Apparatus for transferring metered quantities of material from one location to another

Apparatus is provided for moving controlled quantities of a material from one location to another and increasing the pressure thereof. The apparatus includes at least two cylinders having rams reciprocable therein. The rams are driven by a rocker arm which is pivotally connected to outer ends of both rams and is pivotally supported at a position therebetween. The arm is driven through a fluid-operated cylinder having a piston rod connected to one end of the arm, thereby reciprocating the rams in opposite directions. The ram cylinders have inlets connected to a source of the material under low positive pressure with a ball check valve located between the source and each inlet. Outlets of these cylinders are connected to a common outlet with a ball check valve also located between the common outlet and each cylinder outlet. The valves are arranged so that the inlet check valves and the outlet check valves operate in opposing relationship to provide positive opening and closing action and a precise flow of material. An adjustable back-pressure valve places back pressure on the material at the outlet with the pressure exceeding the pressure of the material at the source.

This invention relates to apparatus for pumping metered quantities of 
materials from one location to another while raising the pressure thereof. 
While the apparatus according to the invention is particularly advantageous 
for moving precise quantities of highly viscous materials, it is also 
effective for low viscosity materials, as long as the outlet pressure 
exceeds the inlet pressure. The apparatus employs substantially 
maintenance-free, self-cleaning check valves and only two seals, one for 
each of two cylinders, are required for the overall system. The apparatus 
can also pump two or more materials in a precise volumetric ratio. 
More specifically, the apparatus according to the invention includes at 
least one pair of cylinders in which rams are located, with drive means 
for reciprocating the rams in opposite directions in the cylinders. A 
source of material under low pressure communicates with inlets at the 
blind ends of the cylinders through inlet lines, each of which has a ball 
check valve for enabling the flow of the material only toward the 
respective cylinder. A common outlet line communicates with outlets at the 
opposite ends of the cylinders through outlet lines, each of which also 
has a ball check valve enabling flow of the material only away from the 
respective cylinder. The ball check valves are arranged so as to be power 
operated, in effect, by the inlet and outlet pressures, as will be 
discussed subsequently in detail. The valves also act with a quick, 
positive action to provide accurate quantities of the material through 
each of the cylinders. 
The rams of the cylinders are reciprocated in opposite directions by means 
of a rocker arm which is pivotally connected to the rams and is pivotally 
supported at a point therebetween. The rocker arm can be oscillated or 
rocked through a fluid-operated cylinder which is connected to an outer 
end of the rocker arm and suitably powered by a source of fluid under 
pressure. In a preferred form, the pivotal engagement of the rocker arm 
with the rams can be changed relative to the pivotal support, thereby 
changing the length of stroke of the rams and, consequently, the 
quantities of material being pumped. If desired, a second material can be 
pumped through a second pair of cylinders and rams which are also mounted 
on the rocker arm in predetermined positions relative to the pivot support 
and to the pivotal engagements with the first rams. A precise ratio of the 
second material to the first one can then be achieved and maintained. Of 
course, more than two pairs of cylinders and rams can be employed if the 
need arises for additional material. 
The common outlet line for each pair of cylinders has an adjustable 
back-pressure valve by means of which the back pressure of the metered 
material can be controlled. Particularly when two or more materials are 
metered by two or more pairs of cylinders, the materials are combined at a 
receiver, such as a mixing head. Adjustable back-pressure valves are then 
located in the outlet lines for the materials near the mixing head. In 
this instance, recirculating lines are provided to recirculate each 
material back to its source from its outlet line when the mixed materials 
are not being dispensed from the mixing head. Each recirculating line then 
has an adjustable back-pressure valve to maintain the same pressure on the 
material at the outlet line whether it is being directed to the mixing 
head or being recirculated. 
It is, therefore, a principal object of the invention to provide apparatus 
for moving precise quantities of material from one location to another and 
for raising the pressure thereof. 
Another object of the invention is to provide apparatus for metering 
materials, which apparatus includes adjustable back-pressure valve means 
for controlling the pressure of the metered material. 
Yet another object of the invention is to provide an improved valve system 
for metering material by the use of cylinders and rams.

The apparatus according to the invention is particularly designed to pump 
and meter highly viscous materials, such as viscous resins that are also 
heavily loaded with fillers, such as calcium carbonate, aluminum hydrate, 
or glass-reinforcing fibers. Further, the apparatus requires minimal 
maintenance. Only two seals which are subject to wear are employed for the 
overall system and the flow of the viscous material through the system is 
designed to render the system substantially self-cleaning. Consequently, 
frequent repairs and cleaning are not necessary. 
