SLIDING SUPPORT DEVICE

Abstract

A support device for slidingly supporting, and linearly moving along a longitudinal axis, an object such as e.g. a leaf.

On the object a magnetic return force develops generated by the cooperation of a magnetic flux generator (54, 56) and an element reactive to the magnetic field. The element can slide parallel to the axis during the displacement of the object and correspondingly exhibits a section which, seen in a plane orthogonal to the axis, has a width that varies along the length of the first element parallel to said axis.

Claims

1. Support device for slidingly supporting, and linearly moving along a longitudinal axis, an object such as e.g. a leaf, comprising: an empty channel extending parallel to the longitudinal axis; a magnetic flux generator for creating a magnetic flux which crosses a segment of the empty channel with magnetic field lines all having the same direction, a first element, reactive to the magnetic field, which is mounted in the empty channel and extends along said longitudinal axis, can slide relatively to the channel parallel to the longitudinal axis during the displacement of the object, and in correspondence of said segment has a cross-section struck by the magnetic flux, which cross-section, viewed in a plane orthogonal to the longitudinal axis, has a dimension along the width of the channel, wherein the first element comprises a displaceable element for increasing or decreasing the width of said cross-section, so that the first element is configured in such a way that a displacement of the displaceable element entails to an increase or decrease in the width of said cross-section.

2. Device according to claim 1, wherein the first element comprises a displaceable element for increasing the width of a first cross-section of the first element viewed in a plane orthogonal to the longitudinal axis and at the same time decreasing the width of a second cross-section of the first element viewed in a plane orthogonal to the longitudinal axis, and vice versa, the first and second cross-sections being aligned inside the empty channel along the axis of the channel and being struck by the magnetic flux.

3. Device according to claim 2, wherein the first element comprises two parts aligned along the longitudinal axis and integral with each other, each part comprising a first and a second portion adapted to engage the empty channel and respectively exhibit therein a cross-section which, viewed in a plane orthogonal to the longitudinal axis, has a first and a second dimension along the width of the channel the first dimension being larger than the second dimension, and the larger cross-section of the first part being aligned with the smaller cross-section of the second part, and the smaller cross-section of the first part being aligned with the larger cross-section of the second part, and is mounted movable with respect to the generator to alternatively place inside the channel the portion with smaller dimension of one part and the portion with larger dimension of the other part.

4. Device according to claim 1, wherein the first element and/or the displaceable element is rotatably mounted about an axis parallel to the longitudinal axis.

5. Device according to claim 4, wherein each said part has a rectangular or substantially rectangular cross-section, and such two cross-sections are arranged so that the rotation axis of the first element passes through the intersection of the diagonals of each cross-section, and the long sides of one cross-section are parallel to the short sides of the other cross-section.

6. Device according to claim 5, wherein the first element, is formed by two adjacent parallelepipeds with a rectangular or substantially rectangular cross-section, which are coaxial and offset by 90 degrees about the common rotation axis.

7. Device according to claim 1, wherein the first element and/or the displaceable element is mounted translatable with respect to the longitudinal axis.

8. Device according to claim 1, wherein the generator inserted inside a magnetic circuit configured for conveying the magnetic flux so that the flux passes through the empty channel, and defining said channel.

9. Device according to claim 1, wherein the generator comprises two rows of magnets arranged uniformly along, and parallel to, the longitudinal axis to determine between the two rows one empty space crossed by magnetic field lines having all the same direction and coming out of one row and entering the other.

10. Device according to claim 1, comprising: a second pair of equal parallel and spaced rows of magnets arranged parallel to the axis to determine in the middle of the two rows an empty space crossed by magnetic field lines exiting from one row and entering the other, and a second element, reactive to the magnetic field, which extends parallel to the axis between the two rows of the second pair, the rows of the second pair and the second element being able to slide relatively to each other parallel to the axis move the object between two positions, wherein the second element at said space has a cross-section which, viewed in a plane orthogonal to the axis, along a direction orthogonal to an imaginary plane containing the two rows, direction along which a load weights, has a decreasing width along said orthogonal direction as it develops away from the imaginary plane, the second element comprising a displaceable element such as that of the first element.

11. Device according to claim 2, wherein the first element and/or the displaceable element is rotatably mounted about an axis parallel to the longitudinal axis.

12. Device according to claim 3, wherein the first element and/or the displaceable element is rotatably mounted about an axis parallel to the longitudinal axis.

14. Device according to claim 2, wherein the first element and/or the displaceable element is mounted translatable with respect to the longitudinal axis.

15. Device according to claim 3, wherein the first element and/or the displaceable element is mounted translatable with respect to the longitudinal axis.

