Method and apparatus for manipulating a length of flexible material

Abstract: The apparatus orients flaccid material such as hose blanks having toe ends (T) and bulkier welt ends (W) while they are being conveyed from a supply point to a receiving point, such as to ensure that blanks arriving at the latter are all received e.g. toe ends first. The apparatus has first (4) and second (6) suction conduits in communication with an outlet (8), the first conduit (4) having an inlet (10) to which hose blanks are successively presented. Orientation determining means (12, 19-22) sense which end of a blank enters the inlet (10); if a toe end is sensed, the hose is permitted to travel unhindered to the outlet (8). If, however, a welt end is sensed at the inlet (10) suction is created in the second conduit (6) and the welt end is temporarily drawn into the second conduit. While the welt end is thus located, suction in the first conduit (4) causes the toe end to be drawn therealong, past the second conduit (6) and toward the outlet (8). In this way the hose blank is turned end-for-end, and on relieving the suction in the second conduit (6) the blank is freed to travel toe first through the outlet to the receiving point.

Description: The present invention relates to methods and apparatus for manipulating a length of flexible material (i.e. limp articles) having dissimilar ends and is particularly, but not exclusively, applicable to manipulating hose blanks. If a length of flexible material is to be processed by an automatic machine it is necessary to first load the material appropriately prior to processing. In the case of pantyhose manufacture, for example, the processing of hose blanks to make pantyhose generally involves three basic machines namely a line closer, a toe closer and a gusset sewing machine. Linking machines are available which can automatically transfer partially processed pantyhose between one machine and the other but in order to obtain a fully automated system it is necessary that the first machine in the sequence is also loaded automatically rather than manually by an operator. In order to effect such automatic loading it is necessary to both retrieve a single length of the flexible material, in this particular example a hose blank, from a collection of them and, if the lengths of material are asymmetric, also to orient the length of material so it can be properly loaded onto the first machine of the series. Most hosiery leg blanks are produced on small diameter knitting machines and after knitting each is sucked pneumatically into a dispensing device which is usually a feature of the knitting machine. The hose blanks are then ejected or dispensed from the dispensing device into a sack where they can be subject to some form of relaxation. Relaxation is a process where the hose blanks are tumbled or vibrated while being subjected to steam or hot air which has the effect of relaxing or "shrinking" them. At the end of the knitting process, therefore, the manufacturer has a number of hosiery leg blanks in bags which are then delivered to the making up room to be processed by the pantyhose processing machines. The hose blanks are asymmetric in that they have a toe end and a bulkier welt end and have to be loaded on the first machine in one orientation, usually welt end first. WO-A-95/27097 discloses an apparatus and method of removing a small number of flexible objects, such as circular knit hosiery blanks from a mass of randomly arranged flexible objects, depositing the flexible objects on a turntable in spaced apart relation, removing individual flexible objects from the turntable, conveying the individual flexible objects to a sensing location, sensing the orientation thereof, returning to the turntable any flexible objects that are not properly positioned for the sensing of the orientation thereof, conveying the flexible objects which have had the orientation thereof determined along one of two alternate paths of travel determined by the orientation that has been sensed and the orientation desired at the delivery point, delivering the properly oriented blanks to a transfer location, transferring the blanks to a further processing apparatus, and further processing the flexible objects. US-A-4,539,924 discloses a system for automatically orienting hosiery blanks upon a conveyor, selectively transferring blanks from the conveyor to a turret assembly by means of a pick-up assembly, the turret assembly including a plurality of support units for sequentially conveying a plurality of blanks in an arcuate path to an automatic toe closing machine, everting the blanks and sewing closed the toe portions of the blanks. EP-A-0,521,206 discloses a system for handling flexible articles such as tubular hosiery blanks each having a toe portion and a welt or band portion and for subsequently closing the toe portions includes an assembly for retrieving randomly oriented blanks from a supply reservoir, pneumatic feed means for displacing the blanks to a magazine, means for selectively displacing the blanks from the magazine such that the toe portion is always first, means for opening the band portion and positioning the band portion on fingers which expand and convey the blank to a transport tube of a toe closing assembly. The blank is inverted on the transport tube and the toe portion subsequently sewn. EP-A-0,508,014 discloses an apparatus for orienting a length of flexible material according to the preamble of claim 1. The present invention is characterised by the features of the characterising portion of claim 1 with optional features of the present invention recited in the dependent claims. Embodiments of the present invention may include a retrieval apparatus for retrieving a single length of flexible material, for example a hose blank, from a collection of such lengths comprises a suction tube having an orifice and means for directing an air blast in the region of the orifice. The retrieval apparatus can be lowered into a bin, tub or the like containing a randomly oriented collection of lengths of material and suction applied to the suction tube. One or more lengths of material may be held at the orifice but by suitable choice of orifice dimensions, readily determined by trial and error for a given application, only the one held most securely by the suction tube will be able to resist the air blast in the region of the orifice which dislodges the remaining lengths. This retrieval apparatus therefore allows a single length of flexible material to be automatically retrieved from the bin. The retrieval apparatus preferably further includes a gripping means for gripping the length of material held at the orifice of the suction tube so the suction can be removed and the material still be held by the retrieval apparatus for future further manipulation. An alternative embodiment may include apparatus for retrieval of a single length of flexible material from a collection of such lengths which has proved more reliable, comprising: removing means for removing one or more of said lengths of material from a storage bin and arranged to release them at the entrance of a conduit; propelling means for selectively sucking and blowing the lengths of material along the conduit to or from an elongate dispenser, the dispenser having