Metering and balancing device and filling machine including such a device

Field of the invention: filling machine industry. Device consisting of a lever made up of two arms arranged on each side of a fixed pivoting axis. The end of the first arm supports the end of a rod, movable axially and vertically to rotate the arm and ending at the other end in a load-carrying platform moving downwards as the load increases. The end of the second arm, consisting of two parts pivoting about a movable axis, carries a counter-weight and by sliding along the pivoting part on a fixed axis may itself slide along a straight inclinable rail. By suitable selection of both the weight of the counter-weight and the slope of the straight rail, the lever is balanced at the same time in two positions, one corresponding to zero load on the platform and the other to a predetermined load placed on the platform, there being substantial equilibrium in intermediate positions. Use: Metering of bulk products discharged into containers by filling machines.

This invention is concerned with a metering device for dispensing bulk 
products into containers, which is applicable in particular to machines 
for filling bulk containers with ice cream. 
Currently known machines for filling containers with products, as for 
example ice cream, and hereafter called bulk (ice cream) containers, 
generally comprise a conveyor with mechanical advance on which the bulk 
containers to be filled are placed, and of which the progress is 
periodically interrupted to allow each of the successive containers to be 
held stationary under the filling device, which only delivers ice cream 
between the instant when the container is stationary below it and the 
instant when, the container being filled, flow of ice cream is stopped, 
the conveyor being then restarted on the one hand, to remove the filled 
container and bring the following one under the filling device, and so on, 
the ice cream flow being interrupted during the time interval in which 
each new container is moved up to that device. 
In machines with high output, that is those having a maximum filling 
capacity of about 1000 filled containers per hour, the ice cream that does 
not flow during the time where a container that has just been filled is 
exchanged for the following empty ice cream container, is stored and 
accumulated within a reservoir acting as a buffer. However, this manner of 
proceeding has the disadvantage of producing, during accumulation in the 
buffer tank between two fillings, compression of the ice cream which has a 
negative effect on the overrun. Moreover, the techniques described above 
are practically inapplicable to "hard" ice cream, that is ice cream which 
is at a temperature below about -9.degree. C. 
On the other hand, the back pressure permitting the ice cream to spread 
over all the surface of the container during filling, back pressure which 
is obtained by mechanical or pneumatic processes, does not take into 
account the weight of the ice cream and its variations during filling of 
the container. 
The present invention overcomes these drawbacks by providing a metering 
mechanism for a bulk product, in particular for metering the quantity of 
ice cream, co-operating with a filling machine in such a way that 
interruption of flow of the product being filled is not necessary and, in 
this manner it becomes possible to increase the hourly filling rate and 
practically eliminate compression of the product which has a negative 
effect on the desired overrun. Such a machine makes possible the filling 
of bulk containers with ice cream at a temperature which is below about 
9.degree. C. and, in addition, to compensate constantly during filling the 
effect of the increasing weight of the container on the back pressure, so 
that the ice cream may spread over the whole surface of the container 
during filling. 
According to the invention the apparatus for metering and balancing the 
total load of each container during filling consists of a movable beam 
rotatable about a horizontal axis fixed with respect to the frame of the 
machine and acting as a first-order lever on the end of the first arm of 
which rests the end of a vertical rod guided in axial movement and of 
which the other end is fixed to the lower surface of the platform 
supporting the container during filling, and of which the other arm is 
made up of two mutually-articulated parts, the first being directly fixed 
to the first arm and movable simultaneously therewith rotatably about the 
axis of the beam; at its free end, this first part of the second arm is 
provided with a slide within which a hinged counterweight may slide 
rotatably about a horizontal axis parallel to the axis of the beam. The 
bearing forming the support of the counterweight is provided with means 
which allow it to move in the slide and is connected to a part which 
constitutes the second part of the second arm of the beam and which 
comprises, at its free end opposed to that carrying the bearing, a slide 
movable along a straight rail acting as a guide; this straight rail, which 
is disposed in a plane perpendicular to the axes of rotation of the beam 
and the counterweight is inclined at a pre-determined angle dependent on 
the amount of product to be dispensed into each container. Moreover, the 
lengths of the arms of the beams on the one hand, and the weight and slope 
of the straight rail co-operating with the second arm on the other, are 
selected and calculated in such manner that moments of forces acting on 
each of the arms are substantially equal at all times. 
