SU981169A1 - Arrester - Google Patents

Description

one

The invention relates to devices for protecting hoisting installations from falling of a terminal load suspended from a flexible traction device (rope, tape), and can be used at various lifting installations as a means of preventing cable entry in the event of a sudden suspension of the terminal load in the ground shaft when feeding alarm signal from the inlet control equipment.

A safety device is known that contains a base on which a case is mounted with pressure elements interacting with a rope, one of which is fixed and the other is spring-loaded relative to the walls of the case and has a squib connected to the alarm source 1.

A disadvantage of the known catcher is a significant fluctuation of the braking force depending on the state of the rope surface and the change in its cross section.

The purpose of the invention is to increase reliability.

The goal is achieved by the fact that the safety device is equipped with a hydraulic cylinder, a lever i mechanism, the support in which

(54) CATCHER

holes, and rods, placed in said holes, wherein the hydraulic cylinder is mounted in a stationary element and its chaff cavity is hydraulically communicated with the support holes, and through a lever mechanism the rod of the stationary element is kinematically connected with a movable one.

FIG. 1 shows schematically the proposed device, a general view; in fig. 2, section A-A in FIG. one; in fig. 3 - scheme

to act forces.

The safety device consists of a base 1 mounted on a scraper of a lifting installation (not shown) and a movable support 2 supported through rods 3 and 4 on the base 1, in which

15 holes a and b are made.

Claims (2)

On the support 2, there is a fixed element 5 and a movable element 6. Moreover, in ele. In the copy 5, the hydraulic cylinder 7 is made so that the gap 8 through the brush 9, the levers 10-12 is connected with element 6 and performs a plane-parallel movement with the latter. The a and b holes and the cavity 7 are connected by a flexible pipe 13, which allows to maintain 39 the same pressure in them. On the opposite side of the working surface of the element 6, a force spring 14 is placed, preloading between the protrusions of the element 6 and the vertical wall of the support 2. To facilitate movement, the element 6 is equipped with rollers 15. Between elements 5 and 6 of the catcher, through the through hole of the support 2 and the base 1 is freely missed hoisting cable 16. As a retainer, which holds 6 in an inoperative position and ensures free passage of the hoisting cable 16 through the safety device, serves a stopper 17, in the form of a squib, which also drives Itel. The safety device works as follows. When an alarm is triggered, the squib explodes and releases element 6 from stopper 17. Element 6 is moved by the force of spring 14 from the inoperative position to approach element 5, crimping cable 16 to position when spring force 14 is balanced by the initial oil pressure in the hydraulic system. When the rope 16 is compressed by the elements 5 and 6, an initial braking force is created, which acts equally on both the rope 16 and the elements 6 2. To the rope 16 this force is applied against its movement (up), and to support 2 according to the motion of the kanite (down). The support 2 through the rods 3 and 4 raises the pressure of the oil ъ holes a and b, and, consequently, in the hydraulic cylinder 7. The rod 9 at the same time through the levers 10-12 presses the movable element 6 to equilibrate with the spring 14. The braking force is defined as V TO f, yy T - the force of reduction; f is the coefficient of friction of the rope against the clamping elements of the catcher and is established by changing the compression of the rope. The compressing force T ,, and, consequently, the braking force T (with a constant friction coefficient determined by the spring stiffness and oil pressure in the system Tp, (x - x) C - S7 P where X is the movement of element 6; X is the final position of the element 6 (at the moment when the spring 14 is fully compressed); C is the spring stiffness coefficient 1 V is the pressure area in the hydraulic cylinder 7 P is the oil pressure in the hydraulic system. The oil pressure in the hydraulic system is determined from the equilibrium condition, i.e. P (So + Sp) T where S,, S- are, respectively, the area of the holes О,. Substituted expressions obtained l effort of compressing Td and oil pressure in hydraulic system P. to the initial formula defining the braking force T., we get T (X - x). C - T 7-1. -f After transforming (Xo-X) -C From the last expression it follows that when the value is 77, the braking force T. is constant, does not depend on the change in the coefficient of friction f and is defined as,) (Ho-x) s, The operation of the device if the coefficient of friction of the rope is 16 o elements 5 and 6 decreases. In this case, the pressure of the support 2 on the base 1 also decreases, as the braking force T decreases, equal to the product T, i f. Consequently, the pressure in the hydraulic system and, accordingly, in the hydraulic cylinder 7 also decreases. This leads to the movement of the rod 9 and the element 6 associated with it in the direction of greater reduction of the rope 16 under the action of the spring 14, which leads to an increase in the braking force T. Similarly, if the friction coefficient f increases, then the pressure of the support 2 on the base 1 increases, which in turn leads to an increase in pressure P in the hydraulic system and hydraulic cylinder 7, while the rod moves in the direction of decreasing reduction. Hence, the braking force T is reduced to a predetermined value determined by the last formula. The use of the catcher of the proposed design allows stabilizing the braking force during its operation in the braking mode and, therefore, eliminating the dependence of the braking force on the coefficient of cable friction against the catcher elements. This makes it possible to increase the reliability of the lifting installation by eliminating two emergency modes of the catcher operation: the first is the appearance of an excessively large rope overlap (with low friction coefficients); the second is the occurrence of an unacceptably high load on a flexible body (with significant coefficients of friction). Claim device containing a base on which a case is mounted with pressure elements interacting with a rope, one of which is fixed and the other is spring loaded relative to the walls of the case and has a squib connected to an alarm source, in order to increase reliability, it is provided with a hydraulic cylinder, a lever mechanism, a support in which holes are made, and rods placed in the said holes, while the hydraulic cylinder is mounted in a fixed element and its The cavity of the cavity is hydraulically communicated with the holes of the support, and through a lever mechanism the rod of the stationary element is kinematically connected with MOTION 1P.1M. Sources of information taken during the examination 1. USSR author's certificate N 541762, cl. B 66 B 5/12, 1975 (prototype). U / ////// city / / / l.