Title of Invention

SYSTEM FOR CONNECTING TWO SHAFTS IN TRANSLATION

Abstract Abstract The invention relates to a system for providing a mechanical and electrical connection between the ends of two essentially-coaxial shafts (1 and 2), whereby each shaft end comprises a groove (11, 12) close to an axial end extension (17 and 8; 18 and 9). Moreover, the aforementioned ends are connected inside a sleeve (10) comprising: a first annular shoulder (13) having a shape that is complementary to that of the groove of the first shaft, such that there is no clearance therebetween; a second annular shoulder (14) having a shape that is complementary to that of the groove (12) of the second shaft, but with a clearance therebetween; and a cavity (16) which is intended to receive the shaft ends, said cavity having an axial height which is greater than the sum of the axial heights of the axial end extensions (17 and 8; 18 and 9). The invention is characterised in that the axial end extensions (17 and 8; 18 and 9) of the two shafts are in permanent mechanical and electrical contact via an elastic conducting means (7).
Full Text

ABSTRACT OF THE DISCLOSURE SYSTEM FOR CONNECTING TWO SHAFTS IN TRANSLATION
Mechanical and electrical connection system between the ends of two approximately coaxial shafts (1 and 2), wherein
• each shaft end comprises a groove (11; 12) close
• to an end axial prolongation (17 and 8; 18 and
• 9),
• the said ends are connected inside a coupling
• (10) provided with:

- a first annular shoulder (13) , with a shape
- complementary to the shape o f the groove in
- the first shaft, without any clearance,
- a second annular shoulder (14), with a shape
- complementary to the shape of the groove (12)
- in the second shaft but with a clearance,
- a cavity (16) that will contain the said
- shaft ends and for which the axial height is
- greater than the sum of the axial heights of
- the end axial prolongations (17 and 8; 18 and
- 9);
and in that
• the corresponding end axial prolongations (17
and 8; 18 and 9) of the two shafts remain in
permanent mechanical and electrical contact due
to an elastic conducting means (7).
Figure 1.

SYSTEM FOR CONNECTING TWO SHAFTS IN TRANSLATION
DESCRIPTION
Technical domain
This invention relates to a mechanical and electrical connection system between the ends of two
coaxial shafts, which move along a globally axial direction and that can transmit approximately axial forces. This type of configuration is used particularly when it is required to separate a shaft in two parts, to protect one of its ends from high strains (temperatures, stresses, lateral shocks, etc.) resisted by the other end.
This invention more particularly relates to crustbreaking devices used in electrolytic aluminium production pots. These are used to break the surface crust of the solidified bath. They are often associated either with metering devices that supply alumina to the pot, or to measurement devices used to measure the temperature and level of electrolyte in the pot so as to enable regulated supply of the bath with alumina.
State of the art
ALUMINIUM PECHINEY patent FR 2 483 965 describes such a crustbreaking device in which the crustbreaker, also called a plunger, is associated with an axial displacement mechanism. It is placed vertically, and periodically descends to break the solidified bath crust at the supply point or to keep the hole formed in this crust open, such that the alumina brought in

through a pipe can penetrate into the molten electrolyte. For several reasons explained in FR 2 483 965, it is important to detect if the plunger comes into contact with molten electrolyte or with solidified electrolyte, during its downward movement. Detection of the contact between the end of the plunger (called the chisel) and the molten electrolyte is made by measuring an electrical voltage between the plunger and a point on the cell used as the reference potential. Typically, the plunger is electrically isolated from the superstructure of the pot, and when the chisel comes into contact with the molten electrolyte bath, its electrical potential is close to the potential of the molten electrolyte. The measurement of this potential is used as information to send the order to raise the plunger.
Patent ^P-B-0 716 165 describes a crustbreaking device surrounding and protecting a measurement device that not only measures the bath level but also its temperature. For this device, it is also important to detect the moment at which the plunger comes into contact with the molten electrolyte and the crustbreaker is also provided with a detection device based on measurement of an electrical voltage between the plunger and a point on the cell used as a reference potential.
Problem that arises
The plunger is subjected to violent thermal and mechanical strains near the chisel. As the time that the chisel remains in the electrolyte bath increases,

