Title of Invention	"A DEVICE USED WITH RAILWAY BOGIE".
Abstract	This invention relates to a device used with railway bogie which comprises a wedge shaped upper plunger casting disposed in the lower box casting separated by a bonded rubber element or elastomer, so as to generate a hollow cavity at the bottom, and constant contact side bearer.

Full Text

FIELD OF INVENTION This invention relates to a device used with the railway bogie. PRIOR ART The existing laminated pad has a very low longitudinal stiffness kN/ mm). If the bogie is to rotate, the current designed laminated pad does not induce sliding between the upper laminated plate and wagon wear plate because of elastomeric shear deformation under normal operating conditions. This means that the low "X" factor of the current pad will allow bogie hunting, especially at speed above 80 kph, which is common. In the worst situation where the bogie is subjected to high lateral impact loads, the vertical rotation of the wagon about it's longitudinal axis will occur and damage the current design laminated pad. If a possible vertical load of 30 kNs is imposed onto the existing IR pad while the bogie is rotating around a curved portion of track, then the upper plate of the pad will be sandwiched between the bogie mounted bearer housing and the wagon wear plate causing high metal to metal shock loads. The upper most rubber layer will also be subjected to very high shear, and pinching forces just prior to bottoming out or sandwich event. OBJECTS OF THE INVENTION The primary object of the present invention is to propose a device with the railway bogie. Another object of the present invention is to propose a device used with the railway bogie which overcomes the disadvantages of the prior art. Still another object of the present invention is to propose a device used with the railway bogie which is best suitable for Indian railways. Yet another object of the present invention is to propose a device used with the railway bogie to provide suitable bogie rotational torsional resistance and to prevent adverse high impact loads to the bogie and supported wagon. STATEMENT OF THE INVENTION According to this invention there is provided a device used with the railway bogie which comprises a wedge shaped upper plunger casting separated by a bonded rubber element or elastomer, so as to generate a hollow cavity at the bottom, and constant contact side bearer. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein: Fig. 1. Shows the device of prior art Fig. 2. Shows compression and shear load Vs deflection plot. Fig. 3. Isometric and sectional view (A-A & B-B) of the presenlt invention. DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO ACCOMPANYING DRAWINGS. Fig. 1 depicts the device of prior art which moves to & fro with the movement of wagon. Reference is made to fig. 3. This invention provides a device used with the railway bogie wherein the wedge shaped upper plunger casting (1) is vulcanised to the lower box casting (2) is such a manner that a hollow cavity (3) is generated at the bottom. .As the wagon gets loaded the constant contact side bearer (4) gets pressed and one plunger moves down generating a desired linear spring rate The hollow cavity at the bottom starts getting filled up with vulcanised rubber (4). The vulcanized bonded rubber elastomeric element exists between the upper and lower castings to provide dynamic spring movements of the upper casting relative to the lower casting. The constant contact side bearer is fitted in a housing provided on the bogie or directly mounted on the bogie bolster. As the load increases substantially deflection reduces. This forms bearer with non linear vertical spring rate, assisted by the reduction the lower hollow cavity i.e. the spring rate changes. The increased spring rate prevents metal-to-metal contact between bogie and wagon under-frame, thereby avoiding damaging shock loads. Under most operating conditions the vertical stability of the wagon is maintained by the flat surfaces at the center pivot, with some assistance from the bearers. A severe lateral load induced by poor track conditions. especially at high speeds and when the loaded wagon center of gravity is higher than normal, can induce wagon rotation relative to the bogie. The relatively stiff longitudinal characteristics ensure occurrence of sliding between side bearer pad and bearer pad of the wagon under small angular bogie movement. The metal to metal sliding occurs due to the overcoming of friction forces between the bearer pad and the underside of the wagon wear plate. The space envelop included in the cast housing governs the specific outer-dimensions of the proposed ductile iron casting and rubber bearer. The design includes as such a 5 to 6 mm steel shim in the bottom of the cast housing to ensure the height relative to the bogie center pivot induces a vertical reaction from the bearer of such as 22.5 kNs. In providing for bogie rotational damping, these bearers have been designed with a high longitudinal spring rate (>4 kN/ mm). This longitudinal stiffness will induce sliding between the upper surface of the bearer and the corresponding wear plate on the wagon under-frame with only minor levels of rotation. The friction controlled sliding surfaces will then induce the correct rotational resistance and