SCREWING-IN SYSTEM FOR INSERTING A THREADED ROD INTO SOIL

A screwing-in system for inserting a threaded rod in the axial direction into a substrate, having a drive machine which rotationally drives a drive sleeve, it being possible to insert the threaded rod into the drive sleeve arranged on the drive machine, which drive sleeve can be connected to the threaded rod in a form-fitting manner and thus rotationally drives the threaded rod, wherein a component provided with an internal thread is fixed between the drive machine and the substrate, which component converts the rotational movement of the drive sleeve into a translational movement of the threaded rod, wherein the screwing-in machine is mounted on a carriage which is movable relative to the component.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to European patent application EP 22203095.9 filed Oct. 21, 2022, the disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The object of the invention is a screwing-in system for inserting a threaded rod into a substrate as well as a method for inserting such a threaded rod.

BACKGROUND

EP 2 689 071 B2 shows a screwing-in system for inserting a threaded rod in the axial direction into a substrate with a drive machine that rotationally drives a drive sleeve, wherein the threaded rod can be inserted into the drive sleeve, which rotationally drives the threaded rod in a form-fitting manner. In addition, a component provided with an internal thread is arranged between the drive machine and the substrate, which converts the rotational movement of the drive sleeve into a translational movement of the threaded rod.

Such screwing-in systems, in which a threaded rod is rotated through a form-fit connection inside a tool, have the problem that the threaded rod moving through the tool loads the mechanics of the screwing-in system. This is due to the high internal friction inside the mold and the associated heat generation. Thus, failures of the screwing-in system can occur or the screwing-in process can be slowed down if care is taken to ensure that the drive sleeve is loaded gently.

The present invention is thus based on the task of enabling safe and cost-effective screwing of threaded rods into a substrate without pre-drilling, using a simple, low-wear mechanism that reduces assembly time.

SUMMARY

The task is solved according to the invention by the features of the independent patent claims, while advantageous embodiments and further developments of the invention can be taken from the subclaims.

An advantageous feature is that the screwing-in machine is mounted on a carriage which is movable relative to a component with a thread. The thrust speeds of the carriage are calculated from revolutions per minute×thread pitch in cm.

The screwing-in system has a mounting with at least one rail on which the carriage can be moved back and forth in translation in order to minimize the internal friction in the drive sleeve that drives the threaded rod in rotation during the screwing-in process.

In principle, the carriage is mounted on a linear support and guide element and can be moved relative to the position-fixed threaded socket. This linear support and guide element is a toothed rack or, preferably, a rail.

The drive sleeve engages positively with a profiling on its inner circumference on the threaded rod in order to rotate it about its axis of rotation. This internal profiling ensures positive engagement on the lateral surface of the threaded rod, in particular on the wrench flats, wherein the profiling of the drive sleeve is matched to the wrench flat of the threaded rod. According to the shape of the threaded rod to be screwed in, a drive sleeve adapted to it is used, which can be interchangeably connected to the drive machine.

In a preferred embodiment, the profiling on the inner circumference of the drive sleeve is provided with two parallel or angularly opposed surfaces which receive the threaded rod with a corresponding “wrench size” within them. These surfaces, figuratively speaking, have a wrench dimension between them, which at least partially matches the profile shape of the threaded rod, and thus fulfill a wrench function.

The profiled inner diameter of the drive sleeve is, so to speak, the negative shape of the rod.

The present invention is not limited to the use of one pair of surfaces, as three or more surfaces can also be driven, for example.

With this screwing-in machine, which primarily has a hydraulic but also electric or air-driven rotary drive, a threaded rod is thus driven in rotation and undergoes a feed movement through an upstream thread of a threaded socket or alternatively of a nut when the thread of the rod engages in the thread of the sleeve, etc. The thread of the threaded socket or, alternatively, of the nut is driven in rotation.

In the following, a threaded socket is understood to be a hollow body of any shape which is formed with an internal thread which is in threaded engagement with the external thread of the threaded rod.

The threaded socket is preferably held within the screwing-in system by a clamping device mounted on the mounting at the substrate end of the carriage. Preferably, the threaded socket is held in position within the clamping device by two or more movable clamping jaws or, alternatively, is fixed to a stock structure by means of one or more clamping jaws or is held in position manually with an open-end wrench.

Rotational engagement with the thread of a fixed threaded socket forces the threaded rod to move axially and moves through the threaded socket.

Thus, in a method for screwing a threaded rod into soil or rock by means of a mounting and a carriage which is translationally movable on rails of the mounting, with a drive machine arranged on the slide, which is in positive engagement with the threaded rod by means of a drive sleeve, compensation of a feed movement of the threaded rod is made possible.