the risk of formation of a crust on its surface as it rises increases, and this crust can get thicker during subsequent operations, causing problems with operation and premature wear of the plunger.
The plunger must not be excessively deformed and must be electrically reliable, otherwise it will not operate correctly; it must remain electrically isolated from the pot superstructure at all times and it must always be able to carry an electrical current to detect contact with the electrolyte bath. Furthermore, since the chisel can wear quickly and deform progressively, it is important to provide a means of replacing it easily and regularly. Finally, the other end of the plunger is connected to an axial movement control device, typically a jack, that can only operate correctly at a temperature close to ambient temperature and provided that no excessive mechanical loads are applied to it, since it is particularly sensitive to lateral shocks.
For all these reasons, the plunger has been decoupled into two approximately coaxial parts; a rod associated with the control jack and a rod (called the extension) that is fitted with the chisel at one of its ends. These two parts are usually connected to each other by a screw - nut system but this system is not fully satisfactory since it transmits mechanical shocks resisted by the chisel without really damping them, particularly sudden lateral forces that prevent smooth operation of the jack. Furthermore, loosening problems frequently occur with the screw - nut system (for

example when the chisel has to be replaced) and cannot guarantee a reliable permanent electrical contact.
Therefore, the applicant has developed a connecting system between the two parts of the plunger that does not have these disadvantages.
Purpose of the invention
The invention consists of a mechanical and electrical connection system between the ends of two approximately coaxial shafts that move along a globally axial direction and are capable of transmitting approximately axial forces, one of the shafts called the "driving shaft" being connected to an axial translation device, typically a jack, and the other shaft called the "driven shaft" typically being equipped with a measurement device. This system is characterised in that:
• the end of the said driving shaft that will
• come into contact with the end of the driven
• shaft comprises an annular groove close to an
• axial end prolongation, with axial height Hi,
• the end of the said driven shaft that will come
• into contact with the end of the driving shaft
• comprises an annular groove close to an axial
• prolongation, with axial height H2,
• the said ends are connected inside an
• approximately cylindrical coupling, the said
• coupling being provided with:
- a first annular shoulder, with a shape complementary to the shape of the said annular groove located close to the axial

prolongation of the end of the said driving shaft, without clearance,
- a second annular shoulder, with a shape
- complementary to the shape of the said
- annular groove close to the axial
- prolongation of the end of the said driven
- shaft, a radial clearance being provided
- between the complementary surfaces of the
- annular shoulder of the said coupling and the
- annular groove in the said driven shaft,
- a cavity that will contain the end axial
- prolongations of the said shafts and for
- which the axial height is greater than the
- sum of the axial heights Hi and H2 of the
- said end axial prolongations;
and in that
• the corresponding end axial prolongations of the driving shaft and the driven shaft remain in permanent mechanical and electrical contact due to an elastic conducting means, typically a metallic helical spring.
According to the invention, the first annular shoulder of the coupling has a shape complementary to the shape of the annular groove of the driving shaft, with no clearance, while the second annular shoulder of the coupling has a shape complementary to the shape of the annular groove of the driven shaft, a radial clearance being provided between the complementary surfaces of the annular shoulder of the said coupling and the annular groove of the said driven shaft.

Since there is no clearance between the groove of the driving shaft and the shoulder of the coupling, it is possible to make the centre lines of the two coincide. On the other hand, the clearance formed between the complementary surfaces of the annular shoulder of the coupling and the annular groove of the driven shaft reduces the amplitude of lateral shocks imposed on the driven shaft at the chisel and transmitted to the driving shaft through the coupling.
Preferably, the annular groove of the driving shaft has a U-section, such that it has two walls perpendicular to the centre line separated by a distance equal to an axial height HO, and a "bottom" in the form of a cylindrical surface coaxial with the said centre line with diameter C and the section of the first annular shoulder of the coupling is also globally a U shape, with two walls perpendicular to the centre line at a distance equal to a value very slightly less
than HO, typically HO - e, where 0.05 mm typically C + ef , where 0,05 m Also preferably, the section of the annular groove of the driven shaft has two walls perpendicular to the centre line separated by a distance equal to an axial height H3 and a cylindrical "bottom" with diameter G and the section of the second annular shoulder of the coupling is also globally in a U shape, with two walls perpendicular to the centre line at a distance equal to a value H4 less than H3, and a cylindrical wall with a diameter greater than the diameter of the annular

