초록

A valve for a pump arrangement which serves on one hand as a one-way outlet valve subject to functioning, after fluid has been dispensed, of drawing back some fluid which has been dispensed.

대표청구항 ▼

1. In combination, as tube member a valve member: the tube member having a tube inner wall defining therein an axially extending fluid passageway for flow of a fluid in an axial downstream direction therethrough,the tube inner wall having a tube upstream portion and a tube downstream portion, the tu

1. In combination, as tube member a valve member: the tube member having a tube inner wall defining therein an axially extending fluid passageway for flow of a fluid in an axial downstream direction therethrough,the tube inner wall having a tube upstream portion and a tube downstream portion, the tube downstream portion located in the downstream direction from the tube upstream portion,the valve member disposed within the passageway,the valve member comprising a spring member and a piston head member,the spring member having a spring first end and a spring second end, the spring member extending axially within the passageway from the spring first end to the spring second end,the spring first end coupled t the tube inner wall at a first location against relative axial movement with the tube member,the piston head member fixedly secured to the spring second end, the spring member being resilient and having an inherent bias to assume an unbiased position in which the spring second end is axially spaced from the spring first end by a distance equal to an unbiased length,the spring member deflectable from the unbiased position to biased positions in which the spring second end is axially spaced from the spring first end by distances different than the unbiased length,in moving from the unbiased position to the biased positions the spring second end is moved in the axial downstream direction relative the spring first end,piston head member having an axial downstream side and an axial upstream side,a pressure differential across the piston head member is measured as a pressure of the fluid in the passageway on the axial upstream side of the piston head member minus a pressure of the fluid in the passageway on the axial downstream side of the piston head member,the spring member deflectable from the unbiased position to a first of the biased positions when the pressure differential is equal to a first pressure level,the piston head member having a peripheral circumferential edge portion wherein when the edge portion of the piston head member is in the tube upstream portion engagement between the edge portion and the tube inner wall of the tube upstream portion prevents fluid flow axially therebetween, and when the edge portion of the piston head member is in the tube downstream portion interaction between the edge portion of the piston head member and the tube downstream portion permits fluid flow downstream therepast,wherein when the pressure differential is less than or equal to the first pressure level the edge portion of the piston head member is in the tube upstream portion and when the pressure differential is greater than the first pressure level the edge portion of the piston head member is in the tube downstream portion:the spring member comprising a tubular member having a wall member extending between the spring first end and the spring second end,the wall member having the shape of a solid of revolution rotated about the central axis,the wall member having a radially outwardly directed outer wall surface and a radially inwardly directed inner wall surface,at least one wall opening radially through the wall member from the outer wall surface to the inner wall surface,the tubular member being resilient having an inherent bias to assume an initial unbiased configuration of an unbiased length measured along the axial length, the tubular member resiliently deflectable to biased configurations, each having a length measured along the central axis loss than the unbiased length, the inherent bias of the resilient member biasing the tubular member to return towards the unbiased configuration from any one of the biased configurations,a reduction in the length of the tubular member as measured along the central axis corresponds to the outer wall surface increasing in convexity as seen in cross-sectional side view in flat planes including the central axis extending radially from the central axis. 2. A combination as claimed in claim 1 wherein the edge portion of the piston head member is elastically deformable between an unbiased condition and biased conditions wherein in the unbiased condition the edge portion engages the tube inner wall to prevent fluid flow therepast and in the biased conditions the edge portion elastically deflects away the tube inner wall to permit fluid flow therepast. 3. A combination as claimed in claim wherein in operation to discharge a fluid through the tube member past the valve member, a. starting with an initial the pressure differential less than the first pressure level and increasing the pressure differential to the first pressure level, the spring second end is moved axially in a downstream direction with the edge portion of the piston head member maintained in the tube upstream portion preventing fluid flow therepast,b. on further increasing the pressure differential from the first pressure level to pressure differentials which exceed the first pressure level the edge portion of the piston head member is moved axially in a downstream direction into the tube downstream portion and maintained in the tube downstream permitting fluid flow therepast,c. on decreasing the pressure differential from pressure differentials which exceed the first pressure level to the first pressure level the edge portion of the piston head member moves from the tube downstream portion into the tube upstream portion preventing fluid flow therepast,d. on further decreasing the pressure differential from the first pressure level to pressure differentials which are less than the first pressure level with the edge portion of the piston head member in the tube upstream portion preventing fluid flow therepast, the spring member deflects under its inherent bias moving the spring second end in an upstream direction towards the unbiased position, wherein in the moving the spring, second end in the upstream direction from the first of the biased positions towards the unbiased position with the edge portion of the piston head member engaging the tube inner wall to prevent fluid flow therepast fluid on the downstream side of the piston head member is drawn within the passageway in the upstream direction. 