Winding Machine

Abstract

Two parallel and coaxial flange plates which are driven separately in rotation carry reels mounted in uniformly spaced relation about the common axis of the flange plates. Threads or ribbons are delivered from the reels and wound on a cylindrical element which is displaced continuously along the axis of the flange plates. Each flange plate is associated with a parallel and coaxial annular member which is mounted upstream of the reels with respect to the direction of displacement of the cylindrical element. The annular members are subjected to a relative movement of rotation in the direction opposite to the movement of the corresponding flange plates and means are provided on the annular members for attaching and cutting the ends of the threads or ribbons of the reels.

Description

This invention relates to an automatic machine for winding on a cylindrical element which may be tubular and passes through this machine successive layers of threads or ribbons which are delivered from a series of reels carried by the machine, and the turns of which do not have any breaks in continuity, especially when one or a number of such reels has been completely emptied and an appreciable period of time is required to replace them with new reels.

Several designs of winding machines are already known and comprise in a general manner a rotary flange plate forming a turntable which is driven in continuous rotation about the cylindrical element to be covered, this element being capable of passing freely through a bore formed at the center of the flange plate and the axis of the flange plate being in coincident relation with the axis of the cylindrical element which travels through the machine at a constant speed. There is mounted on this flange plate an assembly of reels which are uniformly spaced around the cylindrical element and carry threads or ribbons, the ends of which are brought radially onto the cylindrical element and fixed on this latter at the beginning of the winding operation. The rotation of the flange plate combined with the axial forward motion of the tube carries out automatically the winding of the threads or ribbons in continous helices, the pitch of which is a function of the relative speeds of these two movements.

In known winding machines, it nevertheless remains apparent that, if it is desired to obtain a winding having a uniform thickness and structure over the entire length of th cylindrical element, it is absolutely necessary to stop the machine and especially the forward motion of the tube when one or a number of the reels carried by the flange plate have been emptied. During this stoppage, the reel or reels in which the entire quantity of thread has been employed must in fact be replaced by other reels which carry a fresh quantity of thread. It is then necessary to attach the end of the thread to the cylindrical element substantially next to and following the thread supplied from the previous reel and finally to re-start the machine. This results in major disadvantages which arise in particular from the fact that wholly continuous manufacture is thus impossible ; moreover, in the particular case in which the cylindrical element is tubular and comprises an inner sheath of plastic material and windings of external reinforcement threads or ribbons, especially of glass fibers, which are intended to be continuously impregnated with a hardenable binder, this interruption of the manufacturing process which is made necessary by the replacement of one or a number of reels on the rotary flange plate can result in further drawbacks such as excessive and non-uniform impregnation of the glass fibers on the stopped tubular element, hardening of the binder before the proper time or even detachment of the inner sheath and of its reinforcement windings.

This invention is directed to an improved winding machine which overcomes the above-mentioned disadvantages by permitting replacement of reels from which threads or ribbons have been completely unwound without interrupting the operation of the machine and the formation of a continuous winding on the cylindrical element.

To this end, the winding machine under consideration essentially comprises two parallel coaxial flange plates each provided with an assembly of reels uniformly spaced about their common axis and carrying threads or ribbons to be wound on a cylindrical element in continuous displacement along the axis of the two flange plates which are driven separately in rotation about said axis, each flange plate being associated with an annular member which is coaxial with and parallel to said flange plate, said annular member being mounted upstream of the reels with respect to the direction of displacement of the cylindrical element, means for subjecting the annular members to a relative movement of rotation in the direction opposite to the movement of the corresponding flange plates and means provided on the annular members for attaching and cutting the ends of the threads or ribbons of the reels.

During operation, it is only necessary to ensure that only one of the two flange plates is driven in rotation about its axis in order that the threads or ribbons of the reels carried by said flange plate should be subjected to continuous winding on the cylindrical element after having been initially fixed on the wall of said element, the winding being performed in a series of parallel helices, the pitch of which depends on the speed of rotation of the flange plate and the speed at which the element passes axially through said flange plate. The second flange plate does not play any part in this initial winding stage until the thickenss of the thread on one or a number of the reels of the first rotary flange plate, as controlled by any suitable means of the feeler type in particular, reaches a predetermined lower limit and initiates the delivery of an electrical or mechanical signal.

