Edge clamping device and automatic cloth spreading machine including the same

An edge clamping device includes: a two-position holding device having a pair of holding chucks that hold two separate portions of a rectangular piece of cloth Y that are on or near the ridge of a fold, in a state where a right-angled triangular part S is revealed; an edge locating conveyor that is disposed under the two-position holding device and delivers the cloth Y having been released from the two-position holding device; clamping chucks disposed downstream of the edge locating conveyor in a delivery direction; and a position changing means that moves at least one of the two-position holding device, the edge locating conveyor, and the clamping chucks in a crosswise direction such that the right-angled triangular part S of the cloth Y held by the two-position holding device is located at a correct clamping position corresponding to the positions of the clamping chucks.

TECHNICAL FIELD

The present invention relates to an edge clamping device that locates an edge of cloth and clamps that side edge in a cloth washing factory or the like. The present invention further relates to an automatic cloth spreading machine that spreads cloth by hanging the cloth having been clamped by the edge clamping device onto a roller and then pulling the cloth from a rear edge side.

BACKGROUND ART

As this type of edge clamping device, one that includes a two-position holding device, an edge locating conveyor disposed under the two-position holding device, and a clamping chuck disposed downstream of the edge locating conveyor in a delivery direction has been hitherto proposed (see Patent Literature 1). An overview of this configuration is shown inFIG. 35. The two-position holding device has a pair of holding chucks71,72that hold two separate portions (inFIG. 35, a corner end portion and an intermediate portion) of a rectangular piece of cloth Y that are on or near the ridge of a fold, in a state where the cloth Y has been folded with a side edge Yc on a side to be located and the opposite side edge Yd intersecting each other so as to reveal a right-angled triangular part S of which an adjacent side Sa is formed by a portion of the side edge Yc on the side to be located that is adjacent to the corner of intersection while a hypotenuse Sb is formed by a portion of the opposite side edge Yd that defines the corner of intersection with the adjacent side Sa. An edge locating conveyor8delivers the cloth Y having been released from the two-position holding device. In this edge clamping device, the two-position holding device releases the two held portions at different timings such that the portion on the side of the right-angled triangular part S (the side of the corner end portion) follows, and lets them fall onto the edge locating conveyor8. On the edge locating conveyor8, the cloth Y is rotated and the adjacent side Sa of the right-angled triangular part S is thereby located. The clamping chucks92,93operate so as to clamp a peripheral portion inside the right-angled triangular part S including the located adjacent side Sa.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

In a washing factory where many types of cloth varying in size from small to large, such as bath towels, face towels, and pillowcases, are handled, the shape and size of the right-angled triangular part S that appears in cloth Y held by the two-position holding device vary depending on the shape and size of the cloth Y (seeFIG. 36 (a)andFIG. 36 (b)). Further, in some cases, the position of the folding line of cloth Y held by the two-position holding device7does not coincide with that of the diagonal line of the cloth Y, and also in such cases, the size and shape of the right-angled triangular part S to be appeared vary (seeFIG. 36 (c)). This results in variations in the clamping position when the clamping chucks92,93downstream of the edge locating conveyor8clamp a portion of the cloth Y around the adjacent side Sa of the right-angled triangular part S that has been located on the edge locating conveyor8. For example, when a right-angled triangular part S′ as indicated by the dashed line inFIG. 35appears, the clamping chuck92that is the left one of the two clamping chucks92,93is not located at a position at which it can clamp the cloth Y and therefore may fail to grasp the cloth Y. When a right-angled triangular part S″ as indicated by the dashed line appears, both of the clamping chucks92,93can clamp the cloth Y, while portions being clamped are located on an inner side of the correct positions, which is problematic because it decreases the processing accuracy in hanging the cloth Y onto the roller and spreading the cloth Y in later steps. When the right-angled triangular part S having appeared is extremely small as shown inFIG. 37, the clamping chuck93clamps not only the located side edge Yc but also the opposite side edge Yd that is not supposed to be clamped, which is problematic because it makes the entire subsequent processing impossible.

An object of the present invention is to solve the problems with the above prior art and provide an edge clamping device that can clamp cloth, of which an edge has been located on an edge locating conveyor, in a reliable manner and at a correct position, and an automatic cloth spreading machine including this device.

Solution to Problem

To solve the above problem, an edge clamping device of the present invention includes: a two-position holding device having a pair of holding chucks that hold two separate portions of a rectangular piece of cloth that are on or near the ridge of a fold of the cloth, in a state where the cloth has been folded with a side edge on a side to be located and the opposite side edge intersecting each other so as to reveal a right-angled triangular part of which an adjacent side is formed by a portion of the side edge on the side to be located that is adjacent to the corner of intersection while a hypotenuse is formed by a portion of the opposite side edge that defines the corner of intersection with the adjacent side; an edge locating conveyor that is disposed under the two-position holding device with a delivery direction oriented in a direction orthogonal to a direction in which the pair of holding chucks face each other, and delivers the cloth having been released from the two-position holding device; and a clamping chuck disposed downstream of the edge locating conveyor in the delivery direction. The two-position holding device releases the two held portions separately and lets them fall onto the edge locating conveyor at different timings such that the portion on the side of the right-angled triangular part follows, whereby the adjacent side of the right-angled triangular part is located on the edge locating conveyor, and the clamping chuck clamps a peripheral portion inside the right-angled triangular part including the located adjacent side. The edge clamping device includes a position changing means that moves at least one of the two-position holding device, the edge locating conveyor, and the clamping chuck in a crosswise direction relative to the delivery direction such that the right-angled triangular part of the cloth held by the two-position holding device is located at a correct clamping position corresponding to the position of the clamping chuck. Here, “locating an edge” means revealing the adjacent side of the right-angled triangular part on the edge locating conveyor so as to be easily clamped by the clamping chuck. Specifically, this term refers to adjusting the direction of the adjacent side of the right-angled triangular part so as to be substantially at a right angle to the delivery direction of the edge locating conveyor by keeping a part of the cloth in a state of being held by the two-position holding device while delivering and moving the rest of the cloth that has landed on the edge locating conveyor.

