Description:FORM 2
The Patent Act 1970
(39 of 1970)
and
The Patent Rules, 2005

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

TITLE OF THE INVENTION
“PULL TYPE CLUTCH ASSEMBLY FOR A MOTOR VEHICLE”

Endurance Technologies Limited
E-92, M.I.D.C. Industrial Area, Waluj,
Chh. Sambhajinagar – 431136 (formerly Aurangabad),
Maharashtra, India

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of Invention

[001] The present invention relates to a clutch assembly for two and three wheeled vehicles. More particularly, the present invention relates to a pull type assist and slipper clutch having an optimized design of bearing cup holder provided therein to eliminate the lever free play and reduce the assembly cycle time.

Background of the Invention

[002] Generally, a clutch device is positioned between the drive target body, such as a wheel, and the motor or an engine, to transfer the rotary force of the motor to the drive target body in a two or four-wheel vehicle. Multiple friction plates and clutch plates are rotated by the motor's rotary drive force wherein the said plates are coupled to the drive target body arranged facing each other in a clutch device. The friction plates and clutch plates can be separated or come into close contact with one another to transmit or block the rotary force as needed, respectively.

[003] The clutch devices are generally classified as pull type clutch and push type clutch based upon the type of the actuation force viz. pull or push. The pull type clutch utilizes a circlip based design to disengage the plate stack of the clutch assembly during the disengagement of the clutch. The said circlip is generally placed in a groove formed in the moving hub of the clutch assembly wherein a bearing cup holder is locked with the moving hub by the help of the circlip. The bearing cup holder is configured to transmit the axial force to the moving hub during the disengagement of the clutch assembly, thus causing the axial separation of the plate stack of the clutch assembly. This design thus requires an axial clearance of around 1.0 mm to be maintained at the groove of the moving hub on the account of manufacturing tolerances required to fit the circlip therein. This axial clearance thus adds to a free play at the clutch lever fitted at the handlebar of the vehicle which in turn not only deteriorates the clutch actuation but performance of the clutch assembly as well. Also, the said axial clearance may further increase due to the cyclic loading experienced by the clutch assembly which again adds to the free play at the clutch lever resulting in loss of clutch function thereby.

[004] One of the possible solutions for eliminating the free play at the clutch lever is to provide an integrated design of moving hub and bearing cup holder. However, this requires a complex assembly procedure wherein each of the friction plates and steel plates are needed to be placed individually within the housing of the clutch assembly. Also, the serviceability of the said clutch assembly is affected owing to the complex assembly procedure. This leads to an increased assembly cycle time and the overall cost of the clutch assembly.

[005] Thus, there is an unprecedented need to provide a clutch assembly which does not have free play at the clutch lever and which is easy to assemble / dis-assemble thus providing a cost effective solution thereby.

Objectives of the Present Invention

[006] The main object of the present invention is to provide a pull type clutch assembly for two and three wheeled vehicles.

[007] Another main object of the present invention is to provide a pull type clutch assembly having a uniquely profiled bearing cup holder provided therein to eliminate the clutch lever free play at the handle bar of the vehicle.

[008] Another objective of the present invention is to provide a pull type clutch assembly imparting an ease of assembly.

[009] Still another objective of the present invention is to provide a pull type clutch assembly having a fixed hub and a moving hub imparting the assist and slipper function to the clutch assembly.

Brief Description of Drawings

[0010] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein and advantages thereof will be better understood from the following description when read with reference to the following drawings, wherein

[0011] Figure 1 discloses the exploded view of the multi-plate wet clutch assembly in accordance with the present invention.

[0012] Figure 2 shows perspective view of the multi-plate wet clutch assembly in assembled condition as per the present invention.

[0013] Figure 3 presents the cut-sectional view of the multi-plate wet clutch assembly as shown in Fig. 2 as per the present invention.
[0014] Figures 4a and 4b describes the front and back perspective views of the housing clutch of the multi-plate wet clutch assembly, respectively as per the present invention.

