US3113535A

US3113535A - Buttonhole foot with cutting blade for sewing machines

Info

Publication number: US3113535A
Application number: US86649A
Authority: US
Inventors: Bono Luigi
Original assignee: Necchi SpA
Current assignee: Necchi SpA
Priority date: 1960-07-22
Filing date: 1961-02-02
Publication date: 1963-12-10
Anticipated expiration: 1980-12-10
Also published as: GB937680A; BE605325A; AT241251B; CH389372A

Description

Dec. 10, 1963 L. BONO 3,113,535

BUTToNHoLF FooT WITH CUTTING BLADE FoR SEWING MACHINES Filed Feb. 2. 1961 if Se $16.1 e

INVENT OR Bono ATTORNEYS United States Patent O BUTINHJE FT WITH CUTING BLADE FR SEWENG MACHENES Luigi Bono, Pavia, Italy, assigner to Necehi Societa per Azioni, Pavia, Italy Filed Feb. 2, wel, Ser. No. 86,649 Claims priority, application italy July Z2, 19.66 8 Claims. (Cl. lli-68) This invention relates in `general to new and useful irnprovements in sewing machine attachments, and more particular Ito a novel attachment for cutting a buttonhole in fabric subsequent to the sewing of the outline of the buttonhole.

A primary object of this invention is to provide a novel blade attachment for mounting on .a sewing machine particularly adapted for sewing the outlines of buttonholes, and which blade attachment is positioned for cutting ythe necessary -buttonhole in fabric prior to the removal of the fabric from the sewing machine.

Another object of this invention is Ito provide a buttonhole forming foot for sewing machines, which foot is provided wi-th a simple .pivotally mounted blade which may be readily pivoted from a stored position to a projecting fabric cutting position.

Another object of the invention is to provide a blade attachment for a sewing machine for outting fabric in the formation of a buttonhole, the mounting of the blade being very simple to occupy a minimum of space and the blade normally being disposed in a stored out of the way position.

Yet another object of the invention is to provide a *cutting blade for a sewing machine button hole attachment the blade being mounted for pivotal movement to a position where a point of the blade penetrates the usual needle slot in the needle plate and is retained in this fixed position during the fabric cutting operation wherein scratching or otherwise damaging of the needle plate is prevented.

Still another object of the invention is to provide a blade for cutting buttonholes in fabric, the blade being urged 4to `a stored position and there being means for autornatically urging the blade towards the stored position at the end of a cutting opera-tion.

A further object of the invention is to provide a novel blade assembly for cutting buttonlroles in fabric, the blade of the blade assembly being normally spring urged to a stored position and being held in an operative position by lthe fabric being cut.

Another object of this invention is to provide novel Imeans for cutting but-tonholes in fabric, which means includes a blade, a slide movable with fabric during the sewing of the outline of a buttonhole, and the slide having means for controlling the cutting operation of the blade to limit the cutting operation to the desired buttonhole area.

A still further object of the invention is to provide a novel cutting attachment for use with a sewing machine attachment for automatically sewing the outlines of buttonholes, the cutting attachment being controlled by a slide movable with the fabric, the slide having Iboth sewing machine control means and `cutting blade control means thereon.

With the above, and other objects in View that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the Ifollowing detailed description, the appended claims and the several views illustrated in the accompanying drawing.

In the drawing:

FIGURE l is a side elevational view of a presser foot formed in accordance with the invention `and incorporating a fabric cutting blade.

ice

FEGURE 2 is a horizontal sectional view taken along the line ll-ll of FIGURE 1 and shows the presser foot in plan.

lFIZGURE 3 is a longitudinal vertical sectional view taken along the line lill-lll of FIGURE 2.

,FEGURE 4 is a longitudinally ysectional view showing portions of the structure of -FlGURE 3 on a large scale and in conjunction -with a needle plate and fabric.

FlGURE 5 is an enlarged fragmentary transverse sectional view taken along the line V-V of FIGURE 4 and shows the spring loaded mounting of the blade.

FIGURE 6 is an enlarged fragmentary horizontal sectional view taken along the line V-l-Vl of FIGURE l and shows the details of a drum assembly.

FEGURE 7 is a schematic view showing the details of stitching for outlining a buttonhole.

Reference is now made to the drawing wherein it is shown that 4the invention includes a support "l which is secured to the usual presser bar 2 in the customary manner by means of a screw 3. The support ll carries a horizontal pin 4i at the bottom thereof, and a sole plate 5 is pivotally mounted relative to the support l by means of the pin d.

