Abstract:
An apparatus for cutting tubes includes a counter holder arranged to receive a tube, having at least one cutting tool that is movable to a cutting position on the counter holder during a cutting process, having an ejector that ejects cut-off portions of the tube, wherein the ejector is movable relative to the counter-holder, having a slide that is movable along the counter-holder on which the at least one cutting tool and the ejector are provided, and having a programmable control for freely setting cut-off lengths of tubular sleeves by moving the cutting tool on the slide.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The invention relates to an apparatus for cutting tubes, particularly cardboard tubes. 
     TECHNICAL FIELD 
     Cardboard tube cutting machines are already known in which a cutting tool is provided which is stationary relative to the counter-holder. The cardboard tube, which is mounted on a counter-holder, is moved relative to the cutting tool by means of an ejector, the advance path relative to the cutting tool determining the tube length of a cut-off sleeve. These machines require a considerable constructional space, since their length requires at least twice the tube length of the cardboard tube to be processed. 
     Furthermore, an apparatus is known which has a counter-holder to receive a tube, the tube being supported freely on the counter-holder. The tube is held during a cutting process, rotating in a defined position, by means of two manually adjustable guide rollers. A horizontal holding arrangement, on which one or more cutting tools are provided, is provided above the counter-holder. These cutting tools can be actuated individually or simultaneously, so that several sleeves of the same length can be cut at fixed and uniform spacings. A separately driven stripper runs along the counter-holder to eject the sleeves. This apparatus makes it possible for several sleeves to be cut simultaneously in one cutting process, because of the multiplicity of the arranged cutting tools. However, this machine requires a time-consuming setting of the cutting tools and increased change-around times if a cut-off length of sleeves is to be produced, different from that which is set. Moreover, the minimum cut-off length is restricted by the width of the individual cutting tools. In addition, the cut-off length cannot be changed for individual sleeves during the process of cutting one cardboard tube. 
     SUMMARY OF THE INVENTION 
     The invention therefore has as its object to provide an apparatus which is of simple design, which can be selectively set to different cut-off lengths, and which makes possible a quick ejection of the cut tube sleeves after the cutting of the sleeves. 
     This object is attained according to the invention having a counter holder arranged to receive a tube, at least one cutting tool that is movable to a cutting position on the counter holder during a cutting process, an ejector that ejects cut-off portions of the tube, the ejector being movable relative to the counter-holder, a slide that is movable along the counter-holder, on which the at least one cutting tool and the ejector are provided, and a programmable control for freely setting cut-off lengths of tubular sleeves by moving the cutting tool on the slide. 
     A rational processing of a tube for the production of sleeves of different lengths is made possible by the arrangement and constitution, according to the invention, of a slide which is movable relative to the counter-holder and on which both a cutting tool and an ejector are provided. After the same or different cut-off lengths of the sleeves have been cut by means of the cutting tool, the slide is located at an end position of the tube. The ejector can now be simultaneously actuated, so that a simultaneous ejection of the sleeves from the counter-holder takes place during a return travel of the slide into its initial position for a subsequent work cycle. A displaceable element engaged by the ejector when the sleeve or sleeves is/are stripped off can be automatically guided over into an initial position of the ejector by the following introduction or pushing-on of the tube onto the counter-holder. The movement of the slide between the individual cutting processes, and also the resetting into the initial position, can be controlled by the integrated data processing equipment and controller, so that both equal and also different cut-off lengths can be programmed. 
     Furthermore the integration of such a programmable control has the advantage that the individual cut lengths can be optimized for a given tube length and with respect to the individual cut-off lengths, so that substantially the complete length of the tube can be utilized. Thus, for example, one or more sleeves of equal length, and toward the end of the tube one or more sleeves with a cut-off length deviating from the first cut-off length, can be cut during one working process, so that up to a respective cut portion at the end of the tube, no, or nearly no, waste can arise. 
     According to an advantageous embodiment of the invention, it is provided that the cutting knife and the ejector are arranged on a flange which is removably arranged on a slide. A rapid and simple change of the cutting knife can then take place by means of a further unit. Alternatively, it can also be provided that only a rapid change unit of the cutting knife is provided on a holder which in its turn is arranged on the flange. By means of this removable flange, which is preferably arranged by means of quick-acting clamping means, the apparatus can be quickly changed over to cutting tools with and without drive. 
