US3204591A

US3204591A - Pneumatic work controlling devices for sewing machines

Info

Publication number: US3204591A
Application number: US260393A
Authority: US
Inventors: Charles G Pickett
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1963-02-25
Filing date: 1963-02-25
Publication date: 1965-09-07
Anticipated expiration: 1982-09-07
Also published as: AT253340B; DE1485331A1; GB990909A; CH429403A

Description

P 1955 c. G. PICKETT PNEUMATIC WORK CONTROLLING DEVICES FOR SEWING MACHINES Filed Feb. 25, 1963 6 Sheets-Sheet 1 as aqav 6 31';

M 4/, Aim

INVENTOR. CHARLES 6. PICKETT BY WITNESS wzw qg c z v r P 1965 c. G. PICKETT 3,204,591

PNEUMATIC WORK CONTROLLING DEVICES FOR SEWING MACHINES Filed Feb. 25, 1963 a l FEW 6 Sheets-Sheet 2 INVENTOR.

WITNESS ORNEY CHARLES 6. PICKETT Sept. 7, 1965 c. s. PICKETT 3,204,591 PNEUMATIC WORK CONTROLLING DEVICES FOR SEWING MACHINES Filed Feb. 25, 1963 6 Sheets-Sheet 3 INVENTOR. 8 CHARLES PICKETT RNEY C. G. PICKETT Sept. 7,1965

PNEUMATIC WORK CONTROLLING DEVICES FOR SEWING MACHINES 25, 1963 6 Sheets-Sheet 4 Filed Feb.

- INVENTOR. CHARLES G. PICKET? nhomvsv -w mm INVENTOR.

2. f AT/f'ORNEY C. G. PICKETT Sept. 7, 1965 PNEUMATIC WORK CONTROLLING DEVICES FOR SEWING MACHINES 6 Sheets-Sheet 5 Filed Feb. 25, 1963 CHARLES 6. PICKETT United This invention relates to work fabric guiding and manipulating devices, and more particularly, to edge guiding and'folding devices for cloth.

This invention has particular utility as applied to work fabric guiding devices for sewing machine and especially for use with the various cloth edge guides, hemmers, and folders used with sewing machines.

In the use of a sewing machine fitted with a conventional edge guide, heminer, or folder for the work fabric, considerable skill is required in introducing the requisite amount of the cloth to the guide and in manipulating the fabric to maintain the cloth in the guide with uniformity during the entire sewing process. The difficulty is compounded when the fabric edge to be stitched is curved.

It is an object of this invention to provide a means automatically efifective to introduce a cloth panel laterally a predetermined degree into a fabric guiding device and to maintain the cloth panel laterally in the guiding device continuously as the fabric panel is moved lengthwise through the guiding device.

An object of this invention is to provide in association with a device for guiding a fabric longitudinally, a pneumatic means arranged so as to urge the fabric laterally into a predetermined position in the guiding device.

A specific object of this invention is to provide in a sewing machine fabric guide having an edge folding scroll, pneumatic means acting on a fabric adjacent to the guide scroll for urging the edge of the fabric laterally and completely into said scroll.

A sewing machine fitted with a fabric guide built in accordance with this invention may be tended by an operator as is a machine with conventional guide fittings.

In contrast with the skill and dexterity required by con ventional arrangements, the operator using this invention need only advance each work piece into general proximity to the mouth of the guide, the orientation of the fabric into the guide thereafter being accomplished automatically.

This invention also has utility in sewing machine installations adapted to operate completely automatically and without the attendance of an operator. The precise and uniform loading of work fabric automatically into the guide which is provided by this invention makes possible the production of an untended basis of stitched articles and sub-assemblies of far greater complexity than has been heretofore possible.

It is an object of this invention to provide a sewing unit for accomplishing in completely automatic and untended fashion the separation and delivery of fabric panels in seriatim from a stack to a sewing machine, the automatic orientation of each fabric panel into an edge folding guide associated with the sewing machine, the stitching of each panel, and the automatic separation, and stacking of the fabric panels after stitching.

With the above and additional objects and advantages in view, as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 represents a perspective view of an automatically operable sewing unit embodying the features of this invention,

FIG. 2 is a top plan view of that portion of the sewing atent Patented Sept. 7, 1965 unit of FIG. 1 in which thework fabric is acted upon and guided relatively to the sewing machine with the bracket arm portion of the sewing machine deleted,

FIG. 3 represents an enlarged perspective view of a work fabric being stitched showing the relation of the work guiding device of the sewing unit of FIGS. 1 and 2 with the sewing machine needle and presser foot,

FIG. 4 represents a perspective view of .a different form of work guide from that of FIGS. 1, 2 and 3 embodying the features of this invention,

FIG. 5 represents a perspective view of a further modified form of work guide having this invention applied thereto,

FIG. 6 is a vertical cross sectional view taken substantially alongline 6-6 of FIG. 2 illustrating the means for delivering successive work pieces to the sewing machine of the sewing unit of FIG. 1,

