An improvement for a sewing machine used for barring and tacking operations which moves the work piece with respect to the sewing machine needle and produces a preselected number of stitches in programmed directions within the work piece. These machines inherently have a thread surplus extending from the thread source and through the work piece at the commencement of each sewing cycle. Specifically, this invention is a thread surplus separating apparatus which extends the thread surplus in a given manner, retains the thread surplus in this extended direction on the needle side of the work piece to avoid collection on the thread of dirt and grease from the shuttle of the machine and separates the thread surplus from the thread supply.
James Frank, King 925 Goodwood Rd (Winston-Salem, NC)
Howard St., Beamon 2626 Dudley L. (Winston-Salem, NC 27107)
Willie, Dr. Lathery 1342 Tredwell M. (Winston-Salem, NC)
Kenneth, Dr. Newlen 613 Runyon W. (High Point, NC 27260)
1. In a sewing machine suitable for sewing automatically a preselected pattern of stitches and having a movable work piece holding attachment for moving the work piece in predetermined directions with respect to the reciprocating needle of the machine wherein a thread surplus from a thread supply is present at the commencement of each sewing cycle, the holding attachment having a base plate, a frame vertically movable with respect to the plate, means associated with said plate for releasably securing the work piece and means moving the plate, frame and held work piece in preselected paths of travel, the improvement for removing the thread surplus which includes: means extending the thread surplus in a preselected direction; means associated with said frame retaining the thread surplus in the extended direction; and means associated with said frame separating the thread surplus from the thread supply.
2. The improvement as claimed in claim 1 further including means removing the thread surplus to a remote location.
3. The improvement as claimed in claim 2 wherein said thread extending means is a suction source.
4. The improvement as claimed in claim 3, said thread retaining means comprising a pivotally mounted clamp secured to said frame.
5. The improvement as claimed in claim 4, said separating means comprising a severing blade reciprocably mounted adjacent said frame, and means selectively engaging and displacing said blade to sever the thread surplus.
6. The improvement as claimed in claim 5, said removing means including conduit means having a first end proximate the unseparated surplus thread and a second end remote therefrom, and collecting means adjacent said second conduit means end for collecting the surplus thread upon separation thereof when said suction source is activated.
7. The improvement as claimed in claim 1 wherein said thread surplus retaining means retains the thread surplus on the needle side of the work piece.
8. The improvement as claimed in claim 7 wherein said thread surplus retaining means retain the thread surplus on the needle side of the work piece.
9. The improvement as claimed in claim 5 wherein said thread surplus retaining means retains the thread surplus on the needle side of the work piece.
10. The improvement as claimed in claim 6 wherein said thread surplus retaining means retains the thread surplus on the needle side of the work piece.
BACKGROUND, BRIEF SUMMARY AND OBJECTIVES OF THE INVENTION
A number of sewing machines are presently available for barring and tacking operations such as fastening bows, labels, pockets and belt loops on garments. A well known machine of this nature is the apparatus manufactured by The Singer Company referred to as a Class 269 (W) machine. Machines of this design can produce a pattern having a desired number of stitches in various directions and will stop automatically with the sewing needle in the raised position upon completion of the programmed stitching cycle.
Machines such as described above inherently provide a surplus of thread extending from the thread supply through the needle of from 1 to 2 inches in length. This thread surplus, for the most part, does not affect the operation of the machine or the work piece serviced. There are certain operations, however, in which the surplus thread is not desirable. For example, when a label is sewn to a garment, particularly when the garment is an innerwear garment with the label positioned directly against the wearer's skin, this surplus thread will be extended through the label and garment by the action of the needle during the first stitches of the operating cycle. Thread knives located beneath the base plate (below the work piece) on machines such as the Class 269 (W) Singer Machine have cams that move out and hold the correct amount of thread before cutting. When the surplus thread is extended through the label and garment by the needle, a needle thread cam pulls the surplus thread cut end so that the surplus is on the side opposite the needle. In many instances, this surplus catches between the shuttle and the shuttle race which is very dirty with contaminated oil and is drawn by the action of the shuttle to a greater than normal length. The thread becomes dirty with the oil and is wadded or bunched in the first few stitches of the sewing cycle on the side of the waistband of the garment that is most noticeable when the garment is inspected.
