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EP 0 722 365 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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29.03.2000 Bulletin 2000/13 |
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Date of filing: 12.10.1994 |
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International application number: |
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PCT/NZ9400/105 |
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International publication number: |
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WO 9510/358 (20.04.1995 Gazette 1995/17) |
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MINERAL BREAKERS
MINERALBRECHER
BROYEURS A MINERAUX
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Designated Contracting States: |
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DE ES FR GB SE |
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Priority: |
14.10.1993 NZ 24895393
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Date of publication of application: |
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24.07.1996 Bulletin 1996/30 |
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Proprietor: Svedala New Zealand Limited |
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Matamata 2271 (NZ) |
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Inventors: |
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- COLLINS, Timothy, George
Matamata 2271 (NZ)
- RODGER, Ian, Gordon
Matamata 2271 (NZ)
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Representative: Andrews, Timothy Stephen et al |
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Marks & Clerk,
57-60 Lincoln's Inn Fields London WC2A 3LS London WC2A 3LS (GB) |
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References cited: :
EP-A- 0 429 298 US-A- 4 844 364
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US-A- 4 796 822
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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TECHNICAL FIELD
[0001] This invention relates to modifications to mineral breakers.
BACKGROUND ART
[0002] Reference throughout this specification shall be made to use of the present invention
in relation to centrifugal mineral breakers. It should be appreciated however that
the principles of the present invention could possibly apply to alternate mineral
breakers or any other material or size reduction apparatus.
[0003] Centrifugal mineral breakers have mineral material (such as rocks) fed axially into
a rotor assembly which is revolving at high speed. Rocks are also fed into the mineral
breaker so that they fall in a stream outside the rotor assembly. The rocks within
the rotor assembly are flung outwardly so that they impact upon the rock stream. This
impact shatters the rocks into smaller sizes.
[0004] Most of the parts inside a rotor assembly are adequately protected by wear by a rock
lining or wave which builds up within the rotor assembly. Those areas not protected
by rock lining or wave are protected by wear parts. The surfaces located near the
discharge ports of the rotor assembly are particularly vulnerable to erosion by the
passage of mineral material exiting the rotor assembly.
[0005] To address this problem, there are provided tip assemblies located at the discharge
ports of the rotor assembly. At these ports, where it is envisaged that there will
be the greatest amount of wear on the tip assembly, tungsten carbide (or any other
hard material inserts are often inserted. Tungsten carbide is extremely wear resistant,
but unfortunately is also very expensive and therefore it is uneconomical to have
a tip completely made of this material.
[0006] Thus, the material holding the tungsten carbide still wears away (along with the
tungsten) and the tip assembly and tip is required to be replaced regularly.
[0007] The mineral breaker can suffer serious damage if there is no tip assembly in the
proximity of the discharge port. This can happen if the tip assembly wears through
or breaks off due to impact or erosion wear. To avoid damage to the rotor in the event
that the primary tip is worn or broken for any reason, a backup tip of similar construction
may be included in the tip assembly. This backup will give some protection to the
rotor assembly until the tip can be replaced.
[0008] Coarse materials have typically caused premature failure of conventional tip assemblies.
This is because the tip assembly is unable to resist wear and impact of the larger
rocks and further unable to retain the larger sized rocks in the rock lining of the
rotor.
[0009] US Patent No. 4940188 discloses an attempt to address the above problem by providing
an increased volume of space behind the tip assembly which allows the rock lining
or wave to be more firmly held in place by the tip assembly and to hold larger rocks
therein. In some cases, a large rock can overhang the tungsten and provide the wear
surface itself. However, there are still problems with this configuration and a greater
volume available would also be desirable.
[0010] Further, in order to secure the tip assembly to the rotor assembly, it is necessary
for this extra material to extend into the rock wave, thus, still taking up some volume
which could be used to further retain larger rocks and secure the rock wave.
[0011] This prior art assembly also only allows a single mounting system involving bolts
to be utilised which again extend into the rock wave. This makes it difficult to access
the bolts when it is desired to replace the tip assembly. Excessive wear also occurs
at the bolt positions.
[0012] Another problem experienced with conventional rotor tip assemblies for centrifugal
mineral breakers is slip streaming. Slip streaming is a phenomenon which occurs when
water and fine particles of dust and grit from the rocks are accelerated within the
rotor and as it exits the rotor assembly. Because of the size of the particles, they
find their way into various cracks, small gaps and so forth in the rotor assembly
causing considerable wear to the rotor and the tip assemblies. With conventional tip
assembly designs, the slip steaming would wear the ends of the tip assembly as they
did not fully meet with the inside surfaces of the top and bottom rotor assembly plates.
