Abstract:
A sewing bobbin assembly and method that provides access of a sewing machine, and particularly a bobbin in the sewing machine, to a larger supply of thread with automatic reloading of the bobbin during use thereof.

Description:
BACKGROUND OF THE INVENTION  
       [0001]    1. Field of the Invention 
         [0002]    The present general inventive concept relates to a sewing assembly and method for a sewing machine, and in particular, to a sewing assembly and method that enables the sewing machine to utilize a thread supply on a bobbin while permitting automatic reloading of the bobbin during use thereof. 
         [0003]    2. Description of the Related Art 
         [0004]    The textile industry, which includes sewing, quilting, and embroidery, manufactures yarn, thread, and the like (hereinafter “thread”) by winding finished thread onto a carrier or “bobbin” for storage until use of the thread. Bobbins are typically elongated, cylindrical barrels that are attachable to a sewing machine, as illustrated in  FIG. 1 , to be unwound by the sewing machine so that the sewing machine may produce a desired stitch pattern. 
         [0005]    A popular stitch pattern is “lockstitch,” which is performed by most household sewing machines and industrial single-needle sewing machines using two threads, an upper thread passed through a needle and a lower thread coming from the bobbin. Each thread stays on the same side of the material being sewn, interlacing with the other thread at each needle hole. Industrial lockstitch machines with two needles, each forming an independent lockstitch with their own bobbin, are also common. 
         [0006]    The textile industry has long struggled with inefficiencies due to the necessity of winding, rewinding and/or replacing the bobbin and thread. Over the years, there have been a number of attempts to address these inefficiencies by attempting to improve the functionality of bobbins used with sewing machines. 
         [0007]    For instance, U.S. Pat. No. 2,262,665 discloses a bobbin having an annular groove with circumferentially spaced portions to prevent thread slipping relative to the bobbin spindle during winding of the thread on the bobbin. 
         [0008]    Similarly, the bobbin disclosed in U.S. Pat. No. 3,284,023 includes a V-shaped notch or groove and a protuberance formed in its exterior surface to form a yarn trap also to prevent thread slipping relative to the bobbin spindle during winding of the thread on the bobbin. 
         [0009]    More recently, a textile core including a V-shaped start-up groove with a roughened sidewall surface formed therein was disclosed in U.S. Pat. No. 5,211,354. 
         [0010]    Contributing to the aforementioned inefficiencies is the problem that the bobbin with lower thread will often become depleted of thread before the upper thread, which may go unnoticed by an operator. Moreover, both the upper thread and the lower thread are subject to breaking, which can be caused by the thread and also go unnoticed by the operator. Any sewing operation performed without both the upper and lower threads will require repeating of the sewing operation. 
         [0011]    Several methods to facilitate monitoring of the condition of the upper thread have been disclosed, for instance, in U.S. Pat. No. 3,843,883. However, monitoring the condition of the lower thread on the bobbin is relatively difficult for at least the reason that the lower thread and the bobbin are typically concealed from the operator&#39;s view. Thus, the condition of the lower thread is typically not noticeable or detectible until an object being sewed by the sewing machine begins to unravel, which alerts the operator to the missing bobbin thread. 
         [0012]    On multi-head sewing and embroidery machines, this is especially problematic because once the bobbin runs out on one head, the entire machine must be stopped to feed the missing bobbin thread. 
         [0013]    Some conventional machines, such as that disclosed by U.S. Pat. No. 5,143,004 to Mardix, disclose a sensor and complex arrangement of parts that are supposed to sense when thread is not being fed to a sewing needle by a bobbin and to automatically change the bobbin. These machines, however, are prone to malfunction, which causes bobbins to be replaced before they are depleted thereby wasting thread. Additionally, the machines are expensive to manufacture, difficult to maintain, and do not remedy the problem of a bobbin running out of thread or otherwise decrease the frequency of required bobbin changes. Each bobbin change is labor consuming and time consuming, which substantially reduces productivity of the sewing machine. 
         [0014]    Other conventional machines are disclosed by U.S. Pat. No. 3,405,379 to Wilson, U.S. Pat. No. 4,049,215 to Husges, U.S. Pat. No. 4,681,050 to Kosmas, and U.S. Pat. No. 5,143,004 to Mardix. 
         [0015]    Despite these advances in the art, however, a need remains for a long-lasting and inexpensive bobbin that reduces the number of times a bobbin must be changed thereby decreasing the likelihood that a sewing operation must be repeated due to a depleted bobbin, enables an operator to easily observe whether a bobbin thread is depleted or broken, is economical to manufacture, use, and maintain, and prevents waste of thread. 
