READJUSTABLE JIG FOR DRILLING HOLES IN POLYHEDRONS Russian patent published in 1997 - IPC

FIELD: metal working. SUBSTANCE: jig has two collapsible prisms one of which is movable. The prisms consist of top jig planks 1 and 2 and bottom portions 3 and 4 of the base. The movable prism is provided with a boss made up as cylindrical spring-loaded journal 6 and key projection 7 received in opening 8 provided with key groove 9 made in the bottom portion of the base of the fixed prism perpendicular to the vertical plane of symmetry of the prism. The top portions of prisms 1 and 2 are made up as movable jig planks mounted for permitting movement with respect to the bottom portion of base 3 and 4 in the plane perpendicular to the axis of the polyhedron in the direction of the working edges of jig planks 1 and 2. Eccentric-type carriers 15 are rigidly secured to pins turn 17 inside rectangular hollows 16 on movable jig planks 1 and 2. In rotation of carriers 15 Movable jig planks 1 and 2 move and are fixed in a given position by way of screws 23. Movable jig planks 1 and 2 are provided with replaceable jig bushings 24 with chamferings 26 conjugated with the sides of collars 27 of movable jig planks 1 and 2. The polyhedron is mounted until it touches stop 28, the movable prism being moved away. The polyhedron is then clamped by means of this prism. EFFECT: enhanced reliability. 2 cl, 3 dwg