US3088427A

US3088427A - Stitch regulating device

Info

Publication number: US3088427A
Application number: US18923A
Authority: US
Inventors: Bruscaglioni Raffaello
Original assignee: FILOTECNICA SALMOIRAGHI SpA
Current assignee: FILOTECNICA SALMOIRAGHI SpA
Priority date: 1959-04-07
Filing date: 1960-03-31
Publication date: 1963-05-07
Anticipated expiration: 1980-05-07
Also published as: GB948129A

Description

May 7, 1963 R. BRUSCAGLIONIY STITCH REGULATING DEVICE 2 Sheets-Sheet 1 Filed March 31, 1960 INVENTOR. R. Brusca /c'oni AT ORNEBS y 7, 1963 R. BRUSCAGLIONI 3,088,427

s'rxwcu 'REGULATING DEVICE Filed March 31, 1960 2 Sheets-Sheet 2 INVENTOR. I 32 /Z, z usccz /aong OL- gw A'r-ro rLMESS United States Patent Office 3,088,427 Patented May 7., 1963 3,088,427 STITCH REGULATING DEVICE Raffaello Bruscaglioni, Milan, Italy, assignor to Filotecnica Salmoiraghi S.p.A., Milan, Italy, a firm Filed Mar. 31, 1960, Ser. No. 18,923 Claims priority, application Italy Apr. 7, 1959 4 Claims. (Cl. 112-210) Sewing machines equipped with interchangeable templates, or templates grouped in a pack, for automatic embroidery are commonly known in the art. In these machines the stitch length, or the reversing of the sewing direction, forwards and backwards, is obtained by means of a finger key acting on the template.

In machines of this type, when the operation is not automatic, control of the stitch length is obtained by means of a movable hand-operated knob, which remains inactive during automatic operations, while in other types of machines, a second knob is provided for stitch length control, which knob is also hand operated to act on the machine mechanism, thereby allowing different designs to be obtained with only one template.

According to the present invention, a device has been provided for stitch length control, and for changing of the direction of sewing, in which device the same button for stitch length control provided for non-automatic operation, is used also in the automatic mechanism of the machine in such a manner as to achieve different embroideries with one single template in relation to the position of the knob. A movable lever is also supplied for obtaining the reversal of the sewing direction.

The invention clearly establishes that this device is most suitable, easily operated, and reliable in its operation, and also improves the appearance of the machine.

These and other features will be shown in the following description, with reference to the attached drawings, the description and drawings showing, by way of example, a prepared one embodiment of the invention.

In the drawings:

FIGURES 1 and 2 are respectively a frontal part section view, and a side view of the sewing machine equipped with the device to which this invention pertains.

FIGURE 3 shows a detail of FIGURE 2 with the stitch length control button.

FIGURE 4 is a view on an enlarged scale of the device described in the invention.

FIGURE 5 is a vertical section across line VV of FIG. 4.

As can be observed from the drawings, 1 indicates the sewing machine upright, 2 the base plate, and 3 the cam which controls (in the automatic operation of the machine) the stitch length, and the reversal of the sewing direction (forwards and backwards). The earn 3, which is rotated by shaft 4, imparts an oscillating movement to journal 6 and to the finger key 5, carried on the journal and which engages the peripheral surface of said cam. The finger key 5 is provided withan extension 7, and a hooked finger 8. The extension 7 serves for the engaging or disengaging of the automatic feed movement. For this purpose, an eccentric 9 is provided under said extension 7 upon a journal 10 adapted to rotate on a bush in the machine housing, the latter being controlled by means of a hand operated knob (not shown in the drawing) protruding frontally from the machine casing.

In FIGURE 1, eccentric 9 is shown in the nonautomatic operational phase; with extension 7 resting on eccentric 9, and with the contact finger 5 slightly displaced in respect to the maximum diameter position of the cam.

The hooked finger 8 in turn rests on lever 11 (FIG. 5) fixed to shaft 12, which at one extremity carries a key 13 in such a manner that said lever 11, shaft 12, and key 13 form one single piece.

Shaft 12 rotates on two lugs 14 of afork 15, which in turn is rotatably mounted on a journal 16. This latter is fixed by means of a set screw 41 to a bush 17 of the support 18, which in turn is fixed by means of screws 19 to machine upright 1.

