US2758556A - Mechanical clutching and braking device for sewing machines - Google Patents

Description

1956 F L. HOPKINS 2,758,556

MECHANICAL: CLUTCHING AND BRAKING DEVICE FOR SEWING MACHINES 4 Sheets-Sheet 1 Filed Dec. 18, 1953 HVVENIUR.

4, 1956 F. L. HOPKINS 2,758,556

MECHANICAL CLUTCHING AND BRAKING DEVICE FOR SEWING MACHINES Filed Dec. 18, 1953 4 Sheets-Sheet 2 1 L Z i I m 9 I y 55-12 "g E i 82K 4/ l I I 77 97 5E X .IHHIII .lllnl INVENTOR.

Aug. 14, 1956 Filed Dec. 18, 1953 F. L. HOPKINS MECHANICAL CLUTCHING AND BRAKING DEVICE FOR SEWING MACHINES 4 Sheets-Sheet 3 INVENTO R. fiMZJi W? BY Q Aug. 14, 1956 F. HOPKINS MECHANICAL CLUTCHING AND BRAKING DEVICE FOR SEWING MACHINES 4 Sheets-Sheet 4 Filed Dec. 18, 1953 INVENTOR. ,i LEZ/WIYW A rrofikvfm United States Patent F MECHANICAL CLUTCHING AND BRAKING DEVICE FOR SEWING MACHINES Frank L. Hopkins, Minneapolis, Minn., assignor to Bemis Bro. Bag Co., St. Louis, Mo., a corporation of Missour:

Application December 18, 1953, Serial No. 398,999 12 Claims. (Cl. 112-11) My invention relates generally to power driven sewing machines and more particularly to an attachment for machines of this type, which attachment provides for automatic release of the stitched articlefrom the machine when the stitching operation is completed.

More specifically, my invention relates to such an attachment for sewing machines which is utilized to stitch closed the open upper ends of filled bags. In certain instances, the mechanism for driving the machine includes a prime mover, such as a continually operated motor, and driving connections therebetween and the stitching means, said connections including a releasable clutch and an automatic brake whereby the stitching means is stopped immediately upon release of the clutch. Such machines usually include automatic thread cutting means operative to sever the stitching thread in outwardly spaced relation to the side edges of the stitched article. Heretofore, difficulty has been experienced in removing the stitched articles from the machine, particularly when the stitched articles are being fed through the machine by a continuously moving, conveyor or the like, by reason of the fact that the stitching thread and reinforcing tape, when such is used, often becomes clamped between the presser foot of the machine and the underlying base plate thereof. When this occurs, the stitched end of the article is held stationary while the feeding means for the article tends to move the same away fromthe machine, thus often causing damage to the article. An important object of my invention is, therefore, the provision of novel means for releasing the presser foot from engagement with the stitched article immediately upon termination of the stitching operation and severing of the stitching thread and reinforcing tape if such isused.

Another object of my invention is the provision of an attachment for existing machines of the above type which can be quickly and easily applied to such a machine and which will not interfere with the normal sewing operation. To this end I provide mechanism for moving the presser foot release lever which is normally found on stitching machinery, which will permit independent release movements to be manually imparted to the release lever by the operator when desired.

Another object of my invention is the provision of presser foot release mechanism as set forth which is operative to release the presser foot of the sewing machine for a predetermined timed interval and thereafter automatically again rendering said presser foot operative upon the next bag in a succession thereof being fed to the machine.

Another object of my invention is the provision of a device of thetype set forth which may be quickly and easily applied to machines of various sizes and makes of manufacture.

Still another object of my invention is the provision of a release mechanism which is relatively simple and inexpensive to manufacture, which is highly eflicient in end of a presser bar 7.

2,758,556 Patented Aug. 14, 1956 operation, and which is rugged in construction and durable in use.

The above and still further highly important objects and advantages of my invention will become apparent from the following detailed specification, appended claims and attached drawings.