[0013] European Patent No. 429298 discloses an attempt to address the problem of ease of
entry into the rotor for maintenance purposes. It also provides for the provision
of one-piece wear plates for areas within the rotor previously protected from wear
by a number of individual wear plates. However, there are still problems with this
configuration as the tip assemblies cannot be removed without first removing the top
wear plate. Furthermore, the bolts used to secure the tip assemblies may also extend
into the rock wave making it difficult to access the bolts when it is desired to replace
the tip assembly.
[0014] It is an object of the present invention to address the above problems or at least
to provide the public with a useful choice.
[0015] Further objects and advantages of the present invention will become apparent from
the following description which is given by way of example only.
DISCLOSURE OF INVENTION
[0016] According to one aspect of the present invention there is provided a rotor assembly
for a centrifugal mineral breaker characterised in that the rotor assembly has at
least one inset on the inner surface of either its top or bottom plates, said inset
being capable of receiving either the top and bottom side of a tip assembly.
[0017] In preferred embodiments there are insets in both the top and bottom plates.
[0018] It should be appreciated that the inner surface referred to may in some embodiments
be an additional plate attached to the actual top or bottom plates of the rotor assembly.
For example this plate may be a wear plate.
[0019] Reference throughout this specification will be made to material in the form of rocks,
grit and so forth. It should be appreciated that these terms are included merely for
clarity and can be used interchangeably.
[0020] As tip assemblies are required to be replaced on a regular basis, it is preferable
that the insets are shaped so as to allow the easy removal of a tip assembly therefrom.
Thus, in preferred embodiments the insets are substantially curved in shape allowing
for easy insertion of the tip assemblies. This curvature preferably also minimises
the gap between the tip and edge of the inset for the tip in any position and allows
for minimum metal removal on manufacture.
[0021] This invention has a number of advantages over the prior art.
[0022] The rock wave which builds up within the rotor housing varies according to the type
of rock, the size of the rock falling within and the configuration of the rock (say
sharp or rounded). Ideally the rock wave which is built up should cover all of the
vulnerable parts of the rotor assembly not protected by additional wear parts leaving
only the leading edge of the tip (which is mainly tungsten carbide) exposed to the
wear of the rock exiting the rotor. Thus this may be true for a certain type of rock
entering into the mineral breaker set up a certain way. However, as soon as the rock
type is changed, a different rock wave is formed which causes additional wear to the
tip than normally encountered.
[0023] The applicant has found that by adjusting the angle of the tip holder with respect
to the rotor housing, the differing rock waves can be accommodated. Thus, it may be
possible to adjust the angle of a tip holder prior to a different type of rock being
introduced to the rotor and still accommodate the resultant differing rock wave. Ideally
the angle of the tip holder shall be that the majority of wear will occur across the
face of the tungsten and not the edge.
[0024] The present invention can also allow for the tip assembly to be positioned at different
angles with respect to the rotor assembly. For example, if a substantially curved
path is provided on the inset, the tip assembly can be positioned at any portion of
the curved part provided it can be secured there by some other means.
[0025] According to an alternate aspect of the present invention there is provided a method
of altering the angle of a tip assembly with respect to a rotor assembly of a centrifugal
mineral breaker which has at least one inset on the surface of the top or bottom plate
characterised by the step of providing a pivot point about which the tip assembly
can rotate.
[0026] It can be seen that by having a pivot point, the angle of the tip assembly can be
changed which is facilitated in one embodiment by the additional step of locating
the tip assembly within an inset of the rotor assembly.
[0027] The means by which the tip assembly is held at the desired angle can be achieved
by a variety of means. For example, the pivot may be a cog which can interact with
various parts of the tip assembly, the teeth on the cog serving to hold the tip assembly
into place.
[0028] In preferred embodiments, there is provided a smooth pivot with a cam which operates
as a stop preventing movement of the tip assembly past a pre-defined point.
[0029] The force of the rocks hitting tip assemblies tend to throw the tip assemblies outwards.
Because of this, it is not necessary to have stops which secure the movement of the
tip assembly in two directions as the force of the rocks effectively act as a stop
in one of the directions.
[0030] Thus, in one embodiment, there may be provided only one stop which prevents the tip
assembly from moving outwards against the force of the rocks. This can come in a variety
of forms, for example a fixed wedge or block.
[0031] A preferred means of providing a stop is to have an eccentric cam situated within
the rotor housing. The cam may be rotatable about a pivot while capable of bearing
against the base of the tip assembly (preferably the base of the tip assembly). Rotation
of the cam can push the tip assembly until the tip assembly reaches the desired angle.
