Abstract:
A handleset mechanism of the sort having a pivoting thumb latch and a rotary handle is provided with a force transmission path to generally improve the actuation by the thumb latch and reduce the required force. One feature is a heart-shaped cam that communicates movement between a spindle driven by the rotary handle, and a slider plate driven by the thumb latch. By using the cam, the force required by the thumb latch is reduced. Another feature is the provision of a curved surface between the thumb latch and the slider plate. Further, in one embodiment, the rotary handle can be actuated without any corresponding movement of the thumb latch.

Description:
[0001]     This application is a divisional of U.S. patent application Ser. No. 11/088,108, which was filed Mar. 23, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates to a handleset of the sort having a rotating handle on one side, and a pivoting thumb latch on another. Several improvements in this basic type handleset are provided by the inventive design.  
         [0003]     Handlesets are utilized to control the opening and closing of door latches. There are many combinations of actuation systems on the two sides of any handleset. As an example, some handlesets have rotating handles on both sides.  
         [0004]     One other type of handleset utilizes a rotating handle on one side, and a pivoting thumb latch on the other. The pivoting thumb latch is often utilized on an outside side of a door with the rotating handle on an inner side of the door.  
         [0005]     To date, the force required to actuate the thumb latch has been undesirably high. It would be desirable to reduce this force. Further, it would be desirable to provide a more robust handleset than presently available.  
       SUMMARY OF THE INVENTION  
       [0006]     In a disclosed embodiment of this invention, a handleset mechanism has a pivoting thumb latch on one side, and a rotating handle on the other. A force transmission path for actuation by the thumb latch passes through a cam. The cam rotates to in turn rotate a spindle that opens the latch. In one disclosed embodiment, the cam has a generally heart shape.  
         [0007]     In other features of this invention, an interface between the thumb latch and a slide, which moves when the thumb latch is actuated, is curved, to provide a smoother force transmission path.  
         [0008]     In one embodiment of this invention, the rotating handle can be turned without corresponding movement of the thumb latch. This is desirable in that it is sometimes undesirable to have the latch pivoting when the door handle is being turned. To achieve this feature, the spindle is provided of two parts.  
         [0009]     These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view of a handleset mechanism.  
         [0011]      FIG. 2  is an exploded view of the  FIG. 1  handleset mechanism.  
         [0012]      FIG. 3  is a perspective view of one component.  
         [0013]      FIG. 4A  is a cross-sectional view in the unactuated position.  
         [0014]      FIG. 4B  is a cross-sectional view in an actuated position.  
         [0015]      FIG. 5A  is a cross-sectional view along lines  5 A- 5 A of  FIG. 4A .  
         [0016]      FIG. 5B  is a cross-sectional view along lines  5 B- 5 B of  FIG. 4B .  
         [0017]      FIG. 6  shows a second embodiment in exploded view.  
         [0018]      FIG. 7  is a perspective view of one portion of the  FIG. 6  embodiment.  
         [0019]      FIG. 8A  is a view similar to  FIG. 4A , however showing the  FIG. 6  embodiment.  
         [0020]      FIG. 8B  is a view similar to  FIG. 4B , however showing the  FIG. 6  embodiment.  
         [0021]      FIG. 9A  is a cross-sectional view along line  9 A- 9 A of  FIG. 8A .  
         [0022]      FIG. 9B  is a cross-sectional view along line  9 B- 9 B of  FIG. 8B .  
         [0023]      FIG. 10A  is a cross-sectional view along line  10 A- 10 A of  FIG. 8A .  
         [0024]      FIG. 10B  is a cross-sectional view along line  10 B- 10 B of  FIG. 8B . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]     A handleset mechanism  20  is illustrated in  FIG. 1 . A thumb latch  22  is mounted on one side with a rotating handle  24  on the other. Actuation of either the thumb latch  22  or the handle  24  will cause a latch  26  to be actuated to allow a door to be opened. A spindle  32  is provided with two sections  36  and  38 , which each respectively cause actuation of a hub  30  and  28 . The hubs  30  and  28  open a latch  26  as known in the art. An actuation mechanism  34  for transmitting actuation movement of either the thumb latch  22  or the handle  24  is the inventive aspect of this invention.  
         [0026]     As shown in  FIG. 2 , in exploded view, actuation mechanism  34  includes a cover plate  40 , a slider plate  42  and springs  44  that bias slider  42  to an unactuated position. A slot  43  is formed within the slider plate  42 .  
         [0027]     A rotary plate  46  includes a central bore  48 , and a cam  54 . A spring  52  is mounted onto the spindle  32  and biases it to be in contact with the hubs. A groove  202  receives a snap ring  203  to lock the spring and generate the bias force. When spindle  32  is rotated to its unactuated position, it keeps handle  24  in an unactuated position. An outer cover plate  50  encloses the structure.  
         [0028]     As shown in  FIG. 2 , the spindle  32  has two distinct portions  36  and  38 . As will be shown below, portion  38  fits within portion  36  and can rotate the two portions relative to each other.  
