The present invention relates to a support for telescopes, particularly of a portable type for amateur or semi-amateur telescopes, though it can be also applied to fixed telescopes and professional telescopes.
Various types of supports or mounts for telescopes are available. According to a first general classification, mounts can be divided into altazimuth mounts and equatorial mounts.
In altazimuth mounts, the two axes about which the telescope can move are the one orthogonal and the other parallel to the ground, such that the optics can move in all the directions along Cartesian axes. However, this arrangement of the axes of movement does not correspond to the arrangement of the Earth's axis and equatorial plane, which, as is known, at other latitudes than the poles are inclined relative thereto. Consequently, due to the Earth's true motion (spin about the North-South polar axis in the West-East direction), the optics, in order to track a celestial body in apparent motion, requires to be moved instant by instant along both axes in both directions. This movement is very complicated, and together with the rotation of the field of view during the movement, a prerequisite condition is also the constant movement of both motors relative to the two axes of movement (azimuth and altitude) in addition to a sophisticated automation (the so-called field derotator), which is normally inaccessible to beginners and amateur astronomers in general because of the high cost. The advantage of the altazimuth mount, however, is its weight balance, which makes it applicable also to large-sized telescopes.
The second type of mount, i.e. the equatorial mount, is characterized in that one of the two axes (said polar or right ascension axis) is capable of being inclined such as to be arranged parallel to the Earth's axis and thus perpendicular to the equator. Particularly, the right ascension axis (RA axis) is inclined by as many degrees as the ones of the latitude of the observation place and such as to be parallel to the pole (the North Pole for Northern hemisphere, and the South Pole for Southern hemisphere). This configuration allows one to track the apparent motion of a celestial body by moving the telescope about only one axis, i.e. by means of a simple motion that can be easily provided by means of an inexpensive drive. For this reason, the equatorial mount has become the most widely used in amateur telescopes.
Three main categories of equatorial mounts are available.
German mounts
fork mounts
English mounts (also said cradle or frame mounts).
German mounts consist of a cantilever framework supporting an optics that is capable of moving about a declination axis and about the polar axis (RA axis). The loads of the optical components are thus unbalanced to the North relative to the basement supporting the telescope. For this reason, the optical part has to be counter-balanced by suitably sized and spaced counterweights. A particular accessory, called the “equatorial head”, is indispensable for the polar axis to be properly oriented to the Celestial Pole.
Fork mounts also consist of a cantilever framework, with loads unbalanced to the North relative to the barycentre of the basement supporting the telescope. The optics is held by a U-shaped fork which rotates about the RA axis, the optics rotating therein about the declination axis. In this case, as no counter-weights are provided, in order to prevent that, due to the optical part unbalancing to the North, the instrument may fall in that direction, the equatorial head is built cantilevered to the South; thereby, the instrument barycentre is still inside the basement, but both the optics and equatorial head are, in this solution, cantilevered. Also in this case, the “equatorial head” is indispensable for the polar axis to be properly oriented to the Celestial Pole. The framework stiffening, to the purpose of restraining the inevitable vibrations of the cantilevered parts (the equatorial head and the fork), is only obtained by making the basement heavier, thus making the assembly more difficult to transport and also more expensive.
English mounts, on the other hand, consist of a frame placed on two piers, which holds the optics. The great advantage of this mount is that all weights are balanced, as their barycentre is at the intersection between the declination and right ascension axes. Due to this characteristic, the English mount is the elective mount for very large and heavy telescopes, particularly for the large telescopes in astronomical observatories, such as the Hale telescope at the Palomar Mountain observatory. English mount, however, has a drawback that makes it inapplicable to amateur telescopes: the two piers holding the frame along which the RA axis passes must be especially manufactured according to the latitude of the observatory location. In other words, the frame is pivotally fastened to the two piers at such points as dictated by the inclination that the RA axis must have, which, in turn, coincides with the latitude of the observation place. Furthermore, since it requires two support piers or frames, this mount is very bulky and heavy.
