Claims:
1. An interlock mechanism (100) for a gearbox of a tractor, said tractor having a first gear lever allowing said tractor to move in forward direction or reverse direction, a second gear lever allowing said tractor to operate in high gear ratio or a low gear ratio, and a third gear lever allowing said tractor to operate in multiple gear ratios of the gearbox of the tractor, said interlock mechanism comprising:
a housing (110) having a first end (120) and a second end (130);
a first hollow member (140) disposed in said housing (110), said first hollow member (140) having a flat first end (150) and a tapered second end (160);
a second member (170) disposed in said housing (110), said second member (170) passing through said first hollow member (140) and extending beyond said first hollow member (140), said second member (170) having a tapered surface (180) arranged proximal to the first end (120) of said housing (110);
a first biasing member (190) disposed between a first end of said second member (170) and said first end (120) of said housing (110);
a second biasing member (200) mounted on said second member (170) abutting a flat first end (150) of said first hollow member (140);
a first interlocking member (210) coupled to said first gear lever, said first interlocking member (210) configured to selectively intrude in said housing (110) corresponding to the displacement of said first gear lever and prevent displacement of said first hollow member (140);
a second interlocking member (240) coupled to said second gear lever, said second interlocking member (240) configured to selectively intrude in said housing (110) corresponding to the displacement of said second gear lever and slide on said tapered surface (180) of said second member (170);
a third interlocking member (270) coupled to said third gear lever, said third interlocking member (270) configured to selectively intrude in said housing (110) proximal to said tapered second end (160) of said first hollow member (140) corresponding to the displacement of said third gear lever.
2. The mechanism (100) as claimed in claim 1, wherein said first hollow member (140) has a first slot configured to facilitate passing of said second member (170) therethrough.
3. The mechanism (100) as claimed in claim 1, wherein said first interlocking member (210) is coupled to said first gear lever via a first rail (220) coupling said first gear lever to a forward or reverse gear in said gearbox, said first rail (220) having a first rail tapered surface (230) on which said first interlocking member (210) rides upon engagement of a reverse gear in said gearbox via said first gear lever to intrude in said housing (110).
4. The mechanism (100) as claimed in claim 1, wherein said second interlocking member (240) is coupled to said second gear lever via a second rail (250) coupling said second gear lever to a high or low gear in said gearbox, said second rail (250) having a second rail tapered surface (260) on which said second interlocking member (240) rides upon engagement of a high gear in said gearbox via said second gear lever to intrude in said housing (110).
5. The mechanism (100) as claimed in claim 1, wherein said third interlocking member (270) is coupled to said third gear lever via a third rail (280) coupling said third gear lever to predetermined gears in said gearbox, said third rail (280) having a ‘V’ shaped notch (290) configured to receive said third interlocking member (270) that intrudes in said housing (110) upon engagement of said predetermined gears.
6. The mechanism (100) as claimed in claim 5, wherein said third rail (280) is configured to couple said third gear lever to fourth or fifth gear in said gearbox.
7. The mechanism (100) as claimed in claim 1, wherein said mechanism (100) includes spring loaded balls (300) arranged in a second slot (310) configured on said second member (170), and said spring loaded balls (300) configured to prevent displacement of said first hollow member (140) towards said second end (130) of said housing (110) with respect to said second member (170) or displacement of said second member (170) towards first end (120) of said housing (110) with respect to said first hollow member (140).
8. The mechanism (100) as claimed in claim 7, wherein a space (330) is defined between said first hollow member (140) and said second member (170) to facilitate displacement of said balls (300).
9. The mechanism (100) as claimed in claim 1, wherein said flat first end (150) of said first hollow member (140) is configured to prevent intrusion of said first interlocking member (210) in said housing (110) upon intrusion of said second interlocking member (240) and said third interlocking member (270).

10. The mechanism (100) as claimed in claim 1, wherein said first hollow member (140) has a third slot (340) configured to receive said third interlocking member (270) therein.
, Description: FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[See section 10, Rule 13]

AN INTERLOCK MECHANISM FOR A TRACTOR GEARBOX

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

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

.
TECHNICAL FIELD OF THE INVENTION
The present invention relates to the field of interlock mechanisms for a gearbox of a tractor that prevents engagement of reverse gears when a tractor has attained a predetermined speed.
