FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10 and rule 13]
"A CLUTCH PEDAL ASSEMBLY AND A METHOD OF ASSEMBLING
THEREOF"
NAME AND ADDRESS OF THE APPLICANT:
TATA MOTORS LIMITED, an Indian company having its registered office at Bombay house, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001, Maharashtra, INDIA.
Nationality: Indian
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
The present disclosure is related to a mechanical clutch pedal assembly for a motor vehicle. The disclosure more particularly relates to the design of the clutch pedal assembly for providing assistance to reduce the pedal effort during clutch disengagement and assist good clutch pedal return during clutch engagement.
BACKGROUND OF THE DISCLOSURE
The clutch pedal effort during disengagement and engagement are the crucial
parameters in any clutch system and are the important/sensitive customer touch points
in all vehicles having manual transmission. These touch points becomes more critical in
mechanical clutch pedal actuation system where clutch cable is used as a medium to
transfer the pedal input to clutch.
Conventional clutch cover has only diaphragm spring which is the source for the release load. This in turn will be reflecting on the clutch pedal in terms of pedal effort.
Actuation of the clutch can be classified into two different types of system. First . type of clutch actuation mechanism is a Preload system. In this system the Clutch Releasing Bearing (CRB) is constantly in contact with the clutch cover diaphragm fingers, under predefined preload. The preload is maintained by the pedal return spring in the pedal box, exerting force on the pedal lever and thereby on the cable in pulling it to press the CRB against the clutch cover finger tips. This type is used for higher diameter clutch where in the release load is higher. The second type of clutch actuation mechanism is a Free play system. In this system the CRB has some clearance with the clutch diaphragm fingers. Also, here the pedal always tries to release the cable in free condition and the pedal tries to move upwards i.e. away from the floor of the vehicle and is stopped by means of stopper on the pedal bracket. There will be at least 1 to 2 more springs on the clutch housing side in this system. The free play system is used for smaller diameter clutch wherein the preload system cannot be used as it will reduce the Factor of safety.

In case of smaller size clutches the pedal return-ability becomes a concern because of lower release load. When free play system is used with smaller clutches, though the pedal return is maintained at acceptable limit, the forward pedal effort increase because of different springs used for maintaining free play, pedal return etc.
Also, the pre load system cannot be used in its present form for the small clutches as it will reduce the return pedal effort.
Thus, there exists a need to develop a pedal assembly to overcome the above said drawback.
SUMMARY OF THE DISCLOSURE
The shortcomings of the prior art are overcome and additional advantages are provided through the provision of innovated clutch pedal system as described in 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.
The disclosure provides a clutch pedal assembly for a motor vehicle comprising, a pedal bracket (9) mounted to firewall of the vehicle. Further a clutch pedal (1) consisting a pedal lever (la) and a cable arm (1b) are pivoted to the pedal bracket (9). In addition, a preloaded torsion spring (2) with first tangential leg (2a) and second tangential leg (2b) are mounted coaxially at a pivot point (10) on the clutch pedal (1). And a plurality of spring stoppers is provided on each of the clutch pedal (1) and the pedal bracket (9) at predetermined locations to retain the torsion spring in preloaded condition.
In one embodiment of the present disclosure said spring (2) is a coil spring.
In one embodiment of the present disclosure said first tangential leg (2a) and the second tangential leg (2b) are in contact with the stoppers (3) and (6) respectively and exerts a downward force on the clutch pedal (1), when the clutch pedal (1) is in engaged position.

