DESC: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 LOWERING A RAISED DUMP BODY OF A DUMP TRUCK

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

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

[001] The present invention claims priority from Indian patent Provisional Application 202041004067 filed on 29 January 2020.
TECHNICAL FIELD
[002] The present invention relates to a system for lowering a dump body of a dump truck. More particularly, the present invention relates to a system for lowering the dump body of dump truck using a manually operated directional control valve.
BACKGROUND
[003] In a conventional dump truck, it is often required by the operator to conduct regular inspections in and around the dump truck, near control valve and inspection of AFS, ALS (Autonomous Loading System) and hydraulic connections. The inspection is carried out prior to start of work and also at the end of day by the operator using the dump truck. The dump body should be raised and locked in position while doing the inspection. During inspection, the operator shuts-off the engine to prevent damage to human life and equipments. Post completion of the truck inspection, the dump body is lowered on to the rails of mainframe.
[004] As the engine is shut-off most of the times during inspection with dump body in raised condition, operator has to climb up to the cabin to turn the key switch ON for starting the engine to lower the dump body. Once the operator cranks the engine and operates the joystick / lever / button, the raised dump body is lowered. In case of air operated valves, the operator has to override the DC valves to lower the dump body which results in loss of air pressure.
[005] The present invention is directed to overcome one or more limitations of the prior art discussed above.
OBJECT OF THE INVENTION
[006] Main object of the present invention is to provide a manually operated directional control valve for lowering raised body of dumper truck without cranking the engine of said dumper truck.
[007] Another object of the present invention is to provide a directional control valve for directing oil from the hoist cylinder of dump body to the oil tank for lowering the dump body of dump truck.
SUMMARY
[008] Before the present system for lowering the raised dump body of dump truck is described, it is to be understood that this application is not limited to the device(s), and methodologies described, as there can be multiple possible embodiments which 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 implementations or 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 system for lowering raised dump body of dump truck by a directional control valve. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.
[009] A system for lowering a raised dump body of a dump truck in an engine off state comprises a mainframe configured for mounting a dump body, a hydraulic circuit configured for raising and / or lowering said dump body and a directional control valve configured for directing flow of hydraulic fluid from a hoist cylinder to a tank via Hoist control valve which comprises of base spool and rod spool for raising & lowering said dump body.
BRIEF DESCRIPTION OF THE DRAWINGS
[010] The foregoing detailed description of embodiments is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present subject matter, an example of construction of the present subject matter is provided as figures; however, the present subject matter is not limited to the specific process and system disclosed in the document and the figures.
[011] The present subject matter is described in detail 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 various features of the present subject matter.
[012] Figure 1 illustrates a dump truck 100, in accordance with the present invention.
[013] Figure 2 illustrates hydraulic circuit 106, in accordance with the present invention.
[014] Figure 3 illustrates directional control valve 108, in accordance with the present invention.
[015] Figure 4 illustrates directional control valve 108, in accordance with the present invention.
[016] Figure 5 illustrates a symbolic representation of directional control valve 108 in normally closed position.
[017] Figure 6 illustrates a hydraulic oil circuit showing flow of oil during automated raising of dump body.
[018] Figure 7 illustrates a hydraulic oil circuit showing flow of oil during automated lowering of dump body.
[019] Figure 8 illustrates a hydraulic oil circuit showing flow of oil during manual lowering of dump body.
[020] Figure 9 illustrates a symbolic representation of directional control valve 108 in normally open position.
DETAILED DESCRIPTION
[021] Some embodiments of this disclosure, illustrating all its features, may 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. It must also be noted that as used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any assembly, device 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, assembly and methods are now described. The disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms.
