US2509221A - Welt guide and method for avoiding distortion of welts in welt shoes - Google Patents

Description

May 30, 1950 J. P. FREDERICKSEN WELT GUIDE AND METHOD FOR AVOIDING DISTORTION OF WELTS IN WELT SHOES Filed Nov. 6, 1946 Inventor James P EedGrLc/ s-en l atented May 30, 1950 UNITED STATES PATENT oFFIeE WELT GUIDE AND METHOD FOR AVOIDING DISTORTION OF- WELTS IN WELT SHOES James P. Fredericksen, Braintree, Mass, assignoi to United Shoe Machinery Corporation, Flamington, N. Jr, a corporation of New Jersey Application November 6, 1946, Serial No. 708,056

t Claims. 1

The present invention relates to welt shoe sew.- ing machines and to methods for melting shoes. More particularly, the invention relates to imp'roveinents in a guide for directing a welt against the upper of a, lasted shoe during the formation of an inseam in a manner which enables the succ essful manufacture of a novel and improved type of shoe. An example of a somewhat similar guide on a welt or turn shoe inseam sewing machine isillustrated and described in United States Letters Patent No. 2,361,279, granted on October 24, 1-944, on application of the present inventor. An important object of the invention is to provide a welt guide for an inseam sewingmachine of the type referred to in inventors patent by means of which the welt may be directed against the shoe being operated upon in such manner that theunattachedouter edge of the welt will project away from the upperaiter sewing in a uniformly flat condition without subsequent treatment, which condition is particularly advantageous for insertion of an outseam while attachingthe outsole of the shoe. With welt guides heretofore employed ininseam sewing machines, after the inseam sew-ingop'eration is completed, the welt tends to become distorted from a uniformly flattened condition, particularly around the toe of the shoe, so that it is .after the welt has been "attached, no welt locating operation is required to straighten the. welt and the welt extends. outwardly, uniformly throughout its length in a flattened condition for easy; outseaming. A. Sh e having its; welt in such a condition is not only easier to outseam but actually. is more durable by reason of- .reduced strains and stresses in theparts after as- -semb y.

To, the. endsthusindicated, the illustrated Welt s e is. s pe o r strain. m v m nt of e wel outside. its general plane; as it approaches. the

P n t ne dle erat qn il lee ne t l r e te t n within tse eral p thr u he l mi e an u ar m vement re icted to) th m nt-9ineedlenetime as-a e ten B shee- 2-. ing the guidein manner, each stitch iszinserted and tightened sufficiently to bring one edge of the welt into accurate conformity with the changing curvatures of the shoe, particularly about the toeof the shoe without subjecting the welt to excessive tensional strains. The welt guide thus acts in a manner to cause the stitches tocompress the upper engagingedge of the welt, leaving the outstanding unattached edge of the welt unafiected by. such. tensional strain. as will cause it to be distorted either. against or away from the bulgingupperof the shoe about the toe.

Whilea guideof this nature is useful connection with the manutacture of shoes having welts composed of leather: in any of its wellknown forms or shapes, the benefits derived from sewing a 'welt to (a 'shoe without subjecting the unattached edge of the welt-to excessive tensional strain are even more advantageous in use: when sewing-a Welt composed of "rubber, either natural or synthetic, and many othensimilarhighly resilient substances. Such substances are not permanently deformed mechanically bya welt beating operation so that, it a welt so composed is sewn with substantialtension-along its unattached edge it is practically impossible tobeat it flat aft'e r sewing without subj'ectingthe shoe or thread "in the seam connecting the same to disruptive strains. Even if it is beaten into. fiattened condition it frecli-i'ently will return to its distorted condition before the outseaming operation. When properly sewn with-the. use of a guide of the present invention, anouts'ole may be-attached directly after welting and tr mming the inseam in the shoe-without any welt cheating operation whatever. Thus, by'th'ei-simple expedient of providinga guide embodying therfeatures:ofrthevpres- =ent invention, ian -entireaoperation usualiy p'erformedin the normal manufacture. of Goodyear .welt shoe is eliminated :and .a: shoe is produced having desirable constructional. characteristics.