groove of the driven shaft. Finally, to complete the clearance formed between the inner surface of the coupling and the outer surface of the end of the driven shaft and thus reduce the amplitude of lateral shocks that could be transmitted through the coupling to the driving shaft, a radial clearance is formed between the outer surface of the end axial prolongation of the driven shaft and the wall of the cavity formed in the coupling designed to hold the end axial prolongations of the two shafts.
Also preferably, the end axial prolongation of the driving shaft comprises a protuberance, the final end of which has a transverse wall that occupies a plane surface or a surface of revolution with respect to the centre line of the shaft, convex and with low curvature at its mid-point, while the end axial prolongation of the driven shaft comprises a protuberance, for which the final end has a transverse wall with a profile such that when the two shafts are put into contact, the contact area between the said protuberance and the driving shaft is located at a point as close as possible to the centre line of the driving shaft. For example, this type of transverse wall may have a convex surface of revolution about the centre line of the driven shaft, with a greater curvature at its mid-point than the curvature of the transverse wall of the protuberance of the driving shaft.
Preferably, the end axial prolongations of each shaft comprise a base located between the annular groove and the protuberance. The base and the protuberance are arranged such that the said elastic

conducting means can bear on each of the shafts, such that there is a continuous electrical contact between the two shafts. The base of each end axial prolongation may be cylindrically shaped with a diameter greater than the diameter of the protuberance, such that an offset is formed between the said base and the said protuberance. If the elastic conducting means is a metallic helical spring, the shape and position of the offset and the shape of the helical spring are defined such that the spring is guided at its end in the axial direction by the protuberance, and the end of the spring bears in contact with the said offset.
Also preferably, to avoid any lateral disturbance, all contact between the two shafts is avoided at any point other than the contact point between the protuberances, itself located as close as possible to the centre line of the driving shaft. Thus, to avoid transmission of forces through the coupling, the end wall of the said coupling located on the side of the driven shaft is arranged such that it cannot come into contact with the driven shaft, even after running in or even wear of the contact surfaces between the two shafts• Thus, when the geometries of the grooves and the U-shaped shoulders are modified, the difference H3 - H4, in other words the difference between the axial height H3 of the annular groove in the driven shaft and the axial height H4 of the second annular shoulder of the coupling, must remain greater than the maximum clearance that can exist between the corresponding ends of the protuberances of the driving shaft and the driven shaft.

In one preferred embodiment of the invention, the end of the driving shaft comprises an annular groove and an end axial prolongation that are adjacent to each other, such that since the cylindrical base of the end axial prolongation has a diameter greater than the diameter of the annular groove, a transverse wall is formed that will come into contact with the first shoulder of the coupling. Similarly, the end of the driven shaft comprises an annular groove and an end axial prolongation, that are adjacent to each other, such that since the cylindrical base of the end axial prolongation has a diameter greater than the diameter of the annular groove, a transverse wall is formed that will come into contact with the second shoulder of the coupling. In this way, the second shoulder of the coupling is separated from the first shoulder such that together they delimit the cavity within the said coupling into which the end axial prolongations of the shaft will fit.
In practice, the coupling is made in several pieces, for example two shells in the form of half cylinders, comprising the said first and second shoulders on their inner face. These shells are placed such that the first and second shoulders are facing the annular grooves in the driving and driven shafts, and are then held fixed to each other by means of a cylindrical sleeve slid onto one end of one of the shafts and that is made to slide so that it covers the assembly of the two previously assembled shells. This sleeve is then fixed in place using conventional systems such as pins passing through the said sleeve

and one of the shells, retaining ring, nut, needle screw, etc. The coupling and the sleeve are preferably made of metal, typically steel or brass.
Of course, the geometries may be inverted; the shafts may be provided with annular shoulders and the coupling may be provided with one first and one second annular groove, with complementary shapes. Similarly, the corresponding shapes of the ends of the protuberances can be interchanged. Also, the association of the coaxial alignment of the coupling on the driving shaft (no clearance between the annular groove in the driving shaft and the first shoulder of the coupling) and the radial and axial clearances formed between the annular groove of the driven shaft and the second shoulder of the coupling may be replaced by a symmetric combination: coaxial alignment of the coupling on the driven shaft (no clearance between the annular groove of the driven shaft and the second shoulder of the coupling) associated with radial and axial clearances formed between the annular groove of the driving shaft and the first shoulder of the coupling.
To better understand the invention, we will describe a particular embodiment specifically adapted to crustbreaking systems used in electrolytic pots.
Figure 1 illustrates a diametric section through a system according to the invention.
Figure 2 is a section along the plane I-1 of the system shown in Figure 1.

