Abstract:
A method and apparatus are provided for allowing a user to change the stiffness of their headband, thus changing the clamping force of the headset. The section properties of the headband equivalent spring, which is a cantilevered beam, are changed by engaging a secondary spring, which is also a shorter cantilevered beam. The change is achieved by manipulating the effective length of the secondary spring, which can be accomplished with a set of clamps. Thus, the stiffness of the headband can be modified to the desire of the user.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     Traditionally, headsets are complicated devices that are created for an average-sized person in the population. Some manufacturers provide a single design headset that is “tuned” to the center of the perspective population. This design leads to a mediocre solution for people that are not part of the center. Some manufacturers have solved this problem by offering a family of headbands to address the different head sizes and shapes of the population. This solution becomes a potential inventory and logistics problem. Further, many headset designs include a mechanism in order to adjust the clamping forces. Other designs use worm gears, cables, linkages, and adjustment knobs. Therefore, a solution is needed that would allow a headset to fit a large percentage of the population and allow the user to change the stiffness of their headband. 
     SUMMARY 
     Embodiments of the invention are defined by the claims below, not this summary. A high-level overview of various aspects of embodiments of the invention is provided here for that reason, to provide an overview of the disclosure and to introduce a selection of concepts that are further described below in the detailed description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in isolation to determine the scope of the claimed subject matter. 
     Embodiments of the present invention relate generally to a method and apparatus for changing the stiffness of headband resulting in changing the clamping force of the headset. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Illustrative embodiments of the present invention are described in detail below with reference to the included drawing figures, wherein: 
         FIG. 1  is an exemplary illustration of a headband with a least amount of clamping force, implemented in accordance with an embodiment of the present invention; 
         FIG. 2  is an exemplary illustration of a headband with a significant amount of clamping force, implemented in accordance with an embodiment of the present invention; 
         FIG. 3  is an exemplary illustration of headbands with varying amounts of clamping force, implemented in accordance with an embodiment of the present invention; 
         FIG. 4  is a process for changing a stiffness of a headband, implemented in accordance with an embodiment of the present invention; and 
         FIG. 5  is a process for changing a clamping force to a head of a user, implemented in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention relate generally to a method and apparatus for changing the stiffness of headband resulting in changing the clamping force of the headset. Clamps can move along a path changing the clamping force of the headband when worn by a user. More specifically, section properties of the headband are varied by engaging two springs. The variation changes the effective length of a second spring relative to a first spring by changing the engagement length of the springs. The variation changes the stiffness and resulting clamping force allowing a user to adjust the headband to their comfort. 
     In a first aspect, a method for changing a stiffness of a headband is provided that includes aligning a primary spring and a secondary spring together. The primary spring and the secondary spring are flexible curved beams. Each spring has a shape of an arc. The primary spring and the secondary spring are shaped to caress and fit against a human head. The primary spring and the secondary spring are joined together with moveable clamps. A member of the moveable clamps is moved along the primary spring and the secondary spring such that the member clamps the primary spring and secondary spring together at that particular point and varies the stiffness of the headband relative to the member being located at a different point along the primary spring and secondary spring. The stiffness of the headband is increased by increasing a spacing between the moveable clamps positioned along the primary spring and the secondary spring. 
     In another aspect, a method for changing a clamping force to a head of a user is provided that includes elongating a first flexible material and a second flexible material. The first flexible material and the second flexible material are shaped into an arc to fit over the head of the user. The first flexible material is created with a length longer than the second flexible material. The first flexible material and the second flexible material are aligned together. The first flexible material and the second flexible material are clamped together with moveable clamps. The moveable clamps are moved to different positions along the first flexible material and the second flexible material to change a stiffness of the headband. 
     In  FIG. 1 , a headband  100  is shown with a primary spring  110  and a secondary spring  115  held together with clamps  120   a ,  120   b , and  120   c . Primary spring  110  and secondary spring  115  can also be cantilevered beams. As shown in  FIG. 1 , primary spring  110  and secondary spring  115  have curved shapes in the form of an arc. These shapes are created in order to allow primary spring  110  and secondary spring  115  to fit around a human head. 
     In  FIG. 2 , a headband  200  is shown as an alternate illustration to headband  100  in  FIG. 1 . Headband  200  includes a primary spring  210  and a secondary spring  215  clamped together similar to primary spring  110  and secondary spring  115  in  FIG. 1 . However, clamps  220   a ,  220   b , and  220   c  are shown spaced apart from one another. Claims  220   a ,  220   b , and  220   c  are similar to clamps  120   a ,  120   b , and  120   c , but the illustration between  FIGS. 1 and 2  indicate that the clamps can move or slide across the springs into different positions. 
     Turning now to  FIG. 3 , several headbands are shown with the clamps in different positions. Headband  300   a  is similar to headband  100  in  FIG. 1 . As depicted, headband  300   a  shows clamps  120   a ,  120   b , and  120   c  positioned together. With the position of clamps  120   a ,  120   b , and  120   c , forces  310   a  and  310   b  will occur as shown on primary spring  110 . The illustration of forces  310   a  and  310   b  on primary spring  110  can be seen in an equivalent spring representation  301   a . Representation  301   a  shows a representation of a clamp in the form of a stationary clamp  312 . From stationary clamp  312 , a first beam  314  is shown with a second beam  316 . A force  310   c  can be applied to first beam  314 , which represents forces  310   a  and  310   b  applied to primary spring  110 . As one of ordinary skill in the art knows, the forces can become greater as the length of second beam  316  increases. 
     Continuing with  FIG. 3 , headband  300   b  is another representation of headband  300   a  with clamps  220   a ,  220   b , and  220   c  spaced apart from one another in relation to clamps  120   a ,  120   b , and  120   c . Headband  300   b  is similar to headband  200  in  FIG. 2 . As a result of the spacing between clamps  220   a ,  220   b , and  220   c , forces  320   a  and  320   b  occur at primary spring  210 . Forces  320   a  and  320   b  are different and stronger than forces  310   a  and  310   b  by virtue of the movement of clamps  220   a ,  220   b , and  220   c  to their position. This change in force can be seen in representation  301   b  where a first beam  324  is the same as first beam  314 . However, a second beam  326  is shown longer relative to second beam  316 . Because of the longer second beam  326 , force  320   c  is stronger than force  310   c , resulting in a greater stiffness in headband  300   b  relative to headband  300   a.    
     Headband  300   c  is another depiction of headbands  300   a  and  300   b  with clamps  320   a ,  320   b , and  320   c  moved further apart relative to clamps  220   a ,  220   b , and  220   c  and clamps  120   a ,  120   b , and  120   c . Headband  300   c  has a primary spring  310  and a secondary spring  315  that work together to vary the force and stiffness. Forces  330   a  and  330   b  occur as a result in the change of position of clamps  320   a ,  320   b , and  320   c . Because clamps  320   a ,  320   b , and  320   c  are spaced apart relative to clamps  220   a ,  220   b , and  220   c , forces  330   a  and  330   b  will be greater than forces  320   a  and  320   b . The result is that headband  300   c  will have a greater stiffness than headbands  300   b  and  300   a . This greater force and stiffness is shown in representation  301   c  where a first beam  334  is the same in length and size to first beams  314  and  324 . However, a second beam  336  is much longer in length relative to second beams  316  and  326 . As a result, force  330   c  placed on first beam  334  is greater than force  320   c  placed on first beam  324 , which is greater than force  310   c  placed on first beam  314 . Equation  340  illustrates this point by showing forces  330   a ,  330   b , and  330   c , greater than forces  320   a ,  320   b , and  320   c , which are greater than forces  310   a ,  310   b , and  310   c.    
     One of ordinary skill in the art knows that by varying the positions of the clamps, the clamping force and stiffness of the headband can be changed. More particularly, the idea here illustrates that moving the clamps to different positions along the springs in the headbands result into different stiffness of the headbands as well as different clamping forces. Although the headbands in  FIGS. 1, 2, and 3  are shown with headbands with three clamps, other embodiments of the present inventions can be implemented with more or less number of clamps in the headbands. The present invention can be implemented with two clamps in the headbands. Or, the present invention can be implemented with four or more clamps in the headbands. 
     Implementations of embodiments of the present invention allow for headsets to be designed to fit a worldwide end user percentile range of five percent (5%) female to ninety-five (95%) male. The design of the headsets can be pleasing to the user by reducing the need for worm gears, cables, linkages, and adjustment knobs. Further, the present invention focuses on providing flexibility, stability, and comfort to a wide range of users. To achieve a present invention with a broad reach, a stiffness equation is considered that can be expressed as the following:
 
