WO2004006212A1

WO2004006212A1 - Modular bench for studying light or sound waves

Info

Publication number: WO2004006212A1
Application number: PCT/EP2003/050137
Authority: WO
Inventors: Jean Marcel Pierron; Francis Burstert; Raphaël GROSS
Original assignee: Pierron Education Sas
Priority date: 2002-05-07
Filing date: 2003-05-05
Publication date: 2004-01-15
Also published as: PL373427A1; MA27696A1; FR2839575B1; EP1506538A1; TNSN04215A1; AU2003274106A1; FR2839575A1

Abstract

The invention concerns a bench (1) for studying light or sound waves, comprising at least first and second channels (2, 8) for receiving at least one optical or sound device (3) placed in the axis of the light or sound wave itself parallel to the longitudinal axis of at least one of said channels (2, 8), linking means (9) being provided for securing the channels (2, 8) in pairs, wherein said linking means (9) are provided with fixing means (10, 11) for fixing the channels relative to one another. Thus, the various channels can be fixed in modular manner relative to one another, thereby preventing any relative displacement of the channels during the experiments. Said linking means further ensure perfect positioning of the various components of the bench. They can also serve as legs for better stability. The length of the benches thus formed is therefore unlimited. Each channel is provided with graduations for locating the optical and acoustic elements. The optical devices are provided with holes to facilitate the passage of smoke during an experience of light beam visualization.

Description

DESCRIPTION

MODULAR BENCH FOR THE STUDY OF LIGHT OR SOUND WAVES

The invention relates to a bench for the study of light or sound waves, comprising at least a first and a second channel-shaped trough open on the top and intended to receive at least one optical or sound device placed in the axis of the light or sound wave itself parallel to the longitudinal axis of at least one of said chutes, connecting means being provided to secure the chutes two by two.

Benches are commonly used in teaching and research to study geometric optics and acoustic phenomena. The commercial benches generally consist of a main rail on which is fixed a light source or an ultrasound source, supports for various optical devices or diffraction devices and finally a screen for viewing the optical phenomenon or a receiver for the signal measurement These rails are generally long enough to allow experiments with lenses or acoustic devices and are therefore bulky

These rails form an "open" bench. It is therefore necessary, for the study of light rays, to darken the classroom to carry out certain experiments, such as those requiring a dark room

Document US Pat. No. 5,828,502, for example, is known from an optical bench consisting mainly of 4 different elements of the bars which can be fixed at their ends to two external supports, thus forming a sort of cage. Internal supports can be slipped on the bars on which they can slide and be fixed in an appropriate position. Corner elements make it possible to form kinds of cubes provided with perpendicular openings. It is thus possible to form a tubular structure which however is completely open. Furthermore, this system requires numerous screws for the formation of the bench itself and the fixing of the optical elements in their position of use.

To work around this problem, boxes are also known whose base, of square section, serves as an optical bench. The ends of the base are open. The optical devices are placed in notches made in the base of the housing. An opaque cover can be placed on the base of the housing to form a darkroom. These boxes are relatively compact, so it is sometimes necessary to combine several of these boxes to reach a length sufficient for certain experiments. For this, a rail the length of two boxes is used which allows these boxes to be aligned. Here again, the rail is a bulky object and its dimensions are adapted to a predetermined number of housings, generally two. In addition, these alignment rails do not allow the housings to be blocked relative to each other, so that there is a risk of relative displacements of the housings during the experiments, at the risk of distorting the results of the experimental measurements. For this same reason, such devices cannot be used as an astronomical telescope, a telescope or a microscope. In addition, the optical devices being enclosed in the base of the housing, it is not possible to carry out refraction experiments or experiments requiring a deflection of the light beam.

Document GB 575 871 A, for example, presents an optical bench formed by two tubes of square section, the second sliding in the first. The bench thus formed is closed and forms a dark room. The optical devices (a lens in a fixed slot of the first support and a fixed screen in the sliding tube) are stationary relative to their support, these are the supports which move relative to each other. The bench presented is not intended to be assembled with a second bench to increase its length. Furthermore, the optical bench formed is closed.

