EP0548797B1 - Method and device for feeding pieces of laundry to an ironing machine - Google Patents

Description

The invention relates to a method for feeding laundry items to a defect or the like according to the preamble of claim 1. Furthermore, the invention relates to a device for feeding laundry items to a defect or the like according to the preamble of claim 8.

In order to feed items of laundry to a mangle or the like, the items of laundry to be supplied in each case are introduced manually with brackets of a conveying device with opposite corners. By subsequently moving the clips transversely to the feed direction, the respective item of laundry is spread apart by tightening an upper edge located between the corners held on the clips for placement on a transfer conveyor, which finally enters the item of laundry into the ironer or the like.

Such a device is known from DE-B-2 319 654. The laundry is spread out in several movement phases. In a first movement phase, the clamps are moved apart in opposite directions relatively quickly.

This reduces the sag of the laundry. A button or the like initiates a second movement phase at a certain minimum sag of the upper edge of the item of laundry, in which the clamps are moved apart at a lower speed until another button or the like is actuated when the upper edge of the item of laundry is almost or completely tightened to switch off the Drive the brackets.

A disadvantage of this known device is the second movement phase for slowly moving the clamps apart. This leads to relatively long work cycles.

Another generic device is known from EP-A-0 053 562. Here, the item of laundry is spread by a clamp being driven while the second clamp is initially stationary. When the driven first bracket has moved away from the second bracket to such an extent that the upper edge of the item of laundry is tensioned, the second clip is driven briefly and then dragged along by the still driven clip through the tensioned upper edge of the item of laundry until the item of laundry is centered centered before a defect or the like.

A disadvantage of this device is that a high clamping force is exerted on the upper edge of the item of laundry when the second, largely unpowered clip is also dragged through it. So that this clamping force does not become too great, the first clamp can only be driven at a correspondingly low speed. This also leads to relatively long work cycles.

Proceeding from this, the object of the invention is to create a method and a device of the type mentioned at the outset, with which an efficient supply is ensured in a manner which is gentle on the items of laundry.

The method for solving this problem has the features of claim 1. Accordingly, before the spread Laundry item a measurement of the upper edge of the item of laundry located between the corners held in the brackets, from which the positions of the clips with a tight upper edge are determined and the clips can move directly to these positions. There is no need for the different movement phases required in the prior art, in particular the temporarily slow moving apart of the clamps to tighten the upper edge.

A gentle spreading of the items of laundry is ensured that, due to the previous measurement (before tightening or during an initial phase of tightening) of the length of the upper edge, the spreading of the clamps can be controlled so that the item of laundry, and in particular the upper edge thereof , is tightened only so far that damage to the laundry is excluded.

The measurement of the length of the upper edge of the item of laundry is particularly simple in that it is brought into a position describing two sides of a triangle according to the invention. For this purpose, the upper edge of the item of laundry need not be tightened to such an extent that damage is to be feared. In addition, the sides of the triangle and the resulting length of the upper edge of the item of laundry can be easily calculated.

In a development of the method according to the invention, the third side of the triangle is formed by an imaginary straight line between the two brackets. From the known distance between parentheses and the still known apex between the two sides of the triangle formed by the upper edge of the item of laundry, the lengths of these sides can be determined with simple methods of triangular calculation, the sum of which gives the length of the upper edge of the item of laundry.

A triangular side of the upper edge of the item of laundry formed for measurement preferably runs at right angles to the imaginary straight line between the two clips. These two sides then form known triangle catheters, from which, according to Pythagoras' theorem, the hypotenuse of the triangle, ie the second triangular side of the upper edge of the item of laundry formed for measurement, is calculated. However, it is also conceivable to determine the apex of the two sides of the triangle formed by the upper edge of the item of laundry according to the angle functions, which is why the vertex connecting these two sides does not necessarily have to be below one of the two brackets.