a latch means at the end nearer the propelling means and being configured so that only one of the lengths of material can be latched by the latch means and sufficiently long to hold the length of material when positioned lengthwise within it. The dispenser can be a commercially available Detexomat dispenser. When suction is applied to the conduit the one or more lengths of material released at the entrance of the conduit are sucked to the elongate dispenser where they bunch up at the dispenser end. The latch means is then latched and by virtue of its design will engage one only, in general, of the lengths of material in the dispenser. This can be achieved by placing the latch at the apex of a narrow trapping end of the dispenser, for example, where only one of the lengths of material can reach at a time. Usually the end of the length of material will be in a position to be latched but it can happen that a folded length may be gripped at a position not adjacent an end. The fluid flow is then reversed to act to blow the lengths of material out of the dispenser along the conduit back towards the storage bin, for example, containing the collection of lengths of material from which they came. Only the latched length of material will remain in the dispenser, the remainder, if there was more than one in the dispenser, being returned to the collection of lengths of material. This one, latched,length of the material will generally be straightened to extend along the dispenser during this process. The blowing is stopped after a predetermined period of time, sufficient to allow any extra lengths of material to return to the collection of lengths of material, whereupon the latch is released and the dispenser opened to allow the single length of hose to drop free of the dispenser. This embodiment therefore allows a single length of material to be retrieved from the collection of lengths of material even if the removing means element of the apparatus is not sufficiently selective to ensure only one length of material is picked up by it. It should be noted that the retrieval apparatus in configured so that as far as possible only one length of material is latchable, but it may be that on a rare occasion more than one may be latched, if for example two lengths are stuck together for some reason, and that the absolute impossibility of latching two such lengths of material is not intended as a requirement of the retrieval apparatus of the present invention. Generally, an end of the flexible material will be latched and so be extended along the dispenser. If not achieved it is preferable to reload the dispenser without letting the length of material already in the dispenser drop out. This can be achieved by providing means for determining the presence of the length of material a predetermined distance from the latch, e.g. by a photodetector arrangement, e.g. a SYNATEL PE2FO photodetector. If no material is detected, the latch can be released but instead of opening the dispenser the propelling means is caused to blow again, blowing the length of material back to the collection of lengths of material. Should no length of material have been presented to the conduit means, this determination will again show no material present at the determining means. The blowing back is now unnecessary but it can be arrangd that the apparatus do so any way so the same control procedure can be used to properly locate a length of material in the dispenser just as if a folded length, say, had been latched. The single length of material dropped from the dispenser will be in a known position so can conveniently be made available to a further apparatus, as desired, for further processing of the material. Preferably, the apparatus includes a conveyor means positioned beneath the dispenser arranged to move the dropped length of material laterally from beneath the dispenser. Whilst not restricted to this particular use, the conveyor means can be arranged to convey the length of flexible material to a gripping means for picking up the material to present it to an orienting apparatus according to a further embodiment of the present invention. Preferably the orientation determining means of the present invention comprises a first trap which allows the first end of the length of material to pass through but not a bulkier second end and a first detecting means on the side of the trap farther away from the inlet. If the first detecting means, conveniently a photo detector comprising a light source and a photo cell, e.g. an OMRON E3XA11, detects the length of material then it indicates to a controller that the first end is the end which first entered the first suction conduit. If the first detecting means does not detect the presence of the material within a predetermined period, e.g. 0.4s, then it indicates that the bulkier second end first entered the first suction conduit and so could not pass through the trap. In order to determine when the controller should monitor the first detecting means to determine whether a length of material is present, the apparatus may include a further detecting means, again conveniently a photo detector, at the side of the trap nearer the entrance to the first suction conduit. The further detecting means indicates to the controller when the length of material has entered the first conduit and about to pass the first photodetector if in the correct orientation to do so. If the material is in the orientation in which it is to leave the orientation means then suction can be applied to the outlet and the material extracted from the first conduit. If, however, the length of material is in the opposite orientation to that desired then the material is drawn into the second conduit by the end which first entered the inlet which therefore presents the end which entered the first conduit second towards the outlet. This reverses the original orientation of the material to the one that is desired prior to the removal of the material via the outlet. The material can be removed via the outlet by a further suction conduit which preferably includes a further trap. Preferably, when the application is used for orienting a hose blank, the apparatus orientates the hose blank so that the toe portion exits the outlet first and so all the hose blank up to the welt can pass through the further trap in the further conduit. The hose trap of the further suction conduit can then be exposed thereby exposing the welt end of the hose blank for further manipulation and loading on a pantyhose processing machine, e.g. by moving a portion of the second conduit or by way of a movement of the further conduit. In particular this embodiment of the invention preferably includes a hose gripper which engages with an upper portion of the welt and side grippers for engaging opposite sides of the welt which can then be retracted to open the welt end of the hose. The gripping means can be arranged to then move towards a loading arm pulling the hose blank out of the second hose trap and subsequently releasing their grip on the open welt end of the hose allowing the hose blank to engage with the loader. The loader can be configured and operative to load hose blanks on a line closing machine or a toe closing machine. In one arrangement the further conduits can be arranged