Safety chamber plug for firearms

Claim 1

A SAFETY DEVICE FOR FIRE ARMS, COMPRISING A PLUG UNIT INSERTABLE INTO THE FIRING CHAMBER OF SUCH FIRE ARM FROM THE BREECH END THEREOF AND ARRANGED TO BE WHOLLY RECEIVED WITHIN SAID CHAMBER WHEN THE BREECH THEREOF IS CLOSED, SAID UNIT INCLUDING AN EXPANSIBLE CYLINDRICAL SLEEVE CIRCUMFERENTIALLY EXPANSIBLE INTO TIGHT ENGAGEMENT WITH THE INTERIOR OF SAID CHAMBER, SAID SLEEVE HAVING A CENTRAL LONGITUDINAL BORE THERETHROUGH, EACH END OF SAID BORE BEING OUTWARDLY FLARED IN A CONICAL CONFIGURATION, MEANS WITHIN SAID CHAMBER TO RESIST FORWARD MOVEMENT OF SAID PLUG UNIT AND MEANS COACTING WITH SAID SLEEVE TO SO EXPAND THE SAME WHEN SAID PLUG UNIT ENGAGES SAID RESISTANCE MEANS, SAID COACTING MEANS COMPRISING CORE MEANS INCLUDING A STEM PORTION LONGER THAN SAID SLEEVE AND EXTENDING THROUGH THE BORE THEREOF, A CONE ELEMENT INTEGRAL WITH SAID STEM PORTION AT ONE END THEREOF AND COOPERABLE WITH ONE END CONICAL CONFIGURATION OF SAID SLEEVE BORE TO EXPAND SAID SLEEVE CIRCUMFERENTIALLY, A SECOND CONE ELEMENT SLIDABLY RECEIVED ON SAID STEM PORTION AND SIMILARLY COOPERABLE WITH THE OTHER END CONICAL CONFIGURATION OF SAID SLEEVE BORE, ONE OF SAID CONE ELEMENTS HAVING A CYLINDRICAL PORTION OF A MAXIMUM DIAMETER LARGER THAN THE MAXIMUM CYLINDRICAL DIAMETER OF SAID SLEEVE IN RELAXED CONDITION, THE MAXIMUM DIAMETER OF THE CYLINDRICAL PORTION OF SAID LAST MENTIONED CONE ELEMENT BEING LARGER THAN THE MINIMUM DIAMETER AND SMALLER THAN THE MAXIMUM DIAMETER OF A FIRING CHAMBER INTO WHICH SAID UNIT IS TO BE INSERTED.