Underwater electrical connection

1. An underwater electrical connection assembly comprising:

a contact pin comprising an axially extending conductive core and an axially extending annular insulation portion around the conductive core, the annular insulation portion comprising an inner insulating layer and an insulating sleeve;

a front end portion of the conductive core having a front end electrical contact surface;

a rear end portion of the conductive core having a rear end electrical contact surface;

an intermediate portion of the conductive core extending axially at an intermediate location between the front and rear end portions; and

a conductive sleeve positioned at or adjacent to the rear end portion of the conductive core, wherein the conductive sleeve engages with an end of the annular insulation portion in order to prevent the annular insulation portion from moving rearwardly relative to the conductive core,

wherein the rear end portion of the conductive core of the contact pin has a diameter larger than a diameter of the intermediate portion thereof, and

wherein an inside surface of the inner insulating layer is in contact with the intermediate portion of the conductive core and an outside surface of the inner insulating layer is in contact with the insulating sleeve.

2. A assembly as claimed in claim 1 , wherein the inner insulating layer is made of a material which has set or hardened in a space between the insulating sleeve and the intermediate portion of the conductive core.

3. An assembly as claimed in claim 2 , wherein the conductive core has one or more channels at the front end portion of the conductive core communicating with a space occupied by the inner insulating layer.

4. An assembly as claimed in claim 3 , further comprising a socket member having a socket receiving the rear end portion of the conductive core for electrical engagement with the rear end electrical contact surface thereof.

5. An assembly as claimed in claim 4 , wherein the contact pin has an electrically conductive earth shield arranged radially outwardly of the intermediate portion of the conductive core.

6. An assembly a claimed in claim 5 , further comprising first and second connector parts capable of being mated underwater, wherein the first connector part comprises the contact pin.

7. An assembly as claimed in claim 2 , further comprising a socket member having a socket receiving the rear end portion of the conductive core for electrical engagement with the rear end electrical contact surface thereof.

8. An assembly as claimed in claim 2 , wherein the contact pin has an electrically conductive earth shield arranged radially outwardly of the intermediate portion of the conductive core.

9. An assembly a claimed in claim 2 , further comprising first and second connector parts capable of being mated underwater, wherein the first connector part comprises the contact pin.

10. An assembly as claimed in claim 1 , wherein the conductive core has one or more channels at the front end portion of the conductive core communicating with a space occupied by the inner insulating layer.

11. An assembly as claimed in claim 10 , further comprising a socket member having a socket receiving the rear end portion of the conductive core for electrical engagement with the rear end electrical contact surface thereof.

12. An assembly as claimed in claim 10 , wherein the contact pin has an electrically conductive earth shield arranged radially outwardly of the intermediate portion of the conductive core.

13. An assembly a claimed in claim 10 , further comprising first and second connector parts capable of being mated underwater, wherein the first connector part comprises the contact pin.

14. An assembly as claimed in claim 1 , further comprising a socket member having a socket receiving the rear end portion of the conductive core for electrical engagement with the rear end electrical contact surface thereof.

15. An assembly as claimed in claim 14 , wherein the contact pin has an electrically conductive earth shield arranged radially outwardly of the intermediate portion of the conductive core.

16. An assembly as claimed in claim 1 , wherein the contact pin has an electrically conductive earth shield arranged radially outwardly of the intermediate portion of the conductive core.

17. An assembly a claimed in claim 1 , further comprising first and second connector parts capable of being mated underwater, wherein the first connector part comprises the contact pin.

18. An assembly as claimed in claim 1 , further comprising:

an axially split collar positioned at or adjacent to the rear end portion of the conductive core, the axially split collar comprising a radially outer threaded surface,

wherein the radially outer threaded surface of the axially split collar engages with a radially inner threaded surface of the conductive sleeve.

19. An assembly as claimed in claim 18 , wherein the axially split collar is an electrically conductive material.

20. An underwater electrical connection assembly comprising:

a contact pin comprising an axially extending conductive core and an axially extending annular insulation portion around the conductive core, the annular insulation portion comprising an inner insulating layer and an insulating sleeve;

a front end portion of the conductive core having a front end electrical contact surface;

a rear end portion of the conductive core having a rear end electrical contact surface;

an intermediate portion of the conductive core extending axially at an intermediate location between the front and rear end portions; and

a conductive sleeve positioned at or adjacent to the rear end portion of the conductive core, wherein the conductive sleeve engages with the annular insulation portion in order to prevent the annular insulation portion from moving rearwardly relative to the conductive core, wherein the conductive sleeve comprises axial channels on an inner wall of the conductive sleeve, wherein the axial channels are configured to interrupt an internal thread of the conductive sleeve at circumferential intervals and allow communication of a flowable insulating material,

wherein the rear end portion of the conductive core of the contact pin has a diameter larger than a diameter of the intermediate portion thereof, and

wherein an inside surface of the inner insulating layer is in contact with the intermediate portion of the conductive core and an outside surface of the inner insulating layer is in contact with the insulating sleeve.

21. An underwater electrical connection assembly comprising:

a contact pin comprising an axially extending conductive core and an axially extending annular insulation portion around the conductive core, the annular insulation portion comprising an inner insulating layer and an insulating sleeve;

a front end portion of the conductive core having a front end electrical contact surface;

a rear end portion of the conductive core having a rear end electrical contact surface;

an intermediate portion of the conductive core extending axially at an intermediate location between the front and rear end portions;

a conductive sleeve positioned at or adjacent to the rear end portion of the conductive core, wherein the conductive sleeve engages with the annular insulation portion in order to prevent the annular insulation portion from moving rearwardly relative to the conductive core; and

an O-ring positioned at the front end portion of the conductive core, wherein the O-ring is configured to form a seal between the insulating sleeve and the conductive core at the front end portion of the conductive core,

wherein the rear end portion of the conductive core of the contact pin has a diameter larger than a diameter of the intermediate portion thereof, and

wherein an inside surface of the inner insulating layer is in contact with the intermediate portion of the conductive core and an outside surface of the inner insulating layer is in contact with the insulating sleeve.