FR2691389A1 - Device for cutting tubes. - Google Patents

Abstract

A device for cutting tubes into sections of determined length comprises a continuously driven rotary cutting head (10), in which at least one cutting member (17) comprising a circular knife (18) is pivotably disposed on a journal (19). ) whose axis is parallel to the axis (31) of the tube on an annular body (12) rotating with the cutting head. The device is characterized in that the cutting member (17) is pivoted by means of control elements in a radial direction relative to the tube axis (31). The cutting member (17) is adjustable in the radial direction relative to the axis of the tube, in order to be able to cut tubes having very different diameters.

Description

The invention relates to a device for

  cut tubes into sections of determined length, with a rotary cutting head driven continuously, in which at least one cutting member, comprising a circular knife, is pivotally disposed on a pin whose axis is parallel to the axis of the tube on an annular body rotating with the head of

chopped off.

  Such a device for cutting tubes which are formed from strips of sheets via a forming mandrel, into sections of desired length, is disclosed in DE-B-1 652 771 In this device the adjustment of the spacing of the cutting member or cutting members relative to the tube during the carrying out of the cutting process is carried out by means of a roller on the cutting member, which rests on a cone inside of an axially adjustable stop ring The further the stop ring is turned by the roller, the more the cutting member is moved in an axial direction towards the tube This known device has the drawback that when cutting tubes of very different diameters, the stop ring on the cutting head must be replaced each time with an inner cone

  higher or lower inclination.

  The present invention therefore aims to provide a device for cutting tubes with which even tubes of very different diameters can be

  cut without removing the cutting head.

  To this end, a device of the type indicated in the introduction, is characterized in that the at least one cutting member is pivoted by means of control elements in the radial direction relative to the tube axis. such as cams, levers, etc. provide a possibility of adjustment in the radial direction of the

  considerably larger cutting members.

  Particular advantages are obtained by the use of control elements which are formed by a second annular body rotating with the cutting head, on which the at least one cutting member is also pivotally disposed and the annular body is adjustable so limited in its angular position relative to the first annular body By a modification of the relative angular position of the two annular bodies, a continuous adjustment of the cutting members is thus obtained. The diameters of the tubes to be cut thus have practically no lower limit. According to another characteristic, the two annular bodies are driven by means of separate drive shafts which are stressed by means of a differential gear of a common drive unit By instant adjustment of the gear differential and consequently by the exercise of a different moment of rotation on the two drive shafts of the annular bodies, these are moved in their angular position relative to each other. The device is advantageously movable longitudinally parallel to the axis of the tube, the device can then be guided with the tube and an interruption of the cutting process for the tube can be avoided. Other advantages and characteristics of the present invention will appear more clearly on

  reading the following description of an achievement

  preferred with reference to the corresponding accompanying drawings in which: FIG. 1 is a view in central section through a device for cutting according to the invention; Figure 2 is a sectional view through the device taken along line II II in Figure 3; Figure 3 is a front view of the device with three cutting members; and Figure 4 is a schematic representation

  of the drive of the device according to the invention.

  In Figure 1 is shown a cutting head which consists of a cylindrical body 11 on which two annular bodies 12 and 13 are arranged to rotate on ball bearings 14 On the front end 16 of the cylindrical body 11 is arranged a member of cutting 17 with a circular knife 18, the fixing of the cutting member 17 being pivotable both on the annular body 12 and on the annular body 13 On the section according to FIG. 1 is shown the fixing on the annular body 12 This Ci has a pin 19 on which is fitted the cutting member 17 by means

a ring 20.

  With reference to FIG. 3, the cutting members 17, 17 'and 17 "' have, beside the rings 20, other support points 21 The support point 21 is arranged in another corner of a support piece substantially triangular in shape 22 of the cutting member 17 on the annular body 13 The cutting member 17 is fixed on the annular body 13 with this point

support 21.

  As can be seen in FIG. 2, a pin 23 on the support part 22 of the cutting member 17 leads into a socket 24 fixed to the annular body 13 and is anchored there by means of a support roller 25 La bush 24 extends through a recess 26 in the annular body 12 The recess 26 is chosen so that a limited reciprocal rotation of the two annular bodies 12 and 13

is possible.

  With this adjustment of the reciprocal angular position of the two annular bodies 12 and 13 the cutting members 17, 17 'and 17' 'perform a pivoting movement relative to the axis

  longitudinal 31 of a tube 30 illustrated in FIG. 3.

  the cutting member 17 '' is in a rest position in which the circular knife 18 "'is not in contact with a tube to be cut 30 With a slight adjustment of the reciprocal angular position of the annular bodies 12 and 13 , we get the position

  shown in FIG. 3 for the cutting member 17.

  The circular knife 18 has then penetrated into the tube 30 at a depth corresponding approximately to the thickness of the latter With an extreme adjustment of the reciprocal angular position of the annular bodies, the cutting member, as shown by way of example in FIG. 3 for the cutting member 17 ', performs a pivoting movement going even further in the radial direction In this way tubes with very different diameters can be cut by the cutting members 17 to 17 "" function of the reciprocal angular position of the two annular bodies 12 and 13, without parts

  must be replaced on the cutting head 10.

  Figure 4 schematically shows a possible drive of two annular bodies 12 and 13 and a possibility of adjusting their reciprocal angular position The two annular bodies 12 and 13 each have on their outside side an external toothed ring 41, 40 respectively On these toothed rings outer 40, 41 engage toothed belts 42 and 43, which are driven via drive shafts 44 and 45 with toothed wheels 46 and 47 The drive shafts 44 and 45 are driven on their side by an electric motor 48 via a differential gear 49 Via the differential gear 49 it is possible to instantly operate the drive shafts 44 and 45 with a different speed of rotation, the annular bodies 12 and 13 then shifting against each other in their angular position This offset determines, as described above, a movement of pivoting of the cutting members 17, 17, 'and 17 "' in the radial direction In this way it is possible to proceed, by means of the differential gear 49, to continuous adjustments of the cutting members for tubes of different diameters. According to a variant not shown, the entire device is also movable longitudinally

parallel to the axis of the tube 31.

Claims (5)

  1 Device for cutting tubes (30) into sections of determined length, with a continuously driven rotary cutting head (10), in which at least one cutting member (17, 17 ', 17 ") comprising a circular knife ( 18) is pivotally disposed on a pin (19) whose axis is parallel to the axis (31) of the tube on an annular body (12) rotating with the cutting head, characterized in that the at least one member section (17, 17 ', 17 ") is pivotable by means of control elements   radial direction relative to the tube axis (31).   2 Device according to claim 1, characterized in that the control elements are control cams.   3 Device according to claim 1 or 2, characterized in that the control elements are formed by a second annular body (13) rotating with the cutting head, on which the at least one cutting member (17, 17 ', 17 "') is also pivotally arranged and which is adjustable in a limited way in its angular position relative to the first body annular (12).   4 Device according to claim 3, characterized in that the annular bodies (12, 13) are driven by means of drive shafts (44, 45), which are biased by means of a differential gear ( 49) by   a common drive unit (48). 7 2691389   Device according to one of claims 1   to 4, characterized in that it is mobile   longitudinally parallel to the axis of the tube (31).