Exhaust hood system
BACKGROUND OF THE INVENTION 
     The present invention relates to an exhaust hood system which includes a series of universal connecting tubes to connect an exhaust hood to an exhaust fan for permitting the exhaust hood to be moved to the desired position and direction to suck in smoke. 
     It has been apparent that smoking is harmful to the health. However, it is sometimes difficult to prohibit others from smoking. One may be secondarily polluted by smoke when there is other people smoking. Therefore, it is necessary to install exhaust hoods or ventilators in rooms, halls, public places, etc., to draw out smoke. However, regular exhaust hoods and ventilators are commonly of fixed type and cannot be adjusted to the source of smoke to effectively carry smoke away. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the aforesaid circumstances. It is therefore the principal object of the present invention to provide an exhaust hood system which can be turned and bent to the desired position and direction to effectively carry smoke and turbid air out of a room or place. According to the preferred embodiment of the present invention, the exhaust hood system comprises an exhaust fan fastened to a window frame of a room and covered with a hood having an intake port coupled with a guide tube being fastened to the wall of the room by a holder, a series of universal connecting tubes linked together and connected to the guide tube by swivel connectors, and an exhaust connected to the series of universal connecting tubes for carrying smoke outside the room through the series of universal connecting tube upon operation of the exhaust fan. The series of universal connecting tubes is turnable and bendable, and therefore the exhaust hood can be moved to the desired position and direction to suck in smoke effectively. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plain view showing the installation of an exhaust hood system according to the preferred embodiment of the present invention; 
     FIG. 2 is an elevational view of the exhaust hood system shown in FIG. 1; 
     FIG. 3 is a cross section showing two tube sections of a universal connecting tube connected according to the present invention; 
     FIG. 4 is an exploded view of a swivel connector according to the present invention; and 
     FIG. 5 is a longitudinal view in section of the swivel connector shown in FIG. 4. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 2, an exhaust fan 1 is fastened to the window frame 6 at a suitable location and covered with a hood 11. The hood 11 has a hole (not shown) coupled with a guide tube 21. The guide tube 21 is fastened to the wall by a holder 2. A series of universal connecting tubes 4 are linked together and connected to the guide tube 21 by swivel connectors 3. The terminal end of the series of universal connecting tubes 4 is coupled with an exhaust hood 41. A power switch 5 is provided to control the operation of the exhaust fan 1. When the power switch 5 is switched on, the exhaust fan 1 is turned on to suck in air through the exhaust hood 41, causing the smoke of the burning cigarette 7 or the turbid air to be carried away from the room and exhausted to the outside. The universal connecting tubes 4 can be bent in all directions. Therefore, the exhaust hood 41 can be moved to the desired position and direction to suck in smoke. When the exhaust fan 6 does no work, the series of universal connecting tubes 4 can be folded up and put aside to the wall so as not to occupy much space. 
     Referring to FIG. 3, the universal connecting tube 4 is comprised of a series of tube sections, each tube section having a front end terminating in a ball head 43 and a rear end terminating in a ball socket 42 and a longitudinal through hole 44 through the ball head 43 and the ball socket 42. The ball head 43 of one flexible tube section fitted into the ball socket 42 of another, and therefore the universal connecting tube 4 can be turned and bent in all directions. 
     Referring to FIGS. 4 and 5, the swivel connector 3 comprises a cylindrical connector body 31, which has a collar 38 raised around the periphery thereof in the middle, two opposite end holes 311;312 on two opposite ends thereof, and an air passage hole 313, two rotating rings 32;33 respectively mounted around the connector body 31 and retained between a respective pair of locating rings 34;341 or 35;351 at two opposite sides by the collar 38, and two end caps 36;37 having a respective plug rod 361 or 371 fitted into either end hole 311 or 312. The rotating ring 32 or 33 has an inside annular groove 321 or 331 disposed in communication with the air passage hole 313 at either end, and a screw hole 322 or 332 disposed in communication with the inside annular groove 321 or 331 for connecting a respective universal connecting tube 4. Therefore, when the rotating ring 32 or 33 is turned in either direction by the linked universal connecting tube 4, intake smoke is still allowed to pass from one universal connecting tube 4 through the inside annular groove 331 of the lower rotating ring 33 and the air passage hole 313 of the connector body 31 to another universal connecting tube 4 via the inside annular groove 321 of the upper rotating ring 32. 
     While only one embodiment of the present invention has been shown and described, it will be understood that various modifications and changes could be made without departing from the spirit and scope of the invention.