Detailed description of the invention
The system represented according to Figure 1 shows a connecting means between two shafts 1 and 2. This means is designed so as to enable the shaft 1 to drive the shaft 2 in translation in the two directions, either by pulling it or pushing it. Shaft 1 has its own guidance system in translation (not shown). Shaft 2 also has its own guidance system in translation (not shown) and radial forces on shaft 2 must not cause any radial force on the shaft 1 (or as little as possible). Furthermore, the connecting system between these two shafts must be easily separable without any risk of damaging parts.
To obtain this result:
a) The shaft 1 called the driving shaft with
diameter 0A has a centring area with diameter 0B for the proposed system. The two contact areas with
diameter 0B are slightly smaller than the diameter 0A so that they pass freely into the guiding element of
the driving shaft 1 on diameter 0A.
The end of the driving shaft 1 is provided with a circular groove 11 with inside diameter 0C and width -or axial height - HO such that the first shoulder of the proposed connecting system can be inserted. Thus,
this connecting system is centred on the diameters 0B and is connected in translation by a shoulder 13 that
fits into the groove 11 with inside diameter 0C and width HO.
The end of the driving shaft 1 is provided with an end axial prolongation with height H1 close to the circular groove 11. This prolongation comprises a

cylindrical base 17 with diameter 0E and a protuberance 8. The diameter 0E of the end of the
driving shaft 1 may be equal to diameter 0B or very slightly smaller (only a few tenths of millimetre so that the shoulder is sufficient).
b) The shaft 2 called the driven shaft with
diameter 0F has a groove 12 with diameter 0G and width H3 enabling a second shoulder 14 of the proposed connecting system to fit into it. Thus, when this connecting system is in position, the two shafts are connected in translation.
The end of the driven shaft 2 is also provided with an axial end prolongation with height H2 close to the annular groove 12. This prolongation includes a
cylindrical base 18 with diameter 0K and a protuberance 9. The profile of the end of this protuberance 9 is such that when the driving shaft 1 and the driven shaft 2 come into contact, their contact point is located at the smallest possible distance from the centre line of the driving shaft 1. Thus, if the guides of shafts 1 and 2 are offset, the contact between these two shafts is made close to their centre line, for example when shaft 1 pushes shaft 2.
c) The connecting system comprises a coupling 10
composed of three main parts: two identical shells 3
and 4 in the form of half cylinders, each with two
complementary shoulders that form the annular shoulders
13 and 14 of the coupling after the shells come into
contact. The first shoulder 13 fits into the annular
groove 11 of the driving shaft 1, with no clearance.
The second shoulder 14 fits into the groove 12 of the

driven shaft 2, with a clearance. These two shells have a half bore with diameter 0B so that they are centred on the diameter 0B of the driving shaft 1.
The two shells 3 and 4 are made from a cylindrical part that is fully machined to obtain the functions described above, and is then cut along an axial plane so as to obtain two identical pieces. They are held in position by a sleeve 5 that is centred on their outer diameter so as to keep them perfectly in position with respect to the driving shaft 1. The sleeve 5 is fixed in translation with respect to the half shells 3 and 4 by a shoulder 15 and two pins 6 centred in each of the two shells 3 and 4 and fitting into two holes drilled diametrically opposite in the sleeve 5. The sleeve immobilization system is described for guidance knowing that other systems such as a retaining ring, nut, or needle screws could be used.
To enable displacement of the shaft 2 with respect to the shaft 1, the connecting system is designed such as to leave:
- A radial clearance Jl between the connecting part (the coupling 10) and the base of the axial prolongation of the driven shaft 2. The cavity 16 formed in the coupling 10 to hold the axial end prolongation of the driving shaft 1 and the axial end prolongation of the driven shaft 2 is a bore, the diameter of which is defined such that there is a radial clearance Jl between this bore and the diameter 0K of the cylindrical base 18 of the end axial prolongation of the driven shaft 2.

