FORM 2
THE PATENTS ACT, 1970
(39 Of 1970)
As amended by the Patents (Amendment (Act,2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A fixture for assembling a ceiling fan motor
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli Mumbai 400 030 Maharashtra, India, an Indian Company
INVENTORS
Greaves Limited, Goa, Maharashtra, India, both Indian nationals
Jadhav Paresh and Shinde Murar, both of Fans & Appliances Division, Crompton
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION
The invention relates to a fixture for assembling a ceiling fan motor.
PRIOR ART DESCRIPTION
A ceiling fan motor comprises a bottom end shield and a top end shield assembled together to form the housing of the motor. Both the bottom end shield and top end shield are provided with a plurality of pairs of mounting holes each pair comprising a hole formed in the bottom end shield and a corresponding hole formed in the top end shield. The bottom and the top end shields are assembled together by tightening bolts in the pairs of mounting holes.The top and short and bottom and shield are assembled together manually by holding the end shields in position and tightening the bolts in the mounting holes. While tightening a bolt in a pair of mounting holes, misalignment invariably occurs between the end shields and the other pairs of mounting holes. As a result hammering may be invariably required to align the pairs 0f mounting holes. Because of misalignment between the bottom end shield and top end shield, there will be misalignment between the stator and rotor of the motor located within the housing. As a result, the operation of the motor becomes noisy and it may even cause jamming of the motor and lead to rejection. Misalignment will require it networking of the motor and will also cause wear and tear to the stator and rotor. Manual assembly of the motor leads to operator fatigue. Also assembly time is increased and Productivity is reduced. During manual assembly, accidents can also happen to the operator for instance, due to slippage.

OBJECTS OF THE INVENTION
An object of the invention is to provide a fixture for assembling a ceiling fan motor, which fixture holds both the bottom end shield and top end shield firmly in position and keeps the pairs of mounting holes in the bottom end shield and top end shield aligned during the entire assembly and facilitates easy assembly of the bottom and top end shields within reduced time.
Another object of the invention is to provide a fixture for assembling a ceiling fan motor, which fixture reduces the operator fatigue and increases productivity.
Another object of the invention is to provide a fixture for assembling a ceiling fan motor, which fixture avoids the necessity of hammering of the top end shield and reworking of the motor and eliminate rejection.
Another object of the invention is to provide a fixture for assembling a ceiling fan motor, which fixture ensures proper alignment of the rotor and stator of the motor to give noise free operation of the motor, reduces wear and tear to the motor and prevents jamming of the motor.


Another object of the invention is to provide a fixture for assembling a ceiling fan motor, which fixture imparts safety to the operator and prevents accidents.
According to the invention there is provided a fixture for assembling a ceiling fan motor, the fixture comprising a table, a bottom end shield locator means rotatably mounted on the table and a top end shield pressing and holding means disposed above the bottom end shield locator means and up and down movably and rotatably supported on the table.
According to the invention there is also provided a method for assembling a ceiling motor, wherein the bottom end shield and top end shield of the motor are mechanically tightly held together with the pairs of mounting holes in the bottom end shield and top end shield perfectly aligned during tightening of bolts in the pair of mounting holes. -
According to an embodiment of the method of the invention, the bottom end shield and top end shield are rotatably mechanically tightly held together.
The following is a detailed description of the invention with reference to the accompanying drawings, in which:
Fig 1 is an isometric view of the fixture for assembling a ceiling fan motor including the top and bottom end shields of a ceiling fan motor according to an embodiment of the invention;

Fig 2 is a partial crosssectional view of the fixture of Fig1 including the bottom and top end shields of a ceiling fan motor; and
Figs 3 and 4 are schematic views of the pneumatic cylinder and pneumatic control valve of the fixture of Fig 1 with the piston of the cylinder at the bottom dead center and top dead center thereof, respectively.
The fixture 1 as illustrated in Figs 1 to 4 of the accompanying drawings comprises a table 2 whose legs and top are marked 3 and 4 respectively.5 is a recessed body formed with a recess 6 corresponding to the bottom end shield 7 of a ceiling fan motor. The recessed duty is rotatably supported or air oprigh shaft 8 using dearing 9.The bearing 9 is held in position by plate 10 fitted at the bottom of the recessed body by screws 11. Shaft 8 is held in a base plate 12 against collar 13 on the shaft. The base plate is mounted on the top of the table with the help of spaced ribs 14 surrounding the base plate. The recessed body is preferably made of nylon or teflon so as to Provide a smooth surface to the bottom end shield. At the same time, the nylon or teflon made recessed body is also mechanically strong enough to support the bottom end shield besides being durable. The shaft and base plate are preferably made of stainless steel to provide a clean work area and at the same time stainless steel is also mechanically strong and durable. 15 is pneumatic cylinder supported on a C-shaped bracket 16 fixed on the top of the table. The pneumatic cylinder is positioned above the recessed body and is connected to a pneumatic supply (not shown) via a 4-port, 2 position solenoid operated control valve 17. The solenoids of the control valve are marked 18a and 18b. The ports of the valve are


