CA1292640C - Valveless positive displacement metering pump - Google Patents
Valveless positive displacement metering pumpInfo
- Publication number
- CA1292640C CA1292640C CA000520517A CA520517A CA1292640C CA 1292640 C CA1292640 C CA 1292640C CA 000520517 A CA000520517 A CA 000520517A CA 520517 A CA520517 A CA 520517A CA 1292640 C CA1292640 C CA 1292640C
- Authority
- CA
- Canada
- Prior art keywords
- piston
- axes
- cylinder
- swivel
- axis
- 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.)
- Expired - Lifetime
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
- F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
- F04B39/12—Casings; Cylinders; Cylinder heads; Fluid connections
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- 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
- F04B7/00—Piston machines or pumps characterised by having positively-driven valving
- F04B7/04—Piston machines or pumps characterised by having positively-driven valving in which the valving is performed by pistons and cylinders coacting to open and close intake or outlet ports
- F04B7/06—Piston machines or pumps characterised by having positively-driven valving in which the valving is performed by pistons and cylinders coacting to open and close intake or outlet ports the pistons and cylinders being relatively reciprocated and rotated
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- 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
- F04B13/00—Pumps specially modified to deliver fixed or variable measured quantities
Abstract
ABSTRACT OF THE DISCLOSURE
A valveless, variable displacement, reversible, fixed dead volume metering pump formed with a cylinder having ports through which to pump fluid. A rotatable piston is in the cylinder with a duct thereon communicable with the ports to transfer fluid to and from the cylinder.
A drive coupling is provided for the piston. The piston reciprocates in the cylinder while rotating in a timed relation with respect to the ports and the timed relationship is reversible. The relative angularity between the axis of the piston and the axis of the drive coupling is reversible to obtain reversal of fluid flow with the degree of relative angularity determining the volume of fluid being pumped. A substantially constant dead-volume is maintained throughout the range of relative angularity between the axes through the use of a pair of floating swivel axes with a cam to restrict one or both of the axes and free the other depending upon direction of relative angular movement of the axis of the piston with respect to the axis of the drive coupling.
A valveless, variable displacement, reversible, fixed dead volume metering pump formed with a cylinder having ports through which to pump fluid. A rotatable piston is in the cylinder with a duct thereon communicable with the ports to transfer fluid to and from the cylinder.
A drive coupling is provided for the piston. The piston reciprocates in the cylinder while rotating in a timed relation with respect to the ports and the timed relationship is reversible. The relative angularity between the axis of the piston and the axis of the drive coupling is reversible to obtain reversal of fluid flow with the degree of relative angularity determining the volume of fluid being pumped. A substantially constant dead-volume is maintained throughout the range of relative angularity between the axes through the use of a pair of floating swivel axes with a cam to restrict one or both of the axes and free the other depending upon direction of relative angular movement of the axis of the piston with respect to the axis of the drive coupling.
Description
lZ9Z6~0 VALVELESS POSITIVE DISPLACEMENT METERING PUMP
__________________.______________ BACKGROUND OF THE INVENTION
_____________ The present invention relates to the art of valveless positive displacement piston, metering pumps, and, in particular, to improvements which significantly enhance the accuracy of fluid delivery over the entire range of operation of such pumps.
It has been known in the art of valveless positive displacement piston pumps to provide a reversible pumping function and controllable variable displacement by simple variation of the angle between two segments of the pump drive-axis. For example, in U.S. Patent No.
3,168,872 and U.S. Patent No. 4,008,003, both to Pinkerton, a valveless, variable, reversible pump is disclosed including a ducted piston which reciprocates and rotates synchronously in a bi-ported cylinder which is closed at one end to form a cylinder head chamber.
The piston duct is arranged in the piston to provide a fluid transfer conduit in combination with the wall of the cylinder which is alternately in fluid communication with each of the ports such that one port is in communication with the cylinder head chamber on the down stroke of the piston and the other port is in communicatior. with the cylinder head chamber on the up stroke. Reversal of the duct relationship to the ports results in reversal in direction of fluid flow.
In a typical pump of this type, to actuate the piston and effect the appropriate pump action, the piston assembly is coupled with the output of a drive shaft through i29Z6 ~0 . ~
__________________.______________ BACKGROUND OF THE INVENTION
_____________ The present invention relates to the art of valveless positive displacement piston, metering pumps, and, in particular, to improvements which significantly enhance the accuracy of fluid delivery over the entire range of operation of such pumps.
It has been known in the art of valveless positive displacement piston pumps to provide a reversible pumping function and controllable variable displacement by simple variation of the angle between two segments of the pump drive-axis. For example, in U.S. Patent No.
