WO2001024322A1

WO2001024322A1 - Plug ejector mechanism using memory metal piece

Info

Publication number: WO2001024322A1
Application number: PCT/NO2000/000290
Authority: WO
Inventors: Knut Ove Steinhovden
Original assignee: Ejecto As
Priority date: 1999-09-13
Filing date: 2000-09-07
Publication date: 2001-04-05
Also published as: NO312429B1; NO994421L; NO994421D0; AU6880900A

Abstract

The invention relates to an arrangement by an ejector mechanism for a plug (1) on a cable for supplying electricity, electric signals or similar. The ejector mechanism is arranged so that, whenever necessary, the plug (1) can be ejected from a plug socket (2) by an ejector element (3) in the plug (1). The ejection takes place by means of means (4) moving, when the plug (1) is positioned in the plug socket (2), a portion of the ejector element (3) by the plug socket (2) from a position essentially within the plug (1) to a position outside the plug (1), when the plug (1) is to be ejected, so that the plug (1) is ejected from the plug socket (2). To provide an improved ejector mechanism of, among other things, a smaller size and a more simple construction, the means moving the ejector element (3) is formed of a memory metal piece (4). This extends between a flange element (5) on the ejector element (3) and an opposite end piece (12) of a recess (7) for the ejector mechanism in the plug (1).

Description

PLUG EJECTOR MECHANISM USING MEMORY METAL

PIECE

The invention relates to an arrangement by an ejector mechanism for a plug on a cable for the supply of electricity, electric signals or similar. The ejector

5 mechanism is arranged so that, whenever necessary, the plug can be ejected from a plug socket by means of an ejector element, which is movably arranged, preferably in the plug. The ejector element comprises means which move, when the plug is positioned in the plug socket, a portion of the ejector

10 element by the plug socket from a position essentially within the plug into a position, when the plug is to be ejected, sufficiently far outside the plug, so that the plug is ejected from the plug socket.

The use of an electric engine heater is an efficient means of is reducing the consumption of petrol and the contamination from motor vehicles. Power is supplied to the engine heater through a cable with a plug, which is inserted into a plug socket on the vehicle. However, experience shows that the driver often forgets to unplug the cable from the plug ₂o socket, so that the plug is in the plug socket when the vehicle is driven out from a parking place. The jerk effected then on the cable may cause considerable damage to the plug, cable, plug socket or at worst the engine heater itself.

Ejector mechanisms for plugs of the type mentioned above exist already. Of those, NO-C-303955 seems to be the one which comes closest to the present ejector mechanism. Here the ejector mechanism comprises partly a ferromagnetic material on the ejector element, and partly a current- carrying wire wrapped around a portion or an extension of the 0 ejector element. Thereby a coil is formed, which will displace the ejector element as the vehicle is started, thereby simultaneously ejecting the plug from the plug socket. The functionality of the ejector mechanism shown in NO-C-303955 is very good, but a drawback is that it requires s a lot of space, so that the plug is undesirably large. The coil construction itself also contributes to the production costs being relatively high, and additionally only direct voltage can be used. Known ejector mechanisms are not formed to operate in water either.

o An object, on which the invention is based, is to provide an ejector mechanism of a more simple construction, so that the plug can be made smaller, whereby the production costs may be reduced at the same time. Another object is that it should be possible for the ejecting effect to be intensified, without s this increasing the size or complicating the construction of the present ejector mechanism to any extent worth mentioning. It is also an object that the ejector mechanism could function in water, and that various types of voltages and heating media could be used. As far as is known, in the petroleum industry there have not been any simple and reliable solutions when a cable for the transfer of e.g. electric signals is to be connected to or disconnected from an installation under water. Consequently, it is a further object of the invention to remedy this defect through the use of the present ejector mechanism. This is realized in the way that the ejector mechanism is modified in a simple manner to move the ejector element in both directions, so that, additionally, the ejector mechanism may connect the plug to the plug socket on the installation. Thereby, as required, the present ejector mechanism could alternatingly connect and disconnect the cable plug in question. Other objects are that the cable plug could be positioned on the installation by means of an ROV or a diver, that the plug should be connected or disconnected through operation from the surface, and that the plug is to be retained in a stable position near the plug socket on the installation during the entire operation period with the alternating connecting and disconnecting.

