US3724408A - Channel insert attachment for a zipper foot - Google Patents

Abstract

An attachment for a channel zipper foot accommodating the guiding of a zipper chain as the zipper foot stitches the zipper tape to garments. The attachment inserts into the channel of a zipper foot becoming engageable with the zipper tape. The configuration of the body of the attachment will retain the attachment into its inserted position during a forward or rearward stitch of the sewing machine operation. Zipper chains may be received into a channel formed into the underside of the attachment. A specially shaped attachment becomes an accessory part of a zipper foot to be inserted into a channel already present in the zipper foot, to provide the presser foot with a particular and specially shaped configuration of a channel which is capable of turning and rolling a concealed zipper chain from its otherwise natural position as it also guides the chain.

Description

United States Patent 1191 'Gooderum 1451 Apr. 3, 1973 i541 CHANNEL lNSERT ATTACHMENT FOR A ZIPPER FOOT [76] Inventor: Leoda J. Gooderum, 627 Charles Street, La Crosse, Wis. 54601 22] Filed: Mar.3, l97 1 21 Appl. No.: 120,534

[52] US. Cl. "112/240 [51] Int. Cl. ..D05b 29/12 [58] Field Of Search ..1 12/235, 240

[56] References Cited UNITED STATES PATENTS 3,473,498 10/1969 Howell ..1 12/240 11/1957 Marshall 3/ 1969 Pingitore et al.

Primary Examiner Patrick D. Lawson Attorney-Robert E. Louie 57] ABSTRACT An attachment for a channel zipper foot accommodating the guiding of a zipper chain as the zipper foot stitches the zipper tape to garments. The attachment inserts into the channel of a zipper foot becoming engageable with the zipper tape. The configuration of the body of the attachment will retain the attachment into its inserted position during a forward or rearward stitch of the sewing machine operation. Zipper chains may be received into a channel formed into the underside of the attachment. A specially shaped attachment becomes an accessory part of a zipper foot to be inserted into a channel already present in the zipper foot, to provide the presser foot with a particular and specially shaped configuration of a channel which is capable of tuming and rolling a concealed zipper chain from its otherwise natural position as it also guides the chain.

5 Claims, 19 Drawing Figures PATENTEUAPR3 ms 3.724.408

SHEET 3 OF 3 CHANNEL INSERT ATTACHMENT FOR A ZIPPER FOOT This invention relates to an attachment for a zipper foot and more particularly to a guiding attachment for guiding and turning a zipper chain as the zipper foot and the attachment engages and accepts the fabric adjacent to a zipper as it is being sewn into a garment.

The insert attachment is described in connection with a zipper foot attachment for a sewing machine. One such zipper foot is shown and described in my copending application under Ser. No. 40,900, filed May 27, 1970 which is an application as a continuation-in-part of my earlier application Ser. No. 736,166, filed June 1 l, 1968 and both applications are entitled Zipper Foot Attachment for Sewing Machines. The insert attachment will provide the zipper foot as identified in my application Ser. No. 40,900, as well as others, capable of sewing a concealed zipper into a garment.

A close stitch near the zipper chain is desirable to achieve a tight seam joining of the zipper tape to the fabric edges so that after the installation, the zipper tape will hardly be visible on the outside of the garment. To achieve this close stitch, a turning of the zipper chain away from the sewing machine needle is needed so that during stitching the needle will not strike the zipper chain and damage its teeth. The one piece attachment of the present invention is of a specific shape allowing it to be inserted into a channel and into the needle slot of a zipper foot. The insert has a channel shaped into its underside which is of a specific configuration formed so as to turn over the zipper chain.

