FIELD OF THE INVENTION

The present invention proposes an Enhanced Vertical Gathering Range Knuckle on the current Knuckle type Center Buffer Coupler for application on all Indian Railways rolling stock.
BACKGROUND OF THE INVENTION
British introduced screw coupling for the railways in India. Thereafter, all coaching and freight stock were installed with screw coupling and side buffers. In 1960, Indian Railways took to the automatic knuckle type center buffer coupler and today they are on 300000 freight cars (wagons). A Knuckle coupler can couple, haul, and operate on track with certain geometry, speed and vehicle dynamic behavior. A coupler keeps the whole train coupled at all times.
A center buffer coupler has a vertical and a horizontal gathering range, which is the total engaging area between two adjacent couplers. This range permits the train to go over uneven track without letting the couplers disengage. The standard centerline of coupling in India is 1105 mm for all 1000 mm wheel diameter rolling stock from rail level and has an 11-inch (280mm, approx.) vertical gathering range between two adjacent knuckles.

The wheel has a maximum wear of 94 mm on 1000mm diameter wheel. During run, spring offloading / onloading can be seen due to vertical oscillations in empty and loaded conditions. For example, train consist with one empty and one loaded shall have the empty coupling center line will at 1105mm from rail level, while the loaded wagon center line will be dropped down to 1026mm (considering 80mm max deflection in springs). However, the wagons shall not disengage in view of the existing vertical gathering range of 140mm (5.5inch) on either side from centerline of knuckle. Unevenness in track may introduce a further 8 to 10mm difference between two rails at the joints of rail.
The desire for increase in volume of a wagon requires maximizing the width and height of a wagon within moving dimensions. Indian Railways have an electrified operation with the catenary wire becoming the limiting point for any wagons height. Station platform width and other wayside equipment limit the width of a wagon. A minimum gap must be maintained between the wire and the material loaded in a wagon in order to avoid contact. These aspects limit the height and width of the wagon. IR has a high wheel diameter of 1000 mm on all its standard rolling stock as against lower diameter of wheel across different railway networks in the world. With extensive tests, Indian Railways could suitably bring down the diameter to 840 mm and a few wagons have been designed with the same. At present dis-similar coupling heights are accommodated by changing the structure of wagons, i.e. by providing additional packing (Stub sill) or with match wagons.

OBJECT OF THE INVENTION
In view of the above, the present invention proposes a completely redesigned but fully compatible and interchangeable knuckle to convert the current automatic coupler head that has an enhanced vertical gathering range of 432mm (17 inch) as against 279.4 mm (11 inch) in the current design knuckle, thus providing for a higher net area of engagement between adjacent coupler knuckles.
With this invention, it is possible to lower the floor height suitably, which in turn delivers a significant increase in volume. This invention also helps in reducing the unsprung mass since the wagons are fitted with lower diameter wheel. This also gives better stability to wagon body in running conditions as Centre of Gravity has been lowered by this invention.
This invention is a knuckle fully compatible with the coupler heads in service with an extended vertical gathering range knuckle that can be installed in new as well as existing coupler bodies. This also has the potential to lower the coupler centerline over the next 10 years on all rolling stock and maximize the volume above the pivots for carrying payload thus becoming a very cost effective solution for Railways.

To the best of the knowledge of the inventor, while shelves on side, bottom and top have been designed and are available, all these limit the vertical gathering range and do not enhance it. A collateral benefit would be the obviation of any vertical disengagement of couplers both while on run and also in case of an accident. The extended height of the knuckle provides a greater total working surface area thereby reducing the wear due to a greater area of working contact.
The prime objective of this invention is to develop an Enhanced Vertical Range Knuckle that introduces a match Knuckle on the Center Buffer Coupler that allows the coupling centerline to be suitably brought down thus providing a larger contact area than the existing knuckle design.
Another objective of this invention is to develop an Enhanced Vertical Range Knuckle that will eliminate the additional dead load of wagons structure having stub sill & unused air pocket between Centre sill and center pivot.
Another objective of this invention is to develop an Enhanced Vertical Range Knuckle that introduces a Knuckle to suit universal application on all types of freight stock with higher and lower wheel diameter (different centerlines of coupler).
A still another objective of this invention is to develop an Enhanced Vertical Range Knuckle that facilitates a substantive increase in payload on a wagon by lowering the floor height of the wagon and the same translating to lowering of the centerline of coupling, which is comfortably accommodated by the invention.