o As appears from the characterizing part of the independent Claim, the above and other objects are realized in the way that the means which moves the ejector element is formed of a memory metal piece, and that the memory metal piece extends between a flange element on the ejector element and an 5 opposite end piece positioned in a recess for the ejector mechanism in the plug. The modification, which makes it possible for the ejector mechanism also to connect the plug to the plug socket, consists in the connection being effected by means of a further memory metal piece arranged to move the o ejector element in a direction opposite the direction for the disconnection. Other advantageous features of the invention appear from the dependent Claims and otherwise from the description.

In the following part of the description and with reference to the set of Figures, preferred embodiments of the invention will be explained:

Figure 1.1 showing a sectional view with an enlarged section of a first embodiment. As shown, a plug is placed in a plug socket, and is formed with a recess for an ejector mechanism. The ejector mechanism comprises an ejector element and a memory metal piece, which moves the ejector element during the ejection, and which extends between an end piece in the recess opposite the plug socket, and a flange element on the ejector element at a distance from the end piece, seen towards the plug socket;

Figure 1.2 showing the same as Figure 1.1, but after the ejector element has ejected the plug from the plug socket through activation of the memory metal piece, e.g. during the starting of a vehicle;

Figures 2.1 and 2.2 showing corresponding sectional views of a second embodiment with the flange element placed at one end of the ejector element opposite the plug socket, so that the memory metal piece may extend between the end piece in the recess by the plug socket and the flange element;

Figures 3.1 and 3.2 showing corresponding sectional views, with an enlarged section, of a third embodiment comprising a tension spring between the ejector element and the memory metal piece, whereby the spring is tightened when the plug is being plugged into the plug socket; Figures 4.1 and 4.2 showing corresponding sectional views, with an enlarged section of a detail from Figure 4.2, of a fourth embodiment, meant to be used under water, for example, through the operation of e.g. an ROV or a diver. Here the ejector mechanism comprises two memory metal pieces, which may respectively eject the plug from or displace it into the plug socket. For the rest, the ejector element is secured to the plug socket in a key slot, which is shown more clearly in the enlarged section from Figure 4.2, so that the plug stays on the plug socket after the ejection;

Figures 5.1 and 5.2 showing corresponding sectional views of a further embodiment, this one also meant for use under water, for example;

Figure 5.3 showing schematically how the plug in the embodiment shown in Figures 5.1 and 5.2 can be placed, e.g. by an ROV, in a cradle-like holder;

Figures 6.1 to 6.4 showing schematic examples of different electric circuits for the activation of the memory metal pieces;

Figures 7.1 and 7.2 showing sectional views of an embodiment, in which the recess by the plug socket is provided with an inlet and an outlet for a fluid;

Figures 8.1 and 8.2 showing sectional views of an embodiment, in which inductive transmission is used; and Figures 9.1 and 9.2 showing sectional views of an embodiment of the same kind as that in Figures 2.1 and 2.2, but in which the contact pins are not attached to the ejector mechanism.

As mentioned, the present invention relates to an arrangement by an ejector mechanism for a plug 1 at the end of a cable for the supply of electricity, electric signals or similar. When electricity, for example, is to be supplied to an engine heater of a vehicle, or electric signals are to be transferred by cable to an installation under water, the plug 1 is plugged into an associated plug socket 2, which is located either on the vehicle or on the installation. The ejector mechanism is arranged so that, whenever necessary, i.e. when the vehicle is being started or when the transfer of electric signals is terminated, the plug 1 is ejected from the plug socket. The ejection is effected by an ejector element 3, movably arranged in the plug 1. The ejector mechanism is positioned in a recess 7 of the plug 1. The recess 7 has a first end piece 12 by the plug socket 2, and a second end piece 13 opposite the plug socket 2. The first end piece 12 has a bore for the ejector element 3 to pass into abutment against the plug socket 2.

