Abstract:
A method of configuring a soldering device includes the steps of purchasing (or offering for sale) a soldering device package including a handle, a power cartridge containing an AA battery, a power cartridge containing a lithium ion battery, and a power cartridge containing a nickel-hydride battery; selecting (or instructing a user to select) one of the three power cartridges from the purchased soldering device package for use with the handle to form a soldering device; and inserting the selected power cartridge in the handle to form a soldering device. The selecting step includes selecting one of the three power cartridges based on a specific use of the soldering device and based on soldering performance requirements of the specific use and based on operating times and relative costs of the power cartridges.

Description:
[0001]    The present application is a division of U.S. patent application Ser. No. 10/892,780, filed Jul. 15, 2004, the entire disclosure of which application is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Soldering irons are used to make secure electrical connections by melting solder and allowing the solder to bond between two electrical devices such as wires and contact points of a circuit. A number of different types of soldering irons are in wide-spread use and have been available for a number of years. Most soldering devices are powered by electrical current, and particularly for industrial applications, the soldering devices use an AC power source. However, there are a few battery powered soldering devices that are available though their performance is somewhat limited. Examples are shown in U.S. Pat. Nos. 2,973,422; 3,141,087; 3,141,956; 4,064,447 and 5,446,262. In addition, to provide flexibility in a soldering device that has no electrical power connection requirement, there are soldering devices that utilize a gaseous fuel to heat a soldering tip through for example a catalyst or an open flame, as shown for example in U.S. Pat. Nos. 5,799,648 and 5,921,231. 
         [0003]    The need for a soldering device which can provide the performance of industrial soldering irons with the portability of a non-AC powered device have been somewhat limited. Industrial soldering devices allow the use of a number of different interchangeable cartridge soldering iron tips so that the soldering tip can be replaced easily to allow an operator to select the type of tip to be utilized in a specific soldering operation. Examples of cartridge type soldering devices are shown for example in U.S. Pat. Nos. 4,839,501 and 6,710,304. 
         [0004]    For the battery powered types of soldering devices, the various styles available are also somewhat limited as they do not include the flexibility which may be desired for hobbyists as well as professional users and craftsmen. Hobbyists may only require a soldering device to make a couple of solder connections at one time, they are generally not using the soldering iron for repetitive purposes on a continuous basis. By comparison, electricians working in certain circumstances may desire a portable battery powered soldering device that is both convenient and fully functional. Examples of these types of operations would include operations on power lines, changing out telephone systems in the field and home repair servicemen. For these types of operations, the control of the temperature of the soldering tip for use with various types of solders specified for certain types of electronic connections may become more important. 
       INVENTION SUMMARY 
       [0005]    The present invention is directed to a battery powered soldering device with a cartridge type battery system which includes a number of different optional battery packs or connections which can be utilized to provide a full range of soldering features in a cartridge type soldering tip device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a side view of the soldering device of the present invention with the protection cap removed. 
           [0007]      FIG. 2  is a side view of the soldering device with the protection cap attached. 
           [0008]      FIG. 3  is a side view of the soldering device and the various cartridges that can be used to provide power to the soldering iron tip. 
           [0009]      FIG. 4  is a side-partially lateral view of the soldering device and cartridges of  FIG. 3 . 
           [0010]      FIG. 5  is an exploded side view of the soldering device of  FIG. 1 . 
           [0011]      FIG. 6  is a partially cut-away side view of the cartridge soldering tip of the soldering device of the present invention. 
           [0012]      FIG. 7  is a graph depicting the tip temperature performance of the battery cartridges of the soldering device. 
           [0013]      FIG. 8  is a graph depicting tip temperature degradation for successive soldering events for the various battery cartridges of the soldering device of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]      FIGS. 1 and 2  depict side views of a soldering device  10  according to the present invention. The soldering device  10  includes a handle  12  onto which a cartridge soldering tip  14  may be mounted by the use of a securing nut  16 . The soldering device preferably includes a protection cap  18  shown removed in  FIG. 1  and shown attached in  FIG. 2  to the handle  12 . The protection cap  18  covers the cartridge soldering tip  14  when it is not in use. 
         [0015]    The soldering device  10  also includes a battery cartridge  20  which is removably attached to the handle  12 . The battery cartridge  20  provides the electrical power for heating the cartridge soldering tip  14 . 
         [0016]    The battery cartridge  20  depicted in  FIGS. 1 and 2  is preferably configured to contain four AA batteries arranged in two rows of two batteries placed end to end. The AA batteries may be either the non-rechargeable alkaline batteries or rechargeable nickel hydride batteries. 