Referring to the drawings, which illustrate the invention, and in which like characters indicate like parts throughout the several views:

Fig. l is a fragmentary view in side elevation of a power driven sewing machine incorporating my invention; a Fig. 2 is an enlarged fragmentary view of the stitching head of the machine of Fig. 1;

Fig. 3 is a fragmentary section taken substantially on the line 3-3 of Fig. 2;

Fig. 4 is an enlarged fragmentary detail corresponding to a portion of Fig. 3 but showing a different position of some of the parts;

Fig. 5 is an enlarged fragmentary view partly in plan and partly in section as seen from the line 5-5 of Fig. .1;

Fig. 6 is an enlarged detail taken substantially on the line 6-6 of Fig. 5, some parts being removed;

,Fig. 7 is an enlarged view partly in elevation and partly in axial section of the drive means of Fig. 1;

Fig. 8 is an enlarged detail in section taken substantially on the line 88 of Fig. 1; and

Fig. 9 is a diagrammatic view illustrating the control means of my invention.

In the preferred embodiment of my invention illustrated, a power driven sewing machine indicated in its entirety by the numeral 1, is shown as comprising a base 2 and a sewing head 3. The head 3 supports a stitching needle 4 by means of a conventional reeiprocatory needle bar 5 and a presser foot 6 rigidly secured to the inner The presser bar 7 preferably comprises a pair of laterally spaced cooperating bar sections or rods 8 that are longitudinally movable in the head 3, and may be assumed to be yieldingly biased toward the base 2 of the machine by conventional means such as a spring or springs not shown. The base 2 of the machine is provided with a base plate 9 which is provided with apertures 10, one of which is shown, through which project the usual feed dogs 11, see particularly Fig. 5.

The stitching needle and feed dogs are power driven and are operatively connected to a drive shaft 12 that is journalled in the base 2 of the machine, through conventional mechanism not shown but contained in the base 2 and head 3 of the machine 1. The machine 1 is rigidly mounted on a bracket 13 that is anchored to one end of a pair of laterally spaced supporting arms 14, the other ends of which are rigidly mounted on an adjustable bracket 15 which in turn is adjustably secured to a supporting structure or bar 16. The driving mechanism within the machine 1 for the stitching needle and feed dogs is of the type in common use. Hence for the sake of brevity, the same is not described in detail.

The bracket 13 is formed to provide an upstanding arm 17 to the upper end of which is rigidly secured a clutch and brake housing 18 by means of a pair of laterally spaced longitudinally adjustable shafts 17', one of which is shown. A continuously operated drive motor 19 is securely mounted on the housing 18. A pulley 20 is rigidly secured to an output shaft 21 journaled in a housing section 22 of the housing 18, and has running thereover an endless belt 23 which also runs over a second pulley 24 rigidly mounted on the drive shaft 12 of the sewing machine 1. With reference to Fig. 1, it will be seen-that the sewing machine and the driving motor and transmission mechanism therefore is all supported f r'o in'the 'supporting "structure16 and is held in desired set position. with respect .to the supporting structure 16 by means of the adjustable member 15 which is provided with conventional clamping mechanism indicated inits entiretyat'25. L

With reference to Fig. 7, it will be seen that the output shaft'21 isjournalled in bearings 26 in the housing section: or plate22"and"has its upper end keyed or other- Wise rigidly "secured to an annular flange 27. Mounted for axial sliding movements through circumferentially spaced pnrtions of the fiange'27' is a plurality of pins or studs 28"that are rigidly secured at their opposite ends to axially spaced annular armatures"29 and '30 respectiv'ely, The"flai1'ge 27 togethe'nwiththe arinatures'29 and '30 carried thereby is disposed between a pair of electromagnet elements 31 and 32, the former of which is rigidly secured'toa rotary member 33 which is rigidly mounted on the shaft'34 'of the drive motor 19 and the latter of'which is rigidly'secured by: means of machine screws or the like 35 to the stationary housing section 22. The arrangement is such, that when one ofthe armatures 19 'or 30 is in'contact with itsrespective magnet element 31 or 32, there is free running clearance between the othenarmature and its cooperating magnet elemeht. The rotary member 33 is provided with a pair of conductor rings 36 which are engaged by stationary brushes or the like 37' whichare interposed in a circuit hereinafter to be described. The rings 36 may be assumed to be connected to the electromagnet element 31 by 's'uitable mieans not shown. Likewise the stationary electromagnetelement 32is' interposed in" a circuit hereinafter to? bed'e'scrib'ed. The magnetic clutch and brake arrangement above idescribed is of a type in common use'for driving interrnittently operated devices where quick starting'and stopping operating mechanisms are desired. I,

