[0001] This invention relates to a cam system and to a rotary filling head which incorporates
the cam system.
[0002] Machines for dispensing fluid material into containers are well known, an example
of such a machine being that disclosed in British Patent No. 1383506. In such a machine
the containers which are to be filled with fluid material are fed tangentially to
a rotary filler (or rotary filling head) and during the time that the containers are
in the region of the head they are filled, after which the filled containers tangentially
leave the region of the filling head.
[0003] The rotary filling head is provided with a plurality of filling stations which move
around a circular path in conjunction with the same part-circular path followed by
the containers being filled.
[0004] Each filling head includes a dispensing system which comprises a piston in a cylinder,
movement of the piston in one direction, usually downwardly, allowing fluid material
under pressure to be introduced into the piston chamber, and movement of the piston
in the other direction, usually upwardly, causing expulsion of the fluid material
from the chamber towards the container to be filled. In one known arrangement, each
such piston normally has a piston rod which is provided with two rollers which are
to follow respective cams. One such roller, usually the upper roller, is known as
the piston control roller or top control roller and its function is, by following
a piston control cam, to cause movement of the piston in the other (upward) direction
so as to cause expulsion of the fluid material from the piston chamber.
[0005] The other roller is known as a weight control roller and, in conjunction with a weight
control cam, determines the maximum amount of movement in the one (downward) direction,
thereby determining the sweep of the piston and, when multiplied by the cross-sectional
area of the cylinder, the volume being permitted to enter the piston chamber during
the induction stroke.
[0006] Particularly with those pistons which are designed to operate with a diaphragm, which
causes a seal between the piston chamber and the piston head (to prevent the accumulation
of fluid material in the region of the chamber), it is desirable for the fluid material
to remain in a condition of over-pressure (i.e. greater than super-atmospheric pressure)
so as to cause the downward movement of the diaphragm and hence the piston - this
prevents any "gap" occurring between the diaphragm and the head of the piston, as
could happen if the piston where forced downwards by a cam. With this type of arrangement,
when it is wished to vary the volume/weight being dispensed, it is necessary to move
the weight control cam, i.e. the lower cam. So as to allow the piston control roller
to be free to travel further downwards (assuming the weight control cam has been moved
downwards), it is necessary either to have a sufficiently lower guide path on the
piston control cam or to replace the piston control cam by one which has a suitably
low portion so as to be compatible with the new position being adopted. This can obviously
involve stopping the machine for a considerable time while the weight control cam
is positioned and while any necessary adjustments are made to the piston control cam.
It is possible, with certain types of piston control cam, for there to be a sufficient
distance between the upper guide and the lower guide of the cam to accommodate a wide
range of positions for the weight control cam, but this can have the effect, when
small volumes are being dispensed, of meaning that the piston control roller contacts
the lower guide of the piston control cam over only a short distance, and thus the
filling only occurs over a short interval. For many technical and production reasons,
it is best for the filling of the container to occur over as long a period as possible
and also for the filling of the piston chamber from the source of material to occur
over as long a period as possible.
[0007] With another known arrangement of cam system, there is no separate weight control
cam and its associated roller. Instead, the sole cam controls both the upward and
downward movement of the piston (without relying on the over-pressure of the fluid
material to cause the downward movement of the piston). When it is wished to vary
the volume/weight being dispensed with such an alternative arrangement, it is necessary
to stop the machine and replace one particular cam dedicated to a particular volume
by another particular cam dedicated to another particular volume.
[0008] Not only does the changing of cam take a considerable period, especially bearing
in mind the relevant inaccessibility of the cam within the rest of the machine, but
also, when one dedicated cam is replaced by another, it still means that only two
different particular volumes can be dispensed, there being no provision for a variable
weight/volume over a wide weight/volume range.
[0009] US-A-230 7214 discloses an adjustable cam having a pair of generally semi-circular
cam sections with provision for telescopic movement between the sections, with the
whole of the cam remaining planar but with provision for the plane in which the came
lies to be varied by pivotal movement of one cam section relative to a support, and
vertical movement of the other cam section.
[0010] According to a first aspect of the present invention, there is provided a cam which
has a first part in the form of an arc of a circle and a second part in the form of
the remainder of the same circle, characterised in that the first and second parts
of the cam are pivotal with respect to each other at two places spaced apart along
the same pivotal axis.
