Abstract:
Adjusting mechanism for desired angle of an oscillating electric fan is disclosed. The adjusting knob is conveniently located about the top rear portion of the fan motor, adjacent the clutch knob. Adjusting the oscillating angle may be made when the fan is at rest, when it is running and oscillating at the same time, or when it is running at a fixed direction. Adjusting is fast and simple, only one hand is needed and no tools and mechanical know-how is necessary.

Description:
[0001]    This application claims the benefit of PPA Ser. No. 60/903,045 filed Feb. 23, 2007 by the present inventor. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to cranks adapted for use in oscillating fans and more particularly to improved mechanism for fast and simple adjusting for desired oscillation angle of tile fan. 
       RELATED PRIOR ART 
       [0003]    Commonly used oscillating fans operate at fixed angle of about 90-degrees range. These fans however, can be opted to operate for oscillating mode or for fixed-direction mode by simple manipulation of a clutch knob. Fans of the type mentioned above is found not very satisfactory to many users requirements and needs. 
         [0004]    Various schemes have been tried to oscillate the fan to desired oscillating angle in order to maximize utilization of the generated air stream. An example of this is U.S. Pat. No. 6,468,036 which proposed the use of eccentric disks to vary the crank length and hence the oscillation angle. U.S. Pat. No. 7,052,239 B1 is pre-adjustable to a desired oscillation angle, and will adjust automatically to a lesser oscillation angle, or to “0” degrees if an interference by an object is encountered. These efforts do work well however, need for improvement is desired. 
         [0005]    It is the object of the present invention to provide an improved oscillating fan. 
         [0006]    Another object is to provide an oscillating angle adjusting knob which is very conspicuous and readily accessible. 
         [0007]    Yet another object is to provide an adjusting mechanism operable with one hand and without tools. 
         [0008]    Still another object is to provide an adjusting means wherein the oscillation angle may be adjusted even if the fan is running and oscillating at the same time, when the fan is at rest, or when it is running in a fixed direction. 
         [0009]    More objects and advantages will become apparent from a consideration of the drawings and ensuing descriptions. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention include new features and characteristics desirable for the user of the new oscillating fan. The oscillating angle adjusting knob is so conspicuous and accessible being located adjacent to the clutch knob on the rear top portion of the fan motor. The adjusting knob does not move in orbit and this makes it easy to manipulate even if the fan is running and oscillating at the same time. The adjusting knob simply rotate around an axis common with a hollow axle, adjusting rod, cam plate, and carrier disk. 
     
    
     
       THE DRAWINGS 
         [0011]      FIG. 1  is a side view of an oscillating electric fan with an adjusting knob located on the top rear portion of the motor assembly. 
           [0012]      FIG. 2  is a rear sectional view of an oscillating angle adjusting mechanism, taken generally along line  2 - 2  of  FIG. 1 . 
           [0013]      FIG. 3  shows a top view of a carrier disk supporting a straight-piece crank pin assembly (see  FIG. 8 ), taken along line  3 - 3  of  FIG. 2 . The crank pin is shown swiveled closest to the center or common axis. 
           [0014]      FIG. 4  is similar to  FIG. 3  except that the straight-piece crank pin is swiveled furthest from the center or common axis. 
           [0015]      FIG. 5  shows a top view of a cam plate, taken generally along line  5 - 5  of  FIG. 2 , rotated fully clockwise. The crank pin shown here is an offset-piece crank pin (see also  FIGS. 2 and 7 ), actuated closest to the common axis. 
           [0016]      FIG. 6  is similar to  FIG. 5  except that the cam plate is rotated fully counter-clockwise and has actuated the offset-piece crank pin furthest from the axis. 
           [0017]      FIG. 7  is a perspective of the offset-piece crank pin and swivel block assembly. 
           [0018]      FIG. 8  is a perspective of the straight-piece crank pin and swivel block assembly. 
