US3618547A

US3618547A - Zipper foot attachments

Info

Publication number: US3618547A
Application number: US869836A
Authority: US
Inventors: Robert B Howell
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-10-27
Filing date: 1969-10-27
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09

Abstract

The foot component has a front end which is spaced rearwardly of the needle. Channellike guide means are provided at such front end for twisting the zipper teeth as they pass therethrough into an attitude which will result in the zipper teeth adjacent the needle being properly oriented for close-to-the-teeth sewing. No pressure is applied to the zipper tape in the region of the needle. This enables the operator to exert a slight amount of tension on the zipper tape and the material to which it is being sewn, in opposition to the pressure forces of the foot and the advancing force of the advancing mechanism, for maintaining the tape and material substantially straight while it is being sewn.

Description

United States Patent [72] Inventor Robert B. Howell 2115 Madrona Point Drive, Bremerton, Wash. 98310 [21] Appl. No. 869,836

[22] Filed Oct. 27, 1969 [45] Patented Nov. 9, 1971 [54] ZIPPER FOOT ATTACHMENTS 6 China, 9 Drawing Figs.

[52] US. Cl. 112/240 [51] Int. D051) 29/12 Primary Examiner-Patrick D. Lawson AnomeyGraybeal, Cole & Barnard ABSTRACT: The foot component has a front end which is spaced rearwardly of the needle. Channellike guide means are provided at such front end for twisting the zipper teeth as they pass therethrough into an attitude which will result in the zipper teeth adjacent the needle being properly oriented for close-to-the-teeth sewing. No pressure is applied to the zipper tape in the region of the needle. This enables the operator to exert a slight amount of tension on the zipper tape and the material to which it is being sewn, in opposition to the pressure forces of the foot and the advancing force of the advancing mechanism, for maintaining the tape and material substantially straight while it is being sewn.

ZIPPER FOOT ATTACHMENTS CROSS-REFERENCES TO RELATED APPLICATIONS This is a continuation-in-part of my copending application Ser. No. 764,453, entitled Presser Foot Mounting, and filed Oct. 2, 1968. It is also a continuation-in-part of my copending application Ser. No. 764,518, entitled Presser Foot Assemblies and filed on Oct. 2, I968.

U.S. Ser. Nos. 764,453, and 764,518 were both filed as continuation-in-part applications of my copending application Ser. No. 678,742, entitled Installation of Concealed Zippers and Presser Foot Attachments, filed Oct. 27, 1967, as a continuation-in-part of my then copending application Ser. No. 501,066, entitled Zipper Foot Attachment, filed Oct. 22, 1965, as a continuation-in-part of my earlier copending application Ser. No. 475,486, filed July 28, i965 and entitled Universal Presser Foot Attachment.

Application Ser. No. 475,486 issued as U.S. Pat. No. 3,342,151 on Sept. 19, 1967. Application Ser. No. 501,066 issued as U.S. Pat. No. 3,349,736 on Oct. 31, I967. Application Ser. No. 678,742 issued as U.S. Pat. No. 3,473,498 on Oct. 21 1969.

BACKGROUND OF THE INVENTION l. Field of the Invention The present invention relates to presser foot assemblies for sewing machines, and more particularly to such assemblies for use in installing zippers or other types of elongated articles which need guiding during their installation, e.g. cording, piping, etc. Some of the features of the invention specifically relate to presser foot assemblies for use in installing invisible or concealed zippers.

2. Description of the Prior Art Known laterally adjustable presser-foot assemblies are of two types. In the first type the adjustable connection comprises a member having a laterally elongated slot which receives the shank portion of the clamp screw. Examples of foot assemblies of this type are shown by Burgess, U.S. Pat. No. 3,024,751 and Micale, U.S. Pat. No. 3,294,048. The second type Includes a slide joint having only two positions of use. The slidabie member is retained in each of these positions by the pressure of a spring-biased ball detent. This type of foot assembly is shown by Yoshida, U.S. Pat. No. 3,098,460.