17. Device according to claim 8, wherein the generator comprises two rows of magnets arranged uniformly along, and parallel to, the longitudinal axis to determine between the two rows one empty space crossed by magnetic field lines having all the same direction and coming out of one row and entering the other.

18. Device according to claim 9, wherein the generator comprises two rows of magnets arranged uniformly along, and parallel to, the longitudinal axis to determine between the two rows one empty space crossed by magnetic field lines having all the same direction and coming out of one row and entering the other.

19. Device according to claim 8, comprising: a second pair of equal parallel and spaced rows of magnets arranged parallel to the axis to determine in the middle of the two rows an empty space crossed by magnetic field lines exiting from one row and entering the other, and a second element, reactive to the magnetic field, which extends parallel to the axis between the two rows of the second pair, the rows of the second pair and the second element being able to slide relatively to each other parallel to the axis to move the object between two positions, wherein the second element at said space has a cross-section which, viewed in a plane orthogonal to the axis, along a direction orthogonal to an imaginary plane containing the two rows, direction along which a load weights, has a decreasing width along said orthogonal direction as it develops away from the imaginary plane, the second element comprising a displaceable element such as that of the first element.

20. Device according to claim 9, comprising: a second pair of equal parallel and spaced rows of magnets arranged parallel to the axis to determine in the middle of the two rows an empty space crossed by magnetic field lines exiting from one row and entering the other, and a second element, reactive to the magnetic field, which extends parallel to the axis between the two rows of the second pair, the rows of the second pair and the second element being able to slide relatively to each other parallel to the axis to move the object between two positions, wherein the second element at said space has a cross-section which, viewed in a plane orthogonal to the axis, along a direction orthogonal to an imaginary plane containing the two rows, direction along which a load weights, has a decreasing width along said orthogonal direction as it develops away from the imaginary plane, the second element comprising a displaceable element such as that of the first element.

Description

[0096] The advantages of the invention will be clearer from the following description of a preferred embodiment, reference being made to the attached drawing in which—

[0097] FIG. 1 shows an exploded three-dimensional view of a device;

[0098] FIG. 2a, 2b show in plan view some parts of the device;

[0099] FIG. 3 shows a vertical cross-section of the device as assembled;

[0100] FIG. 4 shows a schematic side view of a device;

[0101] FIG. 5 shows a cross-sectional view according to the V-V plane;

[0102] FIG. 6 shows a schematic side view of the device of FIG. 4 in different configuration;

[0103] FIG. 7 shows a cross-sectional view according to the VII-VII plane;

[0104] FIG. 8 shows a schematic side view of another device;

[0105] FIG. 9 shows a cross-sectional view according to the IX-IX plane;

[0106] FIG. 10 shows a schematic side view of the device of FIG. 8 in different configuration;

[0107] FIG. 11 shows a cross-sectional view according to the XI-XI plane.

[0108] In the figures equal numbers indicate equal or conceptually similar parts; the letters N and S indicate north and south magnetic poles, respectively; and arrows indicate lines of magnetic flux.

[0109] The device MC serves e.g. to slidingly support a door (not shown) along an X-axis, and is illustrated herein as the basis for an improvement object of the invention.

[0110] The device MC comprises a fixed straight track 10 and a skid 50, movable on the track 10, which can slide relatively to each other parallel to the X axis during the motion of the door. In the illustrated example, the door would be mounted on top of the skid 50, but the device MC also contemplates reversing the roles between the track 10 and skid 50 so that the former moves and the latter remains fixed.

[0111] The skid 50 comprises a body 52, having an inverted U-shaped cross-section, within which are mounted two equal, parallel and spaced rows 54 of magnets 56 uniformly arranged alongside—and parallel to—the axis X. Between the separation of the rows 54 there is thus created an empty channel 58 crossed by all-equiverse lines of magnetic field coming out of one row 54 and entering the other (see diagram in FIGS. 2a, 2b).

[0112] The fixed track 10 is mounted inside the channel 58 so as to slide.

[0113] The part of the track 10 located in correspondence of the channel 58 has a cross-section that, viewed in a plane orthogonal to the X axis and measured on the line joining the rows 54 (see plane P1 in FIG. 3), has a width L that varies as a function of the position along the X axis.

[0114] The track 10 comprises a first portion 60 and a second portion 62, and said cross-section is greater in the first portion 60 and lower in the second portion 62.

[0115] In the illustrated example, the first portion 60 has a length along the X-axis at least equal to that of the rows 54. In general, the length of the portion 60 needs to be longer than the rows 54 only if an equilibrium condition in full opening is to be guaranteed, otherwise generally this geometric feature is not necessary.

[0116] There is a discontinuity between the cross-sections of the portions 60, 62 at a point P. Such discontinuity may be abrupt, e.g. step-like, or may be gradual, such as a ramp. At point P, a magnetic force develops between the cross-sections of the portions 60, 62 and the magnetic field generated by the rows 54 of magnets.

