HRP930546A2 - A dowel with an expansion sleeve - Google Patents

Description

The invention relates to an anchor screw with an expansion sleeve according to the scope of the main claim.

The anchor screw of the above-mentioned type is anchored in such a way that the tension body is pulled into the tension sleeve, whereby the tension sleeve rests on a bearing element, which is formed by, for example, a spacer sleeve. The same rests on the counter-bearing screw, which is formed by the head of the screw or the washer lying on it. When using a spacer sleeve as a bearing element, an additional plastic spacer is needed between the spacer and the spacer as a clamping area, to guarantee a safe connection of the anchor screw with the object that is being attached.

Objects are also other anchor bolts with expansion sleeves, in which the expansion sleeve firmly grips the expansion body as it is drawn into the well; so that the gapped bushing does not rest on the bearing element.

Inserting an anchor bolt of this type into the tensile area of the anchor base requires a high breaking capacity, in order to avoid a decrease in the holding value when the borehole is enlarged to cause damage. With the friction, which after the anchoring of the anchor bolt acts between the expansion sleeve and the expansion body, it can easily be pulled out of the well in very unfavorable cases when the borehole is enlarged, with the creation of damage to the expansion body by the gripping load of the expansion sleeve, and thus the entire anchor bolt, but not in order to equate the increase of the borehole with disruption.

The task of the invention is how much to improve the rupturing ability by introducing the mentioned anchor screw, so that it is able to equalize the increase of the bore, which occurs with the creation of damage, with the slipping of the rupturing body into the rupturing sleeve.

The solution to this task contains the features given in the main request. When inserting the anchor bolt according to the invention in the pre-earthing of the well into the anchor base, the spring ring is pressed together on the diameter of the well, which corresponds at least to the outer diameter of the expansion sleeve. No additional effort is needed to insert the anchor bolt into the well. After inserting the anchor screw, turning the screw moves the tension body in the direction of the axis, while the tension gun for anchoring it is pulled into the well.

In this case, the expansion sleeve can be directly or indirectly supported on the spring ring, since the latter is firmly attached to the walls of the well.

When opening the spring sleeve, the spring ring can also be supported by the counter bearing on the screw head.

If the hole is enlarged due to damage, the spring ring can be adapted to the enlarged hole, in which case it supports the spacer sleeve against movement in the axis direction. This forcefully achieves that the load acting on the tension sleeve overcomes the friction between the tension body and the tension sleeve, thereby drawing the body into the tension sleeve. With the increased friction of the friction sleeve thus connected, the increase of the well is equalized.

The spring ring can fit on the face of the ring further away from the spacer bushing, with the facing side, which can be shaped on the anchor bolt or further made with the front side of the attached element or the spacer bushing. When driving the anchor bolt into the well, the spring ring resists on this annular surface. In order to maintain the centering of the spring ring before and during assembly, a suitable annular protrusion can be made on the adjacent spring ring ring surface, which is adapted to the cross section of the spring ring. It is not placed on that protrusion just for the purpose of centering, but this ring-shaped protrusion works when compressing the spring ring, so that the spring ring exerts an axial force on the spacer sleeve, which contributes to the friction.

If the anchor bolt between the bolt head and the spring ring comprises an arranged spacer sleeve, the clamping area may preferably be adjacent to the spring ring. It can be arranged either between the spacer sleeve and the sleeve made of synthetic material and the spacer sleeve. In the case of the last arrangement, there is an expedient design, in which the discontinuous bushing has a stepped section with part of its length in the bushing made of plastic mass, on which a spring ring is attached.

When driving the anchor bolt into the receiving hole, the base for anchoring, the spring ring that protrudes over the outer diameter of the expansion sleeve, is compressed to the diameter of the receiving hole. For the purpose of crushing during the construction of the well, as a rule, a funnel-shaped expansion is created in the area of the mouth of the well, into which it is possible to drive an anchor screw with a protruding spring ring without much difficulty.

In the case of sharp-edged boreholes without a funnel mouth, due to the protruding spring ring, there may certainly be resistance when driving to overcome, where stronger blows with a hammer are required, where there is a risk of damage to the anchor bolt.