     According to a further advantageous embodiment of the invention, it is provided that the ejector has a driving element which can travel in the direction toward the counter-holder and which engages with an element on the counter-holder. It can thereby be made possible that, for example when the slide is repositioned from a last cutting position into a starting or null position at the beginning of the tube, an ejection of the cut-off sleeves into a travel path can simultaneously take place. An expensive mechanism which occupies a considerable constructional space is thereby not required in order to strip the cut-off sleeves from the counter-holder. At least two functions, in particular stripping of the sleeves and resetting of the slide into an initial position, can be simultaneously implemented in one movement process. 
     According to a further advantageous development of the invention, it is provided that a recognition means, preferably a proximity switch, is provided on the flange and is arranged at an acute angle to an end of the tube which abuts a counter-holder. The beginning of the tube can thus be recognized with great accuracy, since in contrast to the otherwise usual arrangements, a reflection of the waves or beams by the counter-holder, falsifying the recognition, can be excluded. It is advantageously provided that the first cut or initial cut after the beginning of the tube has a given distance which can be determined by the data processing equipment. Thus a clean first cut shortly after the beginning of the tube can take place, so that the waste is again small and a high utilization of material can be attained. 
     According to the invention, further advantageous developments are set forth herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred embodiment example of the invention is explained in the following examples. 
         FIG. 1  shows a side view of the apparatus according to the invention, 
         FIG. 2  shows an end view of the apparatus, from the left according to  FIG. 1 , and 
         FIG. 3  shows an end view of the apparatus, from the left according to  FIG. 1 , and 
         FIG. 4  shows a side view of an another embodiment of the invention without the alternative structure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a schematic representation of an apparatus  11  for the cutting of tubes  12 , in particular paper or cardboard tubes. Plastic tubes or tubes of further materials can likewise also be cut. The tubes  12  can have different internal diameters. For example, a tube diameter of 20-750 mm can be processed. The wall thickness of the tube  12  can be up to 40 mm, for example. 
     The tube  12  is received by a counter-holder  13  which is mounted on a base frame  14  of the apparatus  11 . The base frame  14  furthermore receives in the upper section a guide rail  16 , on which a slide  17  is arranged to be displaceable along the counter-holder  13 . A flange  18  can be fastened to the slide  17  and receives a cutting tool  19 , an ejector  21 , and a proximity switch  22  ( FIG. 3 ). The range of movement of the slide  17  includes on the one hand an initial position  23  at the right-hand end of the guide rail  16  and an ejector position  24  at the left-hand end of the guide rail  16 . The distance from the initial position  23  to the ejector position  24  corresponds at least to the length of the counter-holder  13  which is available for the support of a tube  12 . 
     The guide rail  16  includes a housing in which a threaded spindle  26  is rotatably mounted. The slide  17  has a corresponding guide element (not shown) which engages the threaded spindle  26 . A servomotor or stepping motor  27  is provided at a drive-side end of the threaded spindle  26 , and engages the threaded spindle  26  via a coupling  28 . 
     The stepping motor  27  is selected such that, for example, a 1:1 transmission can take place from the drive shaft (not shown) of the motor  27  to the threaded spindle  26 , so that precise driving of the slide  17  and thus an exact travel path with respect to the cutting tool  19  can be attained. 
     It can alternatively be provided that a gear is arranged between the threaded spindle and the motor  27 . It can furthermore be alternatively provided that the slide  17  is driven to travel along the guide rail  16  by means of a toothed belt, a chain, or the like, e.g., the threaded spindle  26  shown in  FIG. 1 . 
     The counter-holder  13  is fixedly or rotatably mounted to a left side of the base frame  14 . At its right-hand free end, an abutment  29  is provided which is pivotably arranged on the guide rail  16  and which receives the free end of the counter-holder  13  during the cutting process. The abutment  29  is pivoted out of its holding position for the loading and unloading of the tube  12 . 
     In  FIG. 1 , a unit  30  is provided on slide  17 , and has a non-rotatingly driven cutting tool  19 . A unit  35  is furthermore shown which has the cutting tool  19 , which is driven by the motor  37 . The ejector  21  is arranged to the left of the cutting tool  19  of the unit  35 . This ejector  21  has a movable bolt  39 . The movable bolt  39  is movable in the direction toward the counter-holder  13 . The ejector  21  is spaced apart from the counter-holder  13 . 