FIG. 7 is a vertical cross sectional view taken substantially along line 7-7 of FIG. 3 illustrating the work guide on thei;. sewing machine of the sewing unit of FIG. 1,

FIG. 8 is a vertical cross sectional view taken substantially along line 88 of FIG. 2 illustrating the means for controlling and disposing of work pieces after completion of sewing on the sewing unit of FIG. 1,

FIG. 9 is an enlarged vertical cross sectional view taken substantially along line 88 of FIG. 2 illustrating a portion of the mechanism of FIG. 8 in a different position during operation, and

FIG. 10 is an across the line electrical wiring diagram j illustrating the electrical components and the electrical connections therebetween which are necessary for the operation of the sewing unit of FIG. 1.

The sewing unit illustrated in FIGS. 1 and 2 includes a sewing machine 20 which may be of the type described in detail in the United States patent of Clayton, No. 2,394,511, February 5, 1946 to which reference may be had. The sewing unit also involves automatic fabric handling devices including a separator 21 for stacked work pieces, as described in detail in the copending United States patent-application of O. B. Reid Serial No. 213,433, filed July 20, 1962, guide devices 22 for manipulating the work immediately prior to and during sewing, a stacking device 23 for finished work pieces, and various controls for sustaining completely automatic operation of the sewing unit.

FIG. 3 illustrates the work guide device 22 of FIGS. 1 and 2 in its relation to the sewing machine needle 24, presser foot 25, and feed dog' 26 and includes a representation of a work piece 27 being stitched. As illustrated in FIG. 3 the work piece 27 is advanced toward the left by the sewing machine feed dog 26 during stitch formation. It will be understood that in addition to making possible the completely automatic unit for stitching com plicated hems, seams, and the like, guides built in accordance with this invention are also usable on operator tended sewing machines. The guide construction and arrangement therefore, will first be described followed by a description of its relation to the automatic sewing unit.

The guide 22 shown in FIGS. 2, 3, 6 and 7, is an edge folding guide and comprises a fastening bracket 29 adapted to be secured by a screw 30 to the sewing machine 20 in advance of the presser foot and needle thereof. A sheet metal top plate 31 affixed to the bracket 29 is formed with an edge folding scroll 32. Secured beneath the top plate 31 and spaced therefrom by a spacing block 33 is a sheet metal bottom plate 34 which terminates in the throat of the edge folding scroll 32 and defines with the top plate 31 a fabric constraining passageway 35 for work to be stitched. At the mouth of the guide the top plate may be bent as at 36 flaring away from the bottom plate to assist in introduction of fabric into the guide.

The guide 22 is particularly adapted to manipulate work fabric strips such as the collar portion indicated at 27 in FIG. 3 in which one edge is to be folded back as at 37 and the fold secured by a line of stitches 38. It is important, therefore, that each workpiece 27 he introduced completely into the scroll 32 of the guide with the lateral edge of the workpiece snuggly'abutting a work edge constraining surface 39 which extends longitudinally of the direction of travel of work through the guide. With conventional guides it is necessary for a sewing machine operator to attain the proper introduction and maintenance of the workpiece into the guide by deft manipulation of the workpiece. However, this requires ski-ll as well as the constant attention of the operator.

In this invention the top plate 31 of the guide adjacent to the delivery end of the guide, from which the work fabric issues toward the presser foot and needle of the sewing machine, is formed with an opening 40 extending transversely of the edge folding scroll 32. If the sheet metal top plate 31 is of particularly thin gauge, a re-' enforcing block 41 may be secured thereto and the opening 40 formed through both the top plate 31 and the reinforcing block. A carrier plate 42 is adjustably secured to the reinforcing block by fastening screws 43 passing through slots 44 therein so that an air conduit or nozzle 45 fixed on the carrier plate at an angle downwardly and toward said edge folding scroll may be selectively positioned toward and away from the scroll.

An air hose 46 on the nozzle 45 and connected to a source of air under pressure serves to deliver a stream of air between the

plates

31 and 34 of the guide and toward the folding scroll 32 thereof to urge the work fabric laterally so that the work fabric will be introduced and maintained completely into the edge folding scroll.

An additional air nozzle 47 having an air hose 48 leading thereto may be secured through the top plate and disposed parallel to and at a distance from the folding scroll 32 and inclined downwardly and toward the point of stitch formation. The nozzle 47 serves to assist in transporting the work fabric through the guide 22 with a minimum of resistance.

A flexible hold down wire 49 secured to the reinforcing block 41 and extending between the guide 22 and the sewing machine presser foot serves to prevent flagging of the work fabric and thus assists in directing the work into position beneath the presser foot.

