A Reinforced Polymer Hammer Cap for Eliminating Metal-to-Metal Contact and Reducing Hand-Transmitted Vibration

A hammer fitted with a polymer cap on the impact face has been developed and successfully used to drive nails. As configured, the hammer-cap assembly eliminates direct metalto- metal contact during nail driving. Unlike non-marring and other protective hammers, the design utilizes a high performance reinforced polymer which does not reduce hammer performance. Experiments to measure the nail driving characteristics of conventional hammers and hammers fitted with a polymer cap revealed no significant difference in driving capability. Vibration measurements on the handle of several hammers fitted with caps revealed that vibrations at the handle-hand interface were significantly reduced compared to conventional hammer designs. Sound pressure levels were also significantly reduced. Unlike previous work with hand-struck chisels fitted with a cap, the polymer modulus had much less effect on performance.