DESC:FORM 2

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

COMPLETE SPECIFICATION

(See Section 10 and Rule 13)

Title of invention:
A REVERSE GEAR SAFETY INTERLOCK SYSTEM FOR A VEHICLE AND METHOD OF IT’S ACTUATION

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having Address As:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru - 560 027,
Karnataka, 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 invention claims priority from Indian patent application numbered IN 202241044908 filed on 05th August, 2022.
FIELD OF THE INVENTION
[002] The present subject matter described herein generally relates to a gear safety interlock system, and more specifically to a reverse gear safety interlock system for a vehicle.
BACKGROUND
[003] A gear shift lever is provided in manual transmissions of aircraft towing tractors to engage the forward and reverse gears. The reverse gear is configured to engage immediately based on the movement of the gear shift lever to aft from neutral position. Further, this gear arrangement increases the chances of accidental damage to the aircraft during towing operation. In existing system, accidental engagement of the reverse gear is avoided during engaging of forward gear based on mechanical arrangement with locking pin as cited in prior art CN104455403.
[004] In existing system, accidental engagement of reverse gear during engaging of forward gear is avoided based on mechanical interlocking using locking pin.
[005] Hence to overcome the aforesaid objection there is a requirement to provide the reverse gear safety interlock system for a vehicle to prevent the driver from accidently shifting into reverse gear.
OBJECTS OF THE INVENTION
[006] Main object of the present disclosure is to provide a reverse gear safety interlock system to prevent the driver from inadvertently shifting to reverse gear to prevent accidental damage of the vehicle.
[007] Another object of the present disclosure is to provide a reverse gear safety interlock system which is easy to install.
[008] Yet another object of the present disclosure is to provide a reverse gear safety interlock system to improve reverse gear operation using electrical safety interlock.
[009] Another object of the present disclosure is to provide a reverse gear safety interlock system which demands less effort due to electrical safety interlock.
[0010] Yet another object of the present disclosure is to provide a reverse gear safety interlock system which is compact, cost effective.
SUMMARY
[0011] Before the present system is described, it is to be understood that this application is not limited to the particular machine, device or system, 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 reverse gear safety interlock 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.
[0012] The present subject matter discloses a reverse gear safety interlock system for a vehicle comprising a transmission control system to control the gear shifting of the vehicle. The transmission control system comprising a gear shift lever for selecting the required gear, a transmission control unit (TCU) to receive input signals from the gear shift lever, a solenoid driver to receive output signals from the transmission control unit (TCU) for actuating a preselected solenoid for shifting gear, a reverse switch configured for mounting on a dashboard, plurality of solenoid valves configured to be operated based on the signals received from the gear shift lever and the reverse switch and a latching relay which is energized on the actuation of the reverse switch..
[0013] In another embodiment, a method for the reverse gear safety interlock system for a vehicle comprising checking the status of the reverse gear of the reverse gear safety interlock system. Then checking the status of the reverse switch for disengaging the reverse gear based on “switched OFF” state of the reverse switch. Further, checking the status of the reverse switch for engaging the reverse gear based on “switched ON” state of the reverse switch. The transmission control unit (112) checks for the condition of selecting of the neutral gear from the reverse gear. Operating the gear shift lever by the transmission control unit TCU upon selection of the neutral gear.