[0011] Preferably, the two end faces of the first part of the cam and the two end faces
of the second part of the cam are planar and parallel to each other. The four end
faces have a periphery at least a portion of which has the configuration of an arc
of a circle, with the pivot axis lying at the centre of the circle; a consequence
of this is that even when the second part of the cam pivots with respect to the first
part of the cam there is, over part of the surfaces in the region of the joint, a
continuous smoothness.
[0012] Following from the preferred feature mentioned in the immediately preceding paragraph
is the preferred feature that the circular cam has, in a radial section, a peripheral
region at least part of which takes the form of an ellipse. If the end faces of the
first part and of the second part of the cam were, in the plane of those end faces,
totally circular, the radial section through the circular cam would be totally elliptical.
[0013] According to a second aspect of the present invention, there is provided a rotary
filling head with a plurality of filling stations, in each of which the fluid being
dispensed is expelled from a piston chamber by movement in one direction of a piston
having a piston rod, the movement of the piston in the one direction being in response
to the interaction between a piston control roller associated with the piston and
a piston control cam in accordance with the first-mentioned aspect of the present
invention.
[0014] Preferably in such a rotary filling head each piston rod also has a weight control
roller, the filling head having a weight control cam which can limit the movement
in the opposite direction of the piston rods by rolling abutment between the weight
control rollers and the weight control cam.
[0015] In the filling head of the present invention, the piston control cam is preferably
mounted so that with the first part of the arc lying in a horizontal plane and with
the second part being inclined to the horizontal the centre of the cam lies on the
same vertical line regardless of the angle of inclination of the second part of the
cam. Preferably the first part of the piston control cam is mounted to permit horizontal
translational movement of the first part of the piston control cam so as to allow
variation in the horizontal distance between the first part of the piston control
cam and the aforesaid vertical line, depending on the angle of inclination of the
second part of the piston control cam.
[0016] To assist in this effect, the second part of the piston control cam is provided with
two diametrically opposed pins which are located in vertically slotted brackets, in
order to ensure that the centre of the piston control cam remains on the aforementioned
vertical line.
[0017] In the filling head, preferably there is provision for the weight control cam to
be moved upwardly and downwardly whilst the cam remains horizontal. Preferably this
is achieved by the provision of vertical guides which allow the weight control cam
to be moved vertically upwards and downwards, the vertical movement being controlled
by rotatable screws which, on rotation, cause the upward or downward movement of the
weight control cam. Preferably the screws used to cause the upward or downward movement
of the weight control cam can through gearing be controlled by a single weight adjusting
spindle.
[0018] Additionally, it is preferred for there to be a link between the weight control cam
and the piston control cam such that upward or downward movement of the weight control
cam (for example in the manner described above) causes respective upward or downward
pivotal movement of the second part of the piston control cam with respect to the
first part of that cam.
[0019] With such an arrangement for the filling head, the dosing system becomes fully adjustable.
In fact, adjustment could even be made whilst the machine continues to run, although
this would not be desirable because different volumes would be introduced into adjacent
containers. In practice, the machine would be stopped, the necessary adjustment effected
by rotation of the weight adjusting spindle, and then the machine re-commenced to
fill the containers with the new desired weight/volume.
[0020] It will be appreciated that, with an approximately constant spacing between the piston
control roller (or top control roller) and the weight control roller on each piston
rod, the upward and downward movement of the weight control cam permits a wide range
of infinitely variable volumes to be dispensed. Moreover, and most importantly, the
fact that the lowermost portion of the arc of the second part of the piston control
cam is also generally following the upward or downward movement of the weight control
cam means that the piston control roller can be in contact with the piston control
cam over a large percentage of its travel around the circular path, thus avoiding
the situation, mentioned above, in which the filling and expulsion of the fluid material
into and from the piston chamber occurs only over a short portion of the circular
path, thus wasting valuable filling and discharge time. It will also be readily appreciated
that with the filling head in accordance with the invention, the adjustment of the
single weight adjusting spindle causes not only adjustment of the weight control cam
but also appropriate adjustment of the piston control cam.
[0021] Regarding the rotation of the weight control spindle, this can be done manually or
can be effected by means of a motor which can be linked to an automatic weight control
system, if desired.