A device for achieving the object on which the invention is based has the features of claim 8. The triangle formation required for measuring the length of the upper edge of the laundry item is then formed from sections of the upper edge of the laundry item forming two sides of the triangle on the one hand and the spacing of the clips on the other hand by a retaining element assigned to the clips. This forms an apex between adjacent triangle sides at the upper edge of the item of laundry. This can be formed particularly simply by pulling the upper edge of the item of laundry against the retaining member during the engagement of a part of the retaining member in a preferably vertical vertical plane through the clips by moving at least one clip. The tensile stress exerted on the item of laundry is considerably smaller than the tension required to tighten the upper edge, so that the triangulation required for the measurement can be carried out without any significant load on the item of laundry.

According to a preferred development of the device, the retaining member can be pivoted into the vertical plane (measuring plane) running through the brackets before the measurement and out of the measuring plane after the measurement. The retaining member is preferably pivoted out of the measuring plane automatically, namely through the upper edge of the item of laundry. Appropriate training and storage of the retaining element ensures that, with a predetermined, relatively slight tightening of the upper edge of the item of laundry forming two sides of the triangle, the retaining element leaves the measuring plane and the clamps for the complete spreading out of the retaining element without further force being exerted by the retaining element Laundry can be moved as a function of the length of the upper edge of the item of laundry determined in the previous measurement.

Fig. 1

eine Vorderansicht der Vorrichtung,

Fig. 2

eine schematische Vorderansicht der Vorrichtung gemäß der Fig. 1 mit verschiedenen Positionen von Klammern zum Spreizen eines Wäschestücks,

Fig. 3

eine vergrößerte schematische Seitenansicht zur Darstellung in der Fig. 2,

Fig. 4

eine gegenüber den Darstellungen in den Fig. 1 bis 3 vergrößerte Darstellung eines Randbereichs der Vorrichtung mit Antrieb, und

Fig. 5

einen Schnitt V-V durch die Vorrichtung in gegenüber der Fig. 4 nochmals vergrößerter Darstellung.

Preferred exemplary embodiments of the device according to the invention and of the method are explained in more detail below with reference to the drawing. In this show:

Fig. 1

a front view of the device,

Fig. 2

2 shows a schematic front view of the device according to FIG. 1 with different positions of clips for spreading a piece of laundry,

Fig. 3

2 shows an enlarged schematic side view for illustration in FIG. 2,

Fig. 4

a compared to the representations in FIGS. 1 to 3 enlarged representation of an edge region of the device with drive, and

Fig. 5

a section VV through the device in an enlarged view compared to FIG. 4.

The devices shown here are used for spreading or spreading out laundry items 10 and feeding the spread laundry items 10 to a defect not shown in the figures. The device is composed of a spreading device 11 and a feed conveyor 12. The laundry items 10 spread by the spreading device 11 are transferred to the feed conveyor 12 (possibly with the aid of a transfer conveyor, not shown) and conveyed to the defect by the feed conveyor 12.

The spreading device 11 and the feed conveyor 12 are mounted on a common machine frame 13, which is only indicated in FIG. 1. The spreading device 11 is located in front of the feed conveyor 12 in relation to the feed direction 15 indicated by an arrow in FIG. 3.

The spreading device 11 shown in FIGS. 1 to 4 has two loading stations 16 and 17 on opposite sides of the machine frame 13. Each loading station 16 and 17 has a pair of brackets made up of two brackets 18, 19 and 20, 21. The brackets 18 to 21 can be moved back and forth in front of the feed conveyor 12 transversely to the feed direction 15. The individual pairs of brackets are operated alternately.

Each bracket 18 to 21 is fastened to a carriage 22, 23, 24 and 25 which can be moved with rollers 26 on a rail 27 fastened horizontally in front of the feed conveyor 12 to the machine frame 13 and extending transversely to the feed direction 15.

