Field of Invention:
This invention relates to a fan, wherein the assembly of its blades are so provisioned that they can be reversed/tilted with respect to the rotor of the said fan and consequently the direction of blow of air gets reveres or changed upto certain direction. Consequently, scope of application of such fan changes, particularly with respect to the conventional fans with fixed blade assembly.
Background and object of the invention:
There are several applications of fans at domestic as well as industrial level and various kinds and dimensions of fans are designed for blowing/sucking air. A general use of fan is to blow hot air away from the hotter machine or region. Another important application of a fan is to blow fresh and ambient air into a target region or to a target position, either into an enclosure or onto a machine. Therefore, a fan plays important role in dissipating heat and renders air cooling means.
Normally a fan has fixed blade assembly and it is designed for blowing or sucking air in single direction. Towards diverting air, blown/sucked from said fan, usually certain air-deviating attachments/grills are applied in front of the fan. Towards reversing/changing the air-blow direction, it is not usually possible to replace a fan mounted at a particular position, namely an exhaust fan or a radiator fan or a fan of air-conditioner or fan of any similar device.
Therefore, the present invention is a novel effort to develop such a fan, which comprises of an assembly of reversible blades; wherein reversible/tilting function of said blades can be realized mechanically. Therefore same fan, provisioned for mounting at a particular position can be utilized for blowing air in variable directions.
Objective of the Invention:
The prime objective of the present invention is to provide a mechanically operated fan with reversible blade assembly, which is capable to rotate the direction of its blade through a mechanical actuator.
Another objective of this invention is to provide an easy design of the fan with reversible blade assembly, with respect to its easy installation and operation at a particular position.
Another object of the invention is to propose a fan with reversible blade assembly for different applications.
Another objective of the present invention is to provide a novel mechanism design which removes the complication of installation on the machines like in other products the problem is faced and results in a high cost.

Summary of the Invention:
This invention relates to a fan, wherein the assembly of its blades are so provisioned that they can be reversed/tilted with respect to the rotor of the said fan and consequently the direction of blow of air gets reveres or changed upto certain direction. Consequently scope of application of such fan changes, particularly with respect to the conventional fans with fixed blade assembly.

Brief Description of the Accompanying Drawings:
Preferred embodiments in accordance with the present invention will now be described with reference to the accompanying drawings.
Figure 1 depicts the isometric view of the proposed fan with reversible blade assembly (101) showing an assembly of components such as number of bearings (1), Dowell Pin (2), Bearing Hub (3), a Mounting Bracket (4), a Lever (5), a Fork (6), a Shifter (7), a Hub Rear Cover (8), a Hub Front Cover (9), and a Fan Blade Assembly (10) containing a number of Blades accompanied with its Studs.
Figure 2 depicts the sectional view of said fan with reversible blade assembly (101) showing an arrangement of its internal parts which are said bearings (1), said Bearing Hub (3), said Mounting Bracket (4), said Fork (6), said Shifter (7), said Hub Rear Cover (8), said Hub Front Cover (9), and said Fan Blade Assembly (10), plurality of Springs (11) and a Crank Link (12).
Description of the Invention with the help of accompanying drawings:
The following is a detailed description of exemplary embodiments to illustrate the principles of the invention. The embodiments are provided to illustrate aspects of the invention, but the invention is not limited to any embodiment. The scope of the invention encompasses numerous alternatives, modifications and equivalent; it is limited only by the claims.
Numerous specific details are set forth in the following description in order to provide a thorough understanding of the invention. However, the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the invention is not unnecessarily obscured.
List of numeric references used herewith:
Numeric symbol Particulars
101 Fan with reversible blade assembly
1 bearing
2 Dowell Pin
3 Bearing hub assembly
4 Mounting Bracket
5 Lever
6 Fork
7 Shifter
8 Hub Rear Cover
9 Hub Front Cover
10 blades
11 Springs
12 crank link

The present invention is a novel mechanically designed fan with reversible blade assembly (101) used for one or another applications, wherein blades of the blade assembly (10) are reversed by giving a mechanical actuation. Previously, a reversible fan had either pneumatic or hydraulic actuation to revert the blades direction, which makes the whole setup to cost high and complicated in installation. But in the present design of the fan with reversible blade assembly, the blades’ direction can be reversed by mechanical actuation means provisioned with the said fan assembly.