3,168,872 and U.S. Patent No. 4,008,003, both to Pinkerton, a valveless, variable, reversible pump is disclosed including a ducted piston which reciprocates and rotates synchronously in a bi-ported cylinder which is closed at one end to form a cylinder head chamber.
The piston duct is arranged in the piston to provide a fluid transfer conduit in combination with the wall of the cylinder which is alternately in fluid communication with each of the ports such that one port is in communication with the cylinder head chamber on the down stroke of the piston and the other port is in communicatior. with the cylinder head chamber on the up stroke. Reversal of the duct relationship to the ports results in reversal in direction of fluid flow.
In a typical pump of this type, to actuate the piston and effect the appropriate pump action, the piston assembly is coupled with the output of a drive shaft through i29Z6 ~0 . ~
l an off-axis yoke assembly. The piston includes at its outer end a laterally extending arm which i5 slidably mounted in a spherical bearing member of the yoke assembly, whereby a single point universal joint is provided. The biported cylinder, which receives the piston, is mounted for articulation around a single central axis which is perpendicular to the axis of rotation of the yoke assembly.
Thus when the axis of rotation of the yoke assembly (the drive axis) and that of the piston are substantially coaxial, the piston does not reciprocate in the cylinder during rotation of the yoke, and no pumping action takes place. However, when the cylinder axis - and thus the piston axis - is articulated (relative to the axis of the yoke) at the perpendicular axis, reciprocation occurs. The direction of deflection (to right or left) determines the direction of fluid feed through the pump chamber and the degree of angular movement determines the amplitude of piston stroke and, consequently, its displacement for each rotation of the drive motor shaft.
Inasmuch as diameter of the cylinder, the length of the piston stroke, and the stroke repetition rate are all determinable, the rate of fluid flow should, likewise, be dependably determinable. Surprisingly, however, dependable fluid flow control is not always possible, since unpredictable fluid inconsistencies can occur as a result of, for example, entrained or dissolved gases in the liquid stream which can grossly distort effective displacement values. This is particularly true in the low-flow portion of the flow rate range of such pumps because at low-flow settings they exhibit larger cylinder chamber dead-volume (a 3 1Z 9Z 6 ~0 1 prime source of random bubbles) than at high flow settings.
It will be seen therefore that since a large chamber dead-volume (lo~ flow rate) poses a greater chance of bubbles lodging and flexing in the cylinder head chamber than a small volume ~large flow rate), pumps of this type are often unsuitable for applications wherein accurate fluid delivery in the lower 15% of the possible flow rate range is required.
In view of the increasing demand for accurately adjustable rate flow pumps and the broadening scope of applications for them, a need exists to pro~ide pumps that can be readily utilized for fluid delivery over an increased portion of the possible range of adjustment. Thus, it is an object of the present invention to provide a controllably variable and reversible positive displacement metering pump with a chamber dead-volume that may be minimized and remain constant in volume through the entire adjustment range of the pump whereby the accuracy of fluid delivery is significantly enhancedj even in the low volume portion of its operating range.
It is a further object of the invention to provide enhanced fluid delivery accuracy throughout the operating range of such pumps without modification of the basic pump and drive linkage design.
Another object of the present invention is to provide increased accuracy of fluid delivery over the full range of operation of such pumps utilizing the same method of determining direction of flow and adjustment of fluid delivery. t lZ9Z6~'~0 Other and further objects and advantages will become apparent from the following disclosure which is to be taken in conjunction with the accompanying drawings illustrating preferred as well as exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is an improved valveless, variable displacement, reversible action fluid pump which includes a cylinder having port means for fluid transit to and from it and a rotatable piston with an axis and duct means communicable with the port means for transfer of fluid into and out of the cylinder. The pump further includes a drive means connected to the piston which also has an axis and means for causing the piston to reciprocate in the cylinder while rotating in a timed relation with respect to the port means and means for reversing the timed relationship without reversing the direction of rotation. The reversing means is operable to reverse the direction of angularity between the axes to obtain fluid flow reversal; the degree of relative angularity determines the volume of fluid being pumped.
Finally, the improved pump of the present invention includes means whereby the piston returns, each stroke, to a substantially constant dead-volume point in the cylinder throughout the range of relative angularity and direction between the axes.
As a result of this improved control of dead-volume, the accuracy of the fluid delivery throughout the entire range of fluid flow rate adjustment is increased.
