US2557992A - Reverse stitch attachment for sewing machines - Google Patents

Description

June 26, 1951 L. J. NILLES 2,557,992

REVERSE STITCH ATTACHMENT FOR SEWING MACHINES Filed June 22, 1948 2 Sheets-Sheet 1 mmvron m NARD J-muxs L. J. NILLES REVERSE STITCH ATTACHMENT FOR SEWING MACHINES June 26, 1951 2 Sheets-Sheet 2 Filed June 22, 1948 INVENTOR. ILLE s LEONARD J.

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ATTORNEYS l atentecl june 26, 1951 REVERSE STITCH ATTACHMENT FOR SEWING MACHINES Leonard J. Nilles, Chicago, Ill.

Application June 22, 1948, Serial No. 34,461 9 Claims. (01. 112-210) This invention relates to sewing machines, and more particularly to attachments for such machines to facilitate reverse stitching.

It is a general object of the present invention to provide a novel and improved reverse stitch attachment for sewing machines.

More particularly it is an object of the invention to provide a reverse stitch attachment adapted to be easily applied to certain types of household sewing machines without requiring any machining operations and which is provided with a single adjustment means to simultaneously set to the same length both the forward and reverse stitches and with a lever to permit rapid change from forward to reverse.

An important feature of the invention consists in the provision of a reverse stitch attachment providing a replacement for the adjustable slotted guide block and cooperating roller which is mounted on the eccentric follower link to determine the stitch length, whereby this block may be given a greater degree of angular adjustment to provide the same range of stitch lengths in both forward and reverse directions, and fitted with operating means for the block, attached to the machine by the original stitch adjusting screw, and including single stitch-adjusting mechanism for simultaneously setting identical stitch lengths for both forward and reverse stitching.

Another important feature of the invention comprises the journalling of the slotted guide block of the attachment in the bearing provided for the original block and in the use of external linkage to rotate the same from a quick acting reverse lever spring-biased to forward stitch position and instantly movable to the other position from which it is automatically returned when released.

One of the features of the invention resides in the stitch length adjusting means associated with the reverse lever and including a cooperating adjusting screw and lever stops arranged in a V.

Another feature of the invention resides in the arrangement of the mounting plate for the stitch adjusting lever whereby it cooperates to support the lever, the stitch length adjusting screw and the bias spring.

Still another feature of the invention resides in the construction and arrangement of the parts permitting accurate and indicated stitch length adjustment even at extremely fine stitch settings.

Other and further objects and features of the invention will be more apparent to those skilled in the art upon a consideration of the following specification and accompanying drawings Wherein is disclosed a single exemplary embodiment of the invention with the understanding that such changes and modifications may be made therein as fall within the scope of the appended claims without departing from the spirit of the invention.

In said drawings:

Fig. 1 is a fragmentary front elevation of a commercial form of sewing machine equipped with a reverse stitch attachment constructed and mounted in accordance with the present invention and adjusted for forward stitching;

Fig. 2 is an end, elevation thereof, the main drive shaft being sectioned on line 22 of Fig. 1;

Fig- 3 is a generally longitudinal vertical section taken on broken line 33 of Fig. 2 and illustrating the mounting and assembly of the several parts;

Fig. 4 is a transverse vertical section taken on line 4-4 of Fig. 1 and illustrating the stitch regulating mechanism of the sewing machine;

Fig. 5 is an enlarged transverse section taken on broken line 5-5 of Fig. 1 and looking in the direction of the flywheel, illustrating the stitch length adjusting mechanism and forward adjustment biasing spring; and

Fig. 6 is a section on broken line 66 of Fig. 5 illustrating the cooperation of the V-stops with the adjusting screw.

Most conventional household machines are not adequately equipped with facilities for adjusting the length of stitch nor for reversing the direction of stitching. The stitch setter on the average household sewing machine requires the operation of a very fine threaded screw in order to adjust the stitch length, and delay results when making a considerable change in stitch length. Most of these devices are not arranged to permit passing the stitch length controlling means over the center or minimum stitch length position to effect reversing the direction of stitching. Such reversing is desirable in most cases and is much used in commercial work, for instance to finish off the end of a seam, thus eliminating the need for tying or otherwise fastening off the ends of the threads.

