DESC:FIELD OF THE INVENTION:
This invention relates to the field of mechanical engineering and agricultural engineering.

Particularly, this invention relates to a rotary rake machine with a torque control mechanism for its gear and tine arm.

BACKGROUND OF THE INVENTION:
Agriculture, as a significant contributor to employment and livelihood creation, continues to be the mainstay, of India’s rural economy. Hence, it is imperative to focus on increase in production, productivity, and profitability in agriculture by improving intensity of farm mechanization in the country. Though farm mechanization has improved state of agriculture in certain parts of the country, it is crucial to take concrete steps to propel farmers in large numbers towards adoption of efficient, cost effective and scalable mechanization technologies.

Farm mechanization, in India, is still in its nascent stages and during the last two decades has been able to achieve a meager growth of less than 5%. The sector faces critical challenges in terms of large share of small and marginal farmers, declining land holding sizes, high cost of farm machinery and equipment.

Another Important aspect is environmental Impact created by the agricultural waste/residue burning. According to Environmental research & Public Health and Aerosol and Air Quality research study around 93Mt of agriculture residue is burnt in open fields in India of which Sugarcane trash alone contributes to 20% and rice straw contributes to 40%.

Agricultural waste can be beneficial in various agro-based applications and other industrial processing. However, the cost of collection, processing and transportation can be much higher than the revenue generated. Also, the time available between harvesting and next crop cycle is less which necessitates the use of machines to do this work.

Post harvesting phase consists of Harvest handling and Crop residue management.

Harvest handling / processing includes handling of the harvest, storage, processing, packaging etc. and there is significant research is carried out in this area. Similarly, crop residue management consists of collecting, compacting, and processing so that it can be used in paper factory, Dairy farm, packaging industry, Mushroom farming, grape wine yards and Brick Kiln-Briquetting. This new area is generating additional opportunity for farmers to generate income and reduce the Environmental Impact.

One of the machines used for harvesting and crop residue management activities is a rotary rake machine.

Case New Holland popularly known as CNH was one of the first introduced raker machines in 2015 which is imported from Italy followed by John Deere, Kuhn and Shaktiman. Most of these machines either imported or majority of the parts are imported and assembled here without altering the design.

Most prior art machines exhibited major component failures; their components failed within 900 hours of operation i.e. within one season of 3-4 month period considering 8 hours shift. The failures were predominantly from the rotating group. The failure was preliminary attributed to tine arm or tines getting stuck or seen sudden load which leading to subsequent component failure.

During their research, the inventors found out that major failures, captured from field survey in Maharashtra and Karnataka, were:
(a) Pinion Failure;
(b) Gear Failure;
(c) Connecting rod failure;
(d) Cam failure refer;
(e) Cover failure refer.

Therefore, there is a need for an improved machine that solves the aforementioned problems.

OBJECTS OF THE INVENTION:
An object of the invention is to improve field capacity of a raker / rake machine by reducing its downtime.

Another object of the invention is to improve field capacity of a raker / rake machine by making its operation features easier.

Yet another object of the invention is to provide a mechanism which works well with plain surface and material with relatively low density such as alfalfa hay, paddy, or wheat trash.

Still another object of the invention is to provide a mechanism which works well with uneven / raised bed-type surfaces.

An additional object of the invention is to provide a mechanism which protects a rotary rake machine’s gear, pinion, tine arm and profile tube; in the event of sudden load on the tines.

SUMMARY OF THE INVENTION:
According to this invention, there is provided a rotary rake machine with a torque control mechanism for its gear and tine arm, said mechanism comprising:
- a friction disc between a gear and a casing of a pinion and gear arrangement, such that torque is transmitted through a friction surface provided by said friction disc; and
- a spring support and a disc spring provided on one side of said friction disc such that said friction disc presses against said gear, said spring support being placed over and about a stationary shaft such that as spring support is angularly displaced, it presses said disc spring against said gear.

In at least an embodiment, said mechanism comprising a sleeve (with front spherical shape) and a spring contained within a cage screwed into a spacer, said spring retains said sleeve in its position which, in turn, fixes a tine arm of said rake machine.

In at least an embodiment, reaction torque derived from said rotary rake machine, gets transferred through a tine arm, a profile tube, and said casing to said gear and pinion.

In at least an embodiment, reaction torque derived from said rotary rake machine, gets transferred through a tine arm, a profile tube, and said casing to said gear and pinion, characterized in that, said profile tube comprises:
- a spring-loaded detent pin placed in a semi-circular flange.

