Abstract: An acoustic system kit for a vehicle speaker and associated methods of installation and manufacture are disclosed. A drum of open-cell foam, preferably several inches thick, having a peel-and-stick pressure-sensitive adhesive backing is cut with two concentric circles to create an outer ring, and inner ring, and a core. The parts are sized to correspond in diameter, respectively, to the front edge, rear edge, and back disc of a particular size of speaker. The inner ring is cut circumferentially to reduce its height to a thin strip relative to the outer ring and drum. Using the pressure-sensitive adhesive, the core is affixed to the inside wall of vehicle door directly behind the door's speaker mount, the inner ring is affixed to the rear edge of a speaker to be installed, and the outer ring is affixed to front edge of the speaker. The speaker is then installed on its mount.

Abstract: An improved drilling rig (10) and conversion apparatus for drilling rigs is disclosed. The rig includes a percussion assembly (32) rotatably mounted to a ram (30) above the ground in which drilling is to be made. The rig (10) includes a conversion mandrel (40) structured for insection in, and retention by, the percussion assembly (32) in place of a normally retained bit element (34). The mandrel (40) has an anvil surface (56) to which percussive strokes of a piston (50) disposed within the percussion assembly (32) for reciprocating movement therein are applied. The mandrel (40) further includes a hammer portion (68) to transfer both the percussive force of the piston (50) and continuous downward pressure applied to the percussion assembly (32) by the ram 30 to a length of casing (20) encircling the drill rod (22) which accomplishes the drilling. The conversion apparatus can, therefore, convert a bottom-hole drilling rig to a top-of-the-hole rig.