           [0019]      FIG. 9  is an enlarged sectional view of an adjusting knob for varying the oscillation angle of the fan. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0020]    Referring to  FIG. 1  an oscillating fan is constructed according to the teachings of the present invention. For simplicity some well known parts of the common fan has been omitted. The oscillating fan motor assembly is generally identified by reference numeral  10 . The invention includes an electric motor  12 , fan blade  14 , clutch and worm gear unit  16  with toothed spindle  18  in mesh with a toothed carrier disk  20 . Also shown is the fan motor rear housing  22  wherein the gear housing  24 , enclosing the clutch and worm gear unit  16 , is securely attached. 
         [0021]    The motor shaft  26  rotates the fan blade  14  located on the front end, and a worm  28  integral with said shaft is located on the real end. A swinging arm  30  is articulated with the first end  32  to a guide pin  34  adjacent a support post  36  on the top end of the fan stand, and second end  38  is articulated with a crank pin  40 ′/ 40 ″ (see  FIGS. 7 and 8 ). 
         [0022]    In  FIG. 2 , on the left side, the familiar oscillating clutch and worm gear unit  16  is shown and includes a clutch knob  44 . Pushing down the knob will cause the running fan to engage and oscillate, while pulling up said knob will cause the clutch to disengage and operate in a steady direction. The worm  28  communicates with the toothed spindle  18  via the clutch and worm gear unit  16 . The toothed spindle  18  mesh with the toothed carrier disk  20  which carries the crank pin at an orbit around a common axis  48 . 
         [0023]    The gear housing  24 , which may be made of plastic, with reinforced bottom wall  50  and expanded front wall  52  is mounted onto the real motor housing  22  with screws  54 . It encloses the clutch and worm gear unit  16  and also serves as a rigid support means for a hollow axle  78 . The hollow axle includes a flange  58  on the lower end thereof. 
         [0024]    An offset crank pin assembly is shown in  FIG. 7 . With said offset crank pin, shorter crankthrow can be produced and hence a smaller oscillation angle of the fan. A “0” degree oscillation angle is also possible with a much larger bend or offset of the crank pin. The crank pin may also be made a straight-piece as shown in  FIG. 8 . With this type of crank pin the smallest oscillation angle will be larger than that with an offset crank pin. 
         [0025]    The crank pin, whether an offset-piece ( FIG. 7 ) or a straight-piece ( FIG. 8 ), is mounted perpendicularly underneath one end of a swivel block  60 . On the free end of said swivel block is an opening  62  for a pin  64  to pivotally connect to a strategic location on the upper side of the carrier disk  20 . 
         [0026]    A cam plate  66  ( FIGS. 2 ,  5 , and  6 ), for actuating the crank pin  40 ′/ 40 ″ includes an arcuate through—opening  68  of desirable length and width, and having the ends generally opposing each other from the center or common axis  48 . The ends are each distanced differently from the center or common axis, as shown. A detent pin  70  of about 3 mm. long is disposed on the upper side of the cam plate  66  a convenient distance from the common axis, and generally across from the arcuate opening, shown in  FIGS. 5 and 6 . Normally, the detent pin  70  is “anchored” or received in any one of a plurality of detent holes  72 . 
         [0027]    In  FIG. 5 , the cam plate  66  is shown turned fully clockwise and thus actuated the crank pin  40 ′ closest to the center for smallest oscillation angle of the fan. Oppositely, in  FIG. 6 , the cam plate is turned fully counter-clockwise and thus actuated the crank pin furthest from the center for largest oscillation angle of the fan. The arcuate opening  68  is slightly wider than the diameter of the crank pin  40 ′ to permit rotation of the cam plate  66  when adjusting for oscillation angle of the fan. The cam plate is rigidly attached with adjusting rod  74  dimensioned to have free movement within the hollow  76  of axle  78  when the adjusting rod is manipulated. 
