Method and apparatus for stranding profile strands
AssigneeSumitomo Electric Industries, Ltd.
InventorsTakayuki Matsuura, Kenji Miyazaki
Life of this patent
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Abstract
A plurality of strands (7) of sectorial cross-section is stranded around a central core such as an optical fiber conductor. First, a rigid type stranding machine is used to impart a spiral twist to each strand (7). Then, the twisted strand (7) is heat-treated or otherwise treated to remove any stress caused by the twisting. These strands are then fed to a planetary type stranding machine which provides a planetary motion in which the strands perform an orbital rotation around the optical fiber core of an optical conductor or conductors without rotation about its own axis, whereby the strands are stranded together on the optical fiber core.
Claims29
A method for stranding a plurality of profile strands (7) together around a central wire means having a central axis (2), comprising the steps of:
- first imparting a spiral twist having a given twist pitch to each of said plurality of profile strands (7) whereby a certain stress is introduced into each profile strand, then subjecting said strands to a heat treatment within a temperature range and for a time duration sufficient for again removing said stress from said twisted profile strands for providing twisted but unstressed strands, and then subjecting said twisted and unstressed strands to a planetary motion with respect to said central axis for stranding said plurality of twisted and unstressed profile strands around said central wire means thereby using a stranding twist pitch which is substantially the same as said given twist pitch.
An apparatus for stranding profile strands, comprising:
- a device for producing profile strands which having a spiral twist with a given twist pitch, a plurality of bobbins (12) each holding thereon said twisted profile strand (7) as wound thereon, central core feeding means for feeding a central core in a predetermined direction forming a central axis of said core, an eyeplate (16) forming a guide through which a plurality of profile strands (7) drawn out of said bobbins, are passed, a collector die (18) for collecting and stranding together the plurality of profile strands (7) drawn out of said bobbins (12) around said central core, relative rotation means for causing the plurality of bobbins (12) to execute a planetary motion relative to said central core and for providing relative rotation around said central axis between a first group including the plurality of bobbins (12) and said eyeplate (16), and a second group including said central core and said collector die (18), and restraining means 17, 21, 22, 28-33, 68, 52-57) for restraining the inclined attitudes of said profile strands on their cross-sections at least at one location between said bobbins (12) and said collector die (18).
A method for stranding a plurality of profile strands together around a central wire means having a central axis, comprising the steps of:
- first imparting a spiral twist having a given twist pitch to each of said plurality of profile strands (7) whereby a certain stress is introduced into each profile strand, then subjecting said strands to a mechanical roller treatment for again removing said stress from said twisted profile strands for providing twisted but unstressed strands, and then subjecting said twisted and unstressed strands to a planetary motion with respect to said central axis for stranding said plurality of twisted and unstressed profile strands around said central wire means thereby using a stranding twist pitch which is substantially the same as said given twist pitch.
Dependencies are inferred from the claim text.