Electrical connection apparatus

1. Apparatus for providing an electrical connection path into equipment in an underwater, wet or conductive environment, the apparatus comprising a connecting pin having a conductive core and an insulating sleeve around the conductive core, and a metal collar around the sleeve for axially retaining the connecting pin in the apparatus, the metal collar providing an earth shield radially outwardly of the conductive core, wherein the insulating sleeve has a reduced external diameter over part of its length to form an annular recess, and said metal collar is at least partially received in said recess.

2. Apparatus as claimed in claim 1 , comprising a conductive coating on the recess in the insulating sleeve.

3. Apparatus as claimed in claim 1 , comprising a resilient conductive or semi-conductive layer between the insulating sleeve and the collar.

4. Apparatus as claimed in claim 1 , wherein the collar, viewed in longitudinal cross-section, has a radially inner profile having an axial end portion which slants, in a direction towards the axial end of the collar, from a radially inner position to a radially outer position.

5. Apparatus as claimed in claim 1 , wherein the collar, viewed in longitudinal cross-section, has a radially inner profile which is curved.

6. Apparatus as claimed in claim 1 , wherein the collar is split in an axial plane.

7. Apparatus as claimed in claim 1 , wherein the collar is received in a support member and is retained by a retaining ring.

8. Apparatus as claimed in claim 7 , wherein the collar has a radially outwardly projecting portion against which the retaining ring engages.

9. Apparatus as claimed in claim 1 , in an assembly in which one end of the connecting pin is exposed to a first pressure and the opposite end of the connecting pin is exposed to a second pressure.

10. Apparatus as claimed in claim 2 , comprising a resilient conductive or semi-conductive layer between the insulating sleeve and the collar.

11. Apparatus as claimed in claim 2 , wherein the collar, viewed in longitudinal cross-section, has a radially inner profile having an axial end portion which slants, in a direction towards the axial end of the collar, from a radially inner position to a radially outer position.

12. Apparatus as claimed in claim 2 , wherein the collar, viewed in longitudinal cross-section, has a radially inner profile which is curved.

13. Apparatus as claimed in claim 2 , wherein the collar is split in an axial plane.

14. Apparatus as claimed in claim 2 , wherein the collar is received in a support member and is retained by a retaining ring.