EP2233683A2 - Adapter of a self-drilling chemically anchored attachment element - Google Patents

Abstract

The adapter has a base section provided on an adapter end at a distance from an engagement device (35), and a hollow cylindrical connecting sleeve section (25) connecting the base section and the engagement device. The connecting sleeve section comprises a threadlike inner profile, in part corresponding to a threaded outer profile on a shank, where adapter is formed by two element parts (22, 32) detachably connected to one another via a clutch device (41). A drill bit head is provided on one end of the shank with the threaded outer profile.

Description

The invention relates to an adapter of a self-drilling, chemically anchored fastener, referred to in the preamble of claim 1. Art.

Self-drilling fasteners, such as rock anchors and in particular chemical composite anchors and suitable drilling equipment with rotary tool holders and their use in mining and tunneling have long been known in the art. These fasteners are primarily used to stabilize walls in cavities, such as tunnels, galleries or the like. When creating cavities, the mechanical properties and in particular the load-bearing capacity of the rock strata are reduced. These mountain layers are anchored by means of fasteners, or the chemical composite anchors to more distant, undamaged mountain layers and secured to this.

The shank of the fasteners serves on the one hand as a drill pipe and on the other hand, in a chemical composite anchor, the recording of the mass to be squeezed out. At the first, in the setting direction end of the shaft, a drill head is placed. The second end of the shaft is inserted into a rotary tool holder of an applied drill, with which the fastener is drilled into the ground.

From the DE 103 36 040 B4 is an adapter of a self-drilling, chemically anchored fastener known. The fastening element has a shaft which has a first end with a drill head and a second, free end, wherein the shaft is provided at the second end in regions with a thread-like outer profile. The adapter is arranged at the second, free end of the shaft and has at one end an externally arranged engaging means for a rotary tool holder of an applied drilling device, one to the engaging means spaced, on provided on the other end bottom portion and a connecting the bottom portion and the engaging means, hollow cylindrical connecting sleeve portion. The connecting sleeve portion has in regions complementary to the thread-like outer profile formed on the shaft thread-like inner profiling. The connecting sleeve portion is provided to create predetermined breaking points on the adapter with openings.

The adapter is screwed onto the second, free end of the shaft of the fastener and then the rotary tool holder of the drill on the z. B. plugged as a quick attack device attacking means plugged. After reaching the desired drilling depth is a curable, z. As fast-curing, mass applied. If the hardenable mass has reached a certain degree of hardness, the drill is put into operation again, after exceeding a certain torque breaking the predetermined breaking points and the part of the adapter with the externally arranged engaging means for clamping the anchored in the ground fastener of the drill rotates in the direction of Underground or in the direction of the drill head along the shaft is offset.

With the known adapter, the setting process of the self-drilling, chemically anchored fastener is substantially simplified, the release torque is clearly defined within a certain tolerance range.

The object of the invention is to provide an adapter of a self-drilling, chemically anchored fastener, which has an even narrower tolerance range for the release torque.

The object is solved by the features of the independent claim. Advantageous developments are set forth in the subclaims.

According to the invention, the adapter is formed by a first element part and by a second element part, which are detachably connected to one another via a coupling device.

About the design of the coupling device between the two separate element parts of each other, the release torque can be precisely defined. If this defined release torque is exceeded, the coupling device triggers and the second element part with the engagement means is freely rotatable for biasing the fastening element already anchored in the ground. In this case, the release torque of the clutch device is set such that the two element parts remain in an engaged state during the drilling operation to transmit the drilling torque.

The adapter has a small number of parts which are connected to each other. The two element parts are easy to manufacture and can be made robust, which is a significant economic advantage in particular in a mass product, as is the case with the inventive adapter.

The adapter does not have to be screwed on at the beginning of the drilling process until it reaches the free end of the shaft. During operation of the drilling device, the adapter rotates with the second, free end of the shaft until the screw stop stops. Subsequently, the shaft is drilled into the underground via the adapter by means of the drill until reaching the desired drilling depth. The bottom portion of the adapter forms a screw stop for the adapter.