         [0017]    The battery cartridge  20  is removable and indeed replaceable with alternate battery cartridges  22  and  24  depicted in  FIG. 3 . Battery cartridge  22  is designed to contain a lithium ion type rechargeable battery. Battery cartridge  24  is designed to contain nickel hydride rechargeable batteries. 
         [0018]    As another alternative to the battery cartridges  20 ,  22  and  24 , the soldering device may have an attachment  26  which is essentially an electrical feed through system that allows for the attachment of a cartridge holder  28 , which may for example be held in a pocket or attached to the belt of a user, and is configured to hold any of the battery cartridges  20 ,  22  and  24 . Alternatively attachment  26  allows for attachment to an AC adapter  30  that may be plugged into an AC power outlet and convert the AC power to a nine volt DC output. Both the cartridge holder  28  and the AC adapter  30  have a cable  32  terminating in a connector plug  34  which is configured to plug into a connector receptacle  36  on attachment  26  to provide electrical power thereto. The attachment  26  can be installed into the soldering device  10  in the space configured to receive the battery cartridge  20 . For ease of use, the cartridge holder  28  may include a belt clip  38  to allow a user to secure the cartridge holder  28 , and a battery cartridge attached thereto to a work belt or pocket and yet still provide freedom to work in a remote location without AC power. 
         [0019]    As depicted in  FIGS. 1 through 3 , the handle  12  of the soldering device  10  includes a strap attach extension  40  at its rearward end. This allows for a strap or other securement device to be attached to the end of the handle  12 . In addition, mounted on the handle  12  near the forward end where the operator&#39;s index finger will have ready access is on-off switch  42 . When pushed forward towards the cartridge soldering tip  14 , the on-off switch  42  is in the “on” position. When pushed backwards towards the strap attach extension  40 , the on off switch  42  is in the “off” position. As best depicted in  FIG. 2 , the protection cap  18  features a switch lip  44  extending so as to interengage with the on off switch  42  whenever the protection cap  18  is installed over the handle  12  such that the switch lip  44  will push the on-off switch  42  to the “off” position. This is a protection feature to prevent the soldering device  10  from inadvertently being turned on when the protection cap  18  is in place. 
         [0020]      FIG. 4  depicts a side partially cut away view of the soldering device  10  in particular the handle  12  and the battery cartridges  20 ,  22 , and  24 . As depicted, the electronics included within the handle  12  are minimized. The handle  12  includes two spring contacts  50  and  52  which provide the means for electrical contact between the handle  12  and the various cartridges or attachments  20  through  26 . Spring contact  50  is electrically connected to a first pole of a two position on-off switch  42 . The spring contact  52  is connected to a leaf contact connector  54  which electrically contacts one electrical terminal  56  on the soldering tip cartridge  14 . A second leaf contact connector  58  is adapted to receive electrical power from the on-off switch  42  when it is in the “on” position and is configured so as to contact a second electrical terminal  60  on the cartridge soldering tip  14 . The handle  12  may also include an LED or light  62  which is electrically connected to the switch  42  so that it is illuminated whenever the switch  42  is turned on. In addition, the LED circuit may include a resistor  64  for minimizing the utilization of electric power going to the LED  62 . 
         [0021]    In this configuration, the handle  12  does not have the capacity to regulate the amount of power delivered from the battery cartridges  20 ,  22  or  24  to the soldering tip. When the AA battery cartridge  20  is used, the amount of power that is provided by the four AA batteries is suitable to power the soldering tip without the requirement for regulation. Accordingly, the simple construction of the handle  12  is satisfactory for utilization with the AA battery cartridge and the cartridge tip  14  which is designed for utilization with the soldering device. The cartridge tip  14  is described in greater detail below. 
         [0022]    As shown near the top of  FIG. 4 , the AA battery cartridge  20  includes four AA batteries mounted within a housing. The top set of AA batteries has the positive terminal pointing towards the spring connector  50  while the bottom set of batteries has a negative terminal pointing towards the spring connector  52  on the handle  12 . At the rear end of the battery cartridge  20  is an electrical contact  68  to both contact the positive end of the battery positioned on the bottom and the negative end of the battery positioned on the top to thereby connect all four of the batteries in a series connection. The battery cartridge  20  includes openings at its forward end so that the contacts  50  and  52  of the handle  12  directly contact the exposed battery terminals when the batteries are in place within the cartridge  20  and so there is no need for additional electrical conductors to interconnect to the batteries within the cartridge  20  and the overall size of the battery cartridge  20  is thereby minimized. 
         [0023]    By comparison to the AA battery cartridge  20 , the battery cartridge  22  for the lithium ion battery and the battery cartridge  24  for the nickel hydride battery both include a first chamber for containing the battery or batteries,  70  and  72  respectively, and a second chamber  74  and  76 , respectively for mounting a circuit board  78  and  80 , respectively. 
