An improved torque converter damper disc and/or clutch that includes the use of a parametric spring system. The parametric spring is configured to address critical inflection and pinch points along the spring longitudinal length. These critical points are areas of higher applied stress due to torsional stress and bending stress, the latter of which mainly attributed to centrifugal loading.

A coil spring includes a resilient portion having a first diameter defined by a first central axis that is hypothetical and an end coil abutting on one end of the resilient portion in an axial direction of the resilient portion. The end coil has a second diameter defined by a second central axis that is hypothetical and shifted from the first central axis of the resilient portion in parallelism with the first central axis of the resilient portion by a predetermined shift amount. A coupler has a first width that is smaller than the first diameter of the resilient portion and greater than a second width obtained by subtracting the predetermined shift amount from the first diameter of the resilient portion. The coupler is inserted into the end coil to secure the end coil to the coupler.

A spring assembly includes a first coil spring and a second coil spring. The second coil spring includes a first winding portion and a second winding portion. The first winding portion includes a plurality of windings from a first winding to at least a second winding. The second winding portion is a portion except for the first winding portion. An outer diameter of each of the plurality of windings of the first winding portion is smaller than an outer diameter of each of at least one winding of the second winding portion. Each of the plurality of windings of the first winding portion includes the substantially same outer diameter.

A magazine for storing and feeding ammunition cartridges to a small arms weapon which comprises a casing, a floor plate, a follower, and a magazine spring inside the casing. The magazine spring may comprise a first end connected to the follower, a second end connected to the floor plate, and a plurality of coils. Each of the plurality of coils may include a first segment having a first radius, a second segment having a first length adjoining the first segment, a third segment having a second radius adjoining the second segment, the second radius being greater than the first radius, and a fourth segment having a second length adjoining the third segment, the second length being approximately equal to the first length.

A one-piece balance spring includes a single strip wound on itself between an inner coil and an outer coil. The strip has a geometry such that when the angle of contraction of the balance spring has a value of 360 degrees, there is a constant distance between each coil from the second coil to the penultimate coil.

A one-piece balance spring including a single strip wound on itself between an inner coil and an outer coil, the strip having a geometry such that when the angle of contraction of the balance spring has a value of 360 degrees, there is a substantially constant distance between each coil from the inner coil to the penultimate coil.

A magazine for storing and feeding ammunition cartridges to a small arms weapon which comprises a casing, a floor plate, a follower, and a magazine spring inside the casing. The magazine spring may comprise a first end connected to the follower, a second end connected to the floor plate, and a plurality of coils. Each of the plurality of coils may include a first segment having a first radius, a second segment having a first length adjoining the first segment, a third segment having a second radius adjoining the second segment, the second radius being greater than the first radius, and a fourth segment having a second length adjoining the third segment, the second length being approximately equal to the first length.

A coil spring is formed by winding a wire in a coil shape. In the cross sectional shape of the wire formed in the coil shape, the inner diameter side part in the coil shape includes a semi-elliptical shape having a major radius and a minor radius and the outer diameter side part in the coil shape includes a curved shape circumscribing a circumscribed circle having a radius larger than the minor radius, arc shapes having a curvature larger than the curvature of the circumscribed circle, and linear shapes connecting both ends of the arc shapes to both ends of the semi-elliptical shape. This can increase the cross sectional shape of the wire, reduce a shearing stress, and improve the durability of the coil spring.

A vibration reduction damper is disposed inside a center vent tube having vent holes which pass therethrough in the radial direction, and has a sliding portion which comes slidably into contact with the inner wall surface of the center vent tube while avoiding the region in which the vent holes are formed.

The invention relates to a one-piece balance spring comprising a single strip wound on itself between an inner coil and an outer coil, the strip having a geometry such that when the angle of contraction of the balance spring has a value of 360 degrees, there is a constant distance between each coil from the inner coil to the penultimate coil.