| 摘要 |
A device for measuring pressure between two cylinders of a press which includes a first mirror fixed to the end of a journal of one of the cylinders in a position perpendicular to the cylinder axis and a relatively stationary second mirror spaced substantially parallel to the first mirror. A light emitter at one edge of the mirrors, and lying in the common plane of the cylinders, directs a concentrated beam of light between the mirrors at a shallow angle of incidence for multiple reflection, with the point of exit of the beam at the other edge of the mirrors shifting in accordance with changes in the angular position of the first mirror as a result of slight bowing of the cylinder in response to changes in applied pressure. A photocell at the region of exit receives the beam to produce an output signal which varies in accordance with the shift in the point of exit of the beam to constitute a measure of the applied pressure. In one of the embodiments of the invention a relatively broad beam is used, with the output of the photocell varying in response to the degree of overlap of the beam with the photocell. In another embodiment of the invention a narrow beam is employed to produce an output signal which varies in accordance with the position of the beam within the field of the photocell. Preferably the light emitter, mirror, and photocell are secured to a common mount which is rockable about the cylinder axis for alignment of the optical path with the common plane of the cooperating cylinders. |
