Patent Grant
10132044
The present invention is related to rail clip assemblies for fastening and securing a rail, such as a rail for travelling cranes, to a rail support, such as a flanged girder.
Rail clip assemblies of the above kind can roughly be divided in two basic types. A first type, which e.g. is known from EP 0272874 and WO 2009/013239, has two superposable bodies with a lower body fixed to a rail support and an upper body which overlies a portion of the rail foot on the one hand and overlies the lower body on the other. In this type of rail clip, the fixing of the lower body to the rail support and the fastening of the upper body on the lower body is distinctly made by independent fastening means. In the majority of cases, the lower body is welded to the rail support (made of steel), whereas the upper body is secured to the lower body by one or more bolts. A second basic type, which e.g. is known from GB 1599873 and EP 0258049, also has two superposable bodies, but both the upper and lower body are fixed to the rail support through a same fastener, typically a bolt or a stud. The first basic type is used for securing rails for heavier travelling machinery, such as gantry cranes in ports. Due to its more compact nature, the second basic type is more economical and finds application for securing rails for lightweight travelling machinery, such as overhead travelling cranes in small warehouses.
Both types of rail clip assemblies secure the rail based on a very simple principle. They aim at allowing enough freedom of vertical and rotational movement of the rail so that it can adjust to the wheels of the crane and avoid local constraints while maintaining the rail firmly in place with regard to lateral movement; hence the name “soft mounting”. Other solutions that keep the rail too rigidly are prone to failure as significant forces are passed directly through these bindings, hence resulting in a loosening of joints, breaking of welds and bolts, etc. The soft mounting is obtained by ensuring that the rail clips lock the lateral movement of the rail while still allowing a limited vertical movement. This attenuated vertical clamping is obtained by providing the body part overlying the rail foot with a resiliently compressible member on its downward facing surface to provide resilient vertical clamping to the rail foot. The rail clips further engage in hard abutment against a lateral face of the rail flange. No resilience is provided for the lateral abutment, such that lateral motion of the rail is completely suppressed.
Upon fastening the rail clip, the resilient member is compressed between the overlying body part and the rail foot, and the overlying body part experiences a reaction force due to the compression which tends to back the body overlying the rail foot away from the rail. This backward movement is prevented in the rail clip assemblies of the first basic type by the lower body, which is already fixed to the rail support when the upper body is fastened and therefore the lower body backs up the upper body. However, such a fixed backing is missing in the rail clip assemblies of the second basic type. In the latter type of assemblies, both upper and lower bodies are secured to the rail support simultaneously through fastening with a same fastener, and, if no precautions are taken on fastening, the rail clip will end up being fastened without lateral contact with the rail foot. Therefore, when fastening rail clips of the second basic type, it is current practice to fasten the rail clip in two stages. In a first stage, the fastener (e.g. a nut and bolt) of the rail clip assembly is slightly fastened, such as by hand or a hand driven tool (wrench). As a reaction to the resilient member being squeezed between the rail foot and the overlying body part, the latter body part backs away from the rail foot, thereby losing contact with the lateral face of the rail foot. To bring the body back into abutment against the lateral face of the rail foot, the back of the body is then struck with a hammer. Thereafter, the fastener is fastened tightly, e.g. with a wrench. The above hammer strike ensures that the rail clip is brought laterally against the rail foot which ensures tight lateral fixation of the rail.
In addition, rail clips of the above kind may not be fastened with impact wrenches, but only with calibrated torque wrenches. In the latter ones, the torque is built up gradually by the wrench. This is not the case with impact wrenches, where the torque is delivered suddenly, causing a severe impact (hence the name impact wrench). Using an impact wrench would cause a random movement of the clip body parts, even after the hammer strike. However, the use of calibrated torque wrenches is time consuming.
It will be evident that a proper fixation of rail clip assemblies of the second basic type depends on the skill of the operator with deleterious effects when the rail clip is not properly mounted. Furthermore, the hammer strike is an additional mounting step which increases installation time, as does the required use of calibrated torque wrenches.
It is an object of the present invention to overcome the above mentioned problems in rail clip assemblies of the second basic type.
According to the present invention, there is therefore provided a rail clip assembly as set out in the appended claims. Rail clip assemblies according to the invention comprise superposable first and second bodies arranged for being removably fastened to a rail support by a connector. The first body comprises an abutment surface adapted for abutment with a lateral face of a foot of a rail. Either one of the first and second bodies comprises a projecting member and a resilient member. The projecting member is arranged for projecting from the abutment surface, for overlying the foot of the rail. The resilient member is attached to a downwards facing surface of the projecting member and is adapted to be interposed between the rail foot and the projecting member for providing resilient clamping of the foot of the rail. The first and second bodies comprise corresponding apertures for receiving the connector. One of the apertures is oblong with a longer axis extending in a direction oblique to the abutment surface, to enable the first body to assume different positions relative to the second body. The first and second bodies comprise first corresponding surfaces configured for providing force transmitting contact between the first and second bodies when assembled.