The threaded rod can be inserted into the drive sleeve, which is driven in rotation in the assembly head, via an insertion opening arranged on the assembly head and drives the threaded rod in rotation in the longitudinal direction.

For this purpose, it is known to provide the threaded rods with flat areas on opposite sides so that the thread pitches are only arranged outside these flat areas on the outer circumference of the threaded rod in each case. In the following, these flat areas will be referred to as the wrench flats.

In this way, it is possible to insert the threaded rod into the rotationally driven drive sleeve, which is profiled to match the profile of the threaded rod described above, and there to establish the frictional connection with the flat sides of the threaded rod, after which the drive sleeve is then rotationally driven, transmitting a torque and the threaded rod is screwed through from above downwards through the threaded hole into a component with an internal thread.

There is a small amount of play between the profiling of the drive sleeve and the wrench flats of the threaded rod, so that the threaded rod can be pulled out of the drive sleeve when the surfaces of the profiling and the wrench flats are opposite each other. This also allows the drive sleeve to be moved along the threaded rod without engaging the wrench flats. In particular, when the drive sleeve has reached the threaded socket due to the relative movement of the drive machine, the rotary drive is deactivated and the drive sleeve is pulled back along the threaded rod onto the carriage, where engagement between the drive sleeve and the wrench flats occurs again. For such an engagement, the parallelism between the profiling of the drive sleeve and the wrench flat is eliminated so that the surfaces are slightly oblique to each other and there is contact to transmit the rotary motion of the drive machine to the threaded rod.

In one further development, the rotary drive of the drive sleeve is disengaged during the retraction process. This means that there is little or no resistance from the drive sleeve to the threaded rod.

By placing the threaded rod on an element with a threaded hole, for example a threaded socket, the thread-like profiling of the threaded rod comes into engagement with the thread of the threaded hole of the element, the internal thread of the threaded hole having the same pitch as the threaded rod.

For simplicity, the invention is described below using a threaded socket, but any other element can be used which has an internal thread into which the threaded rod can be screwed.

Due to the drive machine running along in the feed direction, axial movement of the threaded rod is possible without any significant friction.

This makes it possible to achieve a greater speed of movement with a lower drive power. In addition, a profiling of the drive sleeve corresponding to the drive profile of the threaded rod allows for less wear. Thus, according to the invention, there is less frictional resistance than, for example, with the known devices, which have a high surface friction.

Thus, the device according to the invention can reduce wear and tear and setup time.

With the screwing-in system according to the invention, not only a feed, i.e., a screwing-in movement of the threaded rod is possible, but also an unscrewing movement of the threaded rod.

The drive machine is mounted on a mounting and moves with the feed movement of the threaded rod. This feed movement is analogous to the bar length, i.e., an adjustment usually takes place between ⅓ and ¼ of the bar length, for example 1 to 3 meters

With the screwing-in system, hundreds of linear meters of threaded rods can be inserted in a very short time. With the large number of threaded rods inserted, one can either produce many anchorage points in a short time or produce foundations for higher load ranges, e.g., temporary bridge bearings with over 1200 KN foundation load.

As soon as the drive sleeve driven by the rotary drive, which is in a form-fit connection with the threaded rod, has reached the threaded socket as a result of the feed movement, it is pulled along the mounting again in the opposite direction without rotary drive. This prevents the threaded rod from rotating again in the opposite direction. Once the carriage with the drive sleeve has moved back to the starting point at the beginning of the rails, the screwing-in process starts again.

The drive sleeve is interchangeably connected to the drive machine by means of a flange connection.

Depending on the outer profile shape of the threaded rods, a drive sleeve with a corresponding inner profile can be used. For example, rods with a diameter of 15 mm can be turned with one drive sleeve, and to drive rods with a diameter of 26 mm, another drive sleeve is mounted over the flange connection.

The sleeve is made of a hardened steel and is therefore harder than the threaded rod; tungsten carbide-cobalt is the preferred material.

In another embodiment, only the inner sleeve is made of tungsten carbide-cobalt and the outer sleeve is made of a more favorable material with a higher yield strength.

Preferably, the drive machine is a hydraulic rotary drive which, due to its compact cylindrical design, can be mounted on the mounting in a space-saving manner for rotary movements, and which is particularly well suited for applications with large radial loads that occur. This allows the threaded rod to be inserted into the substrate without any problems, as the acting forces can be absorbed by the bearing of the drive.

The drive machine running on the rails thus generates a rotation of the threaded rod, which is converted into a translation by the threaded socket. As the drive machine runs with the drive sleeve during the feed movement of the threaded rod, there is no loss due to friction between the drive sleeve and the threaded rod.

