Telescopically tiltable rule, has telescopic tubes carrying scales, and cord with end connected to smallest pipe, where cord rotates cylinder that is connected with tachometer whose scale is present under peephole

摘要

The rule has telescopic tubes of rectangular or other cross section connected with each other, where the tubes carry scales (8, 10). The tube with a largest cross section includes a peephole. A cord (4) is present inside the rule. An end of the cord is connected with the smallest pipe. The cord rotates a cylinder (6), which is connected with a tachometer whose scale is present under the peephole, where the tachometer is executed as a roller-type counter and a full rotation of a roller of the counter causes rotation of another roller.