US 3733720 A
An orrery, being a mechanical model demonstrating movements of planets in their orbits around the sun, comprises a central sun-carrying member, a plurality of annular planet-carrying members nested one within another and individually rotatable about the central member, and a driving mechanism for driving the annular members at different rotational speeds, which mechanism comprises three sets of friction wheels rotatable respectively about three axes which are radial to and spaced apart about the rotational axis of the annular members, wh
Claims available in
Description (OCR text may contain errors)
limited States Patent [191 Byers I ORRERY  Inventor: Edward Victor Byers, l7 Cavendish Crescent, The Park, Nottingham, England  Filed: Jan. 22, 1971 ] Appl. No.: 108,813
 Foreign Application Priority Data Jan, 29, 1970 Great Britain ..4,262/70  US. Cl ..35/45  Int. Cl. ..G09b 27/02  Field 01 Search ..35/45, 47, 43, 46
 References Cited UNITED STATES PATENTS 3,010,224 11/1961 Roberts ..35/45 575,735 1/1897 Reese ..35/45 1,028,355 6/1912 Huff ..35/45 1,952,024 3/1934 Russert ..35/47 3,387,393 6/1968 Musser ..35/45 3,520,073 7/1970 Baader ..35/45 Primary Examiner-Jerome Schnall Attorney-Ernest F. Marmorek  ABSTRACT An orrery, being a mechanical model demonstrating movements of planets in their orbits around the sun, comprises a central sun-carrying member, a plurality of annular planet-carrying members nested one within another and individually rotatable about the central member, and a driving mechanism for driving the annular members at different rotational speeds, which mechanism comprises three sets of friction wheels rotatable respectively about three axes which are radial to and spaced apart about the rotational axis of the annular members, wherein each set consists of a wheel for each annular member, each said wheel engages and supports a circular track on the associated annular member, a plurality of wheels in each set have differing diameters and the tracks for them are concentric and have differing diameters and are disposed at appropriately different levels, andat least one of the sets is driven.
8 Claims, 5 Drawing Figures PATENTEUMAY22 1975 3733 720 SHEET 1 BF 5 PATENTEDMAYZZ m5 3. 733, 720
SHEET 2 [IF 5 PATENTEDMAYZZISYS 3,733,720
SHEET 5 0F 5 1 w Ln ORRERY CROSS- REFERENCE TO RELATED APPLICATION Reference is made to British Patent Application No. 4262/70 of Jan. 29, 1970, Edward Victor Byers, from which priority is claimed.
The present invention provides an orrery comprising a central sun-carrying member, a plurality of annular planet-carrying members nested one within another and individually rotatable about the central member, and a driving mechanism for driving the annular members at different rotational speeds, which mechanism comprises three sets of friction wheels rotatable respectively about three axes which are radial to and spaced apart about the rotational axis of the annular members, wherein each set consists of a wheel for each annular member, each said wheel engages and supports a circular track on the associated annular member, a plurality of wheels in each set have differing diameters and the tracks for them are concentric and have differing diameters and are disposed at appropriately different levels, and at least one of the sets is driven.
In the orrery of the present invention not only are the aforesaid annular members driven by one or more of these sets of friction wheels but they are each supported at three circumferentially spaced points by the wheels which engage the tracks. Moreover, since a plurality of wheels (e.g. some or all) in each set have differing diameters and the tracks which they engage have differing diameters, a plurality of the annular members are driven at differing rotational speeds. It will beunderstood that some or all of the wheels in each set may have differing diameters.
The annular members may be centred by engagement of side faces of flanges of the wheels (or of separate flanges or discs) with circumferential faces on the annular members.
The three sets of wheels may be geared together so that they all take part in the drive to the annular members. In order to gear them together one set may be connected to a gear wheel disposed between and meshing with two gear wheels connected to the other two sets respectively.
, According to an important subsidiary feature of the invention one annular member carries a moon revolvable about its planet as the latter revolves about the sun, and this moon is driven through a friction wheel, carried by said member and connected to the moon, which friction wheel rolls around a stationary circumferential track coaxial with said member.
One of the annular members may be marked on a visible surface to denote asteriods or minor planets.
Each set of wheels may include at least one wheel driven at a reduced speed through reduction gearing.
There may be a transparent dome, above the annular members.
