FIELD OF THE INVENTION
The present invention relates to a modified and improved dual line automatic greasing
system and an improved configuration of change over valve comprising of detent type
solenoid valves for selectively disposing grease at the application points in heavy
equipments or devices through corresponding dispensing lines. More particularly, a solenoid
operated 2 position 4 way direction control valve has been used with detent type solenoids
of nominal size 10, such that spool type direction control valve, commonly used for
hydraulic systems, is used for this modified device. A new manifold for the dual line
distribution system has been designed to provide a measured quantity of lubricant in a fixed
time interval to the consuming points and the direction control valve has been mounted on
this manifold. The electrical system for the valve actuation to direct flow of lubrication to
either of the dual lines, is subjected to a simple modification. The "Normally open" contact
of the contactor has been used to give power to one solenoid while the "Normally closed"
contact of the contactor has been used to give power to the other solenoid, unlike the
operation of the direction control valve, wherein power used to be given or withdrawn from
both the solenoids at the same time. The dual line automatic greasing system and an
improved change over valve having detent type solenoid valves according to the present
invention, thus enable simplified fault diagnosis as only one solenoid is energized at a time.
Moreover, elimination of poppet type solenoid valve has overcome the problem of internal
leakages. The present change over valve and its operative flexibility allows manual
operation if needed. The dual line greasing system with improved change over valve of the
invention ensures reliability and cost effective installation and long term performance of the
lubrication/greasing system and thus having potential for wide industrial application in Steel
plants, Heavy rolling mills and other heavy industrial equipments.
BACKGROUND ART
The conventional dual line grease system is used to provide a measured quantity of
lubricant in a fixed time interval to the consuming points. Such systems are of immense
importance and widely used in steel and other heavy industries for lubrication system of the
heavy equipments and sliding/friction surfaces or bearing supports. The basic components
of such greasing system comprises a pump, a reservoir, pipelines to the consuming points,
metering devices and a changeover valve which is either motor operated or solenoid
operated and said valve operatively direct the supply of grease to one of the two

distribution line in the tandem manifold system. The pump sends the lubricant to either of
the two lines of the dual line system based on the position of the change over valve. The
changing of the position of the valve directs the grease flow to the corresponding line as per
requirement of the equipment or device being serviced.
The existing changeover valve consist of a main spool and two pilot stage solenoid valves.
The pilot stage valve has been of poppet tube design of "2 position 4 port" type. The pilot
stage solenoid valves are of different types. One was normally open (without power) and
the other was normally closed. For operation of the direction control valve, power was given
or withdrawn from both the solenoids at the same time, said power being given through a
contactor.
The existing system with the kind of changeover valve as described experienced a number
of limitations and disadvantages. The solenoid valves while in operation developed internal
leakages, which affected the performance of the change over valve and the consequent
failure of adequate supply of grease by the system to different parts of
equipments/consuming points. Moreover, as in the existing system, power is being given to
both the solenoids at the same time, it has been found difficult to locate the actual faults, in
the event of occurrence of same. Though the manual override is available for the solenoid,
both have to be kept pressed for any manual operation and there is no detent for the
solenoids. This limitation has been overcome in the modified design.
There had been thus a continuous need for the development: of a dual line automatic grease
system with improved valve configuration such that effective uninterrupted distribution of
grease is automatically reached to the consuming points, as needed, through the dual
pipeline. Further, the new automatic grease system shall favor quick and accurate fault
diagnosis in a simple systematic manner by way of isolated power supply for the operation
of each of the dual solenoid valves and thereby avoiding downtime or failure of supply
system in either pipe line. The improved system shall also prevent the internal leakages
from the solenoid valves. The manual override in case of emergency operation is also
facilitated independent of the operation or position of the solenoid valves.

OBJECTS OF THE INVENTION
The basic object of the present invention is thus directed to a changeover valve with
improved configuration for the dual-line automatic grease system for use in steel plant or
the similar other heavy industry, favoring effective supply of grease to the consumption
points in a running plant in a reliable and cost effective manner.
A further object of the present invention is directed to an improved valve configuration
adapted to ensure uninterrupted grease supply through a dual line automatic grease system
adapted to favor preventing internal leakage from the solenoid valves which adversely
affected the performance of the change over valve.
A further object of the present invention is directed to an improved valve configuration
adapted to improve reliable performance of dual line automatic grease system wherein a
spool type direction control valve is used to function as change over of grease supply to
either of the two lines of said dual line grease system.
A further object of the present invention is directed to an improved valve configuration
adapted to ensure uninterrupted grease supply through a dual line automatic grease system
wherein the power supply of either of the two solenoid valves for each of said supply lines is
operated with independent power supply through the contactor and thereby favoring easy
fault diagnosis simplified as one solenoid is energized at a time.
A further object of the present invention is directed to an improved valve configuration
adapted to ensure uninterrupted grease supply through a dual line automatic grease system
wherein the cost of modified version of valve installation and maintenance is much less
compared to the conventional configuration.
A further object of the present invention is directed to an improved valve configuration
adapted to ensure uninterrupted grease supply through a dual line automatic grease system
wherein the system permit the human interference when needed for operation of the
system/ valves.
A further object of the present invention is directed to an improved valve configuration
adapted to ensure uninterrupted grease supply through a dual line automatic grease system