:
-, ~
lZ926~0 - 4a -In accordance with another embodiment of the present invention there is provided a pump comprising: a cylinder including a working end, an inlet port, an outlet port and a working chamber bounded by said outlet port and said working end; a piston rotatably and reciprocably movable in the cylinder between a retracted position and an extended position, the piston including a free end having a recessed section alternately in fluid communication with the inlet port and the outlet port;
means for pivotally connecting the piston to drive means which rotatably and reciprocably drives the piston in the cylinder; and means for ensuring that the recessed section is positioned entirely in the working chamber when the piston is in the extended position, regardless of the angle between the piston and the drive means.
-` 1295 Z640 Fig. 1 is a perspective view of a preferred embodiment of the improved positive displacement pump of the present invention with a partial section view showing the piston in the cylinder assembly:
Fig. 2 is a plan view of the swivel platform of Fig. 1 with the piston cylinder assembly removed therefrom;
Fig. 3 is a bottom view of the platform shown in Fig. 2; and Fig. 4 is a side-elevational view in section of the entire assembly in accordance with.the one embodiment of the present invention.
DETAILED DESCRIPTION
Referring to Fig. 1, a positive displacement piston/cylinder assembly 10 is shown mounted on a unique support assembly 40 of the present invention. A rotary drive shaft 12 is secured to a yoke 14. The yoke 14 is mounted in a bearing support in housing 11.
Formed in a yoke 14 is a socket 16 of a universal ball and socket bearing in which ball 18 is slidably mounted on an arm 20 projecting laterally from, and seaured to, a piston 24 which is reciprocably and rotatably mounted in a cylinder 26. The circular path of the single point universal coupling 16/18 is the power path which drives the rotation and stroke action of piston 24.
As shown and described herein, the cylinder 26 is provided with two ports 25 and 27 which operate as inlet or outlet ports depending on the direction of flow selected by angular displacement of swivel platform 42.
lZ926~0 _ -6 1 The cylinder 26 is mounted on swivel platform 42 by means of mounting stud 41 which permits swivel movement of the cylinder 26 angularly with respect to support frame 44 both clockwise and counterclockwise. When piston 24, cylinder 26 and yoke 14 are substantially coaxially aligned with each other, i.e., when platform 42 is oriented at the middle of the support frame 44, the piston will have no stroke nor will it reciprocate upon rotation of yoke 14.
Thus, no pumping action takes place in this position.
As is understood with regard to positive displacement pumps of this nature, when the cylinder 26 is pivoted in a counterclockwise direction, as shown in Fig. 1, the piston will be oriented and operate to pump the liquid out of port 27 so that the port 27 becomes the outlet port while the port 25 serves as an inlet port. The greater the angular displacement of the cylinder 26 away from the center of the support frame 44, the greater the displacement of the piston in the cylinder 26 which causes a higher rate of fluid flow. As the cylinder 26 is brought closer to the middle of the support, the displacement of the pumping piston becomes smaller within the cylinder 26, resulting in a lower volume of fluid flow. When the cylinder 26 is pivoted in a clockwise direction from the middle position on the support frame 44, the direction of the fluid flow will reverse resulting in port 2S becoming the outlet port and port 27 becoming the inlet port. Once again the magnitude of the angular displacement of the cylinder 26 from the middle of the support frame 44 will determine the amplitude of piston stroke, and, consequently, the rate of fluid flow.
-- ~Z97z640 1 In the present invention two parallel control axes are provided to cause the cylinder dead-volume to be constant throughout the entire range of stroke length adjustment. These two axes are located tangent to and in the plane of the circular path travelled by the connecting universal coupling provided by socket 16 and ball 18. Thus, when the piston/cylinder assembly is angularly deflected counterclockwise from the central position on support frame 44, the control axis of such deflection is essentially tangent at point 86 of Figure 2 to the right hand extremity of the circular path (at 3 o'clock) while the control axis for angular displacement clockwise is tangent at point 87 of Figure 2 to the left hand extremity of the circular path (at 9 o'clock) of universal coupling 16/18.
In order to provide these dual axes of angular deflection, the cylinder 26 is mounted on a swivelling platform 42 having bearing means in the form of two perpendicular posts 46 and 47 which act cooperatively with an indicator edge 43 on platform 42 as it bears against cam surface 50, and with bearing sockets 56 and S7 formed in the support frame 44 so that dual pivot axes are established to control deflection of platform 42. One of the bearing posts 46/47 is used for each direction of angular deflection of the piston and cylinder with respect to the pump drive axis.
The center lines 86 and 87 of the posts 46 and 47 as they fit into sockets 56 and 57 are tangent to points 76, 77, - respectively.
