FIELD OF THE INVENTION
[0001] The present disclosure relates to an automatic torsional lock assembly. Particularly, the present disclosure relates to an automatic torsional lock assembly for mounting and demounting containers. More particularly, the present disclosure relates to a method for for mounting and demounting containers on the wagon provide with automatic torsional lock assembly.

BACKGROUND OF INVENTION
[0002] It is desirable to use a lock for mounting the containers on rail wagon before transportation. Container locking devices on Indian Railways dates back to pre-1980s wherein BFKI Wagons were fitted with Retractable Anchor Locks to secure the Containers. Container Corporation of India Ltd. (CONCOR), in its draft Technical Specifications for a Global Tender indicated amongst others a requirement of Locking devices to accommodate various combinations of ISO Containers.
[0003] In the year 1996, a decision was taken by CONCOR to evaluate both Semi-Automatic and Automatic Twist Lock devices for suitability of use in their proposed Container Flat Wagons. This was a significant departure for the then-current Retractable anchor locks that were used in BFKI Wagons. During the course of evaluation and development of this product, AAR M 952 – 88 Specifications were consulted and an AAR approved product of M/s Holland Co, USA was chosen for fitment on the Low Platform Container Flat Wagons, the first order of which was executed by M/s Hindustan Development Corp. Ltd. (HDC). In the prototyping stage of the Wagons, both the options – Automatic Twist Lock and Semi-Automatic Twist Lock, were tested in accordance with a Test scheme evolved by Research Design and Development Organization (RDSO) of Indian Railways, derived on the lines of AAR M -952. In Sept. 1997, CONCOR chose the provision of Holland Co make Automatic Twist Locks over the Semi-automatic Twist Locks in its new Container Flat Wagons. Since 1999, Automatic Twist Lock (ATL) devices are being used on Container Flat wagons of IR.
[0004] Automatic Twist Lock (ATL) devices are used at defined location on the flat wagons for holding containers with the car body (flat wagon) involving safety aspects from various points & hence a well-defined, guidelines for multisource is essential. Since the location of these devices and dimensional aspects are controlled by various other factors (i.e., size of ISO containers, corner casting, location dimensions of the wagon etc.), it is equally important that product interchangeability is ensured (in a rake/unit of wagons), to avoid duplication of resources & avoidable inventory costs. Also, the ATL (Automatic Twist Lock) devices to be utilized on the Container Flat Wagons should be such that they can be fitted on the Wagons without involving any modification in the existing Wagons – which is again a cost. ATL Solved the problem to carry ISO containers anywhere in the world without facing time consuming locking issues.
[0005] ATL as exist in the art is shown in FIG. 1A-1E. First of all, during mounting the Lock (ATL Lock) is the main component which come into direct contact with the ISO Containers or Container’s Base Brackets (CBB). When we put a force on an object acting perpendicularly on the angular surface the Second Object, then according to its force, mass, and static coefficient of friction it (perpendicular force) pushes the second object as per its angle and it moves accordingly. In case of ATL lock, their body and their edges are made spiral in shape so that it can rotate while we put force on its edges. Upon rotating, the head of ATL lock is received by the Container’s Base Brackets and after insertion the head of lock comes in original position under the tension of spiral spring and the container gets locked on the rail base.
[0006] ATL as exist in the art is shown in FIG. 1A-1E. First of all, during mounting the Lock (ATL Lock) is the main component which come into direct contact with the ISO Containers or Container’s Base Brackets (CBB). When we put a force on an object acting perpendicularly on the angular surface the Second Object, then according to its force, mass, and static coefficient of friction it (perpendicular force) pushes the second object as per its angle and it moves accordingly. In case of ATL lock, their body and their edges are made spiral in shape so that it can rotate while we put force on its edges. Upon rotating, the head of ATL lock is received by the Container’s Base Brackets and after insertion the head of lock comes in original position under the tension of spiral spring and the container gets locked on the rail base.
