FORM - 2
5 THE PATENTS ACT, 1970
COMPLETE SPECIFICATION (SECTION -10)
10 A FLEXIBLE SHAFT DRIVEN WATER PUMP FOR USE IN COMBINATION WITH AN EVAPORATIVE COOLER AND AN IMPROVED EVAPORATIVE COOLER THERE OF.
15 BAJAJ ELECTRICALS LIMITED,
a company registered in India having its registered office at 45/47, Veer Nariman Road, Mumbai - 400 001. India

The following specification particularly describes and ascertains the
20 nature of this invention and the manner in which it is to be performed: -
1

TECHNICAL FIELD:
The invention relates to a flexible shaft driven water pump for use in combination with an evaporative cooler with propeller fan or blower and particularly to an improved evaporative cooler
5 using a flexible shaft driven water pump.
BACKGROUND ART:

Standard Existing configuration and the working principle
10 involved in standard existing product: (Please refer drawing no
1)
Evaporative coolers, in which air is cooled by evaporation of water into the air, to provide comfort in hot weather are well
15 known. Such coolers are particularly effective in relatively dry climates. Such coolers conventionally include a box like enclosure, the lower portion of which is filled with water to a pre-determined level. Certain—walls are fitted with pads containing fibrous material, which are moistened with water,
20 drawn from the lower portion of the enclosure. The water is delivered by a small electric driven pump, through conduits to the top of the pads. The water runs downwards over the pads, thereby wetting the fibrous material. Any excess water flows back to the lower portion of the enclosure. Such coolers usually
25 consist of a power driven blower or propeller type fan fitted within the enclosure. The blower / propeller fan draws, the
2

relatively hot, dry ambient air through the pads. A portion of the water evaporates on the pads, thus cooling the passing air (adiabatic transfer of heat) and increasing its humidity. The cooled and humidified air is delivered by the blower /propeller
5 fans through a front opening on the enclosure on to the location to be maintained at a comfortable temperature below that of the ambient air.
In such evaporative coolers, separate electrical motors drive the
10 water pump and the propeller fan / blower individually. The water pump has a vertical drive shaft with an impeller secured to the lower end, thereon below the level of the water. The pump has a casing enclosing the impeller and extending upwards from the water concentrically to the vertical shaft. The casing and the
15 shaft, extend upwards from the water to the electric motor of the pump. The output shaft of the motor is an extension of the drive shaft and the motor is secured to the top of the casing so that the pump and the motor form a single unit. A mounting bracket, fixed between the pump and the motor is secured to metal or
20 rigid plastic member of the cooler by screws. The pump is not connected to lower portion of the enclosure. These water pump and motor unit is not connected to the rest of the evaporative cooler, except for the flexible electricity cable and water connections. The pump has only to raise a limited
25 quantity of water required to wet the pads and delivered to the top at a few feet height.
3

As can be noticed, from the preceding description, the water pump motor is located in an extremely disadvantageous location for electric driven equipment. This motor is constantly exposed to the humid atmosphere within the enclosure. Since the motor
5 is positioned at the bottom of the cooler, adjacent to the water surface, the motor is subject to water drips from pads or from defective water conduits or to being potentially submerged if knocked over during careless maintenance. As a result, the motor is susceptible to damage / failure in a relatively short 10 duration, due to electrical and corrosion problems associated with the wet environment. The motors, therefore frequently are replaced during the life of the evaporative cooler at a substantial expense.
15 The water pump motor, contributes significantly to the cost of an evaporative cooler, in spite of it being of a relatively simple design. Such a motor being of very small power rating, for the low head and limited flow required, is indeed expensive for the application. Such motors are inefficient due to their small size
20 and design.