Thus, the cam surface 50 is provided to permit freedom to only one bearing post to float at a time, and to provide directional réstraints to permit such float in only one direction for each bearing post. As a result of this ~Z926~0 1 unique arrangement, when both axes are restrained simultaneously, there is no angular deflection nor piston reciprocation, and thus, no fluid being pumped.
As the piston axis is deflected to the right, for example, as shown in Fig. 1, the left post 47 floats away from its restraint while the right post 46 is cammed against its restraint socket 56 thereby establishing the center line 86 of post 46 as the control axis. Since each control axis is tangent to the circumferential path of travel of coupling 16/18 at the point in each pump cycle corresponding to the minimum volume point of the piston in the cylinder, it will be understood that the same minimum volume point will be reached each cycle regardless of the angle of deflection imposed upon the piston. Thus, a constant minimal dead-volume can be maintained throughout the operating range of the pump system, enhancing both accuracy and control.
While there have been described what are presently believed to be the preferred embodlments of the invention, those skilled in the art will realize that other and further changes and modifications can be made to the invention without departing from the true spirit thereof, and all such changes and modifications as fall within the true scope of the invention are claimed herein.
3o
Thus when the axis of rotation of the yoke assembly (the drive axis) and that of the piston are substantially coaxial, the piston does not reciprocate in the cylinder during rotation of the yoke, and no pumping action takes place. However, when the cylinder axis - and thus the piston axis - is articulated (relative to the axis of the yoke) at the perpendicular axis, reciprocation occurs. The direction of deflection (to right or left) determines the direction of fluid feed through the pump chamber and the degree of angular movement determines the amplitude of piston stroke and, consequently, its displacement for each rotation of the drive motor shaft.
Inasmuch as diameter of the cylinder, the length of the piston stroke, and the stroke repetition rate are all determinable, the rate of fluid flow should, likewise, be dependably determinable. Surprisingly, however, dependable fluid flow control is not always possible, since unpredictable fluid inconsistencies can occur as a result of, for example, entrained or dissolved gases in the liquid stream which can grossly distort effective displacement values. This is particularly true in the low-flow portion of the flow rate range of such pumps because at low-flow settings they exhibit larger cylinder chamber dead-volume (a 3 1Z 9Z 6 ~0 1 prime source of random bubbles) than at high flow settings.
It will be seen therefore that since a large chamber dead-volume (lo~ flow rate) poses a greater chance of bubbles lodging and flexing in the cylinder head chamber than a small volume ~large flow rate), pumps of this type are often unsuitable for applications wherein accurate fluid delivery in the lower 15% of the possible flow rate range is required.
In view of the increasing demand for accurately adjustable rate flow pumps and the broadening scope of applications for them, a need exists to pro~ide pumps that can be readily utilized for fluid delivery over an increased portion of the possible range of adjustment. Thus, it is an object of the present invention to provide a controllably variable and reversible positive displacement metering pump with a chamber dead-volume that may be minimized and remain constant in volume through the entire adjustment range of the pump whereby the accuracy of fluid delivery is significantly enhancedj even in the low volume portion of its operating range.
It is a further object of the invention to provide enhanced fluid delivery accuracy throughout the operating range of such pumps without modification of the basic pump and drive linkage design.
Another object of the present invention is to provide increased accuracy of fluid delivery over the full range of operation of such pumps utilizing the same method of determining direction of flow and adjustment of fluid delivery. t lZ9Z6~'~0 Other and further objects and advantages will become apparent from the following disclosure which is to be taken in conjunction with the accompanying drawings illustrating preferred as well as exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is an improved valveless, variable displacement, reversible action fluid pump which includes a cylinder having port means for fluid transit to and from it and a rotatable piston with an axis and duct means communicable with the port means for transfer of fluid into and out of the cylinder. The pump further includes a drive means connected to the piston which also has an axis and means for causing the piston to reciprocate in the cylinder while rotating in a timed relation with respect to the port means and means for reversing the timed relationship without reversing the direction of rotation. The reversing means is operable to reverse the direction of angularity between the axes to obtain fluid flow reversal; the degree of relative angularity determines the volume of fluid being pumped.
Finally, the improved pump of the present invention includes means whereby the piston returns, each stroke, to a substantially constant dead-volume point in the cylinder throughout the range of relative angularity and direction between the axes.
As a result of this improved control of dead-volume, the accuracy of the fluid delivery throughout the entire range of fluid flow rate adjustment is increased.
