Patent Publication Number: US-2007103111-A1

Title: Power Insert

Description:
This invention relates to an adaptor plug and connector, which facilitates substitution of an external battery for the standard internal batteries which supply power to a hand held power tool. (i.e., cordless drills, reciprocating saws, circular saws, including various other portable tools, for which batteries are required for operation.)  
      As well recognized in the art, rechargeable batteries, such as those comprised of nickel-cadmium alloy, greatly reduce the need for replacement, but require frequent recharging. While sufficient for intermittent use, battery life shortens rapidly with continuous use, i.e. hand held power tools when such a tool is in frequent use. The reduction of available battery power results in annoying operating limitations that require more frequent battery replacement when the power tool is in use for extended periods of time.  
      Various devices exist for substituting power supplied by dry cell batteries including that illustrated in U.S. Pat. No. 3,308,419, which shows power supply featuring a battery shaped connector having helical contacts mounted thereon. Such a device however lacks means to guide and position same snugly within the housing confines of a power-operated tool. Devices such as those disclosed in U.S. Pat. No. 4,835,410 feature a combined corded and cordless system for power operated tools, but contemplate only internal batteries for supplying DC power source, rather than an external battery.  
      It is an important object of the invention to provide a hand held power tool capable of being powered either by internal batteries or alternatively by an external battery. Another important object of the invention is to provide an adaptor, which cooperates with the existing housing and maintains DC continuity. Another important object of the invention is to permit the substitution of alternative DC power for the internal batteries. Another important object of the invention is to provide an adaptor that includes vertically and longitudinally spaced members to guide and position the adaptor within the battery housing of hand held power tool.  
     SUMMARY OF THE INVENTION  
      It has been found that a hand held power tool may be supplied with an adaptor, which facilitates substitution of power from an external DC power source. The adaptor is perfectly formed to the battery housing of the hand held power tool. Enclosed within the adaptor body member is an overcurrent device with contacts that protect the motor of the hand held power tool. Additionally, the adaptor is provided with a swivel interface connector that facilitates power from an external battery-to-battery housing device. The invention thereby allows for an external battery to be readily substituted for internal batteries in a hand-held power tool. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The construction designed to carry out the invention will be hereinafter described, together with other features thereof.  
      The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein.  
      (1)  FIG. 1  is a perspective view illustrating the longitudinal and side elevational exterior of power insert device.  
      (2)  FIG. 2  is a perspective view illustrating the various operating components of the adaptor constructed in accordance with the preferred embodiment of the invention.  
      (3)  FIG. 3  is a partial longitudinal sectional elevation view of  FIG. 2 . 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT  
      The subsequent drawings illustrate an adaptor plug and connector for substituting an external battery for internal batteries that supply power to a hand held tool.  
       FIG. 1  shows an overall drawing of exterior longitudinal and elevated views. The diametrically opposed contacts  1   a  and  1   b  thereof, which connect and conform to the confines of the interior battery compartment of the power tool, are electrically connected to the interior of the battery insert device. The interface connector  2 , and swivel attachment  3 , add to stabilization and ease of use of insert device.  
       FIG. 2  illustrates battery contacts  1   a ,  1   b , attached to Center Stabilizer  4 , secured to base stabilization support  3 A (illustrated in  FIG. 3 ), affixed to fuse holder/insert  7 , supported and stanchioned by insulated spacer  6 , connected through overcurrent protection device  8 , returning through interface connector  2 , via swivel adapter  3 , terminating at external power plug  5 .  
       FIG. 3  depicts top view of battery compartment exterior/interior structural components of battery insert device. Center stabilizer  4 , base/stabilization support  3 A, are offset for stabilization while providing integral structural strength for  1   a / 1   b  battery contacts. Stop/End gap posts  2 , allow balanced movement of Swivel attachment  3 , for flexibility to external power attachment  5 .