According to the invention, the brackets 18 to 21 can be driven individually and independently of one another. For this purpose, each carriage 22 to 25 is assigned a circumferential drive belt which is guided approximately parallel to the rail 27. In the exemplary embodiment shown here, the drive belt is a toothed belt 28, each toothed belt 28 is deflected between opposing toothed belt pulleys 29 which, according to FIG. 1, are assigned opposite loading stations 16 and 17 on the outside. A toothed belt 28 with two opposing toothed belt pulleys 29 is assigned to each of the four carriages 22 to 25, wherein in each case one toothed belt 28 is articulated on the corresponding carriage 22, 23, 24 and 25 at a coupling point 30 shown in FIGS. 3 and 4.

In the embodiment of FIGS. 1 to 3 with two pairs of clamps, four toothed belts 28, each with two toothed belt pulleys 29, are provided, which according to FIG. 3 lie in pairs next to and on top of one another. The two brackets 18, 19 and 20, 21 of each pair of brackets are attached to toothed belts 28 lying one above the other. A drive 31, 32 is assigned to two toothed belts 28, one behind the other in relation to the feed direction 15. There are therefore only two drives 31, 32 for both pairs of clips. The toothed belt pulleys 29 on the side of the drives 31 and 32, that is to say here in the area of the loading station 17, of the toothed belt pulleys 29 lying one behind the other can alternatively be driven by one of the two drives 31 and 32 by a coupling, not shown, between two toothed belt pulleys 29 lying behind one another or the like is arranged. As a result, the brackets 18, 19 or 20, 21 of a pair of brackets can alternatively be driven independently of one another by the drives 31, 32, while by correspondingly actuating the couplings between the toothed belt pulleys 29 one behind the other, the brackets 18, 19 or 20, 21 of the other bracket pair during cannot be driven at this time.

In the exemplary embodiment shown, the spreading device 11 is assigned, approximately in the middle below the rail 27, a preferably non-contact sensing element 48, which lies on or slightly below an imaginary connecting line 49 between the brackets 18, 19 or 20, 21 when it is drove approximately in the middle in front of the feed conveyor 12.

Another essential aspect of the invention relates to a measuring device for determining the length of an upper edge 40 of the same to be tightened for spreading the laundry item 10. In the embodiment of FIGS. 1 to 4 with two loading stations 16 and 17, each loading station 16 and 17 has its own measuring device, which has a retaining element 41, 42. Each of the identically designed retaining members 41, 42 is arranged in a fixed manner in the area of the loading station 16 or 17. It is offset in the feed direction 15 with respect to a vertical plane running through the clamps 18, 19 or 20, 21, and is therefore located outside the same.

Each retaining member 41, 42 has an approximately L-shaped measuring rod 43, the longer leg 44 of which is mounted on its free end so as to be rotatable about its longitudinal central axis on a swivel drive 45. At least the end region of the longer leg 44 assigned to the swivel drive 45 runs with its longitudinal central axis parallel to the vertical plane running through the brackets 18, 19 or 20, 21. In contrast, in the exemplary embodiment shown, a section of the longer leg 44 pointing toward a shorter leg 46 is slightly angled. The shorter leg 46 is in turn angled in such a way that the longitudinal central axis of the shorter leg 46 extends approximately at right angles to the longitudinal central axis of the section of the longer leg 44 mounted in the swivel drive 45 (cf. center lines in FIG. 4).

Due to the described design of the measuring rod 43, it can be pivoted partially by pivoting it into a vertical plane running parallel through the brackets 18, 19 or 20, 21, such that the shorter leg 46 forms a stop 47 across the through the brackets 18, 19 or 20, 21 extending vertical plane protrudes, as is indicated schematically in FIG. 3.

In the exemplary embodiment shown, the retaining members 41 and 42 are specifically assigned to the respective outer bracket 18 or 21 of the individual bracket pairs, in such a way that the shorter leg 46 for measuring the length of the upper edge 40 perpendicularly below the outer bracket 21 (or 18th ) protrudes into the vertical plane running through the brackets 18, 19 or 20, 21, as shown in FIG. 2. In this way, an imaginary horizontal between the brackets 20 and 21 (or 18 and 19) forms a right angle to a perpendicular between the bracket 21 (or the bracket 18) and the stopping point 47. This creates a right-angled triangle, the Corner points related to the loading station 17 in FIG. 3 are formed by the brackets 20 and 21 and the stopping point 47.

Both the swivel drive 45 for the measuring rods 43 of the retaining members 41 and 42 as well as the slide 22 to 25 or one of their toothed belt pulleys 29 for driving the respective toothed belt 28 are provided with displacement transducers through which the positions of the brackets 18 to 21 and the swivel position of the measuring rods 43 can be determined.

Figure 5 shows an alternative embodiment of the invention in which there are four loading stations. There are then two loading stations on each side of the machine frame 13, so that a further loading station is located behind the loading stations 16 and 17 shown in FIG. 1. This spreading device has four pairs of clips with a total of eight clips, of which two clips 20 and 33 of different pairs of clips or loading stations on one side of the machine frame 13 are shown in FIG. 5. Accordingly, there are eight slides, of which only the slides 24 and 35 of different pairs of clamps or loading stations are also shown in FIG. 5.

The carriages 24 and 35 and the other carriages, not shown, are guided on a double rail 37 comprising two parallel rails 38 and 39 one behind the other in the feed direction 15. The carriages of the pairs of clamps which are assigned to the two loading stations lying in front of the double rail 37 in the feed direction 15, run on the first (front) rail 38, while the slides of the loading station located behind the double rail 37 in the feed direction 15 are guided on the rear rail 39. In this way, the pairs of clips can be operated independently of each other in each loading station. For this purpose, a separate toothed belt 28 is in turn assigned to each slide. This assignment is made such that the drive of each rail 38 and 39 corresponds analogously to the arrangement described above in connection with the embodiment of FIGS. 1 to 4. Accordingly, two identical drive sets are provided in the exemplary embodiment shown, each of which is provided with two drives, not shown, which in turn enables the individual clamps or slides of each pair of clamps to be driven independently of one another.

The method according to the invention is described in more detail below with reference to FIG. 3, namely starting from the dispatch station 17.

When the slides 24 and 25 are moved completely to the left into the loading station 17, manually adjacent corners 50, 51 of the item of laundry 10 are suspended in the brackets 20, 21 and the item of laundry is held free hanging thereon. The distance between the brackets 20 and 21 is less than the shortest possible upper edge 40 of the laundry 10 between the corners 50 and 51. The upper edge 40 is clearly sagging. The shorter leg 46 of the measuring rod 43 engages in this sag, so that it projects approximately horizontally through the vertical plane spanned by the laundry item 10. The swivel drive 45 of the restraining member 42 is disengaged or depressurized so that the dipstick 43 is freely rotatable.

Now the exposed, front carriage 24 with the clamp 20 is moved in the direction of the center of the spreader 11, while the carriage 25 with the clamp 21 remains unbraked due to the stopping point 47 lying vertically underneath. The distance between the brackets 20 and 21 thus increases. The upper edge 40 of the laundry item 10, which is restrained or deflected at the stopping point 47, is tightened so that it forms two sides of a triangle, namely a vertical catheter 52 and an oblique hypotenuse 53. The tension that arises in this case on the upper edge 40 of the laundry item 10 is practiced a gradually increasing force on the measuring rod 43, whereby due to the L-shaped configuration of the same and the free rotatability thereof, the latter is rotated so far that the shorter leg 46 is pivoted out of the vertical plane spanned by the item 10 of laundry. The start of this swiveling movement of the measuring rod 43 is determined by a measuring sensor arranged on the swivel drive 45 and at the same time the instantaneous position of the slide 24 or the clamp 20 moved to the center of the spreading device 11 is determined. The distance between the clamps 20 and 21 at the upper edge 40 of the item of laundry 10 formed towards the catheter 52 and the hypotenuse 53 is thus known. Since the vertical distance between the clamp 21 and the stopping point 47, that is to say the length of the catheter 52, is also known, the length of the hypotenuse 53 can be calculated according to the Pythagoras theorem. The length of the upper edge 40 between the opposite corners 50 and 51 of the item of laundry 10 then results from the addition of the cathete 52 and the hypotenuse 53.

The length of the upper edge 40 of the item of laundry 10 determined in the manner described above is used to control the (individual) drives 31 and 32 of the slides 24, 25 or clips 20, 21. This is done in such a way that: The determined length of the upper edge 40 positions of the slides 24 and 25 on the rail 27 are calculated, in which the clamps 20 and 21 and thus the item of laundry 10 held between the two with the upper edge 40 stretched are centered in front of the feed conveyor 12 approximately centered . In this way, both slides 24 and 25 can travel to the intended positions on the rail 27 at a relatively high speed after measuring the upper edge 40 of the item of laundry 10, since it is known from the previous measurement of the upper edge 40 when it will be in its extended position in front of the feed conveyor 12.

In a further embodiment of the method according to the invention, the extended state of the upper edge 40 is checked by the feeler 48. This check is useful if, for safety reasons, the slides 24 and 25 with the brackets 20 and 21 should not always be moved to the positions that result in an optimally stretched upper edge 40, despite the precalculation. For this reason, positions of the slides 24 and 25 are calculated in which the upper edge 40 of the item of laundry 10 is still slightly sagging. When these calculated positions are reached (with the upper edge 40 still slightly sagging), the drive of the carriages 24 and 25 is switched over to a lower speed. At the same time, the drive direction of the slide 25 pointing to the loading station 17 is reversed (starting from the loading station 16, the drive direction of the slide 22 would have to be changed), so that the slides 24, 25 are now moved apart at a reduced speed. The carriages 24 and 25 with the clamps 20 and 21 now move over only a relatively small path at a lower speed to completely stretch the upper edge 40 of the laundry item 10. This results in the laundry item 10 being carefully stretched. The reaching of the upper edge 40 is achieved by the feeler 48 determined and then the drive of the carriage 24 and 25 stopped and / or with known, not shown clamp openers, the clamps 20 and 21 opened for the transfer of the spread laundry 10 to the feed conveyor 12.

After the spread laundry item 10 has been handed over to the feed conveyor 12, the clamps 20 and 21 with the slides 24 and 25 are again moved to the side (to the left) into the loading station 17. In this case, not only this one is assigned by a brake assigned only to the inner slide 24 Carriage; rather, the preceding slide 25 is also fixed on the rail 27 by holding this slide 25 between a stop (not shown) at the end of the rail 27 and the slide 24 locked on the rail 27 by braking. The clips 20 and 21 can now be fitted with a new item of laundry 10. While this loading process is in progress, a piece of laundry 10 suspended in the loading station 16 is spread out in the middle by the clamps 18 and 19 in front of the feed conveyor 12, the method described above again being used. The same drives 31 and 32, which first move the slides 24 and 25 of the pair of brackets of the loading station 17, then serve to move the slides 22 and 23 of the loading station 16. The switch from one to the other pair of brackets is carried out by the couplings or the like, not shown .

The device with four loading stations and consequently four pairs of clamps according to FIG. 5 also works according to the method described above. There are also only two retaining members 41, 42 in that a retaining member 41 or 42 arranged on each side next to the machine frame 13 simultaneously serves both loading stations one behind the other in the feed direction 15, for which purpose the measuring rod 43 is designed such that it can be swiveled back and forth by 180 °, that the shorter leg 46 alternatively is pivoted into the vertical plane of the clamps of one or the other loading station.