[0007] FIG. 1A shows the perspective view of the ATL and its actual position which always remains in locked position. FIG. 1B shows the front of the ATL and its lock, here we can see the spiral shape of the lock and the working edge. FIG. 1C shows top view and direction of the twist of the lock. While container pushed over the lock then lock rotates in the shown direction and after container rested on the lock, then lock returned to its original position. FIG. 1D shows the Spring 40 and Pin 70 at the bottom of the lock. Pin holds the spring in the ATL. Pin is the weak point of the ATL design which brakes very frequently. Major failure issue of the ATL design. FIG 1E shows the section view of the ATL with all its components and their location in the ATL. Components like lock 10, lock pin 20, spindle 30, spring 40, top plate 50, and Base Plate 60.
[0008] The existing ATL (Automatic Twist Lock) has few problems. Water penetrates into the lock resulting in to rusting from inside and damaging spring as well as locking pin. Pin getting damaged due to load and rust, thus causing spring to lose tension and Twist Lock becomes unengaged. Repair and maintenance taking time and money. And sometime even loss of components, which hang with the containers, when the latter is lifted. Maintenance and repairing of the pin is very common. Broken pin usually gets struck inside of the base plate, and it takes time and also costs, to reclaim the part and then redrilling and welding of the pin, is required.
[0009] There is a need of an improved assembly of lock which mitigates the drawbacks of spiral spring, eliminates the problem due to rust and remove the discrepancies arise due to breaking of pin.

OBJECT OF THE INVENTION
[0010] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0011] It is a general or primary object of the present disclosure to provide an automatic torsional lock assembly for mounting and demounting containers which eliminates the problem due to rusting and spiral spring.
[0012] It is another object of the present disclosure is to provide a method of mounting and demounting containers from the rail base provided with torsional lock assembly.

SUMMARY OF THE INVENTION
[0013] This summary is provided to introduce concepts related to an automatic torsional lock assembly for mounting and demounting containers on the rail base and method of mounting containers on the rail base by an automatic torsional lock assembly and a method of dismounting the same. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0014] In an aspect, the present disclosure provides an automatic torsional lock assembly provided on a wagon for mounting and demounting containers on the wagon, the container has at least one slot at each corner for mounting, the automatic torsional lock comprising: a base plate having a circular bore with a centre hole A and a top plate placed over the base plate having a centre B in alignment with centre hole A around a common longitudinal axis. The lock also has a spindle comprises a flat circular base and cylindrical rod with a top end extending upward from the base, wherein the base of spindle is mounted on the base plate and the rod is passed through the centre hole A and centre hole B along the longitudinal axis. A lock head mounted on the top head by a pin. In the lock, the spindle has a torsional spring wound around a part of the cylindrical rod, wherein the torsional spring has a lower end inserted in a slot on the base of the spindle and an upper end inserted in a slot on the top plate, and an O ring is provided between the base of the spindle and the base plate.
[0015] In an embodiment, the present disclosure provides that the top plate and the base plate, each having atleast one drilled hole at each corners and when the top plate is mounted on the base plate, the drilled holes of top plate comes over the tapped holes of base plate.
[0016] In another embodiment, the present disclosure provides that the top plate is mounted on the base plate by introducing screws into the drilled holes and tightened by the bolts.
[0017] In yet another embodiment, the present disclosure provides that the lock head along with spindle is rotatable from a release position to lock position under the tension of spring.
[0018] In still another embodiment, the present disclosure provides that the lock head along with spindle is rotatable from a release position to lock position and the lock head in lock position is receivable by the slot on the container.
[0019] In further embodiment, the present disclosure provides that the base of the spindle has at least a circumferential groove and when the base of spindle is mounted on the base plate on mounting, it seals the cylindrical area of the Base Plate by accommodating the O ring.
[0020] In preferred embodiment, the present disclosure provides that the torsional spring is surrounded by a guide ring.
