DESC:TECHNICAL FIELD

Embodiments of the present disclosure relates to a clutch actuation system, more particularly, embodiments relates to the mechanical clutch actuation system provided with pedal assistance mechanism.

BACKGROUND OF DISCLOSURE

It is well known to provide a clutch actuation system for vehicles for actuating the clutch of the vehicle in response to the actuation of a clutch pedal in the vehicle. Commonly known clutch actuation systems typically have a mechanical linkage mechanism, a clutch cable, or some combination thereof to translate the clutch pedal actuation to the clutch lever on the clutch housing. The engagement and disengagement of the clutch is determined by the manual movement of a clutch pedal, and typically controlled by the vehicle operator with his foot. The efforts to release the clutch pedal in many such applications may be greater than desired for some drivers, particularly in heavy trucks.

The pedal actuation force of the clutch is always been a concern for automobile manufacturers. A high actuation force gives fatigue to the driver. The mechanical clutch actuation system is generally used for low torque engines because of limited overall ratio available with mechanical system and limiting low pedal return force. If mechanical actuations system is used for high torque engines, the pedal effort increases beyond acceptable levels, because of low overall actuation ratio.

In the existing clutch operating systems, a well-known assistance mechanism is used. The basic function of the assistance mechanism is to reduce the clutch pedal effort. The existing mechanism can reduce the clutch pedal effort to a considerable extent. However, there is a limitation of this mechanism because higher assistance may disallow the clutch pedal to return to its original position after the pressure imparted on the clutch pedal is removed. Since the clutch pedal effort usually remains very low during return direction compared to forward direction, which restrict the maximum assistance value.

The mechanical cultch system with pedal assistance mechanism of this type is described in U.S. Pat. No. 5165299 (herein after referred as ‘299 patent) issued to Nissan Motor Co. Ltd. The pedal assistance mechanism of ‘299 patent comprises a clutch linkage arrangement is provided with first and second assist spring units. The first assist spring unit applies a depression resisting force to a pedal arm upon rotation of the pedal arm between a rest position and a transition position, and a depression assisting force upon rotation of the pedal arm exceeding the transition position. The second assist spring unit applies a depressing assisting force to the pedal arm upon rotation of the pedal arm between the rest position and the transition position. The second assist spring unit becomes ineffective on the pedal arm when the pedal arm is in the transition position or rotated beyond the transition position.

In the pedal assistance mechanism as disclosed in the patent ‘299 both the first and second assist springs assist the depression of clutch pedal once the clutch pedal arm exceeds the transition position. This would result in higher assistance and leads to sudden/drastic movement of the clutch pedal to the final position, since the second assist spring applies depressing assisting force to pedal arm upon rotation of pedal arm between the rest position and the transition position and this assistance spring ideally should become ineffective at the transition point. Thus, causing discomfort to the driver of the automobile.

In light of foregoing discussion, it is necessary to provide a mechanical pedal actuation system with an improved pedal assistance mechanism to overcome the limitations stated above.

SUMMARY OF THE DISCLOSURE

The shortcomings of the prior art are overcome and additional advantages are provided through the provision of system and method as claimed in 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 an embodiment of the present disclosure there is provided a mechanical clutch actuation system of a vehicle. The system comprises a support bracket connectable to a firewall of the vehicle. A pedal arm, wherein an upper end of said pedal arm is pivotally mounted to said support bracket, and a lower end of the pedal arm is provided with a pedal pad. The system further comprises a pedal assistance mechanism connected in between the support bracket and the pedal arm to assist the system during clutch disengagement. The pedal assistance mechanism comprises: a stay rod pivotally connected to the pedal arm, wherein said stay rod is configured to pass through a first plate which is connected to the support bracket, and a second plate is fixed to the stay rod with predetermined distance from the first plate. A first resilient member provisioned in between the first plate and the second plate, wherein said first resilient member is configured to apply a depression resisting force to the pedal arm upon movement of said pedal arm between a rest position and a transition position, and a depression assisting force upon movement of the pedal arm exceeding the transition position. Further, pedal assistance mechanism further comprises a second resilient member is provisioned at predetermined location of the system. The second resilient member is configured to apply a depression resisting force to the pedal arm upon movement of said pedal arm exceeding the transition position.

In an embodiment of the present disclosure, the upper end of the pedal arm is pivotally mounted to said support bracket at a first pivot point. Further, the stay rod is pivotally connected at a third pivot point to the pedal arm.

