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(11) | EP 1 004 512 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A process for winding up and binding, by means of a tape of plastic film, lengths of filiform elements, such as cables, ropes and the like, in particular mains cords, wound in the form of skeins, and a machine to implement such process |
| (57) The process and the relating machine (1)for winding up and binding, by means of a
tape, lengths of filiform elements, such as cables, ropes and the like, in particular
mains cords (3), involve two main working stations (4, 6) which are complementary
to each other. Station (4) for preparing the skein (M) is served by a clamp group
(40) which takes the cord (3) and positions it, for winding up, around a couple of
pins (43) spaced ad lib. Subsequently, a clamp group (60) grasps the skein, transferring
it to the binding station (6) where a couple of lateral clamps (66,66') lower it onto
a tape (70) of thermo-weldable plastic material which envelops the skein around its
middle portion, which tape is welded and cut in such a manner so as to maintain it
continuous and in a stretched condition. |
[0001] The present invention relates to a process for winding up and binding, by means of a tape of plastic film, lengths of filiform elements, such as cables, ropes and the like, in particular mains cords, wound in the form of skeins, and a winding and binding machine for implementing such process.
[0002] Merely by way of example the instant invention will be disclosed with reference to a typical application thereof, designed for meeting certain technical requirements, as will be seen hereinafter, without limiting the invention to said disclosed application.
[0003] As it is known, several industries, such as the household electric appliance industry, demand the supply of different types of electric cables or mains cords, even in very large quantities, i.e. up to tens of thousands, said electric cables or mains cords having to be supplied together with the finished appliance at the time of sale of the latter.
[0004] In order to reduce their volume and for the convenience of use, said electric cables are demanded in the form of skeins tied together by means of a binding element, one end of which electric cable, already provided with a user mains coupling plug, projecting from the skein, while the other end of said electric cable, it too projecting from the skein, has the two phase wires and the earth wire ready for connection to the appliance.
[0005] In this manner, the coupling cable can be connected to the electric appliance prior to its packaging, and the installer or user must merely free the skein of its binding element for switching on the appliance.
[0006] The winding-up and binding operations of the electric cables or cords, which have a length prescribed by the appliance manufacturer, are generally performed by outside suppliers using hardly automatized apparatus, which presents the following drawbacks:
- it does not allow to automatically load the electric cables at the starting step;
- it employs a winding mandrel capable of a very limited extension variation;
- loss of time due to the manual loading of the cable lengths onto the mandrel;
- the manual measurement of the projecting end of the cable provided with a plug with respect to the skein itself;
- its production yield is comparatively low, i.e. almost near to that of a manual process, with consequently high costs due to extensive use of labour;
- the skein is bound by a plasticized binding element having a metal core, which is far from welcome because an exposed portion thereof can cause damage to the cable surface or can injure the user.
[0007] The object of the present invention is to overcome the above mentioned drawbacks, by contemplating the use of a machine designed for automatically performing the required operating steps, with a high production yield, thereby allowing few machines to meet a large production volume, saving on labour and performing the binding of the lengths skein using only a tape of thermo-weldable, metal-core-free plastic material which does not cause the cited drawbacks.
[0008] The main design concepts of the automatic binding machine according to the instant invention are as follows:
- manually depositing of the single lengths onto a movable rack;
- automatically grasping of the lengths by a clamp and transferal controlled by photoelectric cells of said lengths from the loading zone to the processing zone;
- automatically setting of the measurement of the extremity of the lengths provided with a plug, projecting from the skein depending on the stroke of the grasping clamp;
- providing a winding-up mandrel group with a broad changing range of the skein coil length, including a winding-up core and clamps for holding the lengths provided during rotation as well as a driving element for deviating the extremity of lengths projecting into a cylindrical basket;
- grasping a still loose skein at its middle portion for transferring it by means of a movable clamp, to a second working station, which is independent from the first but operating in series therewith, with evident saving on time, in said second working station the skein is taken up by a pair of end clamps, is released by a middle clamp and lowered against a tape of plastic material envelopping it substantially around its circumferential perimeter;
- welding the tape of thermo-weldable and optionally thermo-shrinkable plastic material by means of a pair of heated heads, after having compacted the skein;
- cutting of the tape between the two weldings, so as to maintain the continuity of said tape, allowing a length thereof to advance so as to present a fresh tape portion for winding round about a subsequent skein;
- laterally ejecting the envelopped lengths and collecting it in a container;
- a high production yield thanks to the automation of the various operating steps.