In addition, it is preferable that the edge clamping device of the present invention include a sensor that detects the position of a right-angled portion of the right-angled triangular part in a state where the two-position holding device is holding two portions of the cloth, and that the position changing means be configured to move at least one of the two-position holding device, the edge locating conveyor, and the clamping chuck in a crosswise direction relative to the delivery direction based on the position of the right-angled portion detected by the sensor.

In the edge clamping device of the present invention, it is preferable that the position changing means has a moving mechanism that moves the two-position holding device in a crosswise direction relative to the delivery direction.

Further, in the edge clamping device of the present invention, it is preferable that the two-position holding device has an interval changing mechanism that changes the distance between the pair of holding chucks.

An automatic cloth spreading machine of the present invention that solves the above problems includes: one of the above-described edge clamping devices; a vertically inverting device that inverts the clamping chuck having clamped cloth; a roller disposed under the edge locating conveyor; a hanging movable body that receives the cloth from the inverted clamping chuck and hangs the received cloth onto a circumferential surface of the roller; and a forward-backward moving device that is provided so as to be able to move forward and backward relatively to the roller, and spreads the cloth by clamping, at a forward position, the cloth hung on the roller and then moving backward.

Advantageous Effects of Invention

The edge clamping device and the automatic cloth spreading machine including this device of the present invention are configured to be able to move at least one of the two-position holding device, the edge locating conveyor, and the clamping chuck in a crosswise direction relative to the delivery direction of the edge locating conveyor by the position changing means. Even when the shape and size of the right-angled triangular part appearing in cloth held by the two-position holding device vary due to a change in the type of cloth to be processed etc., the position changing means compensates for the positional deviation of the right-angled triangular part from the correct clamping position corresponding to the position of the clamping chuck. Therefore, the edge clamping device and the automatic cloth spreading machine including this device of the present invention can clamp cloth, of which an edge has been located on the edge locating conveyor, in a reliable manner and at a correct position by the holding chucks. This makes it possible to process a plurality of types of cloth varying in shape and size by a single edge clamping device.

DESCRIPTION OF EMBODIMENT

An embodiment of an edge clamping device and an automatic cloth spreading machine including this device of the present invention will be described in detail below based on the drawings.

FIG. 1shows an overall view of the automatic cloth spreading machine of one embodiment of the present invention, andFIG. 2toFIG. 34show individual devices that are parts of the automatic cloth spreading machine ofFIG. 1. In the following description, the directions of front, rear, right, left, up, and down refer to those directions in the state ofFIG. 1.

The automatic cloth spreading machine automatically spreads washed and dried pieces of cloth varying in shape and size, such as bath towels, face towels, sheets, duvet covers, and pillow covers. As shown inFIG. 1, the automatic cloth spreading machine mainly includes a supply conveyor1, a lifting device2, a temporary holding device3, a corner end locating device4, a corner end receiving device5, a horizontal pulling device6, a two-position holding device7, an edge locating conveyor8, a vertically inverting device9, a roller10, a hanging device11, a forward-backward moving device12, a transfer conveyor13, and a controller (not shown) that controls the operations of all devices including the devices1to13. InFIG. 1, a suction conveyor A, a push-out device B, a return conveyor C, and a cloth folding machine D are shown as assisting or related devices. The return conveyor C returns cloth that has fallen during processing to the supply conveyor1.

The automatic cloth spreading machine operates roughly as follows. Specifically, the supply conveyor1supplies washed and dried cloth to below the lifting device2. The lifting device2lifts the cloth to a predetermined level. The temporary holding device3receives the lifted cloth, temporarily holds the cloth, and moves the cloth to a position at which the cloth is passed to the corner end locating device4. The corner end locating device4receives an arbitrary portion of the cloth hanging from the temporary holding device3and reveals a corner end of the cloth. The corner end receiving device5holds this corner end, and moves the cloth toward the horizontal pulling device6while supporting the cloth in a drooping state. The horizontal pulling device6lays the cloth substantially horizontally in a front-rear direction. The two-position holding device7holds the laid cloth at two positions, one near a corner end and the other in a predetermined portion on the rear side of the corner end, at the same level, moves the cloth to above the edge locating conveyor8, and then releases the rear-side portion of the cloth being held. The edge locating conveyor8receives thereon a fallen portion of the cloth that is still held at the position near the corner end by the two-position holding device7, and moves that portion so as to reveal one long-side edge of the cloth. The vertically inverting device9holds the long-side edge of the cloth coming down from the edge locating conveyor8, inverts the cloth upside down, and then holds the cloth in a drooping state. A hanging movable body11A of the hanging device11that moves above the roller10in a left-right direction along the roller10receives the long-side edge of the cloth from the vertically inverting device9and hangs the drooping cloth on the roller10. The roller10delivers the cloth hung thereon such that the cloth droops toward the forward-backward moving device12while a short-side edge of the cloth is left on the roller10. The forward-backward moving device12moves forward and receives the rear-side short-side edge of the cloth left on the roller10, moves backward while holding the short-side edge of the cloth, and then moves the cloth in a spread state onto the transfer conveyor13. The transfer conveyor13discharges the spread cloth and, for example, feeds the cloth into the cloth folding machine D in the next process.