[0021] In more preferred embodiment, the present disclosure provides that the lock head has an upper surface protruded upward in the form of pyramid with at least four triangular sides and round edges.
[0022] In another embodiment, the present disclosure provides that an O ring is provided between the lock head and the top plate.
[0023] In yet another embodiment, the present disclosure provides that wherein the base plate is made up of low carbon forged steel and the top plate and spindle are made up of high tensile forged steel.
[0024] In further embodiment, the present disclosure provides that the torsional spring is made up of spring steel.
[0025] In still another embodiment, the present disclosure provides that the guide ring is made up of low carbon steel.
[0026] In preferred embodiment, the present disclosure provides that wherein the pin is made up of high tensile steel.
[0027] In more preferred embodiment, the present disclosure provides that the lock head is made up of carbon steel.
[0028] In still another embodiment, the present disclosure provides that the O ring is made up of nitrile rubber.
[0029] In another aspect, the present disclosure provides a method of mounting containers on a wagon provided with an automatic torsional lock assembly, the container has at least one slot at each corner for mounting, the method comprising the steps of: placing the container on the wagon. While placing the container on the wagon, the method comprises: pressing the lock head of the automatic torsional lock assembly provided on the wagon and rotating the lock head under the tension of a torsional spring provided in the automatic torsional lock assembly from a release position to lock position due to load of container, then receiving the lock head in lock position by the slot on the container, and rotating the lock head back to release position when the container placed on the wagon.
[0030] In yet another aspect, the present disclosure provides a method of demounting containers from a wagon provided with an automatic torsional lock assembly, the method comprising the steps of: pulling up the container from the wagon and while pulling up the container from the wagon, the method comprises pressing upward the base of lock head of the automatic torsional lock assembly provided on the wagon and rotating the lock head under the tension of a torsional spring provided in the automatic torsional lock assembly from a release position to lock position due to pulling force of the container, then releasing out of the lock head in lock position from the slot on the container and rotating the lock head back to release position when the container is pulled up from the wagon.
[0031] To further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit the scope of the present subject matter.
[0032] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS
[0033] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
[0034] FIG. 1A illustrates a perspective view of an automatic twist lock in accordance with state of the art;
[0035] FIG. 1B illustrates a front view of an automatic twist lock in accordance with state of the art;
[0036] FIG. 1C illustrates a top view of an automatic twist lock in accordance with state of the art;
[0037] FIG. 1D illustrates a bottom view of an automatic twist lock in accordance with state of the art;
[0038] FIG. 1E illustrates sub-component of an automatic twist lock in accordance with state of the art;
[0039] FIG. 2A illustrate a perspective view of an automatic torsional lock in accordance with an embodiment of the present disclosure;
[0040] FIG. 2B illustrate a front view of an automatic torsional lock in accordance with an embodiment of the present disclosure;
[0041] FIG. 2C illustrate a top view of an automatic torsional lock in accordance with an embodiment of the present disclosure;
[0042] FIG. 3 illustrate an exploded view of an automatic torsional lock in accordance with an embodiment of the present disclosure;
[0043] FIG. 4 illustrates a base plate in accordance with an embodiment of the present disclosure;
[0044] FIG. 5 illustrates a top plate in accordance with an embodiment of the present disclosure;
[0045] FIG. 5A illustrates bottom view of top plate with spring cavity in accordance with an embodiment of the present disclosure;
[0046] FIG. 6 illustrates a torsional spring in accordance with an embodiment of the present disclosure;
[0047] FIG. 7 illustrates a spindle in accordance with an embodiment of the present disclosure;
[0048] FIG. 7A illustrates a spindle bottom with spring cavity in accordance with an embodiment of the present disclosure;
[0049] FIG. 8 illustrates a spring guide in accordance with an embodiment of the present disclosure;
[0050] FIG. 9 illustrates a lock pin in accordance with an embodiment of the present disclosure;
[0051] FIG. 10 illustrates a lock head in accordance with an embodiment of the present disclosure;
[0052] The figures depict embodiments of the present subject matter for illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF INVENTION
[0053] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0054] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0055] The terminology used herein is to describe particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0056] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0057] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0058] In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
[0059] Hereinafter, a description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the present disclosure.