Referring to FIG. 1, apparatus according to the invention includes two 
cylinders 12 and 14 in which are reciprocated rams 16 and 18. The rams are 
preferably reciprocated in the cylinders by a lever or rocker arm 20 which 
is centrally pivotally supported by a pin 22 at equal distances from the 
rams. Consequently, the rams 16 and 18 reciprocate through equal strokes 
in opposite directions. 
The cylinders 12 and 14 have inlets 24 and 26 at the blind ends thereof. 
These inlets are connected by inlet lines 28 and 30 and a common inlet 
supply line 32 to a suitable source 34 of a material to be transferred and 
metered. The material of the source 34 is maintained under low pressure. 
In this instance, the pressure is achieved by virtue of the supply source 
34 being positioned above the cylinders 12 and 14. Otherwise, the material 
can be maintained in a closed supply container under pressure or can be 
pumped at lower pressure through the inlet supply line 32 to the supply 
lines 28 and 30. The inlet lines 28 and 30 contain ball check valves 36 
and 38, each of which includes a ball 40 and a seat 42, to permit flow 
only toward the cylinders. The balls can be spring loaded, if desired, 
although this is not necessary. 
The cylinders 12 and 14 also have outlets 44 and 46 to which outlet lines 
48 and 40 are connected. The outlet lines 48 and 50 communicate with a 
common outlet line 52 which can direct the metered, higher pressure 
material to any suitable location. Ball check valves 54 and 56 are located 
in the outlet lines 48 and 50 to direct the material in the lines 48 and 
50 only away from the cylinders 12 and 14. Each of the ball check valves 
54 and 56 has a ball 58 and a seat 60. 
The pressure of the material in the outlet line 52 must exceed that in the 
inlet supply line 32 or the flow of the material through the cylinders 12 
and 14 will be inaccurate and, in fact, flow through the cylinders can 
occur without reciprocation of the rams 16 and 18 at all. In some 
instances, to assure sufficient pressure in the outlet line 52 and the 
lines 48 and 50, an adjustable back-pressure valve 62 is provided in the 
outlet line 52. 
The operation of the systems of FIG. 1 will now be discussed in more 
detail. Assuming that the ram 16 is moving upwardly, as indicated by the 
arrow, the viscous material will be drawn through the inlet line 28 past 
the check valve 36 from the source 34. During this movement, the pressure 
in the outlet line 30 for the cylinder 14 will tend to be lowered and, 
therefore, the check valve 38 will tend to be urged even more completely 
closed. At the same time, the ram 18 is moving downwardly, as indicated by 
the arrow, to force the material out of the cylinder 14 and past the check 
valve 56. This material will flow through the outlet line 50 and, since 
this communicates with the outlet line 48, the pressure therein will 
increase to tend to more completely close the check valve 54 for the 
outlet of the cylinder 12. 
From the above, it will be seen that the check valves are powered, in 
effect, by virtue of the pressures in the system. This assures accurate 
and precise opening and closing of the check valves to aid in assuring 
that precise, metered quantities of the materials will be moved to the 
common outlet line 52 from the source 34. The precision of the metering 
rams is enhanced due to the quick, positive action of the check valves at 
the precise time of cycle reversal. This is particularly important when 
viscous resins with high loadings of abrasive fillers are being pumped 
since quick and responsive valve action is particularly needed in those 
instances. By using this pressure to power operate the check valves, 
separate power arrangements, such as involving separate air, oil, or 
mechanically-powered valves with the necessary circuitry, can be 
eliminated completely. The simplified piping involved also eliminates 
additional heat loads that may otherwise be incurred with alternate 
powered valve systems. With the viscous materials in particular, heat 
generation should be kept to a minimum in order to extend the life of the 
seals employed and to prevent premature catalytic reaction when materials 
subject to such are being pumped. 
The adjustable back-pressure valve 62 is shown in more detail in FIG. 2. 
The valve includes a housing 64 forming an inner chamber 66 communicating 
with the outlet line 52 and an additional outlet line 68. One end of the 
chamber is closed off by a plug 70 and the other end of the chamber, 
communicating with the line 52, has a seat 72 formed by the housing 64. A 
valve ball 74 is urged against the seat 72 by a spring retainer 76 and a 
spring 78. The other end of the spring 78 seats against a disc retainer 80 
connected to a threaded shank 82. The shank 82 extends through a threaded 
passage 84 in the plug 70, terminating outside of the plug in an adjusting 
knob 86, and a lock nut 88 holds the threaded shank 82 in a desired 
position. 
When the knob 86 is turned to move the shank 82 toward the chamber 66, the 
compressive force on the spring 78 is increased to increase the pressure 
of the ball 74 against the seat 72. Thus, more pressure of the metered 
material in the common outlet line 52 is required to unseat the ball so 
that the back pressure on the metered material is accordingly higher. 
