Abstract:
A feed mechanism for a sewing machine, either separate from the rest of the machine or incorporated as a part thereof, greatly improves quality of sewn products, permits a multitude of stitches and increases production rates with less labor content.

Description:
This invention relates to a sewing machine feed device and, more particularly, to a sewing machine feed device separately driven from the rest of the sewing machine, which can feed the sewn product independently of the other sewing machine mechanisms, and which can be configured so as to feed the fabric in any direction, and which can replace existing sewing machine feed mechanisms, without being an add on device to the sewing machine feed devices. 
     CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation in part of U.S. patent application Ser. No. 12/931,853, filed Feb. 10, 2011, and now U.S. Pat. No. 8,850,999; filed by the same inventive entity. 
     BACKGROUND OF THE INVENTION 
     In order to effectively use a sewing machine, it is very desirable to control the feeding of the fabric through the machine to achieve special effects on the material being sewn. To that end, many devices are known to assist this function. These devices primarily employ mechanisms mechanically arranged to achieve an elliptical motion of the fabric feeder. 
     This elliptical motion results from a vertical motion imparted to the cloth feeder combined with a horizontal motion. The feeder rises up to engage the fabric and simultaneously starts moving the fabric horizontally. The vertical motion reaches its peak and begins to drop down as the horizontal motion continues to feed the fabric. When the feeder drops below the cloth support plate the fabric stops moving, the feeder continues down and starts returning horizontally. The fabric is held stationary during this return cycle by the clamping pressure of the presser foot. The feed returns to the start position and begins the vertical motion all over again, repeating the cycle. 
     The current mechanical feed mechanism incrementally moves the fabric in a straight line. The sewing machine operator must guide the fabric manually to achieve a curved stitch pattern. There are available various add on devices to manipulate the fabric as comes into the sewing machine or during the sewing process itself to assist or replace the sewing machine process itself. Also, in some sewn products, there could be a series of discreet areas to be sewn, not connected to each other. The operator must sew one area, stop, trim threads, reposition manually and start sewing the second area. 
     The current cloth feeding mechanisms are mechanically linked to the other sewing mechanisms (for example needle mechanism, hook mechanism, looper mechanisms, and so forth) to provide synchronous motions to produce a stitch. The prior art feed mechanism control features are also all mechanically arranged. Stitch length (the increment the fabric moves for each machine cycle) is adjusted by turning a dial to move a linkage, or by adjusting a mechanical eccentric, or by changing eccentric cams. These changes complicate the sewing process. 
     Better control of the fabric or material feeding through a sewing machine can greatly improve production and quality of sewn products. For the purposes herein fabric and material may be used interchangeably unless otherwise specified. To achieve this feeding of material or fabric with programmability and ease of control offers great advantages. Such features are currently unavailable in the art, unless the sewing machine has many complicated devices attached thereto. 
     SUMMARY OF THE INVENTION 
     Among the many objectives of this invention is the provision of an improved sewing machine feed device to facilitate feeding fabric through a sewing machine. 
     An objective of this invention is a fabric feeding mechanism that is separately driven from the other mechanisms of a sewing machine. 
     A further objective of this invention is a fabric feeding mechanism that can transport the fabric in any direction. 
     A still further objective of this invention is a fabric feeding mechanism that is programmable. 
     Yet a further objective of this invention is a fabric feeding mechanism that has easily operated controls. 
     Also an objective of this invention is a fabric feeding mechanism that can produce a feed motion curve that is programmable. 
     Another objective of this invention is a fabric feeding mechanism that is capable of providing a programmable stitch length. 
     Still another objective of this invention is a fabric feeding mechanism that can produce a sewing path that is programmable. 
     Yet another objective of this invention is a fabric feeding mechanism that can feed the fabric with a “joystick” type control. 
     A further objective of this invention is a fabric feeding mechanism that can easily feed fabric in reverse (backtrack). 