These characteristics make the English mount non-transportable, even if it were built in a size suitable for an amateur telescope. In fact, as small telescopes generally are not placed in a fixed location, they must be easy to transport in order to allow carrying out observation activities in places with low light and high air transparency, such as in the high mountains. Therefore, while on the one hand, a small size and a light weight are a selection factor for a telescope mount, on the other hand, whenever the latter has to be transported to a different place, the latitude requires to be adjusted, which cannot be done with English mounts.
In view of the above, it is understood that the commercially-available mounts for amateur telescopes are normally German or fork equatorial mounts and only seldom altazimuth ones, never English ones.
The problem at the heart of the present invention is thus to provide a support for telescopes which is characterized by being easily transported, free of cantilevered parts (and thus free of the vibrations generating therefrom) and by a perfect weight balance, such that relatively large-sized amateur telescopes are also made transportable.
This problem is solved by means of a telescope support comprising a mount and means for resting said mount on the ground, characterized in that said mount comprises a primary rocking element that allows setting the latitude of the observation place, a frame being pivotally fastened to said primary rocking element, which allows the telescope to be moved about the right ascension axis and/or about the declination axis, such as set forth in the annexed claims.
Further features and advantages of the present invention will be better understood from the description of some exemplary embodiments, which is given below by way of non-limiting illustration, with reference to the following figures:
With reference to the figures, the support of the invention for a telescope 2 is generally indicated with 1.
The telescope 2, which is schematically illustrated in form of a cylinder, can be of any type, though preferably will be a reflector telescope, such as a Newton, Dobson, Cassegrain, Schmidt-Cassegrain, catadioptric telescope, and variants thereof. This type of telescopes comprises a primary mirror, of which the diameter, focal length and optical configuration determine the luminosity and contrast of the image, and a more or less complicated optical system that conveys the image to an eyepiece, which will be responsible for the magnification thereof. As compared with refractor telescopes, reflection telescopes can be made with larger optics, while maintaining compactness and lightness. Furthermore, they are much less expensive than refractor ones, at the same optical aperture, and thus are the ones which are commonly selected by amateur users.
The support 1 comprises a mount 3 and means for resting 4 said mount 3 on the ground.
The rest means 4 shown in
The variant of the rest means 4 as shown in
The mount 3 is removably fixed to the base element 5 by means of a coupling element 12. This coupling element 12 is anchored to the base element 5 by means of suitable removable fixing means that are suitable to firmly stop the two elements, such as suitably dimensioned fixing screws. In the embodiment from
The mount 3 is an equatorial mount and is characterized in that it comprises a circle-arc shaped primary rocking element 13, also said the “declination element”, which has the capacity of rotating about its geometrical center. The primary rocking element 13 is slidingly housed in a first sliding element 14, which is integral with the coupling element 12.
To an end of said declination element 13 there is fixed a second sliding element 15, which slidingly houses a secondary arc of circle-shaped rocking element 16, which is arranged on a plane perpendicular to that on which the declination element 13 is laid. The amplitude of this secondary rocking element 16 ranges between more than 180° and 200°, and the arc of circle has a greater diameter than the tube of the telescope 2.
At both ends of the secondary rocking element 16 there are fastened respective bars 17, 17′, which connect this secondary rocking element 16 to holding means 18 for the telescope 2. A second pair of bars 19, 19′ that ends at the other end with a connecting rod 20 joins these holding means 18 to the declination element 13, by means of pivoting joining means 21. A frame is thus formed 22, which due to these pivoting joining means and said secondary rocking element 16, allows the telescope 2 being held thereon to rotate about the right ascension axis.
The holding means 18 are pivotally connected to the bars 17, 17′, 19, 19′ of the frame 22 via articulation means 23 allowing the telescope 2 to rotate about the declination axis.
The bars 17, 17′ connecting the articulation means 23 at the ends of the secondary rocking element 16 are not aligned with the second bars 19, 19′, but they are inclined upwards. This configuration derives from the fact that the secondary rocking element 16 has an amplitude greater than 180°, such as to allow the telescope 2 to rotate about the polar axis along the whole 180° tract as required, without being hindered by the bulk of the bars 17, 17′ that would otherwise restrain its rotation.
