RAIL CLAMP HANDLING ARRANGEMENT

This invention relates to rail clamp handling arrangement, for moving a clamping element (300) from a position in which said element fastens a rail (800) to a railroad sleeper to a sleeper releasing position and vise-versa, comprising a support structure/housing (500) having a lower part (501) with a central rail fit member (503) and arranged to extend transversally in relation to the longitudinal extension of the rail (800), wherein at each outer end portion (504) of said lower part (501) there is arranged connection means that provide pivot points (401) at an intermediate point of a pivotable lever arm (400), said lever arms (400) being arranged mirror symmetrically, a power and transmission arrangement (2, 3, 6) arranged to simultaneously move an upper part (405) of said lever arms (400) via an upper pivotal connection (402), a lower part (406) of said lever arms (400) comprising contact devices (403) arranged to move a clamping element (300), wherein said power and transmission arrangement (2, 3, 6) includes a power unit in the form of an electric motor (2) and a rotatable threaded shaft (6) arranged to transfer torque applied via said power and transmission arrangement (2, 3 6) into pivotal movement of said lever arms (400).

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a rail clamp handling arrangement.

BACKGROUND

Several different embodiments of arrangements for bringing a clamping element fastened to a railroad sleeper and forming part of a clamping unit to a position in which it fastens said rail section to said sleeper are known in the art.

Example of conventional such arrangements are found in US-A 3,690,264, WO95/13427 and WO99/24669.

These arrangements include large structures carried by wheel equipped wagons intended to be moved along a rail track. As is evident such an arrangement is heavy, and it is therefore a need for lifting machines to move it onto and away from a rail track.

Also smaller arrangements is known for bringing a clamping element fastened to a railroad sleeper, but also these known arrangements are relatively heavy and will therefore need some kind of lifting aid for movement thereof.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a solution to the issues mentioned above by providing an improved rail clamp handling arrangement, as well as an improved method for handling clamps.

The object according to the invention is achieved by a rail clamp handling arrangement according to claim 1.

Thanks to the invention a rail clamp handling arrangement is provided that is substantially lighter than prior art machines, enabling a single person to carry the machine. Further, the invention in the basic principle may completely utilize mechanical drive, which provides an environmental advantage compared to prior art machines that conventionally use hydraulics.

Further beneficial aspects of the invention are apparent from the description and also from what is defined in the dependent claims.

DETAILED DESCRIPTION

The invention provides a rail clamp handling arrangement100of a lightweight kind that may be lifted and moved by one person, possibly without use of any lifting aid.

InFIGS.1and2there are shown schematic views of a rail clamp handling arrangement100according to the invention. There is shown a rail800that is attached to the ground in a traditional way by means of clamping elements300.

The rail clamp handling arrangement100comprises a support structure30,501,502, preferably covered by a housing500The support structure30,501,502includes a lower part501and an upper part502horizontally extending in a transvers direction in relation to the extension of the rail800. Further, the support structure includes a fixed support wall30(schematically shown inFIG.2) attached to the upper part502and horizontally extending in a transverse direction in relation to the upper part502. A motor2and a first part31of a transmission is attached to the support wall30. The first part31of the transmission has an output shaft32that drives a chain321(or belt, seeFIG.2).

The lower part501of the support structure extends symmetrically in the transversal direction in relation to the fixed support wall30and the longitudinal extension of the rail800, i.e. mirror symmetrically in relation to a central plane C. The lower part501of the support structure, at each outer end portion504is arranged with connection means (e.g. through holes provided with shafts) that provide pivot points401for first lever arms400, that are arranged mirror symmetrically. The pivot points401are arranged at an intermediate position of each first lever arm400. Further the lower part501of the support structure, at a position inside of the outer portion504is arranged with connection means (e.g. through holes provided with shafts) that provide pivot points402for second lever arms700, that are also arranged mirror symmetrically. The pivot points401are arranged at an intermediate position of each second lever arm700.

The power and transmission means2,3rotatably drives a threaded shaft6included in the invention. The threaded shaft6is rotated by means of a drive sleeve61, that has a fixed central position in relation to the support structure501,502, e.g. within the housing500, by means of bearings (not shown). The shaft6is positioned such that the driving sleeve61is at the centre of the extension of the drive shaft6. A substantial portion of each threaded shaft6will protrude on each side of an upper part of the housing500.

At each outer portion of the threaded shaft6there are positioned first displacing nuts600which also interfit with the threaded shaft6. The displacing nuts600are attached to one first lever arm400each, by means of an upper pivotal connection402arranged adjacent the upper end of an upper part405of each lever arm400.

