Abstract: Devices and methods for twisting yarn may twist a strip of material, such as a paper strip, into a yarn, such as a paper yarn. Such devices and methods may involve positioning a pad formed from a roll of the material horizontally in a yarn twisting device, such that the strip of material is unwound and drawn from an outer circumference of the pad, but down through the center of the pad, and subsequently through a rotating yarn twister.

Abstract: A frangible clip and method for embedding a concrete insert into a concrete structure. The clip may include at least one frangible member which shears from a base member when a sufficient shearing force is applied. The clip may be formed of plastic as an integrally formed, single unit.

Abstract: A two-sided manhole step. The step includes a first step surface and a second step surface. Lugs extend from ends of the first and second step surfaces. The lugs help to prevent individuals from sliding off the manhole step, regardless of whether the step is installed with the first step surface or second step surface facing upwards.

Abstract: A manhole lift insert with a socket portion and a frangible portion that is inserted in a pre-positioned bushing in the outer wall of a manhole form. A key in the sleeve portion may be received in a keyway in the bushing in the form wall so that the insert is properly oriented in the form.

Abstract: A thermal gravity classifier in which various nonferrous scrap metals are classified and separated, using a single tank containing two layers of molten media. Shredded nonferrous scrap containing metal constituents such as aluminum, zinc, lead, and copper or the like are introduced to the top of the tank containing an upper layer of molten zinc, floating on a lower layer of molten lead. Metals such as aluminum, having a specific gravity less than zinc, by a screw conveyor approximately parallel with the top surface. Heavier metals and alloys such as copper or the like, having a melting point above the temperature within the tank, fall through the zinc layer and are conveyed from the tank by a separate screw conveyor extending up a diagonal wall of the tank. Metals such as lead and zinc, having a melting point lower than the temperature maintained within the tank, melt and gravitate to the appropriate molten layer in the tank.

Abstract: A system for receiving and crushing whole lead acid storage batteries, and for classifying the components of crushed batteries into lead oxide, lead metal, plastic case components, and rubber case components and other fragments. Whole batteries are crushed into component particles, and lead oxide from the batteries is placed in liquid suspension. The lead oxide is subsequently removed by three separate settling and classifying tanks. Lead metal is removed by a liquid upflow column separation. A flotation tank and surface skimming arrangement separates plastic case fragments from rubber fragments.