FR2622486A1 - CHUCK FOR A TAPE - Google Patents

Abstract

The invention relates to a winding mandrel for a sheet metal strip. This mandrel has a clamping slot 11 formed between a clamping band 9, guided movably in radial movement in a support 4, and a counter-support 10 which overhangs the clamping bar 9, a side wall segment 5 being pressed on the clamping bar 9, by free end 8, to describe an elastic movement in the radial direction. To obtain a simple construction, suitable for an expandable mandrel, the counter-support 10 is integral with the support 4 to accompany this adjustment movement, the side wall segment 5, which rests on the clamping bar 9, being able to form a flexion spring recessed at one end.

Description

The present invention relates to a mandrel of

  rolling for a sheet metal strip, having a slot for

  axial rage intended to receive the beginning of band between a clamping bar, guided movable in radial displacement in a support, and a counter-support which is placed upstream of the clamping bar in the direction of the winding of the band and which overhangs the inclined clamping surface of the clamping bar and a sidewall segment placed downstream of the clamping bar, mounted on the support in the region of its edge which is furthest from the clamping bar and which is pressed elastically against the clamping bar in the radial direction, and which together with the clamping bar forms a surface portion

  side wall at least substantially free of

is lying.

  In a winding mandrel of this kind which is de-

  As previously known (DE-A-2,239,904), there are provided two sidewall segments which are mounted oscillating on the mandrel shaft in the region of their edges which are furthest apart from each other, and which, in the region of their edges directed towards each other, are pressed against an axial clamping bar provided between them, by means of radial stacks of washers

  Beautiful city. This clamp bar can be moved radially

  hydraulically outwards against a restoring force and, in combination with one of the two side wall segments, forms a clamping slot for receiving the start of the sheet metal strip at wrap. Given

  that when the beginning of the sheet metal band is tightened between the bar-

  the side wall segment which forms the abutment, this sidewall segment deviates further than the other sidewall segment, which is directly

  against the clamping bar by a distance equal to

  thickness of the strip, a step is formed at the junction between this side wall segment, which constitutes a

  counter-support for tightening the belt, and the service bar

  rage, while the downstream sidewall segment

  in the direction of winding represents, with the service bar

  a portion of the lateral surface at least substantially

  provided with recesses, so that this detachment of the side wall whose height depends on the thickness of the

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  considered band provides compensation for the thickness of the strip at the moment when the second turn turns on the first turn of the strip, since the side wall segment which is

  placed upstream of the clamping bar in the direction of

  It projects above the circumferential surface of the bar to a height approximately equal to the thickness of the strip. The fact that the sidewall segment connects

  without a detachment at the clamping bar thus creates a transi-

  progressive connection which is connected to the maximum diameter of the

  rolling winding mandrel, which should exclude damage to the web in the region of the first turns, even in the case of high tension of the web. However, this known construction has a drawback consisting in the fact that the clamping of the strip must be content with a counter-support which can pivot against the force of a spring, which limits the clamping forces which can be developed. Furthermore, a construction having two sidewall segments that can be rotated one in

  the opposite direction of the other by means of an inter-

  posed is not suitable for expandable mandirs whose expandable segments must be adjusted by a movement of the same direction through an expansion device. In this respect, it should be borne in mind that stacks

  of Belleville washers, intended to solicit

  wall, must be supported on the chuck shaft

  via radial fixing screws.

  To compensate for the setback due at the beginning of the first

  first turn and which acts on the following turns, it is known

  (DE-O-1 574 444), to place, downstream of the

  tightening which fixes the beginning of the band in a slot of

  tightening, a grab bar that can be

  ash and that can be rotated in a bowl of por-

  the winding mandrel to compensate for

  desired thickness. In this construction, the clamping of the beginning of the band is not affected by the thickness compensation of

  band, so that one can also exercise great

  these tightening. However, a disadvantage is that, because the support bar is pivotally movable, the transition leading to the maximum radius of the winding mandrel must occur in the region of this support bar, and

  the fact that the movement of the support bar is linked to a displacement

  the support bowl, which must be activated in

  addition of the clamping device, which considerably increases

  the complexity of construction.

  The object of the invention is therefore to eliminate these

  and to perfect a winding mandrel of the kind described in the beginning with simple means so that not only can high band tensions be obtained, but a space-saving construction which is particularly suitable for expandable mandrels having expansible segments which

move in the same direction.

  The invention solves the problem posed by the fact that the counter-support is secured to the support in its displacements

adjustment.