In an embodiment of the present disclosure, the first plate is pivotally connected to the support bracket at the second pivot point.

In an embodiment of the present disclosure, the first resilient member is a compression spring.

In an embodiment of the present disclosure, the stay rod optionally comprises a third plate fixed on top end of the stay rod.

In an embodiment of the present disclosure, the second resilient member is a compression spring. The second resilient member is provisioned below the third plate such that a predetermined length of gap is formed between the second resilient member and the pedal bracket when the pedal arm is at rest position.

In an embodiment of the present disclosure, the second resilient member is a torsion spring. The torsion spring is provisioned at first pivot point. Further, the pedal arm comprises a slot of predetermined length in the vicinity of first pivot point.

In an embodiment of the present disclosure, at least one leg of the torsion spring is provisioned in the slot.

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.

OBJECTIVES OF THE DISCLOSURE

One object of the present disclosure is to provide a mechanical clutch actuation system having a pedal assistance mechanism to assist the driver during clutch engagement.

Another object of the present disclosure is to provide a mechanical clutch actuation system having the pedal assistance mechanism in which first and second resilient members are provided to assist the clutch pedal actuation.

Yet another object of the present disclosure is to provide a mechanical clutch actuation system having the pedal assistance mechanism to assist the depression movement of the pedal, and the pedal return remains as good as conventional mechanical pedal mechanism without assistance.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

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:

FIGS. 1 and 2 illustrate a side view of mechanical clutch actuation system according to first embodiment of the present disclosure, with clutch pedal which is in rest position and final position respectively.

FIG. 3 illustrates an exploded view of the mechanical clutch actuation system of FIG. 1.

FIG. 4 illustrates a side view of mechanical clutch actuation system according to second embodiment of the present disclosure.

FIG. 5 illustrates an exploded view of the mechanical clutch actuation system of FIG. 4.

FIG. 6 illustrates a detailed schematic view of the clutch assistance mechanism of FIG. 4.

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
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.

To overcome the drawbacks mentioned in the background, a mechanical clutch actuation system is provided with a pedal assistance mechanism comprising pair of resilient members termed as first resilient member and second resilient member to reduce the pedal effort by the driver to disengage the clutch. The first resilient member of the pedal assistance mechanism will resist depression of the pedal during from rest position to transition position, and assist the depression of pedal once the movement of pedal exceeds the transition position. Further, the second resilient member applies a resisting force to the pedal arm when movement of the pedal arm exceeding the transition position. The second resilient becomes ineffective on the pedal arm when the pedal arm is between the rest position and the transition position.

As an exemplary embodiments FIGS. 1 and 2 illustrates side view of the mechanical clutch actuation system (100) according to first embodiment of the present disclosure with clutch pedal arm (4) in rest position and transition position respectively. The system (100) comprises a support bracket (5) mounted on firewall [not shown] of the vehicle for supporting the clutch actuation system mechanism (100). The support bracket (5) comprises a pair of side arms (12) extending from top of the support bracket (5) for mounting a pedal arm (4), stay rod (2) of the system (100). The pedal arm (4) having an upper end (4a) and a lower end (4b) is pivotally mounted on the support bracket (5) at first pivot point (A) through its upper end (4a) using pivot pin (10), and a pedal pad (3) is mounted to a lower end (4b) of said pedal arm (102) for actuating the pedal arm (4) by the driver/operator of the vehicle.