Known zipper foot attachments for sewing machines comprise a member having one or more elongated lower body parts presenting a relatively flat lower surface to the material. Each surface is generally narrow and long and provides a substantial area contact with the material. A disadvantage of presser feet of this type is that they involve a large area of sliding contact with the moving material. This most often results in an uneven movement of the material below the pressure-applying member, due to frictional grab, resulting in the development of puckers in the material. Typical examples of this type of presser foot are disclosed in my aforementioned U.S. Pat. Nos. 3,342,151 and 3,349,736, and in Smallbone, U.S. Pat. No. 1,930,628; Dixon et al., U.S. Pat. No. 2,909,136; and Yoshida, U.S. Pat. No. 3,098,460.

Also, known zipper foot attachments all have a forward end portion which extends forwardly of the needle and makes a pressing contact with the zipper tape and material to which it is being sewn in a region forwardly of the needle and also directly adjacent the needle region. Owing to this arrangement, the sewing is done in a region where puckering can occur, and sometimes the material becomes puckered first and then is sewn in the puckered state.

SUMMARY OF THE INVENTION This invention relates to presser foot assemblies which are characterized primarily by a construction leaving the zipper tape and material to which it is being attached free of a downward pressure force at-and-forwardly-of the needle. The front end of the foot component is spaced rearwardly of the needle. It includes a central guide channel having guide groove means for changing the attitude of the zipper teeth as they pass relatively through said guide means, to place them in an attitude resulting in the zipper teeth which are in the needle region being correctly oriented for sewing. The downward pressure force is applied only rearwardly of the needle and as a result the advancing force of the advancing mechanism is also applied rearwardly of the needle. This permits the operator to exert a slight amount of tension on the zipper tape and the material to which it is being sewn, in opposition to the holding force of the presser foot and/or the advancing force of the advancing mechanism, for the purpose of straightening the material and maintaining it straight in the needle region. A further important advantage of the short foot component of this invention is that it permits machine-sewing very close to the slider of the zipper.

Some zipper foot assemblies of the present invention include a foot component having a presser roller at its forward end. This roller is a guide roller and is formed to include the guide avenue means for the zipper teeth. The roller may be trailed by either an additional one or more rollers, or by flat bottomed surfaces on the foot component. The foot component is sufficiently open rearwardly of the guide avenue means to allow unobstructed travel of the zipper teeth through the foot component after they have left the region of the guide roller.

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

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary pictorial view taken in the needle region of a sewing machine of a type having a high presser bar equipped with a side-entry clamp screw, 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 and needle bar assembly in reference;

FIG. 2 is a front elevational view of the presser foot assembly of FIG. 1, such view showing a guide groove configuration at the front of the zipper chain passageway, adopting such foot component for use in sewing tapes of an invisible zipper of the oval-tooth-type;

FIG. 3 is a top plan view of the foot component portion of the presser foot assembly of FIGS. 1 and 2;

FIG. 4 is a side elevational view of the lower portion of the presser foot assembly of FIGS. 1 and 2, with the forward portion of the foot component shown in section and with the needle shown in reference;

FIG. 5 is a bottom plan view of the foot component portion of the presser foot assembly of FIGS. 1, 2 and 4;

FIG. 6 is a pictorial view of a modified form of presser foot assembly, showing a first mounting shank connected to a sliding and pivotal-mounting block and two substitute mounting shanks, for use in connecting the foot assembly to other types of sewing machines, shown in spaced relationship to their position of connection to the mounting block;

FIG. 7 is a side elevational view of the zipper foot assembly of FIG. 6;

FIG. 8 is a front elevational view of the foot component of FIGS. 6 and 7; and

FIG. 9 is a bottom plan view of the foot component of FIGS. 6, 7 and 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring specifically to FIG. I, a reciprocating needle bar 10 (in reference) is shown spaced forwardly of a presser bar 12 of the upright high-bar type. Bar 12 is equipped with a sideclamp type of presser foot mounting mechanism, and when bar 12 is in its operative position such mounting mechanism is based relatively high above the needle plate (hence the name "high-bar").

The mounting mechanism comprises a flat-sided surface 14 formed on the lower end portion of bar 12, a threaded aperture (not shown) entering into the side of said lower portion, substantially perpendicular to both the surface 14 and the sewing path, and a clamp screw 16. Surface 14 is parallel to the sewing path. Clamp screw 16 has a large head, with a flat inner surface that is parallel to surface 14, and a threaded shank that is threadable into-and-out-from said aperture.

