Patent Publication Number: US-2006014485-A1

Title: Single piece vane knob

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application is related to the applicants&#39; Canadian application 2,474,315 filed Jul. 15, 2004 and claims priority therefrom.  
     FIELD OF THE INVENTION  
      The present invention relates to a control knob for vents in automotive ventilation systems. More specifically, the present invention relates to a closed control knob for vents, which closed control knob can be constructed as a single, molded piece with an integral resilient member.  
     BACKGROUND OF THE INVENTION  
      Automotive ventilation systems typically include one or more vents with vertical vanes and horizontal louvers which can be adjusted by a passenger to direct the airflow from the vent in a desired direction and/or which can, in some cases, be closed to block the airflow from the vent. The designers and stylists of automotive interiors have several concerns when designing a vent, namely: ease of operation; appearance; reliability; and the cost of assembly and manufacture of the vent.  
      A design which is commonly employed to control vents is a closed control knob which has a passage to slidably receive a center louver across the front of the vent and which has fingers which extend into the vent to engage a central vane therein. The louvers of the vent are interconnected to each other such that moving the center louver moves the other louvers a similar amount and the vanes of the vent are interconnected in a similar fashion such that movement of the center vane moves the other vanes by a similar amount. The fingers of the knob engage the center vane such that, left or right movement of the knob along the center louver turns the center vane and correspondingly turns all of the vanes left or right. Further, by moving the knob up or down to tilt the center louver up or down, the other louvers are correspondingly tilted up or down.  
      While this design is widely employed in the automotive industry, it suffers from disadvantages. In particular, as it is desired that the vanes and louvers of the vent remain in position, once adjusted by a passenger, it is necessary to provide a degree of frictional resistance to movement of the knob along the louver. To date, such frictional resistance has been provided by a metal spring or other separate resilient member which acts between the knob and the louver. However, when such a spring or resilient member is employed with the knob, the spring and/or resilient member must be assembled into the knob, which increases the cost of the vent. Further, such knobs must be assembled from two or more components to permit installation of the spring or resilient member into the knob and this can lead to failure of the knob assembly at one or more of the assembly joints if a glued, snapped or welded joint fails.  
      Further, if the spring or resilient member acts against the top or bottom side of the louver, rather than against an edge of the louver, a visible track, groove or other non-aesthetic feature must be formed on the louver, resulting in a vent which is less attractive than may be desired.  
      Previous attempts to overcome the disadvantages of requiring a separate spring or resilient member have been open knob designs, wherein the knob is generally U-shaped, having an open side into which the louver is snapped to engage the knob. These open knob designs have included an integrally formed spring but such previous solutions have not been well received as it is possible in use to detach the knob from the louver, by a user applying too much pressure to the knob, resulting in failure of the knob and vent.  
     SUMMARY OF THE INVENTION  
      It is an object of the present invention to provide a novel closed control knob for a vent which obviates or mitigates at least one disadvantage of the prior art.  
      According to a first aspect of the present invention, there is provided a closed control knob for controlling vanes and louvers in a vent, the control knob comprising: an enclosed passage through which a louver to be controlled can slidably extend; a pair of fingers extending from said control knob to engage at least one vane to be controlled; a resilient member, integrally formed with said control knob, to act between said control knob and said louver to generate a frictional force therebetween, the frictional force acting to maintain the control knob in its current position on said louver; and an aperture to allow said resilient member to be integrally molded with said control knob.  
      Preferably, the resilient member comprises a generally bow-shaped member, the ends of the bow-shaped member being connected to the control knob and the portion of the member between the ends being cantilevered therefrom and being resiliently deformable to act between the control knob and the louver.  
      The present invention provides a control knob for a vent having vanes and louvers includes a resilient member integrally molded within the control knob. The resilient member acts between the control knob and the louver on which it is mounted to provide a frictional force to retain the knob in the position it is placed by a passenger in a vehicle of other user. By integrally forming the resilient member with the control knob, assembly is simplified and failure of glued, snapped or welded joints is avoided.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Preferred embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:  
       FIG. 1  shows a perspective view of the front and side of a single piece closed control knob on a center louver and vane of a vent in accordance with an embodiment of the present invention;  
       FIG. 2  shows a perspective view of the back and top of the single piece control knob and louver and vane of  FIG. 1 ;  
       FIG. 3  shows a perspective exploded view of the top and front of the single piece control knob and louver and vane of  FIG. 1 ;  
       FIG. 4  shows a sectional view taken along line  4 - 4  of  FIG. 1 ;  
       FIG. 5  shows a sectional view taken along line  5 - 5  of  FIG. 2 ;  
       FIG. 6  shows a perspective view of the underside of the single piece control knob and louver of  FIG. 1 ; and  
       FIG. 7  shows a sectional view similar to that of  FIG. 4  of another embodiment of the present invention with two resilient members. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      A vent control knob with an integral resilient member in accordance with the present invention is indicated generally at  20  in  FIGS. 1, 2  and  3 . As illustrated, control knob  20  has an enclosed passage  22  through which louver  24  passes and is thus a closed control knob. A vane  28  is connected to control knob  20  via a pair of fingers  32  extending rearwardly from knob  20  and engaging a rod  36  connected to vane  28 . Control knob  20  includes an aperture  38  extending therethrough and the front of which can be closed with a trim or accent piece, such as chromed insert  40 , for aesthetic reasons. Aperture  38  permits a resilient member, discussed below, to be integrally molded within knob  20 . Control knob  20  can be slid along louver  24  to move rod  36 , and thus turn vane  28 , and the other vanes (not shown), as desired.  
