Abstract:
A novel method of designing a pump by utilizing a cylinder with pistons inserted from each end. The cylinder contains two ports along the top for connection of a prime fluid chamber, a bulk fluid supply chamber and a fluid reservoir. These ports and corresponding connection details are arranged in a fashion that is perpendicular to the axis of the cylinder that comprises the pump chamber. Directly below at a different relative position also perpendicular to the axis of the pump chamber is an exit port for extrusion of fluid. The pump contains no valves or ancillary passages to direct flow between the different machine states of prime, refill, translate and dispense. The states are activated by relative position of the pistons with respect to each port. Fluid moves by translation within the pump by filling the chamber volume between the two pistons with a liquid and synchronizing the advance of the left piston with the retreat of the right piston. Both pistons can be directed toward one another or one piston can remain stationary while the other advances toward it to dispense a liquid. Exceptionally accurate volumes of fluid can be deposited because of the absence of compliant members in the wetted path.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is entitled to the benefit of Provisional Patent Application Ser. No. 60/860,172 filed Nov. 20, 2006. 
     
    
     FEDERALLY FUNDED RESEARCH 
       [0002]    Not Applicable 
       SEQUENCE LISTING OR PROGRAM 
       [0003]    Not Applicable 
       BACKGROUND OF INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    This invention pertains to the field of liquid dispensing equipment. More particularly, it pertains to design of a pump that employs a novel method of pumping or extruding a fluid. The pump design is capable of accomplishing this task without the use of valves or redirection of fluid through ancillary pathways. Both pistons occupy a circular cavity or tube; each piston is inserted from opposite ends, a reservoir and a prime chamber are installed on the topside of the tube. The exit port is directly below and provides for connection of a nozzle or other passage for extrusion of the fluid. 
         [0006]    2. Description of the Prior Art 
         [0007]    At present there are four general types of pumps used to underfill electronic devices with viscous liquid: (1) A screw or auger type pump comprised of a rotating helix or thread turning inside a cylindrical chamber, the liquid is pumped as a result of shear of the fluid, forward pressure builds as a function of the cosine of the helix angle. (2) An air over type pump, constructed using a cylindrical cavity or syringe, utilizes a column of fluid or reservoir with a follower or concave disc placed on top, air pressure creates the force to move the liquid by acting on the surface area of the follower, toggling the air on and off starts and stops the flow. (3) A jet type pump constructed from a poppet valve, the poppet valve is a rod with a spherical end that moves in a translational fashion over a puddle of fluid, a carbide orifice below the puddle provides the path for a minute quantity of liquid to be expelled as the spherical end impacts the puddle. (4) A positive displacement type pump moves a column of liquid by displacement of a volume of fluid in the chamber equal to the quantity extruded through the exit port, the rate of flow through the exit port is a function of the speed the piston advances multiplied by the volume displaced. 
         [0008]    Pumps made for dispensing of viscous fluids by positive displacement require a provision in the design to accomplish the three distinct tasks to ready the pump for its intended function. The three machine states are prime, refill and dispense. 
         [0009]    The first state, prime, is performed apriori of dispensing the fluid. It is always required of this type of pump to fill the pump cavity with fluid that is free of air bubbles. Precision dispensing of fluid using the positive displacement technique is susceptible to error in the dispensed volume from air entrapped in the fluid. The problem has a negative impact on the pump repeatability due to the inherent compressibility of air in contrast to the relative incompressibility of most liquids. Two techniques commonly used to rid the pump of this nuisance variable are: Pushing the fluid through the cavity until all air is displaced and the entire volume is homogeneous with respect to fluid, the second is pulling the liquid through the cavity by use of vacuum to achieve the same. Both techniques require this task to be accomplished until all air is dispelled; usually this requires visual inspection of the fluid exiting the chamber via a clear tube. All pumps available for use in the semiconductor industry today discard primed fluid as waste; this practice is expensive due to the high cost of the fluid. Sensors or cameras can be used to detect the presence of oxygen or bubbles; it is possible to automate the process. 
