US2170948A - Sewing machine - Google Patents

Description

Allg. 29, 1939. c. MEYER 2,170,948

SEWING MACHINE ATTORNEY ug. 29, 1939. c, MEYER 2,170,948

SEWING MACHINE Filed May 20, 1938 2 Sheets-Sheet 2 INVENTOR Ulla/Iles Meyer ATTORNEY Patented Aug. 29, 1939 UNITED STATES PATENT GFFICE SEWING MACHINE Charles Meyer, Yonkers, N. Y., assigner to Bartman & Bixer Inc., New York, N. Y., a. corporation of New York This invention relates to sewing machines, particularly of the type adapted to perform nemnung operations as in the manufacture of curtains.

It is a Well known fact that during the usual hemming operation on curtains, especially those of celanese or similar material, a gathering or warping of the hemmed edge is produced, which cannot be satisfactorily flattened out even by a thorough pressing or ironing thereof. This is l0. generally due to the fact that each stitch during the sewing operation puckers the material slightly, conventional machines not having any instrumentality to prevent such a puckering,l-a condition which has the eiect of producing a rather considerable cumulative gathering throughout the length of the hem. It is primarily within the contemplation of my invention to overcome this shortcoming by enabling material, particularly curtains and the like, to be hemmed at the `edges without any resulting gathering or puckering effect, whereby the nnished product will be perfectly flat and unwarped. 'Ihis I accomplish in my invention by employing a system of rollers located behind the conventional feed dog mechanism, the rollers and the feed dog both being operatively synchronized in accordance with a predetermined setting, and being adapted to coact for effecting a linear feeding movement of the material while it is constantly being kept under tension during the sewing operation. In this manner a pull is applied not only to the material but also to the thread used in sewing, whereby the puckering or gathering in of the material by the thread is obviously obviated.

Cognizance is taken of other roller feed mechanisms, but such devices have heretofore not been coactively synchronized with the conventional serrated dog feed mechanism,-the most common roller feed device being the sole feed employed on the machine, requiring that the material be fed by hand towards the roller immediately after the sewing operation starts. In the device constituting my invention, not only are the rollers cooperatively synchronized with the feed dog mechanism, as aforesaid, but said rollers are in addition independently associated with the drive mechanism of the machine and operable independent of the presser bar mechanism.

In the mechanical embodiment of my invention, a certain tension is, as aforesaid, induced in the material during the sewing operation,an additional objective of this aspect of my invention being the provision of means for varying 5 5 the tension or pull applied to the material, in

accordance with the best practice for different kinds of fabric. I accomplish this result by a mechanism which enables a variation to be effected in the magnitude of feeding pull applied by the roller to the material as it is held between the presser foot and the feed dog; and this is effected by producing various differentials in feeding rates between the roller feed mechanism and the conventional dog feed mechanism.

In the last-referred-to aspect of my invention, it is another object thereof to apply a feeding pull of the roller directly on the stitching line, a result which is rendered possible by a construction employing substantially narrow rollers positioned relatively close to the presser foot.

Another object of my invention is to enable the roller feed mechanism and the conventional dog feed structure to operatively accommodate materials of different and varying thicknesses.

It is also Within the contemplation of this invention to enable tacking operations to be conveniently and readily performed whenever desired, particularly as is frequently necessary in production work where a tacking operation takes place at the end of one piece and is carried over to the beginning of the next piece, the connecting thread to be severed later. It is'particularly my purpose to enable this tacking operation to be performed without interference by the roller feed mechanism, so that the material being sewed can be freely moved forwardly and rearwardly during the performance of this operation.

Another object of this invention is to enable the work to be automatically guided into the feed rollers without the necessity of any careful manual manipulation.

In devices employing feeding rollers it is generally exceedingly difficult to remove the material from the machine inasmuch as the two rollers, which are generally yieldably held together in pressing engagement, must be manually separated. It is hence another objectI of my invention to overcome this difliculty by enabling the 'work being hemmed or sewed to be readily removed without manually manipulating the rollers proper.

