Pleated oil filter

Claim 1

AN OIL FILTER FOR USE IN FILTERING THE LUBRICATING OIL OF ENGINES, COMPRISING: INNER AND OUTER CONCENTRIC CYLINDERS; SAID INNER CYLINDER BEING MADE OF COLD ROLLED STEEL AND HAVING A PLURALITY OF CIRCULAR APERTURES THROUGH WHICH THE OIL TO BE FILTERED PASSES; SAID OUTER CYLINDER BEING MADE OF RIGID SYNTHETIC PLASTIC AND HAVING A PLURALITY OF DOT-DASH APERTURES THROUGH WHICH THE FILTERED OIL PASSES; FIRST AND SECOND ANNULAR END CAPS RESPECTIVELY SECURED TO THE ENDS OF SAID CYLINDERS AND BEING MADE OF TIN PLATE SO AS TO BE IMPERVIOUS TO THE FLOW OF OIL; SAID END CAPS CLOSING OFF THE ANNULAR SPACE BETWEEN THE ENDS OF SAID CYLINDER SO AS TO PREVENT THE FILTERING OIL FROM FLOWING THROUGH SAID SPACE BETWEEN THE ENDS OF SAID CYLINDERS; SAID FIRST END CAP HAVING A CENTRAL DEPRESSION WHICH EXTENDS INTO AND CLOSES OFF ONE END OG SAID INNER CYLINDER SO AS TO PREVENT SAID OIL TO BE FILTERED FROM FLOWING THROUGH SAID ONE END OF SAID INNER CYLINDER; SAID SECOND END CAP HAVING AN UPTURNED FLANGE EXTENDING INTO THE OTHER END OF SAID INNER CYLINDER SO AS TO FORM AN APERTURE THROUGH WHICH SAID OIL TO BE FILTERED PASSED INTO SAID INNER CYLINDER; AN ANNULAR RETAINER SHELL BEING MADE OF TIN PLATE SO AS TO BE IMPERVIOUS TO SAID OIL TO BE FILTERED AND HAVING AN INWARDLY TURNED FLANGE SECURED TO A PORTION OF THE OUTER SURFACE OF SAID SECOND END CAP; AN ANNULAR RETAINER RING SECURED TO THE INNER SURFACE OF SAID RETAINER SHELL AND BEING SEPARATED FROM SAID INWARDLY TURNED FLANGED BY A GASKET; A PRESSURE PLATE TIGHTLY FITTED