BACKGROUND OF THE INVENTION
Conventionally, a tractor is provided with three gear levers. A first gear lever is termed as forward/reverse (FR) gear lever which allows the tractor to run in forward direction or reverse direction. A second gear lever is termed as high/low gear lever which allows the tractor to operate in high gear ratio or a low gear ratio. A third gear lever allows the tractor to operate in multiple gear ratios available at the gearbox of the tractor. For example, the third lever of the tractor engages the transmission of the tractor with 1st, 2nd, 3rd, 4th of 5th gear of the gearbox. Thus, such tractor can achieve 30 different gear ratios by using the various combinations of the first, second, and third gear levers. For example, if the gearbox has five gears, a driver of the tractor can engage the first gear lever in reverse gear position, the second gear in high gear position, and the third gear in 4th or 5th gear position.
As per International Standards IS 12207: 2019, the speed of a tractor in reverse direction is limited to 20 kmph (kilometres per hour) at Engine Rated RPM. However, it is observed that when the tractor is in reverse gear transmission, the high gear lever is engaged at high gear ratio, and the third lever is engaged at 4th or 5th gear, the tractor tends to move in reverse direction at a speed higher than 20 kilometres per hour which is not allowed as per International Standards IS 12207: 2019. A table below shows various speeds a particular tractor can attain when the first gear lever in reverse gear position, the second gear in high gear position, and the third gear in any of the gears of the gearbox. It is to be noted that the below speeds are of Mahindra and Mahindra’s Arjun Novo 57 HP 72 HP tractor models. In the below table, ‘R’ in column gear number represents reverse gear transmission, ‘H’ in column gear number represents the second gear lever is in high gear position and the numbers after ‘RH’ in column gear number represents number of the gear engaged via the third gear lever.
Gear Number Speed of 57 HP model in kmph Speed of 72 HP model in kmph
RH1 9.07 9.41
RH2 13.14 13.63
RH3 18.91 19.62
RH4 23.82 24.70
RH5 32.01 33.21
Form the above table, it is observed that, at gear positions RH4 and RH5, the tractor tends to move in reverse direction at a speed above 20 kmph which is not allowed as per International Standards IS 12207: 2019.
Therefore, there is felt a need of an interlock mechanism for a gearbox of a tractor that selectively prevents the engagement of a reverse gear at high gear ratios.
SUMMARY OF THE INVENTION
The present invention envisages an interlock mechanism for a gearbox of a tractor. The tractor has a first gear lever allowing the tractor to move in forward direction or reverse direction, a second gear lever allowing the tractor to operate in high gear ratio or a low gear ratio, and a third gear lever allowing the tractor to operate in multiple gear ratios of the gearbox of the tractor. The mechanism comprises a housing, a first hollow member, a second member, a first biasing member, a second biasing member, a first interlocking member, a second interlocking member, and a third interlocking member. The housing has a first end and a second end. The first hollow member is disposed in the housing and has a flat first end and a tapered second end. The second member is disposed in the housing. The second member passes through the first hollow member and extends beyond the first hollow member. The second member has a tapered surface arranged proximal to a first end of the housing. A first biasing member is disposed between a first end of the second member and the first end of the housing. A second biasing member is mounted on the second member and abuts a first end of the first hollow member. A first interlocking member is coupled to the first gear lever and is configured to selectively intrude in the housing corresponding to the displacement of the first gear and prevent displacement of the first hollow member. A second interlocking member is coupled to the second gear lever and is configured to selectively intrude in the housing corresponding to the displacement of the second gear and slide on the tapered surface of the second member. A third interlocking member is coupled to the third gear lever and is configured to selectively intrude in the housing proximal to the second end of the first hollow member corresponding to the displacement of the third gear.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
An interlock mechanism of the present invention will be described with reference to accompanying drawings, in which:
Figure 1 illustrates a sectional view of the mechanism, in accordance with an embodiment of the present invention;
Figure 2 illustrates an isometric sectional view of the mechanism of figure 1;
Figure 3 illustrates a schematic view depicting an arrangement of a first and second interlocking member onto a first and second rail of the mechanism respectively; and
Figure 4 illustrates a schematic view depicting an arrangement of a third interlocking member onto a third rail of the mechanism respectively.
DETAILED DESCRIPTION OF THE INVENTION
Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.