And it is within the contemplation of my invention to enable all the foregoing objects to be obtained in a sewing machine in such amanner as to enable it to be readily converted, by a simple manipulation, into one capable of performing only conventional sewing operations.

`Other objects, features and advantages will appear from the drawings and the description hereinafter given.

'In the drawings,

Figure 1 is a side elevation of a sewing machine containing my invention.

Figure 2 is a fragmentary bottom view of Figure 1.

Figure 3 is a front elevation of the sewing machine of Figures 1 and 2.

Figure 4 is a partial sectional plan of Figure 3 taken along line 4-4. y

Figure 5 is a partial section taken along line 5-5 of Figure 4 showing the eccentric and clutch means employed in my invention, and

Figure 6 represents a portion of a curtain with a hemmed edge, containing a line oi' stitching thereon.

In the drawings, the body structure I0 is of conventional sewing machine design, containing a head portion II containing the usual needleactuating mechanism operatively connected in conventional manner to the pulley I2 which in turn is driven by the belt I3 connected to a transmission mechanism or other conventional driving means-these not being shown inasmuch as they are well known in the art. At the lower region of the machine is the gear box I4 containing an arrangement of gears operatively connected to the main drive mechanism, such as by means of gears connected to the shaft upon which said pulley I2 is mounted, such gearing arrangement also being omitted from the drawings because of their conventional construction. The drive shaft I5 operatively connected to the mechanism within gear box I4 and extending along the base of the machine is operatively connected to the feed dog bar I 6 through the eccentric I1 and other conventional mechanism, said shaft I5 also being connected through the gear box I8 to the bobbin container I8, also in conventional manner, and hence need not be described herein in any greater detail.

Mounted upon the drive shaft I5 is an eccentric strap connected to the reciprocating arm 2l which, by means of the pin connection 22 extended through the elongated slot 23 of the rocker arm 24 (see Figures 4 and 5) is adapted to impart an intermittent rotary movement to the clutch mechanism 25 and lupper roller shaft 26 in a manner to be hereinafter described.

It lwill be noted (Figure A4) that the Lsaid rocker arm 24 is shown integral with the rotatable hub 21 which extends into the drum member 28. By referring particularly to Figure 5 it will be seen that said hub member 21 contains four projections 29 in cross formation, providing four chambers 30 within which are operatively accommodated the rollers 3|. 32 of each chamber connecting adjacent projections 29 are somewhat tapered or eccentric with respect to the shaft 26, thereby rendering each of said chambers smaller at one end than at the other. Each of said chambers is also provided with a spring element 33 in engagement with the said rollers. The bushing 34 also projects into said drum-like member 28, as will be clearly seen from Figure 4, and also contains projections similar to those identied by the reference numeral 29, forming chambers therebetween similar to chambers 30 of Figure 5, the floors or bases of said chambers sloping in a direction opposite to that pf bases 32 above referred to. Contained also within the chambers of bushing 34' are the roller bearings 35, as shown in Figure 4. The assembly of bushing 34, drum 28 and member 21 form a conventional roller-wedge-clutch adapted for intermittent op- The base portions eration upon an operative rocking movement of arm 24 in a manner to be hereinafter set forth.

It will be noted that the drum member 28 contains a middle wall 36 into which extends the screw 31 in abutting engagement with the shaft 26, thereby rendering member 28 immovably attached to shaft 28. The set screw 38 extending into the stationary frame 39 is in abutting engagement with the bushing 34, so as to hold it against movement.