     A still further objective of this invention is a fabric feeding mechanism that can move fabric in a zig-zag pattern. 
     Yet a further objective of this invention is a fabric feeding mechanism that can be programmed to move fabric in a pattern to produce buttonholes. 
     A still further objective of this invention is a fabric feeding mechanism that can be programmed to move fabric in a pattern to produce eyelets. 
     Also an objective of this invention is a fabric feeding mechanism that can move fabric to do basting. 
     Another objective of this invention is a fabric feeding mechanism that can move fabric to do tacking. 
     Still another objective of this invention is to provide a fabric feeding mechanism that can be adapted to a wide variety of sewing machines. 
     Yet another objective of this invention is to provide a fabric feeding mechanism that can make an effective use of an eccentric motion. 
     These and other objectives of the invention (which other objectives will become clear by consideration of the specifications, claims and drawings as a whole) are met by providing a feed mechanism for a sewing machine, either separate from the rest of the machine or incorporated as a part thereof, that will greatly improve quality of sewn products and increase production rates with less labor content, by using an eccentric motion and other variations of the feed device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts an exploded, perspective view of the linear drive feature  200  for the sewing machine feed device  100  of this invention. 
         FIG. 2  depicts a block diagram of rotation feature  106  for the sewing machine feed device  100  of this invention. 
         FIG. 3  depicts a top perspective view of the sewing machine feed device  100  with sewing machine  102  in phantom. 
         FIG. 4  depicts an exploded view of the sewing machine feed device  100  of this invention with rotation feature  106 . 
         FIG. 5  depicts a block diagram of the linear drive feature  200  for the sewing machine feed device  100  of this invention. 
         FIG. 6  depicts an exploded, perspective view of a second sewing machine feed device  300  for the sewing machine feed device  100  of this invention. 
         FIG. 7  depicts an exploded, perspective view of a third sewing machine feed device  400  for the sewing machine feed device  100  of this invention. 
         FIG. 8  depicts  FIG. 1  in phantom, with an exploded view of a fourth sewing machine feed device added thereto in the form of a lateral eccentric guide  500 , which cooperates with the sewing machine feed device  100  with the addition of components to achieve omni-directional feeding, while providing lateral eccentric motion  552  in cooperation with the sewing machine feed device  100  shown in phantom. 
         FIG. 9  depicts a box chart showing relationship of lateral eccentric guide  500  cooperating with the sewing machine feed device  100 . 
     
    
    
     Throughout the figures of the drawings, where the same part appears in more than one figure of the drawings, the same number is applied thereto. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to several embodiments of the invention that are illustrated in accompanying drawings. Whenever possible, the same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms such as top, bottom, left, right, up, over, above, below, beneath, rear, and front, may be used with respect to the drawings. These and similar to directional terms are not to be construed to limit the scope of the invention in any manner. The words attach, connect, couple, and similar terms with their inflectional morphemes do not necessarily denote direct or intermediate connections, but may also include connections through mediate elements or devices. 
     The feed mechanism for the sewing machine may be separate from the rest of the machine or incorporated as a part thereof. It can feed the fabric independent of the other sewing machine mechanisms and, with the addition of the rotational or cross feed components of the feed mechanism, fabric can be fed in any direction. The feed dog moving in an elliptical path transports material over the throat plate. There are three computer controlled servo drive motors driving the feed mechanism: a vertical drive motor (feed lift), a horizontal drive motor (feed travel), and a rotational drive motor or a cross drive travel drive motor, all linked to a motor controller, a programming device or computer, and operator control panel or display. In the case of the rotational feed mechanism a “joy stick” type input device can be used to “steer” the fabric in any desired direction or path. 
     Typical sewing machines to which this feed mechanism can be adapted to include, but are not limited to: Lockstitch Machines—301 type stitch, Differential Feeds, Top Feeds, Feed-Off-Arm Type Machines, Chainstitch Machines—401 type stitch, Feed-Up-Arm Type Machines, Coverstitch Machines, Blindstitch Machines, Zig-Zag Machines, Overlock Machines (Sergers), Tackers, and Pattern Sewers. 