to split apart in the vicinity of the hose trap so allowing the welt to hang freely from a further hose gripper to allow more ready access to the welt end by the side hose grips. Embodiments of the present invention can provide apparatus which can variously retrieve and orientate a length of material but it should be appreciated that the orientation means of the present invention could be used with an alternative means of selecting a single length of material from a collection of such lengths and, similarly, the above described retrieval apparatus could be used to load an alternative orientation device. When the retrieval apparatus and orientation apparatus of the above embodiments are used in combination it is preferable that the apparatus includes means for determining whether the portion of the hose blank held at the orifice of the retrieval apparatus hangs below the orifice by a predetermined distance. The distance is selected so that the hose blank is picked up asymmetrically with one end of the hose blank hanging clear of the other end. This ensures that only one end of the hose blank is presented to the orientation apparatus by the retrieval apparatus. The means for determining the length of the longest section of hose hanging from the apparatus conveniently comprises a photo detector at a selected distance from a datum position to which the orifice of the suction tube of the retrieval apparatus is moved prior to operation of the photo detector by the controller. Embodiments of the present invention will now be described by way of example only with reference to the accompanying, non-scale, figures of which: Figures 1 to 5 are diagrammatic plan cross-sectional views of a first embodiment of an orienting apparatus according to the present invention; Figure 6 is a diagrammatic side cross-sectional view of a second embodiment of an orienting apparatus according to the present invention; Figure 7 is a diagrammatic end view of the second embodiment of the present invention in the direction of arrows VII-VII of Figure 6; Figures 8 to 10 are diagrammatic end views of the upper portion of the embodiment as shown in Figure 7 showing the operation of hose grippers gripping the welt end of a hose blank oriented by an orienting apparatus as shown in Figures 6 and 7; Figure 11 is a diagrammatic perspective view showing the loading of the hose blank held shown in Figure 10 onto a hose blank loader; Figure 12 is a diagrammatic side cross-sectional view of a first retrieval apparatus useful with the present invention; Figure 13 is a diagrammatic perspective view of the retrieval apparatus of Figure 12 after retrieval of a hose blank and prior to entry of the hose blank into an orienting apparatus as shown in Figures 1 to 5; Figure 14 is a plan view of a retrieval apparatus useful with the present invention, in the direction XIV-XIV of Figure 15; Figure 15 is a diagrammatic end view of the apparatus of Figure 14 in the direction XV-XV of Figure 14; and Figures 16 to 19 are diagrammatic side cross-sectional views of a second embodiment of an orienting apparatus according to the present invention. Referring to Figures 1 to 5 an orienting apparatus 2 for orienting, in this case hose blanks having a toe end T and bulkier welt end W, is shown. The apparatus has a first, tubular, suction conduit 4 and a second, tubular, suction conduit 6 both in fluid communication with a hose outlet 8. The first suction conduit 4 has a hose inlet 10 defined by a diaphragm 11 which guides a hose blank 16 into the central region of the conduit 4. Inside the first suction conduit 4 is a first hose trap 12 having two gate portions 14 which can be moved apart laterally from a closed position as shown in Figure 1 in which only the toe portion T of a hose blank 16 can pass through its central orifice to an open position as shown in Figures 2, 3 and 5 in which the entire hose blank including the bulkier welt portion W can pass. A photo detector comprising a light bulb 19 and a photo cell 20 located between the hose inlet 10 and the first hose trap 12 detects when a hose blank 16 has entered the first suction conduit. A photo detector comprising a light bulb 21 and a photo cell 22 detects if the hose blank 16 has passed through the hose trap 12 in the first conduit 4. The photo cells 20 , 22 are electrically connected to a suitably programmed general purpose computer (not shown) such as an OMRON CQ series computer, which is the controller of the apparatus. A further suction conduit 24 has a hose trap 26 defining a fixed orifice through which only a toe end T and body of the hose blank 16 can pass. A suction motor (not shown) is coupled to each end of the conduits 24 and 6 which is farther away from the hose outlet 8 via a valve arrangement controllable by the controller which permits the hose blank 16 to be left stationary or sucked in the directions A and B, respectively, as required. The second conduit 6 includes a grill 28 positioned at a distance of about the length of the hose blank 16 from its intersection with the first suction conduit 4. A shorter length of conduit can be used as the hose will crumple to fit inside a shorter length tube of suitable length to present the toe end T of the hose to the first conduit and outlet. Adjacent the grill 28 and hinged to the wall of the suction conduit 6 is a latch 30 for selectively engaging, under the control of the controller, a hose blank 16 drawn against the grill 28 by the suction motor. The end of the second conduit 24 nearer the hose trap 26 is in the form of two semi-cylindrical portions 32 mounted on hinges 34 which can be hinged open to expose a hose blank 16 lying in the second conduit 24 for easier removal by hose grippers as will be described in more detail with reference to Figures 8 to 10. The apparatus of Figures 1 to 5 orientates the hose blank 16 in the following manner. The hose blank 16 is drawn into the hose inlet 10 of the first conduit 4 by applying suction to conduit 24 in the direction A thereby drawing the hose blank 16 towards the hose trap 12, which is in the closed position, and past the photo cell 20. If the toe end T of the hose blank 16 has entered the hose inlet 10 first then it will pass through the hose trap 12 and be detected by the photo cell 22 as shown in Figure 1. The controller monitors the photo cell 22 a short time after the photo cell 20 detects that the hose blank 16 has entered the conduit 4. In this case the hose blank 16 has the required orientation and so the suction continues to be applied in direction A while the controller opens the hose trap 12. This allows the hose blank 16 to be sucked to the hose trap 26. The toe end T of the hose blank 16 passes through the hose trap 26 but the welt end W of the hose blank 16 is trapped as shown in Figure 2. If the hose blank 16 entered the first conduit 4 welt end W first then none of the hose blank 16 will pass through the trap 12 and so photo cell 22 will not detect the hose blank a short time after the hose blank 16 is detected by the photo cell 20. This indicates to the controller that the hose blank 16 is in the reverse orientation to that required. In this case, the controller applies suction to the second conduit 6 in direction B and the hose trap 12 then released thereby allowing the hose blank to be