In order that the invention may be better understood a preferred construction of orrery will now be described by way of example with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of the orrery;
FIG. 2 is a similar perspective view but with the dome removed;
FIG. 3 is a perspective view showing the driving mechanism for the annular members;
FIG. 4 is a cross-section through the annular members and showing a representative set of the friction wheels;
FIG. 5 is a sectional view showing mechanism for driving a moon.
This orrery has a bowl-like base 10 within which there is a central upstanding pedestal 11 carrying a pillar 12 which, at its upper end, is provided a socket 13 for an electric lamp bulb to simulate the sun. Electrical leads to the bulb pass up through the pedestal. An annular orifice in the upper surface of the bowl surrounding the pedestal 11 is occupied by a nested set of annular members, the upper surfaces of said members lying substantially in a common horizontal plane. Eight such members, numbered 14 to 21 are shown in FIGS. 1,2 and 4. Said members have a common vertical axis of rotation on which the centre of the sun is disposed. As shown in FIG. 4, the outer margin of each annular member is rebated from its under-side to provide an upper portion of reduced thickness, and in a corresponding manner the inner margin of each outer annular member is rebated from its upper surface to provide a shallow well in which the reduced portion of the next inner member sits.
Each of a plurality of the annular members 14-21 is provided with an upstanding vertical pin which, at its top end, carries a ball representing a planet; the various balls may be differently coloured. They are all located at substantially the same height. Commencing with the smallest member 14, members 14-17 carry balls l4'-l7' representing Mercury, Venus, Earth, Mars; there is then a member 18 carrying on its upper surface markings denoting asteroids, and then two members 19,20 carrying balls 19', 20 representing Jupiter and Saturn respectively, and finally an outer annular member 21, carrying a time scale, frictionally driven by the Saturn member 20.
For convenience, only the ball 16 representing Earth is shown in FIG. 2. This Fig. also illustrates the fact that the pins by which the other balls are carried are detachably fixed on spigots 14a, 15a, 17a 19a and 20a, protruding from the upper surfaces of the respective annular members.
The nest of annular members is supported by, and the various members are driven by, the driving mechanism now to be described with reference to FIGS. 3 and 4.
Within the interior of the bowl 10 there are three radial driving shafts 23, 24 25 equally spaced apart at angles of about the central axis of rotation of said members. The outer ends of said shafts are suitably supported in bearings 26 in the bowl and their inner ends are supported in bearings in the central pedestal 11. Each shaft 23-25 carries a set of friction wheels, one for each annular member except the outer one, some or all of these friction wheels being of differing diameters. The set of friction wheels 26-32 shown in FIG. 4 on the shaft 23 is representative of the identical sets of wheels on shafts 24 and 25. Each annular member, except the outer member 21, is provided at its under-surface with a downwardly-protruding circular rib the undersurface of which forms a circular track resting on one wheel of each of the three sets. These trackforrning ribs are numbered 33-39 in FIG. 4. Since at least some of the wheels in each set are of differing diameters, the ribs of at least some of the annular members are of differing depths so that their tracks are disposed in appropriate horizontal planes to admit engagement with said wheels.
Thus, each annular planet member is supported at three equidistant points, and since at least one of the shafts is driven, each said member is driven at least at one of these points. Preferably, all three shafts are driven so that each annular member is driven at three points.
The drive is taken from a small reversible electric motor 40 housed within the bowl and is applied through reduction gearing 41 to shaft 23 which is coupled to the other two. For this purpose said shaft 23 is extended through the central pedestal 11 and is there provided with a gear 43 which is disposed between and meshes with corresponding gears 44,45 on the inner ends of the other two shafts 24,25. The three meshing gears 4345 may be bevel gears or may be crown wheels each having teeth which protrude from its inner end face. These gears may be moulded form a suitable plastics material, the teeth resembling protruding pegs.
The reduction gearing 41 may be of any suitable form, but preferably the first-mentioned gear 43 has a circular series of teeth protruding from its outer face (as in a crown wheel) and these teeth are engaged by a driving rib of archimedean spiral form on a disc driven by the electric motor. Thus one revolution of this disc moves the gear which it drives through one tooth space.