Other creatures of; 'the=zinvention hereinafter described and: claimed will! :be apparent frorn. vthe following description and accom anying: drawings, inwhich Fig. .1 is. a topplan viewofi a welt 1gu-i de emdying thezpresent, intention wi h .itssunportins bra ket. 'il-lustratin wthe position oi a-l nath of welt passing through the guide;

e 2 s a seet nal. viewi h sn de il trated in Rig; 1 taken along -the line;l;I-.--.I I; of that figure;

F i 3 eti n ly eia i ew i h. g-u il?c pl ne lustr tin ;iis rene nditecti ea l a ain t EhQUPR F Q 151 0 ake 331. 1 hfi lqlifiea stitch is set while sewing about the toe portion of the shoe;

Fig. 4 is a similar view illustrating the positions of the parts after a stitch has been set and before the welt and shoe have been fed a stitch length preparatory to the formation of the succeeding stitch;

Fig. 5 is a view in side elevation of the toe portion of a shoe after inseaming on the usual welt sewing machine; and

Fig. 6 is a similar view after inseaming with the use of the improved guide of the present invention.

The machine in which the illustrated welt guide is employed is similar in many respects to the welt and turn shoe sewing machines disclosed in United States Letters Patent No. 1,108,560 dated August 25, 1914 on application of Andrew Eppler and No. 1,971,575 granted August 28, 1934 on application of Alfred B. Morrill. The present machine is provided with a curved hooked needle 10, a looper l2, and other stitch- .forming and work-engaging devices, the construction and mode of operation of which are similar to those of the patents referred to.

After the operation of the patented machines while sewing a welt to a lasted shoe, a heavy tension in the outside unattached edge of the welt causes the welt to hug the upper about the toe of a shoe so that it cannot readily be sewn to an outsole. Hugging the upper in this way is commonly called strapping and results in distorting the welt in the manner illustrated in Fig. 5. Numerous expedients are employed to prevent or overcome strapping or other distortion in the welt from uniformly flattened condition after welting a shoe. With the use of heavy inflexible welt it is common practice to slash the unattached projecting marginal portion, particularly about the toe of the shoe, with transverse cuts extending diagonally to the sides of the welt to enable easy stretching after inseaming is completed. To supplement slashing, the welt is permanently flattened after being sewn by performing a beating operation which squeezes the welt in the direction of its thickness tending to lengthen the projecting marginal portion and thus relieving the tension in the unattached edge. With leather welt such expedients are more effective in the results obtained than with other types having high elasticity or where the welt before sewing has already been stretched to the limit. A welt beating operation sufficient to flatten heavy Welt after sewing may cause structural damage in the sewing thread, the insole, welt or upper, causing weakness in the completed shoe. Slashing the welt also produces lines of weakness along the cuts formed during slashing so that in some instances slashing may be undesirable. With rubber or composition welt composed of various natural or well-known synthetic substances, slashing or beating is especially detrimental and ineffective in producing the desired results. Furthermore, as the shoe is fed in a sewing machine the welt is pulled through a. welt guide which may offer suificient frictional resistance to add materially to the tension in the welt so as to ofiset the beneficial effects of slashing.

To avoid these difficulties and to enable sewing a welt l3 to a shoe without distortion along the abruptly curving toe portions of the shoe, the welt guide of the present invention is constructed with a. particularly advantageous form for directing the welt during sewing in a manner which reduces to a minimum the tension applied to the welt during feed of the shoe and renders the sewed welt free of any strains which produce strapping or other distortion.

The illustrated welt guide comprises a shield M of generally U-shaped form shaped to fit the thickness of the welt, secured to a mounting bracket or frame l6 similar to that in the patents above identified. The welt guide is also provided with a welt edge gage I8 having a straight guiding edge l9 disposed within the U of the shield l4. Both the shield 14 and the edge gage [8 are secured to the bracket l6 by a bolt 20 having a clamping nut 22 and passing through openings in the shield and bracket and through a slot in the gage. Loosening the nut 22 enables easy adjustment of the gage toward and from a welt edge confining surface 24 (Fig. 4) of the shield M'. The welt guiding edge of the gage [8 extends in the direction of work feed beyond the plane of the needle and its point of operation to confine the welt closely along the line of intersection between the welt and the plane of the needle so that the welt will be guided accurately at the point of the needle operation.

In the usual form of welt guide illustrated in the machines of the patents referred to, the welt guiding edge 15 on the edge gage is parallel to the edge confining surface 24 of the shield l4. The movements of the welt within the guide are thereby restrained and the welt is heldsnugly against the edge confining surface of the shield.