In: addition to driving the material feeding dogs 11 and the" stitching needle 4, the'motor 19fa1sooperates an oscilla'tory cutting knife 38 through suitable d'rivin g mechanismnot shown but' contained in ,la ho using' '39 mounted on the base} of the sewing machine'l. This mechanism may he of anysuitable type such as that shown in the United States Letters Patent tdKiridsth et'alu' No. 2,539,627. Thecuttingknife 38 is adapted for use in severing: thestitching thread laterally outwardly of opposite sides of articles fed through thejnachine, or' in the case of articlessuch as filled bags wherein reinforcing tape utilized in connection with the stitching operation. knife 38 is preferably utilized "to sever the s t itehed tape as well as the stitching thread. In the drawings, a filled bag to be stitched is indicatedat X and reinforcing tape therefor is indicated by the referenee characterY. The reinforcing tape is preferably of paper or'like material and is commonly fed from a roll mounted one suitable bracket40 and guided and folded over the tep of the bag x by means of a conventional forming device 41 shown t a m a in W e e e ce ef 5 itwill be seen: that the cutting knife 38 normally oyerlies the a e po n. ft e P e ser foot n smovab inwardly through a transverse slot 42in the pressure foot 6 to sever the stitchingthread and reinforcing tape between the presser foot 6 and the base 2 of the machine.

The clutch and brake magnet elements '31 and 32 respectively are. controlled by a switch 43 containedlin a switch housing 44 that'is mounted ona plate-like holder 45 .bolted or. otherwise rigidly secured to the sewing machine head 3. The'switch 43 includes a switch button '46 that is operatively engaged by one endof anopefatin'g rod 47 that is mounted for longitudinal reciprocator'y movements in a tubular housing 48 mounted on "the switch'housing 44. Theoperating'rod 47 is formed to provide a hollo'w'r ece'ss '49 in which'is mounted forlezit ending and retracting movements a stem '50 having :a head 51 adjustably 'secured' to its outerend. Apin and slo't'coii'nection'52 securesthe stem 50 withinthe rec'ess 49 f or limited telescoping movements therein.

A "soil compression spring 53 is interposed,.betweenthehottom of the recess and the inner end of the stem 50 whereby to yieldingly bias the stem 50 in an extended direction. The spring 53 is of sufiicient strength to transfer switch operating movements of the stem 50 to the switch 43, and contracts to take up additional inward movement of the stem50beyond that required to operate the, switch 43. The'swit'ch 431s of the normally ppen momentary contact type comprising a stationary contact element 54 and a movable contact element 55 that is operatively connected to the button 46. 1