- An axial clearance J2 between two ends of the
- shafts 1 and 2. The second shoulder 14 is
- separated from the first shoulder 13 such that
- together they delimit the cavity 16 - that will
- hold the said ends - in the coupling 10, the
- axial height of the cavity being greater than
- the sum of the axial heights Hi and H2 of the
- end axial prolongations of the said shafts.
- A radial clearance J3 between the bottom of the
- groove 12 in the driven shaft 2 and the 2nd
- shoulder 14 of the connecting system.
- An axial clearance J4 between the end L of the
- connecting system and the side M of the groove
- 12 in the driven shaft 2 such that there is no
- contact in this area, even after running in of
- the ends of the two shafts. Thus, to avoid
- transmission of forces through the coupling 10,
- the end wall L of the said coupling located on
- the side of the driven shaft 2 is arranged such
- that it cannot come into contact with the driven
- shaft, even after running in, or even wear of
- contact surfaces between the two shafts. Thus,
- the difference between the axial height H3 of
- the annular groove 12 of the driven shaft 2 and
- the axial height H4 of the annular shoulder 14
- of the coupling 10 always remains greater than
- the maximum clearance J2 that can exist between
- the corresponding ends of the protuberance 8 of
- the driving shaft 1 and the protuberance 9 of
- the driven shaft 2.

This system immobilising the two shafts 1 and 2 in translation is applied firstly in crustbreaking systems and alumina supply systems for aluminium electrolytic pots. The connection between the rod of the pneumatic crustbreaking jack with the extension rod that supports the chisel is thus made.
In fact, the driving shaft 1 is the rod of the pneumatic jack and the driven shaft 2 is the extension rod that supports the chisel. This system enables a mechanical connection between the shafts 1 and 2 and due to this perfectly controlled connection/ a contact spring 7 can be installed between the two rods so that an electrical signal can be passed from one rod to the other and thus enable measurement of an electric potential between the end of the chisel and the a point on the electrolytic pot used as a reference.
Construction measures related to the bearings and guidance of the spring 7 on each of the rods are such that, regardless of the forces or movements applied to each of the rods, continuity of current transfer is guaranteed. The spring 7 is a helical metallic spring centred on each of the ends of the jack rod (driving shaft 1) and the extension rod that supports the chisel (driven shaft 2). The shape and position of the base 17 and the protuberance 8 of the jack rod 1, the shape and position of the base 18 and the protuberance 9 of the extension rod 2, and the shape of the spring 7 itself are defined so that the spring 7 always has good bearing on each rod, so that the spring is permanently in contact on these ends.

Centring the spring 7 on the rod 1 and centring the spring 7 on rod 2 are designed such that the spring 7 can follow the relative axial and radial displacements of the two rods 1 and 2 without being damaged.

CLAIMS
1. Mechanical and electrical connection system between the ends of two approximately coaxial shafts (1 and 2) that move along a globally axial direction (100) and are capable of transmitting approximately axial forces, one of the shafts called the "driving shaft" (1) being connected to an axial translation device, typically a jack, and the other shaft called the "driven shaft" (2), characterised in that:
• the end of the said driving shaft (1) that will
• come into contact with the end of the driven
• shaft (2) comprises an annular groove (11)
• close to an axial end prolongation (17 and 8),
• with axial height Hi,
• the end of the said driven shaft (2) that will
• come into contact with the end of the driving
• shaft (1) comprises an annular groove (12)
• close to an axial prolongation (18 and 9), with
• axial height H2,
• the said ends are connected inside an
• approximately cylindrical coupling (10), the
• said coupling being provided with:

- a first annular shoulder (13), with a shape
- complementary to the shape of the said
- annular groove (11) located close to the end
- axial prolongation (17 and 8) of the said
- driving shaft (1), without clearance,
- a second annular shoulder (14), with a shape
- complementary to the shape of the said
- annular groove (12) close to the end axial