References in the specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
The present invention provides an interlock mechanism for a gearbox of a tractor (hereinafter also referred as ‘mechanism’). The mechanism of the present invention is described with reference to accompanying figures 1-4.
A tractor typically has three gear levers. A first gear lever allows the tractor to move in forward direction or reverse direction. A second gear lever allowing said tractor to operate in high gear ratio or a low gear ratio. A third gear lever allowing said tractor to operate in multiple gear ratios of the gearbox of the tractor. The first , second and third gear levers are coupled with a gearbox via a first rail, a second rail and a third rail respectively. Each gear lever is coupled to respective rail via a pair of cams and a gate shifter. The cams and the gate shifter translate the angular displacement of the gear lever into translational motion of the respective rail. The rails have linear translations in two directions which are opposite to each other. For example, the first rail is linearly displaced in one direction to move the tractor in forward direction and in opposite direction to move the tractor in reverse direction. Similarly, the second rail is linearly displaced in one direction to move the tractor with high gear ratio and in opposite direction to move the tractor in low gear ratio. The third rail is coupled to the various gears in the gearbox to achieve a 1st gear ratio, 2nd gear ratio, 3rd gear ratio, 4th gear ratio, 5th gear ratio and so on. Typically, a plurality of third rails is coupled to the third gear lever to achieve various ratios. Each third rail facilitates achieving two gear ratios by linearly displacing in two opposite direction. For example, a particular third rail can achieve 4th gear ratio when linearly displaced in one direction and 5th gear ratio when displaced in opposite direction.
Referring to figures 1 and 2, a mechanism 100 in accordance with an embodiment is shown. The mechanism 100 is configured for preventing the tractor from achieving speed of over 20 kmph when the reverse gear of the tractor is engaged.
The mechanism 100 comprises a housing 110. The housing 110 is hollow to receive components of the mechanism 100. The housing 110 includes a plurality of holes configured on the circumference thereof to provide a passage to interlocking members. The housing 110 has a first end 120 and a second end 130.
The mechanism 100 comprises a first hollow member 140 disposed in the housing 110. The first hollow member 140 has a flat first end 150 and a tapered second end 160. The first member 140 is disposed in the housing 110 such that the tapered second end 160 is arranged proximal to the second end 130 of the housing 110.
The mechanism 100 comprises a second member 170 disposed in the housing 110. The second member 170 passes through the first hollow member 140 and extends beyond the first hollow member 140. More specifically, the length of the second member 170 is more than the length of the first hollow member 140. The first hollow member 140 has a first slot extending throughout the length of the first hollow member 140. The first slot is configured to facilitate passing of said second member therethrough.
The second member 170 has a tapered surface 180 arranged proximal to the first end 120 of the housing 110.
The mechanism includes a first biasing member 190 and a second biasing member 200 disposed inside the housing 110. The first biasing member 190 is disposed between a first end of the second member 170 and the first end 120 of the housing 110. The second biasing member 200 is mounted on the second member 170 abutting a first flat end 150 of the first hollow member 140. In an embodiment, the biasing members are coil springs.
The mechanism 100 includes a first interlocking member 210 coupled to the first gear lever of the tractor. The first interlocking member 210 is configured to selectively intrude in the housing 110 corresponding to the displacement of the first gear and prevent displacement of the first hollow member 140 towards the first end 120 of the housing 110. More specifically, the first interlocking member 210 is configured to intrude in the housing 110 when a user puts the first gear lever in a reverse gear position. The first interlocking member 210 is coupled to the first gear lever via a first rail 220 coupling the first gear lever to a forward or reverse gear in the gearbox.
Referring to figure 3, the first interlocking member 210 is received on the first rail 220. The first rail 220 has a first rail tapered surface 230. The first interlocking member 210 is configured to ride on the first rail tapered surface 230 upon engagement of a reverse gear in the gearbox via the first gear lever to intrude in the housing 110. The first rail tapered surface 230 is provided on the first rail at only one side of the first interlocking member 210. Thus, the first interlocking member 210 intrudes into the housing 110 only when the first gear lever is pushed in reverse gear position. The first interlocking member 210 is pushed upwards when it slides on the first tapered surface 230.
The first interlocking member 210 intrudes in the housing 110 between the flat first end 150 of the first hollow member 140 and the first end 120 of the housing 110.
