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Patentes

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Número de publicaciónUS2836135 A
Tipo de publicaciónConcesión
Fecha de publicación27 May 1958
Fecha de presentación22 Mar 1956
Fecha de prioridad22 Mar 1956
Número de publicaciónUS 2836135 A, US 2836135A, US-A-2836135, US2836135 A, US2836135A
InventoresRichard Briggs
Cesionario originalBirch Bros Inc
Exportar citaBiBTeX, EndNote, RefMan
Enlaces externos: USPTO, Cesión de USPTO, Espacenet
Sewing machine
US 2836135 A
Imágenes(7)
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Descripción  (El texto procesado por OCR puede contener errores)

R. BRIGGS SEWING MACHINE May 27, 1958 '7 Sheets-Sheet 1 Filed March 22, 1956 naw; CM

HTTOR/Vf Y y 1953 R. BRIGGS 2,836,135

SEWING MACHINE Filed March 22, 1956 7 Sheets-Sheet 2 M VF/I/TOI? Mal/Amp mP/aas AWQM May 1958 R. BRIGGS 2,836,135

SEWING MACHINE Filed March v22, 1956 7 Sheets-Sheet 3 ATTORNEY y 1958 R. BRIGGS 2,836,135

SEWING MACHINE Filed March 22, 1956 7 Sheets-Sheet 4 CLUTCH ff F76. 9 6 0 6 0 I 1 11,11? i6 III A I, O I

May 27, 1958 R. BRIGGS 2,835,135

SEWING MACHINE Filed March 22, 1956 '7 Sheets-Sheet 5 M GM May 1953 R. BRIGGS 2,836,135

SEWING MACHINE Filed March 22, 1956 7 Sheets-Sheet 6 OLLMA. 0M

147'7'019/VEY United States Patent SEWING MACHINE Richard Briggs, Reading, Mass., assignor to Birch Bros,

This invention relates to sewing machines of the type shown in U. S. Patent #1950913, March 13, 1934, and which is designed to stitch together temporarily the ends of a plurality of lengths of cloth preparatory to subjecting the connected length to various cloth-finishing operations, so that the connected lengths can be fed as a unit through the various cloth-finishing machines.

While the stitched connection between the ends of the lengths of cloth is intended for temporary use only, yet it is important that it should be strong enough to maintain the cloth lengths properly connected until all the clothfinishing operations have been completed.

The device of the above patent is constructed to sew a seam in which all the stitches have the same length and which is not reinforced in any way at either end of the seam or at the edges of the cloth. Where a non-reinforced seam is used for the above purpose there is a possibility that during d1e passage of a plurality of connected lengths of cloth through various cloth-finishing machines, the end stitches of a seam may become unraveled or broken, thus weakening the seam and producing a condition under which the seam may give way entirely before the connected lengths of cloth have been subjected to all of the various cloth-finishing operations.

It is an object of the present invention to provide means by which any such weakening of a seam during the cloth-finishing operations is prevented.

A further object of the invention is to provide a sewing machine of the above type which is constructed so that each seam by which any two lengths of cloth are connected together is strengthened and reinforced on each end, that is, at each edge of the cloth, thereby eliminating the danger that the end portions of the seam will give way or become disrupted as the connected lengths of cloth is being carried through the various cloth-finishing operations.

Another object of the invention is to provide a sewing machine which is constructed to make a series of fine stitches at each end of the seam, the main portion of the seam being composed of stitches of normal length.

Still another object of the invention is to provide means controlled by the leading edge of the cloth to produce the fine stitches at the beginning of the seam and controlled by the trailing edge of the cloth to produce the fine stitches at the end of the seam.

In the drawings wherein I have illustrated a selected embodiment of the invention,

Fig. l is a front view of the sewing machine made in accordance with the invention;

Fig. 2 is a sectional view taken on the line 2-2, Fig. l with parts shown in elevation;

Fig. 3 is an enlarged sectional view of the clutch by which the operation of the machine is controlled;

Fig. 4 is a fragmentary sectional view illustrating a portion of the feed wheel and a portion of the stitchforming mechanism; a

Fig. 5 is a sectional view similar to Fig. 4, which view 2,836,135 Patented May 27, 1958 shows the end portions of two lengths of cloth in position for being stitched together;

Fig. 6 is a fragmentary more or less diagrammatic view showing the ends of two lengths of cloth in position for being stitched together;

Fig. 7 is a fragmentary view showing the end portions of two lengths of cloth that have been stitched together;

Fig. 8 is a wiring diagram of the circuits controlling the cloth feeding movement;

Fig. 9 is a partial sectional view of the control mechanism for controlling the change of operation of the sewing machine from the fine stitches to the coarse stitches;

Figs. 10l5 illustrate the manner in which the control mechanism is actuated by the leading and trailing edges of the cloth as it is fed toward and past the stitch-forming point;

Figs. 16-22 show the wiring diagram of the control mechanism, the different views illustrating different circuit connections involved in the change of the stitching from the fine stitches to the normal stitches, and vice versa.