According to an aspect of the invention, the first and second bodies comprise second corresponding surfaces configured to enter into force transmitting engagement with each other upon fastening the assembly. The second surfaces are oriented in a direction of extent of the oblong aperture, and have an inclination at an angle between 20° and 85° relative to the horizontal when considered in a (vertical) plane perpendicular to the longer axis. The latter angle of inclination can be 30° or more and/or can be 80° or less, possibly 70° or less.
According to a further aspect, the first surfaces extend horizontally or inclined at an angle smaller than 20° relative to the horizontal when considered in the same place. The latter angle of inclination can be 15° or less, possibly 10° or less and/or can be larger than 0°, possibly larger than 1°, possibly larger than 2°.
With the above arrangement, it is advantageously obtained that the engagement of the second surfaces with each other produces a net resulting force on the first body oriented towards the rail and resisting backing movement of the first body away from the lateral face of the rail foot upon fastening the connector. It has been proven that rail clips according to the invention can correctly be installed by use of impact wrenches and without any further intervention, such as a hammer strike or the like. Rail clip assemblies according to the invention therefore can be installed in a correct position with greater ease and in less time compared to the prior art.
Additional advantageous aspects are set out in the dependent claims.
Aspects of the invention will now be described in more detail with reference to the appended drawings, in which same reference numerals indicate same features and wherein:
The second portion of the first body is formed as a member 13 projecting from the abutment surface 121. A resiliently compressible member 14 (shown in broken lines on
The function of the rail clip 1 is hence to rigidly clamp the rail in a lateral direction, through the abutment surface 121, while providing some resiliency in vertical direction, through the resiliently compressible member 14. It will be convenient to note that a resiliently compressible pad can additionally be provided underneath the rail, as is known in the art. It will also be clear that the abutment surface 121 is in direct force transmitting contact with the lateral face of the rail foot.
The first body 10 comprises an aperture 122 located in the first portion 12. The aperture 122 is a through hole extending from the lower surface 120 to an upper surface 123 of the first portion 12 and is sized for accepting a possibly threaded fastener 9, which can be formed of a bolt 90 or stud and nut 91 (shown in broken lines on
In case the fastener 9 is a bolt, the head of the bolt will be in force transmitting contact with the support, e.g. flanged girder, on which the rail clip 1 is fastened. In case it is a stud, the stud will be secured to the support. In any case, it will be convenient to note that rail clip assemblies according to the present invention relate to the second basic type as indicated above, wherein the fastener for fastening the first and second bodies to each other also functions as fastener for fastening the assembly to the support.
The aperture 122 of the first body is oblong with a longer axis 150 extending in a direction oblique to the abutment surface 121 and hence oblique to a longitudinal direction of the rail. Suitable values of the angle between the longer axis 150 and the abutment surface 121 are between 20° and 50°, and advantageously not larger than 45°. The aperture 112 of the second body 11 is adapted to the shape of the fastener 90, and is typically circular (cylindrical), possibly of a size to fit the size of the corresponding portion of the fastener 90. The apertures 122 and 112 are arranged to cooperate to enable the first body 10 to assume different positions relative to the second body 11, along the direction of the longer axis 150.
The upper surface 123 of the first body 10 advantageously surrounds the oblong aperture 122, whereas the lower surface 111 of the second body 11 advantageously surrounds the circular aperture 112. When assembled, these surfaces 123 and 111 are in force transmitting contact, such that the tension of the fastener 9 is transmitted to the second body 11 and through the contacting surfaces 123 and 111 to the first body 10.
