SURGICAL BUR WITH A HEAD HAVING PLURAL FLUTES, THE FLUTES SHAPED SO THAT, AT THE EQUATOR, THE HEAD HAS A SHAPE THAT IS NOT CIRCULAR

摘要

A bur with features that minimize the application of substantially identical forces to the tissue against which the bur is applied. One of these features is the arrangement of the flutes so that one pair of flutes projects outwardly from the tip at an acute angle that is greater than the angle at which the other flutes project outwardly from tip. Consequently at the equator of the bur head, the location along the bur head where the bur head has a maximum diameter, the flutes define a perimeter that is non-circular in shape.

主权项

1. A bur for surgical/medical use, said bur including:
a shaft having opposed proximal and distal ends, said shaft having a proximal section adjacent the proximal end shaped for coupling to a surgical handpiece capable of rotating said shaft; and a head attached to the distal end of said shaft, said head having: a tip that is the most distal portion of the head; a longitudinal axis that extends proximally from the tip through said bur head; and an even number of flutes, each said flute having a rake surface and a clearance surface, the rake surface and clearance surface meeting at a cutting edge, wherein as the flutes extend proximally from the tip, the flutes extend outwardly from the longitudinal axis to an equator at which the bur head has a maximum diameter and wherein:
there is at least one first pair of flutes that are symmetric around the longitudinal axis of said bur head that are formed with clearance surfaces that, extending outwardly and proximally from the bur head tip, are located a first acute angle relative to the longitudinal axis of said bur head; andthere is a single second pair of flutes that are symmetric relative to the longitudinal axis of said bur head that are formed with clearance surfaces that, extending outwardly and proximally from the bur head tip, are located a second acute angle relative to the longitudinal axis of said bur head, the second acute angle being greater than the first acute angle so that in cross section along the equator, said first pair of flutes and said second pair of flutes define a perimeter that is not circular.