There is known from US 3,574,954 a game for teaching optics comprising several elements which can be combined together, in particular a tube formed by two half-tubes positioned between them by lugs entering holes and / or tongues penetrating into recesses. These tubes are provided with fixing means formed by a frustoconical end on one side and a corresponding recess having retaining means on the other side. It is thus possible to align two or more tubes by fixing them to one another by these fixing means. However, these fixing means only fulfill their function if the tubes are closed, they are not functional with half-tubes only. Furthermore, the lugs / holes or tongues / recesses system certainly allows two half-tubes to be positioned relative to each other but not to fix them so that an additional fixing device must be provided to ensure rigidity sufficient to move the bench thus formed. Document US 3,533,680 A presents a closed optical bench, consisting of several tubes which can be aligned and fixed to each other by screwing. The tube or tubes can be fixed by pairs of bars to a central cube provided with a perpendicular opening. . The bars have the dimensions of the final bench. The device is particularly complicated, because it requires fastenings by bars, those located below being difficult to access. This device can only be validly used in the closed position.

In addition, to visualize the light ray, it is common, whatever the type of optical bench, to make the light ray pass through a cloud of smoke. For this, the teacher has the choice between two "artisanal" methods. first is to blow cigarette smoke into the light beam, the second to shake a cloth full of chalk dust above the optical bench II goes without saying that the first method is incompatible with prevention campaigns against smoking and that the second is particularly messy. In addition, the cloud thus created quickly diffuses into the surrounding atmosphere, so that it is necessary to generate the cloud several times during the same experiment.

Document GB 229 445 discloses a simple optical bench into which smoke can penetrate to highlight the optical path.

The objective of the invention is therefore to develop a bench for the study of optical and acoustic phenomena which is open to allow easy access to the various optical elements while being space-saving when it is stored and which however makes it possible to carry out refraction experiments or experiments with deflection of the light wave or the sound wave. Another objective of the invention is to allow the simple production of a dark room. A third objective is to allow the use of smoke without it spreading quickly in the atmosphere so that a small amount of smoke may suffice for each experiment. Finally, the optical bench according to the invention must be able to be used for the realization of astronomical glasses, telescopes, microscopes and will allow the realization of experiments in holography

The first objective is achieved by the bench according to the preamble in which said connecting means are provided with fixing means for fixing the troughs with respect to each other. Thus, the different chutes can be fixed in a modular way relative to each other, thus preventing relative movement of the troughs during the experiments. These connecting means will moreover ensure perfect positioning of the various components of the bench. They may also serve as feet for better stability. The length of the benches thus formed is therefore unlimited.

It is in accordance with the invention that the fixing means consist of flanges provided with two slots intended to receive flanges situated at the longitudinal ends of the trough, said flanges being able to be formed to also fulfill the function of support leg.

In addition, it is useful to provide an opening perpendicular to the longitudinal axis of the first chute. It is thus possible to deflect the light or sound wave out of the chute or coming from the outside in the direction of the latter. .

In a preferred embodiment of the invention, the perpendicular opening is placed in a central support into which the first chute opens. This central support can be used not only to carry the perpendicular opening but it can also be used as a stand, which will make the bench more stable. The central support and the first chute can be separable, in particular to facilitate storage. The central support may have two additional openings, one in front of the chute, the other in front of the perpendicular opening.

In order to complete the bench according to the invention, it is provided that at least the second chute can be placed in alignment with the first chute and / or perpendicular to this first chute. By aligning the chutes one behind the other, the optical bench is lengthened By placing an additional trough perpendicular to the first trough, it is possible to deflect the light or sound wave out of the first trough while having the possibility to use optical or sound devices in one or the other chute.

In one embodiment of the invention, the bench can be closed by a cover of corresponding shape to form a sort of channel. If the cover is opaque, it is possible to form a dark room, possibly closing the unnecessary openings with shutters With a transparent cover, it will be possible to have a practically closed system with which we can observe from the outside the optical phenomena inside and from where smoke introduced for this purpose cannot easily escape. In order to facilitate the diffusion of smoke, optical or sound supports can be provided with openings. It is preferable that the cover be formed of elements similar to those composing the part of the bench that it closes. Thus, the same elements can be used to build the base of the bench and to build its cover. At most, it will be necessary if necessary, that certain elements are made of a transparent material.

In the case where the bench is closed by a cover, it may be advantageous that the connecting means which serve to fix the components of the lower part of the bench in relation to each other also serve to connect and fix this part between them. lower and its cover We thus obtain a stable and well aligned bench. We can also use the bench as an astronomical telescope, as a telescope or as a microscope. Its rigidity will be sufficient to be able to be lifted from the table and held in hand.

