Abstract: A window sash tether clasp and anchoring system which is externally mountable for universal use in connection with new or pre-existing conventional double-hung windows, wherein the sash tether clasp is externally mounted on the lower sash of such window and includes an outwardly extending catch having a pair of transversely spaced opposed legs which are designed to engage in the outer diverging walls of a bell shaped anchor that is attached to the end of the balance cord leading from the window balancing system. The externally mountable tether clasp further includes an outwardly extending spring lock which includes an arcuate portion, the extrados surface of which faces the catch and extends within the lower bell mouth of the anchor, thereby holding the anchor in releasable engagement with the catch of the tether clasp.

Abstract: A load signal representing the load between a mold and an oscillating mechanism is separated into its static offset and dynamic components. The static offset signal is compared with a free-running static offset to obtain a substantially DC signal representing the DC component of mold friction. A DC voltage is generated corresponding to the RMS value of the dynamic load signal component, and a reference voltage corresponding to the RMS value of the dynamic signal component of a free-running load signal is subtracted in order to obtain a substantially DC signal representing the dynamic component of mold friction.