US3921550A - Guide and sewing device for fabric layers along a shaped edge - Google Patents

Abstract

An improved apparatus for guiding layers of fabric to be sewn along an edge of irregular configuration having clamping members for moving the work along a working plate to a sewing machine. The apparatus includes sensing elements for detecting irregularities in the edge to be sewn and mechanical driving elements operatively associated with the sensing elements and a stepping motor for orienting the work in the direction of the sewing elements of the sewing machine in timed sequence with the operating speed of the latter.

Description

Nov. 25, 1975 United States Patent 11 1 Martorio XXXMXX 344235 SOOUSO 27k 2 ///I|.// 222 22 lll l.[ m m m 4a. M l feta a 6.... M 06 m M m e h h "S 1.5 m.mh .W a u c h m md0.n. ue S A R K F B 552334 667777 999999 l l l l ll 5233003 1 [2 Filedl y 1974 Primary Examiner-H. Hampton Hunter [21] Appl. No.: 465,907

[57] ABSTRACT An improved apparatus for guiding layers of fabric to Foreign Application Priority Data 243'66/73 be sewn along an edge of irregular configuration having clamping members for moving the work along a May 22, 1973 [52] US. Cl...... 112/121,]2; 112/153 working plate to a sewing machine. The apparatus in- [51 Im. D0513 21/00 chides Sensing elements for detecting irregularities in [58] Field of Search 112/153, 136, 204, 205, the edge to be Sewn and mechanical driving elements 121 11 operatively associated with the sensing elements and a ll2/l2l.l2, 121.15

stepping motor for orienting the work in the direction References Cited of the sewing elements of the sewing machine in timed UNITED STATES PATENTS sequence with the operating speed of the latter.

3,072,081 Milligan et 211...... 112 121L12 3 Claims, 5 Drawing Figures Uus Patent NOV. 25, 1975 SheetlofS 3,921,550

US. Patent Nov. 25, 1975 Sheet20f5 3,921,550

US, Patent Nov. 25, 1975 Sheet 3 of5 Patent Nov. 25, 1975 Sheet40f5 3,921,550

Sheet 5 of5 3,921,550

' US. Patent Nov. 25, 1975 GUIDE AND SEWING DEVICE FOR FABRIC LAYERS ALONG A SHAPED EDGE BACKGROUND OF THE INVENTION The invention relates to an improved guide and sewing device for sewing layers of fabric along an edge of irregular configuration. More particularly, the invention provides a means for forming assembly seams on two or more layers of fabric having aligned edges and a curved profile which includes recesses therein.

There are known types of devices for forming assembly seams on layers of fabric which include a working plate having a sewing machine of the cut-and-seam type mounted on one end thereof.

Above the working plate and in front of the sewing machine a guide with clamping devices for the layers of fabric is provided which includes two parallel tracks ro tatable on a vertical axis and in a plane parallel to the working plate. Each of the tracks include a clamping device slidably carried thereon which is effective in maintaining the edges to be sewn in alignment.

The work is advanced on the working plate by lower feed elements of the sewing machine and by upper feed elements disposed forwardly of or rearwardly of the sewing parts.

Forwardly of the sewing machine and in close proximity with the sewing machine, two photoelectric cells are provided which are assembled in the working plate and disposed transversely to the direction of advance of the work.

During the sewing of a seam, the profile of the sewing edge must be maintained between the two photoelectric cells for proper orientation of the work as it is advanced toward the sewing parts which requires that one of the two photoelectric cells be deenergized and the other energized.

If, during the formation of an assembly seam both photoelectric cells become energized or deenergized as a result of irregularities in the profile of the work, then r a pneumatic device operatively associated with one of the photoelectric cells is activated and is effective in moving the rotatable tracks in a direction corresponding to the dictates of a particular photoelectric cell so as to reorient the work and either energize or deenergize the other of the two photoelectric cells. By moving the tracks in this manner, the clamping devices slidably carried thereon are caused to reorient the work on the working surface so that the profile of said work is again caused to be located between the two photoelectric cells.

With devices of the type described above assembly seams along edges of work having a curved profile cannot be acurately formed when said profile possesses curves and recesses which are pronounced or acute. This is attributed to the pneumatic means utilized to move the tracks in one direction or the other for the substantial amount of inertia possessed by the pneumatic means and the high speeds at which sewing machines operate, creates a condition whereby the work cannot be shifted quickly enough relative to said machines operating speed. In other words, when one of the photoelectric cells has initiated actuation of the pneumatic means to shift the work to sew along a first variation in the profile thereof, a second variation frequently presents itself before the work can be located and sewn for the first variation. Such a condition creates the problem of failing to form stitches in certain areas or forming them in areas where they should not be.

