EP0018296A1 - Coil or trellis utilisable in variable transformers, adjustable power or precision resistors, coding resistors, wound resistors, electric radiators and heat exchangers - Google Patents

Abstract

1. Resistive or insulated or enamelled conductor wire coil useable in variable transformers or in potentiometers the support of which in insulating material includes a boss (3) having the shape of a cylindrical tube with great diameter with regard to the coil set, two side flanges (10) and (13) a central flange (2) and two intermediate flanges (5) and (9) each of them cylindrical, the flanges (5) and (9) have radial slots (6) and the central flange has equally spaced teeth (O) around its periphery and two crimped metal eyelets (1), coil characterized by the fact that the winding is achieved in following manner : the first end of the wire is soldered to one of the conductor eyelets (1) crimped in the central flange (2) in one of the slots (47), crosses the flange (5) through one of its slots (6), passes into the groove (7), makes (N1-epsilon) turns around the boss (3) inside the groove (7), crosses the flange (5) through one of its slots (6), passes one more over the central flange (2) into the slot (48), crosses the flange (9) by one of its slots (6), makes (N2-epsilon) turns in the groove (11), crosses the flange (9) by one of its slots (6), passes again over the central flange (2) into the slots (49) adjacent to the slot (48), crosses the flange (5) by one of its slots (6), makes (N3-epsilon) turns in the groove (7), crosses the flange (5) by one of its slots (6), passes again over the central flange (2) and so on until the insulated resistor or conductor wire covers the desired periphery of the flange (2) ; before the last passage over the central flange (2) the wire makes (Nk-epsilon) turns in the corresponding groove, then passes over the central flange into the corresponding slot, and its end is soldered on the second eyelet (1) crimped in the central flange (2).

Description

The invention relates to a winding of resistive or conductive wire, its support and the slider which, according to the shape which they take, can be used in variable transformers, potentiometers of power or precision, potentiometric encoders and wirewound resistors or heating resistors. An extrapolation of one of the forms of the winding (trellis) finds its application in heat exchangers.

In current variable transformers and power potentiometers the winding support has the shape of a torus. This torus is a ring obtained by stacking magnetic sheets in the form of cylindrical flat rings in the case of variable transformers; in the case of power potentiometers this torus is a ceramic ring. The winding itself is wound on the ring cord in contiguous turns of an enamelled copper wire, in the case of the variable transformer, and an insulated or enamelled resistant wire in the case of the power potentiometer. Laminiaturization of such products is difficult because it is difficult to thread the resistant wire into the ring to execute the turns, and this is all the more delicate as the torus is small and the resistant or conductive wire is thin. On the other hand, in the case of miniature variable transformers, the enamelled copper wire used is necessarily very fine because in fact the smaller the variable transformer and the more it requires a large number of turns, which makes it very fragile because the wire can be very easily damaged by the cursor (even if the latter has the shape of a roulette). Finally the torus shape does not lend itself well to the establishment of the axis which supports the cursor.

In the case of precision wound potentiometers, whatever their size, the cord of the toroid supporting the winding is straight when the latter is produced, then the toroid is obtained by the deformation of this cord. Such a procedure requires great care and on the other hand lends itself very poorly to the realization of a closed circuit.

In the case of coders, these are obtained by screen printing of a design comprising a multitude of lines on a glass disc and this requires great care, a very good screen printing quality and dimensional stability.

In the case of heat exchangers, these latter are generally obtained by assembling a multitude of parallel tubes leading to two collecting tanks and conveying a fluid from which they must transmit heat to the fluid outside the exchanger. Here the problems encountered are the speed of the heat exchange and the renewal of the external fluid.

The invention makes it possible to avoid these drawbacks. In fact, the winding method is simpler because the winding is outside its support and therefore adapts to the production of this product in all dimensions. On the other hand it allows the use of a significantly larger resistant or insulated conductive wire (since it can be accommodated), which makes the product more efficient. Finally, the central flange being able to have the shape of a gear, which obliges the cursor to have the shape of a miniature gear removes practically any "scraping" of the wire of the winding by the cursor of or a still improved longevity and the possibility of producing a very low cost potentiometric encoder. The limiting case which consists in considering only the lattice of wires which will be made to rotate around its axis finds its application in electric radiators and heat exchangers, indeed, it has been shown that a wire moving parallel to it even in a fluid transmits the heat that it creates, or that it conveys, to this fluid the more easily it is thinner and it moves faster.

