EP0761141A1 - Turntable, for instance for advertising purpose, with continuous, reciprocating or fractional rotation - Google Patents

Abstract

The plate (1) is driven by a synchronous motor (10) having a permanent-magnet rotor with oscillatory self-starting, normally without a non-return device, and a stator normally having a single coil connected (11) to AC mains. The rotation may be interrupted and/or reversed periodically by one or more mechanical stops. The plate rests on a fixed base (2) comprising four horizontal arms (3-6) around a central board (7) with rollers (9) at their extremities (15). Each stop has a stud (17) which can pass through a V-shaped portion (8) of each arm unless the latter is fitted with a rider (18).

Description

The present invention relates to a turntable particularly intended for a dynamic presentation in the advertising field, for example.

The turntable, according to the invention, falls into the category of trays resting on a fixed base by means of rotating members such as rollers, bearings and other ball tracks, intended to support the tray at the periphery; the latter is rotated on said members by means of a motor or a central reduction motor coupled to the axis of the turntable provided with a ball stop or a shoulder axis, providing the plate with central support.

Such rotating plates are, for example, described in French patent FR-1421614 which proposes a plate characterized in that it comprises a geared motor group suspended from said plate and immobilized in rotation on the base, the rotating plate resting on a set of rollers integral with said base, rollers whose axes are oriented radially towards the vertical axis of the plate or of the gear motor. Such a device which has the advantage of supporting very heavy loads, such as, for example, mannequins for fashion presentation, must necessarily be equipped with a relatively sophisticated and therefore expensive motor if it is desired to create an animation by means of rotation. said tray; for example, if it is desired to alternate the rotations of the plate, it is necessary to provide motors which can operate alternately in one direction and in the other; similarly, if one wishes to create an animation in rotation according to a sector of determined angle, it is appropriate here again to provide motors making it possible to reverse their rotation from given time or space instructions. All these drives are of course expensive since they require motors equipped with at least two stator windings if it is a synchronous motor and moreover, it is necessary to provide position sensors or time delays in association with power supplies particular adapted allowing the desired reversal of the direction of rotation.

The present invention aims precisely to provide an inexpensive solution for providing a continuous or alternating drive system of the presentation platform allowing, if necessary, alternating rotation over a determined angular sector. In this regard, it is proposed, in accordance with the invention, a turntable in particular for dynamic advertising presentation driven by its central axis by means of an electric motor secured to a fixed base on which said tray rests by its center and in periphery by means of running gear, characterized in that the electric motor is a synchronous motor having a permanent magnet rotor with oscillating self-starting, normally without non-return device, and a stator normally with a single coil connected to an alternative network, capable in combination with one or more mechanical stops of generating an alternating and / or fractional rotation of the plate.

To better understand the advantage of such a synchronous self-starting oscillating motor without non-return device, it should be remembered that this is a motor whose rotor carries permanent magnets at the periphery, for example of the ferrite type, arranged for alternately form North and South poles in a number equal to the number of poles of the stator.

Naturally for the purpose of cost reduction, the stator is itself supplied by a single coil connected to the AC network, and it conventionally exhibits a magnetic asymmetry positioning the rotor at a standstill so that it is acted upon by a oscillating torque when powering up. It is then that such a motor is able to turn in one direction or the other, the direction of rotation being generally determined by a non-return mechanical system eliminated in the solution according to the invention.

In reality, it has been observed that such permanent magnet synchronous motors with the rotor automatically reverse their direction of rotation as soon as the rotor is blocked and a minimum elastic reaction is created on this occasion, providing sufficient mechanical asymmetry. to reverse the direction of rotation.

According to one of the main characteristics of the invention, a special base has therefore been created which makes it possible both to provide the platform with a peripheral support by means of rotating members which are associated with it and to form in combination with a lug fixed under the plate, a set of fixed and removable stops creating on their contact a reversal of rotation; the fixed and removable stops are, in accordance with an accessory although important feature of the invention, can be spatially distributed advantageously using a branch of the base whose construction geometry has been studied accordingly, as will be described later.

In a very timely manner and in accordance with one of the important characteristics of the invention, the lug fixed under the plate, in order to determine the reversals of the direction of rotation as has been said, is a lug of elastically deformable material or , according to a preferred variant, covered with such a material which provides at the time of contact with the fixed stops arranged on the base, in addition to an obvious damping of the stop noises, the creation of a restoring force resulting from the mechanical energy sufficient deformation to force the motor rotor to reverse its direction of rotation.

Furthermore and in accordance with another object of the invention, provision is made to insert, if necessary, a reduction gear between the motor and the axis of the turntable in order to best use synchronous motors finding their power for a volume determined, necessarily as low as possible, at a high speed requiring, consequently, a reduction for a correct plate drive. It is well known that such reducers conventionally comprising several gear trains often have a very noisy operation taking into account, in particular, the axial clearances of each gear.