To correct these problems and to move and locate the profile of the work in proper orientation during its advance toward the sewing parts of the sewing machine, the technical problem to be solved is to provide means for displacement of the tracks having instant response to signals by the photoelectric cells and to reduce to a minimum the inertia of mechanical connections between said means and the rotatable tracks.

SUMMARY OF THE INVENTION The technical problem has been solved by the improved device which is the subject of the invention for guiding and sewing layers of fabric along an edge of irregular configuration. The device includes a working plate for supporting layers of fabric as they are advanced toward a sewing machine, and a guide device with clamping means for orientation of the profile of the work in the direction of the sewing parts of the sewing machine. The device further includes a stepping motor, and sensing elements transversely disposed relative to the direction of advance of the work and in close proximity with the sewing parts of the sewing machine for sensing irregularities in the profile of the work and to control starting of the stepping motor. Mechanical BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a guide and sewing apparatus for layers of fabric to which the present invention is applicable,

FIG. 2 is a perspective view showing the device according to the invention for effecting orientation of the layers of fabric to be sewn,

FIG. 3 is a perspective view showing greater detail of the tracks, carriages and clamping means for orienting and advancing the work to the sewing machine,

FIG. 4 is a perspective view similar to FIG. 3 but showing the switching and pneumatic means for returning the carriages and clamping devices to their starting positions, and

FIG. 5 is a diagrammatical view of the circuitry for controlling the complete apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIG. 1, numeral 1 identifies a working plate on which work 2 is movable and formed by one or more layers of fabric the edges of which are in alignment.

The edges of these layers of fabric have an irregular shaped profile 3. At one end of the working plate 1 a conventional sewing machine 4 of the cut-and-seam type is attached for the forming of an overseam along and adjacent the aligned edges of the layers of fabric.

The sewing machine 4 is provided with an upper feeding device 5 located in front of sewing parts or elements of the sewing machine.

At the left of the sewing machine a box 6, is attached that houses the electric controls, which will be more fully described hereinafter for starting the electromotor 3 of the sewing machine and for the control of other devices, yet to be described.

Extending generally upwardly from the working plate 1 a curved support arm 7 is provided which extends over the upper portion of the sewing machine.

Curved support arm 7 is provided with a second arm 8 which is hinged thereto and which is rotatable about a vertical axis. The second arm 8 also includes a handle 10 for effecting manual movement thereof.

The second arm 8 has a guide means including two parallel tracks 11 and 12 extending therefrom which are disposed in spaced and parallel relation to the working plate 1.

A carriage 13 is slidably carried on track 11 and includes a clamping device generally indicated by numeral 14 having a jaw member 15 disposed for engagement with work on the working plate 1 and which, by suitable means not shown, is attached to a support plate 50 (FIG. 3). Operatively associated with jaw member 15 a pivotable jaw member 16 is provided that is carried on an arm 51 of a bell crank type lever 52 which is mounted on a pivot 53 having one end thereof fixed to the support plate 50. The opposite arm of this bell crank lever 52 is identified by numeral 54 and is pivotably connected to a piston 55 that is carried in a pneumatic cylinder 56.. This pneumatic cylinder 56 is also carried on the support plate 50 by any suitable means not shown. The pneumatic cylinder 56 receives its source of air through a flexible line or tube 96 having a plurality of spiral windings which enable it to follow the carriage 13 during the latters movement on track 11.

In diametrically opposed relation to the arm 51 of the bell crank lever 52 a hook 17 is provided having a detent 57 integrally formed on its free end that is adapted to engage a detent 58 of conforming configuration of a bracket 18 which is fixed to a stop member 19 assembled on track 11 (FIG. 1).

With reference to FIG. 3 the support plate 50 has additional plate members assembled thereto which are depicted by numerals 59 and 60. These plate members 59 and 60 carry rollers 61 which are disposed for engagement with the top and side surfaces of track 11 and serve to guide the carriage 13 in its movement along said track 11 as well as to prevent its possible tilting thereon.

Referring to FIGS. 3 and 4, plate member 60 is adapted to depress an actuator 62 of the microswitch 20 and is effective in actuating in sequence a pneumatic cylinder 56 and the pneumatic propelling device 21.

Above the carriage 13 an L shaped block member 63 is provided having a horizontally extending blind hold 64 into which the pneumatic propelling device 21 is caused to enter as the carriage l3 approaches the limit of its travel. Upon entry into the blind hole 64 the pneumatic propelling unit 21 is timed to release a jet of air under pressure and is effective in returning the carriage 13 to its starting position on track 1 1 whereat detent 57 engages detent 58 carried by the bracket 18. Both the microswitch 20 and the pneumatic propelling device 21 (FIG. 4) are supported on a bracket 65 having slots 66 for adjustable attachment to the second arm 8 by any suitable means such as cap screws (not shown).

