Патент USA US2136995код для вставки
Nov. 15, 1938; ' P. RINKEL SEXTANT Filed Aug. 17, 1936 2,136,995 ' Patented Nov.-15, 1938' 2,136,995.;j_ ‘UNITED STATES PATENT "orFicE Application August 17, 1936, Serial vNo. 96,506 ' I‘ In Germany July 6, 1935 3 Claims. (Cl. 88-217) This intention consists of’ an improved sextant in Whi‘ihfjithe setting. can be particularly easily 5 passes, after re?ection by the two mirrors I0 and ' 9 and by the plane parallel prism members‘ 8 and and reliably effected even from an unsteady posi- 5 into the telescope, the image of the object ob tion such as on'aircr‘aft or ships. served being shown sharply in the geometrical ' . n The sextant in alli'its forms has an arti?cial horizon device which consists, of a re?ecting sur‘face which adjusts itself independently of the manner in which the instrument is held. plane bounded by the shutter l1. Another part ‘5 _ of the parallel light re?ected by the mirrors I0 and 9 strikes the-swinging mirror l2 and after The ' re?ection in the surfaces 1 and 6 also passes to mirror surface may be a level surface located 10 externally‘ of the instrument, for example, may 1 be a liquid mirror. It may, also, be connected with the instrument either as a liquid mirror or ' a mirror (swinging mirror) rigid in itself and ?oating and/or rotatable in bearings (suspended the telescope. The image of the object observed, re?ected by the swinging mirror I2, is also shown 10 sharply in the geometrical plane provided by the _ shutter l1. As the one image is re?ected by an even numberand the other by an uneven number of mirror surfaces,~ the one image is' seen upside - 15 mirror) which may also be inclined in relation to the horizon. ’ down and the other in erect position. In Fig. 2 is shown how the ?eld of vision bound Various embodiments of the invention are illustrated by way of example in the accompanying drawing. -m' In the drawing: Fig. 1 is a diagrammatic view in side elevation ed by the shutter l1 appears. The points a, b, 0 Shown in full lines, indicate ‘ and partly in section illustrating one arrange- ment of the optical elements of the sextant. Figs. 2, 3. 4 and _5 illustrate the ?eld of vision 25 bounded by the shutter of Fig. 1. Figs; 6 and 7 diagrammatically illustrate an- other form of the sextant wherein Fig. 7 is a dotted line is the line of symmetry of the two superposed images. On this line appear the image and the re?ected images of all those points of the ?rmament for the altitude of which the 25 sextant is set. ' 1) In order to obtain better observation of“ the side elevational view partly in section and Fig. 6 relation of the image and the ‘re?ected image one of the two images may be oifset slightly in > _ Fig. 8 is a diagrammatic elevational view of a scale arrangement 'for the sextant. ' In the embodiment illustratedin Fig. 1, I denotes a telescope with the objective 2; the eye ' 35 piece 3 and the eye lens 4. In front of the objec tlve 2 is located a pentagonal prism 5 with the re?ecting surfaces 6 and 1. The prism 5 for the passage of the rays extending therethrough is extended by means of a prism wedge 8 to a body 40” with parallel planes. ' The reflecting surface 6 is transparently mirrored while the surface 1 is entirely mirrored. 9 is a ?xed mirror; 'I'0 a mirror rotatable about the axis as in the known arrangement of ordinary 45 mirror sextants. The angle between the ?xed mirror 9 and the rotatable mirror l0 alone determines the altitude of the star observed. . I2 is a mirror arranged beneath the pentagonal prism 5. The mirror I2 is secured to the swinging 55 three star images visible in the ?eld of vision. The three small circles a’, b’, 0' denote the re- 20 ?ectedl images of the same three stars. The is a cross-sectional view of the elements shown ‘ ‘30 in Fig. '7. 15 relation to the other. The image then appearing 30 in the ?eld of vision is shown in Fig. 3. Three star images d, e, ,f are visible. (1’, e’, f’ denote the laterally displaced re?ected star images. The"—~ sextant is set for the star f. 1 i With the sun‘an‘d moon, as soon as the'image and the re?ected image come into register, &‘ bearing of the centre of the sun or the moon is provided. If only the upper or lower edge is 3?‘ visible then the upper or lower edge itself can ' at once be observed as shown in Fig. 4. 