     A mounting  31  is provided on the flange  18  of the unit  30 , and receives via roller bearings  32  a cutting knife  33  which is freely rotatable. The cutting knife  33  is clamped between two seatings  34  and arranged interchangeably with respect to the mounting  31 . This can be made possible in that one of the seatings  34  is released, or in that the mounting  31  is released, or in that the whole unit  30 , and thus the flange  18 , is removed from the slide  17 . 
     Alternatively to the freely rotatable arrangement according to the unit  30 , a stationary cutting knife can also be provided. For this, a bolt  36  can be inserted in a bore of the seating  34 , so that the freely rotatable arrangement of the cutting knife  33  is locked. 
     Furthermore, the unit  35  can alternatively be provided, the cutting tool  33 , in the form of a cutting knife being driven by a motor  37 . One or more units  30  or  35 , which can also be provided in combination, can be selected according to the respective application. The ejector  21  is spaced apart from the units  30  or  53 , as shown in  FIG. 1 . The cutting units  30 ,  53  and  35  and the ejector  21  are each connected to the threaded spindle  26  by the slide  17  for movement along the guide rail  16 , as shown in the upper portion of  FIG. 1 . 
     The cutting tool  19  can be arranged to be resiliently compliant. During the cutting process, the cutting tool  19  is moved toward the counter-holder  13 , for example, by means of a mechanism, compressed air, pneumatic system, or electric motor, or the like. During the movement, the tube  12  rotating on the counter-holder  13  is cut. After the cutting tool  19  nearly abuts the counter-holder  13  or contacts this, a possible further feed can be compensated by the resiliently compliant arrangement. The life of the cutting tool  19  can thereby be increased. The cutting quality can be thereby increased at the same time, due to the smaller damage to the cutting tool  19 . It can be advantageously provided that the counter-holder  13  is arranged to be insulated with respect to the base frame  14 , so that the cutting tool  19  comes into electrical contact when it strikes, or rests on, the counter-holder  13 , upon which the feed movement or the cutting movement of the cutting tool  19  is immediately stopped. This or a similar kind of electrical monitoring likewise increases the life of the cutting tool  19 . 
     The proximity switch  22  is arranged on the flange  18 , to the right of the cutting tool  19  in the embodiment example. This is arranged on the flange  18  at an acute angle to an end surface of the tube  12 , so that a scan does not take place perpendicularly from above, and thus parallel to the end surface of the tube  12 , but that the end surface of the tube  12  is used as the reference surface. The beginning of the tube  12  can thereby be determined exactly. The proximity switch  22  can for example be provided as an infrared sensor or the like. Further optoelectronic switches can likewise be used. 
     The ejector  21  is arranged to the left of the cutting tool  19  of the unit  35 . This ejector  21  is connected to the guide rail  16  through the ejector sleeve  41  and has a movable bolt  39  which is movable in the direction toward the counter-holder  13  or an ejector sleeve  41 . As soon as, for example, the flange  18  has come into an ejector position  24 , the ejector  21  can be driven by means of a relay or by means of a control, as is known in the art, so that the bolt  39  engages in a groove  42  or in a correspondingly formed recess on the bolt  39 . After this is positively arranged in the groove  42 , the slide  17  can be guided over into the initial position  23 , upon which the cut-off sleeve is ejected and is simultaneously guided away via a chute  43 . Immediately before the end of the counter-holder  13 , the bolt  39  is brought back into its initial position, so that the ejector sleeve  41  remains near the free end of the counter-holder  13 , which is brought back into its initial position by loading a new tube  12  onto the counter-holder  13 . 
     The apparatus  11  furthermore has a programmable data processing equipment and control  44 . The cut-off length of the respective sleeves can be freely programmable by this. Thus, for example, several sleeves of equal or different lengths can be cut from a tube  12 . It can also be provided, according to a program, that an optimizing of cutting is programmable in dependence on the total length of the tube  12 , according to which a number of sleeves with a first cut length, a further number of sleeves with a second cut length, and possibly a further number of sleeves with one or more further cut lengths are cut, in order to make the cutting waste as small as possible. During the stripping phase of the sleeves, a positioning of different goods baskets under the chute  43  can take place, corresponding to the movement of the slide  17  from the ejector position  24  into the initial position  23 , so that a sorting of the different cut lengths can take place simultaneously with the stripping. 
