US3899986A

US3899986A - Apparatus for guiding limp material

Info

Publication number: US3899986A
Application number: US455259A
Authority: US
Inventors: Jr William R Conner
Original assignee: Stahl Urban Co
Current assignee: Stahl Urban Co
Priority date: 1974-03-27
Filing date: 1974-03-27
Publication date: 1975-08-19
Anticipated expiration: 1992-08-19
Also published as: GB1500079A; JPS50130554A; IT1034427B; DE2512290A1

Abstract

Apparatus for guiding limp material, such as a piece or pieces of textile material, in an automatic guidance system comprising a guide wheel and a back-up between which material is fed. The apparatus further includes means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a vertical swing axis offset from the wheel axis on the upstream side of the wheel axis with respect to the direction of material feed. Means is provided for swinging the wheel mounting means about its swing axis to effect lateral swinging movement of the wheel to shift the material. The apparatus is characterized by means for positively driving the wheel in the direction of feed of the material.

Description

United States Patent [191 Conner, Jr.

[ APPARATUS FOR GUIDING LIMP MATERIAL [75] Inventor: William R. Conner, Jr., Shelbyville,

Tenn.

[73] Assignee: Stahl-Urban Company, Brookhaven,

Miss.

22 Filed: Mar. 27, 1974 21 App]. No.: 455,259

[ 1 Aug. 19, 1975 Primary ExaminerWerner I-l. Schroeder Attorney, Agent, or FirmKoenig, Senniger, Powers and Leavitt 57 ABSTRACT Apparatus for guiding limp material, such as a piece or pieces of textile material, in an automatic guidance system comprising a guide wheel and a back-up between which material is fed. The apparatus further includes means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a vertical swing axis offset from the wheel axis on the upstream side of the wheel axis with respect to the direction of material feed. Means is provided for swinging the wheel mounting means about its swing axis to effect lateral swinging movement of the wheel to shift the material. The apparatus is characterized by means for positively driving the wheel in the direction of feed of the material.

9 Claims, 4 Drawing Figures PATENTEU AUG 1 9 ms APPARATUS FOR GUIDING LIMP MATERIAL BACKGROUND OF THE INVENTION This invention relates to guidance apparatus and more particularly to such guidance apparatus for shifting pieces of cloth or the like relative to a reference point, such as the needle of a sewing machine, as the cloth is fed into the sewing machine thereby to automatically guide the cloth through the sewing machine for contour stitching.

More particularly, the guidance apparatus of this invention is an improvement on guidance apparatus such as disclosed in my US. Pat. No. 3,636,898 for Edge Contour Guidance Control for Pieces of Material. By way of background, the above-mentioned patent discloses apparatus which senses the position of the edge of a piece or pieces of fabric by means of a fluidic sensor as the fabric is fed into a sewing machine. The fluidic sensor controls laterally swingable guide wheels bearing on the material as it passes over a back-up plate, the guide wheels rolling on the material. Upon the edge of the fabric deviating to one side or the other from a desired position, the fluidic sensor effects swinging movement of the guide wheels so as to shift the cloth and return the edge of the cloth to its desired location thus insuring stitching of the cloth along the desired sew line. With the stitching line of the stitching determined by the edge of the material being sewn, the above guidance apparatus provides automatic contour stitching of the material.

While the above-described apparatus has proven to be highly desirable in most applications and in sewing most types of cloth, it has presented problems when guiding light-weight stretchable materials, such as light knits. More particularly, since the material is pulled between the guide wheel and the back-up by means of the feed dogs of the sewing head and since the guide wheel does have some drag, light-weight knits and other stretchable materials are sometimes stretched excessively between the guide wheel and feed dogs thus resulting in unsatisfactory stitching of the cloth.

