Automatic seaming machine starting from a strip

Abstract

 A seamer with straight strip automatic feeding device for shaping undulated clips directly from said strip and contemporary seaming, comprising a seaming plate (4) with a clip feeding hole (5) by means of a clip feeding and seaming stem (18) and provided between these ones with a clip shearing and shaping device (19) from a continuous straight steel strip (n) by step by step feeding device (22).
This seamer is particularly suitable for seaming in a semiautomatic way head frames for shaping squares starting directly from a strip and automatically transforming it in clips for seaming (Fig.3).

Description

[0001] The present invention relates to an automatic seamer starting from a strip which can directly make clips starting from a continuous strip and utilze them for the relative seaming.

[0002] More particularly, the invention is directed to an automatic seamer starting from a strip in which the obtained clip has a serpentiform shape, preferably with a lateral cutting edge in order to be used as jointing clip of two adjacent edges of soft material.

[0003] Preferably the clip shape corresponds essentially to an "M" shape and is intended for being inserted by means of its respective cutting edge transversally orthogonally to the edges of the two joined head elements, as for example two frames 45° diagonally cut to form a frame corner.

[0004] In the present state of the art there is a common knowledge of these types of clips which are made by means of special automatic machines which provide first to sharpen a strip on one edge and then to shape it continuously in serpentiform strip.

[0005] Other machines provide successively to shear the serpentiform strip in more or less long elements constituting the clips which can be then used for seaming.

[0006] There are also seamers which use said clips for seaming frames in a semiautomatic way and furthermore there are well known seamers which start from a continuous serpentiform strip and provide in two successive steps respectively to cut a determined serpentiform strip length and then to insert the cut strip piece shaped like a clip for seaming two joined frames.

[0007] Therefore, these known methods require the utilization of various machines and generally seamers involve at the most the feed of a continuous, previously serpentiform shaped strip to cut it in a determined length forming the clips and carry out the relative seaming.

[0008] But this method involves a high operating cost and as much high a cost to make the clips.

[0009] The present invention is intended to provide a remedy to the above-mentioned disadvantages and particularly to reduce the operating costs and the single used clip cost, starting directly from a straight, not shaped strip.

[0010] The invention as claimed solves the problem and attains the appointed objects providing a machine which can carry out automatically the head seaming of the frames starting directly from a straight-lined strip, in an automatic way.

[0011] To be more positive, the machine according to the invention is provided with means of strip automatic feeding, means of strip shearing and contemporary shaping, and means of seaming of the sheared pieces so shaped to join two head frames. These means are integrated in a single, small sized, extremely simple and not expensive machine so that the seaming cost is reduced of more than one half.

[0012] In fact, comparing the previous method with that of the present invention, it can be noticed that the clip cost with the old method was Lit. 7-8 each, whereas with this new method it is reduced to Lit. 2-3 each.

[0013] The above-mentioned characteristics will be better understood and pointed out and more will appear from the following detailed description of one preferred embodiment with reference to the annexed drawings, in which:-

Figure 1 is a perspective view of the clip from the seaming edge side; Figure 2 is a schematic view of the seaming method between two 45° cut heads to form a 90° frame corner; Figure 3 is a front elevation schematic view of the automatic operating unit according to the present invention with the relative hatched crankcase; Figure 4 is a schematic plan view of the automatic seamer operating unit according to the preceding figure; Figure 5 is an enlarged plan view on the section horizontal plane x-x of Figure 3 showing the strip shearing and shaping operating unit for making the clip and the strip feeding first step to the shearing and shaping unit; Figure 6 is the same view of Figure 5 in the step immediately successive to the clip shearing and shaping start; Figure 7 is a view according to the two preceding figures in which the shearing and shaping tools, after clip complete shaping, are retracted to the position of Figure 5 and the completely shaped clip is free to be axially upward thrusted on the plane normal to the figure for the seaming, and this before the successive strip advancement in the automatic repeating step.

[0014] As it can be noticed from the above described figures and with special reference to Fig.l, the clip consists of a piece of strip obtained by a straight strip "n", shaped like a serpentiform "g" for seaming the ends of two frame heads "c" on the respective 45° cut edges 1, as shown in Fig.2.

[0015] More particularly, the automatic seamer according to the present invention, as shown in Figs.3 and 4, consists of a crankcase 2 which supports an operating unit 3 movable fixed on said crankcase and easily extractable for maintenance.