:
-, ~
lZ926~0 - 4a -In accordance with another embodiment of the present invention there is provided a pump comprising: a cylinder including a working end, an inlet port, an outlet port and a working chamber bounded by said outlet port and said working end; a piston rotatably and reciprocably movable in the cylinder between a retracted position and an extended position, the piston including a free end having a recessed section alternately in fluid communication with the inlet port and the outlet port;
means for pivotally connecting the piston to drive means which rotatably and reciprocably drives the piston in the cylinder; and means for ensuring that the recessed section is positioned entirely in the working chamber when the piston is in the extended position, regardless of the angle between the piston and the drive means.
-` 1295 Z640 Fig. 1 is a perspective view of a preferred embodiment of the improved positive displacement pump of the present invention with a partial section view showing the piston in the cylinder assembly:
Fig. 2 is a plan view of the swivel platform of Fig. 1 with the piston cylinder assembly removed therefrom;
Fig. 3 is a bottom view of the platform shown in Fig. 2; and Fig. 4 is a side-elevational view in section of the entire assembly in accordance with.the one embodiment of the present invention.
DETAILED DESCRIPTION
Referring to Fig. 1, a positive displacement piston/cylinder assembly 10 is shown mounted on a unique support assembly 40 of the present invention. A rotary drive shaft 12 is secured to a yoke 14. The yoke 14 is mounted in a bearing support in housing 11.
Formed in a yoke 14 is a socket 16 of a universal ball and socket bearing in which ball 18 is slidably mounted on an arm 20 projecting laterally from, and seaured to, a piston 24 which is reciprocably and rotatably mounted in a cylinder 26. The circular path of the single point universal coupling 16/18 is the power path which drives the rotation and stroke action of piston 24.
As shown and described herein, the cylinder 26 is provided with two ports 25 and 27 which operate as inlet or outlet ports depending on the direction of flow selected by angular displacement of swivel platform 42.
lZ926~0 _ -6 1 The cylinder 26 is mounted on swivel platform 42 by means of mounting stud 41 which permits swivel movement of the cylinder 26 angularly with respect to support frame 44 both clockwise and counterclockwise. When piston 24, cylinder 26 and yoke 14 are substantially coaxially aligned with each other, i.e., when platform 42 is oriented at the middle of the support frame 44, the piston will have no stroke nor will it reciprocate upon rotation of yoke 14.
Thus, no pumping action takes place in this position.
As is understood with regard to positive displacement pumps of this nature, when the cylinder 26 is pivoted in a counterclockwise direction, as shown in Fig. 1, the piston will be oriented and operate to pump the liquid out of port 27 so that the port 27 becomes the outlet port while the port 25 serves as an inlet port. The greater the angular displacement of the cylinder 26 away from the center of the support frame 44, the greater the displacement of the piston in the cylinder 26 which causes a higher rate of fluid flow. As the cylinder 26 is brought closer to the middle of the support, the displacement of the pumping piston becomes smaller within the cylinder 26, resulting in a lower volume of fluid flow. When the cylinder 26 is pivoted in a clockwise direction from the middle position on the support frame 44, the direction of the fluid flow will reverse resulting in port 2S becoming the outlet port and port 27 becoming the inlet port. Once again the magnitude of the angular displacement of the cylinder 26 from the middle of the support frame 44 will determine the amplitude of piston stroke, and, consequently, the rate of fluid flow.
-- ~Z97z640 1 In the present invention two parallel control axes are provided to cause the cylinder dead-volume to be constant throughout the entire range of stroke length adjustment. These two axes are located tangent to and in the plane of the circular path travelled by the connecting universal coupling provided by socket 16 and ball 18. Thus, when the piston/cylinder assembly is angularly deflected counterclockwise from the central position on support frame 44, the control axis of such deflection is essentially tangent at point 86 of Figure 2 to the right hand extremity of the circular path (at 3 o'clock) while the control axis for angular displacement clockwise is tangent at point 87 of Figure 2 to the left hand extremity of the circular path (at 9 o'clock) of universal coupling 16/18.
In order to provide these dual axes of angular deflection, the cylinder 26 is mounted on a swivelling platform 42 having bearing means in the form of two perpendicular posts 46 and 47 which act cooperatively with an indicator edge 43 on platform 42 as it bears against cam surface 50, and with bearing sockets 56 and S7 formed in the support frame 44 so that dual pivot axes are established to control deflection of platform 42. One of the bearing posts 46/47 is used for each direction of angular deflection of the piston and cylinder with respect to the pump drive axis.
The center lines 86 and 87 of the posts 46 and 47 as they fit into sockets 56 and 57 are tangent to points 76, 77, - respectively.
Thus, the cam surface 50 is provided to permit freedom to only one bearing post to float at a time, and to provide directional réstraints to permit such float in only one direction for each bearing post. As a result of this ~Z926~0 1 unique arrangement, when both axes are restrained simultaneously, there is no angular deflection nor piston reciprocation, and thus, no fluid being pumped.
