WO2016193392A1

WO2016193392A1 - Rail clamp with vertical guide

Info

Publication number: WO2016193392A1
Application number: PCT/EP2016/062549
Authority: WO
Inventors: Friedrich Brune
Original assignee: Römer Fördertechnik GmbH
Priority date: 2015-06-02
Filing date: 2016-06-02
Publication date: 2016-12-08
Also published as: DE102015108745A1; DE102015108745B4

Abstract

The invention relates to a rail clamp, comprising a clamp arrangement with two levers which are connected via an articulated arrangement, the first ends of which levers are designed as oppositely acting gripping arms each having a clamping jaw, and the second ends of which levers are designed as lever arms, wherein the lever arms are actuated by a clamp drive, and with a guide for orienting the clamping jaws. In order to provide a low-wear, reliable guide for a rail clamp, provision is made for the rail clamp to have a guide with a guide drive which vertically moves the guide and the clamp arrangement. The invention further relates to a method for orienting a rail clamp.

Description

description

Rail tongs with vertical guide

The invention relates to a rail tongs and a method for aligning the rail tongs.

Rail clamps are known devices that are used for setting heavy components or tools that should not move under external force. Typical is the use of rail clamps for setting free-standing, rail-mounted gantry cranes.

GB 849,706, DE-OS 25 47417 and KR 100978900 Bi describe typical rail clamps in which jaws at the ends of the gripping arms engage opposing sides of a rail to engage e.g. B. to secure rail-mounted gantry cranes. However, the rails do not always run precisely linear or the impact of two consecutive rails often results in a jump or offset. Guide rollers, which are not vertically movable, align the rail tongs with their flange on the rail so that the position of the rail clamp is adapted to a curved course of the rail or a jump, so that both jaws are always arranged at the same distance to the side of the rails and thereby evenly engage with the rail. If the gantry crane moves along the rail, the clamping jaws are open (and also raised in the execution according to DE - OS 25 47417) and the guide rollers roll with the gantry crane. If the gantry crane is to be secured again, the rail pliers are aligned with the rail thanks to the guide rollers that permanently engage the rail, and the rail clamp can lock the crane as the jaws close.

A disadvantage of this embodiment of rail clamps that the rollers are subject to wear, in particular by wear of their flanges. It is an object of the invention to provide a low-wear, secure guide for a rail tongs.

The rail pliers according to the invention comprises a pair of pliers and a guide for aligning gripping arms, wherein the pliers assembly has two connected via a joint lever, the first ends as oppositely acting gripping arms, preferably each formed with a jaw and the second ends are designed as lever arms operated by a pincer drive and wherein the rail pincers of the invention are characterized by having a guide drive which vertically moves the guide and the pincer assembly.

It is the inventor's finding that a guide for a rail pliers does not have to constantly abut a rail to ensure a safe guidance. A guide drive, which moves the guide as well as the rail tongs vertically, ie raises and lowers, ensures that the guide with opened rail tongs as well as the pliers arrangement has distance to the rail, so that the contact with the rail is essentially only given if the object, that is to be kept, z. B. a gantry crane is at a standstill and thus the rail clamp is at a standstill. The rail pliers according to the invention is thus designed for an upper, open position and for a lower, closed position. In the transition from the upper to the lower position, the guide ensures the alignment of the rail clamp with respect to the rail. By means of the vertical guide drive according to the invention, which raises and lowers the guide, the rail pliers according to the invention are therefore particularly wear-resistant. Due to the fact that the guide comes into abutment with the rail at the position at which the forceps arrangement directly engages, the guide is particularly secure.

The pliers arrangement of the rail pliers is known per se and is only briefly explained in its basic elements. Two levers are connected by a hinge arrangement, either as crossed levers having a common hinge or, preferably, as two parallel levers, each connected by a hinge to a bridge connecting the two levers. A first, short gripper arm of the lever preferably carries a jaw which is designed to rest against the side surface of a rail. The jaw is preferably received in a cassette, so that an adaptation to different types of rails or a change of worn jaws with minimal effort is possible. A second, long lever arm is connected to a pliers drive. Both levers are arranged in such a way that the gripping arms work in opposite directions and the gripping arms with the clamping jaws, if applicable, rest on two sides of a rail. The guide proposed herein in connection with the invention can be combined with all types of pliers arrangements. The pliers drive can in any way, for. B. hydraulically, electromechanically or pneumatically or by a combination of such drives done. The rail clamp is used on components that are guided on rails and in which an undesirable movement is to be prevented because the components are stopped and should be kept. Typical applications for rail grabs are cranes, but also gates, roof or wall elements. The rail pliers according to the invention can be used on rails with all known cross sections, in particular those which have a rectangular cross section or those which have a profiled cross section with a head which is placed on a web which stands on a foot. The foot of the rail is attached to the ground, as typically z. B. for railway tracks or crane rails is the case. As far as the following pages surfaces of the rail are addressed, in profiled rails, the side surfaces of the head meant.

