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Publication numberUS3859939 A
Publication typeGrant
Publication dateJan 14, 1975
Filing dateMar 28, 1974
Priority dateMar 28, 1974
Also published asCA1026626A, CA1026626A1
Publication numberUS 3859939 A, US 3859939A, US-A-3859939, US3859939 A, US3859939A
InventorsHowell Robert B
Original AssigneeHowell Robert B
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Presser foot with flex feature
US 3859939 A
Abstract
In one embodiment, a transverse recess is formed in the upper part of a foot component between its heel and toe portions, to define a relatively thin intermediate portion which can bend upwardly. Another embodiment is longitudinally slotted, dividing it into a plurality of independently flexible beam parts. The foot component has a heel-to-toe downwardly sloping lower presser surface. When the foot component is lowered the toe portion makes contact first and the intermediate portion bends so that the presser surface comes to rest generally flat on the material being sewn. A region of increased material thickness passing under the toe portion raises the toe portion and causes additional bending to occur in the intermediate portion. When the increased thickness approaches the rear end of the foot component it lifts the presser bar upwardly against a biasing spring. The toe region remains in contact with the fabric because of the heel-to-toe sloping nature of the presser surface.
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[ Jan. 14, 1975 United States Patent [191 Howell, Robert B.

the upper part of a foot component between its heel and toe portions, to define a relatively thin intermediate portion which can bend upwardly. Another embodiment is longitudinally slotted, dividing it into a plurality of independently flexible beam parts. The foot component has a heel-to-toe downwardly sloping lower presser surface. When the foot component is lowered the toe portion makes contact first and the intermediate portion bends so that the presser surface comes to rest generally flat on the material being sewn. A region of increased material thickness passing under the toe portion raises the toe portion and causes additional bending to occur in the intermediate portion. When the increased thickness approaches the rear end of the foot component it lifts the presser bar upwardly against a biasing spring. The toe region remains in contact with the fabric because of the heelto-toe sloping nature of the presser surface.

c0 306 4 w l E WZW U M 8 l M Hb, ll U U 50 n s T W h m 0 4 m d O m um E0 M 5 m J u n m" mm a H m "m m a 11 T" L .l u A" a S R CB r H 4 m m u P m S w m w MI t M "m mm d& B a "n" C ad r. W 8 mu" A w .l.. 23 e C h T n 5 .nu rTio Cm y 9 U. SRH lr HM h M R.... o mm R ru 4 In we m R: H89 m Er NHH it em ..N. u uaw mm, dl. d I m w sum 26 E Pm FA UIF NB W 7.. a" 1 9 r 4m 2 H. 1 m Mm 57 22 555 5 rt [rl [It [[rt 3 PA ABSTRACT In one embodiment, a transverse recess is formed in t 10 Claims, 9 Drawing Figures l PRESSER FOOT WITH FLEX FEATURE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to presser feet for sewing machines, and in particular to the provision of an improved type of presser foot which is especially adapted for sewing materials which include areas of uneven thickness.

2. Description of the Prior Art My prior presserfeet, are disclosed by US. Pat. Nos. 3,251,326; 3,259,090; 3,342,151; 3,349,736; 3,473,498; 3,511,197; 3,511,199; 3,511,200; 3,511,201; 3,716,008; 3,726,243 and 3,754,519.

US. Pat. Nos. 3,511,199; 3,511,200; 3,511,201; and 3,716,008 of this group disclose presser feet which include means for pivotally mounting the foot component onto its mounting shank, to better adapt the foot component for sewing material which varies in thickness.

US. Pat. Nos. 601,402; 1,820,496; 2,718,857;

2,968,267 and 3,495,560 disclose presser feet which include some sort of spring mountingfor a foot component.

SUMMARY OF THE INVENTION The presser foot of this invention is of molded plastic construction and is generally similar to the styles of presser feet disclosed by my aforementioned US. Pat. Nos. 3,342,151; 3,349,736 and 3,473,498. However, unlike such prior feet it is characterized by a reduced thickness intermediate portion between its heel and toe portions which is adapted to function as a leaf spring. It also includes a heel-to-toe sloping presser surface which together with said spring section better enables the presser foot to be used for sewing materials which vary in thickness.

One form is also characterized by longitudinal slots dividing it into aplurality of beam sections. Such foot exerts a downward pressure on the fabric on both sides of the sewing path, even when there is a difference in material thickness between the two sides.