Track 12 slidably supports a carriage 22 thereon of a well known type and similar to carriage 13 is provided with a clamping device 23 the function of which is similar to that of clamping device 14. Clamping device 23 is adapted to hold the work at a position intermediate its length and particularly. when the edges of the layers of fabric to be sewn have a profile of irregular configuration. Track 12 also includes a limit switch 24 which can be adjustably located on said track and includes hooks for engagement with carriage 22.

Adjacent one end of rail 12 and in close proximity with the sewing machine, a microswitch 25 is provided and a known pneumatic propelling unit 26 which serves to return the carriage 22 to its starting position on track 12 where the limit switch 24 is located.

Forwardly of the upper feeding device 5 of the sewing machine, the working plate 1, is provided with an opening 27, within which two photoelectric cells 28 and 29 are located and aligned transversely to the direction in which the work is advanced toward said sewing machine. Above and in vertical alignment with the photoelectric cells 28 and 29 a source of light is provided which is in the form of a lamp 30.

Both photoelectric cells 28 and 29 serve to sense variations in the profile 3 of the work and to control the starting of a stepping motor 31 which by mechanical means generally indicated by numeral 32 (FIG. 2) is operatively connected to tracks 11 and 12 to effect their movement about axis 9.

To obtain the necessary orientation of profile 3 of the work, the photoelectric cell 29 should be energized while light to the photoelectric cell 28 is interrupted.

With reference to FIG. 2., the mechanical means 32, which is located beneath the working plate 1 includes a drive screw 33 supported at its ends by two brackets 34 fixed to the frame of the device. The means of rotating the drive screw 33 includes an endless belt 35 interconnecting said screw with a gear reducer 36 and a drive belt 37 interconnecting said gear reducer with a stepping motor 31.

Assembled on the drive screw 33 a threaded drive member 38 is provided which is mounted in a support block 39 the latter of which carries a sleeve 40 slidable with said support block 39 on a rod 41 that is also supported by brackets 34 and which is disposed in parallel and spaced in relation to said drive screw 33.

The support block 39 also carries two guide rollers 42 in contact with a guide rod 43 parallel to the drive screw 33 and which is also supported by the two brackets 34. This support block 39 is provided on its upper end with an arm 44 which extends upwardly through a slit 45 in the working plate 1, and between the tracks 11 and 12.

Between the tracks 11 and 12 is fixed, by any suitable means such as welding, 21 plate 46. Beneath plate 46 a guide 47 is provided having opposed sides each of which are in contact with a roller 48 (one only shown in FIG. 2) and the interconnecting surface of said opposed sides is in contact with another roller 49 (FIG. 2).

The two rollers 48 and the roller 49 are supported by a plate 44a fixed to the arm 44.

To describe the operation of the device an operator after closing a main switch 67 (FIG. 5.) on box 6 aligns the edges of the layers of fabric forming the work and inserts them under the presserfoot 97 of the sewing ma chine. The actuation of a manual control 68 on box 6 then causes the presserfoot 97 to be lowered into contact with the work. The closing of the hand control 68 causes the energizing of a relay 69, which closes its holding contact 70 and switches a contact 71 from the feed circuit of a relay 72 to a feed circuit of a relay 73 having a control 74 preferably of the treadle type. The switching of the contact 71 deenergizes the relay 72, which is normally energized to actuate a solenoid-controlled valve 75 that forms a part of the pneumatic circuit for initiating the rise of the presserfoot upon completion of the sewing cycle. The deenergizing of relay 72 causes the opening of its contact 76 and then the lowering of the presserfoot 97 into holding contact with the forward end of the work.

At this time the operator causes the actuation of the intermediate clamping device 23 by actuating a hand control 77 to energize a relay 78 which closes its holding contact 79 that is in series with the microswitch 25 and a contact 80 provided to actuate a solenoid-controlled valve 81. This solenoid-controlled valve 81 controls the feeding of air to the pneumatic cylinder 23a for the intermediate clamping device 23. The closing of contact 80 effects energizing of a solenoid-controlled valve 82 in the pneumatic circuit, for feeding air to the pneumatic propelling unit 26 by actuation of microswitch 25 when the clamping lever 23 reaches the limit of its travel. After the operator has positioned the work between the jaw members of the clamping device 14, a control 74 is actuated which effects closing of the clamping device 14 and the starting of an electric motor 98. The actuation of the control 74 causes the energizing of relay 73 which closes its holding contact 83 in series with microswitch 20, and a contact 84 provided to actuate a solenoid-controlled valve 85 that controls the feeding of air to the pneumatic cylinder 56 for the clamping device 14.