[0060] AToL (Automatic Torsional Lock) 100 as disclosed in accordance with an embodiment of the present disclosure, is a locking device, specially made to lock the ISO Containers on the BLC (Bogie Low Platform Container) flat wagons, and truck platforms for rail-road application i.e. by railways as well as road transportation of ISO Containers. A perspective view of an automatic torsional lock 100 is shown in Fig. 2A, a front view of an automatic torsional lock is shown in Fig. 2B and the top view of an automatic torsional lock in accordance with an embodiment of the present disclosure is shown in Fig. 2C.
[0061] AToL (Automatic Torsional Lock) 100 is fixed on the flat wagons. When container is to be placed on the flat wagon, the slots made on the bottom of the container (to lock the container), are positioned to the centre of the AToL 100. While container is lowered into AToL 100, the container weight gets applied on the AToL 100, the AToL 100 lock rotates, the lock head along with spindle is rotatable from a release position to lock position under the tension of torsional spring and the lock head in lock position is receivable by the slot on the container and after the container rests on the platform, the AToL 100 lock comes to its original position. And in case of pulling up the container (to unload from the flat wagon), AToL 100 lock again rotates to the straight position, thus container is released, and the AToL 100 lock comes to its original position.
[0062] AToL (Automatic Torsional Lock) saves the time and labour to load and unload the containers from the flat wagons. It was required to be developed for the quick, safe, and ease to lock the containers for the freight/goods trains and road transportation. AToL (Automatic Torsional Lock) consist of seven main components and having three supporting components, which are indicated in the exploded view of the ATol as shown in Fig. 3.
[0063] As shown in Fig. 3, a base plate 110 is placed at the bottom of the AToL (Automatic Torsional Lock) 100. It will be welded on the wagon platform. AToL Top plate 120 will be tightened on it with the help of four bolts and screws. AToL Spindle 140 is also placed inside the AToL Base Plate 110. O-ring 170 will also seal the internal diameter of the AToL Base Plate 110 with the spindle.
[0064] The automatic torsional lock AToL 100 assembly has a base plate 110 having a circular bore with a centre hole A and a top plate 120 placed over the base plate 110 having a centre B in alignment with centre hole A around a common longitudinal axis. It has a spindle 140 comprises a flat circular base and cylindrical rod with a top end extending upward from the base 110, wherein the base of spindle is mounted on the base plate 110 and the rod is passed through the centre hole A and centre hole B along the longitudinal axis and a lock head 190 mounted on the top head by a pin 160. The spindle 140 has a torsional spring 130 wound around a part of the cylindrical rod, wherein the torsional spring 130 has a lower end inserted in a slot on the base of the spindle 140 and an upper end inserted in a slot on the top plate 120, and an O ring 170 is provided between the base of the spindle 140 and the base plate 110.
[0065] Fig. 4 shows the base plate 110 of the automatic torsional lock. It is holding the complete AToL (Automatic Torsional Lock) assembly. AToL base plate is made of low carbon, weldable steel AISI 1018.
[0066] Fig. 5 shows the top plate 120 of the automatic torsional lock. It is placed on the AToL base plate 110 and bolted. High tensile alen bolts are provided to fix the top plate with the base plate. The top plate and the base plate, each having atleast one drilled hole at each corner and when the top plate is mounted on the base plate, the drilled holes of top plate comes over the tapped holes of base plate. Spindle 140 will be guided by the AToL top Plate 120. One end of the torsional spring 130 will be engaged in the AToL top plate 120. AToL top plate is made of carbon steel EN 9 and will be hard enough to sustain the load of the container and the tension of the torsional spring 130.
