US1225628A - Feeding mechanism for blindstitching-machines. - Google Patents

Description

T. J. HAYES. FEEDING MECHANISM FOR BLINDSTITCHING MACHINES.

1,225,628 APPLICATION FILED APR- 9, I914- Patented May 8 3 SHEETS-SHEET I.

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T. 1. HAYES. FEEDING MECHANISM FOR BLINDSTITCHING MACHINES.

APP UCAT|0N FILED APR. 9,1914- Patented May 8,1917.

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FEEDING MECHANISM FOR BLINDSTITCHING MACHINES-I APPLICATION FILED APFLQ, I914.

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THOMAS J. HAYES, OF RO-SLINIDALE, MASSACHUSETTS, ASSIGNOR 'I'O ARBETTER FELL- INGr MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

FEEDING MECHANISM FOR BLINDSTITCHING-MACHINES.

Specification of Letters latent.

Patented May 8, 1917.

Application filed April 9,1914. Serial No. 830,790.

To all whom it may concern Be it known that I, THoMAs J. HAYEs, a citizen of the United States, and resident of Roslindale, county of Suffolk, State of Massachusetts, have invented an Improvement in Feeding Mechanism for Blindstitching-Machines, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to improvements in feeding mechanism for sewing machines and particularly machinesadapted for blind stitching for felling in which a curved oscillating needle and complemental stitch forming mechanism are supported above the bed plate and which have means for causing the needle to penetrate alternately the base layer of the fabric and the superimposed layer to form two parallel rows of stitches which when drawn taut by the tension of the thread will produce a felled blind seam.

In feeding the material through machines of this character it is necessary that the superimposed layer of goods be advanced at exactly the same rate of speed at which the lower or base layer of the fabric is forwarded in order to avoid wrinkling or puckering the goods. To accomplish this purpose this invention comprises means for positively clamping both layers of the goods between an upper and a lower feed dog and causing the same to be advanced by the movement of the lower feed dog while thus clamped together.

Another object of the invention is to provide an improved means for clamping the work against a stationary overhead presser foot either by the Work support or the feed dog so that there will be no time in which the work is not positively engaged by one or the other of these mechanisms.

Another object of the invention is to provide improved means for adjusting the extent of forward and backward movement of the dog.

Other objects of the invention will more fully appear from the following description and accompanying drawings and the suboined claims.

In the drawings: Figure 1 1s a horizontal sectional view taken axially of the sewing machine arm,

but showing the main shaft of the machine and the cams thereon in elevation,

Fig. 2 is a front view of the head of the sewing machine showing the relation of the upper and lower feed mechanisms,

Fig. 3 is a rear elevation partly broken away to illustrate the means for adjusting the feeding mechanism,

Fig. 4 isa detail side elevation of the work support and of the lower feeding mechanism and means for actuating the same,

Fig. 5 is a detail front View of the same.

Fig. 6 is a detail plan View of the same showing the connection of the feeding mechanism to the rock shaft and rocking sleeve which respectively cause forward and backward movement of the feed dog and the up and down movement thereof,

Fig. 7 is a median detail sectional view of the work support and feed dog,

Fig. 8 is a detail view of the supporting member for the serrated feed dog, and,

Fig. 9 is a view of the serrated dog.

The preferred form of invention is illustrated herein in connection with an improved stitch forming mechanism for blind stitch sewing machines which forms the subject matter of a companion application filed the 9th day of April 1914, Serial Number 880,788.

The sewing machine illustrated comprises the usual bed plate 1 having a vertical hollow standard 2 rising therefrom and having a horizontal arm 3 extending parallel to the bed plate and terminating in a head a containingthe needle mechanism and the complemental stitch forming mechanism and the upper feeding mechanism.

The arm 3 is provided at its rear end, its middle portion, and adjacent to the head with bosses 5, 6, and? which contain alined bearings for the shaft 8. The shaft 8 is provided at its rear end vith the usual driving pulley 9 and hand wheel 10 and is provided throughout its length with the necessary cams to operate the feed mechanism, the take up and the stitch forming mechanism.

