Multiple hopper weighing and transfer system

The first of the in-series hoppers of the system is carried by a scale to determine the weight of the product batch; a transfer hopper being next in line and finally a holding hopper. A computer senses the batch weight and assigns the weight in sequence first to the transfer hopper, and then to the holding hopper. Both the transfer and holding hoppers participate in each computerized weighing/selection cycle. The forming/weighing hopper includes a shell and double-acting clam shell doors; the upper curved portion of each door extending into the hopper when the doors are open, thereby intercepting any late product in flight and initiating formation of the next batch. The transfer and holding hoppers also incorporate pairs of clam shell type doors. The associated method, is characterized by forming and weighing the product in the first in-series hopper and then discharging the batch in sequence to the transfer and holding hoppers. These steps are repeated in succession, and checking of all hoppers by the computer is provided to generate an extended multiple shift mode of operation. In addition, there is a step of intercepting the product within the forming/weighing hopper to initiate forming of the next batch for further extension. A related method contemplates replacing large capacity in-series hoppers for the relatively small capacity hoppers, and vice-versa.

TECHNICAL FIELD 
The present invention relates to packaging machines and methods for solid, 
substantially free flowing product batches or charges, and more 
particularly, to a computerized weighing system incorporating a plurality 
of in-series hoppers for transferring the weighed batches in an efficient 
manner into the packaging machine. 
BACKGROUND OF THE INVENTION 
Over the past several decades, many advances have been made in improving 
the efficiency of weighing of batches of products for filling packages, 
such as pillow-type packages on a form, fill and seal packaging machine. A 
considerable improvement has been made in the technology of computerized 
combination weighing, that is where multiple product batches or charges 
are sampled and combined to make one product charge. These advances have 
not only provided an increase in speed of the overall packaging system, 
but have proven very successful in reducing product give away. A leading 
approach in computerized weighing is set forth in the computer circuit 
described and claimed in U.S. Pat. No. 4,418,771 entitled "Method and 
Apparatus for Combination Weighing" and U.S. Pat. No. 4,538,692 entitled 
"Method and Apparatus for Combination Weighing With Multiple Storage Cups 
for Each Scale Hopper", owned by the present assignee. 
While there have been several attempts to improve the operation of the 
control circuit of the computerized weighing machines, little attention 
has been given to improving the handling of the product in the hoppers 
that form and weigh the batches. In terms of efficiency, the best 
arrangement has remained substantially unchanged since the time of the 
original machines and methods set forth in the '771 and the '692 patents. 
Specifically, in the past, the typical arrangement includes a scale hopper 
positioned to receive the stream of flowing product directly from a 
vibrating feed conveyor, and then once weight is made the batch is 
transferred to one or more holding hoppers or cups. In order to make 
certain that late, in flight product is not introduced into the scale 
hopper, a lip gate is provided at the end of the vibrating feed conveyor 
in these prior art systems. Some effort has been made to introduce a third 
hopper into the system, but with limited success. One such attempt is 
characterized by a pool hopper positioned above the weighing hopper to 
receive the flow of product from the feed conveyor. Since the weight of 
the product in the pool hopper is unknown, this hopper cannot participate 
in any manner in the combination weighing and selection process. 
Furthermore, improving the efficiency of operation of the hopper itself and 
simplifying its structure has not attracted significant attention in the 
field. An example of this is that lip gates are still used in most 
arrangements to accurately cut-off flow into the batch forming/weighing 
hopper. Other inventors have resorted to using the pool hopper above the 
forming/weighing hopper in an attempt to alleviate the late, in flight 
product problem. Also, some inventors have been led to the use of a 
separate shutter positioned between the lip of the feed conveyor and the 
first in line hopper to catch the late product in flight; however, such an 
arrangement requires substantial additional mechanical components and 
operating mechanism which makes it an expensive alternative. Similarly, 
the operating mechanism for opening and closing of the gates of the 
hoppers have continued to be complicated and characterized by a large 
number of component parts, primarily linkages and springs. Still, no truly 
efficient approach to rapidly open and close the gates for efficient 
transfer of the formed batches of products has heretofore been found. 