[0022] For a better understanding of the present invention and to show how the same may
be carried into effect, reference will now be made, by way of example, to the accompanying
drawings in which:
Figure 1 is a plane view of part of the dosing system of a rotary filling head in
accordance with the present invention; and
Figure 2 is a vertical section taken along the line II - II shown in Figure 1.
[0023] In order deliberately to keep the drawings simple, well known components of the filling
head are not shown. Also for simplicity, although in Figure 1 the head has six filling
stations each with its own piston 1 (shown only in Figure 2) and associated piston
rod 2, only some of the rollers associated with the rods 2 are shown. Similarly, in
Figure 2, only two of the pistons 1 and rods 2 are shown, although more are obviously
present.
[0024] Each piston 1 is located in a conventional cylinder (not shown) and each piston is
mounted on a piston rod 2 which at an intermediate position is provided with a piston
control roller 3 (also known as a top control roller, as it determines the top point
reached by the piston during its upward travel). The piston rod 2 is also provided,
near its lower end region, with a weight control roller 4.
[0025] A piston control cam 5 is in two parts, namely a first part 6 and a second part 7.
When the second part 7 of the piston control cam 5 is horizontal the cam 5 assumes
a perfectly circular configuration, as viewed from above. The first part 6 of the
cam 5 represents a minor arc of a circle and the second part 7 of the cam 5 represents
a major arc of the same circle. The two end faces of the first part 6 of the cam 5
are planar and parallel, as are also the two end faces of the second part 7 of the
cam 5. These planes are vertical. A pivotal axis 8 passes through all four end faces
of the first and second parts 6, 7 of the cam 5.
[0026] Each end face of the first and second parts 6, 7 of the cam 5, as viewed along the
axis 8, has an upper peripheral portion which is circular. The whole of the end faces,
as viewed along the pivot axis 8, could be circular but this is not of importance.
In fact, generally, the end faces are rectangular apart from an upper, part-circular
portion. It is the circularity of the upper portion which is of importance.
[0027] A consequence of the end faces having an upper portion which is part-circular is
that the upper portion of the first and second parts, 6, 7 of the cam 5 have, as seen
in radial cross-section, an elliptical configuration.
[0028] The pivot axis 8 is at a position such that it is at the centre of the circle partly
followed by the upper portion of the end faces of the first and second parts 6, 7
of the cam 5. The consequence of this is that, even when the second part 7 of the
cam 5 is pivoted with respect to the first part 6, the upper most portion of the cam
5 in the region of the join between the first and second parts 6, 7 is smooth and
continuous, thereby avoiding any "step" in the movement of the piston control rollers
3 which are to follow the uppermost portion of the piston control cam 5 over the majority
of its circumference.
[0029] The filling head also includes a support 9 on which are provided two blocks 10 provided
with two respective horizontal bores 11 in which are located respective rods 12, which
are freely movable within the horizontal bores 11. Mounted on the rods 12 is a beam
13 extending beyond the two rods 12. The beam 13 supports the first part 6 of the
piston control cam 5. The sliding relationship along a horizontal line of action between
the rods 12 and the bores 11 permits the beam 13 and hence the first part 6 of the
piston control cam 5 to move horizontally in towards, and out from, a vertical line
14 which is the vertical axis of the whole filling head and is the vertical line on
which the centre of the piston control cam 5 is to lie.
[0030] Projecting outwardly along a diameter of the circle constituted by the first and
second parts 6, 7 of the piston control cam 5, at points 90° remote around the circle
from the centre of the first part 6, are two pins 15, 16 which are pivotally mounted
in two respective blocks 17, 18 which, in turn, are located in two vertical slots,
only one of which 19 is shown in Figure 2, the two vertical slots being provided in
two uprights 20, 21 which project upwardly from two bases 22, 23. The arrangement
is such that the pivotal axis 24 which passes through the centre of the pins 15, 16
remains in the same vertical plane which intersects the vertical line 14 regardless
of the inclination of the second part 7 of the piston control cam 5.
[0031] As the first part 6 of the piston control cam 5 remains at the same, fixed vertical
height, it will be appreciated that the axis 24 rises and falls depending on whether
the second part 7 of the cam 5 has been pivoted upwardly or downwardly with respect
to the first part 6 of the cam 5. The illustrated arrangement ensures that the axis
24 always bisects the vertical line 14.
