US2711589A

US2711589A - Telescope mounting

Info

Publication number: US2711589A
Application number: US452539A
Authority: US
Inventors: Henry W Stock
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-08-27
Filing date: 1954-08-27
Publication date: 1955-06-28
Anticipated expiration: 1972-06-28

Description

June 28, 1955 Filed Aug. 27, 1954 H. W. STOCK TELESCOPE MOUNTING 2 Sheets-Sheet 1 Inventor":

W. Stock,

His Attorn e55.

June 28, 1955 H. w. STOCK TELESCOPE MOUNTING Filed Aug. 27, 1954 2 Sheets-Sheet 2 His Attorney United States Patent() TELESCOPE MOUNTING Henry W. Stock, Albany, N. Y.

Application August 27, 1954, Serial No. 452,539

10 Claims. (Cl. 33-61) My invention relates to telescope mountings and particularly to a mounting which is of simple construction and Within easy financial reach of the junior and adult amateur astronomers.

Professional mountings are made of metal and have many delicately balanced parts which makes them extremely expensive. Therefore, the principal object of my invention is to provide a design for an equatorial mounting of a telescope which can be made and assembled by almost anyone at very little cost but which will well serve to locate celestial objects whose declination and right ascension are known.

I accomplish this object by the means described below and illustrated in the accompanying drawings in which- Fig. l is a perspective view of the mounting;

. Fig. 2 is a top plan viewj'thereof with portions broken away;

Fig. 3 is a section of Fig. 2 in the plane 33;

Fig. 4 is a section of Fig. 2 in theplane 44;

Fig; 5 is an enlarged view of the right ascension setting circle at the end of the polar axis and showing a portion of the declination axis; the means for clamping the index hand in set position being omitted;

Fig. 6 is a view similar to Fig. 5 showing the declina tion setting circle and portions of the polar axis and telescope tube; the clamping nut being omitted; and

Fig. 7 is an exploded view of one of the index hands which cooperate with the setting circles, and the means for clamping it in set position.

Referring to the drawings, my mounting comprises a solid wood cylinder 1, which maybe about 8" long and 2" in diameter, and which forms a housing for a metal rod 2, which is rotatable therein. This forms the polar axis shaft of the mounting.

At one end of the housing 1, is aflat wood disc 3, say about 5" in diameter, which is secured to the housing by means of screws 4. on its outer surface is glued a heavy card 5, which is graduated in degrees, as best shown in Fig. 5, but marked in hours: from zero to 24. Each hour, therefore, extends through an angle of 15 degrees which is sub-divided into three principal parts of 5 degrees each, and each of these parts is divided into 5 equal parts representing intervals of 4 minutes of time. This card is the right ascension setting circle of the mounting, but, instead of using a card, either a disc of Celluloid or brass may be used, or the wood disc itself may be graduated.

About midway between the ends of the housing 1, a metal band 6 is secured thereto by a screw 7. Nuts 8 and 9 are welded to the opposite sides of the band 6 and are designed to receive the studs 10 and 11, respectively, forming trunnions on which the housing 1 is supported in the U-shaped bracket 12.

The bracket 12 has a depending bolt 13, which may be welded thereto and which is rotatably mounted in the tripod head 14 but which may be clamped in fixed position by means of the wing nut 15 (see Fig. 3).

At the other end of the housing 1, the rod 2 is welded ice to aband 16 (see Fig. 2) through which passes the wood housing 17 for the declination axis shaft 18; the housing 17 being secured in the band 16 by means of the screw 19. This housing, like the housing 1, has a wood disc 20 secured thereto at one end by screws 21. Glued or otherwise secured to the outer side of the disc is a card 22 which is graduated in degrees from zero to 180 in each direction; the line indicating the zero graduation being co-planar with the axis of rod 2. Welded to one end of the shaft 18, as best shown at 23 in Fig. 2, is bar 24 having welded thereto at each end an adjustable clamp 25 adapted to secure a telescope, such as shown in dotted outline at 26 in Figs. 1, 2 and 6, in the mounting. The declination axis shaft 18 extends somewhat beyond the disc 20 and is there threaded. It also has a keyway 27 therein. Slidably, but non-rotatably, mounted on the axis 18 is an index hand 28 which cooperates with the declination setting circle 22. In order to clamp the declination axis shaft 18 in set posi- 'tion, I have provided the wing nut 29. Beyond the setting nut 29 is a weight 30 which may be slidable on the shaft 18 and secured in position to counterbalance the weight of the telescope by means of the nuts 31 and 32.

Like the shaft 18, the shaft 2 extends through the disc and isthreaded and provided with a keyway 27 like the keyway in the shaft 18. An index hand 33 like the index hand 28 has a projection thereon which seats in the keyway and is thus made slidable but not rotatable on the shaft 2. In order to clamp the index hand in set position a wing nut 34 similar to the wing nut 21 is provided.

In use, this telescope is set up on the tripod and the head of the tripod is leveled by means of a carpenters level or the like. The telescope is then pointed at the North Star and secured in that position by the clamping nut 15 and also by means of the nut 35 on the trunnions. The telescope and the polar axis of the mounting are then parallel to the axis of the earth. If the index 33 on the right ascension circle is then set at Zero, the telescope may be turned around the declination axis and its field of view will move through all declinations which are on the same hour circle. Also, by clamping the declination axis shaft in one position in housing 17 and turning it about the polar axis, the telescope will pass all hour circles where they intersect the same declination circle. Thus the telescope can be pointed at the intersection of any declination circle and hour circle in space.

