Abstract: The method of coating viscous material onto coaxial bores of different diameters, that includes:(a) inserting an expansible and contractible element into said bores,(b) locating viscous material in said bores to be be retracted by said element,(c) retracting said element to effect retraction of said viscous material, and also controlling the diameter of said element, including decreasing its diameter as the element passes into a bore of reduced diameter, so as to spread said viscous material in the form of a tubular layer onto said bores, and while the element passes through the spread tubular layer.

Abstract: An inflated platform, for bouncing, includes a reinforced upstanding and flexible outer side wall to resist outward expansion during bouncing, and a central upper wall at a lower level than an annular flexible top wall that merges with the central wall and side wall, the central wall overlying and spaced from a bottom flexible wall. A reinforcing layer is carried by the central wall and is centered by air pressure below the annular top wall and surrounding that layer, during bouncing; the reinforced layer and the reinforced side wall cooperating to aid platform stability during bouncing.

Abstract: A portable filter bag house assembly includes a collapsible main frame, a plenum chamber attached to the main frame, and a sub-frame carried by the main frame for shaking movement, the sub-frame supporting filter bags to extend toward the plenum chamber for communication therewith.