Abstract: A reduced size ceramic block filter has trap holes whose center is askew from the line running through the center of the transmission poles such that the height-wise distance between its center and the center line of the transmission poles is approximately between {fraction (1/8 )}and {fraction (3/8 )}of the height of the filter. The trap hole is also width-wise spaced from the next nearest transmission hole by an amount which approximates the distance between transmission holes. Due to this layout the diameter of the trap holes are reduced in order to maintain performance which is equivalent to a conventional filter whose trap holes are timely aligned with its transmission poles. The combination of reduced trap hole diameter and reduced width-wise spacing between traps and transmission holes, results in a reduced size ceramic filter.

Abstract: A novel clasp comprises a casing at least partially hollow, an insert and a pin. The casing includes an opening at one end leading to a recess within the casing for securing a loop to be restrained by the clasp. The insert is contained within the hollow of the casing and includes two holes which act in conjunction with the pin to allow the insert to move between first and second stop positions within the casing. In one position the leading edge occludes the opening in the casing, thus closing the clasp. In a second position the leading edge of the insert is retracted within the casing, exposing the opening in the casing, thus opening the clasp. The pin is fixed within the casing and rests within one of the two stop positions of the insert.

Abstract: A ceramic block filter is designed with a shunt transmission line to attenuate third harmonics. A metallized belt is printed on the top surface of the filter along its edges so that it is connected to the metallized ground of the side surfaces. Along one edge an unmetallized line is left along one edge of the filter, whose ends are grounded. The unmetallized line is designed with a length greater than one-half of the length of the metallized belt, but smaller than the length of the metallized belt. The length and width of the unmetallized line are design choices for the specific frequencies sought to be attenuated.

Abstract: A sports racket, for tennis and the like sports, has an elongated handle attached to a head having a racket face, which is spanned by a uniform string structure. The head has four sides, forming a non-elliptical shape, in which the opposite sides are substantially parallel. Longitudinal strings, all of which are substantially identical in length and run essentially parallel to each other, and transversal strings, all of which are substantially identical in length and run essentially parallel to each other and perpendicular to the longitudinal axis, span the racket face. The racket has a larger racket face than conventional rackets, while maintaining the length and weight measurements of conventional rackets, resulting in a very large sweet spot and more good hits.

Abstract: An improved striking implement is provided. The striking implement includes an essentially cylindrical metal shaft having a central cavity. A massive load is disposed within the central cavity at some distance from the upper end of the implement. When the striking implement is swung to contact an object to be struck, the load imparts a secondary impact, additive to the primary impact of the shaft upon the struck object, thereby increasing the forcefulness of the blow as a whole. Appropriate choice of suspension means for the load and situating of the load and suspension means optimize the additional energy imparted to the struck object. In the case in which the implement is a sports bat for striking a ball such as a softball or baseball, significant increase in the speed with which a hit ball leaves the bat, and thus meaningful athletic performance enhancement, is attainable by using the cavity-loaded bat illustrated as an embodiment of the invention.