The illustrated embodiments are presser feet which are especially adapted for use in installing and finishing invisible or concealed zippers. It is believed that incorporation of the invention into such a foot results in a muchimproved zipper foot in comparison to rigid feet. Objectionable puckering is not experienced, even when sewing light weight fabrics. However, it is also believed that the basic principles of the invention may be incorporated into standard presser feet and into other types of specialty presser feet as well.

These and other features of the invention are exemplified by the embodiment described below with reference to the drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary pictorial view taken in the needle region of a sewing machine, such view showing a presser foot attachment according to the present invention installed in an operative position for sewing a tape of an invisible zipper, and showing the needle in reference;

FIG. 2 is a side elevational view of the presser foot attachment of FIG. 1, showing the presser foot attachment in an elevated position, and the needle assembly in reference;

FIG. 3 is a view like FIG. 2, but showing the presser foot attachment lowered into pressing contact with a fabric article;

FIG.'4 is a view like FIGS. 2 and 3, but showing the foot component deflected upwardly by an increased thickness area of the fabric article;

FIG. 5 is a view like FIGS. 24, showing the increased thickness area repositioned to the rear of the foot component;

FIG. 6 is a bottom plan view of the foot component;

FIG. 7 is a pictorial view of a modified form of foot component, taken from the same aspect as FIG. 1;

FIG. 8 is a front elevation view of the foot of FIG. 7 being used to install a zipper tape; and

FIG. 9 is a bottom plan view of the foot shown by FIGS. 7 and 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT The first illustrated embodiment of presser foot attachment comprises a mounting shank l0 and a foot component 12. The mounting shank 10 may be like anyone of the mounting shanks disclosed by the aforementioned US. Pat. No. 3,342,151. Foot component 12 includes a transverse slide bar 14 which fits in a transverse slideway 16 formed at the lower end of mounting shank 10. The lower end portions of mounting shank 10 which define the slideway 16 function in the nature of a friction clamp. The foot component 12 can be pushed sideways for the purpose of overcoming the friction and moving the foot component 12 in position relative to the mounting shank 10 and the needle N.

The foot component includes a heel portion 18 to which the slide bar 14 is attached, a toe portion 20, a reduced depth intermediate portion 22, and a sloping lower surface 24. The foot component 12 is formed from a suitable structural plastic (e.g., delrin acetyl resin, manufactured by the DuPont Company). The upper intermediate portion of the foot component 12 is recessed during manufacture to form the relatively shallow intermediate section 22 (e.g., about 40/ 1000 of an inch in thickness at y).

FIG. 2 shows the attitude of the foot component when it is attached to the mounting shank l0 and the presser bar (not shown) to which the mounting shank 10 is connected is raised. In preferred form, the slide bar 14 and the upper surfaces of the foot component 12 are parallel to the upper surface 26 of the sewing machine. The lower presser surface 24 of the foot component 12 is manufactured to extend at a relatively shallow acute angle x (e.g., 94) from both the sewing machine surface 26 and the upper surface of slide bar 14.

The first illustrated embodiment is a presser foot that is especially designed for installing an invisible or concealed zipper. The foot component 12 includes four parallel guides. These consist of side guides 30, 32 and bottom guides 34, 36. Needle recesses 38, 40 are fonned in the side parts of the toe portion of foot component l2 and a needle receiving opening 42 is formed vertically through the toe portion 20 of the foot component 12. The bottom guides 34, 36 are in the nature of parallel grooves formed in the lower forward portion of the foot component 12, on opposite sides of a downwardly projecting divider 44. The divider stops at the needle receiving opening 42. The roof. area 46 behind the needle N is elevated so that it does not contact the upper surfaces of the zipper teeth 48. The foot component 12 is open between the side parts of the reduced depth central portion 22. No contact is made by the foot component 12 .with the zipper teeth 48 in this region nor in the heel region where the slide bar 14 is spaced substantially above the path of the zipper teeth. The only frictional contact between the foot component and the zipper teeth 48 during passage of the zipper teeth 48 through the avenues commencing with the guide grooves 34, 36 occurs in the channel regions 34, 36 generally forwardly of the needle N.

Referring to FIG. 2, when the foot component is elevated above the sewing machine surface 26 the lower presser surfaces 24 of the foot component 12 slope downwardly from the heel 18 to the toe 20. When the presser bar is lowered the toe portion 20 contacts the upper fabric member 50. The depth of the heel portion 18 is such that when the presser bar is lowered the reduced depth section 22 will flex to place the lower presser surfaces 24 down flat against the upper pieceof fabric 50. v

In FIGS. 1 thepresser foot attachment is shown being used for sewing a zipper tape 50 onto a fabric member 52. The zipper teeth 48 are secured to the zipper tape 50. The zipper teeth 48 pass through guide avenues 34. The tape 50'extends laterally from teeth 48 and below guide avenue 36 and the presser surface 24 located laterally outwardly from guide avenue 36. During the sewing operation the needle N operates within the opening 42, closely adjacent the zipper teeth 48.