The mechanism 100 includes a second interlocking member 240 is coupled to the second gear lever. The second interlocking member 240 is configured to selectively intrude in the housing 110 corresponding to the displacement of the second gear and slide on the tapered surface 180 of the second member 170. The second interlocking member 240 intrudes into the housing 110 between the first interlocking member 210 and the first end 120 of the housing 110.
More specifically, the second interlocking member 240 is configured to intrude in the housing 110 when a user puts the second gear lever in a high gear position. The second interlocking member 240 is coupled to the second gear lever via a second rail 250 coupling the second gear lever to a high or low gear in the gearbox. The intrusion of the second interlocking member 240 due to the second rail 250 is similar to that of the first interlocking member 210. Referring to figure 3, the second rail 250 has a second rail tapered surface 260. The second interlocking member 240 is configured to ride on the second rail tapered surface 260 upon engagement of a high gear in the gearbox via the second gear lever to intrude in the housing 110. The second interlocking member 240 is pushed upwards when it rides on the second rail tapered surface 260. Similar to the first rail 220, the second rail tapered surface 260 is provided only one side of the second interlocking member 240 resting on the second rail 250. Thus, the second interlocking member 240 is pushed upwards only when the second gear lever is engaged in high gear position.
The mechanism 100 includes a third interlocking member 270 coupled to the third gear lever. The third interlocking member 270 is configured to selectively intrude proximal to the second end 160 of the first hollow member 140 in the housing 110 corresponding to the displacement of the third gear. The third interlocking member 270 is coupled to the third gear lever via a third rail 280 coupling the third gear lever to predetermined gears in the gearbox. In an embodiment, the third rail 280 is configured to couple the third gear lever to fourth or fifth gear in the gearbox.
Referring to figure 4, the third rail 280 has a ‘V’ shaped notch 290 to receive the third interlocking member 270. The third interlocking member 270 is configured to intrude in the housing 110 upon engagement of the predetermined gears. More specifically, the third interlocking member 270 is pushed upwards by the notch 290 upon engagement of the predetermined gears.
The dimensions of the first hollow member 140 are so determined such that the flat end 150 of the first hollow member 140 prevents intrusion of the first interlocking member 210 in the housing 110 upon intrusion of the second interlocking member 240 and the third interlocking member 270.
The mechanism 100 includes spring loaded balls 300 arranged in a second slot 310 configured on the second member 170. The balls 300 and the second slot 310 are arranged on a portion of the second member 170 within the first hollow member 140. A spring 320 is disposed in the second slot 310 and the balls 300 are coupled to free ends of the spring 320 as shown in figures 1 and 2.
The spring-loaded balls 300 are configured to prevent displacement of the first hollow member 140 towards the second end 130 of the housing 110 with respect to the second member 170 or displacement of the second member 170 towards first end 120 of the housing 110 with respect to the first hollow member 140.
In an embodiment, a space 330 is defined between the first hollow member 140 and the second member 170 to facilitate displacement of the balls 300. The space 330 is provided on one side of the balls 300 in the direction of the second end 130 of the housing 110. No such space is provided on other side of the balls 300 in the direction of the first end 120 of the housing 110. This arrangement facilitates displacement of the first hollow member 140 towards the first end 120 of the housing 110 with respect to the second member 170 or displacement of the second member 170 towards second end 130 of the housing 110 with respect to the first hollow member 140, however prevents the vice versa displacement.
The first hollow member 140 includes a third slot 340 configured to receive the third interlocking member 270 therein. Thus, the third interlocking member 270 is received either in the third slot 340 or slides on the tapered second end 160 of the first hollow member 140 when intruded in the housing 110. The sliding of the third interlocking member 270 onto the tapered second end 160 results in displacement of the first hollow member 140 towards the first end 120 of the housing 110. The third slot 340 is configured on the first hollow member 140 such that the third interlocking member 270 in received in the third slot 340 when the first interlocking member 210 and the second interlocking member 240 are not intruded in the housing 110.