SUMMARY OF THE INVENTION Among the several objects of this invention may be noted the provision of improved apparatus for guiding material, such as cloth, which positively feeds the material through the apparatus without causing deleterious stretching of even the light, stretchable knit materials; the provision of such guidance apparatus which operates satisfactorily with many different types of material, and without requiring adjustment; the provision of such guidance apparatus which may readily be swung clear of the cloth when its use is not required; the provision of such apparatus which may be adjusted to positively feed the material to the sewing head at varying speeds relative to the speed of feed of the sewing head; and the provision of such guidance apparatus which may be readily and accurately controlled and which is of simple construction and reliable in operation.

Briefly, apparatus of this invention for guiding material, such as a piece of textile material, in an automatic guidance system comprises a guide wheel and a backup between which the material is fed. The apparatus further includes means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a vertical swing axis offset from the wheel axis on the upstream side of the wheel axis in respect to the direction of feed of the material. Also, the apparatus includes means for swinging the wheel mounting means about the swing axis to effect lateral swinging of the wheel to shift the material. The apparatus is characterized in that means is provided for positively driving the wheel in the direction of feed of the material. The apparatus is adapted to guide material into a sewing machine, the sewing machine having a needle and means for feeding material forward through the machine for stitching thereof by the needle, the guide wheel and back-up being located upstream from the needle and feeding means in respect to the direction of feed. The wheel is positively driven in the direction of feed of the material to feed the material toward said feeding means and needle at a speed so related to the speed of feed of the material by said feeding means as to avoid deleterious stretching of the material between said guide wheel and said feeding means.

Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of the apparatus of this invention with parts omitted for clarity;

FIG. 2 is a vertical section taken on line 2-2 of FIG. 1, illustrating the path of a belt for driving the guide wheel;

FIG. 3 is a horizontal section taken on line 3-3 of FIG. 2, illustrating means for effecting swinging movement above the guide wheel and with parts above line 33 FIG. 2 shown in phantom to illustrate the relationship between the various parts; and FIG. 4 is a plan illustrating the location of the guide wheel relative to the needle and feed dogs of a sewing machine.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, apparatus of this invention is indicated in its entirety at 1 for guiding limp material M (e.g., one or more pieces of textile cloth) in an automatic guidance system 3 (shown in phantom). More particularly, guidance system 3 is substantially the same as the system shown in my coassigned US. Pat. No. 3,636,898 and which is incorporated by reference in this disclosure. More specifically, guidance system 3 automatically guides one or more pieces of material through a sewing machine (not shown) for stitching the material along one edge thereof, with the pieces of material automatically guided in accordance with the contour (either straight or curved) of its respective edge for contour seaming. It will be understood that the apparatus 1 of this invention is an improvement of the means mounting guide wheels 61 and 151 in my above-mentioned US. patent.

The guiding apparatus 1 of this invention comprises a guide wheel 5 and back-up means 7 (a back-up plate or another guide wheel) between which material M is fed. Means, generally indicated at 9, mounts the guide wheel for rotation on a generally horizontal wheel axis W passing through the center of the guide wheel and for lateral swinging movement (as shown by the arrow in FIG. 3) about a generally vertical swing axis S offset from the wheel axis W on the upstream side of the wheel axis in respect to the direction of feed of material M, as noted by the arrow in FIG. 2. Means as indicated at 11 (see FIG. 3) is provided for swinging the wheel mounting means 9 and guide wheel 5 carried thereby about swing axis S to effect lateral swinging movement of the guide wheel thereby to laterally shift material M relative to the backup means 7 or to a reference point. Means 13 is provided for positively driving wheel 5 in the direction of feed of material M.

FIG. 4 shows the location of the guide wheel 5 and back-up 7 relative to the needle and feeding means (feed dogs) of a sewing machine indicated at SM corresponding to the sewing machine indicated at 5 in FIG. I of U.S. Pat. No. 3,636,898. The needle of the sewing machine is indicated at N and the feed dogs at F. The direction of feed of material through the machine is indicated by the arrow. As appears in FIG. 4, the guide wheel 5 and its back-up 7 are located upstream from needle N and the feeding means or feed dogs F in respect to the direction of feed, which is indicated by the arrow.

