PL171839B1 - Multiple telescope type actuator for an anchoring machine - Google Patents

Abstract

Multi-telescopic anchor cylinder, designed especially for anchoring the ceiling in underground mining workings, composed of a cylinder with supply connections and a few telescopic core-holders in relation to each other, characterized by that the pistons (5, 6, 7) have radial holes (13) that connect the piston spaces these pistons through concentric tubes (11, 12) with one of the inlet connectors (15), and their under piston spaces are connected with an oblong hole (14) with a second inlet connection, at as sealing and guiding heads (9) are releasably threaded with both cylinder (1) and core boxes (2, 3).

Description

The subject of the invention is a multi-telescopic cylinder of a bolting machine, intended for anchoring the roof of underground mining excavations.

Known bolters, commonly used in mines for securing the roof in underground workings with bolts, consist of a hydraulic actuator and a drill mounted on this actuator. Depending on the needs and local conditions, the hydraulic cylinder of the anchor can be single-acting or double-acting. Cylinders of this design are known, inter alia, from Polish patents No. 137 353 and No. 148 788. In practice, however, it often happens that the roof of a mining excavation has to be secured with a bolt in a place of low height or in a place of varying height. In such a case, it is advantageous to use multi-telescopic actuators which, when folded, have a low height and are suitable for use in low headings, and when extended, they can be useful in high headings.

Multi-piston lifts are known which have two or three telescopic pistons in the cylinder. The upper part of the central piston rod of such a jack is often connected to the bottom by a helical spring which forces the pistons to return to their starting position. However, some multi-piston lifts do not have a spring and the pistons return to the starting position under the influence of their own weight. Such a solution of the actuator structure is not suitable for use in a bolting machine, because both during drilling of the bolt holes and when placing the bolt in the hole, it sometimes happens that the drill or bolts get jammed and pulling them out of the hole is a serious problem.

These disadvantages are completely eliminated by the multi-telescopic anchor cylinder object of the present invention. The essence of this actuator is the use of several core boxes equipped with pistons and concentric tubes. Each piston of this actuator is equipped with a radial bore, which holes - together with concentric tubes connect their over piston spaces with one of the supply connections. On the other hand, the piston cavities of these pistons are connected to the second supply pipe by means of an undercarriage opening. In addition, the sealing-guiding heads are detachably threaded to both the cylinder and the core boxes. Such a construction of the actuator allows to reduce its height as much as possible depending on local needs. The actuator according to the invention also has the advantage that it allows it to act with a defined force in both directions, which allows both the anchoring of the bolts in the holes and their extraction from the hole in the event of jamming.

The subject of the invention is shown in an exemplary embodiment in the drawing, which shows a multi-telescopic actuator in an axial section and a half view.

As shown in the drawing, the multi-telescopic actuator according to the invention consists of a cylinder 1 and three core boxes 2, 3, 4 equipped with pistons 5, 6, 7,

1721 839 are telescopically arranged to each other. From the bottom, the cylinder is permanently closed with a foot 8 and from the top by a sealing-guiding head 9, connected to this cylinder detachably by means of a thread. 4 ends at the top with a handle 10. Both the outer core-box and the middle core-box have permanently fixed concentric tubes 11, 12, open at the top and at the bottom connected by radial holes 13 with the piston space. The inner core box has a similar opening. In addition, the piston space of the outer core box is connected with the piston spaces of the other two core boxes by an elongated hole 14. Two supply connections 15 are attached to the outside of the actuator; one at the bottom of the cylinder and the other at the cylinder head

The actuator according to the invention functions as follows. After the hydraulic medium is supplied to the nozzle 15 located at the bottom of the cylinder 1, the liquid under high pressure, through the opening 14, will act on the pistons 5, 6, 7, pushing all three core boxes 2, 3, 4 out of the cylinder. down the drain line. In the event of the necessity to lower the anchor or the necessity to withdraw the anchor jammed in the hole, the power supply of the actuator is overridden. Then the upper connector is connected to the supply conduit and the lower connector to the drainage conduit. The liquid under high pressure passes through the radial holes 13 and the tubes 11, 12 into the overpressure spaces of the individual core boxes and, by applying pressure on their pistons, slides these core bodies into the cylinder.

171 839

Publishing Department of the UP RP. Circulation of 90 copies. Price PLN 2.00

Claims (1)

Patent claim A multi-telescopic anchor cylinder, intended especially for anchoring the roof in underground mining excavations, consisting of a cylinder with feed stubs and several core boxes telescopically mounted to each other, characterized in that the pistons (5, 6, 7) have radial holes (13) that connect over piston spaces of these pistons through concentric tubes (11, 12) with one of the feed nozzles (15), and their piston spaces are connected by means of an elongated hole (14) with the other feed connection, while the sealing-guiding heads (9) are connected detachably by means of a thread both with the cylinder (1) and with the core boxes (2, 3).