Background of the invention

The invention relates to a sensing arrangement for planar textile processing machines.

The invention further relates to a planar washing machine and to a method of washing rugs and carpets.

The field of the invention is defined more specif ically in the preambles of the independent claims. Planar washing machines have been developed for washing different kind of planar textile products. Such machines are used for example in self-service laundromats. The present solutions have shown some disadvantages in their user-friendliness . Brief description of the invention

An object of the invention is to provide a novel and improved sensing arrangement and solution for control ling of washing separate textile products in a planar wash ing machine. The sensing arrangement according to the invention is characterized by the characterizing features of the first independent apparatus claim.

The planar washing machine according to the inven tion is characterized by the characterizing features of the second independent apparatus claim.

The method according to the invention is character ized by the characterizing features of the independent method claim.

An idea of the disclosed solution is that the sens- ing arrangement comprises at least three sensing devices mounted to a movable leading edge stopper of a textile processing machine, such as a planar washing machine. The sensing arrangement is configured to detect shape and straightness of a leading edge of the textile product being fed manually inside the machine. The leading edge stopper of the machine is movable so that it can be moved away after the leading edge is properly positioned and treating process is ready to be initiated. In this solution several leading edge sensors are located at least for the duration of the positioning phase at a feed opening of the machine and on the same level with the planar textile product.

An advantage of the disclosed solution is that de tection of the leading edge can be accurate since the sens ing devices are located at the same level with the sensed object. Thus, the sensing devices are close to the sensed textile product. Further, the structure may be simple, du rable and inexpensive.

According to an embodiment, the disclosed sensing arrangement is designed especially for a planar washing machine. However, it can be utilized also in other textile processing machines designed for treating planar textile products.

According to an embodiment, the sensing devices are configured to generate detection signals in response to physical contact between the sensing devices and the leading edge. In other words, the leading edge or front edge is configured to collide the sensing devices when the end of the textile product is manually positioned against the stop per. User of the machine pushes the textile product against the sensing devices which then register the leading edge.

According to an embodiment, the sensing devices are electromechanical switches and their operation is based on on-off principle whereby detection signals are generated when being triggered by means of the contacting leading edge. In other words, manually generated feed force directed to the textile product causes the leading edge to press the switches and to thereby cause the detection signals. The electromechanical switches are simple, reliable and inex pensive. Further, when on-off switches are used, the control signal is simple to process, and no complicated calculation or processing is needed in a control unit of the machine. According to an embodiment, the electromechanical switch comprises a frame and a protruding sensing head mov able relative to the frame. Inside the frame of the elec tromechanical switch may be one or more sets of movable electrical contacts connected to external circuits. When a pair of contacts is touching, current can pass between them, while when the contacts are separated, no current can flow.

According to an embodiment, the sensing device may be an on-off switch or push button. According to an embodiment, the sensing devices are contact-free sensing devices configured to send detection signals in opposite direction relative to a feed direction of the textile product. In other words, the detection sig nals hit the moving edge and reflect back and can thereby constantly measure distance to the leading edge stopper during the feeding phase. This way the arrangement utilizes non-contacting measurement principle. Thus, the leading edge may be detected by using remote sensing techniques. The remote sensing system may comprise ultrasonic sensors or laser sensors, for example. Also, cameras and other op tical systems may also be used to detect planar textile edges.

According to an embodiment, the sensing arrangement comprises three sensing devices. The arrangement is provided with a central first sensing device, a lateral second sens ing device and a lateral third sensing device. The lateral sensing devices are located at uniform intervals on both sides of the central first sensing device. An imaginary line is passing via the sensing devices and the imaginary line is perpendicular to the feed direction. In other words, the mounting of the sensors or sensing devices has linear or straight configuration.

According to an embodiment, the sensing devices are each mounted separately to the stopper. Then locations and distances between the sensing devices may be selected rel atively freely. A further advantage is that individual sens ing devices may be easily removed and substituted if needed.