The ejector element 3 comprises a memory metal piece 4 which ejects the plug 1 from the plug socket 2, whenever necessary. During the ejection a portion of the ejector element 3 by the plug socket 2 is moved from a position essentially within the plug 1 into a position sufficiently far outside the plug 1 and the contact pins 1' thereof, so that the plug 1 is displaced out of the plug socket 2. In the embodiments shown, when the plug 1 is plugged into the plug socket 2, the respective memory metal piece 4 is either compressed or extended by the ejector element 3, so that the ejector mechanism is prepared for the subsequent ejection by either displacement or withdrawal of the ejector element 3. Preferably the ejector element 3 is arranged coaxially within the memory metal piece 4. As is shown in the embodiment in Figures 3.1 and 3.2, the effect during the ejection may be increased by means of a tension spring 11, which is positioned preferably between the ejector element 3 and the memory metal piece 4. Of course, the other embodiments may also be provided with a corresponding tension spring. The ejector mechanisms shown in Figures 4.1 and 4.2, and in

Figures 5.1 to 5.3 comprise a further memory metal piece 4 ' arranged to the ejector element 3. Thereby the respective ejector mechanism may additionally plug the plug into the plug socket 2. These embodiments also comprise a means 16, 17 each, to hold the plug 1 near the plug socket 2 before plugging in and after ejection of the plug 1. The memory metal pieces 4; 4' move the ejector element in respective directions when heat is supplied, e.g. from a hot fluid, or from associated electric circuits which are closed whenever the plug 1 is to be plugged in or ejected.

The respective memory metal piece 4, 4' is preferably formed of an assembly of memory metal discs 8, 8' similar to a disc spring. Thereby the ability inherent in the compressed memory metal piece 4, 4¹ to move the ejector element 3 is considerably increased. Each memory metal disc 8, 8' has a bore for the ejector element 3, and possibly the tension spring 11, to pass. The memory metal discs 8, 8' may be interconnected in a suitable manner, possibly along both the outer periphery and the bore for the ejector element 3, cf. Figures 1.1 and 1.2, or only along the outer periphery, cf. Figures 2.1 and 2.2. The memory metal is preferably made of an alloy of nickel and titanium in a proportion of mixture that provides a memory metal with the desired properties, e.g. 50 % of each. Other alloys, e.g. of copper, zinc and aluminium or copper, aluminium and nickel, may possibly be used. The distinctive characteristic of memory metal is that when influenced mechanically, e.g. by compression or extension, when the plug 1 is being plugged into the plug socket 2, it maintains its new compressed or extended form as a temporarily lasting deformation, the memory metal reverting to its initial shape only when its temperature is increased. Thereby a temperature increase in the memory metal will lead to the ejection, possibly the plugging into the plug socket 2, so that the memory metal pieces 4, 4' revert to their initial shapes with a resulting displacement of or pulling on the plug 1 in the respective direction relative to the plug socket 2. The memory effect can be explained as the material having two different structural phases. In its cold state, the material has an easily workable martensite structure with a yield strength of e.g. about 70 MPa, and above the point of transformation an austenite structure with a yield strength of e.g. about 210 MPa. As mentioned, the result of this is that the "energy of return" of the compressed or extended memory metal may be utilized to move the ejector element 3 of the present ejector mechanism. By changing the proportion of mixture between e.g. nickel and titanium in the memory metal alloy, the temperature of transformation between the martensite and austenite structures may be kept in the range from -100 °C to +100 °C. Memory metals are also known, which may have two positions dependent on the temperature, without mechanical influence, i.e. the metal expands under the influence of heat and contracts when the metal is cooled. In the embodiment shown in Figures 1.1 and 1.2 the memory metal piece 4 extends between a flange element 5 on the ejector element 3 and the second end piece 13 of the recess 7 opposite the plug socket 2. The end piece 13 has a contact ring 6 for an adjacent end of the memory metal piece 4, and a sleeve element 15 of metal, accommodating an end portion of the ejector element 3 when the plug 1 has been plugged into the plug socket 2. The flange element 5 is positioned at a suitable distance on the ejector element 3, seen from the end by the end piece 13 with the sleeve element 15. The end portion of the ejecting element 3 behind the flange element 5 has a sleeve element 14 of metal adapted to bear glidingly on the sleeve element 15 when the ejector element 3 moves.