In FIG. 1 a zipper foot assembly constructed according to the present invention is shown mounted in an operative position by the presser bar 12. Such attachment consists of two interlocking parts; a foot component 18 and a high-bar mounting shank 20. The foot component 18 is shown to be positioned for sewing a tape 22 of an invisible zipper to a piece of material 24. A material advance mechanism (FIG. 4) is located below the material 24 and below those parts of foot component 18 which rest on a press downwardly against the tape 22.

Foot component 18 is shown to be constructed in two parts. The first part is the foot itself, which is illustrated as having rectangular proportions. The second part is an elongated slide bar 26 which is shown to be secured to the upper surface of the rear portion of the foot, and with said rear portion forms the heel of the foot component 18.

The foot component 18 may be provided with side guide surfaces 28, 30, usable as guides for the sewing of the tapes of visible or exposed zippers, as explained in my aforementioned U.S. Pat. No. 3,342,151. The guide surfaces 28, 30 are parallel and may be planar and vertically disposed, as illustrated.

The bottom of foot component 18 is formed to include a centrally disposed longitudinal channel or zipper tooth passageway 28. At its forward end of the channel 28 is divided into two

entrances

30, 32 by a divider 34 depending from the roof of the channel 28.

FIG. 8 of my aforementioned U.S. Pat. No. 3,473,498 shows the natural orientation of the zipper teeth T of a separated zipper string relative to its fabric tape 22. The zipper teeth T shown in FIGS. 1, 2 and 4 herein belong to the same type of zipper and have the same natural orientation. Each tooth T includes an elongated inner portion 36 and a somewhat outer portion 38. Each tooth T is generally of a U-shape with the tumed-in edge portion 40 of the tape 22 being secured between the inner and outer side portions 36, 38 of the tooth T. The teeth T may be individual elements clamped to the inner edge portion 40 of the tape 22, or they may be portions of a continuous metal, plastic or nylon spiral-type string that is sewn or otherwise secured to the inner edge portion 40. The portion 42 of the teeth T are fashioned to interlock with like portions of the teeth T carried by the other half of the zipper. During the manufacturing of the zipper strings, a set is placed in the folds 44 so that the teeth T are oriented relative to the tape 22, substantially in the manner illustrated by FIG. 8 of U.S. Pat. No. 3,473,498, i.e. the inner and outer side parts 36, 38 of the teeth T each make an acute angle to the inner surface of the tape 22. Reference is made to FIG. 8 of my aforementioned U.S. Pat. No. 3,473,498 and the description relating thereto, for a better illustration and a full discussion of the natural position assumed by the teeth T.

According to the present invention, the

entrance avenues

30, 32 of the foot component 18 are configured to roll the zipper teeth contacted by the side surfaces thereof over into a nearly supine position, with the inner side portions 36 of the teeth T closely adjacent the fabric to which the tape 22 is being sewn. Placement of the teeth T in a nearly supine position requires a counterclockwise rolling (as shown by FIG. 2) of the teeth T from their natural attitude into the nearly supine position. According to the present invention, the front end of the foot component 18 is spaced rearwardly of the needle N. Thus, each tooth T occupies when it is adjacent the needle N an attitude which is somewhere between its natural attitude (i.e. the broken-line position in FIG. 2) and the nearly supine position. The

entrance portions

30, 32 of the guide avenues are intentionally configured to place the teeth T being influenced thereby in such a position that the intermediate attitude teeth in the region of the needle N, and not yet in the guide avenue being used, are properly positioned with respect to the needle N. It is desirable to establish a stitch line which is quite close to the portions of the teeth T bounding the needle N. Thus, this criteria is used for designing the

entrance portions

30, 32 of the zipper teeth avenues.

