GB2219317A - Sewing rectilinear edge of first blank to undulating edge of second blank - Google Patents

Description

1 !-,;"' A" C%i -7, -1 4.- 'a- I; '_' 1 7 SEWING APPARATUS FOR

AUTOMATICALLY SEWING A FABRIC HAVING A RECTILINEAR EDGE TO A FABRIC HAVING AN UNDULATING EDGE This invention relates to a sewing apparatus for sewing together straight and undulating edges of pieces of fabric.

This patent application is based on a Japanese patent application No 63134074 filed 31st May 1986, and the sewing apparatus which forms the subject of this application is also related to a further sewing apparatus which forms the subject of Japanese patent application No 63-134073 filed 31 May 1988, and on which a corresponding UK patent application is based, having the same filing date as the present application. The specification of the co-pending UK patent application is hereby incorporated by reference.

In the past, and in general, sewing one piece of cloth or fabric to another one in a curved or sinuous fashion has not, in practice, been accomplished by automatic means because of technical difficulties remaining in such an intricate sewing process. In most cases, an operator has to manually manipulate the separately cut base cloths for curved or sinuous sewing purposes, using a conventional sewing machine. Therefore, an accumulation of skill or expertise has been required to achieve this sewing technique, resulting in obstacles to high efficient and rapid sewing processes of the type which are required to keep abreast with the recent automation-oriented tendency.

The inventor of the present invention previously proposed providing a sewing apparatus to realize the automation of sewing a curved seam. According to this previous proposal, a stationary plate is fixed on the table of a sewing machine and a movable plate is slidably mounted on the stationary plate. The stationary plate has a guide means projected thereon and a sinuous elongated groove 2 formed thereon. On the other hand, the movable plate is formed with a peripheral edge which comforms to a given curved sewing path along which a cloth or base material is sewn from the start point through a generally 90-degreeangle curvature to the end point. This movable plate has a curved guide hole similar in shape to the foregoing sewing path and a dependent guide means projected from the underside of the movable plate. The sinuous elongated groove of the stationary plate is of a configuration corresponding to a track in which the movable plate has to be moved for allowing the cloth or base material to be sewn in such curvature. The guide means of the stationary plate is slidably inserted through the curved guide hole of the movable plate, while the guide means of the movable plate is slidably fitted in the sinuous elongated groove of the stationary plate.

Accordingly, the cloth secured on the movable plate is sewn in a curved manner from the combination of the curved guide hole of the movable plate and sinuous elongated groove of the stationary plate, by virtue of the fact that the curved guide hole serves to guide the movable plate along a generally 90-degree curvature and the sinuous elongated groove serves to cause the movable plate to move along the curved guide hole. Hence, the cloth is automatically sewn in a predetermined curved manner.

But, the above-described first invention hasbeen limited to curved sewing, and sewing to provide a generally sine-shaped or -like sewing pattern has not been made possible. The reason is that the two guide means respectively associated with the stationary and movab.le plates are moved in a mutually co-acting relation for the sole purpose of sewing the cloth along a generally 90 degree-angle curvature. No effective automatic sewing apparatus has yet been proposed for sewing of the sine shaped sewing patterns.

It is therefore an object of the present invention to 3 provide a sewing apparatus which is capable of sewing a rectilinear edge of one piece of base blank material to a sinuous or wavy contoured edge of another piece of base blank material, utilizing the above-mentioned movable and stationary plates.

According to the invention there is provided a sewing apparatus f or sewing a rectilinear edge of one piece of blank material to an undulating or-wavy edge of a further piece of blank material, said apparatus comprising:

a sewing machine body having a stitching head and mounted on a sewing table; stationary plate fixed to said table; movable plate slidably mounted on said stationary plate and having clamp means for securing said further piece of material thereon; three guide grooves provided on a first of said plates and three guide rollers rotatably mounted on a second of said plates and slidably fitted each in a respective one of said guide grooves, wherein the three guide grooves are each formed in conformity with respective paths which are to be followed by said three guide rollers in order that said movable plate can move relative to said stationary plate in such a way that the rectilinear edge of said one piece of material and the undulating or wavy edge of said further piece of material can be maintained adjacent to each other to be sewn together by the stitching head, and wherein two of said guide grooves are formed with widened portions which permit the respective rollers to be slidable along the respective guide grooves; a supplying guide mechanism provided above said movable plate, said guide mechanism being adapted for suppying said one piece of material to a sewing area of said sewing machine body adjacent to said stitching head; and a supportive guide mechanism adapted for supportively guiding and retaining upwardly a free end part of said one piece of material, 4 whereby, in operation of the sewing apparatus, the rectilinear edge of said one piece of material can be sewn to and along said undulating or wavy edge of said further piece of material.

