FIELD OF INVENTION
This invention relates to a novel gearbox with creeper and splitter for
agricultural tractor. The gearbox is particularly used for agricultural tractor
without restricting scope of the invention to 'the same.
BACKGROUND /PRIOR ART' OF THE INVENTION
Conventional gearbox for agriculturgl tractor is know to have been
provided, layout of which is as shown in fig. 1. The gearbox is placed
between engine and differential housing.
,Conventional Transmission Layout of Agricultural Tractor comprises 2 or 3
speed' reduction' compartments within the same gearbox housing. The
details for these compartments are as follows:
1 .' SPEED COMPARTMENT (S) - For primary gear speed
- lSt, 2nd, 3rd, 4 t h Gear ratio; 5thand reverse are also
provided.
2. RANGE COMPARTMENT (R) - For further increasing the torque.
- High and Low Gear ratio; Medium also, is provided.
3. ADDITIONAL FEATURE COMPARTMENT (A)
- For application specific torque/ speed requirement.
- Either of Splitter ratio or Creeper ratio is possible.
These are used for transmitting the power from engine crankshaft through clutch
to rear axle. Since the torque is different for various agricultural implements as
well as non-agriculture practices, the gear ratios are provided accordingly.
Further, within the available space, limited by the vehicle wheelbase and engine;
the required torque is met by utilizing the different gear ratios of different
compartments.
I ratio, the gear ratio is required BETWEEN the successive gek- ratios. Splitter 1
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ratios can be under drive or overdrive. With creeper, the gear ratio is based on :
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the APPLICATION, and VERY HIGH gear ratio is required to achieve the overall
I vehicle speed starting from below 0.5 Km/h. Thus, the gear ratio selection is 1 . different for Splitter and Creeper gearboxes.
, .
Again, in case of conventional transmission assembly, the gearbox housing
length is limited and defined by vehicle dimensions.
With above two considerations, a single gearbox with Creeper as well as Splitter
can't be provided.
I According to a known art, the feature of creeper is integrated to the gearbox.So
that, 1s:. gear is set at creeper mode. Therefore, the tractor can't maintain
. .
standard speed of 1st gear. Splitter gearbox is separately provided, which is r
required to make the tractor take additional load by means of torque by reducing
'speed of the vehicle. However, no tractor is in existence which can maintain
! standard speed of tractor in 1st gear and be set at creeper mode when required
and at the same time which can serve the purpose of splitter.
I-Ience, the present invention has been proposed to address the aforesaid
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drawbacks.
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OBJECTS OF THE INVENTION
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Primary object of the present invention is.to provide a novel gearbox with
I creeper and splitter for agricultural tractor in which creeper speeds and
splitter gear ratios can be provided in one gearbox.
Still. another object of the present invention is to provide a novel gearbox
with creeper and splitter for, agricultural tractor which is efficient and .
reliable.
creeper and splitter for agricultural tractor which overcomes disadvantages
associated with the prior art.
I SUMMARY OF THE INVENTION
According to this invention, there is provided a novel gearbox with creeper
and splitter for agricultural tractor comprises a gearbox having a plurality of
compartments wherein a means is provided between first and last
compartment of gearbox for operating the tractor at creeper and splitter
speed by maintaining standard speed of tractor.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
I Further objects and advantages of this invention'will be more apparent from
'the ensuing description when read in conjunction with the accompanying
drawings of exemplary embodiments of invention and wherein:
Fig. 1 shows: . Conventional gearbox arrangement.
Fig. 2 shows: Gearbox arrangement according to present invention.
DETAIL DESCRIPTION. OF ' THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS (,
Th.e present invention discloses a novel gearbox having creeper and splitter
both in the same gearbox which is implemented particularly in an
agricultural tractor. For the same, an additional shifting system is provided
I between the speed compartment and range compartment.
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The gearbox comprises a plurality of compartments which is atleast three in
the present case, for which reference may be made to fig. 2. The
compartments constitute speed compartment (2), range compartment (6)
and creeper/ splitter compartment (3):
The creeper/splitter compartment is having multiple gears, which play role
when the vehicle is set at creeperlsplitter mode. . The vehicle is set at
creeper/splitter mode by means of a switch/lever, which is placed between
the speed compartment (2) and creeper/splitter compartment (3).
The switch/lever is coupled to output shaft of speed compartment (2) at one
end. and connected to said. multiple gears of compartment (3) through
linkage at other end.
The lever/switch has two modes, namely. Direct (5) and CreeperlSplitter
mode (4). The CreeperlSplitter mode is used for selection of creeper or
splitter speed.
With the above provision, the path of power transmission from the speed
I compartment to range compartment (6) passes. through gear ratio of gearbox
in creeper/splitter compartment (3) which was straight in the prior art in the
absence of Creeper/ splitter gearbox.
