EP0088053B1

EP0088053B1 - Automatic seaming machine starting from a strip

Info

Publication number: EP0088053B1
Application number: EP83830037A
Authority: EP
Inventors: Corrado Giacomet
Original assignee: FIORENZA Srl
Current assignee: FIORENZA S.R.L.
Priority date: 1982-03-02
Filing date: 1983-02-17
Publication date: 1987-10-28
Also published as: ATE30398T1; IT1158077B; IT8283335A0; DE3374186D1; EP0088053A3; EP0088053A2

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.

Description

The present invention relates to a joint-nailer starting from a strip which can directly make clips starting from a continuous strip and utilize them for joining two parts.
More particularly, the invention is directed to a joint-nailer starting from a strip in which the obtained clip has a serpentineform shape, preferably with a lateral cutting edge in order to be used as jointing clip of two adjacent edges of soft material.
Preferably the clip shape corresponds essentially to an "M" shape and is intended for being inserted by means of its respective cutting edge tranversally orthogonally to the edges of the two joined head elements, as for example two frames 45° diagonally cut to form a frame corner.
- 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 for sharpening a strip on one edge and then for shaping it continuously in serpentineform strip (US-A-2050009-McCHESNEY).
Other machines provide successively for shearing the serpentine form strip in more or less long elements constituting the clips which can be then used for joining the two parts.
There are also joint-nailers which use said clips for joining frame components in a semiautomatic way and furthermore, there are well known sea- mers which start from a continuous serpentineform strip and provide in two successive steps respectively cutting a determined serpentineform strip length and then to insert the cut strip piece shaped like a clip for nailing together two joined frames (DE-A-2919564,-MOTTA).
Therefore, these known methods require the utilization of various machines and generally joint-nailers involve at the most the feed of a continuous, previously formed serpentineform shaped strip to cut it in a determined length forming the clips and carry out the relative nailing.
But this method involves a high operating cost particularly to make the clips.
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 non-shaped strip.
The invention as claimed solves the problem and attains the appointed objects providing a machine which can carry out automatically the head joining of the frame components starting directly from a straight-lined strip, in an automatic way.
To be more positive, the machine according to the invention is provided with means for strip automatic feeding, means for strip shearing and contemporary shaping, and means for joining of the sheared pieces so shaped to joint two head frames.
These means are integrated in a single, small sized, extremely simple and not expensive machine so that the joining cost is reduced by more than one half.
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.
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 edge side used for joining; Figure 2 is a schematic view of the joining 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 crankcase shown in hatched section; Figure 4 is a schematic plan view of the automatic joint nailer 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 succeeding 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.
As it can be noticed from the above described figures and with special reference to Fig. 1, the clip consists of a piece of strip obtained by a straight strip "n", shaped like a serpentineform "g" for joining the ends of two frame components "c" on the respective 45° cut edges 1, as shown in Fig. 2.
More particularly, the joint-nailer 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.
The operating unit 3 essentially comprises a plane 4 fixed on the crankcase 2 which plate 4 constitutes the sliding and bearing plate for the components "c" for joining with clips "g" from below by means of a rectangular hole 5 made in it 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 components "c" for joining according to the hole 5 passing through plate 4.
Said plate 4 has two lateral pilot projections 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 at the top to an upper plate 11 and at the bottom to a lower plate 12, the upper plate 11 further comprising a centrally located screw auger 13 supplied with a presser plate 14 and controlled in lowering by a lowering screw knob 15 for hand adjustment; the plate 12 supports, at its lower surface, a pneumatic cylinder 16, the piston rod 17 of which passes through the plate 12 to control the upward movement of a blade or driver 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 joining of the pair of components "c" from below on the plate 4. More particularly, the blade 18 has a rectangular section equal to the rectangular section of the hole 5 of the plate 4 and is fixed at the end of the rod 17 by means of a transversal clamping block 20 which can be further adjusted in height by means of an adjusting screw system 21.
The joint-nailer 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 pressure plate 14 to be lowered by some millimeters to a level above the pair of components "c" to be joined, and to allow the easy inserting of the pair of components "c" horizontally against the square 6 previously fixed in the right position by clamping the pair of screws 8, as shown in Fig. 4.
As the clearance between the pressure plate 14 and the upper edge of the components "c" is only a few millimeters, it will be understood that the rod 17 will thrust upward the 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 insert it on the head of the frame components "c" from below, as shown in Fig. 2; of course, when the clip "g" is below the pair of frames "c" the same pressure 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 will exert pressure on the pair of components "c", without however distorting them and in spite of that will allow the insertion of the clip "g" from below in a perfect way, as there is a slight elastic yielding at the end of the stroke because of sleeves 10. Alternatively, felt bushings 7, 7' between said components slightly yielding for this purpose may be provided.