     Referring now to  FIG. 1 , the sewing machine feed mechanism  200  is provided by a grouping of parts including the feed bar  152 . The feed lift bracket  150  communicates with the feed bar  152  at one end with pivot bracket  154  at the other end of feed bar  152 . The feed travel bracket  156  is secured to the feed bar  152  adjacent to the pivot bracket  154 . 
     First drive block  160  communicates with the pivot cradle  174  on pivot bracket  154 . Second drive block  162  communicates with the feed travel drive block cradle  172  on the feed travel bracket  156 . Then third drive block  164  communicates with feed lift drive block cradle  170  on the feed lift bracket  150 . Thus, front end  180  of feed bar  152  supports the feed lift bracket  150 . The top end  182  of feed bar  152  receives the feed dog  240 . The back end  184  of feed bar  152  has a pivot bracket  154  secured thereto. The bottom side  186  of feed bar  152  has feed travel bracket  156  secured thereto. 
     The feed lift eccentric  190  communicates with third drive block  164  and is driven by feed lift servo motor  210 . The feed travel eccentric  191  communicates with second drive block  162  and is driven by feed travel servo motor  210 . Pivot pin  214  cooperates with first drive block  160 . This structure provides cooperation between vertical feed lift motion  230  of third drive block  164  and horizontal feed travel motion  234  of drive block  162 . Elliptical motion  232  of the feed dog  240  on the feed bar  152  occurs when the feed lift servo motor  210  and the feed travel servo motor  212  are rotated in conjunction. 
     The vertical or feed lift servo motor  210 , and horizontal servo drive motor or feed travel servo motor  212  are capable of being programmed to achieve an elliptical motion. In addition, the motors can be programmed to achieve non-elliptical feed motions. For example, the feed motion could rise slowly vertically so as to reduce damage to the fabric, then move horizontally and retract down quickly and return horizontally quickly. 
     Also, the feed motion stitch length can be programmed by adjusting the time span for the vertical motion or by advancing the vertical motion partially and then retracting (partial rotation of the motor). The motors can also be programmed to do reverse feeding simply by changing the timing of when the vertical motion is activated relative to the horizontal motor. The “tacking” operation can be done with this type of sewing machine feed mechanism by simply programming the motors to move the fabric forward one stitch length and back one stitch length for a set number of sewing machine cycles. 
     Finally, this feed mechanism with separately driven motors can feed the fabric while not sewing. This can be used to achieve any desired stitch length for example by feeding the fabric in increments, sewing one stitch, and feeding the fabric again in increments and sewing one stitch, the effect is a long stitch length. This can be used to do “basting” where one or several stitches are put into a sewn product to temporarily hold pieces together. This is done in a number of areas that could now be programmed into a pattern where the product is moved automatically to the various points where basting is done without operator involvement. 
     A third programmable servo motor or rotation servo motor  140  can be added to this feed mechanism to achieve fabric feeding in a desired or any direction or pattern as will be described next. 
     Adding  FIG. 2  to the consideration, rotation feature  106  is depicted. Needle plate  110  is connected to support plate  112 . Support plate  112  is supported by one or two of support post  114 . Support post  114 , singly or more, receive rotation base plate  116 . Rotation base plate  116  supports two sets of groove rollers  120 . One set of grooved rollers  120  is connected to guide rails  126 . The other set of grooved rollers  120  is optionally connected to guide rails  126 . Guide rails  126  rest on rail support plate  118 . 
     Segment gear  130  is connected to rotation plate  116  and meshes with pinion gear  132 . Pinion gear  132  is operated by rotation servo motor  140 . Rotation servo motor  140  is in turn operated by motor controller  242 . Input device  244  feeds information to motor controller  242  to control servo motor  140 . 