4. A combination as claimed in claim 1 wherein: the spring first end is fixed to the inner wall of the tube member at the first location which is axially downstream from the spring second end,the spring member in moving from the unbiased position to the biased positions is compressed to axially decrease in length between the spring first end and the spring second end. 5. A combination as claimed in claim 1 wherein the valve member including the spring member and the piston head is integrally thrilled as a unitary element by injection moulding. 6. A combination as claimed in claim 1 wherein the tube member is a discharge tube member leading to a discharge outlet from which fluid is dispensed. 7. A combination as claimed in claim 6 wherein in operation after discharging the fluid through the tube member past the valve member and out the discharge outlet under a pressure differential greater than die first pressure level, on a decrease in the pressure differential from the first pressure level to pressure differentials which are less than the first pressure level the spring member deflects under its inherent bias moving the spring second end in an upstream direction from the first of the biased positions towards the unbiased position, with the edge portion of the piston head member moving with the spring second end while engaging the tube inner wall to prevent fluid flow therepast, whereby fluid in the tube member at the discharge outlet is drawn back within the passageway in the upstream direction. 8. A combination as claimed in claim 1 wherein the tube upstream portion being circular in cross section normal to the axis, the tube upstream portion having a diameter, the tube downstream portion bring circular in cross-section normal to the axis, the tube downstream portion having a diameter greater than the diameter of the tube upstream portion. 9. A combination as claimed in claim 8 wherein the edge portion of the piston head member is circular in cross-section normal to the axis, the edge portion having a diameter less than the diameter of the tube upstream portion. 10. A combination as claimed in claim 9 wherein the edge portion of the piston head member is elastically deformable between an unbiased condition and biased conditions wherein in the unbiased condition the edge portion engages the tube inner wall to prevent fluid flow therepast and in the biased conditions the edge portion elastically deflects away the tube inner wall to permit fluid flow therepast and wherein the edge portion of the piston head member is elastically deformable from the unbiased condition toward biased conditions however provided that the pressure differential is less than or equal to the first pressure level while the edge portion is in the tube upstream portion the edge portion prevents fluid flow in the passageway in either direction therepast. 11. A combination as claimed in claim 10 wherein the edge portion of the piston head member is elastically deformable from the unbiased condition toward biased positions however provided that the pressure differential is greater than the first pressure level while the edge portion is in the tube downstream portion the edge portion permits fluid flow in the passageway in the downstream direction therepast. 12. In combination, a tube member and a valve member: the tube member having a tube inner wall defining therein an axially extending fluid passageway for flow of a fluid in an axial downstream direction therethrough,the valve member disposed within the passageway,the valve member comprising a spring member and a piston head member,the spring member having, a spring first end and a spring second end, the spring member extending axially within the passageway from the spring first end to the spring second end,the spring first end coupled to the tube inner wall at a first location against relative axial movement with the tube member,the piston head member fixedly secured to the spring second end,the spring member being resilient and having an inherent bias to assume an unbiased position in which the spring second end is axially spaced from the spring first end by a distance equal to an unbiased length,the spring member deflectable from the unbiased position to biased positions in which the spring second end is axially spaced from the spring first end by distances different than the unbiased length,in moving from the unbiased position to the biased positions the spring second end is moved in the axial downstream direction relative the spring first end,the piston head member having an axial downstream side and an axial upstream side,a pressure differential across the piston head member is measured as a pressure of the fluid in the passageway on the axial upstream side of the piston head member minus a pressure of the fluid in the passageway on the axial downstream side of the piston head member,the spring member deflectable from the unbiased position to as first of the biased positions when the pressure differential is equal to a first pressure level,the piston head member having a peripheral circumferential edge portion for engagement with the tube inner wall to prevent fluid flow axially therebetween unless the pressure differential is exceeds the first pressure level,the peripheral circumferential edge portion of the piston head member being elastically deformable between an unbiased condition and biased conditions wherein in the unbiased condition the edge portion engages the tube inner wall to prevent fluid flow therepast and in the biased conditions