[022] Various modifications to the embodiment may be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments of a system for lowering the raised dump body of dump truck. However, one of ordinary skill in the art may readily recognize that the present disclosure for a system for lowering the raised dump body of dump truck is not intended to be limited to the embodiments described, but is to be accorded the broadest scope consistent with the principles and features described herein.
[023] Referring now to Figure 1, a dump truck 100, in accordance with the present invention is disclosed. The dump truck 100 comprises a mainframe 104 configured for mounting a dump body 102, wherein the dump body 102 is used for carrying materials. The dump body 102 is configured to be raised and/or lowered.
[024] Referring now to Figure 2 a hydraulic circuit 106, in accordance with the present invention is disclosed. The hydraulic circuit 106 comprises control valves, filter and cylinder for raising and/or lowering said dump body 102.
[025] Referring now to Figure 3 and Figure 4,a directional control valve 108, in accordance with the present invention is disclosed. Further, referring to Figure 5 a symbolic representation of directional control valve 108, in accordance with the present invention is disclosed. The directional control valve 108 allow fluid flow into different paths from one or more sources. The directional control valves 108 can be mechanically or electrically actuated.
[026] A system for lowering a raised dump body 102 of a dump truck100 in an engine off state comprises a mainframe 104 configured for mounting a dump body 102.A hydraulic circuit 106 is configured for raising and/or lowering said dump body 102 and a directional control valve 108 configured for directing flow of hydraulic fluid from a hoist cylinder to a tank via base spool and rod spool for lowering said dump body 102.
[027] The directional control valve 108 is configured to operated manually and mounted on inner side of left hand rail of said mainframe 104. Further, the directional control valve 108 is configured to maintain a normally closed position.
[028] Figure 5, Figure 6 and Figure 7 illustrates a symbolic representation of directional control valve 108 in normally closed position, a hydraulic oil circuit showing flow of oil during automated raising of dump body and a hydraulic oil circuit showing flow of oil during automated lowering of dump body respectively. The directional control valve 108 is maintained in a normally closed position during automated raising and lowering of dump body.
[029] During automated raising of dump body, oil flows from tank to hoist cylinder as indicated by arrows in Figure 6. The hydraulic circuit 106 is configured to raise said dump body 102 by directing flow of hydraulic fluid from said tank to said hoist cylinder via inlet line and base spool.
[030] During automated lowering of dump body, pilot valve allows oil flow to rod spool of hoist control valve and then to hoist cylinder lower port. Thus, the oil from hoist cylinder flows to tank.
[031] Figure 8 illustrates a hydraulic oil circuit showing flow of oil during manual lowering of dump body and Figure 9 illustrates a symbolic representation of directional control valve 108 in normally open position.
[032] During manual lowering, upon actuation of directional control valve, base and rod spool of hoist control valve is connected to tank, which allows the oil flow from base end of hoist cylinders to tank.
[033] Exemplary system 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.
[034] Some object of the invention is to provide a system for lowering dump body of dump truck without cranking the engine.
[035] Some object of the invention is to provide a system configured to adapt readily available directional control valves.
[036] Some objective of the invention is to reduce the effort and time of the operator.
,CLAIMS:
1. A system for lowering a raised dump body (102) of a dump truck (100) in an engine off state comprises:
a mainframe (104) configured for mounting a dump body (102);
a hydraulic circuit (106) configured for raising and/or lowering said dump body (102); and
a directional control valve (108) configured for directing flow of hydraulic fluid from a hoist cylinder to a tank via base spool and rod spool for lowering said dump body (102).

2. The system as claimed in claim 1, wherein said hydraulic circuit (106) is configured to raise said dump body (102) by directing flow of hydraulic fluid from said tank to said hoist cylinder via inlet line and base spool of hoist control valve.

3. The system as claimed in claim 1, wherein said hydraulic circuit (106) is configured to lower said dump body (102) by directing flow of hydraulic fluid from said hoist cylinder to said tank via rod spool of hoist control valve.

4. The system as claimed in claim 1, wherein said directional control valve (108) is configured to operated manually.

5. The system as claimed in claim 1, wherein said directional control valve (108) is configured to be mounted on inner side of left hand rail of said main frame (104).

6. The system as claimed in claim 1, wherein said directional control valve (108) is configured to maintain a normally closed position.