An improvement for these barring and tacking machines has been developed to reduce the length of the surplus needle thread, hold it away from the shuttle race and subsequently separate the surplus thread from the thread supply. An added advantage is that the needle is less likely to become unthreaded at the start of the sewing cycle. These machines commonly support a movable work piece holding attachment for moving the work piece in predetermined directions with respect to the reciprocating sewing machine needle so that a preselected number of stitches in the work piece can be produced in a desired configuration. Such a holding attachment includes a base plate which is parallel to the base of the sewing machine, a frame which is vertically movable with respect to the base plate, some securing means for holding the work piece against the plate and a drive mechanism associated with the sewing machine for moving the plate, frame and held work piece in desired directions with respect to the needle.
The improvement for holding and removing the surplus thread includes apparatus for extending the short length of surplus threads in a precise direction, preferably a suction source, for holding the thread surplus in this extended direction and for separating the surplus thread from the thread source. A suction source can be used effectively to hold the thread surplus by positioning a tubular member of conduit adjacent the machine needle so that the suction induced therein will draw the thread surplus into the end of the conduit. When the thread surplus has been separated, it can be carried by the conduit to a collecting receptacle at some remote location.
The background and brief description of the present invention make it apparent that a primary object of this improvement is to provide apparatus that will hold on the needle side of the work piece and remove a thread surplus inherently produced in barring and tacking sewing machines that often results in unsightly and dirty thread masses or bulges on the work piece.
Another object of the present invention is to provide an improvement which can be easily installed on existing barring and tacking sewing machines without requiring extensive part replacement or redesign.
Yet another object of the present invention is to provide an improvement that will not alter in any way the normal operation of barring and tacking sewing machines.
A further object of the present invention is to provide an improvement that is economical in cost, easy to install and simple to maintain.
These and other objects of the present invention will become more apparent after a consideration of the following detailed specification taken in conjunction with the accompanying drawings wherein like characters of reference designate like parts throughout the several views.
FIG. 1 is a perspective fragmentary view of a barring and tacking sewing machine supporting a movable work piece holding attachment which is used to sew labels on loops of banding.
FIG. 2 is a plan and fragmentary view of the sewing machine illustrated in FIG. 1.
FIG. 3 is a side elevational, enlarged and fragmentary view of the needle and work piece holding attachment of the machine shown in FIGS. 1 and 2.
FIG. 4 is a plan, sectional, and further enlarged view of the movable work piece holding attachment showing the suction conduit drawing the surplus thread away from the needle in a predetermined direction.
FIG. 5 is a side elevational view of the apparatus illustrated in FIG. 4 showing the pivotally mounted clamp which will secure the surplus thread in the extended direction.
FIG. 6 is a side elevational view of the apparatus shown in FIGS. 4 and 5 wherein the holding attachment frame had been lowered over an inserted waist band and the surplus thread has been clamped by the pivotal clamp.
FIG. 7 is a plan view of the frame of the holding attachment which has been modified to carry a displaceable severing blade.
FIG. 8 is a sectional view taken along the line 8--8 of FIG. 7.
FIG. 9 is a sectional view taken along the line 9--9 of FIG. 7.
FIG. 10 is a plan, sectional and fragmentary view of the modified frame of the holding attachment positioned where the frame will cause the displaceable blade to be moved.
FIG. 11 is a plan, sectional and fragmentary view of the apparatus shown in FIG. 10 wherein the sewing motion of the holding attachment has continued so that the surplus thread has been severed but remains clamped to the frame.
DETAILED DESCRIPTION OF THE DISCLOSURE
Referring now to the drawings, FIG. 1 shows a sewing machine commonly classified as a "barring and tacking" machine particularly adapted for sewing automatically a preselected pattern of finite stitches. Machines of this nature will produce a precise number of stitches and will stop automatically at the end of the pattern with their needles in the raised position upon completion of the stitching cycle. Machines of this nature are like those manufactured by the Singer Company and referred to as Class 269 (W) machines.
For purposes of illustration, the present invention will be shown in association with a barring and tacking machine adapted for positioning labels to a joined band so that the label covers the junction seam of the band. The band can subsequently be used as the supporting waist portion of, for example, a man's brief.
