Abstract:
A solder feeder includes a housing member, a solder gripper assembly with a solder guide tube, a solder holder, a trigger means, and a solder path tube receiving a straight or a curved nozzle. Solder from a solder spool is extended forward when the trigger means is engaged or activated. The solder guide tube from the solder gripper assembly recesses into the solder path tube to provide a guaranteed solder path when the solder wire is advanced forward. The solder wire is curved at a proper curvature when it escapes from a tip of the nozzle. An electric version of the solder feeder uses a DC motor to drive a pulley to wind a belt or a cable for advancing the solder wire forward. Both devices extend a length of curved solder requiring the use of only one hand and allowing a true non-stop solder operation on copper pipe joints or similar tasks.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the invention  
         [0002]     The present invention generally relates to a solder feeder and more particularly to a solder feeder which allows a plumber or tradesman to reliably dispense lengths of straight or curved solder at a solder joint with one hand while using the other hand to operate a torch in soldering copper pipe joints and similar applications. The solder feeder is capable of dispensing all types and sizes of solders currently available.  
         [0003]     2. Description of the Prior Art  
         [0004]     Solder is melted at high temperature to join and seal copper pipes together to form a watertight connection. Plumbers use a torch with a high temperature flame to melt solders at the joint to join copper pipes. In a typical soldering operation on copper pipes, a plumber uncoils and extends a length of solder from a solder spool with a portion of the extended solder curved to conform to the body of the copper pipe. While using one hand to hold the solder spool and place the tip of the extended length of curved solder at the joint to be sealed, the plumber uses the other hand to hold a torch and applies heat to the joint. A solder joint is formed when the solder from the extended length melts at the joint. Every time the extended length of solder is consumed, additional solder must be extended from the spool and properly curved. Extending and curving additional solder requires two hands. For safety, the plumber must put down his torch to free his hands to do so. This kind of repeated interruption prolongs the plumbing task enormously.  
         [0005]     To save time, some plumbers often use both hands to uncoil and curve additional solder from the solder spool without putting down the torch. One obvious safety problem is that the flame from the torch may burn the plumber. Another safety problem is that the flame may ignite nearby walls, wood frames or structures when the plumber is uncoiling, extending, or bending the solder with a flaming torch still in one hand.  
         [0006]     It is therefore desirable to provide a solder feeder which can be used to hold a solder spool capable of extending a length of undamaged curved solder through a reliable path to a work area. More importantly, the solder feeder requires only one hand to operate. Known prior art solder feeders for plumbing applications having limited success in fulfilling all these capabilities include U.S. Pat. No. 5,813,591; U.S. Pat. No. 5,421,505; and U.S. Pat. No. 3,101,689 and U.S. Pat. No. 6,027,068.  
         [0007]     The device as described in U.S. Pat. No 5,813,591 extends a length of solder by pulling the solder spool backward a distance and then pushing the solder spool forward through a tightly coupled one-way cam. It is questionable that the somewhat soft solder wire is strong enough to reliably push through the one-way cam with only the force of the solder spool itself. Because the solder holder has no housing around it, there is no backing for the solder in any direction. When the solder spool is being pushed forward, the solder wire may escape backward or sideways if there is any resistance at the one-way cam. Also this device requires an operator to bend or curve the solder after it is extended out at the tip. Since the one-way cam is made of hard material, it may break the solder wire when the solder spool is pulled backward suddenly.  
         [0008]     Some disadvantages of the device as described in U.S. Pat. No. 5,421,505 have been pointed out with reference to U. S. Pat. No 5,813,591. Another potential problem is the use of hard material to move the solder forward. The pressing and turning of the hard material against the solder may cause permanent destructive damage to the solder. Also, this device does not curve the solder when extending out of the tip.  
         [0009]     The device disclosed in U.S. Pat. No. 3,101,689 also uses a hard material to press against the solder in order to move it. Other drawback is the need of initial alignment of the solder from the spool to the narrow and covered solder path and through the spring in front. Again, this device does not curve the solder when extending out of the tip.  