Further, by arranging the guide grooves so that two of them are each formed with a widened groove, while on the other hand, one of them is not so formed, an escape or play zone is given for one of the three guide rollers to be placed in an idle state, thereby allowing smooth movements of the other two guide rollers along their respective acutely curved portions of guide grooves.

Accordingly, when the sewing apparatus is actuated for starting the sewing opertion, the piece of cloth secured on the movable plate is sewn by the apparatus and caused to move in a sewing direction, which in turn causes the sinuous movement of the movable plate relative to the stationary plate, with the three guide rollers of the former being slidably moved along the respective guide grooves of the latter.

In addition to the foregoing movable and stationary plates, the supplying guide mechanism for supplying the rectilinear edged base blank material and the supportive guide mechanism for supportively guiding and retaining upward or upright such blank material during sewing the same to the foregoing other base blank material, are provided on the sewing machine body.

The rectilinear edged base blank material is placed on the supplying guide mechanism, whereas the blank material having a wavy edge is secured on the movable plate. In operation, both forward ends of those two blank materials are drawn by the sewing action of the sewing machine body, whereupon while the wavy-edged material is being subjected to the sewing procedure as described above, the recilinear edged blank material is also drawn and sewn with the wavy edged blank material by operation of the sewing machine body. It is to be noted here that the recilinear edged blank material is supplied by the supplying guide mechanism at a proper angle towards the sewing area of the sewing machine body and then precisely sewn with the wavy lateral edge of the other blank material by means of the supportive guide mechanism. The supportive guide mechanism includes a support roller which is automatically brought into contact with the reverse surface of the rectilinear edged blank material, thus retaining it upward and upright, so that, during the sewing operation, one edge of the rectilinear blank material may be precisely sewn along the wavy lateral edge of the other one. Both supplying guide and supportive guide mechanisms are actuated by means of micro switches provided where appropriate in the foregoing first guide groove and controlled by a suitable computerized controlling means.

The invention will now be described in more detail with reference to the preferred embodiments of the apparatus, given only by way of example, and with reference to the accompanying drawings, in which:

Fig l(A) is a perspective view of a resultant seat covering member formed with the use of an embodiment of sewing apparatus according to the present invention; Fig l(B) is a partially broken perspective view of first and second base blank materials to be stichted together to form the covering member shown in Fig l(A); Fig 2(A) is a partially broken perspective view of a base blank material which is to be sewn by a sewing apparatus in accordance with the present invention; Fig 2(B) is a partially broken perspective view of the base blank material which has been sewn by the same sewing apparatus; Fig 3 is a perspective view of the embodiment of sewing apparatus according to the present invention; Fig 4 is a sectional view of a movable plate part of the sewing apparatus; Fig 5 is a plan view of the movable plate; 6 Fig 6 is a sectional view taken along the line V-V in Fig 5; Fig 7 is a plan view of a stationary plate of the sewing apparatus; Fig 8 is a sectional view taken along the line VII-VII in Fig 7; Fig 9 is a partially broken and perspective view of part of the sewing apparatus; Fig 10 is a partially broken perspective view which particularly shows a supportive guide mechanism of the apparatus in operation; Fig 11 is a perspective view of the guide piece; Fig 12 is a plan view of a f irst base blank material, showing its initial position for sewing; fig 13 is a schematic view showing the movements of the movable plate during a sewing operation; Figs 14(1) to 14(8) are sketch view which roughly show a series of movements of the movable plate as well as a series of sewing processes; Fig 15 is a roughly schematic view of the tracks followed by first, second and third guide rollers of the movable plate; Fig 16M to 16M) are views which illustrate the movement of the three guide rollers along their respective guide grooves as well as the attendant movements of the movable plate; Figs 17M, MB), MC), MD) and ME) are plan views which illustrate the way in which the second base blank material is sewn to the first one; and Figs 18 (A), 18 (B), 18 (C), 1SW) and 18 (E) are sectional views showing the way in which the second base blank material is sewn to the first one, and corresponding with each of the views of Figs 17M through 17M.