[0032] Standing upright and opposite the support 9 is another support 25, both the supports
9, 25 being mounted on a main base 26. Provided on the support 9 is a guide 27 which
cooperates, in sliding relationship, with a guide 28 carried on a block 29. Similarly,
the support 25 is provided with a guide 30 which cooperates, in sliding relationship,
with a guide 31 carried on a block 32. The blocks 29 and 32 are located at diametrically
opposed locations on the exterior of a circular weight control cam 33, and the blocks
29 and 32 are provided with internally threaded vertically disposed bores, in which
bores the screwthreads engage with external screwthreads on two upright screws 34,
35. These screws 34,35 are mounted for rotation relative to the main base 26 and,
through respective pairs of bevel gears 36, 37 and 38, 39, are linked to a control
spindle 40. Pivotally mounted on the block 32 are two generally upright arms 41, 42
which are pivotally connected, at their upper end regions, to the second part 7 of
the piston control cam 5 in regions remote from the first part 6 of that cam 5. The
linkage system is such that, upon rotation of the control spindle 40 in one direction
the screws 34, 35 are rotated in one direction so as to cause upward movement of the
blocks 29, 32 and hence upward movement of the weight control cam 33 whilst keeping
the same in a horizontal disposition. The upward movement of the block 32 causes,
through the arms 41 and 42, corresponding upward pivotal movement of the second part
7 of the piston control cam 5.
[0033] In view of the linkage in the forms of the arms 41, 42 between the block 32 and that
region of the second part 7 of the piston control cam 5 remote from the first part
6, the vertical spacing between that region of the second part 7 and the weight control
cam 33 remains approximately the same, although there are slight variations in view
of the fact that the arms 41, 42 become more inclined to the vertical the lower that
the weight control cam 33 descends. The vertical spacing between the piston control
roller 3 and weight control roller 4 on each piston rod 2 remains constant and, therefore,
by virtue of the fact that the region of the second part 7 of the cam 5 descends with
the weight control cam 33, it is possible to ensure that the piston control roller
3 is out of contact with the piston control cam 5 for only a small part of the generally
circular path followed by the piston control roller 3.
[0034] At the right hand side of Figure 2 it can be seen that the piston 1 is in its uppermost
position, as the piston control roller 3 is at the highest point of its travel, namely
resting on the first part 6 of the piston control cam 5. As soon as the piston control
roller moves off the first part 6, it moves on to the second part 7 of the piston
control cam which, because it is downwardly inclined, allows the roller 3 to descend,
being driven down by an over-pressure of fluid material in the piston chamber acting
on the piston 1. The piston 1 continues to descend in a controlled manner, as the
piston control roller 3 follows a first zone of the second part 7 of the piston control
cam 5. However, shortly before reaching the lowermost region of the second part 7,
the weight control roller 4 comes into contact with the horizontal weight control
cam 33 thus preventing any further downward movement of the piston rod 2 and piston
1.
[0035] The piston 1 and piston rod 2 shown in the left hand half of Figure 2 are at their
lowermost position. Further movement of the piston rod 2 in a clockwise direction,
as viewed from above in Figure 1, results in the roller 3 coming into contact again
with the upwardly inclined second part 7 of the piston control cam with the result
that the piston rod 2 and piston 1 are raised to cause expulsion of filling material
from the piston chamber. Obviously, as soon as the roller 3 comes into contact with
the upwardly inclined portion of the second part 7 of the piston control cam 5, the
weight control roller 4 of the associated piston rod 2 is raised clear of the weight
control cam 33.
[0036] When it is desired to alter the volume/weight of material being dispensed by the
rotary filling head, rotation of the control spindle 40 is effected which, as indicated
above, alters the height of the weight control cam 33 whilst causing an almost corresponding
variation in the height of the lowermost portion of the second part 7 of the piston
control cam 5. The degree of variation is fully adjustable. Although the height of
the weight control cam 33 can be infinitely varied over a certain range, it will be
appreciated that the maximum height of the piston 1 remains fixed, as the maximum
height of the path of travel of the piston control roller 3 is associated with the
top of the first part 6 of the piston control cam 5, which remains at a fixed height.