The fact that said secondary rocking element 16 is arc of circle-shaped and has a greater diameter than the tube of the telescope 2 is dictated by the advantage of being able to accommodate the tube of the telescope 2, if the latter is longer than the bars 17, 17′, and thus allowing one to observe a wider celestial field. In fact, in operation (as will be described in greater detail below), the declination element 13 is rotated in order to cause the inclination of the frame 22 until the axis of the bars 19, 19′ is aligned with the polar axis. In this condition, the secondary rocking element 16 rotates about the polar axis and the observation of objects proximate to the Celestial Pole can be carried out only if the telescope 2 is capable of being aligned with the polar axis: this movement is allowed by the particular semicircular shape of the secondary rocking element 16 which creates an observation window in that difficult position.
The articulation means 23 shown in
The holding means 18 are normally band-shaped and are preferably lined with a material that is suitable to dampen the vibrations and has a high friction coefficient, such as to prevent the tube of the telescope from sliding, even when it is in a much inclined position. This material will be, for example, an elastomer or felt or whatever is normally used in these applications.
The holding means 18 will be further structured such as to remove or cause the tube of telescope 2 to slide, according to the mounting/dismounting or adjustment requirements (e.g., in order to obtain a perfect balance of the optical parts on the support 1), and thus will comprise clamping means for the telescope 2. These means for clamping the telescope 2 to the support 1 are well known and therefore will not be described in greater detail below. For example, the holding means 18 can be formed by two semicircular bands which are hinged at one end thereof and comprise suitable clamping means at the other end thereof. Alternatively, the holding means 18 can be provided with clamping screws directly acting on the body of telescope 2. Other systems can be obviously used, without however departing from the scope of the present invention.
The primary (declination element) 13 and secondary 16 rocking elements shown in
The secondary sliding elements 15 for the secondary movable element 16 are substantially provided in the same way, but they do not require clamping means for stopping the movement of the rocking element 16. In fact, this secondary rocking element 16 will have to be free of sliding during observation.
The pivoting joining means 21 and the articulation means 23 will be preferably provided with friction means in order to allow positioning the telescope 2 in the desired position and holding the same in this position. Furthermore, an actuating knob and/or a graduated scale indicating the celestial coordinates can be associated to said pivoting joining means 21 and said articulation means 23.
Alternatively, said pivoting joining means 21 and said articulation means 23 will be provided with a suitable motor drive. The typology of motors to be used can be selected among alternating or direct current motors, stepping, brushless or toroidal motors, according to particular requirements, such as to allow both the pointing and automatic tracking of the celestial body to be observed. This application is particularly advisable in the field of astronomical photography.
The motors must preferably allow for reversible motion.
The motor to be applied to the RA axis (at the pivoting joining means 21) must be provided with such an operating speed to allow the RA axis to perform a full turn over a period of 23 hours, 56 minutes and 4.091 seconds, i.e. as long as the Earth takes to rotate about its own axis, to which the apparent motion of the celestial bodies is linked. During the observation of the apparent motion of a celestial body, the motor applied to the articulation means 23—the so-called declination motor—should remain still. Actually, due to small defects in the observation site, slight inaccuracies in the gears and other factors, declination corrections are required during star tracking. Therefore, on the one hand, the right ascension motor must be capable of accelerating or decelerating the motion according to the requirements, on the other hand, the declination motor must be capable of moving in the two directions in order to correct northbound or southbound drifts.
The support 1 of the invention may also comprise a command and control unit (CCU). With the traditional motors, the CCU calculates the position of the telescope from the number of revolutions of the motor. In case of paired stepping motors, the CCU counts the number of steps made in the two directions by each one of the motors and consequently determines the exact position adopted by the telescope. Brushless motors have a built-in CCU, which allows for an even more accurate control of the movements, speeds and positions. The CCU may have a memory in which the celestial coordinates of a list of observable celestial bodies are stored, which allows automatically pointing the telescope 2 to the selected object.
