EP0389442A2

EP0389442A2 - Improved apparatus for automatically shaping windings for extremely elongated coils, in particular to form dipole or quadrupole magnets

Info

Publication number: EP0389442A2
Application number: EP90830047A
Authority: EP
Inventors: Luciano Selva
Original assignee: EZIO SELVA Srl
Current assignee: EZIO SELVA Srl
Priority date: 1989-03-22
Filing date: 1990-03-06
Publication date: 1990-09-26
Also published as: IT8919531A0; IT1228851B; CA2010023A1; JPH02265225A

Abstract

There are described improvements applied to an apparatus for automatically winding of coils on forms or winding holders (F,11) having a remarkable longitudinal extension in comparison with the transverse sizes, particularly suitable for dipole or quadrupole magnets. The apparatus, already generally known from EP-A-0278924 provides for the reciprocating oscillating movement of said form (F) by about 180°, taken as a whole, being obtained, at least at each end, by meshing a pinion (15) from a geared motor (12, 12a) with a toothed half-ring (19) having a central portion (19a) fixedly mounted to said coil holder (F,11) and two symmetric outer wings (19b, 19c), being hinged at both sides of said central portion (19a), suitable to tilt alternatively by gravity, according to the rotation direction, as soon they are no longer supported by an arc-shaped stationary guide (34) which is coaxial with the said half-ring (19) and such as to minimize the radial clearances The apparatus also comprises a template carriage (2) to support the reel holding arm (3) for the conductor (10) to be wound and preferably provides for a non contemporary but sequential action of the ram means in the length direction of the form (F) for positioning each length of laid down conductor (10).

Description

The present invention relates to an improved apparatus for automatically shaping windings for extremely elongated coils, in particular for dipole or quadrupole magnets, as already described in its generality in EP-A-0278924 in the name of the same applicant.
From that published patent application an apparatus is known which is capable of automatically winding, on a winding holder form, coils in which the conductor path is mainly directed in the longitudinal direction, parallel to coil axis, with head portions having a radius which is variable and in any case relatively narrow, as it is required e.g. in the dipole or quadrupole magnets. The form or winding holder spindle is mounted for an alternate rotation about an axis coincident or parallel to the winding axis, along an oscillating angle of about 180° in the whole, on a stationary bed along a side of which a carriage is slidably reciprocating with a cantilevered bracket mounted thereon for supporting an arm which is rotatable about a vertical axis and carrying a drum or reel to feed a conductor, generally a superconductor to be wound in a coil. The three movements are mutually interpolated and programmable and on each side of the winding holder form there is provided a multiplicity of ram means to bring the last unwound superconductor length to the correct position, each time on opposed sides, so as to keep at such a position the turns pre viously laid down in cooperation with matching curved members. Intermediate tiltable supports are also provided, to follow the support bar movement during the rotation without any interference with the superconductor laying and fitting, respectively at either side of the form.
However, when the coil to be formed has a longitudinal size far greater than the transverse size, for example more than 15 meters length against a width of few tens of millimeters, the support bar or spindle during the alternate movement of oscillation and owing to a high slenderness ratio is subject to non negligible torsional strains which may result into defective windings and an incorrect shaping of coils. Since these types of coils for big magnets, which are especially used in particle accelerators, must be wound in an extremely precise way, whichever inaccuracy in their formation may bring to remarkable inconveniences. Another source of inaccuracy, still in the case of particularly long coils, may be found in the fact that the arm which brings the reel feeding the conductor to be wound is cantilevered on a carriage travelling with a reciprocating motion parallel to a side of the coil being formed.
Therefore it is an object of the present invention to provide improvements to said apparatus, so that the above mentioned inconveniences cannot occur, neither with extremely long coils, e.g. even more than 15 meters, thus ensuring in any case a perfect winding about the support form, with the turns correctly orientated and parallel one another as required, at the same time allowing for a winding speed, i.e. form rotation speeds, to be adopted which are higher and in any case not lower than those commonly adopted in winding coils of less length. This way, even for remarkable lengths coils can be obtained in any case which have no defect, without reducing the shaping speed and consequently the productivity of the apparatus. On the other hand these improvements can be usual also with coils which are not particularly long, as it will be thus possible to increase the winding speed and reduce the time of production.
These objects and advantages are obtained with an improved apparatus of the above-mentioned type, as described in EP-A-0278924, characterized in that the support bar of the winding holder form is fixed, at least at each end, to an oscillating arm which is hinged about an axis coicident with the rotation axis of said form and on the opposite side fixed to the central portion of a toothed half-ring formed in three parts hinged each other by means of a pair of pins symmetrically provided at the ends of said central portion of the half-ring, there also being provided an arc-shaped stationary housing for guiding a length of said half-ring during its rotation in both opposite directions, due to the meshing with a pinion or toothed-wheel from the output axis of a motor gear unit.
According to a preferred embodiment of the present invention said guide extends itself along a portion having at least the same length as the central portion of the half-ring in the region where the latter is located at rest, when the half-ring is symmetrically positioned with respect to a vertical plane passing through the winding holder bar, while it meshes with the said driving toothed wheel at the median point of said central portion. In these rest conditions the half-ring has a continuous semi-circular shape, as the two outer portions are supported by said guide and possibly two symmetrical support rolls which are placed at the outside of said guide and are suitable to accompany the downward tilting, due to the gravity, alternatively occurring at either side during the alternate rotation of the half-ring.
According to another aspect of the invention, the reel with vertical rotation axis from which the conductor is fed for winding is supported by an arm which is in turn rotatably mounted about a vertical axis in the longitudinal plane of the coil on a template carriage being reciprocatable while overheading said coil supporting bed along tracks parallel to said longitudinal plane by means of independent, high-precision gear-motors with electronic control on the axis placed on the two mountings of the carriage to cause at the same time the relative movement with respect to a pair of stationary toothed belts respectively parallel, at either sides, to the tracks associated therewith.
These and additional objects, advantages and features of the improved apparatus according to the present invention will be clear to those skilled in the art from the following detailed description of the particularly preferred embodiment thereof, given by way of a non-limiting example with reference to the annexed drawings in which:

FIGURE 1 shows a schematic end view of the complete apparatus according to the present invention;
FIGURE 2 shows a partial, cross sectional view taken along line II-II of figure 1 and figure 3;
FIGURE 3 shows a fragmentary, partially cut away view taken in the direction of arrows A of figure 2; and
FIGURE 4 shows a view similar to that of figure 3 in a different operating situation.

With reference to figure 1 the apparatus in its generality as already described in EP-A-0278924, basically comprises a bed 1 for supporting a bar 11 which bears a form F on which the winding of a conductor 10, possibly a superconductor, has to be performed. The bar 11 is mounted on the bed 1 so as to ensure the rotation of form F about a longitudinal axis X-X with alternate oscillations along a total angle of about 180°. This to allow that subsequently on both sides of form F is longitudinally laid the conductor 10 fed from a reel 4 which is in turn mounted in a known manner on an arm 3 capable of rotating about a vertical axis Y-Y parallel to the rotation axis Z-Z of the reel 4 and at the same time perpendicular and co-planar with said axis X-X.
According to the present invention the arm 3 is pivotably mounted in Y-Y to the traverse beam 21 of a template carriage 2 comprising two uprights 20 and 20a at either side of said bed 1, which are integrally slidable with a reciprocated motion by means of wheels 22, 22a on tracks 23, 23a parallel to said axis X-X. The movement is obtained preferably through precision geared motor units (not shown) which are respectively housed in the uprights 20, 20a and driving toothed wheels, respectively 24, 24a, which are in meshing relationship, with a minimum slack, with toothed belts 25, 25a respectively, laid along the associates tracks. There is provided an electronic control for keeping aligned the axes of the two geared-motors, whereby the movement of the template carriage proceeds not only without jolts and vibrations, but also keeping as much as possible the correct orientation required for an accurate laying down of the conductor 10 to be wound.
Leaving apart the description of all other components of the apparatus, for which reference is made to the above mentioned EP-A-0278924, the other improvement forming the object of the present invention will now be described with reference to figure 2, 3 and 4, whereas in the known apparatus the rotation movement was imparted to the form F by subjecting in whichever known way the support bar 11 to an alternate oscillation in the two opposite directions by means of brackets and bearings, of which if even only one could be driven.
According to the present invention at least two driving means are provided, one at each end, suitable to impart the desired alternate oscillating movement in full synchronism, through a special drive which will be better described in the following, with the possibility of having additional intermediate driving means along the axis X-X in order to avoid any possible twisting, bending or vibration of the support bar 11, thereby of the form F, during winding.
In figures 2-4 reference is made to one end of the apparatus, but it will be appreciated that the decription can also be adapted to the other end and to possible intermediate points of auxiliary driving. With the numeral reference 1, relating to the bed in its generality in figures 2-4 has been designated also the structure of the support and housing for the motor means driving the form F to rotate. A reversible motor 12 drives, trhough a pair of pulleys 13, 13a and a belt 14, a geared motor group 12a of high precision type on the shaft at the output of which a toothed wheel or pinion 15 is journalled. The geared-motor 12a is stationary with the structure 1 as it is fixed by means of a plate 36 to a vertical shoulder 16 which is welded on one side to a fixed beam 16a of the structure 1 and on the other side at the cylindrical sleeve 17 at the inside of which, preferably trhough the interposition of bushings 17a, a longitudinal pin 18 is rotatably mounted, coaxial with the rotation axis X-X of form F. In a plane parallel to said shoulder 16 on the pin 18 an arm 31 is hinged to which an end of a support bar 11 is welded and, on the opposite side, a toothed segment 19a is fixed, such as by screws 32, which forms the central portion of a toothed half-ring 19 further comprising two side wings 19b and 19c, each of which is hinged at an end of said intermediate segment 19a by means of a respective pin 33. The toothing of the half-ring 19 meshes with the toothed wheel 15 at the intersection of a vertical plane passing through said axis X-X with an half-ring 19.