The guide drive according to the invention can also be used in conjunction with known guides such as permanently applied to the rails guide rollers with flange, provided that the flanges are adapted to the placement on the rail. However, it is preferred if the guide is designed as a receptacle which can at least partially receive a rail and thereby centering and aligning the rail pliers on the rail. In the simplest case, the receptacle is formed from two boundaries, which are also referred to below as side flanks and which lie opposite to the side surfaces of the rail in the lower, closed position. The limitations can z. B. be formed rod-shaped.

The leadership must ensure that not only the laid in a predetermined position Rail is included in the recording, but also a rail with deviating position or with offset. The rail, for example, take a different position by setting the background or by heating or cooling. Offset occurs when the cross sections of opposite ends of two rails are not arranged congruent. In the context of this application, the term offset designates both a deviating position and an offset of the rail. The offset depends on the rail construction and its background and can be a few millimeters, z. B. 0.5 mm can be up to 5 mm, but the offset can also easily be up to 55 mm. Particularly common is an offset of 10 mm to 20 mm. The tolerance of the recording corresponds to the extent of the deviation or the offset. Before building the rail pliers, the maximum tolerance for each rail is determined and the size of the receptacle is determined accordingly. The above simple shots are usually suitable only for rails with low offset.

According to an advantageous embodiment of the invention, the receptacle is made as a guide plate with a recess, wherein the recess is preferably formed in a lower edge of the guide plate U-shaped. The recess in the lower edge of the guide block is directed towards the rail and is dimensioned so that it can at least partially accommodate the rail or the rail head. The recess has a bottom and flanks, in particular side flanks, which extend from the bottom of the recess to the entrance of the recess. The bottom of the recess is at least as wide as the rail. The recess is preferably so deep that the side flanks of the recess extend from the bottom to the bottom end of the gripping arms. By picking up the rail in the recess during lowering of the rail pliers, the pliers arrangement, in particular its gripping arms, if necessary with clamping jaws, is guided securely to the predetermined position laterally of the rail.

In the lower position of the rail pliers, the side edges of the recess are arranged opposite the side surfaces of the rail or of the rail head. The side edges may be parallel to each other, but they may also be inclined to each other, so that the recess at the entrance is further open than at the bottom, depending on the contour of the rail on which the rail tongs to attack. In a simple embodiment, the side flanks of the guide are shaped so that they guide the rail into the recess during lowering when hitting the top of the rail and thereby guide and align the rail clamp with respect to the rail. This can be z. B. can be achieved by an expansion of the side edges in the region of the entrance of the recess. The expansion can also be performed rounded. The extent of the expansion corresponds at least to the offset, so that even at maximum offset, the guide securely grasps the rail and guides the rail clamp onto the rail. This embodiment is particularly suitable when the offset is low or when the top of the rail is strongly rounded.

However, it is particularly preferred if the guide has on the side edge in the region of the input a guide roller which assists the insertion of the rail in the receptacle. Especially with heavy versions of the rail tongs and with a large offset, the preferred embodiment proves to be advantageous. It is particularly preferred if the radius of the guide roller is equal to or greater than the offset of the rail. As a result, a secure guidance of the rail clamp is guaranteed even at maximum offset. When the guide meets the upper side of the rail when lowered, the guide rolls down on the upper side, thereby ensuring that the rail is received in the receptacle. The effect of the guide roller is further enhanced when the top of the rail is rounded. A particularly preferred embodiment of the invention provides that guide rollers are mounted on both side edges of a recess.