Even if the usual screw type of adjustment is arranged for reversal, its use is not feasible, be-

cause of the long time required to make the' change, and because of the difficulty or impossibility of providing for the same length stitch both in the forward and reverse directions. In order that the finish of a seam present a good appearance the reverse stitches should be put in the same holes as the forward stitches. The apparatus of the present invention is designed as an attachment to supplant the usual stitch adjusting mechanism on a conventional household type of sewing machine, and makes use only of openings and fastening means already available on the machine, so that no machining, drilling, boring or the like is required to apply the same to such a sewing machine. The attachment provides lever adjustment of stitch length for rapid changes and also provides for the use of the lever to reverse the direction of stitch while insuring the same size stitches in the reverse direction as were being made in the forward direction.

In the several views of the drawing the invention is illustrated as applied to a well known household type of sewing machine having the usual bed plate Ill on which is secured the standard H supporting the transverse arm H2, in which is journalled the main shaft i3, carrying the usual hand wheel I4.

As shown particularly in Fig. 4 the sewing machine is originally equipped with a transverse rock-shaft l8 journalled beneath the bed plate and associated through mechanism (not shown) with the usual feed dog, for the fabric, which oscillates and is raised and lowered beneath the presser foot for normally feeding the fabric. The arc of oscillation of this shaft 16 determines the length of stitch and the phase of its movement in relationship to the mechanism which raises and lowers the feed dog (not shown) determines the direction of feed.

Shaft i6 is oscillated by means of the attached lever I! having link [8 pivoted thereto at l9. A forked upper end 20 on the link includes parallel follower faces 2! which engage eccentric 22 mounted on main shaft I3 of the machines. The direction of oscillation imparted to head 20 by eccentric 22 is horizontal as will be seen from an inspection of Fig. 4. In order to impart a vertical component thereto to actuate the arm I! on shaft I3 resort is had to a mechanism well known in the sewing machine art and including a roller 24 best shown in Fig. 3 mounted near the upper end of link 18 by means of a bolt 25 and appropriate nut. The roller is adapted to travel in a close fitting transverse slot 2'! in a block 28 having a stem 29 projecting at right angles to the slot axis.

In the sewing machine as originally manufactured the outer end of stem 29 is fitted with a lock nut or the like to maintain it in position in the bearing hole 30 prepared for it in the side of the standard II of the sewing machine. In the initial equipment an operating arm projects downwardly from the block 28 and has a forked end straddling groove 32 on the inner end of fine-pitched screw 33 threaded through an opening in the boss 34 in the forward face of standard H and fitted with a large knurled head 35 by which adjustments of stitch length in a forward direction only were effected by rocking the block 28 to change the angle of the slot 21. When this slot is horizontal or on the axis the upper end of link I8 moves only horizontally and no oscillation is given to shaft [6. As the block 28 is rotated so that its slot axis approaches the position indicated at A, the length of stitch is gradually increased to a maximum since the lateral movement imparted to the head of link i8 is converted more and more to vertical movement.

In accordance with the present invention lever movement is substituted for screw adjustment to permit much more rapid operation of the adjustment. At the same time the range of adjustment of block 28 is increased to permit its angularity to the zero position to be as great in one direction as the other. Thus it may also be adjusted to the position shown by the line B which gives as great stitch length in reverse direction as adjustment to position of line A gives in forward direction.

