Patent Application
20090200817
The present invention relates generally to an axlebox retainer key for use with a sideframe of a rail wagon bogie, to an assembly which includes the key and to a method of fastening said key to be secured to the sideframe.
Railway freight wagons are supported by a railway bogie. Referring to the prior art arrangement shown in
In the prior art configuration shown in
In use, when rail wagon and bogie 10 are lifted up (for example when lifted by a crane, or when being lifted for subsequent inversion for dumping any bulk contents of the wagon) the wheelset 8 must also be lifted therewith. The four axlebox retainer keys 36 on a bogie 10 (ie. two on each sideframe 12 in a pair of sideframes) restrain the bearings 20 (and therefore the wheelset 8 and axle) from falling under the influence of gravity out of the U-shaped cut-out 22 of the sideframe 12. When the rail wagon is lifted, the bearing 20 will move under the weight of the wheelset 8 and axle to rest against the uppermost face portion 38 of the axlebox retainer key 36, and no further downward movement of the axle and wheelset 8 can then occur.
There are normally four axlebox retainer keys 36 for each bogie. During maintenance, which is typically necessary sometime after 9 to 36 months in service depending on the wheel wear rate, all of the keys 36 need to be removed to free the wheelsets 8 for re-profiling of the tread contour. Normally this accomplished by the use of tools such as a spanner or an impact gun to loosen off the nut 44. The access to the nut 44 is from directly underneath the sideframe 12, which can result in lower back strain and sore knees for a maintenance worker, especially if that worker is required to handle up to 10 or 20 wagons a day in a single shift at a maintenance workshop.
In addition, the mounting bolt arrangement is not dependable because the vibrations associated with normal operation of the bogie can work the nut loose and allow the bolt to pop out. The key then easily falls out when the bolt is gone.
In a first aspect, the present invention provides an axlebox retainer key for fitting to a pedestal leg of a sideframe of a rail wagon bogie, the key comprising:
One advantage of having such a locating projection is that it obviates the need for a nut and bolt type fastening arrangement for the key. The projection can be used as a guide for the initial step of locating the key in position at the pedestal and can also be used to limit any movement of the key relative to the pedestal (either sideways or vertical) when used in combination with the locking member.
The use of a projection means that no mechanical device or tool (such as an 8 kg impact gun) is required to enable removal of the retaining key, and that there is no need for an operator to kneel on the ground or to hold a tool in an inverted position for loosening or tightening of a nut whilst restraining the head of the bolt. This means that the retainer keys can be simply changed out in the train yard, rather than needing to go to the expense and time of bringing the whole bogie into a maintenance workshop area. The vibration problem of the prior art nut and bolt arrangement is also solved by eliminating the need for such components.
In one embodiment, the projection can be integral with the body and be formed out of the same mass by cutting or other shaping methods, or techniques such as casting. In an alternative embodiment, the projection can be welded or otherwise formed integral with the body. By having an integral projection that is cast as part of the key, the key can have a greater inherent strength compared with prior art arrangements which use a discrete fastener, and may even be able to be made of a thinner material that can therefore be lighter overall. If a cast connector component is made, because no joining or welding is required the component can also be simpler and cheaper to make because of the reduced number of manufacturing steps compared with a welded product. For example, the cast components can be cast in a single step. However it is within the scope of the invention for the connector components to be formed by processes other than casting, such as by welding.
In one embodiment, the projection can be a basal spigot located on an underside of the body. One preferred arrangement features a round spigot on the key which, when in position, drops into the cored hole in the pedestal leg flange that is currently used to accept the bolt and nut of the prior art fastening arrangement. In some embodiments the spigot can be arranged to have a diameter which can fit into the cored hole quite tightly (close tolerances) to minimise any slight degrees of movement of the key.
In one embodiment, the said recess can be arranged on an in use upper side of the body, and may be arranged of a shape that is suitable for the receipt of a locking member which is axially displaced across the upper surface of the body. In one form the recess can be a closed-end cavity for receiving the end of an elongate locking member, whilst in other forms the recess can be a hollow or cut-out that is located at an upper surface of the body. In such arrangements when the locking member is received in the recess it can inhibit removal of the projection from the cavity, with the effect that the key is restrained from movement in any direction (i.e. either upwardly, or in a lateral or axial direction). In one arrangement, the locking member may be an axially slidable pin which is insertable into the recess via a through-hole in the front face of the sideframe.
In another form, the retaining portion formed at the body to receive the locking member can be a through-hole arranged of a suitable size in the body itself, for example for the in use receipt of a locking member in the form of an axially slidable pin.