Separate attachments provided with a channel and designed to be inserted into a channel of a zipper foot are known. Howell, US. Pat. No. 3,473,498 discloses two separate and different types of insert attachments to accompany a channel zipper foot. Both inserts will guide and turn a zipper chain of a concealed zipper, providing the channel zipper foot with the means for proper installation. One of the two attachments disclosed is designed to be inserted around therear curvature of the needle hole in a hook fashion. This style of insert will require a seamstress to perform a delicate 'handling of the piece with difficult maneuvering to hook and'snap the piece into its inserted and useable position. Also, disclosed is the other type of insert in modified form. This piece is inserted into a front recess in the channel of the zipper foot. However, this front piece will become disengaged from the recess when a back stitch is supplied. The sewing process of back stitching is a required step during the installation of a concealed zipper and is applied after one side of the zipper tape is joined to the fabric. Next, it will again become necessary to insert the front piece a second time, presenting an inconvenience, to complete the joining of the other side of the zipper tape. Furthermore, as the front piece detaches, the zipper chain is solely guided and turned by the rear hook insert and therefore guided only rearward the needle. The foregoing zipper insert attachments are thus limited in use and involve certain inconveniences. An important object of the present invention is to provide a one piece insert attachment which will produce a turning and guiding treatment to a zipper chain both frontward and rearward the needle. A further object is to provide an insert attachment which will remain inserted into position and which will not become disengaged from the zipper foot as a back stitch or forward stitch is applied during the sewing operation. Another object is to provide an insert attachment which is inexpensive to manufacture, easy to insert and easy to remove by the seamstress, simple to use; and which will convert the channel already present in a zipper foot to provide a new channel capable of turning, as well as guiding, a zipper chain. It is also an object to provide interchangeable insert attachments, of which there could be several, allowing a selection of various inserts, and each provided with different lateral configurations to guide zipper chains of different thickness or to guide other objects having elongated raised bodies, such as cordings.

The insert attachment of the present invention features a one piece unit with bodies forming a configuration of a substantially T-shaped block. One rectangular length of the T-block has a channel underside which will become inserted into the channel already present in a zipper foot, having its channel underside to the bottom side of the zipper foot, bothforward and rearward the needle. The insert attachment becomes the guiding channel and its channel is of a shape and configuration different from the channel of the zipper foot into which it is inserted. The other portion of the T-block is a protruding body, a finger shaped plug, which will insert into the needle slot of the zipper foot in a plug fashion. The finger plug also serves to contain the attachment in position during a forward or backward stitch. Also,

when one rectangular body is positioned between the channel and the other finger portion plugged into the needle slot, the T-block is frictionally held and removably attached to the zipper foot. The channel of the attachment has two side legs with a triangular V- shaped body between and a needle slot formed substantially through the center of the V-body. This will provide the channel attachment with two tunnel sections on either side of the V-shape. One tunnel will receive and turn guide the open zipper chain on one side of the zipper tape, while the other tunnel will receive and guide the opposite zipper chain. This specially shaped V portion is therefore the means which will produce the turning or rolling over of the zipper chain as it is fed and guided into the tunnel during the stitching producing the proper installation of the concealed zipper.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part thereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view of the insert attachment constructed in accordance with the present invention.

FIG. 2 is a perspective view of a zipper foot showing the insert placed in position for use.

FIG. 3 is a rear view of the zipper foot showing a sub:

stantially wide-spread adjustment of one limb element from the other.

FIG. 4 is a top plan view of the attachment and the zipper foot showing the attachment inserted between the extended limb elements and'also showing a phantom portion of the slide body for the purpose of identifying the position of two threaded bores, also illustrated in phantom.

FIG. 5 is a top plan view of the auxiliary element removed from its normal attached position onto the zipper foot of FIG. 2.

FIG. 6 is an enlarged partial section view taken substantially through a plane indicated by section line 6-6 in FIG. 4.

FIG. 7 is an enlarged partial sectional view taken substantially through a plane indicated by section line 7--7 in FIG. 41 including one side of an open zipper chain as seen in FIG. 10, illustrating the leaning treatment applied to the zipper chain by the insert attachment and also showing the feeding elements of a sewing machine.

FIG. 8 is a perspective view of the insert attachment showing its underside to view its channel configuration.

FIG. 9 is an enlarged sectional view taken substantially through a plane indicated by section line 9-9 in FIG. 4 showing the plug element of the insert attachment positioned into the needle slot of the auxiliary limb element of the zipper foot.

FIG. 10 is an enlarged sectional view taken across one side of an open chain and zipper tape showing the teeth elements of a concealed zipper chain positioned in their natural attitude.