         [0016]    Therefore, it is desirable to provide a new and unique bobbin assembly and method that satisfies these needs. 
       SUMMARY OF THE INVENTION  
       [0017]    The present invention satisfies these needs and achieves the additional advantages detailed below. 
         [0018]    The present general inventive concept provides a sewing bobbin apparatus and method that monitors for a bobbin that is at and/or nearing depletion of its thread, and automatically refills its thread via a spool of bobbin thread that is much larger than those of conventional machines and oriented to permit observation of the spool during use thereof by an operator. Instead of less than 100 yards of thread on a bobbin, as is the approximate capacity of conventional machines, the present inventive concept allows the utilization of spools with 1000s of yards, thus reducing the number of times the spool must be inspected and/or changed, and thereby decreasing the likelihood that a sewing operation must be repeated due to a depleted bobbin. 
         [0019]    This present general inventive concept allows for the use of large spools of bobbin thread. Instead replacing the bobbin, the bobbin is actually rewound in place. This present general inventive concept allows the utilization of spools with thousands of yards of thread, thus minimizing downtime requiring during bobbin replacement of conventional machines. 
         [0020]    The foregoing and/or other aspects and utilities of the present general inventive concept may be achieved by providing a tube that is operable to feed the bobbin thread via blowing air through the tube, so that the thread is delivered directly into the bobbin case where it is attached to the spinning bobbin through the use of grippers. 
         [0021]    A bobbin winder/rewinding motor with rollers contacts the bobbin and spins the spool, rewinding the bobbin. The bobbin is then released from spinning and the thread is cut and the sewing process continues. The tube containing the bobbin thread rests outside of the bobbin case waiting for a signal from a sensor. The spinning bobbin is driven by a contact roller mechanism entering the side of the bobbin case. As previously stated, the bobbin can be rotated for winding by a direct drive mechanism. The bobbin rewinding mechanism may have rollers that can make contact with the bobbin. An opening in the bobbin case allows the roller or rollers attached to the motor to make contact with the bobbin. Access space accommodates the tube housing the bobbin thread. The motor spins the bobbin independent of the shuttle drive mechanism, allowing for the thread to become attached to the bobbin core through the use of grippers, and the bobbin will be wound full of thread. This same assembly can be used on either a straight shaft machine or an angled drive machine. The bobbin rewinding motor assembly must be able to move in and out, making contact with the bobbin for only the amount of time necessary for rewinding/filling. 
         [0022]    This present general inventive concept improves the sewing machine efficiency by allowing the use of very large spools of thread that rewind the bobbin in place in the machine, minimizing operator attention and improving efficiency. It is also configurable to any type of bobbin shaft/gear configuration. The Bobbin Feed Tube may bring the bobbin thread to the bobbin winding assembly. This can be performed via air blowing the thread or manually fed through the tube. The bobbin winder motor assembly may shift into position to rewind the bobbin and the thread being blown into the spinning bobbin. After the bobbin full of thread, the bobbin winder motor assembly may move back to the start position and the needle with the upper thread moving into the sewing position. The shuttle hook may grab the upper thread and pull it around the bobbin. The shuttle hook with the upper thread may contact the bobbin thread coming from the feeding tube. The upper thread may pull the bobbin thread into the tensioner and past the sensor, and then cut the bobbin thread at the feed tube. In this manner, the present inventive concept provides for continued sewing until the bobbin sensor detects no bobbin thread at which point the aforementioned process is repeated. 
         [0023]    The foregoing and/or other aspects and utilities of the present general inventive concept may further be achieved by providing a bobbin assembly including a bobbin, a thread support element for supporting a spool and thread, and an elongated tube for receiving the thread from the spool and routing the thread through a sewing machine and to the bobbin. An air transmission tube operable to deliver a supply of air may also be provided wherein the tube is at least partially aligned with the air transmission tube so that the tube is operable to receive air transmitted from the air transmission tube. An elongated shaft in communication with and operable to rotate the bobbin may also be provided. A bobbin winder operable to selectively rotate the bobbin may also be provided. The bobbin winder may be selectively movable to and from a use configuration and a non-use configuration. The use configuration may be the bobbin winder abutted against the bobbin and the non-use configuration may be the bobbin winder spaced from the bobbin. The tube may be selectively movable to and from a use configuration and a non-use configuration. The use configuration may be the tube adjacent to the bobbin and the non-use configuration may be the tube spaced away from and not adjacent to the bobbin. A plurality of grippers may be provided to project from the bobbin, the plurality of grippers operable to snag the thread from the spool. 
