Abstract:
A transporting carriage for conveying a coiler can of curved outer circumferential surface in an upright orientation between a can stand of a sliver producing fiber processing machine and a can stand of a sliver comsuming fiber processing machine includes an apparatus for transferring the coiler can from the carriage to the can stand and from the can stand to the carriage in a linear transferring direction. The apparatus includes a gripper element having a jaw opening defined by an inner concave surface of the gripper element for engaging the coiler can along a portion of the curved outer circumferential surface; a turning mechanism for rotating the gripper element along a path generally parallel to the curvilinear length to alter an orientation of the jaw opening; and a linear shifting arrangement for linearly displacing the gripper element parallel to the linear transferring direction for placing the gripper element into a first position in which it is situated within an outline of the carriage and into a second position in which it is situated externally of the outline.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the priority of German Application No. P 41 27 292.7 filed Aug. 17, 1991, which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     This invention relates to a method and an apparatus for transporting coiler cans in a spinning plant between a sliver producing machine (such as a carding machine) and a sliver consuming machine (such as a drafting frame) and/or an intermediate station by means of a transporting carriage which is associated with a loading and unloading device whose gripping and conveying elements are linearly shifted. The gripping elements serve the purpose of grasping the coiler can whereas the conveying elements transfer the coiler cans to or from the transporting carriage. 
     In a conventional method, by means of a loading and unloading device mounted on the transporting carriage, a coiler can filled with sliver or an empty coiler can is transferred to or is taken from the transporting carriage. The gripping device has two horizontal telescoping cylinders having respective pistons. At the end of one piston a pressure cylinder is provided at an angle of 90° which operates in a direction radial to the coiler can and firmly clamps the coiler can against the oppositely located other pressure cylinder. For adapting the gripping device to the round outer surface of the coiler can, two curved, short clamping pieces are provided. First, the clamping pieces are shifted in a linear direction tangentially relative to the coiler can in such a manner that the coiler can is placed between the clamping pieces. Between the clamping pieces and the lateral coiler can surface only narrow spaces remain. The clamping pieces are short to ensure that the can fits therebetween when it is grasped. The stroke of the pressure cylinder which is mounted transversely on a horizontal telescoping cylinder is also short. Thereafter the coiler can is, as the pressure cylinder moves radially in the direction of the coiler can, radially frictionally firmly grasped by the clamping pieces. 
     In the above-outlined grasping process the gripping of the coiler cans requires a very accurate positioning of the transporting carriage at the coiler can stand, because each coiler can has to be positioned (in the x-direction) with very small lateral distances in the intermediate space between the two clamping pieces which face one another. In addition, the telescoping cylinders with the clamping pieces must also be very accurately positioned relative to the coiler can (y-direction) to ensure that the short clamping pieces securely grasp the outer surface of the coiler can. Such an accurate positioning of the clamping pieces in the longitudinal and transverse directions is complicated and may easily lead to operational disturbances. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an improved method and apparatus of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, permits a secure grasping and conveyance of the coiler cans in a simple and rapid manner. 
     This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the transporting carriage for conveying a coiler can of curved outer circumferential surface in an upright orientation between a can stand of a sliver producing fiber processing machine and a can stand of a sliver comsuming fiber processing machine includes an apparatus for transferring the coiler can from the carriage to the can stand and from the can stand to the carriage in a linear transferring direction. The apparatus includes a gripper element having a jaw opening defined by an inner concave surface of the gripper element for engaging the coiler can along a portion of the curved outer circumferential surface; a turning mechanism for rotating the gripper element along a path generally parallel to the curvilinear length to alter an orientation of the jaw opening; and a linear shifting arrangement for linearly displacing the gripper element parallel to the linear transferring direction for placing the gripper element into a first position in which it is situated within an outline of the carriage and into a second position in which it is situated externally of the outline. 
     The measures according to the invention make possible a secure grasping and conveying of the coiler cans in a simple and rapid manner. A further advantage is in the simplification of the precise positioning of the gripper and carrier elements. A further advantage resides in the form-locking straddling and form-locking guidance of the cans. 
     The apparatus according to the invention has the following additional advantageous features: 
     The jaw opening of the gripper element has the shape of a circular segment. 
     The jaw opening of the gripper element is shaped as a semicircular arc. 
     The jaw opening of the gripper element is a one-piece component. 
     The jaw opening of the gripper element is formed of at least two parts, such as circular arc sections. 
     A drive mechanism which is provided for turning the gripper element, includes a stationary drive motor having a toothed gear, a sprocket or the like, being in engagement with a toothed countercomponent connected with the gripper element, for example, an arcuate toothed rack, a sprocket belt or the like. 
     The gripper element is movable along a horizontal track. 
     The driving mechanism for turning the gripper element is mounted on a carrier element which linearly shifts the gripper element and which has at least one pneumatic cylinder. 
     The carrier element has at least one toothed rack displacement device. 
     Opposite the carrier element there is provided a guide element, for example, a guide rail in a parallel relationship therewith. 
     The guide element is shiftable parallel in the direction of the carrier element. 