In
The motor drive may be similarly mounted to the declination axis, coaxially to the articulation means 23.
In
In
All the remaining parts of the support 1 are perfectly similar to the corresponding parts as described above.
The advantage of this embodiment is that it provides the support with greater firmness and furthermore it allows for a comfortable visual access even when Cassegrain or catadioptric telescopes are used, with rear eyepiece.
In
The embodiments in
In
The version shown in
The embodiment shown in
In
In a preferred embodiment, the support 1 of the invention will comprise latitude fine adjusting means. As said above, the primary rocking element (or declination element) 13 has a function of setting the latitude of the place in which the observation is carried out, by allowing the polar axis of the mount to be inclined to the extent required. This is, however a course adjustment.
In order to obtain an accurate latitude setting, the support 1 may thus comprise the fine adjusting means 870. As shown in
On both sides of the bearing 872, along an axis perpendicular to and intersecting the RA axis, there are arranged two threaded bars 873, 873′ that pass through a support element 874, which in the example is shaped as a semicircular fork, but may have an annular shape or any other shape suitable to encompass the bearing. The support element 874 will thus comprise two threaded holes for the threaded bars 873, 873′ to pass and act therethrough. The threaded bars 873, 873′ pass through the support element 874 and emerge therefrom such as to be coupled to respective left-right adjusting knobs 875, 875′, which in the example are embodied by nuts. When the one of said knobs is unscrewed and the other is screwed, and vice versa, a horizontal displacement will be obtained for the bearing 872 and frame 822.
To the support element 874 there is fastened, along an axis perpendicular to and intersecting both RA axis and the axis on which the threaded bars 873, 873′ lay, a threaded bar 876, the free end of which is coupled to a threaded hole which passes through a high-low adjusting knob 877. A further threaded bar 878 being fixed to an end of the declination element 813 is coupled to the same threaded hole of the high-low adjusting knob 877, though on the opposite side. The threaded bars 876, 878 have inverse threads, i.e. a left-hand one and a right-hand one, such that when the knob is rotated in one direction, a threaded bar will be unscrewed and the other will be screwed, and vice versa. When the high-low adjusting knob 877 is unscrewed/screwed, a vertical displacement will be then obtained, in the two directions, for the element 874, bearing 872 and frame 822 therewith.
Suitable graduated ring-nuts, preferably with vernier reading systems indicating the degrees and/or minutes and/or seconds of latitude, will be suitably associated with the adjusting knobs 875, 875′, 877.
In order to allow performing the high-low (vertical) and left-right (horizontal) adjusting movements as described above without torsions occurring in that part of the RA axis that is exposed to the North, an articulation 879 is required to be provided for the declination element 813 at the connection with the sliding element 815 for the secondary rocking element 816. As shown in
Accordingly, the fine adjusting means 870, in addition to connecting the frame 822 of the mount to the declination element 813, also allow the latitude—and thus the inclination of the polar axis—to be accurately set as follows. First of all, the latitude is coarsely set by positioning the plane of the element 13 in coincidence with the plane of the local meridian, by causing the declination element 813 to slide within the corresponding sliding element 814 and locking the same in this position such as discussed above. At this stage, when the high-low adjusting knob 877 is suitably rotated, the support element 874 and thus the frame 822 will be moved away or close from/to the declination element 813 according to a vertical movement. On the other hand, when the left-right adjusting knobs 875, 875′ are screwed/unscrewed, a horizontal movement of the frame 822 will be obtained relative to the support element 874 and thus the declination element 813. The latitude setting can be thus finely adjusted.
The support 1 may also comprise a bubble-level positioning means 30. This bubble-level positioning means 30 can be associated with the support means 4 or coupling element 12 (such as shown in
The support 1 can be made of any material commonly used in this applications, particularly iron, steel and/or aluminium. The perfect balance of the weights to be obtained with the inventive support, however, allows selecting lightweight materials, such as composite materials made of carbon fiber or light metals.