Turning the knob 86 in the opposite direction produces the opposite effect 
on the back pressure of the metered material. As discussed previously, it 
is important that the back pressure of the metered material in the outlet 
line always exceeds the positive pressure of the material at the source 
34. 
A specific application for the transfer metering system or apparatus 
embodying the invention is shown in FIG. 3, by way of further 
illustration. In this instance, two additional cylinders 90 and 92 and two 
additional rams 94 and 96 are employed. As shown, the additional cylinders 
and rams are located closer to the pivot point 22 and are also smaller 
diameter than the cylinders 12 and 14. With the resulting shorter storkes 
for the rams 94 and 96 and the smaller diameters for the cylinders 90 and 
92 and the rams 94 and 96, the output thereof can be substantially less 
than the output of the cylinders 12 and 14 and the rams 16 and 18. With 
this arrangement, it is possible to obtain precise and very high ratios of 
the materials moved by the two systems, in the order of 100 to 1 by way of 
example. Further, high viscosity materials and low viscosity ones can be 
handled by the same system. Also, when higher outputs are desired, all 
four of the cylinders can handle the same material. Of course, it will be 
readily understood that even more than two pair of the cylinders and rams 
can be employed if desired, such as if coloring is to be added to the 
first two materials, for example. 
In this instance, the metered materials from the two pairs of cylinders are 
supplied through the outlet line 52 and an additional outlet line 98 to a 
mixing head indicated at 100. This mixing head can be of the type shown in 
my U.S. Pat. No. 3,920,223, issued on Nov. 18, 1975. Particularly for 
highly-filled resins, the recirculation shown in that patent is preferably 
eliminated and back-pressure valves indicated at 102 are employed at the 
inlet ports of the mixing head. The back pressure valves 102 are 
preferably adjusted so that the pressures of the metered materials 
entering the mixing head 100 are equal when viscosities are similar. When 
the materials have different viscosities, the one at higher viscosity is 
maintained under higher pressure. After the metered materials are mixed 
within the mixing head, the combined material can be supplied through two 
outlets 104 and 106 to points of use. 
When the combined material is not being dispensed by the mixing head 100, 
the metered materials are recirculated back to the source 34 for the 
cylinders 12 and 14 and a source 108 for the cylinders 90 and 92. This is 
accomplished through recirculating outlet lines 110 and 112 communicating 
with the outlet lines 52 and 98 through three-way walves 114 and 116. 
The outlet lines 110 and 112 have the adjustable back pressure valves 62 
therein, preferably near the sources 34 and 108 so that back pressure is 
always maintained in the lines 110 and 112. Similarly, back pressure is 
always maintained in the lines 52 and 98 due to the fact that the 
adjustable back pressure valves 102 are located at the entrances to the 
mixing head 100. This is an important feature in that it always enables 
immediate accurate dispensing to be achieved when the valves 114 and 116 
are turned to supply the metered materials through the lines 52 and 98. 
The back-pressure valves 62 are also adjusted so that the back pressure in 
the recirculating outlet lines 110 and 112 is equal to the pressure of the 
metered material in the outlet lines 52 and 98. This assures that the 
accurate ratio between the two materials will be maintained constant 
whether the valves 114 and 116 are turned to move the metered materials 
through the lines 52 and 98 or through the recirculating lines 110 and 
112. 
One of the valves 102 is shown in more detail in FIG. 4. The valve includes 
a housing 118 forming a chamber 120 communicating with the outlet line 52 
or 98 and with an entrance opening 122 of the mixing head 100. A plug 124 
closes one end of the chamber 120 and the other end has a seat 126 formed 
by the housing 118. A ball or semi-spherical surface 128 at the end of a 
valve stem 130 bears against the seat 126 when a spring 132 urges the stem 
130 toward the left, as shown in FIG. 4. The spring 132 seats against a 
seal 134 at the plug 124 and the opposite end of the spring seats against 
an adjusting nut 136 and a lock nut 138 mounted on a threaded end 140 of 
the stem 130. A suitable cover 142 can be provided for the spring, if 
desired. When the nuts 136 and 138 are turned further onto the stem 130, 
the tension on the spring 132 is increased to urge the surface 128 harder 
against the seat 126. The back pressure in the line 52 or 98 thus 
increases. The opposite occurs when the nuts are turned in the opposite 
direction. 
Various modifications of the above-described embodiments of the invention 
will be apparent to those skilled in the art and it is to be understood 
that such modifications can be made without departing from the scope of 
the invention, if they are within the spirit and the tenor of the 
accompanying claims.