Patent Publication Number: US-7717736-B2

Title: Sheath for a flexible electrical contact

Description:
FIELD OF INVENTION 
   The present invention relates to a sheath for use with a flexible electrical contact incorporated in a sound reproduction device to minimize resonance vibration of the flexible electrical contact during operation of the sound reproduction device. 
   BACKGROUND 
   The explosive growth in demand for portable digital entertainment devices has correspondingly led to an increase in demand for accessories for use with such portable digital entertainment devices. It is likely that such accessories will include, for example, earphones, headphones, speakers and other sound reproduction devices. It is likely that these sound reproduction devices are also portable and either draw power from the portable digital entertainment devices or are independently powered. 
   Portable power sources used by the independently powered sound reproduction devices like speakers include dry cell batteries. These speakers usually have at least one compartment/receptacle for placement of the dry cell batteries to enable the operability of the speakers. It is common practice that conductive electrical contacts are used in the at least one compartment/receptacle to enable electrical connectivity between the dry cell batteries and the speakers. It is also common for such sound reproduction devices to be able to operate using an alternative power source like an AC power source such as an electrical mains supply. In this regard, when the sound reproduction device is operating while using an AC power source, the compartment/receptacle for the dry cell batteries is usually left empty unless the dry cell batteries are able to be recharged by the AC power source when placed in the at least one compartment/receptacle. 
   As such, when the compartment/receptacle for the dry cell batteries is empty when the sound reproduction device is in operation, the conductive electrical contacts would generally tend to resonate and correspondingly create undesirable resonance noise. These resonance noises (vibrations) directly affect the quality of sound reproduction in a detrimental manner. 
   While the resonance vibrations of the conductive electrical contact may be minimized by increasing the stiffness of the material used, this may affect the ease of dry cell battery placement in the compartment/receptacle. This would be detrimental to the usability of the sound reproduction device. 
   SUMMARY 
   In a first aspect of the present invention, there is provided a sheath for a flexible electrical contact that is incorporated within a sound reproduction device. The sheath preferably includes at least one opening at each end of the sheath to enable the sheath to be worn over the electrical contact with each opening having a thickened periphery ring. The main body of the sheath may be either a cylindrical shape or a conical shape. It is advantageous that the sheath damps a resonance vibration of the flexible electrical contact during operation of the sound reproduction device when the sheath is worn over the flexible electrical contact. The flexible electrical contact may be incorporated within a battery compartment of the sound reproduction device. 
   It is preferable that the sheath may be made of a material of a type selected from for example, heat-resistant, chemical-resistant, elastic, flexible, compressible or any combination of the aforementioned. The material may be either rubber or a polymer. 
   Removal of the sheath from the flexible electrical contact may be hampered due to measures such as, for example, constriction of the main body of the sheath around the flexible electrical contact, constriction of the thickened periphery rings on the flexible electrical contact, having a high coefficient of friction in an inner surface of the sheath contacting the flexible electrical contact or any combination of the aforementioned. Advantageously, the thickened periphery rings may aid in securing the sheath to the flexible electrical contact during compression and subsequent rebound of the flexible electrical contact. 
   In a secondary aspect of the present invention, there is provided a method to minimize resonance vibration from a flexible electrical contact incorporated within an operational sound reproduction device by using a sheath worn over the flexible electrical contact. Such a sheath may preferably be made of a material of a type that is heat-resistant, chemical-resistant, elastic, flexible, compressible or any combination of the aforementioned. The material may be either rubber or a polymer. Removal of the sheath from the flexible electrical contact may be hampered due to measures such as, for example, constriction of the main body of the sheath around the flexible electrical contact, constriction of the thickened periphery rings on the flexible electrical contact, having a high coefficient of friction in an inner surface of the sheath contacting the flexible electrical contact or any combination of the aforementioned. Advantageously, the thickened periphery rings may aid in securing the sheath to the flexible electrical contact during compression and subsequent rebound of the flexible electrical contact. 

   
     DESCRIPTION OF DRAWINGS 
     In order that the present invention may be fully understood and readily put into practical effect, there shall now be described by way of non-limitative example only preferred embodiments of the present invention, the description being with reference to the accompanying illustrative drawings. 
       FIG. 1  shows a perspective view of a first embodiment of the present invention. 