[0016] The operating unit 3 essentially comprises a plate 4 fixed on the crankase 2 which plate 4 constitutes superiorly the sliding and bearing plate of the splines "c" for seaming with clips "g" from below by means of a rectangular hole made in it 5 and with a small square 6 fixed on plate 4, said small square 6 being connected with two arms 7 provided with a longitudinal slot 7' which allows the guided sliding on the plate 4 and the clamping in position by means of a pair of clamping screws 8 on said plate 4. The reference square 6 can thus be adjusted in the desired suitable position according to the width of the hatched shown splines "c" for seaming according to the hole 5 passing through plate 4. Said plate 4 has two lateral pilot bosses 4' for the vertical free axial- sliding guide of two vertical tubes 9 and on the plate two slightly yielding or elastic plastic material sleeves 10 are applied constituting end of stroke for the tubes 9 which are fixed superiorly on an upper plate 11 and inferiorly on a lower plate 12, the upper plate 11 further comprising in central axial screwing an auger 13 supplied with a presser plate 14 and controlled in lowering by a lowering screw knob 15 for hand adjustement; inferiorly the plate 12 supports, fixed under it, a pneumatic cylinder 16, which stem 17 passes through the plate 12 over it to control upward at the getting out a seaming blade 18 intended to pass through the hole 5 of the plate 4 after passing through the shearing and shaping unit 19 to carry out the seaming of the pair of splines "c" from below on the seaming plate 4. More particularly, the seaming blade 18 has a rectangular section equal to the rectangular section of the hole 5 of the seaming plate 4 and is fixed at the end of the stem 17 by means of a transversal clamping block 20 which can be further adjusted in heigth by means of an adjusting screw system 21.

[0017] The seaming system is therefore devised in such a way that at first the auger 13 is adjusted by means of the screw system 21 and clamping lever 15 to let the presser plate 14 to lower of some millimeters above the pair of splines "c" to be seamed, and that to allow the easy inserting of the pair of splines "c" horizontally against the square 6 previously fixed in the right position by clamping the pair of screws 8, as shown in Fig. 4.

[0018] Being the slack between the presser plate 14 and the splines "c" upper edge only of some millimeters, it will be understood that the stem 17 getting out from the cylinder 16 will thrust upward the seaming blade 18 which will withdraw the clip from the clip shearing and shaping unit 19 to let it slide upward through the rectangular hole 5 and seam it on the head of the frames "c" from below, as shown in Fig.2; of course, when the clip "g" is below . the pair of frames "c" the same pnessure which thrusts upward the clip "g" will cause a downward counterpressure of the guides 9 acting on the upper plate 11 and the presser plate 14 with the whole movable equipment weight and also with the cylinder 16 weight, in such a way that the presser plate 14 weight will always prevail and consequently its pressure on the pair of splines "c", without however distorting them and in spite of that allowing the seaming of the clip "g" from below in a perfect way, as there is a slight elastic yielding of stroke end 10 or of possible felt bushings between said splines slightly yielding for this purpose. More particularly, the straight strip "n" to be shaped is laterally fed by a feeding device 22 to the shearing and shaping unit 19, being the feeding device 22 placed laterally to the plate 4 and below the plate 4 level and the shearing and shaping unit 19 placed below the plate 4 axially under the hole 5 of said plate 4 for clip feeding by means of the above described seaming stem 18. The feeding device 22 comprises a support plate 22' fixed on the plate 4 and supporting a pneumatic cylinder 24 which stem is fixed on a slide 26 which superiorly has a compressed air cylinder 27 fixed on the slide 26 and in which said slide 26 can be alternately horizzontally to-and-fro moved in the feeding direction of strip "n" guided by the stem 25.

[0019] Therefore the cylinder 27 of the slide 26 moves alternately with the slide 26 and said cylinder 27 controls with the relative stem a holdfast 28 to clamp the strip "n", being said cylinder 27 controlled for clamping the strip "n" before the cylinder 24 stem gets out and said holdfast 28 is released by the recall of the cylinder 27 stem before the cylinder 24 stem is recalled back. At the side of the movable clamping device 26,27,28 a fixed clamping device is placed, comprising a fixed cylinder 29 with fixed holdfast 30 operating similarly as the cylinder and holdfast 27,28, and with exactly corresponding synchronism to it in such a way that when the holdfast 28 is clamped, the holdfast 30 is released and when the holdfast 28 is released the holdfast 30 is clamped; so, in operating cooperation with these three devices consequently controlled by the cylinders 24,27,29, there will be a step by step advancement of the strip "n" blade, being the strip feeding size adjustable either adjusting the cylinder 24 stem getting out or adjusting the time when the holdfast 28 is released.