Advantageously, the upper surface 123 of the first body 10 is inclined relative to the horizontal in the direction of the longer axis 150. In this case, the lower surface 111 of the second body 11 is complementarily inclined. It will be convenient to note that along a section plane through the longer axis 150, both the second portion 12 of the first body 10 and the second body 11 are wedge shaped to obtain that the lower surface 120 of the first body 10 and the upper surface 110 of the second body 11 remain horizontal for all relative positions between the first and second bodies, thus preventing bending of the fastener 9. The inclination of surface 123 is such that the wedge shape of the second portion 12 of the first body 10 increases in thickness in the direction of the longer axis 150 towards the rail, e.g. the wedge shape increases in thickness from the lateral face 126 towards the opposite lateral face 127 of the first body 10. It will be evident that the second body 11 is complementarily wedge shaped to decrease in thickness in the direction of the longer axis 150 towards the rail. With such shaping of the bodies, if the rail tends to move laterally towards the body 10, the body 10 will tend to move in the direction of extent of oblong aperture 122 and in a direction of increase of thickness of the body 10, in the region of the fastener 9. This has the effect of increasing the tension in the fastener 9 and therefore increasing the frictional forces between the first body 10, the second body 11 and the rail support to resist further lateral movement of the rail. Suitable values of the angle of inclination of the upper surface 123 of the first body 10 relative to the horizontal in the direction of the longer axis 150 fall between 1° and 20°, advantageously 15° or less, advantageously 10° or less, advantageously at least 2°, advantageously between 4° and 7°.
In a direction 151 perpendicular to the longer axis 150 (i.e. in a section along a plane perpendicular to the longer axis 150), the upper surface 123 of the first body can be horizontal. Alternatively, the upper surface 123 can be inclined in the direction of axis 151, in addition to the inclination in the direction of the axis 150 described above. The latter inclination is advantageously at an angle γ (
According to an aspect of the invention, the first body 10 comprises a second upper surface 124, advantageously arranged at an edge of the upper surface 123, and advantageously arranged between the oblong aperture 122 and the projecting member (second portion) 13 and/or abutment surface 121. The second upper surface 124 extends along a direction of extent of the oblong aperture 122 and has a slope relative to the horizontal which is oriented in the same direction as, but differs from the inclination of the upper surface 123 when considered in the direction 151 perpendicular to the longer axis 150. The second upper surface 124 is sloped such that the first body 10 (second portion 12) increases in thickness in the direction of approach of the rail, such as along axis 151, i.e. in the direction of approach of the abutment surface 121. In use, the second surface 124 forms a bearing surface for a second lower surface 114 of the second body 11, which is advantageously shaped complementarily to the second surface 124 of the first body 10.
Each of the second surfaces 124 and 114 are advantageously contiguous to the first surface 123 and 111 of the respective first and second bodies, i.e. respective first and second surfaces share a common edge.
The second surfaces 124 and 114 are inclined relative to the horizontal, advantageously at an angle β between 20° and 85°. The angle β is advantageously at least 30°, and advantageously 80° or less, advantageously 70° or less, measured in a plane perpendicular to axis 150. Suitable values for β fall between 40° and 50°. Although surfaces 124 and 114 are advantageously planar as depicted in the example of
The width of the second surfaces 124, 114 (i.e. the extension of the second surfaces as measured in a plane perpendicular to axis 150) is not particularly limited, but is advantageously at least 4 mm, advantageously at least 5 mm.
It will be convenient to note that in the example of
With the above disposition, it is obtained that, at the onset of assembling the rail clip 1 with fastener 9, the second surface 114 of the second body 11 promptly enters in a force transmitting engagement with the second surface 124 of the first body 10 to resist any backing movement of the first body 10 due to the compression of the resilient member 14 when the fastener 9 is fastened.
The obtained effect as best understood will now be described with reference to
It will therefore be appreciated that the effects introduced by the second surfaces 124 and 114 come into play at the onset, i.e. at the very beginning, of fastening the rail clip 1, since it is at this instant of time that there is insufficient tension in the fastener 9 to provide sufficient friction between the lower surface 120 and the rail support, and likewise between the upper surface 123 of the first body and the lower surface 111 of the second body to compensate for backing movement and possibly rotation.
It will be convenient to note that once the second surfaces 124 and 114 enter into force transmitting contact, i.e. at the onset of fastening the assembly, advantageously no (substantial) relative displacement occurs between the two second surfaces.
The angle α of FR to the horizontal falls advantageously between 20° and 85°, and is advantageously at least 30° and advantageously at most 70°. It will be convenient to note that FR refers to the total net force resulting from the interaction of the second body 11 on the first body 10. At the onset of fastening the fastener, the net resulting force will be almost entirely caused by the engagement between the second surfaces 124 and 114.
In order to obtain a net resulting force directed towards the rail, the engaging parts of second surfaces 114, 124 and possibly of first surfaces 111, 123 are advantageously asymmetrically shaped relative to the axis 150. It will be convenient to note that a configuration as in FIGS. 7-9 of GB 1599873 has a symmetrical arrangement of surfaces 11a, 11b and 12a, 12b, which tend to centre the first and second bodies on the axis of the oblong aperture. Any resulting force on the first body is therefore oriented towards the centre of the aperture and not towards the rail.