When the material 50, 52 which passes below the foot component 12 is of uniform thickness the presser surfaces 24 are substantially parallel to the sewing machine surface 26. However, they apply a larger pressure against the fabric members 50, 52 in the region of the needle N than they do rearwardly of such region, due to the heel-to-toe sloping nature of the presser surfaces 24. As previously mentioned, when the presser bar and mounting shank connected thereto are lowered, the reduced depth portions 22 of the foot component 12 flex an amount sufficient to lower the surfaces 24 generally flat against the upper fabric member 50.

When an increase thickness or bulge portion 54 of the fabric members 50, 52 passes under the toe portion 20 of the foot component 12, it raises the toe portion 20 an amount substantially equal to the increased thickness. The foot component 12 flexes an additional amount in the regions 22, to prevent upward movement of the toe portion 20. The downward pressure is maintained on the fabric members 50, 52 forwardly of the needle N, so that the presser foot continues to function as a means for forcing the fabric members 50, 52 against the advance dogs AD which move members 50,

. 52 past the needle. When the bulge 54 approaches the rear of the foot component 12 it comes close to being in line with the spring bias presser bar which is diagrammatically shown at 56. Its increased thickness raises the presser bar upwardly, compressing the loading spring 58. Owing to the heel-to-toe sloping nature of the presser surfaces 24, the forward part of the foot component 12 continues to exert a downward pressure on the fabric members 50, 52. As the bulge 54 moves rearwardly, the bending of the reduced depth portion 22 is relieved and the forward or toe portion of the foot component 12 settles downwardly on the fabric.

Since the presser bar is spring loaded it bounces up and down in response to movement of the advance dogs AD. However, experience has shown that this movement of the presser bar cannot take care of all problems associated with a variance in thickness of the material.

The presser foot embodiment shown by FIGS. 7 9, as a second example of the invention, is also adapted for sewing zipper tapes onto a piece of fabric.. Only the foot component 60 is shown. It is mounted onto the presser bar of a sewing machine by a mounting shank like shank 10 in FIG. 1 or like any one of the mounting shanks disclosed by the aforementioned US. Pat. No. 3,342,151.

Foot component 60 includes a transverse slidebar 62 at its rear which is like slide bar 14. Slide bar 62 is secured to the upper portion of the foots heel 64. Forwardly of the heel 64 the foot component 60 is longitudinally slotted at 66 and 68, to divide the foot component 60 into three cantilever beam sections 70, 72, 74. Preferably, the footcomponent 60 is constructed to have a heel-to-toe downwardly sloping lower presser surface, the same as the embodiment shown by FIGS. 1 6. When attached to the presser bar, the foot component 60 would, in side elevation, occupy essentially the same attitude as foot 12 when in the various conditions depicted by FIGS. 2 5. Thus, side elevation views of foot component 60 are unnecessary and are not presented herein.

Specifically, it is the side beams 70, 74 which provide the lower presser surfaces. It is the lower surfaces of these beams 70, 74 which preferably slope downwardly from theheel portion to the toe portion of the foot. As illustrated, these beam parts 70, 74 are of reduced thickness in comparison with the total depth of the foot component (such as measured between the top of beam section 72 and the level of the bottom surfaces of beam sections 70, 74). The beam section 72 has an upper panel part 76 which is also of reduced thickness in comparison with such dimension of the foot component 60.

The central beam part 72 has a depending forward portion 78. Portion 78 in the embodiment illustrated by FIGS. 7 9 is configured to provide guide avenues 80, 82 for the two chains of slide fastener elements of an invisible zipper. These avenues are formed on opposite sides of a divider 84. The two sloping side walls of divider 84, the roof surfaces of front end member 78 on opposite sides of the divider 84, and the adjacent inside surfaces of the forward end or toe portions of beam members 70, 74 define the two guide avenues 80, 82.

A needle receiving aperture 86, corresponding to aperture 42 in the embodiment of FIGS. 1 6, is provided vertically through beam member 72 rearwardly of front portion 78. Aperture 86 is flanked by two needle receiving recesses 88, 90, respectively formed in the two beam members 70, 74. Recesses 88, 90 correspond to recesses 38, 40 in the embodiment of FIGS. 1 6.