The embodiment in Figures 2.1 and 2.2 shows, on the other hand, that the memory metal piece 4 extends from the first end piece 12 by the plug socket 2. In this case the contact ring 6 is consequently placed at the first end piece 12. The flange element 5 is positioned on the ejector element 3 at the end opposite the plug socket 2, and adapted so that it may bear glidingly on the side wall of the recess 7 during movement of the ejector element 3.

Figures 3.1 and 3.2 show an embodiment with the flange element 5 and the contact ring 6 for the memory metal piece positioned essentially as shown in Figures 1.1 and 1.2. But, the second end piece 13 has a bore extending into it in the extension of the sleeve element 15. The ejector element 3 is adapted to bear glidingly at least on the sleeve element 13. Further, as earlier mentioned, a tension spring 11 of a suitable material is placed between the memory metal piece 4 and the ejector element 3, so that the force during the ejection can be increased. As the plug 1 is being plugged into the plug socket 2, the tension spring 11 is compressed and tightened so that it thereby assists in the subsequent ejection. Moreover, the tension spring 11 is adapted to surround the sleeve element 15 closely, so that emitted heat may be received by the memory metal piece 4. The tension spring 11 bears by one end on an abutment ring 18 on the end piece 13 within the contact ring 6 for the memory metal piece 4.

The ejector mechanism in the embodiment shown in Figures 4.1 and 4.2 comprises a further memory metal piece 4', so that the ejector element 3 can also move in a direction opposite the direction of movement from the first memory metal piece 4 during the ejection. Further the plug socket 2 is provided with means 16 adapted to hold the plug 1 in a position near the plug socket 2. The holding means may for example be formed by the key slot 16 shown, the end of the ejector element 3 facing the plug socket 2 being placed in the key slot 16. As mentioned earlier, this results in the ejector mechanism also being able to plug the plug 1 into the plug socket, so that, whenever necessary, the plug 1 may alternatingly be plugged into and ejected from the plug socket. The embodiment may be used on an installation under water, when for example electric signals are to be transferred via cable. An ROV can be used to force the end of the ejector element 3 into the key slot 16 of the plug socket 2, and the ejector mechanism may then be operated from the surface.

Beyond that, the first memory metal piece 4 for the connection extends from a first end piece 12 and a first flange element 5 by the plug socket 2. The first flange element 5 is now at a suitable distance on the ejector element 3, and further it bears glidingly on a first recess portion 7. The second memory metal piece 4 ' is positioned in a second recess portion 7 ' , which extends in an extension of the first one, away from the plug socket 2. The ejector element 3 has been taken through a bore of an intermediate piece 12' in the recess portions 7, 7'. The second memory metal piece 4' extends between an end piece 13' of the second recess portion 7' opposite the plug socket 2, and a second flange element 5 ' , which is preferably placed at the end of o the ejector element 3. The second flange element 5', too, bears sealingly against the second recess portion 7 ' . By the plug socket 2 the plug 1 has a guide pin 19, passing in a bore of the plug socket 2 and preventing any rotation of the plug 1.

s The embodiment in Figures 5.1 to 5.3 corresponds to the embodiment shown in Figures 4.1 and 4.2, and may be used on installations under water, for example. The difference between the embodiments consists in the plug 1 being positioned in a holding means, e.g. a cradle 17, on the o installation to enable a stable positioning near the plug socket 2. Another essential difference consists in the end of the ejector element 3 being taken out through a bore of the end piece 13' opposite the plug socket 2, so that this end will abut an end wall of the cradle 17 as the plug 1 is being 5 connected through activation of the second memory metal piece 4' .