The recording corresponds in a simple embodiment of the width of the rail. According to an alternative embodiment, the receptacle is dimensioned with play, that is, the receptacle is wider than the rail. The game is preferably at most as wide as the distance of the jaws from each other in the open position. In this way, on the one hand a secure guidance of the pliers arrangement is ensured, on the other hand, jamming of the rail is minimized in the recording, so that the guiding and aligning the pliers assembly is carried out particularly smoothly, especially when opening and raising the rail pliers. According to a further preferred embodiment of the invention, the guide has a stop which indicates the resting of the guide on the upper side of the rail. Advantageously, the stop is arranged on the bottom of the recess. The stopper is preferably used as a signal generator, which indicates the resting on the top of the rail. When resting the stop on the top of the rail, the downward movement of the rail clamp is stopped and the closing operation of the clamp assembly can begin.

According to the invention, a rail clamp is proposed which, when open, in which the clamping jaws do not rest against the rail, is arranged above the rail. In the closed state, the rail pliers according to the invention are lowered and the gripping arms or the clamping jaws attached thereto rest on the rail, in particular on the side surfaces of the rail. The guide drive moves the guide and the tong assembly from an upper, open position to a lower, closed position. The guide drive is preferably designed as a hydraulic drive, but it can also be designed as a mechanical or electromechanical drive (eg spindle, driven by an electric motor) or as a pneumatic drive. It is also possible to combine different types of drives, for. B. a drive with hydraulic and mechanical components. It is preferred if the guide drive and the pliers drive are coordinated, so z. B. are each designed as a hydraulic drive, which is operated uniformly. The guide drive is advantageously attached to a housing which encloses at least parts of the rail clamp. The housing may be equipped with cross members to which the guide drive is attached, so that z. B. in a hydraulic guide drive, a first end of a piston assembly is fixedly secured to the housing, while a second end of the piston assembly is attached to the guide or on the pliers assembly. By displacing the piston in the cylinder, the guide and the tong assembly are then raised or lowered. The guide is preferably mounted in a housing of the rail clamp. In order to ensure a secure guidance of the pliers arrangement, it is advantageous if in each case a guide is arranged in front of and behind the pliers arrangement. As a result, the pliers arrangement is lowered precisely and reliably onto the rail and the clamping jaws are pressed against the side surface when the gripper arms are closed in the intended installation. brought to the rail. Since the rail tongs must absorb considerable forces to z. B. to hold a gantry crane against a wind load, the guide plate is attached according to an advantageous embodiment of a guide block. The guide block is firmly connected to the pliers assembly, so that the guide and pliers assembly are always aligned with each other. In addition, occurring forces can be better absorbed in this way. In a further preferred embodiment extends in the housing a cross member parallel to the rail on which the two guides are held. The two guides can be raised and lowered by a single guide drive, but preferably each guide is equipped with a guide drive, the guide drives then being appropriately synchronized.

According to an improved embodiment of the invention, the rail tongs on a centering device, which ensures that the rail tongs in the raised state is always aligned in a central or zero position. The centering device is advantageously designed as a rod or plate or sheet metal and preferably extends horizontally between the long lever arms of the rail clamp, it may also be arranged in front of or behind the lever arms. The centering device is preferably stationary, d. h., It is not mobile, especially not vertically movable. The centering device is in contact with raised surfaces, ie open rail tongs. The contact surfaces can be formed separately, z. B. on the lever arms. But it can also be existing device elements of the rail bar, z. As rods or tubes that fix the rail clamp on the housing or other components serve as a contact surface. The contact surfaces are preferably formed obliquely or rounded and cooperate with adjusting surfaces of the centering device, which are advantageously formed at the side edges. The side edges of the centering device are preferably bevelled or rounded, so that adjustment surfaces are created, which cooperate with the contact surfaces of the rail pliers. According to a preferred embodiment, the centering device is designed as a trapezoidal plate whose shorter longitudinal edge is arranged below. The adjusting surfaces thus run inclined from outside to inside.

The centering device acts when lifting the rail tongs. The lifting abutment surfaces engage the alignment surfaces after the jaws are free of the rail, so at least open, preferably raised above the rail. The Justierflächen the stationary arranged centering align the movable rail pliers symmetrically, so that the rail clamp in the open position, based on the optimally aligned rail, always assumes a defined middle or zero position. In this way, the rail clamp holds in front of everyone

Closing process the lateral tolerance of the position of the rail. When the rail tongs are lowered and closed, the adjustment and contact surfaces release immediately and the rail tongs are also movable laterally so that the guide adapts to the position of the rail when lowered.