In this initial stage, the ends of the threads or ribbons of the reels of the second flange plate are attached to the corresponding annular member. Moreover, and depending on requirements, this second flange plate can be driven continuously in rotation about its axis or else it can be started up only at the moment at which the above-mentioned signal is delivered, prior to complete emptying of any reel of the first flange plate, the advantage of the first solution being to avoid the delay in setting the flange plate in rotation. From this moment and as a result of the synchronous rotation of the annular member and of the flange plate, there does not take place any contact between the threads of the reels and the cylindrical element which continues its forward motion within the machine.

Finally, when any one of the reels of the first flange plate is completely or amost completely emptied, a second signal initiates the operation of means which produce a relative rotation of the annular member associated with the second flange plate with respect to this latter in the direction which causes said annular member to lag with respect to said flange plate. At a given moment, the reel threads come into contact with the cylindrical element and, by reason of the fact that the annular member is mounted upstream of these reels, initial winding of the threads takes place with the same orientation with respect to the axis of the element but in the direction opposite to the normal direction, that is to say for at least a few revolutions, from the downstream end to the upstream end on the cylindrical element which continues its displacement within the machine.

This initial winding which is caused by the relative rotation of the annular member with respect to the flange plate results correlatively in the progressive application of tension to the threads, the ends of which are then cut and freed from the annular member, the remainder of the winding operation being subsequently due solely to the rotation of the flange plate itself. This results in a reversal of the winding on the cylindrical element ; this winding accordingly starts again in the normal direction from the upstream to the downstream end and covers the few turns of thread produced by the annular member in the manner described, thus securing these threads to the continuously-moving element.

The first flange plate can then be stopped in order to permit replacement of the empty reel or reels and then remains motionless or is again set in rotation in a stand-by position until the completed unwinding of the thread from one or a number of the reels of the second flange plate in turn causes the further relative rotation of the annular member of the first flange plate and the continuation of the winding operation in accordanc with the process described.

With the primary object of maintaining continuity of the winding on the cylindrical element, the signals which actuate the flange plates and/or their associated annular members are necessarily produced in such manner as to ensure that there always takes place a partial overlapping of the windings of the threads delivered from the reels of either one flange plate or the other at the time of changeover of these latter.

Each flange plate preferably comprises an even number of reels, the ends of the threads or ribbons of these reels being joined together in pairs by means for attaching to and cutting on the coaxial annular member. At the exits of the reels, the threads or ribbons pass through radial guide rings which are carried by the corresponding flange plate.

In accordance with another characteristic feature, the attaching and cutting means are constituted by knives disposed on that face of the annular member which is located opposite to the reels of the flange plate in a plane which passes through the axis of this latter, these knives being provided with a curved cutting edge of which the concave portion is directed towards the periphery of the annular member.

In accordance with yet another characteristic feature, the means for subjecting each annular member to a relative movement of rotation with respect to the corresponding flange plate are constituted by a driving shaft which is driven in rotation through a reduction-gear unit by means of a motor carried by the flange plate and effects the rotation of a friction roller in rubbing contact with a track formed in the annular member, said annular member being supported on ball-bearings by means of a coaxial cylindrical member which is rigidly fixed to the flange plate.

Finally and in a preferred embodiment of the invention, each reel comprises a tubular support fitted over a shaft located at right angles to the plane of the corresponding flange plate and having an extension on which is pivotally mounted a right-angle bracket provided with eyelets traversed by the thread which is unwound from the reel and a counterweight for the continuous balancing of said right-angle bracket.

Further characteristic features of a winding machine constructed in accordance with the invention will become apparent from the following description of one exemplified embodiment which is given by way of indication without any implied limitation, reference being had to the accompanying drawings, wherein :

FIGS. 1 and 2 ar diagrammatic views of the winding machine under consideration and serve to explain the general principle of operation of the machine ;

FIG. 3 is a longitudinal sectional view of one-half of the winding machine considered ;

FIG. 4 is a partial front view of the half-winder which is illustrated in FIG. 3 ;

FIGS. 5 and 6 are general arrangement diagrams which serve to explain the operation of this winding machine.

