Abstract: An assembly method, a screwdriving tool and a screw kit for screwing a screw into an internal thread of a medical instrument to connect two branches of the instrument to each other so that the branches are pivotable relative to each other. The method includes: impressing a punch geometry into a screw head of the screw by applying an axial compressive force to the screw by the screwdriving tool, and rotating the screwdriving tool relative to the instrument about a screw longitudinal axis to transmit a torque in a positively locking manner from the screwdriving tool to the screw via the impressed punch geometry and to screw the screw into the internal thread.

Abstract: Punch pins which have further extending lobes, and which are designed to punch sockets that have deeper flutes while not having lobes which extend further toward a center axis of the fastener. Using such a punch pin to form a socket in a fastener provides that the resulting socket has flutes which are deeper than they otherwise would be, without having to provide corresponding lobes which extend further toward the center axis of the socket. This extra deepness in the flutes helps to provide extra room for a coating to deposit.

Abstract: A fastener includes a connecting portion and a head portion connected with the connecting portion. The head portion defines an engaging hole and includes a plurality of protruding teeth separately formed on an inner peripheral wall of the engaging hole, respectively, toward a central axis of the engaging hole of the head portion, and a plurality of recesses are formed between every two adjacent protruding teeth, respectively. The head portion further includes a plurality of resisting projections separately formed on the inner peripheral wall of the engaging hole, toward the central axis of the engaging hole, and received within the corresponding plurality of the recesses of the head portion, respectively. The present disclosure further provides a driver engaging with the fastener and a punch producing the fastener.

Abstract: An aligner and a method for its use in staking a fastener. More specifically, the aligner guides a tip of a staking tool in some portion of a staking operation properly into alignment with a clinch portion of a staked fastener. As a result, the clinch portion is shaped into a head of a generally higher quality than would otherwise occur.

Abstract: A fastener with a recess head wherein the drive head has four lobular recess channels. Each channel comprises a first wall, a second wall, a bottom surface and a recess sidewall. The first and second walls have portions opposing each other and a constant radius of curvature to form a continuously and smoothly forming wall of the channel. A torque producing driver tool is defined with cross sectional signature substantially complementary in size and shape of the recess of the drive head of the fastener for matable engagement. A recess punch for manufacturing the fastener is also defined and comprises a punch holder and a punch pin integral with the holder.

Abstract: A fastener which includes a recess that includes a plurality of alternating lobes and recesses, where each of the flutes and lobes is twisted or angled. The fastener can be driven using a conventional multi-lobular driver. Alternatively, a driver which also has angled or twisted flutes and lobes can be used to engage the recess and drive the fastener. A punch pin includes a head that has a plurality of alternating lobes and recesses that are twisted or angled. The head of the punch pin is configured to punch the recess into the head of the fastener. A device retains the punch pin such that the punch pin can rotate out of the recess after the punch pin punches the recess into the head of the fastener.

Abstract: The fastener of this application is designed to facilitate the insertion of rotating power driven tools into the fastener recess. The recess of this fastener generally uses spirally configured driving surfaces and is formed in a counterbore in the upper surface of the fastener. The driving lobes have upper surfaces that are depressed a distance into the counterbore. A ramp surface is formed on each of the upper surfaces that causes a spinning bit to fall into the recess in an engaged manner. The ramp surfaces are constructed with both removal and installation ramp portions.

Abstract: A fastener is described having a head formed with a recess which accommodates a square head driver, symmetrical drivers, such as PHILLIPS™ style drivers, asymmetrical style cross head drivers, such as POZIDRIV® style drivers, and combination square and cross drivers without compromising performance of the drivers.

Abstract: Recessed head fasteners are provided with a configuration by which the force applied by the blades of the driver to the recessed wings is applied at the radially outer regions of the wings. The wings of the fastener recess may be provided with torque pads at the outer regions of the wings adapted to engage the outer portions of the driver blades. The torque pads may be defined by relieved regions on the drive walls of the recess wings. The relieved regions are formed to avoid contact with the driver blades. Stabilizing ribs also may be defined at the radially inward regions of the drive walls. A recess engageable driver may include a plurality of radially extending ribs configured to promote engagement of the ribs with the most radially outward regions of the recess drive walls. The driver and the recess are compatible with each other as well as with otherwise corresponding conventional recesses and drivers that do not incorporate the invention.

Abstract: The screw has two or three non-circular super-imposed recesses. The depth of each recess is less than 1.2 mm and there is a less than 1° of draw in each recess. The screw head recess is formed using a punch (10) in a cold-heading process. The punch is formed in a profilating CNC machine, cutting the profiles (12,14,16) of the punch to a tolerance of better than ±0.025 mm. A method of manufacture of a cold-forming punch for such a screw comprises providing a profilating head as one of the tools on a turret mounted adjacent the chuck in the CNC machine. The profilating head has several cutting elements, each being adjustable with respect to one another: axially, radially and angularly.

Abstract: A method of making a recess in a drive socket and the like includes forming a groove to extend along a face of an elongated drive opening in a metal workpiece from one end of its drive opening, moving material from the surface of the groove to increase its depth from its outer end along only a portion of its length and gathering the material so moved from the groove surface to form a ledge between ends of the groove, whereby a recess is defined by the groove extending beyond the ledge. In addition, a female drive device for socket wrenches and the like is disclosed having an elongated drive opening, a groove longitudinally extending from one end of the drive opening along a face of the drive opening, and a ledge between ends of the groove. The ledge protrudes radially inwardly such that a recess is defined by the groove extending beyond the ledge for retaining a male drive member.

Abstract: A spiral drive system for threaded fasteners includes driver-engageable surfaces on the head end of the fastener in which at least some of the driver-engageable surfaces are defined by a spiral segment configured to maximize torque transmission while spreading the driving load over a broad driver-fastener interface to reduce the risk of development of high stress regions. Drivers and related tooling also are disclosed.