Thus, the object of the present invention is also to describe a quite remarkable solution for considerably reducing operating noise.

• la figure représente en perspective une vue de dessus d'un plateau tournant conforme à l'invention montrant, au travers du plateau réalisé en polycarbonate transparent, la géométrie particulière du socle ainsi que les principaux organes mécaniques coopérant au fonctionnement alterné du plateau tournant.
• la figure 2 représente une demi-coupe en élévation du plateau tournant de la figure 1 selon le plan de coupe II/II.
• la figure 3 représente, selon une échelle sensiblement agrandie par rapport aux vues précédentes, une vue en perspective d'un réducteur couplé au moteur d'entraînement du plateau tournant muni de son dispositif réducteur de bruit, celui-ci étant représenté monté et en position arrachée sur la même vue.

Other characteristics and advantages will emerge more clearly from the description which will now be given by way of nonlimiting example of the invention with reference to the appended drawing in which:

• the figure shows in perspective a top view of a turntable according to the invention showing, through the tray made of transparent polycarbonate, the particular geometry of the base as well as the main mechanical members cooperating in the alternating operation of the turntable.
• 2 shows a half-section in elevation of the turntable of Figure 1 along the section plane II / II.
• 3 shows, on a scale substantially enlarged compared to the previous views, a perspective view of a reduction gear coupled to the drive motor of the turntable provided with its noise reduction device, the latter being shown mounted and in position torn off on the same view.

With reference to the figures, the turntable in particular for advertising presentation, in accordance with the preferred embodiment of the invention, comprises a plate 1 which is advantageously flat and in the form of a disc, although this form is not exclusive; of dimension (diameter thickness) in relation to the object to be presented, for example a mannequin, the tray 1 is made of a transparent organic material although it could be used any metallic material or simple plywood or blockboard providing, for each of these particular executions, advantages known on a case by case basis.

The tray 1 rests on a fixed base 2, essentially formed by four branches (3,4,5,6) from the same central plate 7 to extend in the horizontal plane according to an advantageously symmetrical distribution towards the periphery of the tray 1.

Naturally, four branches were chosen in a preferred version, but it will be observed that three would have sufficed and that a higher number could be perfectly conceivable taking into account what will be said below; in the example, the branches are therefore distributed in two rectangular directions.

The branches (3,4,5,6) of the base 2 are shaped to form the base 8 of the base 2 resting on the ground at four points, as well as to receive rolling members at their end opposite to the central plate 7 9 allowing the plate 1 rotating around its axis ZZ 'to be supported along a peripheral trajectory, while limiting the coefficients of friction, in particular when the rolling members 9 are simple ball bearings tangent outwardly from the lower part of the plate 1 , the axis of said ball bearings being directed radially towards the center of the plate 1.

The rotation of the plate 1 around its axis ZZ 'is operated by a synchronous motor 10 having a self-starting oscillating ferrite rotor without non-return device cooperating with a stator comprising only a single coil connected to the alternating network by a plug 11. This type of engine is for example distributed by companies such as CROUZET in France.

According to an essential characteristic of the invention, the branches (3,4,5,6) forming the base 2 are identical and obtained from a metal rod of a diameter related to the objects to be presented shaped by folding as it will be said now:

Each branch of the base 2 produced from a single metal rod comprises a first horizontal rectilinear part 12 followed, after folding, by a second descending and normally inclined part 13, itself folded upwards symmetrically with respect to an axis vertical in such a way that these last two parts form substantially the two branches of a V or of a U, the rising branch 14 being last folded outwards and along substantially the same axis as the first rectilinear part 12 for form an axis 15 on which a bearing 9 will force-fit.

Without these proportions being imperative, the rectilinear part 12 will extend after mounting under the plate over substantially two thirds of a radius. The two branches 13 and 14 of the V forming the base 8 will extend vertically downwards over a height making it possible to leave in the center of the plate sufficient height to have the motor 10 coupled if necessary to a reduction gear 16 (Figures 2 and 3 ); the upper opening of the V, that is to say the spacing E, in the upper part of the two branches 13 and 14 will be at least equal to the thickness of a lug 17 fixed under the plate 1 according to a distance by relative to its center such that, in the rotation of said plate 1, the lug 17 can pass through the base 8 or collide with jumpers 18 arranged removably astride the top of the base 8 while supporting a side on the straight part 12 of a branch and the other on the straight part 15 carrying the bearings 9; in this regard, the end portion 15 will be extended sufficiently to constitute a support for the jumpers 18. The latter are made from metal plates or any other suitable rigid material folded in the shape of a U whose vertical planes are spaced apart. 'a value at least equal to the diameter of the rods forming the branches of the base 2. The vertical planes of the jumpers 18, bearing on either side of the V forming the base 8 constitute a stop fixed for the lug 17 during the rotation of the plate 1. In this position of contact between the lug 17 and the jumper 18 in place on the V, the motor 10 for driving the plate 1 is momentarily blocked and subjected to this makes a sufficient mechanical reaction to trigger the reversal of the direction of rotation in accordance with what has been explained above.