Each device will be described in detail. First, as shown inFIG. 1toFIG. 3, the supply conveyor1may be continuously run by a motor1aduring operation. A mass X consisting of, for example, about 10 to 50 washed and dried, still balled-up rectangular pieces of cloth Y is thrown onto the supply conveyor1. The supply conveyor1transfers the mass X of the cloth Y to below the lifting device2(indicated by reference sign X′ inFIG. 2). The suction conveyor A is provided at a terminal end of the supply conveyor1in a transfer direction. The suction conveyor A is composed of a perforated belt A1, a suction fan A2that suctions the cloth Y on the supply conveyor1through the perforated belt A1, and a motor A3that drives the perforated belt A1to rotate and thereby transfers the suctioned cloth Y to directly below the lifting device2(indicated by reference sign X″ inFIG. 3). A wall1bthat prevents the mass X from falling off the supply conveyor1is formed standing near a terminal end of the perforated belt A1. Furthermore, in addition to or instead of the suction conveyor A, the push-out device B that pushes the cloth on the supply conveyor1to directly below the lifting device2may be provided at the terminal end of the supply conveyor1in the transfer direction. The push-out device B is composed of a cylinder B1and a push-out rod B2that is moved forward and backward by the cylinder B1.

The lifting device2has a chuck21that holds an arbitrary portion of the cloth Y, and an upward-downward moving device that moves the chuck21upward and downward. In the example shown inFIG. 4, the upward-downward moving device is composed of a driving belt23and a motor22. The upward-downward moving device may have any structure as long as it can move the chuck21upward and downward between a predetermined level and a transfer surface of the supply conveyor1. For example, a chain-driven device or a slider unit that travels along a rail installed in an up-down direction may be used as the upward-downward moving device. When the chuck21of the lifting device2is moved by the driving belt23and the motor22to a lowermost position (the position indicated by the imaginary lines and reference sign21′ inFIG. 4), the chuck21comes into contact with the cloth Y located at the terminal end of the supply conveyor1and holds the contact portion of the cloth Y. In addition, the portion of the cloth held by the chuck21may be an arbitrary portion. Furthermore, when the chuck21is moved upward, the chuck21is raised to a predetermined level (e.g., uppermost position) indicated by the solid lines inFIG. 4while holding the cloth Y, so that the chuck21then holds the cloth Yin a hanging state. Here, two or more pieces of cloth Y may be held and lifted by the chuck21.

As shown inFIG. 1andFIG. 4, the temporary holding device3has a chuck31and a forward-backward moving device (extending-contracting cylinder32) that moves the chuck31forward and backward in the front-rear direction. When the chuck21of the lifting device2moves to the uppermost position, or the cloth Y held by the chuck21at the uppermost position is detected by a sensor (not shown), the extending-contracting cylinder32of the temporary holding device3extends and moves the chuck31forward to the position indicated by the imaginary lines (indicated by reference sign31′) inFIG. 4, and the chuck31of the temporary holding device3receives a portion near an upper end of the cloth Y lifted by the lifting device2. (At this point, the chuck21of the lifting device2releases the cloth Y.) Thereafter, the extending-contracting cylinder32contracts, so that the chuck31moves backward to a predetermined position as indicated by the solid lines inFIG. 4, with the cloth Y hanging from the chuck31. In most cases, in addition, one of corner ends of the cloth appears at a lowermost end (indicated by reference sign Ya inFIG. 4) of the cloth Y hanging from the chuck31.

As shown inFIG. 5toFIG. 9, the corner end locating device4has: a chuck41that receives the cloth Y hung and held by the chuck31of the temporary holding device3at its backward position; a forward-backward moving device (extending-contracting cylinder42) that moves the chuck41forward and backward in the front-rear direction; a platform43on an upper side of which the cloth Y is placed; a sensor49, such as a photoelectric sensor, that detects a terminal end portion (corner end Ya) of the cloth Y being dragged over the platform43; a pressing plate47that holds a central portion of the cloth Y on the platform43between the pressing plate47and the platform43; an extending-contracting cylinder48that moves the pressing plate47upward and downward; a pair of corner end locating rollers44,45; and an extending-contracting cylinder46that moves the one corner end locating roller45closer to or separated from the other corner end locating roller44.