Thus, to each position of the beam corresponds a fixed weight of product in 
the container being filled. 
In order to provide for the adaptation of a metering and balancing 
mechanism to different possibilities, that is adaptation both to the 
specific gravity of the product being filled and the amount of product to 
be filled into the container, the inclination of the straight rail which 
co-operates with the second arm of the beam of the device for metering and 
balancing the load of containers being filled is made adjustable. For this 
purpose, and in one embodiment, the lower end of the rail is hinged for 
rotation about a fixed axis, parallel to the axis of rotation of the beam, 
whereas its upper end acting as a slide co-operates both with a sliding 
element movable along a straight horizontal rail having its axis at right 
angles to the axis of rotation of the beam the position of which is 
adjustable and, via a part affixed to the sliding element and rotatable 
about an axis fixed with respect thereto, which axis remains parallel to 
the axis of rotation of the beam, with a straight guide-path provided on 
the part. 
A filling machine provided with the metering device according to the 
invention is for example essentially characterized in that it comprises: 
means for stepwise moving the containers to a filling station, means for 
distributing the containers alternatively beneath a first pouring device 
for the product to be filled and beneath a second pouring device for the 
product to be filled, and means for conveying each container filled with a 
pre-determined amount of product to a removal means, each of the filling 
devices being arranged opposite a platform for receiving and supporting 
the container. This platform co-operates at all times with the metering 
and balancing device according to the invention during the filling of the 
total load of the container, this device itself co-operating with a means 
for locking the metering and balancing device in the position which 
corresponds to the filling of a container containing the pre-determined 
quantity of product to be filled. The different means used for obtaining 
the different movements co-operate with each other in a programmed manner 
by means of devices carrying out different logical functions co-ordinating 
the movement and operation of hydraulic jacks controlling different 
movements so that one container out of two is always being filled. 
The features and advantages of the invention will be more apparent from the 
following description, given as a non-limiting example, of one possible 
realization of the invention and with reference to the accompanying 
drawings.

In the drawings like reference numbers are used for like parts. 
Referring first to FIGS. 1, 2 and 3, a filling machine including the 
metering device according to the invention essentially comprises a first 
conveying means 1 for advancing singly the containers to be filled with 
product, that is, in particular, bulk ice cream containers, to the filling 
station 2 and continuous removal means 3 for containers filled with a 
pre-determined weight of product. The conveying means 1 advantageously 
consists of a conveyor in two parts 1a, 1b with stepwise advance of known 
type; the length of each step depends, in particular, on the dimensions of 
the containers, whereas the time interval between two successive steps is 
related to the filling time. Containers 4 are taken from a distributing 
station (not shown) and placed on the entry conveyor, generally by hand 
and marked automatically on passing an automatic marking section (not 
shown) synchronised in known manner with the entry conveyor and taken to 
the entrance of the filling station 2 where two valves 2a and 2b are 
arranged for filling the containers with ice cream drawn from a freezing 
tank (not shown). 
When a container is presented by the conveyor 1, its presence is detected 
by a detector of known type, for example a photosensitive cell, and 
marked; depending on the marking it is moved by a system operated by fluid 
under pressure either to a first platform 4 acting as a support for the 
container and arranged below one of the two pouring valves, or to a second 
platform 4 located at the same level as the first in stationary position 
acting as a support for the container and located beneath the second 
product pouring valve. For this purpose, in the first step the relevant 
container is raised, by an auxiliary platform, up to the level of the 
container receiving and supporting platform, moved by a piston (not shown) 
operated by fluid under pressure. On reaching the common level of the two 
receiving platforms, the container is pushed onto its assigned platform by 
a piston operation of which, for pushing the container onto one or other 
platform, is determined by a controller associated with a receiver which 
registered signals sent by the markings applied to the containers. 