[0009] The machine according to the invention for implementing what disclosed above, by way of example, in connection with the winding-up and binding of an electric cable provided with a plug at an end portion thereof projecting from the skein, will be better understood from the following description with reference to the accompanying drawings, wherein:
Figure 1 is an overall top plan view of the machine;
Figure 2 is a front elevation view showing the machine of Figure 1;
Figure 3 is a top plan view, on an enlarged scale, showing the working surface of the winding-up and binding machine according to the invention;
Figures 4A e 4B are front elevation views, partially cross-sectioned, showing a detail of the winding-up mandrel assembly, in two subsequent operating steps thereof;
Figure 5 shows the clamp group for grasping the horizontally arranged wound skein, and the transferal of the skein to the second working station above the binding tape to be thermo-welded;
Figure 6 shows the opening of the transferring clamp from the first to the second working station and the engagement of the skein, at its two ends, by means of two clamps which cause the skein to be lowered against the binding tape;
Figure 7 shows the thermo-welding of the binding tape and the cutting of the thermo-welded tape; and
Figure 8 is a side elevation view showing a length as wound and bound according to the invention.
[0010] Figures 1 and 2 schematically show, in a top plan view and a front elevation view, respectively, the winding-up and binding machine according to the instant invention.
[0011] This machine, generally indicated by reference numeral 1, has, as seen in a top plan view, an angled, very compact shape, and it is provided with two working stations 4 and 6 which perform, in series, two different, mutually complementary operations so that, while the second station 6 completes the process of the first, the first station 4 is ready to start a subsequent winding-up operation, with an evident advantage with regard to the rapidity of performing the entire process.
[0012] In Figures 1 and 2, an operator A, who avails himself of a control keyboard T to start or stop the machine or one of its parts, will simply feed, on a conveyor belt 2, consisting of articulated elements, the lengths 3 with their end 31 provided with a plug facing the left of the operator. The lengths can be fed in any desired manner or they can be collected from an auxiliary rack R not pertaining to the invention.
[0013] The lengths 3, arranged on the conveyor belt 2, are brought to the working station 4, which will be described thereinafter, to perform the winding-up of the skein, while, in the second working station 6, arranged obliquely on one side of the operator A, the length skein will be bound by a binding tape and ejected into the container 9.
[0015] More specifically, the lengths 3 are arranged by the operator A on the articulated element conveyor belt 2, with the length portion, provided with the plug 31, clamped between a resilient fork 32 and a pair of rollers 33.
[0016] According to a preset operating sequence (see Figure 3), each length 3 deposited on the conveyor belt 2, once the presence of said length has been detected by a photocell, is grasped by a clamp group 40, slidingly supported on a rail 41, and driven to the position 34, shown by a dashed line, in alignment with the skein winding center 42.
[0017] As shown in Figures 4A and 4B, the winding-up of the length is carried out between two pins 43, which can be manually fixed, at a preset distance, on a cross-member 44, coupled to a rotary shaft 45, which member can be vertically driven by a piston 46 and made to rotate by a sleeve 47 in turn driven by a motor 48.
[0018] The winding-up of the skein about the pins 43 offers various advantages, namely i) the possibility of changing the diameter of the skein in a range much broader than that of the winding apparatus known in the art, and ii) that, after having performed the winding, the disengagement of the skein for it to be subsequently taken for binding, is achieved by lowering the pins 43 so as to leave the skein in a compact condition and with its coils orderly arranged.
[0019] The winding-up is started after the clamp group 40, sliding on rail 41, advances by a distance L which can be preset depending on the positions of the pins 43, in order to automatically and uniformly define, for one and the same batch of lengths being worked, the projection of the starting portion from the finished skein on the basis of the distance between the end point of the clamp group 40 stroke and the nearest pins 43.
[0020] When the clamp group 40 has come to a stop at a preset point, the length 3 is clamped and locked onto the winding-up mandrel by means of a pair of clamping means 49, 49', driven by the pistons 50, 50' and turning together with the winding mandrel, in order to obtain a perfectly wound-up skein. With reference to Figure 3, a deviating arm 51 pivoted at 52 is shown, said arm being driven by a small piston 53, which arm, immediately after having released the length 3, grasped by the clamp group 40, deviates, when the pins 43 start to turn anticlockwise, the length portion projecting from the skein into a basket 54 turning together with said pins 43, in order to prevent said length portion from being centrifugally ejected during the winding-up operation, the skein being formed with evenly overlapping coils, since the length being wound up is guided by a pair of small rollers 55 which have facing concave surfaces and which are gradually displaced upwardly in synchronism with the turning of the pins 43.
[0021] Once the formation of the skein has been completed, the second tape binding station 6 comes into action, the operating time of which is coordinated with that of the winding-up station 4 so that in said station 4 can be started the formation of a new skein, while the previously prepared skein is being bound.
[0023] A clamp group 60, slidingly supported on the rail 61 (Figure 3), engages with its arms 62 the middle portion of the wound-up skein M and goes back until it is above the recess 64.
