LOCKING DEVICE Russian patent published in 2012 - IPC F16K1/32 F16K17/168 

FIELD: machine building.

SUBSTANCE: locking device comprises a casing, a ring in a casing bore with a sealed conical surface, a plug with an appropriate sealing surface, an eccentric drive, a bypass bushing. A sleeve is screwed in the casing via a radial threaded bore and an end seal in a circular groove and is fixed in the casing bore by pins. In the sleeve there is a chamber at one side, and a threaded hole, a seat with cylindrical and conical surfaces and an external thread at the opposite side. In the sleeve chamber there is a plunger connected with a drive bushing and a screw with the left thread, at the opposite side in the seat - a threaded sealing bushing with cylindrical and conical surfaces, a screw with the right tubular cylindrical thread, a press ring and a captive nut. The drive bushing via the left thread interacts with the left thread of the screw, and via the right tubular cylindrical thread the screw interacts with appropriate threads in the opening of the sleeve and in the sealing bushing, at the plunger's end there is a conical bore and a channel for hydraulic connection in the sleeve chamber, and on the external surface of the plunger there is a ball segment crossing with the conical bore, and a slot open at the end of the drive bushing, a slot of the appropriate section and rated length is provided in the sleeve chamber, balls are placed in slots. At the same time in the central bores of the casing there are circular grooves, and the following components installed with appropriate grooves - a support bushing with a sealed spherical surface and an inlet channel at one side, and at the opposite side - a bushing with guide surfaces at the end and with an appropriate output channel, forming tight chambers between circular grooves, besides, the stop element is made in the form of a hollow ball, weight of which is equal to or less than the weight of the displaced liquid as capable of displacement along guide surfaces of the bushing and interaction with the ball segment of the plunger for forced closure of the inlet channel of the support bushing via its sealed spherical surface during the right rotation of the screw by levers of control and opening of the inlet channel under action of the pumped liquid flow movement during the left rotation of the screw and arrangement of the hollow ball in the sleeve chamber, and also with the capability to both close the inlet channel of the support bushing and to partially close the inlet and outlet channels of the support and guide bushings in the automatic mode, when the pumped liquid flow is limited by the rated left or right quantity of screw rotations for arrangement of the hollow ball in the conical bore at the plunger's end under action of the liquid flow movement direction change in case of pressure drops upstream and downstream the locking device. To adjust tightness of the screw with the right tubular cylindrical thread by a sealing bushing with the right internal tubular cylindrical thread there is a slot in a protective bushing, an appropriate slot is made in a protective jacket, and screw tightness is adjusted via slots with a captive nut through the press ring.

EFFECT: improvement of device operational reliability.

2 cl, 6 dwg