[0067] Fig. 6 shows the torsional spring 130. Torsional spring 130 is designed to provide a break free torsional movement of the AToL 100. Better quality material is selected, and heat treatment will be done accordingly. One end of the torsional spring 130 will be fixed with spindle’s bottom and other end will be fixed to the top plate 120. For fixing the ends of spring 130, a slot or groove is provided on the spindle bottom and top plate wherein the ends of the torsional spring are inserted. No pin is used for fixing. The bottom of spindle with spring cavity is shown in Fig. 7A and the bottom of the top plate with spring cavity is shown in Fig. 5A. When AToL spindle 140 rotates the torsional spring 130 will also get the torsional effect and it will force AToL spindle 140 to reverse back to the original position. AToL spring material AISI 6150 has been selected for better performance.
[0068] Fig. 7 shows the spindle 140, which is the critical component of the AToL (Automatic Torsional Lock) 100 and will be placed inside the base plate110 and top plate 120. One end of the torsional spring 130 will be engaged by the spindle base 141 and torsional spring 130 will be guided by the spindle 140. Lock head 190 will be fitted to the other end of the spindle 140. The spindle base 141 has a groove 142 for accommodation O-ring. Material of the spindle 140 is taken as AISI 4140 for its toughness and tensile strength.
[0069] Fig. 8 shows a spring guide 150. It is provided between the torsional spring’s two arms. It will work as a spacer between the AToL base plate 110 and AToL top plate 120.
[0070] Fig. 9 shows a lock pin 160. It is provided to engage the AToL Lock 100 and AToL Spindle 140. High tensile material EN 19 is used to sustain the load of the container.
[0071] In the present AToL 100, various O-Rings are provided for providing sealing effect against fluid. One O-Ring 170 Lock is provided to the lock to prevent water penetration into the AToL (Automatic Torsional Lock). The base of the spindle 140 has at least a circumferential groove and when the base of spindle is mounted on the base plate 110 on mounting, it seals the cylindrical area of the base plate 110 by accommodating the O-Ring 170. Another O-Ring 180 is provided to stop draining of the grease from the AToL (Automatic Torsional Lock), and also to prevent water penetration. This O-Ring 180 is provided between the lock head 190 and the top plate 120. O-Rings are made of the Nitrile Rubber for longer life and it is temperature resistant.
[0072] Fig. 10 shows a lock head 190. It is a hardened component specially made to sustain the container’s weight. The lock head has an upper surface protruded upward in the form of pyramid with at least four triangular sides and round edges. Lock head 190 is fitted on the one end of the AToL spindle 140. Lock Pin 160 has been provided to fit the lock head and the spindle 140. When container will be kept on the AToL (Automatic Torsional Lock), lock head 190 will rotate to straight position as per the designed direction and after the container rests, it rotates back to its original position. In case of pulling up the container, lock head 190 again rotate to straight position and container will be released from the AToL 100, and AToL 100 again come to its original position of 45 degree. Lock head 190 is made of the EN 9 material as per the design to sustain the mass of the container and push, pull forces.
[0073] To improve the container locking system, AToL (Automatic Torsional Lock) 100 saves the time and labour to load and unload the containers from the platforms. It was needed to be developed for the quick locking, safe and easy to lock the containers for the goods trains and road transportation.
[0074] The AToL (Automatic Torsional Lock) 100 as disclosed in the present disclosure is designed in a manner that, rainwater cannot penetrate it. To prevent water penetration O-Rings 170, 180 are provided in the lock and on the bottom of the AToL (Automatic Torsional Lock) 100. There is no such protection provided in the current designs in operation.
[0075] Torsional spring 130 is also designed to prevent malfunctioning of the lock and for the smooth operation. Torsional spring 130 is provided with required torque, without pin or clamping system which will give a break free operation, requiring no servicing. There will be no chance of breakage of pin or clamp.