Figs. 23 and 24 are sectional views showing an overrunning clutch suitable for use in operating the feed wheel.

Referring to Fig. 7, 3 and 4 indicate the end portions of two lengths of cloth which have been stitched together by the sewing machine herein illustrated. The seam by which these lengths of cloth are stitched together is reinforced at each end as indicated at 5, that is, at each edge of the cloth, and one way in which this may be accomplished is by forming a plurality of fine stitches at each end of the seam, that is, stitches that are finer than the stitches 6 composing the main portion of the seam.

In stitching the two end portions of the two lengths of cloth together said end portions may be placed in superposed relation as shown in. Fig. 6 and said superposed end portions are then stitched together, and if the stitches are sufiiciently loose the end portions may be opened away from each other after the seam has been completed, to occupy the same plane as shown in Fig. 7.

The sewing machine herein illustrated by which these operations are performed is somewhat similar to that shown in said Patent #l,950,913 and it comprises stitchforming mechanism 7 which is mounted on a frame or pedestal 8, and a cloth-holding member shown as a feeding wheel 9 carried by the pedestal and which is provided in its periphery with pins or spikes 10 on which the superposed or mated end portions 3 and 4 of two lengths of cloth are impaled and thus fed to the stitch-forming mechanism. The stitch-forming mechanism includes the usual needle 11 and is formed with a support or table portion 12 on which rests the edge portions 3 and 4 of the lengths of cloth to be stitched together, as shown in Fig. 5, said stitching mechanism also having a presser foot 13.

The stitch-forming mechanism is driven by any suitable means and in the construction shown it is driven from a driving pulley 14 mounted on a shaft 15 which is journaled in the pedestal or frame 8. The pulley 14 has rigid with it a sprocket wheel 16 which is connected by a sprocket chain 17 with another sprocket wheel 18 which is rigidly connected to another sprocket 19 by means of a sleeve 28) which is mounted for free rotation on a shaft 21 carried by and journaled in the pedestal 8. Said sprocket 19 is connected by a chain 22 with a sprocket wheel on the shaft 23 of the stitch-forming mechanism, and by this means the stitch-forming mechanism is driven directly from the pulley 14 and at uniform speed. The pulley 14 may in turn be driven by any suitable motor.

In the operation of the device the end portions of two lengths of cloth are placed in their mating superposed relation shown in Fig. 6 and then these superposed lengths are impaled on the spikes 10 of the feed wheel which is rotating in the direction of the arrow in Fig. 1 and are thereby carried to and past the stitch-forming mechanism "essence V by which the two ends are stitched together as above described.

. The fine stitches at each end of the seam may be produced either by varying the speed of the feeding movementof the cloth or by varying the speed of operation of thestitch-forming mechanism. In the construction shown the fine stitches are formed by giving the feed wheel 9 arelativelyslow movement as the leading edge of the cloth, is fed to and past the stitching point, and after a sufficient number of fine stitches 5 have been made the feed wheel is then given a, faster. movement by which the stitches 6 of normal length are formed. When the trailing edge ofthe cloth approaches the stitchingpoint the feed wheel 9 is given a slow feeding movement with the result'that the fine stitches Sat the'end of the seam will be formed. When the trailing edge of the cloth is moved-past the stitch-formingmechanism the feed wheel is given a faster movement, which is the normal operating movement thereof. This change of speed of the feed wheel from normalspeed to a slower speed, andfrom slower speed to faster speed, is accomplished by the use of two trains of driving gears, both ofwhich are actuated from the pulley 14, and one of which gives the feed wheel a faster movement than the other.

