taken along line b u2014 b shows the mounting location of dashpot mounting bracket 39 for dashpot 19 on frame 5 and the relative orientation of dashpot 23 and coil spring 29 a it is noted that the coil springs 29 a which support the weight of screen 13 are expected to be greater in number and or to have a higher spring rate than springs 29 b that supports no weight at the top of the screen the springs 29 b may be slightly compressed to be responsive to small vertical movement of the screen springs 29 c and 29 d would in most cases be the same number and spring rate on each side and also slightly compressed the components of the mounting have been described generically and are subject to many variations linear bearings for example include all linear low friction devices that are available from numerous manufacturers and have numerous detail differences for some applications linear bushings are equally functional low friction devices needle bearings 31 may be replaced with a low friction material such as teflon springs as illustrated in the drawings are coil springs leaf springs are an obvious alternative and may be used one per side or in multiples hairpin springs are a suitable substitute for leaf springs and are equivalent depth which makes the mounting thin pneumatic hydraulic and other more exotic springing means are suitable but cost prohibitive dampers or dashpots are described generically and include gas filled liquid filled viscoelastic and any other damping means the frames may be formed from any castable or formable metal although aluminum is preferred for its light weight alternatively engineering plastics.