     Input device  244  and motor controller  242  may be joint or separate devices. Motor controller  242  or input device  244  may be a joy stick, a computer or other appropriate device. With such a structure, the elliptical motion  232  of  FIG. 1  may be adjusted to any desired shape. The structure of motor controller  242  and input device  244  may be applied to the feed lift servo motor  210  or the feed travel servo motor  212  of  FIG. 1  or any other servo motor herein. 
     Referring to  FIG. 3 , sewing machine feed device  100  is positioned on sewing machine  102  under a right turn indicator  104  where needle plate  110  rotates. The feed device  200  and the rotation feature  106  provides a fabric transport method through the sewing machine  102  that is programmable, that can feed fabric in any direction and that is readily controllable and flexible. 
     In  FIG. 4 , sewing machine feed device  200  is shown with its rotation feature  106 . Needle plate  110  is mounted over support plate  112 . Support plate  112  sits on a pair of support posts  114 . Support posts  114  provide connection between support plate  112  and rotational base plate  116 . 
     Below the rotational base plate  116  is a rail support plate  118 . Mounted between rotational base plate  116  and rail support plate  118  is guide rail  126 . While guide rail  126  is secured to support plate  118 , it is not directly secured to rotational base plate  116 . Grooved rollers  120  are secured to rotational base plate  116 , preferably in a rotational fashion. The grooved rollers  120  are four in number and positioned on opposing sides of guide rail  126 . 
     Segment gear  130  is mounted and secured to rotational base plate  116 . Segment gear  130  contacts and meshes with pinion gear  132 . Pinion gear  132  is mounted on and secured to the rotational servo motor  140 , so that a desired rotation can occur. Rotational servo motor  140 , mounted in this structure, permits efficient feeding of material through a sewing machine  102  ( FIG. 3 ). 
     In  FIG. 5 , the linear drive feature  200  is further explained in block diagram form as connecting to needle plate  110 . More particularly feed dog  240  communicates with needle plate  110 . Feed dog  240  also communicates with feed bar  152 . Feed bar  152  is connected to feed lift bracket  150 , pivot bracket  154 , feed travel bracket  156 . Depending on the desired function, at least one of three procedures are followed. In fact elliptical systems and variations thereof may be achieved. 
     In one case, feed lift bracket  150  is optionally connected to third drive block  164 . Third drive block  164  is connected to feed lift eccentric  190 . Feed lift eccentric  190  is operated by feed lift servo motor  210 . Feed lift servo motor  210  is operated motor controller  242  and input device  244  as above described. 
     In another case, feed bar  152  is connected to feed travel bracket  156 . Feed travel bracket  156  cooperates with second drive block  164 , which in turn is connected to feed travel eccentric  191 . Feed travel eccentric  191  is operated by feed travel servo motor  212 , which in turn, is controlled input device  244  as above described. 
     In still another function, pivot bracket  154  cooperates with first drive block  160  as mounted on pivot pin  214 . The set ups are selectively operated in any desired combination. 
     With the rotational feature  106 , the feed mechanism can now feed the fabric in any direction. With the feed dogs in the down position the needle plate is rotated by the rotational servo motor so that the feed dogs are pointing in the desired direction. When the feed dogs are on the vertical portion of their elliptical path they engage the fabric and then move the fabric horizontally in the direction set by the rotational motor. The feed dogs then retract down, the rotational motor repositions to the next desired direction and the cycle repeats. The fabric must be held stationary by the presser foot during the needle plate rotation. By a combination of programming the rotational motor with the forward and reverse directions of the horizontal and vertical motors any fabric direction can be achieved. 
     The control of the fabric movement can be accomplished with a joystick. A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. The left, right, forward, and backward motion of the fabric could be controlled with a joystick. 
     The fabric motion can also follow a programmed path. The location of each stitch can be inputted into a computer and stored. Various programs can then be called up and used to drive the fabric feed mechanism and sewing machine to produce an infinite variety of paths, curves, patterns, and stitch types. 
