Quick-change adapter and tools for use with the adapter

A combination unitary quick-change adapter for use with a chuck of an electric drill and a unitary bit designed for adjustment-free, axial insertion into and removal from the adapter, the combination comprising:

• said adapter including:
• a shaft portion of solid cross-section and having a longitudinal axis and first and second opposing ends, said first end adapted for insertion into the chuck of the electric drill;
• a generally tubular collar portion having an open end and a closed end integral with and immovably fixed to said second end of said shaft, said collar portion being coaxial with said axis of the shaft portion and being provided with an inner peripheral wall portion having a polygonal cross-section centered about the shaft axis and defining an open interior of said collar;
• a throughbore opening in said peripheral wall portion being perpendicular to said shaft axis and having a narrowed inner end and an outer end;
• a ball and a compression spring provided in said opening in direct contact with each other so that said ball is biased by said spring against said narrowed inner end to permit a portion of said ball to project vertically into said interior of said collar and perpendicular to said axis;
• and
• a plug dimensioned to enclose said outer end of said opening and adapted to retain said spring and said ball therein;
• said bit including a shaft end and a work end, said shaft end having a polygonal cross-section adapted to matingly engage said polygonal inner peripheral wall portion in said collar portion, said shaft end further having a circumferential area of reduced diameter adapted to be engaged by said spring-biased ball when said shaft end is inserted into said collar portion so as to be in direct contact with said closed end, said closed end adapted to exert axial driving force upon said shaft end of said tool;
• said tool being secured within said collar by said spring-biased ball and by said mating engagement between said shaft end and said inner peripheral wall so that the tool may be axially inserted into and removed from the adapter without any manipulation or adjustment of the adapter.