DESC:TECHNICAL FIELD
The present disclosure relates to a power transmission device, more particularly relates to a driver pulley assembly for power transmission.

BACKGROUND
Existing speed transmission devices comprises at least a gear arrangement or a control unit or any speed sensor. There are instances when there is a need for high torque and low speed from the driver to driven while the same system has to work at a higher speed at another instance. Ex: A washing machine drum rotates at a high speed during the drying operation as compared to washing operation or an Integrated Starter Generator (ISG) works at a lower speed transmitting much higher torque while starting an engine & rotates at a higher speed while requiring less torque to operate as a generator.

One way of obtaining dual speed in gears is provided in WO2009/068882. The WO2009/068882 provides a Dual speed pulley with a planetary gear and 2 belts / chains between the driver and driven. A brake assembly locks the sun gear for the first speed ratio. The second ratio is achieved using the one-way clutch which locks the input and output shaft for a ratio of 1:1.

Another way of obtaining dual speed in gear is provided in US6071206 (pat 206‘). The pat 206‘ achieve dual speed using a planetary a gear set, an electromagnetic brakes, and a one-way clutch.

The prior arts explained here have been working with epicyclic gear trains and electromagnetic clutches. Such arrangement requires an electronic controlling device to sense the speeds of rotating shafts and engage or disengage the electromagnetic clutches or solenoid. The system which uses the planetary gears and electromagnetic gears are complex in nature and are expensive.

In view of the above limitations, there exists a need to develop a dual speed power transmission device.

OBJECTS OF THE DISCLOSURE
An object of the present disclosure is to provide a driver pulley assembly for power transmission.
SUMMARY OF THE DISCLOSURE
The shortcomings of the prior art are overcome and additional advantages are provided through the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one embodiment, the present disclosure relates to a driver pulley assembly, comprising a first pulley having a first diameter, a second pulley having a second diameter, wherein both the first pulley and the second pulley are independently rotatably and co-axially mounted on a shaft; a dead weight assembly, configured to slidably mount inside the second pulley; and an engaging mechanism mounted slidably on the shaft, and connected to the dead weight assembly, wherein the engaging mechanism selectively engage and disengage with the first pulley due to sliding movement of the deadweight assembly inside the second pulley, wherein the sliding movement of the deadweight is due to rotating speed of the shaft.

In one embodiment, the engaging mechanism is selected from a group comprising a dog clutch and a ratchet.

In one embodiment, the dog clutch surface comprises plurality of notches to engage with the first pulley and splines grooves to engage with the shaft.

In one embodiment, the deadweight assembly comprises pair of deadweights facing each other and connected using springs.

In one embodiment, the deadweight assembly is connected to the engaging mechanism using a plurality of links and pin assembly.

In one embodiment, the deadweight assembly peripheral surface comprises a layer of friction material.

In one embodiment, of the present disclosure, a method for operating a driver pulley assembly. The method comprising acts of rotating a first pulley mounted to a shaft using an engaging mechanism, wherein the engaging mechanism is slidably mounted on the shaft and is connected a deadweight assembly and rotating a second pulley mounted to the shaft using the deadweight assembly, wherein rotating speed of the shaft slides the deadweight assembly mounted inside the second pulley to engage and disengage with the second pulley, wherein sliding of the deadweight assembly engage and disengage the engaging mechanism with the first pulley.

In one embodiment, the engaging mechanism engages with the first pulley during lower speeds of the shaft.

In one embodiment, the engaging mechanism disengage with the first pulley and slidably moves along the shaft due to higher speeds of the shaft for contacting the deadweight assembly with inner surface of the second pulley.

In one embodiment, a friction material provided at peripheral portion of the deadweight assembly transfers power to the second pulley.