Each of the container receiving platforms co-operates with the container 
metering and balancing device according to the invention located inside a 
protective box. These two identical devices operate as described hereafter 
and are synchronised and programmed in such manner that at all times one 
of the containers is either being filled so that the discharge of product 
being filled is never interrupted. 
The two metering and balancing devices according to the invention, 
particularly as represented in FIGS. 1 and 2 are designed for accurate 
metering of the quantity of ice cream to be deposited in the corresponding 
container or in general terms the amount of product to be filled into the 
corresponding container, is essentially made of a beam 10 acting as a 
simple lever, that is a lever having two arms 10a and 10b affixed to each 
other, arranged on either side of a fixed axis X--X and rotatable about an 
axis passing through the point A. This lever, rotatable about the axis 
X--X fixed with respect to the lower frame of the machine, comprises the 
two arms 10a and 10b arranged on either side of this axis corresponding to 
each of the bearings 11 and 12, the two arms being affixed to each other. 
The first of these arms is in one piece whereas the second is made up of 
two parts 10b and 10c. The upper part of the end of the first, that is the 
arm 10a, rests on the end of a vertical rod 13 movable axially and guided 
for this purpose by an assembly of two rails 14 and 15 fixed with respect 
to the lower frame, provided with protecting bellows, the other end 
providing the support for the platform which receives a container being 
filled. 
The contacting ends both of the vertical rod 13 and arm 10a are constructed 
in any suitable manner so that the movement of one on the other produces 
as little friction as possible. 
At the end of the second arm of the lever 10b, opposed to the axis of 
rotation X--X, is provided a rail 16 in which may move longitudinally the 
slide 17 attached to the second part 10c of the second arm, which second 
part, on the one hand, is provided with a bearing 18 the axis of which is 
perpendicular to the axis of the rail and in which the supporting shaft of 
a counterweight 19 may rotate freely about the axis and, on the other 
hand, is movable along a straight rail 20 by means of a slide 21 of a form 
suited to the profile of the straight rail. This is made up of a rod the 
longitudinal axis X1--X1 of which lies in a vertical plane perpendicular 
to the axis X--X and articulated on the one hand at its lower end about a 
fixed axis of rotation X2--X2 arranged in the lower part of the frame of 
the machine and parallel to the preceding and, on the other hand, at the 
opposed other end, about an axis of rotation X3--X3, parallel to the axis 
X2--X2, but of which the position is adjustable between two points 
selected on a fixed horizontal straight line Y--Y, at right angles to the 
fixed axis X2--X2, which provides for adjustment of the slope of the guide 
at any pre-determined value. For this purpose, the end of the rod which 
pivots on the axis X3--X3 is provided with a slide movable along a rail 
formed in part 22, freely rotatable about the axis X3--X3 and disposed on 
a slide 23 movable along the axis Y--Y between the two end points 
mentioned above and lockable at any desired position selected between the 
two end points by any suitable means of known type. 
The filling machine comprises two of these devices which are symmetrical 
one with respect to the other in the longitudinal median plane Z--Z of the 
machine, but remain independent of each other insofar as purely mechanical 
operation is concerned, the corresponding levers being pivoted as shown in 
FIG. 2, on the one hand, on a vertical support 24 of the lower frame of 
the machine and, on the other hand, on the bearing 11 and 12, the 
corresponding coaxial shafts being separated from each other between the 
two bearings. 