Figs 1M and l(B) show a seat covering member B which is affixed over a cushion member (not shown), representing an automotive seat. The covering member B is formed by a 7 sewing apparatus generally depicted at M in Fig 3, which will be described later.

As shown in Fig l(A), the covering member B comprises a central seating portion bl and a pair of side bolster portions b2, each being sewn or stitched with the respective lateral sides of the central seating portion bl.

Fig l(B) shows the shapes of first and second base blank materials bl' and b2', each of them, respectively, corresponding to the central seating portion bl and the two side bolster portions b2, although the figure ony depicts one lateral side of the former bl ' and one of the latter b2'. As shown, one lateral edge bl'-1 and also the other lateral edge of the first base blank material bl' is formed in a sinuous or wavy shape, having a concave-convex contur, with a shape, whereas the inner edge b2'-l of one second base blank b2' and also that of the other one b2' is a rectilinear. The inner edge b2'-l and lateral edge bl'-l are sewn together to form the covering member B which includes a three-layer base blank material al as shown in Figs 2(A) and 2(B) having a sinuously-cut or wavy edge al-1, having a concave-convex contour, or a " " shape. As shown in Fig 2(A) the base blank material al comprises a top cover layer all preferably made of a woven fabric or sythetic resin leather, an intermediate pad payer a12 preferably made of urethane foam and a back layer a13 preferably made of a non-woven cloth.

Fig 2(B) shows the base blank material al with a seam s appearing adjacent and along the wavy edge al-l thereof. In particular, in this figure, the edge al-I is sewn with yarn for preventing fraying which might occur there. - An embodiment of sewing apparatus B is shown in fig 3, and is adapted for sewing the foregoing rectilinear second blank material b2' to the wavy lateral edge bl'-1 of the first blank material bl' so as to produce a threedimensional covering member B with its two lateral side bolster portions b2 dependent from the respective lateral 8 sides of the central seating portion bl.

A stationary plate 1 is f ixed on a table 3 of the sewing apparatus B, and a movable plate 2 is provided on which is mounted the above-stated first base blank material bl' by means of two clamps 20, 20. The movable plate 2 is slidably mounted on the stationary plate 1.

As shown in Fig 5, the movable plate 2 is superposed on the stationary plate 1, and is defined by a sewing operative side 2a adjacent to the sewing machine body 4, a pair of lateral sides 2b, 2b', and a free base side 2c opposite to the sewing operative side 2a.

On the stationary plate 1, a first guide groove 11, a second guide groove 12 and third guide groove 13 are formed (Fig 7), and on the reverse or bottom surface of the movable plate 2, a f irst guide roller 21, a second guide roller 22 and a third guide roller 23 are rotatably provided_ (Figs 5 and 6) in such a manner that the,first, second and third guide rollers 21, 22, 23 can f it and rotate in the first, second and third guide grooves 11, 12, 13, respectively, as can be understood from Fig 4, 5, 6, 7 and 8. A pressing retainer 4b of the sewing apparatus B is adapted to pressingly retain the blank material bl for sewing to blank material b2' in the sewing area 4a.

Referring to Figs 5 and 6, the movable plate 2 comprises a sewing guide plate 25 provided at its sewing operative side 2a. The sewing guide plate 25 extends outwardly from side 2a and includes a concave-convex wavy edge 25a which conforms in shape to the wavy edge bl'-1 of the base blank material bl', a peripheral thickened rim 26 formed along both lateral sides 2b, 2b' and free base sides 2c of the movable plate 2, a pair of the opposingly disposed clamps 20, 20 each being provided on the respective lateral sides 2b, 2b', a recessed area 24 of which is def ined centrally of the movable plate 2 by virtue of the thickened portion 26 being raised circumferentially of the movable plate 2. The first, second and third guide rollers 21, 22, 9 23 are rotatably provided on the reverse surface of themovable plate 2 such that they are dependent therefrom. The concave-convex wavy edge 25a is preferably made of stainless steel or the like material.

The arrangement of these guide rollers 21, 22, 23 is such that, as readily understandable from Fig 5, they are disposed spaced apart from one another in a sense to establish a triangularly positioned relationship with one another, with the first and second rollers 21, 22 being disposed adjacent to the respective lateral sides 2b, 2b' of the movable plate 2 and the second roller 23 being disposed adjacent to the free base side 2c of the movable plate 2.