A stationary arc-shaped housing 34 is also provided, which is fixed to shoulder 16, such as by screws 35, whereby a half-ring portion 19 is guided with the least clearance possible during its movement in both directions upon rotation of the toothed-wheel 15. As better shown in figure 2 this guide 34 is formed so as to embrace almost completely from everywhere the length of toothed wheel 19 that at each moment is located at the inside thereof so as to balance the reaction forces and withstand the thrust in either direction wich may result during the operation. Guide 34 will extend itself along an arc of a circle whose length is at least the same along which the central portion 19a extends of the toothed half-ring formed in three portions. Furthermore it will be symmetrically positioned with respect to said vertical plane passing through axis X-X, therefore it will be located in correspondance with the said central portion 19a when the latter is positioned at the rest condition as illustrated in figure 3. Under this situation the engagement of the toothed wheel 5 with the half-ring 19 occurs at the median region of the central portion 19a and the side portions or wings 19b, 19c of the half-ring are compelled by the guide 34 to take the configuration of a true half-ring as they will be at least partially in contact with its end zones at both sides of pins 33, as the guide is of a greater length with respect to the central segment 19a. Of course guide 34 shall be matching with the half-ring length 19 which is housed at each moment, whereby also the guide will have an arc-shaped path with the center coincident with that of half-ring 19, i.e. also with axis X-X.
In figure 4 a view similar to that of figure 3 is shown, in which however, after a given length rotation of the toothed wheel 15, the point at which the latter meshes with the half-ring 19 has moved to one of the other side portions, namely at the boundary with wing 19c. As one can see in this case the opposite portion 19b is free from guide 34 and therefore can rotate about the corresponding hinge 33 with an action due to the gravity. The same occurs when a movement to the opposite direction has been effected, in which case it will be the wing 19c to fall downwards. Two supporting rolls 37 are preferably provided on the sides of guide 34, being mounted on plates 38 and so positioned as to become tangent to the half-ring 19, as an ideal continuation of guide 34. The function of said two rollers is mainly, as shown for the left end one in figure 4, of guiding and deadening the drop of the ring portion tilting about the hinge 33, and also helping the guide 34 to maintain the normal semi-circular configuration, at a rest condition, as shown in figure 3, particularly if the difference of length between guide 34 and central segment 19a is at minimum.
The basic significance of a portion of toothed half-ring 19 being tilted should been noted to allow the free passage of conductor 10 at the side of form F that is facing in an upward direction as a consequence to the oscillatin movement. This is essential, mainly when a motion drive of this type is provided not only at the ends of the form F and its support bar 11, but also at intermediate points.
According to another aspect of the present invention, still with reference to the above-mentioned EP-A-0278924 it is finally provided that the ram means for correctly positioning the length of conductor laid down along a side of form F are actuated not all at the same time, but sequentially while following the path of the conductor itself during its winding.
With the improvements being the object of the present invention the apparatus according to EP-A-0278924 has been able to operate correctly for lenghts of the form or winding holder up to 17 meters with winding speeds up to 20 m/min.