The support i also carries a second horizontal pin 6 on which there are pivotally mounted two artrns '7 of a small support 5. A cutting blade 9 is secured to the support `ti by 4means of screws lil. The shape of the support l, as is best shown in FlGURE 3, is such that in the rest position of the blade 9, the -blade 9 is disposed within the general yconfines of the support and therefore does not constitute a hazard to the hands of an operator of the associated sewing machine.

The blade 9 is held in the rest position by a small spring ll carried by the pin 6. As is best shown in vFlGURE 5, the spring il is generally disposed within the support l and is coiled about the pin 6. One end l2 of the spring l1 is anchored within la groove ld in the support l and the other end 13 is disposed in a bore .l5y in an ar-rn of the support il.

The support 8 has a handle lo projecting to one side thereof (FIGURE 2) to facilitate the rotation of the support 8 and the blade 9 to a position (FIGURE 4) where the blade 9 passes through fabric 17. The point l of the blade 9 enters into the usual needle slot 19 of the customary needle plate 2i?. The needle slot 19 receives the needle 21 in the operation of the sewing rnachine.

When the cutting blade 9 is lmoved to the fabric penetrating position shown in dotted lines in HGURE 4, the spring l1 urges the blade 9 to the rest position. However, when the fabric 17 is moved in the direction x (FIGURE 3), the fabric 17 exerts a pressure on the blade 9, as occurs in a normal `fabric slitting or cutting operation and this pressure opposes the tendency of the blade 9 -to rotate to the rest position, and the blade `9 is held in an operative position until the cutting of the fabric 17 is completed. When the cutis completed, the retarding force on the blade 9 no longer exists, and the spring il automatically returns the blade to the rest position.

The aforementioned components dene the simplest form of the invention. The presser or buttonhole foot 5 may be provided 'with means Afor controlling the length of cut formed by the blade 9 in the fabric l? and aligning the cut with the button-hole stitching. To this end there is provided a generally channel shaped cross sectional slider 22. The slider 22 has opposed longitudinal grooves 23 and -24 in which the longitudinal edges of the sole plate 5 engage. The slider 22 has toothing 2S formed on the underside thereof for interlocking the slider 22 with the fabric 17 so that the two move together with the fabric being guided by the slider 22` as it is fed by the sewing machine in the operation thereof.

The feeding of the fabric 17 is effected by means of conventional feed dogs (not shown) which protrude from the needle plate 2t and advance the fabric 17 together with the `slider 22. The feed dogs will be of the type which will feed the fabric i7 both forwardly and rearwardly, and the feed dogs are mounted for retraction to permit the manual movement of the Ifabric while it remains clamped between the needle plate Ztl and the slider 22.

The slider 22 carries a pair of stops 27 and 2S. The stop 27 is fixed and is disposed at the right end of the slider. On the other hand, the stop 23 is adjustable longitudinally of the slider 22, the stop 28 being carried by a block 29 which is adjustably secured to the slider 2.2 by a screw 31 passing through a slot 3b in an upstanding flange of the slider. The stops 27 and 28 are adapted to engage the

ends

32 and 33, respectively, of the sole plate and thus limit the movement of the slider 22 relative to the sole plate 5. ln this manner the length of the buttonhole 34 (FGURE 7) may be controlled by the seamstress. if desired, a graduation (not shown) is provided adjacent the lslot of the slider 22 to indicate the position of the screw 31 to which the length of the buttonhole corresponds.

Referring to FIGURE 7 in particular, it will be noted that the two bar tacks 35 and 36 of the buttonhole 34 are made when the sole plate 5 is substantially in engagement with the stops 27 and 28, respectively, and the buttonhole 34 is closed along the line y.

After the stitching of the buttonhole 34 has been completed, including the edge stitching 37, the sewing machine is stopped and the fabric feed dog (not shown) is lowered below lthe needle plate 2l) to permit the manual sliding of fabric 17 Irelative to the needle plate in 4the direction of the arrow x in FIGURES 3 and 4. The cutting blade 9 is then lowered to its dotted line position of FIGURE 4 to penetrate the fabric i7 at the line y (FIGURE 7). The fabric 17 is then displaced by hand, together with the slider 22, with the result that the blade makes the desired length of cut between the two edge stitchings 37 of the buttonhole 34.