The train of gearing for giving the feed wheel its faster feeding movement comprises a pinion 24 which is mounted on a sleeve 25 that in turn is rotatively mounted on the shaft'15, said pinion 24 meshing with a gear wheel 26 carried by ashaft 27 which is journaled in the frame or support 8. The shaft 27 has mounted thereon a pinion 28 which meshes with a'gear 29 fast on the shaft 21 which shaft has the feed wheel 9 rigidly mounted thereon. Thepinion 24 is adapted to be connected to the shaft 15 through the medium of a magnetic. clutch device '40 comprising the two clutch members 30 and 31. This magnetic clutch is one which is operative when it is energizedand it is normally in its energized or closed position asshown in Fig. 2, so that normally the pinion 24 is operatively connected to thedriving wheel 14 and the feed wheel 9 will 'be operating through the trainof gearing above described'including the pinion 2 4, gear 26,

' with a gear 33 mounted on the shaft 27 through the medium-of an overrunning clutch 34 which operatively connects the gear 33 to the shaft 27 and thus to the feed wheel through the gears 28 and 29.

When the clutch 4% is opened, as shown in Fig. 3, the

sleeve 25 carrying the pinion24 is freeto rotate on the shaft 15 and the shaft 27 is free -to be driven by the overrunning clutch 34. The pinion 24 is larger than the pinion 3 2,1 and hence when the clutch '40 is closed, as

' shown in Fig. 2, and the'power is transmitted to the feed wheel through the first train of gears, the shaft 27 will be operated at a-faster rotative speed than when the --clutch is open, as shown in Fig. 3, and the feed wheel is driven through the second train of gears' which includes the smaller pinion 32. .Although whenthe clutch 40 is closedyas shown in- Fig. 2, both ;pinions--24 and '32 are rotated, yet since the rotation of the shaft 27 when driven by the larger pinion 24 is atfasterrate than when driven by thesmaller pinion 32, the overr unning clutch 34 will allow the shaft 27 to move ata faster rate.

than the gear wheel 33, .so that during the'time that the clutch is closed and the first train .of;gears is in operation the gear 33 is anidle gear rotating ata slower-speed than'the shaft 27, an operation whichlis permitted :by the overrunning Tclutjch '34.. r r

On the other hand, when the clutch 40 is open as shown in Fig. 3, the pinion 24 becomes an idle pinion and the driving power is taken from the shaft 15 through the smaller pinion 32, gear 33, and the automatic overrunning clutch 34 becomes operative to clutch the slower rotating The feed wheel is, therefore, driven at normal or faster 1 speed when the ,clutcl1 40 is closed and, is driven atthe slower speed for forming the fine stitches when the clutch is opened, as shown in Fig. 3.

Any suitable overrunning clutch may be used as described above, for'couplingtheshaft 27 to the gear33. in Figs. 23 and 24 I have shown a'simple form of such a clutch and which comprises the clutch element 34a fast on the shaft 27' and which operates within the clutch element 34b that is rigid with the gear 33. The clutch element 34a is shaped to present two recesses 34d which extend circumferentially of the member 34a and each of which has a progressively increasing depth from one end to the other. Situated within each recess is a clutch roll or clutch roller 34c.

When the feed wheel is being operated through the 34d and will have no clutching effect so that the shaft 27 will be free to rotate at its faster speed.

When, however, the clutch 40 is disengaged, as shown in Fig. 2, andthe power is transmitted from the shaft 15 to the feed wheel through the pinion 32 and gear 33, the roller clutch members 34c will be carried toward the narrower end of the recesses 34d and the shaft 27 with its gear 28 will bc'driven from the gear 33, as shown in Fig. 24. During this operation, however, the clutch 40 is open so that although the pinion 24 will be rotated by the gear 26, yet since said pinion is at this time free to merely rotate idly.