In some embodiments, the axlebox key can also be retro-fittable to a prior art pedestal leg of a sideframe which uses the bolted-type retaining key of the prior art. The prior art bolt can simply be discarded and the locating projection on the underside of the key can be positioned into the cored hole in the pedestal that is currently used to accept the bolt and nut of the prior art fastening arrangement.
In a second aspect, the present invention provides an assembly comprising:
One advantage of using a locking member which passes through the side wall of the sideframe of the bogie is that access to the locking member and the key is from the front of the sideframe, and so there is no need for an operator to kneel on the ground or to hold a tool in an inverted position in order to free the axlebox key from the sideframe. In the conventional prior art arrangement, access to the nut and bolt occurs from directly underneath the sideframe, which can be awkward and occupationally dangerous. Also, when the key is loosened it can then fall out and possibly injure a worker operating underneath the pedestal. To avoid this, sometimes two persons are required in the prior art key maintenance procedure. Embodiments of the assembly of the present invention can thus make maintenance of the wheelsets easier and safer.
In one embodiment, the key can further comprise a retaining formation which receives the locking member when the locking member is in the locking position. In one form the retaining formation is a recess arranged at, or a through-hole arranged in, the key.
In one embodiment, the locking member can be an elongate pin which is arranged to be displaced axially when moved into the locking position. In one form of this, the axial displacement can involve horizontally sliding the pin into the through-hole arranged in the side wall of the pedestal leg, and then into the recess or through-hole at the key. In other forms the locking member need not be a pin, and need not be horizontally slidingly received. For example the locking member can be a screw that may be threadingly received into the recess or through-hole, and which can be introduced at an angle that is not horizontally oriented (ie. orthogonal) with respect to the side wall. In still other forms, the locking member can be of shapes other than a pin, for example a flat strip.
In one embodiment, the assembly can further comprise a securing member that is securable to the pedestal leg and which maintains the locking member in the locking position, for example by preventing the locking member from sliding out of the through-hole in the pedestal or out of the recess in the key. In one form of this, the securing member may be secured by one or more lugs that are arranged at the side wall of the pedestal leg.
In one arrangement, the or each lug can have a through-hole arranged for the in use receipt of the securing member, and the or each lug through-hole can extend in a direction that is transverse to the direction of the side wall through-hole of the pedestal. In one form, the securing member can be arranged to be vertically slidingly received in the or each lug through-hole, although other angles are feasible.
In one embodiment, the securing member can be a clip (such as an R-clip) or a pin (such as a lynch pin, or a split pin). In one form, the clip or pin is arranged to be vertically slidingly received in a through-hole located in the locking member, said through-hole being aligned in use with the or each lug through-hole. In still other arrangements, the clip or pin can be secured by other types of fasteners, latches or friction-fit components.
In an alternative embodiment, the or each lug can define a recess arranged for the in use receipt of the securing member. In this embodiment, the securing member is a radial arm which extends from the locking member, the radial arm arranged to be received in the or each lug recess upon axial rotation of the locking member. In some forms there can be two radial arms projecting from opposing sides of the locking member, each arm for receipt into a respective lug recess upon rotation of the locking member.
In one variation of this embodiment, a spring can be located circumferentially about that portion of the locking member which projects from the pedestal side wall, the spring being arranged in use to bias the radial arm(s) away from the pedestal leg and thus into the or each lug recess. In this way, the spring functions to engage the or each arm quite tightly in a respective lug recess, and effort is required to depress the radial arm(s) towards the pedestal leg at the same time as rotating the locking member in order to remove the radial arms from the lug recesses. This version of the securing member still has the advantage that access to the locking member and the key is from the front of the sideframe, and so there is no need for an operator to be in a difficult or dangerous work position to be able free the axlebox key from the sideframe. However the more complex mechanism of depressing and rotating the securing members can limit casual tampering with the assembly by a passer-by or vandal.
In one form, the locking member can be tied to the pedestal leg so that, whether the locking member is or is not positioned in the locking position, it remains tied to the pedestal leg. For example the locking member can be secured by a length of metal wire, chain or cable (for example, stainless steel wire) which at one end is secured through an eyelet in the locking member, and where the other end of the wire, chain or cable is looped around a lug or other attachment positioned at the pedestal leg. In still other forms, the other end of the wire, chain or cable can be directly welded, bolted or otherwise fastened at the pedestal leg. In either circumstance, the clip is always located in proximity to the lugs when not fitted therein, in use. Attaching the clip to the sideframe makes the clip easy to locate and more difficult to lose.