         [0010]     The device disclosed in U.S. Pat. No. 6,027,068 is intended for dispensing small diameter solder for electronic PCB soldering application. It uses a toothy gear to press solder against a grooved wheel and then manually rotates the toothy gear to move the solder forward. It cannot be readily adapted to dispense large diameter solders used for plumbing soldering applications. Large diameter solders require the exertion of greater amounts of force. Large diameter solders if use in this device may stick in between the toothy gear and the grooved wheel or be broken by the toothy gear if the solder path between the toothy gear and the grooved wheel is not spaced properly.  
         [0011]     Therefore, there exists a need in the art for a solder feeder that overcomes the disadvantages of the prior art. There is a further need for a solder feeder that uses a simple “grip &amp; pull” concept to hold and extend a length of solder in one operation that requires only one hand to operate. There is also a need for a solder feeder operable to automatically curve the solder wire when extending the solder wire out from the device. There is a further need for a device capable of dispensing any size of solder without damaging the solder. There is also a need for a solder feeder having a tube design that ensures a reliable solder delivery path with no possibility for the solder to escape in other undesired directions.  
       SUMMARY OF THE INVENTION  
       [0012]     In accordance with one embodiment of the invention, a solder feeder includes a housing member, a solder spool holder, a solder gripper assembly, a plurality of belt rollers, a trigger lever, a solder path tube, a removable solder nozzle and a top cover. The housing member may comprise a unitary left housing member and a unitary right housing member. The left housing member may comprise a left front wall, a left base member, a left rear wall and a left handle. The right housing member may comprise a right front wall, a right base member, a right rear wall and a right handle. The solder spool holder may comprise a bottom half and a top half connected together with a hinge. Circular notches may be cut out at both sides of the top and bottom halves for seating a removable shaft. One end of the removable shaft may be a fixed circular wall and the other end may be threaded and open to receive a roll of solder spool. A threaded end cap may be used outside to lock the shaft in place when the top is swung down and snap closed.  
         [0013]     The solder gripper assembly may comprise a base body sliding on two parallel horizontal rails horizontally. Both ends of these two horizontal rails may be mounted to the walls of the left and right housing members respectively. A left pole and a right pole may extend vertically from the base body to hold a solder path guide using two screws. Pivoting to the left pole may be a left gripper arm and to the right pole may be a right gripper arm. These two gripper arms are normally extended outward from each other by a coiled spring mounted at the poles and return springs. At the end of the left and right gripper arm are left and right rolls for gripping the solder wire running between them.  
         [0014]     Underneath the left and right rolls may be a left blade and a right blade respectively. A screw may hold each of these two blades loosely and secure the left and the right rolls. The other end of each blade may include a hole through which extends a belt screw terminating with a belt screw cap. The trigger lever with a belt attached rolls between the grooves at the inner edges of the left and right base members of the housing members. The other end of the belt passes through a plurality of rollers mounted between the front walls of the left and right front walls to connect with the belt screw.  
         [0015]     The solder path tube may be mounted on top of the left and right front walls of the housing member to receive the solder guide tube and allow the solder nozzle to be screwed on. Finally the top cover is screwed on the housing member using four screws on each side.  
         [0016]     In accordance with another embodiment of the invention, a solder feeder of the same construction may include a pulley instead of the trigger lever. Additionally a trigger switch may be mounted at the front of the handle to provide a means for turning on and off a DC motor, which receives power from an externally snap on DC battery with an on/off switch. The combination of the trigger switch, a stop switch on the left front wall and a enable switch on the base member and a logic Printed Circuit Board inside the handle provides proper on/off control to the motor. The motor, pulley, switches, Printed Circuit Board and power supply are all electrically connected through cable harness in a manner known to one having ordinary skill in the art.  
         [0017]     Both embodiments described above have the same general design except one is manually operated and the other is operated with the help of a DC motor powered by a DC power supply. Their general shape, construction, and concept of operation are similar.  
         [0018]     There has been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and which will form the subject matter of the claims appended herein.  
         [0019]     In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.  