As shown by FIG. 8, when the foot component 60 is moved downwardly onto the material, the three beam members 70, 72, 74 will each flex independently of the others. The side beams or 74 (74 in FIG. 8) which contacts the increased thickness of material (due to the presence of the zipper tape 50) must flex a greater amount than the opposite side beam 70, or 74 (70 in FIG. 8) which rests down upon the fabric member 52 to which the zipper tape 50 is being sewn. However,

both side beam members 70, 74 apply a downward presser on the material on both sides of the needle N,

so that both sides of the material 52 are urged against the advance dogs AD. The central beam member 72 is able to deflect upwardly if necessary in order to adjust itself to differing sizes of zipper teeth. The contact made between this beam member 72 and the zipper teeth occurs only at the front end portion 78. Rearwardly of front end portion 78 the roof of beam member 72 in the tunnel or passageway for the zipper teeth or slide fastener elements is elevated above the slide fastener elements so there is no frictional contact between the two. The relatively small amount of friction which occurs between the front end portion 78 of beam member 72 and the slide fastener elements is not large enough to produce objectionable puckering or to impede the relative movement of the slide fastener elements through the zipper foot.

. The embodiment shown by FIGS. 7 9 is also preferably constructed from structural plastic, and may be injection molded.

One important feature of the zipper feet styles that are illustrated is that they enable a single zipper foot to be used for sewing several zippers of differing tooth size. The guide avenues are designed to guide teeth of a given size. Then, if the foot encounters teeth of a slightly larger size, the teeth act in the same manner as a bulge and cause the foot to flex upwardly, raising the guide avenues so that they ride along the upper portions of the teeth. This of course results in an increase pressure between the zipper and the foot and hence some increased friction where contact is made. However, the elimination of frictional contact behind the needle compensates for the increase in friction where the foot 12 contacts teeth forwardly of the needle. In other words, the increase in friction has been adequately compensated for by a decrease in the area of frictional contact.

The foregoing description and the accompanying drawing together disclose specific embodiments which are within the scope of the present invention. The following claims, benefited by the doctrine of equivalents, serve to define the scope of the invention.

What is claimed is:

l. A presser foot component for a sewing machine equipped with a spring biased presser bar, a material advance mechanism, and a reciprocating needle assem' bly, and attached to said presser bar by a mounting shank, said presser foot component comprising:

a relatively thick and stiff heel portion connectable to the mounting shank, a relatively thick and stiff tow portion, a relatively thin and flexible interme diate portion spanning between said heel and toe portions, and a heel-to-toe downwardly sloping lower presser surface, with the dimensions of said foot component and the slope of said presser surface being such that when the foot is mounted onto the presser bar of a sewing machine, and such presser bar is lowered, the intermediate portion will bend upwardly and the presser surface will press generally flat onto the fabric being sewn, and when an increased thickness portion of the fabric passes under the toe portion said intermediate portion will flex an additional amount and the toe portion will rise upwardly, and when the increased thickness portion approaches the rear end of the presser surface it will move the presser bar upwardly against its spring and the toe portion will continue to make contact with the fabric because of the heel-to-toe sloping arrangement of the presser surface.

2. A presser foot component comprising:

a body including a heel portion by which the foot is mounted, a relatively thick and stiff toe portion, a relatively thin and flexible intermediate portion located inbetween said heel and toe portions, and a heel-to-toe downwardly sloping lower presser surface, with the dimensions of said foot component and the slope of said presser surface being such that when the foot is mounted onto the presser bar of a sewing machine, and such presser bar is lowered, the intermediate portion will bend upwardly and the presser surface will press generally flat onto the fabric being sewn, and when an increased thickness portion of the fabric passes under the toe portion said intermediate portion will flex an additional amount and the toe portion will rise upwardly, said foot portion including at least one bottom guide groove for receiving an invisible zipper chain, and said flexible intermediate portion comprising two laterally spaced apart side portions, with a space existing between said side portions through which the zipper chain passes.