From the above it will be understood that the memory metal pieces 4 of the embodiments shown in Figures 1.1 and 1.2 and Figures 3.1 and 3.2 are compressed when the plug 1 is being o plugged into the plug socket 2 , so that the ejector element 3 is displaced by the memory metal 4 towards the plug socket 2 during the ejection. Whereas, on the other hand, the memory metal pieces 4 of the embodiments shown in Figures 2.1 and 2.2, Figures 4.1 and 4.2 and Figures 5.1 to 5.3 are extended outwards, so that the ejector element 3 is pulled back by the memory metal pieces 4 towards the plug socket 2 during the ejection.

As earlier mentioned, the memory metal pieces 4; 4' are activated for moving the ejector element 3 in the respective direction by means of heat supplied from electricity in a suitable electric circuit 9, 10. Examples of different electric circuits are illustrated schematically in Figures 6.1 to 6.4, Fig. 6.1 showing an electric circuit meant for the embodiment in Figures 1.1 and 1.2. Here a first portion 9 is connected to the sleeve element 15 of metal and to earth, whereas a second portion 10 is connected to the contact ring 6 of the end piece 13. When the electricity circuit is closed, electricity will thereby run through the contact ring 6, the memory metal piece 4, sleeve elements 14, 15 of the ejector element 3 and the end piece 13, respectively. Power break occurs when the sleeve elements 14, 15 disengage during the movement of the ejector element 3.

Figures 6.1 and 6.2 show an electricity circuit for the control of the contact according to the embodiments in Figures 1.1 and 1.2, 2.1 and 2.2 and Figures 3.1 and 3.2, in which the first portion 9 is connected to the end of the memory metal piece 4 at the flange portion 5 and the abutment ring 18 for the tension spring, whereas the second portion 10, which is connection to earth, is connected to the opposite end of the memory metal piece 4 at the end piece 12 by the plug socket 2, and the end of the memory metal piece at the flange element 5. Short-circuiting is effected by means of the respective flange element 5. In Figures 6.3 and 6.4 is shown an electric circuit for the embodiments of Figures 4.1 and 4.2 and 5.1 to 5.3 with a corresponding connection to the memory metal pieces 4, 4', essentially as shown in Figures 3.1 and 3.2. Here Figure 6.3 illustrate the closing of the electric circuit 9, 10 for activation of the first memory metal piece 4, and Figure 6.4 the closing of the circuit 9', 10' for the memory metal piece 4'.

The embodiment in Figures 7.1 and 7.2 corresponds to the embodiment in Figures 2.1 and 2.2, but in addition the plug 1 is provided with two bores 20 and 20' leading into the recess 7. To the bores 20 and 20' are further connected (not shown) hoses or pipes, which are connected to a pump, not shown. By means of the pump a fluid at a desired temperature, e.g. hydraulic fluid, may be supplied to the recess 7, and thus activate the memory metal piece 4 if the electric circuit 10 should be broken, for example.

The embodiment in Figures 8.1 and 8.2 shows an inductive transmission, in which the ejector mechanism is of the same kind as that shown in Figures 2.1 and 2.2.

The embodiment in Figures 9.1 and 9.2 corresponds to the embodiment in Figures 2.1 and 2.2, but the contact pins 1' are not attached to the ejector mechanism.

The plug 1 is provided with a nose portion 21, in which a secondary coil 22 has been fitted. In the secondary coil 22 there may possibly be placed a ferrite core (not shown). The nose portion 21 is complementary to a recess in a primary coil 25. The primary coil 25 is provided with an abutment and support plate 24, for the ejector element 3 to abut.

