arms 32 of the head stem 30.
  • head disc 48 reverts to an unbiased condition in which it prevents fluid flow outwardly therepast as the pressure differential drops to the first pressure level to adopt a position as shown in Figure 24 and, subsequently, with a further drop in the pressure differential to being less than or equal to the first pressure level, the spring forming tubular member 200 assuming an unbiased position as shown in Figure 23 .
  • valve piston member 15 will move in a cycle from the position of Figure 23 to the position of Figure 24 to the position of Figure 25 , returning to the position of Figure 24 and subsequently returning to the position of Figure 23 .
  • Figure 26 shows a pump piston 16 in accordance with an eighth embodiment of the present invention which is identical to that illustrated in Figure 23 with the exception that the valve piston chamber 19 has a chamber wall 220 which is stepped rather than being merely cylindrical as illustrated in Figure 23 .
  • the chamber wall 220 includes an axially inner portion 230 of a first diameter, an axially outer portion 232 of a second diameter joined by an intermediate transition portion 231 which is shown to be frustoconical.
  • Figure 27 shows a ninth embodiment of a pump piston 16 identical to that shown in Figure 26 but for the modification of the chamber wall 220 to show the transition portion 231 as being formed as a radially extending axially outwardly directed shoulder, and to replace the head disc 48, as seen in Figure 26 , with a modified head disc 48 having a substantially increased axial dimension such that the head disc 48, as shown in Figure 27 , has significantly reduced tendencies to have its edge portion deflect out of engagement with the chamber wall 220 over the inner portion 230.
  • FIGS 28 and 29 show a tenth embodiment of a pump piston 16 in accordance with the present invention which has considerable similarities to the embodiment illustrated in Figure 23 .
  • the tubular member 200 has been eliminated and replaced by a helical coil spring 334 which has an outer end 335 engaging the chamber shoulder 226 and an inner end 336 engage an axially outwardly directed surface 337 of the head portion 47 such that the spring 334 biases the head portion 47 axially inwardly to a position axially limited by the hooking member 34 engaging the outwardly directed catch surface 290.
  • the relative resiliency of the spring 334 and the edge portion of the head disc 48 can be selected so as to permit the operation of the embodiment of Figure 28 to be the same as the embodiment of Figure 22 .
  • Figure 28 also shows an optional modification of the chamber wall 220 so as to provide three circumferentially spaced axially extending radially inwardly directed spacing ribs 240 disposed in the outer portion 232 of the valve piston chamber 19.
  • the deflection of the edge portion 48a of the head disc 48 radially inwardly to permit fluid flow therepast is provided by either or both of (1) the resilient deflection of the edge portion due to the increased pressure differential there across, and (2) the edge portion 48a of the head disc 48 on moving axially engaging the spacing ribs 240 which deflect the edge portion of the head disc 48 away from the chamber wall 220 permitting fluid flow therepast.
  • the spacing ribs 240 can best be seen in the cross-section through the valve body 17 as seen in Figure 29 .
  • the spacing ribs 240 are spaced axially outwardly from the location of the head disc 48 in the position as shown in Figure 28 such that the head disc 48 can be moved axially inwardly of the spacing ribs 240 for an axial distance in engagement with the chamber 220 which provides for suitable fluid drawback in operation.
  • valve piston member 15 has included a spring-forming component 200 or 334 which is axially compressed to reduce an axial length as the pressure differential increases.
  • valve piston member 15 includes a spring-forming component which is axially stretched to increase in axial length as the pressure differential increases.
  • FIG. 30 illustrates a pump piston 16 in accordance with an eleventh embodiment of the present invention having considerable similarities to the pump piston shown in Figure 23
  • the valve piston member 15 is modified over the valve piston member 15 shown in Figure 23 so as to conceptually remove the tubular member 200 from its position as illustrated in Figure 23 and locate the tubular member 200 such that it extends axially inwardly from the head portion 47 to a distal end carrying the radially outwardly extending hook members 34 to engage on the axially inwardly directed shoulder 226 at the axial inner end 224 of the valve piston chamber 19.
  • the tubular member 200 is shown to be the same as in Figure 5 but inverted and secured to an inner end of the head portion 47.
  • Figure 30 shows the tubular member 200 in an unbiased condition.
  • the resilient spring forming tubular member 200 is expanded and the head portion 47 is thus moved axially inwardly until the pressure differential is increased sufficiently that the edge portion of the head disc 48 deflects from the chamber wall 220 permitting fluid flow axially therepast.
  • the tubular member 200 returns from a biased extended condition to an unbiased retracted position drawing the head portion 47 axially inwardly. Fluid flow is permitted axially through the tubular member 200 via its opening 212.
  • Figure 31 shows a twelfth embodiment of a pump piston 16 in accordance with the present invention which is substantially the same as the embodiment illustrated in Figure 31 but for three notable exceptions.
  • the chamber wall 220 has a stepped configuration with inner portion 230, transition portion 231 and outer portion 232 similar to that illustrated in Figure 26 rather than being merely cylindrical as in Figure 30 .
  • the spring forming tubular member 200 has a side wall in the form of a relative S shape rather than merely being at shape as seen in Figure 30 .