         [0010]    The second state, refill, is accomplished immediately after priming the pump and after the fluid in the chamber is depleted at the conclusion of a dispense. Refill of the chamber occurs when the piston in the pump is retracted at the same rate as liquid from the fluid reservoir advances. Fluid from the reservoir is pushed forward by gravity, air pressure or mechanical means, simultaneously filling the cavity, preventing entrapment of air in the liquid. Cavitation occurs when a liquid contains air or other compressible gas as a result of not advancing to fill the volume as rapidly as the piston retracts. If this happens, the pump must be primed again or accuracy and repeatability of the volume dispensed will be poor. Solutions used in semiconductor applications are expensive and pumps with no capacity to reuse the fluid expelled from the prime state are costly to operate. 
         [0011]    The third state, dispense, occurs after the pump has been primed, refilled and the piston is at the top of the cylinder poised to push the column of fluid through the exit port. The exit port provides a mechanical connection for a nozzle or attachment of another passage for extrusion of the fluid. 
         [0012]    The current trend in the industry is to construct and design pumps of the positive displacement type using one piston for each fluid cavity. Pumps are generally mounted in the upright configuration; the chamber attitude is perpendicular to the surface of the earth. Some manufacturers employ the concept of dual chambers side by side with one piston per cavity. This method is used to mask refill time, one chamber can dispense while the other refills. 
       OBJECTS AND ADVANTAGES 
       [0013]    Accordingly, the design and the method of operation of a translational displacement pump have inherent objects and advantages that were not described earlier in my patent. Several additional objects and advantages of the present invention are:
       (1.) To provide a method of moving a liquid using the positive displacement principle wherein no valves or ancillary passages are necessary to change the state of the pump from the prime position, to the refill position, to the dispense position. The three different machine states occur in a single cylindrical chamber.   (2.) To provide a design for a pump which is capable of using liquid that is dispelled during the prime operation and reuse it to refill the pump chamber for a dispense cycle. This obsoletes any requirement for operator contact with the solution.   (3.) To provide a design for a pump that is capable of rotating the exit port around the piston to facilitate placing a fluid deposit at angles other than perpendicular with respect to the surface of the earth.   (4.) To provide a design for a pump that can be held close to the mounting platform of a robot and limit force acting on robot mechanics; to prevent a pendulum effect under high acceleration and deceleration. The chamber attitude is parallel to the surface of the earth.   (5.) To provide a design for a pump that has the capability to shut off the exit port from fluid flow without interfering with the dispense cycle.   (6.) To provide a design for a pump that has the capacity to increase flow-rate by an order of magnitude from the inherent design detail of dual pistons occupying the same cavity. Both pistons separated by a column of fluid can push from either end of the fluid column positioned over the exit port of the chamber.   (7.) To provide a pump design with a high degree of rigidity in comparison to existing industry designs through the absence of valves that contain seals or packing that must comply under pressure to stop leakage. The act of compliance changes chamber volume and increases error in the fluid deposit.   (8.) To provide a pump design with the ability to accept a variety of different size pistons and chamber sets. This tailors the dispensed quantity of liquid to the application, since positional error present in piston location can act over a smaller or larger cross sectional area, impacting the percentage of the error present in the volume of material deposited from variance in piston placement.   (9.) To provide a pump design with a fluid path that is as short as possible. The length of the exit port is equal to the thickness of the wall. The wall thickness is sized to resist the internal pressure that results from force exerted by piston advancement on the column of liquid without deflection as a result of hoop stress acting on the wall from pressure inside the chamber, plus the length of the detail required for connection of the nozzle.   (10.) To provide a pump design capable of refilling from a bulk fluid supply.   (11.) To provide a pump design that is able to transport a fluid between two ports by piston movement in opposite directions at the same rate. The right piston would move forward, the left piston would move backward, the column of liquid would occupy the volume between the two.   (12.) To provide a pump design that can switch reservoirs without stopping to change a reservoir that is depleted of fluid.   13.) To provide a pump design that has the ability to suck fluid back to alleviate excess fluid extrusion.   14.) To provide a pump design that can create vacuum by pulling back the piston, eliminating the use of air pressure to push fluid from the prime chamber, reservoir or bulk supply.   15.) To provide a pump design that has the capacity to support formulation of a compressibility offset for fluids like sealants and silicones that have a high degree of elasticity and move sluggishly until compressed slightly.       