It is preferable that positioning means, for example slots, are placed facing the perpendicular opening in the first chute or in the central support, as well as possibly in their respective covers, to allow the positioning of optical or sound devices in different positions relative to the longitudinal axis of the first chute. It will thus be possible for example to place a mirror oriented at 45 ° relative to the longitudinal axis of the first chute to allow a deflection of the light ray from the first chute towards a second chute fixed on the perpendicular opening For the study of waves sound, replace the mirror with a reflective screen oriented at 45 °.

Likewise, it is preferable to provide positioning means, for example grooves, in the first chute and / or in the chutes, as well as, if necessary, than in the openings, and possibly in their respective covers, to allow the positioning of optical or sound devices perpendicular to the longitudinal axis of the troughs and or openings. We can also provide graduations corresponding to the positioning means in order to easily define the relative position of the various optical or sound devices.

In a preferred embodiment of the invention, the chutes, as well as, where appropriate, their respective covers, have a substantially semi-transverse section. circular Thanks to such a configuration, it is possible to easily stack the different components of the bench to reduce the storage space

In order to facilitate the formation of a cloud of smoke and to prevent it from escaping too quickly to the outside, it is possible to provide a possibly removable smoke generator. Thus, the smoke generated will be mainly directed into the bench. closed with a lid

The invention also relates to a bench trunking according to the invention, having the shape of a channel open on the top and intended to cooperate with a central support and / or another trough in order to form a bench according to the invention , a central support for a bench in accordance with the invention that can be opened on top and comprising a first opening into which a first chute can open and a second opening perpendicular to the first, connecting means for a bench according to the invention, intended to link and fix between them chutes and / or central supports in order to form a bench, and a support for optical or sound device for bench according to the invention, comprising positioning means intended to cooperate with the means of positioning of the bench, the support being preferably also provided with means for letting smoke pass, for example openings

Examples of embodiment of the invention are described below using the following figures

FIG. 1 perspective view of a first chute according to the invention,

Figure 2 perspective view of connecting means,

FIG. 3 perspective view of an example of benches according to the invention,

Figure 4 perspective view of a second chute according to the invention; Figure 5 perspective view of a support for a device intended for a chute according to the invention; Figure 6a, 6b perspective view of two examples of benches closed by a cover The examples presented below refer to an optical bench. However, the same device can be used to form an ultrasound bench, the optical devices being replaced by sound devices, such as ultrasonic transmitters and receivers, separators, reflective screens or sheets of foam.

The optical bench (1) mainly consists of two or more troughs (2) which are connected together by connecting means (9). These connecting means (9) have the form of flanges also fulfilling the function of support leg.

The troughs (2) have the shape of a longitudinal channel open at the top as well as at its ends. They are provided with fixing means in the form of flanges (10) located at the longitudinal ends of the troughs (2), perpendicular to their longitudinal axis. These flanges (10) are dimensioned to penetrate into a corresponding slot (11) of the support leg (9). Each support leg (9) thus has two slots (11). To ensure greater stability of the assembly, the flanges (10) are provided with lugs (12) intended to penetrate into holes (13) corresponding to the support leg (9). It is thus possible to assemble to each other a plurality of chutes in order to enlarge the optical bench. The optical bench of the kind shown in FIG. 3 is thus obtained. On the bench shown in FIG. 3, upper support legs (9) are snapped onto the lower support legs (9), which is not not mandatory.

The troughs (2) are provided with positioning means (4) allowing the precise positioning of the optical devices (3). These positioning means may consist of grooves (4) produced on the lateral edges (14) of the troughs (2) and into which protrusions (19) located around the periphery of the optical devices (3) penetrate. Graduations (20) can be provided on or near these positioning means in order to facilitate the measurement of the relative distances of the different optical devices between them. Other grooves can be provided in the bottom of the chute (2) to ensure better positioning of the optical device.

The length of the optical bench according to Figure 3 can be increased at will, while being compact in the disassembled state.

In order to allow the deflection of a light ray, a second type of chute is provided. An opening (5) is provided in this second type of troughs (8), perpendicular to their longitudinal axis This perpendicular opening (5) is placed in the example presented in FIG. 4 in a central support (6) This central support (6) has a first opening (5 ') into which the chute (8) opens and a second opening (5) perpendicular to the first (5 ') and therefore to the longitudinal axis of the chute (8) In order to increase the possibilities of use, two other openings (5 and 5 ") are provided, located opposite the second opening (5) and the first opening (5 ') respectively

These chutes (8) are, like the chutes (2) simple, provided with positioning means for the positioning of optical devices, such as grooves (4) For greater flexibility of use, the positioning means (4) also equip the openings (5, 5 ', 5 ") of the central support (6)