The switch 43 is interposed in a control circuit for'the clutch and brake magnet elements 31and .32 respectively. For the purpose of the present example, a circuit is shown as comprising a two-wire power line 56'to the wires of which are connected leads 57 and 58 having interposed therein a master control switch 59. The lead 57 extends to and terminates at the stationary contact 54of the switch 43; and the lead 58 'terminates'at the movable contact SSQof the switch 43. A control relay com rise relay coil 60 which is interposed in the lead 58 and energized upon closing of the switch 43, anclal pair of twoposition switches 61' and f62. Theswitch 61 includes a movable contact element 63 and spaced" stationary eontacts '64and 65 the former of which is connectedto'the niagnetelement31 bya lead 66 and the latter of which is'connected to"the magnet element 32 by a lead l6 7. The ' electrorna'gnet elements 31 and 32 are preferably energized by direct 'current frorn a conventional rectifier 68 which is'iiriterposed' in a lead 69 connected at its opposite ends to" the power leads 57 and 58. A lead 70pxtends fromthe rectifier 68 to; the magnet element 31, and has a .branch lea'dfll connected to the magnet element32. Y Asecondlead 71 extends from the rectifier 68 te the' moyable contac t elem ent 63' of theg switch 6 1,a d has interposed thereinaconventionalThostat 731p eontrel the a fiQ lnt of direct' cnrrentsnpplied to themagnet el'mentsfldand 32. As shown, when the relaycoil 60 is energized, the switch contacts 63 and 64 are closed thereby energizing the clutch magnet element 31, and when the contact elements and 65 are closed the brake magnet element 32 is' energiz d Whilethe clutch magnet Ieler nent 31 is lde e'nergized,whereby to immediately stop mac ine operands p V A c ontrol finger74 extending generally in the direction of movement of filled bags through the machineis pivot ally connected intermediate its ends, and as indicated at 75,1 to1one end of a rigidi linkflfi thatis pivotally secured at"its. ot her'endlto the plate-like holder 45 as indicated at 77. As sh own inFigs. 4 and' 5, the holder 45 is provided with an inturned flange or ear 78 which engages an adjustable abutment in the natureof a screw 79 that is threaded through a mountingllug 80 in the rear .end of the control finger 74, The control finger 74 isia dap ted to be'receivedina longitudinallyextending slot or channel in the base plate 9 and is yieldingly biased toward itsfposio n in,the channel sl by lthe spring 49 in the switehloperating rod '47 With reference'particularly to Fig. '4,'it will be seen that the channel 81 is located below the presserfoot fi With reference to'Fig. 5, it will be seen that the control finger 74 is ontturned at its frontend similartothe frontend of the presser foot 6, and as indicated "at '82 to facilitate receptionat the upper'end ofthe ba'gtherebetween andithe baseplate .9. 'As illustime inFigfiS, movement of'the'upper end of a filled bag into the machine'fro m'theri'ght to the left causes the control finger 74 to be movedoutwardly of the channel 81"an'd in a'direc'tio'n tocause closingof the switchcontacts'54and SS ofthe' switch '43. With'refe're nce toFig. 4,itwillbe seen that the controlfinger'74 'engages'the bag X below the level of the tape Y in closing the upper end ofthe'bag'X. r g

In 'sewing'machineso f'the type above'de'scribed, it is necessary that the presser foot extend rearwardly beyond the thread and tape cutting blade to support the tape and stitching thread against the base plate while the same is being severed. The relatively quick starting and stopping of the stitching mechanism accomplished by the magnetic clutch and brake arrangement makes possible a considerable saving in stitching thread and tape inasmuch as the stitching mechanism is rendered inoperative immediately upon severing of the tape after a bag or other article has been stitched. In sewing machines of this type, the presser foot must be manually released to permit withdrawal of the severed stitching thread and reinforcing tape from the machine. This is particularly important Where the article to be stitched is fed to the sewing machine on a continuously moving conveyor. Manual means for releasing the presser foot on machines of the type herein disclosed includes a release lever 84 that is pivotally mounted to the stitching head 3 as indicated at 85 and has one of its ends engaging a lug 86 which is rigidly secured to the presser rods 8 within the stitching head 3 and which projects outwardly through a slot 87 therein. Heretofore it has been necessary at the termination of each sewing operation, to manually move the release lever 84 in a direction to cause movement of the presser foot 6 out of engagement with the material therebetween and the base plate 9 for such time as is necessary for the removal of the severed stitching thread and reinforcing tape therefrom. As shown in Figs. 3 and 5, the lug 86 projects laterally outwardly from an arm 88 that is welded or otherwise secured to a head 89 having suitable apertures through which the presser rods 8 extend. Set screws or the like 90 prevent relative movement between the head 89 and the presser rods 8.