In this sense, the lug 17, according to an important characteristic of the invention, is made of an elastically deformable material, for example rubber, so that at the time of contact with a jumper 18 the reaction to compression induced by the 'accumulation of energy at the moment of impact, favors a reversal of the direction of rotation to obtain the desired alternation in the rotation of the disc 1; it will be noted that the lug 17 can advantageously be constituted by a cylindrical lug held on the plate by a screw 19, said lug then being covered with a rubber cylinder of sufficient thickness to produce the desired effect. It is also well understood that such a lug covered with an elastically deformable element contributes to the improvement of the sound level during collisions between the lug 17 and the jumpers 18.

According to another particularly advantageous advantage of the stop system according to the invention, the jumpers 18 can be easily placed in position above the Vs by a simple radial translation A from a rest position (shown in thin dashed lines on the branch 6 of Figure 1) to a position as shown in solid lines called work since it will block the plate 1 and therefore its reversal of rotation. Finally and as detailed in FIG. 2, the radial branches 3, 4, 5, 6, constituting the base 2, converge as has been said on the axis ZZ 'of the plate 1, in order to be held there together by by means of 2 advantageously identical flanges 20 and 21 and each having indentations 22 arranged in the particular example in a rectangular manner to form after meeting by the flat face of the two flanges of the sleeves 22 just enclosing each branch 3, 4, 5, 6 the assembly being held by screws 23 or any other similar fixings passing therethrough and advantageously coming to hold a flange 24 intended for fixing of the motor 10, the axis 25 of the latter being coupled to the plate 1 by means of a shouldered washer 26 fixed to the plate by a set of screws 27, for its drive in rotation.

Of course, the mounting of the base 2 which has just been given is only an example and any other mounting in particular for the central fication of the branches between them could be suitable and would not depart from the scope of the invention.

According to a secondary characteristic of the invention, provision is made to insert between the motor 10 and the plate 1 a reduction gear 16 in all cases where it is necessary to obtain sufficient torque for the slow speed drive of the object to present. In this particular variant of the turntable according to the invention, the person skilled in the art knows how to perfectly adapt such a reduction gear 16 and to fix it by resuming as it was said on the fixing screws of the two flanges 20,21 according to an arrangement described above.

Referring to Figure 3 of the drawings schematically and on a larger scale showing the reducer 16 incidentally interposed between the motor 10 and the plate 1 driven by the axis 25 'of the reducer outlet, in this case instead of the axis 25 cooperate with the shouldered washer 26 for the rotational drive of said plate 1, it will now be described a particular variant of the reducer 16 comprising an anti-noise element particularly appreciated in the dynamic advertising presentation; indeed, everyone knows the noise level of reducers comprising several gear trains whose necessary operating clearances often create unpleasant sound vibrations all the more since they are amplified by coupling to plate 1.

Solutions have therefore been sought in order to reduce the parasitic sources of noise at the level of the reducer 16. For this, in accordance with a last fundamental characteristic of the invention, it is proposed to insert an elastic wedge between the flange 28 of the reducer 16 in contact with the flange 24 of the motor 10 and the face opposite the first gear 29 of said reducer 16 engaging with the gear 30 mounted at the end of the motor shaft 25 so as to catch up in all circumstances and in particular at the time of rotation reversals, the axial play of said first gear 29 between the two flanges 28, 31 of the reduction gear 16 in order to limit the operating noises.

According to a preferred embodiment of the elastic shim usable in this variant of reducer, it is proposed to use a simple blade 32 in domed spring steel in accordance with the cutaway of FIG. 3; the elastic blade 32 rests at its two ends against the flange 28 and bears by its top on the face opposite the gear 29, its maintenance being ensured by the axis of the same gear 29 passing through a bore 33 provided at the same top of the blade 32. Advantageously, at least one end of the blade 32 can be provided with a semicircular notch (as shown in FIG. 3) enclosing a piece in relief on the flange 28 of the reduction gear, for example an overflowing bearing crimped in said flange (not shown in Figure 3); this configuration prevents the blade 32 from moving during the rotation of the pinion 29.

In this way, the gear 29 is constantly and elastically pushed into abutment against the top flange 31 of the reducer 16, which avoids noise from the bearing and more generally from all of the gears forming the reducer 16.