In one embodiment of the present disclosure the spring stoppers (3) and (4) are provided on pedal lever (1a) and cable arm (1b) respectively, and the spring stoppers (5, 6) are provided on pedal bracket (9).
In one embodiment of the present disclosure said first tangential leg (2a) and the second tangential leg (2b) are in contact with the stoppers (5) and (4) respectively and exerts an upward force on the clutch pedal (1), when the clutch pedal (1) is in disengaged position.
In one embodiment of the present disclosure, a method of assembling a clutch pedal assembly for a motor vehicle is disclosed. The method comprises acts of, mounting a pedal bracket (9) to firewall of the vehicle. Further connecting a clutch pedal (1) consisting a pedal lever (la) and a cable arm (lb) to said pedal bracket (9). In addition mounting a torsional spring (2) coaxially at a pivot point (10) on the clutch pedal (1) wherein said spring (2) is provided with first tangential leg (2a) and second tangential leg (2b) And providing plurality of spring stoppers at predetermined locations on said clutch pedal (1) and pedal bracket (9) to retain the torsion spring in preloaded condition,
In one embodiment of the present disclosure said clutch pedal (1) and cable arm (lb) is pivoted to the pedal bracket (9) by a fastening means.
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 illustrates the schematic diagram of free play and preload complete clutch actuation system
Fig 2, illustrates the clutch pedal is in top initial position and the pedal held by mean of clutch cable where the spring tends to pull the clutch pedal down in clock wise direction.
Fig 3 illustrates the changeover point indicating the clutch pedal at middle of its travel where spring force on pedal in clockwise and anticlockwise directions becomes zero.
Fig 4 shows the pedal position along with spring and the spring functioning. And indicates the clutch pedal at the end of travel where spring force on pedal is in clockwise direction making the pedal return to position in Fig 2.
Fig 5 shows the graphical representation of the improved performance of the pedal assembly.
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.
DETAIL DESCRIPTION
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.

Referral Numerals Description
1 Clutch pedal
la Pedal lever
lb Cable arm
2 Torsion spring
2a First tangential leg
2b Second tangential leg
3 Spring stopper in pedal lever
4 Spring stopper in cable arm
5 Spring stopper in pedal bracket
6 Spring stopper in pedal bracket
7 Pedal stopper
8 Clutch cable
9 Pedal bracket
10 Pedal pivot

The present disclosure is related to a mechanical clutch pedal assembly for a motor vehicle. The disclosure more particularly relates to the design of the clutch pedal assembly for providing sufficient assistance to reduce the pedal effort during clutch disengagement as well as ensure good clutch pedal return during clutch engagement.
A new design of the pedal mechanism is developed through this disclosure, to keep the forward pedal effort in acceptable range and ensure good return pedal effort for a mechanically operated clutch pedal systems. The present disclosure discloses a clutch pedal assembly providing assistance in forward direction (when the pedal is pressed from its engaged position) till a predefined position and provides return force till the same predefined point (when the pedal is returning from its disengaged position) during return pedal travel thereby improving the return pedal effort.
Referring to the figs. 2, 3 and 4 which illustrate the clutch pedal mechanism in different positions of the clutch pedal along the travel. The pedal assembly consists of a clutch pedal (1) with pedal lever (la) and cable arm (lb). The clutch pedal (1) is pivoted on the pedal bracket (9) at point (10) by means of a fastener. A torsion spring (2) with first tangential leg (2a) and second tangential leg (2b) is mounted coaxial to the pedal pivot point (10). The spring (2) in its assembled condition is preloaded to reduce the effort applied on the pedal when it is moved in the forward direction from its engaged position. The open end of the tangential legs of the spring always tends to come closer in normal condition due to preloading on the spring. Spring stoppers (3) and (4) are mounted on the pedal (1) and spring stoppers (5) and (6) on the pedal bracket (9). During the clutch pedal (1) is engaged, the spring legs (2a) and (2b) are in contact with stoppers 3 and 6 respectively thereby exerting the downward force on the pedal. When the clutch pedal (1) is pressed forward, the spring leg (2a) comes in contact with the stopper (5) on the pedal bracket (9) and the spring leg (2b) comes in contact with spring stopper (4) on the pedal thereby changing the support of the spring arms from stoppers 3 and 6 to 5 and 4 respectively.
A clutch cable (8) is attached to the cable arm (1b). A stopper (7) is provided on pedal bracket (9) which will only comes in contact with the pedal (1) due to clutch disc wear.