  Providing solidarity against the support of

  port avoids the limitation of clamping forces acting on the beginning of the band and thus avoids the limitation of the

  tape tension, because the sidewall segment

  to give way elastically and which forms the counter-support in the other constructions is thus suppressed. This fact also represents a necessary condition for the realization of such a compensation of thickness of the band in the expanding mandrels which deviate radially from the arbor of the mandrel

  expandable under the action of an expansion device. The sup-

  port, the abutment and the sidewall segment subjected to elastic stress can then together form one of the

  expansible segments of an expandable mandrel and the link

  between the counter-support and the support then makes it possible to obtain

  a mode of construction even more flat.

  To obtain a particular form of construction

  from a small number of pieces, and according to a

  Another feature of the invention is the sidewall segment

  pressed against the clamping bar can form a recessed bending spring on one side. This bending spring, which is assembled integrally in rotation with the support in the region of the axial edge which is furthest from the clamping bar,

  makes unnecessary the radial springs that would be required

  in its absence, as well as their support, so that the

  radial displacement of the end of the segment expandable direc-

  leaning against the clamping bar

  seeks to obtain, can be achieved in a particular way-

  simply by means of a solicitation of the bar-

  tightening, without compromising the compensation of the thick-

  the band. The radial displacement stroke of the bar

  The tightening angle is indeed shortened by the beginning of the strip introduced into the clamping slot, by a value corresponding to the thickness of the strip, which determines the detachment of the surface of the side wall in the region of transition between the counter-support and the clamping bar. Moreover, in each position of adjustment of the side wall segment, it is certain to obtain a transition without offset on

the next expandable segment.

  In order not to compromise the formation of a

  without a gap between the clamping bar and the segment

  downstream side wall by the relative displacement between

  be the clamping bar and the side wall segment, and se-

  Another feature of the invention is that the service bar

  rage may have a bearing boss forming an axis of

  and who is engaged in forming a security liaison

  shape in a recess of the side wall segment

  rale. This safety grip ensures a positive drive of the side wall segment by the clamping bar

  and, therefore, obtaining the transition without

  intended to obtain between the two elements. The rotational movement, which occurs between the side wall segment and the clamping bar in the presence of radial stress

  of the clamping bar, is made possible without

  annoying by the span trunnion, because the boss of

  scope forms an axis of articulation for the wall segment la-

  térale. The flat construction form makes it possible to adopt the compensation of the thickness of the strip according to the invention in the case of expandable mandrels in which the support, the

  clamping bar, counter-support and lateral wall segment

  advantageously form in combination one of a plurality of expandable segments, the expansion device of which may be

  hydraulically activated together with the clamping bar.

  Since the support, the clamping bar, the counter-grip

  and the side wall segment, form an expanding segment

  the thickness compensation remains independent of the movement

  the expandable segment is adjusted by means of the expansion device, which attacks the support. Expansion of the winding mandrel takes place, generally, before or after

  during the winding of the first turns of the strip,

  that the expansion device acting on the ex-

  can be activated hydraulically, preferably

  together with the clamping bar, so that this

  the need for separate controls for clamping the web and for compensating the thickness of the web.

the band.

  Other features and advantages of the invention

  will emerge from the description which follows with regard to the

  annexes which represent, schematically and simply

  As an example, various embodiments of the mandrel.

  In these drawings: Figure 1 shows a detail of the winding mandrel according to the invention in a schematic sectional view, in the expansion position; Figure 2 is a view corresponding to Figure 1, but with the segments retracted; FIG. 3 is a sectional view, on a larger scale, of the

  clamping bar in the region of a reporting spring

  pel; Figure 4 is a sectional view of the clamping bar, in the region of its guidance;

  Figure 5 shows a construction variant of a man

  winding drin according to the invention, by a sectional view of an expansion segment; and

  Figure 6 is a section along the line VI-VI of Figure 5.

  In the embodiment according to 1 and 2, the man-

  winding shaft represented is essentially composed of a

  expansible chuck shaft i on which the expanding segments

  2 are movable in radial displacement, these segments being actuable by means of an expansion device

6 2622486

  formed by a mechanism-at corners. Unlike man-

  conventional expandable drums, one of the expandable segments 2 forms a support 4 for a side wall segment 5, which is rigidly connected to the support 4 in the

  region of its rear edge 7, considered in the sense of the

  bearing which is indicated by the arrow 6 and, because of its unilateral arrangement secured to the support, this segment forms a recessed bending spring on one side which bears on an axial clamping bar 9 in the region of its free front end 8 and, namely, under a predetermined prestress, so that the free end 8 of the side wall segment 5 necessarily accompanies the radial displacement of the clamping bar 9 inwardly, because of the prestressing of the

bending spring.

