FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A revolving grill fan assembly
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTORS
Sathe Mahesh of Crompton Greaves Ltd, Industrial Design Center, Global R&D Centre, Crompton Greaves Ltd. Kanjurmarg (East) Mumbai, Maharashtra, India; all Indian Nationals
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 Specification:
This invention relates to the field of air circulators.
Particularly, this invention relates to revolving grills for air circulators.
Background of the Invention:
Fans consist of blades, which cut through the air. Typically, table fans have blades caged in a grill. This grill is mainly for protection purposes from the fast revolving blades.
Most fans also employ a single grill / cage assembly with an operative posterior side grill connected to an operative anterior side grill and fan blades interspersed there between.
Advancements in fans led to box type fans wherein a box comprising embedded grill and fan blades in the box were provided. For further wind supply, the grill was made to revolve with a second revolving speed in relation to the first revolving speed of the fan blades. Both the fan blades and the grill were mounted on a single shaft in these assemblies.
A limitation of these fan assemblies was that its air supply was limited to the direction in which the box was placed. Normally, such box type fans are not mounted on a base stand, thus not providing for oscillations with respect to base.

There was a need to have an oscillating fan with revolving grill with increased air throw in any direction of its oscillation.
Prior Art:
JP59185893, JP58113597, US 4,365,930, US20100003126 disclose some fan assemblies with revolving grills, either in a box or without a box.
Fans inside protective housings / grills / cages / louvers / guards are known. Some of these (above-mentioned) fans are box type fans wherein the front grill revolves around the same axis as the fan. Each of the above prior art patents / patent applications disclose such fan assemblies. However, the mechanism for each of these revolving / rotating grills does not provide a good air throw, in a defined environment. Also, alignment in each of these assemblies disclose a shaft based alignment. There is not shaft-less, alignment-free revolving grill assembly.
Double oscillating mechanism base fans produce more air cutting noise. When compared with smaller fan cage mechanisms, the revolving mechanism which is normally shaft mounted and hence requires fan's most important feature of balanced blades by perfect annular movement of louver or cage but fails to communicate the same due to backward plays normally present and unavoidable.

Objects of the Invention:
An object of this invention is to provide a air circulator with revolving grill without a box assembly.
Another object of the invention is to provide an oscillating, revolving grill air circulator.
Yet another object of the invention is to provide zero backward play of air through an air circulator.
Still another object of the invention is to provide a shaftless revolving grill for an air circulator.
An additional object of this invention is to provide a well balanced air circulator.
Yet an additional object of this invention is to provide a revolving grill mechanism for an air circulator which shall produce less air cutting noise.
Summary of the Invention:
According to this invention, there is provided a revolving grill fan assembly adapted to provide air throw in directions not restricted by its grill assembly, said revolving grill fan assembly comprising:
a. an operative circular posterior grill, having a first circular rim, adapted to form a part of a housing for said fan assembly;

b. a first annular ring adapted to be fitted onto said first circular rim of
said circular posterior grill and having an operative outer sliding channel
assembly;
c. a second annular ring adapted to be fitted with a plurality of ball
bearings along an annular molded race of said annular ring;
d. an operative circular anterior grill, having a second circular rim;
e. a third annular ring adapted to be fitted onto said second circular rim
of said circular anterior grill and having an operative inner sliding channel
assembly;
f. fan blades between said operative circular posterior grill and said
operative anterior grill;
characterized in that, said inner sliding channel assembly and said outer sliding channel assembly couple together to define a full box (sliding) channel for receiving said plurality of ball bearings fitted in said race such that said ball bearings provide for movement in said defined box (sliding) channel in order to facilitate revolution of said operative circular anterior grill with respect to said operative circular posterior grill to provide a revolving grill fan assembly.
Typically, said operative posterior grill includes radial ribs.
Typically, said operative anterior grill includes radial ribs.
Typically, said operative anterior grill includes angularly tilted radial ribs.
Typically, said first circular rim includes semicircular wire adapted to be fitted between said operative outer sliding channel assembly.

Typically, said second circular rim includes semicircular wire adapted to be fitted between said operative inner sliding channel assembly.
Typically, said ball bearings are annularly located interspaced throughout said second annular ring.
Typically, said sets of ball bearings are located at pre-defined intervals along said second annular ring.
Typically, said assembly includes an axial shaft extending from said operative circular posterior grill for providing axial support to fan blades located between said operative circular posterior grill and said operative circular anterior grill.
Typically, said assembly includes a base shaft to provide oscillation of said assembly with respect to the ground.
Typically, said assembly includes a base stand adapted to support a base shaft for providing oscillating motion to said assembly, with respect to the ground.
Brief Description of the Accompanying Drawings:
Figure 1 illustrates a schematic of the prior art fan assembly.

The invention will now be described in relation to the accompanying drawings, in which:
Figure 2 illustrates a schematic of the fan assembly along with its revolving grill mechanism;
Figure 3 illustrates an exploded view of the revolving grill mechanism of the assembly of Figure 2; and
Figure 4 illustrates a close-up view of the revolving mechanism of the revolving grill assembly of the assembly of Figure 3.
Detailed Description of the Accompanying Drawings:
Figure 1 illustrates a schematic of the prior art fan assembly. According to the prior art fan assembly, a revolving grill assembly is not possible since an operatively anterior grill is coupled with an operatively posterior grill by means of a single wire. This means renders the revolution of anterior grill impossible with reference to posterior grill.
Figure 2 illustrates a schematic of the fan assembly along with its revolving grill mechanism;
Figure 3 illustrates an exploded view of the revolving grill mechanism;
Figure 4 illustrates a close-up view of the revolving mechanism of the revolving grill assembly of the assembly of Figure 3.