More specifically, guidance system 3 includes a pneumatic or fluidic edge sensor 15 (not shown in its entirety herein) comprising an air nozzle 17 positioned above back-up 7 so as to direct a continuous stream of air toward an air inlet hole 19 in back-up 7. Air nozzle 17 is interconnected to an air proportioning device (not shown herein, but similar to the air proportioning device indicated at 247 in my above-mentioned US. patent). The desired or reference position of material M may be considered the position shown when the material edge E halfway closes inlet hole 19. Upon the edge E moving from its reference position, the flow of air inlet passage 19 varies and the air proportioning device effects actuation of means 11 for swinging the guide wheel and for shifting the material E toward its reference position.

More particularly, apparatus of this invention comprises a support constituted by a frame arm 21 pivotally secured, as indicated at 23, to guidance system 3 or to other suitable structure such as the frame of an automatic sewing head. The support or frame arm 21 carries an antifriction bearing 25 on its outer end. Wheel mounting means 9 is shown to comprise a wheel carrier constituted by a clevis or stirrup 27 having two spaced legs 29a, 29b between which a wheel pulley 31 is journalled on a pin 33, the axis of the pin constituting the wheel axis W. A steering arm 35 extends rearwardly (with respect to the direction of feed of material M) from clevis 27 for purposes as will appear. A hollow tubular shaft 37, having a bore 39 therethrough, extends vertically from the upper face of clevis 27 and is received by the inner race of bearing 25, thereby journalling the clevis in the bearing for lateral swinging movement of guide wheel 5.

Means 13 for positively driving guide wheel 5 in the direction of feed material M is shown to comprise a belt and pulley drive including a continuous belt 41 trained around wheel pulley 31 and around a drive pulley 43 located remote from the guide wheel. Drive pulley 43 is shown to be mounted on the outer end of a countershaft 45. The countershaft is journalled in a bearing housing 47 secured to frame arm 21 by means of an angle bracket 49. Belt 41 is preferably of molded elastomeric material and is of circular cross section. However, it will be understood that belts of other cross sections, including flat belts or round belts having a flat outer surface, may be used.

As shown in FIG. 1, belt 41 is trained around wheel pulley 31 generally centrally thereof and is received in a circumferential groove 51 therein (see FIG. 2). As best shown in FIG. 2, the intermediate reaches of belt 41 are spaced close relative to one another and are parallel. These intermediate reaches of the belt pass through bore 39 of hollow shaft 37. Idler pulleys 53 and a guide bar 55 extending horizontally between clevis legs 29a, 29b maintain the intermediate reaches of the belt substantially parallel to one another as they pass through bore 39 of shaft 37. With the belt passing through the shaft and with the swing axis S and the axis of bore 39 being substantially coincident on a common vertical line, the guide wheel is free to swing laterally without effectively changing the tension on belt 41.

Belt 41 extends partially around the periphery of wheel pulley 31 and is of such cross section as to extend at least in part beyond the periphery of the wheel pulley. The wheel pulley further includes a pair of circumferential grooves (not shown) similar to groove 51 on either side of groove 51. O-rings 56 of a resilient nonslip elastomeric material are disposed in the outer grooves and these O-rings are of approximately the same cross section as belt 41 whereby the outer periphery of the O-rings and the outer periphery of belt 41 at the bottom of the wheel pulley form gripping surface 57 for guide wheel 5 and are thus adapted to positively engage material M on the back-up 7 and thus to positively drive the material in the direction of feed as shown by the arrow in FIG. 2.

Countershaft 45 is driven by a pulley 59 on the inner end of the countershaft, this pulley being driven by means of a drive belt 61 and a variable-speed drive unit 63 (shown in phantom) such as is manufactured by the Zero-Max Company of Minneapolis, Minnesota. This variable drive selectively varies the speed at which guide wheel 5 may be driven. Preferably, guide wheel 5 is driven at substantially the same speed as material M is fed into the sewing head thereby eliminating stretching of the material (even of stretchable lightweight knits) between the guide wheel and feed dogs of the sewing head. In some applications, however, a slight amount of stretch in the material may be desirable. In such cases, the variable drive unit 63 may be adjusted so that the guide wheel is driven at a speed somewhat slower than the speed at which material M is fed into the machine, thereby to stretch the material a predetermined amount. Likewise, the speed of the drive wheel may be increased so as to overdrive the fabric toward the needle of the sewing head.