When the chuck31of the temporary holding device3moves to the backward position while holding the cloth Y as shown inFIG. 5, the extending-contracting cylinder42of the corner end locating device4extends and moves the chuck41forward, and the chuck41receives the cloth Y from the chuck31of the temporary holding device3. Subsequently, as shown inFIG. 6, the extending-contracting cylinder42contracts, so that the chuck41, while holding the cloth Y, pulls the cloth Y a predetermined distance over the platform43before releasing the cloth Y. Then, as shown inFIG. 7, the corner end locating roller45located on a far side moves downward from the position indicated by reference sign45′ and holds a leading end portion of the cloth Y between the corner end locating roller45and the corner end locating roller44on a near side. The pressing plate47moves downward from the raised position indicated by reference sign47′ and holds a central portion of the cloth Y between the pressing plate47and the platform43. In this state, as shown inFIG. 8, both the corner end locating rollers44,45rotate in the arrow directions, so that the cloth Y droops. When the terminal end portion (forming the corner end Ya) of the cloth Y being dragged over the platform43is detected by the sensors49,49(or when the cloth Y is not detected by the sensors49,49), the rotation speed of both the corner end locating rollers44,45is adjusted to switch to a low speed. If there is a plurality of pieces of cloth Y, pieces of cloth Z other than one piece of cloth Y that is held at the terminal end portion between the platform43and the pressing plate47, will fall in the course of this series of actions. Thereafter, when the terminal end portion (corner end Ya) of the cloth Y is detected by other sensors4a,4a, such as photoelectric sensors, that are disposed between both the corner locating rollers44,45(or when the cloth Y is not detected by the sensors49,49), the corner end locating rollers44,45stop rotating, and the corner end Ya or a portion near the corner end Ya of the cloth Y is tucked and held between the corner end locating rollers44,45, which completes a corner end locating task.

In the shown example, the cloth Y lifted by the lifting device2is temporarily held by the temporary holding device3and then handed over to the chuck41of the corner end locating device4. In another example (not shown), the temporary holding device3may be omitted and the cloth Y lifted by the lifting device2may be directly held by the chuck41of the corner end locating device4.

As shown inFIG. 10, the corner end receiving device5has a chuck51disposed under the corner end locating rollers44,45, and a forward-backward moving device (extending-contracting cylinder52) that moves the chuck51forward and backward in the left-right direction (seeFIG. 1) within a range directly under a contact portion of the corner end locating rollers44,45. When the corner end Ya or a portion near the corner end Ya of the cloth Y is being held by the pair of corner end locating rollers44,45of the corner end locating device4, the extending-contracting cylinder52of the corner end receiving device5extends and moves the chuck51forward in a leftward direction as indicated by the imaginary lines inFIG. 10. The chuck51holds the cloth Y at a position a little below the corner end Ya so that the chuck51moves backward toward the right side (toward the horizontal pulling device6) with the cloth Y drooping from the chuck51. A sensor53that detects the cloth Y is mounted on the chuck51. The chuck51is activated upon the sensor53detecting that the chuck51has come close to the cloth Y, so that the chuck51can reliably hold the cloth Y.

A platform64is provided at a position in the immediate vicinity of a lower rear side of the chuck51in a state where the extending-contracting cylinder52of the corner end receiving device5is contracted. The platform64supports a terminal end side of the cloth Y when a portion near the upper end of the cloth (corner end Ya) is received and moved backward by the horizontal pulling device6to be described next.

In addition, in this embodiment, to reveal one corner end Ya of the rectangular cloth Y, the lifting device2, the temporary holding device3, and the corner end locating device4are used such that the corner end of the cloth Y in a balled-up state can be automatically located. Alternatively, this cloth corner end locating task may be performed, for example, by a worker manually finding one corner end of a balled-up piece of cloth Y. In this case, the worker may manually have the found corner end Ya of the cloth received by the chuck51of the corner end receiving device5or directly received by a chuck61of the horizontal pulling device6to be described below.

As shown inFIG. 11toFIG. 14, the horizontal pulling device6has the chuck61and a forward-backward moving device that moves the chuck61forward and backward in the front-rear direction. In the shown example, the forward-backward moving device has a driving belt63that holds the chuck61, and a motor62that moves the chuck61forward and backward in the front-rear direction by rotating a pulley around which the driving belt63is wrapped. However, the forward-backward moving device may have any structure and, for example, an extending-contracting cylinder can also be used. As shown inFIG. 11, when the chuck51of the corner end receiving device5holds the cloth Y and moves backward, the chuck61of the horizontal pulling device6moves forward to the position indicated by the imaginary lines and reference sign61′, and the chuck61′ at this forward position holds the cloth at a position a little below the upper end portion (corner end Ya). Subsequently, after the chuck51of the corner end receiving device5releases the cloth Y, as shown inFIG. 12, the chuck61is moved backward while holding a portion near the corner end Ya of the cloth to thereby pull the cloth Y horizontally over the platform64. Then, as shown inFIG. 13, after the cloth Y is horizontally pulled a predetermined distance, an upper pressing plate65is moved downward by a cylinder66from the raised position indicated by reference sign65′ and holds the cloth Y between the upper pressing plate65and the platform64. Also thereafter horizontal pulling continues, and when a sensor67disposed under the platform64detects a terminal end portion Yb of the cloth Y (or when the cloth Y is not detected by the sensor67), the speed of horizontal pulling is switched to a low speed. Then, as shown inFIG. 14, when another sensor68, such as a photoelectric sensor, disposed near the platform64detects the terminal end portion Yb of the cloth Y (or when the cloth Y is not detected by the sensor68), horizontal pulling is stopped. Thus, the rectangular cloth Y has been folded with the side edge Yc on the side to be located in a later step and the opposite side edge Yd intersecting each other so as to reveal a right-angled triangular part S of which an adjacent side Sa is formed by a portion of the side edge Yc that is adjacent to the corner of intersection while a hypotenuse Sb is formed by a portion of the opposite side edge Yd that defines the corner of intersection with the adjacent side Sa.