the edge portion elastically deflects away the tube inner wall to permit fluid flow in the downward direction therepast,the edge portion of the piston head member assuming the unbiased condition when the pressure differential is less than or equal to the first pressure level,the edge portion of the piston head member assuming the biased conditions when the pressure differential exceeds the first pressure levelthe spring first end is fixed to the inner all of the tube member at the first location which is axially downstream from the spring second end,the spring member in moving from the unbiased position to the biased positions is compressed to axially decrease in length between the spring first end and the spring second end. 13. A combination as claimed in claim 12 wherein the spring member assuming the unbiased position when the pressure differential is approximately zero. 14. A combination as claimed in claim 12 wherein in operation to discharge a fluid through the tube member past the valve member: a. starting with an initial pressure differential less than the first pressure level and increasing the pressure differential to the first pressure level, the spring second end is moved axially in a downstream direction with the edge portion of the piston head member in the unbiased position prevent fluid flow therepast,b. on further increasing the pressure differential from the first pressure level to pressure differentials which exceed the first pressure level the edge portion of the piston head member assumes the biased conditions in which the edge portion elastically deflects away the tube inner wall to permit fluid flow therepast,c. on decreasing the pressure differential from pressure differentials which exceed the first pressure level to the First pressure level the edge portion of the piston head member assumes the biased condition in which the edge portion prevents fluid flow therepast and the spring second end moves to the first of the biased positions.d. on further decreasing the pressure differential from the first pressure level to pressure differentials which are less than the first pressure level with the edge portion of the piston head member in the biased conditions in which the edge portion prevents fluid flow therepast, the spring member deflects under its inherent bias moving the spring second end in an upstream direction from the first of the biased positions towards the unbiased position, wherein in the moving the spring second end in the upstream direction from the first of the biased positions towards the unbiased position with the edge portion of the piston head member engaging the tube inner wall to prevent fluid flow therepast and fluid on the downstream side of the piston head member is drawn within the passageway in the upstream direction. 15. A combination as claimed in claim 12 wherein the spring member comprising a tubular member having a wall member extending between the spring first end and the spring second end, the wall member having the shape of a solid of revolution rotated about the central axis,the wall member having a radially outwardly directed outer wall surface and a radially inwardly directed inner wall surface,at least one wall opening radially through the wail member from the outer wall surface to the inner wall surface,the tubular member being resilient having an inherent bias to assume an initial unbiased configuration of an unbiased length measured along the axial length, the tubular member resiliently deflectable to biased configurations, each having a length measured along the central axis less than the unbiased length, the inherent bias of the resilient member biasing the tubular member to return towards the unbiased configuration from any one of the biased configurations,a reduction in the length of the tubular member as measured along the central axis corresponds to the outer wall surface increasing in convexity as seen in cross-sectional side view in flat planes including the central axis extending radially from the central axis. 16. In combination, a tube member and a valve member: the tube member having a tube inner wall defining therein an axially extending fluid passageway for flow of a fluid in an axial downstream direction therethrough,the valve member disposed within the passageway,the valve member comprising a spring member and a piston head member,the spring member having a spring first end and a spring second end, the spring member extending axially within the passageway from the spring first end to the spring second end,the spring first end coupled to the tube inner wall at a first location against relative axial movement with the tube member,the piston bead member fixedly secured to the spring second end,the spring member being resilient and having an inherent bias to assume an unbiased position in which the sprint second end is axially spaced from the spring first end by a distance equal to an unbiased length,the spring member deflectable from the unbiased position to biased positions in which the spring second end is axially spaced from the spring first end by distances different than the unbiased length,in moving from the unbiased position to the biased positions the spring second end is moved in the axial downstream direction relative the spring first end,the piston head member having an axial downstream side and an axial upstream side,a pressure differential across the piston head member is measured as a pressure of the fluid in the passageway on the axial upstream side of the piston head member minus a pressure of the fluid in the passageway on the axial downstream side of the piston head member,the spring member deflectable from the unbiased position to a first of the biased positions when the pressure differential is equal to a first pressure level,the piston head member having a peripheral circumferential edge portion for engagement with the tube inner wall to prevent fluid flow axially therebetween unless the pressure differential is exceeds the first pressure level,the peripheral circumferential edge portion of the piston head member being elastically deformable