Plastic bowling ball with internal lamp and thumb and finger holes

摘要

The sphere (100) incorporates the usual three holes for the bowler's thumb, middle finger and ring finger. There is a fourth hole (6) into which a threaded sleeve (7) is inserted with a cap (9), carrying two flashing light-emitting diodes (5) in holes (4) of about 6 mm diameter. A slot between these holes provides an access for a ball-point pen to operate a rocker switch (3) connecting the diodes to a 6 V battery (1) in a deep compartment (2). After the closure of the switch, the diodes flash alternately or in a predetermined sequence, which can be varied by an electrical circuit.