1. A cam (5) which has a first part (6) in the form of an arc of a circle and a second
part (7) in the form of the remainder of the same circle, characterised in that the
first and second parts (6,7) of the cam (5) are pivotal with respect to each other
at two places spaced apart along the same pivotal axis (8).
2. A cam according to claim 1, wherein the two end faces of the first part (6) of the
cam and the two end faces of the second part (7) of the cam are planar and parallel
to each other.
3. A cam according to claim 2, wherein the four end faces have a periphery at least a
portion of which has the configuration of an arc of a circle, with the pivot axis
(8) lying at the centre of the circle.
4. A cam according to claim 3, wherein the circular cam has, in a radial section, a peripheral
region at least part of which takes the form of an ellipse.
5. A rotary filling head with a plurality of filling stations, in each of which the fluid
being dispensed is expelled from a piston chamber by movement in one direction of
a piston (1) having a piston rod (2), the movement of the piston (1) in the one direction
being in response to the interaction between a piston control roller (3) associated
with the piston rod (2) and a piston control cam (5) in accordance with any one of
claims 1 to 4.
6. A rotary filling head according to Claim 5, wherein each piston rod (2) also has a
weight control roller (4), the filling head having a weight control cam (33) which
can limit the movement in the opposite direction of the piston rods (2) by rolling
abutment between the weight control rollers (4) and the weight control cam (33).
7. A rotary filling head according to claim 6, wherein the piston control cam (5) is
mounted in such a way that with the first part (6) of the arc lying in a horizontal
plane and with the second part (7) being inclined to the horizontal the centre of
the cam lies on the same vertical line (14) regardless of the angle of inclination
of the second part (7) of the cam.
8. A rotary filling head according to claim 7, wherein the first part (6) of the piston
control cam is mounted to permit horizontal translational movement of the first part
(6) of the piston control cam (5) so as to allow variation in the horizontal distance
between the first part (6) of the piston control cam and the aforesaid vertical line
(14), depending on the angle of inclination of the second part (7) of the piston control
cam (5), and wherein the second part (7) of the piston control cam is provided with
two diametrically opposed pins (15, 16) which are located in vertically slotted brackets
(20,21), in order to ensure that the centre of the piston control cam remains on the
aforementioned vertical line (14).
9. A rotary filling head according to any one of claims 6 to 8, which includes provision
for the weight control cam (33) to be moved upwardly and downwardly whilst the first
part (6) of the piston control cam (5) remains horizontal.
10. A rotary filling head according to claim 9, wherein said provision for the weight
control cam to be moved upwardly and downwardly comprises vertical guides (27,28 ;
30,31) which allow the weight control cam (33) to be moved vertically upwards and
downwards, the vertical movement being controlled by rotatable screws (34, 35) which,
on rotation, cause the upward or downward movement of the weight control cam, the
screws used to cause the upward or downward movement of the weight control cam preferably
being, through gearing, controllable by a single weight adjusting spindle (40).
11. A rotary filling head according to claim 9 or 10, which includes a link (41, 42) between
the weight control cam (33) and the piston control cam (5) such that upward or downward
movement of the weight control cam (33) causes respective upward or downward pivotal
movement of the second part (7) of the piston control cam (5) with respect to the
first part (6) of that cam.
1. Nocke (5) mit einem ersten Teil (6) in Form eines Kreisbogens und einem zweiten Teil
(7) ebenfalls in Form eines Kreisbogens, wobei sich die beiden Kreisbögen zu einem
ganzen Kreis ergänzen,
dadurch gekennzeichnet,
daß das erste und das zweite Teil (6,7) an zwei Stellen miteinander gelenkig verbunden
sind, wobei die beiden Dreh- oder Schwenkpunkte axial beabstandet auf der selben Dreh-
oder Schwenkachse (8) liegen.
2. Nocke nach Anspruch 1, wobei die beiden Stirnflächen des ersten Teils (6) der Nocke
und die beiden Stirnflächen des zweiten Teils (7) der Nocke eben und parallel zueinander
sind.
3. Nocke nach Anspruch 2, wobei die vier Stirnflächen eine Begrenzung aufweisen, die
zumindest teilweise die Form eines Kreisbogens hat, wobei die Dreh- oder Schwenkachse
(8) durch den Mittelpunkt dieses Kreises verläuft.