In what follows, the invention is explained in more detail with the aid of drawings representing several modes of execution of the winding or of the trellis, of their support and of their cursor, each mode of execution having its own application .

The most general case of the coil which is the subject of the invention is presented in FIGS. 1 and 2.

The support of this coil, which is made of insulating material comprises a central hub (3) in the form of a large diameter tube (in relative value with respect to the whole of the coil), two lateral flanges (10) and (13) , a central flange (2) comprising on its periphery regularly spaced teeth (0), and two intermediate flanges (5) and (9) comprising radial slots (6). All flanges are cylindrical. At the ends of the coil support we apply the flanges (8) and (12) good conductors of electricity. These flanges will serve as collectors.

The winding of the coil is obtained by winding a copper or resistant wire, enameled or insulated, according to a method which is shown in Figures 12 and 13. The first end is welded to one of the conductive eyelets ( 1) crimped in the central flange (2). The resistant, or conductive, insulated wire then follows the following path: it passes above the central flange (2) in the slot (47), crosses the flange (5) through one of its slots (6), passes through the groove (7), makes N1 turns in this groove (7), crosses the flange (5) through one of its slots (6), goes back above the central flange (2) in the slot (48), crosses the flange (9 ) through one of its slots (6), makes N2 turns in the groove (11), crosses the flange (9) through one of its slots (6), passes back above the central flange (2) in the slot (49) adjacent to the slot (48), crosses the flange (5) through one of its slots (6), makes N3 turns in the groove (7), crosses the flange (5) through one of its slots (6), returns to the above the central flange (2) and so on until the resistant, or conducting, insulated wire has covered the desired periphery of the flange (2). After the last passage above the central flange (2) the wire makes Nk loops in the corresponding groove and its end is welded to the second eyelet (1) crimped in the flange (2). The N1, N2, N3 ..... Nk loops can be made either in contiguous or non-contiguous turns, or in honeycombs depending on the size of the windings and the desired quality. They can be performed in the same direction if the coil is used in a variable transformer. In the case of potentiometers we can consider making these latter aselfic by winding N1, N3, N5, N7 etc ... in one direction and N2, N4, N6 etc ... in the other direction (but other methods are possible.). In the case of variable transformers we have the important case:

N1 = N2 = N3 = ......... = Nk = N (constant number of turns in rows.).

The general appearance of the finished coil is given in FIGS. 1 and 2. The two collectors (8) and (12) are then connected to the eyelets (1) by a conducting wire.

• N1 = N2 = ........... = Nk = 1

et que toutes les spires sont jointives sur l'axe. Nous voyons très facilement la similitude dans les bobinages en observant les figures 7 et 8 :Figures 3 and 4 represent the particular case where the hub (3) becomes a simple cylindrical axis of small diameter (in insulating or insulated material), that the teeth (0) of the central flange (2) and the intermediate flanges ( 5) and (9) are deleted and that:

• N1 = N2 = ........... = Nk = 1

and that all the turns are joined on the axis. We can easily see the similarity in the windings by observing Figures 7 and 8:

The resistant wire starts from the conductive plate (26), passes over the central flange (2) at point (17), makes a turn in the groove (27) around the axis (3), goes back above the flange central (2) at point (18) just in front of the previous passage (17), makes a turn in the groove (28) around the axis (3), goes back above the central flange (2) at point (19) just in front of the point (18), make a turn in the groove (27), and so on until the winding has covered the desired periphery of the central flange (2). The turns are contiguous on the axis (3), (for example the turns (23) and (24).). The second end is welded to the plate (25). The plates (25) and (26) are then connected to the eyelets (1) crimped in the central flange (2) by a conducting wire and the latter will themselves be connected to the two collector readers (8) and (12) by a common thread.

The appearance of the finished coil is shown in Figures 3 and 4: we note that as we carry out the winding the strands produced move away from the central flange; this has the effect of leaving the strands in the air and only touching them in a few very localized places and of very small area. This property can be exploited by using this coil in a power potentiometer because indeed we have a very large dissipation surface (especially if the central axis (3) is of small diameter and the central flange (2) of large diameter. ). This property can be amplified by rotating this coil around its axis with a fairly high speed of rotation.