Referring to Figs 7 and 8, the foregoing first, second and third guide grooves 11, 12, 13 f ormed on the upper surface of the stationary plate 1 are specifically shown. The three grooves are formed in conformity with the respective movement tracks of the f irst, second and third guide rollers 21, 22, 23, the arrangement of those tracks being determined in order for the movable plate 2 to carry proper movement (as can be seen from Fig 14) for subjectng the wavy edge bl'-1 of the base blank material bl' to being sewn in a predetermined sinuous wavy fashion, like a shape, which will be explained later in more detail.

In brief, the first guide groove 11 is formed in a generally dog-leg shape at the left side, the third guide groove 13 is formed in a generally L-shaped configuration at the right side, and the second guide groove 12 is formed in a generally bow shape between the first and third guide grooves 11, 13, as viewed in Fig 7. At one end of the second guide groove 12, there is formed a generally circular widened groove portion 12a, and likewise, at one end portion of the third guide groove 13, an elongated, widened groove portion 13a is formed. Both circular and elongated widened groove portions 13a, 13a are of a greater area than the outer diameters respectively of the second guide roller 23 and third guide roller 22.

The circular widened groove 1 is intended to let the second guide roller 23 remain idle or move freely therein, in the case where (1) the first and third guide rollers 21, 22, both being, of course, fitted in the respective first and third guide grooves 11, 13, pass through such acuately curved portions as indicated at P and P' defined respectively in the first and third guide grooves 11, 13, or (11) the first guide roller 21 is turned in a direction opposite to or different from the direction in which the third guide roller 23 is moved. In this way, the second guide roller 22 does not interfere with the coactive movement of the first and third rollers 21, 22.

The elongated widened groove portion 13a is intended to let the third guide roller 22 remain idle or move freely therein during the initial stage_when the movable plate 2 starts to be moved; namely, when the first and second guide rollers 21, 23 are moved along the respective initial curved points S, S' of the f irst and second guide grooves 11, 12. Accordingly, the third guide roller 22 does not interfere with the initial coactive movements of the first and second guide rollers 21, 23.

As shown in Figs 3, 9, 10 and 11, a supplying guide mechanism 5a is provided on the stationary plate 1, which is adapted for supplying the second base blank material b2' towards the sewing area 4a of the sewing machine body 4, and a supportive guide mechanism 6 is provided on the sewing machine body 4. The supportive guide mechanism 6 is adapted for supportively guiding and retaining the second base blank material b2' upward or upright to thereby cause the latter to be sewn to the first base blank material bl' at a generally right angle relative thereto. In addition, a guide piece 7 is fixed on the stationary plate 2 at the point adjacent to the pressing retainer 4b of the sewing machine body 4.

Referring to Figs 3 and 9, the supplying guide I I mechanism 5a comprises a support arm 51 having a base end fixed on the stationary plate 1, a cylinder 52 mounted fast on the free end portion of the support arm 51, and a guide plate 53 having a channel or U-shaped cross-section which is fixed on the forward end of the rod 52a associated with the cylinder 52. The guide plate 53, therefore, has a pair of lateral vertical walls 53a, 53b and is adapted to receive therein the second blank material b2'. Further, the guide plate 53 is caused to move the support arm 51 in the longitudinal direction by operation of the cylinder 52 for the purpose of adjustably displacing the guide plate 53 towards and away from the forward end of the support arm 51, as shown by the arrows in Figs 9 and 10. As shown, the guide plate 53 is directed towards the sewing area 4a at such an angle as to dispose the initial corner of the inner edge b2'-l of the second blank material b2' in a direction to be flush with the initial corner and descending curved area of the wavy lateral edge bl'-1 of the first blank mater i a 1 b I ', as can be observed f rom F i g 17 (A). Further, the guide plate 53 is inclined at a proper angle which permits smooth downward f low of the second blank material b2' towards the sewing area 4a and facilitates the ease of the natural upturning of the second blank material b2' from the first blank material bl' during sewing, which will be explained later.

The guide piece 7, as best shown in Fig 11, comprises a base rod 7a f ixed to the sewing machine body 4 in the vicinity of the pressing retainer 4b of the latter and a guide support portion 7b having a channel or U-shape in section. The guide support portion 7b has a guide passageway S defined therein having a width which is greater than the thickness of the second blank material b2' and adapted for supportively receiving the inner edge b2'-l of the second blank material b2'. In operation, the second blank material b2' is supplied along such guide piece 7 precisely from the guide plate 53 in a direction towards the 12 needle 8, for sewing with the wavy lateral edge bV-1 of the first blank material bl'.