FIG. 11 is a perspective view of a modified form of the insert attachment constructed in accordance with the present invention.

FIG. 12 is a perspective view of a common type zipper foot showing the modified insert placed in position for use.

FIG. 13 is anenlarged partial sectional view taken substantially through a plane indicated by section line 13--l3 in FIG. 12 showing in sectional the face of the triangular V-body and the extending nose plug and also oneside of an open zipper chain as seen in FIG. 10, illustrating the leaning treatment applied to the zipper chain by the modified attachment and also showing the. feeding elements of a sewing machine.

FIG. 14 is an enlarged partial sectional view taken substantially through a plane indicated by section line 14l4l in FIG. 12 showing the plug element of the modified insert attachment positioned into the needle slot of the common type zipper foot.

FIG. 15 is a perspective view of still another modified form of insert attachment constructed in accordance with the present invention.

FIG. 16 is a perspective view of the common type zipper foot, identical to FIG. 12, showing the modified insert of FIG. 15 positioned for use.

FIG. 17- is an enlarged partial sectional view taken substantially through a plane indicated by section line 17-17 in FIG. 16 showing in sectional the face of the triangular V-body and one side of an open zipper chain as seen in FIG. 30, illustrating the leaning treatment applied to the zipper chain by the modified attachment and also showing the feeding elements of a sewing machine.

FIG. 18 is an'enlarged partial sectional view taken substantially through a plane indicated by section line 18-18 in FIG. 16 showing the lip gripping elements of the modified insert attachment gripping the front and rear of the common type zipper foot.

FIG W is a perspective view of a modified form of the finger plug of the attachment of FIG. 1 showing the attachment positioned for use in an auxiliary element form of zipper foot.

Referring to the drawings in detail and initially to FIG. I, it will be observed that the T-block attachment is generally denoted by reference numeral 10. The T- block includes an elongated rectangular base 12, shaping at its front to a tapered nose 13, with a channel 14 formed into its underside. A needle hole 16 is bored through the center of the base and a finger shaped plug 18 extends substantially perpendicular to the lengthof the base and from one side adjacent to the region where the needle hole is formed.

The T-block is an attachment or accessory part to ac.- company a channel zipper foot. The outside contour of the T-block is shaped in a configuration of a T 50 as to removably insert the T shape block into an elongated channel and into a needle slot of a zipper foot as seen in FIG. 2. A zipper chain 19 may then pass and be guided through the channel formed into the T-block.

Features required within a channel zipper foot to provide the T-block insertable and useable include; a channel with an overhead section providing the channel with a roof, and a needle slot. A zipper foot of this type, including these features, is shown in FIG. 2 and is generally denoted by numeral 20. The following description is offered to outline this zipper foot, pointing out the requirements as stated above and showing how these features are used in combination with the T block to afford the insert useable.

Referring to FIG. 2, the zipper foot assembly 20 includes a support member 22 with an extended elongated grooved guide portion 24 and clamping means 26 to removably mount the zipper foot onto the presser bar 28 of the sewing machine by clamping screw 30.

A slide body 32 includes a material engaging main limb 34 extending toward a needle 36 of the sewing machine. The slide body 32 is mounted onto the grooved guide portion 24 and is slidably received between its upper leg 25 and lower leg 27 by means of a rear threaded clamping screw38. As seen in FIG. 3, the rear clamping screw 38 extends through a horizontal adjustment slot 40 formed into the elongated grooved guide portion 24. The rear clamping screw next enters into a threaded bore hole 42, shown in phantom in FIG. 4, formed into the rear of the slide body 32. Thus, the slide body and its extended main limb is movably mounted to the support member. This mounting means provides the main foot element capable of being frictionally locked in a plurality of adjusted positions on the support member and to positions on either side of the needle.