The working of the mechanism 100 is now elaborated. The mechanism 100 is configured to prevent the tractor to run above a certain speed in reverse direction. To achieve this, the mechanism 100 prevents simultaneous engagement of a reverse gear, a high gear and 4th or 5th gear actuated in any sequence. For illustration purposes, it is considered that the tractor runs in reverse direction above the predetermined speed at 4th or 5th gear and the second gear lever being in high gear position. In an embodiment, the predetermined speed is 20 kmph. However, the mechanism 100 can be used for any other speed restriction requirement of the tractor. In other speed restriction requirement cases, the third interlocking member is to be coupled to a particular rail which engages gears that achieves the speed of tractor beyond the restricted speed.
As there are three rails that can be operated by a user, the working is elaborated in accordance with the sequence of gear engagement. The sequences are chosen such that the tractor runs beyond the predetermined speed limits if the particular sequence is followed. The below sequences are elaborated for example purposes to elaborate the working of the mechanism 100. The below sequences should not be construed as limitations.
The initial position of the mechanism 100 before each sequence is shown in figure 1 and figure 2.
Sequence 1 – High gear 4th or 5th gear Reverse gear
In sequence 1, a user first engages a high gear by using a second gear lever, and engages 4th or 5th gear using the third gear lever, and then tries to engage reverse gear using the first gear lever. Due to the high gear engagement, the second interlocking member 240 rides on the second rail tapered surface 260 and moves upwards to slide on the second member 170. This pushes the second member 170 and the first hollow member 140 towards the first end 120 of the housing 110. Due to the 4th or 5th gear engagement, the third interlocking member 270 slides on the second tapered surface 160 of the first hollow member 140 due to the configuration of the notch 290, and pushes the first hollow member 140 towards the first end 120 of the housing 110. The flat first end 150 of the first hollow member 140, after displacement, prevents intrusion of the first interlocking member 210 as the flat first end 150 closes the passage through which the first interlocking member 210 intrudes. Due to this, the first rail 220 cannot be displaced to engage the reverse gear as the first interlocking member 210 cannot ride on the first rail tapered surface 230. Thus, an engagement of the reverse gear is prevented. Thus, simultaneous engagement of all three gears, i.e., 4th or 5th gear, high gear and reverse gear is prevented.
Sequence 2 – High gear Reverse gear 4th or 5th gear
In sequence 2, the user engages a high gear by using a second gear lever, and engages a reverse gear using the first gear lever, and then tries to engage 4th or 5th gear using the third gear lever. Due to the high gear engagement, the second interlocking member 240 rides on the second rail tapered surface 260 and moves upwards to slide on the tapered surface 180 of the second member 170. This pushes the second member 170 and the first hollow member 140 towards the first end 120 of the housing 110. Due to the engagement of the reverse gear, the first interlocking member 210 intrudes into the housing 110 and blocks further displacement of the first hollow member 140 towards the first end 120 of the housing 110. Thus, when a user tries to engage the 4th or 5th gear, the third interlocking member 270 is unable to intrude into the housing 110 as sliding of the third interlocking member 270 on the second tapered end 160 of the first hollow member 140 is not possible. The first hollow member 140 cannot be pushed towards the first end 120 of the housing 110 as its displacement is blocked by the first interlocking member 210. Thus, the third interlocking member 270 cannot ride on the notch 290 and displacement of the third rail 280 is prevented. This prevents engagement of the 4th or 5th gear when reverse and high gears are engaged. Thus, simultaneous engagement of all three gears, i.e., 4th or 5th gear, high gear and reverse gear is prevented.
Sequence 3 – 4th or 5th gear High gear Reverse gear
In sequence 3, the user engages 4th or 5th gear using the third gear lever and then tries to engage the high gear using the second gear lever and the reverse gear using the first gear lever. Once the 4th or 5th gear is engaged, the third interlocking member 270 intrudes into the housing 110 and is received in the third slot 340. Further, when the user tries to engage the high gear, the second interlocking member 240 cannot slide on the tapered surface 180 of the second member 170 as the first hollow member 140 is locked and the second member 170 cannot be displaced towards the first end 120 of the housing 110 due to the spring-loaded balls 300. Thus, the second interlocking member 240 cannot ride on the second rail tapered surface 260, thereby blocking the engagement of the high gear. A reverse gear can be engaged as the first interlocking member 210 can intrude in the housing 110. Thus, simultaneous engagement of all three gears, i.e., 4th or 5th gear, high gear and reverse gear is prevented.