       FIG. 2  shows a perspective view of a flexible electrical contact. 
       FIG. 3  shows a perspective view of the flexible electrical contact of  FIG. 2  wearing a second embodiment of the present invention. 
       FIG. 4  shows a perspective view of an empty dry cell battery compartment of a sound reproduction device employing the second embodiment of the present invention. 
       FIG. 5  shows a perspective view of a fully loaded dry cell battery compartment of the sound reproduction device employing the second embodiment of the present invention. 
       FIG. 6  shows a perspective view from another angle of the sound reproduction device of  FIG. 4 . 
       FIG. 7  shows a flow chart for a method of the present invention. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1-5 , there is provided preferred embodiments of the present invention in the form of a sheath  20  for a flexible electrical contact ( 30  in  FIGS. 2-3 ) that is incorporated within a sound reproduction device ( 50  in  FIGS. 4-5 ). The sheath  20  may include at least one opening at each end  22 ,  24  of the sheath  20  to enable the sheath  20  to be worn over the electrical contact  30 . Each end  22 ,  24  of the sheath  20  may have a thickened periphery ring  23 ,  25  respectively to aid in securing the sheath  20  to the electrical contact  30  when the sheath  20  is worn over the electrical contact  30 . The thickened periphery rings  23 ,  25  may aid in securing the sheath  20  to the electrical contact  30  during compression and subsequent rebound of the electrical contact  30  (by constricting around the respective ends  22 ,  24  of the sheath  20 ). The sheath  20  may include a main body  26  which may be of either a cylindrical shape (as shown in  FIG. 1 ) or a conical shape (as shown in  FIGS. 3-5 ). The shape of the main body  26  need not be restricted to the aforementioned shapes. 
   The sheath  20  may be made from a material that may be heat-resistant, chemical-resistant, elastic, flexible, compressible or any combination of the aforementioned. Heat resistance of the material may be essential as it would be detrimental to the performance of the electrical contact  30  if the sheath  20  melts or undergoes heat induced deformation. Chemical resistance of the material may be essential as it would be detrimental to the performance of the electrical contact  30  if the sheath  20  chemically reacts when coming into contact with chemicals like alkalis that leak from dry cell batteries. The material used for the sheath  20  may be either rubber or a polymer. The material used may enable the main body  26  of the sheath  20  to constrict around the electrical contact  30  when the sheath  20  is worn on the electrical contact  30  as shown in  FIG. 3 . The constriction of the main body  26  of the sheath  20  around the electrical contact  30  may hamper removal of the sheath  20  when the sheath  20  is worn on the flexible electrical contact  30 . Constriction of the thickened periphery rings  23 ,  25  may also aid in securing the sheath  20  to the electrical contact  30 . Alternatively, an inner surface  28  of the sheath  20  in contact with the flexible electrical contact  30  may have a high coefficient of friction to also hamper removal of the sheath  20  when the sheath  20  is worn on the flexible electrical contact  30 . The high coefficient of friction may be due to grip patterns on the inner surface  28  of the sheath  20 . The sheath  20  may constrict around the flexible electrical contact  30  (with both the main body  26  and periphery rings  23 ,  25 ), and have an inner surface  28  of the sheath  20  with a high coefficient of friction to hamper removal of the sheath  20  when the sheath  20  is worn on the flexible electrical contact  30 . 
   Referring to  FIG. 4 , there is shown an empty dry cell battery compartment/receptacle  52  of the sound reproduction device  50 , where a first electrical contact  54  is shown wearing the second embodiment of the present invention, a sheath  20  with a conical main body  26 . It should be noted that the other electrical contacts  56  are not wearing sheath  20 . A connector  58  connecting the sound reproduction device  50  to an AC power source is shown, denoting that in such an instance where the dry cell battery compartment/receptacle  52  is empty (has no batteries), the sound reproduction device  50  may be powered by the AC power source. When the sound reproduction device  50  is operational in such an instance, the first electrical contact  54 , and other electrical contacts  56  would generally tend to resonate and correspondingly create undesirable resonance noise (vibrations). These resonance noises directly affect the quality of sound reproduction produced by the sound reproduction device  50  in a detrimental manner. Wearing the sheath  20  on each electrical contact  54 ,  56  in the manner shown for the first electrical contact  54  (expanded view shown in  FIG. 3 ) would damp a resonance vibration of each electrical contact  54 ,  56  during operation of the sound reproduction device  50 . Doing this may enhance the quality of sound reproduction produced by the sound reproduction device  50 . 