As shown inFIG. 15, the edge locating conveyor8that is driven by a motor81is installed to the right of the platform64and the upper pressing plate65. The edge locating conveyor8is formed by a plurality of (in the shown example, nine) thin belts8aextending in the left-right direction indicated inFIG. 1that is disposed at intervals in the front-rear direction indicated inFIG. 1.

As shown inFIG. 15toFIG. 20, the two-position holding device7has: a pair of holding chucks71,72mounted at a rear end and a front end, respectively, of a coupling rod70that extends in the front-rear direction; an upward-downward moving cylinder73that moves both the holding chucks71,72upward and downward at the same time; and a forward-backward moving device7A that moves the holding chucks71,72along with the upward-downward moving cylinder73forward and backward in the left-right direction indicated inFIG. 1. The forward-backward moving device7A has a driving belt75that holds the upward-downward moving cylinder73in a vertical state, and a motor74that rotates a pulley around which the driving belt75is wrapped. However, the forward-backward moving device7A may have any structure as long as it can move the holding chucks71,72in the left-right direction, and a forward-backward moving cylinder may also be used. In this embodiment, a moving mechanism7B is provided as a position changing means that moves the two-position holding device7in a crosswise direction (the front-rear direction indicated inFIG. 1) relative to the delivery direction of the edge locating conveyor8. The moving mechanism7B has a driving belt76on which the forward-backward moving device7A is fixed, and a motor77that moves the two-position holding device7along with the forward-backward moving device7A forward and backward in the front-rear direction by rotating a pulley around which the driving belt76is wrapped. However, the moving mechanism7B may have any structure as long as it can move the two-position holding device7in the crosswise direction relative to the delivery direction of the edge locating conveyor8, and a forward-backward moving cylinder may also be used. As shown only inFIG. 15, the coupling rod70is provided with a cylinder70aas an interval changing mechanism that changes the distance between the holding chucks71,72according to the size of the cloth Y to be handled etc. In a preferable configuration, whether or not operation of the cylinder70ais required and the amount of operation thereof are automatically determined by the controller (not shown) in association with the pulling distance in the horizontal pulling device6, and operation is performed accordingly.

As shown inFIG. 15, the front-side holding chuck72is located at a position at which it can hold the front-side end portion (corner end) Yb of the cloth Y laid by the horizontal pulling device6, while the rear-side holding chuck71is located at a position at which it can hold an appropriate portion of the laid cloth Y, on the rear side of the front-side end portion Yb.

In its contracted state, the upward-downward moving cylinder73is configured such that the upward-downward moving cylinder73keeps the holding chucks71,72on standby at positions above the cloth Y having been horizontally pulled, and in its extended state shown inFIG. 15, the upward-downward moving cylinder73moves the holding chucks71,72downward to positions at which they can hold the ridge of the fold in the cloth Y or a portion near the ridge. When the two-position holding device7moves downward as the upward-downward moving cylinder73extends, the front-side holding chuck72holds the front-side end portion (corner end) Yb of the cloth Y while the rear-side holding chuck71holds an appropriate rear-side portion of the cloth Y. Here, the opening degree of the chuck69provided near the rear side of the upper pressing plate65can be reduced from the wide-open state indicated by reference sign69′ to help the front-side holding chuck72hold the cloth Y. When the cloth Y is held by the holding chucks71,72, the cloth Y is released from the chuck61, the upper pressing plate65, and the chuck69of the horizontal pulling device6that have been holding or restraining the cloth Y. Thus, the holding chucks71,72hold two separate portions of the rectangular cloth Y that are on or near the ridge of the fold, in a state where the cloth Y has been folded with the side edge Yc on the side to be located in a later step and the opposite side edge Yd intersecting each other so as to reveal the right-angled triangular part S of which the adjacent side Sa is formed by the portion of the side edge Yc that is adjacent to the corner of intersection while the hypotenuse Sb is formed by the portion of the opposite side edge Yd that defines the corner of intersection with the adjacent side Sa. In addition, in this embodiment, the two-position holding device7is configured to be able to automatically hold two separate portions of the cloth Y that are on or near the ridge of the fold after the cloth Y has undergone the processing by each of the corner end receiving device5and the horizontal pulling device6. However, the processing leading up to the holding chucks71,72of the two-position holding device7holding the cloth Y may be performed by using devices different from those shown in the drawings or may be manually performed by a worker.

Subsequently, as shown inFIG. 16 (a)andFIG. 16 (b), the holding chucks71,72of the two-position holding device7are moved toward the upper side and the right side and disposed directly above the edge locating conveyor8as the upward-downward moving cylinder73contracts and the forward-backward moving device7A operates. Here, a sensor78that is provided under the edge locating conveyor8detects the position of a right-angled portion Sc of the right-angled triangular part S. The sensor78is composed of, for example, a plurality of photoelectric sensors (reference sign78ainFIG. 16indicates an optical axis of the sensor) that is arrayed in the crosswise direction relative to the delivery direction of the edge locating conveyor8, and the position of one of the photoelectric sensors that has detected the cloth to the end can be regarded as the position of the right-angled portion Sc. Based on the position of the right-angled portion Sc detected by the sensor78, the controller (not shown) obtains an amount of positional deviation of the right-angled triangular part S from a correct clamping position corresponding to the positions of clamping chucks92,93to be described later. To compensate for this amount of positional deviation, the controller operates the moving mechanism7B described above as the position changing means so as to shift the two-position holding device7in the crosswise direction relative to the delivery direction of the edge locating conveyor8as shown inFIG. 17. Thus, the right-angled triangular part S of the cloth Y held by the two-position holding device7is adjusted so as to be located at the correct clamping position corresponding to the positions of the clamping chucks92,93to be described later. The sensor78is not limited to an optical sensor, and for example, may also be an image sensor that takes an image of the right-angled triangular part S by a CCD camera or the like and recognizes the right-angled portion Sc by image processing.