The operation of the said clutch 25 can best be understood by considering the movement imparted to rocker arm 24 by the arm 2l due to the eccentric drive. It is obvious that upon a clockwise movement of said arm 24 I(see Figure 5), the rollers 3l will become wedged between the upper and lower walls of the chambers 30 at the reduced portions thereof. But inasmuch as the upper wall of the chamber is part of the drum 28, and the lower wall part of the member 21 actuated by rocker arm 24, a continued clockwise movement of said rocker arm will cause a corresponding movement of the drum portion 28 which will carry with it, through the medium of screw 31, the shaft 26. Inasmuch as the rollers are also positioned within chambers the floors of which are disposed opposite to those identified by reference numerals 32, a continued movement of the drum 28 in the same direction as above referred to will merely cause it to be in rotatable engagement with the said rollers 35 which are now positioned in the enlarged portions of their corresponding chambers, formed by the overhanging flange of drum 23 and bushing 34, which, as aforesaid, is held affixed in place by means of the screw 38. Hence upon a clockwise movement of arm 24, the shaft 26 will also rotate in a clockwise direction within bushing 34 as one of its bearings. In the event however, the said rocker arm 24 is rotated in a counterclockwise direction or moved upwardly (refer to Figure 5) the member 21 will be free to rotate about the shaft 25 while in engagement with the rollers 3| which will obviously be brought to the enlarged portion of their chambers. Under these conditions it is obvious that the drum member 28 will not be operatively actuated by the movement of member 21; and because of such freedom for relative movement, an upward movement of rocker arm 24 will have no effect upon shaft 26. It is thus apparent that shaft 26, with the arrangement illustrated, will be rotatably actuated only when, the rocker arm 24 is moved downwardly in accordance with the position thereof illustrated in Figures 4 and 5.

Positioned at the forward or head portion of the machine and somewhat to the rear of the presser foot 40 are the two feed rollers 4I and 42, -these being yieldably held in engagement and synchrononously actuated in a manner to be hereinafter set forth. In the preferred form of this invention, the upper roller 4I is knurled, whereas the lower roller 42 is preferably smooth. The said upper roller 4I is mounted upon a front shaft 43 which is connected to the said shaft 26 by the intermediate transmission shaft 44 provided at its terminals with the universal joints 45 and 46, the rear end of said shaft 44 being shown connected to a rear shaft 41 provided with longitudinal rods 48 in slidable operative engagement with correspondingly recessed portions in the adjacent terminal of said shaft 26, as clearly shown in Figure 4. The shaft 43 is rotatably supported by a bearing 49 constituting part of the arm 50 which is mounted upon and amxed to the roller lifting shaft 5l. This latter shaft is rotatably supported by the bushings 52 and 53 vmounted within'the tubular support 54 which extends through a suitable aperture in the frame 39 and is held in fixed position with respect thereto by means of the set screw 55.

Surmounted upon said tubular support 54 is the collar 55 which has anchored thereto one terminal of the helical spring 51 mounted' over tube V54 and having its forward terminal suitably anchored to the arm 50, as clearly .shown in Figure 4. Suitably mounted upon said collar 55 and the boss 58 of arm 5|) is the tubular housing 5d which serves not only as a housing for the spring 51 but also as a spacer between the collar 56 and the arm 50. The said collar 56 is rotatably mounted upon the tubular element 54 and adapted `to be held amxed thereto in predetermined position by the set screw B whereby the tension in spring 51 can be regulated by rotatably manipulating the collar 56.

Suitably keyed to the rear terminal of lifting shaft l is the lifting lever 6l which, when moved downwardly or in a counterclockwise direction (see Figures 4 and 5) will obviously cause a rotation of shaft 5I, a consequent lifting of arm 50 and a separation of roller 4l from its coacting roller-42. Positioned preferably above the arm of lever 6| is the eccentric cam 62 engageable with arm 6| upon a rotary manipulation of arm 63. By manipulating said lever 63 upwardly (see Figure 4) it is apparent that the cam portion 62 will serve to move or keep the lever 5| in its lowermost or depressed position. It is thus apparent that if it is desired for any reason whatsoever to maintain the roller 4I in a raised position so that it will not coact with its complementary roller 42 and hence not serve as a feed, an operative manipulation of Alever 63 can readily accomplish this result without in any way affecting any of the other operative parts-of the machine, as will more clearly appear from the description hereinafter given.