When the guide 22 is used on an operator tended sewing machine the work fabric need only be introduced generally into the guide passageway 35. The flow of air from the air nozzle 45 will introduce and maintain the edge of the fabric laterally into the folding scroll 34 and snuggly against the stop surface 39 of the scroll. The work fabric will be urged through the guide by air delivered from the nozzle 47. The operator, therefore, need only introduce the beginning end of the work fabric strips or panels generally into the guide.

FIG. 4 illustrates a modified form of work guide 52 having the features of the guide 22 applied thereto. The work guide 52 is a lap seam feller and comprises a scroll shaped sheet metal plate 53 of which the inside surface cooperates with a substantially fiat metal plate 54 secured in spaced relation thereto to define an upturning edge folding throat 55 for a bottom ply of fabric. A downturned scroll shaped sheet metal plate 56 is formed as an extension of or secured to the plate 53 and extends in spaced relation to the outside surface of the scroll 53 so as to define a downturning edge folding throat 57 for a top ply of fabric so as to guide the folds of top and bottom fabric plys into interleaved relation.

Secured to and extending through the plate 54 is an air nozzle 58 directed transversely of the direction of travel of work fabric through the guide and inclined downwardly and toward the throat 55 so as to urge a bottom ply of fabric snuggly into the throat 55. Similarly, an air nozzle 59 is secured to and extends through-the plate 56 and is directed transversely of the direction of travel of work fabric through the guide and inclined downwardly and toward the throat 57 so as to urge a top ply of fabric snuggly into the throat 57. The air streams of

nozzles

58 and 59 will introduce and maintain the edges of both top and bottom plies completely into the guide 52 to produce an even, consistent lap seam fell.

Where the work guide is formed with edge folding sur faces or an edge folding scroll, a transverse air stream directed into the guide transversely of the scroll will maintain the fabric edge therein and, within rather broad limits of air pressure, the fabric will not be bunched up in the guide. Where a plain edge guideis used, however, such as the edge guide 62 illustrated in FIG. 5, an air nozzle 63 secured to and extending through the top plate 64 of the guide transversely of an edge guiding surface 65' formed on a bottom plate 66 of the guide and inclined downwardly and toward the edge guiding surface 65, is prone to urge an excess of fabric late-rally of the guide against the edge guiding surface. Proper control of the work fabric in the guide may be maintained by the use of an auxiliary air nozzle 67 secured to and. extending through the top plate 64 and extending transversely of the guide and away from the edge guiding surface 65. Preferably the auxiliary air nozzle 67 is arranged between the main air nozzle 63 and the delivery end 68 of the guide and the air stream delivered by the auxiliary nozzle should be adjusted somewhat less than that delivered by 'the nozzle 63. In addition to prevent bunching of work fabric in the guide an auxiliary air nozzle 69 may be used. The air nozzle 69 terminates in spaced relation to the top plate 64 and directs air through an aperture 70 in the top plate 64 of the guide in a direction substantially normal to the bottom plate 66 of the guide. The auxiliary air nozzle 69 is preferably arranged between the main air nozzle 63 and the edge guiding surface 65 of the guide and at a slightly greater distance from the delivery end 68 of the guide than the main air nozzle 63.

It will be appreciated that the air streams delivered by the

air nozzles

45, 58, 59 and 63 of the guides illustrated in FIGS. 3, 4 and 5 do not in themselves fold or guide the work but rather they can be used to influence the insertion of the work laterally into practically any type of known work guiding device. The

auxiliary air nozzles

67 and 69 may of course also be used on folding guides should the need arise.

Referring to FIGS. 1, 2, 6, 8 and 9, the structure of the automatic sewing unit will now be described. The unit is supported on a stand with the separator 21 and the sewing machine 26 being carried on a table top 81. The separator 21 and a guide channel 82 for directing the work pieces into the fabric guide 22 from the separator are carried on a depending limb 83 of a bracket 84. A flat horizontal limb 85 of the bracket is formed with arcuate slots 86 and secured to the table top by fastening bolts 87. The slots 86 provide for adjustment of the angular position of the separator and guide 82 relatively to the line of feed of the sewing machine.

The work piece separator may be constructed and arranged or described on the above referenced O. B. Reid patent application. For an understanding of this invention the following general description of the operation will be sufficient with particular reference to the power operated devices and controls therefor and as illustrated in FIGS. 1, 2 and 6.

The separator 21 includes a platen 90 which supports a stack of fabric blanks 27 and which may be raised and lowered by means of an air cylinder 91. When raised, the platen carries the uppermost fabric blank in the stack against a hinged flipper 92 beneath which is fitted radially directed air nozzles 93. Nozzles 93 are adapted to provide a stream of air between the stack of fabric panels and the flipper to cause the topmost panel to cling to the flipper and to be everted as the flipper 1S turned, as for instance, by an air cylinder (not shown) connected to turn the flipper. An air blast from a nozzle 9 toward the free end of the flipper serves by separating the topmost ply from the stack to discourage more than one fabric panel clinging to the flipper. An air nozzle 95 beneath a foil 96 which engages the top of the raised stack aids in raising the rear of the stack and separating the topmost ply of fabric therefrom. An air nozzle 97 directed downwardly at the stack of fabric panels beneath the flipper serves to straighten the stack after the top ply has been folded back by the flipper and has been withdrawn from the stack.