It should be noted that the guide piece 7 is normally aligned with the inward lateral vertical wall 53a of the guide plate 53, except in the case where the guide plate 53 has to be moved when the sewing procedure approaches a terminal point or returns to an initial point, as will be set forth later.

The supportive guide mechanism 6 comprises a cylinder 63 fixed via a support bracket 64 to the head portion of the sewing machine body 4. The cylinder 63 has a movable rod 63a provided at the rearward end side thereof, a generally dog.-leg shaped arm 62 which is composed of an upper end 62a, a lower end 62c, and a bent pointed part 62b joining the upper end 62a to the lower end 62c. A guide roller 61 is provided rotatably at the lower end 62c of the ar m. 62.' The upper end 62a of the arm 62 is pivotally connected to the rod 63a of the cylinder 63, while the bent pointed part 62b of the same is pivotally connected to the lower part of the support bracket 64. Hence, the forward and backward movements of the rod 62a, by operation of the cylinder 63, causes the backward and forward movements of the support roller 61, respectively.

The above described supplying guide mechanism Sa and supportive guide mechanism 6 are disposed at the opposite sides of the sewing machine body 4, as illustrated. Those two mechanisms 5a, 6 are electically actuated. with such an arrangement that both of them are electrically connected with a first micro switch 101 provided in the first guide -groove 11 at the acutely curved region (substantially as shown in Fig 3). Therefore, in practice. when the first guide roller 21 passes through such region, thus switching on the first micro switch 101, the supportive guide mechanism 6 starts to work. The cylinder 63 causes the forward movement of the rod 63a to move the guide roller 61 via the dog-leg arm 62 in a direction backwards towards the 13 sewing machine body 4, and at a proper time thereafter about seven seconds, for example), the supplying guide mechanism 6 is actuated by means of a suitable timer (not shown), with its cylinder 52 causing the backward movement of the guide plate 53.

Although not exactly shown, the distance between the guide plate 53 and guide piece 7 is relatively small so as to guide the whole body of the second blank material b2' towards the pressing retainer 4b and needle 8 of the sewing machine body 4, so that, at the last sewing process, the terminal end of the second blank material b2' may be moved by the guide plate 53, as will be explained later.

As shown in Fig 3, a second micro switch is provided in the terminal end of the first guide groove 11, the second micro switch being adapted for switching off the sewing operation of the sewing machine body 4. When the f irst guide roller 11 reaches the terminal end of the first guide groove 11, the second micro switch 102 is actuated by the first guide roller 11 so as to cut the current flow to the sewing machine body 4, whereby the sewing action of the latter is stopped.

Now, with reference to Figs 12-16, 17(A) to ME) and 18(A) to 18M, a description will be made of the operation of the above-described sewing apparatus, starting with a description of the movement of the movable plate 2.

Fig 12 shows the initial condition or position of the movable plate 2. Hence, from the shown position, the movable plate 2 starts to be moved, allowing the sewing of the wavy edge bl'-1 of the base blank material bl', as will be described with reference to Figs 13-16.

Fig 13 schematically shows the continuous flow of movements of the movable plate 2 when the sewing operation is being affected. From this f igure, it is seen that the sliding movement of the first, second and third guide rollers 21, 22, 23 along the respective guide grooves 11, 12, 12a, 13, 13a causes the illustrated series of movements 14 of the movable plate 2. In this particular figure, the movable plate 2 is caused to move in the following order; f irst, at the initial point designated by 101, and thereafter, through the subsequent points 102, 103, 104, 105, 106, 107 in the direction of the arrow, down to the terminal point 108. Reference numerals 11', 12', 13' denote the trac - ks or paths which are followed respectively by the first, second and third guide rollers 21, 22, 23 during such series of movements of the movable plate 2.