damping, without adverse wheel wear. The performance of the present bearer differs substantially from known laminated elastomeric steel pad in this area of rotational resistance and resistance to high impact loads thereby avoiding metal to metal contact. The pad has an increasing vertical spring rate pad, which remains resilient with loads for example up to 50 kNs which has been indicated in Table 1 hereinunder and also in fig. 2 which shows the pad's longitudinal deformation during the rotation of the bogie. (Table Removed) A Constant Contact Side Bearer in three-piece freight bogie has basically two function: 1. To provide reliable friction damping to stabilize bogie ride at higher speeds, otherwise known as bogie "Hunting". This requires sliding friction to occur at small movements, as the yawing movements of the bogies are relatively small. 2. To provide suitable bogie rotation in tight curves at lower speeds. An indication of this resistance is the factor ("X"). "X' factor means:- "British Rail X factor". For Bogie Rotation Torsional Resistance. This factorial rotational resistance must lie between 0.03 to 0.08 to comply with British requirements. 3. Both requirements as above should be performed for both, and gross condition of the vehicle. An appropriate solution for a constant contact side bearer should provide the following parameters:- 1. Vertical characteristic to ensure constant contact under new and worn condition of wear plates and center plates. 2. Stiff longitudinal characteristic to ensure occurrence of sliding between side bearer and bearer pad even under small angular bogie movements. 3. Limitation of vertical force to maintain the "X" factor to 0.1 or less. The factor is essentially the ratio of the torque resisting bogie rotation divided by the product of axle load*bogie wheel base. The factor should be 0.03 The two side bearers perform as follows:- 1. The side bearer deforms within its elastic limits. The laterall damping force is provided due to the center plate friction and the friction forces between the scale bearers and wagon under frame wear plate. 2. The pad provides adequate friction under tare and gross conditions. At the latter, the friction of the center plate contributes as well. For curving conditions, side bearers provide suitable resistance to against bogie rotation to minimize wheel wear. At high speed, the bearer pad provides adequate damping to ensure stable ride, with only a small friction contribution from the center plate. For the higher operating speeds of container wagons, adequate yaw damping is more important. The pad provides satisfactory damping for both, tare and gross load conditions. The function in service of these constant contact resilient bearing (bearers) is :- 1 . Provide Torsional rotation resistance to the bogie while traveling on straight track. 2. Allow the bogie to rotate while negotiating curves in such a manner that excessive wheel/ track wear is not induced. 3. Maintain stable running, t speeds in excess of 80 kph, on all kinds of track. 4. Provide wagon rotational or vertical stability, relative to the bogiel, with the incident of high lateral loads. 5. Operate in a range of environmental conditions likely to be encountered in the Indian Sub Continent Temperature range from minus 10 to plus 50 degrees C. 6. Provide a service life of more than five years. 7. Be retrofittable to existing in service bogies without modification to the bogie. An "X" factor figures between 0.03 and 0.10 has been found to provide the optimum balance between "Hunting" and Wheel/Track wear. It is to be noted that the present invention is susceptible modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:- WE CLAIM 1. A device used with the railway bogie which comprises a wedgjs shaped upper plunger casting disposed in the lower box casting separated by a bonded rubber element or elastomer, so as to generate a hollow cavity at the bottom, and constant contact side bearer. 2. A device as claimed in claim 1, wherein the constant contact side bearer is fitted in a housing provided on the bogie or directly mounted on the bogie bolster. 3. A device as claimed in claim 1, wherein the rubber element or elastomer is provided between the wedge shaped upper plunge and the lower box casting, to fill up the hollow cavity. 4. A device as claimed in claim 1, wherein the device has X-factor ranging between 0.03 and 0.08. 5. A device as claimed in claim 1, wherein the lower box casting is provided with a steel shim of for example 5 to 6mm at the bottom. 6. A device used with the railway bogie substantially as hereiiti described and illustrated.

Documents:

281-DEL-2005-Abstract-09-04-2008.pdf

281-del-2005-abstract.pdf

281-DEL-2005-Claims-09-04-2008.pdf

281-del-2005-claims.pdf

281-DEL-2005-Correspondence-Others-(15-07-2008).pdf

281-DEL-2005-Correspondence-Others-09-04-2008.pdf

281-del-2005-correspondence-others.pdf

281-del-2005-correspondence-po.pdf

281-DEL-2005-Description (Complete)-09-04-2008.pdf

281-del-2005-description (complete).pdf

281-del-2005-drawings.pdf

281-del-2005-form-1.pdf

281-del-2005-form-18.pdf

281-DEL-2005-Form-2-09-04-2008.pdf

281-del-2005-form-2.pdf

281-DEL-2005-Form-3-09-04-2008.pdf

281-del-2005-form-3.pdf

281-del-2005-form-9.pdf

281-del-2005-form-gpa.pdf

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