On the one hand, this results in significantly less wear in the sleeve (longer service life), and on the other hand, the threaded rods can be screwed in deeper with the same torque.

A method of screwing a threaded rod into soil or rock, comprising a drive machine having a drive sleeve which produces a positive engagement with the threaded rod by means of an internal profiling to drive the threaded rod rotationally and to screw it through the thread of a threaded socket, wherein the rotational movement of the threaded rod through the threaded socket is converted into a translational movement in order to drive the threaded rod at its front end into the soil or rock, characterized in that the drive machine is mounted on a translationally movable carriage and is moved along the axis of the threaded rod in accordance with the feed movement of the threaded rod.

The carriage is mounted on a guide (e.g., rail, toothed rack, etc. . . . ) and can be moved relative to the position-fixed threaded socket.

The drive sleeve interrupts the positive connection with the threaded rod when the carriage moves against the direction of insertion, in order to create a positive connection again at another area of the threaded rod and to drive the threaded rod to rotate again.

The carriage is moved relative to the threaded socket along one or more rails using a linear drive, whereby rails means a positive longitudinal guide.

The mounting can be mounted on the boom arm of a mobile vehicle. Such a vehicle is a tracked vehicle, a quad, or similar.

The subject-matter of the present invention results not only from the subject-matter of the individual patent claims, but also from the combination of the individual patent claims with each other.

All details and features disclosed in the documents, including the abstract, in particular the spatial configuration shown in the drawings, could be claimed as essential to the invention insofar as they are individually or in combination new compared to the prior art. The use of the terms “essential” or “according to the invention” or “essential to the invention” is subjective and does not imply that the features so designated must necessarily be part of one or more patent claims.

DETAILED DESCRIPTION

FIG.1shows a threaded rod2which can be rotated in the direction of rotation24about a threaded rod axis23running centrally in the axial direction through the threaded rod. The threaded rod has a thread4on its outer circumference at certain sections, which has a continuous helix despite interruptions in the axial direction. Outside these sections, the threaded rod has flat areas which form the drive profile of the threaded rod and are referred to below as wrench flats3.

FIG.2shows the screwing-in system1, with which the threaded rod2can be inserted into a substrate22. For this purpose, the threaded rod2is driven in rotation by a drive sleeve13, with a threaded socket19converting this rotation into translation in the direction of arrow25. The inner profile34of the drive sleeve19forms a clamping chuck for the threaded rod2.

The drive sleeve13is detachably and replaceably connected to the rotary coupling14via a flange connection12, which transmits a rotary motion generated by the drive machine5to the drive sleeve13.

The drive machine5is mounted on a carriage8which can move forward in the direction of arrow25and backward in the direction opposite to the direction of arrow25. For this purpose, the carriage is mounted on two rails11, which are part of the mounting6.

A feed drive27moves the carriage forward on the mounting6while the threaded rod2is rotated about its threaded rod axis23in the direction of rotation24.

The threaded rod2is clamped in the profiling34, which has the function of a clamping chuck, of the drive sleeve13and then the threaded rod is placed with its front end33on the thread of the threaded socket19and then the drive machine5is switched on.

The threaded rods2are screwed into the substrate22automatically, so to speak, because the feed of the threaded rods2is caused by the engagement of the thread4of the threaded rods2in the threaded socket-side thread.

The rotating drive of the drive sleeve13thus drives the rotating threaded rod2, which moves at a feed rate, progressively into the soil or rock below the threaded socket19. This is assisted by the thread4, since the thread pitches of the thread4arranged on its circumference pull the threaded rod into the substrate22.

In this case, the threaded rod2can be inserted into the drive sleeve13, which is driven in rotation at the front of the drive machine5, via an insertion opening38arranged at the rear of the drive machine5, which in turn drives the threaded rod2in rotation in the longitudinal direction.

The threaded socket19is received in the clamping opening18, which is formed between two clamping jaws16. These clamping jaws16are part of the clamping device15.

The mounting6has a guide plate20at its substrate end, after the clamping device15, with a crescent-shaped recess21at the top end through which the threaded rod2passes.

The mounting6also has a similar guide plate9at its insertion end, which has a hole10through which the threaded rod2is inserted.

FIG.3shows another perspective view of the screwing-in system1without threaded rod. One of these is guided through the hole10of the guide plate9in the direction of arrow25to equip the mounting6and is inserted at the rear into the insertion opening38of the drive machine5until contact is made with the drive sleeve13.