Figs 14(1) to 14(8) shows the individual po sitions of the movable plate 2 from the initial point 101 to the terminal points 108 as shown in Fig 13. Thus, the segmental diagrams 101, 102, 103, 104, 105, 106 107 and 108 associated with the movable plate 2, as shown in Fig 13, correspond respectively to the sketch diagrams 101 in Fig 14(l) 102 in Fig 14(2), 103 in Fig (14(3) 104 in Fig 14(4), 105 in Fig 14(5), 106 in Fig 14(6), 107 in Fig 14(7) and 108 in Fig 14(8). From those figures, the positional state of the movable plate 2 relative to the needle 8 of the sewing machine body 4 can be observed, and also there is shown, by the dotted line, the way in which the wavy edge bl'-l of the base blank material bl' is sewn by the needle 8 Referring to Fig 15, the movement tracks which are respectively drawn by the above stated first, second third guide rollers 21, 22, 23 in the course of their movements along their corresponding guide grooves 11, 12, 13 are shown in solid lines. The numerals 11', 12' and 13' refer to the first path followed by the first guide roller 21, the second path followed by the second guide roller 22, and the third path followed by the third guide roller 23, respectively.

In this context, comparison between Fig 15 and Fig 14 leads to the understanding of the positional relation between those three paths 11', 12', 13' and the movable plate 20. Namely, the numerals 111, 121, 131 in Fig 15, which represent the respective initial positions of the first, second and third guide rollers 21, 22. 23 along their respective paths 11 12', 13', indicate the initial point of the movable plate 20 shown in Fig 14(1), the subsequent second set of numerals 113, 123, 133 and third set of numerals 115, 125, 135 in Fig 15, which are of course associated with the three guide rollers 21, 22,- 23, respectively, indicate the second point of the movable plate 20 in Fig 14(3) and the third point of the same plate 20 in Fig 14(5), and the last fourth set of numerals 116, 128, 138, which represent the respective terminal positions of the three guide rollers 21, 22, 23, indicate the terminal point of the movable plate 20.

Fig 16M through 16(IV) show the movements of the movable plate 2 relative to the stationary plate 1. Fig 16(1) shows the initial state where the movable plate 2 is located at the starting point, with its first, second and third guide rollers 21, 22, 23 being respectively located at the initial ends of the first, second and elongated widened grooves 11, 12, 13a formed on the stationary plate 2. This initial state corresponds to Fig 14(1) and the numerals 111, 121, 131, in Fig 15. Subsequent thereto, the second state in Fig 16(11) corresponds to Fig 14(3) and the numerals 113, 13, 133 in Fig 15, the third state in Fig 16(111) corresponds to Fig 14(5) and the numerals-115, 125, 135 in Fig 15, and the fourth state in Fig 16M) corresponds to Fig 14(8) and the numerals 118, 128, 138. Thus, the comparative viewing of the Figs 13 to 15 and 16(1) to 16M) gives

a general understanding of the basic movements of the movable plate 2 relative to the stationary plate 1.

Now, reference will be made to Figs 17(A)-17(E) and 18M-18(E) for a description of the sewing operation.

First, the first base blank material bl' is placed and secured on the movable plate 2, and then the second base blank material b2' is mounted on the guide plate 53 as well as inserted through the guide piece 7, as in Fig 9. In the embodiment shown, the first blank material bl' comprises a 16 three- 1 ayer st ructure 1 i ke that shown i n F 1 gs 2 (A), 2 (B), including a top cover layer bl'-2, an intermediate pad layer bl'-3 and a back layer bl'04, and the second blank material b2' is just one sheet of cloth or the like. But, the latter material b2' may comprise the same three-layer structure as the first blank material b2'.

When the sewing apparatus is turned on to start sewing the inner edge b2'1 of the second blank material b2' to the lateral edge bl'-1 of the first blank material bl', the vertical reciprocal motion of the needle 8 and the feeding action of the pressing retainer 4b and feeding member (not shown) associated with the sewing machine body 4 draw both first and second blank materials bl', b2', to thereby cause the movement of the movable plate 2 from an initial position to a terminal point and simultaneously cause the downward movement of the second blank material b2 through both guide plate 53 and guide piece 7.

This sewing stage is understandable from Figs 17M and MB).

In the course of the sewing procedure in Figs 17M and MB), the free outer edge of the second blank material b2' opposite to its inner edge b2'-1 is forcibly upturned from the upper surface of the first blank material bl', as observed from Fig 18(B). This is based on the reason that as the sewing proceeds to the downwardly arced valley area lb' of the wavy lateral edge bl'-1, the second blank material b2' is twisted, with its free outer edge being naturally upturned as in Fig 18(B).

