Abstract:
The roller assembly includes: a first shaft having a longitudinal axis; a self adjusting pressure drive shaft extending parallel to the longitudinal axis, the self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds the main body portion; and a flexible material is disposed between the main body portion and the ring. An apparatus for a continuously winding a transformer core in an electrical transformer includes: a feed assembly for a material, the feed assembly includes a first shaft disposed adjacent a self adjusting pressure drive shaft, the self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds the main body portion; and a flexible material is disposed between the main body portion and the ring.

Description:
BACKGROUND OF INVENTION  
         [0001]    In the electronic industry, electrical transformers, e.g., current transformers, are often used in wide array of applications, including the use of electrical transformers with printed circuit boards and with circuit interruption devices. The electrical transformers are capable of providing power to the circuit board as well as sensing current in the primary circuit of the circuit board. In order for the electrical transformer to provide adequate power to the circuit board, the transformer has a high magnetic permeability core and the coil of the transformer has a high number of wire turns to provide the required voltage.  
           [0002]    The core of the transformer may be wound on an apparatus that feeds flat stock material through an assembly procedure. The flat stock material is stored on a roll and is rolled out through the first station of the apparatus through a pinch roller assembly that feeds the material to the winding station of the apparatus. An encoder measures the appropriate amount of material for each core. One of the drawbacks of the present apparatus is that the material can slip as it passes through the pinch roller assembly. The slippage then provides erroneous information to the encoder. As a result, an incorrect amount of material is forwarded to create the transformer coil. Pinch roller assemblies have been mounted on spring loaded devices; however, the spring-loaded devices do not provide the flexibility to adjust in all directions when non-uniform flat stock material is fed through the apparatus.  
         SUMMARY OF INVENTION  
         [0003]    The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by a roller assembly for feeding flat stock material. In an exemplary embodiment, the roller assembly includes: a first shaft having a longitudinal axis; a self adjusting pressure drive shaft extending parallel to the longitudinal axis, the self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds the main body portion; and a flexible material is disposed between the main body portion and the ring. In an alternative exemplary embodiment, an apparatus for a continuously winding a transformer core in an electrical transformer includes: a feed assembly for a material, the feed assembly includes a first shaft disposed adjacent a self adjusting pressure drive shaft, the self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds the main body portion; and a flexible material is disposed between the main body portion and the ring. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0004]    Referring now to the drawings wherein like elements are numbered alike in the several Figures:  
         [0005]    [0005]FIG. 1 is a side view of a self adjusting pressure drive shaft;  
         [0006]    [0006]FIG. 2 is a side view of a main body portion of the self adjusting pressure drive shaft of FIG. 1;  
         [0007]    [0007]FIG. 3 is a side view of a ring of the self adjusting pressure drive shaft of FIG. 1;  
         [0008]    [0008]FIG. 4 is a cross-section view of the ring of FIG. 3;  
         [0009]    [0009]FIG. 5 is a side view of an apparatus for continuous core winding of electrical transformers utilizing the self adjusting pressure drive shaft of FIG. 1;  
         [0010]    [0010]FIG. 6 is a top view of a section of the apparatus of FIG. 5;  
         [0011]    [0011]FIG. 7 is a side view of a winding area of the apparatus in FIG. 5; and  
         [0012]    [0012]FIG. 8 is a schematic drawing of the apparatus of FIG. 5 attached to a computer system. 
     
    
     DETAILED DESCRIPTION  
       [0013]    Referring to FIGS. 1 and 2, a self adjusting pressure drive shaft  20  is illustrated. Self adjusting pressure drive shaft  20  includes a main body portion  22  and an extension  24 . Main body portion  22  is cylindrical in shape and includes a first section  26  and two second sections  28 . First section  26  has an outside diameter  30  that is smaller than an outside diameter  32  of second section  28 . Preferably, first section  26  is located at a mid-point  34  of main body portion  22 . First section  26  includes two shoulders  36  located adjacent to a first edge  38  of second section  28  and a second edge  40  of second section  28 .  
         [0014]    In an exemplary embodiment, outside diameter  30  of first section  26  is about 0.47 inches (1.19 mm) and outside diameter  32  of second section  28  is about 0.625 inches (1.59 mm); thus, outside diameter  30  is about 0.155 inches (0.39 mm) less than outside diameter  32 . In addition, first section  26  has a length  42  of approximately 0.35 inches from edge  38  to edge  40 .  
