SET TO BE APPLIED TO AN AUTOMATIC PROGRAMMABLE SEWING UNIT SO AS TO ALLOW DARTS TO BE SEMI-AUTOMATICALLY SEWN

Abstract: The device aims at allowing darts to be semi-automatically sewn on garments, more particularly on trousers and skirts. Said device is made up of a set formed by a clamp (9), a counter clamp (19) and a translation plate (1) driven by the feed mechanism of an automatic programmable sewing unit. Fabrics are folded upon the clamp and held to the translation plate by means of the counter clamp, so that, during the sewing operation which is carried out through slots (7), said fabrics do not touch the working surface of the sewing unit.

Description: "Set to be applied to an automatic programmable sewing unit so as to allow darts to be semi-automatically sewn". TECHNICAL FIELD The invention refers to a semi-automatic dart sewing set. 5. BACKGROUND OF THE INVENTION The automatic dart sewing units comprised in the state of the art do have several drawbacks since, during the dart sewing operation, fabrics are held to the working surface by means of a counter clamp while sliding over said 10. surface. The result is that fabrics are not steadily held during the sewing operation and, consequently, darts often turn out irregular in shape and size. A further drawback is that said automatic dart sewing 15. units do not carry out the sewing of darts at a distance of 10 to 15 millimeters from a pocket opening in trousers or skirts since, because of their structure, it is not possible to hold fabrics to the plate which carries them under the counter clamp by which, in turn, said fabrics 20. are held to the working surface. More generically, said units do not allow fabrics to be quickly applied nor to be easily positioned under the needle of the sewing machine. DISCLOSURE OF INVENTION 25. The present invention chiefly aims at providing a device to be applied to a semi-automatic sewing machine, by which it is possible to overcome the above said drawbacks. More generically, the invention aims at providing a means which makes it easier to carry out darts sewing by using a semi-automatic sewing machine, so as to multiply the uses of this type of machines while making easier the commercia1ization thereof. Therefore, the invention solves the problem of the semi¬ 10, automatic darts sewing by using a set which facilitates the accurate and rapid positioning of fabrics under the needle of the sewing machine and which, by avoiding the sliding of said fabrics over the working surface, allows them to be steadily held under said needle. 15, Moreover, the invention allows the set to get automatically blocked to the devices of the sewing machine which carry out the lifting and the positioning upon the work surface; the invention also allows fabrics to be automatically ejected at the end of the operation. 20, The set and its application are illustrated by the enclosed drawings in a preferred embodiment likely to be improved, said drawings showing respectively: fig 1, the translation plate and a side-view of said plate; 25. fig. 2a, a side-view of a clamp, or rather, of the shaped tool, on which fabrics get folded, and the device which allows the rapid blocking thereof to the feed mechanism of the sewing machine; fig. 2b, a top view of the clamp illustrated in fig. 2a; fig. 3a, a side-view of the counter clamp and the relative blocking device; fig. 3b, a top view of the counter clamp; fig. 4, the translation plate with the clamp and counter clamp positioned so as to carry out the sewing 10. operation; fig. 5, the fabric on which a dart has been sewn; fig. 6, the fabric having reference marks in the area where the dart is to be sewn; fig. 7, the four phases of the dart sewing process; 15, fig. 8, an x-view of phase b) of the above process; fig. 9, the set made up of the translation plate, the clamp and the counter clamp intended for straight closed darts; fig. 10, the closed dart sewn by means of the set 20. illustrated in fig. 9; fig. 11, the translation plate intended for straight open darts; fig. 12, the clamp and the counter clamp to be applied to the translation plate illustrated in fig. 11; 25. fig. 13, the dart sewn by means of the set shown in figs. 11 and 12; fig. 14, the clamp and the counter clamp to be applied to the plate shown in fig. 11 so as to carry out the dart sewing in proximity to pockets openings in trousers or 5. skirts; fig. 15, the dart sewn by means of the clamp and the counter clamp shown in fig.14; fig. 16a, the device by which the clamp and the counter clamp get blocked to the feed device of the sewing machine; 10, fig. 16b, a B-view of the blocking device; fig. 17a, a different embodiment of the clamps allowing the borders of the protruding end of waist-bands in