A wave spring includes an annular body in which crests and valleys are alternately and continuously formed in a circumferential direction. At least a portion of the annular body in the circumferential direction is a joined portion. The joined portion of the annular body is a flat portion extending in a plane orthogonal to a center axis of the annular body.

In one embodiment, a shape-reconfigurable structure includes a rigid base having first and second ends, a rigid first beam having a lateral end and a central end, the lateral end being connected to the first end of the base, and a rigid second beam having a lateral end and a central end, the lateral end of the second beam being connected to the second end of the base and the central end of the second beam being connected to the central end of the first beam, wherein the structure can be placed in an expanded orientation in which the first and second beams extend outward away from the base and a contracted orientation in which the first and second beams extend inward toward the base.

A method for manufacturing a hollow spring member having a hollow steel spring rod having terminal sealed portions at both ends thereof. Each terminal sealed portion has a rotationally symmetric shape in which an axis passing through a center of the spring rod is an axis of symmetry. Each terminal sealed portion has an end wall portion including an end face; an arc-shaped smoothly curved surface between an outer peripheral surface of the spring rod and the end face, and a hermetically closed distal-end-center closure portion on the axis passing through the center of the spring rod. The method includes forming each of the end portions of the spring rod by forming a chamfered portion on an inner or outer peripheral side of the end portion of a hollow wire, the end portion having an opening portion at a distal end, heating the end portion of the hollow wire having the chamfered portion, and spinning the heated end portion to be gathered toward the axis from the outer peripheral side by a jig. The end wall portion, which includes the distal-end-center closure portion, is formed by the distal end of the end portion being joined together on the axis.

A method for manufacturing a hollow spring member having a hollow steel spring rod having terminal sealed portions at both ends thereof. Each terminal sealed portion has a rotationally symmetric shape in which an axis passing through a center of the spring rod is an axis of symmetry. Each terminal sealed portion has an end wall portion including an end face; an arc-shaped smoothly curved surface between an outer peripheral surface of the spring rod and the end face, and a hermetically closed distal-end-center closure portion on the axis passing through the center of the spring rod. The method includes forming each of the end portions of the spring rod by forming a chamfered portion on an inner or outer peripheral side of the end portion of a hollow wire, the end portion having an opening portion at a distal end, heating the end portion of the hollow wire having the chamfered portion, and spinning the heated end portion to be gathered toward the axis from the outer peripheral side by a jig. The end wall portion, which includes the distal-end-center closure portion, is formed by the distal end of the end portion being joined together on the axis.

A damper is disposed in a holding hole that passes through, in a passing-through direction, a supported member that is supported by a supporting member. The dumper includes a tubular body defining therein a through hole extending in the passing-through direction. The tubular body is elastically deformable between a first form and a second form. The tubular body in the first form has an outer shape that is smaller than the holding hole. The tubular body in the second form has an outer shape that is equal to or greater than the holding hole.

A spring steel wire includes a main body made of a steel and having a line shape, and an oxidized layer covering an outer peripheral surface of the main body. The steel constituting the main body contains not less than 0.5 mass % and not more than 0.7 mass % C, not less than 1 mass % and not more than 2.5 mass % Si, not less than 0.2 mass % and not more than 1 mass % Mn, and not less than 0.5 mass % and not more than 2 mass % Cr, with the balance being Fe and unavoidable impurities. The steel constituting the main body has a pearlite structure. The oxidized layer has a thickness of not less than 2 μm and not more than 5 μm. The oxidized layer contains not less than 60 mass % Fe.sub.3O.sub.4.

An assembly has a wheel and a nonpneumatic tire. The nonpneumatic tire includes a plurality of helical springs. Each helical spring includes a first end portion, a second end portion, and an arching middle portion. Each helical spring being is interlaced with at least one other helical spring thereby forming a laced toroidal structure extending about an entire circumference of the nonpneumatic tire. The toroidal structure supports an entire load placed on the nonpneumatic tire. The plurality of helical springs are constructed of a predetermined material that maintains strength and ductility down to 17 K.

The invention relates to an electromagnetic actuator, which can be connected to a backside of a plate like structure and which comprises a voice coil, a magnet system and a spring arrangement connecting the voice coil and a movable part of the magnet system. The spring arrangement comprises at least two spiral springs each having at least three spring legs. The spring legs run in radial and tangential direction in a clockwise or counterclockwise winding direction and are rotational symmetric around the coil axis. The winding directions of the spiral springs are chosen in a way that rotations around the coil axis caused by a relative movement between the voice coil and the movable part of the magnet system in the excursion direction are oriented in opposite directions. The invention also relates to an output device with a plate like structure and an electromagnetic actuator connected thereto.

A personal care appliance which includes at least one flexible spring. The flexible spring having an grounded section with an outer surface and an inner surface, a rotational member arranged radially within the grounded section, wherein the rotational member is arranged to rotate within the grounded section in a first rotational direction about an imaginary rotational axis, and a compliant member having a first end and a second end, wherein the first end is operatively engaged with the inner surface of the grounded section and the second end operatively engaged with the rotational member. The compliant member has a first stiffness such that the compliant member is arranged to resist rotation of the rotational member in at least the first rotational direction.

The metallic crystal structures inspired edge-to-edge tessellations and a tessellation based lattice structures are disclosed. In accordance with an exemplary embodiment of the invention, basic unit lattice cells are stacked and connected to constitute a three-dimensional tessellations, wherein each of the basic unit lattice cells comprises a multiple flat connecting portions formed on a surface of the basic unit lattice cell and intersecting with a multiple of axes intersecting in a center of the basic unit lattice cell, and the flat connecting portions of one of the basic unit lattice cell is connected to the flat connecting portions of the adjacent basic unit lattice cell to constitute a connection structure of edge-to-edge tessellation. The formed tessellations are periodically tessellated in a design domain to form different tessellated lattice structures. The Functionally Tessellated (FT) lattice structures composed of different tessellations by interlocking into each other are also disclosed.