Measuring devices

Claim 1

A tension control device. Adapted for use with a measuring tape of a predetermined maximum length, calibrated, when supported in a flat disposition, while subject to a predetermined first tension, and which tape measures accurately when extended in unsupported catenary suspension only while fixed at one end and having the opposite end of the segment of tape being used subject to a predetermined second tension, different from said first tension, Said device including: a housing configured to be easily hand held; an elongated slide having an inner end and an outer end; said slide being carried by said housing for longitudinal extension and retraction with respect to the housing, clamp means on the slide adjacent said outer end thereof, said clamp means being configured for securing the clamp means to the measuring tape at a point thereon adjacent said opposite end of the unsupported catenary of the tape; extensible/retractile constant tension spring means having one end secured with respect to the housing and operatively associated with the inner end of the slide for resiliently resisting extension of the clamp means by a constant amount, so long as the constant tension spring means is extended by an amount intermediate the opposite extremes of the extensibility thereof; said constant tension spring means providing a constant tension lying intermediate said first tension and said second tension.