In the original installation on the sewing machine the axis of rotation of roller 24 coincides with the axis of the bolt 25 and this in combination with the relative position of the axis of the slotted block permits only adjustment of the slot from a horizontal or zero stitch length position, as shown by the line 0 in Fig. 4 to the position shown by line A. In order to use bearing opening 36 in the standard for the stem 29 of the enlarged slotted block forming part of the attachment of the present invention, resort is had to substituting the roller and mounting combination shown mounted on link (8 in the drawing. Here the eccentricity of roller axis and bolt axis allows adjustments of the roller to a position for cooperation with new slotted block 28 whereby both forward and reverse operation become available. The substituted slotted block has increased overall dimensions and the inner end of its shaft 29 is extended to provide a reduced diameter portion 3'! which receives the hub 40 of a short crank 39 held in position by an axially arranged screw 4!, best seen in Fig. 3. A suitable key 38, which may be integral with extension 31, engages a keyway in the hub bore to prevent relative rotation. The outer end of arm 39 is provided with a pivot 42, to which is articulated a link 43 pivoted at its opposite end 44 to one arm of actuating lever 45, shown in greater detail in Fig. 5.

This lever 45 is a bell crank pivoted at 46 against the inner face of a flange on a mounting plate 41. Such a plate, illustrated in Fig. l, is made of stiff sheet metal and includes the front portion E9, flat and rectangular, having suitable aperture 53 therein, as seen in Fig. 4, to be received over adjusting screw 33, for the stitch length changing mechanism originally on the sewing machine, and clamped against boss 34 by head 35 of the screw. A wing or flange 5| is bent rearwardly at right angles to and from the outer edge of the front portion 49 and extends alongside of the standard II, as seen in Fig. 2, so that the pivot therein for the bell crank lever is parallel to shaft 13 of the sewing machine. The pivot 44 for the link 43 is fastened to the shorter, downwardly directed, rear arm 52 of bell crank lever 45 whereas the longer front arm 53 passes out through a slot 54 on front plate 49 and is formed to provide a convenient finger piece 55.

Movement of the lever 45 and consequent rotation of the axis of the slot in block 28 from the position A to the position B, throughout the full range thereof, causes adjustment of stitch length from a maximum forward to a maximum reverse. The ends of slot 54 limit the throw of lever 45 in either direction, and helical spring 56, secured between an extension tab 58 on flange 5i and an opening 59 in portion 52 of the lever, always biases the latter toward forward stitch direction.

As before mentioned it is highly desirable that the stitches made in reverse direction be of the same length as those just completed in the forward direction, and for that purpose a unique adjusting means is provided to insure identical settings of the lever on opposite sides of the center position as the result of a single stitch length adjustment. This is effected by arranging a pair of diverging stop wings or flanges 60 and 61 on lever 45. The lever is made from sheet metal, as clearly seen in the drawings, and these stop wings are conveniently bent one from each arm thereof and at an angle of substantially 60 to each other, as best illustrated in Fig. 6. They are arranged to alternately cooperate with the pointed tip 62 of an adjusting screw 63, which is threaded through a collar 64 secured on a tab 65 depending from the lower edge of main portion 49 of the base plate and angled backwardly therefrom. A helical spring 61 between the enlarged knurled head 68 of screw 63 and the face of tab 65 insures fixit of adjustment.

Whatever the adjustment of screw 63, the stop wing 6| will be held against the pointed end thereof by bias spring 5'! thereby insuring forward feed of the fabric to the machine for such a stitch length as determined by the setting of adjusting screw 63. This adjusted length may be indicated On the front of the base plate by means of appropriate indicia 15 which may indicate stitch length in stitches per inch if desired.

The angularity and relative positions of the stop wings 63 and 6| are such that, when finger tab 55 is lifted until stop Wing 50 engages pointed tip of adjusting screw, 63, the slotted block is rotated to the same degree of angularity of slot to horizontal but in the reverse direction. This guarantees the same length stitch in reverse as was achieved in the forward direction so that reverse stitches are threaded through the same holes as those made during the previous forward stitching.

The attachment is simply applied to a sewing machine of the type shown by first removing and discarding the slotted block and its lever and taking out the stitch-length adjusting screw 33. The original roller and bolt near the upper end of link [8 are removed and discarded and roller 24 and its bolt 25 substituted and adjusted, which latter is facilitated by the nut-like head 45 of bolt 25 to which the roller pivot is secured. The new slotted block is positioned in its bearing with the roller and slot cooperating. The face plate is applied and secured by screw 33 and the hub 40 of lever 39 secured to the projecting end of stem 29 by its screw-pivot. The machine is now ready for operation in the improved manner permitted by the attachment.

