Rotary Peening Tool

Author:  Harkins et al.
Source:  US Patent 5,727,995
Doc ID:  1994036
Year of Publication:  1994
Abstract:  
A surface preparation tool for peening and removing a coating from a work surface, the tool including a rotating hub which retains plurality of peening flaps with peening particles attached at one end. The peening particles impact the work surface as the hub rotates and cause the coating to fragment and dislodge from the work surface. The tool includes a shroud assembly with a funnel-shaped evacuation port attached thereto. The shroud is positioned above the work surface such that a gap is formed which permits air to enter into the shroud. A sealing structure is affixed to the rear wall of the shroud to block air flow into the shroud below the funnel. When a vacuum is applied to the funnel, the narrow gap formed between the shroud and the work surface accelerates ambient air flow into the shroud while preventing dislodged particles from escaping. The rear wall seal prevents air from flowing into the shroud below the funnel which would oppose the direction of flow from the other three sides into the funnel. This results in a directional airflow, aligned to carry dislodged particles into the funnel mouth. The flaps are mounted at a height which maximizes the life of peening flaps. The height is configured to produce a substantially vertical impact of the peening particles on the work surface with resulting rebound of the flaps that carries the peening particles away from the surface thereby minimizing the wear of the flaps.