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 COUNTER WEIGHT LINKAGE MECHANISM FOR PIPELAYER MACHINE AND METHOD OF ITS OPERATION

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 202141006851 filed on 18 February 2021.

TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to a counter weight linkage mechanism for pipelayer machine and method of its operation.

BACKGROUND
[003] A pipelayer machine is a machine that is specially designed to lay sections of pipe in a trench to create a pipeline. Previously, cranes had been used to raise up pipe sections and lower them into a trench. However, the cranes were not very maneuverable and were commonly modified from cranes designed for other purposes to be used for installing the pipe sections in the trench. Eventually, excavators and crawlers began to be used for installing pipe sections with kits being made and sold to convert an excavator or crawler over for pipe installation duty. Eventually, purpose-made pipelayer machines were designed the sole purpose of which was the installation of pipe section in a pre-made trench.

[004] A pipelayer machine will typically have tracks and a crawler body with an engine. A side boom can extend to one side of the pipelayer machine and the raising and lowering of the side boom is handled by a boom winch. A hook winch, hook cable and hook are used to pick up and raise a load, such as a section of pipe. The hook winch winds and unwinds the hook cable, which is connected to the hook and is suspended from the end of the boom.

[005] These pipelayer machines are used to lay pipe in a trench by using the tracks to maneuver the pipelayer machine next to a trench the pipe section will be placed in. The hook cable and hook are used with the boom to connect to the pipe section and the hook winch is used to raise the pipe section from the ground. Then, using the boom, the pipelayer machine moves the pipe section over the trench and lowers the pipe section into the trench. Commonly, a number of pipelayer machines will be used at the same time to raise and lower the pipe section into the trench with a number of the pipelayer machines working in unison to raise and lower a single pipe section.

[006] Generally, a pipelayer machine is an off-highway equipment used for operations in pipeline laying projects, construction sites, open cast mines for conveyor shifting and the like. Pipelayer machines are equipped with a side boom fitted with a forged type adjustable hook for holding a load. The hook may be lowered or raised at different speeds through one or more wire ropes driven by hydraulic winches. The main function of the pipelayer machine is to handle the load at different boom overhang positions and carry the load over long distances in uneven mine sites. Centre of gravity of the machine changes while lifting or lowering the heavy loads. This causes imbalance, makes the machine to tip one side, and leads to instability of pipelayer machine.

OBJECT OF THE INVENTION
[007] Main object of the present invention is to provide balance and stability to a pipelayer machine during lifting or lowering of heavy loads.
[008] Another object of the present invention to provide counter weight linkage mechanism on the opposite side of hook to maintain the center of gravity of the pipelayer machine.
[009] Another object of the present invention to develop a hydraulic mechanism to achieve a balance point for the pipelayer machine on lifting different loads at multiple boom overhang positions.

SUMMARY
[0010] Before the present system and method for operating pipelayer machines 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 system and method for operating pipelayer machines, and the aspects are further elaborated below in the detailed description.
[0011] 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.
[0012] The present subject matter discloses a counter weight linkage mechanism and method of its operation for pipelayer machine. The system comprises of a counter weight attached on opposite side of a hook of the pipelayer machine. The counter weight is operated through a linkage mechanism. The linkage mechanism comprises atleast one of an arm, a link, a bracket and one or more frame structures. The linkage mechanism is further operated by one or more hydraulic cylinders. The one or more hydraulic cylinders are energized by atleast one of a hydraulic pump, or a directional control valve using a PPC valve. The extension of the one or more hydraulic cylinders enables tipping out of the counter weight on opposite side of the hook for balancing of the pipelayer machine.

STATEMENT OF INVENTION

[0013] Accordingly, the present invention discloses an a counter weight linkage mechanism for a pipelayer machine comprises; atleast one counter weight bracket, atleast one counter weight arm, atleast one counter weight link, atleast one counter weight frame, plurality of pins and atleast one counter weight block to provide balance and stability to a pipelayer machine during lifting or lowering of heavy loads of pipes. A method of operating the counter weight linkage mechanism for a pipelayer machine comprising the steps of – starting the pipelayer machine and detecting the presence of load on boom, marching the pipelayer machine with counter weight fully retracted on detection of boom load within a predefined limit, balancing the pipelayer machine on detecting boom above a predefined minimum boom overhang load by operating the joystick to move the counter weight control valve spool for supplying hydraulic fluid to counter weight cylinders to extend the counter weight linkage mechanism for optimal balancing of the pipelayer machine.