For the purpose of automatically releasing the presser foot from engagement with the severed stitching thread and tape, I provide power operated mechanism including a movable member in the nature of an extendible and retractible plunger rod 91 having its outer end pivotally secured to the free end of the lever 84 as indicated at 92. The plunger rod 91 extends inwardly through one end of a fluid pressure cylinder 93, and is rigidly secured at its inner end to a piston 94 axially movable within the cylinder 93. A supporting rod or bar 95 is anchored at one end to the cylinder 93 and has its other end portion extending slidably through an aperture 96 in a supporting plate or the like 97 that is bolted or otherwise rigidly secured to the arm 17 of the bracket 13. Said other end portion of the rod 95 has mounted thereon a stop collar 98, and is threaded to receive an adjustment nut 99. With reference to Fig. 9, it will be seen that the rod 95 and cylinder 93 carried thereby may move axially in a direction from the right to the left, movement in the opposite direction being limited by engagement of the stop collar 98 with the plate 97. The piston 94 is yieldingly biased in one direction of its movement within the cylinder 93 by a coil compression spring 100 interposed between the piston 94 and one end of the cylinder 93. With this arrangement, the release lever 84 may be manually operated to release the presser foot 6 whenever desired.

The cylinder 93 comprises power operated means utilizing fluid such as air under pressure for the purpose of automatically moving the release lever 84 ina presser foot releasing direction. Air under pressure is supplied to the cylinder 93 from a suitable source, such as a pump 101, through a fluid line 102. A control valve 103 is interposed in the line or conduit 102 and comprisesa valve body 104 defining a chamber 105 and a valve stem 106 having a reduced intermediate portion 107. With reference to Fig. 9, it will be seen that the fluid line 102 is connected to ports 108 and 109 that communicate with the chamber 105 at axially spaced points. A third port or passage 110 in the valve body 104 connects the chamber 105 with atmosphere exterior of the body 104. The valve stem 106 extends outwardly of the valve body 104 and provides an armature for a solenoid 111 which provides anactuator for the valve 103. The valve stem 106 is movable from one positionwherein the reduced portion 107 registers with the ports 109 and wherebyto connect the interior of the cylinder '93 with atmosphere, to another position wherein said reduced portion '107 registers with the ports 108 and 109 whereby to connect the cylinder 93 with the pump 101. A coil compression spring 112 is interposed between the solenoid coil 111 and a washer 113 on the valvestem 106 whereby to yieldingiy bias the valve stem 106 toward its release position indicated by full lines in Fig. 9. A stop pin 114 extending transversely through the valve stem 106 operatively locks the washer 113 to the valve stem 106 for common movements therewith in a spring biasedpdirection. De-energization of the solenoid 111 permits spring imparted movement of the valve stem 106 from its inoperative position to its operative position shown in Fig. 9 wherein the pump 101 is .in' communication with the cylinder 93 to cause release of the presser foot 6.

The relay switch 62 comprises a movable contact element 115 and a pair of spaced stationary contacts 116 and 117. The solenoid 111 is contained in a circuit comprising a portion of the power lead 57, a lead 118, the switch contact element 115 and contact 116, a lead 119, a lead 120, and a portion of the power lead 58. As shown, the solenoid is interposed between the leads 119 and 120. With this arrangement, when a bag to be stitched is moved into engagement with the, control finger 74 and moves the same out of its channel 81 in the base plate 9, the control switch 43 is actuated to close the contacts 54 and 55 thereby energizing the clutch magnet element 31 and de-energizing the brake magnet element 32. Simultaneously, the solenoid 111 is energized to move the valve stem 106 to its inoperative position, thereby permitting air in the cylinder 93 to be exhausted to atmosphere through the fluid line 102 and the port 110, and the release lever 84 to be moved by the spring 100 in a direction to render the presser foot 6 operative for the duration of the stitching operation. Upon completion of the stitching operation, the bag X moves laterally away from the rear end of the control finger 74 thus permitting the same to re-enter its channel 81 with consequent opening of the switch 43. This opening of the switch 43 results in immediate de-energization of the clutch magnet element 31 and energization of the brake magnet element 32 with simultaneous cle-energization of the solenoid 111 whereby to stop the machine and permit entry of air under pressure to the cylinder 93 to cause release of pressure of the presser foot 6 against the severed stitching thread and tape therebetween and the base plate 9. The stitched bag X is thereupon free to continue its movement away from the machine. It should be noted that the stop collar 98 engages the plate-like member 97 to limit movement of the cylinder 93 in the direction of the release lever 84 when air under pressure is introduced to the cylinder 93. Thus, when the air is thus introduced to the cylinder, the piston 94 and parts connected thereto will move in the desired direction to effect releasing movements of the presser foot 6.