In the case of a fastening element in the form of a chemical composite anchor, the shaft is hollow-cylindrical, with the interior formed by the shaft serving to pass the hardenable mass or to receive a hardenable mass arranged in the shaft. The bottom section on the first element part of the adapter can serve as a retaining device for the mass to be pressed out arranged in the shaft. The mass to be squeezed is for example packed in a foil bag and in a receptacle, for. B. in an inner tube, arranged in the shaft. This is particularly advantageous in overhead applications, as the mass to be squeezed out as a result of the bottom portion can not slide out of the hollow cylindrical shaft. Advantageously, a preferably centric opening in the bottom portion is provided, which allows insertion of a Auspressmechanismus for discharging the arranged in the shaft to be squeezed mass without the adapter for this step must be removed from the free end of the shaft.

The shaft, z. As an anchor tube, can be made available by the meter available, which is cut to length on the required, or desired length. Since the drill head is attached only to the shaft, this preassembly step can also be done on site. To improve the pull-out values of fasteners, such as rock anchors, the shaft is often provided on the outside with a profiling on the entire length. The internal thread of the adapter is preferably adapted to the external thread designed as a profiling. If the shaft has no external thread on its outer side, then a suitable thread can be formed on site at the free end of the shaft for the connection of the adapter, for. B. be cut. Between The internal thread on the adapter and the external thread on the shaft generous tolerances may be present without the function of the connection of these two parts is substantially limited. As a result, it is usually possible to dispense with deburring the cut surfaces in the case of a shank cut to length on site.

Advantageously, the rapid attack device on a key coupling. As a key coupling, for example, a twelve or polygonal, which the twist angle for finding the geometries for coupling the rotary tool holder of the drill to the fastener is kept as small as possible. In addition, a tool for screwing and unscrewing the adapter can be attached to the shaft on the key coupling, if necessary.

The coupling device preferably comprises an axially extending abutment surface disposed on the first element part and an axially extending counterstop surface arranged on the second element part for transmitting the drilling torque. In a coupling device with shearing or breaking off elements can be about the size of the contact surface can be brought into contact with each other of the abutment surface with the counter stop surface z. B. simply define a release torque of the coupling device.

In a drilling process with a reversal of rotation of the drive of the drilling rig, the fastener is first drilled into the ground with the abutment face and the counter-abutment face in contact for drilling torque transfer. After reaching the anchoring depth and the at least partial curing of the hardenable mass, the drill is put into operation again, the direction of rotation of the drive relative to the direction of rotation is reversed. The second element part is now freely rotatable and can be used for biasing the already anchored in the ground fastener of the drill in the direction of the substrate or in the direction of the drill head, for example, to rest on an anchor plate provided on the ground.

The coupling device preferably comprises on one of the element parts at least one cam projecting beyond a free edge and at least one recess provided on the free edge of the other element part, wherein the at least one cam engages in the at least one recess for torque transmission. The leading in the direction of rotation side surface of the cam is for Bohrdrehmomentübertragung with the corresponding side surface of the recess in abutment. When bracing the already anchored in the ground fastener example, the cam slides out of the Recess on the other element part out and the element part with the engaging means is freely rotatably displaceable along the shaft.

Alternatively, the at least one cam breaks off when the release torque of the coupling device is exceeded, so that the element part with the engagement means is freely rotatable along the shaft. Advantageously, the height of the at least one cam of the corresponding element part projecting beyond the free edge of the corresponding free edge is selected such that the center of gravity of the sheared or broken cam element is located within the recess. This ensures that the at least one sheared or broken cam element remains after the triggering of the coupling device within the recess.

Preferably, at least one of the side walls of the at least one recess extends in an inclination to the center of rotation of the corresponding element part. The inclined to the center of rotation, d. H. oblique or transverse to a radius extending side wall can serve as a backup surface for holding a sheared or broken cam element or on the other hand as a guide surface for easy sliding out of at least one cam from the at least one recess when exceeding the release torque of the coupling device according to the orientation of the inclination.

If the fastening element is set in a rotational reversal method, advantageously the side wall of the recess lying in the direction of rotation of rotation advantageously has an inclination running essentially in the direction of the center of rotation, thus making available the entire contact surface for transmitting the drilling torque. The lying in the direction of rotation of the side wall opposite or trailing side wall of the recess advantageously extends in an inclination to the center of rotation of the corresponding element part, wherein the inclination to the center of rotation according to the requirements, eg. B. for holding a portion of the at least one cam or for easier sliding out of the at least one cam of the at least one recess, is selected.