         [0015]    Referring to FIGS. 1, 3 and  4 , self adjusting pressure drive shaft  20  also includes a ring  50 . Ring  50  has a circular shape with a hollow center  52  and a lip  54  located on either side of ring  50 . Ring  50  is disposed at first section  26  and is mounted at shoulders  36 . There is a space  56  between first section  26  and an inner diameter  58  of ring  50 . Space  56  is filled with a flexible material  60 , such as elastomeric, rubber, neoprene, or urethane. Space  56  allows flexible material  60  to be self retained on main body portion  22 . Flexible material  60  may also be secured to ring  50  and/or to main body portion  22  by an adhesive so that ring  50  does not rotate independently from main body portion  22 . Flexible material  60  can have varying durometer with a hardness value ranging from about 15 duro to about 90 duro. Within this range, the hardness value may preferably be up about 75 duro to about 80 duro. Flexible material  60  may be placed into space  56  in any manner, such as inserted, injected, or pressed. Ring  50  is made from a hard material such as steel, or the like. The material may also be heat treated so that it has a Rockwell C Hardness of about 50-56.  
         [0016]    Self adjusting pressure drive shaft  20  may be incorporated into any apparatus that utilizes flat stock material. Referring to FIG. 5, in an exemplary embodiment, self adjusting pressure drive shaft  20  is incorporated into a core winding apparatus  100 . Apparatus  100  allows a material  110  to be tightly wound into a core to form an electrical transformer. Material  110  is preferably made from a ferrous material. The ferrous material may include a silicon steel. Apparatus  100  includes a material storage area  120 , which may include any type of conventional feeding devices. In an exemplary embodiment, material  110  is stored on a first reel  124 . A second reel  126  is located adjacent to first reel  124  and holds material  110  on first reel  124  so that first reel  124  does not unwind. First reel  124  allows material  110  to uncoil as a strip and move to a pinch roller area  130 . First reel  124  and second reel  126  are mounted to a frame  127 . Frame  127  may be mounted to the floor or to a frame  128  of apparatus  100 .  
         [0017]    Pinch roller area  130  includes self adjusting pressure drive shaft  20  and a pinch roller  132  located on top of one another and contacting each other at a point  134 . Pinch roller  132  may be any shaft type device that rotates to allow material  110  to feed through pinch roller area  130 . While the exemplary embodiment illustrates self adjusting pressure drive shaft  20  as the roller on top of pinch roller  132 , alternatively self adjusting pressure drive shaft  20  may be located on the bottom and pinch roller  134  may be located on top. Self adjusting pressure drive shaft  20  and pinch roller  132  act as a pair of pinch rollers. A servomotor  136  (see FIG. 6) is coupled to extension  24  of self adjusting pressure drive shaft  20 , which rotates self adjusting pressure drive shaft  20  in a counterclockwise direction. While the rotational force to self adjusting pressure drive shaft  20  illustrated in the exemplary embodiment as servomotor  136 , other means may be employed to generate the rotational force, such as, a stepping motor, standard motor, air power devices, and the like.  
         [0018]    Pinch roller  132  is coupled to a spring  138 , which biases pinch roller  132  towards self adjusting pressure drive shaft  20  and creates pressure between self adjusting pressure drive shaft  20  and pinch roller  132  at a point  134 . Spring  138  may also be coupled to a pneumatic cylinder  140 , which adjusts the tension in spring  138 . In an exemplary embodiment, spring  138  presses against a first end  142  of an arm  144  and pneumatic cylinder  140  is coupled to a second end  146  of arm  144 .  
         [0019]    Pneumatic cylinder  140 , which may be either manually or automatically regulated, may be adjusted to push against second end  146  of arm  144  so that arm  144  rotates in a counterclockwise direction so as to apply additional tension in spring  138 . Pneumatic cylinder  140  can also be adjusted so that less pressure is applied against second end  146  of arm  144  so that arm  144  rotates in a clockwise direction, which in turn releases tension from spring  138 . Alternatively, the force that is provided between self adjusting pressure drive shaft  20  and pinch roller  132  can be generated in a variety of other ways, including, mechanically, electrically, or by hydraulic means.  