     Sensors (can stand location markings) are associated with the transporting carriage and the can readying stations at the sliver producing machine (card) and/or the sliver consuming machine (drafting frame) and/or intermediate stations. 
     On the transport carriage two carrier elements are arranged each having a gripper element with its own drive mechanism. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic top plan view of a spinning preparation system which includes five carding machines and two drafting frames and which incorporates the invention. 
     FIG. 2 is a schematic side elevational view of a preferred embodiment of the invention. 
     FIGS. 3a-3l are schematic top plan views depicting sequential steps in the performance of a loading, conveying and unloading process according to the invention. 
     FIG. 4 is a schematic top plan view of the preferred embodiment of the invention, performing a bilateral loading and unloading process. 
     FIG. 5 is a top plan view of a further detail of the preferred embodiment. 
     FIG. 6 is a schematic top plan view of another preferred embodiment of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The system illustrated in FIG. 1 is formed of five carding machines 1 through 5 which may be, for example, EXACTACARD DK models manufactured by Trutzschler GmbH &amp; Co. KG, Monchengladbach, Germany as well as two drafting frames 6 and 7. The carding machines are sliver-producing fiber processing machines whereas the drafting frames are sliver-consuming (utilizing) fiber processing machines. Each carding machine 1-5 is associated with a feeding apparatus (sliver coiler) 1a for depositing the sliver, produced by the respective carding machine, into a coiler can 8a. Adjacent the sliver coiler 1a there is disposed a pickup station 1b for removing the filled coiler cans 8b from the sliver coiler apparatus. The sliver coiler 1a and the pickup station 1b may be components of a conventional coiler can replacing mechanism. 
     For transporting a coiler can 8c between the carding machines 1-5 on the one hand and the drafting frames 6 and 7, on the other hand, a transporting carriage 9 is provided which carries the coiler can 8c to the standby stations 6a, 6b of the drafting frame 6 or the standby stations 7a, 7b of the drafting frame 7. The stations 6a, 6b each accommodate three cans 8d, 8e, while the stations 7a, 7b each accommodate three cans 8f, 8g. The coiler cans 8e and 8g  are situated at the inlet of the drafting frames 6 and 7, respectively; in that position sliver is taken from the respective cans and supplied to the drafting mechanism of the drafting frames 6 and 7 for doubling and stretching as a preparation for spinning. It is to be understood that instead of three coiler cans 8e and 8g a greater or smaller number of coiler cans 8e and 8g may be positioned simultaneously at the inlet of the respective drafting frames 6 and 7 when a different type of doubling is required. Further, a reserve station 24 is provided for the coiler cans 8 which is disposed between the carding machines on the one, hand and the drafting frames on the other hand and may receive or dispatch empty and/or filled coiler cans 8 in a railroad switching yard fashion. The travelling path of the transport carriage 9 is indicated at broken lines. 
     Turning now to FIG. 2, there is illustrated therein the transport carriage 9 which is designed for handling one coiler can at a time. The coiler can has a diameter of, for example, 1,000 mm. The can 8 to be transferred to a can stand associated with one of the carding machines 1-5 or one of the drafting frames 6, 7 is positioned on a roller track 10 which is mounted on the carriage 9 and which is positioned at a height of about 120 mm above the ground. The chassis of the transport carriage 9 accommodates the non-illustrated drive for propelling the transport carriage as well as a drive for a telescoping cylinder 15, energy supply devices and the like. The chassis is provided with four wheels 12 (only two wheels are visible) and has a steerable shaft, not shown. The coiler can 8 is situated on the transport carriage 9 generally within a rectangular outline defined by the four wheels 12 as shown, for example, in FIG. 4. 
     The loading and unloading device (transferring device) for the coiler can 8 includes a gripper element 13 which is mounted on the chassis 11 by means of a horizontally oriented telescoping power cylinder unit 15 having pistons 15a, 15b and 15c. The gripper element 13 is disposed at the end of the piston 15b. 
     As depicted in FIG. 3a, three full coiler cans 8 are supported in an upright orientation on a stand 1b&#39; at the pickup station 1b of the carding machine 1. For engaging and moving the top (leading) coiler can 8 onto the transport carriage 9, the gripper element 13, having an inner concave engagement surface 13&#39; (constituting a jaw opening) is turned in the direction of arrow A With respect to its holding element 16 in such a manner that its jaw opening is oriented towards the top can 8 (that is, towards the stand 1b&#39;) as illustrated in FIG. 3b. Thereafter, the gripper element 13 is, together with its holder 16, linearly shifted by the power cylinder 15 in the direction B until the gripper element 13 circumferentially engages the outer surface of the can 8 as illustrated in FIG. 3c. It is noted that a linear shifting mechanism including the power cylinder 15 is disclosed in more detail in U.S. Pat. 4,683,619 which is hereby incorporated by reference. Thereafter, as shown in FIG. 3d, the gripper element 13 is moved relative to the holder 16 in a horizontal plane in an arcuate direction coaxially to the can 8, that is, substantially along the curved plane defined by the gripper element surface 13&#39;, until the jaw opening of the gripper element 13, while remaining in engagement with the can 8, is oriented towards the transporting carriage 9. Thereafter, as shown in FIG. 3e, the gripper element 13 is linearly shifted by the transferring element (power cylinder) 15 in the direction of the arrow D until the can is transferred onto the transport carriage 19. During such a transfer motion the can 8 is form-fittingly guided by the gripper element 13. 