A second auxiliary material engaging limb 44 is slidably mounted onto the slide body 32 of the main limb element in a manner similar to that of the slide body mounting onto the support member. Referring to FIG. 2, it is observed that an elongated groove face 46 includes an upper leg 48 and a lower leg 50 adapted to receive the slide body 332 between said legs, as more clearly seen in FIG. 9. The auxiliary limb element 44 is thus slidably received onto the slide body and may be locked in a plurality of adjusted positions by means of a front threaded clamping screw 52. The front clamping screw enters through a horizontal adjustment slot 54 formed through the elongated grooved face and the screw proceeds to enter into a threaded bore hole 56, shown in phantom in FIG. 4, formed into the front of the slide body and longitudinally spaced from the rear threaded bore 42. Thus, the auxiliary limb is movably mounted onto the slide body with adjustment offering selective and frictionally locked space relation toward and from the main limb. This provides the zipper foot with a selective and changeable width channel 58 formed between the two extended limbs 34 and 44, as more clearly seen in FIG. 3 (a wide channel selection is shown, for purposes to be described hereafter). The fixed width of the channel will be selected as such to accept the base 12 of the T-block between the limbs (see FIG. 4) which will be described hereafter in greater detail.

Referring again to the zipper foot assembly in FIG. 2, a mounting arm 60 is of an inverted L shaped configeration so as to form a passage 62, which will allow the slide body 32 and the attached groove face 46 to be displaced through the passage 62. Therefore, the main limb 34 and the attached auxiliary limb 44 are slidably displaceable to at least allow positioning of their inside edges 77 and 79 (see FIG. 3) to opposite sides of the sewing machine needle when the T-block is inserted.

For and a more detailed description of the main limb element, the auxiliary limb element and the support member of the zipper foot assembly, reference is made to my aforementioned copending applications, Ser. Nos. 736,166 and 40,900.

Referring to FIG. 5, the auxiliary limb element is divided into two fabric engaging sections, front section 66 and rear section 68. A U-arm 70 connects said sections and a needle slot 72 develops inside the open area formed between the two sections. The U-arm is also designed to receive the needle of the sewing machine into its open area 74 formed inside the U-arm. The needle slot 72 is in alignment with the extending U-arm, thus, the open area 74 actually becomes an extension in length of the needle slot 72. Therefore, the needle of the sewing machine may be received into the length of the needle slot and continue into and through the open area of the U-arm, as the two limbs are laterally adjusted, with selective and fixed positioning of the limbs relative to the needle. The U-arm also features an elevated bend 76 (see FIG. 2) allowing the U-arm to freely move above the main limb 34 when a selected and fixed position of the auxiliary limbs inside edge 77 (see FIG. 3) is placed from the main limbs inside edge 79, in order to form the channel 58 between.

For a more detailed description of the U-arm assembly of the auxiliary limb element, reference is made to-my aforementioned copending application Ser. No. 40,900.

As hereinbefore indicated, one of the necessary features within a channel zipper foot required to provide the If-block insertable, includes a section of roof above the channel. It is observed in FIG. 5, that the U-arm provides this roof as the U-arm includes a front extension 78 and a rear extension 80. The rear extension is shown above the channel in FIG. 3, while the front extension is shown above the channel with the T-block inserted in FIG. 6. Therefore, both the front and rear extensions of the U-arm serve to provide a partial roof above the channel in a region forward and rearward the needle hole 16 (see FIG. 4).

Now, reference is made to the T-block and to the manner in which it will be inserted into the channel and under the U-arm of the zipper foot. It is observed in FIG. 6, that the height of T-bloclr is determined by the distance between its fiat plain topside 82 to its underside 84. It is also observed that the front extension 78 of the U-arm includes an underside 86. Likewise, the rear extension also has an underside 88, as seen in FIG. '7. The height dimension of the T-block is only slightly less than the distance measured between the undersides of both U-arm extensions to the underside of the auxiliary limb (see FIG. 6). Therefore, the height of the T-block is predetermined and is such to allow its elongated base to rest under and in abutment with the underside of both the extensions of the U-arm (FIGS. 6 and 7), while the T-blocks underside 84, the auxiliary limbs underside 90 and the underside of the main limb have their lowermost undersides thereof at the same level, as seen in FIG. 6.