The opening and closing of the clutch 40 is controlled by the feeding movement of the cloth. As stated above, said clutch 40 is normally "closed and the feed wheel'is' thereby moving at the faster speed. Means are provided whereby'when the leading edge of the cloth reaches'the stitching point of the stitch-forming mechanism said leading edge renders operative mechanism by which the clutch 40 will de-energized and thus the second train of gearing will be thrown into'operation to move the feed wheel at the slow speed with the result that the fine stitches 5 will be formedat the beginning of the seam. After the required number of fine stitches have been formed, the leading edge of the cloth'renders operative mechanism by which the clutch 46 is again energized and the feed wheel is then driven at the faster speed, whereby the nor- 7 mal stitches 6 are formed. As the trailing edge of the cloth approaches the stitching point, it renders operative mechanism'by which the clutch 40 is again de-energized so that the feed wheel will be driven at the slower speed a to produce the fine stitches at the endof the seam or at the trailing edge of the'cloth and when the cloth has passed entirely beyond the stitching point, said trailing" erating the motor which drivesthe drive wheel '14 and-for I I operating the clutch 40. In this wiring diagram 41indicates the wires of a feed line which supplies current for operating the motor 47 from which the drive pulley 14 is operated and also the clutch 40. 43 indicates the wires of a lead-ofi line taking power from the main line 41 and leading to a control switch 45, preferably a foot switch. From the control switch 45 another circuit 46 leads to the motor 47, so that when the switch 45 is closed the motor will be set in operation, thereby operating the pulley 14 and the shaft 15. The circuits 43 and 46 may be the ordinary alternating current circuits. The magnetic clutch 4 3, however, is one which is operated by a direct current circuit, and the wiring diagram of Fig. 8 shows a circuit leading from the foot switch 45 to a power converter 55 which is adapted to convert the alternating current to a direct current. From this power convertor a direct current circuit 51 is taken to the clutch 40, and the circuit 51 is provided with a magnetic switch by which said circuit may be opened and closed in order to render the clutch 4t) inoperative or operative. Said magnetic switch is shown as having two pairs of contacts 53 therein, one pair in each wire. of the line, and the contacts are opened and closed by means of a magnet 52 which is in an alternating current circuit 55 connected to the circuit 49, said magnetic switch being so constructed that the contacts 53 are closed when the magnet 52 is deenergized and are opened by energizing the magnet. The circuit 55 is a normally open circuit and hence the contacts 53 are normally closed so that the clutch circuit 51 is normally closed and the clutch 46 is normally perative. The closing and opening of the circuit 55 is under the control of a control element 56 which is rendered operative by the leading and trailing edges of the cloth as it is fed to and from the stitch-forming mechanism.

When the leading edge of the cloth arrives at the stitching point the control mechanism 56 is actuated thereby for a first time, as will be presently described, to close the circuit 55, and thus energize the magnet 52. which will result in opening the switch contacts 53, and deenergizing the clutch 41). When this occurs the feed wheel 9 will be driven at the slow speed, as above set forth, and the fine stitches will be formed at the beginning of the seam. When a desired number of fine stitches have been formed, the leading edge of the cloth again actuates the control member 56 a second time to open the circuit 55, thus rendering the magnet 52 inoperative and the switch contacts 53 will then close the circuit 51, thus rendering the magnetic clutch 46 operative again, with the result that the feed wheel will be driven at the faster or normal speed.

As the seam is nearing completion and the trailing edge of the cloth approaches the stitching point, the control element 56 is rendered operative a third time by said trailing edge thereby to close the circuit 55, thus energizing the magnet 52 and opening the contacts 53, and thus deenergizing the clutch 48 with the result that the sewing mechanism will be again set to form fine stitches. The making of such fine stitches will continue until the trailing edge of the cloth reaches and passes the stitching point, at which time the control element 56 will be operated a fourth time to open the circuit 55 and de-energize the magnet 52, with the result that the clutch circuit 51 will again be closed and the clutch 40 will become again operative to rotate the feed wheel at the faster speed.

The control device 56 is shown in the form of a casing 60 having therein three switches 61, 62, 63 each of which has a depending feeler airn situated to be engaged by the cloth as it passes beneath the control member. The feeler arm for the switch 61 is indicated at 64 and its lower end is curved as shown at 65 and normally rests in a peripheral groove 66 with which the feed wheel is provided. The feeler arm for the switch 62 is indicated at 67 and the feeler arm for the switch 63 is shown at 68. Each of these arms is normally in the full line position Fig. 9

a 6 and the lower curved ends thereof are resting in the groove 66.

As the cloth is fed into stitching position, the leading edge of the cloth will engage these feeler arms successively and because the lower curved ends of the arms are in the groove 66 and below the face 69 of the feed wheel on which the cloth rests, said leading edge of the cloth will move each feeler from the full to the dotted line position Fig. 9. As the edge of the cloth passes beneath each feeler the latter will then be retained in its dotted line position by its engagement with the cloth.

Each of the switches 61, 62, 63 has the features illustrated diagrammatically in Figs. 16-22. Referring to Fig. 16, for instance, the three switches are diagrammatically shown at 61, 62, 63 and each switch has two contacts and a movable contact arm adapted to engage either contact. The contacts for the switch 61 are indicated at 79 and 71, and the contact arm is indicated at 72.