In order to make it easier to drive the anchor bolt even in undamaged wells, it is possible to use a spring ring placed in the spacer sleeve. With the spring ring, inserted in the annular expansion of the expansion sleeve, only the end of the expansion sleeve, which faces away from the expansion body, expands beyond the diameter of the bore, while the other end of the expansion sleeve has a slightly smaller outer diameter than the diameter of the bore. This creates an initial chamfer on the outer surface of the expansion bushing, which, with less resistance during driving, allows the expansion bushing to be reduced to the diameter of the well. After driving the anchor screw, the tension body is moved in the direction of the axis by turning the screw, while the tension sleeve is pulled into the well to anchor it. If now for the sake of creating damage there is an enlargement of the borehole, while one end of the spacer sleeve with an elastic spring ring is in position to accommodate this expansion of the borehole and firmly prestress it in the borehole. This forcefully achieves that the load acting on the tension body overcomes the friction between the tension body and the tension sleeve and pulls the tension body into the tension sleeve.

The expansion of the borehole is equated with the slippage of the dispersing body and the related displacing of the dispersing sleeve.

The front end of the extension can cover part of the profile of the spring ring. In this way, the spring ring is secured against falling out of the annular expansion of the inner bore of the spacer sleeve.

Furthermore, the gap of the spring ring can be aligned with the through slot of the spacer sleeve. This design achieves optimal use of the radial tensioning force of the spring ring to expand the spacer sleeve.

Implementation examples of the invention are presented in the draft, where they show:

fig.1, an anchor ring with a spring ring is inserted in the borehole, which is placed between the sleeve made of synthetic material and the spacer sleeve,

fig.2 spring ring placed between the spacer sleeve and the sleeve made of synthetic material,

fig.3 anchor screw, where the spring ring is placed between the spacer sleeve and the annular surface of the temporary element,

Fig. 4 anchor bolt with a spring ring placed in a spacer sleeve.

The anchor bolt according to Fig. 1 consists of its front side for the introduction of a spreader sleeve 1 made with multiple slots over one part of its length by means of a screw 2 in the spreader sleeve 1 for the purpose of expanding the same retractable spreader body with the screw, has a spreader body 3 and a threaded screw 2 adapted to the internal thread 4. To bridge the gap when tensioning the object 5, which we fasten, between the expansion bushing 1 and the spacer bushing 6, a bushing 7 made of synthetic material is arranged as a pressure area, which with the connection of the expansion bushing 1 is in the well 8 with extending longitudinal ribs 9, at the same time serves as also a gripping safety for the burst sleeve 1. In order to connect the burst sleeve 1 with the plastic sleeve 7, the spread sleeve has a section 10 removed, which catches the inside of the bore of the plastic sleeve 7. Between the spacer sleeve 6 and the sleeve 7, a spring ring 11 is arranged, the outer diameter of which exceeds the diameter of the spacer sleeve. In the case of the anchor bolt, for a hole diameter of up to about 12 mm, the expedient oversize of the spring ring 11 is about 1 mm, while for larger hole diameters, the oversize is about 1.5 mm.

Due to the oversize of the spring ring 11, it presses firmly against the walls of the well after driving the anchor bolt into the well 8. The head 12 of the screw, which rests on the outer surface of the object to be attached, is used as a counter bearing for tightening the object 5, which is being attached, and for pulling in the expansion body 3. Due to the action of the torque on the head 12 of the screw, the expansion body 3 is pulled into the expansion sleeve 1. In this case, the expansion lamellae of the expansion sleeve 1 created by the longitudinal grooves 14 are pressed into the walls of the borehole. If during anchoring, due to the creation of damage, the borehole increases, it prevents the spring ring 11 pressed into the borehole walls from moving the spacer sleeve in the direction of the axis. This forcibly achieves further pulling of the expansion body 3 into the expansion sleeve, so that the expansion of the borehole is equalized by the additional expansion of the expansion sleeve 1.

When placing the spring ring 11' between the expansion bushing 1 and the bushing 7 according to Fig. 2, the spring ring 11' sits on the removed extended section 10' of the expansion bushing 1 that is caught in the bushing, because this solution requires a small thickness of the wire of the spring ring 11', and it is recommended to make the spring ring from a wire with a rectangular cross-section.

Fig. 3 shows a further embodiment, in which the spring ring 11 is placed between the spacer sleeve 1 and the threaded stand 15. The latter is connected to the spacer body 3 via a threaded section 17, which engages in the thread the bore 16 of the threaded stem. With smaller diameters of the anchor bolt, the spacer body 3 can be made on the threaded stem 15. On the front side 18 of the spacer body 3, there is a protruding annular surface 19, which corresponds to the cross-sectional shape of the spring ring 11, which centers the spring ring 11 before and during assembly. In addition, the projecting annular surface 19 also helps in unfolding.