4. Nocke nach Anspruch 3, wobei die kreisförmige Nocke im Radialschnitt einen Randbereich
aufweist, der zumindest teilweise die Form einer Ellipse hat.
5. Rotierender Füllkopf mit einer Vielzahl von Füllstationen, in denen das zu dispensierende
Fluid durch die Bewegung eines eine Kolbenstange (2) aufweisenden Kolbens (1) in eine
Richtung aus einer Kolbenkammer ausgetrieben wird, wobei die Bewegung des Kolbens
(1) in diese Richtung durch das Zusammenwirken einer Kolbensteuerrolle (3), die an
der Kolbenstange (.2) angeordnet ist, und einer Kolbensteuernocke (5) nach einem der
Ansprüche 1 bis 4 erfolgt.
6. Rotierender Füllkopf nach Anspruch 5, wobei jede Kolbenstange (2) weiter eine Massensteuerrolle
(4) aufweist und der Füllkopf mit einer Massensteuernocke (33) versehen ist, die in
der Lage ist, die Bewegung der Kolbenstangen (2,) in der entgegengesetzten Richtung
durch einen rollenden Eingriff zwischen den Massensteuerrollen (4) und der Massensteuernocke
(33) zu begrenzen.
7. Rotierender Füllkopf nach Anspruch 6, wobei die Kolbensteuernocke (5) so angeordnet
ist, daß, wenn das erste Teil (6) des Bogens in einer Horizontalebene liegt und das
zweite Teil (7) zur Horizontalebene geneigt ist, der Mittelpunkt der Nocke unabhängig
vom Neigungswinkel des zweiten Teils (7) der Nocke auf der selben Vertikalachse (14)
liegt.
8. Rotierender Füllkopf nach Anspruch 7, wobei das erste Teil (6) der Kolbensteuernocke
so angeordnet ist, daß eine horizontale Translationsbewegung des ersten Teils (6)
der Kolbensteuernocke (5) ermöglicht ist, um so eine Veränderung, des horizontalen
Abstands zwischen dem ersten Teil (6) der Kolbensteuernocke und der vorgenanntenen
Vertikalachse (14) in Abhängigkeit vom Neigungswinkel des zweiten Teils (7) der Kolbensteuernocke
(5) zu ermöglichen, und wobei das zweite Teil (7) der Kolbensteuernocke mit zwei einander
diametral gegenüberliegenden Stiften (15,16) versehen ist, die in Trägern (20,21)
mit vertikal verlaufenden Schlitzen gelagert sind, um so sicherzustellen, daß der
Mittelpunkt der Kolbensteuernocke auf der vorgenannten Vertikalachse (14) bleibt.
9. Rotierender Füllkopf nach einem der Ansprüche 6 bis 8, mit Mitteln zur Bewegung der
Massensteuernocke (33) nach oben und unten, während das erste Teil (6) der Kolbensteuernocke
(5) horizontal bleibt.
10. Rotierender Füllkopf nach Anspruch 9, wobei die Mittel zur Bewegung der Massensteuernocke
nach oben oder unten vertikale Führungen (27,28;30,31) umfassen, die es erlauben,
die Massensteuernocke (33) vertikal nach oben und unten zu bewegen, wobei die vertikale
Bewegung durch drehbare Schrauben (34,35) gesteuert wird, die bei Drehung die Aufwärts-
oder Abwärtsbewegung der Massensteuernocke bewirken, und wobei diese Schrauben zur
Aufwärts- oder Abwärtsbewegung der Massensteuernocke vorzugsweise durch eine einzige
Masseneinstellspindel (40) über ein Getriebe steuerbar sind.
11. Rotierender Füllkopf nach Anspruch 9 oder 10, mit einem Verbindungsglied (41,42) zwischen
der Massensteuernocke (33) und der Kolbensteuernocke (5), so daß die aufwärts oder
abwärts gerichtete Bewegung der Massensteuernocke (33) eine entsprechende aufwärts
oder abwärts gerichtete gelenkige Bewegung des zweiten Teils (7) der Kolbensteuernocke
(5) bezüglich des ersten Teils (6) dieser Nocke bewirkt.