sucked towards the grill 28. The latch 30 is catches the welt end W of the hose blank 16 as shown in Figure 5. The suction in direction B along second conduit 6 is then stopped and suction applied to the further conduit 24 in the direction A whereupon the latch 30 is released by the controller allowing the hose blank 16 to pass through the hose trap 26 until again trapped by the bulkier welt end W as shown in Figure 2. The latch 30 could well be omitted and hence is but optional as the hose will pile up against the grill 28 until the suction is reversed whereupon the previously non-leading end will now become the leading end travelling towards the outlet 8. That is, control of the hose in the course of its end-for-end turning can be accomplished merely by appropriately controlling the application, timing and removal of suction in the conduits 6, 24 in this embodiment. The apparatus therefore, orients the hose blank such that it exits the hose outlet 8 toe end first no matter what the orientation of the hose blank 16 on entering the first conduit 4 so that it can be trapped in the second hose trap 26 as shown in Figure 2. In this embodiment the second conduit 24 can be rotated to one side in the horizontal plane to expose the welt end W of the hose blank 16 for further manipulation as shown in Figure 3. Once the second conduit 24 has been rotated to expose the welt end W of the hose blank 16, a hose gripper 40 is lowered and operated to grip the top portion of the welt W as shown in Figure 8. The end sections 32 of the conduit 24 then are hinged open to leave the welt end W hanging freely from the gripper 40 as shown in Figure 9 whereupon side grippers 42 are then operated to move towards and to grip respective side portions of the welt W. The grippers 40 and 42 are then moved apart to open the welt end W as shown in Figure 10. The hose grippers 40 and 42 are then moved together horizontally to position the stretched open welt end W over the loading fingers 44 of a loading device 46 by moving horizontally in the direction of arrow C of Figure 11. When the open welt end W of the hose blank 16 is positioned over the fingers 44 the grippers 40, 42 are opened to release the hose blank 16 whereupon the open welt end W contracts onto the fingers 44 thereby effecting loading of the hose blank on the loading fingers. Thereafter, the loading fingers can transfer the hose blank onto the hose carrier of a line closer or toe closer in readiness for the latter to position the hose blank appropriately before the respective closing operation is performed. An alternative embodiment of the orienting means is shown in Figure 6. Those components in common with the embodiment of Figures 1 to 5 are given the same reference numerals. In this embodiment the second conduit includes the conduit 24 of Figures 1 to 5 but with an additional semi-circular, vertically oriented, conduit portion 50 between the hose trap 26 and the outlet 8 of the first and second conduits 4 and 6. The hose exiting the hose outlet 8 is oriented as described with reference to Figures 1 to 5 but in this case the hose blank 16 is transferred in a vertical semi-circle by the conduit 50 to rotate it through 180°. In this embodiment the welt end W of the hose blank 16 is exposed by rotating the semi-circular conduit portion 50 about its bottom end to the position shown in Figure 7. The hose blank 16 is transferred from the conduit 24 of Figure 6 to the apparatus 46 of Figure 11 in the same manner as described earlier with reference to Figures 8 to 11. In still another embodiment, not shown, the orienting means again comprises the conduits 4, 6. In place of the further conduit 24 shown in Figs 1 to 5 there is a rotary, four-station hose catcher. The four-station catcher has a cruciform array of four open-ended conduits. Each conduit has a welt trap 26 adjacent its open end. The conduits are connected, or connectible, with a source of suction either individually or conjointly via a common suction duct. Suitable suction control valving may be located between the four conduits and the source of suction. Drive means is provided to rotate or index the four station catcher. In use of this embodiment, the drive means rotates the catcher bringing the open ends of the four conduits in turn to the outlet 8 of the conduits 4, 6. Each conduit will, in turn, receive a single oriented hose blank from the outlet 8. The hose blanks received by the catcher are accommodated in the conduits, with their welt ends exposed at or adjacent the open ends. In turn, the conduits with the hose blanks therein are rotated to a hose-removing location. At this location grippers 40, 42 as described above in connection with Figs 8 to 10 take hold of an exposed hose welt, open it and transfer it to the fingers 44 of the loading device 46, which operates as before. Thereafter the grippers 40, 42 return to collect, open, remove and transfer another hose blank from the next conduit of the catcher to arrive at the said location. Referring now to Figure 12 a retrieval apparatus for retrieving a length of flexible material, in the example illustrated a hose blank, comprises a suction tube 60 having an end orifice 62. The tube 60 is coupled to a suction motor (not shown) able to apply suction in the direction of arrow D to hold a hose blank 16 against the end orifice 62. The lower end of the suction tube 60 is laterally enclosed by an open bottomed, generally conical housing 64 in which are located a pair of downwardly and inwardly angled air jet nozzles 66 each coupled to respective air tube 68 by which a blasts of air can be generated at the nozzles 66. The air jets from the nozzles 66 are directed downwards and towards the end of the suction tube 60 so they can dislodge any hose blank which may be lightly held at the orifice 62 of the suction tube 60. Grippers 70 at the bottom of the housing 64 on opposed sides of the housing can be operated to move co-operating grips 80 horizontally towards each other to grip a hose blank 12 at the orifice 62 thereby supporting hose blank 16 when the suction in suction tube 60 is removed. Referring now also to Figure 13 the retrieval apparatus is operated by dropping the end of the suction tube 60 into a tub 82 holding a collection of randomly oriented hose blanks 84. Suction is then applied to the suction tube 60 in the direction D so one or more hose blanks will be sucked towards the orifice 62. The apparatus is then raised vertically and air blasts generated through the nozzles 66 to dislodge all but one hose blank 16 from the end of the suction tube 60. The suction tube 60 is lifted and moved to a pre-determined datum position above a photo detector comprising a light source 85 and a photo cell 86. The light source 85 and photo cell 86 are positioned relative to datum position so that a hose blank 16 will fall between the light source 85 and the photo cell 86 and be detected if it is supported at the orifice 62 sufficiently far from its mid point so that only one end is able to be sucked into the conduit 4 adjacent the photo detectors 86. If the controller determines by monitoring the photo cell 86 that the retrieval apparatus has picked up the hose blank 16 in a suitable position, then suction is applied to the conduit 4 and the hose blank 16 sucked into the conduit 