The two contacts for the switch 62 are indicated at 73, 74 and the movable contact arm at 75. The two contacts for the switch 63 are indicated at 76, 77 and the contact arm at 78.

The wires of the circuit 55 are connected to the terminals of the contact arm 72 of the switch 61 and the contact arm 75 of the switch 62 as shown in Fig. 16. The contact of the switch 61 is connected by the wires 84), 81 to the contact 74 of the switch 62 and the contact 76 of the switch 63. The contact 71 of the switch 61 is connected by the wire 82 to the contact arm 78 of the switch 63. The contact 73 of the switch 62 is connected by the wire 83 to contact 77 of the switch 63.

As stated above, these feeler arms normally have the full line position shown in Fig. 9 and the controlling element 56 is so positioned that the stitching point of the stitch-forming mechanism is beneath the central switch 62.

The manner in which the control member is operated by the leading and trailing edges of the cloth to change the feeding of the cloth to the stitch-forming mechanism, thereby to form the fine stitches, and the coarser stitches, is illustrated in Figs. 1()15. In Fig. 10 the leading. edge 85 of the cloth is shown as about to engage the feeler 64 and as said leading edge actually engages said feeler it will push the latter aside into the dotted line position and the feeler will then be resting on the cloth which will hold it in its dotted line position. The swinging of the feeler arm from the full to the dotted line position actuates the switch 61 by throwing the contact arm 72 from the position shown in Fig. 16 into contact with the contact 71, as shown in Fig. 17. This actuation of the switch 61, however, does not close the circuit 55 as will be evident from Fig. 17.

As the leading edge 85 of the cloth moves forward I from the dotted line position Fig. 10 or the full line position Fig. 11 into the dotted line Fig. 11 and thus arrives at the stitching point, said leading edge engages the feeler 67 of the switch 62 and moves it from the full to the dotted line position as shown in Fig. 11. This movement of the feeler 67 will actuate the switch 62 by moving the contact arm thereof into engagement with the contact 74, as shown in Fig. 18, it being understood that the switch 61 remains in the position shown in Fig. 18 by the engagement of the feeler 64 with the cloth. When the switches 61, 62 are in the condition shown in Fig. 18 then the circuit 55 is closed through the contact arm 72, contact 71, wire 82, contact arm 78 and contact 76 of switch 63, wires 80, 81 and contact 74 and contact arm '75 of switch 62.

The closing of the circuit 55, as stated above, energizes the magnet 52 and opens the switch 53, thus de-energizing the clutch 4t and as a result the [feed wheel will be actuated at a slow speed by the second train of gearing above referred to and thereby the fine stitches 5 at the leading edge of the cloth will be formed.

As the cloth continues to move forward the leading 63 thereby moving it from the full to the dotted line position in Fig 12 Thi perat on Will actuate t sw. 79.1.1 65 by movi th on c am 78 of n engag ment wi h he c ac a ho c and thereby the circuit 55 will be broken. This will resul in L nerg zing th g e 5 ng h switch 53 to close again, thereby energizing the clutch and thus rendering'epe a the fir t rain of g a g by, which the feed wheel is moved at'the faster speed, thereby to form thenormal stitches 6, c

As the trailing edge 94 of the cloth passes out from under the feeler d4 of the switch 61 said feeler will drop baekinto' its norma p sit on with e ur d end resting in the groo e fine sh n in h operation occnrring as said-trailing edge 90 approaches the stitching point. The return of the feel-er 64 to its normal position will-actuate the switch 61 by moving the c'ontact am]; into engagement with the contact 7 as shown in I Fig. 20, and thereby the circuit 55 will be closed e the magnet 2 nergized hi h ill result in p ing the switch 53 and die-energizing the clutch 40. This will render operative the second train of 'gearingwhich opgrates thefeedwheel at the slow speed, and a series of fine stitches will be formed at the end of the seam. I

, t When the trailing edge 90 of the cloth passes the stitching point asshown in full lines Fig. l4 the feeler 67 of the switch 62 will be released and will move into the full line position Fig. 14. This operation results inmoving the contact arm 75 of the switch 62 into the position shown in Fig. 21 and into engagement with the contact 73, thereby opening the circuit 55', and de-energizing the magnet 52. This will result in closing the switch 53 and a a n e rgizing th dumb 40 so t fr m then n th reed wh e ill be op rated by th fi s ra n o ea ing and at the faster speed for the formation of stitches .6 o norma engt Wh he ailing e e 9 9 t e c h pas e e ee1 r-6 of th switch .63, t en s d i h i l e r turne t th pesi en sh n. in Ba 22- V The CCI I 'Ql element is thus restored to its initial condition shown in Fig, 16 and is ready to perform the cycle of operations shown in Figs. 10-15 and Figs. 1622 7 moving at :the faster speed, but is dropped into an operative position'in contact with the cloth during the time that the feed wheel is operating at the slower speed and the fine stitches are being formed.

