EP0018296B1 - Coil or trellis utilisable in variable transformers, adjustable power or precision resistors, coding resistors, wound resistors, electric radiators and heat exchangers - Google Patents

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. Miniaturization 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 indeed 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 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 form of a gear, which obliges the cursor to have the form of a miniature gear, removes practically all "scraping" of the wire of the winding by the cursor from where a longevity still improved and the possibility of the realization of a potentiometric encoder of very low price. 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, in fact, 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 all the more easily the thinner and the faster it moves.

In what follows, the invention is explained in more detail with the help of drawings representing several embodiments of the winding or the trellis, of their support and of their cursor, each embodiment 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 invention relates to a coil of resistant or conductive wire insulated or enamelled usable in variable transformers or potentiometers on the support, in insulating material , comprises a central hub (3) in the form of a cylindrical tube of large diameter relative to the whole of the coil, two lateral flanges (10) and (13), a central flange (2) comprising on its periphery teeth ( 0) regularly spaced and two metallic seals (1) crimped, and two intermediate flanges (5) and (9) having 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 invention is characterized in that the winding is produced in the following way: the first end of the wire is welded to one of these conductive eyelets (1) crimped in the central flange (2), the wire passes over the central flange (2) in one of the slots (47 ), crosses the flange (5) through one of its slots (6), passes through the groove (7), makes (N1-e) turns around the core (3) in this groove (7), crosses the flange (5 ) through one of its slots (6), go back over the central flange (2) in the slot (48) passes through the flange (9) through one of its slots (6), makes (N2-e) turns in the groove (11), passes through the flange (9) through one of its slots (6), goes back above the central flange (2) in the slot (49) adjacent to the slot (48), crosses the flange (5) by one of its slots (6), makes (N3-s) turns in the groove (7 ), crosses the flange (5) through one of its slots (6), goes back over the central flange (2) and so on until the insulated resistant or conducting wire has covered the desired periphery of the flange (2 ). Before the last passage above the central flange (2) the wire makes (NK-e) turns in the corresponding groove pius passes above the central flange in the corresponding bar and its end is welded to the second crimped eyelet (1) in the central 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 the 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:

L'aspect général de la bobine terminée est donné par les figures 1 et 2. Les deux collecteurs (8) et (12) sont reliés ensuite aux oeillets (1) par un fil conducteur.

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.

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 show 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:

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 collectors (8) and (12) by a conducting wire. .

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 above property in the field of heat exchangers: the winding (4) becomes a simple trellis (case where N1 = N2 = ... = Nk = 0) whose strands are metal tubes of fairly small diameter and in which a fluid is conveyed (33); this fluid enters through the collector (15) follows the strands (4) and exits through the collector (16). The two collectors are made as recesses in the axis (3) and are separated by a wall (34). The arrangement of the strands is well represented by the three strands (30), (31), (32): the strand (30) starts from the point (44) of the collector (15) furthest from the central flange (2) passes to the above the latter at point (45) and terminates at point (46) of the manifold (16) closest to the central flange (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 manifold (15) passes above the central flange (2) at the point (42) intermediate between the points (39) and ( 45) and ends at the point (43) of the axis (3): the more the strands (4) start from the inlet manifold (15) from a point distant from the central flange (2) and the more they will lead to the manifold of outlet (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 flange (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 exchanger is 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 conductive or resistant wire with the cursor in the case where these coils are used in variable transformers, potentiometers and potentiometric encoders.

Depending on the applications, the central flange (2) may or may not have teeth. Figure 28 shows the case where the central flange is a gear; the cursor (99) then includes a pinion-shaped wheel (92) made of a material that is good conductor of electricity 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. 28, could serve 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) the tooth (95) will have to touch the strand (96) before the tooth (93) detaches from the strand (94 ) or after it is detached, which gives two different applications in switching.

Figures 26 and 27 show a cursor usable in the case where the coil object of the invention according to Figures 1 and 2 is used in variable transformers. Figures 26 and 27 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) via the tongues (90), or to a carbon plate (91). The two Zener diodes are then joined together on the one hand, and at the output on the other hand as shown in Figure 29. In the case of Figure 27 it is the carbon wafer which is joined to the terminal exit. 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 fast; this disadvantage is avoided by giving the central flange (2) the shape of a gear. Figures 30 and 31 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 26. 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 avoid short cicuit in the winding and cuts in the output voltage.

Figures 18 and 19 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 22 and 23 show a coil (4) used in a variable autotransformer using, for a magnetic circuit (79), sheets cut into E and I. Figures 24 and 25 show the coil (4) used in an autotransformer variable using a magnetic circuit (79) cut (»C« 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 through 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) maintains the pinion (78) in position.