According to an embodiment, the sensing devices are mounted to an elongated frame and form together a sensing unit mountable in one piece to the stopper. In this solution the stopper may be provided with the sensing unit which comprises all the needed means for executing the detection.

According to an embodiment, the sensing unit is an elongated bar provided with the at least three switches. The bar may be provided with a central position marking indicating the central position for the user.

According to an embodiment, the solution relates to a planar washing machine for washing separate planar textile products. The washing machine may comprise: a standing body configured to be mounted on a floor; a feed opening for feeding the textile product into the washing machine; a leading edge stopper, which is a movable mechanical element against which leading edge of the textile product is con- figured to be positioned; at least one sensing device for detecting leading edge of the textile product; a holding device for holding the textile product immovable before a washing process is initiated; transfer means for transfer ring the textile product in the washing machine in a feed direction; at least one washing unit for washing the textile product inside the washing machine; and at least one control unit for controlling operation of the washing machine. Fur ther, the leading edge stopper is provided with at least three sensing devices for sensing the leading edge of the textile product. The sensing devices are in accordance with features and embodiments disclosed in this document.

According to an embodiment, the leading edge stopper of the planar washing machine is configured to move verti cally together with the mentioned sensing devices between a stoppage position and an idle position. In other words, the sensing devices are configured to be moved away from the feed opening after the leading edge is detected and a washing program is to be initiated. On the other hand, it can be considered that the stopper and the sensing devices are moved on a feed track for blocking feeding movement of the textile product further inside the machine until the positioning and shape of the textile product is at first sensed and proper washing program is selected.

According to an embodiment, the sensing devices have sensing directions being transverse to the vertical move- ment direction of the stopper.

According to an embodiment, the leading edge stopper is a planar element, and the sensing devices are mounted at a horizontal lower end of the movable planar element.

According to an embodiment the leading edge stopper is a vertically movable stopper plate or a relatively this structured element with planar outer surfaces.

According to an embodiment, the sensing devices may be moved to a protective position or space so that they are not subjected to moisture and dirt during a washing phase. There may be covering elements and sealing to protect the stopper and its sensing devices when being moved to its uppermost position.

According to an embodiment, several electromechan ical switches are mounted to a leading edge stopper, which is vertically movable and is moved to its lowermost position for the duration of the feeding process of the planar tex tile.

According to an embodiment, the leading edge stopper is provided with a central first sensing device at a central line of a feed opening and at least a lateral second sensing device and a lateral third sensing device at uniform lateral distance from the central line. A control unit of the ma chine is configured to interpret that the leading edge of the textile product is curved when a detection signal is received only from the central first sensing device. The curved leading edge protrudes at the middle longest forwards and this is sensed by means of the central sensing device located on the central line of the feed opening.

According to an embodiment, the control unit is configured to interpret that when the sensing data indicates the above mentioned curved leading edge, then shape of the textile product is round or oval. The control unit is then configured to select a corresponding washing program for treating it. The machine may also be provided with sensing devices for detection of longitudinal edges of the textile product and sensing data from these sensors may be taken into account when determining whether the shape is round or oval.

According to an embodiment, the control unit is configured to automatically initiate operation of a holding device in response to detection of a curved leading edge or detection that a linear leading edge is positioned perpen dicularly relative to the feed direction. This way the user is indicated that he may remove his grip from the textile product and that the machine will automatically continue the processing. Initiation of the holding device may thus indicate for the user that the positioning of the leading edge is executed properly.

According to an embodiment, the control unit may provide the user with a sound or visual signal when the positioning of the leading edge is properly executed.

According to an embodiment, the control unit pro cesses the received planar textile leading edge detection signal and provides instructions for a use on a display device. The control unit may also select a washing program based on the sensing data.

According to an embodiment, the control unit is configured to interpret the planar textile product to be round in response to receiving sensing data only from the central first sensing device.

According to an embodiment, the control unit is configured to determine straightness of the planar textile product in response to received sensing data from at least two sensing devices.