[0014] Accordingly, the present invention discloses a counter weight linkage mechanism for a pipelayer machine wherein the said counter weight linkage mechanism is configured to maintain the varying center of gravity of the pipelayer machine and operated by hydraulic mechanism through one or more hydraulic cylinders. The counter weight linkage mechanism for a pipelayer machine wherein the hydraulic mechanism is configured to maintain the center of gravity of the pipelayer machine on lifting different loads at multiple boom overhang positions. The counter weight linkage mechanism for a pipelayer machine wherein the said counter weight block is configured to be mounted on counter weight bracket with plurality pins of predetermined diameter for easy assembling and disassembling of the counter weights. The counter weight linkage mechanism for a pipelayer machine wherein one or more hydraulic cylinders are configured with atleast one hydraulic pump or a directional control valve using a PPC valve to actuate the hydraulic cylinder for extension and retraction of counter weight linkage mechanism. The counter weight linkage mechanism for a pipelayer machine wherein the hydraulic mechanism to actuate the counter weight linkage mechanism is configured with a counter weight pump, a pilot pump, a counter weight control valve, a slow return valve, a relief valve and a joystick for counter weight control valve. Further, a seal is configured in the hydraulic cylinder to ensure safety and stability of the pipelayer machine by taking the counter weight linkage mechanism to a retracted position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawing. 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 drawing:
[0016] The detailed description is described with reference to the accompanying figure. In the figure, 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 drawing to refer like features and components.
[0017] Figure 1 illustrates a schematic diagram of a counter weight linkage mechanism for a pipelayer machine in accordance with an embodiment of the present subject matter.
[0018] Figure 2 illustrates a schematic diagram of a hydraulic circuit for a counter weight operation performed by a pipelayer machine in accordance with an embodiment of the present subject matter.
[0019] Figure 3 illustrates a schematic diagram of a counter weight linkage mechanism for a pipelayer machine in open position in accordance with an embodiment of the present subject matter.
[0020] Figure 4 illustrates a schematic diagram of a counter weight linkage mechanism for a pipelayer machine in closed position in accordance with an embodiment of the present subject matter.
[0021] Figure 5 illustrates a schematic diagram of a system for operating a pipelayer machine in accordance with an embodiment of the present subject matter.
[0022] Figure 6 illustrates a schematic diagram of components of the system for operating a pipelayer machine in accordance with an embodiment of the present subject matter.
[0023] Figure 7 illustrates a flow chart for performing counter weight operations on a pipelayer machine in accordance with an embodiment of the present subject matter.
[0024] The figure depicts 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
[0025] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, 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 for system and method for operating pipelayer machines are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0026] 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.
[0027] 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.
[0028] As referred in the background, the conventional processes of lifting, lowering and carrying of heavy loads in an open cast mine with an uneven terrain are challenging and may have a direct bearing on production activities due to any delay. In the conventional processes of laying the oil or gas pipelines, huge & massive pipes have to be joined with each other to form long and continuous lines. During the process, the pipes are to be held by pipelayer machines simultaneously. After completion of the process, the pipes have to be carried to the laying sites requiring accurate operations. During lifting or lowering of the heavy loads, the pipelayer machine is required to be stable without any imbalance. Generally, centre of gravity of the pipeline machine changes while lifting or lowering the heavy loads. The change in the centre of gravity causes imbalance and tipping of the pipelayer machine to one side.
[0029] The above problems in the conventional processes are overcome by the present subject matter. The present subject matter discloses a system of counter weight linkage mechanism for operating a pipelayer machine. The system comprises of a of counter weight linkage mechanism attached on opposite side of a hook of the pipelayer machine. The counter weight is operated through a linkage mechanism. The linkage mechanism may comprises atleast one of an arm, a link, a bracket and one or more frame structures. The linkage mechanism is operated by one or more hydraulic cylinders. The one or more hydraulic cylinders are energized by atleast one of a hydraulic pump, or a directional control valve using a PPC valve. The extension of the one or more hydraulic cylinders enables tipping out of the counter weight on the opposite side of the hook for balancing of the pipelayer machine.
