One or more aspects of the present disclosure are directed to components having an optical element that imparts structural color to the component or article. The present disclosure is also directed to articles of manufacture including the component having an optical element, and methods for making components and articles having an optical element that imparts structural color.

A machine tool includes a first main shaft, a first drive source for moving the first main shaft, a second main shaft, a second drive source for moving the second main shaft, and a control means for carrying out a control so as to bring the workpiece held by the first main shaft and the workpiece held by the second main shaft into contact with each other while rotating them relative to each other, thereby to carry out the friction-heating, and to stop the relative rotation of the pair of workpieces and move only the second main shaft in the axial direction while holding the first main shaft stationary, thereby to carry out friction-welding of the pair of workpieces. The control means controls the operation of the first drive source upon the friction-welding of the pair of workpieces, so as to maintain the axial position of the first main shaft.

A lathe capable of shortening a cycle time of workpiece machining. A lathe includes a first spindle, a second spindle opposite the first spindle, a tool post on which a cut-off tool is provided, and a control unit which controls rotation of the first and the second spindles and further controls relative movement of the first and the second spindles and the tool post to cut-off the workpiece. The control unit adds a rotation speed fluctuation to a rotation speed of the first spindle after rotating the first spindle and the second spindle synchronously and detects a rotation speed of the second spindle. The control unit determines that the workpiece is normally cut-off upon determining that a detected fluctuation in the rotation speed of the second spindle is within a predetermined range.

A lathe capable of shortening a cycle time of workpiece machining. A lathe includes a first spindle, a second spindle opposite the first spindle, a tool post on which a cut-off tool is provided, and a control unit which controls rotation of the first and the second spindles and further controls relative movement of the first and the second spindles and the tool post to cut-off the workpiece. The control unit adds a rotation speed fluctuation to a rotation speed of the first spindle after rotating the first spindle and the second spindle synchronously and detects a rotation speed of the second spindle. The control unit determines that the workpiece is normally cut-off upon determining that a detected fluctuation in the rotation speed of the second spindle is within a predetermined range.

One or more aspects of the present disclosure are directed to bladders that incorporate a multi-layer optical film that impart a structural color to the bladder. The present disclosure is also directed to articles including the bladders having a multi-layer optical film, and methods for making articles and bladders having a multi-layer optical film.

Components of articles that include an optical element that imparts structural color to the component are provided. Methods of making the components including the optical element, and methods of using the components such as to make an article of manufacture are provided.

As described above, one or more aspects of the present disclosure provide articles having structural color, and methods of making articles having structural color. The articles incorporate a primer layer having a percent transmittance of about 40% or less in conjuction with an optical element. The optical element and primer layer impart a structural color to the article.

One or more aspects of the present disclosure provide optical element transfer structures that include an optical element releasably coupled with a transfer medium and methods of making and using the optical element transfer structures. The optical element transfer structures can be used to dispose an optical element onto an article, whereby the optical element imparts a structural color to the article.

Disclosed is a friction welding method including: a heating step wherein, in relation to joining surfaces (S1, S2) defined by opposite end surfaces of a pair of materials (W1, W2), the pair of materials (W1, W2) are moved from a state in which their axes are unaligned with each other, in a direction for aligning the respective axes with each other, to a prescribed position where the joining surfaces (S1, S2) are brought into contact with each other and friction heated; and a pressure contacting step wherein the pair of materials are brought into pressure contact with each other. The method is characterized in that the heating step and the pressure contacting step are carried out while rotating each of the materials (W1, W2) at the same rotation speed in the same direction, as seen from one side in the axial direction.

A rotary indexing machine comprises at least one indexing plate, which is in at least one operating state configured to accommodate and transport at least one work piece, and with at least one clocking cell comprising at least one accommodating unit with at least two opposite-situated accommodating elements, which are configured for together accommodating the at least one work piece from the indexing plate, and comprising at least one machining unit for machining the work piece accommodated by the accommodating unit, wherein the at least one clocking cell comprises at least one bridge unit, which extends at least partially over the indexing plate in an axial direction and is configured to guide the at least two accommodating elements of the accommodating unit in a shared coordinate system.