Crusher with variable opening screen grate

Claim 1

IN A CRUSHER FOR ROCK OR THE LIKE COMPRISING WALL DEFINING A BREAKING CHAMBER, A DEFLECTOR SCREEN GRATE IN SAID CHAMBER, AND AN IMPELLER IN SAID CHAMBER EXTENDING BETWEEN TWO WALLS AND ROTATING IN A GIVEN DIRECTION ABOUT A GENERALLY HORIZONTAL AXIS TO THROE ROCK AGAINST SAID GRATE, THE IMPROVEMENT IN SAID GRATE COMPRISING: RIGID FRAME MEANS SECURED TO SAID TWO WALLS AND COMPRISING A HORIZONTAL TOP SUPPORT, A HORIZONTAL INTERMEDIATE SUPPORT, AND A HORIZONTAL BOTTOM SUPPORT, SAID BOTTOM SUPPORT HAVING A FRONT FACE AND SPACED WALL REARWARDLY OF SAID FACE DEFINING A HORIZONTAL UPWARDLY FACING SLOT THEREIN PARALLEL TO AND REARWARDLY OF SAID FACE, SAID SLOT IN TRANSVERSE CROSS SECTION BEING OF THE SHAPE OF AN INVERTED TRUNCATED TRIANGLE, SAID INTERMEDIATE SUPPORT HAVING A FRONT FACE WITH A HORIZONTAL SLOT EXTENDING THROUGH SAID SUPPORT FROM FRONT TO BACK, SAID LATTER SLOT BEING ELONGATED IN THE DIRECTION NORMAL TO THE FRONT AND BACK DIRECTION, SAID TOP SUPPORT HAVING A FRONT FACE AND AN ABUTMENT EXTENDING FORWARDLY OF SAID FACE AND ABOVE SAID FACE, SAID TOP SUPPORT HAVING A PLURALITY OF BOLT OPENINGS THERETHROUGH FROM FRONT TO BACK; TOP SPACER MEANS INCLUDING A PLATE IN JUXTAPOSITION TO SAID TOP SUPPORT FACE AND HAVING A PLURALITY OF PAIRS OF SPACED ABUTMENTS PROJECTING FORWARDLY THEREFROM; INTERMEDIATE SPACER MEANS IN JUXTAPOSITION TO SAID INTERMEDIATE SUPPORT FACE AND HAVING A CORRESPONDING PLURALITY OF PAIR OF SPACED ABUTMENTS PROJECTING FORWARDLY THEREFROM, SAID INTERMEDIATE SUPPORT HAVING BOLT OPENINGS THERETHROUGH POSITIONED BETWEEN EACH PAIR OF ABUTMENTS; A PLURALITY OF GRATE BARS POSITIONED TRANSVERSELY TO SAID SUPPORTS AND IN FRONT OF THE SPACER MEANS, EACH BAR BEING BETWEEN A PAIR OF ABUTMENTS RESPECTIVELY WITH THE SIDES OF THE BAR BEING APPROXIMATELY IN CONTACT WITH THE ABUTMENTS, THE BARS EACH HAVING A BOTTOM HEAD OF INVERTED TRUNCATED TRIANGULAR CONFIGURATION ENGAGED IN THE SLOT ON THE BOTTOM SUPPORT, EACH BAR HAVING A POCKET THEREIN FORWARDLY OF THE SLOT IN THE INTERMEDIATE SUPPORT, AND A BOLT OPENING FROM SAID POCKET TO SAID SLOT, THE TOP OF EACH BAR HAVING A WEDGING FACE SLOPING FORWARDLY AND DOWNWARDLY FROM BACK TO FRONT; BOLTS EXTENDING THROUGH THE SLOT OF THE INTERMEDIATE SUPPORT, AND OPENINGS AND INTO THE POCKET; NUTS IN SAID POCKETS AND SECURED ON SAID BOLTS; A TOP LOCKING BAR ABUTTING AGAINST SAID WEDGING FACE OF THE GRATE BARS AND AGAINST SAID ABUTMENT; BOLTS SECURED IN SAID LOCKING BAR AND EXTENDING REARWARDLY THROUGH THE BOLT OPENINGS IN THE TOP SUPPORT; AND NUTS SECURED TO THE LATTER BOLTS REARWARDLY OF THE TOP SUPPORT.