 
       SUMMARY OF THE INVENTION 
       [0029]    The invention is a novel method of designing such a pump for delivering a measured quantity of viscous liquid or other liquids through a nozzle for deposit or connection to another passage for extrusion of the fluid. Fluid forced through the exit port of the pump enters a nozzle that directs it for deposit. A translational displacement pump comprises: 
         [0030]    A hollow cylindrical chamber with a series of ports through the wall perpendicular to the longitudinal axis, enabling connection of a prime chamber, reservoir, a bulk supply of fluid and a nozzle. Two smaller diameter cylindrical bodies are inserted from each end of the hollow cylindrical chamber; they are slightly smaller than the inside diameter, of the hollow cylindrical chamber. A thin ring of compliant material at the end of each smaller diameter cylindrical body seals against the high pressure created from extrusion of fluid out the exit port, through the nozzle onto the work. 
         [0031]    The conical shape of the interior of the thin ring of compliant material contains a concave cone made to an angle more obtuse than the angle of the cone and conjoined stem. Tensile force applied to the stem connected to the acutely angled cone that resides in the conical shape of the interior of the thin ring of compliant material energizes the compliant material, forcing the forward edge of the thin ring of compliant material outward, creating a surface capable of holding back high pressure. In operation, when pressure resulting from extrusion of the liquid through the nozzle builds, compressive force acts on the flat face of the end of the cone and conjoined stem, further forcing the forward edge of the thin ring of compliant material outward, enhancing seal effectiveness. Low pressure caused by the effect of gravity acting on the fluid in the reservoir is held back by the small difference in size between the small diameter cylindrical body and the hollow cylindrical chamber. 
         [0032]    In contrast to conventional positive displacement pumps used in the industry that use a valve or stopcock to switch between prime, refill and dispense, a translational displacement pump has no such device in the circuit to divert the flow of fluid; however, to accomplish the required machine states of prime, refill and dispense it is necessary to introduce a fourth state, translate. This state is necessary to divert flow before dispense of fluid through the exit port. 
         [0033]    When the pump is in operation, small diameter cylindrical bodies within the hollow cylindrical chamber move in concert with one another to expose or cover ports that form the passages for connection of the prime chamber, reservoir or a bulk supply of fluid for automated refill of the reservoir and a nozzle. The device moves both the small diameter cylindrical bodies at identical rates of speed in opposite directions to move the volume of liquid contained between them to the appropriate port to accomplish the intended function. To clarify the position of the left and right small diameter cylindrical bodies with respect to the ports, the rearward edge of the port is the side that uncovers the port; the forward edge is the side that covers the port. 
