four support members 30 which are preferably aligned with the intended flow of material over the screen these support members 30 extend to flush with the top surface of the screen frame 24 to support the screen cloth 28 the screen cloth 28 may be bonded to these support members 30 a support rod 32 extends from one side of the frame 24 to the other in a perpendicular direction to the support members 30 the rod 32 contributes additional strength to the assembly returning to the resiliently mounted housing 14 a mounting frame 34 includes side rails 36 bordered by upstanding walls 38 two side rails 36 with adjacent upstanding walls 38 define a planar support surface 40 on the side rails 36 within a cavity defined by the upstanding walls 38 the walls 38 are spaced to closely accommodate the width of a screen frame 24 frame cross members 42 extend between the side rails 36 these frame cross members 42 further define the support surface 40 by being spaced to also accommodate the screen frame 24 such that the support surface 40 will receive the underside of the screen frame in juxtaposition intermediate cross members 44 also extend between the side rails 36.