More particularly, the straight strip "n" to be shaped is laterally fed by a feeding device 22 to the shearing and shaping unit 19, the feeding device 22 being 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 blade 18.
The feeding device 22 comprises a support plate 22' fixed on the plate 4 and supporting a pneumatic cylinder 24 the piston rod of which is fixed on a slide 26 above which a compressed air cylinder 27 is fixed on the slide 26 and in which said slide 26 can be alternately horizontally moved to-and-fro in the feeding direction of strip "n" guided by the stem 25.
Therefore the cylinder 27 of the slide 26 moves alternately with the slide 26 and said cylinder 27 controls, with its piston rod, a holding means 28 to clamp the strip "n", said cylinder 27 being controlled for clamping the strip "n" before the cylinder 24 rod is extended and said holding means 28 is released by the retraction of the cylinder 27 rod before the cylinder 24 rod is retracted.
At the side of the movable clamping device 26, 27, 28 a fixed clamping device is placed, comprising a fixed cylinder 29 with fixed holding means 30 operating similar to the cylinder and holding means 27, 28, and with exactly corresponding synchronism to it in such a way that when the holding means 28 is clamped, the holding means 30 is released and when the holding means 28 is released the holding means 30 is clamped; thus, 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, the strip feeding size being adjustable either by adjusting the cylinder 24 rod extension or by adjusting the time when the holding means 28 is released.
Then the strip "n" passes below the plate 4 specially downward guided and stretched by a pair of tightening 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.
More particularly, Fig. 5 is a top view of the shearing and shaping unit 19, which consists of an inlet guide 33 cooperating with a guide member 34 hinged upstream at 35 to the support block of the unit 19 and supplied with an elastic spring 36 which keeps the guide member 34 always counterclockwise rotated against a strip "n" surface, whereas on the opposite side, a control fluid-dynamic cylinder 37 is provided fixed in its turn on the plate 38 fixed to the plate 4, a pair of adjacent tools being provided operating in synchronism and clamped together. A shearing tool 39 and shaping tool 40, respectively fixed on the opposite side of the shearing counter-knife 41 and shaping counter-die 42 are provided, a clearance being also provided between them for the strip "n" advancement and in which, besides the shaping die 40 and the fixed shaping counter-die 42, a groove 43 is provided for free feed of a small quantity of the strip "n".
More particularly, the movable shearing tool 39 and shaping die 40 are at the height of the strip "n" but with a sufficient clearance 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 die 40 so that first the shearing operation 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 retraction of the shearing and shaping dies 39 and 40, to cause, through the cylinder 16, the lifting of the 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 components "c, c" previously placed on the plate 4, as shown in Fig. 4, in order to be joined, as shown in Fig. 2.
The mechanism is devised so that the machine works with pedal control system and after a starting loadless cycle, by control of the pedal (not shown), the fluid-dynamic cylinder 16 is operated causing the lifting of the stem 18 and the joining of the pair of splines "c, c" with consecutive tightening with a slight lowering of the presser plate 14, and only at the end of the rod retraction stroke of the cylinder 16 is the control given to the holding means 28 by the cylinder 27 operation and the simultaneous release of the holding means 30 by the cylinder 29 operation. Next retraction of the cylinder 24 rod causes a one step advancement of the strip "n" in order to be placed as shown in Fig. 5, then the holding means 28 is released and the holding means 30 is clamped and the cylinder 24 rod is retracted to the starting position.
At the same time, that is starting from the end of the advancement caused by the cylinder rod 24 extension, the control is given also to extend the rod of cylinder 37 to advance respectively the shearing tool 39 and shaping tool 40 which immediately cause almost consecutively first the shearing and then the shaping the respective strip portion, to then withdraw at the same time or just after the cylinder rod 24 retracts to its starting position, thus letting the rod 18 carry out one more joining operation. It will be understood that during the time passed between one joining operation and the next caused by the extension 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 joined components "c" from the plate 4 and put again in position, against the square 6, another pair or the adjacent pair for the successive joining operation, after which he will press again the control pedal (not shown) to carry out a successive joining operation, and so on.
Therefore, the working of the strip "n" transformation into a clip and the joining operation are completely automatic, while the machine operating control is manually controlled preferably by means of a pedal system which lets the operator's hands free to place the pair of components "c" against the reference square 6 for the joining operation in a logical sequence. Thus, the machine working is completely automatic with regard to the feeding, shaping of the strip into a clip and joining system, whereas with regard to its operating control the machine can be defined as semiautomatic, this not being however essential to the effects of the invention.