The operating diagram of each of the two assemblies making up the balancing 
device is shown in FIG. 4. If the axes of the two arms of one of the 
levers 10 is represented by AB and AC, the point A being the fulcrum of 
the lever, the distance AB represents the length of the arm 10a at all 
times during its movement, that is the length between point A and point B, 
point of contact of the end of the rod 13 and of the ledge at the end of 
the arm, whereas the distance AC represents a distance from point A to 
point C of the longitudinal axis X.sub.1 -X.sub.2 of the straight rail 20 
with which the center of the slide 21 movable in a straight line along the 
inclined rail 20 coincides at all times. Thus the length of the arm AC 
varies constantly when, the lever rotating about its axis of rotation, the 
bearing carrying the shaft of the counter-weight slides along the end of 
the arm of the lever. Hence, during filling of a container, placed on one 
of the supports, of which as a result the total weight and subsequently 
the force it exerts at the end of the arm 10a via the vertical rod 13 
increases as the container fills and, on the one hand, the length of the 
arm of the lever AB changes because the location of its end itself 
changes, the distance separating the horizontal axis of rotation of the 
lever from the longitudinal axis of the rod itself remains constant, 
whereas, on the other hand, because of the slope of the straight rail 20, 
the distance between the axis X--X and its longitudinal axis X1--X1 is 
itself variable. 
When there is no empty container on the receiving platform, the 
counter-weight-carrying part is at the bottom of the straight rail at O 
whereas the end of the first arm is at point B, the highest position that 
it can reach. 
The force then exerted by the assembly attached to the container-carrying 
platform on the end B of the first arm of the lever is the force T 
resulting from the weight of the platform and the associated vertical rod, 
that of the empty container and of the weight of the first arm whereas the 
force P.sub.1 acting on the second arm of the lever is equal to the weight 
of the counter-weight plus the weight of the whole mechanism making up the 
second arm. If L is the distance between the axis of rotation of the lever 
and the vertical axis of the rod, l.sub.1 the distance between point O 
defined above and this axis of rotation, the moments of the forces T and 
P.sub.1 about this axis of rotation are respectively equal to T.times.L 
and P.sub.1 .times.l.sub.1 and equal in absolute terms so that: 
T.times.L=P.sub.1 .times.l.sub.1. As the weight of the container increases 
because it is progressively filling with ice cream, to each amount of 
product loaded in the container, that is to each weight of product loaded, 
corresponds an equilibrium position of the lever assembly because of the 
slope of the rail and the rise of the second arm of the lever and as a 
result of the counter-weight carrying part along it, because of the fall 
of the first lever under the effect of the force exerted on its end. Thus, 
during the fall of the first and hence of the rise of the second arm, the 
whole system is substantially in equilibrium. When filling of the 
container is determinated, that is when it has been loaded with a 
pre-determined weight P of product, a new state of equilibrium is reached 
in which the point which was initially at B is at B', whereas the point 
initially at O has moved to C, which is situated on a vertical axis 
located at a distance l.sub.2 of the axis of rotation of the lever, the 
moments of the forces acting on the first and second arms being then 
respectively (T+P).times.L and P.sub.1 .times.l.sub.2 and are also equal 
to each other, so that: (T+P).times.L=P.sub.1 .times.l.sub.2, equation in 
which T, L and P.sub.1 are constants dependent on the machine itself 
whereas P, which represents the weight of product to be filled, in the 
present case ice cream, may be variable, but is determined accurately for 
each type of container to be filled and l.sub.2, which represents the 
distance between the axis of rotation of the lever and the vertical of 
point C may be changed by acting on the slope of the straight rail 20; by 
way of example, axis X'1--X'1 has been shown which may be that of the rail 
inclined in a manner to correspond to another value of the quantity of the 
total product loaded into the container. Hence, the values P and l.sub.2 
are connected by a linear relation. In other words to every value of the 
weight P corresponds a value l.sub.2 for given values of T, L and P.sub.1 
for any given machine. It is therefore necessary, for the system to remain 
in equilibrium at different values of the weight P, to incline the 
longitudinal axis X1--X1 of the rail 20 at an angle corresponding to this 
weight P. However, it is clear that as during filling of the container the 
locus of the counter-weight-carrying part is straight, equality between 
the moments of the forces applied to each of the arms of the lever is not 
maintained strictly, equality only being reached at the end of the 
operation when the container is filled with an amount of product weighing 
P and the ends B and C of the arms of the levers described above are in 
the positions B' and C. In intermediate positions the moment, about the 
axis of rotation, of the forces applied to the second arm of the lever, 
that is on the side of the counter-weight, is in fact slightly greater 
than that of the forces applied to the first that is on the side of the 
container. This difference allows the whole system to resist the exit 
pressure of the product exerted on the container. The graph of the 
difference given by way of non-limiting example in FIG. 5 shows different 
values of the moments of the forces acting respectively on the arm 10a 
(ml) and the arm 10b (m2) as a function (shown on the abcissae) of the 
progressive sinking of the container as it is being filled. 