marked a, b, c and d . The control valve is connected to a power supply (not shown) through an operating circuit comprising a timer 19 and two switch on switches 20a and 20b and a switch off switch 21. 22 is a hollow conical member rotatably held at the distal end of the piston rod 23 of the pneumatic cylinder 15 using bearing 24 located in a closed end 22a of the conical member. The bearing 24 is held in position with a holding plate 25 screwed onto the closed end of the conical member 22 with screws 26. 27 is a sleeve fitted over the distal end of the piston rod 23 in thread engagement therewith. Collar 28 on the sleeve 27 is disposed in close tolerance with plate 25. 29 is a screw fitted at the distal end of the piston rod 23 in thread engagement therewith. Head 29a of the screw 29 is in close tolerance with the closed end of the conical member 22. Collar 28 and screw head 29a allow the corneal member to rotate between them about the distal end of the piston rod 23 but at the same time prevent the conical member from slipping out of the distal end of the piston rod. 30 is a through slot or groove provided across the distal end of the piston rod for engaging a thin rod or the like (not shown) for rotating the piston rod and assembling the sleeve 27 onto the piston rod. The conical member is preferably made of nylon or teflon to give a smooth engagement surface against the top end shield 31 of the ceiling fan motor. At the same time the nylon or teflon made conical member is mechanically strong and hard and is also durable. 32 is a safety guard mounted on the table enclosing the three sides thereof. The open side of the safety guard provides access to the bottom end shield locator means namely the recessed body. The table and the guard are preferably made of stainless steel, 33 is a pneumatically operated screw driver suspended from a spring balancer 34 with the help of string 35. The screw driver tip is marked 33a. The spring balancer is supported on the C-shaped bracket. 36 is


a connector line connecting the screw driver to a compressed air supply (not shown). 37 and 38 are connector lines connecting the control valve to the cylinder side and piston side of the pneumatic cylinder. 39 is the piston of the pneumatic cylinder and 40 is the motor shaft.
Using the fixture of the invention, the bottom end shield 7 and top end shield 31 of the ceiling fan motor are assembled together by first locating the bottom end shield in the recess 6 of the recessed body 5. The top end shield is located on the bottom end shield with the pairs of mounting holes (not shown) in the bottom and top end shields aligned. Both the switch on switches 20a and 20b are simultaneously pressed by both the hands of the operator. On holding the switch on switches pressed for a predetermined period of time, the timer 19 activates the pneumatic control valve 17. Air flows into the cylinder side of the pneumatic cylinder 15 via ports a and b and air at the piston side of the pneumatic cylinder exits via ports c and d. The piston 39 moves down in the cylinder to the bottom dead center (Fig 3) along with the conical member 22 and the conical member presses and holds the top end shield against the bottom end shield in position (Fig 2). The pneumatically operated screw driver 33 is pulled down against spring tension of the spring balancer 34 and switched on. Compressed air enters the screw driver and rotates the screw driver in one direction. Bolt (not shown) is engaged in one pair of mounting holes in the bottom and top end shields and tightened in the said one pair of mounting holes with the screw driver. On tightening the bolt in the said one pair of mounting holes, the screw driver is switched off. Air in the screw driver exists from the screw driver and rotates the screw driver in the opposite direction to its original direction. The


bottom recessed member with the bottom end shield and top end shield tightly held by the conical member is rotated by certain angle and another bolt is tightened in the said next pair of mounting holes in the bottom and top end shields as described earlier. Similarly subsequent pairs of mounting holes are tightened with bolts. On completion of assembly of the bottom and top end shields, the control valve is operated to connect ports c and d to exit air from the cylinder side of the pneumatic cylinder and to connect ports a and b to allow air to flow into the piston side of the pneumatic cylinder. As a result the piston rod moves up in the pneumatic cylinder to the top dead center (Fig 4) along with the conical member and disengages from the top end shield (Fig 1). Power supply to the control valve is switched off by switching off the switch 21. After this the assembled bottom and tope end shields of the motor is removed from the recessed body.
According to the invention both the bottom end shield and top end shield are tightly held together in the fixture with the pairs of mounting holes perfectly aligned during the entire assembly time. Manual holding of the endshields has been eliminated and misalignment of the mounting holes has been prevented. There is no need for hammering the top end shield to align the mounting holes. As misalignment of the mounting holes is avoided, there is perfect alignment between the stator and rotor of the motor. As a result noise generation during operation of the motor is eliminated. Jamming of the motor and reworking of the motor are also avoided. Wear and tear to the stator and rotor is reduced. Assembly time is reduced, operator fatigue is reduced and productivity is increased. Because both the switch on switches are to be held pressed by both the hands during switching on of the fixture, accidents due to one hand being elsewhere during switching


