US2145509A - Auxiliary feeding mechanism for sewing machines - Google Patents

Description

F. EBERT Jan. 31, 1939.

AUXILIARY FEEDING MECHANISM FOR SEWING MACHINES Filed Sept. 30, 1936 2 Sheets-Sheet 1 ,Eerz' ii K any F. EBERT 2,145,509

AUXILIARY FEEDING MECHANISM FOR SEWING MACHINES I lab. 31, 1939.

Filed Sept. 30, 1936 2 Sheets-Sheet 2 51 wad; f

Patented Jan. 31, 1939 $145 50 UNITED sTATEs PATENT OFFIC AUXILIARY FEEDING MECHANISM FOR SEWING MACHINES Fritz Ebert, Oberndorf-on-the-Neckar, Germany Application September 30, 1936, Serial No. 103,431 In Germany October 3, 1935 Claims. (Cl. 112-203) The present invention is an improvement in special auxiliary presser foot pivotally mounted sewing machines as disclosed by U. S. Patent No. thereon; Moreover, this lever is provided with 2,044,275 to Ernst Bucher. a cam or projection cooperating with a cam lever In carrying out the method of producing a mounted and connected to said shaft. Hereby 5 combined joining and covering seam as in said the auxiliary presser foot is swung out as soon a U. S. patent it has been found, that the fabric as, during feeding of the fabric, the normal or fed under a certain angle is distorted by the feed usual presser foot is lifted by means of the pedal used hitherto and cannot be properly fed to the or a knee-lever. As soon as the pressure exerted needle. This drawback is eliminated by the upon the knee-lever or pedal is removed, the

1 present invention. To this end a specially auxiliary presser foot returns again into its in formed auxiliary feed-dog is provided which is Working position under the action of a spring. adapted to swing in a horizontal plane and has Two springs act upon the auxiliary presser foot. its engaging face formed at a desired inclined Th tension f these w p n s may be re uangle. The auxiliary feed-dog cooperates with a la e by ea o screws Which ay easily be 1.; portion of th auxfliary presser foot hi h i reached by a screw driver when a cover plate has 116 capable of yielding in a horizontal plane and been swung outwardly upon its pivot. which alsois inclined under at a desired angle, O Of these springs not only serves the pu so that by this arrangement the fabric is pose of returning the auxiliary presser foot to positively fed towards the first needle in a defiits working po n f r vi en piv te 2o u pgsition, t i important t t t layers 0f but is also adapted to exert the proper pressure lit the fabric be fed simultaneously until directly u ab for the material being t eated- This under the first needle, so that a safe piercing of p s r of h p i s men ion d althe fabric is obtained and turning aside of the ready, be r u ated. fabric is thereby prevented. The pressure of the second spring is weaker,

2s The auxiliary feed-dog is driven by the Well and this p ng only acts, when a cross seam is known carrier bar of the usual feed-dog and at p se e auxiliary D e er o s w one side of said carrier bar an eye is provided ably arra d upon a pin, so that, as soon as a and in which is arranged a guide pin for a slidcross seam comes into the range of the auxiliary m block which i t wjngably arranged in presser foot, the latter swings out, so that the sliding block leveh The front end of t spring is somewhat compressed and the front so guide pin is provided with a flange or collar enen of the uxiliary p r f o ly r s s p n gaging th sliding bl ck l v By thi ea thecross seam, whereas the rear end bears not only is the reciprocating motion of said cara st h fabricy this swingable a rier bar transferred, but also the up and down i the l rypr e oot may adap movements of same. The sliding block lever is e automatically to the w as for a po b eas fixed upon ashaft, m te i th bearing bl k If for instance the cross seam reaches the rear for the trimming mechanism, and this movement end of the auxiliary Dresser foot, t e latter is is transmitted to the feed-dog holder provided at swun b and therefore t t s t me its front the front end so that all movements of the auxn i u d again to Dr ss upon the normal 40 iliary feed-dog are derived from said carrier bar. fabric ayer. This is of gr a s importance for 40 Th amount of differential movement may h a cloth feed free of objections encountered hereadjusted i t well known manner, 7 tofore with machines of the type aforesaid.

The auxiliary presser foot cooperating with the The axis shaft carrying the auxiliary p sser auxiliary feed-dog is resiliently mounted to alfoot also serves as hearing for the cover plate.

low cross seams to pass. For the purpose of in- T e la is h in its ClOSed and pe positions 45 troducing the fabric the auxiliary presser foot by a sp g fixed 110 the bearing block by means may, however, also be pivoted simultaneously of a sc w a d ar against a squ p rtion with the lifting of the normal presser foot for orm With said COVE! plate- The P on of the main feed. For this purpose, a shaft is jourthis cover plate may, therefore, easily be altered.