A particular advantage of spacing the front end of the foot component 18 rearwardly of the needle N is that the zipper teeth T which are forwardly of the foot component and in the needle region are free to roll if struck by the reciprocating needle N. It is proven advantageous to let such rolling occur forwardly of the attitude-influencing portions of the foot component. This is partially because the operator can see the stitch line and manually help guide the zipper teeth T if necessary. In the embodiment shown by my aforementioned U.S. Pat. Nos. 3,342,151 and 3,349,736, the forward portion of the foot component to some extent obstructed the view of the operator, and also prevented the operator from manually in fluencing the teeth T in the region where it is desired that the zipper teeth T be free to roll. Another advantage of locating the attitude-influencing portions of the foot component rearwardly of the needle is that less puckering occurs where stitching takes place. Firstly, the foot component 18 is shorter and for this reason presents a smaller surface against the material, lessening the amount of frictional contact with the material. However, the most important reason for a lessening of puckering is that a straightening tension can be maintained in the tape 22 and the material 24 forwardly of the foot component 18. The foot component 18 presses downwardly on the tape 22. This pressure is transmitted through the tape 22 to the material 24, pressing it against the advance mechanism. This pressure is what causes the advance mechanism to grab ahold of the material 24 and advance it across the top of the sewing machine. Since the advance mechanism operates in an intermediate grab and release manner, whereas the pressure of the foot component 18 is constant, puckering of the material can and usually does occur in the region where the material is influenced by both the constant pressure of the foot component l8 and the intermediate pushing effect of the advance mechanism. When the needle N is located entirely of the forwardly of the foot component 18 the operator can exert a slight holding force on the fabric 24 and tape 22. This holding force exerted in one direction and the advancing force and/or pressure force exerted in the opposite direction causes a straightening of the material 24 and tape 22 in the region forwardly of the foot component 18. This then becomes the ideal place to locate the needle N and according to the invention this is where the needle is located.

A further advantage of the zipper foot component of this invention is that it enables the user to machine-sew in close to the slider. In this respect, reference is made to FIG. I of my U.S. Pat. No. 3,555,627, granted Jan. 19, 1971, and to the description relating to such figure. Elimination of the forward portion of the foot component would allow relative movement of the slider into almost a position of contact with the slider.

In FIG. 1 of the present drawing the high-bar mounting shank 20 is shown to be of channel form and to comprise a pair of spaced-

apart flanges

46, 48 and a web 50 interconnected between corresponding edges of the

flanges

46, 48. Each end of web 50 is provided with an end surface adapted to slidably abut against the side portions of the upper surface of the slide bar 26. The end portions of web 50 are also formed to each include an outwardly opening blind slot. These slots, designated 52, 54, respectively, are colinearly related. At each end of shank 20 the end portions of the

flanges

46, 48 extend beyond the end of web 50 an amount substantially equal to the depth of slide bar 28. The end portions of the

flanges

46, 48 are in effect tines or side parts of a spring clamp. Each is provided with a groove in its inner surface for receiving one of the

slide bar lips

56, 58.

At one end of the mounting shank 20 the interiorly grooved end portions of the

flanges

46, 48, and the end surfaces of web 50 adjacent thereto, together define a slideway for the slide bar 26. Such slideway has a cross-sectional shape thatis substantially identical to the cross-sectional shape of the slide bar 26, but is slightly undersized in comparison to the slide bar 26. Therefore, the end portions of the

flanges

46, 48 must be sprung apart slightly, or the bar 26 must be slotted so that it can be compressed slightly, to allow entry of the slide bar 26 into the slideway. This assures a tight fit and results in the slide bar being frictionally retained in any position in which it is set. It also pennits easy repositioning of the foot component 18 relative to the mounting shank 20. The operator need only exert an endwise force on the slide bar 26 relative to the mounting shank 20 which is of sufficient magnitude to overcome the friction forces.

The slideway shown in FIG. 1 to be mated with the slide bar 26 is oriented relative to the shank 20 in such a way that the mounting shank 20 is perpendicular to the foot component 18 and is colinearly relatable to the upright presser bar 12. The slideway at the opposite end of mounting shank difiers from such first slideway only in that it is oriented so that when the slide bar 26 is received in it the mounting shank 20 tilts rearwardly and is colinearly relatable to a slanted presser bar of the high-bar type. The particular construction of the high-bar mounting shank 20 is more specifically illustrated and described in my aforementioned U.S. Pat. Nos. 3,342,151 and 3,349,736. Such patents also disclose a low-bar mounting shank and an end-clamp-type mounting shank which are usable in place of the mounting shank 20 for mounting the foot component 18 onto differing presser bars of different makes of sewing machines. Alternatively, the foot component 18 may be mounted by any one of the various mounting means disclosed in either my U.S. Pat. No. 3,473,498 or in my copending application Ser. No. 764,453.

The disclosures of all my aforementioned U.S. Pat. Nos. 3,342,151, 3,349,736 and 3,473,498 are hereby expressly incorporated herein by reference.