prolongation (18 and 9) of the said driven shaft (2) , a radial clearance being provided between the complementary surfaces of the annular shoulder (14) of the said coupling (10) and the annular groove (12) of the said driven shaft (2) ,
- a cavity (16) that will contain the end axial prolongations (17 and 8; 18 and 9) of the said shafts, the axial height of the said cavity (16) being greater than the sum of the axial heights H1 and H2 of the said end axial prolongations; and in that
• the end axial prolongation (17 and 8) of the driving shaft (1) and the end axial prolongation (18 and 9) of the driven shaft (2) remain in permanent mechanical and electrical contact due to an elastic conducting means (7), typically a metallic helical spring.
2. Mechanical and electrical connection system between the ends of two approximately coaxial shafts (1 and 2) according to claim 1, in which the annular groove (11) of the driving shaft (1) has two walls perpendicular to the centre line (100) separated by a distance equal to an axial height HO, and a bottom in the form of a cylindrical surface coaxial with the said centre line (100) with diameter C and in which the section of the annular shoulder (13) has a shape complementary to the shape of the coupling (10) and also has two walls perpendicular to the centre line

separated by a distance equal to a value slightly less than HO, typically HO - e, where 0.05 mm 3. System for connecting two shafts in translation
according to either claim 1 or 2, in which the annular
groove (12) of the driven shaft (2) has two walls
perpendicular to the centre line of the shaft (2)
separated by a distance equal to an axial height H3,
and a bottom in the form of a cylindrical surface with
diameter 0G and in which the annular shoulder (14) with a complementary shape to the coupling (10) has also two walls perpendicular to the centre line of the coupling and separated by a distance equal to a value H4 less than H3, and a cylindrical wall with a diameter greater than the diameter of the annular groove (12) of the driven shaft (2).
4. Mechanical and electrical connection system
5. between the ends of two approximately coaxial shafts (1
6. and 2) according to claim 3, in which there is a radial
7. clearance Jl between the outer surface of the end axial
8. prolongation (18 and 9) of the driven shaft (2) and the
9. wall of the cavity (16) formed in the coupling (10) and
10. designed to hold the end axial prolongations (1 and 2)
11. of the two shafts.
12. Mechanical and electrical connection system
13. between the ends of two approximately coaxial shafts (1
14. and 2) according to claim 3, in which the difference
15. between the axial height of the said cavity (16) and
16. the sum of the axial heights H1 and H2 corresponds to a

maximum clearance J2 between the said shaft ends and the difference between the axial height H3 of the annular groove (12) of the driven shaft (2) and the axial height H4 of the second annular shoulder (14) of the coupling (10) corresponds to a maximum clearance J4 greater than the maximum clearance J2 between the said shaft ends.
6. Mechanical and electrical connection system
7. between the ends of two approximately coaxial shafts (1
8. and 2) according to any one of claims 1 to 5, in which
9. the end axial prolongation (17 and 8) of the driving
10. shaft (1) comprises a protuberance (8) , the final end
11. of which has a transverse wall that occupies a convex
12. surface of revolution with respect to the centre line
13. of the driving shaft (1), while the end axial
14. prolongation (18 and 9) of the driven shaft (2)
15. comprises a protuberance (9) , the final end of which
16. has a transverse wall with a profile such that when the
17. two shafts are put into contact, the contact area
18. between the said protuberance (9) and the protuberance
19. (8) of the driving shaft (1) is located at a point as
20. close as possible to the centre line (100) of the
21. driving shaft (1) .
22. Mechanical and electrical connection system
23. between the ends of two approximately coaxial shafts (1
24. and 2) according to claim 6, in which the end axial
25. prolongation (18 and 9) of the driven shaft (2)
26. comprises a protuberance (9) for which the final end
27. has a transverse wall that occupies a convex surface of
28. revolution about the centre line of the driven shaft
29. (2), with a greater curvature at its mid-point than the

curvature of the transverse wall of the protuberance (8) of the driving shaft (1).
8. Mechanical and electrical connection system
9. between the ends of two approximately coaxial shafts (1
10. and 2) according to any one of claims 1 to 7, in which
11. the end axial prolongations of each shaft (1 and 2)
12. comprise a base (17 and 18 respectively) located
13. between the annular groove (13 and 14 respectively) and
14. the protuberance (7 and 8 respectively) , the base (17
15. and 18 respectively) and the protuberance (7 and 8
16. respectively) being arranged such that the said elastic
17. conducting means (7) can bear on each of the shafts,
18. such that there is a continuous electrical contact
19. between the two shafts.
20. Mechanical and electrical connection system
21. between the ends of two approximately coaxial shafts (1
22. and 2) according to any one of claims 1 to 8, in which
23. the end of the driving shaft (1) comprises an annular
24. groove (11) and an end axial prolongation (17 and 8)
25. adjacent to each other, such that since the cylindrical
26. base (17) of the end axial prolongation has a diameter
27. greater than the diameter of the annular groove (11), a
28. transverse wall is formed that will come into contact
29. with the first shoulder (13) of the coupling and in
30. which the driven shaft (2) comprises an annular groove
(12) and an end axial prolongation (18 and 9) that are adjacent to each other, such that since the cylindrical base (18) of the end axial prolongation has a diameter greater than the diameter of the annular groove (12), a transverse wall is formed that will come into contact with the second shoulder (14) of the coupling, the said