In one embodiment of the present disclosure, a method of assembling a driver pulley assembly is provided. The method comprising acts of providing a first pulley having a first diameter on a shaft, providing a second pulley having a second diameter. Both the first pulley and the second pulley are independently rotatably and co-axially mounted on the shaft. The method also comprises act of mounting a dead weight assembly slidably inside the second pulley; and mounting an engaging mechanism slidably on the shaft, and connecting to the dead weight assembly. The engaging mechanism selectively engage and disengage with the first pulley due to sliding movement of the deadweight assembly inside the second pulley, wherein the sliding movement of the deadweight assembly is due to rotating speed of the shaft.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

Fig. 1 shows line diagram of arrangement of a transmission assembly according to one embodiment of the present disclosure.
Fig. 2 shows top view of arrangement of the transmission assembly according to one embodiment of the present disclosure.
Fig. 3 shows assembled view of the driver pulley assembly according to one embodiment of the present disclosure
Fig. 4 shows exploded view of the driver pulley assembly according to one embodiment of the present disclosure.
Fig. 5 shows perspective view of a deadweight assembly the driver pulley assembly according to one embodiment of the present disclosure.
Fig. 6 shows exploded view of the deadweight assembly with the dog clutch according to one embodiment of the present disclosure.
Fig. 7 shows rear view of a first pulley of a driver pulley assembly according to one embodiment of the present disclosure.
Fig. 8 shows front view of a dog clutch of the driver pulley assembly according to one embodiment of the present disclosure.
.Fig. 9 shows cross sectional view of the driver pulley assembly during low speed/high torque mode according to one embodiment of the present disclosure.
Fig. 10 shows cross sectional view of the driver pulley assembly during high speed/low torque mode according to one embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily 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 THE DISCLOSURE
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

It is to be noted at this point that all of the above described components, whether alone or in any combination, are claimed as being essential to the disclosure, in particular the details depicted in the drawings and reference numerals in the drawings are as given below.

Table of referral numerals

Referral Numerals Description
1 Second pulley
2 Deadweight assembly
3 Rolling element/Bearing
4 Shaft
4a Splines on the shaft
5 Rolling element/Bearing
6 First pulley
6a Grooves on the first pulley
7 Driver pulley assembly
8 Linkage
9 Pin
10 Dog clutch
10a Notches on the Dog clutch
10b Spline grooves on the Dog clutch
11 Deadweights
12 Coil spring
13 Friction material/lining
14 First Rotating machine
15 Second Rotating machine
16, 17 Belts
18 Pulley on rotating machine 14
19 Transmission assembly
20 Engaging mechanism

The present disclosure relates to a power transmission device, more particularly relates to a driver pulley assembly for power transmission. The driver pulley assembly comprises a first pulley and second pulley with plurality of deadweights, link, and input shaft. A locking mechanism like a dog clutch / ratchet and a spring arranged to facilitate switching between the first pulley and the second pulley. The first and second pulleys are supported by a friction reducing element like a bearing / bush. The locking mechanism is slidable over the input shaft but not rotatable about it. The locking mechanism is connected to the deadweights using linkages. The plurality of deadweights is connected to each other using tension elements like coil spring / flexible bands /etc. and is slideably placed inside the second pulley. The outer surface of the deadweights has a layer of friction material which can engage with the inner surface of the second pulley during operation. The disclosure further relates to connecting two rotating shafts connected by means of a belt / pulley, where in one of the rotating shafts is connected to one rotating machine. The rotating machine is capable to deliver and accept torque. At any case this mechanism is used to establish two different speeds of operations at the driven shaft. In this manner the same machine can be used for low speed high torque applications and high speed low torque applications. The system does not require an electronic control unit or any speed sensor. The system is entirely self-contained. The scope of application is not only limited to automobiles. It can be used on home appliances, agricultural machines, etc. The dual speed pulley makes 2 different ratios available for a smaller rotating machine to operate in a more efficient manner.

Figs. 1 and 2 illustrate front and top views of a transmission assembly 19 according to an embodiment of the present disclosure. A pulley 18 of a rotating machine 14 and a driver pulley assembly 7 connected to a second rotating machine 15 are coupled to each other by means of belts 16 and 17. The driver pulley assembly 7 is configured with at least one first pulley 6 and at least one second pulley 1. In one embodiment, the pulleys 1 and 6 are having varying diameters. In one embodiment, the second pulley 1 is having larger diameter than that of the first pulley 6 and are aligned coaxial to each other. In one embodiment, during low speed or higher torque requirements, the power transmission is carried out between the first pulley 6 and the pulley 18. In another embodiment, during higher speed and low torque requirements, the power transmission is carried out between the second pulley 1 and the pulley 18.