         [0024]    The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a method of sewing using a bobbin assembly, the method including installing a spool having a thread on a thread support element, and feeding the thread from the spool into an elongated tube. The method may further include the step of blowing the thread through the tube via air transmitted from an air transmission tube. The method may further include the step of blowing the thread through the tube and to a bobbin. The method may further include the step of rotating the bobbin to accumulate a supply of the thread on the bobbin. The method may further include the steps of catching an upper thread via a bobbin element, adding tension to the thread via the upper thread, and cutting the thread via a cutting element. 
         [0025]    The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a non-transitory computer readable medium containing computer instructions stored therein for causing a computer processor to perform the steps of monitoring a condition of a bobbin, and executing a refilling process when the condition indicates that the bobbin is at least partially depleted of a thread, wherein the refilling process includes feeding the thread from a thread supply into an elongated tube. The non-transitory computer instructions may further cause a computer processor to further perform the steps of blowing the thread through the tube via air transmitted from an air transmission tube, blowing the thread through the tube and to a bobbin, rotating the bobbin to accumulate a supply of the thread on the bobbin, catching an upper thread via a bobbin element, adding tension to the thread via the upper thread, and/or cutting the thread via a cutting element. 
         [0026]    Additional aspects and utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept. 
         [0027]    The foregoing and other objects are intended to be illustrative of the present general inventive concept and are not meant in a limiting sense. Many possible embodiments of the present general inventive concept may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of present general inventive concept may be employed without reference to other features and subcombinations. Other objects and advantages of this present general inventive concept will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this present general inventive concept. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0028]    These and/or other aspects and utilities of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
           [0029]      FIG. 1  is a left side elevation view of a conventional sewing machine having a bobbin; 
           [0030]      FIG. 2  is a left side elevation view of the present general inventive concept illustrating a bobbin assembly in use with a sewing machine; 
           [0031]      FIG. 3  is a magnified side elevation view of the bobbin of the present general inventive concept illustrated in  FIG. 2  with related components; 
           [0032]      FIG. 4  is a magnified front elevation view of the bobbin of the present general inventive concept illustrated  FIG. 2  with related components; 
           [0033]      FIG. 5A  is a front elevation view of a wire tensioner of the present general inventive concept illustrated  FIG. 2  with related components; 
           [0034]      FIG. 5B  is a magnified front elevation view of the wire tensioner of the present general inventive concept illustrated  FIG. 5A  with related components; 
           [0035]      FIG. 5C  is a top plan view of the wire tensioner of the present general inventive concept illustrated  FIG. 5A  with related components; 
           [0036]      FIG. 6  is a magnified side elevation view of the bobbin of the present general inventive concept illustrated in  FIG. 2  with related components; 
           [0037]      FIG. 7  is a magnified side elevation view of the bobbin of the present general inventive concept illustrated in  FIG. 2  with related components; 
           [0038]      FIG. 8  is a magnified side elevation view of the bobbin of the present general inventive concept illustrated in  FIG. 2  with related components; 
           [0039]      FIG. 9  is a magnified side elevation view of the bobbin of the present general inventive concept illustrated in  FIG. 2  with related components; 
           [0040]      FIG. 10  is a magnified side elevation view of the bobbin of the present general inventive concept illustrated in  FIG. 2  with related components; 
           [0041]      FIG. 11  is a magnified side elevation view of the bobbin of the present general inventive concept illustrated in  FIG. 2  with related components; 
           [0042]      FIG. 12  is a magnified side elevation view of the bobbin of the present general inventive concept illustrated in  FIG. 2  with related components; 
           [0043]      FIG. 13  is a left side elevation view of another embodiment of the present general inventive concept illustrating a straight-shaft bobbin assembly and a winder assembly in use with a sewing machine; and 
           [0044]      FIG. 14  is a left side elevation view of another embodiment of the present general inventive concept illustrating a top-loading bobbin assembly and a winder assembly in use with a sewing machine. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0045]    Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures. 
         [0046]    Turning to  FIGS. 2-4 , a bobbin assembly  20  includes a sewing machine  22  having a working surface  24  and a bobbin  26  housed beneath the working surface  24  and within the sewing machine  22 . The bobbin  22  is at least partially enclosed by a bobbin cover  28  and/or the shuttle  100  and is controlled by an elongated cylindrical shaft  30 , which engages the shuttle  100  and is operable to selectively rotate the shuttle  100 . 