In the above described stitching of bags in succession, the bags X are often fed to the stitching machine in relatively closely spaced relationship. In such instances, it is desirable that the pressure foot 6 be rendered operative immediately upon release of the severed tape, so that faulty stitching will not occur at the beginning of the new stitching operation. For this purpose I provide a time delay relay 121 including a switch 122. The coil of the relay 121 is interposed in a lead 123 which extends from the power lead 58 to the contact 117 of the switch 62, and the switch 122 is interposed in a lead 124 which extends from the power lead 57 to the solenoid lead 119. With reference to Fig. 9 it will be seen that the switch 122 and the portion of the switch 62 which comprises the contact element 115 and the contact 116 are in parallel circuits.

Preferably the relay 121 is of the type which has a time delay of approximately one second duration between the energization thereof and its closing of the switch 122. Thus, when the relay 60 is de-energized upon movement of a bag X away from the control finger 74, the time delay relay 121 is energized through closing of the switch contacts 115 and117. After approximately one second, the switch 122 is closed, thereby re energizing the solenoid 1 11 and causing the mechanism controlled thereby to render the presser foot 6 operative until such time as a subsequent bag X enters the machine and causes re-en'er= gization of the relay 60. This re-energization of the relay 60 causes the contact element 115 of the switch 62 to move out of engagement with the contact 117 and into immediate engagement with the contact 116 to maintain the solenoid 111 energized for the duration of the subsequent operating cycle. Hence during the time that the control switch 59 is closed, the presser foot 6 is continuously operative except for the one second interval wherein the same is released to permit free travel of a stitched bag X away from the machine.

My invention has been thoroughly tested and found to be completely satisfactory for the accomplishment of the objectives set forth; and while I have shown and described a commercial embodiment thereof, it will be understood that the same is capable of modification without departure from the spirit and scope of the invention.

What I claim is:

1 An attachment for sewingmachines having stitching means including a needle and pressei foot for sewing articles fed in succession; means forfeeding a strip of reinforcing tape with said articles to the stitching means, drive means for the stitching and tape feeding means, control means for the drive means, and a release lever for said presser foot; said attachment comprising a fluid pres sure system including a cylinder element and a cooperatmg piston plunger element, one of said elements being adapted to be secured to said lever for common movements therewith in opposite directions, means for securing the other of said elements to said machine against movement with said lever in one direction of movement of said lever, an actuator valve in said fluid pressure system, and valve operating means adapted to be connected to the control means for said drive means, whereby to cause movement to be imparted to said release lever in a direction to move the presser foot out of operative engagement with the tape when the drive means is rendered inoperative. 2. The structure defined in claim 1 in further combination with yielding means urging said one of the elements and said lever in a direction whereby said presser foot will move into engagement with said tape.