4 of an orientation apparatus as described with reference to Figures 1 to 7. The controller causes the grippers 78 to be released so allowing the hose blank to drop from the retrieval apparatus 12 to be sucked into the conduit 4. If the hose blank 16 was picked up by the retrieval apparatus near the mid-point, the grippers 78 are opened so the hose blank 16 falls back to the container 82. The retrieval process is then repeated until a single hose blank is picked up in the required position for being drawn into the conduit 4. Referring now to Figures 14 and 15, there is shown a system of combined retrieving and orienting apparatus including a retrieving apparatus indicated generally by the reference numeral 100 and an orienting apparatus indicated generally by the reference numeral 200. The retrieving apparatus includes a gripping means 102 for gripping and removing one or more lengths of flexible material, in this case tubular hose 104, (not shown in Figure 15) from a storage bin 106. The gripping means includes a pair of opposable gripping arms 108 which are pivotable to permit the arms 108 to move together thereby gripping a tubular hose between the arms. The gripping arms can be raised and lowered vertically along a guide rail 110 to lower the gripping arms into the storage bin 106 to be in a position to grip a tubular hose 104 and to lift the tubular hose out of the storage bin 106 by moving vertically upwards. The motive power for these operations is obtained from a motor 112 which is shown, for clarity reasons, in simplified form with no indication of the controls or particular constitution of this arrangement. It falls readily within the skills of a person familiar with this field to construct this and the other features of this embodiment to put the invention into practice. A conduit 114 has one open end positioned above the storage bin 106 at a location where tubular hose raised out of the bin by the gripping means 102 can be presented to the opening of the conduit 114. The conduit 114 extends horizontally rearward of the apparatus to an elongate dispenser 116 and extends from the other end of the dispenser 116 via portion 118 of the conduit to a suction motor 121 located beneath the dispenser 116. The dispenser 116 has two longitudinally extending wings 118 hinged along a central hinge line 120. When the wings 118 of the dispenser 116 are closed the interior of the dispenser completes a airflow path from the conduit 114 through to the conduit 118. The flow path in the dispenser 116 towards the conduit 118 and suction motor 121 narrows to form a constricted throat 122 at the end of the dispenser. Positioned close to the apex of the throat 122 is a latch 124 which can be moved from a retracted position to a position extending across the throat 122 across the dispenser 116 as shown in Figure 14. Located in one of the wings 118 is a photodetector 124 which is arranged to detect whether or not any material lies within the dispenser at this position. The dispenser 116 is supported above a bed 126 which is in the form of a metal panel 128 across which run endless belts 130 fitted around shafts 132 and 134 at opposite ends of the plate 128. The shaft 132 is a driven shaft rotatable by motor 134 via a transmission 136. The shaft 134 is a driven shaft which rotates when the belts 130 are rotated by the driven shaft 132. The belts are spaced sufficiently close such that they can move a length of tubular hose 138 across the plate 128 which the hose contacts where it sags between the conveyor belts 130 and rubs against the plate 128. The retrieval apparatus 100 of Figures 14 and 15 operates as follows. The gripper 102 is lowered into the bin 106 until it reaches the collection of hose 104. The distance the gripper is lowered into the storage bin can be controlled by any convenient sensor which determines when the gripper is at or close to the top of the pile of tubular hose. For example a contact switch can be located at the end of the gripper 102 which closes on contact with the topmost tubular hose 104 thereby indicating to an automated control system (not shown) that the gripper 102 has reached the desired position within the storage bin 106. Alternatively, a photocell with a limited focal length may be used. The control then causes the gripper arms 108 to rotate and meet together thereby gripping one or more of the tubular hose 104 whereupon the gripper arm is raised to a position where the lower end of the tubular hose gripped by he gripper is adjacent the opening of the conduit 114. This raised position of the gripper arm 102 can be determined by means of a photodetector arrangement, for example, positioned below the opening of the conduit 104 which will give an indication to the control means when the lowermost end of the hose gripped by the gripper has just passed the photodetector thereby indicating that the lowermost extremity of the tubular hose is in the required position adjacent the opening of the conduit 114. The suction motor 121 is then coupled to the conduit 118 dispenser 116 and conduit 114 to suck the gripped hose into the conduit 114 whereupon the gripper arms 108 are retracted away from each other thereby releasing the hose 104 so that they are sucked along the conduit 114 into the dispenser 116. The hose 104 entering the conduit 114 will bunch up at the distal end of the conduit of the dispenser 116 at the throat 122. Generally speaking only one hose will be in the throat 122 in a position to be latched by the latch 124 when it is now closed across the throat 122 although it is possible that in some circumstances two hose may be in such a position. After the latch 124 has been extended across the throat 122 the motor 121 is connected to the conduit 118 such that the flow of air through the conduit 118 is reversed. If more than two hose had entered the conduit 114 initially, of which one is now gripped in the dispenser, those additional hose will now be blown back along the conduit 114 to return to the storage bin 116 whilst the hose latched in the dispenser 116 will be extended along the dispenser 116 from the latch 124 towards the end of the dispenser 116 nearer the conduit 114. If only one hose was initially introduced into the conduit 114 then the above blowing operation still takes place but in this case the only action is to extend the hose 104 latched by the latch 124 in the manner just described. In either case there will be, except in exceptional circumstances, only one hose latched by the latch 124. In this particular application shown in Figure 14 it is preferable that it is the end of the hose in the dispenser 116 that has been latched by the latch 124. That this has been achieved can be determined in this embodiment by use of the photodetector 124 which can be used to indicate whether there is any material in the dispenser at the position of the photodetector 124. Because the photodetector 124 is located in a position slightly short of the length of the hose 104, if the photodetector indicates the presence of material then the controller will have determined that the trapped hose is indeed latched near one of its ends. If, however, the photodetector 124 indicates that there is no material in that position then the inference the controller can make is that the latch 124 has