The breadth of the base 12 of the T-block is defined as the dimension between its two outside edges 92 and 94 (see FIG. 8). The breadth will be such to allow the channel 14 to be formed into its elongated underside. As hereinbefore indicated, the zipper foot 20 features an adjustable width channel, therefore the edges 77 and 79 of the two extended limbs, will be selectively adjusted and fixedly spaced at a width only slightly wider than the breadth of the base 12, thus allowing a snug abutment and frictional insert of the base edges into the channel, as seen in FIG. 6.

Referring to FIG. 8, the channel 14 of the T-block is shaped both forward and rearward the needle hole 16. The channel is of a configuration so as to produce a turning treatment to a zipper chain as seen in FIG. 7, by its camming action which will be explained in greater detail hereafter. In describing the channel configuration, reference is made to FIGS. 6 and 8 where it is observed that a substantially triangular V-body 116 is formed by the base topside 82 and two oblique walls 122 and 124 slanting at an incline and diminishing to a center vertex 126. Two legs 122 and 124 are extended in a perpendicular direction from the topside base 82 and extended in equal distance downward and toward the vertex 126, including two inside walls 112 and 114, respectively. The vertex does not extend below the underside of the legs.

Reference is now made to the finger plug 18 which extends from the same level of the base topside 82 and leg bottomside 84. The breadth of the finger plug is predetermined and such to allow it to insert snugly into the needle slot of the auxiliary limb. The breadth is defined as the dimension between its front side 96 and its rear side 98 (see FIG. 8). This breadth dimension is only slightly less than the needle slot opening indicated from the needle slots front wall 100 to its rear wall 102, as clearly seen in FIG. 5. Now, referring to FIG. 9, the inserting of the finger plug is observed as its outside edges 96 and 98 abut the two walls 100 and 102 of the needle slot. This type of insert could be described in a manner or fashion as a plug and socket insert. The needle slot serves as the socket in which to plug the finger extension Thus inserted, there becomes a certain amount of frictional gripping of the abutting surface edges of the base legs and the finger plug, which will discourage the T-block from falling out from its inserted placement.

One convenient manner in which to insert the T- block would be to first spread the two limbs, allowing a wide channel separation (see FIG. 3); next, insert the finger plug into the needle slot of the auxiliary limb; and finally, adjust the auxiliary limb laterally toward the main limb until the outside edge of the T-blocks leg touches and abuts the inside edge of the main limb.

' Still, another method of easy inserting would be to first laterally adjust the auxiliary limb a selected distance from the main limb so that the channel width is just slightly wider than the breadth of the base; then from the underside of the limbs, position the. shape of the T- block to coincide with the channel opening and the needle slot opening and push the T-block from its channel underside and it will insert into position for use. The zipper foot will be attached to the sewing machine, adjusting the limbs to align the needle above the needle hole and the insert attachment is-rcady to receive a zipper chain.

Referring to FIG. 7, the zipper tape 134 and fabric 106 are fed by means of the sewing machine feeding elements 108, while the fabric and zipper are pressed down onto the bed 109 by the zipper foot and the T- block. When applying a front stitch, the action of the feeding elements is one upward and rearward motion, in contact with the fabric and pushing the fabric and zipper rearward of the needle. Next, the feeding elements drop downward and out of engagement with the fabric and move forward for its next upward and rearward circular cycle. The motion of this cycle is repeated in cooperation with the reciprocating needle and other actions within the sewing machine, producing the actual stitch joining of the fabric and zipper tape. During the front stitch feeding, the rearward motion of the feeding elements will also be exerted to the underside legs of the T-block and will likewise react upon it with a rearward pushing. A rearward movement of the T block is discouraged, however, because as earlier indicated, the rear edge 98 of the finger plug is in abutment with the rear wall 100 of the auxiliary limbs needle slot (see FIG. 9). Next, a back or reverse stitch may be applied from the feeding elements to the fabric and zipper, which is a reverse action or motion in comparison to the frontward stitch. In this case, the feeding elements move upward and frontward during their cycle causing the fabric to move in thissame direction. Again, the T-block willhave a tendency to move in a likewise frontward direction, because this frontward motion is exerted to'the underside of the T- block. However, a frontward movement is discouraged because as previously indicated, the front edge-96 of the finger plug abuts the front wall 100 of the needle slot of the auxiliary limb. Thus, the finger plug serves to restrain forward and-rearward movement and serves to contain the T-block into its position between the channel of the zipper foot.

