Drill shock absorber

In a drill shock absorber having hollow drive shaft and driven shaft members with their open ends aligned with and spaced from one another, a drive plate fixed on the end of said drive shaft member, a driven plate fixed on the ends of said driven shaft member which is in spaced, faced relation to said drive plate, and annular resilient means sandwiched between said drive and driven plates with a hollow interior encircling the ends of said drive and driven shaft members, the improvement therein of:

• a shielding sleeve extending through said hollow interior of said resilient means that has one end secured in one of said drive and driven shaft members and an opposite end telescoped into the other of said drive and driven shaft members with a loose fit to provide a duct communicating between the hollow shaft members that shields said resilient means from fluids flowing through said shaft members;
• and
• a sealing ring encircling said opposite end of said shielding sleeve to form a fluid tight seal between such opposite end and the shaft member into which it extends with said loose fit.

In a drill shock absorber having a first plate attached to a first hollow shaft, a second plate attached to a second hollow shaft, resilient means located between said first and second plates, said resilient means having a hollow interior, the combination therewith comprising:

• a shielding sleeve connected to said first shaft and extending through said hollow interior of said resilient means in a loose, sliding relationship between said first and second shafts, said sleeve cooperating with said first and second shafts to provide a duct communicating between said first and second hollow shafts that shields the resilient means from fluids flowing through said hollow shafts;
• and
• a sealing ring encircling said shielding sleeve to form a fluid tight seal between said second shaft and said shielding sleeve.

In a drill shock absorber having a drive plate attached to a hollow drive shaft member, a driven plate secured to a hollow driven shaft member, resilient means located between said drive and driven plates, said resilient means having a hollow center portion, the combination comprising:

• a shielding sleeve connected to said drive shaft member and passing through said hollow center portion of said resilient means, said sleeve being telescoped within a seat formed in said driven shaft member, said sleeve presenting a duct cooperating with said hollow drive and driven shaft members to form a passageway isolated from said drive plate, said resilient means and said driven plate, said duct being utilized for transporting fluid through the drill;
• and
• a sealing ring encircling said shielding sleeve to form a fluid tight seal between said driven shaft member and said shielding sleeve.