         [0029]     As shown in  FIG. 3 , the rotary plate  46  has cam  54  with two curved surfaces  56  and  58 . A cut-out  59  in the cam  54  forms a portion of the bore  48 . It could be said the cam  54  is generally heart-shaped.  
         [0030]      FIG. 4A  shows the thumb latch  22  pivoting on a pin  60  within the cover  40 . A lower surface  62  of the slider plate  42  engages an upper surface  64  of the thumb latch  22 . The surfaces  62  and  64  are both curved, such that when the latch  22  is pivoted downwardly, as shown in  FIG. 4B , to in turn move the slider plate  42  upwardly, the surfaces  62  and  64  provide a relatively smooth force transmission path. As is clear from the Figures, the curved contact surfaces on the thumb latch and the slider plate are curved about radii that are perpendicular to a pivot axis of said thumb latch. As such, the two surfaces move relative to each other as the thumb latch moves.  
         [0031]     As shown in  FIGS. 5A and 5B , when the slider plate  42  is in the unactuated position of  FIG. 4A , the cam  54  sits within slot  43 . One curved surface  58  sits on an end wall of the slot  43 . When the thumb latch  22  is actuated such as shown in  FIG. 4B , it forces slider plate  42  upwardly. As slider plate  42  moves upwardly, rotary plate  46  is driven to turn by the slot  43  driving the cam  54 . As rotary plate  46  is driven to rotate, it in turn rotates spindle portion  36 . When portion  36  rotates, it actuates the latch  26  through hub  30 , again through a known mechanism. The thumb latch is movable between an actuated ( FIG. 5B ) and an unactuated ( FIG. 5A ) position by pivoting. A surface on the slider plate is in contact with the cam when the thumb latch is in the unactuated position such that initial movement of said thumb latch to the actuated position causes immediate movement of the slider plate and the cam.  
         [0032]     If the door handle  24  is actuated, it will turn spindle portion  38  and open the latch  26  through hub  28 . When this occurs, the rotary plate  46  will not rotate since the portion  38  can rotate within the portion  36 . Thus, the thumb latch  22  will not pivot.  
         [0033]     With this embodiment, should someone be actuating the door handle, the latch mechanism will not be caused to pivot. This would provide benefits, such as the external thumb latch not being actuated when someone leaves from inside.  
         [0034]     Another embodiment  80  is shown in  FIG. 6 . A cover plate  82  is provided along with a slider plate  86 , and a rotating plate  84  having the cam  85 . Again, springs  88  bias the slider plate  86  and an outer cover plate  90  is provided. In this embodiment, the spindle  94  includes a first cylindrical portion  96 , and a second portion  92  having a central, cylindrical bore  98  to receive portion  96 . An outer surface of second portion  92  is shown as square.  
         [0035]     An end  100  of the spindle extends to the rotary handle (not shown). An inner end of portion  96  has flats  102 . A pivoting actuation member  104  has a bore  106  that receives the flats  102 .  
         [0036]     As shown in  FIG. 7 , the spindle extends through the plate  90  to an inner side, and the slider plate  86  has a surface  110  in contact with ears  108  on the pivoting actuation member  104 . A short, machined section  204  allows for extra door width adjustment.  
         [0037]     As shown in  FIG. 8A , the actuation of the embodiment  80  is somewhat distinct from the actuation of the  FIG. 1  embodiment. As can be compared between  FIGS. 8A and 8B , when the rotary handle is turned, as shown in  FIG. 8B , the slider  86  is caused to move and actuate the latch. As shown between  FIGS. 8A and 8B , with this movement, the thumb latch  122  does move.  
         [0038]     As shown in  FIGS. 9A and 9B , the rotary plate has actuation similar to the earlier embodiment due to the heart-shaped cam. However, as shown in  FIGS. 10A and 10B , when the spindle  100  is turned, the pivoting actuation member  104  will pivot, and one of its ears  108  will cam a surface  132  of the slider plate  86 , causing the slider plate to move upwardly.  
         [0039]     When the pivoting actuation member  104  cams the slider plate  86  upwardly as shown in this figure, the slot  87  in the slider plate  86  will cause the heart-shaped cam  85  to be driven to rotate, in turn rotating the rotary plate  84 . When this occurs, the hub  200  as illustrated schematically in  FIG. 8 , will be actuated. Again, the hub structure utilized to actuate the latch is as known in the art, and is disclosed schematically within this application.  
         [0040]     A slot  123  within the slider plate  86  guides the thumb latch  122 . The interface surface between the thumb latch  122  and the slider plate is again curved, as can be appreciated from  FIGS. 8A and 8B . Since the slider plate  86  does move when the handle is turned, the thumb latch  122  will pivot. When the thumb latch  122  is pivoted, it moves the slider plate. However, the portion  92  of the spindle  94  can pivot relative to the portion  100  in this instance. Thus, the handle does not turn when the thumb latch is actuated.  
         [0041]     In both embodiments, a clip  300  is received on an inner end  301  of the spindle to hold the several disclosed components.  
         [0042]     Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.