Then, the sewing proceeds to the midway point c and the first guide roller 21 of the movable plate 2 passes the acutely curved region in the first guide groove 11, switching on the first micro switch 101. As a result, the cylinder 63 is actuated to move the rod 63a forwardly, which in turn causes the dog-leg arm 62 to rotate about the pivot point at its bent pointed part 62b in an upward direction thereby causing the backward movement of the support roller 17 61 f ixed at the lower end 62c of the arm 62. The support roller 61 is thus brought in to contact with the reverse surface of the second blank material b2' which is being upturned, and retains it generally upright, as observed f rom F i g 18 (C), so that the i nner edge b2'- 1 thereof i s precisely sewn along the wavy lateral edge bl'-l of the first blank material bl'.

When the sewing proceeds close to the top of the crest area 2b of the wavy lateral edge bl'-l, as shown in Fig 17(D), the supportive guide mechanism 6 is automatically caused to reversely actuate the cylinder 63 by means of a suitable computerized control (not shown) so as to move the rod 63a backwardly, causing the dog-leg arm 62 to rotate upwardly, thereby tilting the support roller 61, as shown in Fig 18(D), to gently bend the second blank material b2' towards the sewing machine body 4, for the purpose of precisely sewing the inner edge b2'-l along the convex crest area 2b of the wavy lateral edge bl'-I. This reverse motion of the supportive guide mechanism 6 is necessarily effected in view of the fact that, (1) the movable plate 2 is tilted at a reverse angle, as seen in Fig 18(D), with respect to its early states shown in Figs 17(B) and 17(C), as a result of which the position of the support roller 61 has to be changed downwardly from the circle given in Fig 17(C), which indicates the needle 8 situated below the support roller 61, down to the circle in Fig 17(D) which indicates the needle 6 situated above the support roller 61, and that, (ii) the free outer edge of the second blank material b2' tends to bend downwardly towards the upper surface of the first blank material bl' in contrast to its early upturning phenomenon as shown in Fig 18(B), which requires further forcible bending of the second blank material b2' so as to bias its inner edge b2'-l in a direction to run along the crest area 2b of the wavy lateral edge bl'-l of the first blank material bl' for precise sewing purposes.

However, as shown in Fig 17(D), before the sewing 18 operation is effected to sew the remainder terminal part 3 of the inner edge b2'-1 along the corresponding remainder part of the wavy lateral edge bl'-1, attention is drawn to the difference d between those two remainder edges, which is created due to the unmoved status of the guide plate 53 in relation to the rotational movement of the movable plate 2. In other words, the teminal part b2' remains in a nondisplaced condition by reason of its being placed on the guide plate 53 in relation to the displaced condition of the corresponding terminal part of the second blank material b2' secured on the movable plate 2, with the result that the remainder terminal part b2'-2 can not be sewn along the corresponding terminal part of the wavy lateral edge bl'-1 associated with the first blank material bl'. Then the sewing apparatus is so programmed to actuate the supportive guide mechanism 6 to move the support roller 61 backwards towards the sewing machine body 4, thereby standing the second blank material b2' upright as shown in Fig 18M, and at the same time, to actuate the supplying guide mechanism 5a to move the guide plate 53 backwards by means of the previously stated timer (not shown) in assocliation with the first micro switch 101, as set forth above in the arrow direction as shown in Fig 9, whereby the remainder terminal part b2'-2 of the second blank material b2' is sewn precisely along the corresponding part of the first blank material bl'.

Accordingly, at the final sewing stages, as shown in Fig ME), the sewing procedure is completed, with the second base blank material b2' being sewn along the wavy lateral edge bl'-1 of the first base blank material bl', whereupon there is obtained such three-dimensional covering member B as in Fig 1 (A), in which the lateral portions b2, which corresponds to the foregoing second base blank material b2', are integrally formed at the respective lateral sides of the central seating portion bl which corresponds to the foregoing first base blank material bl'.

19 In accordance with the embodiments of the invention, it will be appreciated that the rectilinear base blank material can be sewn along the sinuous or wavy edge of other blank material precisely in an automatic manner, by virtue of the supplying guide mechanism 5q acting to supply the rectilinear base blank material towards the sewing area of the sewing machine body and of the supportive gude mechanism 6 acting to retain such base blank material in an upwardly standing posture for precisely sewing with the wavy edge of other blank material in cooperation with the particular movements of the movable plate.