As the piston axis is deflected to the right, for example, as shown in Fig. 1, the left post 47 floats away from its restraint while the right post 46 is cammed against its restraint socket 56 thereby establishing the center line 86 of post 46 as the control axis. Since each control axis is tangent to the circumferential path of travel of coupling 16/18 at the point in each pump cycle corresponding to the minimum volume point of the piston in the cylinder, it will be understood that the same minimum volume point will be reached each cycle regardless of the angle of deflection imposed upon the piston. Thus, a constant minimal dead-volume can be maintained throughout the operating range of the pump system, enhancing both accuracy and control.
While there have been described what are presently believed to be the preferred embodlments of the invention, those skilled in the art will realize that other and further changes and modifications can be made to the invention without departing from the true spirit thereof, and all such changes and modifications as fall within the true scope of the invention are claimed herein.
3o
Claims (12)
1. A valveless, variable displacement, fixed dead volume, piston metering pump comprising:
a cylinder having port means to direct fluid and a head chamber to contain fluid:
a rotatable piston in said cylinder, said piston having an axis;
duct means on said piston communicable with said port means for transfer of said fluid to and from the cylinder head chamber;
drive means for said piston, said drive means having an axis and means for causing said piston to reciprocate in said cylinder to and from a fixed dead volume point while rotating in a timed relation with respect to said port means; and means for reversing said timed relationship through reversal of relative angularity between said axes to obtain fluid flow reversal at flow rates determined by the degree of relative angularity of the two axes.
a cylinder having port means to direct fluid and a head chamber to contain fluid:
a rotatable piston in said cylinder, said piston having an axis;
duct means on said piston communicable with said port means for transfer of said fluid to and from the cylinder head chamber;
drive means for said piston, said drive means having an axis and means for causing said piston to reciprocate in said cylinder to and from a fixed dead volume point while rotating in a timed relation with respect to said port means; and means for reversing said timed relationship through reversal of relative angularity between said axes to obtain fluid flow reversal at flow rates determined by the degree of relative angularity of the two axes.
2. The invention in accordance with Claim 1 wherein pivot means is provided to permit adjustment of the relative angle between said axes to control the fluid flow rate as desired.
3. The invention in accordance with Claim 2 wherein said pivot means includes a pair of coordinated floating swivel axes with each one being for an opposite direction of relative angular movement.
4. The invention in accordance with Claim 3 wherein the swivel axes are located oppositely tangent to the circular path travelled by a point at the extremity of said drive means.
5. The invention in accordance with Claim 4 wherein cam means are provided to restrict floating of one or more of said swivel axes, said cam means being positioned so that when both axes are restrained from floating, angular deflection is 0 and there is no piston reciprocation nor pumping of fluid, shifting of the relative angularity between said axes in one direction permits one of said swivel axes to float away from its restraint by said cam means while the other of said swivel axes is cammed against its restraint to thereby become the control axis, and as the relative angularity of the axes is changed in the opposite direction, the other of said swivel axes floats away from its restraint while the one swivel axes is cammed against its restraint thereby becoming the control axis.
6. The invention in accordance with Claim 5 wherein the cam means includes a platform including a pair of spaced posts adapted to each removably engage a pair of corresponding spaced sockets in the fixed support for said pump, each of said swivel axes being located through a post when the post is engaged with said socket.
7. The invention in accordance with Claim 6 wherein swivelling of the platform in one direction will cause the surface on said support surrounding said one socket to engage and restrain said mating post while the other post is freely displaced from engagement with the surface of said support surrounding the other socket.
8. The invention in accordance with Claim 5 wherein the swivel axes are arranged so that the control axis intersects and is tangent to the piston coupling path at one point in each pump cycle and, at that point, the minimal volume point will be reached each cycle regardless of the angle of deflection imposed upon the piston thereby maintaining a substantially constant minimal dead volume throughout the operating range of pump and enhancing both accuracy and control.
9. The invention in accordance with Claim 1 wherein actuator means is provided for reciprocating said piston upon operation of said drive means whereby fluid is drawn into said cylinder head chamber through said duct means from one of said ports and then out of said cylinder head chamber through said duct means and out through the other of said ports, said actuator means including swivel means for changing the angular relationship between the axes of the piston and said drive means to change the stroke length of the piston and vary the fluid flow, said swivel means pivotally supporting said cylinder, such that said cylinder is pivotable about one of a pair of spaced swivel axes depending upon the chosen direction of angular displacement, the two swivel axes being located oppositely tangent to the circular path travelled by a point at the extremity of said drive means, and cam means engageable with respect to at least one of said swivel axes so as to permit float freedom of only one swivel axis at a time and including directional restraints to permit float in only one direction for each swivel axis and to restrain both swivel axes simultaneously when the relative angular deflection is zero and there is no piston reciprocation and no pumping of fluid, the cam means being responsive to deflection of the piston axes relative to the drive axis to permit floating of one swivel axis and fixing of the other depending upon the direction of deflection.
