Mining shield base lift methods

1. A method of replacing a wear pad on a base lift, comprising:

loosening at least one retaining bolt threaded into an axial wall extending from and forming a part of an old wear pad threaded onto a mining shield base lift cylinder rod until that retaining bolt does not impinge upon the cylinder rod;

placing a bar in a spanner hole extending into the old wear pad and rotating the old wear pad to break loose the threading of the old wear pad from the cylinder rod;

removing the old wear pad from the cylinder rod;

placing a new wear pad onto the cylinder rod; and

tightening a retaining bolt through the new wear pad until it engages the cylinder rod.

2. The method of claim 1 , further comprising tightening the retaining bolt into an axial groove in the cylinder rod.

3. The method of claim 1 , further comprising using the bar to unthread the old wear pad from the cylinder rod.

4. The method of claim 3 , wherein the spanner hole extends axially into the old wear pad.

5. The method of claim 4 , wherein the spanner hole extends through the axial wall extending from the old wear pad.

6. The method of claim 1 , further comprising placing a bar in a spanner hole in the new wear pad and using the bar to thread the new wear pad onto the cylinder rod.

7. The method of claim 6 , wherein the spanner hole extends axially into the new wear pad.

8. The method of claim 7 , wherein the spanner hole extends through an axial wall extending from the new wear pad.

9. The method of claim 1 , further comprising tightening the retaining bolt into a hole in the cylinder rod.

10. The method of claim 1 , wherein removing the old wear pad from the cylinder rod includes unthreading the old wear pad from the cylinder rod.

11. The method of claim 1 , wherein placing a new wear pad onto the cylinder rod includes threading the new wear pad onto the cylinder rod.

12. A method of replacing a wear pad on a base lift, comprising:

unthreading an old wear pad from a mining shield base lift cylinder rod using a bar placed into a spanner hole extending into the old wear pad to break loose the threading;

removing the old wear pad from the cylinder rod;

removing a gland compressed between the wear pad and the cylinder rod;

placing a new gland on the cylinder rod; and

threading a new wear pad onto the cylinder rod.

13. The method of claim 12 , wherein the bar is placed through a first spanner hole in an axial wall extending from the old wear pad and the bar is also placed into a second spanner hole extending through the axial wall.

14. The method of claim 12 , wherein the bar is placed through a second spanner hole.

15. The method of claim 12 , further comprising loosening a retaining bolt from the old wear pad until it does not engage the cylinder rod.

16. The method of claim 12 , further comprising tightening a retaining bolt through the new wear pad until it engages the cylinder rod.

17. A method of removing an old wear pad from a base lift cylinder and installing a new wear pad on the base lift cylinder, comprising:

loosening at least one retaining bolt threaded into an old wear pad on a mining shield base lift until that retaining bolt does not impinge upon a cylinder rod;

placing a bar in a spanner hole that extends into the old wear pad;

rotating the wear pad using the bar until the old wear pad is loose on the cylinder rod;

removing the old wear pad from the cylinder rod;

placing a new wear pad onto the cylinder rod; and

tightening a retaining bolt through the new wear pad until it engages the cylinder rod.

18. The method of claim 17 , wherein the bar is placed through a first spanner hole in an axial wall extending from the old wear pad and the bar is also placed into a second spanner hole extending through the axial wall.

19. The method of claim 17 , further comprising tightening the retaining bolt into an axial groove in the cylinder rod.