Furthermore, these prior art operating mechanisms are not only more 
expensive to manufacture, but make clean up of the weighing machine much 
more difficult. 
Besides the improvements in the control circuitry, some improvements have 
been made in other sections of the packaging machines, such as set forth 
in U.S. Provisional Patent Application Ser. No. 60/000,750, filed Jun. 30, 
1995 and entitled "Packaging System With Improved Transitional Product 
Flow and Adaptive Control". Furthermore, substantial advances in 
continuous feed of the packaging film, the actual forming of the packages 
has likewise reached a very advanced state, such as provided in U.S. 
patent application Ser. Nos. 08/212,548 and 08/350,877 and entitled 
"Continuous Vertical Form-Fill-Seal Packaging Machine With Constant Motion 
Carriage" and "Continuous Vertical Form-Fill-Seal Packaging Machine With 
Synchronized Product Clamp", also owned by the assignee of the present 
invention. Such a scenario provides additional impetus to improvement in 
the efficiency and overall speed of the weighing system in order to reach 
the next level of operating efficiency and technology in the form, fill 
and seal packaging industry. 
Thus, an important aspect of the present invention is to provide a multiple 
in-series hopper system and related method that improves the product batch 
or charge weighing and transfer of successive batches for maximizing the 
speed and efficiency of the packaging system. 
SUMMARY OF THE INVENTION 
Accordingly, it is a primary object of the present invention to provide a 
hopper system for handling solid, flowing product within a computerized 
weighing machine to enhance the efficiency of the operation. 
Another object of the present invention is to provide such a system that 
incorporates multiple in-series hoppers including a first in line batch 
forming/weighing hopper to directly receive the product from a stream, a 
transfer hopper next in line to receive and reform the batch, and finally 
a holding hopper next in line, so that computerized weighing/selection may 
be operative to select one or both of the transfer and holding hoppers and 
thereby making the forming/weighing hopper available at all times for 
weighing, all in a multiple shift mode of operation. 
A related object of the present invention is to provide an improved hopper 
structure including a shell for forming the batch and a pair of clam shell 
doors, the upper portions of which come together inside the hopper to 
intercept any late product in flight, and thereby extend the multiple 
shift mode. 
An additional object of the present invention is to provide an improved 
manner of operating the clam shell doors of each of the hoppers through a 
single nautilus style cam operating directly on followers attached to the 
doors. 
Still another object of the present invention is to provide a system that 
incorporates a curved transition chute directly below the holding hopper 
for receiving each batch of product in a manner to minimize disruption of 
the batch and bouncing of the product. 
Another object of the present invention is to provide a system having 
improved batch reforming and retention characteristics, prior to the batch 
being discharged into the transition chute. 
An objective of the related method of the present invention includes the 
concept of feeding the flowing product stream directly into the batch 
forming/weighing hopper, discharging the batch into the transfer hopper 
and the holding hopper in sequence, and simultaneously repeating the steps 
for second and third batches, to provide the multiple shift operation. 
Still another object of the method of the present invention is to extend 
the multiple shift operation by intercepting late, in flight product in 
the batch forming/weighing hopper. 
Another object of the invention is to provide an efficient and cost 
effective manner of switching from relatively small capacity hoppers to 
large capacity hoppers, and vice-versa. 
Additional objects, advantages and other novel features of the invention 
will be set forth in part in the description that follows and in part will 
become apparent to those skilled in the art upon examination of the 
following or may be learned with the practice of the invention. The 
objects and advantages of the invention may be realized and obtained by 
means of the instrumentalities and combinations particularly pointed out 
in the appended claims. 
