Indian Patents. 216813:"AN IMPROVED OIL/SUPPLY SYSTEM FOR WET BRAKES"

Title of Invention	"AN IMPROVED OIL/SUPPLY SYSTEM FOR WET BRAKES"
Abstract	This invention relates to an improved oil system for wet brakes. An improved oil system has an oil filter connected to a pump. A response body is connected to the pump through a delivery line. A control body is connected to the response body for supply of oil to a brake housing. A hollow bush is connected to the brake housing to a transmission housing.

Full Text	FIELD OF INVENTION This invention relates to an improved oil Spply system for supplying oil to wet brakes of a tractor without the requirement of an additional auxilliary pump, for supply of oil. BACKGROUND OF THE INVENTION It is generally known that oil supply systems for wet brakes utilize assemblies that employ 1) are auxilliary oil pump to supply forced oil quantity for the functioning of wet brakes, where oil is received from a transmission housing and returns back to the source or 2) the wet brakes are an integral part of the transmission housing and receives required quantity of oil from the same housing on account of its location. However, such a construction of integral construction complicates wet brakes serviceability in case of problems. Further, the oil received by the wet brake is unfiltered and contain small impurities and particles which lessen the life of the brake due to wear and impregnation. OBJECTS OF THE INVENTION An object of the present invention is to propose an improved oil supply system for supply of oil to the wet brakes of a tractor without the requirement of an auxiliary oil pump. Another object of this invention is to propose an improved oil supply system for supplying oil to wet brakes and obviates the disadvantages of the known art as described here inabove. Still another object of this invention is to propose an improved oil supply system for supply of filtered oil to wet brakes. SUMMARY OF THE INVENTION According to this invention an improved oil supply system is proposed for the supply of filtered oil to wet brakes without the requirement of auxiliary pump. A connection has been provided on the drain line of the hydraulic lift system of tractor, which partially taps the required amount of oil and supplies it to wet brakes of the tractor. A hollow bush, acting as an oil passage between brake housing and transmission housing, is so sized and positioned in the brake housing so as to maintain the required level of oil in the brake housing and to drain the excess oil in the transmission housing. Since the drain line of the hydraulic lift system already receives filtered oil, this oil supply system ensures the supply of filtered oil to the wet brakes. Thus the advantage of required amount of filtered oil supply to the wet brakes as well as ensuring no additional requirement of auxiliary pump are achieved through this invention In accordance with this invention an improved oil supply system has been provided on the drain line of the hydraulic system which supplies the oil to wet brakes of the tractor. A connection has been provided on the drain line of the hydraulic system which supplies oil to the wet brakes through a passage with a line pressure of average 2-3kg/cm2Thus this oil supply system positively ensures the oil supply to wet brakes. A hollow bush is so sized and located on the brake housing so as to maintain the required level of oil in the brake housing and to drain the excess oil in the transmission housing. Since the drain line of the hydraulic system already receives the filtered oil, the oil system ensures the supply of filtered oil to wet brakes. Thus the advantage of required amount of filtered oil supply to wet brake as well as ensuing no additional requirement of auxilliary pump are achieved through this invention DESCRIPTION OF THE ACCOMPANYING DRAWING The present invention will be described with eference to the accompanying drawings and wherein: shows an isometric view of the oil supply system for wet brake of tractor; and shows a schematic hydraulic circuit of a oil supply system for wet brake of a tractor. Figure 1 shows the oil supply system to wet twin brakes located on either side of the tractor. There is a oil filter (1) located inside the ^transmission housing (11) which acts as an oil tank or reservoir and is connected to pump (3) through suction line (2). Pump (3) supplies oil through delivery line (4) to response body (5), which is further connected to control body (6). A brake housing (9) is connected to control body (6) (which is housed in rear cover (12)) through oil tapping line (7) and oil supply, line 8. There is an oil passage from brake housing (9) to transmission housing (11) through hollow bush (10). Referring to figures 1 and 2, filtered oil is sucked by the pump (3) from transmission housing through filter (1) and the pressurised oil is then supplies to control body (6). The hydraulic control body, which is a standard fittment of the tractor can be in three conditions that is neutral, raising and lowering. At neutral condition of control body, port B is open and the oil flows through check valve A and reaches the point (E) as shown in figure 2. Depending upon the requirement the drain oil point (E) is partially tapped and is supplied to the wet brakes through hole (F). Balance oil is drained to transmission housing (11) through drain hole (G). During the raising conditions the port (B) and port (C) are closed and oil from the CCL) pump goes to hydraulic cylinder (CL) through check valve (H) and port (D), which in turn actuates the hydraulic lift. This condition remains for 1-2 seconds. After this immediately the control body comes to the neutral condition, in lowering condition of the hydraulic lift, port (C) opens and oil from hydraulic cylinder flows through port (C) to transmission housing (11). At this time port (B) is also in open condition and the oil from pump goes to wet brakes as described in natural condition earlier. Referring to figure 1, a hollow bush (10) is provided as a connector between transmission housing (11) and the brake housing (9) and the position is to designed that the required minimum level of oil is always maintained in the brake. The excess oil drains back to transmission housing through this bush. WE CLAIM 1. An improved oil supply system for wet brakes, comprising; - an oil filter (1) disposed adjacent to a transmission housing (11) of a tractor; - a suction line (2) extending from the oil filter (1); - a pump (3) for receiving filtered oil from the suction line (2); - a delivery line (4) coupled to the pump (3) for delivering filtered oil from the pump (3); - a control body (hydraulic control valve) (6) for receiving filtered oil from the delivery line (4); - an oil tapping line (7) coupled to the control body (6) which acts as a supply means for filtered oil to a brake housing (9) and simultaneously allowing excess oil to drain to the transmission housing (11); - and a hollow bush (10) defining an oil passage between the brake housing (9) and transmission housing (11), for allowing oil to overflow into the transmission housing (11). Where a required amount of filtered oil is supplied to the wet brake without the use of any auxiliary pump and oil supplied to the brake housing (9) has been tapped from a drain of a hydraulic lift system of the tractor. 2. The oil supply system as claimed in claim 1, wherein said oil tapping line (7) is incorporated in a hydraulic lift system of a tractor, to deliver oil to wet brakes. 3. The oil supply system as claimed in claim 2, wherein said oil tapping line (7) is configured in registration with the required amount of oil delivered to the wet brakes. 4. The oil supply system as claimed in claim 1, wherein the oil tapping line (7) is made of either metal or braided flexible pipe. 5. The oil supply system as claimed in claim 1, wherein the control body (6) is having an oil passage with a first hole (F) and a second hole (G). 6. The oil supply system as claimed in claim 5, wherein the first hole (F) and the second hole (G) of the control body are sized so that the required amount of oil is delivered to wet brakes and the remaining oil drains to the transmission housing (11) respectively. 7. The oil supply system as claimed in claim 1, wherein the hollow bush (10) is interposed between the brake housing (9) and the transmission housing (11), and wherein the hollow bush (10) is dimensionally so configured that the required level of oil is only maintained in the brake housing (9) and the excess oil is drained into the transmission housing (11).