Additional positioning means (7) are placed opposite the perpendicular opening (5) to allow positioning of optical devices (3) in different positions relative to the longitudinal axis of the chute (8). example place a mirror 45 ° from the longitudinal axis to allow a right angle deflection of the light ray

This second type of trough is also provided with fixing means (10) similar to those described above for the troughs (2) simple These flanges (10) are located on the one hand at the free longitudinal end of the trough (8) and on the openings (5, 5 ', 5 ") It is thus possible to combine trunking of the first type (2) and trunking of the second type (8) together to form complex optical benches, in particular allowing 'study the deflection of light or all types of optical system. We can place first type trunking (2) in line with the trough (8), directly on the free end of the trough (8) or on the opening (5 ") facing it and / or on the perpendicular openings (5 ') An example of an optical bench using trunks (8) of the second type and provided with a cover is presented in FIG. 6b

In the example presented in FIG. 4, the chute (8) and the central support (6) form only one part. It would however be possible to use a simple chute (2) and a central support (6) which can be connected to the chute (2) by the support legs (9) using the flanges (10). The optical elements can be lenses, diaphragms, diffusing discs, diffraction gratings, filters, polarizing filters, or any other accessory for the study of geometrical optics phenomena. They are preferably composed of a support (3) in which the optical element is placed. The support (3) is provided with positioning means (19) complementary to the positioning means (4, 7) of the troughs (2, 8) and of the central support (6). These complementary positioning means may have the form of projections (19) which penetrate into the grooves (4) of the troughs (2, 8) and the openings (5, 5 ', 5 ").

In order to create a darkroom, it is planned to close the optical bench with a cover complementary to the base. For this, the troughs (2, 8) and the central support (6) are provided with support flange (14) extending radially outward. It is thus possible to place on a chute (2, 8) a second identical chute or on a central support (6) a second central support. The cover can be fixed on the base of the optical bench with the connecting means (9, 10, 1 1) already serving to fix the troughs (2, 8) and the central support (6) relative to each other . In the examples presented in FIGS. 6a and 6b, the cover is composed of an assembly similar to that serving as a base. The support legs (9), which serve to connect the components of the base to one another and on the other hand apart from those on the cover, can also be used to fix the cover on the base. For this, the support legs (9) are provided with snap-on devices composed, on the one hand, of a lug (15) provided with lugs (16) on one side and, on the other hand, of a notch (17) on the other side of the support leg into which the lugs (16) of the tab (15) can engage. To ensure darkness, shutters are provided to close the unnecessary openings. These shutters are dimensioned to be compatible with the slots (1 1) of the support leg (9).

This gives a kind of channel, like those shown in Figures 6a and 6b. The lateral edges (14) of the troughs (2, 8) and of the central support (6) are dimensioned so that, when two troughs or two central supports (6) are superimposed, a groove forms in which the projections (19) of optical devices (3)

An optical bench such as that presented in FIG. 6a, provided with suitable lenses, can serve as an astronomical telescope, a telescope or a microscope. In fact, the rigidity obtained with the connecting means (9) and the fixing means (10 , 11) is sufficient for hold the lenses in place inside the channel formed by the troughs superimposed two by two and so that the optical bench does not need to be supported by a table.

It is also possible that the second assembly intended to be placed on the first assembly forming the base of the optical bench is made of a transparent material. We can then follow the optical ray in the assembly. The light ray can be generated for example by a laser, an LED or an incandescent lamp. This solution will be used in particular to study the propagation of light and visualize its propagation through smoke. In this case, the troughs serving as a cover will not carry positioning means (4) for optical devices in the part used for observation. The positioning means (4) will only be provided on the lateral edges (14) of the troughs (2, 8).

For this, smoke or fog will be brought in for example through the chute (8) of the optical bench of FIG. 6b. One or more troughs (2) will be fixed to the central element (6) on an opening (5) perpendicular to the first trough. A light ray will enter the system through the opening (5) of the central element (6) facing the second chute (2), while the last opening (5) will be closed. An optical object, such as a lens, can be placed in the second chute (2).

The rectangular shape of the support legs (9) makes it possible to place an optical bench not only with its base at the bottom and its cover above, as shown in Figure 6a, but also on the side, the two parts being not placed one on top of the other but one next to the other. This second position allows, when the cover is transparent, to observe the optical phenomena, not from above but from the side. The optical bench can then be placed opposite the assembly of students.

In order to allow the circulation of smoke or fog throughout the closed optical bench, the optical devices are provided with holes (18) which allow the smoke to circulate freely in the channel formed by the two superposed chutes.