In FIGS. 1 and 2, the reference A designates in particular a tubular cylindrical element which is driven by any suitable means (not shown in the drawings) in a continuous axial movement of displacement through the winding machine considered, this movement of displacement being shown diagrammatically by the arrow B.

In accordance with the invention, the winding machine essentially comprises two parallel rotary flange plates in oppositely-facing relation and designated respectively by the references C and D, the flange plate C being intended to support a series of reels of which only two reels E.sub.1 and E.sub.2 appear in the figures whilst the flange plate D supports reels F.sub.1 and F.sub.2 in the same manner. The threads or ribbons G.sub.1 and G.sub.2 which are unwound from the reels E.sub.1 and E.sub.2 pass at H through guide rings which bring them substantially at the exits of these reels in a radial direction towards the tubular element A ; taking into account the rotation of the flange plate C and the forward motion of the element A, this causes the continuous winding of these threads on said element as shown diagrammatically at I. When the reels E of the flange plate C are thus in service, the reels F of the flange plate D are not in use. The threads J.sub.1 and J.sub.2 which are supplied from the reels F.sub.1 and F.sub.2 pass through the guide ring K and are then taken back to an annular member L which is parallel to the flange plate D and supported by this latter.

When the thickness of thread on any one of the reels E.sub.1 or E.sub.2 of the first plate C becomes smaller than a given limit, a feeler or the like (not shown) delivers an electrical signal which starts up a motor and initiates the rotation of the second flange plate D and of the annular member L which is associated therewith. By way of alternative, the annular member and the flange plate can be continuously drive in synchronous rotation. Taking into account the position of the threads J.sub.1 and J.sub.2 which are derived from the reels F.sub.1 and F.sub.2, this synchronous rotation takes place freely without thereby placing the element A in contact with the threads J.sub.1 and J.sub.2.

In the following stage and in particular when the thread G.sub.1 or G.sub.2 of any one of the reels E.sub.1 or E.sub.2 becomes completely or almost completely emptied, a second signal produces by means of a second motor or by means of any other suitable device the relative rotation of the annular member L with respect to the rotary flange plate D and especially a retardation of said annular member which lags with respect to the flange plate. In consequence, inasmuch as the annular member is located upstream of the reels with respect to the direction of displacement of the element A, the result thereby achieved is not only to apply a progressive tension to the threads J.sub.1 and J.sub.2 but to cause the threads to become more and more inclined to the axis of said element, thereby bringing said threads into contact with this latter at a given moment and wound in the direction opposite to the normal direction. The tensile stress applied to the threads increases and means are provided on the annular member L to cut said threads which are then wound on the element in the reverse direction and the winding operation proceeds in a continuous manner.

The winding I which is formed on the element A is therefore carried out in the machine without any discontinuity whilst the two flange plates C or D are put into service in alternate sequence, the control signals which are necessary for the changeover of these latter being produced at instants which are suitably spaced in time so as to result simply in overlapping of the threads G and J on the element A over a distance M (FIG. 2) which depends on the speed of forward motion of the element through the machine and on the speed of rotation of the flange plates.

FIGS. 3 and 4 illustrate to a larger scale the constructional detail of one-half of the winding machine described above, namely of a rotary flange plate and of the associated annular member. The assembly is mainly composed of a supporting frame 1 having a base plate 2 which serves to secure the frame to a bed 3. This frame 1 is provided along its axis with a bore 4 having sufficient dimensions to permit any tubular element 5 on which it is desired to form a continuous winding of threads or ribbons to pass freely through the frame 1 and especially to carry out a uniform forward movement of displacement within the apparatus.