0 nailed at both front faces of the work support A slot is provided in t bearing b ck to latand upon one end of this shaft a lever is fixed erally limit the cover plate. Against the one engaging a chain which is connected to the lever boundary wall of this slot bears the bearing serving to lift the normal presser foot. At the. member of the'cover plate and against the other other side of the work. support a lever is loosely boundary wall the hub of the lever carrying the t5 pivoted upon this shaft and this lever has the auxiliary presser foot. If the cover plate is swung out, simultaneously the looper for drawing in the thread is rendered easily accessible. Below the auxiliary feed-dog and the resilient auxiliary presser foot, the two knives operate. It is of great importance to interrupt the cloth feed during trimming, so that the horizontally yielding auxiliary presser foot may press the lower part of the fabric edges against the edge of the fixed knife and the upper part of the fabric edges may bear against the edge of tongues adjustably fixed to the throat plate.

To allow for an adjustment of the width of the trimmed off portion, i. e., to prevent an unnecessary broad portion ofthe fabric being cut off and thereby to avoid waste of material, a guide, adjustably mounted in a longitudinal slot, is provided at the front side of the bearing block. This guide is provided with an index mark and may be adjusted from to 10".

In the accompanying drawings, forming part of the specification, one construction according to the invention is shown by way of example.

In these drawings:

Fig. 1 is a perspective view illustrating the most important parts of a machine according to the invention,

Fig. 2 shows, also in a perspective view, the drive of the novel auxiliary feed-dog and also shows the different motions thereof,

Fig. 3 is a perspective view, showing the arrangement of the new auxiliary presser foot including the device for pivoting the same,

Fig. 4 is a perspective view of the throat plate, the bearing block, the guide and the feeding means,

Fig. 5 is a cross-sectional view, showing the manner in which the fabric is fed, held and trimmed,

Fig. 6 is a side elevation, partly in section and showing the resilient arrangement of the new auxiliary presser foot, and

Fig. 7 is an and elevation, partly in section, of the device illustrated in Fig. 6.

The drive and the adjustment of the carrier bar I for the normal feed-dog is obtained in a well known manner as in sewing machines of the aforementioned U. S. Patent No. 2,044,275, and does not form the subject matter of the present invention. At one side of the front end of carrier bar i of the normal feed-dog is formed a split eye 2 in which a guide pin 4 is fixedly mounted by means of a tightening screw 3 bringing the two portions of said split eye toward one another. Formed with and extending from said guide pin 4 is a sliding block 5 moving within a sliding block lever B. Said sliding block 5 is provided on one end with a collar I which, with the aid of said guide pin 4 upon the opposite end of said sliding block 5, causes the longitudinal movement of carrier bar i to be transmitted to the sliding block lever B. Said slidin block lever 5 is adjustably mounted at an angle from vertical upon a shaft 9. A bearing block 8 has said shaft 9 slidably and pivotally mounted therein. At one end of said shaft 9 outside of said bearing block 8 is adjustably mounted a feed-dog holder I0, which feed-dog holder i0 supports an auxiliary feed-dog II, which is adjustable vertically thereon.

Said carrier bar I is normally given both vertical and horizontal reciprocations and, therefore, eye 2 imparts through guide pin 4 to sliding block 5 a vertical as well as a horizontal reciprocation. Inasmuch as sliding block lever 6 is mounted at an angle and said sliding block 5 moves vertically as well as horizontally. sliding block lever 6 is moved radially with respect to shaft 9 and, therefore, shaft 9- receives a'pivotal movement which by connection imparts to auxiliary feed-dog il its work engaging and disengaging movements. The horizontal reciprocations of sliding block 5 impart through sliding block lever 6 to shaft 9 a horizontal reciprocation which in turn through feed-dog holder ll imparts to auxiliary feed-dog ll its feed and return strokes.

The auxiliary feed-dog ll cooperates with a special auxiliary presser foot l3 which is pivotally mounted upon a pin II fixed in a lever II.

The lever i4 is pivotally mounted upon a shaft il arranged in the work-carrying arm I9.

Another pin l9 engaging in a slot I8 of the auxiliary presser foot I3 and mounted in the lever l4 serves to limit the swinging movement of said presser foot i3. In a bore provided in the lever i4 a spring 20 is arranged bearing with one of its ends against a screw 2| adjustably mounted in the bore and with its other end against a downwardly directed projection 22 at the front portion of the auxiliary presser foot. By adjusting the screw 2| the pressure of the spring 20 may be regulated.

Below the spring 20 a stronger spring 22 is arranged in a recess of the lever I4 and this spring bears against a screw 24 fixed in a bore provided in the bearing block 8 for resiliently holding the lever M in position. The pressure of this spring also may be regulated by adjusting the screw 24.

Fixed upon the shaft i1, Fig. 3, is a chain lever 25 engaging a chain 26 serving to lift the normal or usual presser foot. Fixed to the front end of the shaft i1 is a cam lever 21, cooperating with a cam 28 provided on the lever l4. If the pedal or the knee-lever of the chain 26 is operated, the normal or usual presser foot is lifted, simultaneously the movement is also transferred to the lever 25 and thereby to the shaft II. By means of the cam lever 21, the lever I4 is swung against the action of the spring23 and space is thereby obtained at the auxiliary feeddog I l for introducing the fabric.