         [0034]    The first machine state, Prime, is achieved by movement of the right small diameter cylindrical body to a position within the hollow cylindrical chamber tangent to the rearward edge of the prime port, exposing the port. The left small diameter cylindrical body is moved to a position tangent to the rearward edge of the reservoir port, exposing the port. This exposes a path for fluid to flow between the two openings. The force required to move the liquid can be produced by a number of methods, air pressure acting on the area of the column of fluid contained in the reservoir can be applied to push the fluid, vacuum can be applied to the prime chamber to pull the liquid from the reservoir through the hollow cylindrical chamber into the prime chamber or movement of the two small diameter cylindrical bodies can be used to create a vacuum. This can be accomplished by movement of both small diameter cylindrical bodies to a position under the reservoir port, with ends touching each other that bisect the opening across its diameter. The left small diameter cylindrical body retracts to a position tangent to the rearward edge of the reservoir port and stops at that position, the right small diameter cylindrical body moves backward and parks tangent to the rearward edge of the prime chamber port. The left small diameter cylindrical body moves from the stationary position forward, closing the reservoir port, pushing the fluid column into the prime chamber and comes to rest against the right small diameter cylindrical body. The right small diameter cylindrical body moves forward and the left small diameter cylindrical body moves backward with ends touching each other, bisecting the reservoir opening across its diameter to repeat the process, if required to expel air entrapped in the fluid. 
         [0035]    The second machine state, Refill, is achieved by positioning the left small diameter cylindrical body at the forward edge of the reservoir port, the right small diameter cylindrical body resides in the same location with the ends of the thin ring of compliant material in contact with each other. 
         [0036]    The right small diameter cylindrical body remains stationary while the left small diameter cylindrical body moves backward creating a negative pressure, allowing fluid from the reservoir to advance to fill the increasing volume formed by the retreat of the left small diameter cylindrical body. Retreat of the left small diameter cylindrical body is halted once a position tangent to the forward edge of the exit port is reached. 
         [0037]    The third machine state, Translate, occurs after Refill or when movement of fluid is desired without displacement or extrusion. The Translate state is a function of the specific application of the pump. The right small diameter cylindrical body advances while the left small diameter cylindrical body retreats, the volume of fluid flanked by the two cylindrical bodies is moved; therefore, in this machine state the velocity of advance of the right small diameter cylindrical body is equal to the retreat of the left small diameter cylindrical body. 
         [0038]    The fourth machine state, Dispense, requires the left small diameter cylindrical body be positioned at the rearward edge of the exit port. The right small diameter cylindrical body is separated from the left small diameter cylindrical body by the volume of fluid. Advance of the right small diameter cylindrical body toward the left small diameter cylindrical body causes pressure inside the hollow cylindrical chamber to build and the fluid is displaced through the exit port and out the nozzle for deposit on the work. Alternately, the column of liquid can also be positioned in the center of the exit port and left and right small diameter cylindrical bodies can advance toward each other extruding the fluid out the exit port at a rate of flow equal to twice the rate possible from the advance of one small diameter cylindrical body. 
         [0039]    Ordinarily, width of the fluid deposit is a function of the nozzle diameter selected, the flow rate through the pump and the velocity the pump is moved over the work; however, the translational displacement pump can rotate the exit port to which the nozzle is attached to angles other than 90° with respect to the surface of the earth. This attribute enables further control of line width by virtue of the following relation: √Ø Inside Nozzle   2 −Z 2 =X Approximate Line Width Effect The X Approximate Line Width Effect  requires application of fluid along the positive or negative Y axis, convention for axis orientation is established according to the, “right-hand rule”. No X Approximate Line Width Effect  is observed as a result of the nozzle angle if the fluid dispensed by the pump is oriented in a direction parallel to the angle, the pump must dispense fluid perpendicular to the angle of the nozzle for the angle to have an effect on the width of the line. Rotation of the exit port is also useful to move the nozzle out of the way to clear components to move the pump to a different dispense location and aid in fluid break off without a change in Z-axis height. 
         [0040]    Additionally, the design of the translational displacement pump lends itself to replenishment of the onboard fluid reservoir by mating to a bulk supply of fluid. The addition of a bulk supply port allows the pump to position the small diameter cylindrical bodies tangent to the bulk feed supply port. The right small diameter cylindrical body remains tangent to the rearward edge of the bulk feed supply port, exposing the port and the left small diameter cylindrical body retreats to the rearward edge of the onboard fluid reservoir port exposing the port. Providing the path for fluid to flow from the bulk fluid supply to refill the onboard fluid reservoir. The prime operation in this configuration is accomplished using the bulk fluid supply port for connection to a prime chamber to act as the repository for expulsion of fluid in the prime state. 