As hereinbefore indicated, the auxiliary limb is attached to the main limb. Also, the base topside of the T-block abuts both underside sections of the U-arm. This abutment will serve to contain the T-block into its position between the two limbs while the lowermost undersides of the main limb, the T-block, and the underside of the auxiliary limb remain at the same level. Also, because of this abutment and the attachment of the two limbs, the equal level of the three undersides 95, 8d, and (see FIG. 6), is maintained even though an uneven thickness of fabric 106 and zipper tape 134 are under only one of the two limbs, as more clearly seen in FIG. 7. Then too, the upward and vertical movement from the feeding elements is transmitted through the T-block and through both limbs, again by reason of their abutment and attachment. The ultimate upward motion is carried to the presser bar of the sewing machine and provides displacement of the presser bar in both directions because the zipper foot is attached thereto. Thus, both limbs 34 and 44 and the T- block 10 are displaceable by the feeding elements in coordination during engagement with the zipperand fabric being fed along the machine bed 1 10. For a more detailed description of the displacement action of the presser bar through the zipper foot itself, reference is made to my two copending applications, Scr. No. 736,166 and Ser. No. 40,900.

The arrangement of the triangular V-body and the side legs will provide the channel 14 with two tunnels, 128 and 130.and each tunnel is three-sided and of substantially equal configuration. The contour forming tunnel 128 includes outside wall 112 and oblique wall 122. Likewise, the contour comprising tunnel includes outside wall 1 14 and oblique wall 124. Referring to FIG. 7 and 8, the needle hole 16 is formed through the topside 82 of the base and substantially through'the center vertex 126 of-the triangular V-body to receive the needle 36.

FIG. 10 shows the natural attitude of the zipper teeth 19 of a concealed zipper, being in a substantially upright position. Referring to FIG. 7, the open chain 19 of zipper tape 134 is initially fed during, the sewing operation, into tunnel 123 and the slantingside wall 122 of the triangular V-body will produce the carnrning action to the zipper chain and will turn and roll the chain away from its otherwise natural attitude, both forward and rearward the needle. The zipper chain is also received in sliding abutment with the wall 1-12 and is therefore containedand guided past the reciprocating needle. Therefore, the needle will stitch near the zipper chain but will not strike the chain and damage it because the chain is turned and rolled away from the needle. The opposite tunnel 130 will be used when joining zipper tape 132 to the fabric, as seen in FIG. 2. Here, the tunnel 130 will produce a likewise turning treatment to the zipper chainas a result of the slanting side 124 (FIG. 6) producing the camming action; and in combination with wall 114, will produce the longitudinal guiding.

It is possible to provide more than one T-block for interchangeable inserts. Each T-block would have different channel configurations to accept a variety of different size zipper chains or shapes of raised longitudinal bodies. If wider channels are formed into the insert, the base of the T-block will accordingly become broader and a wider channel adjustment will be selected to accommodate the inserting of a wider base.

Thus, the zipper foot 20 is readily adjustable for inserting various size T-blocks.

In FIG. 19, a modified arrangementof the finger plug 18 will provide the T-block attachment useable on another type of zipper foot 23. This zipper foot is composed of an auxiliary limb element and is of the type disclosed in FIG. 7 of my copending application Ser. No. 40,900. It is observed that the main limb, which served to contain the leg edge 92' of the T-block is not a feature of this zipper foot. Therefore, and because the main limb is eliminated, the modified finger plug 18' includes a crossbar 29 having two inside sections 31 and 32 which will serve to frictionally grip and abut one outside edge 45, while the leg edge 94' of the T-block abuts the other edge 77' of the auxiliary limb 44'. This abutment is achieved because the dimension from the leg edge 94' to the inside sections 31 and 32 of the crossbar is predetermined and only slightly greater than; the dimension of the breadth of the auxiliary limb measured between its edges 77' and 45. This abutment will contain the leg edge 94 of the T-block against the inside edge 77 of the auxiliary limb and will discourage a sideway movement of the base 12' as it rests under the U-arm 70'. The base 12' with its channel 14' has identical features and functions of guiding and turning a zipper chain as hereinbefore indicated.