         [0024]    The battery cartridge  22  contains a lithium ion battery  82  having positive and negative terminals  84  and  86  respectively. The lithium ion battery is generally rectangular in shape and fits within the chamber  70  of the battery cartridge  22 . The circuit board  78  within the chamber  74  of battery cartridge  22  includes electrical contacts to both contact the positive terminal  84  and the negative terminal  86  of the lithium ion battery  82  as well as terminals  88  and  90  that allow interconnection to the spring connectors  50  and  52  of the handle  12 . The circuit board  78  includes a control circuit for controlling the output power of the lithium ion battery  82  provided to the cartridge soldering tip  14  whenever the on-off switch  42  is in the “on” position, to maintain a desired tip temperature. The control circuit controls the tip temperature by cycling the delivery of power from the battery to the cartridge tip. 
         [0025]    Battery cartridge  24  includes chamber  72  adapted to hold at least two and preferably six nickel hydride batteries  100 . The chamber  72  includes electronic contact board  102  to provide series connections with the various ends of the batteries  100 . The chamber  76  including the circuit board  80  is adapted to allow the circuit board  80  to have contacts  104  and  106  that electrically contact to a circuit on the forward end of the chamber  72  to allow interconnection of the positive and negative terminal of the plurality of batteries  100  to provide a complete series circuit to deliver power from the nickel hydride batteries  100  to the contacts  104 ,  106  of the circuit board  80 . The circuit board  80  also includes electrical contact terminals  108  and  110  for interconnecting to the spring contacts  50  and  52  of the handle  12  whenever the battery cartridge  24  is installed into the handle  12 . 
         [0026]    The circuit board  80  includes the circuitry for controlling the output power delivered to the cartridge soldering tip  14  to maintain a desired tip temperature so that too much power is not delivered during normal usage of the cartridge soldering tip  14 . The circuitry for controlling the power output for the battery cartridges  22  and  24  by cycling the delivery of power is dependent upon the required input power for the particular type of cartridge soldering tip  14 , and the desired tip temperature. However, generally, the circuit boards are designed to take the input power from the lithium ion battery in the battery cartridge  22  or the nickel hydride battery in the battery cartridge  24  and cycle a 7.2 to 7.4 volt output. 
         [0027]    In  FIG. 4 , each of the cartridges  20 ,  22  and  24  as well as the attachment  26  include a tab at a rear end and a slide switch on their rear face that allows for securing and disconnecting the cartridge to the handle  12 . The forward end of each of the cartridges  20 ,  22  and  24  as well as the attachment cartridge  26  are sized to fit within the receiving slot of the handle  12  such that the attachment tab at the rear edge of the respective cartridge can secure the cartridge in place. Accordingly, the cartridges are easily removed from the handle  12  and can be replaced. 
         [0028]      FIG. 5  depicts an exploded partially cross-sectional view of the cartridge system of the soldering device  10 . The rear portion of the handle  12  is cut away to expose the inner surface  120  which has a slot  122  extending upward. In  FIG. 5 , the battery cartridge  20  is depicted. The battery cartridge has a rear end having a sliding lock assembly  124  with a mount release  126  that moves up so that it can be inserted into slot  122  of the handle  12  to secure the battery cartridge  20  in place and allow the battery cartridge  20  to be removed when the sliding lock assembly  124  and mount release  126  move down, where upon the battery cartridge  20  can be slid rearward and extracted from the handle  12 . This simple configuration allows the respective battery cartridges to be easily installed and removed from the handle  12 . 
         [0029]    In  FIG. 5 , the securing nut  16  is shown removed forward from the soldering tip cartridge  14  which slides into a receiving hole in the handle  12 . Once the cartridge soldering tip  14  is installed, the securing nut  16  is inserted over the cartridge soldering tip  14  to allow securement to the handle  12 . As configured, the securing nut  16  includes a plurality of beveled tabs  130  which extend through slots  132  in the receiving orifice  134  of the handle  12  and thereby the securing nut  16  can be rotated in order to lock in place in the handle  12 . Alternatively, the securing nut  16  could have threads which mount to a threaded orifice on the end of the soldering handle  12  and there are other types of attachment mechanisms which could be utilized. For convenience and ease of use, the relatively simple configuration depicted is used so that the securing nut  16  only needs to be rotated a partial rotation in order to be locked in place. 
         [0030]    The cartridge soldering tip  14  as shown in  FIG. 5  has a ridge  140  which engages with an inner lip (not shown) of the securing nut  16  and is thereby positioned securely in place. As noted above, the cartridge soldering tip  14  also has at least two electrical terminals  56  and  60  which connect electrical power received from the handle  12 . 