Full Text

FIELD OF INVENTION
This invention relates to an improved oil

Spply system for supplying oil to wet brakes of a tractor without the requirement of an additional auxilliary pump, for supply of oil.
BACKGROUND OF THE INVENTION
It is generally known that oil supply systems for wet brakes utilize assemblies that employ 1) are auxilliary oil pump to supply forced oil quantity for the functioning of wet brakes, where oil is received from a transmission housing and returns back to the source or 2) the wet brakes are an integral part of the transmission housing and receives required quantity of oil from the same housing on account of its location. However, such a construction of integral construction complicates wet brakes serviceability in case of problems. Further, the oil received by the wet brake is unfiltered and contain small impurities and particles which lessen the life of the brake due to wear and impregnation.

OBJECTS OF THE INVENTION
An object of the present invention is to propose an improved oil supply system
for supply of oil to the wet brakes of a tractor without the requirement of an
auxiliary oil pump.
Another object of this invention is to propose an improved oil supply system for
supplying oil to wet brakes and obviates the disadvantages of the known art as
described here inabove.
Still another object of this invention is to propose an improved oil supply system
for supply of filtered oil to wet brakes.
SUMMARY OF THE INVENTION
According to this invention an improved oil supply system is proposed for the
supply of filtered oil to wet brakes without the requirement of auxiliary pump. A
connection has been provided on the drain line of the hydraulic lift system of
tractor, which partially taps the required amount of oil and supplies it to wet
brakes of the tractor. A hollow bush, acting as an oil passage between brake
housing and transmission housing, is so sized and positioned in the brake
housing so as to maintain the required level of oil in the brake housing and to
drain the excess oil in the transmission housing. Since the drain line of the
hydraulic lift system already receives filtered oil, this oil supply system ensures
the supply of filtered oil to the wet brakes. Thus the advantage of required
amount of filtered oil supply to the wet brakes as well as ensuring no additional
requirement of auxiliary pump are achieved through this invention

In accordance with this invention an improved oil supply system has been provided on the drain line of the hydraulic system which supplies the oil to wet brakes of the tractor. A connection has been provided on the drain line of the hydraulic system which supplies
oil to the wet brakes through a passage with a line
pressure of average 2-3kg/cm2Thus this oil supply
system positively ensures the oil supply to wet brakes. A hollow bush is so sized and located on the brake housing so as to maintain the required level of oil in the brake housing and to drain the excess oil in the transmission housing. Since the drain line of the hydraulic system already receives the filtered oil, the
oil system ensures the supply of filtered oil to wet

brakes. Thus the advantage of required amount of
filtered oil supply to wet brake as well as ensuing no additional requirement of auxilliary pump are achieved through this invention