       FIG. 6  depicts another embodiment of a sewing machine feed mechanism with second sewing machine feed device  300 . This top feed arrangement can be incorporated into a typical blindstitch machine. In this case, the feed dog  270  grips the fabric from the top. The primary feed dog  270  again moves in an elliptical motion driven by the vertical servo motor or feed lift servo motor  210  and its eccentric  190  and first drive block  160  and the horizontal servo motor or the feed travel servo motor  212  and its eccentric  191  and second drive block  162 . The primary feed dog  270  may also grip the fabric from the top and pulls the fabric through the sewing machine  102 . Pivot pin  214  works to hold first drive block  160  in position pivot bracket  154  of motion bracket  152 . Feed travel bracket  156  of motion bracket  152  receives second drive block  162 . Feed lift bracket  150  of motion bracket  152  receives third drive block  164 . This structure permits the feed dog  270  to operate efficiently. 
     In  FIG. 7 , another embodiment of sewing machine feed device  100  in the form third sewing machine feed device  400  is shown. A differential feed is accomplished. Two mechanisms are arranged side-by-side such that the first feed dog  250  is behind the second feed dog  260 . Each side can be activated separately. When first feed dog  250  is programmed to move a greater horizontal distance than second feed dog  260  the fabric is gathered. When first feed dog  250  is programmed to move less than second feed dog  260  the fabric is stretched. Having the capability to program the sewing machine, when the fabric is to be gathered or stretched, can be important when sewing knit materials that act differently when pulled in different directions. 
     In this case, there are two feed mechanisms placed side-by-side. The motors can be programmed so that the first feed dog  250  can move a greater horizontal distance than the second feed dog  260  resulting in stretching the fabric. When the first feed dog  250  is programmed to move a lesser horizontal distance than the second feed dog  260  the fabric  110  is gathered as desire. 
     This is basically a duplicate version of  FIG. 6 . Each of first feed dog  250  can move a greater horizontal distance than the second feed dog  260  motion is driven by its own vertical servo motor or feed lift servo motor  210  and its own eccentric  190  and first drive block  160 ; and the horizontal servo motor or the feed travel servo motor  212  and its eccentric  191  and second drive block  162 . Each pivot pin  214  works to hold first drive block  160  in position pivot bracket  154  of motion bracket  152 . Feed travel bracket  156  of motion bracket  152  receives second drive block  162 . This applies to each feed lift bracket  150  of motion bracket  152  receives third drive block  164 . 
       FIG. 8  provides an exploded view of a fourth embodiment for an omni-directional feed mechanism in the form of lateral eccentric guide  500 . In this case, a lateral component (left or right) is added to the sewing machine feed device  100  of  FIG. 1 , which  FIG. 1  is shown in phantom without numbers as cooperating with lateral eccentric guide  500 . This arrangement allows the three motions to move completely independent from one another. 
     For the lateral eccentric guide  500 , first cross travel guide plate  502  and second cross travel guide plate  504  are positioned on opposite sides of sewing machine feed device  100 . Third cross travel guide plate  506  aligns with first cross travel guide plate  502 . Fourth cross travel guide plate  508  aligns with second cross travel guide plate  504 . Four spacers  546  in two pairs are positioned between the third cross travel guide plate  506  and first cross travel guide plate  502 , and fourth cross travel guide plate  508  and second cross travel guide plate  504 . 
     The four spacers  546  include first spacer  520  and second spacer  522 , and third spacer  524  and fourth spacer  526 . The first set of four apertures  548  appear in pairs in each of first cross travel guide plate  502  and second cross travel guide plate  504 . The second set of four apertures  550  appear in pairs in each of third cross travel guide plate  506  and fourth cross travel guide plate  508 . First spacer  520  and second spacer  522  connect a pair of the first set of apertures  548  and a pair of the second set of apertures  550 . Third spacer  524  and fourth spacer  526  connect a separate pair of the first set of apertures  548  and a separate pair of the second set of apertures  550 . 