         [0020]     As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     The invention will be better understood and the objectives and advantages will become apparent from the accompanying drawings and descriptions. Such descriptions make reference to the accompanying drawings wherein:  
         [0022]      FIG. 1  is a perspective view of a solder feeder according to the present invention;  
         [0023]      FIG. 2  is a perspective view of the solder feeder with a top cover removed and with a top half of the solder holder open to expose a solder spool on a shaft and the solder nozzle detached to show the internal mechanical structure of the present invention;  
         [0024]      FIG. 3  is a perspective view of the solder feeder shown in  FIG. 2  having a shorter version of solder nozzle installed;  
         [0025]      FIG. 4  is a perspective view of the solder feeder in use showing the solder gripper assembly being advanced to a maximum forward position when the trigger lever is pulled all the way backward;  
         [0026]      FIG. 5  is a side view of the solder feeder with the top cover off;  
         [0027]      FIG. 6  is a side view of the solder feeder in use with the top cover off showing the solder trigger assembly being advanced with the solder wire all the way to its maximum front position;  
         [0028]      FIG. 7  is a top view of the solder feeder with the top cover off;  
         [0029]      FIG. 8  is a top view of the solder feeder in use with the top cover off;  
         [0030]      FIG. 9  is a perspective view of the solder gripper assembly;  
         [0031]      FIG. 10  is an exploded view of the solder gripper assembly;  
         [0032]      FIG. 11  is a perspective view of an alternate embodiment of the solder feeder with the top cover removed;  
         [0033]      FIG. 12  is a perspective view of an alternate embodiment of the solder feeder in use with the top cover removed showing the solder gripper assembly being advanced to its maximum forward position;  
         [0034]      FIG. 13  is an exploded view of the solder feeder of  FIG. 2 ;  
         [0035]      FIG. 14  is an exploded view of the alternate embodiment of the solder feeder show in  FIG. 12 ; and  
         [0036]      FIG. 15  is a schematic representation of the circuit components on the Printed Circuit Board to the motor, DC battery and control switches.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0037]     The present invention provides a solder feeder generally designated  10  for holding a spool of solder and allows an operator to extend a length of curved or straight solder at the tip using only one hand.  
         [0038]     With reference to  FIG. 1  and  FIG. 2 , the solder feeder  10  may include a left housing member  13 ,  13 A with a left handle  45 , a right housing member  14 ,  14 A with a right handle  46 , a top cover  90 , and a solder gripper assembly  80 . A solder holder may comprise a bottom half  39  with a sidewall  92  connected to a top half  40  by a hinge  41 , a spool of solder  43  loaded onto a shaft  42  with a locking end cap  44 , a trigger lever  12 , a solder path tube  36 , and a nozzle  16 .  
         [0039]     The left housing member including a left base member  13 , a left front wall  13 A, a left rear wall  13 B and the left handle  45  may be unitarily molded into a single piece ( FIG. 5  and  FIG. 13 ). Similarly the right housing member including a right base member  14 , a right front wall  14 A, a right rear wall  14 B and the right handle  46  may be unitarily molded into a single piece ( FIG. 13 ). Also shown is an optional shorter, curved solder nozzle  70 , a slightly curved long solder nozzle  71 , a 90 degree bent solder nozzle  71 , and a long straight solder nozzle  72 .  
         [0040]     With reference to  FIG. 3 , the solder feeder  10  is shown with the curved solder nozzle  70  and the solder gripper assembly  80  resting at its initial standby position ready to be engaged. Top cover  90  is removed to show the internal structure.  
         [0041]     A solder path tube  36 , which is larger in diameter than a solder guide tube  15 , may be mounted securely on top of the left front wall  13 A and the right front wall  14 A by two screws  64 . The solder nozzle  70  of the solder feeder  10  may be bent at an angle for curving a solder wire when being extended out. The trigger lever  12  may be mounted at the center between the left base member  13  and the right base member  14 . The trigger lever  12  has two rollers  94 ,  95  ( FIG. 13 ) that may slide along a groove  96  formed at the inner edge of the left base member  13  and the groove  93  formed at the inner edge of the right base member  14 .  
         [0042]     With reference to  FIG. 4 , the solder feeder  10  is shown in use. After a spool of solder  43  is loaded onto the removable shaft  42  and placed on the notched centers of the bottom half  39  of the solder holder, the top half  40  may be closed and lips  91  snapped over the sidewall  92  to close. The shaft  42  may be retained in position with the threaded end cap  44 . Because the diameter of the shaft  42  is smaller than the hole of the solder spool  43 , the solder spool  43  can rotate freely on the shaft  42  when being pulled while the shaft itself is constrained by the end cap  44  at one end and a fixed circular wall at the other end of the shaft  42 . Solder wire from the solder spool  43  may be extended and fed into the solder guide tube  15  by passing it through a left gripper arms  17  and a right gripper arm  18  of the solder gripper assembly  80 .  