[0015] Figures 5a and 5b describes the front and back perspective views of the fixed hub of the multi-plate wet clutch assembly, respectively as per the present invention.

[0016] Figures 6a and 6b discloses the front and back perspective views of the moving hub of the multi-plate wet clutch assembly as per the present invention.

[0017] Figure 7 presents the isometric view of the bearing cup holder of the multi-plate wet clutch assembly as per the present invention.

[0018] Figure 8 shows the cut-sectional view of the bearing cup holder of the multi-plate wet clutch assembly as per the present invention.

Detailed Description of the Present Invention

[0019] The invention will now be described in detail with reference to the accompanying drawings which must not be viewed as restricting the scope and ambit of the invention. Referring to Figs. 1 to 3, the pull type multi-plate wet clutch assembly (300) comprises of a housing clutch assembly (100) and a plate clutch assembly (200). The housing clutch assembly (100) comprises of a housing (10), a gear (12) and a damper plate (14).

[0020] Referring to Figs. 4a and 4b, the housing (10) of the housing clutch assembly (100) is configured to have cylindrical structure with a closed side (10CS) and an open side (10OS). The closed side (10CS) has an annular step (15) and a circumferential cylindrical portion (10CP). The said annular step (15) is formed on a flat surface (10FS) of the closed side (10CS) and the circumferential cylindrical portion (10CP) projects out circumferentially from an inclined circumferential surface (10AS) towards the open side (10OS) of the clutch housing. The inclined circumferential surface (10AS) is formed circumferentially around the flat surface (10FS) of the clutch housing (10). The said circumferential portion (10CP) forms a cavity (10C) in the open side (10OS) of the housing (10) and the circumferential cylindrical portion (10CP) is configured to have a plurality of slots (10S) for mounting of friction plates with matching outer projections (52P) of the friction plates of plate stack (52). The annular step (15) forms an opening (11) in the center of the clutch housing (10). The said opening (11) provides the required confined space for accommodating and supporting a gear (12) and an input shaft from the engine along with the clutch actuation system (not shown). The clutch actuation means (not shown) is typically linked with a clutch lever that is mounted either on the handlebar (in case of two wheeled vehicle) or along with other foot pedal (in case of three wheeled vehicle) of the motor vehicle user. The flat surface (10FS) is configured to have a plurality of spring seats (10R) formed on the flat surface (10FS) of the clutch housing (10). Further, the said flat surface also has a plurality of hollow cylindrical projections (10P) projecting out from the flat surface (10FS) to receive the rivets (16) therein so as to fit the gear (12) with the housing clutch (10).

[0021] Referring to Figs. 1 to 3, the gear (12) is configured to have a plurality of teeth (12T) on its outer peripheral surface, a central opening (12OP) at the center of the gear (12), a plurality of spring pockets (12SP), and three elliptical slots (12ES) formed in between the outer diameter of the central opening (12OP) and the inner diameter of the teeth periphery (12T). The said spring pockets (12SP) houses the damper springs (12b). Further, the gear (12) is fitted with the clutch housing (10) by getting the projections (10P) of the housing clutch inserted into the elliptical slots (12ES) and locked there with the help of rivets (16) wherein said rivets (16) are getting inserted into the openings on the projections (10P) of the housing clutch (10). The teeth (12T) of the gear (12) are in mesh with an output shaft of the engine (not shown) for transmitting torque/power to the clutch assembly (300).

[0022] The damper plate (14) is configured to have a front face (14F), a rear face (14B), a central opening (14C), six spring pockets (14SP) and three rivet receiving openings (14RO). The said spring pockets (14SP) are formed in such a way that it maintains the angular orientation with the corresponding spring pockets (12SP) of the gear (12).