In a different embodiment of the invention, a detail thereof being shown in
In accordance with the embodiment in
In accordance with the embodiment in
The section of the band forming the rocking element can have varying shapes according to the particular requirements. For example, it can have an elliptic shape, such as in the example in
In the embodiment in
This configuration of the primary sliding element 14 allows further reducing the development of the arc of circle of the primary rocking element 13. As may be seen in
This reduction in the amplitude of the arc of circle of the primary sliding element 14 allows easier observation with Cassegrain or catadioptric telescopes, which have the eyepiece placed in the rear area (such as the one in
As may be seen, the support according to the invention allows an easy use of these telescopes, with the provison that a counterweight is provided that is suitable to balance the cantilevered weight. Thereby, the system barycentre is brought back to the middle of the rest means 4, the condition in which the support 1 according to the invention ensures best performance. Of course, the counterweight can comprise, instead of a simple ballast, an auxiliary telescope and/or other equipment used for observation.
In
As may be noted, the arc of circle of the secondary rocking element 16 has an amplitude slightly greater than 180°. Due to the mutual dimensions of the primary sliding elements 14 and secondary sliding elements 15, the amplitude of the secondary rocking element 16 is the minimum amplitude allowing 180° rotation to the secondary rocking element 16.
The figures annexed herein, particularly
It should be further noted how, see particularly
The annexed figures, particularly
The mutual perpendicularity as defined above and the axis AR passing through the centre of the secondary rocking element 16 are critical for proper operation of the support 1 and must be set upon manufacture with the utmost precision.
If this perpendicularity is ensured, the assembly consisting of the secondary rocking element 16 and frame 22 can adopt different configurations.
In the embodiment in
In the embodiment in
In the embodiment in
In the embodiment in
In the embodiments of the adjacent
In accordance with possible embodiments, the coupling element 12, rotating relative to the base element 5, further comprises a compass and/or a GPS satellite detection system.
Furthermore, in
The adjusting means 32 comprise, for example, three screws located about a circumference, spaced 120° away from each other, and height-adjustable independently of one another.
In accordance with an embodiment, the coupling element 12, rocking relative to the base element 5, comprises bubble-level positioning means 30.
In accordance with several embodiments, such as those in
The polar telescope 33 is integral with the mount 3 and has the optical axis XP aligned upon manufacture with the axis AR defined by the pivoting joining means 21 and the centre of the circle of the secondary rocking element 16. Particularly, in the embodiment in
The alignment upon manufacture ensures the maximum geometrical precision. When the telescope is properly oriented, the polar telescope 33 will remain constantly pointed to the astronomical pole.
The finder telescope 34 is preferably integral with the holding means 18 and has the optical axis XC aligned upon manufacture with the geometrical axis of the housing for the telescope 2 formed by the holding means 18. The alignment upon manufacture ensures achieving the maximum geometrical precision. When the telescope is properly oriented, the finder telescope 34 will remain constantly aligned with the telescope 2.
In the particular configuration adopted by the support 1 in
To cause the polar telescope 33 to point to the astronomical pole, it is sufficient to properly orientate the support 1. An elementary orientation sequence of the support will be described below.
To cause the finder telescope 34 to be aligned with the polar telescope 33, it is sufficient to rotate the holding means 18 about the axis D until the astronomical pole is framed in the center of the visual field of the finder telescope 34.
The alignment of the telescope 2 results to be more complicated. In fact, the telescope 2 is an object physically separated from the support 1, interchangeable and of a quality not defined beforehand.
Accordingly, it may occur that, when the telescope is being mounted, the geometrical axis of the tube does not exactly coincide with the geometrical axis of the housing as defined by the holding means 18. This error can occur to different extents from time to time.
It may also occur that the telescope 2 is not perfectly collimated. Incidentally, a telescope is said to be collimated when the optical axis XT coincides with the geometrical axis of the tube (or other support of the optics). Any collimation error generates a constant systematic error.
Finally, it may happen that the two errors described above occur together.
