Description:FORM 2
THE PATENTS ACT, 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[See Section 10, Rule 13]

A CLUTCH MASTER CYLINDER ASSEMBLY FOR A VEHICLE

BY
MAHINDRA & MAHINDRA LIMITED, A COMPANY REGISTERED UNDER THE INDIAN COMPANIES ACT, 1913, HAVING ADDRESS AT MAHINDRA RESEARCH VALLEY (MRV), MAHINDRA WORLD CITY, PLOT NO.41/1, ANJUR P.O., CHENGALPATTU, KANCHIPURAM DISTRICT, TAMILNADU – 603004, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

A CLUTCH MASTER CYLINDER ASSEMBLY FOR A VEHICLE

TECHNICAL FIELD OF THE INVENTION
The present disclosure relates to a clutch master cylinder assembly for a vehicle.

BACKGROUND OF THE INVENTION
Generally, vehicles having a hydraulic system to transform the movement of a clutch pedal to a clutch plate, use a Clutch Master Cylinder (CMC) which acts as a transmitter in the hydraulic system, sending the driver input to a clutch. Traditionally, the locking of a cup of the CMC and a clevis pin, which is part of a clutch lever assembly, is done using one or more lugs integral to the cup of the CMC and a groove in the clevis pin. Apart from this, other methods that are used to lock the cup of the CMC and the clevis pin include snap-fitting of the clevis pin to lock the cup of the CMC.
However, many complications arise due to these types of locking arrangement. One complication related to the above arrangement is that it either requires a tool for disassembling a clutch master cylinder assembly for unlocking or the whole pedal assembly is required to be removed from a Body-In-White (BIW) during maintenance and/or repair. Therefore, there is a requirement of simple, fast, and tool-less clutch master cylinder assembly to reduce both time and effort during repair and/or maintenance.

SUMMARY OF THE INVENTION
In one aspect of the present invention, a clutch master cylinder assembly for a vehicle is provided. The clutch master cylinder assembly includes a hollow clevis pin fixedly coupled to a clutch lever. The hollow clevis pin has a hole on a circumferential surface. The clutch master cylinder assembly also includes a plunger slidably engaged within the hollow clevis pin and having an outer surface. The plunger has a first groove on the outer surface. The clutch master cylinder assembly further includes a spring disposed between the plunger and the clutch lever. The clutch master cylinder assembly includes at least one ball bearing disposed within the hollow clevis pin and at least partially received by the hole of the hollow clevis pin. The ball bearing is selectively movable in downward direction. The clutch master cylinder assembly also includes a cup coupled to a clutch master cylinder. The cup has a second groove on an inner surface. The cup is removably coupled to the hollow clevis pin in such a manner that the second groove is aligned above the hole of the hollow clevis pin. In a locked position, the ball bearing is at least partially received in the hole of the hollow clevis pin and in the second groove of the cup in such a manner that lower end of the ball bearing rests on the outer surface of the plunger. In an unlocked position, when the plunger is pushed against the spring, the axial movement of the plunger allows alignment of the first groove of the plunger below the hole of the hollow clevis pin and the ball bearing moves downward in such a manner that the ball bearing is at least partially received in the hole of the hollow clevis pin and in the first groove of the plunger, thereby allowing disengagement of the ball bearing with the second groove of the cup, thus allowing removal of the cup.
According to the present invention, the first groove has a profile corresponding to shape of the ball bearing.
According to the present invention, the second groove has a profile corresponding to shape of the ball bearing.

BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates an exploded view of a conventional clutch master cylinder assembly for a vehicle;
FIG. 2 illustrates a cross-sectional view of the conventional clutch master cylinder assembly associated with FIG. 1;
FIG. 3 illustrates an exploded view of a clutch master cylinder assembly for a vehicle, according to the present disclosure; and
FIG. 4 illustrates a top view of the clutch master cylinder assembly associated with FIG. 3, according to the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth relating to specific components to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated elements, modules, units and/or components, but do not forbid the presence or addition of one or more other elements, components, and/or groups thereof.
FIGS. 1 and 2 illustrate a conventional clutch master cylinder assembly (100) for a vehicle (not shown). The clutch master cylinder assembly (100) includes a clutch master cylinder (CMC) (102) having a cup (104). The cup (104) of the CMC (102) includes a plurality of lugs (106) integral to the cup (104). The clutch master cylinder assembly (100) also includes a clevis pin (108) having a stepped profile. The clevis pin (108) is fixedly coupled to a clutch lever (110), more particularly, the clevis pin (108) is welded to the clutch lever (110). The clevis pin (108) includes a groove (112) to receive the plurality of lugs (106) of the cup (104). The cup (104) of the CMC (102) is coupled to the clevis pin (108) by a snap-fit arrangement. Further, when the cup (104) is pressed on the clevis pin (108), the lugs (106) expand outwardly due to the stepped profile of the clevis pin (108) and snapped into the groove (112) of the clevis pin (108), thus, locking is achieved between the CMC (102) and the clevis pin (108).
FIGS. 3 and 4 illustrate a clutch master cylinder assembly (200) for a vehicle (not shown) of the present disclosure. The clutch master cylinder assembly (200) includes a clutch master cylinder (CMC) (202) and a clutch lever (204). The clutch master cylinder assembly (200) also includes a hollow clevis pin (206) fixedly coupled to a clutch lever (204). In an embodiment, the hollow clevis pin (206) is welded to the clutch lever (204). The hollow clevis pin (206) has a hole (208) on a circumferential surface. The hollow clevis pin (206) has a cylindrical shape.
The clutch master cylinder assembly (200) further includes a plunger (210) slidably engaged within the hollow clevis pin (206) and having an outer surface (212). The plunger (210) has a cylindrical shape corresponding to the hollow clevis pin (206). The plunger (210) has a first groove (214) on the outer surface (212). The first groove (214) is positioned between two ends of the plunger (210). The clutch master cylinder assembly (200) includes a spring (216) disposed between the plunger (210) and the clutch lever (204). One end of the spring (216) is fixedly coupled to the plunger (210) and another end of the spring (216) is fixedly coupled to the clutch lever (204). In the illustrated embodiment of FIGS. 3 and 4, one end of the springs (216) is welded to the plunger (210) and another end is welded to the clutch lever (204).
The clutch master cylinder assembly (200) also includes at least one ball bearing (218) disposed within the hollow clevis pin (206) and at least partially received by the hole (208) of the hollow clevis pin (206). The ball bearing (218) has a spherical shape. Further, diameter of the hole (208) is less than that of diameter of the ball bearing (218), thus, the ball bearing (218) is prevented to move further in an upwards direction. However, the ball bearing (218) is selectively movable in downward direction.
The clutch master cylinder assembly (200) further includes a cup (220) coupled to the clutch master cylinder (202). The cup (220) has a second groove (222) on an inner surface. The cup (220) is removably coupled to the hollow clevis pin (206) in such a manner that the second groove (222) is aligned above the hole (208) of the hollow clevis pin (206).
In a locked position, the ball bearing (218) is at least partially received in the hole (208) of the hollow clevis pin (206) and in the second groove (222) of the cup (220) in such a manner that lower end of the ball bearing (218) rests on the outer surface (212) of the plunger (210). The outer surface (212) of the plunger (210) restricts the downward movement of the ball bearing (218). In an embodiment, the second groove (222) has profile corresponding to shape of the ball bearing (218). In another embodiment, the second groove (222) may have any profile without limiting the scope of the present disclosure.
Further, in an unlocked position when the plunger (210) is pushed against the spring (216), the axial movement of the plunger (210) allows alignment of the first groove (214) of the plunger (210) below the hole (208) of the hollow clevis pin (206) and the ball bearing (218) moves downward in such a manner that the ball bearing (218) is at least partially received in the hole (208) of the hollow clevis pin (206) and in the first groove (214) of the plunger (210), thereby allowing disengagement of the ball bearing (218) with the second groove (222) of the cup (220), thus allowing removal of the cup (220). In an embodiment, the first groove (214) has a profile corresponding to shape of the ball bearing (218). In another embodiment, the first groove (214) may have any profile without limiting the scope of the present disclosure. Due to the downwards movement of the ball bearing (218) within the hole (208) of the clevis pin (206), the ball bearing (218) completely moves out of the second groove (222) of the cup (220), thus, the cup (220) can be easily removed, and plunger (210) can be released.
Furthermore, the plunger (210) is pressed against the spring (216) and the cup (220) is disposed on the clevis pin (206) in such a manner that the second groove (222) of the cup (220) is aligned exactly with the ball bearing. Once the exact alignment is achieved, the plunger (210) is released so that the ball bearing (218) moves upwardly from the first groove (214) of the plunger (210) and rests on the outer surface (212) of the plunger (210) while at least partially received in the second groove (222) of the cup (220). This causes the ball bearing (218) to move out of the first groove (214) of the plunger (210) and to move into the second groove (222) of the cup (220), resulting in a positive locking between clevis pin (206) and the cup (220).
The present invention does not require a tool to remove the CMC, nor does it require the clutch pedal assembly to be removed from a Body-In-White (BIW) to remove the CMC, rather it just requires a push on the plunger against the spring to remove and attach the cup which is coupled to the CMC. The present invention provides a robust clutch master cylinder assembly by providing fast and easy locking and unlocking means for the clutch master cylinder assembly.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
Any discussion of devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
, Claims:
1. A clutch master cylinder assembly (200) for a vehicle, the clutch master cylinder assembly (200) comprising:
a hollow clevis pin (206) fixedly coupled to a clutch lever (204), the hollow clevis pin (206) has a hole (208) on a circumferential surface;
a plunger (210) slidably engaged within the hollow clevis pin (206) and having an outer surface (212), the plunger (210) has a first groove (214) on the outer surface (212);
a spring (216) disposed between the plunger (210) and the clutch lever (204);
at least one ball bearing (218) disposed within the hollow clevis pin (206) and at least partially received by the hole (208) of the hollow clevis pin (206), the ball bearing (218) is selectively movable in downward direction; and
a cup (220) coupled to a clutch master cylinder, the cup (220) has a second groove (222) on an inner surface, the cup (220) is removably coupled to the hollow clevis pin (206) in such a manner that the second groove (222) is aligned above the hole (208) of the hollow clevis pin (206),
in a locked position, the ball bearing (218) is at least partially received in the hole (208) of the hollow clevis pin (206) and in the second groove (222) of the cup (220) in such a manner that lower end of the ball bearing (218) rests on the outer surface (212) of the plunger (210), and
in an unlocked position, when the plunger (210) is pushed against the spring (216), the axial movement of the plunger (210) allows alignment of the first groove (214) of the plunger (210) below the hole (208) of the hollow clevis pin (206) and the ball bearing (218) moves downward in such a manner that the ball bearing (218) is at least partially received in the hole (208) of the hollow clevis pin (206) and in the first groove (214) of the plunger (210), thereby allowing disengagement of the ball bearing (218) with the second groove (222) of the cup (220), thus allowing removal of the cup (220).
2. The clutch master cylinder assembly (200) as claimed in claim 1, wherein the first groove (214) has a profile corresponding to shape of the ball bearing (218).
3. The clutch master cylinder assembly (200) as claimed in claim 1, wherein the second groove (222) has a profile corresponding to shape of the ball bearing (218).