According to an embodiment, the control unit is configured to interpret that shape of the leading edge is straight and is positioned perpendicularly relative to the feed direction when the detection signal is received from both lateral sensing devices. The control unit is configured to select a washing program for the recognized rectangular object. According to an embodiment, the leading edge stopper is provided with a central first sensing device at a central line of a feed opening and at least a lateral second sensing device and a lateral third sensing device at uniform lateral distance from the central line. Further, the control unit is configured to interpret that the leading edge is straight and oriented angularly relative to the feed direction when detection signal is received only from one of the lateral first and second sensing devices.

According to an embodiment, the control unit is configured to indicate the user that repositioning of the textile product is required before initiating a washing program for the rectangular textile product.

According to an embodiment, the control unit is configured to initiate the washing program automatically in response to the received sensing data from the leading edge sensing devices. Thereby, the washing program is started without a need for additional selections made by a user.

According to an embodiment, the machine is without any hand-actuated manual press buttons for the user for initiating the washing program after the feeding and posi tioning of the textile product.

According to an embodiment, the solution relates to a method of washing separate planar textile products with a planar washing machine. The method comprises: feeding an end of the textile product manually into a feed opening and positioning a leading edge of textile product against a mechanical stopper; holding the textile product by means of a holding device before a washing process is initiated; feeding the textile product in a feed direction with trans fer means during the washing process; detecting a leading edge of the textile product by means of at least one sensing device; washing the textile product by means of at least washing unit and moving the washing unit in a transverse direction relative to the feed direction during the washing; directing a washing fluid jet from at least one washing nozzle of the washing unit towards a surface of the textile product; and directing suction from at least one rotating suction head to the surface of the textile product in order to remove moisture from the textile product. The method further comprises providing the stopper with at least three leading edge sensing devices, whereby shape and straight ness of the leading edge is detected in response to received sensing data of the sensing devices.

According to an embodiment, the disclosed method comprises controlling initiation of a washing process of the machine by means of a control unit in response to the received sensing data from the sensing devices and without making a separate manual selection with hand-actuated switches.

The above disclosed embodiments may be combined in order to form suitable solutions having those of the above features that are needed.

Brief description of the figures

Some embodiments are described in more detail in the accompanying drawings, in which Figure 1 is a schematic side view of a planar wash ing machine mounted on a floor,

Figure 2 is a schematic view of a feed opening of machine when a textile product is manually positioned,

Figure 3 is a schematic view of the feed opening disclosed in Figure 2 after a feed process is completed and a washing process is initiated, Figure 4 is a schematic top view of a leading edge of a textile product and sensing arrangement for sensing it,

Figure 5 is a schematic top view of monitoring skew- ness of a leading edge of a textile product,

Figure 6 is a schematic top view of detecting shape of a curved leading edge of a textile product,

Figure 7 is schematic and highly simplified top view of a sensing unit comprising several leading edge sensors, Figure 8 is schematic and highly simplified view of a contactless leading edge sensor, and

Figure 9 is a schematic diagram showing issues and features disclosed in this document.

For the sake of clarity, the figures show some em- bodiments of the disclosed solution in a simplified manner. In the figures, like reference numerals identify like ele ments.

Detailed description of some embodiments

Figure 1 shows a planar washing machine 1 for wash- ing planar textile products 2 such as rugs or similar fur nishing textiles. The washing machine 1 comprises a body 3. The textile product 2 may be fed into the washing machine 1 through a feed opening 4 wherein it is taken over by gripping means 5. The gripping means 5 may comprise one or more holding devices 6 which may include suction ports 7. An underpressure or suction may be led to the suction ports 7 from a suction unit SU or source. The washing machine further comprises feeding means 8, such as rollers, by means of which the textile product 2 may be moved forward in the washing machine 1. In the vicinity of the feed opening 4 there may be a transverse stopper 9against which a leading end of the textile product 2 is at first fed manually. The stopper 9 may be a mechanical member that may be adapted to be moved in the vertical direction so that it may be moved out of the way of the textile product 2 when the washing cycle is started. The actual washing may be performed by means of a washing unit WU. The washing unit WU may comprise one or more washing nozzles and two or more suction heads. Washing agent or washing liquid is fed with high pressure from a washing liquid unit LU, and a drying suction may be formed with a suction unit or source SU.