.When the leverlswitch is in Direct mode the power transmission takes place
1 directly from speed compartment to the range compartment following a
straight path.
Within the Splitter/Creeper compartment, the selection of two modes:
Creeper & Splitter (4), can be made thru' the sliding gear. At creeper mode,
the standard speed of vehicle is reduced to make the vehicle creep. Under
splitter mode, the vehicle is made to take additional load with the help of
torque increase due to splitter gear ratio.
. . . .
Thus, in accordance with the present invention a creeper/splitter means
with a particular gear ratio according to configuration of tractor has been
devised that is positioned between first and last compartment of gearbox
adjacent to differential housing.
Depending on the requirement of application, the gear ratio can be selected
by operator.
The gear ratios for the reduction compartment as well as splitterlcreeper
compartment are designed for meeting the overall basic vehicle speeds,
creeper speed and splitter ratios.
Thus, the present invention provides Splitter as well as. Creeper in single
gearbox housing. Further, the' ratios for range compartment and
spl.itter/creeper compartment may be util'ized to achieve the gear ratios for
. Creeper as well as Splitter. It provides an opportunity to offer to the end
customer, the features of both splitter as well as creeper speeds within one
single Vehicle, in place of vehicle variants. Additionally it eliminates more
gear ratios, shafts and longer housing. . .
.Thus, the invention has provision of both splitter gear ratio as well as
creeper gear ratio in one gearbox, for agricultural tractor and off-highway
vehicle. It is also' applicable for provision of both under drive & overdrive
splitter ari-angement in the same gearbox. This includes new concept of
gearbox layout. With the new layout& gear ratio selection the splitter and
creeper ratios can be achieved with.the single gearbox itself vis-a-vis current
gearbox layout that limit single provision from either of above. This design
offers unlque selling proposition and. cost effective solution for providing '
creeper and splitter gear ratios that are frequently used in .agriculture
application, within, the same gearbox.
The novel gearbox of invention can maintain 'standard speed at all gears (1-5
and Reverse). The creeper and splitter mode are applicable to all the gears.
- Unique' selling proposition..
- Cost effective.
- Low maintenance
- Versatility
- Flexibility
- It can maintain standard speed at all gears.
1tis to be noted that the present invention is susceptible to modifications, '
adaptations and changes by those skilled in the art. Such variant
embodiments employing the concepts and features of this invention are
intended to be within the scope of the present invention, which is further set
forth under the following claims:-

We Claim:
1. A novel gearbox with creeper and splitter for agricultural tractor
comprises a gearbox having a plurality of compartments wherein a
means is provided between first and last compartment of gearbox for
operating the tractor at creeper and splitter speed by maintaining
standard speed of tractor.
2. A rlvvel gearbox with creeper and splitter for agricultural tractor as
claimed in claim 1 wherein the first and last compartment is speed
and range compartment.
3. A novel gearbox with creeper and splitter for agricultural tractor as
claimed in claim 1 or 2, wherein the means comprises a switchllever
having Direct and Creeper and Splitter mode.
4. A novel gearbox with creeper and splitter for agricultural tractor as
claimed in any of the preceding claims wherein said switchllever is
coupled to output shaft of the speed compartment and connected to
multiple gears of creeperlsplitter compartment through linkage.
5.' A novel gearbox with creeper and splitter for agricultural tractor as
claimed in any of the preceding claims wherein said switchllever is
coupled to creeper gear of the cre~per/splitter compartment and
connected to multiple gears of creeperlsplitter compartment through
linkage.
6. A novel gearbox with creeper and splitter for agricultural tractor as
claimed in any of the preceding claims wherein the CreeperISplitter
mode is meant for selection of creeperlsplitter so as to operate the
vehicle at creeper speedlsplitter speed such as herein described.'
7. A novel gearbox with creeper and splitter for agricultural tractor as
claimed in claim 6 wherein the path of power transmission from the
. speed compartment to range compartment passes through gear ratio
of gearbox in the creeperlsplitter c~nipartment.
8. A novel gearbox with creeper and splitter for agricultural. tractor as
claimed in any of the preceding claims wherein in the Direct mode of
the leverlswitch the power transmissi.~nta kes place directly from the
speed compartment to the range compartment following a straight
path.
9. A novel gearbox with creeper a n d splitter for agricultural tractor as
claimed in any of the preceding claims which is having provision of
both splitter gear ratio and creeper gear ratio in one gearbox and
I which .is applicable for both under drive and overdrive splitter
I arrangement in the same gearbox.
10. A novel gearbox with creeper and splitter for agricultural tractor
I as claimed in. any of the preceding claims is associated with the
advantageous features such as herein. described.