Method and apparatus for filling containers

An apparatus for filling containers including a pump housing having a pump chamber, a product inlet in communication with a supply of product under pressure, a product outlet and a piston positioned therein. The piston is movable by the supply of product under pressure between advancing and retracting positions where product is discharged from the chamber and through the outlet during the advancing stroke and the chamber is filled with product during the retracting stroke. A first valve is included to regulate the flow of product through the outlet and a second valve is included to regulate the flow of product between opposite sides of the piston. By controlling the opening and closing of the first and second valves, the pressure of the product enables movement of the piston to eject product and fill the chamber as desired.

FIELD OF THE INVENTION 
The present invention relates generally to a method and apparatus for 
continuously and sequentially filling containers with a product, and more 
particularly to such a method and apparatus that utilizes pressure from 
the flow of a product, such as a food product, to consistently fill the 
containers with a precise amount of product. 
BACKGROUND OF THE INVENTION 
Food products that are substantially flowable, such as margarine, butter, 
sour cream, ice cream, yogurt or the like, typically are packaged in 
individual containers for retail sale and consumer use. Packaging of these 
types of food products is ordinarily effected with the use of fill pump 
devices and associated container conveyors that present containers in a 
continuous, sequential manner to the filling device which is operated to 
dispense food product to each of the containers. 
In such systems, precise control of the filling device is necessary in 
order to assure that each container receives the desired quantity of 
product. In practice, such precision can be difficult to achieve due to 
inherent fluctuations in product consistency and temperature as well as 
the periodic start-up and shut-down of a filling line which typically 
complicates accurate filling of the containers. 
Existing systems typically are either pneumatically controlled or 
cam-operated. Pneumatically controlled systems typically include 
pneumatically actuated pumping devices including a piston for dispensing 
the food product into the associated containers when the piston is 
advanced during a container-filling stroke. Pneumatic systems, however, 
are affected by inevitable fluctuations in air supply pressure, the 
limited service life of the pneumatic cylinders and the attendant problems 
of maintaining the various seals and like components of the system. 
Cam-operated filling systems can provide enhanced product weight control as 
well as consistent, dependable operation of the pump device, which can be 
operated independently of or mechanically linked to the container 
conveyor. However, cam-operated systems cannot always deliver the desired 
pump piston velocity during initial start-up of the filling line, which 
can sometimes affect the appearance of the food product with which the 
containers are being filled. Additionally, such systems require the 
provision of cams, linkages, etc. necessary to effect pump operation. 
It therefore would be desirable to provide a product filling method and 
apparatus which operates independently of the container conveyor and 
permits versatile, dependable operation of a filling system while 
maintaining the appropriate product weight and appearance under a wide 
variety of operating conditions. It would also be desirable to provide a 
system which minimizes product seals, operating linkages, and like 
components for reduced cost and enhanced reliability. 
SUMMARY OF THE INVENTION 
An apparatus for filling containers embodying the principles of the present 
invention has been particularly configured for improved operation and 
cleaning by providing an arrangement whereby the pressure of product being 
supplied to the apparatus effects its drive and operation. Not only does 
this obviate the need for an associated cam or pneumatic drive system, the 
apparatus is desirably configured to facilitate cleaning without 
substantial disassembly of the apparatus. 
In accordance with the illustrated embodiment, the present apparatus 
includes a pump housing having a pump chamber therein. The housing 
includes a product inlet adapted to transfer food product under pressure 
from an associated supply of food product to the chamber, and a first 
product outlet adapted to deliver product to each container. 
A piston is reciprocally movable in the pump chamber under the influence of 
the pressurized product. The product under pressure moves the piston 
between a first, retracted upper position and a second, advanced lower 
position within the chamber to provide advancing and retracting strokes 
during each pumping cycle. During the piston advancing stroke, product 
within a portion of the chamber, in front of the piston, is dispensed 
through the first product outlet, while a portion of the chamber on the 
rear side of the piston is simultaneously filled with new product as the 
pressurized product advances the piston. 