In at least an embodiment, reaction torque derived from said rotary rake machine, gets transferred through a tine arm, a profile tube, and said casing to said gear and pinion, characterized in that, said tine arm consists of a flange which contains holes, with preloaded bolts, to match detent pin of a spring-loaded detent pin placed in a semi-circular flange, said spring loaded detent pin being a part of said profile tube.

In at least an embodiment, reaction torque derived from said rotary rake machine, gets transferred through a tine arm, a profile tube, and said casing to said gear and pinion, characterized in that, said tine arm consists of a flange which contains holes, with preloaded bolts, to match detent pin of a spring loaded detent pin placed in a semi-circular flange, said spring loaded detent pin being a part of said profile tube, in that, an initial set position is achieved by angularly displacing said tine arm such that said detent pins match with holes on said tine arm.

In at least an embodiment, reaction torque derived from said rotary rake machine, gets transferred through a tine arm, a profile tube, and said casing to said gear and pinion, characterized in that, said tine arm consists of a flange which contains holes, with preloaded bolts, to match detent pin of a spring loaded detent pin placed in a semi-circular flange, said spring loaded detent pin being a part of said profile tube, in that, when reaction torque exceeds set torque said detent pin lifts thereby reliving load coming onto said tine arm and said profile tube.

In at least an embodiment, a rotating group consisting, essentially of said pinion, said gear, said casing, received power from a PTO in order to angularly displace said pinion which, in turn, angularly displaces a helical gear and said casing, said angular displacement motion being transferred to a connecting rod connected by a cam profile which gives desired motion to said connecting rod, said connecting rod, in turn, angularly displaces said tine and tine arm; thereby, collecting trash.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a general arrangement of raker / rake and hydraulic power transmission; and
Figure 2 illustrates a prior art assembly of tine arm.

The invention will now be described in relation to the accompanying drawings, in which:
Figure 3 illustrates the pinion and gear arrangement according to this invention;
Figure 4 illustrates a quick connect tine arm according to this invention;
Figure 4A illustrates a spring-loaded spherical ball type torque limiter; and
Figure 5 and Figure 6 shows external and internal construction of the machine.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
FIGURE 1 illustrates a general arrangement of raker / rake and hydraulic power transmission.
FIGURE 2 illustrates a prior art assembly of tine arm.
Reference numeral 12a refers to pinion.
Reference numeral 12b refers to gear.
Reference numeral 14 refers to cast iron casing
Reference numeral 18 refers to stationary shaft.
Reference numeral 19 refers to cover.

Rakes can be divided into three groups:
a) Finger-Wheel Rakes;
b) Parallel Bar Rakes;
c) Rotary Rakes.

This invention relates to Rotary Rakes.

Prior arts require about 30 – 45 minutes for assembly of tine arm which is done by a bolted joint where appropriate tools are required. There is no overload protection between pinion and gear in cases the tine arm encounters obstacles while it is being used.

According to this invention, there is provided a rotary rake machine with a torque control mechanism for its gear and tine arm.

FIGURE 3 illustrates the pinion and gear arrangement according to this invention.
FIGURE 4 illustrates a quick connect tine arm.

In at least an embodiment, in an existing pinion and gear arrangement (12a, 12b), as shown in Figure 4, a friction disc (15) is arranged between the gear (12b) and cast-iron casing (14) such that torque is transmitted through the friction surface provided by the friction disc (15).

Typically, the gear (12b) is pressed against the friction disc (15) through a spring support (17) and a disc spring (19). The spring support (17) is placed over / about a stationary shaft (18) through threading; as spring support (17) is angularly displaced, it presses the spring against the gear. Here, torque capacity is proportional to spring force. The force can be modulated using the spring support (17).

The reaction torque coming from a hay / trash load, of the rotary rake machine, gets transferred through a tine arm (22), a profile tube (24), and a cast-iron casing (14) to the gear and pinion (12a, 12b). The arrangement, shown in Figure 5, consists of a profile tube (24) which includes spring (23) loaded detent pin (25) placed in a semi-circular flange (27). The tine arm (22) consists of a flange (27) which contains holes, with preloaded bolts (29), to match the detent pin (25). The tine arm (22), in assembled condition, resists reaction torque through the detent mechanism (25). The spring (23) load and number of pins determines the resisting torque. When the reaction torque exceeds the set torque. the detent pin (25) lifts there by reliving the load coming onto the tine arm (22) and the profile tube (24). The arrangement can be set to its initial position by angularly displacing the tine arm (22) such that the detent pins (25) match with the holes on the tine arm (22).

