Dear Jackie: I never heard the term "pump drill". There used to be on the market a gadget that had a shaft perhaps
3/4" in diameter with deeply cut helical grooves,with both right hand and left hand threads,with a chuck for a bit.
Pressing on handle at top made drill turn. My vision is not good enough to see how the pump drill in the picture worked,
nor how it could accurately drill very small holes, nor how the bit was constructed. Something just clicked in my senile cerebrum the-- word "Dazey" may be name of the gadget my father had when I was ten, and electric drills had not become available. Thanks for your superior search skills. Bill