Claims:
WE CLAIM:
1. A system for automatically closing side discharge loader bucket doors, the system comprising:
a Left Hand Side (LHS) bucket door (1) and a Right Hand Side (RHS) bucket door (2) hinged on LHS and RHS of a bucket respectively, wherein the LHS bucket door (1) and the RHS bucket door (2) are coupled with a LHS Door Cylinder (3) and a RHS Door Cylinder (4) respectively,
a control valve with lever (17) having three control modes for controlling opening of the LHS bucket door (1) and the RHS bucket door (2), wherein the three control modes comprise ‘Forward’ mode (13), ‘Reverse’ mode (14), and ‘Neutral’ mode (15);
a Flame Proof Induction Motor (21) configured to actuate a triple Gear pumps, wherein a first Gear pump (6) or the second Gear pump (20) provides hydraulic power to actuate the control valve in either ‘Forward’ mode (13) or ‘Reverse’ mode (14) respectively, and wherein the first Gear pump (6) or the second Gear pump (20) facilitates to deliver Fire Resistant Hydraulic Fluid (FRHF) from a Hydraulic tank (9) to a Control valve in order to maintain a pressure up to a first predefined threshold limit thereby enabling the LHS Door Cylinder (3) or the RHS Door Cylinder (4) to expand and keep either the LHS bucket door (1) or the RHS bucket door (2) in an Opened position, and wherein a third Gear pump (7) facilitates to deliver FRHF through a pressure reducing valve (8), and wherein the pressure reducing valve (8) is configured to maintain a constant pressure of a second predefined threshold limit in order to retract the LHS Door Cylinder (3) and the RHS Door Cylinder (4) and bring both the LHS bucket door (1) and the RHS bucket door (2) to a Closed position, thereby ensuring automatic closing side discharge loader bucket doors.

2. The system as claimed in claim 1, wherein the LHS Door Cylinder (3) and the RHS Door Cylinder (4) comprises a bottom end and a rod end, wherein the bottom end and the rod end facilitate opening or closing the LHS bucket door (1) or the RHS bucket door (2).

3. The system as claimed in claim 1, wherein the FRHF is delivered from the Hydraulic tank to the Control valve via a Relief valve (11).

4. The system as claimed in claim 1, wherein the LHS bucket door (1) and the RHS bucket door (2) are held to the Closed position by supplying FRHF flow at a constant pressure of 20±2 bar by the third Gear pump (7) using the pressure reducing valve (8).

5. The system as claimed in claim 1, wherein one of the LHS bucket door (1) or the RHS bucket door (2) is kept at the Opened position by supplying the FRHF to pressure line corresponding to one of the LHS Door Cylinder (3) or the RHS Door Cylinder (4).

6. The system as claimed in claim 1, wherein the first predefined threshold limit ranges between 120 bar to 140 bar, and wherein the second predefined threshold limit ranges between 20±2 bar.

7. The system as claimed in claim 1 further comprises a conveyor mechanism operated by a bi-directional Conveyor Motor (5), wherein the conveyor mechanism dispenses objects, lying on the conveyor mechanism coal, through one of the LHS bucket door (1) or the RHS bucket door (2).
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
A SYSTEM FOR AUTOMATICALLY CLOSING SIDE DISCHARGE LOADER BUCKET DOORS

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru,
Karnataka - 560 027, India

The following specification describes the invention and the manner in which it is to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application does not claim priority from any patent application.

TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to system and method for automatically closing side discharge loader bucket doors without manual intervention. More specifically, the system and method for automatically closing side discharge loader bucket doors.

BACKGROUND
[003] In a conventional Side Discharge Loader Bucket, one side of the Bucket Door, either left side or right side bucket door, is connected to a Hydraulic Cylinder which in turn is connected to a 3-position (Forward, Neutral and Reverse) control valve. When an operator pushes the control valve lever in either Forward or Reverse direction, the conveyor in the Side Discharge Bucket starts moving in either clockwise or anti-clockwise direction (as per the selected position). Accordingly, the Hydraulic Cylinder opens the Bucket Door and material is discharged through opening of the Bucket Door.
[004] After complete discharging of the material, the operator has to manually operate the control valve lever in opposite direction in order to close the door. This becomes a very tedious and fatigues task, as the operator has to pay attention for closing the bucket door by operating the control valve lever in the opposite direction. The conventional Side Discharge Loader Bucket further becomes cumbersome, considering the extreme working conditions in underground mines, in changing the piping when the direction of the conveyor needs to be changed.

