SU1225945A1 - Device for unauthorized unscrewing - Google Patents

Description

The invention relates to mechanical engineering, in particular to threaded fasteners, which can be used as measures against unauthorized unscrewing of locking elements or fasteners.

The purpose of the invention is to increase reliability and secrecy.

FIG. 1 shows a device for unauthorized unscrewing; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. one; in fig. 4 — assembled device, transverse section.

The device for unauthorized unscrewing includes a threaded element 1 with an eccentric head 2 screwed into one of the joined parts 3, a cup 4 with a bottom 5 and an annular collar 6. The cup covers the head of the threaded element rotatably. Between the bottom of the glass and the head of the threaded element installed gasket 7 of hard-to-machine material.

The device also includes a housing 8 fixedly mounted on the part 3 to be joined or made in one piece with it. An annular bore 9 is made in the body, in which the bead 6 of the beaker 4 is placed. The body is fixed to the part to be connected with a gap relative to the beaker designed for key placement.

The inner surface of the housing is eccentric relative to the axis of the threaded element by an amount equal to the eccentricity e of the head of the threaded element. The key-wrench 10 is made with a cylindrical bore 11 covering the cup 4 with the surface a, and is provided with a centering sleeve 12, covering the core-wrench over the surface b, with the eccentric axis by an amount equal to the eccentricity e of the head of the threaded element.

The outer surface in the centering bushing of the stem-key corresponds to the inner surface of the housing 8. The sleeve can be made removable or assembled with a stem-key (Fig. 1).

The device works as follows.

A centering sleeve 12 is inserted into the gap between the housing 8 and the glass 4, and a key 10 is inserted into the gap between the sleeve and the glass. The mating surfaces f of the housing and the centering sleeve, as well as the mating surfaces of the key and the centering sleeve b, they enter into tight contact with a minimum gap, providing only their axial movement. In this position, the device is ready for operation: unscrewing or screwing the threaded element. The head is offset relative to the axis of rotation of the threaded element by the amount of eccentricity e. The inner surface of the housing is displaced by the same amount relative to the axis of the threaded element, the surface of the key relative to the outer surface b and the axis of the key, the surface in the sleeve relative to the inner surface in contact with surface b key. So

As the eccentricities of the said surfaces are equal and assembled are mutually opposite (they cannot be installed otherwise), they are mutually compensated, ensuring the coaxiality of the key and the threaded element (Fig. 4). Rotating the key rod and together rotate the glass with the head and the threaded element around the axis of rotation of the latter. In this case, the threaded element is screwed into the part to be joined, and the centering sleeve remains in place,

held by a fixed body. The latter occurs because the axis of rotation of this sleeve in the housing does not coincide with the axis of rotation of the rod and the threaded element. When removing a rod-key from the head of a threaded element, the presence of eccentricity cannot be detected, since all the surfaces in plan form concentric surfaces (Fig. 3). This hides the principle of the device due to eccentricity. In the case of unequal eccentricities of the head and body, the principle of action can be detected, but the true value of e cannot be determined, i.e. The design contains a fraudulent effect, disorienting when trying to make a key. The bottom and the shoulder of the glass fix the position of the glass

in both axial directions and hide the presence under the glass of the head and gasket. Difficult material in the form of a plate made of hard alloy, ceramic, or in the form of a set of hardened balls (Fig. 1 and 3) makes it difficult to drill out the head

and the rotating cup makes it impossible to turn the head with a pipe wrench.

The matching surfaces of the housing and the centering sleeve can be made of any configuration in plan: rectangular, triangular, oval, etc.

Aa

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Fig.Z

Key rotation axis

five

F (M.CH

Claims (2)

1. DEVICE FOR UNSOLVED UNPLEASING, containing a threaded element screwed into one of the parts to be connected with an eccentric head, a bead with a shoulder covering the head of the threaded element with the possibility of rotation relative to the latter, and a housing fixed to the connected part with a gap relative to the beaker, as well as a key with a cylindrical hole for the cup, coaxial with the threaded element, characterized in that, in order to increase reliability and secrecy, the key rod is equipped with a centering sleeve, mating with hydrochloric sterzhnemklyuchom by eccentric surface, the eccentricity which equals the eccentricity of the head of the screw member, the inner surface of the housing is eccentric with respect to the screw member by an amount equal to the eccentricity of the head of the screw member, and is formed with an annular bore, wherein the glass bead is placed. 2. The device according to π. 1, characterized in that it is provided with a gasket of a hard-to-work material placed g between the bottom of the glass and the head of the threaded element. FIG. I SU „„ 1225945>