Figures 9 and 10 show another application of the property previous in the field of heat exchangers: the winding (4) becomes a simple lattice (case where N1 = N2 = .... = Nk = 0) whose strands are metal tubes of fairly small diameter and in which is conveyed a fluid (33); this fluid enters through the collector (15) follows the strands (4) and exits through the collector (16). The two collectors are recesses in the axis (3) separated by a wall (34). The arrangement of the strands is well represented by the three strands (30), (31), (32): the strand (30) leaves from the point (44) of the manifold (15) furthest from the central flange (2) passes above the latter at point (45) and ends at point (46) of the collector (16) closest to the central puddle (2 ); the strand (32) starts from the point (38) of the collector (15), the point closest to the central flange (2), passes above the latter at point (39) and ends at point (40) of the collector (16) point furthest from the central flange (2); the strand (31), which is a strand which occupies an intermediate position, starts from the point (41) of the collector (15) passes above the central flange (2) at point (42) intermediate between points (39) and (45) and ends at point (43) of the axis (3): the more the strands (4) start from the input manifold (15) by one point away from the central flange (2) and the more they will reach the outlet manifold tie (16) at a point close to the central flange (2); the strands (4) can be contiguous or non-contiguous. This arrangement of these strands will give them the property of being almost the same length, which is very important for balancing the pressure drops in the different strands and the latter will carry the same amount of fluid (33). The central flange (2) has holes (29). Figure 9 shows that the CC section of the strands (4) gives in Figure 11 small circles almost aligned at two angles and relative to the puddle (2) and variable depending on the position of the cut. The heat exchanger rotating around its axis, in the direction (53) for example, the fluid (35) is on the one hand stirred by the strands (4) and on the other hand conveyed as indicated by the arrow in the figure 11. The heat exchanger therefore behaves at the same time as a fan.

Figures 14, 15, 16 and 17 on page 3 show a pouring spout (50) projecting alumina suspended in water (51) through the screen (52) on the periphery of the central flange (2 ) the coils rotating around their axes, in the direction (53) for example. This has the effect of removing the enamel at the point of contact between the thread conductor had resistant with the cursor in the case where these coils are used in variable tranaforsatsnrs, potentiometers and potentiometric coders.

Depending on the applications, the central flange (2) may or may not have teeth. FIG. 23 presents the case where the central flank is a gear; the cursor (99) then comprises a pinion-shaped roller (92) made of a good conductive material which comes to touch the strands of the winding which are at the bottom of the teeth: the tooth (93) comes to touch the strand (94) of the winding and, the central flange rotating, the tooth (95) will touch the strand (96). The strands (97) and (98) leading to the eyelets (1), the entire periphery of the central flange (2) is used and all the strands can play the same role and, in particular, a coil obtained as shown in Figures 7 and 8, with the particularity of FIG. 23, can be used as a potentiometric coder. According to the play that will be given between the teeth of the flange (2) and the teeth of the cursor (92) we can have the tooth (95) touch the strand (96) before the tooth (93) detaches from the strand ( 94) or after it is detached, which gives two different possibilities of application in switching.

FIGS. 21 and 22 show a cursor which can be used in the case where the coil which is the subject of the invention according to FIGS. 1 and 2 is used in variable transformers. Figures 21 and 22 show a cursor holder (84) with its plug (82) and the cursor in two parts (86) and (87) good conductors of electricity and separated by an insulating part (83). These two parts lead either to two Zener diodes (85) and (88) by means of the tongues (90), or to a carbon plate (91). The two Zéner diodes are then joined together on the one hand, and at the output on the other hand as shown in Figure 24. In the case of FIG. 22, it is the carbon plate which is joined to the output terminal. The springs (89) maintain the contact of the sliders on the manifold (2). It goes without saying that the distance between the two parts (86) and (87) must be such that there is always at least one of the parts in contact with the winding.

Such a device avoids short circuits in the winding and cuts in the output voltage. However we have, by this method, a "scraping" of the copper wire of the winding (4) by the cursor and therefore a wear which can be quite rapid; this disadvantage is avoided by giving the central flange (2) the shape of a gear. Figures 25 and 26 show the cursor to be used in this case: it has two parts (105) and (106) good conductors of electricity and in the form of gears from which one tooth has been removed in two; the two parts are placed so that together they form a complete gear. These two parts are placed on the same axis (109) of insulating material, are separated by an insulating plate (107) and are brought into contact with the plates (90), (these plates will lead to the Zener diodes (85) and (88 ) of figure 21. Here the cursor will have a sufficient number of teeth and the clearance between the teeth of the cursor and the teeth of the central flange will be such that the tooth (100) can touch the wire (102) before the tooth (103 ) has left the wire (104). Here again the device will prevent short baked currents in the winding and cuts in the output voltage.

