Abstract: A reamer used in earth boring by the rotary method includes a body having a plurality of sockets in its outer periphery. Upper and lower blocks are disposed in the socket for supporting a shaft. A roller is rotatably mounted on the shaft with the inner periphery of the roller and the outer periphery of the shaft providing bearings for the roller. The shaft has an upper annular shoulder with a downwardly facing sealing surface disposed above the bearings. Upper and lower seals are disposed above and below the bearings with the upper seals having a facing seal sealingly engaging the roller and the downwardly facing sealing surface on the shoulder of the shaft.

Abstract: A target release system, particularly suited for use in simulating the hunting of wild game, characterized by a portable signal transmitter for transmitting detectable signals in a terrestrial space environment, a plurality of visually secluded signal receivers for singly detecting signals transmitted by said transmitter, and a target release subsystem connected with each of the signal receivers for releasing at least one target in response to transmitted signals detected by the receiver.