[0023] The gear (12) is configured to house a belleville spring (12a), a washer (12b) and a plurality of damper springs (12b). The spring pockets (12SP) of the gear (12), corresponding spring pockets (14SP) of the damper plate (14) and spring seats (10R) of the clutch housing (10) jointly houses the damper springs (12b). The rivets (16) are inserted in the rivet receiving opening (14RO) of the damper plate (14) and then passes through the hollow cylindrical projections (10P) of the clutch housing before the riveting operation is performed. Thus, the gear (12) along with the damper plate (14) is attached to the closed side (10CS) of the housing (10) and riveting is done to form the housing clutch assembly (100).

[0024] Referring to Figs. 1 to 3, the plate clutch assembly (200) of the multi-plate wet clutch comprises of a fixed hub (50), a plate stack (52), a PAJ (progressive and antijudder) spring (54a), a PAJ washer (54b), a moving hub (56), a plurality of kidney washers (85W), a plurality of compression springs (58), a set of bolt and washer assembly (59), a roller bearing (57), a bearing cup holder (60) and a plurality of bolts (62).

[0025] The fixed hub (50) is configured to have a front side (50FS) and a back side (50BS) (refer Figs. 5a and 5b). The front side (50FS) of the fixed hub (50) is configured to have at least three lugs (70) projecting out from a flat surface (50S1) and positioned at an equal angular distance from each other on the front side (50FS) of the said fixed hub (50). The said lugs (70) are formed at an angular distance of 120 degrees from each other. The fixed hub (50) is configured to have an annular disk portion (50DP) formed around the flat surface (50S1) in such a way that a step is formed in between the said disk portion (50DP) and the flat surface (50S1) of the fixed hub (50). The fixed hub (50) is configured to have a hub insert (84) wherein the said hub insert (84) projects out from the center of the flat surface (50S1). The hub insert (84) has a splined opening (84a) at its center for accommodating the input shaft.

[0026] The fixed hub (50) is configured to a plurality of hollow cam projections (75) projecting out from the flat surface (50S1) wherein the said projections (75) are formed consecutively in between the two consecutive lugs (70). The said cam projections (75) are positioned around the splined opening (84a) in such way that they are equidistantly spaced apart from each other by an angular distance of 120 degrees. Each of the cam projections (75) is configured to have an assist cam surface (75a) and a slipper cam surface (75b). The assist cam surface (75a) and slipper cam surface (75b) are configured in a manner to form a ramp helix wherein the helix angle ranges from 10°-28°. Further the said hollow cam projections (75) are configured to have a pocket (75P). The pocket (75P) is configured to receive a tubular portion of the moving hub (56).
[0027] Referring to Figs. 6a and 6b, the moving hub (56) is configured to have a disc portion (56D) and a cylindrical projection (56P) wherein the cylindrical projection (56P) is integral to the disc portion (56D) and projects away from a flat face (56FS) of the said disc portion (56D). The said cylindrical projection (56P) is configured to have a set of clustered splines (56s) formed at regular interval on the outer peripheral surface of the said cylindrical projection (56P). The said splines (56s) receives the stack of steel plates and friction plates of the plate stack (52) thus facilitating the axial movement of the plate stack (52) thereby.

[0028] The moving hub (56) is configured to have a plurality of projections (85) projecting out from a front inner base surface (56FB) and up to the top peripheral edge of the cylindrical projection (56P). The projections (85) are positioned around a central opening (56a) in such way that they are equidistantly spaced apart from each other by an angular distance of 120 degrees. The said projections (85) thus form a plurality of consecutive cavities (85C) formed alternatively in between the projections (85). Each of the cavity (85C) is configured to have an assist cam surface (85a) and a slipper cam surface (85b). The assist cam surface (85a) and the slipper cam surface (85b) are configured to form a ramp helix wherein the helix angle ranges from 10°-28°.