Claims

1. Joint-nailer utilizing clips obtained from a steel strip sharpened at one edge comprising a nailing plate (4) having a clip feeding opening (5) with which a reciprocating clip-feeding and nailing driver (18) cooperates and a discontinuous feeding device (22) for the steel strip (n) synchronised with a strip shearing device (39, 41) located between said clip feeding opening (5) of the nailing plate (4) and said clip-feeding and nailing driver (18), which strip shearing device (39, 41) is aligned in a plane orthogonal to said clip feeding and nailing driver (18) and orthogonal to the strip-feeding direction and comprises a reciprocating shearing tool (39) cooperating with a shearing counter tool (41) characterised in that a shaping device (40, 41) is positioned in the same plane as, immediately adjacent to, and downstream of, the strip shearing device (39; 41) and consists of a movable shaping die (40) reciprocated together with said reciprocating shearing tool (39) and a corresponding fixed counter die (42) respectively aligned on opposite sides of the steel strip, whereby operation of the strip shearing device (39, 41) takes place prior to operation of said shaping device (40; 42).

2. A joint-nailer 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 clearance between them corresponds axially to the feed opening (5) so as to allow the passage of the driver (18) in order to transfer a shaped clip (g) released between the shaping die and counter-die (40, 42) and feed it, through the feed opening (5).

3. A joint-nailer as claimed in claim 1, characterised in that upstream of the shearing tools (39, 41) and in juxtaposition to the movable shearing tool (39), an elastic guide member (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 feeding, after joining and releasing of the shaping seat between the shaping die and counter-die (40, 42) for the relative feeding between them.

4. A joint-nailer as claimed in claim 1, 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.

5. A joint-nailer as claimed in claim 1, characterised in that said discontinuous feeding device consists of three fluid-dynamic feeding and clamping cylinders (24, 27, 29) in which two of them respectively (24, 29) are fixed on a fixed support (22') as regards the nailing plate (4) and the other (27) is movable on a slide (26) and controlled by a rod of the first advancing cylinder (24) placed axially to the straight strip (n) for clip shaping, the other two (27, 29) being orthogonally placed and cooperating with two holding means (28, 30) respectively: the first (28) being movable along said strip and the second (30) 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), said shearing and shaping device (19) being 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 drive cylinder (16) to move said driver (18) in said way that after the joining operation and retraction of the driver (18), the strip (n) is made to advance by one said clamping cylinder (27) by clamping with its holding means (28) at the end of the stroke of the feeding cylinder (24), the forming and shearing cylinder (37) being actuated, operating the shearing tool and shaping die (39, 40) to advance, and after shearing and shaping, the rod of said cylinder retracted while releasing of the movable holding means (28) and clamping of the fixed holding means (30) is started to make the movable holding means (28) be recalled to the starting position to clamp again and wait for the following feeding.

6. A joint-nailer as claimed in claim 1, characterised in that the nailing 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 countertightness plate (11) cooperating with a pair of vertical sliding guides (9) connected with the seaming cylinder (16) under the nailing plate (4) and freely sliding with respect thereto.