Finally, the above descriptions have been made with reference to the embodiment illustrated, but it should be understood that the present invention is not limited to this embodiment and any other various modifications, alterations and additions may structurally be possible without departing from the spirit and scope of the appended claims for the invention. For instance, the guide rollers 21, 22, 23 and guide grooves 11, 12, 13 may be provided at the stationary plate 1 and moveable plate 2 respectively, contrary to the above-described embodiment, and the arrangements of those guide rollers and grooves may be altered to other suitable manner insofar as it permits a proper movement of the movable plate 2 for creating any kind of sinuous or wavy pattern of sewing path. The same goes for the wavy edge 25a of the movable plate 2. Also, the base blank material bl ' is not limited to the one having a sinuously-cut edge bl'-1 but may be provided as an ordinary rectangular material, with a view to using the sewing apparatus Bas a means for giving a decorative sinuous or wavy seam on such ordinary material.

The present invention is not limited to the illustrated embodiment, but, for example, the above-stated three guide rollers 21, 22, 23 and guide grooves 11, 12, 13 may be provided on the stationary plate 1 and movable plate 2, respectively, in contrast to those of the above-described embodiment. Also, a suitable blade may be equipped adjacent the needle 8 of the sewing machine body 4, whereby a 'I rectilinear base blank material can be sewn and cut at one time to create a wavy edge with seam at its lateral side. P, T 21

Claims (6)

1 A sewing apparatus for sewing a rectilinear edge of one piece of blank material to an undulating or wavy edge of a further piece of blank material, said apparatus comprising: a sewing machine body having a stitching head and mounted on a sewing table; a stationary plate fixed to said table; a movable plate slidably mounted on said stationary plate and having clamp means for securing said further piece of material thereon; three guide grooves provided on a first of said plates and three guide rollers rotatably mounted on a second of said plates and slidably fitted each in a respective one of said guide grooves, wherein the three guide gr-ooves are each formed in conformity with respective paths which are to be followed by said three guide rollers in order that said movable plate can move relative to said stationary plate in such a way that the rectilinear edge of said one piece of material and the undulating or wavy edge of said further piece of material can be maintained adjacent to each other to be sewn together by the stitching head, and wherein two of said guide grooves are formed with widened portions which permit the respective rollers to be slidable along the respective guide grooves; a supplying guide mechanism provided above said movable plate, said guide mechanism being adapted for supplying said one piece of material to a sewing area of said sewing machine body adjacent to said stitching head; and a supportive guide mechanism adapted for supportively guiding and retaining upwardly a free end part of said one piece of material, whereby, in operation of the sewing apparatus, the rectilinear edge of said one piece of material can be sewn 22 to and along said undulating or wavy edge of said further piece of material.

2. Apparatus according to Claim 1, in which the three guide grooves are formed on an upper surface of the stationary plate, and the three guide rollers are rotatably mounted on the underside of said movable plate.

3. Apparatus according to Claim 1 or 2, wherein said supplying guide mechanism includes a support arm fixed on said stationary plate, a cylinder mounted on said arm and having a rod, and a guide plate f ixed at a forward end of said rod, said guide plate being formed so as to be capable of receiving thereon said one piece of material in such a manner that operation of the cyliner can cause forward and backward movement of said guide plate; and wherein said supportive guide mechanism includes a cylinder having a rod, a generally dog-leg shaped arm. having one end portion pivotally connected to said rod and being arranged to be rotatable about its middle part, and a support roller rotatably mounted at the other end portion of said arm in such a way that operation of the cylinder causes forward and backward movement of said support roller via said arm, in order to bring said support roller to contact said one piece of material and to retain said free end part thereof upwardly during sewing of the rectilinear edge of said further piece of material to the undulating edge of said one piece of material.

4. Apparatus according to Claim 3, wherein said supplying guide mechanism and said supportive guide mechanism are arranged to be actuated under timed control sufficient for the rectilinear edge of said further piece of material to be sewn along said undulating edge of said one piece of material, the control being exercised by means of a micro switch provided in one of said three guide grooves.

5. Apparatus according to Claim I and substantially herein described with reference to, and as shown in the accompanying drawings.

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6. A method of sewing or stitching a rectilinear edge of one piece of material to an undulating edge of a further piece of material automatically, using apparatus according to any one of the preceeding Claims.

Published 1989 at The Patent office, State House, 66 71 High Holborn. London WClR 4TP. Further copies maybe obtained from The Patent Office. Sales Branch, St Mary Cray, Orpington, Kent BR5 3PM. Printed by Multiplex techniques Ad. St Mary Cray, Kent, Can. 1/87