The propeller fan / blower motors are more expensive than the water pump motors due the higher power requirement to drive the blower or the propeller fan. However these motors are not
25 subjected to as damaging wet environment since they are securely mounted away at the top of the enclosure away from the wettest area near the water surface. The propeller fan /
4

blower motors being of larger size ratings are more efficient and are of better construction than to water-pump motors.
OBJECT OF THE INVENTION :
5
The object of the present invention is to eliminate the electric
motor on the water pump by using a flexible shaft to drive the
water pump on the evaporative cooler.
Another objective of the present invention is to reduce cost of
10 the evaporative cooler.
Another objective of this invention is to prevent failure of pump
on account of the electric motor failure.
Thus overall objective of the invention is to increase value of the
appliance to the customer.
15
SUMMARY OF THE INVENTION:
The new art envisages, use of a flexible shaft assembly, to drive the water pump for use in combination with an evaporative
20 cooler with propeller fan or blower, consisting of:
a pump housing top-15 and pump housing bottom- 25,
a SS shaft- 14 vertically and centrally disposed within said
pump housing-15,
bearings (topside engineering plastic bush-18 and bottom side
25 metal bush-21) placed and confined in the pump housing top-15 to the keep the shaft in rotational relationship with the pump housing,
5

a flexible shaft connected by slide and rotate type flexible joint
to one end of the SS shaft- 14 ,
an impeller- 23 mounted on the other end of the SS shaft-14,
a split pin-24 locking the impeller to the shaft,
5 an output nozzle for discharging the water from the pump
housing bottom-85,
a strainer, to the pump housing bottom-25 at lower level to
prevent entry of dirt / any other solid particles, and hole made
on top of the pump housing top-15 to vent air traps as and
10 when it occurs.
the pump housing assembly placed in water in such a way that
the lower portion with the impeller and the output pipe being
submerged in water while the upper portion remains above
water level.
15 The improved evaporative cooler now comprises of
a box like, substantial cubical enclosure 31 ( Drawing 1)
a tank 27( Drawing 1), located at the lower portion of the
enclosure , which forms a watertight basin ,
a top cover 38, ( Drawing 1)
20 a solid wall front cover 33( Drawing 1) forming one of the
vertical sides of the enclosure,
the remaining three vertical sides of the enclosure being
substantially identical,
each of these three vertical sides may have large rectangular
25 openings, which in turn are fitted with pads; -35 (drawing
number 1) (cellulose pads or corrugated pads, or fibrous
material packing) substantially covering the openings,
6

a rectangular plastic frame with openings enclosing and supporting the pad,
each frame, mounted on the enclosure 31 ( Drawing 1), are detachable,
5 such that the entire frame with the pads can be removed for replacement/ service and to the access to the interior thereof,

a propeller fan or a blower-motor assembly 36 mounted centrally of the enclosure 31 towards the front opening such that air
10 delivered is from the front opening of the front cover 33,
The said assembly including a propeller fan /blower motor 1(
Drawing 2)
with a left hand taping on rear end of the shaft,
15 a flexible shaft cable 3, ( Drawing 2)
a cable socket motor end 2 ( Drawing 3) securely crimped to
motor end of the flexible shaft cable 3 , ( Drawing 2)
another cable socket pump end 4 ( Drawing 2)secured to pump
end of the flexible shaft cable 3 , ( Drawing 2) at the other end.
20 a flexible shaft casing 5( Drawing 2) with two ends , casing
socket motor end 6 ( Drawing 2)and casing socket pump end 7(
Drawing 2)
circumferentially enclosing the said assembly,
a motor bracket 8 (Drawing 2) mounted on the motor tie rods
25 10 with spring washers 11 and nuts 12,
the casing sockets at the motor end 6 connected to motor
bracket 8 with circlip 9,
7