The frame 1 is provided in its external surface with bearings 6 and 7 for supporting coaxially with the axis of the bore 4 a cylindrical sleeve 8 which is thus capable of rotating freely about the element 5. This sleeve 8 is provided at one of its extremities with a circular flange plate 9 which extends at right angles to the axis of the element 5 and on which is mounted an assembly of half-shafts such as 10. These half-shafts are uniformly spaced over the circumference of the flange plate and are each intended to support a reel 11 of threads or ribbons of the material which is to be wound on the element 5. These reels 11 which are fitted over the half-shafts 10 come into abutment against a washer 12 which separates them from the flange plate and are then maintained in position by means of a nut 13. On the other side of the nut 13, each half-shaft 10 is further provided with an extension 14 on which is pivotally mounted a right-angle bracket 15 having a horizontal return 16 provided with eyelets 17 and 18 for the passage of the thread of the corresponding reel and with an axial guide ring 19. Finally, a counterweight 20 continuously balances the right-angle bracket 15 on the extension 14.

Irrespective of the position of the reel on the rotary flange plate 9 and irrespective of the position on said reel of the thread 21 which is in process of being unwound, it is possible by means of the arrangements just described to ensure that the thread is always brought back in the axis of the reel without any danger of jamming and breakage of the thread during operation. At the exit of ring 19, the thread 21 passes through a guide 22 carried by an annular flange 23 which is rigidly fixed to the sleeve 8, thereby guiding the thread in the radial direction substantially towards the axis of the element 5 on which it is then continuously wound in a helix, the pitch of which is a function of the speed of forward motion of said element and of the speed of rotation of the flange plate 9.

In order to permit in accordance with the invention, the controlled putting into service of the half-winder as thus contemplated, the sleeve 8 is provided at the end remote from the flange plate 9 with a flat annular shoulder 24 joined by spacer members 25 to a cylindrical member 26 which is coaxial with the sleeve 8 and consequently with the tubular element 5 which passes through the bore 4. In said member 26 is mounted by means of roller-bearings 27 a circular ring 28, or annular member, which extends parallel to the plane of the flange plate 9. On that face which is directed towards the flange plate, said annular member 28 is fitted with a set of knives 29 and the cutting edge of each knife has a curved shape which is directed towards the exterior of the annular member 28. As will become apparent hereinafter, said knives 29 perform the functio of means for attaching and cutting the ends of the threads carried by the reels of the flange plate 9 and taken in pairs. By constructional design, the number of knives 29 is one-half the number of reels 11 on the flange plate 9 and provision is consequently made for an even number of these latter.

The rotation of the flange plate 9 and consequently of the annular member 28 which is supported by the sleeve 8 by means of the member 26 and the annular shoulder 24 is obtained by means of a reduction-gear motor set 30 driving a pinion 31 disposed in meshing engagement with a chain 32 or the like which is in turn engaged with the teeth of a ring-gear 33 carried by the flange plate 9.

Moreover, and independently of the control system described above, the relative rotation of the annular member 28 can be carried out with respect to the flange plate 9 by means of the sleeve 8 which carries an electric motor 34, the supply of current to the motor being effected by means of contacts 34a applied against collectors 34b which are provided in the external surface of the frame 1. The shaft of said motor 34 is connected by means of a coupling member 35 to a shaft 36 at the end of which is carried a roller 37 and this latter is intended to bear on the external surface 38 of the annular member 28 which forms a friction track and permits the relative rotation of this latter on the roller-bearings 27.

FIG. 5 and 6 illustrate diagrammatically the method of operation of the half-winder which has been described in the foregoing. In a preparatory stage in which the reels 11 of the flange plate 9 are not employed for the purpose of forming the winding of the element 5 (this latter being formed, for example, by the second half-winder in the manner which was mentioned earlier with reference to FIGS. 1 and 2), the threads 21 of these reels are first passed through the guides 22, then joined together in pairs from one reel to one of the adjacent reels and so on in sequence between all the reels on the flange plate. The ends of the threads which are thus joined together are then brought substantially radially in a direction opposite to that of the element 5 in order to be attached to the cutting portions of the knives 29. In this first stage, the threads 21 are not subjected to any tension and are unwound from the reels 11 over the distance which is necessary to bring them to the knives 29 through the eyelets 17 and 18, the guide rings 19 and the guides 22.