         [0041]    These and other objects of the invention will become clearer when one reads the following specification, taken together with the drawings that are attached hereto. The scope of protection sought by the inventor may be gleaned from a fair reading of the Claims that conclude this specification. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
       Figures 
         [0042]    Turning now to the drawings wherein elements are identified by numbers and like elements are identified by like numbers throughout the seven figures, the prior art is depicted in  FIG. 1 . 
           [0043]      FIG. 2  is an illustrative view of first machine state of operation, “Prime”, this state is also identical to the process of re-supply of the on board fluid reservoir from a bulk supply of liquid; 
           [0044]      FIG. 3  is an illustrative view of the second machine state of operation, “Refill”; 
           [0045]      FIG. 4  is an illustrative view of the third machine state, “Translate”; 
           [0046]      FIG. 5  is an illustrative view of the fourth machine state, “Dispense”. 
           [0047]      FIG. 6  is an illustrative view of the basic Translational Displacement Pump components. 
           [0048]      FIG. 7  is an illustrative view of the basic Bulk Fluid Reservoir and Prime Chamber assembly. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0049]    Referring now to the drawings wherein the showings are for the purpose of illustrating preferred embodiments of the invention only and not for the purpose of limiting it.  FIG. 1  Prior Art positive displacement pump is an automated device that moves fluid by filling a cavity with fluid and extruding the fluid through displacement of volume by a cylinder that is pushed into the fluid filled cavity. A seal around the cylinder prevents fluid leakage upward so as to direct fluid downward out the end of the cavity. Fluid is directed through a disposable polycarbonate medical stopcock to a nozzle for deposit onto the work. The stopcock is an essential component of the device. It is used to switch between refill of the chamber and extrusion of fluid out of the cavity. The pump is primed by retracting the cylinder to a position above the seal to enable fluid to flow from an on board reservoir through the stopcock up the chamber and out the pump for the purpose of ejecting air bubbles and air pockets that can be present when fluid first fills the pump cavity. The pump uses a rotary encoder to determine speed and relative position; photoelectric switches and flags are used to determine absolute position limits. A pneumatic actuator toggles the stopcock between refilling of the pump cavity and dispensing fluid. A Hall effect sensor and two magnets indicate stopcock position. The pump is sensitive to over pressurization of the stopcock at high rates of flow. Constrictive nozzle designs, a long fluid path combined with high viscosity liquids cause high pressures, when this occurs the pump leaks fluid from around the rotary seal of the stopcock. Lack of a linear encoder means all measures of cylinder position are estimated and are not an absolute measure of position. 
         [0050]    The invention is a novel design for a Translational Displacement Pump. The inventive Translational Displacement Pump is depicted in  FIG. 2 , in a horizontal attitude, as it would be used in service in the industry. The sequence of steps or “machine states” is a key aspect to novel operation of the device. To accurately show the sequence of moves,  FIGS. 2 ,  3 ,  4 ,  5  are displayed as cut away views of the device. It is preferred the pump be made from a hollow cylindrical chamber  1  with a series of holes through the wall perpendicular to the longitudinal axis enabling connection of a prime chamber, a reservoir, a bulk supply of fluid and a exit port  4  for attachment of a nozzle to dispense the liquid onto the work. Two smaller diameter cylindrical bodies  5  are inserted from each end of the hollow cylindrical chamber  1 , they are slightly smaller than the inside diameter of the hollow cylindrical chamber  1 . A thin ring of compliant material  8  at the end of each smaller diameter cylindrical body  5  seals against the high pressure created from extrusion of fluid out the exit port  4 , through the nozzle onto the work. It is energized by application of tensile force through the conical cone and conjoined stem  7 , this provides a means for connection of the thin ring of compliant material  8  to the end of the smaller diameter cylindrical bodies  5  and moves the mechanism for application of tension to force the forward edge of the thin ring of compliant material  8  outward against the walls of the hollow cylindrical chamber  1  from the wetted path. The position of the two smaller diameter cylindrical bodies  5  provide the means to shut off or block the flow of liquid from the reservoir port  2  and prime or bulk feed port  3 . 