FIGURE 4 illustrates a spring-loaded spherical ball type torque limiter; and

FIGURE 4 depicts a system that provides protection against sudden loads on tines. The design consists of a sleeve (22) (with front spherical shape) and a spring (24) contained within a cage (26) which can be screwed into a spacer (28). The spring (24) retains the sleeve (22) in its position which, in turn, fixes the tine arm. Tune arm torque control: The idea includes sleeve with front spherical shape, cage and spacer. The sleeve (22) is placed into the cage (26) with spring (24) such that it pushes sleeve (22) against cage (26). This assembly is screwed into the spacer (28) having female threads such that the spherical part of sleeve (22) slides into the tine arm hole. The spring (26) force pushes the sleeve (22) against the hole which keeps the tine arm (23) and profile tube (21) held together. When torque exceeds the predetermined set value, the sleeve (22) lifts against spring (24) and tine safely rotates without damage. The arrangement can be reset before next operation. The torque from the tine arm can be modulated with spring force.

When torque on the tine arm exceeds a set limit, force Fy (Resultant force Fr is split into Fx and Fy) lifts the sleeve (22) from its position and the tine arm slips from its position – thereby, protecting the tines and subsequent components along the load path.

FIGURE 5 and FIGURE 6 shows external and internal construction of the machine.

The machine has two groups mainly:
a. Rotating group; and
b. Non-rotating group.

Machine frames, generally, are made from tubular structures welded together supported with two, three, or four wheels. These wheels provide support to the rotating group, serves as transport trailed machine unit, but also for tracing ground as reference to adjust the height of the fingers in relation to ground surface.

REFERENCE NUMERAL PART / ITEM
1 THREE-POINT LINKAGE
2 LOWER LINK
3 RIGHT HAND GUARD
4 TINE
5 TINE ARM
6 LIGHTING BRACKET
7 GEARBOX
8 CRANK
9 DRAWBAR
10 RATCHET
11 CARDAN SHAFT PROTECTION
12 CARDAN SUPPORT
13 PARKING SUPPORT
14 LEFT HAND GUARD
15 WHEEL UNIT
16 TELESCOPING TUBE
17 SWATHING DEFLECTOR
18 ANTI-SNAKING KIT
19 TRAVERSE

In at least an embodiment, the rotating group consists of pinion (19), gear (2), casing (1).
In at least an embodiment, the non-rotating group consists of cover (4), shaft (27), cam (31), cover (27).
Power is supplied, to this machine, from a tractor PTO; this power is transmitted to the rotating group through a pinion (19) which, in turn, angularly displaces a helical gear (3) and casing (1). With this angular displacement, a connecting rod (34) follows a cam profile which gives desired motion to the connecting rod (34). The connecting rod (34), in turn, angularly displaces the tine and tine arm; thereby, collecting trash.

According to a non-limiting exemplary embodiment, a main objective of testing is to establish baseline performance and demonstrate improvement of this current invention. Speed sensors and torque sensors are mounted over the PTO shaft and data is captured at the rake 1k data points/sec through wireless blue tooth.

Field Conditions: The dimensions of the field are given in Figure 7
Soil Condition: Dark black soil of Krishna valley and clayey texture and granular to crumb structure

FIGURE 7 illustrates field conditions
FIGURE 8A illustrates various graphs showing working of the invention.
FIGURE 8B illustrates various graphs showing working of the invention.
FIGURE 8C illustrates various graphs showing working of the invention.

FIGURE 8 consists of 2 parts
The first picture shows friction surface below the gear. When the load on the tine arm i.e. F1 exceeds the predetermined value the gear and casing will slip.
The ides provided in second picture also helps for ease of removal and assembly of the tine arms. The second picture shows the friction clamp, this addresses the issue of torsional load due to F2 by allowing the tube to slip by frictional force.

The following observations are made:
1. The invention’s raker tine arm is functioning as per its intended function of collecting straw without any issue;
2. When the load on the tines exceeds preset load by the detent mechanism, the tine arm lifts allowing the load to relieve without mechanical fracture/failure;
3. This testing shows major failure mode is eliminated by the implemented idea;
4. Different loads can be set using the spring force to suit field conditions.

TECHNICAL ADVANTAGES:
This invention provides a mechanism to limit maximum torque in its associated rake machine.
This invention provides a mechanism to connect tine arm with profile tube to limit maximum torque in the rake machine.
This invention provides a mechanism to vary safe operating torque by varying spring force.
This invention provides a mechanism to improve ease of assembly of tine arm which is currently being a bolted joint.
This invention provides a mechanism to significantly improve assembly time for the rake machine.
This invention provides a mechanism to handles time varying loads for the rake machine.
This invention works well with raised bed plantations such as sugarcane in addition to existing plain surface and material with relatively low density such as alfalfa hay, paddy, or wheat trash.
In the prior art, there was no overload protection built in; as a result, frequent failures were seen in applications subjected to time-varying loads due to uneven surfaces. The uneven surfaces are results of different crop bed preparation: e.g. paddy and wheat will have flat bed whereas sugarcane have raises bed arrangement. These problems are addressed by the current invention.
In the prior art, due to sudden loads, the weakest link in a load path would be damaged; the prior art failures include, tine arm, tines, profile tube, cam, gear and pinion or sometimes the casting parts as well; all of this is addressed by the current invention since it protect gear, pinion, tine arm and profile tube due to sudden load on the tines.