In order to operate a sewing machine provided with the attachment of the present invention,

the operator merely manipulates the adjusting screw 63 to set the length stitch desired in sewing the fabric as indicated by the scale adjacent the lever 55. When the end of a seam is reached and it is desired to fasten the thread, the operator stops the machine, lifts the finger tab 55 of lever 45 to the maximum permitted by the setting of screw 53, holds it in that position and stitches back for the distance desired to fasten off the thread. The machine is again stopped and the lever 55 is released, which returns the adjustment for normal forward stitching when the machine is again to be used.

I claim:

1. A reverse feed and stitch regulator attachment for a conventional sewing machine having a standard supporting a head in which the main shaft is rotatably mounted, said standard having a bearing opening parallel to the axis of said shaft and having an adjusting-screw hole in the front face thereof; said attachment including a slotted block adapted to be mounted in said standard for stitch length control in both forward and reverse directions, a stem extending from said block for mounting in said bearing opening, a lever having a hub for attachment to said stem outside said standard, a mounting plate having an opening adapted to receive the said adjusting screw to secure the plate to the standard, a flange projecting rearwardly from said plate and alongside the standard, a control lever pivoted to said flange and having a finger piece extending through a slot in the plate, a link connecting said control lever to the first lever for adjustment of the slotted block in either direction from a zero stitch length position, and means biasing the lever-link system toward forward-stitch position for the block.

2. The attachment as defined in claim 1 in which a single adjustable stop is provided on said plate for said control lever and stop wings so positioned on said control lever for cooperation with said stop that for each setting of the stop, maximum movement of the control lever in one direction provides the same stitch length adjustment as maximum movement in the opposite direction.

3. The device as defined in claim 2 in which the single stop is a screw disposed radially of the pivot of the control lever.

4. The attachment as defined in claim 1 in which cooperating stop means are provided on the said plate and control lever, one of said means being bifurcated to straddle the other to provide lever stopping at opposite sides of a position corresponding to the zero position of said block, said stop means being relatively adjustable toward each other along an axis radial to the lever pivot.

5. A stitch regulator and feed reverser attachment for a conventional sewing machine having a standard journalling a main shaft, said standard having a bearing therethrough with its axis parallel to that of the shaft, and having an adjusting screw threaded in a hole in the front of the standard, said attachment including a substi-.

tute slotted block having a stem arranged to pass outwardly through said bearing, a lever having a hub for attachment to said stem outside the standard, a bellcrank lever, a link connecting one end of the bellcrank to the end of the first lever, a plate having an opening to receive the said adjusting screw to secure the same on the front face of said standard, said plate having a rearwardly directed flange and a vertical slot adjacent thereto, means pivoting said bellcrank against the inner face of said flange with the opposite end thereof extending through said slot to cooperate with a scale on the plate indicating stitch length adjustment for forward sewing, said scale also indicating the position for said bell crank lever opposite end to adjust for reverse stitching.

6. The device as claimed in claim 5 including cooperating stops on the bell crank lever and plate adjustable to stop the bell crank lever at any desired indicated stitch length.

'7. The device as claimed in claim 6 in which means is provided to bias the bell crank lever against the stop for forward sewing.

8. The device as claimed in claim 5 in which the bell crank lever is fitted with a pair of diverging stop wings, a stop screw adjustable toward and from the bell crank lever pivot for engagement selectively by said wings, said wings being so positioned on the bell crank lever as to fix the stitch length the same forward as reverse for any one setting of the stop screw, and a flange on 7 said plate having threaded engagement with said stop screw.

9. The device as claimed in claim 5 in which the bell crank lever is fitted with a pair of diverging stop wings, a stop screw adjustable toward and from the bell crank lever pivot for engagement selectively by said wings, said wings being so positioned on the bell crank lever as to fix the stitch length the same forward as reverse for any one setting of the stop screw, a flange on 10 said plate having threaded engagement with said stop screw, and spring means biasing said bell crank lever toward forward stitch adjustment.

LEONARD J. NILLES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number

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