Stiffness=3 E*I/l   3 ,
 
where E is the elastic modulus of the spring (material property), I is the bending moment of inertia, and l is the length of the beam. I is also a function of the width (b) and thickness (h) of the cross section of the spring or beam, and the equation can be further expressed as follows:
 
Stiffness=(3 E*b*h   3 )/(12 *l   3 ) or Stiffness= E*b*h   3 /4 *l   3  
 
     Turning now to  FIG. 4 , a method for changing a stiffness of a headband is provided in a process  400 . In a step  410 , a primary spring  210  and a secondary spring  215  are aligned together. Primary spring  210  and secondary spring  215  are flexible curved beams and have the shape of an arc. In a step  412 , primary spring  210  and secondary spring  215  are shaped to caress and fit against a human head. Primary spring  210  and secondary spring  215  are joined together with moveable clamps  220   a ,  220   b , and  220   c , in a step  414 . In a step  416 , a member of moveable clamps  220   a ,  220   b , and  220   c  is moved along primary spring  210  and secondary spring  215  such that the member clamps primary spring  210  and secondary spring  215  together at a particular point and varies the stiffness of headband  200  relative to the member being located a different point along primary spring  210  and secondary spring  215 . In a step  418 , the stiffness of headband  200  is increased by increasing spacing between moveable clamps  220   a ,  220   b , and  220   c  positioned along primary spring  210  and secondary spring  215 . 
     In  FIG. 5 , a method for changing a clamping force to a head of a user is provided in a process  500 . In a step  510 , a first flexible material  310  and a second flexible material  315  are elongated in a headband  300   c . In a step  512 , the first flexible material  310  and the second flexible material  315  are shaped into an arc to fit over the head of a user. The first flexible material  310  is created with a length longer than the second flexible material  315 , in a step  514 . In a step  516 , the first flexible material  310  and the second flexible material  315  are aligned together. In a step  518 , the first flexible material  310  and the second flexible material  315  are clamped together with moveable clamps  320   a ,  320   b , and  320   c . Moveable clamps  320   a ,  320   b , and  320   c  are moved to different positions along the first flexible material  310  and the second flexible material  315  to change a stiffness in headband  300   c , in a step  520 . 
     Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of embodiments of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated to be within the scope of the claims.