The presser footI 40 is operatively connected with the manual presser foot lifter 64 as in most conventional sewing machines. vIn the structure illustrated, the said lifter 64 is operatively engageable with one terminal 55 of the presser foot lever 56 rotatably mounted at 61, the terminal 68 of said lever being suitably attached to the link 69 extending vertically downwardly so that the lowermost terminal thereof is in operative engagement with one terminal of the knee-pres sure lever 1| rotatably lmounted at 12. The forward end 13 of said lever 1| is adapted to be actuated in the direction of the arrow A (see Figure 1) by any conventional means operated by foot vor knee pressure, the details of such construction not being illustrated inasmuch as it is well known in the art. Suitably secured to the link 69 is the block 14 containing pin 15 upon which is rotatably mounted the bar 16 the lowermost terminal thereof containing the elongated slot 11 within which the pin 1B of the arm 6I is slidably movable.

suitably mounted upon the rear portion of shaft 26 is the gear 19 which is in operative engagement with the gear 80 mounted upon the shaft BI to the forward terminal of which the lower roller 42 is attached. The diameters of gears 19 and 80, and of rollers 4l and 42, are so designed that the peripheral speeds of each of the feeding rollers will be exactly equal to each other, so that there will be no slippage between these rollers.

In the operation of this machine, particularly for the formation of hemmed edges, the rollers 4I and 42 are, as aforesaid, in operative engagement under normal working conditions. The material is fed from the platform 82 to the conventional serrated feed dog 83 operatively con- .nected to the aforesaid feed dog bar I E' illustrated in Figure 2. This coacts with the presser foot 40 and the needle 84 in conventional manner to cause stitches to be formed and the ma'- terial to be fed rearwardly. In the construction illustrated and forming part of my invention, the material moves rearwardly under the guidel 85 the terminal of which is positioned near the line of engagement of rollers 4l and 42. As the said movement of the material continues, it is obvious that it will automatically come into engagement with saidrollers which, because of their rotary movement, will coact in feeding the material rearwardly. It will bel observed that both sides of the material are being securely engaged by cooperating feed mechanisms, the upper surface by the rearwardly disposed knurled upper roller 42 and the undersurface by the forwardly disposed serrated feed dog 83,--the said knurled and serrated surfaces reducing the possibility of unwanted slippage. It will further be observed that inasmuch as the said rollers are positioned in close proximity to the base of the presser foot 4U and guide element 85, no manual guiding or careful manipulation of the material by the operator will be'necessary in directing the material from the presser foot region to the feed roller region, the feeding operation from the feed dog to the feed rollers being performed automatically.

In accordance with conventional construction and operation, the rotation of the drive shaft l5 from gear box I4 produces certain rearwardly di rected feed movements of the said feed dog 83, there being generally one such movement for each revolution of the shaft I5. By properly designing and positioning the eccentric 2liv and associated mechanism, operative rotational feed 4movements of both the rollers 4| and 42 can be obtained in predetermined synchronous relation with respect to the aforesaid feed movements of the feed dog 83,-the eccentric movements imparted to the reciprocating arm 2| causing corresponding operative movements of the rocker arm 24 and the uni-directional clutch mechanism above described, and consequently producing `corresponding movements of the parallel roller actuating shafts 26 and 8|. .By this means it is apparent that the feed rollers 4I and 42 are operatively actuated only when the feed dog 83 is actuated, so that both feed mechanisms may operate simultaneously in coactive relation. And by this means the material as Well as the sewing thread are both kept under constant tension during the sewing operation, inasmuch as the roller feed mechanism is continuously applying a feeding pull away from the feed dog mechanism.

In the preferred design of the feed parts, the peripheral feeding movement of the coacting rollers (which control the extent of the linear feed movement imparted to'the material at that point for each operative rotation of the feed rollers) is slightly greater than the feed movement vproduced by the feed dog 83, thereby providing the necessary tension in the material between both feeds. And because of this tension being maintained at all times during sewing, each individual thread, during the creation of a stitch, is prevented from puckering or gathering the material (as is the case where such tension is not v rollers are in actual contact.

present, as indicated during the discussion of the objects of this invention hereinabove given). With the elimination of such a puckering of the material at each stitch, it is obvious that the finish hem will Alie flat and be in an unwarped condition.