         [0047]    In communication with the bobbin  22  is a conical spool  32  having a supply of thread  34  thereon. The spool  32  is mounted on a support element  36  located outside of and adjacent to the sewing machine  22 . The supporting element  36  is stationary with an upwardly-projecting element  38  that is insertable into a center of the spool  32 . The supporting element  36  is capable of supporting spools of a variety of sizes such that larger spools, relative to conventional spools (not illustrated), to enable longer spans of use of the present inventive concept without requiring changes of the spool  32 . 
         [0048]    The bobbin  26  is in the form of a cylindrical reel with a circumferential receiving surface  40  on an interior of the bobbin  26  that is operable to receive and support the thread  34  thereon. On either side of the receiving surface  40  are two walls  42  that are operable to contain the thread  34  on the receiving surface  40 . In the exemplary embodiment, the receiving surface  40  has a plurality of thread grippers  44 , e.g., depending fibers or the like, that are each operable to further secure the thread  34  to the receiving surface  40 , e.g., via trapping the thread  34  between the thread grippers  44  to prevent lateral movement of the thread  34  along the receiving surface  40  yet permitting vertical movement of the thread  34  when a force, e.g., a pulling or tugging force, is applied to the thread  34 . It is foreseen, however, that the thread gripper  44  may be omitted without deviating from the scope of the present inventive concept. 
         [0049]    The thread  34  is wound onto the bobbin  26  via securing a portion of the thread  34  to the bobbin  26  and then rotating the bobbin  26 . The bobbin  26  is rotated via a bobbin winder  46  that includes a motor  48  that is operable to rotate a shaft  50  that has a bobbin-engagement portion  52  at an end thereof, as illustrated in  FIG. 4 . The motor  48  is powered by an AC/DC power source (not illustrated). The bobbin-engagement portion  52  abuts one or both of the walls  42  of the bobbin  26 , and is made of a resilient material, e.g., rubber or the like, so that the bobbin-engagement portion  52  may be slightly pressed into one or more walls  42  to provide sufficient friction and ensure constant engagement therebetween. Additionally, a hole  54  is provided within the bobbin winder assembly  46  to provide access thereto should such be required during maintenance of the bobbin winder assembly  46  or bobbin  26 . 
         [0050]    The bobbin case  28  is equipped with a bobbin tensioner  56  that is operable to maintain a sufficient degree of tension between the bobbin  26 , the thread  34 , and the spool  32  to prevent any slack in the thread  34 . The bobbin tensioner  56  is a spring or the like that prevents rotation of the bobbin  26  unless a slight amount of force, e.g., a pull force from the thread  34  and/or a rotating force from the bobbin winder assembly  46 , is applied to the bobbin  26 , in which case the bobbin tensioner  56  permits rotation of the bobbin  26 . 
         [0051]    The bobbin case  28  is also equipped with a bobbin sensor  58  that receives the thread  34  therethrough, e.g., between two walls that form a void to receive the thread  34 , and/or is operable to sense whether the thread  34  is no longer within or adjacent to the sensor  58 , which in turn indicates that the thread  34  is or is becoming depleted and replacement is or is about to be required. The bobbin sensor  58  may be, for example, be a circuit that is closed when the thread  34  is not present in the void and that is open when the thread  34  is present within the void. The sensor  58  may be connected to an indicator, e.g., a light (not illustrated), such that when the circuit is open because the thread is not present within the void, the light is off, and when the indicator is closed because the thread is present within the void, the light is on to indicate that the thread  34  is or is becoming depleted and replacement is required or is about to be required. 
         [0052]    The thread  34  is installed onto the bobbin  26  via at least one air supply (not illustrated), e.g., a fan, compressed air, or the like. The air supply is operable to transmit a stream of air from an elongated air-transmitting tube  62  to an elongated air-receiving tube  64  so that when the thread  34  is placed in front of the receiving tube  64 , the thread  34  is blown into and through the receiving tube  64 , through an opening  65 , and to the bobbin  26 . The air supply is preferably manually activated via a switch only during installation of the thread  34  onto the bobbin  26 . It is foreseen, however, that the air supply may be activated automatically and/or maintained in an active state during use of the present inventive concept. Also included is a thread cutter  66 , which is operable to selectively cut the thread  34  between the bobbin  26  and the spool  32  when desired by the user, e.g., after the bobbin  26  has been loaded with the thread  34 . 