In a third aspect, the present invention provides an axlebox retainer key assembly comprising an axlebox retainer key as defined in the first aspect and a locking member.
In one embodiment, the assembly also comprises a securing member as defined in the second aspect.
In one embodiment, the assembly also comprises one or more lugs as defined in the second aspect.
In a fourth aspect, the present invention provides a method of fastening an axlebox retainer key to a pedestal leg portion of a sideframe of a rail wagon bogie in which the pedestal leg comprises a side wall and a flange extending therefrom at which the key is located in use, the method comprising the steps of:
In one embodiment of the method, the axlebox retainer key is as otherwise defined in the first aspect.
In one embodiment of the method, the resulting assembly is as otherwise defined in the second aspect.
In one embodiment of the method, the axlebox key can be retro-fittable to a prior art pedestal leg of a sideframe which previously used the nut and bolt retaining arrangement. In such a circumstance, when the locking member (such as a horizontal removable pin) is to be used, the pedestal leg will need one or possibly two holes to be drilled into the or each parallel side wall of the pedestal leg to accept the locking member, as well as perhaps a requirement to weld lugs onto the pedestal leg outer side wall.
In order to facilitate a better understanding of the nature of the present invention a preferred embodiment of an axlebox retainer key and a fastening arrangement for such a key at a wagon sideframe will now be described in some detail, by way of example only, with reference to the accompanying drawings in which:
In the following detailed description, where reference is made to parts of a rail wagon bogie which are in all respects are the same as described in the foregoing Background to the Invention, these parts will be referred to by the same reference numerals already used. Where a reference is made to a part which has been modified in some way but is a part with an equivalent function described in the foregoing Background to the Invention, these parts will be referred to by the same reference numerals but with an additional apostrophe, for example pedestal leg 24′.
Also, when referring to various embodiments of the invention, in order to avoid repetition and for ease of reference, similar components and features of the alternative embodiments which have a similar function have been designated with an additional letter “A”, “B”, “C” etc, such as the axlebox key 50, 50A, 50B, and so on.
Referring now to
The key 50 shown in
The in use uppermost surface 56 of the key 50 features a retaining formation which is a recess in the form of a transverse groove 60 that is semi-circular in cross-section and which is arranged to extend from one side 62 to the opposite side 64 of the key 50. The transverse groove 50 is shaped for receipt of a locking member in the form of a round cylindrical pin 66, as part of the fastening arrangement which will shortly be described.
In other forms of the invention, the recess can be of other shapes for mating receipt of a pin of an alternative cross-sectional shape, for example in situations where the pin and recess are oval, triangular, square-shaped, strip-like or of other shapes in cross-section. In some other arrangements, the recess need not necessarily extend fully across the width of the key. In still other forms, the uppermost surface of the key may not feature a recess at all, and instead the key may have an inset through-hole, or even a closed hole (or cavity) for receipt of a pin (or the end of a pin) of any corresponding cross-sectional shape. In any of these examples, an elongate pin or other member is inserted in a generally axial movement across the upper surface of the key via a hole located in the front face of the inner pedestal leg 24′, as will shortly be described.
The axlebox retainer key 50 is basically shaped as an elongate rectangular block or prism with a central, axial cut-out 68 that is rectangular in cross-sectional shape and which extends over the length of the key 50 to define two raised wings or webs 70, 72 located at opposing sides 62, 64 of the key 50. The semi-circular transverse groove 60 is formed in each of these webs 70, 72 so that the pin 66 can freely slide across the uppermost surface 56 of the key 50. Towards one end region 74 of the key 50, the height of each web 70, 72 tapers smoothly downward so that the end region 74 of the key 50 is shaped as a rectangular flange. The opposing (head) end of the key 50 is shaped as a tang 76 with a snub nose 78. The tang 76 features an evenly-sloping, uppermost flat face portion 80. When the key 50 is positioned between the parallel side walls 30′, 32′ of the pedestal leg 24′ and the spigot 52 is mounted in the hole 42, the tang 76 protrudes from the pedestal 24′ toward the bearing 20. The flat face 80 of the tang 76 of the key 50 is arranged to be approximately tangential to, and located a small clearance D from, a peripheral edge of the bearing 20. The flat face 80 of the tang 76 bears against the bearing 20 when deployed, so as to retain the bearing and wheelset at the bogie.