The belts of the edge locating conveyor8are rotating in the direction of the arrow inFIG. 18. The right-angled portion Sc of the cloth Y is located near an upper surface of a belt of the edge locating conveyor8or at a position at which the right-angled portion Sc comes into contact with the upper surface. Air blown by a blowing device82installed between upper and lower portions of the belts of the edge locating conveyor8causes the right-angled triangular part S to trail in the delivery direction of (move along) the conveyor8.

Next, as shown inFIG. 19, the two-position holding device7releases the two portions of the cloth Y being held at such timings that the portion on the side of the right-angled triangular part S is released later, i.e., that in the shown example, the cloth Y is released first by the rear-side holding chuck71and then by the front-side holding chuck72. Thus, as a portion of the cloth Y that has first fallen onto the edge locating conveyor8flows toward a downstream side, the cloth Y rotates in the plane of the edge locating conveyor8with the front-side holding chuck72serving as a base point. This results in a positional relationship in which the adjacent side Sa of the right-angled triangular part S of the cloth Y is at a substantially right angle to the delivery direction of the edge locating conveyor8. When this positional relationship is established, as shown inFIG. 20, the other holding chuck72releases the cloth Y, so that the entire cloth Y falls onto the edge locating conveyor8, which completes locating of the edge of the cloth Y. For example, two optical sensors83that detect the adjacent side Sa (side edge Yc) of the right-angled triangular part S of the cloth Y being delivered on the edge locating conveyor8are installed near a downstream end of the edge locating conveyor8, and the edge locating conveyor8may be switched to a low speed when the sensors83detect the cloth Y.

As shown inFIG. 21, the vertically inverting device9has: for example, two clamping chucks92,93that are disposed near the downstream end of the edge locating conveyor8in the delivery direction and clamp a peripheral portion of the right-angled triangular part S of the cloth Y including the adjacent side Sa (a portion of the side edge Yc); two optical sensors94,95provided near the clamping chucks92,93; a reversing shaft96that supports the clamping chucks92,93; and a turning cylinder91that turns the reversing shaft96through a link. In addition, any mechanism may be used as long as it can reverse the cloth Y clamped by the two clamping chucks92,93, and instead of the turning cylinder91, a motor that rotates the reversing shaft96in normal and reverse directions may also be used. The two clamping chucks92,93may be configured to move independently of each other based on signals output by the sensors94,95upon detecting the side edge Yc of the cloth Y. In this case, even when the direction of the adjacent side Sa of the right-angled triangular part S of the cloth Y being delivered by the edge locating conveyor8deviates significantly from the direction of a right angle to the delivery direction of the edge locating conveyor8, the adjacent side Sa of the right-angled triangular part S of the cloth Y can be clamped straight between the clamping chucks92,93by shifting the clamping timings of the clamping chucks92,93so as not to coincide with each other.

The vertically inverting device9operates as follows. First, until the adjacent side Sa of the right-angled triangular part S of the cloth Y being transferred on the edge locating conveyor8is detected by the sensors94,95, each of the clamping chucks92,93remains on standby in a substantially horizontal (slightly upward-inclined) posture as shown inFIG. 20. When the adjacent side Sa of the right-angled triangular part S of the cloth Y being transferred on the edge locating conveyor8is detected by the sensors94,95, each of the clamping chucks92,93holds a peripheral portion of the right-angled triangular part S of the cloth Y including the adjacent side Sa based on detection signals from the sensors94,95. Immediately thereafter, the turning cylinder91contracts and causes each of the clamping chucks92,93to turn downward at a high speed while holding the peripheral portion (side edge Yc) of the adjacent side Sa of the right-angled triangular part S and to assume the downward-facing posture shown inFIG. 22. Here, the cloth Y having been held by each of the clamping chucks92,93is rapidly swung down and thereby an unfolding action is exerted on the cloth Y in a short-side direction. Each of the clamping chucks92,93holding the side edge Yc of the cloth Y in the downward-facing posture releases the peripheral portion of the side edge Yc they are clamping after this peripheral portion is passed to each of chucks111,112of the hanging device11to be described below, and immediately thereafter are turned upward and returned to the original standby positions.

Thus, the two-position holding device7, the edge locating conveyor8, and the clamping chucks92,93work together to constitute the edge clamping device that locates an edge of cloth Y and clamps a peripheral portion of the right-angled triangular part S including the located adjacent side Sa.

Next, as shown inFIG. 23, the roller10and the hanging device11that hangs the cloth Y received from the vertically inverting device9onto the roller10are installed directly under a front-side portion of the edge locating conveyor8, in a positional relationship with the hanging device11located above the roller10.