a rubber gasket 13 fixed on motor bracket 8 from the motor 1
side,
a pump housing comprising a pump housing top 15 and a pump
housing bottom 25 mounted on the tank 27 bosses by three
5 plain washer 28 and screws 29.
three screws 26 connecting the pump housing top 15 to the
pump housing bottom 25 ,
a SS shaft -14 vertically and centrally disposed within said
pump housing top-25 ,
10 bearings placed and confined in the pump housing keep the
shaft in rotational relationship with the pump housing,
the cable socket pump end 4 slide fit (cardon joint) to the SS
shaft 14,
four screws 16 securing the casing socket pump end 7 to the
15 pump housing top-15,
the SS shaft 14 having a hole on its topside for a pin 17 to fix
within,
a locked engineering plastic bush 18 housed in the pump
housing top 15 circumferentially enclosing the SS shaft 14,
20 two hylam washers 19 and a e-clip 20 fitted with the SS shaft-14
on top side of the engineering plastic bush 18,
an insert molded metal bush-21 positioned at the lower end of
the pump housing top 15 ,
one hylam washer 19, an e-clip 20 and a rubber seal 22 fitted on
25 the lower end of the SS shaft 14 below the insert molded metal
bush-21, an impeller 23 secured on SS shaft 14 by a split pin
8

24, the exit from the pump housing bottom being connected to humidity control valve 30 to control the water delivery. The rubber cap -34 placed on the flexible shaft casing-5 covers the casing socket pump end-7 in the end-assembly ensuring that
5 no water / moisture enters the bearing housing.
Now the invention will be described with the following non-limiting figures.
BRIEF DESCRIPTION OF DRAWINGS:

Drawing no 1: shows the configuration of the standard existing
10 evaporative cooler,
Drawing no 2: shows the configuration of the invention on the evaporative cooler.
DETAILED DESCRIPTION OF THE INVENTIONS:
15 Referring to Drawing no 2
A water pump drive mechanism for an evaporative cooler, which includes
Propeller fan /blower motor 1 with a left hand taping on rear end of the shaft to hold Cable socket motor end-2
20 which is securely crimped to the flexible shaft cable 3 .
The other end is secured to Cable socket pump end 4. This assembly is circumferentially enclosed by the flexible shaft casing 5 with two ends namely Casing socket motor end 6 and Casing socket pump end 7.
9

· The Casing sockets motor end 6 is connected to motor
bracket 8 with a circlip 9. The motor bracket 8 is mounted
on motor tie rods 10 with spring washers 11 and nuts 12.
· A rubber gasket 13 is fixed on motor bracket 8 on the
5 motor 1 side.
· The cable socket pump end 4 is slide fit (cardon joint) to
the SS shaftl4 while the casing socket pump end 7 is
secured to the pump housing top 5 by four screws 16.
· The SS shaft 14 has a hole on its topside where a pin 17
10 is fixed.
· The pump housing top 15 houses a locked engineering
plastic bush 18 circumferentially enclosing the SS shaft
14.
· The SS Shaft 14 is fitted with two hylam washers 19 and
15 an e-clip 20 towards top side of the engineering plastic
bush 18.
· The pump housing top 15 has an insert molded metal
bush-21 positioned towards its lower end.
· The SS Shaft 14 is fitted with one hylam washer 19, an e-
20 clip 20 and a rubber seal 22 on its lower end below the
metal bush 21.
· An Impeller 23 is secured on SS shaft 14 by split pin 24.
· Pump housing top 15 is connected to the pump housing
bottom 25 by three screws 26.
25 · The pump housing bottom 25 is mounted on the tank 27
bosses by three Plain washer 28 and Screws 29.
10

• The exit from the pump housing bottom 25 is connected
to humidity control valve 30 to control the water delivery.
The rubber cap -34 placed on the flexible shaft casing-5 covers the casing socket pump end-7 in the end-assembly ensuring that
5 no water / moisture enters the bearing housing.
Working Principle:
Referring to drawing no 2 as shown, a representative evaporative
cooler, which forms an operating environment for a water pump
10 drive mechanism embodying the principle of present invention, the following is being submitted.
The evaporative cooler includes a box like, substantial cubical enclosure indicated generally by 31 and constructed largely of plastic material or steel metal material. The enclosure has at its
15 lower portion, a tank 27, which forms a watertight basin. A top cover 32. A solid wall front cover 33 of plastic or sheet material forms one of the vertical sides of the enclosure. The remaining three vertical sides of the enclosure are substantially identical, each of these three vertical sides may have large rectangular
20 openings, which in turn are fitted with pads; -35 (drawing number 1) (cellulose pads or corrugated pads, or fibrous material packing) substantially covering the openings, Bach pad peripherally is enclosed and supported by a rectangular plastic frame-39 fitted with its respective opening.
25 Each frame-39 is detachable, so that the entire pad can be removed for replacement / service and to provide access to the interior thereof.
11