[0029] Each of the projections (85) of the moving hub (56) is configured to have a kidney shaped cavity (85K) wherein the said cavity (85K) houses a kidney shaped washer (85W). The kidney shaped cavity (85K) is configured to house the springs (58) wherein the said springs (58) rests over the kidney shaped washer (85W). The kidney shaped washer (85W) is made from hardened steel and is configured to prevent the direct contact of the spring (58) which made from a harder material i.e. steel and the softer material of the moving hub (56) i.e. the aluminum thus preventing the fouling of the surfaces of the moving hub (56) thereby.

[0030] Further, the moving hub (56) is configured to have a plurality of hollow tubular projections (56TP), preferably three projections, projecting out from the front base surface (56FB) wherein the said tubular projections (56TP) are positioned in between the two consecutive projections (85) and adjacent to the cavities (85C). The tubular projections (56TP) protrudes across the front base surface (56FB) wherein the said projections starts from a rear base surface (56RB) of the said moving hub (56). The tubular projections (56TP) are formed in a manner to have a base profiled in a shape of a fidget spinner having three lobes. The tubular projections (56TP) are bored from its base side and are configured to have threads over its inner peripheral surfaces which facilitates the fitment of the bearing cup holder (60) with the moving hub (56). The moving hub (56) has a central opening (56AS) formed across the front base surface (56FB) and the rear base surface (56RB) wherein the said opening (56AS) is configured to receive the bearing cup holder (60) therein.

[0031] The moving hub (56) is configured to be axially mounted in relation to the fixed hub (50), wherein the cam projections (75) of the fixed hub (50) are received in the cavities (85C) of the moving hub (56). The assist surface (75a) of the fixed hub (50) is configured to mate with the assist surface (85a) of the moving hub (85). Similarly, the slip surface (75b) of the fixed hub (50) is configured to mate with the slip surface (85b) of the moving hub (85). The said assist and slip surfaces (75a, 85a and 75b, 85b) are made in the form of helix like structure which helps leveraging the smooth torque transfer. This allows reducing the axial load (in general more than a halve) that the springs must sustain, thereby drastically reducing the effort required at the lever to command the clutch, thus making the driving/riding more comfortable.

[0032] Referring to the Figs. 7 and 8, the bearing cup holder (60) is configured to have a cylindrical body portion (60B) and a flange portion (60F) wherein the said flange portion (60F) is formed annularly over the outer peripheral surface of the cylindrical body portion (60B). The said cup holder (60) has a central opening (60a) to accommodate the input shaft. The said body portion (60B) is configured to have an inner stepped profile (S1) and an outer stepped profile (S2) wherein the inner stepped profile (S1) is configured to house the bearing (57) and the stepped profile (S2) passes through the central opening (56AS) of the moving hub (56). The flange portion (60F) is configured to have three ears (60E) profiled in a shape of a fidget spinner having three lobes. The said profile helps to save the material and reducing the overall weight of the assembly thereby. The said ears (60E) has an opening (60EP) which facilitates the fastening of the bearing cup holder (60) with the moving hub (56). The bearing cup holder (60) is fitted over the moving hub (56) with the help of the bolts (62) wherein the said bolts (62) passes through the opening (60EP) of the ears (60E) of the flange (60F) and through the tubular projections (56TP) of the moving hub (56).

[0033] Thus, the plate clutch assembly (200) is formed by positioning the plate stack (52) within the moving hub (56) in a manner such that the PAJ washer (54b) is placed in abutment with the front base surface (56FB) of the moving hub (56) and the said plate stack (52) rests over the PAJ spring (54a). The PAJ spring (54a) and the PAJ washer (54b) helps the preventing the fouling of the softer material of the moving hub i.e. aluminium by the steel plates of the plate stack (52). The moving hub (56) along with the plate stack (52) is coupled with the fixed hub (50) wherein the lugs (70) of the fixed hub (50) passes through the kidney shaped cavity (85K) of the moving hub (56). The springs (58) are positioned within the cavity (85K) in a manner to be guided by the outer peripheral surface of the lugs (70) wherein the bottom face of the spring rests over the kidney washer (85W) placed in the cavity (85K). The top surface of the springs (58) is closed with the special bolt and washer assembly (59) wherein the washer (59W) closes the springs (58) from its top end.