[0117] At point P, and only at that point, a force develops tending to relatively move the track 10 and the rows 54 along the X-axis so that the portion 60 of the track 10 with smaller cross section comes out of the empty channel 58, i.e. so that the portion 60 with smaller cross-section is no longer hit by magnetic field lines.

[0118] The situation is shown in FIGS. 2a. 2b.

[0119] When inside the channel 58 there is only the portion 62 with larger cross-section (FIG. 2a), there is no retraction force.

[0120] When (FIG. 2b) the portion 60 is displaced inside the channel 58 (toward the left in the drawing), a return force F arises at the point P which tends to oppose the position change and to bring the system back as in FIG. 2a (toward the right in the drawing).

[0121] If, for example, the relative position between the track 10 and the rows 54 of FIG. 2a corresponds to the closed door position, when the door is opened (FIG. 2b) the device MC generates a force F that brings the door back to the closed position.

[0122] The force F has approximately constant amplitude, independent of the position of the point P between the rows 54.

[0123] The variation of cross-section entails a reluctance variation of the magnetic circuit, and the amplitude of the force remains almost constant because it is linked to the reluctance variation, which is also constant.

[0124] Clearly, all this is also valid for a movement in the other direction along the X-axis (i.e. by turning the FIGS. 2a, 2b upside-down), being enough that the track 10 has a symmetrical shape with respect to a plane orthogonal to the X-axis. This is the case of FIG. 1, in which for the skid 50 a magnetic force F is generated tending to bring it back to the center of the track 10 because the track 10 has two discontinuity points for the cross-sections of the portions 60, 62 that are at least as far apart as the length along X of the skid 50.

[0125] Preferably, the device MC also generates a force to slidingly support the skid 50 on the track 10.

[0126] In order to generate such a force that opposes to the load W, e.g. the track 10 at the portions 60, 62 comprises a T-shaped or +-shaped or H-shaped portion. or in general, such portion, along a direction orthogonal to an imaginary plane P1 containing the two rows 54, has a decreasing width as it develops away from the plane. In other words, preferably the cross-section of the portions 60, 62, along a direction orthogonal to the plane P1, has decreasing width as it develops away from the plane P1. Thus, this portion of the device MC also generates load-bearing force.

[0127] To increase the support force, the skid 50 preferably comprises a second pair of equal, parallel, spaced-apart rows 70 of magnets arranged parallel to the X-axis to create between the two rows 70 a second empty space or channel 72 crossed by magnetic field lines coming out of one row 70 and entering the other. Within the space 72 there is a second element 74 of the track 10 that is responsive to the magnetic field and extends parallel to the X-axis between the two rows 70.

[0128] The portion of the track 10 running inside the space 72 has a cross-section 76 that, when viewed in a plane orthogonal to the X-axis, remains constant along the X-axis but, along a direction orthogonal to an imaginary plane P2 containing the two rows 70, has a decreasing width as it develops away from the plane P2.

[0129] In the illustrated example, the cross-section 76 is included in a +-shaped portion. Other variants comprise, for example, a T- or H-shaped part for the cross-section 76, and/or the use of different material for various parts of the cross-section 76.

[0130] As illustrated, it is preferred that the portions 60, 62 and the cross-section 76 belong to a single piece, e.g. a profile for simplicity of construction, or that however they all develop from the same plane.

[0131] By the physical principles described in PCT/IB2017/052588, when the cross-section 76 moves away from the plane P2 a magnetic reaction force is created, directed orthogonally to the plane P2 and toward the space 72, which tends to bring the cross-section 76 back into the space 72. Thus the weight W of the object is opposed.

[0132] The change along the direction of the load results in a change in reluctance that generates a reaction magnetic force that tends to bring the system into the least reluctance configuration. An equilibrium position is then reached in which the magnetic force balances the load.

[0133] The magnets of the rows 70 may be installed so that the field lines are all equiverse (as in FIG. 2a) or with alternating direction. In the second case, the device MC is added the feature of incorporating a magnetic brake, caused by the eddy currents induced by the alternating magnetic field in the track 10.

[0134] The magnetic brake is advantageous because it has a viscous-type dynamic response, i.e. the braking action increases with the speed of the skid 50. Therefore, it does not significantly hinder the door during normal use but intervenes to prevent unwanted accelerations. It has therefore the effect of limiting the speed.

[0135] Note that the feature of incorporating a magnetic brake into the device is independent of the presence of the rows 54 and the means for generating the retraction force F.

[0136] To facilitate construction, in the device MC it is preferred that [0137] the rows 54, 78 lie on respective planes P1, P2 which are parallel; and/or [0138] one row of the two rows 54 and one of the two rows 70 lie on a plane that is parallel to the planes P1, P2.