As illustrated in the drawing the needle mechanism comprises a curved oscillating needle carried by a needle bar 11 which is pivotally mounted to vibrate in the plane inclined to the work supporting surface of the work support in bearings 12 upon the lower end of a supporting member 13 which is pivotally mounted upon a shaft 14 journaled in the top of the sewing machine head, means being provided including a link 15 for vibrating the needle support 13 upon its pivotal shaft to produce the shogging movement necessary to form two parallel lines of stitching.

Suitable mechanism, not shown, is provided for oscillating the needle. The complemental stitch forming mechanism preferably comprises a rotary hook 16, suitably mounted in a hook bracket 17 and driven through suitable gearings carried by said bracket from a counter shaft 18 which has a gear 19 which meshes with a gear 20 upon the main shaft of the machine. (See Fig. 1.) The hook bracket is desirably pivotally supported by the shaft 18 so that the hook may be removed laterally from its normal position relative to the needle for the purpose of replacing the bobbin. The hook bracket is normally maintained in operative relation to the needle mechanism by means of a spring pressed. latch 21 which engages a lug 22 carried by a segmental front plate 23 attached to the head of the machine. The presser foot 24 preferably is secured rigidly to a projection 25 on the lower end of the hook bracket so that the presser foot is maintained in a relatively rigid relation to the bed plate. The goods are clamped against said presser foot plate and are fed forward to produce the line of stitching by the relative movement of the work support and the feed-dog which will hereafter be described.

The lower feeding mechanism is supported upon a U-shaped frame preferably made integral with and depending from the under surface of the base plate and comprising vertical portions 26, 27 and horizon tal members 28 and 29, said horizontal members being provided with alined bearings. The work support 30 comprises an inverted L-shaped member having a cylindrical sleeve 31 provided with a lateral projection 32 providing a seat for a spring 33 which is supported at its lower end in a socket 34 in the cross piece 28 and is provided with an .adjusting screw 35 adapted to bear upon the end of the spring to regulate the tension thereof. The sleeve 31 surrounds and telescopically supports a cylindrical standard 36 having at its upper end a horizontal arm 37 provided with an L-shaped member 38 secured thereto by screw 39 to provide a sliding way for the horizontal web 40 of the feed dog support.

The feed dog support which is shown in detail in Fig. 8 is provided with a pair of parallel. ribs 41, 42. The rib 41 being provided at its forward end with screw holes 43 to receive screws whereby the feed dog 44 may be secured thereto. The feed dog is illustrated in detail in Fig. 9 and comprises three united parallel serrated work engaging faces, the intermediate of said faces being shortened and adapted to engage the work immediately in the rear of the needle throat. The web 40 of the feed dog support is slidably mounted upon the arm 37 beneath the member 38 which fits in the channel formed by the web 40 and the ribs 41-42. The dog support is provided with a downwardly extending ear 45 through which the forward and backward movement is imparted to said dog. It will be obvious that the horizontal member 40 is so guided beneath the overhanging member 38 that the feed dog will reciprocate in a substantially horizontal plane in its forward and backward movement.

The work support is provided with the usual work engaging plate having parallel slots through which the serrated members of the lower feed dog are permitted to proj ect to engage said work, the work engaging plate being secured to the work support 30 in any suitable manner as by pins or screws.

In order to provide the forward and backward movement of the dog the depending ear 45 is pivotally attached to a member 46 having a cylindrical stem 47 telescopically arranged within a link 48 which. is pivotally mounted upon a stud 49 projecting laterally from a cross head 50 which is secured to the standard 36 by a set screw 51 (see Fig. 5). The link 48 is oscillated about its pivotal support 49 through a link 52 which is pivoted to a forward extension 53 of said member 48, the opposite end of the link 52 being connected to the end of an arm 54 of a rock shaft 55 which is suitably supported in journals depending from the under surface of the bed plate and extends to a floating link 56 having at its upper end a yoke inclosing a cam 57 mounted upon the main shaft of the machine.