During the piston retracting stroke, the portions of the pump chamber on 
opposite sides of the piston are joined in fluid communication, and 
product within the chamber portion on the rear side of the piston is 
transferred to the front side of the piston to be dispensed during the 
subsequent piston advancing stroke. The transferring of the product from 
the front side to the rear side of the piston itself provides for return 
movement of the piston within the chamber from the second position back to 
the first position. 
To provide for the flow of the product into and out of the pump chamber, a 
first outlet valve member is provided to selectively open and close the 
first product outlet and regulate the flow of product therethrough. One or 
more selectively openable second valve members also are provided to 
selectively join opposite sides of the piston in communication and thereby 
enable the flow of product between opposite sides of the piston. By 
regulating the opening and closing of the first and second valve members, 
the product flow between the opposite sides of the piston is provided 
thereby advancing and retracting the piston. 
To provide the piston advancing stroke, the first outlet valve is opened 
while the second valve or valves are closed. Product under pressure then 
is introduced from the inlet into a first portion of the pump chamber to 
the first rear side of the piston which enables advancing of the piston 
between the first upper position to the second lower position while 
ejecting product on the front side of the piston through the outlet. 
To provide the piston retracting stroke, the first outlet valve member is 
closed while the second valve or valves are opened to permit product to 
flow to the front side of the piston. The pressure supplied by the product 
inlet contacts the larger surface area of the front side of the piston to 
propel the piston from the second position to the first position. 
Accordingly, the pressure of the product itself provides both the 
advancing and retracting strokes of the piston. 
In a preferred embodiment of the invention the piston includes a piston 
head having one or more product flow channels extending therethrough 
interconnecting opposite sides of the piston head. The second valves are 
respectively positioned within the product flow channels and can be 
activated from the exterior of the apparatus to open and close the product 
flow channels as desired. 
In another embodiment of the invention, the housing includes an auxiliary 
product flow path connecting opposite ends of the pump chamber and 
opposite sides of the piston head. The second valve member is positioned 
within the auxiliary product flow path and can be activated from the 
exterior of the apparatus to open and close the auxiliary product flow 
path as desired. 
In either embodiment, the first and second valve members preferably are 
diaphragm type pinch valves which provide a straight through flow of 
product with good cleanability of the valve. Additionally, the design of 
the apparatus provides product on both sides of the piston and very 
desirably eliminates the need for any "O" rings on the piston for sealing 
opposite sides thereof. 
The piston includes a piston stem which can extend out of the housing, with 
an arrangement provided for wiping or cleaning the piston stem. If 
desired, the piston stem can operably connect with a separate pneumatic 
cylinder for balance of forces acting on the piston. The cylinder can also 
be operated to act as a volume stop or to assist in retraction of the 
piston. To balance or maintain the pressure of the product infeed line or 
other portions of the apparatus, one or more flow compensators also can be 
provided. 
Additionally, to recirculate product through the apparatus, the housing can 
include a recirculation outlet controlled by its own valve member. The 
recirculation outlet can be utilized to circulate any stale or residual 
product out of the apparatus as desired and can be utilized for cleaning.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
While the present invention is susceptible of embodiment in various forms, 
there are shown in the drawings and will hereinafter be described 
preferred embodiments of the invention, with the understanding that the 
present disclosure is to be considered as an exemplification of the 
invention, and is not intended to limit the invention to the specific 
embodiments illustrated. 
Referring to FIG. 1, a product filling apparatus embodying the principles 
of the invention is generally designated by the reference numeral 10. The 
filling apparatus 10 is configured for use with an associated container 
conveyor 12 which conveys containers C generally beneath the filling 
apparatus 10 whereby the containers C are continually and sequentially 
filled with food product. Filling apparatus 10 can be suitably employed 
for filling containers C with flowable food product, particularly dairy 
food products such as butter, margarine, sour cream, ice cream, yogurt or 
the like. 
The filling apparatus 10 is straightforward in configuration for reliable 
and consistent operation with minimal maintenance and ease of cleaning. 
The apparatus 10 includes a generally upstanding frame 14 on which 
preferably are mounted two food product pumps 16 of substantially 
identical configuration carried by mounting brackets 18. 