         [0051]    To clarify the position of the left and right small diameter cylindrical bodies  5  with respect to the ports, the rearward edge of the port is the side that uncovers the port; the forward edge is the side that covers the port. 
         [0052]      FIG. 2  is a cutaway view of the Translational Displacement Pump in the first machine state “Prime”. It illustrates the position of the two smaller diameter cylindrical bodies  5 . The left smaller diameter cylindrical body  5  is tangent to the rearward edge of reservoir port  2 , the smaller diameter cylindrical body  5  on the right side maintains a position tangent to the rearward edge of the prime or bulk feed port  3 . This opens a path for fluid to flow between the two openings. If the pump reservoir is full of liquid the first machine state that must be performed is “Prime”, fluid flows from the reservoir port  2  into the space between the two smaller diameter cylindrical bodies  5  then out the prime or bulk feed port  3 . When all air has been expelled from the fluid entering the space, the smaller diameter cylindrical body on the right moves to the forward edge of the prime or bulk feed port  3  shutting off the port. 
         [0053]    If the on board reservoir is depleted of fluid, the smaller diameter cylindrical bodies  5  in the pump return to the position illustrated in  FIG. 2 . In this situation, fluid can be pushed through the bulk feed port  3 , through the path in the hollow cylindrical chamber  1 , through the reservoir port  2  and into the empty reservoir chamber connected to the reservoir port  2 . Alternately, the same process could occur with the exception that fluid is pulled through by a source of vacuum connected to the reservoir chamber. In cases where air pressure or vacuum is not available, the smaller diameter cylindrical body  5  tangent to right side or rearward edge of the bulk feed port  3  would remain in the same position as in  FIG. 2  but the smaller diameter cylindrical body  5  on the left would change position, the edge of the thin ring of compliant material  8  on each smaller diameter cylindrical body  5  touching, the left smaller diameter cylindrical body  5  moves backward creating the vacuum necessary to draw the fluid from a bulk supply into the expanding volume contained within the hollow cylindrical chamber  1 . The left smaller diameter cylindrical body  5  stops tangent to the right side or forward edge of the reservoir port, then both left and right smaller diameter cylindrical bodies  5  move, the right one forward shutting off the bulk feed port  3 , the left one stops at the opposite tangent edge or rearward edge of the reservoir port  2 , exposing the passage. The right smaller diameter cylindrical body advances toward the now stationary left smaller diameter cylindrical body  5 , extruding the fluid contained between the two smaller diameter cylindrical bodies  5  into the reservoir. Once fluid has been displaced into the reservoir, the two smaller diameter cylindrical bodies  5  move to the bulk feed port  3 , the right one retracts, the left one advances. The right smaller diameter cylindrical body  5  stops at a position tangent to the rearward edge of the bulk feed port  3 , the left smaller diameter cylindrical body  5  continues to move forward until the thin ring of compliant material  8  on each smaller diameter cylindrical body  5  touches at the rearward edge of the bulk feed port  3 . This sequence of movements occurs until the on board reservoir is refilled. 
         [0054]      FIG. 3  is a cut away view of the Translational Displacement pump in the “Refill” state. It illustrates the position of the smaller diameter cylindrical bodies  5  in the machine state of replenishing the hollow cylindrical chamber  1  with liquid. The right smaller diameter cylindrical body  5  is stationary at a position tangent to the rearward edge of the reservoir port  2 . In this position the right smaller diameter cylindrical body  5  shuts off the prime or bulk feed port  3 . The left smaller diameter cylindrical body  5  retracts; the vacuum produced pulls fluid through the reservoir port  2  and fills the space between the two thin rings of compliant material  8 . The left smaller diameter cylindrical body  5  stops before reaching the forward edge of exit port  4 ; the remaining distance must be equal to the diameter of reservoir port  2  to allow for shutoff of the port in the next state. 