         [0031]    A cross-sectional view of the cartridge soldering tip  14  is depicted in  FIG. 6 . Therein, the ridge  140  as well as the two electrical terminals  56  and  60  are illustrated at the rearward end of the cartridge tip  14 . Positioned inside the cartridge soldering tip  14  are wire leads  142  and  144  which extend forward and are protected by a thin protection pipe  146 . Mounted at the forward end of the protection pipe  146  is a soldering iron tip  148  which can have a number of different shapes. The soldering iron tip  148  is preferably formed from a copper material and may include an iron coating. The soldering iron tip  148  includes a hollow interior portion  150  which receives a heater element  152  electrically connected to the connections or wire leads  142  and  144 . The heater element  152  is a wire wound about a ceramic core  154 . The tip temperature is controlled, if necessary through a feedback sensor which interacts with the circuit boards on the battery cartridge  22  and  24 . 
         [0032]    The cartridge soldering tip  14  is configured to allow ease of interchangeability depending on the particular configuration of the tip design desired by the operator. The ease of replacement also allows the cartridge soldering tip  14  to be replaced when the tip is corroded to the point where it is no longer serviceable. The relatively simple construction of the cartridge soldering tip  14  is specifically designed to be utilized with the voltage outputs provided by the interchangeable battery packs and yet provide adequate heat to allow soldering irrespective of the cartridge pack that is utilized. The thin wall of the protection pipe minimizes the heat transfer rearward towards the handle  12  so as to concentrate the heat at the soldering iron tip. 
         [0033]    The present invention provides a number of advantages in that the operator or user of the soldering device  10  can choose what battery cartridge to mount on the handle  12  depending on the soldering performance requirements, the operating time and the relative cost of the various cartridges. This allows the operator to choose the right battery or power pack for the work that is being done and allows the operator to tailor the power output to the requirements for the specific task while, if desirable, minimizing the cost that the operator needs to pay to acquire one or more of the various cartridge packs. 
         [0034]    The cartridge soldering tip  14  is configured to prevent the heat transferring from the protection pipe to the soldering device and configured so that a majority of the heater element  152  is not even within the dimensions of the protection pipe  146 . The protection pipe  146  has a minimal thickness of example approximately 0.15 mm. so that it provides the necessary structural rigidity yet minimizes the heat transfer. To improve the heat conductivity from the heater element  152  to the outer surface of the soldering iron tip, the hollow portion  150  within the soldering tip extends as far as possible into the soldering tip so that the heater can be dimensioned and disposed within the soldering tip so that heat from the heater effectively transfers directly to the soldering iron tip and therethrough to the surface of the soldering iron tip. To increase the heat produced from the heater, the diameter of the heater wire is minimized, for example to approximately 0.18 mm., and the heater wire leads are formed from a copper—nickel alloy. 
         [0035]    The various types of battery cartridges  20 ,  22  and  24  that are used with the handle  12  can be provided either individually or as a set with the handle  12  depending on the user&#39;s preference. Generally, the battery cartridge  20  for the four AA batteries is suitable for hobby or non-industrial use featuring low cost for the overall system. Indeed, the overall cost is minimized by utilizing the terminals of the battery as the terminals of the cartridge assembly as discussed above. This also allows easy replacement of the batteries as the AA batteries are generally available in the marketplace. 
         [0036]    The cartridge having the battery cartridge  24  having the nickel hydride batteries features a higher output and higher performance, wherein temperatures controlled again at a relatively low cost however, the charging time for these types of batteries is longer and the size of the battery cartridge when six batteries are configured for use is relatively large as compared to the four AA battery cartridge  20 . 
         [0037]    The battery cartridge  22  for containing the lithium ion battery also features a high performance with temperature control, however this type of battery is more expensive and is generally designed for a particular use. The advantages would also include a smaller battery cartridge and a relatively short charging time as compared to the charge time of the nickel hydride batteries in the battery cartridge  24 . 
         [0038]    As compared to these battery cartridge configurations, the use of the attachment cartridge  26  which may be plugged into either a cartridge holder  28  to which any of the cartridges  20 ,  22 , and  24  may be attached, or to the AC adapter  30 , provide even more flexibility for the user who needs extended duration power for remote locations using the cartridge holder  28  and spare battery cartridges or who may have access to AC power and therefore wishes to conserve on battery usage by simply plugging into the AC adapter. 
         [0039]    For each of the configurations, it is necessary to obtain a relatively high temperature at the tip in order to perform effectively soldering. High temperature in the tip requires both attainment of the high temperature and it is stabilized regardless of the amount of the battery power that is left. The following chart compares the performance of each of the types of battery cartridges tested with the foregoing configuration. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Alkaline/nickel hydride cartridge 
                 Nickel hydride 
                 Lithium-ion 
               