To achieve the foregoing and other objects, and in accordance with the 
purposes of the present invention as described herein, an improved 
multiple in-series hopper system is provided for receiving a stream of 
solid, flowing product, forming the product into a defined batch or charge 
and efficiently transferring the batch into a packaging machine, such as a 
form, fill and seal type machine. In the preferred embodiment, three in 
line hoppers are utilized to advantage; namely, a batch forming and 
weighing hopper to directly receive the flow of product, a transfer hopper 
for receiving the batch from the forming/weighing hopper and a holding 
hopper for receiving and reforming the batch from the transfer hopper for 
later discharge into the packaging machine. Within the system, a scale is 
provided to initially determine the weight of the product in the 
forming/weighing hopper and a computer senses the batch weight for 
assignment in sequence to the transfer and holding hoppers. The computer 
is operative to select one or both of the transfer/holding hoppers for 
discharge, which in turn results in an efficient multiple shift weighing 
operation. At the same time, the forming/weighing hopper remains available 
to receive a new charge of product from the feed conveyor and to be 
available for selection to thereby further extend the multiple shift mode 
of operation. 
The preferred structure of the forming/weighing hopper comprises a shell 
with an opening adjacent the top for receiving the feed of product and a 
pair of clam shell type doors for closing the bottom of the hopper. Upper 
curved portions on the doors extend into the hopper and have sufficient 
length to come together to intercept any late product in flight in the 
stream from the feed conveyor. Thus, with one or more of the hoppers 
available for use in making combinations during the weighing process, the 
next, or fourth in line batch can be initially formed. Once the doors are 
closed so that the lower lips close the bottom of the hopper, the product 
caught on top of the curved portions drops to the bottom of the 
forming/weighing hopper in readiness for continuation of the weighing and 
transfer operation. 
In addition, the transfer and holding hoppers are provided with a pair of 
clam shell doors and each of the three pairs of doors for the hoppers are 
provided with a unique mechanism for opening and closing. Specifically, 
the doors are oscillated by a cam having a substantially nautilus profile. 
A pair of cam followers is mounted on each of the doors, one follower on 
each side of the cam for direct engagement. A rotary driver for each of 
the cams opens and closes the doors in proper cycle sequence. By direct 
cam drive to the doors, relatively expensive and hard to clean linkage and 
spring systems are advantageously eliminated. As for the cam drive system 
for the forming/weighing hopper, the cam followers are spaced from the cam 
except during the opening and closing sequence, thus providing freedom for 
the hopper to move during the weighing cycle. 
The doors of the holding hopper slope at an 8.degree.-14.degree. angle in 
the direction along the closing lips of the door so that the batch is 
reformed in this hopper and closely nested together to minimize string out 
and bouncing of the product as it is discharged. The lower transition 
chute receiving the batch is curved in the direction toward the center of 
the weighing machine, starting from the lower end of the bottom of the 
holding hopper. 
in accordance with the related computerized weighing method of the present 
invention designed to fill or assist in filling a package or the like, 
there is provided a series of steps through the in-series hoppers that 
provide substantial improved results and advantages. The first step is 
forming in a single lane the solid flowing product stream. The second step 
is feeding the stream directly to the batch forming/weighing hopper. After 
forming and weighing, the first batch is discharged into the transfer 
hopper and then into the holding hopper, each time reforming the product 
into a batch. These steps of feeding, weighing, discharging and reforming 
are repeated for second and third batches. The weights assigned to the 
hoppers are checked by computer, so that the product from one or more of 
the batches can be selected. 
An additional important aspect of the method is intercepting the product 
stream of late, in flight product to initiate forming of a fourth batch, 
thus extending the multiple shift mode by at least a third batch and a 
fourth partial batch for packaging. As soon as the doors for the 
forming/weighing hopper are closed, the partial batch drops to the bottom 
of the hopper and feeding of the product continues from the feed conveyor 
in a stream. 
