RU2281397C2 - Tightening device for rope anchoring bolt - Google Patents

Abstract

FIELD: mining, particularly means for mine contour bolting.

SUBSTANCE: tightening device comprises clutch connected to rope in axial orifice by means of wedge-like bush. The bush comprises thread and nut located on outer surface thereof. Annular groove is formed in clutch end, which receives rope. Guiding means surrounding the rope is installed in the annular groove. Opposite clutch end has outer surface defining hexahedron.

EFFECT: increased flexural rigidity of cable part connected to clutch, simplified clutch structure and increased operational efficiency.

2 cl, 2 dwg

Description

The proposal relates to the mining industry, in particular to deep anchors for fastening the contour of mine workings.

Known cable anchor [1], including the supporting sleeve connected to the rope in the axial hole (by means of a wedge sleeve), connected by a thread to the shaft of the shank of the anchor.

This rope is widely used for suspension of monorails to the roof of mine workings, as well as for hardening the roof of mine workings, when the direct roof is destroyed and it is not possible to drill a hole with a diameter of 25-30 mm, it is possible to drill a hole with a diameter of 43 mm and more, in which can accommodate an anchor coupling. The disadvantage of the anchor is that the outer surface does not contain threads and nuts for the preliminary tension of the anchor. If it is impossible to place the coupling in a hole with a diameter of 25-30 mm, the need for thread and nut on the outer surface is obvious.

The closest analogue in technical essence is the tensioner of the rope anchor [2], including a coupling connected to the rope in an axial hole containing a thread with a nut on the outer surface.

The disadvantage of this solution is as follows. With the ampoule method of securing the anchor by means of a drilling machine by axial feed and rotation, as the anchor is introduced into the hole at a finite interval, the resistance to axial feed and torque increases. As a result, the rope bends and leaves under load, which slows down and complicates the process of introducing the anchor into the hole at the last (300-400 mm) interval.

Another disadvantage is the complexity of the design, due to the need to contain in the end of the coupling bolt to transmit torque from the drilling machine through the coupling to the rope.

The aim of the invention is to eliminate these drawbacks, namely, to increase the bending stiffness of the rope in conjunction with the coupling in the range of 300-400 mm, to simplify the design of the coupling, to increase the efficiency of operation of the cable anchor.

This goal is achieved by the fact that in the tensioning device of the rope anchor, including the coupling connected in the axial hole with the rope by means of a wedge sleeve containing thread and nut on the outer surface, an annular groove is made in the end face of the rope, in which a guide covering the rope is installed, and at the opposite end, the outer surface of the coupling is hexagonal. The guide in the annular groove, as well as the outer strands of the rope on the wedge bush and in conjunction with the central strand in the axial bore of the coupling, are fixed with a metallized putty.

The introduction of the guide is necessary to prevent the bending of the rope in the interval of 300-400 mm from the mouth of the hole to the support sleeve, where maximum axial forces and torque are observed with the ampoule method of fixing the rope in the hole with a diameter of 25-30 mm. The placement of the guide in the annular groove of the coupling, its fixation in it by metallized putty is explained by the simplification of the technology of connecting the guide to the coupling compared to a threaded connection, which, in addition, weakens the thin body of the guide in strength.

Giving a hexagonal shape to the end of the outer surface of the coupling is necessary for transmitting torque from the drilling machine through the coupling to the rope. This eliminates the bolt that was screwed into the internal thread of the axial bore of the coupling and was designed to transmit torque. Since the coupling is made by injection molding, giving the end of the outer surface of the coupling a hexagonal shape does not complicate the manufacturing technology of the coupling, in contrast to the manufacture of a separate part (bolt) by turning.

The fixation of the outer strands of the rope by metallized putty on the surface of the wedge bush and in conjunction with the central strand in the axial bore of the coupling is necessary to create some volumetric stress state around the strands, unlike linear strands along two narrow strips. This increases the tensile strength of the strands of the rope by 4 ÷ 5%. The introduction of putty makes the wedge method of connecting the coupling to the rope reliable, technologically advanced and more reliable compared to the collet connection.

The essence of the proposal is illustrated by drawings.

Figure 1 shows an axial section of a tensioning device.

In Fig.2 - view A in Fig.1.