According to this invention, there is provided a fan assembly with a revolving grill (200). In one embodiment, said fan assembly with revolving grill is mounted on an oscillating base.
In accordance with an embodiment of this invention, there is provided an operative circular posterior grill (270), having a first circular rim, adapted to form a part of a housing for said fan assembly. The grill, typically, includes radially dispersed ribs for protection purposes.
In accordance with another embodiment of this invention, there is provided a first annular ring (210) adapted to be fitted onto said first circular rim of said circular posterior grill and having an operative outer sliding channel assembly. The outer sliding channel assembly forms one half of a full box (sliding) channel which will provide the channel for revolution of front grill.
In accordance with yet another embodiment of this invention, there is provided a second annular ring (230) adapted to be fitted with a plurality of ball bearings along an annular molded race (240) of said annular ring.
In accordance with still another embodiment of this invention, there is provided an operative circular anterior grill (280), having a second circular rim. This is the revolving grill which revolves in the formed channel with the help of ball bearings in race.
Typically, the operative circular anterior grill includes radially dispersed ribs which are angularly tilted, instead of being perpendicular to the plane of the

grill. This angular tilt helps in revolution of the grill when air from the fan blades, inside the grill, hit the angularly tilted blades.
In accordance with an additional embodiment of this invention, there is provided a third annular ring (220) adapted to be fitted onto said second circular rim of said circular anterior grill and having an operative inner sliding channel assembly. The inner sliding channel assembly forms the other half of a full box (sliding) channel which will provide the channel for revolution of front grill.
In accordance with yet an additional embodiment of this invention, there is provided fan blades (290) between said operative circular posterior grill and said operative anterior grill, which provide the air flow.
The inner sliding channel assembly and said outer sliding channel assembly couple together to define a full box (sliding) channel for receiving said plurality of ball bearings fitted in said race such that said ball bearings provide for movement in said defined box (sliding) channel in order to facilitate revolution of said operative circular anterior grill with respect to said operative circular posterior grill to provide a revolving grill fan assembly.
Typically, the fan with grill which is not ensconced in a box may be mounted on a base stand and a base shaft for oscillating purposes. The grill thus oscillated about the base stand for providing a wider range of air dispersion.

Due to this assembly of this invention, the grill allows use of a perfect cylindrical grill to compete with axial flow fans and prevents the grill from getting damaged due to wrong placement of fan (i.e. too close to wall) during oscillations or even during transit of fan from one location to another.
There is zero backward play due to proper balancing and alignment. This makes the cage relatively more silent compared to the prior art's moving louver construction as with revolving slide extra dampening component is added in the grill system.
In accordance with still an additional embodiment of this invention, semicircular wires (250, 260) are provided for joining the ribs to the annular rings for support.

We claim:
1. A revolving grill fan assembly adapted to provide air throw in directions not restricted by its grill assembly, said revolving grill fan assembly comprising:
a. an operative circular posterior grill, having a first circular rim, adapted
to form a part of a housing for said fan assembly;
b. a first annular ring adapted to be fitted onto said first circular rim of
said circular posterior grill and having an operative outer sliding
channel assembly;
c. a second annular ring adapted to be fitted with a plurality of ball
bearings along an annular molded race of said annular ring;
d. an operative circular anterior grill, having a second circular rim;
e. a third annular ring adapted to be fitted onto said second circular rim
of said circular anterior grill and having an operative inner sliding
channel assembly; and
f fan blades between said operative circular posterior grill and said
operative anterior grill; characterized in that, said inner sliding channel assembly and said outer sliding channel assembly couple together to define a full box (sliding) channel for receiving said plurality of ball bearings fitted in said race such that said ball bearings provide for movement in said defined box (sliding) channel m older to facilitate revolution of said operative circular anterior grill with respect to said operative circular posterior grill to provide a revolving grill fan assembly.

2. An assembly as claimed in claim 1 wherein, said operative posterior grill includes radial ribs.
3. An assembly as claimed in claim 1 wherein, said operative anterior grill includes radial ribs.
4. An assembly as claimed in claim 1 wherein, said operative anterior grill includes angularly tilted radial ribs.
5. An assembly as claimed in claim 1 wherein, said first circular rim includes semicircular wire adapted to be fitted between said operative outer sliding channel assembly.
6. An assembly as claimed in claim 1 wherein, said second circular rim includes semicircular wire adapted to be fitted between said operative inner sliding channel assembly.
7. An assembly as claimed in claim 1 wherein, said ball bearings are annularly located interspaced throughout said second annular ring.
8. An assembly as claimed in claim 1 wherein, said sets of ball bearings are located at pre-defined intervals along said second annular ring.
9. An assembly as claimed in claim 1 wherein, said assembly includes an axial shaft extending from said operative circular posterior grill for providing axial support to fan blades located between said operative circular posterior grill and said operative circular anterior grill.

10.An assembly as claimed in claim 1 wherein, said assembly includes a base shaft to provide oscillation of said assembly with respect to the ground.
11.An assembly as claimed in claim 1 wherein, said assembly includes a base stand adapted to support a base shaft for providing oscillating motion to said assembly, with respect to the ground.