The two screws 2| and 24 may easily be reached by a screw driver after a cover plate 29 has been swung into its open position. The shaft i1 serves as pivot for the cover plate 29. The latter is provided with a bearing member 30 having a number of flat faces and is loosely pivoted upon said shaft I1. The bearing block 8 is provided with a slot in which the hub of the lever i4 and the bearing member 30 are arranged. The slot in the bearing block 8 thus forms the lateral limitation for this hub and bearing .member. A spring 32, fixed to the bearing block 8 by means of a screw 3|, bears upon a corresponding fiat face of the bearing block 30 and thereby serves to hold the cover plate 29 in an open or closed position. A tongue 34 is adjustably fixed upon the throat plate 33. The tongue 34 mainly serves as cover plate for the auxiliary feed-dog II and simultaneously determines the piercing of the edges of the fabric fed under at a desired angle, because these edges are placed around this tongue and are pressed against this edge by means of the auxiliary presser foot i3.

The auxiliary presser foot l3 also presses the fabric edges against the fixed knife 35, so that the fabric is safely held during trimming, as at this time no feeding is effected by the auxiliary feed-dog. A guide 3!, adjustably fixed in a longitudinal slot 36 by a screw 38, is provided at the front end of the bearing block 8 in order to allow adjustment of the width of the portion to be cut off, which width, by the arrangement described above and serving to safely guide the fabric during trimming, may now be considerably smaller. The guide 31 carries an index mark 39 cooperating with a scale 40 provided at the bearing block 8. By a corresponding adjustment which may be exactly fixed by the scale 40, a portion as small as possible may be trimmed off, whereby a considerable amount of material is saved.

What I claim is:

1. An improvement in a sewing machine of the character described comprising in combination an auxiliary feed-dog, means giving said auxiliary feed-dog a reciprocal feeding motion comprising an eye provided at one side of the normal feed bar of said sewing machine, a guide pin mounted in said eye, a sliding block provided on said guide pin, a sliding block lever having said sliding block workably mounted therein, a collar on said sliding block for retaining said sliding block in said sliding block lever, means connecting said sliding block lever with said auxiliary feed-dog, and an auxiliary presser foot having a pressing surface on one side thereof inclined at a desired angle resiliently mounted for yielding horizontally and for cooperating with said auxiliary feed-dog.

2. An improvement in a sewing machine of the character described comprising in combination an auxiliary feed-dog mounted for swinging horizontally, means in conjunction with said sewing machine for operating said auxiliary feeddog, and an auxiliary presser foot, a lever resiliently and pivotally carrying said auxiliary presser foot, means for operating said lever simultaneously with the raising of the lifting means for the normal presser foot of said sewing ma-- chine and a spring for returning said lever into its operative position upon relief of the pressure on said lifting means.

3. An improvement in a sewing machine of the character described comprising in combination an auxiliary feed-dog mounted for swinging horizontally, means in conjunction with said sewing machine for operating said auxiliary feed-dog, and an auxiliary presser foot, a, lever carrying said auxiliary presser foot, said lever having a projection formed therewith, a cam lever cooperating with said projection, a shaft supported by the work-carrying arm of said sewing machine and having said cam lever mounted thereon, and means operatively connecting said shaft with the pedal for lifting the usual presser foot of said sewing machine in order that both of said presser feet may be moved for introducing fabric to said sewing machine when desired.

4. An improvement in a sewing machine of the character described comprising in combination an auxiliary feed-dog mounted for swinging horizontally, means in conjunction with said sewing machine for operating said auxiliary feed-dog, and an auxiliary presser foot, a lever pivotally mounted within the work-carrying arm of said sewing machine and having said auxiliary presser foot pivotally mounted on the free end thereof, said auxiliary presser foot having a projection formed therewith, a spring mounted within said lever and adapted to bear against said presser foot projection, a second spring mounted within said work-carrying arm and adapted to bear against said lever in opposition to said first spring, and a screw for each of said springs mounted for regulating the tension of said springs.

5. An improvement in a sewing machine of the character described comprising in combination an auxiliary feed-dog, means giving said auxiliary feed-dog a reciprocal feeding motion comprising a bearing block provided at the free end of the work-carrying arm of said sewing machine, a shaft journalled in said bearing block, a sliding block connected to the normal feed bar of said sewing machine for receiving vertical reciprocation, a sliding block lever having said sliding block workably mounted therein and mounted upon said shaft at an angle from vertical, a holder having said auxiliary feed-dog adjustably mounted thereon and fixed to said shaft, and an auxiliary presser foot resiliently mounted for yielding horizontally and for cooperating with said auxiliary feed-dog.

FRITZ EBER'I.

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