Goniometer

Claim 1

A GONIOMETER FOR MEASURING ANGULAR MOVEMENT OF JOINTS BETWEEN BONES IN A HUMAN BODY AND COMPRISING: A PROTRACTOR HEAD HAVING A ARCUATE SECTOR WITH AN ANGLE INDICATING SCALE ON THE UPPER FACE THEREOF AND HAVING THE ENDS OF THE SECTOR LATERALLY JOINED TO AN ELONGATED BASE MEMBER HAVING AN OPEN SLOT IN THE LOWER FACE THEREOF SUBSTANTIALLY PARALLEL WITH A CHORD THROUGH THE ENDS OF THE SCALE, A FIRST ELONGATED COVER PLATE JOINED TO THE LOWER FACE OF THE ELONGATED BASE MEMBER OF SAID PROTRACTOR HEAD AND COVERING THE OPEN SLOT TO FORM AN ELONGATED OPEN ENDED PASSAGE IN SAID PROTRACTOR HEAD, AN ELONGATED POINTER HEAD IN SUPERIMPOSED RELATIONSHIP WITH SAID PROTRACTOR HEAD AND HAVING AN OPEN SLOT EXTENDING LONGITUDINALLY IN THE LOWER FACE OF SAID POINTER HEAD, A SECOND ELONGATED COVER PLATE JOINED TO THE LOWER FACE OF SAID POINTER HEAD AND COVERING THE OPEN SLOT TO FORM AN ELONGATED OPEN ENDED PASSAGE IN SAID POINTER HEAD, SAID SECOND ELONGATED COVER PLATE HAVING A POINTER MEANS EXTENDING FROM ONE END FOR INDICATING A POSITION ON THE SCALE OF SAID PROTRACTOR HEAD, PIVOT MEANS PIVOTALLY JOINING SAID POINTER HEAD AND SAID PROTRACTOR HEAD BY PASSING THROUGH SAID POINTER HEAD AND SAID SECOND ELONGATED COVER PLATE ON THE EXTENDED LONGITUDINAL AXIS OF THE POINTER ON SAID SECOND ELONGATED COVER PLATE AND THROUGH THE SAID PROTRACTOR HEAD AND SAID FIRST COVER PLATE ON THE GEOMETRIC CENTER OF THE ARCUATE SCALE ON SAID PROTRACTOR HEAD, SAID PIVOT MEANS COMPRISING A PIVOT PIN PASSING THROUGH SAID POINTER HEAD AND SAID SECOND ELONGATED COVER PLATE AND THROUGH SAID PROTRACTOR HEAD AND SAID FIRST ELONGATED COVER PLATE AND HAVING AN EXTERNALLY THREADED END EXTENDING FROM THE LOWER FACE OF SAID FIRST ELONGATED COVER PLATE, AND A PIVOT HOUSING HAVING AN AXIAL INTERNAL THREAD ENGAGING THE THREADED END OF SAID PIVOT PIN AND FURTHER HAVING A COAXIAL OPEN END CAVITY THE OPEN END OF WHICH IS PROXIMATE THE LOWER FACE OF SAID FIRST ELONGATED COVER PLATE; A BIASING MEANS COMPRISING A COMPRESSION SPRING COAXIALLY SURROUNDING SAID PIVOT PIN AND NESTING WITHIN THE OPEN END CAVITY IN SAID PIVOT HOUSING TO AXIALLY BIAS TOGETHER SAID PROTRACTOR HEAD AND SAID POINTER HEAD AND TO FRICTIONALLY RESIST RELATIVE ANGULAR MOVEMENT BETWEEN SAID PROTRACTOR HEAD AND SAID POINTER HEAD ON SAID PIVOT MEANS, A FIRST ARM SLIDABLY EXTENDING FROM THE ELONGATED OPEN ENDED PASSAGE IN SAID PROTRACTOR HEAD, A SECOND ARM SLIDABLY EXTENDING FROM THE ELONGATED OPEN ENDED PASSAGE IN SAID POINTER HEAD, A FIRST SPRING ACTUATED PRESSURE EXERTING MEANS ACTING LATERALLY BETWEEN THE ELONGATED BASE MEMBER OF SAID PROTRACTOR HEAD AND SAID FIRST ARM TO FRICTIONALLY RESIST THE SLIDING MOVEMENT OF SAID FIRST ARM, A SECOND SPRING ACTUATED PRESSURE EXERTING MEANS ACTING LATERALLY BETWEEN SAID ELONGATED POINTER HEAD AND SAID SECOND ARM TO FRICTIONALLY RESIST THE SLIDING MOVEMENT OF SAID SECOND ARM, A FIRST LOCATING POINT COAXIALLY JOINED TO THE EXTENDING END OF SAID PIVOT MEANS, A SECOND LOCATING POINT JOINED TO SAID FIRST ARM, A THIRD LOCATING POINT JOINED TO SAID SECOND ARM, SAID SECOND AND SAID THIRD LOCATING POINTS EXTENDING IN THE DIRECTION OF AND SUBSTANTIALLY PARALLEL WITH SAID PIVOT MEANS AND SAID FIRST LOCATING POINT, THE POINTER ON SAID SECOND ELONGATED COVER PLATE INDICATING ON THE SCALE OF SAID PROTRACTOR HEAD THE ANGULAR RELATIONSHIP BETWEEN SAID ARMS WHEN SAID LOCATING POINTS ARE PLACED AND RETAINED DURING BODY MOVEMENT ON BONY LANDMARKS OF THE HUMAN BODY.