[0076] Servicing of the AToL (Automatic Torsional Lock) 100 will only be required if the seal is damaged or water has entered the AToL (Automatic Torsional Lock). In case of water having entered the AToL (Automatic Torsional Lock) 100, there will be no damage happening to the internal parts and it will work in the normal course. If the seals are intact there will be no requirement of servicing for the whole life of 5 years. In case of service, the user need to clean the AToL (Automatic Torsional Lock) internally and change the seals and re-assemble by filling the grease for operation. Very easy to assemble and easy to service.
[0077] The present disclosure also provides a method of mounting containers on a wagon provided with an automatic torsional lock assembly, the container has at least one slot at each corner for mounting. The method comprising the steps of placing the container on the wagon and while placing the container on the wagon, the container body pressing the lock head of the automatic torsional lock assembly provided on the wagon and the pressure due to the weight of the container, rotating the lock head under the tension of a torsional spring provided in the automatic torsional lock assembly from a release position to lock position due to load of container. Upon rotating the lock head comes in line with the slot and the slot on the container receiving the lock head in lock position. When the container placed on the wagon, the torsional spring’s tension rotating the lock head back to release position.
[0078] The present further provides a method of demounting containers from a wagon provided with an automatic torsional lock assembly. The method comprising the steps of: pulling up the container from the wagon and while pulling up the container from the wagon, the pulling pressure pressing upward the base of lock head of the automatic torsional lock assembly provided on the wagon which rotating the lock head under the tension of a torsional spring provided in the automatic torsional lock assembly from a release position to lock position due to pulling force of the container. Upon rotating the lock head again gets aligned with the slot which releasing out the lock head in lock position from the slot on the container. When the container is pulled up from the wagon, the tension of the spring rotating the lock head back to release position.

TECHNICAL ADVANTAGES
[0079] The advantages of AToL (Automatic Torsional Lock) 100 disclosed in the present disclosure are given below:
a. AToL (Automatic Torsional Lock) is designed in a manner so that no water penetrates inside as likely inlet areas are sealed with O-Rings.
b. Torsional spring is provided with required torque, without pin or clamping system, which will result in a reliable operation without breaking and without requiring any service. There will be no chance of breakage of pin or clamp, either.
c. Grease will be filled into the AToL (Automatic Torsional Lock) to provide frictionless operation.
d. No service will be required till 2-3 years. Only seals (O-Rings) will be required to be checked. If needed, the same can be replaced.
e. Best raw materials used to achieve the working strength of the AToL (Automatic Torsional Lock and also due care is taken to avoid any breakage of the components.
f. Bolting of the upper plate is also improved w.r.t the lower plate. It will provide the strength to the whole assembly, and durability to the AToL (Automatic Torsional Lock) design.
g. With all these modifications in design, the life of the AToL (Automatic Torsional Lock) will improve and experience a break free operation.
h. Servicing of our AToL (Automatic Torsional Lock) will only be required if the seal is damaged or water has entered the AToL (Automatic Torsional Lock). In case of water having entered the AToL (Automatic Torsional Lock), there will be no damage happening to the internal parts and it will work in the normal course. If the seals are intact there will be no requirement of servicing for the whole life of 5 years. In case of service, we need to clean the AToL (Automatic Torsional Lock) internally and change the seals and re-assemble by filling the grease for operation. Very easy to assemble as well as to service.
i. Design of the AToL Base Plate is made in a manner so that welding it to flat wagon provides strength to the whole AToL (Automatic Torsional Lock), when container is pulled up to unlock from the flat wagon.
.
Equivalents
[0080] The foregoing description of the preferred embodiment of the invention has been presented for illustration and description. It is not intended to be exhaustive, nor is it intended to limit the invention to the precise form disclosed. It will be apparent to those skilled in the art that the disclosed embodiment may be modified in light of the above teachings.