wherein any custom made components are not required to develop the system and thereby
facilitating maintenance/ replacement of standard spares,
SUMMARY OF THE INVENTION
The basic aspect of the present invention is directed to a changeover valve system for dual-
line automatic grease system adapted for reliable supply of grease to the consumption
points comprising,
a solenoid operated 2 position 4 way direction control valve ;
two detent type solenoids; and
a manifold block for mounting said direction control solenoid valve thereon.
According to another aspect; of the present invention said changeover valve system for dual-
line automatic grease system adapted for reliable supply of grease to the consumption
points wherein said direction control valve comprise spool type direction control valve.
A further aspect of the present invention is directed to a changeover valve system for dual-
line automatic grease system adapted for reliable supply of grease to the consumption
points wherein said manifold for the dual line distribution system is configured to provide a
measured quantity of lubricant at a fixed time interval to the consuming points.
A still further aspect of the present invention is directed to a changeover valve system for
dual-line automatic grease system adapted for reliable supply of grease to the consumption
points wherein only one of the said two detent type solenoid is energized at a time and
thereby directing the flow of grease in the corresponding pipeline of the dual-line grease
system.
A still further aspect of the present invention directed to a changeover valve system for
dual-line automatic grease system adapted for reliable supply of grease to the consumption
points wherein, the electrical power supply to the solenoids through a contactor is adapted

such that the 'Normally Open' contact of the contactor provides power to one solenoid, while
'Normally Closed' contact of the contactor supply power to the other solenoid.
According to an advantageous aspect of the present invention directed to said changeover
valve system for dual-line automatic grease system adapted for reliable supply of grease to
the consumption points wherein, fault diagnosis is simplified as only one solenoid is
energized at a time.
A still further aspect of the present invention directed to said changeover valve system for
dual-line automatic grease system adapted for reliable supply of grease to the consumption
points wherein, the system provides for preventing the internal leakage of grease.
According to yet another aspect of the present invention directed to said changeover valve
system for dual-line automatic grease system adapted for reliable supply of grease to the
consumption points comprising means adapted for manual override without complexity in
case of fault of automation system.
The present invention and its objects and advantages are described in greater details with
reference to the accompanying non-limiting exemplary illustrative figures.
BRIEF DESCRIPTION OF THE FIGURES
Figure 1: is the schematic illustration of the existing change over valve for the dual line
automatic grease system.
Figure 2: is the schematic illustration of the modified and improved configuration of the
changeover valve according to the present invention, favoring simple and reliable change
over of grease supply and easy and prompt fault diagnosis.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING FIGURES
Reference is first invited to the accompanying Figure 1, that illustrates the conventional
changeover valve used for the diversion of flow of grease selectively in one of the two lines

of the dual line grease system by automated operation of solenoid valves. As already
described, such a system comprises the existing changeover valve comprising of a main
spool type changeover valve and two pilot stage solenoid valves. It is clearly apparent from
the accompanying Figure 1 that the pilot stage valves are of poppet tube design of "2
position 2 port" type. The pilot stage solenoid valves usually may be of a number of
alternative types. One was normally open (without power) and the other was normally
closed. For operation of the direction control valve, power was given or withdrawn from
both the solenoids at the same time, said power being given through a contactor.
The existing design of poppet type solenoid valves developed internal leakages while in
operation which in turn affected the performance of the change over valve. Moreover, since
the power is being supplied to both the solenoids at the same time, it is found to be difficult
to locate the occurrence of any online faults. Further, although the manual override facility
is made available for the solenoid, both had to be kept pressed for any manual operation
and there was not detent for the solenoids.
The present invention is directed to a modified and improved configuration of the
changeover valve for the dual-line automatic capable to overcome the limitation of existing
changeover valve, providing enhanced reliability of performance, leak free operation and
easy fault detection along with option for easy and simple manual override if needed.
Reference is now invited to the accompanying Figure 2, that schematically illustrates the
modified and improved configuration of the change over valve for the automatic dual line
grease system suitable for application in steel plants, rolling mills and similar other heavy
engineering industrial application. The improved design configuration of the change over
valve (CV) to achieve enhanced reliability of performance of the lubrication system enabling
easy fault diagnosis. The present invention makes use of a solenoid operated 2 position 4
way direction control (DC) valve with detent type solenoids (DS) of nominal size 10. Spool
type direction control (DC) valve, commonly used for hydraulic systems has been used for
this modified device for grease lubrication system. Also a new manifold block (MB) has been
designed and the direction control (DC) valve has been mounted on this manifold block
(MB). The new assembly has completely replaced the existing electromagnetic change over
valve. Importantly, the present system advantageous application of the electrical power
supply system modified to simplify operation of detent type solenoid (DS) valves and at the
same time make fault detection easier and faster and thus improving the system reliability.