Accordingly, the apparatus 10 preferably fills two containers C 
simultaneously as they pass underneath. It is to be understood, however, 
that the particular number of pumps 16 can vary to in turn vary the number 
of containers C being filled. 
As FIG. 2 illustrates, in a first embodiment of the invention each pump 16 
includes a pump housing 20 which defines a pump chamber or cavity 22. The 
housing 20 includes a product inlet 24 and a first product outlet 26 
extending therethrough for communication with the chamber 22. 
A reciprocating piston 28 is also included and is movable within the 
chamber 22. The piston 28 includes a piston head 30 having a front surface 
32 and a rear surface 34 with a stem 36 extending therefrom. 
To control the flow of food product out of the outlet 26 and enable 
operation of the piston 28 as described below, the outlet 26 is in 
communication with an outlet nozzle 37 including an outlet valve 38 
therein. The outlet valve 38 cooperates with one or more product flow 
control valves 40 that are substantially identical to the outlet valve 38. 
In this embodiment, the valve or valves 40 extend through the piston head 
30 to control the flow of food product between the front surface 32 and 
the rear surface 34 of the piston head 30. The valves 40 thus are 
configured to selectively join, in fluid communication, portions of the 
chamber 22 or respective opposite sides of the piston 28. 
By selectively activating the outlet valve 38 and the product flow control 
valves 40 the pressure of the food product alone can be utilized to drive 
the piston 28. This feature not only eliminates the need for an external 
piston driving mechanism, but also greatly reduces the complexity of the 
apparatus 10 to reduce costs while enabling enhanced performance and 
easier cleaning. 
In operation, the piston 28 is cyclically driven by the product under 
pressure supplied by the inlet 24 between a first, retracted upper 
position within the chamber 22, illustrated in FIG. 2, to a second, 
advanced lower position, illustrated in FIG. 3. Before dispensing product, 
the chamber 22 must first be filled with product from the inlet 24. As 
FIG. 5 illustrates, by opening the valves 40 and closing the valve 38, 
product can fill the chamber 22 from the inlet 24. 
In order to dispense product within the chamber 22 in front of the piston 
28 from the outlet 26 to an associated container C, the product flow 
control valves 40 are closed and the outlet valve 38 is opened, as 
illustrated in FIG. 2. In this position, pressure is provided against the 
rear surface 34 of the piston head 30 by the food product supplied by the 
inlet 24 to advance the piston 28 downward within the chamber 22 in the 
direction of arrow "A" from the first upper position to the second lower 
position within the chamber 22. 
As the piston 28 advances under the influence of the pressurized product 
acting on the rear surface of the piston, product within the chamber 22 
between the front surface 32 of the piston head 30 and the outlet 26 is 
forced through the open outlet valve 38 out of the outlet 26 and into the 
desired container C. As the piston head 30 is advanced to the lower 
position illustrated in FIG. 3, the chamber 22 between the rear surface 34 
of the piston head 30 and the inlet 24 is simultaneously filled with food 
product for the next cycle. 
To return the piston to the upper position within the chamber 22 for 
dispensing product to a subsequent container C, the outlet valve 38 is 
closed and the product flow control valves 40 are opened as illustrated in 
FIG. 4. Food product under pressure then flows through the valves 40 to 
the front surface 32 of the piston head 30 which causes the piston head 30 
to retract to the top of the chamber 22 in the direction of arrow "B" due 
to the larger surface area of the front surface 32 compared to the 
rearward surface or "rod side" of the piston. 
As the piston head 30 is retracted from the second lower position 
illustrated in FIG. 4 to the first upper position illustrated in FIG. 5, 
the piston head 30 moves through the food product within the chamber 22 
and is positioned for a subsequent advancing stroke. This continuous cycle 
of advancing and retracting the piston head 30 provides filling of 
containers C at a desired speed and consistency. 
Structural details of the apparatus 10 now will be described. It is to be 
understood, however, that the particular structure of the apparatus 10 can 
vary so long as it functions as described herein. 