skirts or trousers to be sewn on the reverse side; fig. 17b, the translation plate which allows the 15. protruding end of waist-bands to be sewn on the reverse side by using the clamp shown in fig. 16a. The device subject of the present invention is essentially made up of: - a translation plate supporting fabrics, which slides 20. touching the sewing unit working surface by means of the feed mechanism of said sewing unit; - a rod, i.e. a shaped little plate, also named clamp, on which fabrics get folded; - a counter clamp serving for holding fabrics to the 25. translation plate which moves them towards the needle of the sewing machine; - a device applied to the clamp and to the counter clamp so as to allow them to be semi-automatically applied to the feed mechanism of the sewing machine. As it can be seen in fig. 1, the translation plate 1 for angled darts has a rectangular shape and is connected to a supporting smaller plate 2 by means of an additional transversal element l.l and screws 3. The supporting plate 2 gets positioned upon pins PI of an 10. orizontal plate P2 of the sewing machine under the feed mechanism, said pins being introduced into holes 4; said plate 2 is blocked by a piston 5 of a pneumatic type sliding inside a cylinder 35 integral with the supporting arm of said feed mechanism of the sewing machine. 15. Knob 6 does make it easier to hold plate 2 and to assemble it to the orizontal plate P2. The translation plate is provided with a slot 7 allowing the needle of the sewing unit to pass through, and with a little plate 8 having an adjustable position in order to 20. give fabrics a seat 8.1 when they are positioned upon the clamp before the beginning of the dart sewing process. The clamp, on which the fabric has been folded, rests upon the plate 1, see figs. 4, 7b and 8, said clamp being differently shaped according to the type of dart to be 25. sewn, that is, it has a pointed shape, see reference 9 in fig. 2, so as to get angled darts, it has a rounded end, see reference 10 in fig. 9, so as to get straight closed darts, and it is shaped as in fig. 12 and 14, see reference 11, so as to get straight open darts. 5. Each clamp is provided with an additional plate-like element 9.1 having holes so as to let it be integral with a base plate 18 of a device, by means of screws 18.1, see figs. 2, 3, 16a and 16b, said device being made up of a vertical frame 13 joining, on the upper end, a block 14 10, which allows the application to a bearing device 21 integral with a little plate 21.1 vertically sliding inside a guide bearing of the feed mechanism of the sewing machine, so that each clamp moves from the translation plate upwards and vice versa. 15. For this purpose, block 14 is provided with an eyelet 15 and with a hole 17 each receiving, respectively, pin 21.2 and pin 21.3 of the bearing device 21. Said bearing device is, in turn, integral with a plate 30 which is parallel to pins 21.2 and 21.3; plate 30 is 20. provided with a hole 31 into which a pneumatic piston 32 gets introduced to compress hollow 36 of block 14, said piston sliding inside a cylinder 33 integral with said plate 30 by means of screws 34. Fig. 3 shows the counter clamp 19 which has the function 25. of pressing, i.e. blocking, the fabric folded on the clamp upon the translation plate 1. For this purpose, the counter clamp stands by the clamp so as to allow the needle to pass through slot 7, i.e. so as to allow darts to be sewn in the interspace between 5. the clamp and the counter clamp. Also the counter clamp 19 is provided with an additional element 19.1 by which it is connected with the base 18 of device 13 having the same features as the one shown in fig. 2a; the rest surface of counter clamp 19 is provided 10. with a layer 25 made of rubber, felt or any other suitable material so as to facilitate the blocking of the below-sistuated fabric T. Fig. 4 shows the set made up of plate 1, clamp 9 and counter clamp 19 before the beginning of the dart sewing 15, process, i.e. said figure shows the fabric T folded on clamp 9, and counter clamp 19 before pressing the fabric upon the translation plate 1. In order to facilitate the application of the fabric to the clamp, said fabric has cuts Ti which mark the 20. boundaries of the dart to be sewn. Fig. 7 illustrates phases a), b) , c), d) of the sewing operation. Phase a) shows clamp 9 lifted above the translation plate 1 so as to allow the area of fabric T marked by 5 cuts Ti to be folded on said clamp; counter clamp 19 as well is lifted above the translation plate. In phase b) , clamp 9, with the fabric thereupon folded, touches plate 1 in the area of the fabric where the dart is to be sewn and the counter clamp is still lifted. Phase c) illustrates the