For example, assuming that the observer is inBuiialo, New York on December 25 and wishes to locate the giant red star Betelg'eux at .8 oclock that evening: From tables which are available the stars declination will appear as -7.5 north and hence its distance from the North Pole is minus 7.5 or 825. The index hand cooperating with the declination circle is then set between 82 and 83 and clamped in that position.

The index on the right ascension circle is next set. Since it is 279 days since March 21 (the vernal equinox), the earth has moved 18 hours and 20 minutes in its orbit around the sun. In order to obtain the suns right ascension the observer must take into account the fact that, in reference to the sun, any star appears to move into the same position a little earlier every night. Astronomers have measured this time interval and found it to be 3.943 minutes per day (of 24 solar hours). Hence, the suns right ascension at the assumed time of observation is changes by one hour, a correction for Buffalo must be made to the suns right ascension. For Buffalo this is =18 hours, 20 minutes minus 15 minutes. Subtracting 15 minutes from 8 oclock will give the local time at the Buffalo meridian of 7 hours and 45 minutes. Adding this to the suns right ascension we obtain a total of 26 hours and 5 minutes. From tables which are available, the right ascension of Betelgeux may be noted as 5 hours and 53 minutes, which subtracted from 26 hours and 5 minutes results in 20 hours and 12 minutes. If the indicator on the right ascension circle is set at 20 hours and 12 minutes, at 8 oclock standard time in Buffalo on December 25, Betelgeux should be in the telescopes field of vision.

From the foregoing, it will be apparent that the manner in which the declination setting circle is marked permits expeditious setting of the north polar distance, or any desired declination. Furthermore, a device such as described above brings within easy reach of everyone a simple, practical, inexpensive, equatorial mounting for a telescope that will be both entertaining and instructive.

What I claim is:

l. A telescope mounting comprising a first metal rod forming the declination axis shaft thereof and having means at one end for clamping a telescope thereto; a housing for said rod in which it is rotatable; a second metal rod forming the polar axis shaft of said mounting and having means at one end thereof to which the housing for said declination axis shaft is secured; a housing for said second rod in which it is rotatable; each of said rods being threaded at the other end thereof, projecting beyond its housing, and having an index hand slidably but non-rotatably mounted thereon together with a manually operable clamping nut; a declination setting circle secured to the end of the housing for said declination axis shaft and cooperating with the index hand on said shaft; and a right ascension setting circle secured to the end of the housing for said polar axis shaft and cooperating with the index hand on said shaft; the housing for the rod forming said polar axis shaft being provided intermediate the ends thereof with trunnions having their axis normal to said polar axis shaft.

2. The structure set forth in claim 1 in which said housings are of wood.

3. The structure set forth in claim 1 in which the threaded end of the rod forming the declination axis shaft is provided with a weight cooperating therewith and forming an adjustable counterbalance for a telescope when said telescope is secured to the other end of said rod.

4. The structure set forth in claim 1 in which the declination setting circle is graduated in degrees in both directions from a zero index line coplanar with the polar axls.

5. A telescope mounting comprising a U-shaped bracket provided at the bottom thereof with a depending threaded rod having a manually operable nut thereon and adapted rotata ly to attach said bracket to a tripod head; a first metal rod forming the declination axis shaft of said mounting having adjustable means at one end thereof for clamping a telescope at right angles thereto, and threaded at the other end thereof; a wood housing for said rod; a disc, coaxial with said rod and secured to said housing adjacent the threaded end of sad rod, forming the declination setting circle of said mounting; an index hand slidably but non-rotatably mounted on the threaded end of said rod cooperating with said circle, and a manually operable nut for clamping said hand and circle together; a second rod forming the polar axis shaft of said mounting; a wood housing therefor; means fixedly securing one end of said housing to the housing for said first rod at right angles thereto; a disc, coaxial with said second rod and secured to the housing thereof adjacent the threaded end of said rod, forming the right ascension setting circle for said mounting; an index hand slidably but non-rotatably mounted on the threaded end of said second rod cooperating with said right ascension setting circle, and a manually operable nut for clamping said hand and circle together; trunnions mounting the housing for said second rod between the upright portions of said U-shaped clamp; and manually operable means for clamping said mounting to said bracket.

6. The structure set forth in claim 5 in which said housings are formed of wood.

7. The structure set forth in claim 5 in which the threaded end of the rod forming the declination axis shaft is provided with a weight cooperating therewith and forming and adjustable counter-balance for a telescope when said telescope is secured to the other end of said rod.

8. The structure set forth in claim 4 in which said housings are formed of wood and the threaded end of the rod forming the declination axis shaft is provided with a weight cooperating therewith and forming an adjustable counter-balance for a telescope when said telescope is secured to the other end of said rod.

9. The structure set forth in claim 5 in which the declination setting circle is graduated in degrees in both directions from a zero index line coplanar with the polar axis.

10. The structure set forth in claim 5 in which the right ascension setting circle is divided with twenty four equal parts, indicating hours, from a zero index line in a plane normal to the axis of said trunnions and above the polar axis of said mounting.

References Cited in the file of this patent UNITED STATES PATENTS 583,518 Stoller June 1, 1897 690,008 Berger Dec. 31, 1901 1,852,166 'Kaster Apr. 5, 1932 FOREIGN PATENTS 474,100 Germany Mar. 26, 1929