[0034] The lugs (70) of the fixed hub (50) are threaded with the bolt (59B) wherein, the inner surface of the lugs (70) is configured to have matching threads with that of the threads of the bolts (59B). The bearing (57) is positioned within the inner step profile (S1) of the bearing cup holder (60) and the said bearing (57) along with the bearing cup holder (60) is mounted over the moving hub (56). The bearing (57) may be press-fitted within the step profile (S1) or may be positioned therein without impacting the torque transmitting performance thereby. The bearing cup holder (60) is fitted over the moving hub (56) with the help of the bolts (62) wherein the said bolts (62) passes through the opening (60EP) of the ears (60E) of the flange (60F) and through the tubular projections (56TP) of the moving hub (56).

[0035] The plate clutch assembly (200) is placed within the cavity (10C) of the housing (10) of the housing clutch assembly (100) to form the pull type multi-plate wet clutch assembly (300). The slots (10S) of circumferential cylindrical portion (10CP) of the housing (10) receives the outer peripheral projections of the friction plate of the plate stack (52) and the flat surface (50S2) of the fixed hub (50) rests in the cavity (10C) of the housing (10) of the housing clutch assembly (100).
[0036] During the working condition, when the multi-plate wet clutch assembly (300) is in engaged condition, the whole clutch assembly acts in unison by due to the interfacial pressure applied on the plate stack by the compression spring (58) and as a result of which, the torque is transferred from the engine to gear box via the multi-plate wet clutch assembly (300). In this condition, the moving hub (56) rotates relative to the fixed hub (50) by cam action in which the assist cam surface (85a) formed at the moving hub (56) moves over the assist cam surface (75a) formed at the fixed hub (50). This leads to action of the assist function of rapidly enhancing pressing force. Accordingly, the moving hub (56) is pressed against the fixed hub (50) with strong force by the assist mechanism.

[0037] When the torque interruption from engine to the gearbox is required, the user presses the clutch lever placed on the handlebar of the vehicle which in turn transmits the force to the bearing cup holder (60). The force on the bearing cup holder (60) is then transmitted to the moving hub (56) which leads to the axial displacement of the over the moving hub (56) as a result of which the interfacial pressure between the plate stack (52) is reduced and the multi-plate wet clutch assembly (300) is disengaged. In this condition, the moving hub (56) rotates relative to the fixed hub (50) in opposite direction and the slip surface (85b) formed at the moving hub (56) slips over the slip surface (75b) formed at the fixed hub (50) due to the wedging action, leading to the separation of the moving hub (56) and the fixed hub (50).

[0038] This unique profile of the bearing cup holder (60), moving hub (56) and the fixed hub (50) eliminates the requirement of the circlip, facilitates the ease of assembly and dis-assembly of the clutch assembly (300). Further, the bearing cup holder (60) can be used with any type of pull type clutch irrespective of the AnA (Assist and Assist), (AnS) (Assist and Slip), Conventional Clutches and like. Thus, the mere improvement in the profile of the bearing cup holder (60) and the application thereof should not establish the inventive step over this invention.

[0039] The multi-plate wet clutch assembly (300) of the present invention provides the following technical advantages that contributes to the advancement of technology:
- It eliminates the loss of clutch function as evident in the conventional pull type multi-plate wet clutch.
- It eliminates the handle lever free play at the clutch lever making is quite convenient for rider for actuation.
- Cycle time reduction and cost saving because of ease of assembly process.
- Simple and easily implementable design solution.
- Eliminates the requirement of circlip and integrated bearing holder thereby reducing he weight and cost of the clutch assembly.

