Rigid shell helmet and rigging and sound attenuating means therefor

Claim 1

A SOUND ATTENUATING DEVICE COMPRISING: (A) AN EAR CUP ADAPTED TO RECEIVE THE EAR OF A WEARER; (B) CUSHION MEANS ON THE RIM OF THE CUP ADAPTED TO ENGAGE THE HEAD OF THE WEARER ABOUT HIS EAR SO AS SUBSTANTIALLY TO CLOSE OFF COMMUNICATION OF THE SOUND PASSAGE OF THE EAR WITH THE ATMOSPHERE; (C) A BODY OF SOUND ABSORBING MATERIAL INSIDE THE EAR CUP AND CONFINED BY THE EAR CUP FOR ABSORBING EXTRANEOUS SOUND TRANSMITTED INTO THE CUP; (D) VALVE MEANS MOUNTED ON THE EAR CUP AT ONE SIDE OF THE OUTER END THEREOF, AND MANUALLY OPERABLE FROM THE OUTSIDE THEREOF BETWEEN OPEN AND CLOSED POSITIONS; (E) SAID BODY OF SOUND ABSORBING MATERIAL DEFINING A PASSAGE ALONG SAID ONE SIDE OF THE EAR CUP AND COMMUNICATING WITH SAID VALVE MEANS AT ONE END AND ADAPTED TO COMMUNICATE WITH THE SOUND PASSAGE OF THE WEARER''S EAR AT THE OTHER END; (F) SAID BODY OF SOUND ABSORBING MATERIAL FURTHER DEFINING A CENTRAL POCKET ADAPTED TO RECEIVE A TELEPHONE TRANSDUCER AND ALSO ADAPTED TO COMMUNICATE WITH THE SOUND PASSAGE OF THE WEARER''S EAR.