Figures 13 and 14 show a first application of the coil (4) object of the invention in the case of a variable transformer. This coil (4) has the appearance of a coil shown in Figures 1 and 2 and is placed on the same central core (61) of the magnetic circuit as a normal coil (54). We see the cursors (69) connected to the outputs (66) and (68) and rubbing on the collectors (8) and (12) and the cursor (56) connected to the output (67) and rubbing on the periphery of the central flange (2) of the coil (4) object of the invention. The flanges (62) and the outer frame (63) form the rest of the magnetic circuit. By turning the gear (58) the latter rotates the double pinion (57) and the latter rotates the coil (4), which will vary the output voltage between the terminals (67) and (68) and the terminals (66) and (67). Here it is assumed that the input voltage is applied to the input terminals (64) and (65) which lead to the coil (54). The plate (60) connected to the gear (58) has graduations which indicate the output voltage. The handle (59) makes it possible to manually rotate the gear.

Figures 17 and 18 show a coil (4) used in a variable auto transformer using, for a magnetic cieuit (79), sheets cut into E and I. Figures 19 and 20 show the coil (4) used in a variable autotransformer using a cut magnetic circuit (79) ("C Il Core). The coil (4) is centered on the axis of the magnetic circuit by a support (80) whose central hole has the shape of the branch of the magnetic circuit which passes in the axis of the coil (4) and whose periphery has the shape of a cylinder. The rotation of the coil is obtained by rotating the axis (77) driving the pinion (78) in rotation The support (81) keeps the pinion (78) in position.

Figures 15 and 16 show an example of the use of the coil (4) in a three-phase variable transformer. Here the magnetic circuit comprises three magnetic cores (72), (73), (74) parallel and equidistant from each other; the magnetic circuit is closed by the two flanges (70) and (71). Each magnetic core has a coil (4) and a coil (54). The three coils rotate by the same relative angle thanks to the pinion (78), and we have access to this pinion thanks to the axis (77). We have for each branch of the magnetic circuit, outputs and sliders similar to those of Figures 13 and 14.

FIGS. 26 and 27 represent a potentiometer with a coil (4), the obtaining of which has been described on page (4) of this same patent, from line 6 to line 27. The sliders (69) rub against the collectors (8) and (12) and are connected to the output terminals (66) and (68). The reference voltage is applied between terminals (66) and (68); the cursor (56) senses the intermediate voltage and is connected to the output terminal (67), the assembly is enclosed in a box (112). The resistor (113) which is shown here outside the housing (112) is applied between the terminal (67) and (68), the latter being connected to the slider rubbing on the collector (12) which itself is connected to the strand (114) furthest from the central flange (2). It can be demonstrated that there is a value for the resistance (113) making it possible to obtain a potentiometer whose linearity is acceptable in many applications.

Figures 28 and 29 show an electric radiator comprising a coil (4) whose winding was obtained by winding an enameled copper wire on a central flange (2) of large diameter and an axis (3) of small diameter. The two collectors (8) and (12) of Figures 3 and 4 here become the slip rings (126) isolated from the axis (3) by rings (125) of insulating material. The axis (3) has a gear (124). The coil (4) is rotated, in the direction (53) for example, by the micromotor (122) thanks to its output pinion (123. The mains voltage is taken to the slip rings (126) via coals (129) placed in their carbon holder (131). The radiator has two compartments (118) and (120) separated by a wall (119) which is poor conductor of heat: the compartment (118) contains the coil (4 ) and the compartment (120) the micromotor and the thermostat. The ambient air enters through the lower part of the two compartments according to the arrows (130) and (132) and leaves hot through the upper part of the compartment (118) according to the arrow (135) The ambient air, entering the compartment (120), maintains the temperature of the engine (122) at a reasonable value and on the other hand gives exact information of the room temperature to the thermostat.