[0030] The present subject matter uses such counter weight linkage mechanism during lifting, lowering and free marching with the heavy load in order to maintain the balance and stability of the pipelayer machine.
[0031] In addition, in the present subject matter, one or more counter weight brackets are mounted on a vertical face or plate of track frame structure unlike the conventional processes. The counter weights are mounted on two 150 diameter pins of counter weight bracket that helps in easy assembling and disassembling of the counter weights. The counter weights are extended with an extension of one or more cylinders connected to counter weight arm such that flow is going to piston side of the cylinder. Further, any failure of seal of the cylinder makes the counter weight linkage mechanism to come to a retracted position and ensure the safety and stability of the equipment. In addition, a slow return valve is introduced in return line during retraction of the cylinder. Hence, the speed of the counter weight is reduced during closing towards the pipelayer machine and avoids a sudden impact on the pipelayer machine.
[0032] Referring now to figure 1, a schematic diagram of a counter weight linkage mechanism for a pipelayer machine is illustrated in accordance with an embodiment of the present subject matter.
[0033] Referring now to figure 2, a schematic diagram of a hydraulic circuit for a counter weight operation performed by a pipelayer machine is illustrated in accordance with an embodiment of the present subject matter.
[0034] Referring now to figure 3, a schematic diagram of a counter weight linkage mechanism for a pipelayer machine in open position is illustrated in accordance with an embodiment of the present subject matter.
[0035] Referring now to figure 4, a schematic diagram of a counter weight linkage mechanism for a pipelayer machine in closed position is illustrated in accordance with an embodiment of the present subject matter.
[0036] Referring now to Figure 5, a schematic diagram of a system for operating a pipelayer machine is illustrated in accordance with an embodiment of the present subject matter.
[0037] Referring now to Figure 6, a schematic diagram of components of the system for operating a pipelayer machine is illustrated in accordance with an embodiment of the present subject matter.
[0038] Referring now to figure 7, a flow chart for performing counter weight operations on a pipelayer machine is illustrated in accordance with an embodiment of the present subject matter.
[0039] Further, the figure 1, figure 2, figure 3, figure 4, figure 5, figure 6 and figure 7 are explained together.
[0040] The present subject matter discloses a system counter weight linkage mechanism (100) for operating a pipelayer machine (70). The system comprises of a counter weight attached on opposite side of a hook of the pipelayer machine. The counter weight is operated through a linkage mechanism. The linkage mechanism is a four-bar linkage mechanism. The four-bar linkage mechanism for the operation of the counter weight of a BP100 pipelayer machine is as shown in the figures 1-6. The linkage mechanism comprises of atleast one of an arm, a link, a bracket and one or more frame structures. The one or more frame structures are designed to maintain a total centre of gravity (76) of the counter weight interconnected using one or more heat-treated pins with bushes to form one or more pin joints. The one or more pin joints are well lubricated.
[0041] In one embodiment, the counter weight linkage mechanism (100) comprises a counter weight bracket (10), a counter weight arm (20), a counter weight link (30), a counter weight frame (40), one or more counter weight blocks (50), one or more pins (60), one or more bushes, one or more bolts, one or more washers, one or more shims and the like as shown in figure 6.
[0042] Further, the counter weight linkage mechanism is operated by one or more hydraulic cylinders using a hydraulic mechanism. The one or more hydraulic cylinders is energized by atleast one of a hydraulic pump, or a directional control valve using a PPC valve. The extension of the one or more hydraulic cylinders enables tipping out of the counter weight on opposite side of the hook for balancing of the pipelayer machine. The hydraulic mechanism comprises of a counter weight pump, pilot pump, a counter weight control valve, a slow return valve, a relief valve, a joystick for counter weight control valve.
[0043] In one implementation, there may be no load on the hook and the counter weight may be in home position with an arm structure in vertical condition. In another implementation, lifting of the load by the hook may cause an overturning moment on the pipelayer machine. At this time, the pipelayer machine may be likely to tip about an inner side of left side track and may lose stability. At this point, the counter weight mounted on right side is tipped outside to get the required balance point in order to maintain the stability of the pipelayer machine. Further, a stability equation is written based on the different loads acting at different positions. The equation is shown below.
[0044] By taking moments about the tipping line,
P*1700=W*1.485+Cw*x
[0045] In the above equation, the different load values for P and relevant overhang
distances ‘x’ are substituted to achieve a balance point under each condition.

