APPARATUS FOR PROVIDING PRESSURE VARIATIONS UTILISABLE AS SIGNALS DEPENDENT UPON VARIABLE COMPRESSION FORCES EXERTED ON THE APPARTUS.

摘要

We claim: 1. An apparatus for providing pressure variations utilisable as signals dependent upon variable compression forces exerted on the apparatus, the latter comprising hydraulic means including a pressure chamber filled with hydraulic fluid and means to establish variable pressure upon said hydraulic "fluid in proportion to said compression forces, pressure-regulating means actuated by said hydraulic means to create said pressure variations, and fluid circulating means including a hydraulic fluid sump or reservoir and pumping means responsive to fluctations of said compression forces for circulating hydraulic fluid from said sump or reservoir to said pressure chamber, characterised in that said pumping means are mounted in a piston which serves for transmitting the total compression force to said pressure chamber from spring means mounted in said hydraulic fluid sump or reservoir.