  • annular catch member 34 provided at the axialtv inner end of the tubular member 200 extends radially outwardly and then axially inwardly so as to provide an axially inwardly directed annular groove 242 adapted to receive the outer end 224 of the internal coil spring 222 as can be of assistance in maintaining the axially inner end 224 of the tubular member 200 coupled to the axially inner end shoulder 226 of the valve body 17.
  • FIG. 32 shows a thirteenth embodiment of a pump piston 16 in accordance with the present invention.
  • the valve body 17 is illustrated as being formed from two elements, an axially outer portion 230 and an axially inner portion 232 which are secured together as in a snap-fit relation to jointly form the valve piston chamber 19 with the chamber wall 220 having a stepped configuration similar to that shown in Figure 31 .
  • the inner portion 232 has a support plate 234 which extends across the axial inner end of the valve piston chamber 19 presenting openings 236 for fluid flow axially therethrough and also a central opening 238.
  • the valve piston member 15 comprises a head portion 47 carrying a head disc 48 and a variable length intermediate portion 45.
  • variable length intermediate portion 45 An axially outer end 240 of the variable length intermediate portion 45 is coupled to the head portion 47.
  • the axially inner end 242 of the variable length intermediate portion 45 carries an enlarged catch button 244 with an axially outwardly directed catch surface 246 to engage the support plate 234 and prevent axial outward movement of the inner end 242 of the variable length intermediate portion 45.
  • the intermediate portion 45 is resilient and adapted to elastically deform from an unbiased position as shown in Figure 32 to extend in axial length as the pressure differential across the head disc 48 increases and to return from biased positions to the unbiased position shown in Figure 32 .
  • the intermediate portion 45 is stretched and expands to increase in axial length such that with sufficient pressure differential increase, the head portion 47 carrying the head disc 48 is moved axially outwardly until fluid is permitted to flow axially outwardly therepast as by the head disc 48 coming to become axially located in the enlarged diameter outer portion 232 of the chamber wall 220 and/or by radially inward deflection of the head disc 48,
  • the valve piston member 15 includes a helical coil spring 250 as the variable length intermediate portion 45 which helical coil spring 250 biases the head portion 47 axially inwardly to an unbiased position.
  • the coil spring has an axially outer end 251 engage an axially inwardly directed surface 252 of the support plate 234 and an axially inner end 254 engage an axially outwardly directed surface 256 of the catch button 244.
  • the element forming the head portion 47 includes an inwardly extending stem 258 ending at the catch button 244. This head portion 47 need not have any substantial resiliency to axial deflection.
  • FIGS 34 and 35 illustrate a fifteenth embodiment in accordance with the present invention adopting a configuration for the pump piston 16 having many similarities to that shown in the embodiment of Figure 22 , however, in which the valve body 17 is, as contrasted with the unitary element shown in Figure 22 , includes two elements, namely, a sealing member 740 and a valve seat member 742.
  • the sealing member 740 carries the annular base disc 50.
  • the sealing member 740 is adapted to sealably engage a discharge tube 716.
  • the valve seat member 742 carries the check valve piston chamber 19 and the valve piston member 15 which are substantially identical to that illustrated in Figure 22 .
  • a lower end of the tube 716 is frictionally and sealably received inside the cylindrical inner side wall 754 of the socket 744 abutting on the shoulder 756.
  • the pump piston 16 comprises three elements, namely, a casing 832, the valve piston member 15 and the discharge tube 716.
  • valve piston member Operation of the valve piston member is in the valve piston chamber 19 is the same as that described with reference to Figure 32 such that as the pressure differential across the head disc increases, the intermediate portion 45 is stretched and expands or increases in axial length such that with sufficient pressure differential, the head disc 48 is moved axially outwardly until fluid is permitted to flow axially therepast as by the head disc coming to become axially located in the larger diameter outer portion 232 of the chamber wall 220 and/or by radially inward deflection of the head disc 48.
  • the casing and its discharge tube effectively forms the valve body 17 about the valve piston member 15.
  • the head disc 48 when the pressure differential reduces, then the head disc 48 preferably to provide drawback will under its resiliency deflect radially outward into sealed engagement with the annular side wall of the valve body 17 to form a seal therewith before the length of the tubular portion 200 has increased to return the head disc 48 into engagement with the support plate 234.
  • Figures 45 and 46 shows an embodiment identical to that in Figures 40 and 41 , respectively, however, in which the annular groove 858 between the head disc 48 and the tubular member 200 as seen in Figures 40 and 41 , has been eliminated such that the head disc 48 is solid and merges radially into the tubular member 200.
  • the inherent resiliency of the material forming the head disc 48 can provide the desired deflection and inherent bias to the head disc 48.
  • the resiliency of the head disc 48 can be adjusted either by increasing the relative size of the annular groove 858 in the embodiment of Figures 40 and 41 or by adjusting the resiliency of the material forming the valve piston member 15 as in the embodiment of Figures 45 and 46 .
  • Figure 43 shows a thin member in accordance with a twentieth embodiment of the invention.