With the invention, it is possible to produce a large number of different optical benches and to adapt their geometry and their size to the current experiment. Unlike known optical benches, it is possible with elements of short length to build a rigid bench open on the top without limitation of length. The same pieces also make it possible to form a cover which, depending on whether it is transparent or opaque, makes it possible to form a dark room or to observe optical phenomena in a fog. Once dismantled, the components are compact. With these four different components (2, 3, 8, 9), this optical bench is very flexible to use Requiring only a few different parts, it is also very economical

List of references

I optical bench 2 first type of chute

3 optical device

4 means for positioning the optical devices 5, 5 ′ 5 "openings

6 central support 7 means for positioning the optical devices

8 chute

9 main means of connection

10 additional means of connection

I I slot 12 lug

13 hole

14 side edges of trunking

15 paw

16 pins 17 notch

18 means of passage

19 positioning means

20 graduations

Claims

claims

1. Bench (1) for the study of light or sound waves, comprising at least a first and a second channel (2, 8) in the form of a channel open on the top and intended to receive at least one optical device (3) or sound placed in the axis of the light or sound wave itself parallel to the longitudinal axis of at least one of said troughs (2, 8), connecting means (9) being provided for securing two by two the trunking (2, 8), characterized in that said connecting means (9) are provided with fixing means (10, 11) for fixing the trunking (2, 8) relative to each other.

2. Bench (1) according to claim 1, characterized in that the fixing means consist of flanges (9) provided with two slots (11) intended to receive flanges (10) situated at the longitudinal ends of the trough (2, 8), said flanges (9) being able to be formed to also fulfill the function of support leg.

3. Bench according to one of the preceding claims, characterized in that it is provided with an opening perpendicular (5) to the longitudinal axis of the first chute (8) at least.

4. Bench according to the preceding claim, characterized in that the perpendicular opening (5) is placed in a central support (6) into which opens the first chute (8).

5. Bench according to one of the preceding claims, characterized in that the second trough (2) at least can be placed in alignment with the first trough (2, 8) and / or perpendicular to this first trough (8) .

6. Bench according to one of the preceding claims, characterized in that it can be closed by a cover of corresponding shape to form a sort of channel, the elements forming the cover can be similar to those making up the lower part of the bench that 'he closes.

7. Bench according to the preceding claim, characterized in that the connecting means (9) serve to connect and fix together the lower part of the bench and its cover.

8. Bench according to one of claims 3 to 7, characterized in that positioning means (7), for example slots, are placed facing the perpendicular opening (5), in the first chute (2) or in the central support (6), as well as possibly in their respective covers, allowing the positioning of optical or sound devices in different positions relative to the longitudinal axis of the first chute (2).

9. Bench according to one of the preceding claims, characterized in that positioning means (4), for example grooves, are placed in the troughs (2, 8) as well as, if necessary, that in the openings (5 ) perpendicular, and possibly in their respective covers, to allow the positioning of optical (3) or sound devices perpendicular to the longitudinal axis of the troughs (2, 8) or the openings (5).

10. Bench according to one of the preceding claims, characterized in that the troughs (2, 8), as well as their respective lids, if necessary, have a substantially semi-circular cross section.

1 1. Bench according to one of the preceding claims, characterized in that it is provided with a possibly removable smoke generator

12. Bench according to one of the preceding claims, characterized in that the troughs (2, 8) are provided with graduations (20) to facilitate the identification of optical devices (3) or sound.

13 chute (2, 8) for bench according to one of the preceding claims, characterized in that it has the form of a channel open on the top and that it is provided with fixing means intended to cooperate with a support central (6) and / or a chute (2, 8) to form a bench according to one of the preceding claims.

14. central support (6) for bench according to one of claims 1 to 12, characterized in that it can be opened on top and that it comprises a first opening (5 ') into which can open a first chute (2) and a second opening (5) perpendicular to the first (5 ').

15. Connection means (9) for bench according to one of claims 1 to 12, characterized in that they are provided with fixing means intended to link and fix between them chutes (2, 8) and / or central supports (6) in order to form a bench according to one of claims 1 to 12.

16. Support for optical (3) or sound device for bench according to one of claims 1 to 12, characterized in that it comprises positioning means intended to cooperate with the positioning means (4, 7) of the bench according one of claims 1 to 12.

17. Support for optical device (3) or sound according to the preceding claim, characterized in that it is provided with means for letting smoke pass, for example openings.