The fork 15 is provided with an oblique arm 20, which carries a small roller 21 at its extremity, and which acts on a suitable slot provided on a plate 24 carried by journal 25, mounted on gearing 26 carried by the support 28. The slot of plate 24 has an internal and external surface, with which the small roller 21 cooperates; these surfaces are so shaped as to obtain, by means of the rotation of said disc 24, control of all the feed motion. To be more precise, the internal surface 22 of the slot provides control of the positive feed (forward sewing), While the external surface 23 provides control of the negative feed (backwards sewing).

In the automatic operation of the machine, or in zigzag sewing or straight line sewing, roller 21 is maintained in contact with the internal surface 22 of plate 24, by a tension spring 27, which at one of its extremities carries a toggle lug fitted to a small journal 28, fixed to fork 15, and at its other extremity, carries a second toggle lug fitted to a small journal 28 fixed to support 18.

An extremity of shaft 30' which is free to move vertically on two bearings 31 of support 18 cooperates with key 13. By means of the action of said key 13, and by means of a rack 32, and a gear 33, the vertical movements of shaft 30 are transmitted to and transformed into angular movements of a forward movement control shaft 34, which by means of units commonly known to those skilled in the art to which this invention pertains, acts on the forward movement bar.

On shaft 34 is mounted a cylindrical spiral tension spring 35, which is fixed at one of its extremities to said shaft, and the other extremity to an extension 36 of the machine base plate, by means of screws 37.

Spring 35 operates to push the shaft 30 upwards, assuring contact with key 13, and as a consequence, provides contact between lever 11 and the hooked arm 8 of the finger key.

On journal 25 is fitted a graduated knob 38; for control of the forward mot-ion amplitude. The knob protrudes from the housing exterior, and is manually revolved relatively to a fixed index 39.

From the description given above, the operation of the device pertaining to the present invention is easily understood.

This device is suitable to control the magnitude of the displacements imparted to the cloth feeder provided under the presser foot of the sewing machine in such a way that the cloth feeder can accomplish oscillations of a predetermined magnitude so as to move the cloth forward or backward for a predetermined length. The

device which control the cloth feeder is of a known type and does not form a part of this invention. Said device also comprises shaft 34 which controls the oscillation or reciprocation of the cloth feeder in combination with the presser foot. During the normal sewing operation, that is when eccentric 9 prevents the oscillation of lever 5 (FIG. 1), spring 27 acts on

lever

15, 20 so that the latter is oscillated in an anti-clockwise direction (FIG. 4) about pivot 16. As a result, pin 21 is always kept engaged with inner spiral profile 22 of disk 24. This profile is so shaped that it defines the normal length of the sewing stitch, when the sewing operation is accomplished in the conventional way. It is possible to adjust the stitch length by rotating knob 38.

In the drawings a line X has been applied between the two

spiral profiles

22 and 23, at which line the stitch length is that is the cloth feeder does not impart any movement to the cloth.

When the cloth feeder is required to reverse to cloth feeding direction, the operator depresses handle 40 and, consequently lever 15--20 is oscillated in clockwise direction (FIG. 4) against the action of spring 27. Pin 21 is, therefore, engaged with the outer spiral profile 23 and the cloth feeder causes the cloth to be moved backwards. Upon the release of handle 40, spring 27 causes the return of lever 15-20 to the starting position at which pin 21 cooperates with the spiral profile 22.

The actuation of handle'40 moves also pin 12 along an arcuated path, the center of which coincides with the axis of pin 16 so that pin 12, by its displacement in clock. wise direction (FIG. 4), causes rocker 1113 to be rotated about a hinge consisting of the end of arm 8 of lever 5, 8 and the end of arm 11 of said rocker. This displacement of pin 12 causes (through end 13 of said rocker) the axial displacement of rod 30 which controls shaft 34 through rack 32 against the action of spring 35; said shaft controls in turn the oscillation of the lever.

The automatic control of the device is similarly accomplished; upon the disengagement of eccentric 9 from projection 7, lever 5, 8 is oscillated by the profile of cam 3. The end of said lever is held in engagement with the profile of cam 3 by spring 35 acting through rod 30 and

rocker

11, 15, on the end of lever 5, 8.

In this case, the profile of cam 3 which is rotated in the direction of the arrow in FIG. 1 causes the oscillation of lever 5, 8 about pivot 6. Accordingly,

rocker

11, 15 is oscillated about pivot 12 and the latter is held stationary 'by means of spring 27 acting on

lever

15, 20 and, consequently, pin 21 is held engaged, as already stated, with inner spiral profile 22. The oscillation of

rocker

11, 15 is transmitted through end 13 to rod 30 which is axially slide against the action of spring 35 whereby shaft 34 is oscillated dependently of the profile of cam 3.