It should finally be noted that, in this stage and in a suitable angular position with respect to the flange plate 9 of the annular member 28 which carries the knives 29, the threads of the reels 11 are disposed symmetrically around the element 5 but are not in direct contact with this latter in any way. The flange plate 9 and the annular member 28 can therefore be driven together in rotation by the reduction-gear motor set 30 without thereby having any effect on the element 5 which continues to advance freely within the machine (FIG. 5).

In the following stage (FIG. 6), in which the winding of the threads 21 of the reels 11 on the element 5 must actually be performed, for example when it is necessary to replace one or a number of reels of the other half-winder, the motor 34 is in turn controlled so that a relative displacement of the annular member 28 in the direction opposite to the flange plate 9 should take place independently of the rotation of said flange plate and said annular member, thus resulting in an orientation of the ends of the threads 21 which is increasingly tangential to the surface of the element 5. At a given moment, the threads come into contact with the element and are wound on this latter in the direction opposite to the normal direction, that is to say from the downstream to the upstream end.

At the same time and as a result of the rotation of the annular member, the tension applied to the threads 21 increases until the knives 29 produce action by cutting said threads and freeing them from the annular member which can then be stopped by interrupting the supply of current to the motor 34, for example. As a result of the continuous rotation of the flange plate 9, the winding of the threads is resumed in the opposite direction, or in other words, reverts to the normal direction, by covering the turns of threads which were previously formed and securing them to the element which continues its forward motion within the machine without interruption.

There is thus provided an automatic winding machine which permits continuous winding of threads or the like on a cylindrical and especially tubular element but in which the stoppages arising from the need to replace empty reels do not result in any interruption of the winding operation itself. Each half-winder is employed in turn, the operating time of one being considerably longer than the period which is necessary to replenish the other. The instants of start-up of each half-winder are determined by any suitable control means in order to provide a sufficient overlap of corresponding windings.

It must clearly be understood that the invention is not limited in any respect to the mode of execution which has been more especially described with reference to the drawings but extends to all alternative forms. In particular, no exclusive assumption has been made either in regard to the nature of the threads or ribbons employed or to the nature and composition of the tubular element itself which can be of any kind desired.

Claims

What I claim is :

1. A continuous winding machine, wherein said machine comprises two parallel coaxial flange plates each provided with an assembly of reels uniformly spaced about their common axis and carrying threads or ribbons to be wound on a cylindrical element in continuous displacement along the axis of the two flange plates which are driven separately in rotation about said axis, each flange plate being associated with an annular member which is coaxial with and parallel to said flange plate, said annular member being mounted upstream of the reels with respect to the direction of displacement of the cylindrical element, means for subjecting the annular members to a relative movement of rotation in the direction opposite to the movement of the corresponding flange plates and means provided on the annular members for attaching and cutting the ends of the threads or ribbons of the reels.

2. A continuous winding machine in accordance with claim 1, wherein each flange plate comprises an even number of reels, the ends of the threads or ribbons of said reels being joined together in pairs by means for attaching to and cutting on the coaxial annular member.

3. A continuous winding machine in accordance with claim 1, wherein the threads or ribbons pass at the exits of the reels through radial guide rings carried by the corresponding flange plate.

4. A continuous winding machine in accordance with claim 1, wherein the attaching and cutting means are constituted by knives disposed on that face of the annular member which is located opposite to the reels of the flange plate in a plane which passes through the axis of said flange plate, said knives being provided with a curved cutting edge of which the concave portion is directed towards the periphery of said annular member.

5. A continuous winding machine in accordance with claim 1, wherein the means for subjecting each annular member to a relative movement of rotation with respect to the corresponding flange plate are constituted by a driving shaft which is driven in rotation through a reduction-gear unit by means of a motor carried by the flange plate and effects the rotation of a friction roller in rubbing contact with a track formed in the annular member, said annular member being supported on roller-bearings by a coaxial cylindrical member which is rigidly fixed to said flange plate.

6. A continuous winding machine in accordance with claim 1, wherein each reel comprises in each flange plate a tubular support fitted freely over a shaft located at right angles to the plane of the corresponding flange plate, said shaft being provided with an extension on which is pivotally mounted a right-angle bracket provided with eyelets traversed by the thread which is unwound from the reel and a counterweight for the continuous balancing of said right-angle bracket.