   With reference to  FIG. 5 , there is shown an instance of the dry cell battery compartment/receptacle  52  of the sound reproduction device  50  being fully loaded with batteries  60 . It should be noted that the connector  58  has been removed (omitted), showing how the same sound reproduction device  50  is also operable using only batteries  60 . More importantly, it can be seen that the first electrical contact  54  is still able to wear the sheath  20  when the batteries  60  are in contact with the electrical contact  54 . Even though the sheath  20  may be made from an electrically insulating material, it can be seen from  FIG. 3  that the sheath  20  does not hamper contact between the electrical contact  30  and a battery due to the open first end  22 . It can be seen that the sheath  20  may be left on the electrical contact  54  regardless of power source selected by a user. 
     FIG. 6  shows a perspective view of the sound reproduction device  50  of  FIGS. 4-5  from another angle. It should be noted that while the sound reproduction device  50  is shown to be a speaker  51  cum dock  53  for a portable digital entertainment device, the use of the sheath  20  should not be restricted for use with such specific types of devices. 
   With reference to  FIG. 7  and also by inference from the earlier sections of the description, there is also provided a method  100  to minimize resonance vibration from a flexible electrical contact  30  incorporated within an operational sound reproduction device  50  using a sheath  20  worn over the flexible electrical contact(s)  30 . 
   Initially, there is a determination in relation to whether there are flexible electrical contact(s)  30  incorporated within the sound reproduction device  50  ( 102 ). If no, there would be no resonance vibration due to flexible electrical contact(s)  30  when the sound reproduction device  50  is in operation ( 104 ). If there are flexible electrical contact(s)  30  incorporated within the sound reproduction device  50 , the sheath  20  should be worn over each flexible electrical contact(s)  30  ( 106 ). In this regard, resonance vibration from each flexible electrical contact(s)  30  may be minimized (damped by the sheath  20 ) when the sound reproduction device  50  is in operation ( 108 ). 
   It should be noted that the sheath  20  may be made from a material that may be heat-resistant, chemical resistant, elastic, flexible, compressible or any combination of the aforementioned. Heat resistance of the material may be essential as it would be detrimental to the performance of the electrical contact  30  if the sheath  20  melts or undergoes heat induced deformation. Chemical resistance of the material may be essential as it would be detrimental to the performance of the electrical contact  30  if the sheath  20  chemically reacts when coming into contact with chemicals like alkalis that leak from dry cell batteries. The material used for the sheath  20  may be either rubber or a polymer. The material used may enable the main body  26  of the sheath  20  to constrict around the electrical contact  30  when the sheath  20  is worn on the electrical contact  30 . The constriction of the main body  26  of the sheath  20  around the electrical contact  30  may hamper removal of the sheath  20  when the sheath  20  is worn on the flexible electrical contact  30 . Constriction of the thickened periphery rings  23 ,  25  may also aid in securing the sheath  20  to the electrical contact  30 . Alternatively, an inner surface  28  of the sheath  20  in contact with the flexible electrical contact  30  may have a high coefficient of friction to also hamper removal of the sheath  20  when the sheath  20  is worn on the flexible electrical contact  30 . The high coefficient of friction may be due to grip patterns on the inner surface  28  of the sheath  20 . The sheath  20  may constrict around the flexible electrical contact  30  (with both the main body  26  and periphery rings  23 ,  25 ), and have an inner surface  28  of the sheath  20  with a high coefficient of friction to hamper removal of the sheath  20  when the sheath  20  is worn on the flexible electrical contact  30 . 
   It should also be noted that the flexible electrical contact  30  need not refer only to those found in the dry cell battery compartment/receptacle  52  of the sound reproduction device  50 . The flexible electrical contact  30  may refer to any such part incorporated in the sound reproduction device  50  that may vibrate during operation of the sound reproduction device  50 . 
   Whilst there has been described in the foregoing description preferred embodiments of the present invention, it will be understood by those skilled in the technology concerned that many variations or modifications in details of design or construction may be made without departing from the present invention.