Abstract: An athletic field is constructed using side-by-side conjoined layers of resilient synthetic material placed over a drain blanket and extending to a peripheral trench drain. The primary material construction is a reliable layer approximately 4 feet wide by 200 feet long comprising a dimpled polyethylene core material with bonded top and bottom thin, flexible geotechnic fabric layers. A flange and flap system along one edge receives the opposite edge of the joining strip to bond the laterally adjoining layers together in a shingling or tiered manner to promote drainage and to keep water out of the resilient pliable structure.

Abstract: A hook and rail for use with tensioned webs and the like wherein the hook is defined by an opening in a stamped plate body having a throat through which a rail is received when the hook is angularly oriented to the rail in a particular manner. The hook body has a tension axis and the dimension of the hook throat parallel to the tension axis is less than the dimension of the rail in the direction of the tension axis during hook operation. The hook opening includes a recess and a guide surface whereby upon release of the tension in the web, and movement of the hook under gravity, positions the rail in the opening recess maintaining the anchor captured within the hook opening and the rail configuration prevents disengagement of the hook unless the hook is rotated through a specific motion.

Abstract: A stock stop for screw machines and the like for determining bar stock positioning and which is capable of sensing short stock. The stock stop includes a housing affixed to the machine tool having a slidable sleeve in which a threaded stop is adjustably positioned. A spring biases the sleeve and stop toward the advancing bar and the sleeve is displaced to a stop position by the advancing bar stock. Motion multiplying means multiply the sleeve movement upon engagement by the bar stock to actuate a proximity switch indicating proper advancement of the bar stock and permitting continued machine tool operation. As the components of the stock stop are encased and protected against contamination, a high degree of reliability is attained while providing accurate machine tool control with respect to the presence of adequate bar stock for machining.

Abstract: A connection for interconnecting adjacent playground slide sections in end-to-end relationship wherein slide sections formed of molded synthetic material will be accurately aligned and the fasteners holding the sections together are recessed and do not interfere with the sliding surfaces. The interconnection utilizes a projection received within a complementary recess in an overlapping manner to produce a smooth aligned sliding surface relationship between adjacent slide sections capable of producing a high strength fastener produced connection.

Abstract: A retrofit system for biological treatment sanitation vaults wherein evaporation of the liquid waste is accelerated by locating a conduit within the waste receptacle into which only liquid may flow and evaporate within the conduit in the air flowing therethrough. A double conduit system substantially connected in parallel may be used to evaporate liquids accumulating in vaults receiving heavy use for short durations as a float operated air control system permits the most effective utilization of the air movement through the conduit circuit as automatically controlled by the liquid level.

Abstract: A playground structural member characterized by its economy of manufacture, durability and colorfastness consisting of an elongated steel tube core encapsulated within an envelope formed of recycled synthetic plastic, preferably of the polyethylene type. The upper end of the structural member includes a bulbous head, and the lower length is of a cylindrical configuration adapted to receive brackets having attachment tabs whereby the structural members may function as supporting columns for playground apparatus.