Due to the internal profiling34of the drive sleeve13, which has a certain amount of clearance to the wrench flats3of the threaded rod2, the rod can be pushed through the drive sleeve until it protrudes from the drive sleeve13. Preferably, the carriage8is located at the guide plate9, i.e., at the insertion end of the rails11. The threaded rod2is passed through until it rests on the thread of the threaded socket19at the substrate-side end of the carriage11. Subsequently, the drive sleeve13is driven to rotate by the drive machine5so that this rotation is transmitted to the threaded rod2.

Here, the threaded rod2experiences a feed in the direction of arrow25due to the thread engagement in the thread of the threaded socket19, wherein the drive machine5also travels on the carriage at the same speed in the direction of arrow25. The movement of the carriage is controlled by the control unit26, which transmits the corresponding control commands to the feed drive27shown inFIG.4.

Thus, the drive sleeve13engages only in a constant section of the threaded rod2during the entire feed distance of the carriage8between the end on the insertion side and the end on the substrate side of the rails11and drives it in rotation.

When the maximum feed movement in which the carriage11can travel is reached, which is the case when the drive sleeve13has reached the threaded socket19, the positive locking between the drive sleeve13and the threaded rod2is cancelled and the carriage8with the drive machine5is moved against the direction of the arrow25along the threaded rod axis23of the threaded rod2until the insertion end of the rails11is reached. At this position, the drive sleeve13again engages the wrench flats3of the threaded rod2, although this time it is a different area of the threaded rod.

FIG.4shows a partially cutaway view of the screwing-in system1. The control unit26controls, among other things, the feed drive27of the carriage8. The feed drive27rotationally drives a roller28, which rolls along the underside29of the rail11. Alternatively, a toothed wheel is provided which engages with a toothed rack on the underside. The frictional connection thus created thus moves the carriage8, which is connected to the feed drive27, along the longitudinal extent of the rail11. Thus, the drive sleeve13can be moved to any position along the rail11and engage the threaded rod2at defined areas.

In addition, the follower rollers30are located laterally of the rails11, which support the linear movement of the carriage11laterally.

FIG.5shows the clamping device15, which actuates the two clamping jaws16in and against the opening direction39via a clamping drive17. The two clamping jaws16form a clamping opening18between them, into which a threaded socket19not shown here can be received and fixed in position. The guide plate20, which also forms the substrate end of the mounting6, is located at the substrate end of the clamping device15.

FIG.6shows a tracked vehicle31, which in the example shown here is an excavator, with a hydraulically raisable and lowerable boom arm32, on which the mounting6is mounted and can be freely moved by means of the boom arm and aligned in the desired direction of insertion of the threaded rod2. Thus, the threaded rod2can be inserted into the substrate22in the direction of arrow25by the screwing-in system1according to the invention.

FIG.7shows a sectional view of the screwing-in system1. The threaded rod2is guided along the threaded rod axis23within the drive machine5. The drive machine5drives the drive sleeve13via the rotary coupling14and a flange connection12. This drive sleeve13has an internal profiling34, which enables positive engagement with the threaded rod2, in particular its wrench flats3. In this way, it is possible to insert the threaded rod2into the rotationally driven profiled drive sleeve13, which is adapted to the profile of the threaded rod2described above, and there to establish the frictional connection with the flat sides of the threaded rod2, after which the drive sleeve13is rotationally driven and the threaded rod2is screwed through the thread of the threaded socket19from top to bottom and driven into the soil or rock with its front end33. The threaded rod2is advanced by engaging the threaded rod in the threaded socket.

FIG.8shows a retracted drive machine5, which is located at the insertion end in the area of the rear guide plate9. InFIG.8, the clamping device and threaded socket are not shown.

In order to ensure that it runs as smoothly as possible on the rails1, the carriage8has sliding bodies35which grip laterally around the rail11. When the screwing-in machine is put into operation, the rotating drive sleeve13moves in the direction of the guide plate20, which is located at the insertion end, and drives the threaded rod2to rotate.

The control unit26is arranged on the side of the mounting5and a part of the boom arm32can be seen.

To unscrew the threaded rod2from the substrate22, the drive machine5on the translationally movable carriage8is moved along the threaded rod axis23in accordance with the backward movement of the threaded rod2and the drive sleeve13is rotated in the direction opposite to the screwing-in direction.

The present invention is not limited to the use of a threaded socket as shown inFIG.9. In the example shown here, the thread which allows the translational movement of the threaded rod2into the substrate22is located as a threaded hole37in an anchor plate36which rests on the substrate22. In this way, the driven threaded rod2rotating through the drive machine5or drive sleeve13can be inserted into the substrate22.