3. An attachment for sewing machines having stitching means including a needle and presser foot for sewing articles fed in succession, drive means for the stitching means, article engaging control means for the drive means, and a release lever for said presser foot; said attachment comprising a fluid pressure system including a cylinder and a cooperating piston plunger extending outwardly from one end of said cylinder, yielding means biasing said plunger in one direction of movement relative to the cylinder, the extended end of said plunger being adapted to be secured to said release lever, means for operatively securing the cylinder to said machine for common movements with Said plunger and including a stop element limiting said movements in one direction, an actuator valve in said fluid pressure system, and valve control mechanism adapted to be connected to the control means for said drive means, whereby to cause fluid under pressure to be introduced to said cylinder to move said plungerand lever against the bias of said yielding means in a direction to move the presser foot from its operative article engaging position to its inoperative position when the drive means is rendered inoperative.

4. An attachment for sewing machines having stitching means including a needle and presser foot for sewing cluding a needle articles fed in succession, means for feeding a strip of reinforcing tape with said articles to the stitching means, drive means for the stitching and tape feeding means, article-engaging control means for the drive means, and a release lever for said presser foot; said attachment comprising a fluid pressure system including a cylinder and a cooperating piston plunger extending outwardly from one end of said cylinder, yielding means biasing said plunger in one direction of movement relative to the cylinder, the extended end of said plunger being adapted to be secured to said lever, means for operatively securing the cylinder to said machine for common movements with said plunger and including a stop element limiting said movements in one direction, an actuator valve in said fluid pressure system, and valve control mechanism adapted to be connected to the control means for said drive means, whereby to cause fluid under pressure to be introduced to said cylinder to move said plunger and lever against the bias of said yielding means in a direction to move the pressure foot out of operative engagement with the tape when the drive means is rendered inoperative.

5. An attachment for sewing machines having stitching means including a needle.and presser foot for sewing articles fed in succession, means for feeding a strip of tape to the stitching means, drive means for the stitching and tape feeding means including a motor and an electrically operated clutch and brake mechanism and a circuit therefor, article engaging control means for the drive means including a switch in said circuit, and a release lever for said presser foot, said attachment comprising a fluid pressure system including a cylinder and a cooperating piston plunger extending outwardly from one end of said cylinder and adapted to be secured to said lever, yielding means biasing said plunger in a direction of movement relative to the cylinder whereby to permit engagement between said presser foot and tape, means for operatively securing the cylinder to said machine for common movements with said plunger and including a stop element limiting said movements in one direction, an actuator valve in said fluid pressure system operatively associated with said cylinder, and electrically operated valve control mechanism adapted to be connected to said circuit whereby to cause fluid under pressure to be introduced to said cylinder to move said plunger and lever against the bias of said yielding means in a direction to move the presser foot out of operative engagement with the tape when the drive means is rendered inoperative.

6. In a machine for stitching articles fed thereto in succession, said machine comprising stitching means including a needle and presser foot, means for feeding a strip of reinforcing tape with said articles to said stitching means, drive means for the stitching and tape feeding means, control means for the drive means, a release lever for said presser foot, a fluid pressure system including a cylinder element and a cooperating piston plunger element, one of said elements being secured to said lever for common movements therewith in opposite directions,

,means operatively connecting the other of said elements tosaid machine against movement with said lever in one direction of movement of said lever, an actuator valve in said fluid pressure system, and valve operating means operatively associated with the control means for said drive means, whereby to cause movement to be imparted to said release lever in a direction to move the presser foot out of operative engagement with said tape when the drive means is rendered inoperative.

7. In a machine for stitching articles fed thereto in succession, said machine comprising stitching means inand presser foot, drive means for the stitching means, article engaging control means for the drive means, a release lever for said presser foot, a fluid pressure system including a cylinder and a cooperating piston plunger extending outwardly from one end of said cylinder, yielding means biasing said plunger in one direction of movement relative to the cylinder, the extended end of said plunger being secured to said release lever for common movements therewith, means operatively connecting the cylinder to said machine for common movements with said plunger and including a stop element limiting said movement in one direction, an actuator valve in said fluid pressure system and valve control mechanism connected to the control means for said drive means, whereby to cause fluid under pressure to be introduced to said cylinder to move said plunger and lever against the bias of said yielding means in a direction to move the presser foot from its operative article engaging position to its inoperative position when the drive means is rendered inoperative.