Fig. 3 illustrates assembled view of the driver pulley assembly 7 according to one non limiting embodiment of the present disclosure. In one embodiment, the driver pulley assembly 7 comprises the first pulley 6 and the second pulley 1, both having varying diameters.

Fig. 4 illustrates exploded view of the driver pulley assembly 7 according to one embodiment of the present disclosure. In one embodiment, the driver pulley assembly 7 is a two speed power transmitting device. The driver pulley assembly 7 comprises a first pulley 6 having a first diameter and a second pulley 1 having a second diameter. The first pulley 6 and the second pulley 1 are independently rotatably and co-axially mounted on a shaft 4. In one embodiment, the first pulley 6 is supported by a rolling element 5 and the second pulley 1 is supported on another rolling element 3. The rolling elements 3, 5 can be but not limited to bearings or bushes. The rolling elements 3, 5 are fitted coaxially on the shaft 4. The driver pulley assembly 7 is also provided with a dead weight assembly 2 which is configured to slidably mount inside the second pulley 1. An engaging mechanism 20 is provided in the driver pulley assembly 7 and mounted slidably on the shaft 4. The engaging mechanism 20 is connected to the deadweight assembly 2 in such a manner that the engaging mechanism 20 selectively engage and disengage with the first pulley 6 due to sliding movement of the deadweight assembly 2 (shown in Fig. 5) inside the second pulley 1. The sliding movement of the deadweight assembly 2 is due to rotating speed of the shaft 4. In one embodiment, the engaging mechanism 20 is selected from a group comprising a dog clutch and a ratchet. In one embodiment, the dog clutch 10 (shown in Fig. 8) surface comprises plurality of notches 10a (shown in Fig. 8) to engage with the first pulley 6 and splines grooves 10b (shown in Fig. 8) to engage with the shaft 4. In one embodiment, the deadweight assembly 2 comprises pair of deadweights 11 facing each other and connected using springs 12 as shown in Fig. 5. In one embodiment, the deadweight assembly 2 is connected to the engaging mechanism 20 using a plurality of links 8 and pins 9 as shown in Fig. 6. In one embodiment, the deadweight assembly 2 peripheral surface comprises a layer of friction material 13 (as shown in Fig. 5). The friction materials can be the materials that are used in clutch or a brake.

In one embodiment, the second pulley 1 has a space coaxially machined to accommodate the deadweights 11 of the deadweight assembly 2 and plurality of coil springs 12 (as shown in Fig. 9). The deadweight assembly 2 is connected to the linkage 8 using pins 9. The linkages 8 protrude out from the second pulley 1. Another end of the linkages 8 is connected to engaging mechanism 20 using the pins 9. The dog clutch 10 slides over splines 4a provided on the shaft 4. The shaft 4 is integrated with external splines 4a. The dog clutch 10 is provided with notches 10a. The notches 10a avoid rotation of the dog clutch 10 which in turn guides and engages with the grooves 6a of the first pulley 6. Thus, the dog clutch 10 acts as a selector mechanism at different operations.

In one embodiment, the first pulley 6 comprises plurality of grooves 6a to accommodate notches 10a of a dog clutch 10 so as to lock and unlock with the dog clutch 10 (as shown in Fig. 7). The deadweights 11 are integrated with friction material 13 while the dead weights 11 are connected by the coil spring 12. Inside surface of the deadweights 11 is configured with a stepped portion such that inside surface of the second pulley 1 rests on the step configured in the deadweights 11 and thus helps in avoiding the lower deadweight from rubbing / sliding against inside surface of the second pulley 1 due to gravity.