Preferably this action is along the path set by the insets. The cam can then be locked
in position such that it cannot rotate.
[0032] The tip assembly may be capable of moving forwards into the rotor housing when the
mineral breaker is not in operation. However, once the mineral breaker is in operation
the force of the rocks exiting the rotor assembly will push the tip assembly outwards
to the desired angle which in some embodiments is governed by the force of the cam
against the base of the tip assembly.
[0033] It should be appreciated that the present invention can apply to tip assemblies of
various designs whether they have back up tips or not.
[0034] The present invention has a number of advantages over the prior art. One major advantage
of the present invention is that considerably less material is used than in conventional
tip constructions, as there is no additional material required to extend into the
rock wave to secure the tip assembly. This provides advantages in the management of
the rock wave. Less material in front of the tip assembly means a greater volume of
space behind the tip is available for the rock wave to be more firmly held in place
and for larger rocks to be held within. This leads to less wear on the tip assembly.
[0035] A further advantage of not having the attachment means extending into the rock wave
is that the tip assembly can be more readily removed from the rotor assembly. Bolts
are not required, which again can make it easier to detach the tip assembly from the
rotor.
[0036] Yet another advantage of the present invention is that the top and bottom sides of
the tip assembly cannot be worn away by slip streaming as they are contained within
the paths. That is, there is now no gap between the ends of the tip assembly and the
rotor assembly which has been vulnerable to slip streaming.
[0037] Thus it can be seen that the present invention offers a number of advantages. Firstly,
there is greater volume provided to aid in the securing of the rock wave. Secondly
there is provided a relatively easy means by which the angle of the tip assembly can
be altered to accommodate the parameters of the rock wave. Thirdly, problems associated
with slip streaming have been reduced.
BRIEF DESCRIPTION OF DRAWINGS
[0038] Aspects of the present invention will now be described by way of example only and
with reference to the accompanying drawings in which:
- Figure 1:
- is a diagrammatic cross-sectional view of one embodiment of the present invention,
and
- Figure 2:
- is a diagrammatic perspective view of the above embodiment.
BEST MODES FOR CARRYING OUT THE INVENTION
[0039] With respect to Figures 1 and 2, there is illustrated means of attachment for a rotor
tip assembly generally indicated by arrow 1.
[0040] Only one plate 2 is shown of the rotor assembly 1, although it should be appreciated
that both plates of the rotor housing will be substantially identical as regards the
present invention.
[0041] The plate 2 has an inset 3 which provides a substantially curved path for the tip
assembly 4 to slide along. In this embodiment, the tip assembly 4 is shown to be a
single tip with no back up tip, however it should be appreciated that the present
invention can be used in relation to tip assemblies having other configurations.
[0042] The tip assembly 4 is connected to a pivot 5 which can slot into an appropriate inset
(not shown) in the rotor housing 2.
[0043] An eccentric cam 6 is bolted via bolt 7 to a plate 8 within the rotor housing. Rotation
of the cam 6 can be restricted or permitted by the bolt of which holds the cam 6 with
respect to the rotor assembly 1. For example, rotation of the cam 6 around the bolt
7 can be achieved by loosening off the bolt 7. Likewise tightening the bolt 7 restricts
rotation of the cam 6.
[0044] Between the inside face of the tip assembly 4 and the cam 6 is a linkage block 9.
The linkage block 9 acts to transfer force from rotation of the eccentric cam 6 to
the tip assembly 4. It is envisaged that the linkage block 9 is a semi-permanent part
of the rotor assembly 1 which is not replaced along with the tip assembly 4. In some
embodiments the linkage block may act as a backup tip.
[0045] The top arrow in Figure 1 illustrates the effect of the direction of the force that
the rocks exiting the discharge port of the rotor applies to the tip assembly 4. The
bottom arrow on Figure 1 illustrates the force that the cam 6 exerts against the linkage
block 9 and hence the inside face of the tip assembly 4 below the pivot point 5.
[0046] As the above forces are on opposing sides of the pivot, the cam 6 acts as a counter
to the force of the rocks exiting the rotor assembly 1. Thus, the most outward position
of the tip assembly 4 is governed by the cam 6.
[0047] Aspects of the present invention have been described by way of example only and it
should be appreciated that modifications and additions may be made thereto without
departing from the scope of the appended claims.
1. A rotor assembly (1) for a centrifugal mineral breaker characterised in that the rotor
assembly (1) has at least one inset (3) on the surface of either its top or bottom
plate (2), said inset (3) being capable of receiving either the top or bottom side
of a tip assembly (4).
2. A rotor assembly (1) as claimed in claim 1 which has insets in both the bottom and
top plates (2).