STATEMENT OF INVENTION
[0014] The present subject matter discloses, a reverse gear safety interlock system for a vehicle comprising a transmission control system to control the gear shifting of the vehicle. The transmission control system comprising a gear shift lever for selecting the required gear, a transmission control unit (TCU) to receive input signals from the gear shift lever, a solenoid driver to receive output signals from the transmission control unit (TCU) for actuating a preselected solenoid for shifting gear, a reverse switch configured for mounting on a dashboard, plurality of solenoid valves configured to be operated based on the signals received from the gear shift lever and the reverse switch and a latching relay which is energized on the actuation of the reverse switch.
[0015] In an embodiment, the transmission control system is configured to be an electro hydraulic transmission.
[0016] In an embodiment, the gear shift lever is configured to shift in a Neutral, a forward and a reverse positions.
[0017] In an embodiment, the gear shift lever is configured to be rotated in predetermined direction for selecting the required gear. The predetermined direction is configured to be a clockwise direction or an anti-clockwise direction to select lower or higher gear respectively.
[0018] In an embodiment, the reverse switch is configured to be a momentary ON rocker switch.
[0019] In an embodiment, the actuation of the reverse switch is configured for energizing the latching relay and the solenoid valve.
[0020] In an embodiment, the plurality of solenoid valves are configured to be de-energized on the shifting of the gear shift lever to neutral gear, de-energizing of the latching relay.
[0021] In an embodiment, the reverse gear is configured to be engaged on actuation of the reverse gear switch, and moving of the gear shift lever in aft position.
[0022] In another embodiment, a method for the reverse gear safety interlock system for a vehicle comprising checking the status of the reverse gear of the reverse gear safety interlock system. Then checking the status of the reverse switch for disengaging the reverse gear based on “switched OFF” state of the reverse switch. Further, checking the status of the reverse switch for engaging the reverse gear based on “switched ON” state of the reverse switch. The transmission control unit (112) checks for the condition of selecting of the neutral gear from the reverse gear. Operating the gear shift lever by the transmission control unit TCU upon selection of the neutral gear.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] 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.
[0024] Figure 1 illustrates a circuit schematics of a reverse gear safety interlock system for a vehicle, in accordance with an embodiment of the present subject matter.
[0025] Figure 2 illustrates a block diagram of a reverse gear safety interlock system for a vehicle, in accordance with an embodiment of the present subject matter.
[0026] Figure 3 illustrates a flowchart of a reverse gear safety interlock system for a vehicle, in accordance with an embodiment of the present subject matter.
[0027] 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 OF INVENTION
[0028] 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.
[0029] 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.
[0030] The present subject matter discloses a reverse gear safety interlock system for a vehicle and method of its actuation. The reverse gear safety interlock system comprises a transmission control system (110) (not shown in diagram). The transmission control system (110) comprises a transmission control unit (TCU) (112), a gear shift lever (114), a solenoid driver (116), a reverse switch (102), a latching relay (104) and a solenoid valves. The reverse gear safety interlock system (100) for a vehicle comprising a transmission control system (110) to control the gear shifting of the vehicle. The transmission control system (110) comprising the gear shift lever (114) for selecting the required gear, the transmission control unit (TCU) (112) to receive input signals from the gear shift lever (114), the solenoid driver (116) to receive output signals from the transmission control unit (TCU) (112) for actuating a preselected solenoid for shifting gear, the reverse switch (102) configured for mounting on a dashboard, plurality of solenoid valves (118) configured to be operated based on the signals received from the gear shift lever (114) and the reverse switch (102) and the latching relay (104) which is energized on the actuation of the reverse switch (102). The a transmission control unit (TCU) (112) is configured to receive inputs signal from the gear shift lever (114) and controls the output signal sent to the solenoid driver (116) to actuate the solenoids accordingly for shifting gear. The logic for gear shifting is shown in Table 1.

Table 1
[0031] The transmission control system (110) is configured to be an electro hydraulic transmission to control the gear shifting of the vehicle. The reverse switch (102) is configured to be a momentary ON rocker switch mounted on the dashboard.
[0032] Further, the reverse gear safety interlock system for a vehicle is disclosed in accordance to an embodiment of the present subject matter. The gear shift lever (114) is configured with three positions, these positions are Neutral, Forward and Reverse. Thus, the gear shift lever (114) is configured to shift in a Neutral, a forward and a reverse positions. The forward gear is configured to be engaged due to shifting of the gear shift lever (114) to fore position from neutral position. The reverse gear is configured to be engaged upon actuating the reverse gear switch (102) manually by the operator and then the gear shift lever (114) is configured to move aft position. A knob of the gear shift lever (114) is configured to be operated by rotating the knob in clockwise or anti clockwise direction to select lower or higher gear respectively. The transmission comprises of two forward gears and two reverse gears as shown in Table 1. The solenoid driver (116) is configured to provide a smooth clutch operation and programmed to provide current output to the proportional solenoid valves based on shifting gears from neutral position to forward/ reverse gears as per requirement. Upon actuation of the momentary ON rocker switch/ reverse gear switch (102), the set coil of the latching relay (104) and the solenoid valve (118) ‘A’ are configured to be energized. Further, when the gear shift lever (114) is configured to be shifted to neutral gear, the reset coil of the latching relay (104) is configured to be energized and the solenoid valve (118) ‘A’ is configured to be de-energized.
[0033] The gear shift lever (114) is configured to be rotated in predetermined direction for selecting the required gear. The predetermined direction is configured to be a clockwise direction or an anti-clockwise direction to select lower or higher gear respectively. The actuation of the reverse switch (102) is configured for energizing the latching relay (104) and the solenoid valve (118). The plurality of solenoid valves (118) are configured to be de-energized on the shifting of the gear shift lever (114) to neutral gear, de-energizing of the latching relay (104). The reverse gear is configured to be engaged on actuation of the reverse gear switch (102), and moving of the gear shift lever (114) in aft position.
[0034] The reverse gear safety interlock system (100) is configured to prevent the driver from inadvertently shifting to reverse gear to prevent accidental damages of a vehicle. The said vehicle to use the reverse gear safety interlock system can be an aircraft towing tractor, JCB, heavy vehicles, light commercial vehicles, trucks, forklifts, earth movers, tractors and etc.
[0035] Now referring to figure 2, a block diagram (200) for the reverse gear safety interlock system for a vehicle is disclosed in accordance to an embodiment of the present subject matter. At step 202, the transmission control unit (112) is configured to receive signal from a gear shift selector (114). The transmission control unit (112) is configured to operate the solenoid driver (116) based on the reverse interlock logic (206) as shown in step 208 and step 204 respectively. Further at step 210, the solenoid valves is selected as per the required gear.
[0036] In another embodiment, referring to figure 3 a flowchart (300) for the reverse gear safety interlock system for a vehicle is disclosed in accordance to an embodiment of the present subject matter. At step 302, checking the status of the reverse gear of the reverse gear safety interlock system. If reverse gear is selected, the transmission control unit (112) moves to step 304. In step 304, checking the status of the reverse switch for disengaging the reverse gear based on “switched OFF” state of the reverse switch. If the reverse switch (102) is in switched OFF state, the reverse gears are not engaged. In Step 306, checking the status of the reverse switch for engaging the reverse gear based on “switched ON” state of the reverse switch (102). If the reverse switch (102) is in switched ON state, the reverse gears are engaged. At step 308, the transmission control unit (112) checks for the condition of selecting of the neutral gear from the reverse gear. At step 310, operating the gear shift lever (114) by the transmission control unit TCU (112) upon selection of the neutral gear.
[0037] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include the following.
[0038] Some embodiments of the subject matter enable to provide a reverse gear safety interlock system to prevent the driver from inadvertently shifting to reverse gear to prevent accidental damages to the vehicle.
[0039] Some embodiments of the subject matter enable to provide a reverse gear safety interlock system which is easy to install.
[0040] Some embodiments of the subject matter enable to provide a reverse gear safety interlock system to improve reverse gear operation using electrical safety interlock.
[0041] Some embodiments of the subject matter enable to provide a reverse gear safety interlock system which demands less effort due to electrical safety interlock.
[0042] Some embodiments of the subject matter enable to provide a reverse gear safety interlock system which is compact, cost effective.
[0043] Following is a list of elements and reference numerals used to explain various embodiments of the present subject matter.
Reference Numeral Element Description
100 Circuit Schematic for Reverse Gear Safety Interlock System
102 Reverse Switch
104 Latching Relay
106 Input Signal To Reverse Solenoid From Controller
108 Output Signal To Solenoid Driver (A Solenoid)
110 Transmission Control System
112 Transmission Control Unit
114 Gear Shift Lever
116 Solenoid Driver
118 Solenoid Valves
206 Reverse Interlock Logic