latched the hose more towards the middle causing the effective shortening of the hose within the dispenser 116 or not trapped a hose at all. In this case the controlling means releases the latch means 124 while still blowing air in the direction of the storage means 116 thereby removing any hose 104 from the dispenser 116 and returning it to the storage bin for a repeat attempt at reloading a length of hose to attempt to once more to latch hose at one end by the latch means 124 as required. If the gripper 102 failed to grip any hose 104 in the bin 106 then there will be no hose in the dispenser 116 to be dispensed by the latch means 124. Again the photodetector 124 will indicate to the controller that there is no material at that position and so will continue to blow air in the direction towards the storage bin 106 for the time required to transport hose back to the storage bin, even though there is none present in this case, whereupon reloading will again take place. Once the dispenser has latched a hose which extends to a photodetector 124 whilst air is blowing through the conduit 118 toward the storage bin 106 then the blowing is stopped and the latch 124 can be released to leave a hose lying within the dispenser in an extended position. The dispenser can then be opened by pivoting the wings 116 apart about the hinge line 120 thereby allowing the hose to drop onto the conveyor belts 130 to be moved laterally away from beneath the dispenser. This action is then repeated the result being a succession of hose 138 laid out along the conveyor belts 130 separated from each other by an amount the conveyor belt is incremented after the controller determines that the hose has been successfully trapped in the dispenser 116 and subsequently dropped onto the conveyor belts 130. The net result of the above operations of the retrieval apparatus 100 is that during each cycle of the operation of the retrieving apparatus 100 a single hose is retrieved from the storage bin 116 whether or not the gripping means itself retrieves more than one hose 104 from the storage bin 106. In the apparatus of Figure 14 the conveyor belts 130 transfer each of the successively transferred single hose 104 towards a orienting apparatus 200 which will now be described also with reference to Figures 14 and 15. However, it should be noted that the retrieval apparatus 100 as just described whether with the conveyor belts 130 of not, can be used with other apparatus than that about to be described where a single length of flexible material needs to be retrieved from a collection of such articles. The orienting means 200 includes a gate 207 including a gate blade 204 which can be moved into and out of the gate 207 by a drive 205 to open or close the gates 207. At the entrance of the gate is a photodetector 206 (see Figures 16 to 21). The entrance of the gate defines the opening of a first conduit 208 (see Figures 16 to 20) which extends to an outlet 210. Beyond the gate 207 on the opposite side from the photodetector 206 is a further photodetector 210. A second conduit 212 intersects the first conduit 208 beyond the second photodetector 210 and, in the path direction moving away from the conduit 208 includes a gate 214, a photodetector 216 and a grill 218. The conduit 212 extends beyond the grill 218 to a suction motor 221 below the conveyor belts 130 as shown in Figure 15. For clarity the conduit connection to the motor 221 is not shown. Continuing along the length of the path of the first conduit 202 beyond the junction with the second conduit 212 there is a further photodetector 220 positioned in front of the outlet 210 of the first conduit 208. Beyond the outlet 210 of the first conduit 208 is a further gate 222 at the entrance to a further conduit 224 which extends to a suction motor 226 located underneath the conveyor belts 130 as shown in Figure 15. Again the connection of the conduit 224 to the suction motor 226 is not shown for reasons of clarity. Although the orienting means 200 can be used to orient a length of flexible material as will be described below, a length of material presented to the input of the inlet of the conduit 208 by whichever method is convenient in the circumstances when using the orienting means of the present invention, there will now be described a preferred arrangement in which hose retrieved by the retrieving apparatus 100 as previously described is presented to the entrance of the conduit 208 by the following apparatus as will now be described with reference to Figures 14 and 15. A gripper mechanism designated generally by the reference numeral 300 includes a gripper 302 which can be raised or lowered vertically along a guide rail 304 by means of a conveyor track (not shown) which conveyor track is driven by a motor 306 coupled to the conveyor track by means of belt 308 between a driving shaft 310 of the motor 306 and a driven shaft 312 about which the conveyor track is mounted. The gripping means 302 is positioned such that when it is moved to the lowered position, as shown in Figure 15, it is adjacent the end of a length of hose 138 as conveyed to the gripping means 302 by the conveyor belt 130 from the dispenser 116. The advantage of this arrangement is that the gripping position is known to be at the end of the hose so that the distal end of the hose can be reliably presented to the of the orienting apparatus 200 as will now be described. In the position of the gripper 302 as shown in Figure 15 gripper arms (not shown) close together and grip the hose adjacent one end. The motor 306 then drives the gripper arms and hose upwards past a hinged trough 314 which is pivoted to allow the gripper arm to pass by by a piston cylinder arrangement 316 from the position shown in Figure 15 to one in which the right hand lower inclined surface is substantially vertical. The gripper is driven vertically sufficiently for the lower, hanging, end of the hose to be above the trough 314. When the gripper arms are in this position the piston cylinder arrangement 316 is operated to lower the trough 314 into position shown in Figure 15. The gripper 302 is then driven downwards by the motor 306 to lower the hanging end of the hose into the trough 314 whose sloping bottom surface guides the end of the hose to the inlet of the conduit 208. The operation of the orienting means will now be described with reference also to Figures 16 to 20. There are two situations which will now be considered in turn. Firstly, when the end presented to the inlet of the conduit 208 is the toe end of the hose and secondly when it is the bulkier welt end of the hose that is presented to the inlet of the conduit 208. At this point gate 207 is in the partially open position in which the toe but not the welt of the hose can pass through, whereas gate 214 is open and gate 222 is open so as to apply maximum suction to the conduit 208 from the conduit 224. If it is a toe end T that is being presented to the input of the conduit 208 then as the gripping means 302 is lowered so the toe end T of the hose will be able to pass through the gate 207 and within a known time be detected by the photodetector 210 which indicates to the controller that it is indeed the toe end T that has entered the conduit 208 as shown in Figure 16. In this case the orienting apparatus