Claims

1. An improved apparatus for automatically shaping windings of a superconductor (10) on a form (F) in manufacturing of coils particularly suitable for dipole or quadrupole magnets of the type described in EP-A-0278924, in which a support bar (11) of said form (F) is mounted for rotation about an axis (X-X) on a stationary structure (1) so as to cause the form (F) to alternately oscillate along an arc of about 180°C in the whole, the superconductor (10) being fed by a reel (4) rotatably mounted about a vertical axis (Z-Z), on an arm (3) which in turn can rotate about a vertical too axis (Y-Y) co-planar and perpendicular to said axis (X-X), there being also provided ram means mounted in pairs to said bar (11) at both sides of said form (F), pushing elements of which direct their action tangentially to said form in association with shaped matching and guide profiles, characterized in that said support bar (11) is caused to be fixed, at least at each end, to an oscillating arm (31) being hinged at one side on an axis coincident with the said axis (X-X) and at the opposite side fixed to the central portion (19a) of a toothed half-ring (19) formed of three portions (19a,19b,19c) which are mutually hinged each other by means of a pair of pins (33) symmetrically provided at the ends of said portion (19a), with a stationary housing (34) being also provided having an arc of a circle shape guiding a length of said half-ring (19) during its rotation in both directions due to the meshing with a toothed wheel (15) from the shaft of a geared motor unit (12,12a).

2. An improved apparatus according to claim 1, characterized in that said guide (34) extends itself along an arc of a circle coaxially with the said half- ring (19) and said axis (X-X) along a portion of a length at least equal to the length of said central portion (19a) and is positioned in the region of the latter at a rest condition, thereby symmetrically with respect to a vertical plane passing through said axis (X-X) and intersecting said half-ring (19) at the meshing point with the said toothed wheel (15).

3. An improved apparatus according to claim 2, characterized in that the arc-shaped guide (34) is substantially U-shaped for housing a corresponding arc of a circle length of half-ring (19) to embrace the same from everywhere except from the side of engagement with the said toothed wheel (15), said guide (34) being fastened by means of screws (35) to a shoulder (16) which is fixed to said structure (1) and has mounted thereon said geared motor unit (12, 12a), to which shoulder a cylindrical sleeve (17) is caused to be fixed for supporting a pin (18), coaxial with (X-X), on which said oscillating arm (31) is pivotably mounted.

4. An improved apparatus according to one or more of the preceding claims, characterized by further comprising on either side of said guide (34) two rolls (37) supporting the half-ring (19) and being tangent to the same arc of circle formed by said guide (34).

5. An apparatus according to claim 1, characterized in that said arm (3) supporting the reel (4) is mounted for rotating about said axis (Y-Y) to a cross beam (21) of a template carriage (2) which can reciprocate while overheading said structure (1) with two uprights (20,20a) being slidable on either side of structure (1) on tracks parallel to said axis (X-X) by means of the action exerted by independent and electronically controlled motor means, capable of causing toothed pulleys, respectively (24, 24a) to rotate while meshing with a minimun clearance with stationary toothed belts (25, 25a) parallel to said tracks and said axis (X-X).

6. An improved apparatus according to claim 1, characterized in that said pushing means of the ram means are sequentially operating in the direction of the conductor path during its winding.