The anchor screw according to fig. 4 consists of its leading front end to over one part of its length a multiple groove and at least one continuous groove 14', including the expansion bushings 1 and from the screw 2 into the expansion bushing 1 for the purpose of expanding the retractable expansion body 3. Last is connected in one piece by a screw 2, which, for the purpose of connection with the threaded stem 15, engages again in its threaded screw 16. The internal screw 20 of the expansion sleeve 1 is equipped with an annular extension 21, in which the spring ring 11 is inserted, at its end facing away from the expansion body. Through the same, the end of the expansion sleeve 1 expands to an outer diameter, which is larger than the diameter of the anchor bolt.

Based on the measurement of that end of the expansion sleeve, it is firmly pressed against the walls of the well after driving the anchor bolt into the well 8. The nut 12 serves as a counter bearing for tightening the body 5, which is attached, and for pulling in the expansion body 3, which rests on the outer surface of the object, which is being attached, via the washer 13. Due to the action of the torque on the nut 12, the expansion body 3 is screwed into the expansion sleeve 1. In this case, the expansion lamellae of the expansion sleeve 1 made by longitudinal grooves 14 are radially pressed into the walls of the borehole. If after anchoring, due to damage, the borehole is enlarged, the spring ring 11 firmly pressed against the walls of the borehole by the end of the expansion bushing prevents movement of the expansion bushing 1 in the direction of the axis. This forcibly achieves a further pulling of the expansion body 3 into the expansion sleeve, so that with the additional expansion of the expansion sleeve 1, the increase of the well is equalized.

To secure the spring ring 11 in the annular extension 21 of the expansion sleeve 1, the front end of the extension is covered by a part of the profile of the spring ring. Furthermore, the spring ring 11 in the expansion 21 is arranged in such a way that the gap of the spring ring coincides with the all-passing groove 14 of the expansion sleeve 1 in order to optimally use the tensioning force of the spring ring.

Claims (10)

1. Brain with a retentive sleeve, which includes in the retentive sleeve a retractable retentive body by means of a screw and a bearing element, on which the retentive sleeve rests when the retentive body is retracted, characterized by the fact that a spring ring (11, 11'), whose outer diameter exceeds the diameter of the expansion sleeve (1) and which can be pressed to the diameter of the expansion sleeve (1). 2. The hub according to claim 1, characterized in that the spring ring (11) rests with its vertical side away from the spacer sleeve (1) on the annular surface, which is formed on the counter-bearing and performed on the hub. 3. Brain according to claim 2, characterized by the fact that the annular surface is formed by the front side of the screw (2), there will be spacer bushings (6), an inclined element on the screw (2), a step or the like. 4. The brain according to one of the previous claims, characterized in that the spring ring (11) rests laterally on the projecting annular surface (19), which corresponds to the cross-sectional shape of the spring ring (11). 5. The brain according to one of the previous claims, characterized in that the spring ring (11, 11') adjoins the shrinking area. 6. Brain according to claim 5, indicated by the fact that the shrinking area is performed as on the expanding sleeve (1) a boundary sleeve (7) made of artificial material, in which the expanding sleeve (1) includes a removed section (10,10'), which with part of its length engages in a sleeve made of synthetic material and on which a spring ring (11,11') is attached. 7. The brain according to one of the previous claims, characterized in that the spring ring (11') is at least partially angular in cross-section. 8. Brain with a retentive sleeve, which contains at least one all-passing entrance, a retentive body retractable by means of a screw and with a bearing element, which fixes the retentive sleeve in the well, and which is designed as a spring ring, indicated by the fact that the internal bore (20) of the retentive the sleeve (1) includes, at its vertical end further from the expansion body, an annular extension (21), into which a spring ring (11) is inserted, where the end of the expansion sleeve is with the spring ring (11) on the diameter, which protrudes over the outer diameter of the brain stretchable and in the well (8) compressed to its diameter. 9. The brain according to claim 1, characterized in that the front end of the extension covers part of the profile of the spring ring. 10. The brain according to claim 1, characterized in that the gap of the spring ring is aligned with the all-through groove of the spacer sleeve.