At the other end of the first lever arm4, adjacent a lower end of a lower part406of the first lever arm400, there is arranged a contact member403for active contact with a clamping element300.

Further at intermediate positions, between the sleeve61and the first displacing nuts600, there are positioned second displacing nuts601which also interfit with the threaded shaft6. The second displacing nuts601are attached to an upper part705of each second lever arm700each, by means of an upper second pivotal connection702arranged adjacent the upper end of the upper part705of each second lever arm700.

At the other end of the second lever arm700, adjacent a lower end of a lower part706of the second lever arm700, there is arranged a contact member703for active contact with a clamping element300.

The threads of the threaded shaft6are arranged mirror symmetrically on each side of the driving sleeve61. Accordingly, the contact members403,703of the lever arms400,700will move towards or away from each other dependent on the direction of rotation of the shaft6. Thanks to having exactly the same configuration, but mirror symmetrically, the movement will be synchronized on both sides, i.e. moving the contact devices403,703outwards simultaneously or inwardly simultaneously.

Hence, when driving the transmission in a first direction the contact members403of the first lever arms400may be used to push clamps300into clamping action for a rail800, whereas when driving the transmission in a second direction the contact members703of the second lever arms700may be used to push clamps300into clamping action for a rail800, thanks to providing a sufficient distance between each pair of facing contact members403,703that enables the positioning of a clamp300in between. It is evident for the skilled person that merely one pair of lever arms400may suffice to both push clamps300into place and remove clamps300, respectively, by adjusting the position of the contact members403to a desired position (inside of or outside of the clamps300) prior to use.

By use of basically the same power and transmission means2,3for rotatably driving the threaded shaft6as is used for driving weld cutting jaws, as disclosed in PCT/SE2019/050523 the machine may be made substantially lighter than known machines. In the following the principle of using that power and transmission means2,3will be described in relation to schematically revised figures used in PCT/SE2019/050523, i.e. originally showing a weld cutting machine. InFIG.3there is shown a perspective view of such a weld cutting machine1and in and inFIG.4there is shown a perspective view of an outgoing part32of a preferred transmission mechanism3.

It is to be noted that in a preferred embodiment according to the invention, seeFIG.7, there is merely needed one threaded shaft6, i.e. not two shafts as shown inFIGS.4,5and6. It is evident that the skilled person will have no problem in understanding that a single shaft6may preferably be positioned centrally, i.e. below the central dented wheel320(shown inFIG.4) and that then there will merely be needed one central dented wheel320.

However, it is not excluded that two parallel shafts6may be of use in an alternate embodiment, i.e. having two parallel shafts6assisting in driving each lever arm400.

A relatively small high-speed electric motor2operates the transmission mechanism3adapted for the purpose of providing a desired transmission.

The transmission mechanism3comprises, two parts. On the one hand, a planetary gear31(preferably including an arrangement, shown inFIGS.5and6) driven by the output shaft312of the motor2and a chain/wheel mechanism32(seeFIG.2) driven by the output342from the planetary gear31.

The drive shaft/s6extend along the same longitudinal direction as the motor2and as shown inFIGS.1and2in both directions away from the driving sleeve61.

The driving sleeve61may be rotation wise fixed onto the shaft6by means of form fitting, e.g. splines. However, it is evident for the skilled person that the driving sleeve61may be fixed to the shaft6in various manners, e.g. by means of welding, fixation screws, etc. Further, it is evident for the skilled person that the shaft6will have to protrude the same distance on both sides of the driving sleeve61in accordance with actual invention, wherein the direction of the threads on each side of the driving sleeve61are opposite to each other. As a consequence, upon rotation of the drive shaft6, the lever arms400will move in the desired directions either increasing or decreasing the distance between the contact members403, depending on the rotational direction.

The support structure/housing500may include a separate housing30,35,37of the transmission mechanism3, similarly as shown inFIG.1. Inside, that housing or a common housing500, there is a chain/wheel mechanism32, which in the preferred embodiment will merely drive one drive sleeve61(seeFIG.7), i.e. to transfer torque from the chain/wheel mechanism32to the drive shaft6.

The output shaft312from the planetary gear31may preferably have a fixed position within the support structure. There may preferably be arranged a transversal wall30providing support for bearings/parts of the transmission mechanism3, e.g. a first supporting structure301for the motor2that is attached to an inner side of the transversal wall30. Further there may be a second supporting structures302, providing support for the drive member61of the drive shaft6.

The output342of the planetary gear31drives a shaft having one central chain wheel320fixed thereto that drives the chain321that drives the chain wheel610attached to the driving sleeve61. (Alternatively, if two shafts6, one chain321A drives an output chain wheel610at one side of the housing, and another chain321B symmetrically positioned drives another chain wheel630at the opposite side of the upper part of the housing). The chain/wheel mechanism32thereby may transfers an output rotating torque to the (torque transmitting) drive sleeve61connected the shaft6, which thereby moves the lever arms400,700synchronously.