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  • Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Details Of Reciprocating Pumps (AREA)
  • Reciprocating Pumps (AREA)
EP13172419.7A 2012-06-19 2013-06-18 Rückzug-Sperrventil Active EP2676737B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA2780503A CA2780503C (en) 2012-06-19 2012-06-19 Telescopic bell piston for pump
CA2808550A CA2808550C (en) 2012-06-19 2013-03-08 Drawback check valve

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EP2676737A1 true EP2676737A1 (de) 2013-12-25
EP2676737B1 EP2676737B1 (de) 2019-02-27

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015048698A1 (en) * 2013-09-30 2015-04-02 Gojo Industries, Inc Dispensers, refill units and pumps having suck-back features

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JPS62129168A (ja) * 1985-12-02 1987-06-11 Tokushu Aerosol Kk クリ−ム状流動物の分与装置
US5165577A (en) 1991-05-20 1992-11-24 Heiner Ophardt Disposable plastic liquid pump
US5282552A (en) 1991-05-20 1994-02-01 Hygiene-Technik Inc. Disposable plastic liquid pump
US5676277A (en) 1991-05-20 1997-10-14 Ophardt; Heiner Disposable plastic liquid pump
WO1997048322A1 (en) * 1996-06-21 1997-12-24 Minnesota Mining And Manufacturing Company Drip resistant nozzle for a dispenser
US5975360A (en) 1991-05-20 1999-11-02 Ophardt; Heiner Capped piston pump
US6557736B1 (en) * 2002-01-18 2003-05-06 Heiner Ophardt Pivoting piston head for pump
US7267251B2 (en) 2004-06-09 2007-09-11 Hygiene-Technik Inc. Draw back pump
US20080112830A1 (en) 2006-11-09 2008-05-15 Heiner Ophardt Autoclavable piston guide ring
US8070844B2 (en) 2007-08-31 2011-12-06 Maguire Stephen B Dust clearing blow-back valve and reservoir
EP2446971A1 (de) * 2010-11-01 2012-05-02 Gotohti.com Inc. Teleskopischer Kolben für eine Pumpe

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62129168A (ja) * 1985-12-02 1987-06-11 Tokushu Aerosol Kk クリ−ム状流動物の分与装置
US5165577A (en) 1991-05-20 1992-11-24 Heiner Ophardt Disposable plastic liquid pump
US5282552A (en) 1991-05-20 1994-02-01 Hygiene-Technik Inc. Disposable plastic liquid pump
US5676277A (en) 1991-05-20 1997-10-14 Ophardt; Heiner Disposable plastic liquid pump
US5975360A (en) 1991-05-20 1999-11-02 Ophardt; Heiner Capped piston pump
WO1997048322A1 (en) * 1996-06-21 1997-12-24 Minnesota Mining And Manufacturing Company Drip resistant nozzle for a dispenser
US6557736B1 (en) * 2002-01-18 2003-05-06 Heiner Ophardt Pivoting piston head for pump
US7267251B2 (en) 2004-06-09 2007-09-11 Hygiene-Technik Inc. Draw back pump
US20080112830A1 (en) 2006-11-09 2008-05-15 Heiner Ophardt Autoclavable piston guide ring
US8070844B2 (en) 2007-08-31 2011-12-06 Maguire Stephen B Dust clearing blow-back valve and reservoir
EP2446971A1 (de) * 2010-11-01 2012-05-02 Gotohti.com Inc. Teleskopischer Kolben für eine Pumpe

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015048698A1 (en) * 2013-09-30 2015-04-02 Gojo Industries, Inc Dispensers, refill units and pumps having suck-back features

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CA2808550C (en) 2021-07-20
CA2808550A1 (en) 2013-12-19
EP2676737B1 (de) 2019-02-27

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