Claims (11)

1. Coil of resistant or insulated or enamelled conductive wire usable in variable transformers or potentiometers whose support, in insulating material, comprises a hub (3) in the form of a cylindrical tube, two lateral flanges (10) and (13), a central flange (2) and two intermediate flanges (5) and (9), all cylindrical, the flasks - (5) and (9) have radial slots and the central flange has teeth regularly spaced around its periphery and two metal eyelets (1) crimped,
characterized in that the winding is obtained as follows: the first end of the wire is welded to one of the conductive eyelets (1), the wire passes over the central flange in one of the slots (47), crosses the flange (5) through one of the slots (6), passes through the groove (7), makes N1 turns around the hub (3) in the groove (7), crosses the flange (5) through one of the slots (6) , goes back above the central flange (2) in the slot (48), crosses the flange (9) through one of the slots (6), makes N2 turns in the groove (11), crosses the flange (9) through one of the slots (6), go back over the flange (2) in the slot (49), cross the flange (5) through one of the slots (6), make N3 turns in the groove (7), cross the flange (5) through one of the slits (6), pass over the flange (2) and so on until the resistant or insulated conductive wire has covered the desired periphery of the flange (2). After the last passage above the flange (2) the wire makes Nk loops in the corresponding groove and its end is welded to the second eyelet (1) crimped in the flange (2). 2. Coil of resistant or insulated or enamelled conductive wire usable in potentiometers and radiators whose winding is obtained by the method set out in claim 1 with the particular case:

the turns being contiguous on the hub (3), characterized in that the intermediate flanges (5) and (9) are eliminated, the central hub (3) is a cylinder of small diameter and the central flange (2) is a Large diameter cylindrical disc with regularly spaced teeth on its periphery (ultimately these teeth may not exist.). 3. Coil of resistant or insulated conductive wire usable in variable transformers and potentiometric encoders, the winding of which is obtained according to one of claims 1 or 2, characterized in that the central flange has the form of a gear and that, in the case of potentiometric encoders, the entire periphery of the central flange is used to carry out the winding. 4. Coil of resistant wire or insulated conductor usable in variable transformers, potentiometers, potentiometric encoders according to one of claims 1, 2 or 3,
characterized by the fact that it has at its two ends two flanges (8) and (12) good conductors of electricity, serving as collectors and which will be connected to the eyelets (1) by a conductive wire. 5. Variable transformer according to claim 1,
characterized in that the cursor is in two parts (85) and (86) separated by an insulating wall (83) and the distance of which is such that there is always at least one in contact with the winding of the coil. 6. Variable transformer or potentiometer comprising a coil according to claim 3,
characterized by the fact that it uses a cursor in two parts (105) and (106) in the form of gears from which every other tooth has been removed, placed on the same axis (109) of insulating material and separated by a plate insulating (107) and arranged relative to each other in such a way that they generally form a gear; the number of teeth of the cursor and the clearance between the teeth of the cursor and the teeth of the central flange will be such that there will always be at least one tooth in contact with the winding of the coil. 7. Slider for variable transformer according to one of the two claims 5 or 6,
characterized in that the two conductive parts (85) and (86) or (105) and (106) are connected to the output by two Zener diodes whose Zener voltage is just sufficient to avoid short circuits in the winding connecting two successive notches. 8. Coil according to claims 2 and 3 usable for potentio - potentiometric meters and encoders,
characterized by the fact that an electrical resistance is connected between the output corresponding to the slider (56) and the output corresponding to the slider rubbing on the collector (12) connected to the turn furthest from the central flange; this resistance has a value making it possible to linearize the potentiometer and the potentiometric encoder. 9. Lattice of metal tubes usable in heat exchangers obtained according to claim 1 with the following specific case:

characterized in that the support comprises on the one hand a hub (3) comprising two recesses (15) and (16) called collectors, separated by a wall (34) and on the other a central flange (2) of large diameter and having holes (29). The fluid enters through the manifold (15), follows the pipes of the metal tubes and exits through the manifold (16). 10. Lattice of metal tubes according to claim 9, characterized in that the tubes have the following arrangement: the first strand starts from the collector (15) at the point (44) furthest from the central flange (2), passes above the flange central (2) at point (45) and ends at point (46) of the collector (16) closest to the central flange (2), the next strand starts from the collector (15) at the point adjacent to point (44) but more close to the central flange (2), passes above the latter at a point adjacent to point (45) and ends at point (46) but further from the central flange and so on for the other strands, the strands can be joined or not joined and their length will be practically the same. 11. Coil of resistant or insulated conductive wire according to claim 1 or lattice of metal tubes according to claims 9 and 10 usable in electric radiators or heat exchangers,
characterized by the fact that these active elements are used rotating.

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