A propeller fan / blower-motor assembly 36 is mounted centrally of the enclosure 31 towards the front opening such that air delivered is from the opening of the front cover 33, The motor shaft of
5 the propeller fan / blower motor assembly generally is such that it is horizontal to the ground surface and perpendicular to the water pump shaft of the present invention.

This invention replaces existing separate motor driven pump by
10 a water pump coupled to the drive source (propeller fan / blower motor assembly 36 by flexible shaft drive. When the propeller fan or blower motor assembly 36 is operated, the flexible shaft rotates in unision with the rotation of the motor shaft of the propeller fan / blower-motor assembly 36. Since the general
15 direction of the rotation of the fan or a blower motor assembly 36 when seen from front is counter clockwise, a left hand tapping ensures that the flexible shaft cable socket motor end 2 is always engaged and screwed in.
20 The flexible shaft cable 3 is made up of small diameter wires, wound over each other in alternate opposing directions with outer layer wound in direction such that the outer layer winding tightens when in rotation. The flexible shaft rotates at the same speed as that of the source (propeller fan or a blower motor
25 assembly 36) speed.
12

The Casing socket motor end 6 is connected to the motor bracket 8 through circlip 9 and is mounted to motor tie rods 10 using spring washer 11 and nut 12. This arrangement maintains proper fitment of the flexible shaft casing 5 with respect to the
5 flexible shaft cable-3 and avoids formation of cable radius right at the fan or a blower motor assembly 36 end. A rubber gasket 13 is provided to avoid any ingress of water into the motor side.

The flexible shaft casing 5 through its outer tube, guides the
10 flexible shaft cable 3, The flexible shaft casing 5 has spring steel
wires wound which rub against flexible shaft cable 3 wires at
points where their paths match. The material properties of these
wires are such that they can withstand the rotational speed of
appropriate rpm of the flexible shaft cable 3.
15 The other end of the flexible shaft casing 5 is connected to
casing socket pump end 7. The flange of this is mounted by four
screws 16 to the pump housing top 15.

The flexible shaft cable 3 has cable socket pump end 4, which
20 has slots 2 nos and is fit to SS shaft 14 by cardon joint. This joint makes sure that the axial movement of the flexible shaft cable 3 is allowed and at the same time maintains the rotational motion transfer to the SS shaft 14. The rotational motion transfer is due to placement of the pin 17 in the SS shaft 14 on
25 topside.
13

The SS shaft 14, thus rotates at the same speed of that of the flexible shaft cable 3. In order to maintain the axis of the SS shaft 14, it is guided through an engineering plastics bush 18 on top side and metal bush 21 on bottom side of pump housing
5 top-15. The vertical movement of the SS shaft-14 is arrested by the e-clip 20, placed at top as well as bottom of the SS shaft 14 above and below engineering plastic bush 18 and metal bush 21 respectively. The engineering plastics bush 18 and metal bush 21 are placed in the pump-housing top 15 with their all
10 movements locked. At lower side of the SS shaft 14, a rubber seal 22 is provided to avoid any water ingress towards the metal bush. 21. The Pump housing top 15 has its upper portion above water while lower end below water. Impeller 23 is joined to the lower end of the SS shaft 14 by split
15 pin 24. The pump housing top 15 is connected to the pump housing bottom 25 by 3 screws 26. This combined assembly encloses impeller 23. This volume of the assembly is below water. When the fan or a blower motor assembly 36 is operated, the rotational motion gets transferred to impeller 23. When the
20 impeller 23 rotates, the water is forced to move in circular motion. Along tangent to the pump housing bottom 25 is the outlet, which is connected to the humidity control valve 30. The water is forced through outlet to humidity control valve 30, which distributes and controls water going towards the top
25 cover 32.
14