The means for adjusting the forward and backward movement of the feed dog preferably comprises a bell crank lever 58 pivoted at its elbow on a stud 59 projecting from the inner portion of the standard, one

arm 60 of said bell crank lever being connected at its extremity to a link (not shown) which in turn is connected to the floating link 56. The other arm of said bell crank lever is provided with an extension 61 projecting through a slot 62 in the standard and provided with a milled screw 63 by which the arm 61 may be clamped in adjusted positions along the slot against the arcuate surfaces 64 of the walls of said slot. By this construction the position of the movable fulcrum of the floating lever 56 may be adjusted in respect to the axis of said link to produce a greater or less upward and downward movement thereof and consequently a greater or less oscillation of the rock shaft to determine the extent of forward and backward movement of the feed dog.

In order to provide for a positive clamping action upon the goods at all times and thus avoid displacement of the relative positions of'the base layer and superimposed layer of the fabric I have devised a novel means for normally forcing the work support against the under surface of the fabric to clamp it against the presser foot during the stitch forming operation combined with means whereby the forcing of the feed dog into engagement with the fabric will cause the withdrawal of the work support from its clamping engagement to permit the advance of the work by the feed dog. This mechanism in the form of the invention illustrated herein comprises a toggle mechanism connecting the feed dog support with the work support so that when either the feed dog or the work support is in clamping relation to the presser foot the other mem-' her will be withdrawn from its clamping engagement.

By this construction it will be obvious that the work will be positively clamped during the movement of the needle in its penetrating action to form the stitch and that it will be withdrawn from such clamping position when the dog rises to clamp the work against the presser foot while it advances the work for the next succeeding stitch.

The toggle mechanism illustrated in the preferred embodiment of the invention shown herein comprises a link pivoted upon a stud 66 projecting from the end of the cross head 50, the upper end of said link being pivotally connected to a boss 67 substantially in the middle of a bell crank lever, one arm of which 68 is pivoted upon a stud 69 secured to the side of the work support 30 the other arm 70 of said lever being pivotally attached to the end of a link 71 which is pivoted at its opposite end to an arm 72 projecting from a split collar 73 which may be adjustably secured by a clamping screw 74; upon a sleeve 75 surrounding the rock shaft The sleeve 7 5 is desirably given a rock ing movement by a link 76 having at its upper end a strap 77 engaging a suitable eccentric 7 8 located upon the main shaft of the machine within the vertical hollow standard 2.

In the operation of the feed dog and the work support the forward movement of the link 71 will cause a shortening of the toggle connection formed by the link 68 and the bell crank lever 70 permitting the work support 30 to be forced against the under surface of the cloth to clamp the same upon the stationary presser foot by the spring 33.

During the time the work is thus engaged between the work support and the presser foot the stitch forming mechanism performs its function of making a stitch either in the superimposed layer or in the base layer as the case may be. ll hen the stitch has been completed the rocking sleeve will be oscillated in the opposite direction straightening the toggle and causing the feed dog to rise and engage the under surface of the work, clamping the work against the stationary presser foot. Further straightening the toggle causes the downward depression of the work support through the cross head 50 and the standard 30 thus removing the work support from its engagement with the under surface of the work. As soon as the work support has released its engagement with the goods the link 52 is advanced by the rocking of the shaft 55 causing the member &8 to be oscillated upon its pivot 4.9 so that its upper portion will advance, the telescopic connection between the parts a7 and 48 permitting the feed dog to advance in a horizontal plane parallel to the work supporting surface of the work support by reason of the guiding action of the members 37, 38 upon the horizontal web 40 of the feed dog support.

By the construction above described a simple and effective means is provided for feeding the work through the machine and this feed alone would be ample for ordinary purposes. I have however found it to be desirable to provide an upper feed dog to co operate with the lower feed dog in its forward movement in order to insure the simultaneous movement of the superimposed layer of fabric with the base layer of fabric. This mechanism comprises preferably a walking feed dog adapted to be forced downward into engagement with the upper surface of the work as the lower feed dog rises to engage the under surface of the work. The upper feed dog is thereupon ad vanced by the lower feed in its forward feeding movement so that the cooperating upper and lower feed dogs move absolutely in unison and their amplitude of movement necessarily is exactly the same.