In the welt guide of the present invention, the welt guiding edge l9 of the gage I8 is inclined in respect to the edge confining surface 24 of the shield so that, with the distance between the edge I9 and the surface 24 near the point of needle operation adjusted to a dimension equal to the width of the welt, the corresponding distance at the entrance side of the guide, as shown at the right in Figs. 3 and 4, is sull'iciently reater to enable the welt to swing freely within its general plane through a limited angular movement of approximately ten degrees about the point of needle operation as its center. The shield, however, fits closely with the thickness of the welt so that movement of the welt beyond its general plane at the point of sewing operations is prevented. By arranging the guide for a limited angular movement of the welt within its general plane thus restricted to the point of sewing operation as its center, the welt is enabled to move freely through the guide and to be contracted by the tightening of the stitches readily along its upper engaging edge without imparting substantial tension to the laterally projecting edge of the welt in a manner which prevents distortion of the unattached welt edge after being sewn. The action of a chain stitch seam in this respect is particularly beneficial where the chain of the seam is laid on the welt.

The manner in which angular movement of the welt within its general plane of operation is instrumental in avoiding distortion in the unattached projecting edge of the welt is illustrated more clearly in connection with Figs. 3 and 4 of the drawings. During the penetrating stroke of the needle, the needle first engages the welt close to the edge confining surface 24 of the shield and enters the upper and sewing rib of the shoe indicated at 26 and 28 respectively. If a relatively heavy welt is being sewn the force of the needle in passing through the welt may be insufiicient to press it firmly against the upper amass-1 and the upper may yield somewhat as the point of the needle engages it, causing it toform a slight bulge to separate it from the welt at the point of needle penetration. This separation gives rise to the formation of a small triangular space 30 between the welt and the upper, the shorter side of the space corresponding to the thickness of the end of the shield l4. During the penetration of the needle, therefore, the welt will assume a substantially straightened position with its inner edge engaging the edge confining surface 24 of the shield. After the stitch has been set by tensiom'ng the thread passing through the looper I2 while the needle is still-inthe work and before a new stitch is formed and'tightened by the needle as shown in Fig. 4, the welt is brought by the tension on the thread into close conformity with the upper 26 causing the welt to be deflected against the edge of the shield nearest the needle path. In so doing, the unattached projecting edge of the welt is forced outwardly away from the shoe within the guide against the edge gage with an angular swinging movement, thus producing a slight bend within the plane of the welt in a direction reverse to that produced in bringing the welt into conformity with the curvature of the shoe upper. This reverse bend causes the unattached projecting outer edge of the welt to be compressed somewhat along its length as much as the inner edge. After the shoe and welt are fed a stitch length the welt is bent in the opposite direction enough to straighten it and the needle again enters the parts to draw them together without substantial tension in he projecting welt edge, leaving the aggregate strain in the welt predominantly that of compression. Any strain then existing in the welt is taken up in compression of the upper engaging edge of the welt. Thus, the effects of tension in the unattached edge of the welt which produce distortion of the welt from its general plane are avoided. A shoe to which the welt is sewn by the use of the improved guide is illustrated in Fig. 6. In this shoe the welt is shown projecting outwardly away from the rib of the insole radially of its curvature.

The preferred form of guide is advantageously employed with extruded rubber welt either of natural or synthetic origin or with a welt composed of similiar synthesized substances of wellknown nature. Most of these substances possess characteristics of delayed elasticity, memory effect or long term creep, so called, to an unusual degree. Such characteristics cause a welt composed of these substances after being deformed to return to the shape in which it originally was manufactured unless continually restrained. For this reason, it is common practice to manufacture welt from these substances with a preformed cross sectional shape fitting the angle between the upper and rib of an insole so that after insertion of an inseam connecting the welt to a shoe the projecting marginal portion of the welt will remain in the position at which it is sewn to the shoe without possibility of returning to a flat shape. The illustrated shield 14 of the present invention is shaped to receive a welt having a preformed upper engaging flange of a height substantially greater than the thickness of the main body of the welt which projects outwardly away from the upper. The upper engaging flange is designated by the numeral 32 in Fig. 2. In some instances a moisture excluding storm rib 34 also is added to the welt and in such instances 6, the shield must be shaped to provide sp'ae 'rer the rib. To guide the fl'ange and ther'ib accurately the shieldisshaped to fit these parts close to the point of needle operation by bulges '36, 38 in the shield for receiving these parts. The bulges thus formed are of greater width-at the welt entering side of the shield than at the side close to the point of needle operation from which the welt leaves and accordingly do' not interfere with the swinging movement of the welt.

