Abstract: A distally-actuated scanning mirror includes: a mirror block with reflective surface on one side; torsional hinges with proximal ends rigidly attached to the mirror block, and with distal ends attached to flexural structures configured to transform translational motion of the piezoelectric elements into rotational motion of the distal ends of the hinges; and piezoelectric elements providing such translational motion. The distally-actuated scanning mirror also includes flexural structures made of separate flexures attached to the opposite surfaces of the distal ends of the hinges, which flexural structures have defined thinned-down flexural points. Portions of the distally-actuated scanning mirror may be 3D printed and/or fabricated by silicon MEMS technology. The mirror is fabricated from a Silicon-on-Insulator wafer, having a relatively thick (e.g., 380 um) handle layer, and a relatively thin e.g., 50 um), where photolithography with backside-alignment allows separate patterning of these two layers.

Abstract: A ring puzzle has a plurality of rings having a through going slot through which the rings can be introduced into one another, and each of the ring being provided with a plurality of groups at least two circumferentially spaced protrusions and at least two axially spaced grooves, such that when one of the rings is introduced in another of the rings and turned relative to the latter and the protrusions of one of the rings are engaged in the grooves of another of the rings at least one of the groups two of the rings become firmly connected with one another.

Abstract: A stellated icosahedron puzzle has a plurality of assembled together parts forming in an assembled condition a stellated icosahedron, the assemblies including six mated together hollow octahedron assemblies and twelve hollow pyramid assemblies located on the hollow octahedron assemblies rotatable around each of the octahedron assembly via pivot shafts of the octahedron assemblies and stoppable every 180° of rotation, and the pyramid assemblies being independently attachable to and detachable from each of the pivot shafts.

Abstract: A ring puzzle has a plurality of rings having a through going slot through which the rings can be introduced into one another, and each of the ring being provided with a plurality of groups at least two circumferentially spaced protrusions and at least two axially spaced grooves, such that when one of the rings is introduced in another of the rings and turned relative to the latter and the protrusions of one of the rings are engaged in the grooves of another of the rings at least one of the groups two of the rings become firmly connected with one another.

Abstract: A stellated icosahedron puzzle has a plurality of assembled together parts forming in an assembled condition a stellated icosahedron, the assemblies including six mated together hollow octahedron assemblies and twelve hollow pyramid assemblies located on the hollow octahedron assemblies rotatable around each of the octahedron assembly via pivot shafts of the octahedron assemblies and stoppable every 180° of rotation, and the pyramid assemblies being independently attachable to and detachable from each of the pivot shafts.

Abstract: A push-up device has at least one tubular element, a spring means located inside the tubular element and providing a spring resistance, and a handle associated with the tubular element and a movable by a user against the spring resistance applied by the spring to provide exercising for a user.

Abstract: A push-up device has at least one tubular element, a spring means located inside the tubular element and providing a spring resistance, and a handle associated with the tubular element and a movable by a user against the spring resistance applied by the spring to provide exercising for a user.

Abstract: A three dimensional logical game element has a body formed as a part of a three dimensional member, the body has a plurality of elements with corners whose apexes are removed on sides which are located in planes to be in contact and slide over one another during assembly or disassembly of at least two such elements, the body having at least one fixing member for fixing a position of the logical game element, the fixing member being formed as a projection.

Abstract: A logical toy has two coaxial, spring-biased parallel plates formed as disks which are concentrically turnable about a common axis and are provided with arcs, a plurality of toy logical elements surrounded by the arcs and turnable inside the arcs, the toy logical elements being formed as parts of a cylinder, one of the plates having an inner surface provided with a ring-shaped passage with depressions for fixing of a mutual turning of the plates, the other of the plates having an inner surface provided with ring-shaped projection corresponding to a diameter of the ring-shaped passage and having spherical projections, the ring-shaped projections having a height which is greater than a height of spherical projections, the ring-shaped passage with the depressions and the ring-shaped projection with the spherical projections being located concentrically to the axis of turning of the plates at the minimal distance from the axis, the arcs and the inner surfaces of the plates having a common sides provided with radi