8. In a machine for stitching articles fed thereto in succession, said machine comprising stitching means including a needle and presser foot, means for feeding a strip of reinforcing tape with said articles to the stitching means, drive means for the stitching and tape feeding means including a motor and an electrically operated clutch and brake mechanism and a circuit therefor, article engaging control means for the drive means including a switch in said circuit, a release lever for said presser foot, a fiuid pressure system including a cylinder and a cooperating piston plunger extending outwardly from one end of said cylinder and secured to said lever, yielding means biasing said plunger in a direction of movement relative to the cylinder whereby to permit engagement between said presser foot and tape, means operatively securing the cylinder to said machine for common movements with said plunger and including a stop element limiting said movements in one direction, an actuator valve in said fluid pressure system operatively associated with said cylinder, and electrically operated valve control mechanism interposed in said circuit whereby to cause fluid under pressure to be introduced to said cylinder to move said plunger and lever against the bias of said yielding means in a direction to move the presser foot out of operative engagement with the tape when the drive means is rendered inoperative.

9. An attachment for a machine for sewing articles fed in succession, said machine having stitching means including a needle and presser foot, drive means for the stitching means, control means for the drive means, and a release lever for said presser foot; said attachment comprising power operated mechanism including a movable member adapted to be connected to said release lever, a control element for said power operated mechanism, an actuator for said control element, and means for operatively connecting said actuator to the control means for said drive means, said actuator being responsive to deenergization of said drive means by said control means to render said control element operative to cause movement of said movable member and said release lever in directions whereby the presser foot is shifted from its operative article engaging position to an inoperative position in spaced relation to said article, and held in said inoperative position.

10. An attachment for sewing machines having stitching means including a needle and presser foot for sewing articles fed in succession, means for feeding a strip of reinforcing tape with said articles to the stitching means, drive means for the stitching and tape feeding means, control means for the drive means, and a release lever for said presser foot; said attachment comprising power operated mechanism including an extensible and retractable link adapted to be connected at one end to said release lever, a control element for said power operated mechanism, an actuator for said control element, and means for operatively connecting said actuator to the control means for said drive means, said actuator being responsive to de-energization of said drive means by said control means to render said control element operative to cause movement of said link and release lever in directions whereby the presser foot is shifted from its operative article engaging position to an inoperative position in spaced relation to said article, and held in said inoperative position.

11. In a machine for stitching articles fed thereto in succession, said machine comprising stitching means including a needle and presser foot, drive means for said stitching means, control means for the drive means, a release lever for said presser foot, power operated mech anism including a movable member connected to said release lever for moving said release lever in a direction to move said presser foot from an operative stitching thread engaging position to an inoperative position, a control element for said power operated mechanism, an actuator for said control element, and means operatively connecting said actuator to the control means for said drive means, said actuator being responsive to de-energization of said drive means by said control means to render said control element operative to cause movement of said movable member and said release lever in directions whereby said presser foot is shifted from its operative article engaging position to an inoperative position in spaced relation to said article, and held in said inoperative position.

12. In a machine for stitching articles fed thereto in succession, said machine comprising stitching means including a needle and presser foot, drive means for said stitching means, control means for the drive means, a release lever for said presser foot, power operated mechanism for moving said release lever in a direction to move said presser foot from an operative stitching thread engaging position to an inoperative position spaced therefrom, said mechanism including an extensible and retractable member connected at one end to said lever and means operatively connecting the other end thereof to said machine, a control element for said power operated mechanism, an actuator for said control element, and means operatively connecting said actuator to said control means for the drive means, said actuator being responisve to deenergization of said drive means by said control means to render said control element operative to cause movement of said extensible and retractable member and said release lever in directions whereby the presser foot is shifted from its operative article engaging position to an inoperative position in spaced relation to said article, and held in said inoperative position.

References Cited in the file of this patent UNITED STATES PATENTS

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