Referring to FIGS. 6, 7, 8 and 9, the zipper foot assembly shown by these figures comprises three interchangeable mounting

shanks

60, 62, 64, and a foot component 66. The foot component 66 comprises a body 68 having opposite

sidepanel parts

70, 72 and a top panel 74. Top panel 74 includes a pair of oppositely projecting

extensions

76, 78 having upturned

end portions

80, 82 which are parallel to each other. The

ears

80, 82 include recesses for receiving reduced diameter end portions of an adjustment screw 84. One end of the adjustment screw 84 is provided with a turning knob 86 spaced immediately outwardly from the car 80.

A connector block 88 is mounted on the adjustment screw 84 for lateral travel relative to the body 74. Connector block 66 includes a transverse bore through which the screw 84 extends. The bore is provided with internal threads which mate with the external threads on screw 84. Block 54 is formed to include a joint component, illustrated in the form of a laterally directed T-shaped tension 90. The mounting shank 60 is provided with a pair of selectively usable,

complementary mortises

92, 94; mounting shank 62 includes a single complementary mortise 96 and shank 64 also includes a single complementary mortise 98.

When the connector block 88 is secured to a mounting shank, such as shank 60 as shown in FIG. 6, for example, rotation of the screw 84 will cause such screw 84 to move axially relatively through the bore in the block 88. Since screw 88 is a part of the foot component 16, rotation of screw 88 causes the foot component 66 to move sideways relative to the mounting shank 60, the presser bar 12 and the needle 10.

As best shown by FIG. 2, the bottom surface of block 88 is spaced slightly above the top panel 74 of body 68. The bottom surface of mounting shank 60 is also spaced above top panel 74. This arrangement permits a limited amount of pivotal movement of the adjustment screw 84 within the transverse bore in mounting block 88 upon pitching movement of the foot component 66. Such pitching movement of foot component 66 is caused by changes in the thickness of material below the foot component 66.

The mounting shank 60 is constructed so that it can be turned end-for-end and be used for mounting the foot component 66 onto a slanted presser bar of a slant-needle-type sewing machine. Mounting shank 62 is a low-bar-type mounting shank and mounting shank 64 is an end screw-type mount-.

ing shank. The mounting shank 60 is provided with clamp

screw receiving slots

100, 102 at its opposite ends; shank 62 is provided with a single mounting screw receiving slot 104 and shank 64 includes a single mounting screw receiving slot 106. Mounting shank 62 is to be used with the low-bar-type presser bar, such as shown by FIG. 7 of my U.S. Pat. No. 3,342,151. Shank 64 is to be used with the end-screw-type presser bar, such as shown in FIG. 9 ofrny U.S. Pat. No. 3,342,151.

The presser foot of this embodiment comprises two rollers 108, 110. Each roller 108, is mounted for free rotation about an axis which is substantially parallel to the adjustment bar 84 and are transversely related to the sewing path. Rollers 108, 110 may be formed to include live end shafts or axles 112 which are loosely fitted in openings provided for them in the

side panels

70, 72 of the body 68. The front roller 108 is configured to include a central guide avenue groove 114 flanked by peripheral presser surfaces. The exact configuration of the guide avenue groove 114 will vary in accordance to the type of zipper or other article for which the foot is adapted. The rear roller 110 is also centrally grooved. However, such groove is provided merely to allow free passage of the zipper tooth chain through the foot component in the region rearwardly of the front roller 108. The central groove 114 of the front roller 108 is what orients the zipper teeth. As shown by FIG. 7, the front roller 108 is spaced rearwardly of the needle N. This is done for the reasons expressed above in connection with the description of the embodiment shown by FIGS. l-S.

The particular zipper for which groove 114 is adapted to guide is the type of zipper disclosed by U.S. Pat. No. 3,121,928, issued Feb. 25, 1964 to lkuo Takamatsu. The teeth of such a zipper are characterized by enlarged rounded end portions which abut the inside of the fold of the fabric portions of the zipper tape. The groove 114 includes a central portion configured to closely conform to the shape of the bight portion of the zipper teeth when such teeth are correctly oriented. On each side of such central portion there is included a shoulder 116 (FIGS. 8 and 9) adapted to closely contact the upwardly oriented surface portion of the rounded-end portion of the zipper teeth. Shoulders 116 aid in establishing the correct attitude of the teeth T. Reference is made to my copending application Ser. No. 764,518 for a showing of a zipper tooth of the type described being situated in and guided by a groove like groove 114.