The two outermost wheels 31,32 in each set, which drive the Jupiter and Saturn members 19,20 are not fastened directly to their shaft (as are the other wheels) but are driven from the shaft through 12 to l a reduction gearing 47 so that the annular members 19,20 with which they are associated are driven ultra slowly. These two wheels 31,32 are carried by a sleeve 48 rotatably surrounding the shaft and driven by the reduction gearing. This reduction gearing 47 may be of any suitable form, but is preferably hypocycloid gearing, and comprises an eccentric on the shaft which eccentric carries a gear prevented from rotation by a torque arm but capable of being moved bodily by the eccentric in a circular path. In this path the gear travels in mesh with an internal gear, having a greater number of teeth (e.g. one more), on the sleeve, the gear ratio being preferably 12 to 1.
In order to centralise the annular members 14-21 the inner or outer peripheral surface of the aforesaid rib of each of them is engaged by a face of a flange associated with the appropriate wheel. These flanges are numbered 26a to 320 in FIG. 4.
One annular member (and specifically member 16) carries a coloured ball 49, representing a moon, which revolves around its planet 16' as the latter travels in a circular path. For this purpose, the vertical pin 16b (FIG. 5) carrying the planet 16 at its top end is surrounded by a rotatable sleeve 50, the top end of which has an arm 51 carrying the moon 49 and the lower end of which extends down through a hole in the annular member 16 and is there provided with a friction wheel 52 which rolls on the outer periphery of a stationary member 53. The lower end of the pin 16b is supported by a bracket 54, below the wheel 52, attached to the underside of the annular member 16.
The stationary member 53 may be a ring, below the annular members, having three depending forks 55 through which the three shafts 23-25 aforesaid extend,
said stationary member 53 thus being supported and positioned by the shafts.
Above the annular members 14-21 and resting on the upper surface of the bowl 10 there is a transparent dome 57 occupying somewhat more than a hemisphere and having its centre substantially coincident with the central sun. This dome is marked at its interior surface with the celestial equator and a pole (e.g. the north pole), the ecliptic, lines of latitude and longitude, and with the stellar constellations and their names. Thus by looking through one side of the dome an observer may see the constellations at the other side of the dome and may read their names. The celestial north pole is offset 23.5 from the vertical axis of rotation of the annular members.
A circumferential surface 58 on the top of bowl 10 outside the base of the dome 57 is graduated in degrees and months, and is also marked with the signs of the Zodiac.
Inside the bowl 10 there are sockets 59 for electric lamp bulbs which latter illuminate the interior of the dome, through suitable apertures in the top of the base within the dome, to give a night sky effect. Suitable manual control knobs 61, 62, 63 are provided at the exterior of the bowl for controlling the direction of rotation of the electric motor, and its speed, and for switching on, alternatively, the sun bulb and the night sky bulbs.
What is claimed is:
1. An orrery comprising a central sun-carrying member, a plurality of annular planet-carrying members concentrically nested one within another and individually rotatable about the central member, each of which has a circular track at its underside said track being concentric and having different diameters, and driving mechanism for driving the annular members about the central member at different rotational speeds which mechanism comprises three sets of friction wheels disposed below the annular members and rotatable respectively about three axes which are radial to and spaced apart in intervals of about about the rotational axis of the annular members, wherein each set of friction wheels comprises a wheel for the sole support of each respective annular member which wheel is in frictional driving and supporting contact with the track of the respective member and wherein the wheels in each set have differing diameters, and means driving at least one of the three sets of wheels.
2. An orrery according to claim 1, having means gearing the three sets of wheels to rotate in unison whereby all three sets take part in the drive to the annular members.
3. An orrery according to claim 2, having two gears connected one to each of two sets and a gear, connected to the other set, disposed between and meshing with said two gears.
4. An orrery according to claim 1, having means for centering the annular members which means comprises circumferential faces on the annular members and flanges, associated with each set of wheels, having side faces engaging said circumferential faces.
5. An orrery according to claim 1 having, in combination with a planet carried by an annular member, a moon carried by that member and revolvable about the planet as the latter revolves about the sun-carrying member, and means for driving said moon to revolve about said planet which means comprises a stationary wheels being fastened to the shaft and at least one other of the wheels being rotatable in relation to the shaft,
and having a reduction gearing driving the last said wheel from the shaft.
8. An orrery according to claim 1, having a transparent dome above the annular members, which dome is marked with the celestialequator and a pole, the ecliptic, lines of latitude and longitude, and with the stellar constellations and their names.