Tire pressure indicating apparatus for road vehicles

Claim 1

APPARATUS FOR INDICATING A LOSS IN EFFECTIVE AIR PRESURE OF A VEHICLE TIRE, COMPRISING DETECTING MEANS FOR ATTACHMENT TO EACH WHEEL OF THE VEHICLE TO DETECT A LOSS IN THE PRESSURE OF THE AIR IN THE TIRE ON THE RESPECTIVE WHEEL; INDICATING MEANS FOR ATTACHMENT TO THE VEHICLE NEAR THE DRIVER''S POSITION FOR GIVING A WARNING INDICATION WHEN A LOSS IN THE PRESSURE OF THE AIR IN A TIRE IS DETECTED BY SAID DETECTING MEANS; AND MEANS FOR OPERATIVELY CONNECTING SAID DETECTING MEANS TO SAID INDICATING MEANS AND COMPRISING AN ELECTRICAL CIRCUIT FOR EACH WHEEL OF THE VEHICLE TO BE MOUNTED IN ASSOCIATION WITH THE RESPECTIVE DETECTING MEANS AND INCORPORATING A SOURCE OF CURRENT, NORMALLY OPEN CIRCUIT CLOSING MEANS TO BE CLOSED BY THE RESPECTIVE DETECTING MEANS WHEN A LOSS IN THE PRESSURE OF THE AIR IN A TIRE IS DETECTED BY THE RESPECTIVE DETECTING MEANS, AND A TRANSMITTER TO BE RENDERED OPERATIVE WHEN THE CIRCUIT CLOSING MEANS IS CLOSED BY THE DETECTING MEANS TO GENERATE AND TRANSMIT A RADIO FREQUENCY SIGNAL, AND A RECEIVER JUXTAPOSED TO SAID INDICATING MEANS FOR RECEIVING THE RADIO FREQUENCY SIGNALS FROM SAID TRANSMIT; TERS AND ELECTRICALLY CONNECTED TO SAID INDICATING MEANS TO OPERATE SAID INDICATING MEANS TO GIVE A WARNING INDICATION WHEN A LOSS OF THE PRESSURE OF THE AIR IN THE TIRE IS DETECTED BY ANY OF SAID DETECTING MEANS, EACH DETECTING MEANS COMPRISING A COMPARTMENT, A SUBSTANTIALLY SPHERICAL BLADDER ENCLOSED IN SAID COMPARTMENT NEAR ONE END THEREOF AND HAVING A FLEXIBLE TUBE COMMUNICATING THEREWITH AND EXTENDING THROUGH AN END WALL OF SAID COMPARTMENT FOR CONNECTING TO AN INFLATING VALVE ON A TIRE, A CAPPED STEM EXTENDING BETWEEN THE OPPOSITE END OF SAID COMPARTMENT AND SAID SPHERICAL BLADDER, A SPRING URGING THE CAPPED END OF SAID STEM AGAINST THE BLADDER AT A PRESSURE SOMEWHAT LESS THAN THE PRESSURE OF THE AIR IN THE TIRE WHEN THE TIRE IS FULLY INFLATED, AND A LEVER PIVOTALLY CONNECTED AT ONE END THEREOF TO SAID STEM AND HAVING ITS OTHER END CONNECTED TO SAID CIRCUIT CLOSING MEANS TO CLOSE SAID CIRCUIT CLOSING MEANS WHEN SAID SPHERICAL BLADDER IS COMPRESSED BY REASON OF LOSS OF THE PRESSURE OF THE AIR IN THE TIRE AND THE PRESSURE DEVELOPED BY SAID SPRING.