The rail pliers according to the invention is based on the finding that the guide does not have to follow every movement of the rail pliers by direct contact of guide rollers on a rail in order to ensure the correct engagement of the clamping jaws on the rail. The vertically movable rail clamp is low-wear and simple in construction; It avoids the wear-prone rollers that roll permanently on the rail by using a simply designed, vertically movable guide that works reliably and without interference.

The inventive method for aligning a rail tongs, which has a tongs arrangement and a guide with guide drive, provides the steps of

Lowering the guide with a predetermined rate of descent until reaching a predetermined end position, the

Aligning the guide relative to the rail by picking up the rail in the receptacle

Lowering the pliers assembly, and the

Closing the pliers assembly to the system of jaws on the rail after the guide has reached the predetermined end position. The lowering of the guide and the lowering of the tong assembly is preferably carried out simultaneously. According to an advantageous embodiment, the rail pliers according to the invention sinks by their own weight, but they can also be lowered by the guide drive. Guide and pliers assembly are lowered simultaneously. The Pliers assembly is open when lowered over the rail. It is further open than the entrance of the recess.

During the lowering, the rail or the rail head is received in the recess, wherein an alignment of the rail pliers takes place in that the rail tongs possibly performs a lateral movement, because the stationary rail forces an alignment of the recess of the rail transversely movable rail tongs. The lowering of the guide takes place up to a predetermined end position, typically the resting of the guide on top of the rail. It is preferred if the resting of the guide on the rail, so the contact with the rail brings the lowering to a standstill. A lowering over a predetermined distance is also possible, but is unfavorable because the rail can not only be laterally displaced on the ground but also may have a different height. Reaching a predetermined end position is preferably signaled by a stop. The stop can advantageously be arranged on the bottom of the recess. If the stop comes into contact with the rail, the downward movement of the guide stops. After reaching the lower end position of the guide and pliers arrangement are the ends of the gripping arms on which the jaws are arranged, at the level of the side surface of the rail. The pliers drive is set after reaching the lower end position in operation to press apart the free ends of the lever arms, so that the free ends of the gripping arms which carry the jaws are moved in opposite directions against the side surfaces of the rail until the jaws firmly on the Rail or rest on their side surfaces.

According to an advantageous embodiment of the method, the method described above is carried out after previously stopping the object, typical z. B. a gantry crane, has occurred. Shutting down the rail pliers or, in advance, stopping the object to be secured in each case is an expedient prerequisite for aligning the rail pliers.

According to a further advantageous embodiment of the invention, the guide is arranged before lowering above the rail. Although the method according to the invention can Ren also be executed when the guide and rail partially overlap and the rail tongs so only slightly raised. However, there is then the risk that the guide, in particular the side flanks of the recess, nevertheless strike against the rail in the case of lateral movements of the object to be secured. It is therefore particularly preferred if the rail pliers is raised altogether until it is arranged completely above the rail in the open position.

A rail pliers according to the invention allows the passage of transitions, in which z. B. road surfaces close to close to the rails, because-unlike in known designs, the lever of the rail clamp during the process are just not arranged next to the rail head. The rail clamps can therefore be designed without restriction to the technical requirements of each component or tool to be secured, without the free space next to the rail head is taken into account.

Details of the invention are explained in more detail below with reference to an embodiment. Show it:

1 shows a cross section through a rail pliers in the opened state,

Fig. 2 is a longitudinal section through a rail tongs with two guides parallel to a rail

Fig. 3 is a cross-section of an open rail tongs over a rail with offset

Fig. 4 is a cross-section of an open rail tongs upon contact with the rail

Fig. 5 is a cross section of an open rail tongs in the lowered state

Fig. 6 is a cross section of a closed rail tongs

Fig. 7a rail pliers with centering in the lowered position

Fig. 7b rail pliers according to Fig. 7a during the lifting process

Fig. 7c rail pliers according to Fig. 7a raised and centered.

Fig. 1 and Fig. 2 show a rail clamp 2 with a clamp assembly 4 and a guide 6. The rail clamp 2 is designed for setting a gantry crane, which runs on rails. The rail clamp 2 is fastened to the foot of a gantry crane, preferably a rail clamp 2 is fastened to each foot of a gantry crane. A rail 8 is indicated under the rail clamp 2. The rail clamp 2 is made of metal.