In the above is mentioned that the invention may be used in connection with engine heaters on vehicles and installations under water, but clearly the invention can be used in any connection, in which electricity, electric signals or similar is/are to be supplied to an object, in which it is necessary to control the connection or disconnection, e.g. by the charging of batteries for electric vehicles, supply of signals to cable-operated missiles, disconnection of modems in computers, tools for use in wells on shore etc. In the embodiments shown in Figures 1.1 and 1.2 the memory metal piece is shown as an assembly of memory metal discs, similar to a disc spring. Clearly, the memory metal piece according to the invention may have another configuration than the one shown, like a helical spring for example (as shown in the rest of the figures), in the form of sets of rectangular memory metal pieces etc. Further the ejector mechanism may possibly, if found to be more suitable, be positioned in the plug socket.

Claims

C l a i s

1. An arrangement by an ejector mechanism for a plug (1) on a cable for the supply of electricity, electric signals or similar, in which the ejector mechanism is arranged so that, whenever necessary, the plug (1) can be ejected from a plug socket (2, 23) by means of an ejector element (3) movably arranged in the plug (1) or the plug socket (2), and in which the ejector element (3) comprises means (4), which moves a portion of the ejector element (3), when the plug (1) is placed in the plug socket (2, 23), from a position essentially within the plug (1) or the plug socket (2) into a position, when the plug (1) or the plug socket (2) is to be ejected, sufficiently far outside the plug (1) or the plug socket (2), so that the plug (1) or the plug socket

(2) is ejected from the plug socket (2, 23) or the plug (1), c h a r a c t e r i z e d i n that the means , which moves the ejector element (3), is formed by a memory metal piece ( 4 ) .

2. An arrangement according to claim 1, c h a r a c t e r i z e d i n that the memory metal piece (4) extends between a flange element (5) on the ejector element (3) and an opposite end piece (12; 13) positioned in a recess (7) for the ejector mechanism in the plug (1) or the plug socket (2).

3. An arrangement according to claim 1 or 2, c h a r a c t e r i z e d i n that the ejector element

(3) is coaxially movable within the memory metal piece (4).

4. An arrangement according to any one of the preceding claims, c h ar ac t er i z e d i n that the memory metal piece (4) is formed of an assembly of memory metal discs (8), preferably similar to a disc spring.

5. An arrangement according to any one of the preceding claims, c h ar ac t er i z e d i n that the ejector element (3) has a second memory metal piece (4') arranged thereto and arranged to move the ejector element (3) in a direction opposite the direction of movement of the first memory metal piece (4), so that the ejector mechanism may also plug the plug (1) into the plug socket (2, 23).

6. An arrangement according to claim 4, c h a r ac te r i z ed i n that the first memory metal piece (4) is positioned by the plug socket (2), and the second memory metal piece ( 4 ' ) at the end of the ejector element (3) opposite the plug socket (2).

7. An arrangement according to claim 4 or 5, c h ar a c t e r i z e d i n that the arrangement comprises means (16; 17) arranged to retain the plug (1) in a position near the plug socket (2) before the plugging in and after the ejection.

8. An arrangement according to any one of the preceding claims, c h ar ac t er i z e d i n that the ejector element (3) has a spring (11) arranged thereto, which is tightened, possibly relaxed, when the plug (1) is being plugged into the plug socket (2), and that emitted heat may be received by the memory metal piece ( 4 ) .

9. An arrangement according to any one of the preceding claims, c h a r ac t e r i z e d i n that the memory metal piece (4) is activated to move the ejector element (3), by means of heat from an electric circuit (9, 10).

10. An arrangement according to any one of the preceding claims, c h ar ac t e r i z e d i n that the memory metal piece (4) is activated to move the ejector element (3), by means of heat from a fluid.

11. An arrangement according to any one of the preceding claims, c h ar ac te r i z e d i n that the ejector element (3) is arranged telescopically in a current- carrying sleeve element (15).

12. The application of a memory metal for the displacement of an ejector element (3), positioned in a plug or plug socket.