By way of example, simultaneously possible values are given hereafter for 
certain elements of the balancing device for which the graph of FIG. 5 and 
the Table below were drawn up: 
______________________________________ 
AB = 185 mm AC = 200 mm 
T = 8 kg P.sub.1 = 9.064 kg 
______________________________________ 
The quantities of products filled may vary between 3.390 kg at least and 
4.038 kg at most. In the selected example the weight is the minimum 
weight, that is 3.390 kg, the value of the distance L being then 160 mm 
and the angle through which the arm AB rotates being 60.degree., the arm 
being in its original position inclined at 30.degree. to the horizontal. 
Moreover, in the initial position of the lever, the end O of the second 
arm is disposed in such manner that the distance L.sub.1 is equal to 141 
mm. After filling of the container the second arm arrives, having rotated 
through an angle .alpha.=60.degree., in the position AC such that the 
distance L.sub.2 from the point C to the vertical of the axis of rotation 
is equal to 201.3 mm, the length of the second arm then being AC=210.3 mm 
(in the case where the weight P of the product loaded into the container 
is the maximum weight, that is to say 4.038 kg, the inclination of the 
longitudinal axis of the guide of the counter-weight-carrying part is such 
that the end of the second arm of the lever arrives in position C' at the 
end of the filling operation so that its distance L.sub.2, measured 
vertically, from the axis of rotation is 212.8 mm, the length AC' being 
then 220.4 mm). The Table given below gives by way of example, for a 
strawberry ice cream, the values of the moments of forces acting on the 
arm of the lever on the side of the container (column 2) and on the arm of 
the lever on the side of the counter-weight (column 3) as a function of 
the stroke of the container (column 1) as well as the difference between 
two corresponding values of these moments (column 4) and the value of the 
corresponding theoretical minimum force caused by the pressure acting on 
the ice cream (column 5). 
______________________________________ 
(2) (3) (5) 
Moment of Moment of the 
(4) Theoretical 
(1) the forces 
forces on the 
Difference 
minimum 
Stroke of 
on the side of the between (3) 
force on 
container 
side of the 
counterweight 
and (2) the ice 
(mm) container (m.kg) (m/kg) cream (g) 
______________________________________ 
0 1.281 1.281 0 0 
40 1.373 1.395 0.022 137 
80 1.478 1.511 0.033 205 
120 1.589 1.628 0.039 243 
153 1.691 1.727 0.036 224 
185 1.824 1.824 0 0 
______________________________________ 
When the container is filled with the set quantity, that is the 
predetermined weight of product, and thereafter the level of the filling 
platform, that is the end of the rod to which it is connected, is lowered 
through the corresponding predetermined height, the assembly is locked to 
allow removal of the container from its supporting platform and its 
conveyance to the removal and transport means. For this purpose, a locking 
device, advantageously a hydraulic jack 25, the end of the shaft of which, 
when it is in fully extended position, is inserted into an opening made 
for this purpose at the end of the rod 13 and provided, for example, by 
the space between two small annular flanges affixed to the rod carrying 
the filling platform and spaced at a distance equal to the thickness of 
the end of the shaft of the jack. 
Complete extension of the shaft of the locking jack is controlled in known 
manner via the switch tripped by the corresponding rod carrying the 
filling platform. 