40 Moreover, provision may be made for sub-divi . sion of the one and preferably the image 11017 re?ected into tWo images one above the other. This result can be attained by means of a double , prism or by means of a Wollaston prism l8, which 45 is interposed if desired in front of the pentagonal prism in the path of the rays (shown in dotted lines in Fig. 1) . I v . This procedure is convenient when the position member l3. I4 is the axis of the swinging system I2, l3. The member 13 serves in the example shown both as a damping disc which swings between the poles of a braking magnet l6. Other of the observer is- particularly unsteady and the 50 star image observed is continuously oscillating or vibrating. In taking a bearing of the star the unsteady re?ected moving image is permitted to damping devices may, however, also be used. ‘The parallel light from the object observed swing between the steady double image. In Fig. 5 the zig-zaglines g’, h’, 1" denote the vibrating 55 " 2,136,995 image, 99, Mt, ii the double images of the cor responding three stars. The angle of de?ection of the pentagonal prism I is in the example shown 90°, the angle of in between the actual and expected angle can be read off on the scale 31. The further necessary and usual devices such as dark shades, a protecting casing for the swing clination of the swinging mirror 45°. when this ‘ ing devices, vibration devices for reducing the angle of inclination di?ers from 45° it makes no friction of the stationary pivoting axis, tilt indi difference. The instrument should then be used cator (cross inclination levels) and verniers, are in a position differing from the horizontal by the not shown. Compared with pendulum sextants of known 10 same amount in order that the line of symmetry 10 of the image and of the re?ected image comes kind with swinging scale, the new pivoted mirror sextant possesses a number of further advan in the centre of the ?eld of vision. In order to give the new sextant a stumpy form Greater accuracy of readings is obtained, since in particular in order to be able to keep the mirrors 3 and II small, it is preferable to arrange ?ner sub-division and also additional scale devices 1‘ the paths of light for the image and the image can be used. Further, after the observation the to be re?ected not in a position one above the result of the measurement is retained and can be examined again. High angle ‘observation is not other as shown in Fig. 1_ but side by side. In Figs. 6 and 7 is shown how this result can necessary, in fact sighting is always effected in an tages. the attained. no ~ ‘ ‘ approximately horizontal direction. ' In front of the objective 22 of a telescope 2! is located the mirror 23 pivoting about the axis 23. Beneath the latter is arranged the pentago nal prism 24 with the re?ecting surfaces 25, 25'. In front of the prism 24 is disposed a Fresnel prism 25 with the re?ecting surfaces 21 and 28. This prism 25 is arranged at an inclination in such manner that the path of the light is dis placed parallel so far upwards and laterally that it lies at the same height as the path of light for the non-re?ected image. The arrangement . is shown in Fig. 6 in cross section. As the heavy segment on a pendulum is dis 20 pensed with very much shortened periods of vibra tion can be obtained. It is particularly suitable to form the damping disc serving as a pendulum weight as a pendulum having the minimum period of vibration. The arrangement for observing the natural horizon permits control of the arti?cial swing ing mirror horizon and inversely there can be de termined whether an unreliable natural horizon 30 can be used for a measurement. Finally the dip of the horizon can be measured by re?ection of The order of arrangement of the three optical aids, swinging mirror, pentagonal prism and the horizon on itself. Fresnel prism may be as desired. and the manner in which the same is to be per In the embodiment shown in Figs. 6 and 7 the‘position of the swinging mirror and of the formed, I claim: prism are interchanged in relation to the ar rangement shown in Fig. l. The pivoted mirror in this case consists oi.’ a transparent mirrored 40 ' plane parallel plate. Thesurfaces 25. 25' of the pentagonal prism are entirely mirrored. 