Equivalents
[0044] 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.
[0045] 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."
[0046] Although implementations for a reverse gear safety interlock system and method for 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 reverse gear safety interlock system for a vehicle and method of its actuation.
,CLAIMS:
1. A reverse gear safety interlock system (100) for a vehicle comprising
a transmission control system (110) configured to control the gear shifting of the vehicle; wherein the transmission control system (110) configured with
a gear shift lever (114) configured for selecting the required gear;
a transmission control unit (TCU) (112) configured to receive input signals from the gear shift lever (114);
a solenoid driver (116) configured to receive output signals from the transmission control unit (TCU) (112) for actuating a preselected solenoid for shifting gear;
a reverse switch (102) configured for mounting on a dashboard;
plurality of solenoid valves (118) configured to be operated based on the signals received from the gear shift lever (114) and the reverse switch (102); and
a latching relay (104) configured to be energized on the actuation of the reverse switch (102).

2. The reverse gear safety interlock system (100) for a vehicle as claimed in claim 1, wherein the transmission control system (110) is configured to be an electro hydraulic transmission.

3. The reverse gear safety interlock system (100) for a vehicle as claimed in claim 1, wherein the gear shift lever (114) configured to shift in a Neutral, a forward and a reverse positions.

4. The reverse gear safety interlock system (100) for a vehicle as claimed in claim 1, wherein the gear shift lever (114) configured to be rotated in predetermined direction for selecting the required gear; and wherein the predetermined direction configured to be a clockwise direction or an anti-clockwise direction to select lower or higher gear respectively.

5. The reverse gear safety interlock system (100) for a vehicle as claimed in claim 1, wherein the reverse switch (102) configured to be a momentary ON rocker switch (102).
6. The reverse gear safety interlock system (100) for a vehicle as claimed in claim 1, wherein the actuation is reverse switch (102) is configured for energizing the latching relay (104) and the solenoid valve (118).

7. The reverse gear safety interlock system (100) for a vehicle as claimed in claim 1, wherein the plurality of solenoid valves (118) are configured to be de-energized on the shifting of the gear shift lever (114) to neutral gear, de-energizing of the latching relay (104).

8. The reverse gear safety interlock system (100) for a vehicle as claimed in claim 1, wherein the reverse gear is configured to be engaged on actuation of the reverse gear switch (102), and moving of the gear shift lever (114) in aft position.

9. A method (300) for the reverse gear safety interlock system (100) for a vehicle, the method (300) comprising;
checking, the status of the reverse gear of the reverse gear safety interlock system,
checking, the status of the reverse switch (102) for disengaging the reverse gear based on “switched OFF” state of the reverse switch (102),
checking, the status of the reverse switch (102) for engaging the reverse gear based on “switched ON” state of the reverse switch (102),
checking, by the transmission control unit (112) for the condition of selecting of the a neutral gear from the reverse gear; and
operating, the gear shift lever (114) by the transmission control unit TCU (112) upon selection of the neutral gear.