When the latter is in locked position, that is when the lever of the 
filling device is in equilibrium in the position where the moments of 
forces applied to each of its arms are equal, the shaft of the locking 
jack, in its turn, activates a control switch for stopping discharge of 
the ice cream into the container and also controlling extension of the 
hydraulic jack shaft which removes the filled container from the filling 
platform and moves it to the conveyor transporting full containers to the 
labelling station. Using switches similar to those previously described 
and which are activated by the shafts of corresponding jacks when they are 
in suitable predetermined positions, the various jacks provided for the 
different movements of the containers take up their corresponding desired 
positions. In this manner, when the container which has just been filled 
on a filling platform has been pushed onto the removal conveyor, the shaft 
of the corresponding jack activates the control switch for withdrawing the 
shaft that locks the lever of the filling device, the effect of which is 
to permit the lever, acted upon by the counter-weight, to rotate in the 
opposite direction and thereby cause the corresponding platform-carrying 
rod to rise and hence also the platform. At end of the stroke of the 
platform-carrying rod produced by extension of the shaft of the 
corresponding jack, extension which is controlled through a switch 
activated by the platform-carrying rod, a container is pushed onto this 
platform, whereas once this container is in position, the means for 
discharging ice cream into this container opens to fill the latter until, 
when the weight of product discharged is attained, the rest of the 
operations described above is repeated in the same order. 
Needless to say, the same operations take place successively, in the same 
manner and in the same order, in the second filling station which is 
identical with the first and comprises the same elements. Moreover, the 
different means for moving the containers, either for their distribution 
or for their removal, consisting as indicated above of hydraulic jacks, 
locking means also in the form of jacks, valves controlling the opening 
and closing of the filling means for the containers, as well as means for 
advancing the different conveyors are with respect to their operation and 
starting, on the one hand co-ordinated and synchronised among themselves 
within each container filling assembly, whereas the two assemblies 
themselves are on the other hand co-ordinated in such a manner that when a 
container in the filling position has received the predetermined amount of 
product and that, subsequently, the metering device is locked, flow of 
product into the container is interrupted by closure of the corresponding 
outlet valve, this closure causing immediate opening of the valve of the 
other filling means underneath which is placed, on the corresponding 
platform, the container which had been brought there during filling of the 
preceding, or of the operations being interrupted should for whatever 
reason this container has not been conveyed during filling of the other. 
The coordination and synchronisation of these different movements, 
operations and operation cycles is secured in known manner using pneumatic 
control relays, some with two positions and three ports, others with two 
positions and five ports, connected to pneumatic mechanisms for performing 
logical functions such as the functions "AND", "OR" (inclusive) and the 
"block" function, in a programmed manner whereby the technical results 
described above may be obtained automatically. All of the connexions and 
control mechanisms of these different parts are advantageously grouped in 
a common cabinet, with a control panel. 
The filling machine described above, provided with fully pneumatic 
equipment for controlling the different operations and routines makes 
possible the filling of containers distributed between two discharge 
stations whilst at the same time the discharge rate of the ice cream is 
synchronised automatically; thus, the containers 4 are advanced in 
parallel, so that there is no interruption in the flow of ice cream of 
which the density and overrun consequently remain uniform because the 
closing of a feed valve on a feeding station causes automatic opening of 
the feed valve of the adjoining filling station, the effect being a 
substantial increase in output per unit of time. Moreover, this 
arrangement makes it possible so to dimension the piping as to permit flow 
of ice cream at a low temperature, and thus of high viscosity. 
Moreover, the balancing and metering device with a beam of which the 
counterweight moves along an inclined rail, permit constant compensation 
for the weight increase of the container being filled, which acts via the 
rod connected to the container-carrying platform on the first arm of the 
beam. 
Moreover since the rail along which moves the balancing counter-weight has 
a slope which may be adjusted by a manual and visible control the 
counter-weight may be adapted to the different densities of products being 
filled. 
It is to be understood that the present invention has only been described 
and shown by way of preferred example and that its constituent parts may 
be replaced by technical equivalents without going outside the scope of 
the invention as hereafter claimed.