         [0020]    Material  110  is available in a variety of dimensions and in particular, is available in a range of widths and thicknesses. Moreover, as material  110  is fed through apparatus, material  110  can varying in thicknesses, as the material is not perfectly uniform. Referring to FIGS. 1 and 5, self adjusting pressure drive shaft  20  and pinch roller  132  are set to provide a certain amount of tension at point  134  so that material can be pulled through apparatus  100 . When self adjusting pressure drive shaft  20  is assembled into apparatus  100 , ring  50  pinches against the pinch roller  132  and contacts material  110 . Because ring  50  is made from a hard material, ring  50  provides a proper amount of pressure against pinch roller  132  to feed material  110  through apparatus  100 . However, because ring  50  is mounted on flexible material  60 , the pressure between ring  50  and pinch roller  132  can adjust and flex in different directions for varying thicknesses of material  110 .  
         [0021]    Referring to FIG. 6, servomotor  136  includes an encoder  150  that measures a predetermined amount of material  110  being fed into pinch roller area  130 . Optionally, apparatus  100  may also include an external encoder (not shown), which also measures the amount of material  110  that is being fed through pinch roller area  130 . The external encoder may also serve as a backup system for encoder  150  included within the servomotor  136  so that the desired and appropriate amount of material  110  is fed through pinch roller area  130 . Other known encoding devices may be used in combination with apparatus  100 . Servomotor  136  also includes a controller  152  that allows servomotor  136  to be operated automatically.  
         [0022]    Referring to FIGS. 5 and 6, material  110  moves from pinch roller area  130  to a cutter area  160 . Cutter area  160  includes a cutter assembly  162  that is driven by pneumatic cylinders  164 . Pneumatic cylinders  164  are adjusted to supply a certain amount of force so that cutter assembly  162  can cut material  110 .  
         [0023]    Referring to FIGS. 5 and 7, material  110  moves from cutter area  160  to a winding area  170 . Winding area  170  includes a winding cavity  172 , which can be divided into three movable quadrants  174 ,  176 , and  178  and a fixed quadrant  180 . As material  110  enters winding cavity  172 , material  110  begins to wind in a circle. As more material  110  enters winding cavity  172 , quadrants  174 ,  176 , and  178  begin to move in an outwards direction to allow additional material to enter winding cavity  172 . Quadrant  180  remains fixed and does not move.  
         [0024]    Quadrant  174  is located at a top side  182  of winding cavity  172  and includes a side roller  184 . A servomotor  186 , which is coupled to side roller  184  by a linkage  188 , drives side roller  184 . Quadrant  174  is also coupled to a servomotor  190  by a linear slide  192 . Servomotor  190  drives linear slide  192  and moves top side  182  away from a center  194  of winding cavity  172 . Quadrant  176  is located at a right side  196  of winding cavity  172 . Quadrant  176  is coupled to a servomotor  198  by a linear slide  200 . Servomotor  198  drives linear slide  200  and moves right side  196  away from center  194  of winding cavity  172 . Quadrants  174  and  176  are interlaced so that as quadrant  174  moves away from center  194  of winding cavity  172 , quadrant  176  moves away from center  194  of winding cavity  172 . Quadrant  178  is located on a bottom side  202  of winding cavity  172 . Quadrant  178  is coupled to a spring loaded slide  204 . As quadrant  176  expands away from center  194 , quadrant  178  also moves away from center  194 . Quadrant  178  moves at approximately half the speed as quadrant  176 . Servomotors  186 ,  190 , and  198  also include controllers  206 ,  208 , and  210 , respectively, so that servomotors  186 ,  190 , and  198  can be controlled automatically.  
         [0025]    Apparatus  100  also includes a plasma welder  220 , which is mounted to a top side  222  of frame  128 . Plasma welder  220  includes a hose  224  that is coupled with an opening  226  in quadrant  176 . Plasma welder  220  utilizes argon gas to provide a spot weld on material  110  at the last turn of material  110  in winding cavity  172 . The spot weld prevents material  110  from unwinding when it is removed from winding cavity  172 . Alternatively, material  110  is secured by any suitable process. Other securing means include laser welding, resistance welding, case-welding, bonding, mechanically lancing or crimping, strapping the diameter of the coil, and the use of wire wraps.  