         [0055]      FIG. 4  is a cut away view of the Translational Displacement Pump in the “Translate” state. At the conclusion of the “Refill” state the right smaller diameter cylindrical body  5  moves simultaneously with the left smaller diameter cylindrical body  5 , the right moves forward as the left retreats closing the reservoir port  2 . Since both smaller diameter cylindrical bodies  5  move in unison no force is exerted across the area of the fluid column; therefore, there is no increase in pressure, the volume of liquid is simply moved in a linear fashion along the bore of the hollow cylindrical chamber  1 . The machine state, “Translate”, concludes when the volume of fluid is positioned over the exit port. This can occur two ways: The fluid volume between the two thin rings of compliant material  8  connected to the ends of the smaller diameter cylindrical bodies  5  can be moved to a position that straddles the exit port  4 , or the left thin ring of compliant material  8  connected to the left smaller diameter cylindrical body  5  can park in a position tangent to the rearward edge of the exit port. 
         [0056]    Some liquids like sealants and silicones exhibit a degree of compressibility, it is desirable when pumping fluids with these attributes to determine the compressibility offset. This is useful because pressure must be exerted on the fluid to compress it before it actually moves. In these instances the illustration in  FIG. 4  can be used to demonstrate not only translation but also force versus smaller diameter cylindrical body  5  position to determine an offset. To accomplish this task, instead of translating the liquid column, the smaller diameter cylindrical bodies  5  would move toward each other against the fluid column at a point in the hollow cylindrical chamber  1  without access to any port, but a pressure sensor would need to be installed at the location. The offset would be a function of volume compressed and pressure. 
         [0057]      FIG. 5  is a cut away view of the Translational Displacement Pump in the “Dispense” state. End of the “Translate” state readies the pump for extrusion of fluid contained between the two thin rings of compliant material  8 . The fluid column can be positioned as illustrated in  FIG. 5  with the left smaller diameter cylindrical body  5  stationary at a position with the thin ring of compliant material  8  tangent to the rearward edge of the exit port  4  or the fluid column can straddle the exit port. In the first scenario the right smaller diameter cylindrical body  5  moves toward the stationary smaller diameter cylindrical body  5 , the force exerted on the area of the cross section of the fluid column creating the pressure required to move the fluid out the exit port  4  through a nozzle and onto the work. The second scenario places the column of fluid in a position so the center of the column is in line with the exit port  4 ; each smaller diameter cylindrical body  5  advances toward each other, pushing against the fluid column from both ends. This aspect of the invention is useful to enable the pump to achieve high rates of flow from high viscosity fluids; pressure requirements increase in this situation, demanding more force exerted across the area of the fluid column. To produce the force, more torque is necessary. A low gear ratio is desirable; however, as torque is increased the velocity of advancement of the smaller diameter cylindrical bodies  5  is decreased. Since both smaller diameter cylindrical bodies  5  can move toward each other the relative velocity of extrusion with respect to the fluid out the exit port  4  is doubled. 
