Abstract: Disclosed is a rolling cone cutter and drill bit employing multiple inserts retained as a cluster in an aperture in the cone cutter. Apertures in which the insert clusters are retained are multilobed apertures formed by intersecting bores formed in the cone steel. The apertures may also be created by forming spaced apart bores and milling regions of the cone steel that extends between the bores. The inserts in a cluster may be retained within the aperture to differing depths, may extend above the cone steel to differing extension lengths, and may have cutting portions having a variety of shapes. The inserts in a cluster may be made of different materials in order to optimize cutting duty.

Abstract: Disclosed is a rolling cone cutter and drill bit employing multiple inserts retained as a cluster in an aperture in the cone cutter. Apertures in which the insert clusters are retained are multilobed apertures formed by intersecting bores formed in the cone steel. The apertures may also be created by forming spaced apart bores and milling regions of the cone steel that extends between the bores. The inserts in a cluster may be retained within the aperture to differing depths, may extend above the cone steel to differing extension lengths, and may have cutting portions having a variety of shapes. The inserts in a cluster may be made of different materials in order to optimize cutting duty.

Abstract: A method is disclosed for forming a drill bit structure to which a cutting element is to be affixed. The method includes applying a layer of hardfacing material to a basic bit structure, removing the layer of hardfacing material in a location to which the cutting element is to be affixed, and forming an attachment structure at the location. In one embodiment, the removing is performed by electrode discharge machining. In one embodiment, the basic bit structure is a roller cone, and the cutting element is an insert adapted to be interference fit within a socket in the roller cone.

Abstract: A method is disclosed for forming a drill bit structure to which a cutting element is to be affixed. The method includes applying a layer of hardfacing material to a basic bit structure, removing the layer of hardfacing material in a location to which the cutting element is to be affixed, and forming an attachment structure at the location. In one embodiment, the removing is performed by electrode discharge machining. In one embodiment, the basic bit structure is a roller cone, and the cutting element is an insert adapted to be interference fit within a socket in the roller cone.

Abstract: A method of manufacturing a rock bit leg from a rough bit leg forging is disclosed whereby multiple machining operations are performed by a six-axis CNC machining center. Three dimensional datum surfaces are initially formed on a rough leg forging. The rough leg forging is then mounted in a holding fixture. The fixture, including the leg forging, is secured to the six-axis CNC machining center. A three dimensional datum reference from the leg forging is set into the NC function of the six-axis machining center.The rough leg forging includes a pair of extended flanges coincident with the 120.degree. leg surfaces. The leg flanges mount to complimentary surfaces formed on the leg holding fixture, thus securing the leg within the fixture without interference of any of the machining processes.The CNC machining center performs a majority of the material removal operations to prepare the leg for subsequent assembly through manipulation of the six interactive axes of the CNC machining center.

Abstract: In a method of and means for producing musical note relationships there is provided an array of staggered lines or rows (1) of symbols, in which each symbol represents a musical note. Each line (1) comprises a repeated series of twelve symbols forming a musical series of semitones known as a chromatic scale, and each line is staggered with respect to adjacent lines such that groups of the symbols which represent the same musical note relationship, such as intervals, scales, chords, etc, form the same visual configuration, for example diagonal configurations (6 to 9) or vertical configuration (14 to 19), at respective locations in the array. In one embodiment, a device including means bearing such an array may be used as a learning aid comprising two overlapping members slidably movable relative to each other. Alternatively the contact positions of a keyboard of a keyboard musical instrument or a fingerboard of a stringed musical instrument may be arranged in accordance with the array.