Fig. 8 illustrates front view of the dog clutch 10 according to one embodiment of the present disclosure. The plurality of notches 10a to fit into the grooves 6a made on the first pulley 6 during engaging/locking with the first pulley 6. Also, a plurality of spline grooves 10b is provided around central axis of the dog clutch 10 for accommodating with the input shaft 4 for assembling.

In one embodiment, (as shown in Fig. 7) the grooves 6a in the inner side of the first pulley 6 are longer than the teeth/notches 10a in the dog clutch 10. Also, the un-grooved areas in the inners side of the first pulley 6 are smaller than the length of the notches made in the dog clutch 10. Thus, it is ensured that the teeth/notches 10a engage positively with the grooves 6a inside the primary pulley 6. The edges of the teeth/notches 10a do not have chamfers so that there is no slippage or sliding of the teeth over edges of the grooves 6a.

In one embodiment, of the present disclosure, a method for operating a driver pulley assembly 7 comprises acts of rotating a first pulley 6 mounted to a shaft 4 using an engaging mechanism 20, wherein the engaging mechanism 20 is slidably mounted on the shaft 4 and is connected a deadweight assembly 2; rotating a second pulley 1 mounted to the shaft 4 using the deadweight assembly 2, wherein rotating speed of the shaft 4 slides the deadweight assembly 2 mounted inside the second pulley 1 to engage and disengage with the second pulley 1, wherein sliding of the deadweight assembly 2 engage and disengage the engaging mechanism 20 with the first pulley 6.

In one embodiment, the engaging mechanism 20, preferably the dog clutch 10 engages with the first pulley 6 during lower speeds of the shaft 4. In one embodiment, the engaging mechanism 20 disengage with the first pulley 6 and slidably moves along the shaft 4 due to higher speeds of the shaft 4 for contacting the deadweight assembly 2 with inner surface of the second pulley 1. The lower speeds and the higher speeds are dependent on the applications of the driver pulley assembly 7. In one embodiment, a friction material 13 provided at peripheral portion of the deadweight assembly 2 transfers power to the second pulley 1.

In one embodiment of the present disclosure, low speed/high torque operation using the driver pulley assembly 7 is disclosed. During low speed/high torque operation, the dog clutch 10 couples shaft of the rotating machine’s 15 with the first pulley 6 (See Fig. 9). As the speed picks up and when the need is to operate at a higher speed the dog clutch 10 is made to disengage from the primary pulley 6. With the increase in speed of the shaft the masses are moved outwards against the spring force holding them in a contracted state. The friction lining or friction material 13 on outer side of deadweights 11 engages with the inner surface of the second pulley 1 and thereby transmitting power at a higher speed. The first pulley 6 rotates freely over the roller bearing. In one embodiment, the driver pulley assembly 7 helps in using a smaller rotating machine for high torque as well as high speed applications.

In one embodiment of the present disclosure, a method of assembling a driver pulley assembly 7 is provided. The method comprising acts of providing a first pulley 6 having a first diameter on a shaft 4, providing a second pulley 1 having a second diameter. Both the first pulley 6 and the second pulley 1 are independently rotatably and co-axially mounted on the shaft. The method also comprises act of mounting a dead weight assembly 2 slidably inside the second pulley 1; and mounting an engaging mechanism slidably on the shaft 4, and connecting to the dead weight assembly 2. The engaging mechanism selectively engage and disengage with the first pulley 6 due to sliding movement of the deadweight assembly 2 inside the second pulley 1, wherein the sliding movement of the deadweight assembly 2 is due to rotating speed of the shaft 4.

Fig. 9 illustrates cross sectional view of the driver pulley assembly 7 during low speed/high torque mode according to one embodiment of the present disclosure. During the start of rotation or the case, when a low speed operation or at a high torque is required, the deadweights 11 by the virtue of the coil springs 12 holds the deadweights 11 together and are held towards the center of the input shaft 4. Thus, there is no contact of the friction material 13 with the inner surface of the secondary pulley 1. The links/linkage 8 connecting the deadweights 11 with the dog clutch 10 hold the dog clutch 10 to slide over the shaft 4. As a result, teeth around the dog clutch 10 engage with the grooves inside the first pulley 6.

