DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
A HILL ASSIST SYSTEM FOR A VEHICLE

Applicant:
Tata Motors Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
Bombay House, 24 Homi Mody Street,
Hutatma Chowk, Mumbai 400001,
Maharashtra, India

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

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application claims priority from Indian Patent application no. (201921012075) filed on 27th March, 2019.
FIELD OF THE INVENTION
[002] The present subject matter described herein generally relates to vehicles and more specifically it relates to a hill assist system for a vehicle.
BACKGROUND
[003] In recent years, the optimization of automotive vehicle to improve passenger safety has been a priority in vehicle design and hence today’s vehicle comes with lot of safety features. The reason behind this is increasing accident rate. If we look at various accidental data, it would come to notice that many of the accidents take place in hilly areas (Ghats) or while driving up gradient. This is because the vehicle will be under unbalanced force in such conditions. These forces are nothing but component of vehicle weight parallel to the road, which tend to drag the vehicle down the gradient due to its self-weight. So while moving up hill the driver experiences difficulty in maneuvering. If there is bumper-to-bumper traffic on such roads, the vehicle need to move with continuous switching between braking and acceleration. Also every time when the vehicle moves from rest, it rolls back little before moving forward. This roll back motion can give rise to accidental situations in hilly areas. The present subject matter provides solution for this problem by locking rolling motion of vehicle, allowing easy climbing on gradient.
OBJECTS OF THE INVENTION
[004] An object of the present subject matter is to provide a hill assist system to restrict motion of the vehicle in one direction.
[005] Another object of the present subject matter is to prevent roll back of a vehicle while driving uphill.
[006] Another object of the present subject matter is to prevent accidents caused by unintentional reverse motion of the vehicle.
[007] A yet another object of the present subject matter is to provide the hill assist system that provides comfortable and hassle free driving experience for the driver.
SUMMARY
[008] Before the present system is described, it is to be understood that this application is not limited to the particular machine or device, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to a hill assist system for a vehicle, and the aspects are further elaborated below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[009] The present subject matter describes a hill assist system for a vehicle. The hill assist system comprises a driven gear and a unidirectional drive. The driven gear may be rigidly mounted on an output shaft of the gear box assembly. The unidirectional drive may be mounted on an idler shaft of the gear box assembly. The unidirectional drive is configured to be engaged with the driven gear to provide rotation to the driven gear during forward motion of the vehicle and to prevent rotation of the driven gear during unintentional reverse motion of the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and device disclosed in the document and the drawing. The detailed description is described with reference to the following accompanying figures.
[0011] Figure 1 illustrates a view of a hill assist system and a transmission system of a vehicle, in accordance with an embodiment of the present subject matter.
[0012] Figure 2 illustrates a view of a unidirectional drive, in accordance with an embodiment of the present subject matter.
[0013] Figure 3a illustrates a flow of the power during forward motion of the vehicle, in accordance with an embodiment of the present subject matter.
[0014] Figure 3b illustrates a flow of the power during reverse motion of the vehicle, in accordance with an embodiment of the present subject matter.
[0015] Figure 3c illustrates a flow of the power during roll back condition of the vehicle, in accordance with an embodiment of the present subject matter.
[0016] The figures depict various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0017] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any devices and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, devices and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0018] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0019] The present subject matter discloses a hill assist system for a vehicle to prevent rolling back motion of the vehicle due to a gradient on the road and thereby avoiding accidents caused by unintentional reverse motion of the vehicle.
[0020] Referring to figure 1, a gear box assembly of a vehicle is illustrated along with disclosure of the hill assist system 100. In the gear box assembly, an input shaft 102 is connected to the engine of the vehicle to receive a rotational motion. The input shaft 102 transfers this rotational motion to the layshaft 104 through a gear 112. The rotational motion from the layshaft 104 to an output shaft 106 by engaging a forward drive gear 114 mounted on the layshaft 104 with a respective forward driven gear 116 mounted on the output shaft 106. The rotational motion from the output shaft 106 may be transferred to wheels of the vehicle through some intermediate transfer means. To provide a reverse motion to the vehicle, a reverse drive gear 118 and a reverse driven gear 120 is provided on the layshaft 104 and the output shaft 106 respectively. To engage the reverse driven gear 120 with the reverse drive gear 118 an idler gear 122 is provided on an idler shaft 108.
[0021] Further the hill assist system 100 is provided along with the gear box assembly. The hill assist system 100 may comprise a driven gear 126 and a unidirectional drive 124. The driven gear 126 may be rigidly mounted on the output shaft 106. The unidirectional drive 124 may be mounted on the idler shaft 108. The unidirectional drive 124 may be configured to be engaged with the driven gear 126 to provide rotation to the driven gear 126 during forward motion of the vehicle and to prevent rotation of the driven gear 126 during unintentional reverse motion of the vehicle. The unintentional reverse motion of the vehicle is configured during the engagement of the gears (114, 116) for forward motion of vehicle and the vehicle is forced to move in the reverse direction due to external force.