     Thereafter, as illustrated in the sequential FIGS. 3f and 3g, the transporting carriage 9 leaves the pickup station 1b of the carding machine 1 in the direction of the arrow E, then travels to the drop-off station 6a associated with the non-illustrated drafting frame 6 as indicated by the arrow G in FIG. 3g. It is further seen that prior to the carriage travel, the gripper element 13 is turned coaxially to the can 8 until the jaw opening of the gripper element 13 is oriented towards the direction of travel E, G. 
     Upon arrival of the transport carriage 9 into the station 6a, the gripper element 13 is turned in the direction of the arcuate arrow H coaxially to the transported can 8 until the jaw opening of the gripper element 13 is oriented similarly to FIG. 3d. This position is shown in FIG. 3h. Thereafter, the gripper element 13 is, together with the can 8, linearly shifted as indicated by the arrow I in FIG. 3i until the can is moved onto the stand 6a&#39; of the station 6a. 
     Subsequently, the gripper element 13 is withdrawn linearly in the direction of the arrow K until it assumes its position within the outline of the transporting carriage 9 and, as a last step before the carriage 9 leaves the station 6a, the gripper element 13 is moved arcuately relative to its holder 16 as shown in FIG. 31, to assume the same position as illustrated in FIG. 3a. 
     In the arrangement illustrated in FIG. 4 there are provided two side-by-side arranged, parallel-oriented can standby ramps 20 and 21. Between the ramps 20 and 21 a guide rail 23 extends on the ground for guiding the transporting carriage 9 between the two ramps. On the ramp 20 each can 8h-8k and 8l-8n is associated with a can position (presence) determining device, such as a sensor 22a, 22b, 22c and, 22d, 22e and 22f, respectively. By virtue of this arrangement the transporting carriage 9 is capable of handling cans from both sides, since, as already described in connection with the sequential FIGS. 3a-3l, the gripper element 13 may be arcuately turned approximately 180° as will be apparent upon a comparison of, for example, FIGS. 3b and 3h and further, the gripper element 13 may be linearly shifted outward from the carriage 9 to either side thereof as it is apparent from, for example, a comparison of FIGS. 3c and 3i. 
     Across from the transfer (telescoping) element 15 a guide rail is provided which may be shifted together with the transfer element 15 parallel therewith. During the transport of the can 8, the end 10&#39; of the gripper element 13 which in the position illustrated in FIG. 4 is in the immediate vicinity of the transport element 15, projects beyond a vertical central plane of the coiler can 8. The central plane is oriented parallel to the travel direction of the transport carriage 9. In such an orientation, the end 10&#39; serves as a braking counterelement making possible a more rapid can transport. 
     Turning to FIG. 5, the one-piece gripper element 13 has the shape of a semicircular annular segment. The inner circular surface 13&#39; of the gripper element 13 which serves as the engaging jaw surface has a diameter Which is greater than that of the can 8 so that an unobstructed entry and exit of the can 8 into and out of the concave curvature of the jaw opening is ensured. The gripper element 13 is mounted on the gripper carrier 16 which, in a sled-like fashion, is displaceable as indicated by the arrows M and N. A toothed belt 17 is secured to the gripper element 13 at both ends and is designed to have a loop which is guided around a drive sprocket 18 which, in turn, is rotated by a motor 18&#39; accommodated, for example, in the chassis 11 of the carriage 19. The drive sprocket 18 is supported on the gripper carrier 16. The gripper carrier 16 further supports two deflecting rollers 19 and 28 for guiding the sprocket belt 17. Guide rollers 27, 29 and 31, also supported on the gripper carrier 16 are in engagement with inner and outer circular tracks 13&#39;&#39;, 13&#39;&#39;&#39; provided on the gripper element 13 for positioning and guiding the same when turned by the drive assembly 17, 18, 18&#39;. The gripper carrier 16 is mounted on the telescoping cylinder 15 and is movable in the direction of the arrows M and N relative to the telescoping cylinder 15 and is also movable with the gripper carrier 16 in the direction of arrows B and I (FIGS. 3 c and 3i) with the telescoping cylinder 15 as a unit. As the roller 18 is driven by the motor 18&#39;, the toothed belt 17 arcuately moves the gripper element 13 in the direction of the arrows A, H substantially in a path defined by the concave surface 13&#39; of the gripper element 13. 
     In FIG. 6, there are shown two telescoping elements 15a, 15b each carrying a separate gripper element 13a, 13b.  In this manner it is feasible to deposit an empty can 8 and to receive a full can 9 on the transport carriage 9 thus reducing the duration of the can handling cycles. 
     By virtue of the circumferential straddling arrangement of the gripper element 13 about the surface of the can 8 the force effect for shifting is on a greater circumferential surface sector of the can and, at the same time, a lateral escape of the can is effectively prevented. 
     It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.