Referring back to figure 2, the clutch pedal (1) is held in engaged position by the cable (8). The spring leg (2b) is held by the stopper (6) on the pedal bracket (9) and the opposite spring leg (2a) is in contact with pedal stopper (3) which tends to pull the pedal (1) due to preloading of the cable (8). The forward assistive force acts on the pedal (lb) till the pedal (1) comes to position shown in figure 3 during the clutch disengagement. Thus, the system remains in preload condition during its initial phase.
Due to the clutch pedal (1) movement from its initial position i.e. as shown in fig. 2 to the position as shown in figure 3, the spring legs (2a) and (2b) are in contact with the stoppers (3 & 4) on pedal and in contact with (5 & 6) on the pedal bracket (9). And both the spring legs (2a & 2b) are locked by the stoppers (5 & 6) provided on the pedal bracket (9). At this point pedal assistance becomes zero and the spring (2) starts resisting beyond this pedal travel. Further movement of the pedal beyond this travel the torsion spring leg (2a) will be still in same position as in figure 3, but the other spring leg (2b) is carried away from the pedal bracket stopper (6) by means of cable arm (lb), due to which the spring (2) is compressed and a reaction force in opposite direction is applied to the clutch pedal (1). Thus, the system is converted to free play from preload.
During the pedal return from its disengaged position the torsion spring (2) leg which is operating against spring stopper (5) and (4) on bracket (9) and cable arm (la) respectively exerts a force on the clutch pedal lever (1) thereby providing assistance in the returning as required for better return pedal force. This is continued till changeover point as shown in figure 3. After changeover point, the spring once again starts operating against the spring stoppers (3) and (6), while the pedal returns to its disengaged position.
The pedal stopper (7) provided in the pedal box avoids any upper pedal movement to avoid dislocation of the clutch cable (8) from cable arm of pedal lever (la). It also functions as an indicator for readjustment of the clutch cable (8) over clutch wear.
The positions of the stoppers (3), (4), (5) and (6) can be configured in combination with torsion spring to get desire pedal feel in forward and return direction.

In an alternative embodiment, the assembly may also be provided with a torsional spring (2) having an extended tangential legs to form hooks at its ends. The hooks formed contacts the clutch pedal (1) in its engaged position and contacts the stoppers (5) and (6) when it is moved forward from its engaged position. This would reduce the number of stoppers required to hold the spring during engagement and disengagement of the clutch pedal (1).
Advantages of the invention:
In one embodiment, the assembly works partial up to 40 % of the travel as preload and then it converts into freeplay system.
In one embodiment, Single spring provides the assistance/resistance force on to
the pedal which in case of existing preload is only assistance and in case of free
play is only resistance.
In one embodiment, the locking and relieving arrangement of the single spring for assistive and resistive mode is different and unique.
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.

We claim:
1. A clutch pedal assembly for a motor vehicle comprising;
a pedal bracket (9) mounted on firewall of the vehicle;
a clutch pedal (1) consisting a pedal lever (la) and a cable arm (lb) pivoted to said pedal bracket (9);
a preloaded torsion spring (2) with a first tangential leg (2a) and a second tangential leg (2b) mounted coaxially at a pivot point (10) on the clutch pedal (l)and
a plurality of spring stoppers provided on each of the clutch pedal (1) and the pedal bracket (9) at predetermined locations.
2. The clutch pedal system as claimed in claim 1. wherein a clutch cable (8) is attached to the cable arm (1B).
3. The clutch pedal system as claimed in claim 1, wherein said spring (2) is a coil spring.
4. The clutch pedal system as claimed in claim 1, wherein the spring stoppers (3) and (4) are provided on pedal lever (la) and cable arm (1b) respectively, and the spring stoppers (5, 6) are provided on pedal bracket (9).
5. The clutch pedal system as claimed in any one of the preceding claims, wherein said first tangential leg (2a) and the second tangential leg (2b) are in contact with the stoppers (3) and (6) respectively when the clutch pedal (1) is in clutch engaged position.
6. The clutch pedal system as claimed in any one of the preceding claims, wherein said first tangential leg (2a) and the second tangential leg (2b) are in contact with the stoppers (5) and (4) respectively when the clutch pedal (1) is in clutch disengaged position,
7. The clutch pedal system as claimed in claim 1, wherein the spring (2) mounted between the plurality of spring stoppers assists downward and upward force exerted on the clutch pedal (1).

8. A method of assembling a clutch pedal assembly for a motor vehicle, said method
comprising;
mounting a pedal bracket (9) to firewall of the vehicle;
connecting a clutch pedal (1) consisting a pedal lever (1a) and a cable arm (1b) to said pedal bracket (9);
mounting a torsional spring (2) coaxially at a pivot point (10) on the clutch pedal (1), wherein said spring (2) is provided with a first arm (2a) and a second arm (2b) and
providing plurality of spring stoppers at predetermined locations on said clutch pedal (1) and pedal bracket (9).
9. The method of assembling the clutch pedal assembly as claimed in claim 5. wherein
said pedal lever (1a) and cable arm (lb) are pivoted to the pedal bracket (9) by a
fastening means.