The operation of the washing machine 1 may be con trolled by a control unit CU. The control unit CU may au tomatically control the suction of the holding device 6, a hatch 10, feeding or transfer means 8, washing unit WU and generally the entire work cycle of the washing machine 1.

The washing machine 1 washes the rug with the aid of one or more washing agent jets and two or more rotating suction heads. The washing agent used in the washing is water to which washing agent may have been mixed. Further, the washing machine 1 sucks off the water left in the rug after the washing, drying the rug so that when the rug is taken out of the washing machine, no water will run out of it and it will dry fast. The disclosed washing machine 1 may be installed in a launderette where the customers them selves use the washing machine.

Figure 1 further shows that the feed opening 4 is provided with a nip N provided with a movable upper roll 12 and a short transfer belt 13 below the feed line. The upper roll or press roll 12 pressed against the upper surface of the textile product 2 and the transfer belt 13 is driven for moving the textile product further inside the machine after shape of the leading edge of the textile is at first detected and straightness of it is ensured. The sensing of the leading edge can be made by means of sensing devices S, which may be located at a lower edge of the vertically movable stopper 9.

Figure 2 discloses that a textile product 2 is fed manually against a stopper 9, which is moved to its lower position. Then the sensing devices S are on the same level with a leading edge E of the textile product 2. When the leading edge E is sensed and its positioning is accepted by a control unit CU, the holding device 6 is actuated and suction S is directed to suction ports 7. The suction causes vacuum force F which keep the textile product immovable and manual grip can be removed and the user takes his hands out of the feed opening. Thereafter the stopper 9 moves away, a hatch 10 closes and pressing roll 12 is moved against the textile product thus producing desired nip force NF in a nip N. A transfer belt 13 is then activated and the textile product 2 may be transferred in the feed direction A. This is disclosed in Figure 3.

Let it be mentioned that it may be possible to ar range the stopper to move alternatively in a horizontal plane. A further possibility is to arrange it to be turnable between a stoppage position and an idle position. Also, in these cases the stopper is provided with the disclosed sens ing arrangement.

Figure 4 discloses that a textile product 2 is fed manually in a feed direction A towards a stopper 9 provided with several sensing devices S or sensors. The textile prod uct 2 has rectangular shape whereby a leading edge E is straight. The leading edge E, when being fed in the feed direction A, will press physically the sensing devices SI - S3 when colliding them. Evenly detected pressing of at least the lateral sensing devices S2 and S3 indicates that the orientation of the textile product is correct. In Figure 5 the textile product is skewed in relation to the feeding direction and the stopper 9, whereby a third sensing device S3 is triggered. The incorrect position of the textile prod- uct 2 may be indicated to the user by means of a user interface UI, for example. Figure 5 further discloses an angular deviation D. The sensing devices SI - S3 may be on- off switches or simple electromechanical switches.

Figure 6 discloses that a textile product 2 may be round or oval and may then comprise a curved leading edge E. When the curved leading edge E is fed in the feed direc tion towards a stopper 9, then it collides only to a central first sensing device SI which is located on a central line CL of a feed opening. Based on the sensing data B a control unit CU determines that the textile product 2 is round or ellipse and selects suitable washing program.

In Figures 4 - 6 a holding device 6 below the textile product 2 is also shown. The holding device may comprise one or more suction ports 7 provided with several suction openings.

Figure 7 discloses a sensing unit 15 provided with three sensing devices SI - S3 and frame 16. The frame 16 comprises fastening lugs 17 or corresponding mounting ele ment for fastening the sensing unit 15 in one piece to a leading edge stopper element.

Figure 8 discloses a sensing device S capable of sending and receiving measuring signals 18 against a leading edge E of a textile product.

Figure 9 discloses a diagram showing some opera- tional principles and features in a simplified presentation.

The drawings and the related description are only intended to illustrate the idea of the invention. In its details, the invention may vary within the scope of the claims.