Side-loading filtering apparatus

Claim 1

In combination with a rectangular side-loading filter housing having open front and rear ends and a side access door, the front end of the housing having an inwardly extending sealing flange around it for engagement by the front of a filter in the frame of a filter-clamping mechanism comprising a filter contact bar in the housing extending across the bottom thereof and movable forward and backward, a screw journaled in the housing behind said bar and parallel thereto, the screw having right- and lefthand threads, a nut registering with each of said threads, a pressure bar between the contact bar and said screw, links extending forward from the nuts and inclined laterally relative to each other, means pivotally connecting the ends of the links to the nuts and said pressure bar on vertical axes, springs between the two bars to resist movement of the bars toward each other, means for turning the screw to cause the links to approach parallelism, whereby to move said bars forward to press the contact bar against the back of the lower part of a filter, a second filter-clamping mechanism substantially the same as said just-mentioned mechanism, and means for supporting the second mechanism in said housing above the first mechanism for pressing against the upper part of a filter.