The prcsser foot has connected to it an upstanding operating rod 98 which is connected at its upper end to a lever 97 pivotally mounted on the stitch-forming mechanism, as shown at 96. The other end of the lever is connected to a depending'rod 95 which extends to and is-controlled by an armature and a magnet 94 that is secured .to the under side of the supporting plate, 8 on which the stitch-forming mechanism is mounted. The coils of. the magnet 94 are in a circuit 55a which leads ofi from- ,the -circuit;5 5, as shown ;in Fig. 8, and this circuit has th e rein a switch 93 which is controlled by the magnet 52 so-thatwhen said magnet 52 is energized to open the contacts 53 and thus open the clutch circuit 51, the switch 93 will be opened, thereby de-energizing the magnet 94.

Themagnet 94-is, therefore, energized and de=energized simultaneously with the clutch 40. So long as 'thetclutch 5,0 is energized and thus closed, as shown in Fig. l, and

th eed w eel onseq e tly tating at t as e peed,

the magnet :94 will belenergized and'the presserfoot 13 will beheld in its raised position. a

t th magn t 572 s en gize to qpen h lut t"? .eirwitSl andhereby set in ep re eh th me ns fe rotatingt e feed heel a the lewe speed to fo m hefin magnet 94, thus allowing the presser foot to drop into its lower operative position in contact with the cloth.

The device herein shown includes a stripper element While the embcdimentof the invention herein shown is one in which the finc'cstitches are produced by varying the speed of the cloth feeding means relative to that of the stitch-forming mechanism, yet it is within my invention to provide fortmaking the fine stitchestat the beginning and at the end of the same by varying the speed of operation of the stitch-forming mechanism relativeto that of the cloth-feeding mechanism, since the broad concept of the invention is to produce the fine stitches by establishing a different relative speed of operation between the clothefeeding mechanism and the stitch-forming mechanism, said two mechanisms operating at one relative speed for forming the fine stitches and at another relative speed for forming the coarser stitches for the body of the scam. I V e I claim: a 7 l 1. A sewing machine comprising stitch-forming mechanism, means 'for operating-the same, a cloth-feeding member, actuating means capable of operating the clothfeeding member at either one of two difierent speeds, control means rendered operative for a first time by the leading edge of the cloth as it reaches the stitching point of the stitch-forming mechanism thereby to set the actuating means to operate the cloth-feeding member at the slower of the two speeds whereby a series of fine stitchesiis formed at the beginning of the seam, and'also rendered operative for a second time after a predetermined number, of fine stitches have been formed thereby to set the actuating means'again to operate the cloth-feeding member at the faster of the two speeds whereby coarser stitches are formed. a

2. A sewing machine as defined in claim 1 in which the control means is also rendered operative for a third time bythe trailing edge of the cloth as it approaches the stitching point of the stitch-forming mechanism thereby to set said actuating means to operate the cloth feeding mema her at the slower of the two different speeds, whereby a series of fine stitches is formed at the end portion of the seam.

3. A sewing machine as definedin claim 1 in which the control means is also rendered operative for a third time by the trailing edge of the cloth as it approaches the stitching point of the stitch-forming mechanism thereby to set said actuating means to operate the cloth feeding member at the slower of the two different speeds, whereby a series of'fine stitches is formed at the end portion of the seam, and again rendered operative a fourth time by the trailing edge of the cloth when said trailing edge reaches the stitching point and the seam is finished, thereby to set the cloth feeding member for the faster speed.

4, A sewing machine comprising stitch-forming mechanism, means for operating same, a cloth-feeding member, actuating means capable of operating the cloth-feeding member at either one of two difierent speeds, control means for the actuating means including a plurality of feelers-having a tandem arrangement and adapted to be engaged and displaced sequentially by'the leading edge of the cloth asit is fed to and passesthc stitching point of the displacement of oneof the feelers by theleading edge of the cloth as it reaches the stitching point :to set .the cloth fe din pepper to ,operate at the .Slower speed st tches, the opening of thecswitch 93 will ie-energize the whereby fine stitches are formed at the beginning of the seam.