3. A presser foot attachment for a sewing machine equipped with a spring biased presser bar, a material advance mechanism, and a reciprocating needle assembly, said attachment comprising:

a mounting shank connectible to the presser bar; and

a presser foot component connectable to said mounting shank, said component including a heel portion by which it is mounted, a relatively thick and stiff toe portion, a relatively thin and flexible intermediate portion located inbetween said heel and toe portions, and a heel-to-toe downwardly sloping lower presser surface, with the dimensions of said foot component and the slope of said presser surface being such that when the foot is mounted onto the presser bar of a sewing machine, and such presser bar is lowered, the intermediate portion will bend upwardly and the presser surface will press generally flat onto the fabric being sewn, and when an increased thickness portion of the fabric passes under the toe portion said intermediate por tion will flex an additional amount and the toe portion will rise upwardly, and when the increased thickness portion approaches the rear end of the presser surface it will move the presser bar upwardly against its spring and the toe portion will continue to make contact with the fabric because of the heel-to-toe sloping arrangement of the presser surface, said foot portion including at least one bottom guide groove for receiving an invisible zipper chain, and said flexible intermediate portion comprising two laterally spaced apart side portions, with a space existing between the said side portions through which the zipper chain passes.

4. A presser foot component comprising:

a body having a heel portion by which the foot component is mounted, said body being longitudinally slotted forwardly of said heel portion, to divide the body into at least two side beam parts and an intermediate beam part between said side parts, each of which parts extends forwardly from said heel portion in cantilever fashion;

each said beam parts being flexible so thatduring use each will independently flex in response to variations in thicknesses of an object below it; and

a needle receiving space formed vertically through said foot component laterally between said side beam parts.

5. A presser foot component according to claim 4, wherein at least the two side beam parts each has a heel-to-toe downwardly sloping lower presser surface, with the dimensions of said foot component and the slope of said presser surface being such that when the foot is mounted onto the presser bar of a sewing machine, and such presser bar is lowered, the beam parts will bend upwardly and the presser surface will press generally flat onto the fabric being sewn, and when an tween said two side beam parts and rearwardly of the guide groove through which the zipper chain passes.

7. A presser foot component according to claim 6, wherein each said beam part includes a toe portion, the intermediate beam part includes the said guide avcnue in its toe portion and includes a relatively thin elevated panel behind its toe portion, below which said zippcr chain space is defined.

8. A presser foot component according to claim 7, wherein the toe portions of said side beam parts are relatively thick and said side beam parts each has a relatively thin and flexible intermediate portion between its toe portion and the heel portion of the foot component.

9. A presser foot component according to claim 8,

' wherein the toe portion of said intermediate beam part includes a downwardly depending divider, providing a zipper chain guide avenue on each of its sides.

10. A presser foot component according to claim 9, wherein each zipper chain guide is laterally outwardly bounded by a toeportion of one of the side beam parts.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,859,939 Dated January 1 1975 Inventor(s) Robert B. Howell It is certified that error'appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 53, change "3/ to 3 4 Column 5, line 52, change "tow' to toe Signed and sealed this 1st day oi April 1975.

C. ELXRSZTAILL DJLIZIT TJJ'EEI C. iL-KJOZT coi'missionor oi Patents :LttQ-Stlfii; .x. floor Trad-exerts FORM PO-IOSO (10-69) uscMM Dc s76 pgg ".5. GOVIINIIIIIT PRINTING OFFICE "I! 0-8G-ll4.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US601402 *Sep 14, 1896Mar 29, 1898 Presser-foot for sewing-machines
US3349736 *Oct 22, 1965Oct 31, 1967Howell Robert BZipper foot attachments
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3967567 *Mar 7, 1975Jul 6, 1976Wm. E. Wright Co.Unitary adaptor for presser foot attachment
US4411211 *Oct 22, 1981Oct 25, 1983Optilon W. Erich Heilmann GmbhMethod of and apparatus for attaching slide fastener coupling chains to a flexible support
US4704781 *Jul 31, 1986Nov 10, 1987Opti Patent- Forschungs-Und Fabrikations-AgProcess and apparatus for mounting a slide fastener near opposing edges of two pieces of material
US7914296 *Jan 5, 2010Mar 29, 2011Exatron, Inc.Interconnecting assembly with conductive lever portions on a support film
CN102691180A *Jun 14, 2012Sep 26, 2012吴江伊华丽丝绸时装有限公司Height-adjustable presser foot
CN103750585A *Jan 21, 2014Apr 30, 2014广东溢达纺织有限公司Auxiliary sewing fixture and device
WO1996010348A1 *Sep 16, 1995Apr 11, 1996A. Raymond & CiePlastic fasteners sewable on textile materials
Classifications
U.S. Classification112/235
International ClassificationD05B29/06, D05B29/08, D05B29/00
Cooperative ClassificationD05B29/06
European ClassificationD05B29/06