[0020] Then the strip "n" passes below the seaming plate 4 specially downward guided and stretched by a pair of tightness rollers 31,31' cooperating with spring systems 32,32' to insert the blade into the shearing and shaping device of the clip "g", as it will be below described in the device 19.

[0021] More particulraly, Fig.5 is a top view of the shearing and shaping unit 19, which consists of an inlet guide 33 cooperating with a guide prong 34 hinged upstream at 35.to the support block of the unit 19 and supplied with an elastic spring 36 which keeps the guide prong 34 always counterclockwise rotated against a strip "n" surface, whereas on the opposite side, in removable way controlled by a fluid-dynamic cylinder 37 fixed in its turn on the plate 38 fixed to the seaming plate .4, a pair of adjacent tools are provided operating in synchronism and clamped together, respectively shearing tool 39 and shaping tool 40, being on the opposite side respectively fixed the shearing counter-knife 41 and shaping counter-die 42, a port being provided between them for the strip "n" advancement and in which, besides the shaping tool 40 and the fixed shaping counter-tool 42, a groove 43 is provided for free feed of a small quantity of the strip "n".

[0022] More particularly, the movable shearing tool 39 and shaping tool 40 are at the height of the strip "n" but with a sufficient port to let the strip "n" pass freely and the cutting edge of the shearing tool 39 be slightly more projecting than the top of the projecting parts of the shaping tool 40 so that first the shearing start is carried out on the cut edge 44 and only after the shearing for the width of the strip blade "n" the shaping of the sheared piece starts, as shown in Fig.6, to complete the shaping of the sheared piece "g" and then, by recall of the shearing and shaping tools 39 and 40, to cause, through the seaming cylinder 16, the lifting of the seaming blade 18 which extracts the shaped clip "g", as shown in Fig.7, making it slide upward for the shearing from below of the pair of splines "c,c" previously placed on the seaming plate 4, as shown in Fig.4, in order to be seamed, as shown in Fig.2.

[0023] The mechanism is devised so that the machine works with pedal control system and after a starting loadless cycle, by control of the relative pedal (not shown), the fluid-dynamic cylinder 16 is operated causing the lifting of the seaming stem 18 and the relative seaming of the pair of splines "c,c" with contemporary tightness with a slight lowering of the presser plate 14, and only at the stroke end recall of the stem 17 of the cylinder 16 the control of the clamping of the holdfast 28 is given by the cylinder 27 operation and the contemporary releasing of the holdfast 30 by the cylinder 29 operation, and in a few moment sequence the getting out of the cylinder 24 stem causing a one step advancement of the strip "n" in order to be placed as shown in Fig.5, then the holdfast 28 is released and the holdfast 30 is clamped and the cylinder 24 stem is recalled back to the starting position.

[0024] At the same time, that is starting from the end of the advancement caused by the getting out of the cylinder stem 24, the control to get out of its stem is given also to the cylinder 37 to make advance the two tools respectively shearing tool 39 and shaping tool 40 which immediately cause almost contemporarely first the shearing and then the shaping the respective strip portion to then withdraw at the same time or just after the cylinder stem 24 withdraws to come back at the starting position, thus letting the seaming stem 18 to carry out one more seaming.

[0025] It will be understood that during the time passed between one seam and the other caused by the getting out of the stem 17 of the cylinder 16, the machine reloading will be carried out as above described by means of: strip "n" advancement, its shearing and shaping; but these loading operations are carried out in a working dead time not otherwise usable, because in said period the operator must extract the pair of seamed splines "c" from the seaming plate 4 and put again in position, against the square 6, another pair or the adjacent pair for the successive seaming, after which he will press again the control pedal (not shown) to carry out a successive seaming, and so on.

[0026] Therefore, the working of the strip "n" transformation into a clip and the relative seaming is completely automatic, while the machine operating control is manually controlled preferably by means of a pedal system which let the operator's hands free to place the pair of splines "c" against the reference square 6 for the relative seaming in a logic sequence. After all, the machine working is completely automatic with regard to the feeding, shaping of the strip into a clip and seaming system, whereas with regard to its operating control the machine can be defined as semiautomatic, not being this anyhow essential to the effects of the invention.

[0027] Therefore, changes and modifications can be made, without departing from the spirit or scope of the invention as described, illustrated and defined in the appended claims. Udine, March 11, 1983.