Fig. 10 illustrates cross sectional view of the driver pulley assembly 7 during high speed/low torque mode according to the present disclosure. At higher speeds, by virtue of centrifugal force acting on the deadweights 11, the deadweights 11 tend to move away from axis of rotation. When the centrifugal force becomes high enough to overcome the spring force holding the deadweights 11 towards the center, the deadweights 11 starts moving towards the inner side of the second pulley 1 circumference. The friction material 13 rubs against the inner side of the second pulley 1. The radial displacement on the centrifugal masses produces a proportional linear displacement of the locking mechanism/dog clutch 10 and is pulled towards the second pulley 1. This results in the disengagement of the engaging mechanism 20 from the first pulley 6. Hence the first pulley 6 is now set free, while power transmission is established through the second pulley 1.

In one embodiment of the present disclosure, transition from higher rotating speed to lower rotating speed is disclosed (Fig. 9). As the speed of the rotating shaft 4 drops from a higher speed to substantially lower speed range or to a complete halt, the reduction in centrifugal force on the deadweights 11 causes the deadweights to retract towards the axis of rotation. This in turn slides the dog clutch 10 towards the first pulley 6. The projections or teeth in the dog clutch 10 engage into the mating grooves in the inner side of first pulley 6.

In one embodiment, the lower speeds is ranging from 0 rpm to predetermined rpm and the higher speed is ranging from the predetermined rpm to more than predetermined rpm.

The technology of the disclosure is further elaborated with the help of following examples. However, the examples should not be construed to limit the scope of the disclosure.

Examples:
Example 1: Automotive
In one embodiment, the driver pulley assembly finds it application in automotive field. In the Automotive application, the first rotating machine (14) is to be considered as an IC Engine700cc and the second rotating machine (15) is to be considered as an Integrated Starter-Generator (ISG).

Firstly, during cranking mode, the torque requirement is higher while the speed is low i.e. 0-500 rpm. The first pulley (6) is rotated by the ISG machine to crank the engine.

Secondly during power generation mode, the engine is cranked and the ISG machine is converted to a generator. The speed of the engine ramps up from 500-4500 rpm. Above 500 rpm, the friction lining on the deadweight assembly (2) engage with inner housing of second pulley (1). The centrifugal force causes the dead weight assembly (2) to firmly press into the inner housing of the second pulley (1).

Thus, the low speed in the above example is ranging from 0-500 rpm and the high speed is ranging from about 500-4500 rpm.

Example 2: Home appliance
In one embodiment, the driver pulley assembly (7) finds its application in home appliances such as washing machine. The first rotating machine (14) in the washing machine is a loader
And the second rotating machine (15) in the washing machine is an electric motor.

Firstly, during washing mode, the torque requirement is higher while the speed is low i.e. 0-150 rpm. The first pulley (6) is rotated by the electric motor to run the loader.

Secondly, during drying mode or operation, the speed of the loader should ramp up from 150-1200 rpm. Above 150 rpm, the friction lining on the deadweight assembly (2) engage with the inner housing of second pulley (1). The centrifugal force causes the dead weight assembly to firmly press into the inner housing of the second pulley.

Thus, the low speed in the above example is ranging from 0-150 rpm and the high speed is ranging from about 150-1200 rpm.

In one embodiment, the speed limits in the driver pulley assembly (7) may vary with the capacity of first rotating machine and the second rotating machine.

Advantages
In one embodiment, the disclosure relates to connecting two rotating shafts connected by means of a belt / pulley 16, 17, wherein one of the rotating shafts is connected to one rotating machine 15. The rotating machine 15 can in a way deliver and receive torque. At any case driver pulley assembly 7 can be used to establish two different speeds of operations at the shaft 4. In this manner, the same driver pulley assembly 7 can be used for low speed high torque applications and high speed low torque applications. The driver pulley assembly 7 does not require a control unit or any speed sensor and is entirely self-contained. The scope of application is not only limited to automobiles. It could be used on home appliances, agricultural machines, etc. The suggested construction of driver pulley assembly makes two different ratios available for a smaller rotating machine to operate in a more efficient manner.