One preferred embodiment of the proposed fan with reversible blade assembly (101), basically comprises three subassemblies. Bearing hub assembly (3) containing said Hub Front Cover (9) and said Hub Rear Cover (8), said Fan Blade assembly (101) and said Mounting Bracket assembly (4) are the three sub-assemblies. Assembling these three subassemblies leads to the said fan with reversible blade assembly (101), as shown in Figure 1 and Figure 2. Said blade assembly (10) is an integral assembly of plurality of blades and its stud with the bearing (1) and crank link (12). In said fan (101) a number of blades can be utilized in the blade assembly (10), more particularly 10 blades are used herein for performing better air-blow operation. The main part of said fan assembly (101) is said Shifter (7) whose shape is polygon with number of sides 20. It requires only 14mm of axial travel to flip the blades (10) by 90 degree. Bearing hub assembly (3) containing said Hub Front Cover (9) and said Hub Rear Cover (8), said Shifter (7) and said Crank Link (12) completes the Slider-Crank mechanism of the present invention. Said Crank Link (12) is constraint to rotate because of the sliding motion of the said Shifter (7). Said Crank Link (12) has said Dowell Pin (2) of 3mm diameter, which is constrained in the groove of said shifter (7). On the end of said shifter (7) there is step turning on which said bearing (1) is mounted which is further inserted in said bearing Hub assembly (3) with a 6mm wide slot for the said Fork (6) with Dowell Pin (2). This shifter bearing is used to give the relative motion between the whole fan (101) and the bearing hub assembly (3).
For positioning said fan blade (10) in its cooling mode (or in its normal mode of the said fan), springs (11) are provided inside the bearing hub assembly (3) in a preloading condition as shown in Figure 2. The preloaded springs (11) push said shifter (7) towards the rear direction of the hub and said crank link (12) rotates to keep said blades (10) at an initial angle of 45 degree. Till said bearings (1), said fan assembly (101) has its rotating parts and thereafter the static parts are assembled, which are used to give the axial motion to said bearings (1). As shown in the Figure 1, said Fork (6) has been used to give the axial motion to said bearing hub assembly (3) which is hinged about said Mounting Bracket (4) by means of said lever (5).
A twisting motion can be provided to said lever (5) by means of any mechanical linkage and can be transmitted by the operator. When the operator will provide the actuation, it will pull said lever (5) in downward direction which will further rotate said fork (6) by some angle. Rotational motion of said fork (6) will give the translational motion to the stationary bearing hub assembly (3) in which the outer race of said bearing (1) is resting. Thus the translational motion of said bearing (1) will push said shifter (7) against the set of said springs (7) till 14 mm. This 14mm axial motion of said shifter (7) will rotate said crank link (12) of said blade assembly (10) by an angle of 90 degree approx. As said crank link (12) is directly fixed on the stub link of said blade, so said blades will also rotate by same angle of 90 degree. Thus whole blade will be reverted by the same angle simultaneously.
Due to provision of changing/reversing the air-blow direction by changing/reversing the blade assembly (10), easily by actuation through a mechanical actuation means, said fan with reversible blade assembly (101) is capable of being used domestically or in industry. Such fan with reversible blade assembly, as per the optional requirements at a particular moment, can play important role in maintaining air quality in an enclosure as a human comfort zone, such as house, office, school, hospital, theater, vehicle’s cabin, gas-chambers, work-station etc., either by expelling air from the enclosure to outside; and when required by supplying fresh air from outside into said enclosure. Said fan (10) can supply desired quality air, namely normal ambient air, in its normal condition of blade assembly (10) and whenever there is occurrence of such need for expelling out dirt and other unwanted material (for example dust, smell, smoke) from close vicinity of the mounting position of said fan (101), simply its blade assembly (10) is reversed so that the said fan (101) can expel those dirt and undesired material with the out-blowing air.
Once mounted at a particular position, said fan with reversible blade assembly (101), in normal condition of its blade assembly (10) is capable of dissipating/throwing-out heat, smell, gases, steam, dust, husk etc. with the out-blowing air; wherein in reversed condition of said blade assembly (10), said fan (101) may supply fresh air (or any desired quality air) inwardly or vice versa.
Fan with reversible blade assembly (101), being installed at a particular position, is also characterized in its application as heat exchanger-cum-air-cleaner, particularly when mounted near the radiator of a vehicle (such as truck or a tractor) or a DG-set will, wherein in normal mode said fan (101) acts as air-cooling device and by reversing the blade-assembly (10) and without altering or removing the installation of said fan (10) from its position, it is made to clean said radiator by its air-blow in reversed direction.
Although a preferred embodiment of the invention has been illustrated and described, it will at once be apparent to those skilled in the art that the invention includes advantages and features over and beyond the specific illustrated construction.