In the embodiment shown in
In the form shown in the drawings, the elongate pin 66 is horizontally slidingly received via the through-hole 82 arranged in outermost side wall 30′ of the pedestal leg 24′, and then into the groove 60 that is located at the uppermost surface 56 of the key 50. An operator standing at the front region of the sideframe 12 needs merely to insert or withdraw the pin 66, without needing to bend down under the sideframe 12, or to lie on surrounding ground etc. In the embodiment shown, the pin extends across the key 50 and into a further through-hole 84 arranged in the other side wall 32′ of the pedestal leg 24′. This location of the pin 66 across and above the axlebox key 50 prevents the key 50 from being lifted out of its seated position, by maintaining the recessed position of the basal spigot 52 in the hole 42.
In other embodiments, the fastening arrangement can employ another type of locking member, for example a non-sliding fastener such as a screw which may be threadedly received into a recess in the uppermost surface of the key and in the or each through-hole in the side wall(s) of the pedestal leg. In still other embodiments it is envisaged that the angle of the pin or other selected fastener need not be horizontally oriented with respect to the side wall of the pedestal leg, so long as operator access is maintained via the front region of the sideframe and the pedestal leg.
In order to secure the pin 66 in position in the pedestal leg 24′, the external side wall 30′ of the pedestal leg 24′ is modified (for example by welding or cutting) to fit two like, protruding lugs 86, 88 thereonto. Each lug 86, 88 defines a central, vertically-oriented through-hole 90 which is aligned with the through-hole 90 of the respective other lug 86, 88. As shown in the drawings, in use a securing member in the form of an elongate R-clip 92 is inserted by a vertical sliding movement into each aligned through-hole 90. The R-clip 92 is thus secured to the exterior wall 30′ of the pedestal leg 24′ at the lugs 86, 88 and, when in position, the clip 92 is arranged to block the axial slide path P-P of the elongate pin 66. The vertically-oriented R-clip 92 maintains the pin 66 in the inserted locking position by preventing the pin 66 from being slidingly removed from its horizontal orientation in the groove 60 at the uppermost surface 56 of the key 50. The positioning of the elongate pin 66 in turn secures the axlebox key 50 at the pedestal leg 24′.
In other arrangements, the R-clip can be replaced by other equivalent types of fasteners, latches, pins or other types of friction-fit components, depending on the requirements.
As shown in the Figures, the R-clip 92 is separately secured to the pedestal leg 24′ by a length of stainless steel metal wire 94. One end 96 of the wire 94 is secured through an eyelet 98 at an uppermost end 100 of the R-clip 92, and the other end 102 of the wire 94 is bolted to the outermost side wall 30′ of the pedestal leg 24′ by bolts 104 so that the R-clip 92 can always be located in proximity to the lugs 86, 88 when not inserted in the respective through-holes 90. In other arrangements, the metal wire 94 can be replaced by any appropriate linkage, such as a length of chain, cable or cord to retain the R-clip or other securing member at the pedestal leg 24′.
Further arrangements to secure the locking member in position at the pedestal leg 24′ are provided in
In
In
The embodiment shown in
Referring now to
In the embodiment shown in
Either end of the spring 113 is contacted with a respective washer plate 115 which can assist in preventing migration of the spring 113. The spring 113 biases the position of the arms 109, 111 away from the pedestal side wall 30′ and thus into the respective lug recesses 90D. The spring functions to engage each arm 109, 111 quite tightly in a recess 90D of a respective lug 86D, 88D, and some effort is required by a maintenance worker to depress the radial arm(s) in a direction towards the pedestal side wall 30′ at the same time as rotating the locking pin 66D, so as to disengage and remove the radial arms 109, 111 from their respective positions in the lug recesses 90D. The spring 113 also helps absorb vibration and rattling noise while the pin 66D is in the locking position.
The embodiment shown in
Referring now to
The embodiment shown in
Referring back to the embodiment shown in
Now that a preferred embodiment of the invention has been described in some detail it will be apparent to those skilled in the art that the axlebox retainer key and its fastening arrangement has at least the following advantages:
Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. For example, in other arrangements it is envisaged that the same type of axlebox retainer key can be fitted to the outermost pedestal leg 26 rather than only onto the inner leg 24.
Also, although the particular orientation and configuration of a locking member and a fastener have been described in a preferred orientation, these types of fasteners may be oriented in a variety of dispositions relative to the pedestal leg and the axlebox key. Any shape of axlebox key is also within the scope of the invention, and need not be restricted to the snub-nosed form shown in most of the embodiments.
All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the foregoing description. It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms a part of the common general knowledge in the art in any country.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005903964 | Jul 2005 | AU | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/AU06/01041 | 7/26/2006 | WO | 00 | 7/16/2008 |
