A Side-Intake piston water jet propulsor for marine vehicles employs a concept of Side-Intake of water and generates thrust through piston's reciprocating motion in cylinder. The concept of Side-Intake makes intake openings on the side and near the discharging end of the cylinder wall to achieve that the piston separates the cylinder into a dry and a wet compartment during its movement. The dry compartment is kept at atmospheric or ambient pressure. As a result, the piston confronts air or ambient pressure instead of water during its recovering stroke for water intake. From hydrodynamics point of view, this characteristic of piston's recovering stroke through air achieves the same function as an oarsman recovering his oar through air. However, said propulsor achieves that under water or a vessel's water line.

Boat rowing apparatus including a framework having spaced horizontal flotation members disposed outside the boat sides and extending into the body of water supporting the boat. A plurality of spaced paddle members are pivotally mounted on the flotation members to propel the boat when the framework is moved back and forth by a rower.

Boat rowing apparatus including a framework having spaced horizontal flotation members disposed outside the boat sides and extending into the body of water supporting the boat. A plurality of spaced paddle members are pivotally mounted on the flotation members to propel the boat when the framework is moved back and forth by a rower.

A Pulsed Locomotor (120), for propelling media, fluids and crafts, in fluids and on land, comprising a blade (124) securely connected to a drive shaft (122). Upon reciprocation, the ambient medium is forced towards the trailing edge of the blade (124) thereby causing a reactive locomotion of the apparatus, substantially along the plane of the blade. Apparatus is secured to motor M by fastening through aperture (130). The apparatus can be operated directly by motor M, and indirectly by the reaction momentum imparted to a supporting platform P. Thrust is directed by steering handle (128) about a bearing (126), rotatably coupling to platform P and base C. Lubricant L is supplied to outlets (134) via conduit (136) and inlet (132), to coat the apparatus with a lubricant cavity, for drag reduction. The blade (124) planes along a figure 8 reciprocation path s1e1s2e2s1. Crafts are embodied.

A Pulsed Locomotor (120), for propelling media, fluids and crafts, in fluids and on land, comprising a blade (124) securely connected to a drive shaft (122). Upon reciprocation, the ambient medium is forced towards the trailing edge of the blade (124) thereby causing a reactive locomotion of the apparatus, substantially along the plane of the blade. Apparatus is secured to motor M by fastening through aperture (130). The apparatus can be operated directly by motor M, and indirectly by the reaction momentum imparted to a supporting platform P. Thrust is directed by steering handle (128) about a bearing (126), rotatably coupling to platform P and base C. Lubricant L is supplied to outlets (134) via conduit (136) and inlet (132), to coat the apparatus with a lubricant cavity, for drag reduction. The blade (124) planes along a figure 8 reciprocation path s1e1s2e2s1. Crafts are embodied.

A human propelled watercraft having a pair of flexible fins extending into the water each adapted to oscillate through an arcuate path in a generally transverse direction with respect to the central longitudinal dimension of said watercraft. Pedals are provided for applying input force whereby as input force is applied, the flexible fins can twist to form an angle of attack for providing forward thrust with respect to the longitudinal dimension of the watercraft while moving in both directions along the arcuate path. The user can pull a lever and cause the fins to rotate 180 and produce thrust in the reverse direction. The fins are able to pivot and swing aft to avoid damage if there is a collision with a submerged object. The fins are more efficient, durable, and adjustable. Simple plastic roller bearings have been adapted to reduce mechanical friction without the need for oil seals.

A human propelled watercraft having a pair of flexible fins extending into the water each adapted to oscillate through an arcuate path in a generally transverse direction with respect to the central longitudinal dimension of said watercraft. Pedals are provided for applying input force whereby as input force is applied, the flexible fins can twist to form an angle of attack for providing forward thrust with respect to the longitudinal dimension of the watercraft while moving in both directions along the arcuate path. The user can pull a lever and cause the fins to rotate 180 and produce thrust in the reverse direction. The fins are able to pivot and swing aft to avoid damage if there is a collision with a submerged object. The fins are more efficient, durable, and adjustable. Simple plastic roller bearings have been adapted to reduce mechanical friction without the need for oil seals.

A jewelry display includes a ferromagnetic planar substrate having a front surface opposite a back surface. A bracket is configured to be attached to a wall, the bracket comprising at least one bracket magnet which is a permanent magnet. The back surface of the ferromagnetic planar substrate is configured to removably attach to the bracket due to the magnetic force of the at least one bracket magnet. A plurality of jewelry fixtures are configured to be removably attached to the front surface of the ferromagnetic planar substrate. Each jewelry fixture includes at least one permanent fixture magnet and a jewelry holding structure. The at least one permanent fixture magnet of each jewelry fixture is magnetically attracted to the ferromagnetic planar substrate. The at least one bracket magnet may be at least 2, 5, 10 times or more as powerful as the at least one permanent fixture magnet.

This invention discloses a flapping wing with multi film sheets listed on a net frame, wherein a fuselage is disposed on the flapping wing, transmissions are installed on both sides of the fuselage, a frame is installed on a side of each transmission, the frame is composed of supports and a fine net structure, one side edge of each film sheet is fixed on the fine net structure, and the other side edge of the film sheet can move freely; one end of a limit thread is connected with the fine net structure, while the other end of the limit thread is connected with the movable side edge of the film sheet. All the film sheets are arranged on the same side of the fine net structure.

This invention discloses a flapping wing with multi film sheets listed on a net frame, wherein a fuselage is disposed on the flapping wing, transmissions are installed on both sides of the fuselage, a frame is installed on a side of each transmission, the frame is composed of supports and a fine net structure, one side edge of each film sheet is fixed on the fine net structure, and the other side edge of the film sheet can move freely; one end of a limit thread is connected with the fine net structure, while the other end of the limit thread is connected with the movable side edge of the film sheet. All the film sheets are arranged on the same side of the fine net structure.