T heflipper 92 everts the top ply of fabric onto a feed roller 98 protruding upwardly through the guide M, which feed roller may be driven by an electric motor (not shown) and opposed by a feed leaf spring 91 which may be raised and lowered by an air cylinder (not shown).

As the fabric ply everted by the flipper is fed by the feed roller toward the sewing machine along the guide channel 82,

air nozzles

100 and 101 assist in carrying the fabric to the edge folding guide 22.

The various air nozzles, air cylinders and the electric motor for the feed wheel described above in connection with the separator 21 are operated in sequence as will be described hereinbelow by an electric control circuit, the operation of which is initiated by an electric relay lER controlled by a photoelectric cell 111) arranged at the delivery end of the guide channel 82 immediately in advance of the guide 22.

The operation of the sewing machine stitch forming instrumentalities by a power transmitter 111, which in cludes both a clutch and a brake device, and the raising and lowering of the sewing machine presser foot 25 is influenced by an electric relay 2BR as will be described hereinbelow and controlled by a photoelectric cell 120 set into the sewing machine alongside the presser foot and slightly in advance of the needle 24. The presser foot 25 may be raised by a solenoid or by an air cylinder (not shown) by way of a pull rod 121 illustrated in FIG. 8. The pull rod 121 is pivoted to a lever 122 fulcrumed on a bracket 123 fixed on the presser bar bushing 124. The forward end of the lever 122 carries a stop element 125 which is depressed against the sewing machine into the path of the fabric panel issuing from the guide 22 when the presser foot is raised.

Referring to FIGS. 2 and 8, provision is made for in fiuencing the lateral position of the trailing end of a work piece 27 after the work has left the guide 22. To this end a plate 115 is secured to the table top 81 and arranged overhanging the sewing machine bed rearwardly of the needle so that work fabric will pass beneath the plate. A bracket 116 is adjustably secured to the plate and formed with a depending rounded guide pin 117 about which thetrailing end of a work piece may be turned. Two air nozzles 108 and 109 are set into the plate 115 beyond the guide pins 117 each air nozzle being inclined and preferably arranged at an angle of substantially 45 degrees to the line of work feed and facing one forwardly and the other rearwardly so that by selectively adjusting the air flow the desired degree of work turning or deflection may be obtained.

Referring particularly to FIGS. 2, 8 and 9, a fabric guiding channel 126 is carried on the table top 81 rearwardly of the stitch forming instrumentalities and surmounted by a bracket 127 sustaining a plurality of air nozzles 128 directed away from the stitch forming instrumentalities to transport finished work pieces along the channel 126 away from the sewing machine 211).

Set into the guide channel 126 slightly beyond the delivery end of the nozzle 128 is an anvil 129 of a thread chain cutting device into which anvil is positioned a photoelectric cell 130. A reciprocating knife blade 131 operated by an air cylinder (not shown) cooperates with the anvil to sever the thread chains between work pieces. The

photoelectric cell 130, as will be described hereinbelow, senses the passage of work fabric panels in the guide channel 126 and by way of an electric relay BER controls an air cylinder (not shown) for influencing reciprocation of a knife blade 131 of the thread chain cutting device and also controls the operation of the stacking device indicated generally as 23 for the finished fabric panels. A lamp 132 or other source of light is preferably arranged above the path of fabric through the sewing unit as illustrated in FIG. 1 to insure operation of the photoelectric cells 110, and 130.

To ready the fabric panels for the stacking device 23 a bracket 141 supports a plurality of air nozzles 142 beyond but directed substantially normal to the guide channel 126. As fabric panels are urged along the channel by the nozzles 128 the nozzles 142 deflect the panels downwardly.

The stacking device 23 illustrated in FIGS. 8 and 9 comprises a pair of rails 143 supported beneath the table top as by hangers 144. A carriage 145 ,shiftably c0nstrained to move along the rails 143 by a plurality of rollers 146 thereon is secured to the piston rod 147 of.

an air cylinder 148 secured beneath the rails. The air cylinder 1% is preferably of the double acting type having air inlets 149-450 one at each end.

Pivoted on the carriage 145 are a plurality of links 151 each pivoted to an upwardly open fabric supporting tray 152 with each of the links 151 being of equal length so as to support the tray 152-for translatory motion relatively to the carriage 145. A piston rod 153 of a double acting air cylinder 154 having air inlets 155 and 156 is pivotally secured to the carriage and is pivoted to one of the limbs 151 thus providing for control of the vertical position of the tray relatively to the carriage.

The tray 152 is formed with a protruding downwardly curved extension 157 from the bottom wall thereof which cooperates with a leaf spring operating arm 156 of an electric switch 159 carried beneath the sewing machine table top 81.