29 is -_ the ?xed mirror and 30 the mirror rotatable about the axis 3i in a known manner. \ It is particularly simple to arrange the new 45 sextant so that it can be used for taking observa tions with a natural horizon. In the embodi Having described the nature of the invention 35 1. In a sextant, an index mirror for re?ecting light proceeding from an object to be observed, an eye-piece arranged at one end of the sextant, a ?xed mirror positioned at the other end of the sextant for re?ecting the light of the index mirror in a direct path into the eye-piece so that a ?rst image of the object may be viewed at the ?rst end of the sextant, angularly disposed transparent re ?ecting means interposed in the direct path of the light re?ected by the ?xed mirror allowing the 45 light forming the ?rst image to pass there ment shown in Fig. 6 the two'mirrors 29 and 30 , through, re?ecting means arranged intermediate are extended for this purpose to the one side. the ?xed mirror and the eye-piece and positioned laterally of the direct path between the ?xed Parallel to and adjacent the telescope 2! is lo cated a second telescope 32. On observation mirror and the eye-piece including at least two to through this telescope 32 the stars are observed angularly arranged complete re?ecting means one for intercepting light forming a. second image of by way of the ?xed mirror 29 and of the rotata ble mirror 33 and adjacent the ?xed mirror 29 the the observed object proceeding from the ?xed natural horizon is observed. The arrangement mirror and the second complete re?ecting means re?ecting the light forming the second image 55 55 consisting of the swinging mirror and the prism transversely with respect to the direct path of the thus do not lie in the path of the rays. In Fig. 8 is shown diagrammatically a special ?rst image onto the transparent re?ecting means, scale arrangement which cannot be ?tted to said transparent re?ecting means being arranged known sextants having a swinging arc. , to re?ect said transverse light image into said The index arm 34 with the index 35 is ?rmly connected with the rotatable mirror 33. With the rotatable system 33, 34, 35 is connected 9. scale carrier 33 which has a scale 31 and a pointer 33. The pointer 33, on rotation of the system 33 to 33, passes along the arc 39 on the scale carrier 43. If now the index 35 is adjusted to the zero point of the scale 31 located in the middle and the system 33 to 38 is turned as a " unit about the common axis, then by means of 70 the pointer 33 the set altitude can be read off on the scale 33. If a de?nite expected,‘ value is set on the scale 33 and ?xed in this position and then on the observation only» the arm 34 with the mirror 33 and the index 35 is moved 75 then by means of the pointer 35 the difference eye-piece, and one of the re?ecting means inter 60 mediate of the ?xed mirror and the eye-piece be ing swingably mounted to be moved by gravity. 2. In a sextant, an index mirror for re?ecting light proceeding froman object to be observed, an eye-piece arranged at one end of the sextant, a 65 ?xed mirror positioned at the other end of the sextant for re?ecting the light of the index mirror in a direct path into the eye-piece so that a ?rst image of the object may be viewed at the‘ ?rst end of the sextant, a pentagonal prism interposed in 70 the direct path of light re?ected by the ?xed mirror, one face of said prism having a transpar- I ent mirrored surface permitting the light forming ' the ?rst image to pass therethrough, another face; of the prism having a completely mirrored sur-l‘ 2,136,995 'face so as to re?ect a transverse beam of light onto the transparent mirrored surface 01’ the prism, said transparent mirrored surface being positioned to re?ect the re?ected transverse beam of light into the eye-piece, and a pendulum actu ‘ ated mirror positioned laterally of the direct path of light forming the ?rst image and arranged in termediate of the ?xed mirror and the eye~piece for re?ecting light forming a second image pro 10 ceeding from the ?xed mirror onto the completely mirrored surface of the prism whereby the second image is inverted in being re?ected into the eye piece. - n 3. In a sextant, an index mirror for re?ecting 15 light proceeding from an object to be observed, an ‘ eye-piece arranged at one ?xed mirror positioned at end of the sextant, a the other end of the sextant for re?ecting the light of the index mirror in a direct path into the eye-piece so that 3 a ?rst image of the object may be viewed at the ?rst end of the sextant, a transparent‘ swingable mirror interposed in the direct path of light form ing the ?rst image and adapted to be moved by gravity to re?ect transverse beams of light into the eye-piece, a pentagonal prism arranged later 5 ally of the direct path of light forming the ?rst image, said prism having two mirrored surfaces and one mirrored surface being arranged to re ?eet light onto said transparent mirror, and prism re?ecting means positioned intermediate the ?xed 10 mirror and the pentagonal prism for intercepting light from‘ the ?xed mirror and re?ecting the same onto the other mirrored surface of said pentagonal prism to provide a second image of the observed object which appears inverted in the I eye-piece in being re?ected thereinto. PAUL RINKEL.