In another related method of the present invention, there is provided a 
simple manner of converting the multiple in-series hopper system on a 
machine frame from relatively small to relatively large capacity. For 
example, when there are provided three relatively small in-series capacity 
hoppers that operate in the manner set forth above, a conversion can be 
made to two large capacity hoppers. The hoppers are supported by at least 
one support member at corresponding spaced locations on the frame to carry 
out the weighing and transfer operation as described. When a large 
capacity operation is desired, at least two of the small capacity hoppers 
are removed and replaced with at least one large capacity hopper. The 
third hopper can also be changed to large capacity. In doing so, a 
different combination of support members on the frame are engaged. Using 
this method, conversion from a small capacity system to a large capacity 
system, and vice-versa, is very economical and efficient. In addition, 
this method contemplates sensing the location of the support members on 
the frame and automatically updating the computer to adapt the weighing 
operation to the proper capacity mode of operation.

Reference will now be made in detail to the present preferred embodiment of 
the invention, an example of which is illustrated in the accompanying 
drawings. 
DETAILED DESCRIPTION OF THE INVENTION 
Reference is now made to FIG. 1 showing an improved multiple in-series 
hopper system, generally designated by the reference numeral 10 and 
mounted on a typical computerized combinational weighing machine frame 11. 
As illustrated in this figure, a stream of solid, flowing product P is 
being fed from a typical center distributor plate 11 and into a vibrating 
feed conveyor 12. It is to be understood by those of skill in the art that 
the illustration in FIG. 1 is a single lane of a weighing machine and that 
a typical arrangement is for additional lanes to be situated around the 
periphery of the machine with the distributor plate 11 forming the center. 
As is apparent from the above description and viewing FIG. 1, the overall 
objective is to form and transfer a batch of product P from the stream 
flowing from the feed conveyor 12. 
A batch forming and weighing hopper 15 receives the stream of product, as 
noted by the reference indicia P.sub.1. A scale S, which typically can be 
of the strain gauge type with a dampening mechanism is operative to 
determine the weight of the product within the batch forming/weighing 
hopper 15. As further illustrated in FIG. 1, a transfer hopper 16 receives 
the batch of product P.sub.2 from the forming/weighing hopper 15 when the 
doors are opened, as will be described further in detail below. In turn, a 
holding hopper 17 holds the final batch of weighed product P.sub.3, which 
batch is discharged onto a transition chute 18 when the gates are opened, 
also as will be described below. 
With reference to FIG. 8, a computer/CPU 20 is provided for operation of 
the system in combination with a controller 21. The scale S of the 
forming/weighing lane of the weighing machine illustrated in FIG. 1, plus 
n scales of the other lanes (not shown) provides its signal to the 
controller 21. Thus, the signal from the scale S indicates the batch 
weight and in turn this signal is transmitted to the computer/CPU for 
processing and selection of one or more batches for making weight in the 
system. The computer 20 may select one or both of the transfer and holding 
hoppers 16, 17 for discharge in the basic multiple shift operation of the 
present invention. Advantageously, according to the present invention the 
forming/weighing hopper remains available for batch forming and weighing 
at all times during selection of one or both of the batches within the 
transfer/holding hoppers 16, 17, and is also selectable as an extension of 
said multiple shift. 
Preferably, the forming/weighing hopper 15 comprises a shell 20 and a pair 
of opposed, clam shell type doors 21, 22 (see FIGS. 3 and 5 in 
particular). As is apparent, the doors 21, 22 close the bottom of the 
hopper which of course results in formation, and allows for weighing of 
the batch of product P.sub.1 ' on the inside (see FIG. 2). 
The clam shell doors 21, 22 include an upper portion 21a, 22a, respectively 
(see FIGS. 4 and 5). These upper portions 21a, 22a are curved and are 
positioned to extend from the top of the respective doors into the hopper 
15. As illustrated, the portions 21, 22 have sufficient length so that the 
upper edges come together on the inside of the hopper when the doors are 
open for discharge of the product batch (see FIGS. 4a-4c). As illustrated 
in FIG. 1, with the doors 21, 22 open, in flight late product P.sub.1 in 
the stream of product entering the hopper from the conveyor 12 is 
intercepted and thus initiates formation of a batch of product separate 
from the product batch P.sub.2 being discharged at that time. 