[0139] Preferably, the portion of the track 10 corresponding to the portion 60, 62 and/or 76 is made of ferromagnetic material, e.g. iron. The track 10 may be made entirely of ferromagnetic material, e.g. iron, or may comprise a portion 80 that joins the portions 60, 62 and the cross-section 76 and is made of different material than that of the portions 60, 62 and/or 76, e.g. aluminum.

[0140] Preferably, the track 10 has a H-shaped cross-section of which the two parallel rods of the H form the cross-section of the portions 60, 62 and 76.

[0141] Preferably, the rows 70 and 54 are mounted on the inner surface of the body 52 for compactness.

[0142] Preferably, wheels 90, having a rotation axis orthogonal to the planes P1 and P2, are mounted on the body 52. The wheels (or other centering devices, e.g. sliding skids, etc.) touch the, and slide on, the track 10, and serve to facilitate the sliding of the skid 50. The wheels also serve to keep the skid centered along the transverse direction (acting as a centering device).

[0143] The device MC, in all the variants described so far, is improved according to the invention for controlling the linear movement of the skid 50, e.g. as in the variant of FIGS. 4-11. The concept is employable in a skid with magnets exploited to move the load linearly, with or without the second row of magnets 70 as in FIGS. 4-7. With appropriate design, even a single row of magnets can support a load, albeit a small load.

[0144] The portions common to the basic device MC retain the same numbers increased by 100, and are not described again. Unlike the device MC, the portion 60 and the portion 62 are no longer integral with the track 10 but belong to an elongated element 199 that is mounted within the channel between the rows 154 and is rotatable with respect to the skid 50.

[0145] The element 199 extends along a Z-axis parallel to the X-axis, and is formed by the juxtaposition of two (e.g. equal) parallelepipeds 160, 162 having a rectangular cross-section (or base).

[0146] The parallelepipeds 160, 162 have major axis (the height) coaxial to the Z axis, are placed abutted to each other (adjacent) along the Z axis and offset angularly by 90 degrees about the Z axis.

[0147] At the point of conjunction of the parallelepipeds 160, 162 a cross-section discontinuity 100P is formed, like the discontinuity between the cross-sections of the portions 60, 62 at point P, because the base of the parallelepiped 160 joins the base of the parallelepiped 162 intersecting it orthogonally. That is to say that when looking at the element 199 from the front, namely placing oneself on the Z axis, a cross is viewed. The two different cross-sections of the parallelepipeds 160, 162 are visible in FIGS. 5 and 7.

[0148] The element 199 is movable with respect to the skid 150, in particular rotatable about the Z-axis, for example manually or by means of an electric actuator.

[0149] As a result, a 90-degree rotation of the element 199 can vary the cross-section of the material that lies in the channel 158 between the rows 154 of magnets. If earlier the parallelepiped 160 had exhibited a wide cross-section, corresponding to the long side of its rectangular cross-section, after the rotation such cross-section becomes narrow, corresponding to the short side of the rectangular cross-section. At the same time, if earlier the parallelepiped 162 had exhibited a narrow cross-section, corresponding to the short side of its rectangular cross-section, after the rotation its cross-section in the channel becomes wide, corresponding to the long side of the rectangular cross-section.

[0150] Another rotation of the element 199 reverses again the relationship between the widths that the cross-sections of the parallelepipeds 160, 162, taken in a plane orthogonal to the Z axis, exhibit in the channel 158.

[0151] Note that the position along the Z-axis of the cross-section discontinuity 100P does not vary with the rotation of element 199.

[0152] By what has been explained above for the device MC, it is understood that a 90-degree rotation of the element 199 results in the reversal of the magnetic force F that moves the skid 150 along the X (and Z) axis. The effect of the rotation of element 199 is equivalent, in FIG. 2b, to the track 10 being pulled out of the channel, rotated by 180 degrees, and put back into the channel.

[0153] The modification of the cross-sections made of ferromagnetic material present in the channel is implemented by a displacement of the element 199, in the illustrated case through a rotation. A translation may be used if the movable element has e.g. two parts with T-shaped cross-sections, the two T-shaped cross-sections being rotated by 180 degrees about the Z-axis.

[0154] In a simpler variant, the cross-section discontinuity 100P is also obtainable if the element 199 has only one of the rotatable parallelepipeds 160, 162 and the other is fixed.

[0155] The same concept can be employed in a skid 150 with auxiliary magnets 170 for supporting the load, as already explained in FIG. 3. See FIGS. 8-11 for this variant.

[0156] In a variant, even between the magnets 170 there may be a displaceable element such as the element 199 to modulate the load-bearing force.