Preferably, a holding means in the region of the coupling device is provided, which advantageously holds together the two element parts in the mounted state of the adapter. This allows the adapter to be arranged as a unit at the free end of the shaft, so that the two element parts do not have to be assembled separately at the free end of the shaft. In addition, the holding element ensures that z. B. a sheared or broken cam element remains in the recess. Advantageously, the holding means is flexible and further advantageously generates a radially inward bias on the corresponding edges of the element parts, which ensures easy installation. The holding means is made of plastic or metal, for example, and is further advantageously designed as a closed ring. Alternatively, the holding element is formed by a plurality of interconnected tab elements, which connect the two element parts in their contact area with each other in regions.

Preferably, a radially circumferential recess is provided at the free edges of the element parts and the holding means is arranged in this recess, whereby a simple assembly of the adapter is ensured.

Preferably, the first element part is rotationally fixed at the second end of the shaft, whereby accidental release of the first, the bottom portion having element part is prevented during the setting process of the fastener. In particular, in a setting method of the fastener with rotational reversal of the drill drive ensures the second end of the shaft rotatably fixed, the first element part a simple anchoring and bias of the fastener. During the drilling operation, the second element part is moved with the engagement means in the direction of the free, second end of the shaft, wherein the non-rotatably fixed at the second end of the shaft, the first element part prevents twisting of the adapter from the shank of the fastening element. In the subsequent rotation reversal, the second element part is moved away from the rotationally fixed, first element part. The manner of fixing the first element part is advantageously selected such that it can absorb the forces occurring during the drilling process to a sufficient extent.

Preferably, the first element part is positively fixed to the second end of the shaft, which ensures a secure fixation of the first element part at the second end of the shaft to a sufficient extent. Advantageously, axially extending bores are provided in the first element part and the shaft of the fastening element, which together form a receptacle for a connecting pin. The holes extend advantageously starting from the bottom portion of the first element part and are accessible from the outside for the assembly of the connecting pin. Alternatively, the section of the bore runs at least in the first element part, starting from the end facing the second element part in the direction of the bottom portion of the first element part, wherein the connecting pin is used according to this end for rotationally fixed fixing of the first element part at the second end of the shaft. In a further alternative, a radially inwardly oriented bore is provided on the first element part, in which is used in the end region of the second end of the shaft engaging connecting pin.

Further possibilities for the rotationally fixed fixing of the first element part to the second end of the shaft are the arrangement of an adhesive or a clamping connection, for. B. by partially deformation of the corresponding contact surfaces, between the first element part and the end portion at the second end of the shaft. Another non-exhaustive possibility is shrinking the first element part onto the second end of the shaft.

Advantageously, the adapter is manufactured in a casting process. A rework of the cast adapter can be omitted due to the allowable tolerances. In addition to this cost-effective manufacturing process, the adapter can for example also be produced in a casting / milling process.

Fig. 1

Ein selbstbohrender, chemisch verankerbarer Gebirgsanker in Seitenansicht;

Fig. 2

ein erstes Ausführungsbeispiel eines Adapters in vergrösserter Seitenansicht;

Fig. 3

das erste Elementteil des Adapters gem. Fig. 2 in einem Teilschnitt;

Fig. 4

den Adapter gem. Fig. 2in einem Längsschnitt;

Fig. 5

ein zweites Ausführungsbeispiel eines Adapters in Seitenansicht;

Fig. 6

den Adapter in einem ersten Längsschnitt gem. Linie VI-VI in Fig. 5;

Fig. 7

den Adapter in einem gegenüber dem ersten Längsschnitt um 90° versetzten, zweiten Längsschnitt gem. Linie VII-VII in Fig. 5; und

Fig. 8

den Adapter in einem Querschnitt gem. Linie VIII-VIII in Fig. 5.

The invention will be explained in more detail below with reference to embodiments. Show it:

Fig. 1

A self-drilling, chemically anchored rock anchor in side view;

Fig. 2

a first embodiment of an adapter in an enlarged side view;

Fig. 3

the first element part of the adapter acc. Fig. 2 in a partial section;

Fig. 4

the adapter acc. Fig. 2 in a longitudinal section;

Fig. 5

a second embodiment of an adapter in side view;

Fig. 6

the adapter in a first longitudinal section acc. Line VI-VI in Fig. 5 ;

Fig. 7

the adapter in a relative to the first longitudinal section offset by 90 °, second longitudinal section acc. Line VII-VII in Fig. 5 ; and

Fig. 8

the adapter in a cross section gem. Line VIII-VIII in Fig. 5 ,

Basically, the same parts are provided with the same reference numerals in the figures.