[0040] It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the invention herein has been described in terms of a generalized form, those skilled in the art will recognize that the invention herein can be practiced with modification within the spirit and scope of the invention as described herein.
, Claims:We Claim:

1. A pull type clutch assembly (300) for a motor vehicle having a housing clutch assembly (100) and a plate clutch assembly (200), said plate clutch assembly (200) comprises of a fixed hub (50), a plate stack (52), a PAJ (progressive and anti-judder) spring (54a), a PAJ washer (54b), a moving hub (56), a plurality of kidney washers (85W), a plurality of compression springs (58), a set of bolt and washer assembly (59), a roller bearing (57), a bearing cup holder (60) and a plurality of bolts (62)
wherein,
- the bearing cup holder (60) is configured to have a cylindrical body portion (60B) and a flange portion (60F), and said flange portion (60F) is formed annularly over the outer peripheral surface of the cylindrical body portion (60B);
- the body portion (60B) is configured to have an inner stepped profile (S1) and an outer stepped profile (S2) wherein the inner stepped profile (S1) is configured to house the roller bearing (57) and the stepped profile (S2) passes through the central opening (56AS) of the moving hub (56);
- the fixed hub (50) has a front side (50FS) and a back side (50BS), and said front side (50FS) of the fixed hub (50) is configured to have at least three lugs (70) projecting out from a flat surface (50S1) and positioned at an equal angular distance from each other on the front side (50FS) of the said fixed hub (50);
- the moving hub (56) is configured to have a plurality of projections (85) projecting out from a front inner base surface (56FB) and up to the top peripheral edge of the cylindrical projection (56P);
- each of the projections (85) of the moving hub (56) is configured to have a kidney shaped cavity (85K), and said cavity (85K) houses a kidney shaped washer (85W) and the spring (58) in such a way that said spring (58) is configured to rest over the kidney shaped washer (85W); and
- said bearing cup holder (60) is fitted over the moving hub (56) with the help of the bolts (62), and said moving hub (56) along with the plate stack (52) is coupled with the fixed hub (50) wherein the lugs (70) of the fixed hub (50) passes through the kidney shaped cavity (85K) of the moving hub (56).

2. The pull type clutch assembly (300) as claimed in claim 1, wherein
- the bearing cup holder (60) has a central opening (60a) to accommodate the input shaft;
- the flange portion (60F) of the bearing cup holder (60) is configured to have three ears (60E) profiled in a shape of a fidget spinner having three lobes;
- each of the ears (60E) is configured to have an opening (60EP) that facilitates the fastening of the bearing cup holder (60) with the moving hub (56);
- the moving hub (56) is configured to have three hollow tubular projections (56TP) projecting out from the front base surface (56FB), and said tubular projections (56TP) are positioned in between the two consecutive projections (85) and adjacent to the cavities (85C); and
- the bolts (62) are configured to pass through the opening (60EP) of the ears (60E) of the flange (60F) and through the tubular projections (56TP) of the moving hub (56) so as to fit said bearing cup holder (60) over the moving hub (56).

3. The pull type clutch assembly (300) as claimed in claim 2, wherein
- the tubular projections (56TP) of the moving hub (56) protrudes across the front base surface (56FB) in such a way that said projections (56TP) starts from a rear base surface (56RB) of the moving hub (56), and are configured to have a base profiled in a shape of a fidget spinner having three lobes;
- said tubular projections (56TP) are bored from its base side and are configured to have threads over its inner peripheral surfaces so as to facilitate the fitment of the bearing cup holder (60) with the moving hub (56);
- the inner step profile (S1) of the bearing cup holder (60) is configured to house the bearing (57) and the said bearing (57) along with the bearing cup holder (60) is mounted over the moving hub (56), wherein the bearing (57) is press-fitted within the step profile (S1) without impacting the torque transmitting performance thereby; and
- said moving hub (56) has a central opening (56AS) formed across the front base surface (56FB) and the rear base surface (56RB) wherein the said opening (56AS) is configured to receive the bearing cup holder (60) therein.