We Claim:
1. Fan with reversible blade assembly (101) and method of its operation thereof, wherein said fan assembly (101) comprises three subassemblies: namely the bearing hub assembly (3), the blade assembly (10) and said mounting bracket assembly (4); and
wherein said fan assembly (101) is characterized in mechanically tilting/ reversing the blades of the blade assembly (10) by giving a mechanical actuation through the mechanical actuation means provisioned with the said fan assembly (101) and consequently changing/reversing the direction of air-blow upto certain optionally selected direction or in reversed direction.
2. Fan with reversible blade assembly (101), as claimed in claim 1 wherein Fan blade assembly (10) is an integral assembly of plurality of blades and its stud with the bearing (1) and crank link (12).
3. Fan with reversible blade assembly (101), as claimed in claim 1 wherein bearing hub assembly (3), comprises of the Hub Front Cover (9), the Hub Rear Cover (8), the Shifter (7) and the Crank Link (12); wherein said bearing hub assembly (3) is characterized in the Slider-Crank mechanism of the said fan with reversible blade assembly (101).
4. Fan with reversible blade assembly (101), as claimed in claim 1 wherein the bearing hub assembly (3) is preferably hinged about the Mounting Bracket (4) by means of the lever (5)
5. Fan with reversible blade assembly (101), as claimed in claim 1 and 3, wherein the shifter (7) is shaped as polygon, preferably with 20 sides, and it is characterized in its requirement of only 14mm of axial travel for flipping the blade assembly (10) by 90 degree.
6. Fan with reversible blade assembly (101), as claimed in claim 1 and 3, wherein the Crank Link (12) comprises of Dowell Pin (2) of 3mm diameter, which is constrained in the groove of said shifter (7) and wherein said Crank Link (12) is constraint to rotate because of the sliding motion of the said Shifter (7); and
wherein on the end of said shifter (7) there is step turning on which the bearing (1) is mounted, which is further inserted in said bearing Hub (3) having a 6mm wide slot for the Fork (6) with Dowell Pin (2); enabling the bearing (1) to give the relative motion between the whole fan (101) and the bearing hub assembly (3).
7. Fan with reversible blade assembly (101), as claimed in claim 1, wherein actuation of blades of the blade assembly (10) through the mechanical actuation means include following major steps:
i. positioning of blades of the blade assembly (10) in its cooling mode (or in the normal mode of the fan), wherein the springs (11) are provided inside the bearing hub assembly (3) in a preloading condition;
ii. the preloaded springs (11) push said shifter (7) towards the rear direction of the bearing hub assembly (3);
iii. said crank link (12) rotates to keep said blades (10) at an initial angle of 45 degree;
iv. Fork (6) has been used to give the axial motion to said bearing hub (3) which is hinged about said Mounting Bracket (4) by means of said lever (5).
8. One preferred embodiment of Fan with reversible blade assembly (101) and method of its operation thereof, as claimed in claim 1, are characterized in:
i. A twisting motion provided to said lever (5) by means of any mechanical linkage, preferably transmitted by the operator;
ii. the actuation the operator pulls said lever (5) in downward direction which further rotates the fork (6) by some angle;
iii. Rotational motion of said fork (6) gives translational motion to the stationary bearing hub assembly (3) in which the outer race of said bearing (1) is resting;
iv. the translational motion of said bearing (1) pushes said shifter (7) against the set of said springs (11) till 14 mm;
v. the 14mm axial motion of said shifter (7) rotates said crank link (12) of said blade assembly (10) by an angle of 90 degree approx.;
vi. said crank link (12), directly fixed on the stub link of said blade, drive said blade to rotate by same angle of 90 degree;
vii. consequently, simultaneous tilting or reversal of whole blade assembly (10) by the same angle is realized.
9. Fan with reversible blade assembly (101), as claimed in claim 1, being installed at a particular position, is characterized in its application as heat exchanger-cum-air-cleaner, particularly when mounted near the radiator of a vehicle (such as truck or a tractor) or a DG-set will, wherein in normal mode said fan (101) acts as air-cooling device and by reversing the blade-assembly (10) and without altering or removing the installation of said fan (10) from its position, it is made to clean said radiator by its air-blow in reversed direction.
10. Fan with reversible blade assembly (101), as claimed in claim 1, is characterized in maintaining air quality in an enclosure as a human comfort zone, such as house, office, school, hospital, theater, vehicle’s cabin, gas-chambers, work-station etc., wherein said fan (10) can supply desired quality air, namely normal ambient air, in its normal condition of blade assembly (10) and whenever there is occurrence of such need for expelling out dirt and other unwanted material (for example dust, smell, smoke) from close vicinity of the mounting position of said fan (101), simply its blade assembly (10) is reversed so that the said fan (101) can expel those dirt and undesired material with the out-blowing air.