[0046] In one embodiment, it may be observed that by increasing the tipping of the counter weight, greater stability of the pipelayer machine may be achieved, such that the heavy loads at higher boom overhang positions may be easily lifted or lowered. Further, one or more mechanical stoppers are provided on relevant links of the four-bar linkage mechanism such that the tip-out or tip-in range is well controlled.
[0047] A counter weight linkage mechanism (100) for a pipelayer machine (70) comprises; atleast one counter weight bracket (10), atleast one counter weight arm (20), atleast one counter weight link (30), atleast one counter weight frame, plurality of pins (60) and atleast one counter weight block (50) to provide balance and stability to a pipelayer machine (70) during lifting or lowering of heavy loads of pipes. A method of operating the counter weight linkage mechanism (100) for a pipelayer machine (100) comprising the steps of – starting the pipelayer machine and detecting the presence of load on boom, marching the pipelayer machine with counter weight fully retracted on detection of boom load within a predefined limit, balancing the pipelayer machine on detecting boom above a predefined minimum boom overhang load by operating the joystick to move the counter weight control valve spool for supplying hydraulic fluid to counter weight cylinders to extend the counter weight linkage mechanism for optimal balancing of the pipelayer machine.
[0048] The counter weight linkage mechanism (100) for a pipelayer machine (70) wherein the said counter weight linkage mechanism (100) is configured to maintain the varying center of gravity (76) of the pipelayer machine (70) and operated by hydraulic mechanism through one or more hydraulic cylinders. The counter weight linkage mechanism (100) for a pipelayer machine (70) wherein the hydraulic mechanism is configured to maintain the center of gravity of the pipelayer machine on lifting different loads at multiple boom overhang positions. The counter weight linkage mechanism (100) for a pipelayer machine (70) wherein the said counter weight block (50) is configured to be mounted on counter weight bracket (10) with plurality pins of predetermined diameter for easy assembling and disassembling of the counter weights. The counter weight linkage mechanism (100) for a pipelayer machine (70) wherein one or more hydraulic cylinders are configured with atleast one hydraulic pump or a directional control valve using a PPC valve to actuate the hydraulic cylinder for extension and retraction of counter weight linkage mechanism (100). The counter weight linkage mechanism (100) for a pipelayer machine (70) wherein the hydraulic mechanism to actuate the counter weight linkage mechanism (100) is configured with a counter weight pump, a pilot pump, a counter weight control valve, a slow return valve, a relief valve and a joystick for counter weight control valve. Further, a seal is configured in the hydraulic cylinder to ensure safety and stability of the pipelayer machine (70) by taking the counter weight linkage mechanism (100) to a retracted position.
[0049] The whole movement of the linkage mechanism is controlled with a hydraulic mechanism. Multiple safety features are built in the hydraulic mechanism to safe guard against jerks, sudden shocks, causing sudden pressure rise, etc. All components of the hydraulic mechanism have a compact design to keep frictional losses due to fluid flow to minimum.
[0050] In one embodiment, during designing of the hydraulic mechanism that actuates to operate the counter weight linkage mechanism on BP100 Pipe layer, the one or more hydraulic cylinders are not be loaded always. Further, care is taken so that the hydraulic cylinder does not directly take the load of the counter weight. The hydraulic cylinder is used to swing the counter weights along with the frame. In case of seal failure of the hydraulic cylinder, the whole linkage mechanism comes back to the home position without falling off onto the ground from the pipelayer machine, leading to smooth operation of the counter weight with slow return valve. The hydraulic cylinder will not always be in extended position when the machine is in off-condition or free marching, which prevents exposure of piston rod to the dusty atmosphere resulting in physical damages. Exemplary embodiments discussed above may provide certain advantages.
[0051] Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features.
[0052] Some embodiments of the present subject matter provides balance and stability to a pipelayer machine during lifting or lowering of heavy loads at different boom overhang positions.
[0053] Some embodiments of the present subject matter provides smooth controls and operations of the pipelayer machine while lifting or lowering heavy loads.
[0054] Some embodiments of the present subject matter enables lifting or lowering heavy loads by the pipelayer machine without requiring larger number of mechanical items due to compact structure of the linkage mechanism provided in the pipelayer machine.
[0055] Some embodiments of the present subject matter provides compact structure of the linkage mechanism requiring less maintenance and better serviceability.