The forceps assembly 4 has two levers 10 a and 10 b, which are connected via a hinge assembly 12. The hinge assembly 12 is constructed of a bridge 14 and two hinges 16a, 16b. A lever 10a has a first, short end, the articulated arm 18a extending from the hinge 16a to the jaw 20a. The jaw 20a is arranged in a cassette 22a, which is particularly easy to assemble or change. Thereby, a rail clamp 2 can be adapted to the side surfaces of different rails and worn jaws 18 can be easily changed. The lever 10a has a second, long end, the lever arm 24a, which extends from the hinge 16a to its free end 26a. The lever 10b has the same configuration. The levers 10a, 10b cooperate against the same, since the free ends 26a, 26b are connected to a pliers drive, which is not shown here. A typical pliers drive is designed, for example, as a hydraulic or pneumatic drive, in which a piston-cylinder arrangement is arranged between the two free ends 26a, 26b or as a spring drive, which is tensioned by a hydraulic or pneumatic drive, possibly with interposition a toggle lever arrangement. Fig. 1 shows a rail clamp 2 in the open state above the rail 8. The mutually inclined free ends 26a, 26b also indicate the open state of the gripper arms 18a, 18b and the attached jaws 20a, 20b. When open, the distance between a clamping jaw and the rail is about 5 mm.

Fig. 2 shows in longitudinal section parallel to the rail, a guide 6 according to the invention, which consists of a guide block 30, the guide plates 32a, 32b holds at its lower edge on both sides of the rail 8 guide rollers 34a and 34b wear, in the running direction of the rail. 8 before and behind the gripping arms 18, each below the guide block 30 are arranged. The guide block 30 is seen in the direction of the rail - connected at its front and its rear end respectively with a hydraulic guide drive 36, a piston-cylinder arrangement 36a, 36b. The piston-cylinder arrangement 36 a, 36 b is fixed to the housing and supported on a cross member 38. In this way For example, a piston-and-cylinder arrangement 36a or 36b may be centrally located above the rails and the guide 6, which is to be lowered or raised on either side of the rail 8, operated smoothly and without tilting. The guide drive 36 is supplied by the hydraulic system, which is already provided for the forceps drive 4. By the guide drive 36, the guide 6 is raised or possibly lowered. In the concrete embodiment of Fig. 2, however, the rail tongs 2 sinks by its own weight when the rail tongs to secure the stationary gantry crane. Together with the guide 6 connected to the guide 6 by screwing pliers assembly 4 is raised or lowered.

Figures 3 to 5 show essential details of the rail tongs according to the invention in the transition from the upper, open position (Figure 3, 4) to the lower, closed position (Figure 5). Fig. 3 shows a fully open rail clamp 2, in which the guide 6 and the pliers assembly 4 are arranged above the rail 8. The gantry crane can be moved back and forth on the rail 8 without the rail tongs provided for securing the gantry crane at standstill coming into contact with the rail. The cross-section shows a guide 6 with a receptacle, here formed as a guide plate 32a, which is fixed to the guide block 30a. The guide plate 32a has at its lower edge a recess 40 which may be described approximately as a downwardly open "U." The recess has a base 42 which faces an entrance (the open side of the "U") and two side flanks 44, which extend down towards the rail 8. At the ends of the side edges 44 each guide rollers 34a are mounted. The recess 40 is designed so large that it can accommodate the rail 8 and its rail head. At the base 42 of the recess 40, a stop 46 is mounted, the placement of which stops on the upper side 48 of the rail 8 (see Fig. 5) the lowering of the guide 6 stops. The guide 6 then rests on the top of the rail. 8

FIG. 3 further shows that the guide 6 is not centered above the rail 8, and accordingly the pliers arrangement 4 is not centered on the rail 8. The offset "X" is indicated in Figures 3, 4. In the present embodiment, it can be a maximum of 20 mm When the guide 6 is lowered, first the guide rollers 34a come into contact with the top 48 of the rail 8 and roll up this Top 48 off. The guide rollers 34a, as shown in Fig. 4, roll toward the nearest side surface 50 of the rail 8. Rolling of the guide in the right direction is assisted by the weight of the rail clamp but also by the often rounded top 48 of the rail 8 This embodiment of the invention proves to be particularly useful when the radius of a guide roller is equal to or greater than the offset.