That in the FIG. 1 illustrated chemically anchorable fastener 11, in the form of a rock anchor, has a hollow cylindrical shaft 12 and anchor tube, which is provided at a first end 13 with a drill head 16 and having a first end 13 opposite second, free end 14. The shaft 12 is on an end region at the second end 14 partially provided with a thread-like outer profile 15. Advantageously, the thread-like outer profiling 15 extends over the entire longitudinal extent of the shaft 12. In the receiving space formed by the hollow cylindrical shaft 12, an extrudable, hardenable mass 17 packed in a foil bag is provided.

At the second, free end 14 of the shaft 12, an adapter 21 is provided, which in detail in the FIGS. 2 to 4 is shown. The adapter 21 is formed by a first element part 22 and by a second element part 32, which are detachably connected to one another via a coupling device 41.

The first element part 22 has a bottom portion 23 with a central opening 24 and a first hollow cylindrical connecting sleeve portion 25 which protrudes from the bottom portion 23 on one side of the bottom portion 23. In the opening 24 in the bottom portion 23, a sealing element 27 is arranged. The first hollow cylindrical connecting sleeve portion 25 is provided on the inside with a thread-like inner profiling 26, which can be screwed onto the thread-like outer profiling 15 at the end region at the second end 14 of the shaft 12.

Starting from the bottom portion 23 extend two opposing bores 28, which pass in some areas in each case a groove 18 at the second, free end 14 of the shaft 12. In these holes 28, two connecting pins 29 are inserted, whereby the first element part 22 rotatably and positively to the second end 14 of the shaft 12 can be fixed.

The second element part 32 is formed as a hollow cylinder and has at one end 33 a radially outwardly projecting collar 34, to which a trained as a polygon, outside arranged attacking means 35 for a rotary tool holder of an applied, not shown drill adjoins. The adjoining the engaging means 35 section forms the second hollow cylindrical connecting sleeve portion 36. The second element part 32 is on the inside partially provided with a thread-like inner profiling 37, which is screwed onto the thread-like outer profile 15 of the shaft 12.

Next, the second hollow cylindrical connecting sleeve portion 36 on the outside partially a thread-like outer profile 15 for the arrangement of a fastening means, such as a clamping nut, not shown here. Since the adapter 21 remains mostly after the setting of the fastening element 11 on the shaft 12, can the adapter 21 z. B. are used for fixing a mat on the wall of the cavity to be secured. Such mats are, for example, reinforcing nets or mesh mats made of metal, or plastic, which provide protection against unsecured, falling rocks. These mats are advantageously arranged overlapping in the region of the set fastener 11. By means of the arrangement of a fastening means on the adapter 21, a first mat with the adapter 21 can be fixed to itself in a first step. Subsequently, a second mat is laid over the adapter 21 and fixed by means of the same or another fastening means.

The coupling device 41, which releasably connects the first element part 22 to the second element part 32, comprises two oppositely disposed abutment surfaces 42 arranged on the first element part 22 and two axially extending ones arranged on the second element part 32 for transmitting the drilling torque Counter stop surfaces 46. The free end of the first hollow cylindrical connecting sleeve portion 25 of the first element part 22 extends spirally between the stop surfaces 42, wherein the slope is greater than the pitch of the thread-like outer profile 15 of the shaft 12 is formed. The free end of the second hollow cylindrical connecting sleeve portion 36 of the second element part 32 also extends helically between the counter stop surface 46, the pitch being greater than the pitch of the thread-like outer profile 15 of the shaft 12.

After arranging the adapter 21 at the free end 14 of the shaft 12, the fastening element 11 is rotated via the adapter 21 in the rotational direction of rotation 49 by means of a drilling device, not shown here. After reaching the desired drilling depth, the drill is turned off and the hardenable mass 17 is pressed out, for example by means of an inserted through the opening 24 in the bottom portion 23 of the first element part 22, not shown here squeezing. If the hardenable mass 17 has reached a certain degree of hardness, the drill is put into operation again, wherein this time a rotation in the clamping direction 50, which is opposite to the direction of rotation of the drill 49, is exerted on the adapter 21. In this case, the second element part 32 is freely rotatable in the direction of the drill head 16 along the thread-like outer profile 15 of the shaft 12 is offset until the fastener 11 is braced. Due to the spiral configurations of the free ends of the first connecting sleeve portion 25 as well as the second connecting sleeve portion 36, the counter stop surfaces 46 on the stop surfaces 42 of the rotationally fixed at the free end 14 of Shaft 12 fixed first element part 22 in the axial displacement of the second element part 32 slide past.