4. The pull type clutch assembly (300) as claimed in claim 1, wherein
- the kidney shaped washer (85W) is made from hardened steel and is configured to prevent the direct contact of the spring (58) with the moving hub (56) so as to prevent the fouling of the surfaces of the moving hub (56) thereby;
- the fixed hub (50) is configured to a plurality of hollow cam projections (75) projecting out from the flat surface (50S1) wherein the said projections (75) are formed consecutively in between the two consecutive lugs (70);
- said hollow cam projections (75) are configured to have a pocket (75P) and said pocket (75P) is configured to receive a tubular portion (56TP) of the moving hub (56);
- said cam projections (75) are positioned around the splined opening (84a) in such way that they are equidistantly spaced apart from each other by an angular distance of 120 degrees; and
- each of the cam projections (75) is configured to have an assist cam surface (75a) and a slipper cam surface (75b), and said assist cam surface (75a) and said slipper cam surface (75b) are configured to form a ramp helix wherein the helix angle ranges from 10° to 28°.

5. The pull type clutch assembly (300) as claimed in claim 4, wherein
- the springs (58) are positioned within the cavity (85K) of the moving hub (56) and are configured to be guided by the outer peripheral surface of the lugs (70) wherein the bottom face of the spring rests over the kidney washer (85W) placed in the cavity (85K); and
- the top surface of the springs (58) is closed with the special bolt and washer assembly (59) wherein the washer (59W) closes the springs (58) from its top end.

6. The pull type clutch assembly (300) as claimed in any of the claims 3 and 5, wherein
- the moving hub (56) is configured to have a disc portion (56D) and a cylindrical projection (56P) wherein the cylindrical projection (56P) is integral to the disc portion (56D) and projects away from a flat face (56FS) of the said disc portion (56D); and
- said cylindrical projection (56P) is configured to have a set of clustered splines (56s) formed at regular interval on the outer peripheral surface of the said cylindrical projection (56P), and said splines (56s) are configured to receive the stack of steel plates and friction plates of the plate stack (52) to facilitate the axial movement of the plate stack (52).

7. The pull type clutch assembly (300) as claimed in claim 6, wherein
- the projections (85) of the moving hub (56) are positioned around a central opening (56a) in such way that they are equidistantly spaced apart from each other by an angular distance of 120 degrees;
- said projections (85) are configured to form a plurality of consecutive cavities (85C) alternatively in between the projections (85);
- each of the cavities (85C) is configured to have an assist cam surface (85a) and a slipper cam surface (85b), and said assist cam surface (85a) and said slipper cam surface (85b) are configured to form a ramp helix with the helix angle ranging from 10° to 28°;
- said moving hub (56) is configured to be axially mounted in relation to the fixed hub (50), wherein the cam projections (75) of the fixed hub (50) are received in the cavities (85C) of the moving hub (56); and
- the assist surface (75a) of the fixed hub (50) is configured to mate with the assist surface (85a) of the moving hub (85), and the slip surface (75b) of the fixed hub (50) is configured to mate with the slip surface (85b) of the moving hub (85) forming a helix like structure so as to leverage the smooth torque transfer.

8. The pull type clutch assembly (300) as claimed in claim 7, wherein
- the fixed hub (50) is configured to have a hub insert (84) and said hub insert (84) projects out from the center of the flat surface (50S1) and has a splined opening (84a) at its center for accommodating the input shaft;
- said fixed hub (50) is configured to have an annular disk portion (50DP) formed around the flat surface (50S1) in such a way that a step is formed in between the said disk portion (50DP) and the flat surface (50S1) of the fixed hub (50); and
- the lugs (70) of the fixed hub (50) are formed at an angular distance of 120 degrees from each other and are threaded with the bolt (59B) wherein the inner surface of the lugs (70) is configured to have matching threads with that of the threads of the bolts (59B).

Dated this 30th day of Dec. 2024

Sahastrarashmi Pund
Head – IPR
Endurance Technologies Ltd.

To,
The Controller of Patents,
The Patent Office, at Mumbai