Abstract:
An apparatus for severing ties or a wrapper surrounding a fiber bale includes a severing device having a cutting element and a drive for actuating the cutting element; a counterelement positioned adjacent the cutting device; a supporting device for positioning the fiber bale; and a displacing device for moving the severing device and the cutting device as a unit relative to the supporting device for causing the counterelement to penetrate into the fiber bale underneath the tie to countersupport the tie during severing of the tie by the severing device.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the priority of German Application Nos. P 40 25 890.4 filed Aug. 16, 1990 and P 41 19 336.9 filed Jun. 12, 1991, which are incorporated herein by reference. This application further contains subject matter related to a United States application filed concurrently with this application and based on German Application Nos. P 40 25 889.0 filed Aug. 16, 1990 and P 41 19 158.7 filed Jun. 11, 1991. 
     BACKGROUND OF THE INVENTION 
     This invention relates to a method and an apparatus for severing securing ties such as wires, straps or bands and/or the wrapper of textile fiber bales, particularly cotton bales and chemical fiber bales. The fiber bales and a severing device for the ties and/or the wrapper are moved relative to one another and at least one severing element of the severing device is driven. 
     In a known arrangement a pneumatically rapidly accelerated chisel is impacting the bale tie. Such a method, however, cannot be used universally; in particular, in case of relatively soft textile fiber bales, the ties may be pressed into the soft fiber material without a complete severance. It is a further disadvantage of the prior art structures that they do not permit a continuous operation. 
     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, may find universal application and ensures a secure severing of the bale ties. 
     This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the apparatus for severing ties or a wrapper surrounding a fiber bale includes a severing device having a cutting element and a drive for actuating the cutting element; a counterelement positioned adjacent the cutting device; a supporting device for positioning the fiber bale; and a displacing device for moving the severing device and the cutting device as a unit relative to the supporting device for causing the counterelement to penetrate into the fiber bale underneath the tie to countersupport the tie during severing of the tie by the severing device. 
     By virtue of the fact that the severing device cooperates with a counterelement which extends below the tie, the latter is prevented from avoiding the severing device during the severing operation. In this manner a secure severing of the tie is ensured regardless of the type or firmness of the fiber bale. It is a further advantage of the invention that by virtue of the penetration and travel of the counterelement with the severing device, a continuous operation is ensured. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a schematic top plan view of a preferred embodiment of the invention, showing a travelling severing device and stationarily supported fiber bales. 
     FIG. 2 is a top plan view of a wrapperless fiber bale, provided with ties and being engaged by severing components according to the invention. 
     FIG. 3 is a top plan view of a wrapped fiber bale, provided with ties extending above the wrapper, and being engaged by components of the severing device according to the invention. 
     FIG. 4 is a top plan view of a wrapped fiber bale provided with ties extending underneath the wrapper and being engaged by components of the severing device according to the invention. 
     FIG. 5a is a schematic side elevational view of a preferred embodiment of a severing device including a rotatable cutting wheel, a toothed disc and a counterelement provided with knife blades. 
     FIG. 5b is a sectional view taken along line Vb--Vb of FIG. 5a. 
     FIG. 6 is a schematic side elevational view of another preferred embodiment of a spike-like counterelement and a rotatable toothed cutting wheel. 
     FIG. 7 is a schematic top plan view of another preferred embodiment of the severing device. 
     FIG. 8 is a schematic top plan view of a still another preferred embodiment, formed of a cutting wheel and a finger-shaped blade. 
     FIG. 9a is a schematic top plan view of yet a further preferred embodiment of the invention, including a stationary severing device with shears and a finger-shaped knife according to the invention. 
     FIG. 9b is a schematic side elevational view of the construction shown in FIG. 9a. 
     FIG. 10 is a schematic top plan view of still another preferred embodiment of the invention. 
     FIG. 11a is a schematic side elevational view of another preferred embodiment of the invention. 
     FIG. 11b is a schematic front elevational view of the structure shown in FIG. 11a. 
     FIG. 12a is a schematic side elevational view of yet another preferred embodiment, including a percussion knife. 
     FIG. 12b is a schematic front elevational view of the structure shown in FIG. 12a. 
     FIG. 13 is a schematic top plan view of a further preferred embodiment, including parallel shears. 
     FIG. 14 is a schematic top plan view of a hook component of a further preferred embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a textile fiber bale 1 which is positioned stationarily on a conveyor belt 2 driven by a motor 3. A bale retaining device 4 which is stationarily supported externally of the belt 2 and which can be pivoted into and out of the illustrated operative position, forms a counterpressure surface at one end of the fiber bale 1. The fiber bale 1 is surrounded by a plurality of securing ties 5 which are under significant circumferential tension. A counterelement, such as a spike 6 which may be, for example, 20 cm long, is attached at its root to a spike block 6c which is secured to an endless carrier element, such as a chain 11c of a carrier device generally designated at 11. The spike 6 is oriented at an angle α to its travelling direction A as advanced by the carrier device 11. The pointed end of the spike 6 is oriented towards the fiber bale 1. The chain 11c is supported by two opposite end rollers 11a, 11b rotating in the direction as indicated by respective arrows B and C. A cutting wheel 7, slowly rotated in the direction D and also mounted on the chain 11c is propelled in unison with the spike 6 and cooperates therewith. The spike 6 and the cutting wheel 7 are in an overlapping relationship with one another. The cutting wheel 7 has a rotary axis 7a which is perpendicular to the travelling direction A. As seen in the top plan illustration of FIG. 1, the cutting wheel 7 and the counterelement 6 are supported laterally of the conveyor belt 2 for engaging and severing the ties 5 on a lateral, vertical face of the fiber bale 1. 
