Patent ID: 9513111
Filing Date: 2016-12-06
CPC Classification: G01B

Claim Text:
1. A self-tensed and fully spring jacketed optical fiber sensing structure, comprising: a single-mode optical fiber, comprising a lengthwise fiber grating therein; a cylindrical coil spring, having a fixed length, jacketing and protecting the single-mode optical fiber been placed therein, comprising a longer cylindrical tension coil spring, a shorter cylindrical compression coil spring connected in series to the cylindrical tension coil spring, and a longer cylindrical tension coil spring connected in series to the cylindrical compression coil spring, the shorter cylindrical compression coil spring being located between the two longer cylindrical tension springs; a pre-tensing front-end connecting ring of optical fiber and spring, externally connected to the spring and internally connected to the optical fiber; and a pre-tensing rear-end connecting ring of optical fiber and spring, externally connected to the spring and internally connected to the optical fiber; wherein, the optical fiber sensing spring structure is characterized that, a predetermined gauge length is formed between the pre-tensing front-end connecting ring and pre-tensing rear-end connecting ring; the gauge length is determined by first fixing the front-end and rear-end connecting rings when a maximum tolerable compression strain amount is obtained from compressing two ends of the cylindrical compression coil spring surrounding and protecting the fiber grating to the predetermined fiber grating been placed therein, and then releasing a force applied, and thus by a pre-tensing effect achieved by elastically stretching the fiber grating within an elastic region; the cylindrical tension coil springs extended from the two ends of the cylindrical compression spring that jackets and protects the fiber grating and having a same outer diameter provide a protection function by a full jacketing spring material to protect the optical fiber placed therein, thereby becoming the self-tensed and fully spring jacketed optical fiber sensing structure.