GB556296A - Staybolt testing device - Google Patents

Abstract

556,296. Electric tests. GREENSLADE, G. R. Jan. 31, 1941, No. 1290. [Class 37] In a staybolt testing device as described in U.S.A. Specification 1,567,728, the tubular member is in the form of a probe having a rigid core member 9 and an insulating and protecting sleeve 11, the tip end of the core projecting beyond the sleeve, and the probe being readily sharpened by simultaneously cutting away the end of the core and the sleeve so that the end of the probe is a cone and the tip always protrudes. The core 10 provided with a casing 9 and an inner layer 11 of insulating material passes through a bushing 8 fitting in a central opening 5 with a large recess 6 in the end member 4 which is screwed into the end of a metallic barrel or handle member 2 closed at its other end by a plug 3. An insulating disc 13 is interposed between the head 7 of the bushing 8 and a thrust-disc 12 to which is secured the core 10 and against which bears a disc 14 having a tongue 15 adapted to make contact with the terminal 16 of an electric bulb 17. In the member 4 is screwed an insulated liner or sleeve 18 into which is screwed a lamp socket 19. Opposite ends of a wire yoke 29 are secured in the member 19 the yoke bearing against the pole 21 of a battery comprising one or more dry cells 22 and held against the yoke by a spring 23 seating against a terminal member 24 provided with an extension 25 into which one of a flexible cable 26 is soldered. The cable 26 is connected at its other end to a given terminal 27 comprising a handle 28 with a metal plug 29, having a coarse thread thereon so that it can be forced into contact with a stay bolt other than the one being tested. In a modification the probe 10 is provided only with an outer covering of insulating material.