In the drawings, the movable holding attachment 22 is pivotally supported by the superstructure, shown generally as 23, of the machine 20 to swing from an operating location parallel with the machine through and angle of 90° (see FIG. 2) so that the holding attachment is perpendicular to the superstructure of the machine. When in this position, the holding attachment will, by appropriate suction means (not shown), obtain a label from a reservoir 24 and subsequently return to the working position illustrated in FIG. 1.
The movable work piece holding attachment 22 is operated in synchronism with the sewing machine and contains a base plate 26, a frame 28 and clamping means 30 releasably securing the work piece to the plate. The label is picked up in registry with a rectangular member 32 supported by the frame. A rectangular path 34 permits movement of the holding attachment with respect to the needle 36 of the machine. A rectangular stitch path about the edge of the label establishes a directional guide for the needle to affix the label to the joined band.
The holding attachment briefly described above is well known and is presently used in various machine designs to achieve a variety of stitch patterns. Attachments of this nature in conjunction with the associated sewing machine inherently result in a surplus thread 38 (FIG. 4) of from 1 to 2 inches in length extending from the thread source (not shown) through needle 36. Unlike the illustration in FIG. 4, this thread surplus usually takes no prescribed configuration or direction and will be carried by the needle during the initial stitch of the sewing cycle through the label and banding. The thread will become lumped in a rather unsightly manner on the opposite side of the work piece from the needle where the sewing cycle is initiated. Additionally, even if the surplus thread is not pushed into the first few stitches holding the label to the band, it is still undesirable from an appearance point of view.
The present invention results from the modification of the holding attachment without any change in the operation of that attachment or the associated sewing machine. A pivotal clamp 40 is secured to one edge of frame 28 as illustrated in FIG. 4. The latch is biased by a spring 42 so that it will remain in the position shown in FIG. 5 so long as frame 28 is in an elevated position with respect to plate 26. This plate supports the work piece, in this case the elastic, joined band, and the frame 28 is lowered to carry the label 44 downwardly to the band 46 and remains in that position until the sewing operation has been completed. When frame 28 is lowered, the lower end 48 of clamp 40 engages a hardened surface 50. Clamp 40 continues to pivot as frame 28 continues downwardly until the surplus thread 38 is clamped by the action of the leading edge 52 of the clamp and the edge of channel 54 through which the surplus thread extends.
When the sewing cycle commences, the holding attachment 22 moves rearwardly with respect to the sewing machine needle (see FIGS. 10 and 11). Frame 28 has been modified from its conventional form to support a displaceable severing blade 56 as shown in FIG. 7. The blade is biased by a spring 58 and other appropriate structure shown more particularly in FIGS. 8 and 9.
A pivotal linkage 60 is affixed to the superstructure 23 of the sewing machine and biased by a spring 62. Linkage 60 has a forwardly extending blade engaging end 64 which rests in the path of blade 56 when that blade is carried rearwardly by frame 28 of the holding attachment.
When the sewing cycle commences, the holding attachment is moved rearwardly so that the sewing machine needle sews from the first edge 66 of the band 46 transversely of the band toward the second edge 68. A number of stitches 70 are formed. When the blade 56 engages the end 64 of linkage 60, it is held stationary while frame 28 continues to move rearwardly. This motion causes end 64 to urge blade 56 forward and sever the surplus thread leaving only a new thread surplus of approximately 1/8 inch or less extending from the initial stitch made by the machine. Thus no trusting or lumping of the excess thread can occur. The sewing motion of the holding attachment continues with the eventual restriction of the blade by the frame 28 overcoming the bias of spring 62. The sewing motion then continues according to the pattern of track 34, and the thread ends on the underneath side of the band are severed by a conventional blade or heating element (not shown) at the termination of the sewing cycle.
After the surplus thread has been separated from the thread source, a suction conduit 72 will withdraw the surplus thread to a suitable collection device 74 remote therefrom. Since the completion of a sewing cycle inherently leaves a surplus thread extending from the machine needle of approximately 1 to 2 inches in length, the suction conduit 72 also serves to collect this thread and extend it in a preselected direction through a channel 54 in frame 28.
The invention is not limited to the specific embodiment herein shown and described and departures may be made therefrom within the scope of the accompanying claims without departing from the principals of the invention and without sacrificing its primary advantages.