In the preferred embodiment of the invention disclosed herein the upper feed dog 80 is desirably adjustably secured to the lower end of a link 81 which is secured at its upper end to a stud 82 projecting later ally from the elbow 83 of a bell crank lever the lower arm 84 of which is pivoted to a stud 85 projecting inwardly from the mental front plate 23 the end of the other arm 86 of the said bell crank lever being pivotally connected to a link 87 which is pivotally attached at its opposite end to the end of an arm 88 of a rock shaft 89. The rock shaft 89 desirably is journaled in lugs and 91 projecting laterally from the head and side of the sewing machine arm, and has on its opposite end an arm 92 pivotally connected to a link 93 which has a strap 94: embracing a cam 95 on the main shaft. It will be obvious that the oscillation of the shaft 89 by the cam 95 will cause a substantially longitudinal reciprocation of the link 87 which will rock the bell crank lever upon its supporting pivot 85 and thereby cause the elbow thereof to raise and lower in a substantially vertical plane thus raising and lowering the feed dog support 81 and the feed dog 80 to disengage and reengage the same with the upper surface of the work.

In operation the downward movement of the upper feed dog is timed to correspond with the upward movement of the lower feed dog so that the two feed dogs will approach and simultaneously engage the opposite surfaces of the work. The forward movement of the lower feed dog heretofore described will cause the upper feed cog to be carried with it until it reaches the eX- tremity of its forward movement whereupon the operation of the cam 95 will cause the upper feed dog to be released from the work and simultaneously therewith the lower feed dog will be depressed from its engagement with the lower surface of the work. Upon being released the upper feed dog is permitted to return to its original position preparatory to engagement for the next forward movement. It may desirably be assisted in the return action by a light spring 96 secured to a stud 97 upon the feed dog supporting arm 81 and to a stud 98 projecting from the segmental front plate.

A suitable bender mechanism is illustrated in Figs. 2 and 3 which is adapted to cooperate with the stitch forming mechanism in forming a row of stitches in the lower or base layer of fabric but inasmuch as this forms no part of the present invention, and is included in the companion application above referred to, it need not be specifically described herein.

It is to be understood that the embodiment disclosed herein is illustrative merely but is not restrictive and that this invention may be embodied in other specific forms and that the following claims are intended to cover equivalent mechanical structural features and combinations.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. Feeding mechanism for sewing machines comprising a work support, a feed dog, toggle mechanism connected to said work support and said feed dog adapted to cause relative movement between said feed dog and said work support alternately to raise and lower said work support and feed dog into engagement with the under surface of the work, means for actuating the same and means actuated intermediate of the raising and lowering of said feed dog automatically to advance and to retract said dog.

2. Feeding mechanism for sewing machines comprising a reciprocable work support, an under feed dog movable relatively thereto, toggle mechanism connecting said work support and said feed dog to cause relative up and down movement therebetween, means for actuating said toggle, and means actuated intermediate of successive movements of the feed dog alternately to advance and to retract said dog.

Feeding mechanism for sewing machines comprising a reciprocable work support, an under feed dog movable relatively thereto toggle mechanlsm connecting said work support and said feed dog to cause relative up and down movement therebetween, means for actuating said toggle, means actuated intermediate of said move ments of the feed dog alternately to ad-' vance and to retract said dog, an upper feed dog and means for causing the same to clamp the work against the lower feed dog and to partake of the advancing movement of the lower feed dog.

4:. Feed mechanism for a sewing machine comprising a reciprocable work support, a feed dog pivotally and slidably mounted thereon, a toggle mechanism connecting said feed dog and said work support, means for actuating said toggle mechanism to cause said work support and said dog alternately to engage the goods and means for advancing and retracting said dog.

5. Feeding mechanism for sewing machines comprising a work support and a feed dog pivotally and slidably mounted there on, a rock shaft, means connecting the pivotal support for said feed dog to said rock shaft to cause forward and backward movement thereof, toggle mechanism connecting said work support and said feed dog adapted to raise and lower said support and dog alternately, a rocking sleeve mounted upon said rock shaft, means connecting said sleeve to said toggle and means for actuating said rock shaft and said sleeve.