The air cylinder 154 serves to draw the carriage 145 and tray 152 from the position illustrated in FIG. 8 to that illustrated in FIG. 9 at the appropriate time so as to fold the depending portion of the work fabric over the tray extension 157. When the thread chain between successive panels is severed, the air nozzles 142 will urge the severed panel onto a stack on the tray following which the carriage and tray will be shifted outwardly along the rails 143.

The extension 157 is shifted by the air cylinder 154 into a position adjacent to the switch operating arm 158 each time the carriage is drawn toward the sewing unit. As the fabric panels build up on the tray, those portions of fabric deposited over the extension 157 will contact the switch operating arm 158 to close the switch. The switch 159, as will be explained in detail hereinbelow, is connected in an electric control circuit so as to influence the air cylinder 154 to lower the tray 152 when the switch 157 is closed. The top of the stack of finished work pieces 27 on the tray 152 will thus always be maintained substantially at a constant level relatively to the table top.

As illustrated in FIG. 1, a bank of air pressure regulating devices 160 is carried on the stand. 80 for regulating the pressure of air delivered to those of the air'nozzles in which pressure may be critical as for instance with

nozzles

45 and 47 on the work guiding device.

A control cabinet is provided on the stand 80 for the electrical components necessary for automatic operation of the sewing unit. The various switches and controls indicated generally as in FIG. 1 are those requiring operator manipulation in the electrical circuitry of FIG. 10 and may be arranged on the cabinet 170.

in order to explain the automatic operation of the sewing unit of this invention particular reference is made to the wiring diagram of FIG. 10.

FIG. is an across the line wiring diagram in which a plain relay is indicated by the letter R and time delay relays are indicated by the letters TR. The contacts in the diagram bear the designation of the relay with which they are associated. Where no time delay factor is involved, the contacts are indicated by parallel lines traversed by a diagonal line if normally closed. Those contacts of which the operation is delayed are indicated as switches shown in the normal position open or closed corresponding to the de-energized condition of the controlling relay. Those contacts of which the motion in only one direction is delayed include an arrowhead indicating the direction of motion of the contacts which is delayed.

In order to explain the automatic operation of the sewing unit of this invention, and with particular reference to the wiring diagram of FIG. 10, the sewing unit will be considered first in a condition which exists during the sewing of a work piece 26. The work piece being stitched will have been separated from the initial pile, advanced to the folder 22 on the sewing machine, and the conditions will first be explained during the interval while the work piece being stitched covers the

photoelectric cells

110, 120 and 130 of all three electric relays lER, 2BR and SER respectively, in the diagram of FIG. 10.

Within the area bounded by the dashed line marked work introduction in FIG. 10, the contacts lER-A will remain normally open whilethe photoelectric cell of electric relay 1BR is covered so that the means for separating and introducing the next collar band to the sewing machine will be dormant.

Within the area bounded by the dashed line marked Sewing Machine Operation in FIG. 10, the contacts ZER-A being closed While the photoelectric cell of electric relay 2BR is covered will have energized time delay relays 2TR, 3TR and STR and will maintain these relays energized while the photoelectric cell 120 of electric relay 2ER remains covered. Contacts ZTR-A and 2TR-B being held open during energization of time delay relay 2TR will die-energize the presser lifter solenoid I thus maintaining the sewing machine presser foot lowered, while contacts 2TR-C will be held closed to maintain the solenoid K effective to deliver air to the nozzles 4S and 47 on the work folder 22.

The time delay relay 3TR being energized, will after its delay period, maintain contacts 3TR-A closed to energize a solenoid Z which renders the sewing machine transmitter effective to drive the sewing machine while at the same time contacts 2ERB and 3TR-B will be maintained open to de-energize a solenoid Y which renders the sewing machine transmitter brake ineffective.

Within the area bounded by the dashed line marked Cutting and Stacking'in FIG. 10, the plain relay R will remain de-energized while the photocell 130 of electric relay 3BR remains covered. This results from the fact that within the area marked Sewing Machine Operation in FIG. 10 the contacts 3ER-A will remain open holding time delay relay 4TR de-energized. The contacts 4TR-B in the Cutting and Stacking" portion of FIG. 10 will thus remain open and the knife solenoid X will thus remain de-energized. With contacts R-C normally closed the double pole contacts STR-A close acircuit to a solenoid L which admits air to the inlet 150 to move the stacker forwardly. The contacts STR-A close to the solenoid L because of the time delay relay STR will be energized while the photocell 120 of relay 2ER remains covered by a work piece.