     Furthermore, the distance of the first cut from the beginning of the tube  12  can be set by this data processing equipment. This cut can be situated immediately after the beginning of the tube  12 , or for example one or two centimeters behind it. 
     Alternatively, two or more slides  17  can be provided on the guide rail  16 , arranged at a given distance from each other, whereby a cut optimization can take place by means of the program control to the effect that, for example with three slides with cutting tools  19  arranged on them, the cutting time of the whole tube can be reduced to a third. Furthermore, it can be alternatively provided that two or more guide rails are provided to a counter-holder, so that on each guide rail respectively one or more cutting tools  19  can follow, independently of the cutting tool or tools  19 , on the further guide rail or rails. In particular, with very long tubes, such an arrangement can lead to a reduction of cycle times. The individual cutting processes can be coordinated by a common control, so that a frictionless cutting of the sleeves into the respectively required lengths can take place. 
     The tube  12  is held in a defined position during a cutting process by guide rollers  46  arranged to left and right of the counter-holder  13 , as is shown, for example, in  FIG. 2 . The guide rollers  46  engage such that they hold the tube  12  down on the counter-holder  13 . The counter-holder  13  is advantageously made small in comparison with the tube diameter of the tube  12 , so that the latter is freely supported on the counter-holder  13 . It can likewise be provided, for example with a small diameter of the tube  12 , that the counter-holder corresponds approximately to the internal diameter of the tube  12 . In this case of application, the guide rollers  46  have a supporting action, in particularly so that the counter-holder is supported when it receives the cutting force. The guide rollers  46  can, for example, be arranged in a ten o&#39;clock or two o&#39;clock position. The guide rollers  46  advantageously extend almost over the whole length of the counter-holder  13 . At least one of the two guide rollers  46 , or advantageously both guide rollers, are driven, in order to set the tube  12  in rotation. In  FIG. 2 , the drive for the guide rollers  46  by belts or chains or the like is represented, a gearwheel drive  47  being illustrated which makes it possible for both the left and the right guide rollers  46  to have the same drive speed. The guide rollers  46  are received on supporting arms  48 , which are respectively mounted for pivoting around a shaft  49  by means of a power element  51  which is preferably driven by compressed air. The synchronous movement of the supporting arms  48  during the advance movement is made possible by the gearwheel pair  52  according to  FIG. 3 . The power element  51  can be driven either electrically or pneumatically. The use of compressed air has the advantage that on exceeding a given operating pressure a further feed movement of deflection of the supporting arms  48  is prevented, so that it can be ensured that the guide rollers  46  rest on the tube  12  with a minimum pressure and also drive it in rotation. The guide rollers  46  are advantageously hinged on the supporting arms  48  so that a fine adjustment to different diameters of the tube  12  can take place; it is advantageously provided that the drive of the guide rollers  46  can remain the same, independently of the fine adjustment. The compressed air supply and also the drive of the supporting arms  48  is shown schematically in  FIG. 1  in the left-hand portion of the base frame  14 . 
     In  FIG. 1  it is furthermore shown as an alternative that the apparatus  11  can also be provided with cutting tools  19  fixed to the guide rail  16  for specific applications, as is shown, for example, by the unit  53 . Such a unit  53  can be additionally provided, for example between two movable slides  17 , or instead of displaceable slide  17 . 
     It can furthermore be alternatively provided that the ejector  21  engages with a movable bolt or the like directly at the end of a tube  12  in order to strip the cut sleeves from the counter-holder  13  without an ejector portion  41  being provided. Likewise, instead of the ejector  21 , the cutting knife could take over the stripping function. 
     A feed movement of the cutting tool  19  can likewise be driven by the programmable data processing equipment and control during the cutting process in dependence on the raw material and also on the wall thickness of the tube. The feed speed can likewise be adjusted in dependence on a driven cutting tool  19 . 
     A complete set of claims currently in this application, with status indicators, is attached hereto. 
     In  FIG. 4 , the apparatus is shown without the alternative structure.