Abstract: A rotary propulsion engine system designed to propel a craft. Such a rotary propulsion engine system comprises a power supply, a counterrotating disc assembly including two axially and rotatably connected discs, a drive mechanism to rotate the two counterrotating discs, an axle assembly, at least two reaction masses or armatures, at least two reaction mass driver assemblies, and at least two travel pathways for the reaction masses. Reaction masses are fired into a rotational environment wherein the kinetic energy of the reaction masses is recycled, thereby reducing or eliminating the need for chemical propellant-based propulsion systems, and transporting heavy, finite, and expensive fuels for combustion.

Abstract: A rotary propulsion engine system designed to propel a craft. Such a rotary propulsion engine system comprises at least two reaction masses or armatures, at least two reaction mass driver assemblies, at least two travel pathways for said reaction masses or armatures, two counterrotating discs housing an equal number of the at least two said reaction mass driver assemblies, and a counterbalancing means used to maintain a balanced distribution of masses about the axis of rotation of each counterrotating disc in order to maintain a zero horizontal torque sum as each reaction mass or armature moves along its ballistic trajectory. Reaction masses are fired into a rotational environment wherein the kinetic energy of said reaction masses is recycled, thereby reducing or eliminating the need for chemical propellant-based propulsion systems, and transporting heavy, finite, and expensive fuels for combustion.

Abstract: Hypodermic needle safety apparatus includes an embodiment having a shield which includes a longitudinal slot and a cover which rotates on the shield and an embodiment in which the shield must be moved axially, along the longitudinal axis of the syringe and needle, to allow the needle to be moved through a slot for use. The shield is then pivoted by thumb or finger movement so that the needle moves through the exposed slot to allow use of the syringe and the needle. The shield or cover moves through an arc of about 180 degrees so that the shield is away from the needle during the use of the needle and syringe. The shield is pivoted back downwardly to cover the needle and then the shield is again moved longitudinally or axially so that the bottom of the needle is away from the slot. The longitudinal or axial movement of the cover or shield requires a positive movement, and accordingly the shield may not be accidently or inadvertently pivoted away from the needle to expose the needle.