As stitching of the collar band proceeds, the trailing end of the collar band will eventually be carried beyond the photoelectric cell 110 of the electric relay llER thus signalling for an operation of the means for separating and introducing the next collar band to the sewing machine. This i accomplished by closure of the contacts lER-A which energize the relay lTR to close the contacts llTR-A. The relay ETR is a part of a motor driven cam controlled time delay relay. Closure of the contacts lTR-A supplies power to the motor MTR-B of the cam controlled time delay relay and renders the contacts llTR-B through H ready for operation. It will be understood that the cam controlled time delay relay is of the conventional program type in which cam means driven by the motor MTR-B serves to control opening and closing of the contacts zllTR-B through H during a predetermined time period and in which the cam means serves to open the contacts llTR-A to terminate the time period. Each of the contacts lTR-B through H is connected, as illustrated in the wiring diagram, to one or more pneumatic control solenoids or motors and the preferred sequence of operation is as follows.

Contacts llTRB through E close and energize in seriatim the solenoids A through E which respectively raise the platen 931, turn on the flipper air blast nozzle 93, turn on the separator air nozzle 94, turn the flipper 92 and turn on the foil air nozzle 95.

The double throw contacts 1TR-F are shifted to open the circuit to the feed spring lift controlling solenoid F and to close the circuit to the feed motor MTR-C.

Contacts llTR-G are closed to energize the solenoids which serves to turn on the straightener air nozzle 97.

The topmost collar band inthe initial stack is thus separated from the stack and introduced to the feed wheel 98.

Next in sequence the contacts lTR-B through E are opened thus lowering the platen, turning off the flipper air blast, the straightener jet, and the foil jet, and allowing the fiipper to be spring returned.

The contacts llTR-H are next closed to energize the solenoid H which serves to turn on the carrier jets -101 following which the double throw contacts lTR-F are returned to the position illustrated in FIG. 10 de-energizing the feed motor C and raising the feed spring 99.

The contacts JlTR-G and H are then opened to shut off the straightener and carrier assist air jets, and finally the contacts llTR-A are opened by the cam to complete the cycle of operation of the motor driven cam controlled time delay relay.

Thus as the trailing end of each collar band nears the stitching point of the machine, the uncovering of the photocell lllltl of the electric relay lER initiates another cycle of operation of the motor driven cam controlled time delay relay which results in the delivery of a succeeding collar band to the folder.

Shortly after uncovering the photoelectric cell of electric relay ill-3R, the trailing end of the collar band on continued stitching by the sewing machine will be moved to uncover the photoelectric cell of the electric relay 2BR which will open the contacts ZER-A and de-energize the time delay relays ZTR, 3TR and STR.

The solenoid Z rendering-the sewing machine transmitter effective will be de-energized immediately by the opening of contacts ZER-A and power will no longer be supplied to the sewing machine. The contacts 2ERB will also be closed immediately and will energize the solenoid Y rendering the sewing machine transmitter brake etfective. The stitching will terminate, therefore, as soon as the brake can stop the sewing machine. The resulting coasting period when a modern high speed sewing machine is used is on the order of 12 stitches which is sufficrent to provide a short chain of stitches beyond the trailing end of the collar band being stitched.

The operation of the presser foot lifter will be delayed after the photocell 120 of electric relay 2BR is uncovered, since closing the cont-acts 2TR-B is delayed. The purpose of delaying the presser lift is to insure perfect thread concatenation even during chaining while the machine is being braked to a stop. For similar purpose the opening of contacts ZTR-C is delayed so as to insure that the air will continue to be supplied to the folder until after the end of the collar band has been stitched.

As the succeeding collar band is delivered to the stitching point and the leading edge of the cellar band covers the photoelectric cell 120 'of the electric relay 215R, conta-cts-2ER-A and ZER-C will he closed and contacts 2ERB will be opened immediately. The time delay relays ZTR, 3TR, and STR will be energized but the sewing machine will not be started immediately because the closingof contacts 3TR-A to engage the transmitter and the opening of contacts 3TRB to disengage the brake will be delayed. The lowering of the presser foot will also be delayed by delay of the opening of contacts 2TR-A. Such delay provides time for the collar band to be properly introduced into the folder by the

air locating nozzles

45, 47 which will be turned on immediately by the contacts 2TR-C which have no delay in closing and thus immediately energize the solenoid K which serves to turn on the air for the

nozzles

45, 47, 118 and H9.

The operation of the knife 131 for severing the chain of threads between collar bands and for operating the stacker as indicated in the area bounded by dashed lines marked Cutting and Stacking in FIG. 10, is controlled by the uncovering of the photocell 130 of the electric rel-ay 3ER when the gap between successive collar bands passes thereover as the finished work is directed toward the stacker by the continuous air streams provided by the nozzles 128. As indicated within the area marked Sewing Machine Operation in FIG. 10, the contacts SEER-A of the electric relay 3BR are in series with the contacts 2ER-A which means that the knife and stacker cannot be operated unless a fresh-collar band has been properly introduced into the sewing machine folder. In this manner when the last of a stack of collar bands has been stitched, the knife and stacker cease operation. Assuming, therefore, that a fresh collar band has been forwarded to the stitching point so as to close the contacts 2ER-A, the uncovering of the photocell 130 of the electric relay 3BR by the gapbetween previously finished collar bands closes the contacts 3ER-A and energizes the time delay relay 4TR closing the contacts 4TR-A of a holding circuit for the time delay relay 4TR. The contacts 4TR-B will also be closed upon energization of the relay 4TR thus energizing a plain relay R. Normally closed contacts R-A complete a charging circuit for a capacitor through a circuit which includes a diode rectifier, while normally open contacts R-B (when closed) complete a discharging circuit for the capacitor through a knife actuating solenoid X. Upon each energization of the relay R the'reversal of contacts R-A and RB provides for a single knife actuation from the capacitor discharge.