on of the fixture are avoided. Accidents due to holding both the bottom end shield and top end shield during tightening of the bolts are also avoided. The fixture thus also imparts safety to the operator.
The safety guard is optional. The fixture can work without the safety guard. However, the safety guard imparts added safety to the fixture. The pneumatically operated screw driver is also optional. The fixture can still give the benefits as explained above without the pneumatically operated screw driver. However, the pneumatically operated screw driver renders bolt tightening easy and convenient. It also reduces bolt tightening time. The bottom end shield locator means and top end shield pressing and holding means can be of different configuration and construction. The invention is in essentially in mechanically holding both the bottom end shield and top end shield with the mounting holes aligned during the entire assembly time. The recessed body need not be made of nylon or teflon. Nylon or teflon provides a smooth holding surface and is also at a same time mechanically strong and rigid, besides being durable. It is also easy and convenient to clean and maintain it. However, the recessed body can be made of any other mechanically strong and durable material. The recessed body can be rotatably held in a different manner. The shaft and base plate need not be made of stainless steel. They can also be made of any other mechanically strong and durable and easy to clean and easy to maintain material. The top end shield pressing and holding means can be a screw and nut arrangement. The conical member need not be made of nylon or teflon. Nylon or teflon made conical member provides a smooth surface to hold the top end shield without damaging it. It is also durable and easy and convenient to clean and maintain. However,


the conical member can also be made of any other material which is durable, easy and convenient to clean and maintain. The conical member can be rotatably held at the distal end of the piston rod differently. The table and guard need not be made of stainless steel. They can also be made of any other material which is mechanically strong and durable and easy to clean and maintain. Instead of table, there can be an elevated surface. The recessed body and conical member need not be rotatable in which case also the invention will have all the advantages as described above. In case the recessed body and conical member are not rotatable, the operator will have to go around the bottom end shield and tope end shield assembly to tighten the bolts and thus may cause little inconvenience to the operator as compared to the rotatable recessed member and conical member which will facilitate rotation of the entire bottom end shield and tope end shield assembly towards the operator so as to enable the operator to remain at the same location. The mounting bracket 16 need not be C-shaped. The top end shield pressing and holding means and the screw driver can be supported on the table by a different arrangement. Such variations of the invention are to be construed and understood to be obvious to those skilled in the art and within the scope of the invention. It is also be understood that the fixture can be used for assembling any motor or article similar in construction to the ceiling fan motor.


We claim:
1. A fixture for assembling a ceiling fan motor, the fixture comprising a table, a bottom end shield locator means rotatably mounted on the table and a top end shield pressing and holding means disposed above the bottom end shield locator means and up and down movably and rotatably supported on the table.
2. The fixture as claimed in claim 1, wherein the bottom end shield locator means comprises a recessed body formed with a recess corresponding to the bottom end shield and rotatably mounted on the table.
3. The fixture as claimed in claim 2, wherein the recessed body is made of nylon or teflon.
4. The fixture as claimed in claim 2 or 3, wherein the recessed body is rotatably supported on an upright shaft using a bearing, the upright shaft being held in a base plate mounted on the table.
5. The fixture as claimed in claim 4, wherein the shaft and base plate are made of stainless steel.
6. The fixture as claimed in any one of claims 1 to 5, wherein the top end shield pressing and holding means comprises a pneumatic cylinder supported on a C-shaped


bracket fixed on the table, the pneumatic cylinder being connected to a pneumatic supply through a 4-port, 2-position solenoid operated pneumatic control valve, the control valve being connected to a power supply through an operating circuit comprising a timer, two switch on switches and one switch off switch, the piston rod of the pneumatic having a hollow conical member rotatbly held at the distal end thereof.
7. The fixture as claimed in claim 6, wherein the hollow conical member is made of nylon or teflon and is rotatably held at the distal end of the piston rod using a bearing.
8. The fixture as claimed in any one of claims 1 to 7, which comprises a safety guard mounted on the table enclosing three sides thereof, the open side of the safety guard providing access to the bottom end shield locator means.
9. The fixture as claimed in claim 8, wherein the table and safety guard are made of stainless steel.
10. The fixture as claimed in anyone of claims 1 to 9, which comprises a pneumatically operated screw driver suspended from a spring balancer which is supported on the table.
11. A method for assembling a ceiling motor, wherein the bottom end shield and top end shield of the motor are mechanically tightly held together with the pairs of mounting


holes in the bottom end shield and top end shield perfectly aligned during tightening of bolts in the pair of mounting holes.
12. The method as claimed in claim 11, wherein the bottom end shield and top end shield are rotatably mechanically tightly held together. Dated this 23rd day of October 2008
(Prita Madan)
of Khaitan & Co
Agent for the Applicants