CHISEL Russian patent published in 1997 - IPC

FIELD: traumatology and orthopedics. SUBSTANCE: chisel has handle 1 with head 2. Handle 1 is connected with curved neck 5. Working part 6 of chisel is mounted on end of neck 5. Working part 6 has restrictor 18 and end cutting edge 7 extending at an angle to axis of working part 6. Restrictor 18 is spring-loaded and positioned transverse to longitudinal axis of working part 6 and has stop 14 connected with lever 10 fixed on handle 1. End cutting edge 7 has teeth 8 oriented to one side and inclined toward elongate edge of working part 6. Eccentric 12 fixed on end of lever 10 has immovable spindle 13 carrying stop 14 with yoke 16. Stop 14 is formed as U-shaped slide with internal serrated notches 15. Side surface of working part 6 is provided with serrated notches 9 engageable with serrated notches 15 of stop 14. Restrictor 18 attached on yoke 16 is formed as flat supporting spring. Rectangular cut 20 for receiving working part 6 of chisel is made in surface of restrictor 18, yoke 16 and lining 19. Restrictor 18 is positioned for axial displacement along working part 6. Double-armed lever 10 positioned in slot 4 of handle 1 is made bent. Spring-loaded sleeve 3 disposed in upper part of handle 1 is adapted to retain lever 10 on it. Lever 10 is provided with grip projections 11. EFFECT: increased efficiency in conducting osteotomy without bone breaking effect, elimination of bone and adjacent tissues traumatizing, reduced dynamic loading of bone and surrounding tissues and enhanced reliability in operation. 12 cl, 6 dwg