It has been found that it is at times necessary to vary the tension thus induced in the material depending upon the nature and property of both the material and thread. 'Ihis can be accomplished by moving the pin 22 into a predetermined position within the slot 23 (see Figures 4 and 5) and immovably aiiixing said pin in such selected position by means of the nut and bolt arrangement 86, whereby the stroke of the rocker arm 24 and consequently the peripheral movement of the shaft 26 and rollers 4| and 42, can be controlled. For example, should it be desired to increase the feeding movement eiiectuated by the said rollers 4| and 42 for each operative revolution of the drive shaft I5, the said pin 22 is moved towards the left of the slot 22 (Figure 5) whereby a greater movement of rocker arm 24 will be obtained, and consequently a greater peripheral feeding movement of the said feed rollers. I

Should it be desired to raise the presser foot 40, such as for tacking operations, this could be accomplished by operating the knee pressure level 1| by any conventional mechanism provided for that purpose. The construction is so arranged that when such pressure is applied, a force in the direction of arrow A (see Figure 1) will be applied to the terminal 13 of the lever 1|, to cause a downward movement of link 69, and a corresponding movement of the block 14 and bar 16. This will cause the upper terminal wall of slot 'I'lto engage the pin 18 and move the arm 6| downwardly (see Figures 1, 3 and 4) in a counterclockwise direction, to cause a corresponding rotation of lifting shaft 5| and an elevation of arm 50 to cause a consequent separation of roller 4| from roller 42,-all against the action of spring 51. This obviously is rendered possible by virtue of the universal connection of shafts 43 and 26 above described.

When the rollers are thus separated it is obvious that they cannot perform any feeding operation, thereby permitting a tacking operation to be effected by the operators moving the material forwardly and rearwardly in conventional manner,this being further rendered possible by the fact that the aforesaid downward movement of link 69 has caused an upward movement of the forward arm of lever 66 and a consequent raising of the presser foot 40. This arrangement is of particular importance in production Work where at unwarped hems must be produced upon a succession of pieces fed through the machine, the tacking operation being performed at the end of one piece and carried over tothe beginning of the new pece,-the connecting threads to be severed at a subsequent time.

I'his device is further adapted to permit the rollers 4| and 42 and the conventional feed mechanism including the presser foot and feed dog 83 to simultaneously accommodate a piece of material of varying thickness. When the material is being fed by the feed dog 83 and has not as yet reached the rollers, the feeding is accomplished in conventional mannenand the As soon as some of the material enters theroller feeding mechanism, the said rollers must of necessity be separated due to the thickness of the material therebetween. 'I'his is rendered possible by the arrangement of the slot 11 which extends below the position of pin 18 in its normal position (Figure 3). When the rollers are separated by the interposition of material as aforesaid, the arm 50 will be rotated in a counterclockwise direction about shaft 5|, permitting a lowering of theV pin 18 within the slot 11. Also, should the material be of varying thickness, the rollers will be permitted to adjustably separate a corresponding amount Vas the material is being fed through, by virtue of the said slot 11.

In the preferred form of this invention, the rollers 4| and 42 are relatively narrow, and are, as aforesaid, relatively close to the presser foot,- thereby providing an operative pull along the line of stitching 96 (Figure 6), and eliminating the danger of an uneven, irregular or wavy stitch line, which might readily result from a wide set of rollers remotely positioned with respect to the primary feed mechanism.

Should it be desired to operate this machine in conventional manner without the use of the roller feed mechanism, all that need be done is to detach the bar 'I6 from the block 14 by removing the cotter pin 8|, and then operativel;vv raising roller 4| through the medium of arm 6| in the manner above describedmaintaining said lever 6| in this position by operatively manipulating arm 63 with its eccentric portion 62, all as aforesaid. The rollers being separated, and the presser foot mechanism being disconnected from the roller feed mechanism, the machine is obviously adapted for conventional operation.

Note should also be taken of the fact that the material being sewn can readily be removed from the machine by simply raising the manual lifting bar 64 or operating the knee presser apparatus in a manner above described, which will cause an elevation of the presser foot 40 and the roller 4 I, thereby enabling the material to be readily disengaged from the machine. In eertain other feed roller devices,particularly the commonly employed type not synchronized with the conventional feeding mechanism but rather exerting an independent feeding pull,-the rollers must be forcibly urged apart in order to remove material therebetween,-a shortcoming which is completely eliminated by my invention.