Thus, with reference back to FIG. 1 of the drawings, it will be realized 
that in one state of the operation of the system of the present invention, 
the in flight product P.sub.1 is intercepted, a batch of product P.sub.2 
enters the transfer hopper 16 with the doors closed. At the same time, the 
computer 20 makes the selection for combining the batch of product P.sub.3 
with other batches (not shown) to make weight for a package. 
Then, in next state of operation upon closing of the doors 21, 22, as shown 
in FIG. 2, the intercepted product P.sub.1 drops to the bottom of the 
forming/weighing hopper 15 and forms a new batch P.sub.1 '. At the same 
time, the discharged batch of product P.sub.2 has dropped to the bottom of 
the transfer conveyor 16 to form the completed weighed batch P.sub.2 '. 
Similarly, in this state of operation, the product batch P.sub.3 ' now 
fills the holding hopper 17. 
With respect to the transfer hopper 16, an upper shell 30 and clam shell 
type doors 31, 32 are provided in a manner similar to the structure of the 
forming/weighing hopper 20 and related doors 21, 22. These doors include 
lower lips that come together and close the bottom of the transfer hopper 
16 (see FIGS. 2 and 3). Similarly, the holding hopper 17 includes a shell 
35 and opposed clam shell style doors 36, 37. All three sets of doors 21, 
22 and 31, 32 and 36, 37 are oscillated by a rotary driver to open and 
close in an efficient manner as illustrated. 
More particularly, the present invention contemplates the use of a single 
oscillating cam with the operative face 40a formed to simulate a nautilus 
shell; the cam being designated by the reference numeral 40 and supported 
on a shaft and driven in an oscillatory manner by a servo motor 41, or a 
similar driver such as a rotary solenoid. Advantageously, the cam 40 
directly engages cam followers 42, 43 positioned on the outer skirt of the 
doors 21, 22. This is best shown with respect to the weighing hopper 15 in 
FIGS. 4a-4c. The cam 40 with the nautilus profile operating face 40a is 
positioned between the two followers 42, 43 and upon rotation equally and 
progressively moves the doors 21, 22 to the open position, as best shown 
in FIGS. 4a-4c. As shown in FIG. 4a, the followers 42, 43 are out of 
engagement with the face 40a when in the home position thereby allowing 
the hopper 15 to be free for weighing action (see FIG. 4a). The doors 31, 
32 and 36, 37 of the hoppers 16, 17 are operated by an identical 
oscillating cam (shown generally, but not numbered). 
As mentioned above, the curved transition chute 18 is positioned below the 
holding hopper 17, and as illustrated in FIG. 1, receives the batch of 
product P.sub.3 in a very efficient manner. The entry point for the chute 
18 is adjacent the lower end of the bottom of the holding hopper. In this 
manner, as the product P.sub.3 is released, it tends to remain nested 
together and not string out so that the product travels primarily as a 
batch. This arrangement contributes to not only the speed of transition of 
the product P.sub.3 down the chute 18, but also prevents bouncing and 
possible breakage of individual pieces of the product. 
As illustrated in FIG. 1, and also in FIG. 2, the slope of the bottom of 
the hopper 17 along the closing lips of the doors 36, 37 is in the range 
of 8.degree.-14.degree. and extends toward the entry point of the 
transition chute 18. Advantageously, the product ready to be discharged 
from the hopper 17, namely product P.sub.3 ' (see FIG. 2), is nested and 
settled at the lower end of the bottom that results in the minimum string 
out and bouncing of the product along the chute 18. The optimum angle for 
assuring this function is 10.degree. (see FIG. 2). Also, to maximize the 
effectiveness of the curved entry to the transition chute 18 there is an 
extension of between 1/4 and 1/2 of the length of the holding hopper 17 
(see dashed dot line in FIG. 1). 