InFIGS.5and6the design of the planetary gear31is shown in more detail. The motor2and the planetary gear31are attached to opposite sides of the fixed support wall30, i.e. the planetary gear31is attached to a first side of the support wall30, whereas the motor2is attached to the second side of the support wall30. Hence the output shaft312of the motor2passes through the support wall30through central passages313of the shaft with the central chain wheel320.

At the outer end of the motor output shaft312there are dents forming a sun wheel314that mesh with dents353at the inner side of planet wheels351of the planet assembly350. The planet assembly350includes three circular planet wheels351symmetrically attached to a planet carrier352, having a central collar354providing support/bearing (not shown). Hence, the planet carrier352may rotate together with the planet wheels351. The planet wheels351at their outer sides mesh with dents of a fixed ring wheel (not shown) and also with dents341of a rotatable ring wheel340. The rotatable ring wheel340is non rotatably attached via dents342at its inner periphery to a shaft (not shown) carrying the two central chain wheels320and thereby drives the chain/wheel mechanism32. In the preferred embodiment the planetary gear is a harmonic gear, i.e. the rotatable ring wheel340and the fixed ring wheel have different amounts of dents, e.g. 51 and 48 respectively, which provides for a drastic reduction of the rotational speed from the motor shaft312to the rotate able sun wheel340.

In an exemplary embodiment the number of dents314of the motor shaft312is 6 and each planet (3 pcs) has 22 dents. In combination with a ring wheel (first outer ring) that is fixed having 48 dents and a rotatable ring wheel (second outer ring) having 51 dents there will be achieved a gear ratio of 1:153, i.e. when the sun wheel has made 9 turns, each planet has made one turn (360 degrees) and thereby have driven the rotate able outer ring 1/17 of a turn.

Thanks to the transmission mechanism3and its combination of the (preferably harmonic kind) planetary gear31and the chain/wheel mechanism32, an extra reliable and compact torque transfer/rotational motion may be provided to the drive shaft/s6.

The use of an electric motor2may further provide the advantage that an adaptive torque/speed is automatically created to the drive shaft6, in that the higher the resistance the lower the transmitted speed to the drive rods6, i.e. when the resistance increases the rotational speed is reduced and the torque of the motor2increases and thus the force that effect the moving lever arms400,700. Preferably an out board electric motor2is used that may provide a larger torque than traditional motors.

FIG.2indicates that there is a kind of support structure that fixates basics parts of machine100, e.g. the electric motor2, the fixed wall30of the chain/wheel gearing32, the planetary gearing31and other parts that need to be fixated. Moreover, there may be a housing500that have grips/handles (not shown) attached thereto for ease of carrying and lifting the machine.

In operation of the machine is transported to a desired rail part, having clamping members300that are to be handled. The transportation may easily be performed by carrying the machine by hand. A protective plate may be arranged at the bottom of the gear wheel housing30,35,37, or the larger housing500, in order to enable the machine to be put down also on uneven ground without risk of causing damages. The machine is then lifted on to the rail800having the clamping members300that is to be handled. The rail800will fit into a rail fit recess503of the machine100, which has the form of an inverted U.

A batterie, (not shown), which may be carried separately, is positioned in a batterie holder34, seeFIG.3, preferably positioned on top (not shown) of the housing500. The batterie provides power to the electric motor2and also a control unit33, e.g. attached to upper side of the housing500.

Now the machine1is ready to be operated. First it is operated to position the contact members403,703at a desired position in relation to the clamping member that are to be handled, e.g. to be pushed in as shown inFIG.1. Once the machine is started the electric motor2starts spinning where by the rotation will be transmitted first to the planetary gearing31and then to the chain/wheel gear32to rotate the drive shaft6in a first direction, whereby the lever arms400,700will start moving towards each other and start pushing the clamping elements300against each other to securely clamp the rail800.

To remove clamps300from the rail800the machine is operated in a similar manner, but starting with the lever arms400,700in an inner position to have the contact devices703of the second lever arms700to to be inside of and in level with the clamping members300. Thereafter the machine100is started and rotated in a second direction.

Preferably a harmonic planetary gear is used that provides a gear ratio of at least 1:100 and an electric motor2rotating with at least 3000 rpm, preferably about 4000-6000 rpm. The invention is not limited to the examples described above. For instance, it is foreseen that various transmission gears may be used to achieve the desires function, e.g. a worm wheel gear, or traditional dented wheels.