It will be convenient to note that the second surfaces 124 and 114 provide a force resisting backing movement and possibly rotation of the first body when the fastener is not yet tensioned, or at the onset of tensioning. When the clip is assembled, with the fastener 9 under operational tension, the force resulting from the inclination of the surfaces 123 and 111 along axis 151 becomes more pronounced and takes over. Even though the latter inclination is less pronounced, a large resulting force is obtained due to a much larger area of contact between surfaces 123 and 111 as compared to the area of contact between the second surfaces 124 and 114.
The effect of resisting backing movement can be enhanced when the circular aperture 112 of the second body 11 advantageously has a narrow dimensional tolerance with respect to the dimensions of that part of the fastener 9 extending through the aperture 112 (e.g. stud or bolt 90). A suitable tolerance for the circular aperture 112 is an oversize of 0.7 mm or less, advantageously 0.6 mm or less, advantageously 0.5 mm or less, relative to the corresponding dimension (diameter) of the fastener 90. In addition, or alternatively, it will be advantageous to tolerance the dimension (distance) between the centreline 152 of the aperture 112 and the second surface 114 on the second body 11 with a positive deviation (i.e. oversize) compared to the dimension (distance) between the axis 150 of the oblong aperture 122 and the second surface 124 on the first body 10 of at least 0.1 mm, advantageously at least 0.25 mm. The positive deviation of the latter tolerance is advantageously less than or equal to 1 mm, advantageously less than or equal to 0.5 mm. With such tolerancing, it is ensured that the second surfaces enter into immediate engagement when the rail clip assembly is being mounted, even before the fastener 9 is tightened. To this same end, and in addition, or alternatively to the above, the inclination of the second surface 114 on the second body 11 can be made somewhat smaller than the inclination of the second surface 124 on the first body 10.
Advantageously, the second surface 114 of the second body 11 is shaped to be asymmetrical relative to a transverse median plane, i.e. a plane comprising the centre line 152 of the aperture 112 and perpendicular to axis 150. That is, the second surface 114 advantageously has a geometric centre 116 which is offset from the transverse median plane towards a side facing away from the rail. This can be seen in
A groove 125 and corresponding projection 115 can be provided on the first and second bodies at ends of the surfaces 123 and 111 opposite the second surfaces 124 and 114 respectively. Groove 125 and projection 115 are aligned with axis 150. Sufficient play is provided between groove 125 and projection 115 such that there is no substantial force transmitting contact between the two. The purpose of the groove 125 and projection 115 is merely to ensure that the second body 11 is correctly oriented when assembling the rail clip.
It will be convenient to note that the provision of the second surfaces 124 and 114 particularly allows for using impact wrenches for fastening the fastener 9. With such impact wrenches, the fastening/tightening of the fastener occurs instantaneously hence not giving the rail clip sufficient time to position correctly by action of the surfaces 123 and 111. In these cases, the second surfaces 124 and 114 ensure an immediate effect.
The suitability of the above rail clip for use with impact wrenches was tested in an experiment involving three different rail clip assemblies as described above with regard to
A second example of rail clip assembly 2 according to aspects of the invention is depicted in
Either one, or both the first and second bodies can be made of cast iron, or alternatively steel.
| Number | Date | Country | Kind |
|---|---|---|---|
| 14166148 | Apr 2014 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2015/058776 | 4/23/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2015/165790 | 11/5/2015 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1670994 | Snyder | May 1928 | A |
| 3923245 | Marchant | Dec 1975 | A |
| 4193544 | Marchant | Mar 1980 | A |
| 4251030 | Marchant | Feb 1981 | A |
| 4802624 | Marchant | Feb 1989 | A |
| 4889282 | Marchant | Dec 1989 | A |
| 8205803 | Couvreur | Jun 2012 | B2 |
| 9657445 | Awi Abalo | May 2017 | B2 |
| 20100193598 | Couvreur | Aug 2010 | A1 |
| 20160002864 | Awi Abalo | Jan 2016 | A1 |
| 20160024722 | Awi Abalo | Jan 2016 | A1 |
| 20170051457 | Couvreur | Feb 2017 | A1 |
| Number | Date | Country |
|---|---|---|
| 10200480 | Jul 2003 | DE |
| 0258049 | Mar 1988 | EP |
| 0272874 | Jun 1988 | EP |
| 1013827 | Jun 2000 | EP |
| 744067 | Apr 1933 | FR |
| 2240319 | Mar 1975 | FR |
| 1599873 | Oct 1981 | GB |
| 1003022 | Nov 1997 | NL |
| 1003022 | Nov 1997 | NL |
| WO 2009013239 | Jan 2009 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20170051457 A1 | Feb 2017 | US |
