Abstract:
A vibrator counterweight assembly for use in an electronic device includes an electric motor ( 201 ) and shaft ( 203 ) for providing rotational movement adjacent to a substrate ( 209 ). An eccentric counterweight ( 205 ) is connected to the electric motor ( 201 ) through the shaft ( 203 ). A bend reduction stop ( 207 ) is attached to the eccentric counterweight ( 205 ) and works to prevent damage to the shaft ( 203 ) during a high stress loading condition on the electronic device.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to a vibration assembly used in an electronic device and more particularly to the use of a vibrator counterweight used in the vibration assembly. 
       BACKGROUND 
       [0002]    Vibratory motors are commonly used in connection with electronic devices to tactically notify a user of an alert condition. Most often the motor is used to vibrate the housing of a cellular telephone when an incoming voice call or text message is received. In operation, the motor is mounted within the housing of the electronic device where an off-center or eccentric counterweight is connected with the motor&#39;s drive shaft such that activation of the motor causes a vibration due to the rotation of the weight.  FIG. 1  is a diagram illustrating a side and end view of the motor and eccentric weight assembly  100  as used in the prior art. A motor  101  uses a shaft  103  to rotate an eccentric weight  105 . The weight  105  rotates such that it clears a substrate such as a printed circuit board (PCB)  107  or other housing.  FIG. 2  is a diagram illustrating a side and end view of the motor and eccentric weight assembly  200  as shown in  FIG. 1  however the eccentric weight  105 ′ attached to the shaft  103 ′ is shown in an elevated position during rotation such that there is a greater degree of clearance with the printed circuit board  107 . 
         [0003]    A problem can occur with the motor and eccentric weight assembly when the assembly is dropped or otherwise subjected to some high load or stress condition within the electronic device. Under these conditions, it is often possible to bend or deform the shaft so that the eccentric weight is out of longitudinal alignment with the motor.  FIG. 3  is a diagram illustrating a side and end view of the motor and eccentric weight assembly  300  that is damaged after the assembly is subjected to a high stress condition. In this example, the shaft  103 ″ has been bent or deformed due to the forces applied as a result of the fall or other high stress event.  FIG. 3  shows the eccentric weight  105 ″ bent in a direction toward the PCB  107  such that it may sometimes contact the PCB  107  and prevent it from rotating in a normal manner. In this situation, it is possible the vibration feature of the electronic device using such a weight may no longer operate and will have to be repaired in order to restore this type of functionality. 
         [0004]    Accordingly, the need exists to provide a vibrator counterweight assembly that can sustain the high stresses, loads and other forces without damage when subjected to a fall or other stress condition when used within an electronic device. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0005]    The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention. 
           [0006]      FIG. 1  illustrates a side and end views of a vibrator and counterweight assembly used in the prior art showing an eccentric weight positioned close to a printed circuit board during rotation. 
           [0007]      FIG. 2  illustrates a side and end views of a vibrator and counterweight assembly as shown in  FIG. 1  where the eccentric weight is positioned distant from the printed circuit board during rotation. 
           [0008]      FIG. 3  illustrates side and end views of a vibrator and counterweight assembly as shown in  FIG. 2  where the eccentric weight is damaged to restrict movement of the eccentric weight to prevent proper vibration. 
           [0009]      FIG. 4  illustrates side and end views of a vibration motor and counterweight assembly using a bend reduction stop directed away from the printed circuit board in accordance with an embodiment of the invention. 
           [0010]      FIG. 5  illustrates side and end views of a vibration motor and counterweight assembly as in  FIG. 4  with a bend reduction stop directed toward the printed circuit board in accordance with an embodiment of the invention. 
           [0011]      FIG. 6  illustrates side and end views of a vibration motor and counterweight assembly as in  FIG. 5  after a high stress event with a bend reduction stop limiting the stress on the eccentric weight when contacting the printed circuit board in accordance with an embodiment of the invention. 
       
    
    
       [0012]    Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. 
       DETAILED DESCRIPTION 
       [0013]    Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to a vibrator counterweight assembly. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. 
         [0014]    In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. 
         [0015]      FIG. 4  illustrates side and end view of the vibrator counterweight assembly  400  where a motor  201  utilizes a shaft  203  to connect to an eccentric weight  205 . The eccentric weight  205  further includes a bend reduction stop  207  connected to its outside end so that protrudes substantially orthogonally from the eccentric weight  205  for operating as a stop during a high stress drop condition. The bend reduction stop  207  is typically positioned on the eccentric weight  205  such that the bend reduction stop  207  points away from the substrate such as printed circuit board  209  when the eccentric weight  205  is positioned closest to the printed circuit board  209 . As seen in  FIG. 4 , the bend reduction stop  207  is oriented away from the printed circuit board  209  while it is at its closest rotation to the printed circuit board  209 . 
         [0016]      FIG. 5  illustrates a side and end view of a vibrator counterweight assembly  500  where the shaft  203  is rotated such that the eccentric weight  205  is rotated 180 degrees from that shown in  FIG. 4 . In this embodiment the bend reduction stop  207  is directly facing the printed circuit board  209 . In a fall or other high stress environment, since the eccentric weight is furthest from the printed circuit board  209 , the bend reduction stop  207  will operate to prevent substantial damage to the shaft  203 . This occurs since the bend reduction stop  207  will contact the printed circuit board  209  before the shaft  203  will flex to the point of unrecoverable damage. Although the shaft  203  may be partially resilient along its longitudinal axis, a high stress condition will cause the shaft to yield with a permanent bend. 
         [0017]      FIG. 6  illustrates side and end view of a vibrator counterweight assembly  600  like that in  FIG. 5  where the vibrator counterweight assembly  600  has been subject to a drop or other high stress condition. When the internal load is placed on the shaft  203 , the shaft and eccentric weight  205  may begin to bend in a direction toward the printed circuit board  209 . Before a high amount of permanent damage can be done to the shaft  203 , the bend reduction stop  207  may contact the surface of the printed circuit board  209 . In most cases, the bend reduction stop  207  will prevent the shaft  203  from flexing or yielding to a point where the bend would allow the bend reduction stop to permanently touch the printed circuit board  207 . This allows the eccentric weight  205  and the bend reduction stop  207  to remain clear of the printed circuit board  209  so that it may freely rotate through its full range of motion. 
         [0018]    Thus, the present invention is a vibratory counterweight assembly and is arranged such that a counterweight includes a bend reduction stop which is added to its end that prevents the weight from bending into printed circuit board or other housing. By limiting the strain to a level below yield of the motor shaft, the shaft will not presently bent such that the counterweight would contact the printed circuit board during rotation. This allows the vibratory counterweight assembly to continue to operate in the electronic device normally, irrespective of the drop. 
         [0019]    In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.