Figures 20 and 21 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 through the axis (77). We have, for each branch of the magnetic circuit, outputs and sliders similar to those in Figures 18 and 19.

Figures 32 and 33 show a potentiometer with a coil (4), the obtaining of which was exposed on page (4) of this same patent, from line 6 to line 27. The sliders (69) rub on 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 housing (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 34 and 35 show an electric radiator comprising a coil (4), the winding of which 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 brought to the slip rings (126) via the coals (129) placed in their charcoal holder (131). The radiator has two compartments (118) and (120) separated by a wall (119) poor conductor of heat: the compartment (118) contains the coil (4) and the compartment (120) the micromotor and the thermostat (127) . The ambient air enters through the lower part of the two compartments following 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 engine temperature (122) at a reasonable value and on the other hand gives exact information of the room temperature to the thermostat (127).

Claims (11)

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-e) 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-e) 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-e) 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-s) 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).

2. The resistor wire or insulated or enamelled conductor coil useable in the potentiometers, the potentiometric coders and radiators the winding of wich is achieved according to the claim (1) with the special case:

the convolutions being close on the boss (3) characterized by the fact that intermediate flanges (5) and (9) are suppressed, the central boss (3) is a small diameter cylinder and the central flange (2) is a cylindrical disc with large diameter including on its periphery equally spaced teeth that may be, if need be, cancelled.

3. The resistant wire coil or the insulated conductor useable in the variable transformers and the potentiometric coders the winding of which is achieved according to either claim 1 or 2 is characterized by the fact that the central flange (2) is gear-shaped and, in the case of the potentiometric coders the whole periphery of the central flange (2) is utilized for winding purposes.

4. The resistive or insulated or enamelled conductor wire coil useable in variable transformers, potentiometers, potentiometric coders, according to the claims 1, 2 or 3, characterized by the fact that it includes at its both ends two flanges (8) and (12) good electricity conductors acting as collectors and which will be interconnected to eyelets (1) via a conducting wire.

5. Variable transformer including a coil according to the claims (1) characterized by the fact that it utilizes a two parts (86) and (87) cursor, separated by an insulating partition (83) the distance of which is such that there is always at least one in contact with the coil winding.

6. Variable transformer or potentiometer including a coil according the claim 3, characterized by the fact that it utilizes a two parts (105) and (106) cursor having the shape of gears with one on two missing tooth placed on the same axis (109) made in insulating material and separated by an insulating plate (107) and disposed one relatively to the other so that they form a complete gear; the number of teeth (100) of the cursor and the clearance between the teeth (100) of the cursor and the teeth (101) of the central flange (2) will be such that there will always be at least one tooth (100) in contact with the coil winding. ^t

7. Variable transformer according to both claims 5 or 6 characterized by the fact that the both conducting parts (86) and (87) or (105) and (106) of the cursor are interconnected to the output via two zener diodes (85) and (88) the Zener voltage is just sufficient to avoid the shortcircuits in the winding linking two successive slots.

8. Coil according to the claims 2 and 3 useable for potentiometers and potentiometric coders, characterized by the fact that a resistor (113) is connected between the output corresponding to the cursor (56) and the output corresponding to the cursor sliding on the collector (12) connected to the farthest convolution away from the central flange (2); this resistor (113) has a value allowing to linearize the potentiometer and the potentiometric coder.

9. Metal tube lattice useable in heat exchangers the winding of which is achieved according to the claim 1 with the following special case:

characterized by the fact that the support includes on the one hand a boss (3) comprising two . recesses (15) and (16) called collectors, separated by a partition (34) and on the other hand a large diameter central flange (2) with holes (29). The fluid enters via the collector (15), follows the metallic pipings and gets out via the collector (16).

10. Metal tube lattice according to the claim 9, characterized by the fact that the tubes have the following disposition: the first section starts from the collector (15) at the point (44) which is the farthest away from the central flange (2), passes over the central flange (2) at the point (45) and arrives to the point (46) of the collector (16) which is the nearest from the central flange (2) the next section starts from the collector (15) at the point adjacent to the point (44) but nearer from the central flange (2), passes over this last at a point adjacent to the point (45) and arrives to the point (46) but further away from the central flange, and so on for the next sections may be joined or not and their lenght will practically be the same.

11. Insulated resistor or conductor wire coil, according to the claim 1, or the lattice of metal tubes according to the claims 9 and 10 useable in the electric radiators or in heat exchangers, characterized by the fact that these active items are utilized as rotating.

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