         [0043]     When the trigger lever  12  is pulled backward, a belt  22  may pull a left blade  19  and a right blade  20  of the solder trigger assembly  80  forward in a V-shape manner which in turn may pull the left gripper arm  17  and the right gripper arm  18  toward each other until both a left roll  37  of the left gripper arm  17  and a right roll  38  of the right gripper arm  18  sandwich the solder wire tightly there between. Diameters of rolls  37  and  38  may be sized to provide a desirable gripping force on the solder wire. Alternatively, a flexible cable may be used in place of left blade  19  and right blade  20 . Continuing pulling the trigger lever  12  may move the complete solder gripper assembly  80  together with the solder wire forward along rails  27  and  28  until stop switches  23 ,  24  disposed at the left and right front walls  13 A,  14 A of the left and right housing members stop them. The solder guide tube  15  may recess into the solder path tube  36 . This action may result in a length of solder being extended forward at a predefined length equivalent to the distance of the solder gripper assembly  80  being moved forward.  
         [0044]     When the trigger level  12  is released, springs  31  and  32  may force the left gripper arm  17  and the right gripper arm  18  to separate one from the other until they are in line with their corresponding returns spring  29  and  30 . Further releasing the trigger lever  12  allows the returns springs  29  and  30  to contract and return the solder gripper assembly  80  to its initial standby position.  
         [0045]     The solder guide tube  15 , being part of the solder gripper assembly  80 , always moves together with the solder gripper assembly  80  to recess into the larger solder path tube  36 . This overlap design ensures that the solder wire is always confined in an intended solder delivery path without any opportunity for the solder wire to escape in any undesired directions.  
         [0046]     The sidewall  92  of the solder holder is attached to the left rear wall  13 B and the right rear wall  14 B of the housing member by two screws  63  ( FIG. 13 ). The shape of the solder holder may be conformed to the shape of the solder spool  43  so as to provide a backing to the solder during forward extension to prevent the solder from escaping backward.  
         [0047]     With reference to  FIG. 5 , the bottom half  39  and the top half  40  of the solder holder may be sized and configured to accept the spool of solder  43 .  
         [0048]     With reference to  FIG. 3 ,  FIG. 4  and  FIG. 13 , the trigger lever  12  may have two rollers  94  and  95  that slide along the two grooves  96  and  93  at the inner edges of the left and right base members  13 ,  14  during operation. When the trigger lever  12  is pulled backward, the belt  22  attached to the trigger lever  12  may pull the solder gripper assembly  80  together with the solder wire until the front walls  13 A,  14 A of the housing member stop it. When the trigger lever  12  is released, the two springs  32  and  31  may cause the two solder gripper arms  17  and  18  to open. Further releasing the trigger lever  12  may cause the solder gripper assembly  80  to return to its initial starting position by the contraction of the two returns springs  29  and  30 .  
         [0049]     With reference to  FIG. 14 , the solder feeder generally designated  100  may include a DC motor  47  powered by a DC battery  54  for driving a pulley  48  to wind the belt  22  instead of a manually operated trigger lever  12  pulling the belt  22 . A Printed Circuit Board  51  mounted inside the handle  55  and  56  together with the trigger switch  49 , stop switch  23 , enable switch  25  and cable harness  50  control the movement of the DC motor  47 .  
         [0050]     With reference to  FIG. 11  and  FIG. 14 , solder feeder  100  is shown in standby mode. Pulling the trigger switch  49  will start the DC motor  47  and turn the pulley  48  in a direction of winding the belt  22 . This action may cause the solder trigger arms  17  and  18  to move toward each other until they sandwich the solder wire in between the left roll  37  and the right roll  38  of the trigger arms  17  and  18 . Further winding of the belt  22  may cause the solder trigger assembly  80  together with the solder wire to move forward until it is stopped by the stop switch  23 . When the stop switch  23  is pressed, it sends a signal to the control circuits on the Printed Circuit Board  51  to stop the DC motor  47 . Once the DC motor  47  is stopped, it may go into a neutral or a free running state releasing the pulley  48 . Without force from the pulley  48 , the two return springs  29  and  30  may contract and pull the solder trigger assembly  80  backward until it is stopped by the enable switch  25 . The enable switch  25  provides an arming or enable signal to the control circuits on the Printed Circuit Board  51  [ FIG. 15 ]. When it is enabled or armed, a push on the trigger switch  49  will turn on the DC motor  47  again.  