stays in the same configuration as the gripping means 302 is lowered allowing the toe end T of the hose to extend down the conduit 208 until it reaches the photodetector photodetector 220 whereupon the gate 222 at the outlet 210 of the conduit 208 is narrowed to a gap which allows only the toe end of the hose to pass through and the gripping means is released as shown in Figure 17. On release of the hose from the gripping means the hose is sucked toe end T first through the gate 222 into the conduit 224 until its progress is halted when the welt end W reaches the gate 222 as shown in Figure 18. The hose is then in the required position with respect to the gate 222 whereupon the conduit 224 can be moved away from the first conduit 208 to position the welt where required for the next processing step to be carried out upon it. In the case that the welt end of the hose is presented to the input of the conduit 208 the photodetector 206 will detect its presence but it will not reach the photodetector 210 in the predetermined amount of time because it will be unable to pass through the gate 207 which as noted above is set to a gap which only allows the narrow toe-end T of the hose to pass through. When the fact that it is the welt end that has been presented to the conduit 208 is detected in this manner then the suction applied to conduit 224 is switched off and instead suction is applied to the second conduit 212 and the first gate 207 is opened to allow the welt end W through the gate 207 to be sucked into the second conduit 212 past the photodetector 216 to be arrested in its progress by the grill 218 as the gripper 302 lowers allowing the hose to pass into the conduit 212. When the welt end W of the hose reaches the photodetector 216 in the second conduit 212 the controller causes the gate 214 to close so trapping the welt end W of the hose which is now adjacent to the grill 218 and for the gripper 302 to release so arriving at the situation illustrated in Figure 20. The suction to second conduit 212 is removed and suction again applied to the conduit 224 which has the effect of sucking the hose along the conduit 208 until the hose extends through the gate 222 with the welt still trapped behind the gate 214 as shown in Figure 21. Shortly thereafter the gate 222 can be closed to the partially open position which allows all but the welt end W of the hose to pass through. The gate 214 is then opened to release the welt end W of the hose whereupon the hose passes along the conduit 208 and into the conduit 224 until trapped by the gate 222 as shown in Figure 18. It can thus be seen that whether the welt end or the toe end is presented to the inlet of the conduit 208 the hose will in each case end up in the position shown in Figure 18 where the welt end is trapped by the gate 222 whereupon the conduit 224 can be moved to a different station for further processing of the hose for example by applying gripper means to the welt end to remove the hose from the conduit 224 for further processing as previously described. It will be appreciated that those of ordinary skill in this art given the description of the operation of the various components as described above will understand how to construct a suitable pneumatic control system, the provision of a controlling means to operate the various motors, gates and other aspects of the embodiments of the invention described are achieved using well known and generally available microprocessor based control systems, the particular details of which are incidental to the invention and can be implemented as convenient to provide apparatus or methods according to the invention which is as claimed in the appended claims. The foregoing description is concerned with the handling of flaccid articles e.g. in the manufacture of garments, e.g. hosiery garments. Automatic dispensing of limp articles having dissimilar ends, and their conveyance in an orderly manner to a receiver so that they always arrive there with given ends leading, are beset with problems. Such problems are avoided when dispensing is done manually. The human operator takes an article e.g. from a bin, inspects it and then simply lays it on a conveyor or the like in the required orientation. Such articles, of course, include hose blanks to be made up into pantihose. The blanks are flaccid tubular knits having toe and welt ends, which are dissimilar. At a supply point, the blanks will ordinarily be in a random jumble. From here, they need to be taken sequentially and conveyed e.g. to a machine instrumentality which loads them onto a support, for further processing. There is a need for the blanks to be conveyed in an orderly manner, e.g. with their welt ends always leading so that the receiving machine instrumentality can correctly perform its designated task. One prior approach involves a conveyor which receives hose and conveys them welt or toe leading as the case may be to a location at which the conveyor divides into two lines. Hose are directed into the different lines depending on whether they arrive at the said location toe first or welt first. Toe-leading hose, for instance, are directed in a reverse direction to welt-leading hose and into a loop line, while welt-leading hose continue onwards without any reversal of motion. Thanks to the reversal of motion of the toe-leading hose, they enter the loop line welt first, and are then conveyed along that line to a machine instrumentality so as to arrive there welt first. Hose which originally arrived at the said location welt first are conveyed directly to the machine instrumentality without any reversal of motion. This prior approach involves pneumatic or suction conveyors, lengthy duct-work, numerous valves and a microprocessor to control the system, and overall is relatively complex and inevitably costly to realise. The apparatus and process of the present invention accomplishes the same end more simply and cost effectively. According to the invention in its apparatus and process realisations, limp articles having dissimilar first and second ends are advanced lengthwise along a single path, first or second ends leading as the case may be. In the path, means are provided to discriminate between the first and second ends and further means responsive to the discriminating means are provided momentarily to arrest any article moving along the path, e.g. second end leading, while permitting articles moving opposite end leading to continue unhindered along the path. The arresting means may engage an article advancing second end leading at or adjacent that end and, while that end is arrested the remainder of the article continues its motion along the path; in the process the article is effectively turned end-for-end until its opposite end is leading whereupon the arresting means releases the article for continuing movement along the path. It will be appreciated that this aspect of the invention can be realised simply and reliably in a pneumatic or suction conveying system. Typical line closers and toe closers with which this invention may be associeted are represented e.g. by the Takatori Model 360 WPD machine and by the Detexomat DLC-600L 600L or VHS machines. The hose gripper (40) can be a commercial device such as a WALTON Picker, made by the PICK ROBOTIC Company of the USA.