As FIGS. 1 and 2 illustrate, the pump housing 20 preferably is formed from 
metal, such as stainless steel, substantially is cylindrical in shape and 
is oriented in a vertical plane. The particular material, shape and 
orientation of the pump housing 20, however, can vary. 
The pump housing 20 is defined by a first circular top portion 42 including 
the product inlet 24 extending laterally therein, a second circular bottom 
portion 44 proximate the outlet 26 and a cylindrical side wall 46 
extending therebetween. To enable the piston stem 36 to exit the pump 
housing 20, the first top portion 42 includes a first aperture 48 
extending therethrough. 
To provide flow of food product out of the pump housing 20, the second 
bottom portion 44 includes a second aperture 50 extending therethrough. 
Preferably, both the first and second apertures 48 and 50 include tapered 
portions 52 and 54, respectively, to assist in the flow of food product. 
To enable product to recirculate out of the pump chamber 22, such as during 
periods when the container conveyor is not operating, the second bottom 
portion 44 of the pump housing 20 includes a secondary outlet 56 
controlled by a valve (not illustrated). As explained in detail below, the 
secondary outlet 56 can be opened to recirculate product out of the pump 
housing 22 back into the food product supply or to a waste container or 
the like. 
As FIG. 2 illustrates, the piston head 30 preferably is cylindrical in 
shape defined by a piston housing 58 having a first end 60 and a second 
end 62 which is substantially covered by a piston plate 64. The piston 
head 30 includes one or more flow channels 66 extending therethrough for 
interconnecting the front surface 32 to the rear surface 34 of the piston 
head 30. 
Preferably, two or four flow channels 66 are provided in a desired 
positions about the piston head 30, each having a respective product flow 
control valve 40 positioned therein. The particular number and positioning 
of the flow channels 66, however, can vary. 
To connect the piston plate 64 to the piston housing 58 and provide 
compressed air to the flow control valves 40 from the piston stem 36, the 
housing 58 includes a central bore 68 having a first top end 70 and a 
second bottom end 72. The second bottom end 72 of the bore 68 is threaded 
for accepting a bolt 74 therein for securing of the piston plate 64. 
To connect the piston stem 36 to the piston housing 58, an exterior surface 
of the closed end 60 of the piston housing 58 includes a ferrule 76. The 
ferrule 76 is retained within a corresponding channel 78 formed within the 
piston stem 36 and includes the bore 68 extending therethrough. 
To provide compressed air to the bore 68 and the flow control valves 40, 
the piston stem 36 includes a central passageway 80 extending along its 
length. A first end 82 of the passageway 80 is aligned with the bore 68 
while a second end 84 is closed. To supply compressed air to the 
passageway 80, a compressed air outlet 86 is provided in the piston stem 
36 connected to a compressed air supply hose (not illustrated) which 
preferably moves with the piston stem 36. 
Since food product is provided on both the front surface 32 and the rear 
surface 34 of the piston head 30, no sealing or "O" rings are required 
about the periphery of the piston head 30 for sealing engagement with the 
cylindrical sidewall 46 of the pump chamber 22. To prevent contamination 
of the food product within the pump chamber 22, the piston stem 36 enters 
a scrubbing, purging and sealing assembly 88 as it exits the top aperture 
48 in the pump housing 20. 
The assembly 88 is secured to the exterior of the top housing portion 42 
and includes an interior chamber 90, first and second opposite ends 92 and 
94, an inlet 96 and an outlet 98. To seal and wipe the piston stem 36 
within the chamber 90, two "O" rings 100 are provided, one each proximate 
the first and second opposite ends 92 and 94. 
The inlet 96 and outlet 98 convey a cleaning medium, such as air, fluid or 
the like, to flood the chamber 90. The particular cleaning medium can 
vary, and can be at a high temperature if desired, so long as it provides 
cleaning of the piston stem 36 as it travels through the assembly 88. 
Accordingly, as the piston stem 36 moves during the advancing stroke of the 
piston 28, a portion of the stem 36 within the cleaning assembly 88 enters 
the pump housing 20. As the piston 28 is retracted, that same portion of 
the stem 36 re-enters the cleaning assembly 88. Thus, the sterility of the 
apparatus 10 is maintained during operation. 