The system (100) further comprises a pedal assistance mechanism (P) connected in between the support bracket (5) and the pedal arm (4) to assist the system (100) during clutch disengagement. The pedal assistance (P) mechanism includes a stay rod (2) pivotally connected to the pedal arm (4) at third pivot points (C) using pivot pin (8) [best shown in FIG. 3]. The stay rod comprises a circular hole at one end which can be pivoted to the pedal arm (4) through pivot pin (8) and the stopper pin (9) [shown in FIG. 3]. Further, the stay rod (2) is configured to pass through a first plate (2a) pivotally connected to the support bracket (5) at the second pivot point (B), and a second plate (2b) fixed to the stay rod (2) with predefined distance below the first plate (2a), and the third plate (2c) fixed at top end of the stay rod (2). The second plate (2b) is configured to slide up and down up to predetermined length on the circumference of the stay rod (2). Further, a first resilient member (1) is provisioned in between the first plate (2a) and the second plate (2b) of the stay rod (2) to assist the depression of the clutch pedal arm (4). The first resilient member (1) is a compression spring, and is configured compress when the second plate (2b) moves upwards along with the stay rod (2), and retract when the second plate (2b) moves downwards along with the stay rod (2). The first resilient member (1) applies a depression resisting force to the pedal arm (4) when movement of the pedal arm (4) between a rest position (RP) and a transition position (TP), and a depression assisting force upon movement of the pedal arm (4) exceeding the transition position (TP). The pedal assistance mechanism (P) further includes, a second resilient member (6) provisioned below the third plate (2c) of the stay rod (2). In an embodiment of the present disclosure, the second resilient member (6) is a compression spring and is positioned such that a predetermined length of gap (G) is formed between the second resilient member (6) and the pedal bracket (5) when the pedal arm (4) is at rest position. The second resilient member (6) is configured to apply a depression resisting force to a pedal arm (4) upon movement of the pedal arm (4) exceeding the transition position (TP). The second resilient becomes ineffective on the pedal arm when the pedal arm is between the rest position and the transition position.

Initially, when the pedal arm (4) is in rest position as shown in FIG. 1, the secondary resilient member (6) will have a gap (G) with the pedal bracket (5). When the clutch pedal arm (4) is being displaced from its initial (rest) position (RP), the primary resilient member (1) resists the pedal arm (4) during such displacement between a rest position (RP) and a transition position (TP). Upon crossing the transition position (TP) the resilient member (1) will start assisting the pedal arm (4) for the forward travel beyond the transition position (TP). During this operation the gap (G) between the secondary resilient member (6) and the clutch pedal bracket (5) starts reducing. Once the secondary resilient member (6) starts touching the bracket (5) i.e. on reaching the transition position (TP), the secondary resilient member (6) will start resisting the clutch pedal (4) till the pedal arm reaches final position (FP) [best shown in FIG. 2] thus reducing overall assistance to the system (100). The gap (G) between the secondary resilient member (6) and the pedal bracket (5) is provided in such a way that over all assistance reduces after peak pedal arm effort. This arrangement reduces the pedal arm (4) effort and allows the proper return of the pedal arm (4) to the rest position.

FIGS. 4 and 5 are exemplary embodiments of the present disclosure illustrating side view and exploded view of the of the mechanical clutch actuation system (100) according to second embodiment the present disclosure. In the second embodiment of the present disclosure, a torsional spring has been used as the secondary resilient member (6). The detail of torsional resilient spring is shown in FIG. 5. This arrangement works on similar principles and gives similar clutch pedal characteristics as explained in the above embodiment. The torsional spring (6) is provisioned in the first pivot point (A), and is configured as second resilient member (6). Further, a slot (S) [best shown in FIG. 6] is formed in the pedal bracket (5) in the vicinity of first pivot portion. One end i.e. at least one leg (6a) of the torsion spring (6) is located in a slot (S) provided on the pedal arm (4), and said leg (6a) configured to move freely during initial displacement of the pedal i.e. between the rest position (RP) and the transition position (TP) of the pedal arm. The other leg (6b) of the torsion spring is provisioned in the pedal arm (4). The torsion spring starts resisting the pedal arm (4) movement beyond the transition position (TP). The torsion spring (6) becomes ineffective on the pedal arm (4) when the pedal arm (4) is between the rest position (RP) and the transition position (TP).

Initially, when the pedal arm (4) is in rest position as shown in FIG. 4, the leg (6a) of the torsion spring will rest in one end of the slot (S) provided in the pedal arm (4). When the clutch pedal arm (4) is being displaced from its initial (rest) position (RP), the primary resilient member (1) resists the pedal arm (4) during such displacement between a rest position (RP) and a transition position (TP). Upon crossing the transition position (TP) the resilient member (1) will start assisting the pedal arm (4) for the forward travel beyond the transition position (TP). During this operation the leg (6a) of the torsion spring starts moving to the other end of the slot (S). Once the leg (6a) of the torsional spring (6) starts touching other end of the slot i.e. on reaching the transition position (TP), the torsion spring (6) will start resisting the clutch pedal (4) till the pedal arm reaches final position (FP) [best shown in FIG. 2] thus reducing overall assistance to the system (100). The gap (G) in the slot (S) is provided in such a way that over all assistance reduces after peak pedal arm effort. This arrangement reduces the pedal arm (4) effort and allows the proper return of the pedal arm (4) effort also.