     The cross travel servo motor  510  connects to the cross travel eccentric  512 , which in turn connects to the cross travel bracket  514 . Centered in the cross travel bracket  514  is the cross travel drive block  516 . The cross travel bracket  514  is connected to the cross travel guide plate  518 . 
     Bushings  566  contact cross travel guide plate  518  and guide rods  544 . Guide rods  544  also contact second set of apertures  550  at the opposing end thereof. More particularly, bushings  566  include first bushing  560 , second bushing  562 , third bushing  564 , and fourth bushing  566 . Guide rods  544  include first guide rod  528 , second guide rod  530 , third guide rod  532  and fourth guide rod  534 , each of which contact its own member of the second set of apertures  550 . 
     Likewise first bushing  560  cooperates with first guide rod  528 . Second bushing  562  cooperates with second guide rod  530 . Third bushing  564  cooperates with third guide rod  532 . Fourth guide rod  534  cooperates with fourth bushing  564 . 
     This structure provides an inward movement  540  and an outward movement  542 , as shown by the respective arrows. The lateral eccentric motion  552  is depicted by an arcuate arrow. 
     Turning now to  FIG. 9 , sewing machine feed device  100  cooperates with lateral eccentric guide  500 . Sewing machine feed device  100  has feed lift bracket  150  cooperating with third drive block  164 . The third drive block  164  is connected to the feed lift eccentric  190 , which is in turn connected to motor controller  242 . 
     Feed bar  152  is connected to both pivot bracket  154  and feed travel bracket  156 . Feed travel bracket  156  is optionally connected to second drive block  162 . Second drive block  162  is connected to feed travel eccentric  191 , which is in turn connected to feed travel servo motor  212 . Feed travel circular  212  connects to motor controller  242 . Motor controller  242  follows instructions from input device  244 . Also connected to pivot bracket  154  is first drive block  160  which receives pivot pin  214 . 
     Motor controller  242  is connected to the feed cross travel servo motor  510  of the lateral eccentric guide  500 . The feed cross travel servo motor  510  is connected to the feed cross travel eccentric  512 , which in turn cooperates with the feed cross travel guide block  516 . The feed cross travel guide block  516  cooperates with the feed cross travel guide bracket  514 , which is connected to the center feed cross travel guide plate  518 . Guide rods  544  supports the center feed cross travel guide plate  518  and the right feed cross travel guide plate  550 . Spacers  546  separate the right feed cross travel guide plate  550  and left feed cross travel guide plate  548 . 
     These arrangements allow fabric to be moved in any direction in the X-Y horizontal plane (X axis being the feed cross travel and Y axis being the feed travel). This method of fabric movement is useful for all sewing machines that produce a lockstitch (Stitch Type  301 ) where the stitch can be formed with the fabric moving forward, reverse, left, or right. Arcuate or elliptical movements are also permitted, especially with the structures as shown in  FIG. 8  and  FIG. 9 . 
     For sewing machines that produce chainstitches (Stitch Types  401 ,  500 &#39;s) the fabric must have some forward component of movement in order to properly form the stitch. A single omni-feed mechanism as described above can be used to replace the feed mechanism in single and multi-needle chainstitch machines and sergers to do curved or straight patterns. By combining two omni-feed mechanisms these types of machines can produce closed patterns that include inside and outside turns. The material can be rotated 360 degrees by placing one feed dog behind the needle and the other feed dog in front of the needle. By programming the two cross feed motors to move in opposite directions the fabric can be rotated. 
     This application, taken as a whole with abstract, specification, claims, and drawings being combined, provides sufficient information for a person having ordinary skill in the art to practice the invention as disclosed and claimed herein. Any measures necessary to practice this invention are well within the skill of a person having ordinary skill in this art after that person has made a careful study of this disclosure. 
     Because of this disclosure and solely because of this disclosure, modification of this method and device can become clear to a person having ordinary skill in this particular art. Such modifications are clearly covered by this disclosure.