The hanging device11has a hanging movable body11A, and the hanging movable body11A has a forward-backward moving platform110facing the vertically inverting device9, the two chucks111,112that are disposed on both sides of the forward-backward moving platform110and receive the cloth Y from the clamping chucks92,93of the vertically inverting device9, and chuck sensors113,114. The hanging movable body11A is moved forward and backward in the left-right direction (in the direction of a rotational axis of the roller10) by a forward-backward moving device. In the shown example, the forward-backward moving device is composed of a driving belt116that holds the hanging movable body11A and a motor115that rotates a pulley around which the driving belt116is wrapped. However, the forward-backward moving device may have any structure as long as it can move the chucks111,112forward and backward in the left-right direction, and, for example, a forward-backward moving cylinder may also be used.

The hanging movable body11A moves from the standby position shown inFIG. 23to a predetermined forward position beyond one end (inFIG. 23, the right-side end) of the roller10in an axial direction so as to come closer to the cloth Y held by the vertically inverting device9. As shown inFIG. 24, when the chuck sensors113,114detect the cloth Y, the chucks111,112are closed toward both sides of the forward-backward moving platform110and hold the cloth Y. Here, the position at which the chucks111,112hold the cloth Y is a position near the position at which the clamping chucks92,93of the vertically inverting device9hold the cloth Y. In addition, the two chucks111,112may be configured to move separately and independently, and in that case, the portion of the side edge Yc of the cloth Y between the two chucks111,112can be held straighter. As shown inFIG. 25, after passing the cloth Y, the vertically inverting device9turns around and returns to the original position, and moves away from the path of the hanging movable body11A. Since the roller10is disposed such that the rotational axis thereof is parallel to the forward-backward moving direction of the hanging movable body11A, when the hanging movable body11A holding the cloth Y in a drooping state moves backward, as shown inFIG. 25, the cloth Y is hung on the roller10and droops from the roller10. Here, a side edge Yd on the opposite side from the long-side edge Yc held by the chucks111,112is detected by a sensor101, and the chucks111,112release the cloth Y after a predetermined time has elapsed since the detection. The predetermined time is appropriately set such that the chucks111,112release the cloth Y when the center of the cloth Y in a width direction thereof substantially coincides with the center of the roller10in a width direction thereof. In addition, the hanging device11continues to move backward a predetermined distance also after the chucks111,112release the cloth Y.

As shown inFIG. 26, the roller10is composed of a first roller part102and a second roller part103disposed next to each other on the same axis. The first roller part102is connected to a motor104through a driving belt105and driven to rotate by the motor104. The second roller part103is connected to a motor106through a driving belt107and driven to rotate by the motor106. The rotation directions and the rotation speeds of the motors104,106can be controlled separately and independently. It is preferable that the rotation directions and the rotation speeds of the motors104,106be controlled separately and independently such that the direction of the cloth Y on the roller10can be corrected to the right direction (e.g., a direction in which a long-side direction of the cloth Y coincides with the front-rear direction) based on detection signals from a plurality of sensor groups108,109that is arrayed under each of the roller parts102,103parallel to the rotational axis of the rollers as shown inFIG. 27. For example, when the cloth Y is obliquely hung on the roller10as shown inFIG. 26, and only one sensor group108or109of the sensor groups108,109, or only some sensors of the sensor group108or109detect the short-side edge Ye of the cloth Y, the first roller part102and the second roller part103are repeatedly stopped, rotated in a normal direction, and rotated in a reverse direction based on a detection result of that sensor group or those sensors, until the side-edge Ye becomes parallel to the sensor groups108,109and both the sensor groups108,109detect the short-side edge Ye of the cloth Y at the same time. In addition, in the shown example, each of the sensor groups108,109consists of five sensors respectively. However, the number of the sensors is not limited to five, and four or less or six or more sensors may be provided according to the width of the cloth Y to be processed, and the sensors to be activated may be switched according to the cloth Y to be processed.

The forward-backward moving device12moves the cloth Y having been oriented in the right direction on the roller10onto the transfer conveyor13and spreads the cloth Y. As shown inFIG. 28, the forward-backward moving device12has a holding unit that has a clamping width larger than the maximum width of a plurality of types of cloth Y to be processed and clamps a short-side end portion of the cloth Y, and a forward-backward moving mechanism that moves the holding unit forward and backward in the front-rear direction. In the shown example, the above holding unit is composed of a holding platform123ainclined facing the roller10, and a holding plate123bthat is opened from and closed onto the holding platform123aby a cylinder124or the like. Furthermore, the above forward-backward moving mechanism is composed of a driving belt122that is coupled to the holding platform123aand a motor121that rotates a pulley around which the driving belt122is wrapped. However, a forward-backward moving cylinder may also be used for the forward-backward moving mechanism.

To move the cloth Y from the roller10onto the transfer conveyor13by the forward-backward moving device12, as shown inFIG. 28, the first roller part102and the second roller part103are rotated toward the forward-backward moving device12at the same time and at the same speed, so that the side edge Ye (the upper end inFIG. 28) of the cloth Y located near the sensor groups108,109is moved closer to the forward-backward moving device12. Furthermore, as shown inFIG. 29, the holding unit of the forward-backward moving device12is moved forward, and a leading end of the holding platform123aof the holding unit with the holding plate123bopened is pressed against a blowing member10ainstalled under the roller10, so as to hold a portion of the cloth Y on the roller10, which is a portion on the side of the transfer conveyor13, between the leading end of the holding platform123aand the blowing member10a. In this state, as shown inFIG. 30, air is ejected from the blowing member10aand, at the same time, the first roller part102and the second roller part103are further rotated toward the forward-backward moving device12. As a result, the above side edge Ye of the cloth Y is placed on the holding platform123a. Thereafter, as shown inFIG. 31, the holding plate123bis closed and the side edge Ye of the cloth Y is held between the holding plate123band the holding platform123a. The portion of the cloth Y other than the portion held between the holding platform123aand the holding plate123bof the holding unit droops from the holding platform123a. In this state, as shown inFIG. 32, the holding unit of the forward-backward moving device12is moved toward the transfer conveyor13. After the holding unit is moved backward a predetermined distance, as shown inFIG. 33, the holding plate123bis opened again and the cloth Y is moved onto the transfer conveyor13. In addition, the holding unit of the forward-backward moving device12continues to be moved backward a predetermined distance also after the holding plate123breleases the cloth Y.