As FIG. 1 illustrates, if necessary, in order to assist in moving the 
piston 28 during the retraction stroke the second closed end 84 of the 
piston stem 36 can be connected to an air or fluid actuated cylinder or 
similar driving mechanism generally illustrated with the reference numeral 
102. The air cylinder 102 also can be utilized for selectively balancing 
and adjusting the effect of the food product pressure acting on the piston 
28. The cylinder 102 can also selectively control the volume of product 
dispensed during each pumping cycle. 
FIGS. 6 and 7 illustrate structural details of the outlet valve 38, it 
being understood that such details also apply to the product flow control 
valves 40. The valve 38 is designed as a "pinch" type diaphragm valve and 
includes a substantially flexible, cylindrical pinch valve element 104, a 
first cylindrical housing portion 106, two secondary housing portions 108 
and two housing end plates 110. 
As FIG. 6 illustrates, in the at-rest position of the outlet valve 38 the 
pinch valve element 104 defines a longitudinal channel 112 extending 
therethrough for conveying food product. As FIG. 7 illustrates, when 
activated, preferably by compressed air, the pinch valve element 104 
collapses substantially along a central lateral axis as illustrated by 
arrows "D" to close off the longitudinal channel 112 and prevent the flow 
of food product therethrough. 
To provide the compressed air as desired to operate the outlet valve 38, 
the first cylindrical housing portion 106 includes a central lateral 
channel 114 formed about its periphery. The first housing portion 106 
preferably includes three apertures 116 formed therethrough and positioned 
within the channel 114 which communicate compressed air between the 
lateral channel 114 and a chamber 118 formed between the first housing 
portion 106 and the pinch valve element 104. 
With regard to the outlet valve 38, as FIG. 2 illustrates the outlet nozzle 
37 includes an air supply inlet 120 in operable communication with the 
central lateral channel 114. Accordingly, when the air supply inlet 120 is 
activated, air flows from the inlet 120, into the lateral channel 114, 
through the apertures 116 and into the chamber 118 to collapse or "pinch" 
the pinch valve element 104 to close off the channel 112. 
Similarly, with regard to the product flow control valves 40, air flows 
from the air outlet 86 proximate the second closed end 84 of the piston 
stem 36, through the stem passageway 82 and into the bore 68 of the piston 
head 30. As FIG. 3 illustrates, the bore 68 includes at least one lateral 
outlet 122 for each flow control valve 40 which provides a flow of air 
from the bore 68 into the lateral channel 114 of each flow control valve 
40. 
Accordingly, when the air outlet 86 is activated, air flows down the stem 
passageway 80, into the bore 68, the channel 114, through the apertures 
116 into the chamber 118 to collapse or "pinch" the pinch valve element 
104 and close the pinch channel 112. 
Referring to FIG. 4, in order to recirculate or purge the chamber 22, the 
outlet valve 38 is closed and the product flow control valves 40 are 
opened. With the piston 28 in the lower or upper position within the 
chamber 22, the secondary recirculating outlet 56 then is opened. Food 
product thus flows from the product inlet 24 into the chamber 22, through 
the open flow control valves 40 and out of the secondary recirculating 
outlet 56 for recycling or disposal. 
As FIG. 2 illustrates, in order to clean out the outlet nozzle 37, a flow 
tube 124 can be provided in operable communication with the outlet nozzle 
37. During cleaning of the apparatus 10, a cleaning medium, such as air, 
water, a sterilizing solution or the like, can be flushed through the flow 
tube 124 to clean and/or sterilize the outlet nozzle 37. 
In order to maintain the proper pressure of the food product to the inlet 
24, one or more product flow compensators (not illustrated) can be 
provided. The type and position of such flow compensators can vary so long 
as they provide a substantially constant supply of food product to the 
apparatus 10 and at a desired pressure. 
FIG. 8 illustrates another embodiment of the apparatus 10a where similar 
elements are identified with the same reference numerals as in the 
embodiment of FIGS. 1-7 and including the subscript "a". In this 
embodiment, the piston head 30a is provided without the flow control 
valves 40. 