Therefore, the cloth feeder, together with the presser foot, is oscillated for a predetermined magnitude in a direction or in the opposite direction to perform the forward or backward feed of the cloth.

It is apparent that, during the automatic sewing, the smallest length of the sewing stitch which takes place when end of the lever cooperates with the profile corresponding to the greatest radius of cam 3 is adjusted by rotating disk 24 while the cloth feeder accomplishes the greatest displacement. When said end cooperates with the profile corresponding to the smallest radius of said cam, said greatest displacement plus the above displacement allows also a negative motion of the cloth feeder to take place in accordance with cam 3.

The dimension of the various moving units of the above described device are such, that when the finger key 5 is in contact with points of maximum diameter of cam 3, the length of the stitches made by the machine is equal to that indicated on button knob 38. On the other hand, when the finger key 5 is in contact with points of minimum diameter of cam 3, a negative variation in the length of the stitches occurs with respect to that indicated on the button knob 38, which variation amounts to a predetermined value, for example 2 mm.

It is understood that for contact positions between finger key 5 and cam 3, which are between the maximum and minimum diameters of the cam, the continual negative variation of the stitch length will be contained between 0 and 2 mm.

It will be understood, therefore, that with the above described device applied to an automatic sewing machine using one single cam for the forward motion, it is possible to vary the shape and development of an embroidery simply by rotating knob 38 to the different positions indicated on same.

However if the machine is not automatically operated, that is to say when cam 3 is excluded, because of the blockage of the finger key, extremity 7 being under the action of eccentric 9, said button knob 38 serves for manual control of the stitch length, and further, with the movement of a lever 40 applied to fork 15, and which protrudes through an opening in the exterior of upright 1, reversal of the sewing direction is obtained. In fact, the lowering of lever 40 causes the oscillation of the oblique arm 20, and therefore also of fork 15 around the axis of journal 16, until the roller 20 comes into contact with the external surface 23 of disc 24.

The oscillation of oblique arm 20, because of the particular conformation of the two

surfaces

22 and 23, acts in such a manner that on the lowering of lever 40, a reversal of the advance feed by the absolute amount occurs, but in an opposite direction; and the machine carries out backwards stitching with a stitch length equal to that indicated on knob 38.

On releasing lever 40, by means of the action of spring 27, the machine returns to forward stitching, with a stitch length equal to the original length.

It is understood that variations in detail may be made in the device described in the foregoing, without altering the scope of the present invention and the protection rights to which the present invention is entitled, and as defined in the following claims.

I claim:

1. A device for controlling the stitch length in sewing machines comprising in combination with a base plate, an upright supported on said base plate, and a movement control shaft carried by said base plate and extending parallel to said base plate for controlling the feed mechanism, a journal carried by said upright, a finger key pivoted on said journal and having an extension and a hooked finger, a rotary cam supported in said upright and engaging said finger key, another journal supported rotatably in said upright and extending parallel to the first-mentioned journal, an elongated fork supported rotatably at one end on said other journal, said fork havinglugs at its other end, a shaft supported rotatably in the lugs on said fork and extending parallel to said other journal, a lever firmly connected at one end to the lastmentioned shaft, the other end of said lever engaging said hooked finger, a key firmly connected to the lastmentioned shaft, a plate having a slot formed therein, said slot having an inner surface and an external surface, means supporting said plate rotatably on said upright whereby said plate is rotatable in a plane normal to the axis of said other journal, an arm firmly connected to said fork and extending away therefrom alongside said plate, a roller carried by said arm and engaging the inner surface of the slot in said plate, a spring connected to said upright and engaging said fork for maintaining said roller in engagement with said inner surface, a rotary eccentric supported in said upright alongside said finger key extension and in a position whereby said eccentric may be moved into engagement with said extension for moving said finger key out of engagement with said cam, a rod supported slidably in said upright and extending normal to said base plate, a rack firmly connected to one end of said rod, said rod at its other end engaging said key, a gear carried by said movement control shaft and engaging said rack, resilient means connected to said movement control shaft and acting to urge said movement control shaft into rotation for maintaining said rod in engagement with said key, a control knob, means connecting said control knob with said plate for rotating said plate to a predetermined position designating a selected stitch length for providing that when said cam is rotated, said key oscillates causing said rod to slide whereby said movement control shaft rotates a distance equal to the preselected stitch length.

2. A device in accordance with claim 1 wherein rotation of said control knob with said roller engaging the inner surface of the slot in said plate controls the stitch length during forward feed and rotation of said control knob with said roller engaging the external surface of the slot in said plate controls the stitch length during reverse feed.