         [0026]    Apparatus  100  operates in the following manner. Servomotor  136  energizes and turns self adjusting pressure drive shaft  20 , which in turn causes pinch roller  132  to also turn. Self adjusting pressure drive shaft  20  and pinch roller  132  pull material  110  from first reel  124 . Material  110  moves between self adjusting pressure drive shaft  20  and pinch roller  132  to cutter area  60 . Material  110  will continue to move through cutter area  160  to winding area  170 . After a predetermined amount of material  110  moves through pinch roller area  130 , cutter  162  cuts material  110 . In winding area  170 , material  110  enters winding cavity  172  and pushes against the walls of winding cavity  172  to form a coil. As more material  110  enters winding cavity  172 , quadrants  174 ,  176 , and  178  expand to allow more material to enter winding cavity  172  and form the coil. Plasma welder  220  provides a spot weld on material  110  at the last turn of material  110  to hold material  110  in the coil and keep coil from unwinding. The formed coil drops out of winding cavity  172  and additional material  110  enters winding area  170  to begin a new coil.  
         [0027]    Referring to FIG. 8, controllers  152 ,  206 ,  208 , and  210  are operably coupled with a computer  300  by a data transmission media  302 . Computer  300  is a suitable electronic device capable of accepting data and instructions, executing the instructions to process the data, and presenting the results. Therefore, computer  300  can be a microprocessor, microcomputer, a minicomputer, an optical computer, a board computer, a complex instruction set computer, an ASIC (application specific integrated circuit), a reduced instruction set computer, an analog computer, a digital computer, a molecular computer, a quantum computer, a cellular computer, a superconducting computer, a supercomputer, a solid-state computer, a single-board computer, a buffered computer, a computer network, a desktop computer, a laptop computer, a scientific computer, a scientific calculator, or a hybrid of any of the foregoing. While computer  300  is shown as being separated from apparatus  100 , computer  300  can also be mounted to and/or integrated with apparatus  100 .  
         [0028]    Data transmission media  302  includes, but is not limited to, twisted pair wiring, coaxial cable, and fiber optic cable. Data transmission media  302  also includes, but is not limited to, radio and infrared signal transmission systems. Computer  300  is configured to provide operating signals to controllers  152 ,  206 ,  208 , and  210  and to receive data from these components via data transmission media  302 .  
         [0029]    In addition to being coupled to controllers  152 ,  206 ,  208 , and  210 , computer  300  may also be coupled to external computer networks such as a local area network (LAN)  304  and the Internet. LAN  304  interconnects one or more remote computers  306 , which are configured to communicate with computer  300  using a well-known computer communications protocol such as TCP/IP (Transmission Control Protocol/Internet Protocol), RS-232, ModBus, and the like. Additional apparatus  100  may also be connected to LAN  304  with the computers  300  in each of these apparatus being configured to send and receive data to and from remote computers  306  and other apparatus  100 . LAN  304  is connected to the Internet via a server computer  308 . This connection allows computer  300  to communicate with one or more remote computers  310  connected to the Internet.  
         [0030]    Computer  300  is preferably controlled by a PC or PLC base processor. All electrical and mechanical components of apparatus  100  are integrated to achieve the best quality product that meets all predetermined specifications and achieves the most optimum manufacturing cycle. Because of possible variations of the thickness (tolerance) of material  110 , at least one thickness measuring device (not shown) constantly measures the thickness of material  110  so that the exact length necessary is calculated to achieve the correct amount of material  110  to winding area  170 . As is known in electrical transformer technology, the amount of material  110  (surface area) of the coil is related to the current output of the transformer.  
         [0031]    Self adjusting pressure drive shaft  20  provides the necessary latitude to feed material  110  with precision and in a reliable manner. Because flexible material  60  is inserted between main body portion  22  and ring  50 , self adjusting pressure drive shaft  20  has the flexibility to adjust in all directions while still maintaining the required force to pinch material  110  so that material  110  can be displaced forward through apparatus  100  when self adjusting pressure drive shaft  20  is rotated. Moreover, self adjusting pressure drive shaft  20  compensates axially to the forces applied as material  110  passes through pinch roller area  130 . In addition, the utilization of self adjusting pressure drive shaft  20  as part of a material feeding system provides the accuracy required to calculate an accurate amount of material  110  that passes through pinch roller area  130 .  
         [0032]    While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.