FIG. 11 shows a modified arrangement of the insert attachment and will hereafter be referred to as T-block This form of insert will be particularly desirable when used in combination with a common or basic model channel zipper foot, shown in FIG. 12, and hereafter referred to as numeral 21. This zipper foot features an elongated extended limb 35 with a channel 37 formed into its elongated underside, a roof section 39 and a needle slot 41 (as clearly seen in FIG. 16). Here, the channel 37 is of fixed width, having two channel walls 113 and 115 (FIG. 13). Therefore, it is only required to supply a triangular V-shaped body 116' insertable into the channel to provide the channel with a camming ability.

The modified T-block 10' differs from the T-block 10 (seen in FIG. 8) with the elimination of the two side legs 118 and 120 and also differs with the placement of a newly shaped nose plug 17, as seen in FIG. 11. The nose plug replaces the finger plug.

Referring to FIG. 11, 13, and 14, the T-block features the substantially isoceles triangular V-body 116' including its base top 82 and two oblique side walls 122' and 124 slanting to a center vertex 126. The breadth of the base is the distance between two points 136 and 138. The breadth is predetermined and such to allow a frictional insert of the triangular V-body 116' into the channel, while its points 136 and 138 touch the channel walls 113 and 115, respectively (FIG. 13). In FIG. 14, it is observed that the base topside 82' of the triangular V-body is in flush abutment with the roof 39 of the channel while its vertex 126' does not extend lower than the channel side walls 113 and 115.

It will be observed in FIG. 11 and 14 that the nose plug !7 protrudes from the base topside 82 of the triangular V-body. The nose plug will be inserted into the needle slot 41 (more clearly seen in FIG. 16) of the zipper foot and is of a circular configuration equal to the circular configuration of the needle slot opening. Also, the outside perimeter of the nose plug is only slightly less than the inside perimeter of the needle slot to allow the snug and frictional insert in a plug and socket fashion. The nose plug is shown and described in a round shape, however, it could be of other shapes which would conform to the configuration of other needle slot shapes.

As hereinbefore indicated, during the sewing process the feeding elements 108 (FIG. 13) exert either a forward or rearward pushing action to the underside of the fabric 106 and zipper tape 134, and the zipper foot 21.

This action is also exerted to the vertex 126' and the oblique wall 122' (FIG. 13) through the fabric and the zipper and will create a tendency to move the T-block 10' in a likewise direction. However, in FIG. 14 it is observed that the front and rear curvatures 117 and 119 of the nose plug 17 are in abutment with the front and rear curvatures 121 and 123, respectively, of the needle slot. This abutment will discourage a forward or rearward movement of the T-block.

Referring to FIGS. 11 and 13, a needle slot 16' is formed substantially through the center of the nose plug 17 and through the center vertex 126' for needle reception.

In FIG. 13 it is observed that a tunnel 128' is formed by the oblique wall 122' and the channel wall 113 of the zipper foot. The tunnel will receive the zipper chain 19 with the oblique wall 122'. exerting its cam action to lean the chain in an outward position, both forward and rearward the needle, as well as away from the needle. Also, the chain is guided longitudinally as it is also contained by the channel wall 1 13. Likewise, tunnel 130' is formed by oblique wall 124' and thewall 115 of the channel and the tunnel 130 will produce the same guiding and cam action to the zipper chain, as seen in FIG. 12.

Furthermore, as the zipper chain is fed into one of the two tunnels, the feeding elements exert an upward force upon the fabric and zipper chain. This upward force is first transmitted through the fabric and zipper to the underside 153 of the zipper foot and through the oblique wall 122' and vertex 126' of the triangular V- body. As earlier indicated, the base topside 82' of the triangular V-body abuts the channel roof 39. Thus, the upward vertical force is carried through the T-block and the zipper foot, to the lower end of the presser bar 28 where the zipper foot is attached; providing vertical displacement of the presser bar in both directions.