10. A pump comprising:
a cylinder including a working end, an inlet port, an outlet port and a working chamber bounded by said outlet port and said working end;
a piston rotatably and reciprocably movable in said cylinder between a retracted position and an extended position, said piston including a free end having a recessed section alternately in fluid communication with said inlet port and said outlet port;
means for pivotally connecting said piston to drive means which rotatably and reciprocably drives said piston in said cylinder; and means for ensuring that said recessed section is positioned entirely in said working chamber when said piston is in said extended position, regardless of the angle between said piston and said drive means.
a cylinder including a working end, an inlet port, an outlet port and a working chamber bounded by said outlet port and said working end;
a piston rotatably and reciprocably movable in said cylinder between a retracted position and an extended position, said piston including a free end having a recessed section alternately in fluid communication with said inlet port and said outlet port;
means for pivotally connecting said piston to drive means which rotatably and reciprocably drives said piston in said cylinder; and means for ensuring that said recessed section is positioned entirely in said working chamber when said piston is in said extended position, regardless of the angle between said piston and said drive means.
11. A pump according to claim 10, wherein said means for ensuring includes guide means for guiding said cylinder during pivotal movement of said piston with respect to said drive means to ensure that said recessed section is positioned entirely in said working chamber when said piston is in said extended position.
12. A pump according to claim 10, wherein said piston includes a driven end opposite to said free end; and said means for pivotally connecting includes yoke means connected to said drive means and having a socket therein, arm means extending generally transverse from said driven end of said piston and a ball mounted on said arm means and mating with said socket in a ball and socket arrangement.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/829,398 US4941809A (en) | 1986-02-13 | 1986-02-13 | Valveless positive displacement metering pump |
| US829,398 | 1986-02-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1292640C true CA1292640C (en) | 1991-12-03 |
Family
ID=25254429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000520517A Expired - Lifetime CA1292640C (en) | 1986-02-13 | 1986-10-15 | Valveless positive displacement metering pump |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4941809A (en) |
| EP (1) | EP0248110A3 (en) |
| JP (1) | JPS62294779A (en) |
| KR (1) | KR950007514B1 (en) |
| CA (1) | CA1292640C (en) |
| IN (1) | IN172012B (en) |
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| FR2656046B1 (en) * | 1989-12-18 | 1992-04-03 | Oreal | AIR COMPRESSION AND ACCUMULATION DEVICE. |
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| US5482448A (en) * | 1994-06-10 | 1996-01-09 | Atwater; Richard G. | Positive displacement pump with concentrically arranged reciprocating-rotating pistons |
| US5656499A (en) * | 1994-08-01 | 1997-08-12 | Abbott Laboratories | Method for performing automated hematology and cytometry analysis |
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| US5631165A (en) * | 1994-08-01 | 1997-05-20 | Abbott Laboratories | Method for performing automated hematology and cytometry analysis |
| US5601421A (en) * | 1996-02-26 | 1997-02-11 | Lee; W. Ken | Valveless double acting positive displacement fluid transfer device |
| US5741126A (en) * | 1996-03-01 | 1998-04-21 | Stearns; Stanley D. | Valveless metering pump with crisscrossed passage ways in the piston |
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| US6224347B1 (en) | 1999-09-13 | 2001-05-01 | The Gorman-Rupp Company | Low volume, high precision, positive displacement pump |
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| US20020107501A1 (en) * | 2001-02-02 | 2002-08-08 | Smith James E. | Weight dependent, automatic filling dosage system and method of using same |
| WO2002085521A1 (en) * | 2001-04-25 | 2002-10-31 | Oyster Bay Pump Works, Inc. | Reagent addition system and method |
