Abstract: A fail-safe arrestor for electrical circuits utilizes a gas-filled tube to conduct at an over-voltage and also provides a clip to solidly couple the circuit to a ground lead at the melting from continuous current flow of an insulator interposed between an electrode and the ground lead, which insulator is a mesh with a plurality of passages allowing arcing between the electrode and clip at or above a predetermined voltage, and thus the ground lead, for a vented gas-filled tube.

Abstract: A set of golf club shafts for a set of golf clubs is made so that the natural frequencies of vibration of the shaft for the various clubs are matched. Each of the shafts includes a butt portion, a tip portion, and a plurality of stepped portions between the butt portion and the tip portion. The length of the butt portion, the length of the tip portion, and the length of all of the stepped portions except one is the same for all of the shafts. The length of said one stepped portion of each shaft is selected to provide the shaft with the desired natural frequency of vibration, and the difference in the overall length of two shafts corresponds to the difference in the lengths of said one stepped portion of the two shafts. The torsional resistance of each shaft is increased without increasing the weight of the shaft by providing a shaft with relatively large inside and outside diameters and a relatively small thickness.

Abstract: A golf clubhead has weight distributed on opposite sides of a non-vertical axis which extends through the center of gravity of the clubhead in a plane which intersects the axis of the shaft above the clubhead to provide more accurate off-center hits. Wooden clubs are provided with bulge and roll which curve, respectively, about said axis and an axis perpendicular thereto. The radius of the roll is increased to make the loft of the club substantially uniform from top to bottom.