         [0028]    The toothed carrier disk  20  ( FIG. 2 ) is shown in mesh with the toothed spindle  18 . The carrier disk include a step bore  80  in the center and an easement opening  82  ( FIGS. 3 and 4 ) sized such that the crank pin upper portion can swivel with ease closer to or further from the axis  48  when adjusting the crank pin. 
         [0029]    Plurality of detent holes  72  are disposed on the carrier disk  20  and sized to readily accommodate the detent pin  70 . These detent holes  72  are at intervals and each one having same distance to the common axis, and which distance, is also same distance between the common axis and the detent pin. The 5 detent holes represent five different selections of oscillation angles in 10-degrees increments, like for example, from the smallest oscillation angle of 50-degrees up to the largest oscillation angle of 90-degrees. 
         [0030]    In  FIG. 9  the adjusting knob is shown enlarged. It includes diametrical slot  84  on the bottom end thereof for accommodating a crosspin  86  disposed through an opening in the adjusting rod  74 . The crosspin supports the adjusting knob  88  and also keep same form turning relative to the rod. 
         [0031]    The assembled oscillating mechanism is best understood in  FIG. 2 . On the left side is the familiar design of clutch and gear unit  16  to include the toothed spindle, and therefore, further discussion is deemed not necessary. On the right side however, is a unique, fast and convenient approach to change to a new oscillation angle. The hollow axle  56  is secured tight fit through an opening  90  on the reinforced bottom wall  50  of the gear housing  24 . The rotating carrier disk  20  is supported by the flanged bottom end of the hollow axle, as shown. On the top end of the hollow axle is a washer  92  upon which a rated compression spring  94  is seated. A second washer  96  is disposed between the upper end of the spring and the bottom end  98  of the adjusting knob  88 . The adjusting knob is secured with a barrel nut  100  onto the top end of the adjusting rod  74 . 
         [0032]    The cam plate  66  with adjusting rod  74 , and the knob  88  are all floated by the compression spring  94 . The spring is so rated such that when the mechanism is assembled as shown in  FIG. 2 , the detent pin  70  locks—in with a detent hole  72 , and the upper surface of the cam plate  66  slightly make contact with the lower surface of the carrier disk  20 . Thereby, friction is minimal and thus energy loss is negligible. 
       Operation 
       [0033]    The new invention may be operated between oscillating mode or non-oscillating mode. The oscillating angle may be changed when the fan is at rest, when it is running and oscillating at the same time, or when it is running in a steady direction. It is suggested however, for a beginner-operator, to disengage the clutch before adjusting the oscillation angle. This helpful tip may be later ignored after several occasions of successful practice, in favor of shortcuts. 
         [0034]    To change oscillation angle, say from 70-degrees oscillation for example, is to first disengage the clutch, preferably when the fan is facing directly in front, by pulling up the clutch knob  44 . Next, press down the adjusting knob  88  until the detent pin  70  is off the detent hole  72  or until the lower side of the cam plate  66  abuts the shoulder of the crank pin, in the case of an offset-piece crank pin, shown in  FIG. 2 . With the adjusting knob still depressed, turn it clockwise for selection to any of 2 smaller oscillation angles, in the order of 60-degrees and 50-degrees. Oppositely, turning the adjusting knob counter-clockwise (from 70-degrees) will give a selection to any of the 2 larger oscillation angles, in the order of 80-degrees and 90-degrees. 
         [0035]    When locating for new detent hole with the detent pin  70 , start turning the already depressed adjusting knob  88  just a few degrees after the pin has cleared the previous detent hole. Slightly ease the (depressed) pressure on the knob and continue on turning until the “feel” of the desired new detent hole is detected. After the new detent hole is located, release the adjusting knob to lock—in or “anchor” the detent pin. Press down the clutch knob to engage and oscillate the fan. 
         [0036]    The embodiment having been described, changes in shape and form may be incorporated by those skilled in the art and such may be within the spirit and scope of the invention as defined by the claim herein appended.