DESCRIPTION OF THE ACCOMPANYING DRAWING
The present invention will be described with eference to the accompanying drawings and wherein:
shows an isometric view of the oil supply system for wet brake of tractor; and
shows a schematic hydraulic circuit of a oil supply system for wet brake of a tractor.
Figure 1 shows the oil supply system to wet twin brakes located on either side of the tractor. There is a oil filter (1) located inside the ^transmission housing (11) which acts as an oil tank or reservoir and is connected to pump (3) through suction line (2). Pump (3) supplies oil through delivery line (4) to response body (5), which is further connected to control body (6).
A brake housing (9) is connected to control body (6) (which is housed in rear cover (12)) through oil tapping line (7) and oil supply, line 8. There is an oil passage from brake housing (9) to transmission housing (11) through hollow bush (10).
Referring to figures 1 and 2, filtered oil is sucked by the pump (3) from transmission housing through filter (1) and the pressurised oil is then supplies to

control body (6). The hydraulic control body, which is a standard fittment of the tractor can be in three conditions that is neutral, raising and lowering. At neutral condition of control body, port B is open and the oil flows through check valve A and reaches the point (E) as shown in figure 2. Depending upon the requirement the drain oil point (E) is partially tapped and is supplied to the wet brakes through hole (F). Balance oil is drained to transmission housing (11) through drain hole (G). During the raising conditions
the port (B) and port (C) are closed and oil from the
CCL) pump goes to hydraulic cylinder (CL) through check valve
(H) and port (D), which in turn actuates the hydraulic lift. This condition remains for 1-2 seconds. After this immediately the control body comes to the neutral condition, in lowering condition of the hydraulic lift, port (C) opens and oil from hydraulic cylinder flows through port (C) to transmission housing (11). At this time port (B) is also in open condition and the oil from pump goes to wet brakes as described in natural condition earlier. Referring to figure 1, a hollow bush (10) is provided as a connector between transmission housing (11) and the brake housing (9) and the position is to designed that the required minimum level of oil is always maintained in the brake. The excess oil drains back to transmission housing through this bush.

WE CLAIM
1. An improved oil supply system for wet brakes, comprising;
- an oil filter (1) disposed adjacent to a transmission housing (11) of
a tractor;
- a suction line (2) extending from the oil filter (1);
- a pump (3) for receiving filtered oil from the suction line (2);
- a delivery line (4) coupled to the pump (3) for delivering filtered oil
from the pump (3);
- a control body (hydraulic control valve) (6) for receiving filtered oil
from the delivery line (4);
- an oil tapping line (7) coupled to the control body (6) which acts as
a supply means for filtered oil to a brake housing (9) and
simultaneously allowing excess oil to drain to the transmission
housing (11);
- and a hollow bush (10) defining an oil passage between the brake
housing (9) and transmission housing (11), for allowing oil to
overflow into the transmission housing (11).
Where a required amount of filtered oil is supplied to the wet brake without the use of any auxiliary pump and oil supplied to the brake housing (9) has been tapped from a drain of a hydraulic lift system of the tractor.
2. The oil supply system as claimed in claim 1, wherein said oil tapping line
(7) is incorporated in a hydraulic lift system of a tractor, to deliver oil to
wet brakes.
3. The oil supply system as claimed in claim 2, wherein said oil tapping line
(7) is configured in registration with the required amount of oil delivered
to the wet brakes.

4. The oil supply system as claimed in claim 1, wherein the oil tapping line
(7) is made of either metal or braided flexible pipe.
5. The oil supply system as claimed in claim 1, wherein the control body (6)
is having an oil passage with a first hole (F) and a second hole (G).
6. The oil supply system as claimed in claim 5, wherein the first hole (F) and
the second hole (G) of the control body are sized so that the required
amount of oil is delivered to wet brakes and the remaining oil drains to
the transmission housing (11) respectively.
7. The oil supply system as claimed in claim 1, wherein the hollow bush (10)
is interposed between the brake housing (9) and the transmission housing
(11), and wherein the hollow bush (10) is dimensionally so configured that
the required level of oil is only maintained in the brake housing (9) and
the excess oil is drained into the transmission housing (11).

Documents:

416-del-2000-abstract.pdf

416-del-2000-claims.pdf

416-del-2000-correspondence-others.pdf

416-del-2000-correspondence-po.pdf

416-del-2000-description (complete).pdf

416-del-2000-drawings.pdf

416-del-2000-form-1.pdf

416-del-2000-form-19.pdf

416-del-2000-form-2.pdf

416-del-2000-form-3.pdf

416-del-2000-gpa.pdf

416-del-2000-petition-137.pdf

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Patent Number

216813

Indian Patent Application Number

416/DEL/2000

PG Journal Number

13/2008

Publication Date

31-Mar-2008

Grant Date

19-Mar-2008

Date of Filing

07-Apr-2000

Name of Patentee

PUNJAB TRACTORS LIMITED

Applicant Address

INDIAN COMPANYPHASE PHASE IV, S.A.S. NAGAR, DISTT. ROPAR-160055, NEAR CHANDIGARH.

Inventors:

#	Inventor's Name	Inventor's Address
1	R. K. MANRAO	INDIAN NATIONALS OF PHASE IV, S.A.S. NAGAR, DISTT. ROPAR-160055, NEAR CHANDIGARH.
2	JATINDER SINGH CHAWLA	INDIAN NATIONALS OF PHASE IV, S.A.S. NAGAR, DISTT. ROPAR-16005, NEAR CHANDIGARH.

PCT International Classification Number

B01D 35/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA