EP0053562B1 - Apparatus for feeding laundry pieces, particularly to an ironing machine - Google Patents

Abstract

1. Apparatus for feeding laundry pieces, particularly to an ironing machine, of the type comprising a conveyor (1), at the upstream end of which is provided at least one pair of grippers (3, 4; 5, 6), able to move transversely with respect to the feed direction of the conveyor (1) and able to grip a laundry piece by two of its corners, means (11 to 28) being provided for driving the two grippers of each pair, with a view to separating them from each other in order to stretch the laundry piece gripped and to bring this laundry piece into a centered position with respect to an axis (8) defined in advance, characterised in that the means for driving the two grippers of each pair are arranged in order to move, in a first stage, a single gripper (3) until the laundry piece is stretched and then to move the two grippers (3, 4) simultaneously, in a second stage, until they are brought into a symmetrical position with respect to the centering axis (8) under the control of means (30, 31) detecting the movement (X, X') of the first gripper (3) and reacting to tensioning of the laundry piece.

Description

The present invention relates to a device allowing the insertion of pieces of linen, such as sheets, in particular in an ironing machine. More particularly, this device is of the type of those comprising a conveyor at the upstream end of which is provided at least one pair of grippers, movable transversely to the direction of advance of the conveyor, and capable of gripping a piece of laundry by two of its angles, means being provided for driving the two clamps of each pair, in order to separate them from one another in order to tension the piece of laundry grasped, and to bring this piece of laundry into position centered by relative to a defined axis of advance, which is not necessarily the axis of the conveyor.

• - Dans un premier temps, les deux pinces de la même paire, ayant saisi un drap, se déplacent simultanément, depuis un poste de chargement latéral jusque vers le centre du dispositif.
• - Dans un deuxième temps, ces deux pinces s'écartent l'une de l'autre, jusqu'à ce que le drap soit tendu.

This type of device makes it possible, in laundromat installations, to properly spread the pieces of laundry, before introducing them into an ironing machine. A device currently known operates according to the following principle (US-A-4,106,227):

• - At first, the two clamps of the same pair, having grasped a sheet, move simultaneously, from a lateral loading station to the center of the device.
• - In a second step, these two clamps move away from each other, until the sheet is stretched.

The implementation of this principle leads to a complex embodiment, with regard to the command and control of the movements of the two grippers, and in particular of that whose direction of movement is reversed between the two operating phases.

The present invention overcomes this drawback by providing an improved device, of the kind defined above, in which the drive means of the two clamps of each pair are arranged so as to move, in a first phase, a single clamp up to that the piece of laundry is stretched, and then simultaneously move the two clamps, in a second phase, until bringing them in a symmetrical position relative to the centering axis under the control of means detecting the movement of the first clamp and reacting to the tensioning of the piece of laundry.

Preferably, the means for detecting the displacement of the first clamp translate this displacement into pulses, exploited using a counter which counts one pulse out of two during the first phase, that is to say between the start of the first clamp and the instant when the piece of laundry is stretched, and which counts all the pulses during the second phase, that is to say from the moment when the piece of laundry is stretched and when the second clamp is also driven, the content of the counter being compared with a fixed value such that at the time when equality is obtained, the two clamps have reached their symmetrical position with respect to the centering axis.

The counter can operate by counting down, and in this case it is advantageous to provide that its initial content is equal to the difference between, on the one hand, the distance separating the rest position of the second clamp and the centering axis, and on the other hand, half of the initial spacing of the two clamps, so that the centering is obtained at the precise instant when the content of the counter cancels out, as will be demonstrated below.

The means for detecting the displacement of the first clamp consist, for example, of an optical pulse generator, associated with the drive means of this first clamp.

According to a particular embodiment of the invention, the two clamps of the same pair are driven by means of endless transmission elements, from two separate motors, the optical pulse generator being mounted so as to detecting the movement of the transmission element causing the first clamp, while the second clamp cooperates, in the rest position, with a presence detector. This detector reacts, to modify the counting mode of the pulses, at the moment when, the sheet being stretched, the first clamp begins to pull the second through the sheet. The two clamps can be connected, in particular by means of endless cables passing over idler pulleys, to two electric brake motors.

According to another possible embodiment, only the first clamp of each pair is driven, by means of an endless transmission element, from a motor, the second clamp being provided with means allowing its locking on said transmission element, during the second operating phase. By means of a sort of clutch mechanism, the drive system can thus be further simplified.

• Figure 1 est une vue d'ensemble en perspective, très schématique, d'un dispositif conforme à la présente invention ;
• Figure 2 représente, plus particulièrement, le mécanisme d'entraînement et de centrage de l'une des deux paires de pinces de ce dispositif ;
• Figures 3, 4 et 5 sont des schémas explicatifs du fonctionnement du dispositif considéré.

In any case, the invention will be better understood with the aid of the description which follows, with reference to the appended diagrammatic drawing representing, by way of nonlimiting example, an embodiment of this device for the introduction of pieces of linen, especially in an ironing machine:

• Figure 1 is an overall perspective view, very schematic, of a device according to the present invention;
• Figure 2 shows, more particularly, the drive and centering mechanism of one of the two pairs of pliers of this device;
• Figures 3, 4 and 5 are explanatory diagrams of the operation of the device considered.

The device visible in FIG. 1, intended to supply laundry items, such as sheets, an ironing machine placed downstream, not shown, comprises a conveyor 1 bringing the laundry items to said machine. To properly spread these pieces on the conveyor 1, pressure discs 2 and especially two pairs of pliers 3, 4 and 5, 6 are provided, located upstream of the rear end of the conveyor 1. All these clamps 3 to 6 are movable transversely to the direction of advance of the conveyor 1, along a sliding rail 7 (see FIG. 2), and the present invention is more particularly concerned with the mechanism drive these pliers.

The mechanism in question is shown in FIG. 2, only for the clamps 3 and 4 which constitute the first pair and which, in the rest position, are stored near the left end of the sliding rail 7, outside the width of the conveyor 1, this useful working width being designated by E. The other two clamps 5 and 6, which constitute the second pair and which, in the rest position, are stored near the right end of the sliding rail 7, are driven by symmetrical means, relative to the median plane represented by the axis 8, of those appearing in FIG. 2.

Each of the clamps 3 to 6 consists of a carriage 9 rolling on the rail 7, and two jaws 10 constituting the clamp itself, designed so as to be able to tighten for example the angle of a sheet.

The carriage 9 of the clamp 3 is secured with an endless drive cable 11 shown in dotted lines. This cable 11 passes over various return pulleys 12 to 17, as well as over a drive pulley 18 coupled to a first brake motor 19. Similarly, the carriage 9 of the clamp 4 is secured with an endless drive cable 20 , shown in phantom; this cable 20 passes over various return pulleys 21 to 26, as well as over a drive pulley 27 coupled to a second brake motor 28.

The cable 11 used to drive the clamp 3 passes over an additional pulley 29, coupled to an optical pulse generator 30. This generator, associated with an electronic pulse counter, measures the movement of the cable 11, therefore the clamp 3.

The other clamp 4 cooperates with an electrical contact 31 placed at the end of the rail 7, and detecting the presence or absence of this clamp 4 at its stop station.

The two motors 19 and 28, the generator-pulse counter 30 and the presence contact 31 are connected to a central control unit 32.

To use the device, the operator introduces two angles of the sheet into the jaws 10 of the two clamps 3 and 4, initially stored near the left end of the rail 7. When the two clamps 3 and 4 are loaded, the brake motor 19 is started, while the engine brake 28 is released. The clamp 3 is thus moved, in the direction of its distance from the clamp 4 which initially remains stationary, at its stop station. The sheet therefore deploys and, when stretched, it starts to drive the clamp 4 which then leaves its stop position and causes the actuation of the presence contact 31.

At this moment, the motor 28 starts up for a very short time, to give its speed to the clamp 4. The clamp 3 then drives the clamp 4, by means of the stretched sheet, until the two clamps 3 and 4 are centered, that is to say arrive in positions in principle symmetrical with respect to the axis 8. The two motors 19 and 28 are, at this time, braked so as to immobilize the two cables d drive 11 and 20, as well as the two clamps 3 and 4, and the sheet is itself centered, in the stretched position. This sheet can then be spread on the conveyor 1 and separated from the jaws 10.

• - A désigne l'écartement initial des deux pinces 3 et 4 ;
• - B désigne la distance séparant le poste d'arrêt de la pince 4 de l'axe 8 du dispositif ;
• - L désigne la longueur de la pièce de linge ;
• - X représente le déplacement de la pince 3, entre l'instant de la mise en route du moteur 19 et l'instant où le drap D est tendu, donc durant la première phase ; et
• - X' représente le déplacement de la pince 3, ainsi que celui de la pince 4, entre l'instant où le drap est tendu et l'instant où le drap est finalement centré, donc durant la seconde phase.

To obtain exact centering, the generator-pulse counter assembly 30 is used in the manner which will be described below, with reference to the diagrams in FIGS. 3 to 5, in which:

• - A denotes the initial spacing of the two clamps 3 and 4;
• - B denotes the distance separating the stop station of the clamp 4 from the axis 8 of the device;
• - L indicates the length of the piece of laundry;
• - X represents the movement of the clamp 3, between the moment when the motor 19 is started and the moment when the sheet D is stretched, therefore during the first phase; and
• - X 'represents the movement of the clamp 3, as well as that of the clamp 4, between the moment when the sheet is stretched and the time when the sheet is finally centered, therefore during the second phase.

The content of the pulse counter is initially equal to a preset value P. At the start of the clamp 3, during the first operating phase illustrated by the diagram in FIG. 3, a countdown begins and is carried out as follows: content C of the counter decreases by one for the reception of two pulses from the optical pulse generator 30. The content of the counter is given by the formula:

This counting of one pulse out of two continues until the time when the sheet D is stretched, therefore until the spacing of the two clamps 3 and 4 is equal to the length L (see FIG. 4). At this precise moment, the clamp 3 has traversed the distance (LA), so that the content of the counter is:

The contact 31 for the presence of prince 4 causes, at this instant, a change in the countdown mode: all the pulses emitted by the generator 30 are counted down, therefore the content of the counter is given by the formula:

As shown in FIG. 5, the displacement X ′ of the clamp 3, equal to that of the clamp 4 since the piece of laundry is stretched, must reach the value: X '= B - (L / 2) to reach an exactly centered position. By reporting this last value in the previous formula, we establish that the content of the counter, at the end of the second phase, will be:

To easily detect the centering position, in which the two motors 19 and 28 must be braked, provision is made for the content C of the counter to be canceled in this position. For this, taking into account the previous relation, it suffices to provide that the preset value of the counter is:

Note that this value is a constant independent of the variable length L of the laundry items.

• Bien entendu, l'invention ne se limite pas à la seule forme de réalisation de ce dispositif qui a été décrite ci-dessus, à titre d'exemple ; elle en embrasse, au contraire, toutes les variantes conçues suivant le même principe, à l'intérieur du cadre des revendications.

Finally, it will be noted that after opening of the clamps 3 and 4 and engagement of the piece of linen on the conveyor 1, these clamps 3 and 4 will be returned to their starting position by the respective motors 19 and 28, to allow the similar course of the following cycle:

• Of course, the invention is not limited to the only embodiment of this device which has been described above, by way of example; on the contrary, it embraces all the variants designed according to the same principle, within the scope of the claims.

Thus, in an interesting variant, the motor 28 of the second clamp 4, as well as the corresponding drive cable 20 are eliminated. This clamp 4 is then provided with mechanical locking means on the drive cable 11 of the first clamp 3, these means being triggered when the second clamp 4 begins to be pulled by the first clamp 3, by means of the stretched sheet . The principle of measurement by pulse counting is not changed. This variant has the advantage of allowing the second clamp to be automatically locked, when it leaves its stop station, and it also allows said clamp to unlock itself, when it returns to the station. stop. The two clamps are thus driven by a single mechanism, which provides a very great simplification in comparison with the existing systems, and which always allows automatic operation, including to return the two clamps to their starting position.

Claims (8)

1. Apparatus for feeding laundry pieces, particularly to an ironing machine, of the type comprising a conveyor (1), at the upstream end of which is provided at least one pair of grippers (3, 4 ; 5, 6), able to move transversely with respect to the feed direction of the conveyor (1) and able to grip a laundry piece by two of its corners, means (11 to 28) being provided for driving the two grippers of each pair, with a view to separating them from each other in order to stretch the laundry piece gripped and to bring this laundry piece into a centered position with respect to an axis (8) defined in advance, characterised in that the means for driving the two grippers of each pair are arranged in order to move, in a first stage, a single gripper (3) until the laundry piece is stretched and then to move the two grippers (3, 4) simultaneously, in a second stage, until they are brought into a symmetrical position with respect to the centering axis (8) under the control of means (30, 31) detecting the movement (X, X') of the first gripper (3) and reacting to tensioning of the laundry piece.

2. Apparatus according to claim 1, characterised in that the means for detecting the movement (X, X') of the first gripper (3) translate this movement into pulses, processed by means of a counter (32) which counts every other pulse during the first stage, i. e. between the starting-up of the first gripper (3) and the instant when the laundry piece is stretched and which counts all the pulses during the second stage, i. e. from the instant when the laundry piece is stretched and when the second gripper (4) is also driven, the contents (C) of the counter (32) being compared with a fixed value such that at the time when equality is obtained, the two grippers (3, 4) have reached their symmetrical position with respect to the centering axis (8).

3. Apparatus according to claim 2, characterised in that the said counter operates by counting-down, its initial contents (P) being chosen to be equal to the difference between, on the one hand, the distance (B) separating the inoperative position of the second gripper (4) and the centering axis (8) and on the other hand, half the initial spacing (A) of the two grippers (3, 4), so that centering is obtained at the precise instant when the contents (C) of the counter are cancelled.

4. Apparatus according to claim 2 or 3, characterised in that the means for detecting the movement (X, X') of the first gripper (3) are constituted by an optical pulse generator (30), associated with means (11 to 19) for driving this first gripper (3).

5. Apparatus according to claim 4, characterised in that the two grippers (3, 4) of the same pair are driven through the intermediary of endless transmission members (11, 20) by two separate motors (19, 28), the optical pulse generator (30) being mounted in order to detect the movement of the transmission member (11) driving the first gripper (3), whereas the second gripper (4) cooperates, in the inoperative position, with a presence detector (31).

6. Apparatus according to claim 5, characterised in that the two grippers (3, 4) of the same pair are connected, through the intermediary of endless cables (11, 20) passing over return pulleys (12 to 17, 21 to 26) with two electrical brake motors (19, 28).

7. Apparatus according to one of claims 1 to 4, characterised in that only the first gripper (3) of each pair is driven, through the intermediary of an endless transmission member (11), by a motor (19), the second gripper (4) being provided with means enabling it to be locked to said transmission member (11) during the second stage of operation.

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