      As best seen in  FIGS. 4 and 5 , passage  22 , through control knob  20 , includes an integrally formed resilient member, in this embodiment spring  48 , which acts between control knob  20  and the front of louver  24  and which forces louver  24  against a pair of bosses  52  located one at each end of passage  22 . Spring  48  is generally bow-shaped with the ends  56  of the bow being attached to control knob  20  and the center bow portion  60  being cantilevered out from ends  56  such that center bow portion  60  is resiliently deformed when louver  24  is inserted into passage  22 , as described below.  
      In conjunction with the frictional force generated between the center bow portion  60  of spring  48  and the front of louver  24  and between louver  24  and bosses  52 , spring  48  creates a frictional force to maintain control knob  20  in the position it is placed in by a passenger using control knob  20  to adjust a vent. To enhance the feel and operation of control knob  20 , louver  24  preferably includes a raised track portion  64 , best seen in  FIGS. 3 and 4 , along its front edge for the center bow portion  60  of spring  48  to act against and which also serves to limit the portions of knob  20  which actually contact louver  24 , thus assisting in preventing movement of knob  20  along louver  24  from scratching portions of louver  24  which would be visible to users. Track portion  64  is shorter in length than the width of control knob  20  so that track portion  64  is not visible to vehicle passengers as it is always located within control knob  20 .  
      As will be apparent to those of skill in the art, control knob  20 , including a resilient member, such as spring  48 , can be molded as an integral member avoiding the need for a separate step of assembling spring  48  within control knob  20  and avoiding the need for a separate assembly step and/or the need for welded, snapped together or glued joints in control knob  20 .  
      As will also be apparent to those of skill in the art, the resilient member can be formed in a variety of manners without departing from the scope of the present invention. For example, one or more cantilevered resilient arms can be formed within control knob  20  to act between control knob  20  and louver  24 .  
      As shown in  FIG. 6 , control knob  20  includes a spring tab  68   a  and  68   b  on each opposed edge of its underside and spring tabs  68   a ,  68   b  run in a track  72 , which is formed, on the underside of louver  24 . One end of track  72  includes an end stop  76  against which spring tab  68   a  on control knob  20  will abut to prevent further movement of control knob  20  in that direction. The other end of track  72  includes a second end stop  80  which spring tab  68   b  will abut to prevent further movement of control knob  20  in that direction.  
      As shown, end stop  80  includes a ramped back portion  84  to allow assembly of control knob  20  onto louver  24 . Specifically, during assembly louver  24  is slid into passage  22  of control knob  20 , from right to left in the orientation shown in  FIG. 6 , such that first spring tab  68   a  rides up ramp portion  84  of end stop  80  and then snaps down into track  72 , and as louver  24  is further inserted into passage  22 , spring tab  68   b  will ride up ramped portion  84  of end stop  80  and then snap down into track  72 .  
      Once louver  24  has been inserted into passage  22  to the extent wherein both spring tabs  68   a  and  68   b  are in track  72 , control knob  20  can be moved horizontally along track  72  within a range limited by a respective spring tab  68   a ,  68   b  abutting a respective end stop  76 ,  80 .  
       FIG. 7  shows another embodiment of the present invention which includes two resilient members  100 . Each member  100  has a first end  104  fixed to control knob  20  and a cantilevered end  108  which acts against louver  24 . As will be apparent, the actual shape of members  100  is not particularly limited provided that cantilevered ends  108  are resiliently biased against louver  24 .  
      As will be apparent to those of skill in the art, while the embodiment illustrated herein has control knob  20  mounted to a horizontal louver, the present invention is not so limited and can be advantageously employed with vents with vertical louvers and horizontal vanes, or in other configurations as desired.  
      By incorporating a molded resilient member within control knob  20  to provide a frictional force between control knob  20  and louver  24 , an advantageous vent control knob is obtained. Fabrication and assembly are simplified as it is not required to mount a spring or resilient member inside the control knob, nor is it required to glue, snap or weld a multi-part knob together. Further, as the resulting control knob is a single piece, it is more reliable then multi-piece knobs.  
      The above-described embodiments of the invention are intended to be examples of the present invention and alterations and modifications may be effected thereto, by those of skill in the art, without departing from the scope of the invention which is defined solely by the claims appended hereto.