The in the FIGS. 5 to 8 shown adapter 51 differs substantially from the previously set out adapter 21 by the configuration of the coupling device 71, which connects the first element part 52 releasably connected to the second element part 62. The first element part 52 is advantageously rotationally fixed at the free end of the shaft of the fastening element. The coupling device 71 comprises two opposing cams 76, which project beyond the free edge 63 of the second connecting sleeve section 66 of the second element part 62. Furthermore, the coupling device 71 comprises at the free edge 53 of the first connecting sleeve portion 55 of the first element part 52 provided corresponding to the alignment of the cam 76 arranged recesses 72, in which engage the cam 76 for transmitting torque.

Further, two spacer cams 64 are provided opposite one another at the free edge 63 of the second connecting sleeve section 66 of the second element part 62, which bear against the free edge 53 of the first connecting sleeve section 55 of the first element part 52 in the mounted state of the adapter 51. The spacer cams 64 prevent a flat contact of the free edges 53 and 63 against each other, whereby adhesion between them and thus an influence of the same on the release torque of the coupling device 71 is prevented.

The lying in the direction of rotation 78, leading side wall 73 of the recesses 72 extends substantially in the direction of the center of rotation 56 of the first element part 52. The lying in Verspanndrehrichtung 79, trailing side wall 74 of the recesses 72 extends at an inclination to the center of rotation 56 of the first element part 52, wherein the inclination of these side walls 74 is aligned to hold a broken cam portion in the recess 72.

In the area of the coupling device 71, the first element part 52 as well as the second element part 62 are provided with a radially encircling recess 81, in which a flexible, designed as a circumferentially closed ring holding means 82 is provided.

Claims (8)

Adapter of a self-drilling, chemically anchorable fastener (11) having a shank (12) with a first end (13) on which a drill head (16) is provided and a second free end (14), the shank (12) at the second end (14) at least partially provided with a thread-like outer profile (15), wherein
the at the second, free end (14) of the shaft (12) arrangeable adapter (21; 51) at one end an externally arranged engaging means (35) for a rotary tool holder of an applied drilling, one to the engaging means (35) spaced , at the other end provided bottom portion (23) and a bottom portion (23) and the engagement means (35) connecting, hollow cylindrical connecting sleeve portion (25, 36), wherein at least the connecting sleeve portion (36) at least partially complementary to the thread-like outer profile (15 Has on the shaft (12) formed thread-like inner profiling (37), characterized in that
the adapter (21; 51) is formed by a first element part (22; 52) and by a second element part (32; 62) which are releasably connected to one another via a coupling device (41; 71). Adapter according to Claim 1, characterized in that the coupling device (41) has an axially extending abutment surface (44) arranged on the first element part (22) and an axially extending counter abutment surface (46) arranged on the second element part (32) for transmitting the Includes drilling torque. Adapter according to claim 1 or 2, characterized in that the coupling device (71) on one of the element parts (62) at least one, a free edge (63) superior cam (76) and at least one at the free edge (53) of the other element part ( 52) provided recess (72), wherein the at least one cam (76) for transmitting torque in the at least one recess (72) engages. Adapter according to claim 3, characterized in that at least one of the side walls (74) of the at least one recess (72) extends in an inclination to the center of rotation (56) of the corresponding element part (52). Adapter according to one of claims 1 to 4, characterized in that a holding means (82) in the region of the coupling device (71) is provided. Adapter according to claim 5, characterized in that at the free edges of the element parts (52, 62) each have a radially encircling recess (81) is provided and the holding means (82) in this recess (81) is arranged. Adapter according to one of claims 1 to 6, characterized in that the first element part (22) at the second end (14) of the shaft (12) is fixed against rotation. Adapter according to claim 7, characterized in that the first element part (22) is fixed in a form-fitting manner to the second end (14) of the shaft (12).

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