3. A rotor assembly (1) as claimed in either claim 1 or claim 2 wherein the inset (3)
is substantially curved in shape.
4. A rotor assembly (1) as claimed in any one of claims 1 to 3 wherein the tip assembly
(4) can be positioned at different angles with respect to the rotor assembly (1).
5. A tip assembly (4) adapted to being used within a rotor assembly (1) as claimed in
any one of claims 1 to 4.
6. A method of altering the angle of a tip assembly (4) with respect to rotor assembly
(1) of a centrifugal mineral breaker which has at least one inset (3) on the surface
of the top or bottom plate (2) characterised by the step of providing a pivot point
(5) about which the tip assembly (4) can rotate.
7. A method as claimed in claim 6 characterised by the further step of locating the tip
assembly (4) within an inset (3) in the rotor assembly (1).
8. A method as claimed in either claim 6 or claim 7 wherein the pivot (5) is in the form
of a cog.
9. A method as claimed in either claim 6 or claim 7 wherein the pivot (5) is smooth.
10. A method as claimed in any one of claims 7 to 9 wherein there is provided a cam (6)
which operates as a stop preventing movement of the tip assembly (4) past a pre-defined
point.
11. A method as claimed in claim 10 where in the cam (6) is eccentric.
12. A method as claimed in either claim 10 or claim 11 wherein the cam (6) is rotatable
about a pivot (7) and capable of bearing against the tip assembly (4).
13. A method as claimed in any one of claims 10 to 12 wherein rotation of the cam (6)
can push the tip assembly (4) until the tip assembly (4) reaches a desired angle.
14. A method as claimed in any one of claims 10 to 13 wherein the cam (6) is capable of
being locked into position so that it cannot rotate.
15. A method as claimed in any one of claims 10 to 14 wherein the rotation of the cam
(6) can be restricted or permitted by a bolt (8) holding the cam (6) with respect
to the rotor assembly (1).
16. A method as claimed in any one of claims 10 to 15 wherein there is provided a linkage
block (9) that acts to transfer force from rotation of the cam (6) to the tip assembly
(4).
17. A method as claimed in claim 16 wherein the linkage block (9) acts as a backup tip.
1. Rotorbaugruppe (1) für einen Zentrifugalerzbrecher, dadurch gekennzeichnet, daß die
Rotorbaugruppe (1) mindestens einen Einsatz (3) auf der Fläche von entweder ihrer
oberen oder unteren Platte (2) aufweist, wobei der Einsatz (3) in der Lage ist, entweder
die obere oder die untere Seite einer Kopfbaugruppe (4) aufzunehmen.
2. Rotorbaugruppe (1) nach Anspruch 1, die Einsätze in sowohl der oberen als auch der
unteren Platte (2) aufweist.
3. Rotorbaugruppe (1) nach entweder Anspruch 1 oder Anspruch 2, bei der der Einsatz (3)
im wesentlichen eine gekrümmte Form aufweist.
4. Rotorbaugruppe (1) nach einem der Ansprüche 1 bis 3, bei der die Kopfbaugruppe (4)
unter verschiedenen Winkeln mit Bezugnahme auf die Rotorbaugruppe (1) angeordnet werden
kann.
5. Kopfbaugruppe (4), die so ausgeführt ist, daß sie innerhalb einer Rotorbaugruppe (1)
nach einem der Ansprüche 1 bis 4 eingesetzt werden kann.
6. Verfahren zum Ändern des Winkels einer Kopfbaugruppe (4) mit Bezugnahme auf die Rotorbaugruppe
(1) eines Zentrifugalerzbrechers, der mindestens einen Einsatz (3) auf der Fläche
der oberen oder unteren Platte (2) aufweist, gekennzeichnet durch den Schritt des
Bereitstellens eines Drehpunktes (5), um den sich die Kopfbaugruppe (4) herum drehen
kann.
7. Verfahren nach Anspruch 6, gekennzeichnet durch den weiteren Schritt des Anordnens
der Kopfbaugruppe (4) innerhalb eines Einsatzes (3) in der Rotorbaugruppe (1).
8. Verfahren nach entweder Anspruch 6 oder Anspruch 7, bei dem der Drehpunkt (5) in der
Form einer Nase vorliegt.
9. Verfahren nach entweder Anspruch 6 oder Anspruch 7, bei dem der Drehpunkt (5) gleichmäßig
ist.
10. Verfahren nach einem der Ansprüche 7 bis 9, bei dem ein Nocken (6) bereitgestellt
wird, der als ein Anschlag funktioniert, der die Bewegung der Kopfbaugruppe (4) an
einer vorbestimmten Stelle vorbei verhindert.