Advantages:
The present disclosure provides a mechanical clutch actuation system having a pedal assistance mechanism to assist the driver during clutch engagement. This will reduce the effort of the driver greatly.

The present disclosure provides a mechanical clutch actuation system having the pedal assistance mechanism in which first and second resilient members helps to reduce the clutch pedal effort.

The present disclosure provides a mechanical clutch actuation system having the pedal assistance mechanism which is simple in construction, easy to assemble and retrofitable.

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.

Referral Numerals:

Reference Number Description
100 Mechanical clutch actuation system
1 First resilient member
2 Stay rod
2a First plate
2b Second plate
2c Third plate
3 Foot pedal
4 Pedal arm
4a and 4b End of the pedal arm
5 Pedal bracket
6 Second resilient member
6a and 6b Leg of torsion spring
8 Pivot pin
9 Stopper pin
10 Pivot pin
11 Pivot bush
12 Arm on pedal bracket
RP Rest position
TP Transition position
FP Final position
G Gap
S Slot
A First pivot point
B Second pivot point
C Third pivot point
,CLAIMS:1. A mechanical clutch actuation system (100) of a vehicle comprising:
a support bracket (5) connectable to a firewall of the vehicle;
a pedal arm (4), wherein an upper end (4a) of said pedal arm (4) is pivotally mounted to said support bracket (5), and a lower end of the pedal arm (4) is provided with a pedal pad (3); and
a pedal assistance mechanism (P) connected in between the support bracket (5) and the pedal arm (4) to assist the system (100) during clutch disengagement, wherein said pedal assistance (P) mechanism comprises:
a stay rod (2) pivotally connected to the pedal arm (4), wherein said stay rod (2) is configured to pass through a first plate (2a) which is connected to the support bracket (5), and a second plate (2b) is fixed to the stay rod with predetermined distance from the first plate (2a);
a first resilient member (1) provisioned in between the first plate (2a) and the second plate (2b), wherein said first resilient member (1) is configured to apply a depression resisting force to the pedal arm (4) upon movement of said pedal arm (4) between a rest position (RP) and a transition position (TP), and a depression assisting force upon movement of the pedal arm (4) exceeding the transition position (TP); and
a second resilient member (6) provisioned at predetermined location of the system (100), wherein said second resilient member (6) is configured to apply a depression resisting force to the pedal arm (4) upon movement of said pedal arm (4) exceeding the transition position (TP).

2. The system as claimed in claim 1, wherein the upper end (4a) of said pedal arm (4) is pivotally mounted to said support bracket (5) at a first pivot point (A).

3. The system as claimed in claim 1, wherein the stay rod (2) is pivotally connected to the pedal arm (4) at a third pivot point (C).

4. The system as claimed in claim 1, wherein the first plate (2a) is pivotally connected to the support bracket (5) at second pivot point (B).

5. The system as claimed in claim 1, wherein the first resilient member (1) is a compression spring.

6. The system as claimed in claim 1, wherein the stay rod (2) optionally comprises a third plate (2c) fixed on top end of the stay rod (2).

7. The system as claimed in claim 1, wherein the second resilient member (6) is a compression spring.

8. The system as claimed in claim 7, wherein the second resilient member (6) is provisioned below the third plate (2c) such that a predetermined length of gap (G) is formed between the second resilient member (6) and the pedal bracket (5) when the pedal arm (4) is at rest position.

9. The system as claimed in claims 1, wherein the second resilient member (6) is a torsion spring.

10. The system as claimed in claim 9, wherein the torsion spring (6) is provisioned at first pivot point (A).

11. The system as claimed in claim 1, wherein the pedal arm (4) comprises a slot (S) of predetermined length in the vicinity of first pivot point (A).

12. The system as claimed in claims 10 and 11, wherein at least one leg (6a) of the torsion spring (6) is provisioned in the slot (S), and other leg (6b) of the torsion spring is provisioned in the pedal bracket (4).

13. A vehicle having a mechanical clutch actuation system as claimed in claim 1.

Dated this 26th Day of September, 2013 GOPINATH A.S.
IN/PA 1852
OF K&S PARTNERS
AGENT FOR THE APPLICANT