In one embodiment, the driver puller assembly finds its applications such as engine and its Integrated Starter-Generator (ISG), motor in a washing machine, Electric motor used for traction of vehicle, etc.

Equivalents
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

,CLAIMS:We claim:
1. A driver pulley assembly (7), comprising:
a first pulley (6) having a first diameter;
a second pulley (1) having a second diameter, wherein both the first pulley (6) and the second pulley (1) are independently rotatably and co-axially mounted on a shaft (4);
a dead weight assembly (2), configured to slidably mount inside the second pulley (1); and
an engaging mechanism (20) mounted slidably on the shaft (4), and connected to the dead weight assembly (2), wherein the engaging mechanism (20) selectively engage and disengage with the first pulley (6) due to sliding movement of the deadweight assembly (2) inside the second pulley (1), wherein the sliding movement of the deadweight is due to rotating speed of the shaft (4).

2. The driver pulley assembly (7) as claimed in claim 1, wherein the engaging mechanism (20) is selected from a group comprising a dog clutch and a ratchet.

3. The driver pulley assembly (7) as claimed in claim 2, wherein the dog clutch (10) surface comprises plurality of notches (10a) to engage with the first pulley (6) and splines grooves (10b) to engage with the shaft (4).

4. The driver pulley assembly (7) as claimed in claim 1, wherein the deadweight assembly (2) comprises pair of deadweights (11) facing each other and connected using springs (12).

5. The driver pulley assembly (7) as claimed in claims 1, wherein the deadweight assembly (2) is connected to the engaging mechanism (20) using a plurality of links (8) and pin assembly (9).

6. The driver pulley assembly (7) as claimed in claim 1, wherein the deadweight assembly (2) peripheral surface comprises a layer of friction material (13).

7. A method for operating a driver pulley assembly (7), said method comprising acts of:
rotating a first pulley mounted to a shaft using an engaging mechanism, wherein the engaging mechanism is slidably mounted on the shaft and is connected a deadweight assembly (2); and
rotating a second pulley mounted to the shaft using the deadweight assembly, wherein rotating speed of the shaft slides the deadweight assembly mounted inside the second pulley to engage and disengage with the second pulley, wherein sliding of the deadweight assembly engage and disengage the engaging mechanism (20) with the first pulley.

8. The method as claimed in claim 7, wherein the engaging mechanism (20) engage with the first pulley (6) during lower speeds of the shaft (4).

9. The method as claimed in claim 7, wherein the engaging mechanism (20) disengage with the first pulley (6) and slidably moves along the shaft (4) due to higher speeds of the shaft (4) for contacting the deadweight assembly (2) with inner surface of the second pulley (1).

10. The method as claimed in claim 7, wherein a friction material provided at peripheral portion of the deadweight assembly (2), transfers power to the second pulley (1).

11. The method as claimed in claim 8 and 9, wherein the lower speed is ranging from 0 rpm to predetermined rpm and the higher speed is ranging from the predetermined rpm to more than predetermined rpm.

12. A method of assembling a driver pulley assembly (7) as claimed in claim 1, the method comprising acts of:
providing a first pulley (6) having a first diameter on a shaft;
providing a second pulley (1) having a second diameter, wherein both the first pulley
(6) and the second pulley (1) are independently rotatably and co-axially mounted on the shaft (4);
mounting a dead weight assembly (2) slidably inside the second pulley (1); and
mounting an engaging mechanism (20) slidably on the shaft (4), and connecting to the dead weight assembly (2), wherein the engaging mechanism (20) selectively engage and disengage with the first pulley (6) due to sliding movement of the deadweight assembly (2) inside the second pulley (1), wherein the sliding movement of the deadweight assembly (2) is due to rotating speed of the shaft (4).

Dated this 18th day of February, 2014
P.H.D.RANGAPPA
IN/PA-1538
OF K & S PARTNERS
AGENT FOR THE APPLICANTS