11. Verfahren nach Anspruch 10, bei dem der Nocken (6) exzentrisch ist.
12. Verfahren nach entweder Anspruch 10 oder Anspruch 11, bei dem der Nocken (6) um einen
Drehpunkt (7) herum drehbar und in der Lage ist, gegen die Kopfbaugruppe (4) zu drücken.
13. Verfahren nach einem der Ansprüche 10 bis 12, bei dem die Drehung des Nockens (6)
die Kopfbaugruppe (4) drücken kann, bis die Kopfbaugruppe (4) einen gewünschten Winkel
erreicht.
14. Verfahren nach einem der Ansprüche 10 bis 13, bei dem der Nocken (6) in Position verriegelt
werden kann, so daß er sich nicht drehen kann.
15. Verfahren nach einem der Ansprüche 10 bis 14, bei dem die Drehung des Nockens (6)
durch eine Schraube (8), die den Nocken (6) hält, mit Bezugnahme auf die Rotorbaugruppe
(1) eingeschränkt oder gestattet werden kann.
16. Verfahren nach einem der Ansprüche 10 bis 15, bei dem ein Verbindungsblock (9) bereitgestellt
wird, der wirkt, um eine Kraft von der Drehung des Nocken (6) auf die Kopfbaugruppe
(4) zu übertragen.
17. Verfahren nach Anspruch 16, bei dem der Verbindungsblock (9) als ein Stützkopf wirkt.
1. Assemblage de rotor (1) pour un broyeur de minéraux centrifuge, caractérisé en ce
que l'assemblage de rotor (1) comporte au moins une entaille (3) sur la surface de
sa plaque supérieure ou inférieure (2), ladite entaille (3) étant capable de recevoir
le côté supérieur ou inférieur d'un assemblage de tête (4).
2. Assemblage de rotor (1) selon la revendication 1, comportant des entailles dans les
plaques inférieure et supérieure (2).
3. Assemblage de rotor (1) selon les revendications 1 ou 2, dans lequel l'entaille (3)
a une forme essentiellement courbée.
4. Assemblage de rotor (1) selon l'une quelconque des revendications 1 à 3, dans lequel
l'assemblage de tête (4) peut être positionné à des angles différents par rapport
à l'assemblage de rotor (1).
5. Assemblage de tête (4) destiné à être utilisé dans un assemblage de rotor (1) selon
l'une quelconque des revendications 1 à 4.
6. Procédé de modification de l'angle d'un assemblage de tête (4) par rapport à l'assemblage
de rotor (1) d'un broyeur de minéraux centrifuge, comportant au moins une entaille
(3) sur la surface de la plaque supérieure ou inférieure (2), caractérisé par l'étape
d'établissement d'un pivot (5) autour duquel l'assemblage de tête (4) peut tourner.
7. Procédé selon la revendication 6, caractérisé par l'étape additionnelle de positionnement
de l'assemblage de tête (4) dans une entaille (3) dans l'assemblage de rotor (1).
8. Procédé selon les revendications 6 ou 7, dans lequel le pivot (5) a la forme d'un
pignon.
9. Procédé selon les revendications 6 ou 7, dans lequel le pivot (5) est lisse.
10. Procédé selon l'une quelconque des revendications 7 à 9, comportant la fourniture
d'une came (6) faisant fonction d'arrêt empêchant le déplacement de l'assemblage de
tête (4) au-delà d'un point prédéfini.
11. Procédé selon la revendication 10, dans lequel la came (6) est excentrique.
12. Procédé selon les revendications 10 ou 11, dans lequel la came (6) peut tourner autour
d'un pivot (7) et est capable d'exercer une pression contre l'assemblage de tête (4).
13. Procédé selon l'une quelconque des revendications 10 à 12, dans lequel la rotation
de la came (6) peut pousser l'assemblage de tête (4) jusqu'à ce que l'assemblage de
tête (4) atteint un angle voulu.
14. Procédé selon l'une quelconque des revendications 10 à 13, dans lequel la came (6)
peut être bloquée dans sa position, de sorte à empêcher sa rotation.
15. Procédé selon l'une quelconque des revendications 10 à 14, dans lequel la rotation
de la came (6) peut être restreinte ou autorisée par un boulon (8) retenant la came
(6) par rapport à l'assemblage de rotor (1).
16. Procédé selon l'une quelconque des revendications 10 à 15, comportant un bloc de liaison
(9) servant à transférer la force de la rotation de la came (6) vers l'assemblage
de tête (4).
17. Procédé selon la revendication 16, dans lequel le bloc de liaison (9) sert de tête
de soutien.