In order to insure that the upper portions 21a, 22a of the doors 21, 22 
remain free of product build up, a suitable flexible scraper 50 is 
positioned in the opening along the side of the shell 20 (see FIG. 5a). 
With reference back to FIG. 3, and by comparison to FIG. 3a, each of the 
hoppers 15, 16 and 17 are mounted on the machine frame 11 by three 
mounting pins. The pins are illustrated in cross section on three 
separate, spaced mounting plates 65, 66 and 67. As will be apparent, the 
weighing hopper 15 is supported by the three pins engaging the plate 65; 
the transfer hopper 16 is supported by the pins shown with respect to 
plate 66 and the holding hopper 17 is supported by the pins shown with 
respect to the plate 67. The pins fit into apertures in these plates and 
extend through support tubes, as can be seen in detail in FIG. 2. 
In particular, one of the mounting pins for each of the hoppers 15, 16, 17 
are shown in a representative fashion in FIG. 7. Mounting pin 70 extends 
through the plate 65 and into a support tube 71. The movement of the 
mounting pin 70 into and out of final locked position is shown by the 
dashed line action arrow in this figure. On the end of the mounting pin 17 
is a tapered extension 72 that cooperates with resilient detent members 
73, 74 to hold the pin 70 in position. In the final full line position, 
the end of the extension 72 is moved into proximity or in contact with a 
magnetic sensor S, which can be the type operating in accordance with the 
Hall effect or other suitable principle. The sensor S is connected to the 
computer 20, as illustrated in FIG. 8, in order to provide indication of 
the presence of that particular pin 70 of the weighing hopper 15. Of 
course, each of the other pins, as illustrated in FIG. 3a, is associated 
with the n sensors that also provide an input to the computer 20 (see FIG. 
8). 
In the alternative embodiment of FIG. 6, a large capacity weighing hopper 
80 is provided and is supported by an array of three pins, as illustrated 
with respect to the mounting plate 65' in FIG. 6a. To operate the doors of 
the hopper 80, the same cam 4 that is operative for operation of the doors 
21, 22 in the smaller capacity hopper 15 is utilized. A large capacity 
holding hopper 82 takes the place of the smaller capacity transfer hopper 
16 and the holding hopper 17. In this instance, the plates 66', 67' 
receive (instead of six mounting pins for the smaller capacity hopper 16, 
17) only three pins for the larger capacity holding hopper 82, as shown by 
cross section depiction. In this instance, since the sensors S cooperating 
with the pins 70 of the large capacity holding hopper 82 are in a 
different pattern, namely two upper pins in plate 66' and one lower pin in 
plate 67', then the signal to the computer 20 is different and updating to 
the large capacity mode is automatically entered. 
With reference now to the computerized weighing method for a series of 
product batches for filling or assisting in filling a package or the like, 
the steps can be readily understood by reference to FIGS. 1, 2 and 2a of 
the drawings. First, with reference to a single lane, and referring 
specifically to FIG. 2, a solid flowing product stream P.sub.1 ' enters 
the weighing hopper 15 directly from the feed conveyor 12 through an 
opening in the upper part of the shell 20. Forming and eventual weighing 
of the batch takes place within the hopper 15 with the signal from the 
scale S being fed to the controller 21 for processing. Upon command, the 
batch of product P.sub.1 ' within the forming/weighing hopper 15 will be 
discharged into the transfer hopper 16 for reforming as represented by 
P.sub.2 '. In turn, the batch of product P.sub.2 ' is fed to the holding 
hopper 17 as P.sub.3 ' until selected by the computer 20 and controller 
21. As the batches are discharged (see FIG. 1) the feeding, weighing, 
discharging and reforming steps for second and third batches of product 
are again carried out. The computer 20 continuously checks the product 
weights assigned to each of the hoppers 16, 17 and is operative at all 
times for combining product from one or more of the batches within these 
hoppers 16, 17. 