Although the fabric 17 may be directly pulled by hand, in order to facilitate the movement of the fabric 17 and the slider 22, there are provided on the slider 22 two outwardly projecting ns 38, best shown in FIGURE 2, which may be grasped by the seamstress.

The slider 22 carries a second adjustable block 4i) which is adjustably secured to the slider by a screw 39 which passes through a longitudinal slot in the slider 22, the slot not being illustrated in the drawing. The block 40 carries an inclined plate 41 which prevents the cutting blade 9 from cutting portions of the bar tack 35 by mistake. When the movement of the fabric 17 brings the bar tack 35 near the blade 9, an appendage 42 of the blade 9 (FIGURE. 2) engages the inclined plate 41 and urges the blade 9 up out of the fabric 17, after which the blade 9 is moved to the rest position thereof by the spring 1l.

When a new buttonhole is to be made, it is necessary to raise the entire buttonhole foot by elevating the presser bar 2 in the normal manner. The fabric 17 can now be shifted or removed and replaced. The slider 22 is then shifted so that the stop 28 thereon is in engagement with the end 33 of the sole plate 5, after which the buttonhole foot is ready to be lowered into engagement with the fabric.

The return of the slider 22 to its initial position with the stop 2S engaging the end 33 of the sole plate may be automatically accomplished. To this end a bracket 43 is secured to the left end of the slider 22. as an extension thereof. As is best shown in FIGURE 6, a horizontal pin 44 is secured to the bracket 43 by a screw 45'. A drum l5 is journalled on the pin lll and has a groove 47 in which there is wound a portion of a small cable ,liasse l- 43 'which has the free end t' ereof connected to the pin l of the support All.

A spring `49 is seated in the end of the `drum 46 adjacent the bracket and encircles the pin 44. One end of the spring 49 is fastened in a slot Sli of the pin 44. The other end of the spring 49 is seated in a hole 51 in the drum 46. The spring 49 is tensioned and tends to wind the cable 4S in the groove 47 and urge the slider 22 in a direction opposite to the direction of the arrow :c in FIGURE 3 to force the stop 28 against the end of the sole plate 5.

rIhus when the slider 22 is released following a fabric cutting action, the slider Z2 is automatically returned to the initial position thereof. Accordingly, when a new buttonhole is to be formed, it is merely necessary'to lower the foot so that the slider 22 clamps the Ifabric i7 against the needle plate 2t).

The button-hole foot of this invention can be usefully employed to automatically make the buttonholes 34. This can be accomplished by utilizing a sewing machine mechanism such as is described in my copending application Serial No. 71,043, tiled November 22, 1960. In such event, a lever 52 is pivoted to the support l by means of a pin S3. The lever 52 tends by its own weight or through the action of a spring (not shown) to rotate in the direction of the arrow w (FIG. l) insofar as this is permitted by the groove 5@ in which a pin 55 carried by the support l is seated.

The lower end of the lever 52 carries a feeler Se. rl`he feeler 56 is engageable with two inclined surfaces S7 and 53 carried by the slider 22 to pivot the lever 52 in a direction opposite to the direction of the arrow w. The upper end 59 of the lever 52 is connected to means of the sewing machine not shown in the drawings but described in my aforementioned patent application, Serial No. 711,643, such that when the lever 52 moves against the

inclined planes

57 and 58, there is controlled the production of the two conventional bar tacks of the buttonhole, and that when the lever 52 leaves the inclined planes, there is controlled the making of the two conventional lateral braids of the buttonhole, so that the sewing machine automatically makes buttonholes of a length equal to the distance between the inclined planes 57 and :"SS. The two

inclined surfaces

57 and 58 should obviously be arranged on the slider 22 so as to engage the feeler Se and thus rotate the lever 52 when the sole plate 5 is near the

stops

27 and 2 of the slider 22. It will be apparent that the inclined surface S3 should be adjustable relative to the slider 22, as is the stop 28, and to this end the inclined surface 58 is formed directly on the block 29 which is adjustable relative to the slider 22.

It will be apparent that the presence of the two

inclined surfaces

57 and 53 cooperating with the lever 52 to make the forming of the buttonhole 34 completely automatic, makes it possible to eliminate the stops 27 and 28, if desired. The presence of the two stops 27 and 2S is, however, useful since it prevents the slider 22 from becoming separated from the sole plate 5.

lt will also be understood that the

inclined surfaces

57 and 58 could be replaced by two simple pins or similar means against which one end of the lever S2 could strike. This would be necessary if the lever S2 should have to rotate first in one direction and then the other with respect to the intermediate rest position in order to act on the means of the sewing machine for controlling the production of a buttonhole.