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| US20030236489A1 (en) | 2002-06-21 | 2003-12-25 | Baxter International, Inc. | Method and apparatus for closed-loop flow control system |
| KR100566455B1 (en) * | 2003-06-24 | 2006-03-31 | 엘지.필립스 엘시디 주식회사 | Liquid crystal dispensing system using spacer information and method of dispensing liquid crystal material using thereof |
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| CN100362399C (en) * | 2003-11-17 | 2008-01-16 | Lg.菲利浦Lcd株式会社 | Liquid crystal distributing method and device thereof |
| KR100987910B1 (en) * | 2003-11-28 | 2010-10-13 | 엘지디스플레이 주식회사 | An apparatus and method of dispensing liquid crystal |
| US7159507B2 (en) | 2003-12-23 | 2007-01-09 | Philip Morris Usa Inc. | Piston pump useful for aerosol generation |
| US8562310B1 (en) * | 2004-09-16 | 2013-10-22 | Fluid Metering, Inc. | Chlorination system with corrosion minimizing components |
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| US20080187449A1 (en) * | 2007-02-02 | 2008-08-07 | Tetra Laval Holdings & Finance Sa | Pump system with integrated piston-valve actuation |
| US20090157219A1 (en) * | 2007-05-03 | 2009-06-18 | Parker Jr Lance T | Intelligent Sleeve Container for Use in a Controlled Syringe System |
| CN103470466B (en) | 2007-12-10 | 2016-08-17 | 拜耳医疗保健公司 | Continuous print fluid delivery system and method |
| WO2009120692A2 (en) * | 2008-03-25 | 2009-10-01 | Animal Innovations, Inc. | Syringe mechanism for detecting syringe status |
| WO2010126622A1 (en) * | 2009-04-27 | 2010-11-04 | Animal Innovations, Inc. | Injection syringe plunger valve assembly |
| US8864475B2 (en) * | 2009-05-28 | 2014-10-21 | Ivek Corporation | Pump with wash flow path for washing displacement piston and seal |
| WO2011044294A1 (en) | 2009-10-06 | 2011-04-14 | Flex Partners, Inc. | Precision fluid delivery systems |
| WO2011113469A2 (en) * | 2010-03-15 | 2011-09-22 | Diener Ag Precision Machining | Metering pump |
| WO2011114285A2 (en) * | 2010-03-17 | 2011-09-22 | Sensile Pat Ag | Micropump |
| US9261085B2 (en) | 2011-06-10 | 2016-02-16 | Fluid Metering, Inc. | Fluid pump having liquid reservoir and modified pressure relief slot |
| WO2015089355A1 (en) * | 2013-12-13 | 2015-06-18 | Fluid Metering, Inc. | Mechanism for fine adjustment of flows in fixed displacement pump |
| US10935021B2 (en) | 2013-12-13 | 2021-03-02 | Fluid Metering, Inc. | Mechanism for coarse and fine adjustment of flows in fixed displacement pump |
| AU2016205275B2 (en) | 2015-01-09 | 2020-11-12 | Bayer Healthcare Llc | Multiple fluid delivery system with multi-use disposable set and features thereof |
| JP2022542402A (en) * | 2019-07-31 | 2022-10-03 | フルード・メタリング・インコーポレイテッド | mechanism for electronically regulating the internal flow of a fixed displacement pump |
| FR3125203B1 (en) | 2021-07-16 | 2023-10-27 | Exel Ind | LIQUID CIRCUIT FOR AGRICULTURAL SPRAYER INCLUDING A WATERPROOF TRANSFER SYSTEM AND A DOSING MECHANISM |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH128278A (en) * | 1926-08-05 | 1928-10-16 | Friedmann Alex Fa | Drive device on pumps, especially for pumping small amounts of liquid. |
| US4536140A (en) * | 1983-11-14 | 1985-08-20 | M&T Chemicals Inc. | Pump apparatus and system for containing and metering uniform pulses of a small amount of a hazardous liquid |
| US4575317A (en) * | 1985-06-26 | 1986-03-11 | M&T Chemicals Inc. | Constant clearance positive displacement piston pump |
-
1986
- 1986-02-13 US US06/829,398 patent/US4941809A/en not_active Expired - Lifetime
- 1986-10-07 IN IN893/DEL/86A patent/IN172012B/en unknown
- 1986-10-15 CA CA000520517A patent/CA1292640C/en not_active Expired - Lifetime
- 1986-10-25 EP EP86114848A patent/EP0248110A3/en not_active Ceased
- 1986-11-11 JP JP61266823A patent/JPS62294779A/en active Pending
- 1986-11-18 KR KR1019860009745A patent/KR950007514B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| KR950007514B1 (en) | 1995-07-11 |
| US4941809A (en) | 1990-07-17 |
| IN172012B (en) | 1993-03-13 |
| KR870008117A (en) | 1987-09-24 |
| EP0248110A2 (en) | 1987-12-09 |
| JPS62294779A (en) | 1987-12-22 |
| EP0248110A3 (en) | 1988-03-02 |
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| Date | Code | Title | Description |
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| MKEX | Expiry | ||
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Effective date: 20081203 |