[0056] REFERENCE NUMERALS
Element Description Reference Numerals
Counter weight bracket 10
Counter weight arm 20
Counter weight link 30
Counter weight frame 40
Counter weight blocks 50
Pins 60
Pipelayer Machine 70
Counter weight linkage in open position 72
Counter weight linkage in closed position 74
Center of gravity 76

,CLAIMS:

1. A counter weight linkage mechanism (100) for a pipelayer machine (70) comprises;
atleast one counter weight bracket (10),
atleast one counter weight arm (20),
atleast one counter weight link (30),
atleast one counter weight frame (40),
plurality of pins (60) and
atleast one counter weight block (50)
to provide balance and stability to a pipelayer machine (70) during lifting or lowering of heavy loads of pipes.

2. The counter weight linkage mechanism (100) for a pipelayer machine (70) as claimed in claim 1, wherein the said counter weight linkage mechanism (100) is configured to maintain the varying center of gravity (76) of the pipelayer machine (70).

3. The counter weight linkage mechanism (100) for a pipelayer machine (70) as claimed in claim 1, wherein the said counter weight linkage mechanism (100) is configured to be operated by hydraulic mechanism through one or more hydraulic cylinders.

4. The counter weight linkage mechanism (100) for a pipelayer machine (70) as claimed in claim 1, wherein the hydraulic mechanism is configured to maintain the center of gravity of the pipelayer machine on lifting different loads at multiple boom overhang positions.

5. The counter weight linkage mechanism (100) for a pipelayer machine (70) as claimed in claim 1, wherein the said counter weight block (50) is configured to be mounted on counter weight bracket (10) with plurality pins of predetermined diameter for easy assembling and disassembling of the counter weights.

6. The counter weight linkage mechanism (100) for a pipelayer machine (70) as claimed in claim 1, wherein one or more hydraulic cylinders are configured with atleast one hydraulic pump or a directional control valve using a PPC valve to actuate the hydraulic cylinder for extension and retraction of counter weight linkage mechanism (100).

7. The counter weight linkage mechanism (100) for a pipelayer machine (70) as claimed in claim 1, wherein the hydraulic mechanism to actuate the counter weight linkage mechanism (100) is configured with a counter weight pump, a pilot pump, a counter weight control valve, a slow return valve, a relief valve and a joystick for counter weight control valve.

8. The counter weight linkage mechanism (100) for a pipelayer machine (70) as claimed in claim 1, wherein a seal is configured in the hydraulic cylinder to ensure safety and stability of the pipelayer machine (70) by taking the counter weight linkage mechanism (100) to a retracted position.

9. A method of operating the counter weight linkage mechanism (100) for a pipelayer machine (70) comprising the steps of –

• starting the pipelayer machine and detecting the presence of load on boom,
• marching the pipelayer machine with counter weight fully retracted on detection of boom load within a predefined limit,
• balancing the pipelayer machine on detecting boom above a predefined minimum boom overhang load by operating the joystick to move the counter weight control valve spool for supplying hydraulic fluid to counter weight cylinders to extend the counter weight linkage mechanism for optimal balancing of the pipelayer machine.