As shown inFIG. 34, the transfer conveyor13has a belt133having a large number of through-holes, a motor132that drives the belt133, and a suction fan131that suctions the spread cloth Y on the belt133through the through-holes formed in the belt133. As the cloth Y on the transfer conveyor13is thus suctioned, the side edge Ye of the cloth Y held by the holding unit of the forward-backward moving device12can fall and smoothly move onto the transfer conveyor13. Thereafter, the transfer conveyor13discharges the cloth Y and transfers (feeds) the cloth Y to the next process (here, the cloth folding machine D). In addition, the belt133of the transfer conveyor13need not be driven while the holding unit of the forward-backward moving device12moves the cloth Y onto the transfer conveyor13. However, it is preferable that the belt133be driven from the viewpoint of increasing the number of pieces of cloth to be processed.

The automatic cloth spreading machine configured as described above requires simply feeding the washed and dried cloth Y onto the supply conveyor1. Then, the cloth Y can be automatically spread and transferred (fed) to the next process by the lifting device2, temporary holding device3, corner end locating device4, corner end receiving device5, horizontal pulling device6, two-position holding device7, edge locating conveyor8, vertically inverting device9, roller10, hanging device11, forward-backward moving device12, transfer conveyor13, etc.

Further, the edge clamping device and the automatic cloth spreading machine including this device of the embodiment are configured to be able to move the two-position holding device7in the crosswise direction (the front-rear direction inFIG. 1) relative to the delivery direction of the edge locating conveyor8by the moving mechanism7B as the position changing means. Even when the shape and size of the right-angled triangular part S appearing in the cloth Y held by the two-position holding device7vary due to a change in the type of cloth Y to be processed etc., the moving mechanism7B thereby compensates for the positional deviation of the right-angled triangular part S from the correct clamping position corresponding to the positions of the clamping chucks92,93. Therefore, the edge clamping device and the automatic cloth spreading machine including this device of the embodiment can clamp the cloth Y, of which the edge has been located on the edge locating conveyor8, in a reliable manner and at the correct position by the clamping chucks92,93. This makes it possible to process a plurality of types of cloth varying in shape and size by a single edge clamping device.

When the configuration is adopted in which the edge clamping device includes the sensor78that detects the position of the right-angled portion Sc of the right-angled triangular part S in a state where the two-position holding device7is holding two portions of the cloth Y, and in which the moving mechanism7B as the position changing means moves the two-position holding device7in the crosswise direction relative to the delivery direction of the edge locating conveyor8based on the position of the right-angled portion Sc detected by the sensor78, measurement and compensation of the amount of positional deviation of the right-angled triangular part S can be automatically performed.

Further, when the two-position holding device7has the interval changing mechanism that changes the distance between the pair of holding chucks71,72, which is formed by the cylinder70ain the above example, the distance between the pair of holding chucks71,72can be changed according to the size of the cloth Y to be processed. Thus, when processing a plurality of types of cloth Y varying in shape and size, it is possible to always hold similar portions, for example, a front end portion and an intermediate portion, or a front end portion and a rear end portion, and to prevent deformation etc. of the cloth Y being held, which can enhance the accuracy in locating the edge on the edge locating conveyor8.

In addition, in the above description, an aspect in which the positional deviation of the right-angled triangular part S from the correct clamping position is compensated for by the position changing means moving the two-position holding device7in the crosswise direction relative to the delivery direction of the edge locating conveyor8has been described. However, the present invention is not limited to this aspect, and the edge locating conveyor8itself may be moved in the crosswise direction. Further, the clamping chucks92,93or the vertically inverting device9itself that supports the clamping chucks92,93may be moved in the crosswise direction. Alternatively, two or more of the two-position holding device7, the edge locating conveyor8, the clamping chucks92,93, and the vertically inverting device9may be relatively moved at the same time. Also in these modified examples, it is preferable that the sensor78detect the right-angled portion Sc of the right-angled triangular part S to obtain the amount of positional deviation from the correct clamping position, and that the amount of movement is determined so as to compensate for this amount of positional deviation. Further, also in these modified examples, it is preferable that the two-position holding device7is provided with an interval changing mechanism like the cylinder70athat changes the distance between the pair of holding chucks. Moreover, the two-position holding device7may have three or more holding chucks, and arbitrary two of these holding chucks may be used as the pair of holding chucks according to the dimension of the cloth to be processed etc.

INDUSTRIAL APPLICABILITY

The present invention can provide an edge clamping device that can clamp cloth, of which an edge has been located on an edge locating conveyor, in a reliable manner and at a correct position, and an automatic cloth spreading machine including this device.

REFERENCE SIGNS LIST