6. Feeding mechanism for sewing machines comprising a work support, a feed dog pivotally and slidably mounted thereon, a rock shaft, means connecting the pivotal support for said feed dog to said rock shaft to cause forward and backward movement thereof, toggle mechanism connecting said work support and said feed dog adapted to raise and lower said support and dog alternately, a rocking sleeve mounted upon said rock shaft, means for actuating said sleeve and said rock shaft, and means for adjustin the amplitude of vibration of the latter.

chines comprising a work support and feed dog pivotally and slidably mounted thereon, a rock shaft, means connecting the pivotal support for said feed dog to said rock shaft to cause forward and backward movement thereof, toggle mechanism connecting said work support and said feed dog adapted to raise and lower said support and dog alternately, a rocking sleeve mounted upon said rock shaft, means for actuating said sleeve and said rock shaft, and means for adjusting the amplitude of vibration of the latter com prising a floating lever, a cam for vibrating the same and a fulcrum for said lever adjustable relative to the axis thereof to vary its longitudinal movement.

8. Feeding mechanism for sewing machines comprising a work support, a feed dog slidably mounted thereon, means for reciprocating said feed dog in a plane parallel to the work supporting surface of the work support to advance and retract the same comprising an extensible lever pivotally mounted on said work support and con nected to said feed dog, means for oscillating said lever, and means for raising and lowering said feed dog relative to the surface of said work support.

9. Feeding mechanism for sewing machines comprising a work support, a feed dog slidably mounted therein, means for reciprocating said feed dog to advance and retract the same comprising an extensible lever pivotally mounted on said work support and connected to said feed dog, means for oscillating said lever, toggle mechanism for raising and lowering said feed dog relative to the work support and meansfor actuating said toggle.

10. Feeding mechanism for sewing machines comprising a yielda-bly mounted work support having a vertical guideway, a feed dog supporting stand slidably mounted in said guideway and having a horizontal guideway, a feed dog mounted in said h0rizontal guideway, means for causing relative movement between the work support and the feed dog supporting stand to cause said work support and feed dog alternately to engage the work and means for advancing and retracting the feed (10 11. Feeding mechanism for sewing ma chines comprising a yieldably mounted work support having a vertically depending sleeve, a feed dog supporting stand comprising a stem slidably mounted in said sleeve, a horizontal guideway in said feed dog supporting stand, a feed dog mounted in said guideway, a toggle connecting the work support and said stem and means for actuating said toggle whereby the work support and feed dog will alternately be raised into engagement with the work and means for reciprocating said feed dog.

12. Feeding mechanism for sewing machines comprising a yieldably mounted work support having a vertically depending sleeve, a feed dog supporting stand comprising a stem slidably mounted in said sleeve, a horizontal guideway in said feed dog supporting stand, a feed dog mounted in said guideway, a toggle connecting the work support and said stem and means for actuating said toggle whereby the work support and feed dog will alternately be raised. into engagement with the work and means for reciprocating said feed dog, comprising a bell crank lever supported upon said stem, one arm of said lever having a telescopically extensible connection with said feed dog.

13. Feeding mechanisms for sewing machines comprising a yieldably mounted work support having a depending sleeve, a feed dog' supporting stand having a stem slidably mounted in said sleeve, a horizontal guideway upon said stand, a feed dog support having a depending ear slidably mounted in said guideway, a cross-head connected to said stem, a toggle connected to said cross head and said work support, and means for actuating the same, a bell crank lever mounted upon said cross head one arm of said lever having a guideway, a member pivotally mounted upon the ear of said feed dog support and having a stem slidably mounted in said guideway and means for actuating said bell crank lever.

14. Feeding mechanisms for sewing machines comprising a feed dog supporting stand, a feed dog support slidably mounted thereon having a horizontal web, and downwardly extending ribs spaced. apart to form a channel, a member secured to said stand and projecting into said channel to form a guideway for said feed dog support, a feed dog connected to said support comprising extended parallel serrated work engaging faces and a short intermediate serrated work engaging face, means for actuating said feed dog supporting stand to raise and lower said feed dog and means to impart forward and backward movement to said feed dog.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

THOMAS J. HAYES. Witnesses:

FREDERICK A. TENNANT, THOMAS J. DRUMMOND.

Copies of this patent may be obtained for five cents each, by addressing the Gommissioner of Patents,

Washington, D. G. I

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