  In the retracted position of the expanding segments 2

  the clamping bar 9 forms, in combination with a counter-support 10, secured to the support, a clamping slot 11

  axial end for receiving the beginning of the sheet metal strip

  l. As the drawing shows, the counter-support 10 overhangs the

  inclined clamping surface 12 of the clamping bar 9.

  The clamping bar 9 is movably mounted in radial transition in the abutment 10 or in the support 4 by means of guide pins 13 (FIG. 4), distributed over the axial length of the clamping bar 9, and it can be pushed radially outwards by means of pistons 14, against the force of return springs 15 (FIG. 3), the activation of the pistons 14 can take place together with the activation of the expansion device 3. In the presence of

  this activation of the winding mandrel, on the one hand, the segments

  expansions 2 are being expanded and, on the other hand,

  clamping bar 9 is pressurized against the counter-

  10, as can be seen in FIG. 1. As a result of this radial displacement of the clamping bar 9, the free end 8 of the side wall segment 5 is pushed at the same time outwards, so that that we are certain to obtain a transition without step between the clamping bar 9 and

  the downstream sidewall segment 5, even in the

  expansion position, in the region of the side wall. The in-

  sidewall segment 5 dragging through the service bar

  rabies 9 is favored by a rounded bearing boss 16 provided on the clamping bar 9, which engages, forming a connection

  by safety of form, in a recess 17 corresponding correspon-

  of the side wall segment 5 and thus forms an axis of

  ticulation between the clamping bar 9 and the sidewall segment 5. If, after introducing a beginning of the tape into the

  slot 11, the winding mandrel is

  the beginning of the tape is blocked in the service slot.

  rage 11 between the clamping bar 9 and the counter-support 16, under the effect of the expansion of the expandable segments 2, the adjustment stroke of the clamping bar being limited by the beginning of the band engaged in the clamping slot 11, and a recess forming between the lateral surface of the clamping bar 9 and the abutment 10, this recess depending on the thickness of the strip. The second turn of the tape to be wound can

  this way, to be rolled up without the formation of

  between the lateral surface of the abutment 10 and the first

  first turn of the band, since the step, which is formed

  between the clamping bar 9 and the counter-support 10, is just-

  offset by the beginning of the band. The transition from the clamping bar 9 to the sidewall segment 5 remains free of

  regardless of the position of the service bar

rabies 9.

  During the contraction of the expandable segments 2, the course of the movement occurs in the order of succession

  the beginning of the tape being released by the bar 9 of ser-

  rage urged by the return springs 15. The behavior

  pre-stressed bending springs of the wall segment 5

  teral determines a simultaneous recall of the segment 5

  expansible in the starting position represented on the

gure 2.

  In the construction variant according to FIGS. 5 and 6, the side wall segment 5 is not constituted by a

  bending spring recessed at one end, but on the contrary

  re, it is mounted oscillating in a bearing bowl 19 of the support 4, by means of an oscillating bar, in

  the rear edge region 7. The elastic application of this segment

  lateral wall 5 against the clamping bar 9 is

8 2622486

  hereby by pins 20 loaded by springs which are integrally connected in tension to the side wall segment 5

  and rely, through a stack of ron-

  delles Belleville 21, on the bottom of a blind hole 22 formed in the support 4. The segment 5 of the side wall can therefore here

  also accompany the adjustment movements of the service bar.

  rage 9, to ensure the offset compensation that is desired during the winding of the first turn of the strip.

Claims (4)

  1. Winding mandrel for a sheet metal strip, pre-   sensing an axial clamping slot for receiving the   tape end, formed between a movable guided clamping bar in radial displacement in a support, and a counter-support which   is placed upstream of the clamping bar in the direction of the   rolling the band and overhanging the clamping surface   angle of the clamping bar, and a sidewall segment   downstream of the clamping bar, mounted on the support in the region of its edge which is furthest from the clamping bar, and pressed plastically against the clamping bar in the radial direction, and which, together with the bar of tightening, forms a portion of the lateral surface which is at least substantially free of   recess, characterized by the fact that   support (10) is integral with the support (4) in its displacements adjustment.   2. Winding mandrel according to claim 1, characterized in that the side wall segment (5), which is supported on the clamping bar (9), forms a spring recessed bending on one side.   3. Winding mandrel according to claim 1 or 2, characterized in that the clamping bar (9) has a bearing boss (16), which forms a hinge pin and which is engaged, forming a connection by safety of form, in a recess (17) of the side wall segment (5).   4. Winding mandrel according to one of the claims   1 to 3, characterized in that the support (4) forms, with the clamping bar (9), the abutment (10) and the side wall segment (5), one of several expandable segments. (2), whose expansion device (3) can be hydraulically activated, together with the bar of tightening (9).