[0022] In an embodiment, the unidirectional drive 124, mounted on an idler shaft 108 of the gear box assembly, is configured to form an integrated assembly with the idler gear 122. The engagement of the idler gear 122 with reverse gears (118, 120) during reverse gear engagement is configured to disengage the meshing of the unidirectional drive 124 with the driven gear 126 of the vehicle, allowing intentional reverse motion of the vehicle.
[0023] Now referring to figure 2, the unidirectional drive 124 is illustrated in accordance to an embodiment of the present subject matter. The unidirectional drive 124 comprises a ratchet 130, a collar 132, a drive gear 134 and a plurality of balls 136. The ratchet 130 may rigidly mounted on the idler shaft 108. The collar 132 may be configured to surround the ratchet 130. The drive gear 134 may be rigidly mounted on the collar 132 and the drive gear 134 may be configured to be engaged with the driven gear 126. The plurality of balls 136 may be filled in a gap between the ratchet 130 and the collar 132. In a preferred embodiment of the present subject matter, the drive gear 134 is configured to engage with the driven gear 126 when one of the forward drive gears 114 is engaged with their respective forward driven gears 116.
[0024] While an inner race of the ratchet 130 may be rigidly fixed on the idler shaft 108, an outer race of the ratchet 130 may comprises a plurality of ridges 130a and valleys 130b. The position of the plurality of balls 136 in the ridges or the valleys define the motion of the drive gear 134. During forward motion of the vehicle, the drive gear 134 is configured to rotate in counterclockwise direction (CCW). The plurality of balls 136 may be configured to fall in the valleys 130b of the ratchet 130 during the CCW rotation of the drive gear 134. Therefore, the driven gear 126 is configured to rotate with the drive gear 134 to allow forward motion of the vehicle.
[0025] During roll back condition, the vehicle is engaged in forward gear but due to any reason the vehicle starts moving in reverse direction and the drive gear 134 is configured to rotate in clock wise direction (CW). The plurality of balls 136 may be configured to get locked between the collar 132 and the ridges 130a of the ratchet 130 when the drive gear 134 is intended to rotate CW and therefore preventing rotation of the drive gear 134 in CW. As a result, the driven gear 126 is configured to prevent rotation of the output shaft 106 during reverse motion of the vehicle which eventually prevents reverse motion of the vehicle when forward gears are engaged.
[0026] When the vehicle is intended to move in reverse direction, the reverse gears 118 and 120 are engaged by the idler gear 122 and the unidirectional drive 124 is configured to disengage from the driven gear 126. Hence the unidirectional drive 124 doesn’t prevent reverse motion of the vehicle when the reverse gears 118, 120 are engaged.
[0027] The flow of power during different vehicle motion conditions is as shown in figures 3a to 3c. As shown in figure 3a, during the forward motion of the vehicle, power from engine may be transferred to wheels via clutch to the input shaft, the layshaft, the output shaft to final drive. During this condition the unidirectional drive may be engaged with the driven gear present on the output shaft and free to rotate (assume CCW direction of the drive gear 134). As shown in figure 3b, when the reverse gear is engaged, the unidirectional drive gets disengaged and the idler gear gets engaged between the layshaft and the output shaft there by reversing the direction of rotation of wheels.
[0028] Referring to figure 3c, in a situation where the vehicle is driven uphill from stand still condition, when the forward gear is engaged and the driver shifts his foot from brake pedal to accelerator the vehicle starts to rollback. In this condition the rotary motion gets transferred from wheels to final drive to output shaft of transmission via propeller. As the unidirectional drive may be engaged to the output shaft in all forward motion conditions, when the drive gear 134 tries to rotate in CW direction, the rotation gets locked as the plurality of balls locked in the ridges of the ratchet and stop the rotation there by stopping the vehicle rollback.
[0029] Therefore the present subject matter provides solution to the roll back problem of the vehicle to prevent accidents caused by unintentional reverse motion of the vehicle.
[0030] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include the following.
[0031] Some embodiments of the subject matter provides a hill assist system to restrict motion of the vehicle in one direction.
[0032] Some embodiments of the subject matter enable to prevent roll back of a vehicle while driving uphill.
[0033] Some embodiments of the subject matter enable to prevent accidents caused by unintentional reverse motion of the vehicle.
[0034] Some embodiments of the subject matter enable to provide the hill assist system that provides comfortable and hassle free driving experience for the driver.
[0035] Although implementations for the hill assist system 100 of a vehicle have been described in language specific to structural features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features described. Rather, the specific features are disclosed as examples of implementation for the hill assist system 100 of a vehicle.
,CLAIMS:
1. A hill assist system (100) for a vehicle to prevent roll back of the vehicle wherein the hill assist system (100) comprises;
a driven gear (126) is configured to be rigidly mounted on an output shaft (106) of the gear box assembly;
a unidirectional drive (124) is configured to be mounted on an idler shaft (108) of the gear box assembly;
wherein the unidirectional drive (124) is configured to be engaged with the driven gear (126) to provide rotation to the driven gear (126) during forward motion of the vehicle and to prevent rotation of the driven gear (126) during unintentional reverse motion of the vehicle.
2. The hill assist system (100), as claimed in claim 1, wherein the unidirectional drive (124), mounted on an idler shaft (108) of the gear box assembly, is configured to form an integrated assembly with the idler gear (122).