         [0053]    Turning to  FIGS. 5A-5C , a wire tensioner  70  is provided on a grooved base  72  of the working surface  24  of the sewing machine  22 . The wire tensioner  70  is manufactured from a wire or like material having a degree of resilience. In the exemplary embodiment, the wire tensioner  70  is biased toward the grooved base  72 , so that the thread  34  may be trapped between the wire tensioner  70  and the grooved base  72  so that the user is able to maintain the thread  34  in a desired position on the working surface  24 . 
         [0054]    The sewing machine  22  has a cavity  80  for receiving and supporting the shaft  30  that is operable to rotate the shuttle  100 . The sewing machine  22  receives the shaft  30  into a side thereof. While the shaft  30  is depicted as received parallel to a length of the sewing machine  22 , it is foreseen that the shaft  30  can be received perpendicular to the length of the sewing machine  22 . 
         [0055]    The elongated transmitting tube  64  extends through the sewing machine  22  parallel to the shaft  30  and communicates the thread  34  from an exterior of the machine  22  to an interior of the machine  22 . In this manner, the tube  64  delivers the thread  34  to the bobbin  26 . 
         [0056]    Turning to  FIGS. 6-12 , in use, the machine  22  is activated and the bobbin sensor  58  is operable to sense whether the thread  34  is present on the bobbin  26  and available for use. If not, the thread  34  is either manually or automatically fed until the bobbin sensor  58  senses that the thread  34  is present on the bobbin  26 . In other words, the spool  32  is installed onto the support element  36  and the thread  34  is fed into the tube  64 . The air supply is activated to transmit air from the tube  62 , to the tube  64  and the thread  34  is blown through the tube  64  and to the bobbin  26 . The tube  64  is selectively moveable to and from a closer proximity to the bobbin  26  through opening  65 . 
         [0057]    Once the thread  34  is fed through the tube  64 , the thread  34  is continued to be blown until it engages the surface  40  and the grippers  44 , and is then rotatingly wound onto the bobbin  26  by the winder  46 . To perform the winding, the winder  46  is selectively movable through the opening  54  to an abutting relationship with the walls  42  of the bobbin  26  and then activated to rotate the bobbin  26 . At a predetermined point (e.g., after a certain time period passes or a number of complete revolutions of the bobbin  26 , the winder  48  stops and is backed away from the bobbin  26 . When the winder  46  ceases to operate, the air source is deactivated and the tube  64  is also backed away from the bobbin  26 . 
         [0058]    An upper needle  90  and upper thread  92  are then positioned for use with the machine  22 . A shuttle  100  begins rotation a shuttle cock  101  catches the upper thread  92  and positions the upper thread  92  around the bobbin  34  and in relationship to the thread  34  for a sewing operation. The upper thread  92  pulls the thread  34  so that the thread  34  has a tension, which causes the thread  34  to be received into the thread sensor  58 , so that the thread sensor  58  may monitor usage of the thread  34  and alert the user when the thread  34  is depleted or malfunctions (e.g., is no longer capable of being used with the upper thread  92 ). At this point, the thread cutter  66  cuts the thread  34  and the sewing operation may begin. 
         [0059]    It is foreseen that the present inventive concept may be modified without deviating from the scope of the present inventive concept. For instance, bobbin gears may be provided so that the bobbin  26  is oriented horizontally or vertically with respect to the machine  22 , as illustrated in  FIGS. 13 and 14 . 
         [0060]    It is also foreseen that various embodiments of the present generally inventive concept can be embodied as computer readable codes (e.g., computer instructions) on a non-transitory computer readable recording medium for causing a computer processor to perform (e.g., functions of the present general inventive concept). The computer readable recording medium may include any data storage device suitable to store data that can be read by a computer system. A non-exhaustive list of possible examples of computer readable recording mediums include read-only memory (ROM), random-access memory (RAM), CD-ROMS, magnetic tapes, floppy disks, optical storage devices, and carrier waves, such as data transmission via the internet. The computer readable recording medium may also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distribution fashion. Various embodiments of the present general inventive concept may also be embodied in hardware, software or in a combination of hardware and software. For example, a user interface (not illustrated) may be provided with a controller (not illustrated) to permit a user to operate the present general inventive concept. For instance, when the sensor  58  indicates the bobbin  26  is depleted, the controller may automatically activate the air source (not illustrated) to cause the thread  34  to be routed to the bobbin  26 , which then undergoes the reloading process as previously discussed. In other words, these functions may be embodied in software, in hardware, or in a combination thereof. 
         [0061]    Although a few embodiments of the present general inventive concept have been illustrated and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.