The forward and reverse movements of the stacker are controlled by the time delay relays 4TR and STR and as mentioned above can function only when fresh work pieces are delivered to the sewing unit sensed by the photocell 120. As soon as the trailing end of a work piece uncovers photocell 120 electric relay 2BR is energized, contacts ZER-A open and relays ZTR, 3TR, 4TR and STR are de-energized. Contacts 4TR-B open and plain relay R is de-energized. Contacts R-C close and the switch -5TR-A immediately shifts to complete a circuit through R-C and a solenoid M which serves to admit air to-the inlet 149 to position the stacker in a retracted position i.e. as illustrated in FIG. 8.

Upon insertion of a fresh work piece into the guide 22 .and covering of photocell 120, electric relay 2BR will be tie-energized, contacts 2ER-A will close and relays ZTR, 3TR and 5TR will be energized. Contacts 3TR-A will close with no immediate result. After a short delay. the switch 5 TR-A will shift to complete a circuit through R-C and solenoid L shifting the stacker into forward positionie. with the extension 157 of the tray 152 beneath the-guide 126 as illustrated in FIG. 9.

When photocell130 is uncovered and electric relay 3BR is energized,.closing of contacts SER-A will energize relay 4TRwhich will then be held energized by the closure of contacts 4TRB, thus opening contacts R-C. The solenoid L. shifting the. stacker forwardly will thus N be tic-energized but the stacker retracting solenoid M will not be energized until the delayed closing of contacts tTR-C, thus providing time for the knife 131 to sever the thread chain and for the severed work piece to be carried onto the tray 152 before the tray is shifted into reversed position. 7

Covering of the photocell 1 30 by the succeeding work piece will open the contacts 3ER-A but the relay 4TR being held energized; by the holding contacts 4TR-A will continue to operate by way of contacts 4TR-C to energize the stacker retracting solenoid M.

Uncovering of the photocell as the trailing end of the succeeding collar band proceeds toward the stitching point will change merely the circuit by which the stacker retracting solenoid M is maintained energized substituting the contacts R-D and STR-A for the contacts 4TRC.

The stacker tray 152 is lowered gradually to maintain the top of the stack constantly at a level just beneath that of the guide channel 126 by means of two solenoids N and 0 each controlling the flow of air under pressure to opposite inlets 155 and 156 of the double acting air cylinder 154. Normally each solenoid N and O is energized thus equalizing the pressure in the double acting air cylinder 154 and maintaining the existing vertical position of the tray 152. Opening of the switch 157 indicated as LS-A on the diagram of FIG. 10 by the build up of fabric panels on the tray 154 de-energizes the solenoid 0 until lowering of the stacker tray 154 by continued delivery of air under pressure by solenoid N permits the switch LS-A to close.

Whenever the tray is emptied, it may be raised to begin accommodating a fresh stack by closing the manual switch MS A de-energizing the solenoid N.

Having thus set forth the nature of this invention, what is claimed herein is:

l. In a work guiding device for a sewing machine or the like having a work supporting surface and a work edge guiding surface associated therewith, said work edge guiding surface extending longitudinally of the direction of travel of work through the work guiding device, an air conduit associated with said work guiding device, and means supporting said air conduit relatively to said work guiding device for delivering air under pressure obliquely against said work supporting surface at a. point spaced from said work edge guiding surface and laterally of the direction of travel of work through the work guiding device toward said work edge guiding surface thereof for bodily urging the work fabric edge contiguous to said work edge guiding surface.

2. In a fabric guiding device for a sewing machine or the like including spaced plates between which is defined a fabric constraining passageway closed along one lateral edge by a fabric edge guiding surface disposed longitudinally of the direction of travel of fabric through the fabric guiding device, an air conduit, and means securing said air conduit obliquely through one of said spaced plates so as to deliver air into said fabric constraining passageway laterally of the direction of travel of fabric therethrough and toward said fabric edge constraining surface.

3. In a fabric guiding device for a sewing machine or the like including spaced plates between which is defined a fabric constraining passageway closed along one lateral edge by a fabric edge guiding surface disposed longitudinally of the direction of travel of fabric through the fabric guiding device, a plurality of air conduits, means securing each of said air conduits relatively to said fabric guiding device so as to deliver air against a fabric within said fabric constraining passageway, and at least one of said air conduits being disposed for delivery of air laterally of the direction of travel of fabric through said passageway and toward said fabric edge guiding surface.

