Wear resisting hold-down means for screening machine

Claim 2

A screening machine comprising, a base, a vibratory frame having a peripheral mounting surface which is resiliently mounted to said base for vibratory movement with respect to the latter, a drive for imparting a vibratory motion to said vibratory frame, a screen assembly including a screen, said screen assembly being seated on said vibratory frame, a layer of rigid, inelastic composite friction material affixed to one of said screen assembly and said frame, said material extending for a substantial portion about said peripheral surface and facially engaging the other thereof in a plane parallel to the plane of said screen, said composite material presenting a weight-supporting interface between said screen assembly and said frame, the weight of said assembly being applied to said frame through said composite material at said interface, and clamping means detachably connected between said screen assembly and said frame, said clamping means acting in a direction generally perpendicualr to the plane of said Screen and exerting an inelastic clamping force on said composite material at said interface, said clamping force holding said screen assembly on said frame for vibratory movement therewith, the screen assembly being positioned with respect to said frame solely by the force of said clamping means acting through said composite material.

Claim 3

The machine of claim 1 wherein said vibratory frame is oversize with respect to said screen assembly at said interface such that said frame does not confine said assembly to a rigidly fixed position.

Claim 4

The machine of claim 2 wherein an upstanding rim extends substantially around said vibratory frame, the said rim having dimensions sufficiently greater than said screen assembly such that said screen assembly does not engage said rim.

Claim 5

The machine of claim 1 wherein said frame comprises a table having a flat surface, and said composite friction material is interposed between said assembly and said flat surface.

Claim 6

The machine of claim 1 wherein said composite friction material is a brake lining material.

Claim 7

The machine of claim 1 wherein said composite friction material comprises a layer having an upper surface and a lower surface, one of which is adhesively secured to one of said assembly and said frame, the other of which surfaces engages the other of said assembly and frame.

Claim 8

The machine of claim 1 wherein said screen assembly includes a top cover, a screen, and a bottom pan, said screen being disposed and held between said cover and said pan.

Claim 9

The machine of claim 7 wherein the clamping means include clamps connectable between the top cover and the frame to draw said top cover, screen and bottom pan against said frame.

Claim 10

IN A SCREEINING MACHINE HAVING A SCREEN ASSEMBLY WHICH IS DEMOUNTABLY SEATED ON A PERIPHERAL PLANAR MOUNTING SURFACE PRESENTED BY A VIBRATORY TABLE HAVING A VIBRATORY DRIVE TO VIBRATE SAID TABLE, AND WHEREIN CLAMPS GENERALLY PERPENDICULAR TO SAID SURFACE ARE ENGAGE BETWEEN THE TABLE AND THE SCREEN ASSEMBLY AND EXERT A CLAMPING FORCE HOLDING THE SCREEN ASSEMBLY ON THE SAID SURFACE, THERE BEING AN INTERFACE BETWEEN THE TABLE AND THE SCREEN ASSEMBLY AT SAID SURFACE, THE IMPROVEMENT COMPRISING, A RIM AROUND SAID SURFACE WHICH IS OVERSIZE WITH RESPECT TO THE DIMENSION OF THE SCREEN ASSEMBLY AT THE INTERFACE, AND A LAYER OF RIGID, INELASTIC COMPOSITE FRICTION MATERIAL EXTENDING FOR A SUBSTANTIAL PORTION OF SAID PERIPHERAL SURFACE AT THE INTERFACE BETWEEN THE TABLE AND THE SCREEN ASSEMBLY, THE WEIGHT OF THE SCREEN ASSEMBLY BEING APPLIED TO THE TABLE THROUGH THE COMPOSITE MATERIAL AT THE INTERFACE, THE CLAMPING FORCE ACTING THROUGH THE COMPOSITE MATERIAL IN A DIRECTION GENERALLY PERPENDICULAR TO IT, THERE BEING NO MECHANICAL ABUTMENT BETWEEN THE SCREEN ASSEMBLY AND THE VIBRATORY TABLE TO RESTRAIN SAID SCREEN ASSEMBLY FROM MOVEMENT IN THE PLANE OF SAID SURFACE, EXCEPT THROUGH SAID COMPOSITE MATERIAL, SAID MATERIAL PREVENTING RELATIVE MOTION BETWEEN SAID SCREEN ASSEMBLY AND SAID TABLE AT SAID INTERFACE WHICH WOULD OCCUR IN THE ABSENCE OF SAID MATERIAL.

Claim 11

IN A SCREEINING MACHINE HAVING A SCREEN ASSEMBLY WHICH IS DEMOUNTABLY SEATED ON A PERIPHERAL PLANAR MOUNTING SURFACE PRESENTED BY A VIBRATORY TABLE HAVING A VIBRATORY DRIVE TO VIBRATE SAID TABLE, AND WHEREIN CLAMPS GENERALLY PERPENDICULAR TO SAID SURFACE ARE ENGAGE BETWEEN THE TABLE AND THE SCREEN ASSEMBLY AND EXERT A CLAMPING FORCE HOLDING THE SCREEN ASSEMBLY ON THE SAID SURFACE, THERE BEING AN INTERFACE BETWEEN THE TABLE AND THE SCREEN ASSEMBLY AT SAID SURFACE, THE IMPROVEMENT COMPRISING, A RIM AROUND SAID SURFACE WHICH IS OVERSIZE WITH RESPECT TO THE DIMENSION OF THE SCREEN ASSEMBLY AT THE INTERFACE, AND A LAYER OF RIGID, INELASTIC COMPOSITE FRICTION MATERIAL EXTENDING FOR A SUBSTANTIAL PORTION OF SAID PERIPHERAL SURFACE AT THE INTERFACE BETWEEN THE TABLE AND THE SCREEN ASSEMBLY, THE WEIGHT OF THE SCREEN ASSEMBLY BEING APPLIED TO THE TABLE THROUGH THE COMPOSITE MATERIAL AT THE INTERFACE, THE CLAMPING FORCE ACTING THROUGH THE COMPOSITE MATERIAL IN A DIRECTION GENERALLY PERPENDICULAR TO IT, THERE BEING NO MECHANICAL ABUTMENT BETWEEN THE SCREEN ASSEMBLY AND THE VIBRATORY TABLE TO RESTRAIN SAID SCREEN ASSEMBLY FROM MOVEMENT IN THE PLANE OF SAID SURFACE, EXCEPT THROUGH SAID COMPOSITE MATERIAL, SAID MATERIAL PREVENTING RELATIVE MOTION BETWEEN SAID SCREEN ASSEMBLY AND SAID TABLE AT SAID INTERFACE WHICH WOULD OCCUR IN THE ABSENCE OF SAID MATERIAL.

Claim 12

The improvement of claim 9 wherein said vibrating drive is operable to establish an acceleration on said screen assembly of at least about 4 g.