1. Une came (5) qui présente une première pièce (6) en forme d'arc de cercle et une seconde
pièce (7) en forme du reste du même cercle, caractérisée en ce que les première et
seconde pièces (6, 7) de la came (5) sont pivotantes l'une par rapport à l'autre en
deux endroits espacés sur le même axe de pivotement (8).
2. Une came suivant la revendication 1, dans laquelle les deux faces d'extrémité de la
première pièce (6) de la came et les deux faces d'extrémité de la seconde pièce (7)
de la came sont planes et parallèles l'une à l'autre.
3. Une came suivant la revendication 2, dans laquelle les quatre faces d'extrémité présentent
une périphérie dont au moins une partie présente la configuration d'un arc de cercle,
l'axe de pivotement (8) se trouvant au centre du cercle.
4. Une came suivant la revendication 3, dans laquelle la came circulaire présente, dans
une section radiale, une zone périphérique dont au moins une partie prend la forme
d'une ellipse.
5. Une tête de remplissage rotative avec une pluralité de postes de remplissage, dans
chacun desquels le fluide distribué est expulsé d'une chambre à piston par le déplacement
dans une direction d'un piston (1) présentant une tige de piston (2), le déplacement
du piston (1) dans une direction s'effectuant en réponse à l'interaction entre un
rouleau de commande du piston (3) associé à la tige de piston (2) et une came de commande
du piston (5) suivant l'une ou l'autre des revendications 1 à 4.
6. Une tête de remplissage rotative suivant la revendication 5, dans laquelle chaque
tige de piston (2) présente un rouleau de commande de charge (4), la tête de remplissage
présentant une came de commande de charge (33) qui peut limiter le déplacement dans
la direction opposée des tiges de piston (2) par l'aboutement en roulant entre les
rouleaux de commande de charge (4) et la came de commande de charge (33).
7. Une tête de remplissage rotative suivant la revendication 6, dans laquelle la came
de commande de piston (5) est montée de telle manière que, lorsque la première pièce
(6) de l'arc se trouve dans un plan horizontal et la seconde pièce (7) est inclinée
par rapport à l'horizontale, le centre de la came se situe sur la même ligne verticale
(14), quel que soit l'angle d'inclinaison de la seconde pièce (7) de la came.
8. Une tête de remplissage rotative suivant la revendication 7, dans laquelle la première
pièce (6) de la came de commande de piston est montée pour permettre le mouvement
de translation horizontal de la première pièce (6) de la came de commande de piston
(5), de manière à permettre une variation de la distance horizontale entre la première
pièce (6) de la came de commande de piston (5) et la ligne verticale (14) précitée
en fonction de l'angle d'inclinaison de la seconde pièce (7) de la came de commande
de piston (5) et dans laquelle la seconde pièce (7) de la came de commande de piston
est pourvue de deux goupilles diamétralement opposées (15, 16) qui se situent dans
des supports (20, 21) à rainures verticales, de manière à assurer que le centre de
la came de commande de piston reste sur la ligne verticale (14) précitée.
9. Une tête de remplissage rotative suivant l'une ou l'autre des revendications 6 à 8,
qui comporte un dispositif pour faire monter et descendre la came de commande de charge
(33) tandis que la première pièce (6) de la came de commande de piston (5) reste horizontale.
10. Une tête de remplissage rotative suivant la revendication 9, dans laquelle ledit dispositif
pour faire monter et descendre la came de commande de charge comprend des guides verticaux
(27, 28; 30, 31) qui permettent de déplacer la came de commande de charge (33) verticalement
vers le haut et le bas, le déplacement vertical étant commandé par des vis rotatives
(34, 35) qui, lors de la rotation, provoquent le mouvement ascendant ou descendant
de la came de commande de charge, les vis utilisées pour provoquer le mouvement ascendant
ou descendant de la came de commande de charge pouvant, de préférence, être commandées,
via un engrenage, par une simple broche de réglage de charge (40).
11. Une tête de remplissage rotative suivant la revendication 9 ou 10, qui comporte une
liaison (41, 42) entre la came de commande de charge (33) et la came de commande de
piston (5), de manière que le mouvement ascendant ou descendant de la came de commande
de charge (33) provoque le mouvement de pivotement vers le bas ou le haut respectif
de la seconde pièce (7) de la came de commande de piston (5) par rapport à la première
pièce (6) de la came.