SUMMARY
[005] Before the present system and method are described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to a technology being implemented in a system for automatically closing side discharge loader bucket doors and the aspects are further elaborated below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[006] In one implementation, a system for automatically closing side discharge loader bucket doors is disclosed. The system comprises a Left Hand Side (LHS) bucket door and a Right Hand Side (RHS) bucket door hinged on LHS and RHS of a bucket respectively. In one aspect, the LHS bucket door and the RHS bucket door are coupled with a LHS Door Cylinder and a RHS Door Cylinder respectively. The system further comprises a control valve with lever having three control modes for controlling opening of the LHS bucket door or the RHS bucket door, by pushing or pulling the control valve lever and upon releasing the control valve lever, the lever comes back to neutral condition. The system further comprises a Flame Proof Induction Motor configured to actuate a triple Gear pump, of which hydraulic power of the first Gear pump is used for controlling the opening of either of the bucket doors.
[007] In another aspect, a third Gear pump facilitates to deliver FRHF through a pressure reducing valve. The pressure reducing valve is configured to a second predefined threshold limit in order to retract the LHS Door Cylinder and the RHS Door Cylinder, ensuring both the LHS bucket door and the RHS bucket door in a Closed position. Based on the aforementioned functioning, the system may automatically facilitate closing side discharge loader bucket doors.
[008] It may be noted that the first Gear pump facilitates to deliver Fire Resistant Hydraulic Fluid (FRHF) from a Hydraulic tank to a Control valve and maintains a pressure up to a first predefined threshold limit, when control valve lever is pushed forward or pulled reverse thereby enabling the LHS Door Cylinder or the RHS Door Cylinder to expand when the pressure in the respective cylinder port exceeds above second predefined threshold limit, ensuring respective bucket door in an Opened condition until the control valve lever is released to the ‘Neutral’ mode. Upon releasing the control valve lever to neutral position, since there is continuous constant pressure of 20±2 kg/cm² on the rod end side of LH / RH bucket cylinder (a second predefined threshold limit) supplied by the third Gear pump, the corresponding bucket door closes automatically without the intervention of operator.