The rubber cap -34 placed on the flexible shaft casing-5 covers the casing socket pump end-7 in the end-assembly ensuring that no water / moisture enters the bearing housing.
5 In this system since the invention is connected to the fan or a blower motor assembly 36, its operation is always in unison with the operation of fan or a blower motor assembly 36.
The pump housing bottom 25 is mounted on tank 27 on three
10 bosses such that gap of approximately 1.5 to 2 mm is maintained below its lower portion and tank 27 base surface. The periphery of the pump housing bottom 25 is provided with fine slits. The water enters the pump through these slits. This small size entry points make sure that no sediments of large size
15 enter the pump which may otherwise clog the pump.
At the base surface of the pump housing bottom 25, a secondary strainer is provided again to filter out similar sediments, Thus it is made sure that the water entering the pump is dirt free. A hole made on the top surface of the pump housing topl5 makes
20 sure that no air is trapped in the pump leading to lowering the water delivery and loss of energy. This feature also makes sure that the lowest water level in tank 27 whilst in use is maintained minimum. The mounting of the pump can be alternatively made such that
25 there is good radius of the flexible shaft casing 5 and cable 3.
15

The raw materials used for the invention are such that they are non corrodible and are durable so as to sustain long service hours in humid and dirty environments. Since this unit drives the water pump from propeller fan / blower motor assembly 36,
5 the expense of providing the additional electric motor in each cooler is avoided. Once installed, the unit requires no attention, except for occasional cleaning which is facilitated by the detachable back cover.
10 While the present invention has been described and illustrated in terms of certain specific embodiments, those of ordinary skill in the art will understand and appreciate that it is not so limited. Additions to, deletions from and modifications to these specific embodiments may be effected without departing from
15 the scope of the invention as defined by the claims.
16

Claims:
Having described the invention, we claim following as new and desire to secure patent for
5 1. A flexible shaft driven water pump for use in combination
with an evaporative cooler with propeller fan / blower
comprising:
a pump housing assembly (consisting of pump housing top and
bottom) ,
10 a pump shaft vertically and centrally disposed within said pump
housing assembly,
bearings placed and confined in the pump housing assembly
keep the shaft in rotational relationship with the pump housing,
a flexible shaft connected by slide and rotate type joint to one
15 end of the SS shaft ,
an impeller mounted on the other end of the SS shaft,
a split pin locking the impeller to the shaft,
an output pipe for discharging the water from the pump
housing,
20 a strainer provided to the pump casing at lower level to enable
clean water entry and hole made on top of the housing top to
ensure no air trap occurs,
the pump housing placed in water in such a way that the lower
portion with the impeller and the output pipe being submerged
25 in water while the upper portion remains above water level.
2. An improved evaporative cooler comprising
17

a box like, substantial cubical enclosure 31
a tank 27 defined at a lower portion of the enclosure , which
forms a watertight basin ,
a top cover 32,
5 a solid wall front cover 33 forming one of the vertical sides of
the enclosure,
the remaining three vertical sides of the enclosure being
substantially identical,
each of these three vertical sides may have large rectangular
10 openings, which in turn are fitted with pads; -35 (drawing
number 1) (cellulose pads or corrugated pads, or fibrous
material packing) substantially covering the openings,
a rectangular plastic frame-39 fitted with the respective
openings enclosing and supporting the pad,
15 each frame being detachably mounted on the enclosure 31 so
that the entire pad can be removed for replacement and to the
access to the interior thereof,