Although a preferred form of the invention and example modifications thereof have been disclosed, it is to be understood that other minor modifications of the invention may be made in accordance with the spirit and scope of the invention, as deiined in the appended claims.

I claim:

l. A buttouhole foot for a sewing machine comprising a sole plate, a support carrying said sole plate and hava ing means thereon for attachment to a presser bar, a blade, means pivotally mounting said blade on said support for pivotal movement to a fabric penetrating position Within the connes a sewn outline of a buttonhole for cutting the fabric in response to movement of the fabric in the general direction of the buttonhole, together with a fabric gripping slider slidably mounted on the sole plate, and cooperating stop means on said sole plate and said slider to limit the movement of the slider and fabric engaged by the slider to control the length of the cut formed by the blade in the sliding of the fabric.

2, The buttonhole foot of claim 1 together With means adjustably mounting one of said stop means to Vary the length of cut.

3. The buttonhole foot of claim l together with means on said slider to act on the blade to rotate the blade out of the fabric at the end of the desired cut.

4. The buttonhole foot of claim 1 together with means on said slider to act on the blade to rotate the blade out of the fabric at the end of the desired cut, said means including an inclined member on said slider and an appendage on the cutting blade.

5. The buttonhole foot of claim 1 together with elastic return means for said slider for automatically returning the slider to a starting position.

6. The buttonhole foot of claim 1 together With elastic return means for said slider for automatically returning the slider to a starting position, said elastic return means including a spring urged drum and a cable.

7. The buttonhole foot of claim 1 together with a control lever associated with said slider for eiecting the automatic operation of the associated sewing machine.

8. A buttonhole foot for a sewing machine compris- 6 ing a support having upper and lower ends, means at the upper end of said support for attaching said support to a conventional presser bar, a small sole plate, means at the lower end of said support mounting said sole plate, a blade, means carried by said support normally mounting said blade in overlying relation to said sole plate for swinging movement to a fabric penetrating position beyond said sole plate remote from said support, and a larger fabric gripping slider underlying said sole plate, said slider having edge guide portions engaging edges of said sole plate and mounting said slider on said sole plate for guided sliding movement.

References Cited in the le of this patent UNITED STATES PATENTS 312,932 Ulmer et al Feb. 24, 1885 332,676 Pratt Dec. 15, 1885 421,463 Williams Feb. 18, 1890 735,699 Bissinger Aug. 11, 1903 887,503 Nelson May 12, 1908 949,401 Nelson Feb. 15, 1910 1,475,235 Mattingly Nov. 27, 1923 1,535,025 Martinek Apr. 21, 1925 1,727,807 Bunin Sept. 10, 1929 2,548,361 Ginwright Apr. 10, 1951 2,581,046 Rich Jan. 1, 1952 FOREIGN PATENTS 569,762 Italy Nov. 26, 1957 OTHER REFERENCES Berthold: German application, 1,044,570, printed Nov. 20, 1958, K1. 52 a 18/08.

Claims

1. A BUTTONHOLE FOOT FOR A SEWING MACHINE COMPRISING A SOLE PLATE, A SUPPORT CARRYING SAID SOLE PLATE AND HAVING MEANS THEREON FOR ATTACHMENT TO A PRESSER BAR, A BLADE, MEANS PIVOTALLY MOUNTING SAID BLADE ON SAID SUPPORT FOR PIVOTAL MOVEMENT TO A FABRIC PENETRATING POSITION WITHIN THE CONFINES A SEWN OUTLINE OF A BUTTONHOLE FOR CUTTING THE FABRIC IN RESPONSE TO MOVEMENT OF THE FABRIC IN THE GENERAL DIRECTION OF THE BUTTONHOLE, TOGETHER WITH A FABRIC GRIPPING SLIDER SLIDABLY MOUNTED ON THE SOLE PLATE, AND COOPERATING STOP MEANS ON SAID SOLE PLATE AND SAID SLIDER TO LIMIT THE MOVEMENT OF THE SLIDER AND FABRIC ENGAGED BY THE SLIDER TO CONTROL THE LENGTH OF THE CUT FORMED BY THE BLADE IN THE SLIDING OF THE FABRIC.