Claims

1. Seamer provided with a seaming plate (4), with a clip feeding hole (5) cooperating with an alternately moved clip feeding and seaming stem (18), utilizing clips essentially obtained by a serpentine shaped steel strip possibly sharpened on one edge (g), characterised in
that it comprises a step by step feeding device (22) of straight steel strip (n) cooperating with a strip shearing and shaping device (19) placed between said feeding hole (5) of the seaming plate (4) and said clip feeding and seaming stem (18).

2. A seamer as claimed in claim 1, characterised in that said strip shearing and shaping device (19) is provided, on the orthogonal plane to said clip feeding and seaming stem (18) and orthogonal to the strip (n) feeding direction, with a shearing tool (39) and a shaping die (40) alternately movable and cooperating respectively in contraposition with a shearing counter-tool (41) and a shaping counter-die (4a) placed in a fixed position and aligned respectively at one side and the other of the feeding straight steel strip (n).

3. A seamer as claimed in the preceding claim, characterised in that the shaping die and counter-die (40,42) are placed in such a position that when one (40) is recalled, the free port between them corresponds axially to the seaming free hole (5) so as to allow the passage of the clip feeding and seaming stem (18) in order to transfer a shaped clip (g) released between the shaping die and counter-die (40,42) and feed it, through the feeding hole (5), to the seam getting out from said hole.

4. A seamer as claimed in claims 2 and 3, characterised in that immediately upstream and adjacent to said shaping die and counter-die (40,42), shearing tool and counter-tool (38,41) are placed, being the second one (41) fixed at the height of the projecting parts of the fixed shaping counter-die (42), while the cutting edge of the movable shearing tool (38) is slightly more projecting as regards the most projecting parts of the movable shaping die (40) to cause the strip shearing (n) just a moment before the relative shaping.

5. A seamer as claimed in any preceding claim from 2 to 4, characterised in
that upstream the shearing tools (39,41) and in contraposition to the movable shearing tool (39), an elastic guide prong (34) is placed in order to guide the advancement of the feeding straight strip (n) and, after shearing, to take back, by elastic means (36), the continuous feeding strip (n) head in a straight-line position and adjacent to the cutting edge of the shearing tool (39) now recalled for the relative feeding, after seaming and releasing of the shaping seat between the shaping die and counter-die (40,42) for the relative feeding between them.

6. A seamer as claimed in any preceding claim from 2 to 5, characterised in
that, besides the shaping die and counter-die (40,42), a groove (43) is provided to make the advancement of the strip (1) to be sheared easier.

7. A seamer as claimed in any preceding claim, characterised in that said step by step feeding device consists of three fluid-dynamic feeding and clamping cylinders (24,27,29) in which two of them feeeding and clamping respectively (24,29) are fixed on a fixed support (22') as regards the seaming plate (4) and the other clamping one (27) is movable on a slide (26) and controlled by a stem of the first advancing cylinder (24) placed axially to the straight strip (n) for clip shaping, being the other two (27,29) orthogonally placed and cooperating with two holdfasts (28,30) respectively: the first movable along said strip and the second fixed on the path of said strip to alternately clamp said strip in order to make it advance step by step for the feed to said shearing and shaping device (19), being said shearing and shaping device (19) operated by a fluid-dynamic cylinder (37) working in synchronism with said feeding and clamping cylinders (24,27,29), connected with the fluid-dynamic system that actuates a seaming cylinder (16) to move said seaming stem (18) in such a way as after seaming and recall of the seaming stem (18), the strip (n) is made advance by said clamping cylinder (27) by clamping with its holdfast (28) and at the complete getting out of stem stroke of the feeding cylinder (24), the forming and shearing cylinder (37) is actuated, operating the shearing tool and shaping die (39,40) to advance, and after shearing and shaping, recall back is made while releasing of the movable holdfast (28) and clamping of the fixed holdfast (30) is started to make the movable holdfast (28) be recalled to the starting position to clamp again and wait for the following feeding.

8. A seamer as claimed in any preceding claim, characterised in that the seaming plate (4) cooperates with a reference square (6) adjustable in position (8) and with a counterpressure tightness head (14) adjustable in position (21,15) and controlled in counterpressure by a countertighness plate (11) cooperating with a pair of vertical sliding guides (9) connected with the seaming cylinder (16) under the seaming plate (4) and freely sliding as regards this one. Udine, March 11, 1983.

Drawing