In order to provide product flow between opposite sides of the piston head 
30a and the desired advancing and retracting strokes, an auxiliary product 
flow path or conduit 130 is provided. The flow path 130 includes a first 
end 132 in operable communication with the top portion 42a of the pump 
chamber 22a and a second end 134 in operable communication with the bottom 
portion 44a of the pump chamber 22a. 
To control the flow of product through the flow path 130, a product flow 
control valve 40a is positioned therein which is similar to the product 
flow control valve 40 of the previous embodiment. Although the flow 
control valve 40a is positioned proximate the second end 134 of the flow 
path 130, it can be placed anywhere along the length of the flow path 130 
if desired. 
In operation, the piston 28a is driven within the pump chamber 22a by the 
product under pressure supplied by the inlet 24a between a first, 
retracted upper position illustrated in solid lines to a second, advanced 
lower position illustrated in dotted lines. In order to dispense product 
from the outlet 26a to an associated container, the piston head 30a is 
positioned in the first upper position within the chamber 22a, the chamber 
22a is initially filled with product, the product flow control valve 40a 
is closed and the outlet valve 38a is opened. 
In this position, pressure is provided against the rear surface 34a of the 
piston head 30a by the food product supplied by the inlet 24a to advance 
the piston 28a downward within the chamber 22a in the direction of arrow 
"E" from the first upper position to the second lower position. As the 
piston 28a advances, product within the chamber 22a between the front 
surface 32a of the piston head 30a and the outlet 26a is forced through 
the open outlet valve 38a out of the outlet 26a and into the desired 
container. 
As the piston head 30a is advanced to the second bottom position 
illustrated in dotted lines, a portion of the chamber 22a between the rear 
surface 34a of the piston head 30a and the inlet 24a is simultaneously 
filled with food product for the next cycle. 
To return the piston to the first upper position within the chamber 22a for 
dispensing product to a subsequent container, the outlet valve 38a is 
closed and the product flow control valve 40a is opened. Food product 
under pressure then flows through the auxiliary flow path 130 and the 
valve 40a to the front surface 32a of the piston head 30a which causes the 
piston head 30a to retract to the top of the chamber 22a due to the larger 
surface area of the front surface 32a. 
To assist in movement of the piston 28a and provide volume control, if 
desired, an air or fluid control cylinder (not illustrated) can be 
connected to the second closed end 84a of the piston stem 36a. 
Alternatively, the second closed end 84a can include a lever arm or link 
136 or similar member which can be operated pneumatically or by a cam 
mechanism. 
Suitable automatic, electronic controls facilitate operation and 
coordination of the apparatus 10 with the container conveyor 12. A signal 
from the container conveyor 12 is employed for coordinating operation of 
the apparatus 10 with the conveyor 12, although the apparatus 10 can be 
selectively operated independently of the speed of the conveyor 12. 
Thus, it will be appreciated that the present filling apparatus 10 greatly 
facilitates accurate packaging of food product with a desired consistency 
and in an aseptic manner. Since the pressure supplied by the food product 
itself propels the piston 28, no expensive linkages, cams or motors are 
required which significantly reduces the size and cost of the apparatus 
10. 
Additionally, since food product flows on both the front and rear side of 
the piston 28, no sealing or "O" rings are required on the piston 28. By 
using pinch valves, a straight through design is provided which enhances 
the cleanability of the design and enables clean-in-place or CIP cleaning 
where disassembly of the apparatus 10 is not required for cleaning. 
Despite the small, compact design, the apparatus 10 can handle extreme line 
pressures while providing excellent volume adjustment. Furthermore, due to 
the simple design, the apparatus 10 readily can be disassembled for 
service or repair if needed. 
From the foregoing, it will be observed that numerous modifications and 
variations can be effected without departing from the true spirit and 
scope of the novel concept of the present invention. It is to be 
understood that no limitation with respect to the specific embodiments 
illustrated herein is intended or should be inferred. The disclosure is 
intended to cover by the appended claims all such modifications as fall 
within the scope of the claims.