[0024] Figure 5 shows that above the recess 64 is transversely arranged a tape of a plastic material 70 delivered from a tape bobbin 72, braked by an arm 73, said tape being fed and held in a stretched condition by a recovery assembly 74.
[0025] The skein M, carried by the clamp 60, is now grasped at its two end portions by a pair of side clamps 66, 66', it is released by the clamp 60 (Figure 6) upon the opening of the arms 62 and it is lowered against the tape 70 which envelops the skein for more than half its cross extension. In order to maintain the skein in a compacted condition, it is made to bear against a flexible tongue 67, arranged on a slider 68, sliding on a rod-free piston 69.
[0026] The side clamps 66, 66', coupled to a common base 66a which can be vertically driven by a piston 66b, are shown in Figure 5 in a raised position and in Figure 6 in a lowered position.
[0027] Figure 7 substantially shows the final step of the winding-up and tape binding process. With reference to Figure 6, two pairs of heated heads 80, 80' are neared one to the other and they perform simultaneously two neighbouring welding operations on the plastic tape, which will then immediately be cut by a blade 82 situated between the welding heads 80, 80', so that the binding tape 84 (see Figure 8) is welded together, while maintaining the wound-up skein in a well compacted condition, while the second welding of the tape 70 will keep it continuous, which tape can be made to advance by the recovering assembly 74, thereby presenting a fresh portion of tape 70 for binding a subsequent skein.
[0028] Upon the opening of the side clamps 66, 66', the slider 68, driven by the rod-free piston 69, will eject the wound-up and bound skein (M) into a container 9, as shown in Figure 1.
[0029] As stated in the introductory clause of the description, the process and machine for implementing said process can be used for winding-up and binding any type of filiform elements, such as mains cords lengths ending with plugs and mating sockets or without these elements, telephone cables or cables for other use, ropes for any applications, and the like.
a) depositing said lengths onto a movable rack;
b) transferring, step by step, said lengths to a pick-up point controlled by a photocell;
c) grasping and raising each length by means of a movable clamp;
d) positioning said length in a winding-up zone while taking into account that an optional portion of the filiform element could project from the skein once the latter has been wound up and bound at its middle portion;
e) retaining said length on a winding mandrel and starting the winding up operation after having introduced the first portion of said length projecting from said skein into a rotary basket, and forming a skein;
f) grasping said skein at its middle portion by means of a transporting clamp after having removed downwards the winding-up elements;
g) transferring said skein to a tape binding station at the opening of said station, above which a tape of thermo-weldable material is caused to pass;
h) engaging the ends of said skein through two side clamps and opening the arms of the transfer clamp;
i) lowering the skein through the side clamps against a tape of thermo-weldable, optionally thermo-shrinking, material;
j) binding the skein with a single tape layer;
k) welding said tape by means of two pairs of corresponding thermo-welding clamps and forming two tape welded portions at two neighbouring but spaced positions;
l) cutting the tape between said two neighbouring welded portions so as to maintain the tape continuous and disengaging the thus formed bound tape;
m) recovering a portion of the tape simultaneously with the opening of the side clamps and ejecting the tape bound skein into a container.
a) a movable rack (2) whereon said rectilinear lengths (3) are deposited, for transferring said lengths step by step to the subsequent grasping step controlled by a photocell;
b) means for grasping and positioning each filiform element length (3), said grasping and positioning means comprising a movable clamp group (40), capable of moving to an end point at a maximum distance from the winding-up zone (4) or, possibly, for a further distance corresponding to the length of an optional filiform element portion which must project from the finished skein;
c) a length winding-up assembly (43) provided with means (49, 49') for clamping said length and a basket (54) for inserting therein the optional skein projecting portion;
d) clamp group (60) for clamping the skein at its middle portion, after having removed downwards the winding-up elements, and for transferring said skein to a tape binding station in alignment with an opening of a recess (64), above which a tape of thermo-weldable material (70) is caused to pass;
e) means for engaging the ends of a skein, said skein engaging means comprising two side clamps (66, 66'), followed by the opening of the arms of the clamping and transferring group (60);
f) means (66a, 66b) for lowering the skein retaining side clamps (66, 66') against a tape of thermo-weldable, optionally thermo-shrinking material (70) to cause said tape to form a single layer binding enveloping said skein;
g) means for welding said tape (70), comprising two pairs of corresponding welding heads (80, 80'), in order to form two simultaneous welded portions on the tape at two neighbouring but spaced positions;
h) cutting means (82) for cutting said tape between said two neighbouring welded portions;
i) recovering means (74) for recovering a portion of said tape simultaneously with the opening of said side clamps; and
j) ejecting means (68, 69) for ejecting said tape bound skein into a container.