The guide rollers 34a roll down the side surfaces 50 of the rail 8 so that the rail 8 is received centrally in the recess 40 through the entrance of the recess 40. 5 shows that the offset "X" has given way to a centric alignment The axes of the rail 8 and the recess 40 lie in a plane, Fig. 5 shows no offset Side surfaces 50 of the rail 8 opposite. Thus, the guide 6 centers the rail pliers 2, in particular the pliers assembly 4 on the rail eighth

The embodiment of the rail clamp 2 shown in FIGS. 3 to 5 shows a guide 6, in which the recess 40 and the guide rollers 34 abut against the side surfaces 50 of the rail 8. The clearance between the guide rollers and the side surfaces 50 is minimal. It is - depending on the shape and size of the rail and the object that is to be secured by the rail pliers - but also possible that the guide rollers 34 in the closed lower position of the rail pliers game, that is usually that the recess 40 is greater than the rail or the rail head, which is to be received in the recess. In such an alternative embodiment of the guide 6, it is expedient if the gripper arms with the jaws optionally attached thereto in the upper, open position at least the same, preferably a greater distance from each other than the side edges 44 of the recess 40th

The pliers arrangement 4 with the clamping jaws 20a, 20b is - as can be seen in FIG. 2 - arranged slightly above the recess 40 or the guide rollers 34. If the lower position on the upper side of the rail 8 is reached by lowering the rail clamp 2 due to its own weight, the guide 6 lies with the side edges 46 on both sides of the rail against the side surfaces 50 and the clamping jaws 20 are also opposite the side surfaces 50 of the rail 8 in an optimal position. If the guide 6 has reached the lower end position, the forceps drive starts and closes the gripping arms until the clamping jaws 20a, 20b bear against the side surfaces of the rail 8, as shown in FIG.

The opening of the rail tongs takes place in reverse order; First, the forceps drive opens the jaws 20a, 20b by contracting the levers until a predetermined distance of the jaws 20a, 20b from the side surfaces 50 of the rail 8 is reached. Then, the guide drive 36 starts and raises the tong assembly 4 and the guide 6. It is advantageous that the guide 6 does not have to be opened, it can be easily lifted. The stroke of the guide drive 36 is preferably dimensioned such that the guide and the pliers arrangement are raised to a height completely above the rail 8. The stroke of the guide drive 36 depends essentially on the dimensions of the rail 8, of the elements used for fastening the rail and possibly provided crossings on the rails and can be from a few millimeters to a few centimeters, z. B. 10 cm, typically 50 mm.

The guide 6 also works with a receptacle without guide rollers, in particular when the side flanks 44 are widened toward the lower edge of the guide plate 42, in particular rounded. The expansion or rounding should preferably be at least equal to or greater than the offset. However, the embodiment with guide rollers 34 is still low-wear. The splint 2 is preferably designed so that in an emergency, z. B. in case of failure of the power supply, is automatically transferred to the lower, closed position. It is therefore advantageous if a rapid lowering of the guide 6 is guaranteed up to the top of the rail 8. The closing of the pliers assembly 4, however, takes place more slowly to ensure that the pliers assembly can be pressed smoothly and safely to the side surfaces 50 of the rail 8 only after centering by the guide 6. In a hydraulic drive, this can be achieved in a particularly simple manner by hydraulic lines with different cross sections. The insertion and adjustment of throttle valves in a hydraulic circuit is known in the art.

Further, it is preferred that when opening the rail clamp 2, first, the gun assembly 4 is opened and then only the guide 6 is raised, so that the gun assembly 2 is not damaged by premature lifting.

7a-7c show a pliers assembly 4 with centering device 52. The centering device 52 is designed as a sheet steel, which is fixed in a fixed position independently of the rail clamp 2, z. B. on a housing in which the rail clamp 2 is arranged. The centering device 52 is disposed between the two long lever arms 24a, 24b of the tong assembly 4; it is designed as a trapezoidal plate whose short longitudinal side 54 faces downward. The centering device 52 therefore has side edges which extend obliquely downwards relative to one another, and which are designated as adjusting surfaces 56a, 56b. As can be seen in Figure 7c, the adjusting surfaces 56a, 56b cooperate with abutment surfaces 58a, 58b, here the surface of support arms 60a, 60b, which are mounted in bearing bushes on the long lever arms 24a, 24b, and with which the rail pliers 2 in the lowered state on the cross member (see Fig. 1, Fig. 6) is supported. The support arms 60a, 60b are designed as tubes, resulting in rounded abutment surfaces 58a, 58b. This is advantageous, because thus tilting between the corresponding contact surfaces 58a, 58b and adjusting surfaces 56a, 56b is avoided when lifting the tong assembly 4.