When the assemblies being used for sewing a right tape of a zipper, the needle N is located to the immediate right of the right-hand shoulder 116. When the opposite or left tape is being sewn, it is necessary to slide the foot component 68 sideways to the right until the needle is to the immediate left of the left-side shoulder 116. Preferable, the center groove 118 of the rear roller 110 is both wider and slightly deeper than the forward groove 114. This is so no contact at all is made with the zipper chain and the roller 110.

What is claimed is:

1. For use with a sewing machine equipped with a presser bar, a reciprocating needle and a material-advancing mechanism, a zipper foot assembly, comprising:

a foot component having a forward end, a zipper tooth passageway extending rearwardly from said forward end through at least the lower portion of said foot component, said passageway being defined at least in part by guide surface means configured to guide and orient the zipper teeth into a predetermined path of travel and attitude relative to the needle, and a presser surface for exerting a downward pressure on the zipper tape and the material to which it is being sewn;

mounting means for securing said foot component to the presser bar in a position at least partially over said material-advancing mechanism; and

the improvements comprising:

the forward end of the foot component being spaced rearwardly of said needle, so that the needle region is in full view of the user and the downward pressure of the presser surface is exerted only rearwardly of the needle region and the user can pull on the materials being sewn in opposition to the pull of the advancing mechanism, and in that manner straighten such materials and maintain them substantially flat while they are being sewn in the needle region, for lessening puckering; and

said guide surface means being configured to twist the zipper tooth chain from its natural attitude into an attitude at the guide means which will result in the zipper teeth adjacent the needle being substantially properly oriented for close-to-the-teeth sewing.

2. A zipper foot assembly according to claim 1, wherein said foot component includes at least one presser roller mounted for rotation about an axis which extends generally transversely of the sewing path, said roller including a material-contacting peripheral surface, and at least one peripheral groove, the defining surfaces of which groove are the said guide surfaces for the zipper teeth.

3. A zipper foot assembly according to claim 2, wherein said roller includes a divider dividing the peripheral groove into two parts, said parts having mirrorlike symmetry, with one being usable to guide and orient one of the zipper teeth chains of a zipper and the other being usable to guide and orient the other zipper tooth chain of the zipper, and wherein said mounting means permits lateral adjustment of the foot component relative to the presser bar.

4. A zipper foot assembly according to claim 2, wherein said foot component includes at least one additional roller spaced rearwardly of the forward guide roller, said additional roller also including a peripheral groove which is a part of the zipper tooth passageway.

5. A zipper foot assembly according to claim 2, wherein said mounting means includes a fixed member on at least one side of the zipper tooth passageway which has a lower presser surface substantially colinearly related with the material-contacting peripheral surface of the forward guide roller.

6. A zipper foot assembly according to claim 1, wherein said guide surface means has laterally related guide surface portions for the two zipper tooth chains of a zipper, and said mounting means permits lateral adjustment of the foot component relative to the presser bar.

$ l i t

Claims

1. For use with a sewing machine equipped with a presser bar, a reciprocating needle and a material-advancing mechanism, a zipper foot assembly, comprising: a foot component having a forward end, a zipper tooth passageway extending rearwardly from said forward end through at least the lower portion of said foot component, said passageway being defined at least in part by guide surface means configured to guide and orient the zipper teeth into a predetermined path of travel and attitude relative to the needle, and a presser surface for exerting a downward pressure on the zipper tape and the material to which it is being sewn; mounting means for securing said foot component to the presser bar in a position at least partially over said materialadvancing mechanism; and the improvements comprising: the forward end of the foot component being spaced rearwardly of said needle, so that the needle region is in full view of the user and the downward pressure of the presser surface is exerted only rearwardly of the needle region and the user can pull on the materials being sewn in opposition to the pull of the advancing mechanism, and in that manner straighten such materials and maintain them substantially flat while they are being sewn in the needle region, for lessening puckering; and said guide surface means being configured to twist the zipper tooth chain from its natural attitude into an attitude at the guide means which will result in the zipper teeth adjacent the needle being substantially properly oriented for close-to-theteeth sewing.