second shoulder being separated from the first shoulder such that together they delimit the cavity (16) within the said coupling into which the end axial prolongations of the shaft will fit.
10. Mechanical and electrical connection system
11. between the ends of two approximately coaxial shafts (1
12. and 2) according to any one of claims 1 to 9, in which
13. the said coupling (10) comprises two shells (3 and 4)
14. in the form of half cylinders, comprising the said
15. first shoulder (13) and the said second shoulder (14)
16. on their inner face, the said shells being placed such
17. that the first shoulder (13) and the second shoulder
18. (14) are facing the annular grooves (11 and 12
19. respectively) in the driving shaft (1) and the driven
20. shaft (2), and being held fixed to each other by means
21. of a cylindrical sleeve (5) slid onto one end of one of
22. the shafts (1).
23. Mechanical and electrical connection system
24. between the ends of two approximately coaxial shafts (1
25. and 2) according to claim 10, in which the said sleeve
26. (5) is fixed in place at one end using a shoulder (15)
27. acting as a stop to the shells (3 and 4) and at the
28. other end using an attachment means fixing each shell
29. in place with the sleeve (5), typically a pin (6)
30. passing through the said sleeve.
31. Electrolytic aluminium production pot
32. equipment comprising a mechanical and electrical
33. connection system between the ends of a driving shaft
34. (1) and a driven shaft (2) approximately coaxial to
35. each other, according to any one of claims 1 to 11.

13. Crustbreaking and measuring device, used to break the surface crust of the solidified bath and measure the temperature and level of the electrolyte in a pot for the production of aluminium by fused bath electrolysis of the alumina dissolved in the said electrolyte, the said device being characterised in that it comprises a mechanical and electrical connecting system between the ends of an approximately coaxial driving shaft (1) and a driven shaft (2) according to any one of claims 1 to 11, in which the said driving shaft (1) is the rod of the pneumatic crustbreaking jack and the said driven shaft (2) is the extension rod that supports the chisel that will plunge into the electrolyte.
Dated this 16 day of June 2006

Documents:

2151-CHENP-2006 AMENDED CLAIMS 22-06-2011.pdf

2151-CHENP-2006 EXAMINATION REPORT REPLY RECEIVED 22-06-2011.pdf

2151-chenp-2006 form-3 22-06-2011.pdf

2151-CHENP-2006 OTHER PATENT DOCUMENT 22-06-2011.pdf

2151-CHENP-2006 POWER OF ATTORNEY 22-06-2011.pdf

2151-CHENP-2006 CORRESPONDENCE OTHERS 11-02-2011.pdf

2151-CHENP-2006 CORRESPONDENCE PO.pdf

2151-CHENP-2006 FORM-18.pdf

2151-chenp-2006-abstract.pdf

2151-chenp-2006-claims.pdf

2151-chenp-2006-correspondnece-others.pdf

2151-chenp-2006-description(complete).pdf

2151-chenp-2006-drawings.pdf

2151-chenp-2006-form 1.pdf

2151-chenp-2006-form 3.pdf

2151-chenp-2006-form 5.pdf

2151-chenp-2006-pct.pdf


Patent Number 249236
Indian Patent Application Number 2151/CHENP/2006
PG Journal Number 41/2011
Publication Date 14-Oct-2011
Grant Date 12-Oct-2011
Date of Filing 16-Jun-2006
Name of Patentee E.C.L.
Applicant Address 100, rue Chalant, F-59790 Ronchin
Inventors:
# Inventor's Name Inventor's Address
1 BOURGES, Bernard 23, rue Jean Duvivier, F-59710 Avelin
PCT International Classification Number F16B7/00,F16L21/06
PCT International Application Number PCT/FR2004/002918
PCT International Filing date 2004-11-16
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 03/13446 2003-11-18 France