between an unbiased condition and biased conditions wherein in the unbiased condition the edge portion engages the tube inner wall to prevent fluid flow therepast and, in the biased conditions, the edge portion elastically deflects away the tube inner wall to permit fluid flow in the downward direction therepast,the edge portion of the piston head member assuming the unbiased condition when the pressure differential is less than or equal to the first pressure level,the edge portion of the piston head member assuming the biased conditions when the pressure differential exceeds the first pressure level,wherein the spring member comprising a tubular member having a wall member extending between the spring first end and the spring second end,the wall member having the shape of a solid of revolution rotated about the central axis,the wall member having a radially outwardly directed outer wall surface and a radially inwardly directed inner wall surface,at least one wall opening radially through the wall member from the outer wall surface to the inner wall surface,the tubular member being resilient having an inherent bias to assume an initial unbiased configuration of an unbiased length measured along the axial length, the tubular member resiliently deflectable to biased configurations, each having a length measured along the central axis less than the unbiased length, the inherent bias of the resilient member biasing the tubular member to return towards the unbiased configuration from any one of the biased configurations,a reduction in the length of the tubular member as measured along the central axis corresponds to the outer wall surface increasing, in convexity as seen in cross-sectional side view in flat planes including the central axis extending radially from the central axis. 17. In combination, a tube member and a valve member: the tube member having a tube inner wall defining therein an axially extending fluid passageway for flow of a fluid in an axial downstream direction therethrough,the tube inner wall having, a tube upstream portion and a tube downstream portion, the tube downstream portion located in the downstream direction, from the tube upstream portion,the valve member disposed within the passageway,the valve member comprising a spring member and a piston head member,the spring member having a spring first end and a spring second end, the spring member extending axially within the passageway from the spring first end to the spring second end,the spring first end coupled to the tube inner wall at a first location against relative axial movement with the tube member,the piston head member fixedly secured to the spring second end,the spring member being resilient and having an inherent bias to assume an unbiased position in which the spring second end is axially spaced from the spring first end b a distance equal to an unbiased length,the spring member deflectable from the unbiased position to biased positions in which the spring second end is axially spaced from the spring first end by distances different than the unbiased length,in moving from the unbiased position to the biased positions the spring second end is moved in the axial downstream direction relative the spring first end,piston head member having an axial downstream side and an axial upstream side,a pressure differential across the piston head member is measured as a pressure of the fluid in the passageway on the axial upstream side of the piston head member minus a pressure of the fluid in the passageway on the axial downstream side of the piston head member,the spring member deflectable from the unbiased position to a first of the biased positions when the pressure differential is equal to a first pressure level,the piston head member having a peripheral circumferential edge portion wherein when the edge portion of the piston head member is in the tube upstream portion engagement between the edge portion and the tube inner wall of the tube upstream portion prevents fluid flow axially therebetween, and when the edge portion of the piston head member is in the tube downstream portion interaction between the edge portion of the piston head member and the tube downstream portion permits fluid flow downstream therepast,wherein when the pressure differential is less than or equal to the first pressure level the edge portion of the piston head member is in the tube upstream portion and when the pressure differential is greater than the first pressure level the edge portion of the piston head member is in the tube downstream portion,the spring first end is fixed to the inner wall of the tube member at the first location which is axially downstream from the spring second end,the spring member in moving from the unbiased position to the biased positions is compressed to axially decrease in length between the spring first end and the spring second end. 18. A combination as claimed in claim 17 wherein the spring member comprising a tubular member having a wall member extending between the spring first end and the spring second end, the wall member having the shape of a solid of revolution rotated about the central axis,the wall member having a radially outwardly directed outer wall surface and a radially inwardly directed inner wall surface,at least one wall opening radially through the wall member from the outer wall surface to the inner wall surface,the tubular member being resilient having an inherent bias to assume an initial unbiased configuration of an unbiased length measured along the axial length, the tubular member resiliently deflectable to biased configurations, each having a length measured along the central axis less than the unbiased length, the inherent bias of the resilient member biasing the tubular member to return towards the unbiased configuration from any one of the biased configurations,a reduction in the length of the tubular member as measured along the central axis corresponds to the outer wall surf increasing in convexity as seen in cross-sectional side view in flat planes including the central axis extending radially from the central axis.