     In operation, the travelling spike 6 penetrates the surface of the fiber bale 1 and extends underneath the tie 5 which, as a result, is slightly pulled away from the bale surface. Thereafter, the tie 5 is introduced into the gap between the spike 6 (which has a cutting edge) and the driven cutting wheel 7, whereby the tie 5 is severed between the two cutting edges. In FIG. 1 a severed tie is designated at 5&#39;, while a tie on which the cutting operation is just being performed is designated at 5&#39;&#39;. The cross-sectional surface of the severed wire has at its edge two bright cut surfaces and a mat ruptured surface. This indicates that first the wire is nicked by the severing device and then torn apart by the significant tension in the wire. 
     FIGS. 2, 3 and 4 illustrate a severing device formed of the spike 6 and the cutting wheel 7 which is moved in the direction of the arrow E while the bale 1 is immobilized. In all three FIGS. 2, 3 and 4 the solid-line illustration of the cutting device 6, 7 shows the moment of penetration of the spike 6 into the bale surface while the phantom-line illustration shows the cutting device at the moment of the severing operation, while the spike 6 is situated underneath the tie 5. FIG. 2 shows a wrapperless fiber bale 1 surrounded by ties 5, FIG. 3 shows a fiber bale 1 with a wrapper 8, surrounded by the ties 5, while FIG. 4 shows a fiber bale 1 with a wrapper 8 surrounding the ties 5. The wrapper 8 is pierced by the spike 6 and, as the spike 6 is further conveyed in the direction of arrow E, it rips open the wrapper 8. 
     Turning to FIGS. 5a and 5b, the spike 6 has a wear-resistant cutting face 6a made, for example, of hard metal. The spike 6 cooperates with the rotary cutting wheel 7 which is in a face-to-face engagement, on the surface remote from the spike 6, with a disc 9 which has on its periphery teeth 9a, alternating with tooth gaps 9b. The teeth 9a and the tooth gaps 9b radially project beyond the circumference of the cutting wheel 7. In operation, one of the tooth gaps 9b holds the tie 5 in a form-fitting manner such that it cannot escape while the cutting face 6a of the spike 6 and the cutting wheel 7 together perform the severing operation. The tooth gaps 9b thus serve as carriers as well as counter-supports for the ties 5. Behind the knife edge 6a an auxiliary knife edge 6b is provided for cutting open the fiber bale wrapper. 
     In FIG. 6 the cutting wheel 7 of the severing device has, along its circumference, angled tooth flanks 7a which are oriented in their working position substantially parallel to the cutting edge 6a of the spike 6. In this manner, substantially linearly applied pressures P 1  and P 2  are exerted on the tie 5 from both sides. The cutting edge 6a of the spike 6 forms an acute angle B with the wheel diameter 7c drawn to the initial point of overlap 7d between the wheel 7 and the knife edge 6a. 
     FIG. 7 shows severing shears 10 for cutting the ties 5. The severing shears 10 have two cutting blades 10a and 10b. The cutting blade 10a which extends underneath the tie 5 is arranged at the end of a cutter frame 10c. The cutting blade 10b which is rotatably secured to the frame 10c by a pivot 10d is operated by a pneumatic cylinder 10e which is, at one end, supported on the frame 10c. In this embodiment the severing device (shears) 10 is held stationarily, while the fiber bale 1 is advanced by a conveyor belt 2&#39; in the direction F. 
     In FIG. 8, the severing device comprises a cutting wheel 7&#39;&#39; which has a sharpened circumference that cooperates with the cutting blade 6a&#39; of a finger-shaped knife 6&#39; and which is driven by a motor 7&#39;&#39;&#39;. The cutting wheel 7 and the knife 6&#39; may cooperate with one another without an overlap. The knife 6&#39; has a spike portion 6b&#39; which lifts the tie 5 off the bale surface. Instead of a cutting wheel 7&#39;&#39;, the finger-shaped knife 6&#39; may cooperate with shears 10 (FIGS. 9a, 9b) or with a rapidly rotating grinding wheel 12 (FIG. 10). 
     FIG. 11a illustrates a travelling cutting device 13 having a frame 13a and being movable in the direction of the arrow G. The frame 13a pivotally supports a penetrating hook 14 operated by a hydraulic cylinder 14a and shears 10 operated by a hydraulic cylinder 10e. As shown in FIG. 11b, the hook 14 lifts the tie 5 off the bale surface 1a through a distance a. 
     In the embodiment shown in FIGS. 12a and 12b, the hook 14 cooperates as a counterelement with a percussion knife 15 which is accelerated by a pneumatic cylinder 15a. 
     Turning to the embodiment illustrated in FIG. 13, parallel shears 16 are provided as the severing device for the tie 5. 
     FIG. 14 shows the hook 14 which is movable in the direction of the arrow H in engagement with the bale 1. Thereafter, the angled end 14b of the hook 14 is pressed in the hook 14 is pulled away from the bale 1 in the direction of the arrow I so that the tie 5 is pulled immediately from the bale surface la through a distance a. 
     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.