Fig. 7a shows the pliers assembly 4 in the lowered state. The stationary centering device 52 is arranged clearly above the support arms with the abutment surfaces 58a, 58b. The rail clamp is moved laterally, so it is lowered on a non-centrally located rail.

Fig. 7b shows the tong assembly 4 during lifting. First, the lower end of the adjusting surface 56a comes into contact with the abutment surface 58a. The gripper assembly 4 is laterally movable, while the centering device 52 is stationary. Upon further lifting, therefore, the pliers arrangement 4 is aligned symmetrically with respect to the centering device 52 in that the abutment surfaces 58a, 58b align themselves uniformly by means of a horizontal or lateral compensating movement on the adjusting surfaces 56a, 56b. Fig. 7c shows a tong assembly 4 in raised and centered orientation. It will be clear that the centering device 52 is aligned symmetrically between the abutment surfaces 58a, 58b of the long lever arms 24a, 24b as a result of a lateral compensation movement. In this way, the forceps assembly 4 of the rail clamp 2 is aligned symmetrically before each new closing operation. It is avoided that the lateral displacement caused by the tolerance of z. B. 25 mm, added at successive opening and closing operations. The rail clamp 2 is brought back into a central or zero position by means of the centering device after each opening operation.

Claims

claims

Rail pliers, comprising a pliers arrangement (4) with two levers (10a, 10b) connected via a joint arrangement (12), the first ends of which are designed as counteracting gripping arms (18a, 18b) each with a clamping jaw (18) and their second ends as Lever arms (24a, 24b) are formed, wherein the lever arms (10a, 10b) are actuated by a tong drive, and with a guide (6) for aligning the jaws (18), characterized in that the rail tongs (2) a guide drive ( 36) which vertically moves the guide (6) and the tong assembly (4).

Rail pliers according to claim 1, characterized in that the guide (6) has a receptacle (40) for a rail (8).

Rail pliers according to claim 1 or 2, characterized in that the receptacle as a recess (40) for receiving a rail (8) is formed, wherein the recess (40) has flanks (44) facing the rail (8).

Rail pliers according to at least one of claims 1 to 3, characterized in that the flanks (44) of the recess (40) extending from the bottom (42) of the recess (40) to the lower edge of the clamping jaw (18).

Rail pliers according to at least one of claims 1 to 4, characterized in that a guide roller (34a, 34b) on the receptacle (40) is provided.

Rail pliers according to claim 1 to 5, characterized in that the radius of the guide roller (34a, 34b) is equal to or greater than an offset of the rail (8).

7. rail pliers according to at least one of claims 1 to 6, characterized in that the recess (40), relative to the rail, a game.

8. rail pliers according to at least one of claims 1 to 7, characterized in that the guide (6) has a stop (46).

9. rail pliers according to at least one of claims 1 to 8, characterized in that the guide drive (36) and the pliers drive is designed hydraulically, pneumatically or electrically or has a combination of these drives.

10. Rail pliers according to at least one of claims 1 to 9, characterized in that a centering device (52) is provided.

11. A method of aligning a rail tongs comprising a tong assembly (4) and a guide (6), comprising the steps

Lowering the guide (6) with a predetermined rate of descent until reaching a predetermined end position,

Aligning the guide (6) relative to the rail by picking up the rail in the receptacle

Lowering the tong assembly (4),

Closing the pliers arrangement (4) until the clamping jaws (18) rest against the rail (8) after the guide (6) has reached the predetermined end position.

12. The method according to claim 11, characterized in that the guide (6) is arranged before lowering above the rail.

13. The method according to at least one of claims 11 to 12, characterized in that the alignment of the rail tongs (2) takes place only after the stopping of a festzusetzenden object (2).

14. The method according to at least one of claims 11 to 13, characterized in that the rail tongs (2) is brought into a zero position before each closing of the tong assembly (4).