4. A fabric guiding device as set forth in claim 3 in which one of said other air conduits is disposed for delivery of air substantially normal tosaid fabric guiding passageway.

5. A fabric guiding device as set forth in claim 3 in which one of said other air conduits is disposed for de livery of air longitudinally of the fabric guiding device and in the direction of travel of fabric therethrough.

6. A sewingunit comprising a sewing machine having stitch forming instrumentalities and a work feeding mechanism for advancing work fabrics relatively to said stitch forming instrumentalities, a work guiding device carried on said sewing machine and arranged to deliver a work fabric to said stitch forming instrumentalities substantially in the direction that the work fabric is advanced by said work feeding mechanism, a work edge guiding surface on said work guiding device disposed longitudinally of the direction that the work fabric is advanced by said Work feeding mechanism, a first means for delivering air under pressure laterally of the direction of travel of work fabric through said work guiding device and toward said work edge guiding surface thereof for maintaining Work fabric against said work edge guiding surface, and a second means for delivering air under pressure in a direction of travel of work fabric through said work guiding device for automatically introducing work fabric panels in seriatim into said work guiding device.

7. A sewing unit comprising a sewing machine having stitch forming instrumentalities and a work feeding mechanism for advancing work fabrics relatively to said stitch forming instrumentalities, a work guiding device carried on said sewing machine having a work edge guiding surface disposed longitudinally of the direction that the work fabric is advanced by said work feeding mechanism, a fabric delivering extremity adjacent to said sewing machine stitch forming instrumentalities and a work fabric receiving mouth, means for delivering air under pressure laterally of the direction of travel of work fabric through said work guiding device and toward said work edge guiding surface thereof, fabric sensing means adjacent the mouth of said work guiding device responsive to the absence of a work fabric in the mouth of said work guiding device, and means operated by response of said sensing means for automatically introducing a fresh work piece into the mouth and through said work guiding device.

8. In a device as set forth in claim 7, a second fabric sensing means responsive to absence of a work fabric and located between said work guiding device and said sewing machine stitch forming instrumentalities, a drive means for said sewing machine stitch forming instrumentalities and work feeding mechanism, and means operated by response of said second sensing means for,

automatically interrupting said drive means.

9. In a device as set forth in claim 8, a third fabric sensing means responsive to absence of a work fabric and located at the opposite side of said sewing machine stitch forming instrumentalities from said work guiding device, mechanism located at the opposite side of said sewing machine stitch forming instrumentalities from said Work guiding device, for severing stitches between adjoining work pieces and for stacking severed work pieces, and means operated by response of said third sensing means for automatically operating said severing and stacking mechanism.

References Cited by the Examiner UNITED STATES PATENTS 1,796,334 3/31 Kristofek et al. 112-2 2,038,853 4/36 Popper 112-124 2,060,511 11/36 Learnard et al. 112-2 2,483,138 9/49 Helmer 112-219 2,673,495 3/54 Hecker et a1. 93-35 2,766,044 10/56 Schulze 271-64 2,791,424 5/57 Noon 271-28 2,797,656 7/57 Reid 112-147 2,819,073 1/58 Murray 271-11 2,940,404 6/60 Damon 112-10 2,953,371 9/60 Smith 271-26 2,985,122 5/61 Abel et al. 112-2 3,052,469 9/ 62 Dale.

3,066,563 12/62 George et al. 112-2 3,099,970 8/63 Hite 112-2 JORDAN FRANKLIN, Primary Examiner.

Claims

1. IN A WORK GUIDING DEVICE FOR A SEWING MACHINE OR THE LIKE HAVING A WORK SUPPORTING SURFACE AND A WORK EDGE GUIDING SURFACE ASSOCIATED THEREWITH, SAID WORK EDGE GUIDING SURFACE EXTENDING LONGITUDINALLY OF THE DIRECTION OF TRAVEL OF WORK THROUGH THE WORK GUIDING DEVICE, AN AIR CONDUIT ASSOCIATED WITH SAID WORK GUIDING DEVICE, AND MEANS SUPPORTING SAID AIR CONDUIT RELATIVELY TO SAID WORK GUIDING DEVICE FOR DELIVERING AIR UNDER PRESSURE OBLIQUELY AGAINST SAID WORK SUPPORTING SURFACE AT A POINT SPACED FROM SAID WORK EDGE GUIDING SURFACE AND LATERALLY OF THE DIRECTION OF TRAVEL OF WORK THROUGH THE WORK GUIDING DEVICE TOWARD SAID WORK EDGE GUIDING SURFACE THEREOF FOR BODILY URGING THE WORK FABRIC EDGE CONTIGUOUS TO SAID WORK EDGE GUIDING SURFACE.