3. A device in accordance with claim 1 comprising a control lever connected to said arm for rotating said arm whereby said roller may be moved into contact with the external surface of the slot in said plate for reversing the direction of feed.

4. A device in accordance with claim 3 wherein said References Cited in the file of this patent UNITED STATES PATENTS Benink et a1. May 26, 1959

Claims

1. A DEVICE FOR CONTROLLING THE STITCH LENGTH IN SEWING MACHINES COMPRISING IN COMBINATION WITH A BASE PLATE, AN UPRIGHT SUPPORTED ON SAID BASE PLATE, AND A MOVEMENT CONTROL SHAFT CARRIED BY SAID BASE PLATE AND EXTENDING PARALLEL, TO SAID BASE PLATE FOR CONTROLLING THE FEED MECHANISM, A JOURNAL CARRIED BY SAID UPRIGHT, A FINGER KEY PIVOTED ON SAID JOURNAL AND HAVING AN EXTENSION AND A HOOKED FINGER, A ROTARY CAM SUPPORTED IN SAID UPRIGHT AND ENGAGING A SAID FINGER KEY, ANOTHER JOURNAL SUPPORTED ROTATABLY IN SAID UPRIGHT AND EXTENDING PARALLEL TO THE FIRST-MENTIONED JOURNAL, AN ELONGATED FORK SUPPORTED ROTATABLY AT ONE END OF SAID OTHER JOURNAL, SAID FORK HAVING LUGS AT ITS OTHER END, A SHAFT SUPPORTED ROTATABLY IN THE LUGS ON SAID FORK AND EXTENDING AT ONE END TO THE LASTJOURNAL, A LEVER FIRMLY CONNECTED AT ONE END TO LASTMENTIONED SHAFT, THE OTHER END OF SAID LEVER ENGAGING SAID HOOKED FINGER, A KEY FIRMLY CONNECTED TO THE LASTMENTIONED SHAFT, A PLATE HAVING A SLOT FORMED THEREIN, SAID SLOT HAVING AN INNER SURFACE AND AN EXTERNAL SURFACE, MEANS SUPPORTING SAID PLATE ROTATABLY ON SAID UPRIGHT WHEREBY SAID PLATE IS ROTATABLE IN A PLANE NORMAL TO THE AXIS OF SAID OTHER JOURNAL, AN ARM FIRMLY CONNECTED TO SAID FORK AND EXTENDING AWAY THEREFROM ALONGSIDE SAID PLATE, A ROLLER CARRIED BY SAID ARM AND ENGAGING THE INNER SURFACE OF THE SLOT IN SAID PLATE, A SPRING CONNECTED TO SAID UPRIGHT AND ENGAGING SAID FORK FOR MAINTAINING SAID ROLLER IN ENGAGEMENT WITH SAID INNER SURFACE, A ROTARY ECCENTRIC SUPPORTED IN SAID UPRIGHT ALONGSIDE IN FINGER KEY EXTENSION AND IN A POSITION WHEREBY SAID ECCENTRIC MAY BE MOVED INTO ENGAGEMENT WITH SAID EXTENSION FOR MOVING SAID FINGER KEY OUT OF ENGAGEMENT WITH SAID CAM, A ROD SUPPORTED SLIDABLY IN SAID UPRIGHT AND EXTENDING NORMAL TO SAID BASE PLATE, A RACK FIRMLY CONNECTED TO ONE END OF SAID ROD, SAID ROD AT ITS OTHER END ENGAGING SAID KEY, A GEAR CARRIED BY SAID MOVEMENT CONTROL SHAFT AND ENGAGING SAID RACK, RESILIENT MEANS CONNECTED TO SAID MOVEMENT CONTROL SHAFT AND ACTING TO URGE SAID MOVEMENT CONTROL SHAFT INTO ROTATION FOR MAINTAINING SAID ROD IN ENGAGEMENT WITH SAID KEY, A CONTROL KNOB, MEANS CONNECTING SAID CONTROL KNOB WITH SAID PLATE FOR ROTATING SAID PLATE TO A PREDETERMINED POSITION DESIGNATING A SELECTED STITCH LENGTH FOR PROVIDING THAT WHEN SAID CAM IS LOCATED, SAID KEY OSCILLATES CAUSING SAID ROD TO SLIDE WHEREBY SAID MOVEMENT CONTROL SHAFT ROTATES A DISTANCE EQUAL TO THE PRESELECTED STITCH LENGTH.