Abstract: The present invention comprises a horizontal, perforated agitator element and means to cause the agitator element to reciprocate vertically within a reservoir containing a fluid suspension, solution, or mixture. The perforations in the agitator element are sized and located so that an array of pipette tips may be inserted into the fluid through the moving agitator element without interference.

Abstract: An improved safety needle, including a needle base, for fixing therein a rigid needle containing a hollow hub at one end, a hollow needle connected thereto and a sharp needle tip at the other end, the base defined by a proximal end and a distal end spaced-apart therefrom, the distal end of the needle base having formed therethrough a first bore concentric to the needle and covering the sharp needle tip, and a cap covering the first bore and rotatably positioned thereover, having formed therethrough a second bore, wherein the cap is rotatable between a first, safe position placing the first and second bores out of alignment and preventing passage of the needle and the sharp needle tip therethrough, and a second, armed position placing the first and second bores in alignment to allow passage of the needle therethrough to expose the sharp needle tip.

Abstract: A self-locking nut designed to work with a male thread's that have a slot, keyway or hole along their threads. A novel locking ring (13) placed in a cavity (23)in one end of the nut. One or more fingers (24) on the locking ring lock into a slot, recess, hole or keyway in the male thread and multiple projections on the clip lock into recesses (22) in the female component. By locking the male component to the clip and the female component to the clip the device locks the male component to the female component.

Abstract: A braking system is disclosed for foot-bound roller skates, particularly in-line roller skates, consisting of a method and apparatus for activating the brake, continuously applying braking force while the brake is activated without the application of force to the activating apparatus, and stowing the brake. Preferably, the brake deploys to serve as the aft point on which the skate rides, along with one or more forward wheels.