The "Normally open" contact of the contactor has been used to give power to one solenoid
while the "Normally closed" contact of the contactor has been used to give power to the
other solenoid. Thus fault diagnosis become more simple and faster as only one solenoid is
energized at a time. The modified and improved changeover valve (CV) thus derive the
following salient advantageous features as compared to the conventional changeover valve
(CV) used in dual line automatic grease systems for heavy industrial applications:
• Fault diagnosis is fast and simplified as only one solenoid is energized at a time;
• Elimination of poppet type solenoid valves overcome the problem of internal
leakages;
• Manual operation is possible without any complexity;
• Less costly than the existing version of changeover valve;
• Higher reliability of operation is achieved;
• Spool type direction control valve normally used for hydraulic system used for grease
system with advantage;
• No involvement of custom made components and thus favoring faster maintenance
and easy and prompt replacement of spares.
It is thus possible by way of the present invention to develop an improved and efficient yet
cost effective device/changeover valve arrangement comprising spool type 2 position 4 way
direction control valve with detent type solenoid for the dual line automatic grease system
for application in steel plant or the like heavy engineering industries, adapted to provide
isolated power to each said solenoid and thus make fault diagnosis simpler and enhance
reliability of performance of the system. The system, according to the present invention,
eliminates use of poppet type solenoid valves and thereby prevents internal leakages of
lubricant and thus arresting waste and poor system reliability. Importantly, also the manual
intervention to such a automated lubrication system has been made simple, in case of fault
or emergency. The present improved changeover valve configuration of the invention is
having the potential for wide industrial application in steel plants, rolling mills and other
heavy engineering industries where the dual line automatic grease system are in place for
lubrication of heavy equipments.

We Claim:
1. A changeover valve system for dual-line automatic grease system adapted for
reliable supply of grease to the consumption points comprising,
a solenoid operated 2 position 4 way direction control valve ;
two detent type solenoids; and
a manifold block for mounting said direction control solenoid valve thereon.
2. A changeover valve system for dual-line automatic grease system adapted for
reliable supply of grease to the consumption points as claimed in claim 1 wherein
said direction control valve comprise spool type direction control valve.
3. A changeover valve system for dual-line automatic grease system adapted for
reliable supply of grease to the consumption points as claimed in anyone of claims 1
or 2 wherein said manifold for the dual line distribution system is configured to
provide a measured quantity of lubricant at a fixed time interval to the consuming
points.
4. A changeover valve system for dual-line automatic grease system adapted for
reliable supply of grease to the consumption points as claimed in anyone of claims 1
to 3 wherein only one of the said two detent type solenoid is energized at a time and
thereby directing the flow of grease in the corresponding pipeline of the dual-line
grease system.
5. A changeover valve system for dual-line automatic grease system adapted for
reliable supply of grease to the consumption points as claimed in anyone of claims 1
to 4 wherein, the electrical power supply to the solenoids through a contactor is
adapted such that the 'Normally Open' contact of the contactor provides power to
one solenoid, while 'Normally Closed' contact of the contactor supply power to the
other solenoid.

6. A changeover valve system for dual-line automatic grease system adapted for
reliable supply of grease to the consumption points as claimed in any one of claims 1
to 5 wherein, fault diagnosis is simplified as only one solenoid is energized at a time.
7. A changeover valve system for dual-line automatic grease system adapted for
reliable supply of grease to the consumption points as claimed in any one of claims 1
to 6 wherein the system provides for preventing the internal leakage of grease.
8. A changeover valve system for dual-line automatic grease system adapted for
reliable supply of grease to the consumption points as claimed in any one of claims 1
to 7 comprising means adapted for manual override without complexity in case of
fault of automation system.
9. A changeover valve system for dual-line automatic grease system adapted for
reliable supply of grease to the consumption points in steel plants or similar heavy
industry as herein described with reference to the accompanying non limiting
illustrative figure 2.

A modified and improved dual line automatic greasing system having improved changeover
valve comprising of detent type solenoid valve for selectively disposing grease at the
consumption points in heavy equipments through dispensing lines. Importantly, a solenoid
operated 2 position 4 way spool type direction control valve with detent type solenoids of
nominal size 10 has been used for this modified device. The manifold is configured to provide a measured quantity of lubricant in a fixed time interval to the consuming points. The electrical system for the valve actuation is modified such that the "Normally open" contact of the contactor is used to give power to one solenoid while the "Normally closed" contact of the contactor is used to give power to the other solenoid. The present system using detent type solenoid enable simplified fault diagnosis and overcome the problem of internal leakages and allows manual override. The dual line greasing system with improved change over valve is adapted for industrial application in Steel plants, Heavy rolling mills and the like.