5. A sewing machine comprising stitch-forming mechanism, means for operating same, a cloth-feeding member, actuating means capable of operating the cloth-feeding member at either one of two different speeds, control means for the actuating means including a plurality of feelers having a tandem arrangement and adapted to be engaged and displaced sequentially by the leading edge of the cloth as it is fed to and passes the stitching point of the stitch-forming mechanism, said feelers when displaced riding on the cloth as it is fed forward and thus being held in displaced position, and means rendered operative for a first time by the displacement of one of the feelers by the leading edge of the cloth as it reaches the stitching point thereby to set the cloth feeding member to operate at the slower speed whereby fine stitches are formed at the beginning of the seam, and rendered operative for a second time by the subsequent displacement of another feeler by the leading edge of the cloth, thereby to set the clothfeeding member to operate at the faster speed whereby coarser stitches are formed.

6. A sewing machine comprising stitch-forming mechanism, means for operating same, a cloth-feeding member, actuating means capable of operating the cloth-feeding member at either one of two difierent speeds, control means for said actuating means including a plurality of feelers having a tandem arrangement and adapted to be engaged and displaced sequentially by the leading edge of the cloth as it is fed to and passes the stitching point of the stitch-forming mechanism, said feelers when displaced riding on the cloth as it is fed forward and thus being held in displaced position until released by the trailing edge of the cloth during its forward feeding movement, and means rendered operative for the first time by the displacement of one of the feelers by the leading edge of the cloth as it reaches the stitching point to set the actuating means to operate the cloth feeding member at the slower speed whereby fine stitches are formed at the beginning of the seam, and also rendered operative for the second time by the subsequent displacement of another feeler by the leading edge of the cloth to set the actuating means to feed the cloth feeding member at a faster speed, said last named means being rendered operative for the third time by the release of one of the feelers by the trailing edge of the cloth as it aproaches the stitching point to set again the cloth feeding member to operate at the slower speed whereby a series of fine stitches is formed at the end portion of the seam.

7. A sewing machine comprising stitch-forming mechanism, a presser foot associated therewith, means for operating the stitch-forming mechanism, cloth-feeding means to feed cloth to the stitch-forming mechanism, means rendered operative by the leading edge of the cloth as it is fed to the stitch-forming mechanism to actuate the cloth feeding means at the slower of two different speeds, thereby to form fine stitches at the beginning of the seam, and after a predetermined number of fine stitches have been formed to actuate the cloth feeding means at the faster of said two different speeds, whereby coarser stitches will be formed, means for holding the presser foot in raised inoperative position while the cloth feeding means is operating at the faster of the two speeds and in lowered operative position in contact with the cloth while the cloth feeding means is operating at the slower of the two speeds.

8. A sewing machine comprising stitch-forming mechanism, means for operating thesame, cloth-feeding means to feed cloth to the stitch-forming mechanism, means rendered operative by the leading edge of the cloth as it is fed to the stitch-forming mechanism to actuate the cloth-feeding means at the slower of two different speeds, thereby to form fine stitches at the beginning of the seam, and after a predetermined length of seam formed of fine stitches has been formed to actuate the cloth-feeding means at the faster of said two different speeds, whereby coarser stitches will be formed, a presser foot associated with the stitch-forming mechanism and movable from a lowered operative position in contact with the cloth to a raised inoperative position out of contact with the cloth, and means to maintain the presser foot in operative engagement with the cloth while the cloth-feeding means is operating at the slower of the two speeds and finer stitches are being formed, and to raise the presser foot into and hold it in its inoperative position out of engagement with the cloth while the cloth-feeding memer is operating at the faster of the two speeds and coarser stitches are being formed.

9. A sewing machine as defined in claim 8 in which the means for moving the presser foot from one of its positions to the other is rendered operative by the leading edge of the cloth as it is fed by the cloth-feeding means.

it). A sewing machine comprising stitch-forming mechanism, means for operating the same, cloth-feeding means, means for operating said cloth-feeding means, means rendered operative by the leading edge of the cloth as it is fed to the stitch-forming mechanism to establish a relation between the means for operating the stitch-forming mechanism and the means for operating the cloth-feeding member by which a reinforced seam is produced at the beginning of the sewing operation and also rendered operative by the leading edge of the cloth after a reinforced seam of a predetermined length has been formed to establish another relation between the means for operating the stitch-forming mechanism and the means for operating the cloth-feeding mechanism by which a non-reinforced seam is formed.

11. A sewing machine comprising stitch-forming mechanism, means for operating the same, cloth-holding means, means to give the stitch-forming and cloth-holding means a relative movement for forming a seam in the cloth, control means rendered operative for a first time by the leading edge of the cloth when it and said stitchforming mechanism have been brought by such relative movement to the relative position which is required for starting the seam, thereby to establish a slow relative movement between the cloth-holding means and the stitch-forming mechanism by which a series of fine stitches is formed, said means also rendered operative for a second time by the leading edge of the cloth after a seam of fine stitches of a predetermined length has been made, thereby to establish a different and faster relative movement between the cloth-holding means and stitch-forming mechanism by which coarser stitches are formed.

12. A sewing machine as defined in claim 11 in which the control means is also rendered operative for a third time by the trailing edge of the cloth when it has been brought to a predetermined position relative to the stitchforming mechanism, thereby to establish again the siow relative movement between the cloth-holding means and the stitch-forming mechanism whereby a second series of fine stitches is formed.

13. A sewing machine as defined in claim 11 in which the control means is also rendered operative for a third time by the trailing edge of the cloth when it has been brought to a predetermined position relative to the stitchforming mechanism, thereby to establish again the slow relative movement between the cloth-holding means and the stitch-forming mechanism whereby a second series of fine stitches is formed, said control means also being rendered operative for a fourth time by the trailing edge of the cloth when the second series of fine stitches of a predetermined length has been formed, thereby to establish again the faster relative movement between the cloth-holding means and stitch-forming mechanism.

14. A sewing machine comprising stitch-forming mechanism, a cloth-feeding member, means for operating If e.

11 he titeh f rming rne ns, m ns f rp a ng t c o r g member at either of two difierent, speeds and pomprising a driving member, two trains, of gearing-for.

-- connecting the driving member to the cloth-feeding IQEHI? her, the first train of gearing operating the cloth-feeding member at the faster of the two speeds, and the second train of gearing operating the cloth-feeding member, at the slower of the two speeds, a control device rendered operative a first time by the leading edge of the cloth as it reaches the stitching point of the stitch-forming mechanism to connect the driving member to the cloth-feeding member through the second train of gearing, whereby the cloth-feeding member is moved at the slower sgeed and fine stitches are formed at the beginning of the seam, said control device rendered operative a second time by the leading edge of the'cloth after a seam of fine stitches of a predetermined length has been formed to'connect the driving membento the cloth-feeding member through 'thefirs't train of gearing, whereby the 'cl0th-feeding'rne1i ber moves at the faster speed andccoarser stitches are formed. t

15. A sewing machine as, defined in claim 14 in which stitching point to disconnect the driving member from the first train of gearing and establish an operative drives em mg flpllllgfli l e we sa d iv m mber and the cloth-feeding member, whereby the latter is moved'at the slower speed and fine stitches are formed at the end bolftion' of' the seam. V V

1 1 6, 23; sewing machine as defined in claim 14 in which the control device is rendered operative for a third'time byjthe trailing edge'of the "cloth as it approaches the stitching point :to disconnect the driving member froin' the first train of gearing and establish an operative'driv;

iag connection between said driving imember and the 1 cloth-feeding member, whereby the latter is moved at the 4 moved atlthe faster speed. 7 V

' References Cited in the file of this patent UNITED ST ATESVPATENT S V 1,950,913 Birch et a1. Mar; 13,1954 2,724,352 Gentry et a1. Nov. 22, 1 955 Hopkins Aug. 14, 1956

Citas de patentes
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US2724352 *4 Sep 195322 Nov 1955Gentry Norman LVariable speed feed mechanism for railway sewing machine
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Citada por
Patente citante Fecha de presentación Fecha de publicación Solicitante Título
US3299843 *21 Ago 196424 Ene 1967Ind Ovens IncSplicing method and apparatus
US3745947 *6 May 197117 Jul 1973Riegel Textile CorpDiaper machine
US3890911 *11 Abr 197424 Jun 1975Usm CorpAutomatic hemming machine
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US4700642 *24 Abr 198520 Oct 1987Young Engineering Inc.Joining continuous lengths of web materials
Clasificaciones
Clasificación de EE.UU.112/322, 112/2, 112/315
Clasificación internacionalD05B81/00
Clasificación cooperativaD05B81/00
Clasificación europeaD05B81/00