BRIEF DESCRIPTION OF THE DRAWINGS
[009] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawings:
[0010] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
[0011] Figure 1 illustrates a schematic of a bucket assembly, in accordance with an embodiment of the present subject matter.
[0012] Figure 2 illustrates a Hydraulic Circuit for Control valve in ‘Forward’ mode, Right Hand Side (RHS) bucket door opened, in accordance with an embodiment of the present subject matter.
[0013] Figure 3 illustrates a Hydraulic Circuit for Control valve in ‘Reverse’ mode, Left Hand Side (LHS) bucket door opened, in accordance with an embodiment of the present subject matter.
[0014] Figure 4 illustrates Hydraulic Circuit for Control valve in ‘Neutral’ mode, LHS bucket door and RHS bucket door are closed, in accordance with an embodiment of the present subject matter.
[0015] The figures depict various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion 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
[0016] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, systems and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0017] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0018] In the underground mine galleries are confined due to space constraints and as such in convention SDLs, it has been observed that the material may not be discharged directly onto a conveyor by curling out operation. It has been noted that Side Discharge Loader (SDL) with a bucket is designed to scoop material heap in the bucket, carry the material to the loading point and discharge the material (without curling out the bucket) onto a conveyor or tubs for taking them to surface from underground.
[0019] Thus, the regular practice of discharging the material from the side of the bucket in underground coal mines is carried out through hydrostatically driven conveyor mechanism. It may be noted that the material may be discharged from either right or left side of the bucket. More specifically, the material may be discharged by opening either a Left Hand Side (LHS) bucket door or a Right Hand Side (RHS) bucket door. After discharging the material through one of the LHS bucket door or the RHS bucket door, the operator has to manually pull the control valve lever in opposite direction in order to close the bucket door. This becomes a very tedious and fatigues task as the operators has to pay attention for closing the bucket door by pushing or pulling the control valve lever. To overcome the limitation, the system ensures automatic closing of bucket doors without intervention of an operator.
[0020] Referring to figure 1 illustrating a schematic diagram of the bucket is disclosed. As shown in the figure, the bucket comprises the LHS bucket door 1 and the RHS bucket door 2 hinged on LHS and RHS of the bucket respectively on the bucket. The LHS bucket door 1 and the RHS bucket door 2 are coupled with a LHS Door Cylinder 3 and a RHS Door Cylinder 4 respectively. More specifically, the LHS Door Cylinder 3 and the RHS Door Cylinder 4 comprises a bottom end and a rod end which facilitate opening or closing the LHS bucket door 1 or the RHS bucket door 2. In addition of the above, the bucket is also equipped with a bi-directional Conveyor Motor 5 configured to drive a chain conveyor mechanism for discharging the material through the opening of either the LHS bucket door 1 or the RHS bucket door 2.
[0021] Referring to figures 2, 3, and 4 illustrating schematic diagrams of Hydraulic Circuit for various positions of a control valve and its corresponding positions of the bucket doors. In addition to the LHS bucket door 1, the RHS bucket door 2, the LHS Door Cylinder 3, and the RHS Door Cylinder 4 as shown in the figure 1, the Hydraulic Circuit further comprises a control valve with lever 17, a Flame Proof Induction Motor 21, triple Gear pumps including a first Gear pump 6, a second Gear pump 20, and a third Gear pump 7, Fire Resistant Hydraulic Fluid (FRHF) stored in a Hydraulic tank 9.
[0022] It may be understood that the control valve with lever 17 is having three control modes for controlling opening and closing of the LHS bucket door 1 and the RHS bucket door 2. The three control modes comprise may ‘Forward’ mode 13, ‘Reverse’ mode 14, and ‘Neutral’ mode 15. It may be noted that when the control valve lever 17 is pushed to the ‘Forward’ mode 13, the LHS Door Cylinder 3 facilitates opening of the LHS bucket door 1. Whereas, when the control valve lever 17 is pulled to the ‘Reverse’ mode 14, the RHS Door Cylinder 4 facilitates opening of the RHS bucket door 2. In addition to the above, when the control valve lever 17 is released to the ‘Neutral’ mode 15 either from 'Forward' or 'Reverse' mode, the LHS Door Cylinder 3 and RHS Door Cylinder 4 facilitate closing of the LHS bucket door 1 and the RHS bucket door 2 respectively, since the hydraulic pressure in the respective opposite cylinder port is less than the second predefined threshold limit or nil.
[0023] The Flame Proof Induction Motor 21 is a prime mover, which drives the triple Gear pumps i.e. the first Gear pump 6, the second Gear pump 20, and the third Gear pump 7. Once the Flame Proof Induction Motor 21 is actuated, FRHF is extracted from Hydraulic tank 9 and delivered to respective pressure lines 12, 18, 19 via a control valve through a relief valve 11. It may be noted that the FRHF is delivered by at least one of the first Gear pump 6, the second Gear pump 20, and the third Gear pump 7. In one aspect, the pressure lines 12, 18, 19 helps in maintaining a pressure in the range between 120 bar to 140 bar.
[0024] In order to elucidate functioning of the Hydraulic Circuit facilitating automatic closure of the side discharge loader bucket doors, refer to figures 2, 3, and 4 illustrating various positions of the control valve with lever 17 and corresponding positions of discharge loader bucket doors. Consider a scenario where the operator shifts the control valve lever 17 to a ‘Forward’ mode 13, the first Gear pump 6 deliver FRHF from the Hydraulic tank 9 to a Control valve in order to maintain a pressure up to a first predefined threshold limit. In one aspect, the first predefined threshold limit ranges between 120 bar to 140 bar.
[0025] Similarly, when the operator shifts the control valve lever 17 to a ‘Reverse’ mode 14, the first Gear pump 6 deliver FRHF from the Hydraulic tank 9 to the Control valve in order to maintain a pressure up to a first predefined threshold limit. In both modes (i.e. ‘Forward’ mode 13 and ‘Reverse’ mode 14), the FRHF is supplied to respective pressure lines 18, 19 corresponding to one of the LHS Door Cylinder 3 and the RHS Door Cylinder 4.
[0026] In other words, the hydraulic operating pressure ranges between 50 to 80 bar and relieves between 120 bar to 140 bar is transferred to the pressure lines 18, 19 based on the ‘Forward’ mode 13 / ‘Reverse’ mode 14 respectively. The mentioned operating pressure ranges between 120 bar to 140 bar when applied on the LHS Door Cylinder 3 or the RHS Door Cylinder 4 enables opening of the LHS bucket door 1 or the RHS bucket door 2 respectively. Once the LHS bucket door 1 or the RHS bucket door 2 is opened, the material in the bucket is discharged by a bi-directional conveyor motor 5 through the opening of the LHS bucket door 1 or the RHS bucket door 2.
[0027] After discharging the material from the bucket and on release of control valve lever 17, a control valve comes back to the ‘Neutral’ mode and the pressure in pressure lines 19, 18 will be less than second predefined threshold limit. When the control valve lever 17 is at the ‘Neutral’ mode 15, FRHF from Pressure line 16 is not supplied to pressure lines 18, 19. Instead, FRHF is directed to travel circuit through a flow divider 21.
[0028] The FRHF oil from the third Gear pump 7 lead to pressure line 12 through the relief valve 23, a check valve 10 and the pressure reducing valve 8. The relief valve 23 ensures the pressure in pump 3 line shall not exceed more than 50 bar and the check valve 10 ensures that flow direction of the FRHF is maintained. It may be noted that main function of the pressure reducing valve 8 is to maintain a constant pressure of a second predefined threshold limit in order to retract the LHS Door Cylinder 3 and the RHS Door Cylinder 4 and bring both the LHS bucket door 1 and the RHS bucket door 2 to a Closed position. In one aspect, the second predefined threshold limit ranges between 20±2 bar. In other words, when the constant pressure within the range of 20±2 bar is applied at the rod end of the LHS Door Cylinder 3 and the RHS Door Cylinder 4 resulting into automatically closure of the respective doors without operator’s intervention. Thus, in this manner, the present system ensures that the Side Discharge Bucket Door is closed automatically without intervention of an operator, once the control valve lever is released to ‘Neutral’ mode 15 after discharging the material from the bucket.
[0029] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features.
[0030] The present system ensures that the Side Discharge Bucket Door is closed automatically without intervention of an operator, once the control valve lever is released to ‘Neutral’ mode after discharging the material from the bucket.
[0031] The present system facilitates enhanced operator's comfort by reducing the operator's fatigue and improves productivity.
[0032] The present system helps in avoiding spillage of the material when the loader is travelling with bucket in fully loaded condition.