3. The hill assist system (100), as claimed in claim 2, wherein engagement of the idler gear (122) with reverse gears (118, 120) during reverse gear engagement is configured to disengage the meshing of the unidirectional drive (124) with the driven gear (126) of the vehicle, allowing intentional reverse motion of the vehicle.

4. The hill assist system (100), as claimed in claim 1, wherein said unintentional reverse motion of the vehicle is configured during the engagement of the gears (114, 116) for forward motion of vehicle and the vehicle is forced to move in the reverse direction due to external force.

5. The hill assist system (100), as claimed in claim 1, wherein the unidirectional drive (124) comprises;
a ratchet (130), rigidly mounted on the idler shaft (108) wherein the ratchet (130) comprises a plurality of ridges (130a) and a plurality of valleys (130b);
a collar (132), configured to surround the ratchet (130);
a drive gear (134), rigidly mounted on the collar (132), wherein the drive gear (134) is configured to be engaged with the driven gear (126); and
a plurality of balls (136), filled in a gap between the ratchet (130) and the collar (132).
6. The hill assist system (100), as claimed in claim 5, wherein the unidirectional drive (124) is configured with the ratchet (130), the drive gear (134), the plurality of balls (136), the collar (132), the plurality of ridges (130a) and the plurality of valleys (130b) together to restrict unintentional reverse motion of the vehicle by locking the plurality of balls (136) between the collar (132) and the ridges (130a) of the ratchet (130) for preventing rotation of the drive gear (134), thereby locking the rotation of driven gear (126) in unintentional reverse motion, with vehicle engagement in the forward gears (114, 116).

7. The hill assist system (100), as claimed in claim 6, wherein the plurality of balls (136) are configured to fall in the valleys (130b) of the ratchet (130) to allow rotation of the drive gear (134) and the driven gear (126) and thereby allowing forward motion of the vehicle, with vehicle engagement in the forward gears (114, 116).