The tensioning device includes a sleeve 1 connected in the axial bore by means of a wedge sleeve 2 with a cable 3. The end face of the sleeve 1, into which the cable 3 enters, is made with an annular groove in which a guide 4 is inserted, covering the cable 3.

The outer surface of the coupling is made with a thread on which the nut 5 is placed. The very end 6 of the outer surface of the coupling 1 is made of a hexagonal shape for transmitting torque from the drilling machine through the coupling 1 to the cable 3. The maximum cross section of the hexagon 6 of the end of the coupling 1 is less than the diameter of the nut 5 thread The guide 4 in the annular groove of the coupling 1 is fixed from axial movement relative to the coupling metallized putty. This method of fixing is more reliable and cheaper than a threaded one. The threaded connection method weakens the flexural strength of the guide. The outer strands 7 of the rope 3 are fixed on the surface of the wedge bush 2 and in conjunction with the central strand 8 of the rope 3 in the axial bore of the coupling 1 of the metallized putty 9. The metallized putty 9 creates a volumetric stress state in the gaps between the strands in contrast to linear contact strands. This increases the strength of the strands of rope.

The tensioner of the cable anchor operates as follows. After drilling a hole, for example, to a depth of 5 m, for example, 3 ampoules with a mineral composition or polyester resin are introduced into its mouth. Next, the end face of the rope 3 is abutted on the end face of the last ampoule and the ampoule is extended with the rope to the end face of the first ampule in the face of the hole. The end of the rope 3 remaining outside the borehole with the support sleeve 1 is connected via an adapter (not shown) to the drilling machine. The hexagonal socket of the adapter interacts with the hexagon 6 of the end of the coupling 1, and the adapter glass with the nut 5 to ensure stable interaction with the coupling 1.

Then, by rotating and feeding the drilling machine, a rope is introduced into the hole. A rope with broadening nodes is introduced into the contents of the ampoules, mixing the components of the ampoules. As the rope is introduced into ampoules, resistance to rotation and feeding increases. In the last interval (300-400 mm), the rope tends to bend under the influence of increasing feed resistance and torque, subjecting the guide tube 4 to bending stresses and axial deformations. This is prevented by the bending stiffness of the guide 4 and fixation of the end of the guide by metallized putty in the axial groove of the coupling 1. Subsequently, the rope and the guide enter the hole, and the coupling penetrates the nut 5 into the hole of the support element. Then the adapter together with the drilling machine is disconnected from the coupling 1 Replace the adapter. The drilling machine is brought back to the coupling 1 and, by rotating the nut 5, the cable anchor is pre-tensioned. After tightening the nut 5, the adapter and the drilling machine are disconnected from the tensioner. The key is then tightened further with a nut, pre-tensioning the cable anchor. Further, the rope anchor operates in an operating mode. The unstable part of the array transfers the load to the cable 3 through the support washer (pickup), nut 5, sleeve 1, wedge sleeve 2. In this case, the strands 7 of cable 3 due to the cured metallized putty as they move relative to the sleeve 1 under load approach in radius. In the spaces between them, putty 9 is subjected to deformations. In the putty 9, a certain volumetric stress state is created, which is transmitted to the strands 7, 8 of the rope 3 in the axial bore of the coupling 1. In this case, the strength of the strands 7, 8 of the rope 3 increases.

Thus, the introduced features improve the functionality of the cable anchor. The introduction of the guide pipe 4 increases the rigidity of the rope. The formation of the hexagonal surface of the coupling eliminates the detail - the bolt in the tensioner, and the introduction of metallized putty increases the strength of the strands of the rope, simplifies the technology of connecting the guide to the coupling.

Information sources

1. Patent 2178082 (Application 99117674. 01/10/2002, Bull. No. 1).

2. Certificate 29749 (Application No. 2000131814. 05.27.2003. Bull. No. 15).

Claims (2)

1. The tension device of the cable anchor, including a sleeve connected to the rope in the axial hole by means of a wedge sleeve, containing a thread and a nut on the outer surface, characterized in that an annular groove is made in the end face of the rope, in which a guide covering the rope is installed, and the opposite end, the outer surface of the coupling is made hexagonal. 2. The tensioner of the rope anchor according to claim 1, characterized in that the guide in the annular groove, as well as the outer strands of the rope on the wedge bush and in conjunction with the central strand in the axial hole of the coupling, are fixed with a metallic filler.

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