counter clamp 19 lowered so as to hold the fabric to plate 1 and to allow the sewing operation by means of the needle A through an element 23 and slot 7. At the end of the sewing operation, phase d) , clamp 9 and 10. counter clamp 19 are lifted above the translation plate 1, so that the sewn dart may be removed from the sewing machine. Said removal is automatically provoked by means of a pneumatic device blowing an air jet into bush 24 15. provided with a threaded connection 24.1. Clamps 9, 10 and 11 are provided, at one of their ends, with the air device 24. Fig. 8 shows more in detail phase b) of the dart sewing operation, before lowering the blocking counter clamp 19; 20 in said figure air device 24 is well illustrated. Fig. 9 shows a translation plate 26 provided with slot 27 having a rounded end for straight closed darts as illustrated in fig. 10. Said plate 26 is provided with an additional element 26.1 25. to allow the application to a smaller plate similar to the above described plate 2 to which the translation plate 1 is connected; clamp 10 has a rounded end for closed darts. The clamp has an additional plate-like element 10.1 5. having holes 10.2 which allow the clamp to be connected to the base 18 of the vertical frame 13 which blocks the clamp itself to bearing device 21 integral with the feed mechanism of the sewing machine; the counter clamp which allows closed darts to be sewn is similar to the one 10. used for pointed darts. It is made up of a straight narrow plate 12 having an underlying layer of a material suitable for allowing the below-situated fabric to be held to the translation plate, said counter clamp being provided with an 15. additional plate-like element 12.1 having holes 12.2 which allow the counter clamp to be connected to the base 18 of the device which blocks it to bearing device 21. Features of closed darts are shown in fig. 10. Straight open darts are sewn by using a translation plate 20, similar to the one used for straight closed darts, said translation plate being provided with a rectangular (rather than rounded) slot 28 as well as by using clamp 11 having quite parallel borders, see figs, ll, 12 and 13. 25. Also in this case, clamp 11 has an additional element 11.1 with holes 11.2 which allow the clamp to be connected to the base 18 of the blocking device; counter clamp 20 has the same features as counter clamp 19 and is provided with an additional element 20.1 with holes 20.2 so as to be connected to the base 18 of the blocking device. Fig. 14 shows the clamp and the counter clamp 29 thereupon positioned so as to sew darts in proximity to pockets openings, for example at a distance of about 10 10, millimeters, by means of a translation plate 26, see the pocket border indicated as BT in fig. 15. The size of the various elements which form the set in its different embodiments depends on the size of the garment to be manufactured. 15. The slot allowing the needle to pass through, may also be structured according to other types of darts to be sewn. The present invention also refers to the whole sewing operation carried out by means of the so far described set. 20. Fabrics may be placed upon the clamp from right to left or, vice versa, from left to right, by manufacturing clamps having an inverted structure, i.e. by exchanging the position of the additional plate-like elements by which the clamp and the counter clamp get connected to 5, the feed mechanism of the sewing machine, so that the ends of said clamp and counter clamp be turned in opposite directions; a different inclination of the slots through which the needle passes will also follow. The enclosed drawings illustrate clamps allowing fabrics to be placed from right to left. Figs. 17a and 17b show clamp 37, i.e. a different embodiment of the clamp, shaped so as to allow the borders of the protruding end of waist-bands, which gets buttoned up to said waist-bands other end in trousers or 10. skirts, to be sewn on the reverse side; for this purpose, clamp 37 has a pointed end 37.1 and is provided with an additional plate-like element 37.2, by which said clamp gets connected to the base 18 of the blocking device. After superposing the ends of the two fabric bands 15. forming the waist-band upon a special counter clamp 38.1 of the translation plate 38 for sewing the protruding end of the waist-band, clamp 37.1 is lowered so as to get exactly superposed to said similarly shaped counter clamp 38.1. 20. After sewing the borders of said protruding end on the reverse side through slot 39, the protruding end gets turned on the right side. By means of screws 18.1, plate 38 gets applied to base 18 of the vertical frame 13 of the device which allows said 25. plate to be connected to bearing device 21.

