Abstract: Disclosed herein is a lock suitable for use with sliding type windows which are constrained to ride within trackways. The apparatus comprises a pair of links pivotally connected having tab portions to provide for manipulation of these two links relative to each other and a biasing apparatus which tends to retard the two links from assuming a position in which one link would substantially totally overlie the other link. Further, downwardly extending tabs provide the nesting area for opposed extremities of the biasing spring which is wrapped in a preferred embodiment around the pivoting juncture of the two links and these tabs ride in the trackway or channel of the sliding windows and provide a resistive reaction to unauthorized opening of the window to such an extent that the window can not be opened in the conventional manner.

Abstract: A drill bit having a central shank having an "S" shaped cutter integrally formed on or detachably secured to the shank. A collar is detachably secured to the shank above the cutter and is keyed to the cutter to prevent rotation of the collar. A generally flat secondary cutter is secured to the collar and has a plurality of depending cutter elements on the peripheral edge thereof as well as a plurality of radially extending chisel cutters depending therefrom.