         [0058]      FIG. 6  is an exploded view illustration of the basic components in the novel Translational Displacement Pump. The illustration shows the basic components required to construct the pump. The hollow cylindrical chamber  1  provides the structure for the smaller diameter cylindrical bodies  5  to move within. The smaller diameter cylindrical bodies  5  move the thin ring of compliant material  8  and the cone with conjoined stem  7  hold the thin ring of compliant material  8  to the end of the smaller diameter cylindrical bodies  5 . Application of tension to the stem of the cone and conjoined stem  7  forces the forward edge of the thin ring of compliant material  8  outward radially against the walls of the hollow cylindrical chamber  1 . The flat face of the cone and conjoined stem  7  is recessed slightly below the forward edge of the thin ring of compliant material  8  once tension is applied to the stem of the cone  7 . This occurs because the forward edge of the more acute angle of the cone and conjoined stem  7  acts  12  to deflect the forward edge of the more obtuse interior angle of the thin ring of compliant material  8  outward symmetrically around it&#39;s perimeter. Removal of the mechanism to energize the thin ring of compliant material  8  through tensile force acting on the cone and conjoined stem  7  from the wetted path of the pump allows the thin ring of compliant material  8  to be made more economically and more useful in the relevant industry. The thin ring of compliant material  8  and the O-rings  6  used for secondary containment of fluid are consumable components of the pump; the thin ring of compliant material  8  is subject to wear from abrasion as a result of contact with the walls of the hollow cylindrical chamber  1  and the abrasiveness of the fluid used; the o-rings  6  are subject to wear by abrasion from movement of the small diameter cylindrical bodies  5 . 
         [0059]      FIG. 7  is a cut away view of an alternative embodiment of the Translational Displacement Pump in the “Refill” state. The illustration shows another method of combining the basic components required to construct the pump. The hollow cylindrical chamber  1  provides the structure for the smaller diameter cylindrical bodies  5  to move within. The smaller diameter cylindrical bodies  5  are smooth with a small chamfer or radius around the perimeter of the closed oblate ends. O-rings  6  adjacent to the perimeter of reservoir port  2 , the pump bulk feed port  3  and the exit port  4  provide the means to seal the ports as the pump moves fluid through various machine states. 
         [0060]      FIG. 8  is a cut away view of an alternative embodiment of the Translational Displacement Pump in the “Refill” state. The illustration shows another method of combining the basic components required to construct the pump for use with low viscosity fluids at low pressures. The hollow cylindrical chamber  1  provides the structure for the smaller diameter cylindrical bodies  5  to move within. Only the reservoir port  2  and exit port  4  are required in this embodiment. The smaller diameter cylindrical bodies  5  are constructed from an elastomer, the elastomer complies radially to provide the means to seal the stepped interior bore around reservoir port  2  and exit port  4  as the pump moves fluid through various machine states. The smaller diameter cylindrical bodies  5  only contact the interior bore at the two discrete locations, reservoir port  2  and exit port  4 . 
         [0061]      FIG. 9  is an illustration of the off board prime chamber  10  for capture of the fluid expelled during the prime cycle and the bulk fluid chamber  9  used for re-supply of the on board reservoir chamber. A robot is generally employed to move the pump to the desired location for deposit of fluid onto the work. The pump is moved by the robot and connects to these components when required by the machine state. A means for opening or closing the access port  15  to the prime chamber  10  or bulk fluid supply chamber  9  is employed at the point of connection to the pump  14 . Pot life is defined as the amount of time necessary for thermo set materials to double their viscosity. A means for heating or cooling the bulk fluid supply chamber  9  is useful. Fluid is stored in the frozen state to retard the propensity of thermo set fluids to cross-link and harden and can be thawed gradually to make them available to the pump on demand and then kept at a temperature below ambient to maximize pot life. A source of vacuum or negative pressure is connected to the vacuum port  13  and is useful to transfer fluid expelled during the prime state into the prime chamber  10  back to the bulk fluid supply chamber  9  for reuse. The prime chamber  10  is connected to the bulk fluid re-supply chamber  9  by the fluid transfer port  11 . Pressure applied to the bulk fluid chamber port  13  can be used to speed re-supply. 
         [0062]    While the invention has been described with reference to a particular embodiment thereof, those skilled in the art will be able to make various modifications to the described embodiment of the invention without departing from the true spirit and scope thereof. It is intended that all combinations of elements and steps, which perform substantially the same function in substantially the same way to achieve substantially the same result, be within the scope of this invention.