A further objective of this invention is to develop an Enhanced Vertical Range Knuckle that facilitates a notable increase in volumetric capacity on a wagon through lowering of floor height thus translating to adept utilization of the higher contact surface area knuckle that lets the centerline of coupling being lowered
A still another objective of this invention is to develop an Enhanced Vertical Range Knuckle that suits application for lowering the coupling centerline and thus promotes development of low floor height wagons with a lower Center of Gravity and stable riding.
Another objective of this invention is to develop an Enhanced Vertical Range Knuckle that introduces a design with a substantially larger area of contact for the adjacent knuckles and thus help distribute the wear over a larger area hence reducing total wear on the knuckle contact faces a still another objective of this invention is to develop an Enhanced Vertical Range Knuckle that offers a design solution for universalization at a nominal cost for adoption in different wheel diameter wagons.
Another objective of this invention is to develop an Enhanced Vertical Range Knuckle that includes an integrated rib connecting diagonally to extended nose & knuckle pin rib. This integrated rib on either side of knuckle strengthens the extended nose to withstand longitudinal forces during run.

A further objective of this invention is to develop an Enhanced Vertical Range Knuckle that allows for universal fitment on new couplers that are being manufactured for wagons as well as installation on existing couplers that are taken for maintenance thereby being a quick solution for different wheel diameter wagons
SUMMARY OF THE INVENTION
The present invention proposes an Enhanced Vertical Gathering Range Knuckle with a gathering range of 17 inches. The design is to accommodate lowering of floor height to attain maximum possible volume in a wagon. Existing knuckle design used in Indian Railways has a total vertical gathering range of 11 inches with a minimum engagement requirement of 152.4 mm (6 inches) at all times with the adjacent knuckle. The difference between the centerline of coupling between two adjacent knuckles can be attributed to difference in wheel diameter due to wear, offloading, track irregularity etc. The same can be maintained while lowering the coupler height by 150 mm and resultant floor height is arrived at 1115 mm.
The existing 1000mm wheel diameter wagons with a coupling centerline of 1105 mm from rail level have a floor height of 1273mm and utilize the space to attain highest volume. However, the 840mm wheel diameter wagons are designed with the same floor height of 1273mm to match existing coupling height 1105mm by providing a stub sill below the floor. Such a design completely obviates the benefits of having a lower wheel

diameter on a wagon and is not able to attain higher volume. It is almost equal to having the same 1000mm diameter wheel. On the contrary, the lower diameter wheel wagons have acquired significant weight due to provision of the stub sill.
The condemnation limit on a 840mm diameter wheel is at 760mm. With a total difference of 240mm between the lowest condemnation limit of 760mm (for 840mm wheel rolling stock) and 1000mm new wheel diameter the centerline is at a difference of about 120mm. This brings us to the introduction of the present invention with a redesigned knuckle that introduces an additional 152.4mm (6 inches) of vertical gathering range thus adjusting for the difference of centerline.
The present invention utilizes the low wheel diameter optimally and provides space for lowering the floor by 158 mm and is capable of enhancing the total volume by up to 8 percent. This translates to 58 wagons carrying a commodity that 62 wagons would carry otherwise in view of the existing design knuckles. The present invention provides a cost effective design suitable for Railways in terms of low cost installation and potential of earn higher revenue on wagons.
This present invention proposes an automatic coupler knuckle with a vertically longer horn face for better engagement with adjacent knuckles. The invention construction is compatible with the existing AAR automatic Center Buffer Coupler for freight application.

The invention is inserted into the cavity of the coupler body and is attached with a pin. In view of the high impact longitudinal forces on the frontal lobe of the knuckle, the enhancement to the vertical gathering range has led to a redesign of the frontal lobe (nose) with a longer knuckle face and an extended integrated rib on the inside face of the knuckle. The enhanced gathering range increases the area of contact between two knuckles and reduces total wear on each knuckle face. The invention also suitably strengthens the extended portion with an integrated rib that provides equal strength to the extended portion of the knuckle to withstand longitudinal forces.
BRIEF DESCRIPTION OF THE DRAWINGS
1. Figure 1 - Drawing of Center Buffer Coupler with existing Knuckle (side view)
2. Figure 2 - Drawing of Center Buffer Coupler with existing Knuckle (top view)
3. Figure 3 - Drawing of Center Buffer Coupler with improved Knuckle (side view)
4. Figure 4 - 3D Model of the improved Knuckle
5. Figure 5 - Drawing comparative of the existing and enhanced vertical gathering range Knuckle
DETAILED DESCRIPTION OF THE INVENTION
The present invention is an Enhanced Vertical Range Knuckle with a re-designed frontal lobe that provides a higher area of contact with adjacent knuckles. The design is suitable and compatible with automatic center buffer coupler body and can be installed with ease on new as well as existing operational couplers at the time of overhaul. The central lobe