The shoe sewed by the illustrated welt guide has the unattached edge of its welt projecting outwardly about the toe portion, radially of the toe curvature, as shown in Fig. 6, and, after the outsoling operation has been completed, there is a close-fitting engagement of the outwardly projecting edge of the weltwith the outsole. These results are particularly desirable-not only for general reasons of durability in the completed shoe but also for assistance in maintaining the adjacent surfaces of the welt and outsole in firm contact with each other, thus preventing entry of moisture or deleteriousforeign materials during wear of the shoe. The use of an extruded plastic welt makes such results mandatory, since it is impossible to restrain the unattached edge of the welt in the completed shoe aside from cementing it to an outsole or by inserting the outseam which is spaced some distance inwardly from theedge'. Due to the nature of an extruded plastic welt, if there is any appreciable tension in the projecting welt edge, the edge will tend to separate from the outsole in spite of cement or outseam.

The feature of the invention relating to the method of welting shoes includes the steps of lasting the upper to a ribbed insole about a last, indicated at 40 in Fig. 6, directing one edge of an extruded plastic welt, while in the same structurally relaxed condition occurring after extrusion, against the marginal portion of the upper along the rib of the insole, inserting a chain-stitch seam and straining that edge of the welt being sewn sufficiently in lengthwise compression to cause the desired results to be obtained as above explained. The use of the chain-stitch seam in compressing the welt is taken advantage of by laying the chain of the seam against the welt in the usual way and spacing the welt slightly from the upper during the insertion of each stitch sufiiciently to cause it to be contracted in a lengthwise direction progressively while being drawn toward the rib of the insole as the stitches are being tightened.

Having thus described the invention, what is claimed is:

1. A welt shoe sewing machine having stitch forming devices including a needle in combination with a welt guide, for directing one edge of the welt toward the point of operation of the needle on a shoe, constructed and arranged to fit the thickness of the weld with an edge confining surface and an inclined welt guiding edge disposed at a distance from the confining surface near the point of needle operation equal to the width of the welt, the corresponding distance at the entrance side of the guide being sufficiently greater to enable the welt to swing within its general plane through a limited angular movement restricted to the point of needle operation as its center.

2. A welt shoe sewing machine having stitch forming devices including a needle, in combination with a welt guide for directing one edge of the welt toward the point of operation of the needle on a shoe, said guide comprising a welt enclosing shield formed to fit the thickness of the welt, and a welt edge gage within the shield formed with a straight welt engaging edge disposed opposite the point of needle operation acting with an edge confining surface of the shield to restrain the welt widthwise and extending at an angle to the edge confining surface to enable angular movement of the welt restricted to the point of needle operation as its center.

3. A welt shoe sewing machine having stitch forming devices including a needle, in combination with a weltguide for directing one edge of the welt toward the point of operation of the needle on a shoe, said guide comprising a welt enclosing shield formed to fit the thickness of the welt, and a welt edge gage within the shield formed with a straight welt engaging edge disposed opposite the point of needle operation, acting with an edge confining surface of the shield to restrain the welt widthwise and extending at an angle to the edge confining surface to enable angular movement of the welt restricted to the point of needle operation as its center, said shield being shaped to receive an upper engaging flange on the welt of substantially greater height than the thickness of the main body of the welt, with the width in its flange receiving portion greater at the welt entering side of the shield than at the side of the shield from which the welt leaves to enable angular swinging movement of the welt restricted to the point of needle operation as its center.

4. That method of welting shoes which consists of providing a last having thereon a ribbed insole to which an upper is lasted and an extruded plastic welt in a structurally relaxed condition, directing one edge of the welt, the marginal portion of the upper and the rib on the insole toward the point of operation of a chainstitch sewing machine progressively to attach the welt to the upper and rib in proper relation to lay the chain of the seam against the welt, separating the welt from the upper at the point of needle operation, and tightening each stitch to cause the welt to be compressed along its length and to swing within its own general plane sulficiently to cause the welt to be compressed lengthwise by the chain of the seam progressively during sewing as the stitch is tightened.

JAMES P. FREDERICKSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,151,365 Kiewicz Aug. 24, 1915 2,361,279 Fredericksen Oct. 24, 1944 2,390,485 Wright Dec. 4, 1945

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