FIG. 15 features still another modified form of the insert attachment, including means to adopt the zipper foot 21 with the triangular V-body extending from its channel roof, as seen in FIG. 16. It will be observed that the insert attachment has appearance of an overall 1- configuration; so hereafter, the descriptive reference to the insert will be entitled the I-block, numeral 15 The triangular V-body 116" is also a feature of the I- block and will also perform identical to the triangular V-body 116' of the T-block 10', because it is identical in structure, as seen in the comparison of the faces of includes an elongated tail 125 (see FIGS. 15 and 18) extending rearward from one end of the triangular V- body 116", including a rear lip 129 forming upward and perpendicular from one end of the tail, having an inside face 133. Also, extending upward from the front face of the triangular V-body is a projected from lip 127 also having an inside face 131. A description of how the two lips provide the frictional gripping will follow.

Referring to FIG. 18, the dimension measured from the front inside face 131 to the rear inside face 133 of the I-block is only slightly more than; the dimension measured from the front nose 140 to the rear end 142 of the zipper foot. Therefore, when the triangular V- body 116" is positioned and inserted between the channel walls, the inside faces 131 and 133 will frictionally grip and abut the ends 140 and 142 ,respectively; while the needle slots 16" and 41 fall into alignment. The position of the l-block needle hole 16" is therefore a selected and predetermined distance from its front lip 127. The abutment of the lips with the zipper foot is the means by which the I-block will remain contained in its inserted position during a frontward or rearward motion exerted from the feeding elements.

Both the T-block l and the l-block provide easy inserting. A simple alignment of the nose'plug with the needle slot will obtain the insert of the T-block as it is pushed from its underside. In the case of the I-block, simple positioning of its lips in alignment to receive the length of the zipper foot limb between, pushing upward, will allow the lips to snap around the limb.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a sewing machine presser foot attachment including spaced-apart forward and rearward material engaging portions, said portions being operatively connected by a U-shaped member, the improvement comprising an insert having a longitudinal portion and a transverse portion, said transverse portion adapted to fit snugly into the space between said forward and rearward material engaging portions, said longitudinal portion having a triangular rib along the central portion of its underside. I

2. The apparatus of claim 1 wherein said longitudinal portion includes side walls depending from the longitudinal edges of the underside thereof, said side walls and said rib cooperating to form parallel triangular channels on each side of the apex of said rib.

3. The apparatus of claim 1 wherein said longitudinal portion includes a needle receiving aperture in the central portion thereof.

4. The apparatus of claim 1 including a third material engaging portion spaced transversly from and substantially parallel to said forward and rearward material engaging portions forming a longitudinal .slot therebetween and wherein said longitudinal portion of said insert is adapted to fit snuglyin said longitudinal slot.

5. The apparatus according to claim 4 wherein said forward and rearward material engaging portions are moveable in a transverse direction toward and away from said third material engaging portion, whereby the width of said longitudinal slot may be varied to firmly grip said insert. v

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Claims (5)

1. In combination with a sewing machine presser foot attachment including spaced-apart forward and rearward material engaging portions, said portions being operatively connected by a U-shaped member, the improvement comprising an insert having a longitudinal portion and a transverse portion, said transverse portion adapted to fit snugly into the space between said forward and rearward material engaging portions, said longitudinal portion having a triangular rib along the central portion of its underside.

2. The apparatus of claim 1 wherein said longitudinal portion includes side walls depending from the longitudinal edges of the underside thereof, said side walls and said rib cooperating to form parallel triangular channels on each side of the apex of said rib.

3. The apparatus of claim 1 wherein said longitudinal portion includes a needle receiving aperture in the central portion thereof.

4. The apparatus of claim 1 including a third material engaging portion spaced transversly from and substantially parallel to said forward and rearward material engaging portions forming a longitudinal slot therebetween and wherein said longitudinal portion of said insert is adapted to fit snugly in said longitudinal slot.

5. The apparatus according to claim 4 wherein said forward and rearward material engaging portions are moveable in a transverse direction toward and away from said third material engaging portion, whereby the width of said longitudinal slot may be varied to firmly grip said insert.

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