(nose) of the knuckle is redesigned with an integrated rib that extends from the central hub of the knuckle and gets tapered at the distal ends of the inside face thus providing strength to the modified knuckle horn face frontal lobe.
This invention is designed with a higher vertical gathering range of 17 inches to accommodate the lower wheel diameter rolling stock with a lower coupling centerline along with the 1000mm diameter wheel rolling stock. The 17-inch (432mm) vertical contact surface length is suitably strengthened with an integrated rib in view of extensive draft and buff impacts during coupling operation. A primary objective of this invention is to adjust different coupling centerlines (9) (Fig. 1) of two types of rolling stock and streamline buff and draw forces for smooth operation. The invention through its modified design helps attain a higher volume in wagons with lower wheel diameter.
The coupler body (13) (Fig. 2) shows the existing design center buffer coupler with a knuckle (14) (Fig. 2) as the frontal portion that engages with the adjacent knuckle. The pin (15) (Fig. 2) is used to engage the knuckle with the coupler body and stay in position tightly to take buff and draft forces. The draft gear (16) (Fig. 2) at the rear end of the coupler is responsible for absorbing the impacts of buff and draft forces. The whole center buffer coupler system keeps a train in formation by keeping the contact constant at all times. The frontal lobe of the existing knuckle (17) (Fig. 5) seen vertically is the gathering range measured at a vertical length of 11 inches is responsible for

engagement. The said design is only suitable with 1000 mm diameter wheel with a condemnation limit of 906 mm. A maximum of 47 mm could be the maximum difference between two adjacent knuckles without adjusting for track irregularities. With track irregularities, the same can be at a maximum of 60 mm.
However, the existing design does not allow universal application and is not compatible for 840 mm and 1000 mm wheel diameter wagons. The existing design knuckle on the center buffer coupler can be seen from a side view in Figure 1, where the knuckle (18) (Fig. 1) item is fitted inside the coupler body (19) (Fig. 1) with a pin (20) (Fig. 1). The redesigned knuckle can be seen in Figure 3; where the center buffer coupler body (21) (Fig. 3) has the redesigned knuckle (22) (Fig. 3) with an enhanced vertical gathering range (23) (Fig. 3) at the frontal portion (24) (Fig. 3) placed in the coupler cavity (25) (Fig. 3) and tightly attached to the coupler body (21) (Fig. 3) with a pin (26) (Fig. 3). The redesigned knuckle is designed with a longer frontal portion (24) (Fig. 3) to accommodate the longitudinal forces generated from different centerlines of coupling. The frontal portion (3) (Fig. 5) of the knuckle (1) (Fig. 5) as seen in figure 5 has an integrated rib (4) (Fig. 5) that extends beyond the central hub (5) (Fig. 5) of the knuckle to the inside face distal ends (6) (Fig. 5) of the knuckle inside face in a tapered manner. The redesigned frontal part (3) (Fig. 5) of the knuckle thus incorporates a vertically longer face (2) (Fig. 5) and is strengthened through integrated ribs (4) (Fig. 5) to cope with longitudinal forces during operation.

WE CLAIM

1. An enhanced vertical gathering range knuckle comprising:
- a knuckle (1) having a vertically longer knuckle face (2) (Fig. 5) on the frontal portion (3) (Fig. 5) in the inside knuckle face (7), (Fig.5), the said frontal face (3) being strengthened by integrated rib (4) that run through the central hub (5) to the vertical distal end (6) of the inside knuckle face (7), the said knuckle being inserted into the coupler body cavity (8) (Fig.2) and firmly fixed to the coupler body (13) (Fig.2) by pins (15) (Fig.2) for securing the knuckle while being fixed along the vertical pin cavity (11) (Fig.5) through the knuckle hub (12) (Fig.5) wherein the said knuckle facilitates utilization of different diameter wheel rolling stock by accommodating different centerlines (9) (Fig. 1) of coupling through a larger area of contact between adjacent knuckles.
2. The knuckle with enhanced vertical gathering range as claimed in claim 1 wherein the knuckle allows 840 mm wheel diameter wagons to lower floor height from standard height used for 1000 mm wheel diameter wagons and obtain a substantively higher payload and volumetric capacity.
3. The knuckle with enhanced vertical gathering range as claimed in claim 2 wherein the improved knuckle allows standardization of wagons by coupling centerline and allows mixed utilization of all forms of wagons.

4. The knuckle with enhanced vertical gathering range as claimed in claim 1 wherein the invention knuckle allows wagons to eliminate stub sill inclusions on the underframe to match coupling height of 1105mm and suitably reduces the tare weight of the wagons and the same can be utilized for carrying additional payload.
5. The knuckle with enhanced vertical gathering range as claimed in claim 1 wherein the invention knuckle promotes development and utilization of low floor high payload wagons with a lower center of gravity thus resulting in a stable wagon design.
6. The knuckle with enhanced vertical gathering range as claimed in claim 1 wherein the invention knuckle provides a design for a higher contact surface area between adjacent knuckles that result in net reduction in wear due to distribution of wear over a larger area.
7. The knuckle with enhanced vertical gathering range as claimed in claim 1 wherein the invention knuckle is a solution for universalization at a nominal cost and is suitable for installation on existing as well as new couplers.