As previously mentioned, frame arm 21 is pivotally secured to the guidance assembly 3. The frame arm is pivotally movable between a lowered operating position (shown in FIGS. 1 and 2) in which guide wheel 5 is in gripping engagement with material M on back-up 7 and a raised retracted position (not shown) in which the guide wheel is clear of the material. The frame arm is raised and lowered by means of an air cylinder assembly 65 (shown in phantom in FIG. 1) interposed between the frame arm and guidance assembly 3. The frame arm is biased toward its lowered operating position by means of a tension coil spring 67. In other instances, it will be understood that the frame arm may be biased toward its lowered operating position by means of application of air pressure to air cylinder assembly 65.

Interconnected between clevis 27 and frame arm 21 is a linear actuator, more specifically a double rod end air cylinder assembly 69 (see FIG. 3) pivotally interconnected to the frame arm 21 as indicated at 71 by a universal bearing. This air cylinder has a piston (not shown) movable therewithin and a piston rod 73 extending from both ends thereof with one of its ends interconnected to steering arm 35 of clevis 27 as indicated at 75 by a universal bearing at a point spaced from swing axis S. This air cylinder constitutes means 11 for swinging the clevis about swing axis S so as to effect lateral swinging movement of guide wheel 5 and to effect lateral shifting of material M relative to a fixed reference (i.e., relative to air inlet hole 19 or relative to the sewing needle of the sewing head). Air cylinder 69 is pressurized by means of

air lines

77 and 79 at opposite ends of the air cylinder body. These air lines are supplied with pressurized air by the previously mentioned air proportioning device. With edge E of material M in its desired reference position relative to the air inlet hole 19 in back-up 7, the air pressure supplied to both ends of air cylinder 69 is substantially equal and thus guide wheel 5 is maintained in a neutral position for guiding the cloth in a straight line as it is fed forward toward the needle of the sewing head. Upon the fabric edge E deviating from its reference position, the air proportioning device increase the pressure of air supplied to either

line

77 or 79, thereby to effect swinging movement of guide wheel 5 in such direction as to move the edge E of the material toward its reference position (i.e., toward inlet hole 19). Again upon attaining its desired reference position, the material M is maintained in that position by the guide wheel. It will be understood that the guiding apparatus of this invention functions so as to guide material either for straightline or curvilinear sew lines.

lt will be understood that the guidance apparatus 1 of this invention may be adapted for use on equipment other than contour stitching apparatus. For example, the guidance apparatus may be used to guide limp sheet plastic material in heat-sealing apparatus or in adhesive bonding apparatus or other type equipment.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Apparatus for guiding material, such as a piece of textile material, in an automatic guidance system, said apparatus comprising a guide wheel and a back-up between which the material is fed, means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a generally vertical swing axis offset from the wheel axis on the upstream side of the wheel axis in respect to the direction of feed, and means for swinging said wheel mounting means about said swing axis to effect lateral swinging of the wheel to shift the material, characterized in that means is provided for positively driving the wheel in the direction of feed of the material, wherein said drive means comprises a belt and pulley drive wherein the belt is trained around a pulley on the wheel axis, wherein said drive means further comprises a drive pulley located remote from said guide wheel, said belt being trained around said wheel pulley and said drive pulley, and wherein said apparatus further comprises a frame adapted to be secured to a sewing machine or the like and bearing means carried by the frame mounting said wheel for lateral swinging of the wheel, said wheel mounting means including a hollow shaft joumalled in said bearing means, said shaft having said vertical swing axis on its axis, said belt intermediate said wheel pulley and said drive pulley passing through said shaft.