Claims: An apparatus for orienting a length of flexible material (16), for example a hose blank, having a first end (T) and a dissimilar second end (W) comprising a first suction conduit (4) and a distinct second suction conduit (6) both in fluid communication with an outlet (8), the first conduit (4) having a inlet (10) for receiving a length of material, an orientation determining means (12,21,22) for determining which end of the length of material, the leading end, first enters the first conduit (4), and characterized by: means arranged to selectively draw at least the leading end portion of the length of material into the second conduit (6) only if the second end (W) is leading in which case the apparatus is arranged to present the first end (T) as the leading end in the first conduit (4) for continued motion along the first conduit (4), the second end (W) exiting the second conduit (6) in the opposite direction to which it entered the second conduit (6). An apparatus as claimed in claim 1 for orienting a length of flexible material in which the second end (W) is bulkier than the first end (T) in which the orientation determining means comprises a first trap (22) in the first conduit (4) near the inlet moveable between an open position in which the first end (T) of the length of material can pass and a closed position in which the second end (W) of the length of material cannot pass and first detecting means (21,22) for detecting the presence of the material in the conduit (4) on the side of the first trap farther from the inlet. An apparatus as claimed in claim 2 in which the orientation determining means further includes a second detecting means (19,20) on the side of the first trap nearer the inlet. An apparatus as claimed in any one of the preceding claims in which the second conduit (6) includes a grill (28) across its internal section. An apparatus as claimed in any preceding claim including a further suction conduit (24) for drawing a length of material entering the inlet to a second trap (26) arranged to trap the second end (W) of the length of material. An apparatus as claimed in claim 5 in which the further suction conduit (24) has a portion moveable to expose the second end (W) of the length of material trapped by the second trap (26). An apparatus as claimed in claim 6 in which the further conduit can be opened to leave the second end (W) of the length of material in the further conduit (24) unsupported by the further conduit (24). An apparatus as claimed in claim 5, wherein the further suction conduit (24) comprises a cruciform array of four conduits each containing a second trap, the array being rotational to bring each conduit in turn to the said outlet (8), to receive said length of material therefrom. An apparatus as claimed in either one of claims 6, 7 or 8, including gripping means (40,42) arranged to grip and open the welt end of a hose blank in the further conduit (24). An apparatus as claimed in claim 9 in which the hose gripping means (40,42) is further arranged to move the open welt end (W) of the hose blank to a loading element of further apparatus. An apparatus as claimed in any preceding claim in which the second conduit (24) is sufficiently long to contain the whole length of the flexible material. An apparatus as claimed in any one of claims 1 to 10 in which the second conduit (6) includes arresting means (30) (e.g. a latch) for arresting the length of material at or near the second end (W) when drawn into the second conduit (6), the apparatus being arranged to cause the remainder of the length of material to continue its motion along the first conduit (4) whereby the length of material is turned end-for-end until the first end (T) becomes the leading end and to then release the arresting means (30). A method for orienting a length of flexible material, for example a hose blank, having a first end (T) and a second dissimilar end (W) comprising; (a) drawing the length of material into a first conduit (4); (b) determining the orientation of the length of material; (c) selectively drawing at least the leading end portion of the length of material into the second conduit (6) if the second end (W) is leading and, in this case, (d) presenting the first end (T) as the leading end for continued motion along the first conduit (4), the second end (W) exciting the second conduit (6) in the opposite direction to which it entered. A method as claimed in claim 13 including, when the second end (W) is drawing into the second conduit (6), arresting the length of material at or near the second end (W), by an arresting means (30) causing the remainder of the length of material to continue its motion along the first conduit (4) whereby the length of material is turned end-for-end until the first end (T) becomes the leading end and then releasing the arresting means (30) for continuing movement of the length of material along the first conduit (4). An apparatus as claimed in any preceding claim, and further including an for retrieving the length of flexible material from a collection of such lengths, comprising a suction tube (60) having an orifice (62) and means (66) for directing an air blast in the region of the orifice, including optionally, a hose grip (80) for gripping the portion of material held at the orifice of the suction tube, and, preferably, means for determining whether the length of material is held at the orifice (62) hangs below the orifice (62) by at least a predetermined distance. An apparatus as claimed in any preceding claim, and further including apparatus for retrieving the length of flexible material from a collection of such lengths of material comprising: removing means for removing one or more of said lengths of material (16) from a storage bin (82) and arranged to release them at the entrance of a conduit (114); propelling means for selectively sucking and blowing the lengths of material along the conduit (114) to or from an elongate dispenser (116), the dispenser (116) having a latch means (124) at the end nearer the propelling means and being configured so that only one of the lengths of material can be latched by the latch means (124) and sufficiently long to hold the length of material when positioned lengthwise within it. An apparatus as claimed in claim 16 including a conveyor means (126) positioned beneath the dispenser (116) for catching the length of material dropped from the dispenser (116). An apparatus as claimed in claim 17 in which the conveyor means (126) is arranged to move the dropped length of material laterally from beneath the dispenser (116). An apparatus as claimed in claim 18 including gripping means (300) for gripping the single length of material after it has dropped from the dispenser (116). An apparatus as claimed in claim 19 in which the gripping means (300) is positioned laterally from the dispenser (116) the single length of material being conveyed to the gripping means (300) by the conveyor means (126). An apparatus as claimed in any one of claims 16 to 20 including means for determining whether a single length of material latched by the latch means (124) can extend a predetermined distance from the latch means (124). A method as claimed in any one of claims 12 to 14, further including the steps of retrieving a single length of material from a collection of such lengths of material comprising: presenting one or more lengths of material from the collection of lengths of material to the entrance of a conduit (114); sucking the lengths of material through the conduit (114) to an elongate dispenser (116) which includes a latch means (124) arranged so that only the end of one of the lengths of material can be latched by the latch means (124) and which is sufficiently long to hold the length of material when positioned lengthwise within it; latching the end of one of the lengths of material within the dispenser (116); blowing through the conduit (114) to blow any lengths of material not latched by the latch means (124) back to the collection of lengths of material. A method as claimed in claim 22 including determining if the length of material latched by the latch means (124) fails to extend a predetermined distance along the dispenser (116) from the latch means and, if so, releasing the latch means (124) whilst continuing to blow through the conduit (114) thereby returning the now unlatched length of material to the collection of lengths of material. A method as claimed in claim 22 or 23 including opening the dispenser (116) to allow the single length of material positioned lengthwise within it to drop from the dispenser (116). A method as claimed in claim 24 in which the single length of material falls onto a conveyor means (126) positioned beneath the dispenser (116) the method including moving the single length of hose laterally on said conveyor means (126). A method as claimed in claim 26 in which the single length of material is moved to a gripping means (300) positioned to be able to grip the single length of material at a predetermined distance from the end which was latched by the latch means (124). A system for retrieving and orienting a hose blank comprising a retrieval apparatus as claimed in claim 15 or 20 and an orienting apparatus as claimed in any of claims 1 to 10 in which the retrieval apparatus is arranged to move the hose blank (16) to the vicinity of the inlet of the first conduit (4) of the orienting apparatus when the hose blank (16) held at the orifice of the retrieval apparatus hangs below the orifice by at least the predetermined distance.

Inventors: HODGES MICHAEL JOHN, HODGES, MICHAEL JOHN
Applicants: DETEXOMAT MACHINERY LTD, DETEXOMAT MACHINERY LIMITED
Application year: 1996
Main classification: D05B23
IPC codes: B65G47, D05B23