We claim:

1. An automatic torsional lock assembly provided on a wagon for mounting and demounting containers on the wagon, the container has at least one slot at each corner for mounting, the automatic torsional lock comprising:
a base plate having a circular bore with a centre hole A;
a top plate placed over the base plate having a centre B in alignment with centre hole A around a common longitudinal axis;
a spindle comprises a flat circular base and cylindrical rod with a top end extending upward from the base, wherein the base of spindle is mounted on the base plate and the rod is passed through the centre hole A and centre hole B along the longitudinal axis;
a lock head mounted on the top head by a pin;
characterized in that the spindle has a torsional spring wound around a part of the cylindrical rod, wherein the torsional spring has a lower end inserted in a slot on the base of the spindle and an upper end inserted in a slot on the top plate, and
an O ring is provided between the base of the spindle and the base plate.
2. The automatic torsional lock assembly as claimed in claim 1, wherein the top plate and the base plate, each having atleast one hole at each corners and when the top plate is mounted on the base plate, the drilled holes of top plate comes over the tapped holes of base plate.
3. The automatic torsional lock assembly as claimed in claim 2, wherein the top plate is mounted on the base plate by introducing screws and bolts into the drilled holes.
4. The automatic torsional lock assembly as claimed in claim 1, wherein the lock head along with spindle is rotatable from a release position to lock position under the tension of torsional spring.
5. The automatic torsional lock assembly as claimed in claim 1, wherein the lock head along with spindle is rotatable from a release position to lock position and the lock head in lock position is receivable by the slot on the container.
6. The automatic torsional lock assembly as claimed in claim 1, wherein the base of the spindle has at least a circumferential groove and when the base of spindle is mounted on the base plate on mounting, it seals the cylindrical area of the Base Plate by accommodating the O ring
7. The automatic torsional lock assembly as claimed in claim 1, wherein the torsional spring is surrounded by a guide ring.
8. The automatic torsional lock assembly as claimed in claim 1, wherein the lock head has an upper surface protruded upward in the form of pyramid with at least four triangular sides and round edges.
9. The automatic torsional lock assembly as claimed in claim 1, wherein an O ring is provided between the lock head and the top plate.
10. The automatic torsional lock assembly as claimed in claim 1, wherein the base plate is made up of low carbon forged steel.
11. The automatic torsional lock assembly as claimed in claim 1, wherein the top plate and spindle are made up of high tensile forged steel.
12. The automatic torsional lock assembly as claimed in claim 1, wherein the torsional spring is made up of spring steel.
13. The automatic torsional lock assembly as claimed in claim 1, wherein the guide ring is made up of low carbon steel.
14. The automatic torsional lock assembly as claimed in claim 1, wherein the pin is made up of high tensile steel.
15. The automatic torsional lock assembly as claimed in claim 1, wherein the lock head is made up of carbon steel.
16. The automatic torsional lock assembly as claimed in claim 1, wherein the O ring is made up of nitrile rubber.
17. A method of mounting containers on a wagon provided with an automatic torsional lock assembly, the container has at least one slot at each corner for mounting, the method comprising the steps of:
placing the container on the wagon and while placing the container on the wagon, the method comprises:
pressing the lock head of the automatic torsional lock assembly provided on the wagon;
rotating the lock head under the tension of a torsional spring provided in the automatic torsional lock assembly from a release position to lock position due to load of container;
receiving the lock head in lock position by the slot on the container;
rotating the lock head back to release position when the container placed on the wagon.
18. A method of demounting containers from a wagon provided with an automatic torsional lock assembly, the method comprising the steps of:
pulling up the container from the wagon and while pulling up the container from the wagon, the method comprises
pressing upward the base of lock head of the automatic torsional lock assembly provided on the wagon;
rotating the lock head under the tension of a torsional spring provided in the automatic torsional lock assembly from a release position to lock position due to pulling force of the container;
releasing out of the lock head in lock position from the slot on the container;
rotating the lock head back to release position when the container is pulled up from the wagon.