Sequence 4 – 4th or 5th gear Reverse gear High gear
In sequence 4, the user engages 4th or 5th gear using the third gear lever, the reverse gear using the first gear lever, and then tries to engage the high gear using the second gear lever. Once the 4th or 5th gear is engaged, the third interlocking member 270 intrudes into the housing 110 and is received in the third slot 340. The reverse gear is engaged as the first interlocking member 210 can easily intrude into the housing 110. However, when the user tries to engage the high gear, the second interlocking member 240 cannot slide on the tapered surface 180 of the second member 170 as the first hollow member 140 is locked and the second member 170 cannot be displaced towards the first end 120 of the housing 110 due to the spring-loaded balls 300. Thus, the second interlocking member 240 cannot ride on the second rail tapered surface 260, thereby blocking the engagement of the high gear. Thus, simultaneous engagement of all three gears, i.e., 4th or 5th gear, high gear and reverse gear is prevented.
Sequence 5 – Reverse gear High gear 4th or 5th gear
In sequence 5, a user engages reverse gear using the first gear lever, high gear using the second gear lever, and then tries to engage 4th or 5th gear using the third gear lever. Once the reverse gear is engaged, the first interlocking member 210 intrudes into the housing 110 after sliding on the first rail tapered surface 230. Once the high gear is engaged, the second interlocking member 240 intrudes into the housing 110 after sliding on the second rail tapered surface 260. This results in displacement of the second member 170 and the first hollow member 140 towards the first end 120 of the housing 110. When the user tries to engage 4th or 5th gear, the third interlocking member 270 cannot intrude into the housing 110 to slide onto the second tapered end 160 of the first hollow member 140 as the further displacement of the first hollow member 140 is restricted by the first interlocking member 210. Thus, the displacement of the third rail 280 is prevented. Thus, simultaneous engagement of all three gears, i.e., 4th or 5th gear, high gear and reverse gear is prevented.
Sequence 6 – Reverse gear 4th or 5th gear High gear
In sequence 6, a user engages reverse gear using the first gear lever, then engages 4th or 5th gear using the third gear lever, and then tries to engage high gear using the second gear lever. The reverse gear is engaged as the first interlocking member 210 can easily intrude into the housing 110. The engagement of 4th or 5th gear results on the third interlocking member 270 gets received in the third slot 340 of the first hollow member 140, thereby locking the movement of the first hollow member 140. In such case, when the user tries to engage a high gear using the second gear lever, the second rail 250 cannot be displaced to engage the high gear as the second interlocking member 240 cannot intrude into the housing 110 by sliding on the tapered surface 180 of the second member 170. The second interlocking member 240 cannot slide on the tapered surface 180 because the displacement of the second member 170 is restricted in the direction of the first end 120 of the housing 110 due to locking of the first hollow member 140 and the spring-loaded balls 300. Thus, the high gear cannot be engaged, thereby preventing engagement of all three gears, i.e., 4th or 5th gear, high gear, and reverse gear simultaneously.
After executing each sequence, the first hollow member 140 and the second member 170 returns to its initial position as shown in figure 1 and 2 due to the first biasing member and the second biasing member. During the executing the sequences, the first and second biasing members get compressed due to the movement the first hollow member 140 and the second member 170. Once the force onto the first hollow member 140 and the second member 170 is removed, the first biasing member 190 and the second biasing member 200 push the second member 170 and the first hollow member 140 respectively to their initial positions as shown in figures 1 and 2.
The mechanism 100 prevents simultaneous engagement of all three gears, i.e., 4th or 5th gear, high gear and reverse gear, thereby controlling the speed of a tractor within predetermined limit in reverse gear position. The mechanism 100 is easy to implement and maintain. Further, the mechanism 100 automatically controls the speed of the tractor in reverse gear without any human intervention.
The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.
LIST OF REFERENCE NUMERALS
100 – Mechanism
110 – Housing
120 – First end of housing
130 – Second end of housing
140 – First hollow member
150 – Flat first end of first hollow member
160 – Tapered second end of first hollow member
170 – Second member
180 – Tapered surface of second member
190 – First biasing member
200 – Second biasing member
210 – First interlocking member
220 – First rail
230 – First rail tapered surface
240 – Second interlocking member
250 – Second rail
260 – Second rail tapered surface
270 – Third interlocking member
280 – Third rail
290 – Notch on third rail
300 – Spring loaded balls
310 – Second slot
320 – Spring
330 – Space
340 – Third slot