               
                   
                 4 batteries 
                 cartridge (6) 
                 cartridge 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Used battery 
                 Alkaline (AA) 
                 Nickel hydride (AA) 
                 Nickel hydride 
                 Lithium ion 
               
               
                   
                   
                   
                 (AA)/(AAA) 
                 (exclusive) 
               
               
                 Controlling method 
                 saturate 
                 saturate 
                 Controlled 
                 controlled 
               
               
                 Possible time of use 
                 About 30 min. 
                 80 min. 
                 120 min. 
                 70 min. 
               
               
                 price 
                 Low priced 
                 Middle priced 
                 Middle priced 
                 expensive 
               
               
                 Charging time 
                 N/A 
                 4-10 h 
                 4-10 h 
                 1 h 
               
               
                   
               
             
          
         
       
     
         [0040]    Attached as  FIG. 7  is a graph depicting the property of the tip temperature when the battery pack is fully charged until the battery power is lost. As depicted, the battery power is reduced or the temperature drops most with the alkaline batteries and least with the lithium ion batteries. In this figure, the tip temperature can rapidly rise to about 300 degrees Centigrade where it is useful. The startup time for the alkaline batteries is approximately 80 seconds and has an operable life of about 30 minutes. By comparison, the lithium ion battery has an operable life of over one hour and a start up time of about 30 seconds, while the nickel hydride battery has a operable time of over 2 hours and a start up time of about 2 minutes. 
         [0041]    The graph of  FIG. 8  shows the results of a test of the recovery property when the soldering iron is used a plurality of times in succession. The test was conducted on a solder wire having a diameter of 1.6 mm. and a length of approximately 5.0 mm. soldered to a circuit board substrate having a 10 sq. mm. contact area for a 3 second solder interval. The alkaline and nickel hydride battery cartridge was used to make 6 to 7 repetitive solder connections. By comparison, the lithium ion battery allows soldering of up to approximately 1,000 times before the battery lost power. The graph depicts each of the soldering times for the soldering occurrences for the alkaline and the nickel hydride batteries and depicts the tip temperature on the vertical axis over time duration on the horizontal axis. 
         [0042]    As may be appreciated from the foregoing charts, that the lithium ion battery provides the most power and the longest soldering life for one charge, however it is the most expensive yet easy to recharge. The various configurations available, however, allow the operator to choose both the performance requirement and the expense associated with the soldering operations. The present invention thus provides a soldering device  10  which includes interchangeable cartridge assemblies and a convenient replacement system so that the cartridge can be matched to the handle  12  for necessary and desired performance. The circuitry for maintaining the power output for the higher power output cartridge configurations is included within the cartridge assembly as opposed to in the handle assembly, so the handle assembly is primarily an electrical contact feature system thereby minimizing its cost. The assembly of the foregoing soldering system has not heretofore been available and provides users with a viable option to existing battery powered soldering irons or gas powered soldering irons for industrial applications. The foregoing description is provided to describe the present invention but is not intended to limit the scope of the invention which is to be defined by the appropriate construction of the claims appended hereto.