Claims: CLAIMS 1) "Set to be applied to an automatic programmable sewing unit so as to allow darts to be semi-automatically sewn", characterised by three main component parts: 5. a) a flat translation plate to be blocked to the feed mechanism of the sewing unit, so that said plate slides in parallel to the working surface; b) a clamp or plate-like little rod having or not a pointed shape, said clamp having a plate-like extension 10, to it orthogonal, to which a suitable device gets integrally applied, said device allowing the clamp to be blocked to a special bearing device vertically sliding inside a guide bearing of the feed mechanism of the sewing unit, so that said clamp moves from the 15. translation plate upwards and vice versa; c) a counter clamp, i.e. a plate-like little rod provided with a a plate-like extension to it orthogonal which is made integral with a device similar to the one described in point b) , so as to apply said clamp to the feed 20. mechanism, by means of the special bearing device described in point b) ; 2) Set as claimed in claim 1, characterised by the fact that the translation plate is provided with: - a slot which may be straight-lined (7), partially 5, curved (27) or rectangular (28) in shape, so as to allow the needle of the sewing unit to pass through; - a little plate (8) which gives fabrics a seat (8.1) while they get positioned before the beginning of the sewing operation; - a plate-like extension (1.1) allowing the application of a little plate (2) having holes (4) in which pins Pi of the feed mechanism of the sewing unit get introduced, so as to move said plate over the working surface. 3) Set as claimed in claim 1, characterised by the fact 10, that clamps have a plate-like shaped or curved cross section, and straight-lined convergent borders for angled darts or, rather, parallel borders for straight darts. 4) Set as claimed in claims 1, characterised by the fact that the counter clamp holds folded fabrics to the clamp 15. by placing itself by the side of said clamp or, rather, by directly resting upon it; in the first case darts are sewn in the interspace between the clamp and the counter clamp, whereas, in the second case, they are sewn beyond the two overlapped borders of the clamp and the counter 20, clamp. 5) Set as claimed in claim 1, characterised by the fact that the plate-like extension (9.1), (10.l), (20.1) of each clamp or (19.1), (12.1), (20.1) of each counter clamp is provided with holes allowing the steady 25. application to a device by which the clamp or the counter clamp are allowed to get semi-automatically applied to bearing device (21) connected to a little plate (21.1) vertically sliding inside a guide bearing of the feed mechanism of the sewing machine, so as to allow the 5 - latter to move upwards and downwards, said device including a base (18) to which the clamp or the counter clamp get applied by means of screws (18.1), and also including a vertical frame (13) and a block (14) thereupon positioned, said block having orizontal holes 10 • into which two pins (21.2) and (21.3) of bearing device (21) get introduced. 6) Set as claimed in claim 5, characterised by the fact that bearing device (21) is also integral with a little orthogonal plate (30) having hole (31) allowing air 15 • piston (32) to pass through, said piston being driven by cylinder (33) applied to plate (30) by means of screws (34), so as to steadily keep block (14) to bearing device (21) by means of the piston pressure on the hollow (36). 7) Set as claimed in claims 1 and 3, characterised by the 20. fact that each clamp, whatever the embodiment, is provided with bush (24) applied opposite to the end which gets introduced into the fabric fold, said bush (24) receiving an under pressure air jet at the end of the sewing operation, so as to allow the fabric to be 25 • automatically removed. 8) Set as claimed in claims 1 and 2, characterised by the fact that the translation plate is made steadily integral with the feed mechanism of the sewing machine by means of an air piston (5) driven by a cylinder (35) properly 5. applied to said feed mechanism. 9) Sewing process by which darts may be sewn on any type of garments, said process being composed of: a) folding one area of the fabric on a clamp, i.e. a plate-like little rod having suitable length and shape so 10. as to sew different types of darts; b) positioning folded fabrics on a translation plate and pressing them by means of a counter clamp, said translation plate sliding over the working surface of the sewing unit and moving fabrics towards the needle of the 15. sewing unit, so that, during the sewing operation, said fabrics do not touch the working surface of the sewing machine, said sewing operation being carried out by allowing the needle to pass through a suitable slot of the translation plate; 20. c) automatic removal of fabrics by means of an air jet at the end of the sewing operation. 10) Application of the set as claimed in claim 1, characterised by the following phases: phase a: manually folding on the clamp the fabric area 25. marked by two cuts Ti, said clamp being lifted above the translation plate; phase b: lowering the clamp so as to make fabrics touch the translation plate; phase c: lowering the counter clamp in order to block 5e fabrics to the translation plate; phase d: sewing the dart by causing forward movements of the translation plate under the needle A of the sewing unit; phase e: lifting the clamp and counter clamp and 10 . automatically ejecting fabrics at the end of the sewing operation by means of an air jet set on a timer. 11) Application of a translation plate and of a flat clamp so as to allow the borders of the protruding end of waist-bands in trousers or skirts to be sewn on the 15> reverse side, characterised by the fact that clamp (37.1), which is provided with the device allowing it to be applied to the feed mechanism of the sewing unit, has the same shape as said protruding end of waist-bands, and by the fact that the translation plate (38) is provided 2 0 . with counter clamp (38.1) which has size and shape equal to those of clamp (37.1) and which is touched along its perimeter by slot (39) allowing the needle of the sewing machine to pass through. 25.

Inventors: VENTRELLA FRANCESCO, VENTRELLA, FRANCESCO
Applicants: VENTRELLA FRANCESCO, VENTRELLA, FRANCESCO
Application year: 1997
Main classification: D05B
IPC codes: D05B35, D05B39