Support bracket

1. A support bracket for supporting insulating rods inside an insulator tube of a hollow core insulator, the support bracket comprising:

a cylindrical ring with an outer surface for abutting against the inner surface of an insulator tube, an inner surface for supporting an insulating rod and two opposing end sides, denominated as first and second end sides,

the support bracket being configured to be inserted into an insulator tube of a hollow core insulator so that the cylinder axis of the cylindrical ring essentially coincides with the central longitudinal axis of said insulator tube,

characterized in that the support bracket comprises an expansion assembly having means configured to be actuated so as to expand the cylindrical ring in at least one radial direction when the support bracket has been inserted in an insulator tube of a hollow core insulator.

2. The support bracket of claim 1 , characterized in that said means is accessible for actuation from the first end side of the cylindrical ring.

3. The support bracket of claim 1 , characterized in that the expansion assembly comprises a radial slit which opens the cylindrical ring, and that said means of the expansion assembly is configured to be actuated so as to expand the cylindrical ring by expanding the width of the radial slit.

4. The support bracket of claim 3 , characterized in that the means of the expansion assembly comprises a member movable in the radial slit in a direction parallel to the cylinder axis of the cylindrical ring and having surfaces cooperating with surfaces defining said radial slit so as to expand the width of said radial slit.

5. The support bracket of claim 3 , characterized in that the cylindrical ring on the first end side has members engageable by a tool for compressing the ring.

6. The support bracket of claim 3 , characterized in that the cylindrical ring on the first end side has two notches, adjacent to and on each side of the radial slit.

7. The support bracket of claim 4 , characterized in that said member and/or radial slit has a cross-section dimension changing in the direction parallel to the cylinder axis so as to expand the cylindrical ring upon movement of said member in said radial slit in the direction parallel to the cylinder axis.

8. The support bracket of claim 7 , characterized in that said member comprises a cone or a wedge configured for expanding the cylindrical ring by moving in said radial slit in the direction parallel to the cylinder axis.

9. The support bracket according to claim 7 , characterized in that the radial slit is wider on one of the end sides than it is on the other end side so as to form a wedge-shaped radial slit, wherein said member is configured to move in the wedge-shaped radial slit and thereby expand the cylindrical ring by widening the wedge-shaped radial slit.

10. The support bracket of claim 3 , characterized in that:

the expansion assembly comprises a bore in the cylindrical ring, parallel to the cylinder axis, from the first end side,

the radial slit cuts through the bore,

the width of the radial slit is broader on the second end side than on the first end side and the width of the radial slit from the second end side is tapering inwardly towards the bore so as to form a wedge-shaped radial slit from the second end side,

the member comprises a bolt and a wedge, which wedge has a threaded through-hole configured for receiving the bolt by means of screwing, and

the wedge is configured to be received in the mating wedge-shaped radial slit from the second end side and the bolt is configured to be inserted into the bore from the first end side, wherein the bolt is partially screwed into the wedge whereby the radial slit is expanded.

11. The support bracket of claim 3 , characterized in that:

the expansion assembly comprises a bore in the cylindrical ring, parallel to the cylinder axis, from the second end side,

the radial slit cuts through the bore,

the width of the radial slit is broader on the first end side than on the second end side and the width of the radial slit from the first end side is tapering inwardly towards the bore so as to form a wedge-shaped radial slit from the first end side,

the member comprises a bolt, a nut and a wedge, which wedge has a through-hole, the nut being configured to receiving the bolt via the through-hole of the wedge by means of screwing,

the wedge is configured to be received in the mating wedge-shaped radial slit from the first end side and the bolt is configured to be inserted through the through-hole in the wedge and further through the bore, wherein the bolt is partially screwed into the nut on the second end side of the cylindrical ring.

12. The support bracket of claim 3 , characterized in that:

the expansion assembly comprises a cone-shaped hole in the cylindrical ring, tapering from the second end side to the first end side, wherein the centre line of the cone-shaped hole is parallel to the cylinder axis of the cylindrical ring,

the radial slit cuts through the cone-shaped hole,

the member comprises a bolt and a cone, which cone has a threaded through-hole configured for receiving the bolt by means of screwing, and

the cone is configured to be received in the mating cone-shaped hole from the second end side and the bolt is configured to be inserted into the cone-shaped hole from the first end side, with the head of the bolt abutting against the edges surrounding the cone-shaped hole from the first end side, wherein the bolt is partially screwed into the cone whereby the radial slit is expanded.

13. The support bracket according to claim 3 , characterized in that:

the expansion assembly comprises a cone-shaped hole in the cylindrical ring, tapering from the first end side to the second end side, wherein the centre line of the cone-shaped hole is parallel to the cylinder axis of the cylindrical ring,

the radial slit cuts through the cone-shaped hole,

the member comprises a bolt, a nut and a cone, which cone has a through-hole, the nut being configured to receiving the bolt via the through-hole of the cone by means of screwing,

the cone is configured to be received in the mating cone-shaped hole from the first end side and the bolt is configured to be inserted through the through-hole in the cone and further through the cone-shaped hole, wherein the bolt is partially screwed into the nut on the second end side of the cylindrical ring whereby the radial slit is expanded.

14. A method for using a support bracket of claim 1 for supporting insulating rods inside an insulator tube of a hollow core insulator.