Finally, it will be entirely possible to replace the organic material of the tray 1 with any other material able to support the objects to be presented; it has been noted that a blockboard of plywood undoubtedly contributed to a much quieter alternating operation in so far as this material hardly amplifies the vibrations generated by the motor or the reduction gear.

It is easy to understand that such a turntable can operate as well continuously, in a single direction of rotation by putting all the jumpers 18 in the rest position (central arrangement in accordance with arrow A in FIG. 1), as in rotation alternating on an angular sector depending on the number of jumpers 18 put in the working position E on the legs 8 determining, as we have seen with each collision of the lug 17, a reversal of the direction of rotation.

According to all the variants which have just been described in detail, the turntable is particularly suitable for the presentation of advertising objects but could also be used in any situation where it is necessary to present an object alternately from more than one of its angles.

Claims (11)

Turntable (1) especially for dynamic advertising presentation driven by its central axis (ZZ ') by means of an electric motor (10) secured to a fixed base (2) on which said plate (1) rests by its center and at the periphery by means of rolling elements (9) characterized in that the electric motor (10) is a synchronous motor having a rotor with permanent magnets with oscillating self-starting, normally without non-return device, and a stator normally with a single coil connected to an alternating network, capable in combination with one or more mechanical stops (17,18) of generating an alternating and / or fractional rotation of the plate (1). Turntable (1) according to the preceding claim characterized in that the base (2) is constituted by at least three branches (3,4,5,6) normally horizontal identical and radial, meeting at the level of the central axis of the plate (22 ') on a fastening means (7) also supporting the motor (10) whose axis (25) is directly or indirectly coupled to the plate (1) for its rotational drive, said branches supporting the rolling members (9) preferably located at the free ends of said branches (3,4,5,6) which are further shaped, substantially in their middle part, along a substantially V-shaped vertical profile (13,14), to serve as a base (8 ) at the base (2). Turntable (1) according to the preceding claim characterized in that each mechanical stop (17,18) is constituted by a vertical lug (17) fixed under the plate (1) at a point on a trajectory allowing it either to escape on collision with one or more of its branches (3,4,5,6), passing between the two branches (13,14) of the V of the legs (8), either to cause a stop of the plate (1) by collision with a removable rider (18) straddling a branch to join the parts upper sides of the V and cause the direction of rotation of the motor (10) to be reversed. Revolving plate (1) according to any one of the preceding claims, characterized in that the lug (17) fixed under the plate (1) is made of an elastically deformable material, or is covered with it, restoring by its deformation an energy contributing to reversing the direction of rotation of the synchronous motor while damping the stop noise during rotation reversals. Turntable (1) according to any one of Claims 2 to 4, characterized in that the means for securing the branches (3,4,5,6) is obtained by accommodating their ends close to the central axis ZZ ', between two advantageously identical flanges (20,21), each having recesses in the indentations (22) forming, after joining by their flat face, sheaths coming to grip just each branch (3,4,5,6), the assembly being maintained by screws and nuts or the like (23) passing through the assembly and advantageously holding the motor fixing flange (24), the axis (25) of the latter being coupled to the plate (1) for its rotational drive. Turntable (1) according to any one of claims 3 to 5 characterized in that the jumpers (18) forming base stops (2) can be moved (arrow A) radially along the branches thus releasing, or not, the 'upper opening (E) of the V-shaped legs to determine either continuous operation by eliminating any jumper (18) on the Vs, or alternating rotation on an angular sector varying by approximately 350 ° by placing a single jumper (18) in position stop, 180 ° with two jumpers (18) on opposite branches (3,5), 90 ° with two jumpers (18) placed on the two branches at quarter (3,4) or (4,5) or (5 , 6), etc ... Turntable (1) according to any one of the preceding claims, characterized in that the permanent magnets of the motors (25) are ferrites. Revolving plate (1) according to any one of the preceding claims, characterized in that a reduction gear (16) is interposed between the plate (1) and its motor (25 for driving. Turntable (1) according to claim 8 characterized in that an elastic shim is inserted, advantageously a blade (32) of domed spring steel, between the flange of the reducer (28) and the face opposite the first gear (29) of said reducer (16) engaged with the gear (30) at the end of the motor shaft (25), so as to catch up, in all circumstances, the axial play of said first gear (29) between the two flanges (28,31) of the reducer (16) in order to limit the operating noises. Turntable (1) according to claim 9 characterized in that the curved blade (32) rests by its two ends having, for at least one of them, a semi-circular notch to grip a fixed piece in relief on the flange (28) of the reducer (16) and bears by its top on the first gear (29) whose axis passes through a bore (33) provided at the top of said blade (32) to ensure its hold in place. Revolving plate (1) according to any one of the preceding claims, characterized in that the plate (1) is made of an organic material, transparent or not, of metal or wood, for example simple or block plywood, or the like.

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