The TECHNICAL ADVANCEMENT of this invention lies in providing friction control in a pinion and gear arrangement such that the torque is transmitted through this friction surface. Furthermore, toque is proportional to spring force provided in this mechanism; this spring force, and hence torque, can be modulated accordingly.

While this detailed description has disclosed certain specific embodiments for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

,CLAIMS:WE CLAIM,

1. A rotary rake machine with a torque control mechanism for its gear and tine arm, said mechanism comprising:
- a friction disc (15) between a gear (12b) and a casing (14) of a pinion and gear arrangement (12a, 12b), such that torque is transmitted through a friction surface provided by said friction disc (15); and
- a spring support (17) and a disc spring (19) provided on one side of said friction disc (15) such that said friction disc (15) presses against said gear (12b), said spring support (17) being placed over and about a stationary shaft (18) such that as spring support (17) is angularly displaced, it presses said disc spring (19) against said gear (12b).

2. The mechanism as claimed in claim 1 wherein, said mechanism comprising a sleeve (22) (with front spherical shape) and a spring (24) contained within a cage (26) screwed into a spacer (28), said spring (24) retains said sleeve (22) in its position which, in turn, fixes a tine arm of said rake machine.

3. The mechanism as claimed in claim 1 wherein, reaction torque derived from said rotary rake machine, gets transferred through a tine arm (22), a profile tube (24), and said casing (14) to said gear and pinion (12a, 12b).

4. The mechanism as claimed in claim 1 wherein, reaction torque derived from said rotary rake machine, gets transferred through a tine arm (22), a profile tube (24), and said casing (14) to said gear and pinion (12a, 12b), characterized in that, said profile tube (24) comprises:
- a spring (23) loaded detent pin (25) placed in a semi-circular flange (27).

5. The mechanism as claimed in claim 1 wherein, reaction torque derived from said rotary rake machine, gets transferred through a tine arm (22), a profile tube (24), and said casing (14) to said gear and pinion (12a, 12b), characterized in that, said tine arm (22) consists of a flange (27) which contains holes, with preloaded bolts (29), to match detent pin (25) of a spring (23) loaded detent pin (25) placed in a semi-circular flange (27), said spring (23) loaded detent pin (25) being a part of said profile tube (24).

6. The mechanism as claimed in claim 1 wherein, reaction torque derived from said rotary rake machine, gets transferred through a tine arm (22), a profile tube (24), and said casing (14) to said gear and pinion (12a, 12b), characterized in that, said tine arm (22) consists of a flange (27) which contains holes, with preloaded bolts (29), to match detent pin (25) of a spring (23) loaded detent pin (25) placed in a semi-circular flange (27), said spring (23) loaded detent pin (25) being a part of said profile tube (24), in that, an initial set position is achieved by angularly displacing said tine arm (22) such that said detent pins (25) match with holes on said tine arm (22).

7. The mechanism as claimed in claim 1 wherein, reaction torque derived from said rotary rake machine, gets transferred through a tine arm (22), a profile tube (24), and said casing (14) to said gear and pinion (12a, 12b), characterized in that, said tine arm (22) consists of a flange (27) which contains holes, with preloaded bolts (29), to match detent pin (25) of a spring (23) loaded detent pin (25) placed in a semi-circular flange (27), said spring (23) loaded detent pin (25) being a part of said profile tube (24), in that, when reaction torque exceeds set torque said detent pin (25) lifts thereby reliving load coming onto said tine arm (22) and said profile tube (24).

8. The mechanism as claimed in claim 1 wherein, a rotating group consisting, essentially of said pinion (19), said gear (12a), said casing (14), received power from a PTO in order to angularly displace said pinion which, in turn, angularly displaces a helical gear (3) and said casing (14), said angular displacement motion being transferred to a connecting rod (34) connected by a cam profile which gives desired motion to said connecting rod (34), said connecting rod (34), in turn, angularly displaces said tine and tine arm; thereby, collecting trash.

Dated this 26th day of June, 2023

CHIRAG TANNA
of INK IDEE
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA – 1785