         [0051]     With reference to  FIG. 15 , Printed Circuit Board  51  may comprise integrated circuits IC 1 , IC 2 , a relay S 1 , resistors R 1 , R 2 , and R 3 . IC 1  may include a Quad  2  input NAND gate, IC 2  may include a anti-bouncing circuit with inverting output, and relay S 1  may include a semiconductor analog switch. Switches  23 ,  25  and  49  may be push button type switches wired to output a low signal when engaged, or pushed. G 1  and G 2  may be connected to function as a latch such that when enable switch  25  is engaged, output pin  3  of G 1  would be high and when stop switch  23  is engaged, output pin  3  of G 1  would be low. Output pin  3  of G 1  may be connected to input pin  9  of G 3 . When input pin  9  is high, output pin  8  of G 3  would be low whenever input pin  10  is high or the trigger switch  49  is engaged. When the input pin  9  is low, output pin  8  of G 3  would be always high regardless of the signal at input pin  10  of G 3 . Output pin  8  of G 3  may be connected to enable pin  3  of S 1 . When pin  3  of S 1  is low, it connects input pin  1  to output pin  2  and thus allows the DC output of the battery  54  to power on the DC motor  47 .  
         [0052]     When first powered up or the device  100  is in standby mode, the enable switch  25  may be engaged by the base  11  of the solder gripper assembly  80  ( FIG. 11 ). A low signal at pin  1  of G 1  causes an output at pin  3  and input pin  9  of G 3  to go high. Output of pin  8  of G 3  or enable pin  3  of S 1  would be low or the DC motor  47  would be powered on whenever input pin  10  of G 3  is high or the trigger switch  49  is engaged. The DC motor  47  then turns the pulley  48  and advances the solder trigger assembly  80  forward until it engages the stop switch  23  ( FIG. 12 ). When the stop switch  23  is engaged it causes the output pin  3  of G 1  and the input pin  9  of G 3  to go low. A low at input pin  9  causes the output pin  8  of G 3  or the enable pin  3  of S 1  to go high regardless of the state of the trigger switch  49 . A high at pin  3  of S 1  disables it and turns off the power to the DC motor  47 . Without power to turn the pulley  48 , the belt  22  will be unwinded by the force of the two returns springs  29  and  30  and causes the solder trigger assembly  80  to go backward until it is stopped by the enable switch  25 . When the enable switch  25  is engaged, it causes the input pin  9  of G 3  high again and the DC motor  47  would be powered on whenever the trigger switch  49  is engaged or pressed.  
         [0053]     The logic diagram of  FIG. 15  is for illustration purpose only, there are existing in prior arts many dc motor control circuits that can be readily adapted for this solder feeder application. However the concept of a solder feeder being controlled by dc motor to extend solder wire may be new.  
         [0054]     The housing member  13 ,  45 ,  14 ,  46 , trigger lever  12  and the solder holder of the solder feeder  10 ,  100  may be manufactured with plastic but metal or alloy is preferred for use in the solder path tube  36 , the solder gripper arm  17  and  18 . Very soft material or rubber is best used for the left roll  37 and the right roll  38  of the solder gripper arms  17  and  18  to avoid potential damages to the solder wire. Because the tips of the solder nozzles  16  and  70  often make contact with the flame from a torch during soldering operation, it is necessary that the solder nozzle must be made of fire resistance materials such as metal or alloy  
         [0055]     Advantageously, the solder feeder extends a length of solder and curves it at the tip of the solder nozzle allowing a plumber or tradesman to perform soldering operations on copper joints without periodically stopping to extend and curve the solder with both of their hands. With different optional solder nozzles that are easily changed, straight or curved solder wire in different degrees can be extended out as desired.  
         [0056]     The solder feeders  10  and  100  provide an operator the ability to continuously dispenses a length of curved solder with one hand while holding a torch with the other hand during the soldering operation to greatly improving soldering speed.