To avoid this serious drawback, the support 1 according to the invention comprises means 35 for aligning the optical axis XT of the telescope 2 with the optical axis XC of the finder telescope 34.
As those skilled in the art may certainly appreciate, this structure is a reversal of prior art established concepts, where a finder telescope is always attempted to be aligned with a telescope. With this known method, the system remains affected by all the systematic errors described above. These errors will require continuous adjustments throughout the observation, and will prevent, beforehand, the possibility of correctly carrying out an automatic tracking of a celestial body in its apparent motion.
With reference to
The telescope 2 in
The alignment means 35 in
After the support 1 has been properly oriented, the polar telescope 33 and finder telescope 34 properly point the astronomical pole. By means of the alignment means 35, the telescope 2 can be also aligned therewith. After the alignment has been thus obtained, the system is free of systematic errors. The observation and automatic tracking of a celestial body may be carried out without further pointing corrections.
One of the possible methods for properly orienting a support 1 according to the invention of the type shown in
First of all, the observation system consisting of the telescope 2 and support 1 according to the invention has to be arranged according to the steps of:
fastening the telescope 2 in the holding means 18 at the barycentre of the optics tube;
set the mount 3 in the usage configuration.
The method for achieving a proper pointing with the thus arranged observation system comprises the steps of:
firmly positioning the rest means 4 such as to obtain that the plane defined by the base element 5 is approximatively horizontal;
operate the adjustment means 32 such as to obtain that (optionally with the aid of the bubble-level positioning means 30) the plane defined by the coupling element 12 is preferably horizontal;
rotate the coupling element 12 relative to the base element 5 such as to obtain that (with the aid of the compass or other systems such as spherical astronomy calculation techniques) the primary rocking element 13 is parallel to the local meridian, particularly with the pivoting joining means 21 toward the Equator and the secondary rocking element 16 toward the astronomical pole (North Pole in the example in
rotate the primary rocking element 13 within the primary sliding element 14 thereof, such as to obtain that the axis AR takes an inclination relative to the horizon which is approximatively equal to the latitude of the observation place;
operate the fine adjustment means 870 such as to precisely align the axis AR to the polar axis, for example by framing the astronomical pole by means of the polar telescope 33;
preferably, pointing the finder telescope 34 to the astronomical pole such as to align the geometric axis XG of the housing of the telescope being defined by the holding means 18 also to the polar axis;
preferably, acting on the alignment means 35 such as to align also the optical axis XT of the telescope to the polar axis.
After the steps described above have been carried out, the telescope is properly pointed to the astronomical pole. From this position, it can be properly pointed to any celestial body, simply by setting the coordinates thereof.
The advantages of the support for telescopes being the object of the present invention are clear and have been partially set forth above.
Particularly, the support 1 associates a perfect weight balance, which is normally typical with English mounts, with easy transportability which characterizes the fork or German equatorial mounts; which transportability is obtained both due to the lower weight and the adaptability to different latitudes that derives from the adjustability of the primary rocking element.
The lower weight and small bulk of the support, which is due to the particular compact structure, without cantilevered parts, allows also relatively large-sized telescopes to be also transported, such as those with mirrors of 50 cm diameter and more, which are normally intended for fixed stations.
The support of the invention does not require equatorial heads, balance counterweights or basement overweight, with a consequent saving of material and costs.
It will be appreciated that only some specific embodiments of the support for telescopes being the object of the present invention have been described herein, to which those skilled in the art will be able to make any and all modifications necessary for its adjustment to specific applications, without however departing from the scope of protection of the present invention.
For example, the primary rocking element may also not have the shape of an arc of circle, but for example any fork or squared C shape. In this case, the rocking effect will be performed by fastening this element to a suitable rocking support, such as a roller or other known rocking system. This solution may be obviously applied also to the arc of circle-shaped primary rocking element as described above or the secondary rocking element, regardless of the same having the shape of an arc of circle or any other shape.
Number | Date | Country | Kind |
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06425297.6 | May 2006 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IT2007/000330 | 5/3/2007 | WO | 00 | 3/9/2009 |