Abstract: Adherent packed beds of ceramic beads, each comprising a ceramic body coated with a biodegradable polymer, and fabric bags containing such beads in a packed, self-supporting configuration. The polymeric coating provides some resilience to a packed bed of the ceramic beads, and prevents the beads from moving with respect to each other when placed under stress, leading to reduced breakage. The ceramic beads desirably are osteoconductive, and preferably are formed of a ceramic material that is resorbed during bone growth, such as hydroxyapatite, tricalcium phosphate, or mixtures of these materials. The beads may contain, either internally or on their surfaces or both, a bone morphogenic protein, and the latter may also be included in the biodegradable polymer coatings on the beads.

Abstract: A molded plastic one-piece hollow expansion nut comprises an outwardly expandable shank which is insertable through a panel hole and a head at one end of the shank for engaging the panel surface. A screw-receiving bore extends axially through the nut and receives the threaded shank of a screw whose screw head bears against the nut head. The portion of the bore along which shank wall expansion occurs is cylindrical and of slightly larger diameter than the screw thread. The inmost end of the bore is of oblong cross-section and its minor axis is shorter than the diameter of the screw thread. A single screw-engaging thread in the cylindrical bore initially holds and guides the screw. The shank walls opposite the ends of the minor axis have oblique screw-thread receiving slots therethrough which define very sturdy damage resistant nut threads which engage the screw thread.

Abstract: A self-sealing expansion rivet assembly comprises an expandable hollow plastic rivet and a plastic drive pin therefor. The rivet has a head and a slotted expandable shank for insertion in aligned holes in sheets which are to be joined together. The drive pin has a head and a serrated shank which, when inserted in the rivet bore and axially drawn thereinto by a tool, causes the pin head to engage the insertion end of the rivet shank and effect outward expansion of the rivet shank to fasten the sheets together, as well as break-off of the projecting end of the pin shank. The pin shank serrations engage a serrated reduced-bore portion in the rivet to hold the pin and rivet together permanently. Integrally formed annularly-shaped conical flexible liquid sealing flanges are provided on the rivet on, at or near the rivet head. As the rivet is expanded by the tool, the sealing flanges are forced against the adjacent panel around the hole therethrough to form a leak-proof seal.

Abstract: A one-piece, plastic fastener for lockable engagement in a workpiece opening, including a stem having an outer end and also having an inner end from which a pair of integrally formed arms extend. The arms have two ends, one end forming an acute angle with the inner end of the stem, and the other or free end terminating at an integrally formed head portion. The head portions are swingable with their respective arms about the inner end of the stem to cooperatively engage each other and to form a complete head having an orifice embracing the stem. The stem and arms are insertable into the opening to locate the head against the outer side of the workpiece. Positive and outward withdrawal of the stem through the opening and orifice causes the arms to swing laterally and abut firmly against the inner side of the workpiece. Serration means between the head and stem maintain the fastener in lockable engagement with the panel by readily permitting outward movement of the stem while resisting its inward movement.

Abstract: A rotatably engaging head for a fastener for attaching a complementary panel member to a support member. The head includes a substantially flat underside and also includes a generally radially extending slit. One edge of the slit is connected to and defined by a lead-in tongue spaced above and generally parallel to the head. The tongue permits facile introduction of the head through an aperture in the panel, which aperture is smaller than the head. Extending from the head is a shank, for engagement of the support member to the panel member.

Abstract: A one-piece, plastic fastener for lockable engagement in an opening in a panel, comprising a stem having an inner and an outer end. A pair of legs is formed integrally with and extends from the inner end, the legs being in parallelism with one another and in general axial alignment with the stem. Each of the legs has integrally formed therewith at a juncture an elongated arm positioned at an acute angle relative to its leg. The arms each have a free end which terminates in an integrally formed head portion, and the head portions are cooperatively engageable with one another and swingable about the juncture and with their respective arm towards one another to form a complete head having an orifice embracing the stem. The stem and arms are drivable into the opening in the panel to locate the head against an outer side of the panel. Serration means are provided between the head and the stem to maintain the fastener in lockable engagement with the panel.

Abstract: A two-piece plastic fastener has a sleeve-like body comprising forwardly projecting flexible legs and having a concentric radially enlarged head at its rear end. Longitudinal slots in the body define the legs and space them apart laterally. A cylindrical plunger, forwardly insertable in the body to an operative position at which it holds the legs forwardly diverged, has two radially outwardly opening circumferential grooves, one near its front end, the other near its rear end. At the rear end of each slot in the body is a detent lug that has its rear end integrally connected with the body to have its front end flexible radially outwardly. These lugs detent-wise engage in the front groove to define a projecting position of the plunger and in the rear groove to define its operative position. Lugs and grooves are so configured as to offer more resistance to rearward than to forward plunger displacement.