The closing of contact 84 effects energizing of a solenoid controlled valve 86, in the pneumatic circuit of the pneumatic propelling device 21 so as to effect its actuation when microswitch 20 is activated by the clamping device 14. In other words, the actuation of microswitches 20 and 25 causes the deenergizing of the solenoid-controlled valves 86 and 81 and the release of a predetermined quantity of air from the pneumatic propelling units 21 and 26 which effects the return movement of carriages 13 and 23 to their initial or starting positions.

The electric motor 98 operates normally until the opening of the microswitch 20 that is controlled by the carriage 13.

As heretofor described the profile 3 of the work is of irregular configuration and when a variation occurs which requires reorienting the work as it is fed to the sewing machine, light to the photoelectric cell 29 is in'- terrupted and photoelectric cell 28 is exposed to the light to effect energizing thereof. The deenergizing of photoelectric cell 29 and the energizing of photoelectric cell 28 causes the actuation of the stepping motor 31.

If the profile variation exposes the photoelectric cell 28, which is normally deenergized, to a light source it is energized effecting the closing of a contact 89 that causes the stepping motor 31 to rotate in a direction which will effect movement of the tracks 11 and 12 6 toward the right. This movement of the tracks 11 and 12 toward the right continues until light to the photoe-. lectric cell 28 is interrupted.

The interruption of light to the photoelectric cell 28 causes it to deenergize resulting in the opening of the contact 89 and the stopping of the stepping motor 31.

On the other hand, if a variation in the profile causes interruption of light to the photoelectric cell 29 which is normally energized, contact 91 is opened causing the stepping motor to rotate in the opposite direction to move tracks 11 and 12 toward the left.

Although the present invention has been described in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.

What is claimed is:

1. An apparatus for guiding and sewing layers of fabric along an edge of irregular configuration comprising:

a. a working plate;

b. a sewing machine fixed to one end of said working plate;

c. a support arm extending from said working plate having rotatable guide means carried thereby in a plane parallel with and spaced from said working plate;

d. means movable along said rotatable guide means for clamping the fabric and advancing the same toward said sewing machine on said working plate;

e. sensing means carried by said working plate for detecting variations in the edge of the layers of fabric to be sewn; and

f. drive means interconnecting said sensing means with said rotatable guide means which includes;

1. a stepping motor; and

2. means operatively connecting said stepping motor with said rotatable guide means for actuating the latter and orienting the edge of the layers of fabric in the direction of said sewing machine in timed sequence with the operating speed thereof.

2. The apparatus for guiding and sewing layers of fabric according to claim 1 wherein said actuating means includes a drive screw operatively connected to said stepping motor and rotatable in a direction controlled by the dictates of said sensing means.

3. The apparatus for guiding and sewing layers of fabric according to claim 2 wherein said actuating means includes a threaded drive member movable along the length of said drive screw having a support block fixed thereon in operative association with said rotatable guide means and movable with said threaded drive member in a direction dependent upon the direction of rotation of said drive screw.

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Claims (4)

1. An apparatus for guiding and sewing layers of fabric along an edge of irregular configuration comprising: a. a working plate; b. a sewing machine fixed to one end of said working plate; c. a support arm extending from said working plate having rotatable guide means carried thereby in a plane parallel with and spaced from said working plate; d. means movable along said rotatable guide means for clamping the fabric and advancing the same toward said sewing machine on said working plate; e. sensing means carried by said working plate for detecting variations in the edge of the layers of fabric to be sewn; and f. drive means interconnecting said sensing means with said rotatable guide means which includes; 1. a stepping motor; and 2. means operatively connecting said stepping motor with said rotatable guide means for actuating the latter and orienting the edge of the layers of fabric in the direction of said sewing machine in timed sequence with the operating speed thereof.

2. The apparatus for guiding and sewing layers of fabric according to claim 1 wherein said actuating means includes a drive screw operatively connected to said stepping motor and rotatable in a direction controlled by the dictates of said sensing means.

2. means operatively connecting said stepping motor with said rotatable guide means for actuating the latter and orienting the edge of the layers of fabric in the direction of said sewing machine in timed sequence with the operating speed thereof.

3. The apparatus for guiding and sewing layers of fabric according to claim 2 wherein said actuating meaNs includes a threaded drive member movable along the length of said drive screw having a support block fixed thereon in operative association with said rotatable guide means and movable with said threaded drive member in a direction dependent upon the direction of rotation of said drive screw.

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