a fan or a blower-motor assembly 36 mounted centrally of the
20 enclosure 31 towards the front opening such that air delivered is
from the front opening of the front cover 33,
said assembly including a fan /blower motor 1 with a left hand
taping on rear end of the shaft,
a flexible shaft cable 3,
25 a cable socketmotor end 2 securely crimped to motor end of the
flexible shaft cable 3 ,
18

another cable socket pump end 4 secured to pump end of the flexible shaft cable 3 ,
a flexible shaft casing 5 with two ends , casing socket motor end 6 and casing socket pump end 7 circumferentially enclosing
5 the said assembly,
a motor bracket 8 mounted on motor tie rods 10 with spring washers 11 and nuts 12,
the casing sockets motor end 6 connected to motor bracket 8
with circlip 9 ,
10 a rubber gasket 13 fixed on motor bracket 8 from the motor 1 side,
a pump housing comprising a top 15 and a bottom 25 mounted
on the tank 27 bosses by three plain washer 28 and screws 29.
15 three screws 26 connecting the pump housing top 15 to the
pump housing bottom 25 ,
a SS shaft-14 vertically and centrally disposed within said
pump housing,
bearings placed and confined in the pump housing keep the SS
20 shaft-14 in rotational relationship with the pump housing top-
15,
the cable socket pump end -4 slide fit (cordon joint) to the SS
shaft 14 ,
four screws 16 securing the casing socket pump end 7 to the
25 pump housing top-15,
the SS shaft 14 having a hole on its topside for a pin 17 to fix
within,
19

a locked engineering plastic bush 18 housed in the pump housing top 15 circumferentially enclosing the SS shaft 14, two hylam washers 19 and a e-clip 20 fitted with the shaft on top side of the engineering plastic bush 18,
5 an insert molded metals bush-21 positioned towards the lower end of the pump housing top 15 ,
one hylam washer 19, an e-clip SO and a rubber seal 22 fitted on the lower end of the SS shaft 14 below the metal bush 21, an impeller 23 secured on SS shaft 14 by a split pin 24, the exit
10 from the pump housing bottom-25 being connected to humidifier system 30 to control the water delivery. The rubber cap -34 placed on the flexible shaft casing-5 covers the casing socket pump end-7 in the end-assembly ensuring that no water / moisture enters the bearing housing.
15
3. An improved evaporative cooler as claimed in claim 2,where
in there are arrangement for transmitting rotating motion from
drive source to flexible shaft and then to the water pump shaft
so as to enable the system to rotate in desired manner when the
20 drive source is operational.
4. An improved evaporative cooler as claimed in claim 2,where
in means of connecting and transmitting motion between two
rotating elements placed in substantially orthogonal positions or
25 placed at less acute and obtuse angles and supporting these elements in the housing so as to enable them function in desired way.
20

10

5. An improved evaporative cooler substantially described as
here in with reference to the example and the accompanying
drawings.

6. The reduced cost of the product with respect to the separate
pump for both manufacturing / development and during
operation thereby reducing the raw material being used in
separate pump
7. In combination to claim no 6, the reduction in power
consumption offered by invention.

Dated this 8th day of February 2007

15

21

ABSTRACT OF THE INVENTION :
An invention relating to a flexible shaft driven water pump for
use in combination with an evaporative cooler with propeller fan
5 / blower comprising:
a pump housing assembly (consisting of pump housing top and
bottom) ,
a pump shaft vertically and centrally disposed within said pump
housing assembly,
10 bearings placed and confined in the pump housing assembly
keep the shaft in rotational relationship with the pump housing,
a flexible shaft connected by slide and rotate type joint to one
end of the SS shaft ,
an impeller mounted on the other end of the SS shaft,
15 a split pin locking the impeller to the shaft,
an output pipe for discharging the water from the pump
housing,
a strainer provided to the pump casing at lower level to enable
clean water entry and hole made on top of the housing top to
20 ensure no air trap occurs,
the pump housing placed in water in such a way that the lower
portion with the impeller and the output pipe being submerged
in water while the upper portion remains above water level.
25 Dated this 8th day of February 2007.

22