Although the construction hereinabove described lllustrates the eccentric 20 as being operatively associated with the shaft l5, it is obvious that it can be in operative engagement with other portions or at other points of the main drive, the particular disposition of the said eccentric being merely illustrative of one possible design within the contemplation of my invention. The eccentric motion may obviously be just as readily obtained from the upper shaft along the axis of the pulley l2. also forming a part of the main drive, within the contemplation of this invention.

It is of course understood that the various embodiments above describedv and shown in the drawings are illustrative Aof my invention and not employed by way of limitation, inasmuch as numerous changes and modifications may be made within the scope of the appended claims without departing from the spirit of this invention.

What I claim is:

1. In a sewing machine, a feed dog mechanism, a pair of coacting feed rollers operatively synchronized with said mechanism and adapted to coact therewith for effecting a rearward feeding movement of material being sewed, one of said rollers being positioned above the other, shafts for both of said rollers, actuating means for said mechanism and shafts, an arm rotatably supporting the upper roller shaft and remote from the outer lateral surface of the roller thereon a suitably mounted lifting shaft substantially parallel to the roller shafts. said arm being affixed to the lifting shaft, a lifting lever affixed to said lifting shaft whereby, upon an operation of the lifting lever, said shaft is rotatably actuated to cause a corresponding movement of the arm and roller shaft carried thereby, and yieldable means urging said arm into its lowermost position where both rollers are in operable relation.

2. In a sewing machine, the combination according to claim 1, further provided with a presser foot, a presser foot lifter, a pivotally mounted presser foot lever one terminal of which is operatively engageable with saidlifter, a link connected to the other end of the presser foot lever, actuating means associated with said link, and connecting means between said link and said lifting lever, whereby an operative movement of said actuating means will cause a simultaneous operative movement of the said lifting shaft and said presser foot lifter, together with their associated parts. v

3. In a sewing machine, the combination according to claim 1, further provided with a presser foot, a presser foot lifter, a pivotally mounted presser foot lever one terminal of which is operatively engageable with said lifter, a link connected to the other end of the presser foot lever, actuating means associated with said link, and a detachable bar connecting said link and' said lifting lever, whereby an operative movement of said actuating means will cause a simultaneous operative movement of the said lifting shaft and said presser foot lifter, together with their associated parts; said bar containing an elongated slot therein, and said lifting lever having a pin therein extending through said slot and engageable with the walls thereof.

4. In a sewing machine, a feed dog mechanism, a presser foot, a rearwardly extending guide at the base of the presser foot for directing rearwardly the material being operatively fed through the machine, a pair of relatively narrow feed rollers operatively synchronized with said mechanism and adapted to coact therewith for effecting a rearward feeding movement of said material, said rollers being directly on the stitching line at the rear of the-feed dog mechanism and in close proximity to the rearmost terminal of said guide, actuating means for said feed dog mechanism and presser foot, and independently operable driving means for said rollers for imparting a linear feeding movement thereof greater than that of said feed dog mechanism whereby the material being sewed is kept under tension the juncture of the two rollers `being above the normal level of the material underneath the presser foot while being se'wn.

5. In a sewing machine, a feed dog mechanism, a pair of coacting feed rollers operatively syn- .chronized with said mechanism and adapted to coact therewith for effecting a rearward feeding movement of material being sewed, one of said rollers being positioned above the other, shafts for both of said rollers, actuating means for said mechanism and shafts, an arm rotatably supporting the upper roller shaft, a suitably mounted lifting shaft substantially parallel to the roller shaft, said arm being amxed to the lifting shaft, a lifting lever aflixed to ysaid lifting shaft whereby, upon an operation of the lifting lever, said shaft is rotatably actuated to cause a corresponding movement of the arm and roller shaft carried thereby, and yieldable means urging said arm into its lowermost position where both rollers are in operable relation.

CHARLES MEYER.

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