Claims (11)

1. Method of feeding items of laundry (10) to a mangle or the like, two adjacent corners (50, 51) of a particular item of laundry (10) being fed into two pegs (18, 19; 20, 21) of a spreading device (11), which pegs can be moved transversely in front of a feed conveyor (12) which feeds items to the mangle or the like, and by moving the pegs (18, 19; 20, 21) transversely the item of laundry (10) is stretched out in front of the feed conveyor (12) due to the upper edge (40), which is situated between those corners (50, 51) held in the pegs (18, 19; 20, 21), being pulled tight, characterized in that before the upper edge (40) is completely pulled tight the length thereof is determined and the pegs (18, 19; 20, 21) are moved in a controlled and directed manner as a function of the determined length of the upper edge (40).
2. Method according to Claim 1, characterized in that the length of the upper edge (40) is determined before or during the pulling tight of the item of laundry (10), in particular directly after the corners (50, 51) of the item of laundry (10) are fed into the pegs (18, 19; 20, 21) or after an initial phase of the spreading procedure.
3. Method according to Claim 1 or 2, characterized in that to determine the length the upper edge (40), which is to be pulled tight, of the item of laundry (10) is brought to a measuring position describing two sides of a triangle, preferably in such a manner that the upper edge (40) forms two sides of a right-angled triangle, in particular a small side (52) with a hypotenuse (53).
4. Method according to one or more of Claims 1 to 3, characterized in that a third side of the triangle is formed by an imaginary straight line between the two pegs (18, 19; 20, 21), in each case holding the opposite corners (50, 51) of the item of laundry (10), in particular a right angle is formed between one side of the upper edge (40) of the item of laundry (10) and the imaginary straight lines between the pegs (18, 19; 20, 21).
5. Method according to one or more of Claims 1 to 4, characterized in that the upper edge (40) is brought into the measuring position, describing two sides of a triangle, by means of a hold-back member (41, 42), in particular in such a manner that the hold-back member (41, 42) forms a corner point of the triangle, in particular between those sides of the upper edge (40) which are formed in the measuring position.
6. Method according to Claim 5, characterized in that by increasing the distance between the pegs (18, 19; 20, 21) the sagging upper edge (40) of the item of laundry (10) is moved towards the respective hold-back member (41, 42) in such a manner that in order to achieve the triangular measuring position the two sides of the upper edge (40) of the item of laundry (10) are at least approximately pulled smooth.
7. Method according to one or more of Claims 1 to 6, characterized in that the driving speed of the pegs (18, 19; 20, 21) is reduced shortly before the stretched-out state of the upper edge (40) is reached, in particular when the correspondingly calculated end position of the pegs (18, 19; 20, 21) is reached.
8. Device for feeding items of laundry (10) to a mangle or the like, having a spreading device (11) which is arranged in front of a feed conveyor (12) guiding items to the mangle or the like, and has at least two pegs (18, 19; 20, 21) for holding opposite corners (50, 51) of the item of laundry (10), the pegs (18, 19; 20, 21) being movable transversely to the feed direction in order to stretch the item of laundry (10) out due to an upper edge (40) of the item of laundry (10), which edge lies between the two adjacent corners (50, 51), being pulled tight, characterized in that a hold-back member (41, 42) is assigned to the pegs (18, 19; 20, 21) to transfer the upper edge (40) into a measuring position from which the length of the upper edge (40) can be determined before the item of laundry (10) is stretched out.
9. Device according to Claim 8, characterized in that part of the hold-back member (41, 42) can be moved into, and out of, a vertical plane which runs through the pegs (18, 19; 20, 21) and in which in particular, for example, the upper edge (40) of the item of laundry (10) is situated, preferably by pivoting.
10. Device according to Claim 8 or 9, characterized in that the hold-back member (41, 42), in particular a section thereof which comes into contact with the upper edge (40) of the item of laundry (10), is arranged at a distance below a peg (18; 21), preferably in such a manner that a straight line runs between the hold-back member (41, 42), or the section thereof, and the peg (18; 21) assigned thereto, perpendicularly to an imaginary straight line between the two pegs (18, 19; 20, 21) holding the item of laundry (10).
11. Device according to one or more of Claims 8 to 10, characterized in that the hold-back member (41, 42) has a measuring stick (43) which is preferably of L-shaped design and can be rotated around a longitudinal centre line running at least partially through a, preferably longer, leg (44), in such a manner that a shorter leg (46) of the measuring stick (43) can be moved into a vertical plane of the item of laundry (10) as well as out of the vertical plane.

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