2. Apparatus for guiding material, such as a piece of textile material, in an automatic guidance system, said apparatus comprising a guide wheel and a abck-up between which the material is fed, means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a generally vertical swing axis offset from the wheel axis on the upstream side of the wheel axis in respect to the direction of feed, and means for swinging said wheel mounting means about said swing axis to effect lateral swinging of the wheel to shift the material, characterized in that means is provided for positively driving the wheel in the direction of feed of the material, wherein said drive means comprises a belt and pulley drive wherein the belt is trained around a pulley on the wheel axis, wherein said pulley on said wheel axis constitutes said wheel and said belt is trained therearound and extends at least in part beyond the periphery of the wheel thereby to constitute a gripping surface of the wheel engageable with said material, further comprising one or more rings of resilient, nonslip material disposed on the outside of said wheel and constituting a portion of said gripping surface.

3. Apparatus for guiding material, such as a piece of textile material, in an automatic guidance system, said apparatus comprising a guide wheel and a back-up between which the material is fed, means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a generally vertical swing axis offset from the wheel axis on the upstream side of the wheel axis in respect to the direction of feed, and means for swinging said wheel mounting means about said swing axis to effect lateral swinging of the wheel to shift the material, characterized in that means is provided for positively driving the wheel in the direction of feed of the material, wherein said drive means comprises a belt and pulley drive wherein the belt is trained around a pulley on the wheel axis, adapted for use on a sewing machine or the like wherein said drive means includes a variable speed drive operable in response to the speed of the feed of the material into the sewing machine, said variable speed drive positively driving said wheel substantially at the speed of feed of said material.

4. Apparatus for guiding material such as a piece of textile material, in an automatic guidance system, said apparatus comprising a guide wheel and a back-up between which the material is fed, means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a generally vertical swing axis otfset from the wheel axis on the upstream side of the wheel axis in respect to the direction of feed, and means for swinging said wheel mounting means about said swing axis to effect lateral swinging of the wheel to shift the material, characterized in that means is provided for positively driving the wheel in the direction of feed of the material, wherein said drive means comprises a belt and pulley drive wherein the belt is trained around a pulley on the wheel axis, wherein said drive means further comprises a drive pulley located remote from said guide wheel, said belt being trained around said wheel pulley and said drive pulley, and wherein said apparatus further comprises a frame adapted to be secured to a sewing machine or the like and bearing means carried by the frame mounting said wheel for lateral swinging of the wheel, said wheel mounting means including a hollow shaft joumalled in said bearing means, said shaft having said vertical swing axis as its axis, said belt intermediate said wheel pulley and said drive pulley passing through said shaft, wherein said frame is swingably mounted on said sewing machine between a lowered operating position in which said wheel is engageable with said material on said back-up and a raised retracted position, and wherein said apparatus of this invention further comprises means biasing said wheel into gripping engagement with said material on said back-up when said frame is in its lowered operating position.

5. An automatic guidance system for guiding material, such as a piece of textile material, into a sewing machine, said sewing machine having a needle and means for feeding material forward through the machine for stitching thereof by the needle, said system comprising a guide wheel and a back-up between which the material is fed to the needle and said feeding means, said guide wheel and back-up being located upstream from the needle and feeding means in respect to the direction of feed, means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a generally vertical swing axis offset from the wheel axis on the upstream side of the wheel axis in respect to the direction of feed, and means for .swinging said wheel about said swing axis to effect lateral swinging of the wheel to shift the material, wherein the improvement comprises the provision of means for positively driving the wheel in the direction of feed of the material to feed the material toward said feeding means and needle at a speed so related to the speed of feed of the material by said feeding means as to avoid deleterious stretching of the material between said guide wheel and said feeding means.

6. An automatic guidance system as set forth in claim 5 comprising a support, a tubular shaft joumalled in said support for rotation on said vertical swing axis, and a wheel carrier on the shaft carrying the wheel downstream from said swing axis, said drive means for the wheel comprising a belt and pulley drive comprising a pulley carried by said support and a belt trained around said pulley, extending through said shaft, and trained around said wheel.

7. An automatic guidance system as set forth in claim 6 wherein the wheel has a central peripheral groove receiving the belt.