In one extended operational mode as depicted in FIG. 2a, a first batch 
P.sub.1 " is selected and discharged from the forming/weighing hopper 15; 
a second batch of product P.sub.2 " is selected and being discharged from 
the transfer hopper 16 and a third batch P.sub.3 " is selected and being 
discharged from the holding hopper 17. In this manner, the multiple shift 
mode is extended to supply a maximum number of weighed batches for 
packaging. 
Furthermore with respect to the method of the present invention, at the 
same time batches of product are being discharged as noted in FIG. 2a, the 
product stream entering the forming/weighing hopper 15 is being converted 
into at least a partial batch of product P.sub.4 ", whereby is provided 
the same multiple shift mode plus one. 
With reference again to FIG. 6 of the drawings, the method of converting 
the multiple or three in-series hopper system from relatively small to 
relatively large capacity can be visualized. First, the three relatively 
small capacity hoppers are provided, as set forth in FIGS. 1, 2 and 2a. At 
least one support pin is engaging each of the plates 65-67, as shown in 
FIG. 3a. According to the method of conversion, at least the two small 
capacity transfer and holding hoppers 16, 17 are removed and replaced with 
the single large capacity holding hopper 82 (see FIG. 6). In doing so, the 
plates as designated by 66', 67' have pins 70 located in a different 
combination of support tubes 71. The pattern of pins 70 thus represented 
in FIG. 6a is recognized by the computer 20, thereby providing direct 
updating to the selected hopper capacity operating mode of the system. 
Advantageously, the conversion is made by moving each hopper 15-17 and 80, 
82 in substantially a straight line with respect to the support tubes 71 
on the machine frame 11. The tubes 71 are operative to guide the mounting 
pins in a substantially straight line for easy manipulation. To lock the 
hoppers in position, suitable detents 73, 74 for each of the support tubes 
are utilized, as illustrated in FIG. 7. 
In summary, it will be realized that substantial results and advantages are 
obtained by the multiple in-series hopper system of the present invention. 
By providing a forming/weighing hopper 15 in combination with the transfer 
hopper 16 and the holding hopper 17 an improved multiple shift operation 
is obtained. The computer 20 is operative to select one or both of the 
transfer and holding hoppers 16, 17 for discharge of the batches P.sub.2 ' 
and P.sub.3 ', as desired (see FIG. 2). In the optimum operational mode, 
the multiple shift operation can be extended further to select and 
discharge batches of product P.sub.1 ", P.sub.2 ", P.sub.3 ", and at the 
same time initiate formation of batch of product P.sub.4 ", as shown in 
FIG. 2a. The forming/weighing hopper includes clam shell doors 21, 22 with 
upper portions 21a, 22a that are operative to intercept the late product 
in flight, so as to initiate the formation of the batch P.sub.4 ". In 
addition, the holding hopper 17 includes a sloped bottom in the direction 
along the closing lips of the doors 36, 37 in order to better control the 
discharge of each batch into the transition chute 18. Preferably, the 
upper portion of the transition chute 18 is curved to further enhance the 
controlled flow of the product. Finally, the system can be converted from 
a relatively small capacity to a relatively large capacity by removing the 
transfer and holding hoppers 16, 17 and replacing these with a single high 
capacity holding hopper 82. In doing so, the computer 20 receives signals 
for direct updating of the selected hopper capacity. Furthermore, the 
conversion is simplified by straight line movement of the hoppers due to 
the mounting pin 70 and the support tube 71 combination. 
The foregoing description of a preferred embodiment of the invention has 
been presented for purposes of illustration and description. It is not 
intended to be exhaustive or to limit the invention to the precise form 
disclosed. Obvious modifications or variations are possible in light of 
the above teachings. The embodiment was chosen and described to provide 
the best illustration of the principles of the invention and its practical 
application to thereby enable one of ordinary skill in the art to utilize 
the invention in various embodiments and with various modifications as is 
suited to the particular use contemplated. All such modifications and 
variations are within the scope of the invention as determined by the 
appended claims when interpreted in accordance with breadth to which they 
are fairly, legally and equitably entitled.