8. An automatic guidance system as set forth in claim 7 wherein the belt extends at least in part beyond the periphery of the wheel thereby to constitute a gripping surface of the wheel engageable with said material, and the wheel has material gripping rings on opposite sides of the belt.

9. An automatic guidance system as set forth in claim 5 wherein said drive means for the wheel includes a variable speed drive for varying the speed of the wheel in accordance with variation in the speed of feed of the material by said feeding means.

Claims

1. Apparatus for guiding material, such as a piece of textile material, in an automatic guidance system, said apparatus comprising a guide wheel and a back-up between which the material is fed, means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a generally vertical swing axis offset from the wheel axis on the upstream side of the wheel axis in respect to the direction of feed, and means for swinging said wheel mounting means about said swing axis to effect lateral swinging of the wheel to shift the material, characterized in that means is provided for positively driving the wheel in the direction of feed of the material, wherein said drive means comprises a belt and pulley drive wherein the belt is trained around a pulley on the wheel axis, wherein said drive means further comprises a drive pulley located remote from said guide wheel, said belt being trained around said wheel pulley and said drive pulley, and wherein said apparatus further comprises a frame adapted to be secured to a sewing machine or the like and bearing means carried by the frame mounting said wheel for lateral swinging of the wheel, said wheel mounting means including a hollow shaft journalled in said bearing means, said shaft having said vertical swing axis on its axis, said belt intermediate said wheel pulley and said drive pulley passing through said shaft.

4. Apparatus for guiding material such as a piece of textile material, in an automatic guidance system, said apparatus comprising a guide wheel and a back-up between which the material is fed, means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a generally vertical swing axis offset from the wheel axis on the upstream side of the wheel axis in respect to the direction of feed, and means for swinging said wheel mounting means about said swing axis to effect lateral swinging of the wheel to shift the material, characterized in that means is provided for positively driving the wheel in the direction of feed of the material, wherein said drive means comprises a belt and pulley drive wherein the belt is trained around a pulley on the wheel axis, wherein said drive means further comprises a drive pulley located remote from said guide wheel, said belt being trained around said wheel pulley and said drive pulley, and wherein said apparatus further comprises a frame adapted to be secured to a sewing machine or the like and bearing means carried by the frame mounting said wheel for lateral swinging of the wheel, said wheel mounting means including a hollow shaft journalled in said bearing means, said shaft having said vertical swing axis as its axis, said belt intermediate said wheel pulley and said drive pulley passing through said shaft, wherein said frame is swingably mounted on said sewing machine between a lowered operating position in which said wheel is engageable with said material on said back-up and a raised retracted position, and wherein said apparatus of this invention further comprises means biasing said wheel into gripping engagement with said material on said back-up when said frame is in its lowered operating position.

5. An automatic guidance system for guiding material, such as a piece of textile material, into a sewing machine, said sewing machine having a needle and means for feeding material forward through the machine for stitching thereof by the needle, said system comprising a guide wheel and a back-up between which the material is fed to the needle and said feeding means, said guide wheel and back-up being located upstream from the needle and feeding means in respect to the direction of feed, means mounting the wheel for rotation on a generally horizontal axis and for swinging movement about a generally vertical swing axis offset from the wheel axis on the upstream side of the wheel axis in respect to the direction of feed, and means for swinging said wheel about said Swing axis to effect lateral swinging of the wheel to shift the material, wherein the improvement comprises the provision of means for positively driving the wheel in the direction of feed of the material to feed the material toward said feeding means and needle at a speed so related to the speed of feed of the material by said feeding means as to avoid deleterious stretching of the material between said guide wheel and said feeding means.

6. An automatic guidance system as set forth in claim 5 comprising a support, a tubular shaft journalled in said support for rotation on said vertical swing axis, and a wheel carrier on the shaft carrying the wheel downstream from said swing axis, said drive means for the wheel comprising a belt and pulley drive comprising a pulley carried by said support and a belt trained around said pulley, extending through said shaft, and trained around said wheel.