US 2879995 A
Description (OCR text may contain errors)
March 31, 1959 HARRISON lll 2,879,995
MOUNTING OF PLAYGROUND APPLIANCE Filed March 16, 1956 WHHHHWHM H'H m/EA/Tm: LEE HARE/510M122,
United States Patent i 2,879,995 MOUNTING or PLAYGROUND APPLIANCE Lee Harrison nrneueviue, 111.
Application March 16, 1956, Serial No. 571,955
' 1 Claims. (Cl. 272-30 The present invention relates to a mounting for a play ground appliance and for the playground appliance itself. The appliance is in the nature of a merry-go-round, but it has, in addition to the rotary operation, the function of providing a compound rolling undulatory motion.
The appliance consists of a column or base which has a concave'bearing element therein. This bearing device includes-a generally hemispherical socket at its lowest end, aconicalwall surface flaring outwardly from the upper part of the hemispherical socket, and a cylindrical or conical wall surface extending upwardly from the top of the first-conical surface. Into the foregoing concave bearing element there fits a shaft or positive bearing element. It has a spherical portion at its bottom that can bear in the socket portion at the lowest part of the concave part, a conical section above the spherical section which has a lesser angle of flare than the intermediate section on the support, and a top conical or frusto-conical part. The top part is at such an angle as to have line engagement with the top section of the concave bearing element when there is line support between the intermediate section of the shaft and the intermediate conical section of the hearing.
The shaft can support at its top a table or other section upon which persons or other objects can ride or stand, either at the center or at the periphery as the case may be.
There have heretofore been various types of rotary apparatus of this kind, of which the merry-go-round is the most familiar. The present invention, however, differs in that it provides the spherical surface which can take the first part of the load, as will appear, coupled with the two conical. surfaces that have rolling inter-engagement with line contacts. This gives a different kind of a mo tion than that heretofore obtained. But more especially it gives its particular kind of motion with a minimum number of wearing parts, and yet with a minimum of service required for the parts. In the particular design the bearing parts are covered so as to keep out dirt, to keep in lubrication, and especially so as to keep children from getting their arms and legs involved with the bearing parts.
The action of this appliance can greatly aid in the development of muscles and -muscular coordination, as well as in providing exercise. The appliance is safe, yet movable; it is self-contained and self-controlled, durable and yet challenging and interesting to the users. In some sizes it can be made into apparatus like merry-gorounds and see-saws, to be employed in playgrounds. In other sizes it may be made small enough so that the user may stand upon it at the center, and operate it for strengthening ankles and the lower leg muscles. In appropriate size it may be used in rehabilitation centers for its particular value in connection with leg exercising. In miniature sizes it may be used in toys. Particular types of appliances used on the table will vary with the choice of the user, but it is immediately contemplated that seats or grab-bars may be placed on the larger sizes, and foot 2,879,995 Patented Mar. 31, 1959 supports may be used on the smaller sizes, with or without means by which the user may hold himself against falling off the appliance.
In the drawing:
Figure 1 is an elevation of the appliance, broken away somewhat to reduce its height; and
Figure 2 is a diametrical, vertical section through the upper parts of the appliance.
The appliance comprises three main parts: a socket or concave bearing 5, a shaft or convex element 6, and a table or like object support 7.
The lower or concave part 5 of the device may include some appropriate base 8, with a column 9 of suitable character rising therefrom. Needless to say the choice of means to support the bearing parts of this appliance may be varied widely within the skill of those in the art.
At its upper end the column 9 has a socket 10 generally of hemispherical shape, usually with a cylindrical wall rising some distance above the hemispherical portion for a purpose to appear, and also usually with a circular recess or well 11, in the bottom for a purpose to appear.
" Above the socket 10, and flaring outwardly from the an apex.
upper edge of the circular wall, there is a frusto-conicalbearing wall surface 13, here illustrated as having a flaring angle of about 45 degrees. The wall surface 13 is formed from the center of the hemispherical socket 10 as This surface 13 has a base 14, and is surmounted by an additional wall surface 15, that is illustrated as vertical. need to be vertical but for simplicity of manufacture, should not be reentrant towards the top. On the other hand, the circular wall surface 15 should not flare outwardly at a great angle, because it is designed to resist lateral movement of the shaft, as will be described. Above thecylindrical wall surface 15, the bearing element flares downwardly and outwardly in a wall 16, the upper surface of which is made as a portion of a sphere struck about the center of a hemispherical center socket 10.
The shaft or convex portion 6 of the support includes a lowest spherical part 17, that is adapted to' fit and bear in the hemispherical socket 10. An annular recess 18 around the lower part of the spherical part 17, receives a ball bearing 181 that can travel around the well 11. Above the spherical part 17, the shaft is necked-in somewhat at 19, and then is formed with an integral conical part 20 formed with the center of the hemispherical part 18 as an apex, and a base 21. This conical part of the shaft has an angle from the apex which is less than the angle of flare of the socket bearing surface 13, for a purpose to appear. It has a length such that thedistance along it from the apex to the base 21 equals the distance conical section 23 has its base coinciding with the base 21 of the section 20; and it converges upwardly therefrom. The arrangement described is such that, when the spherical part 17 rests in the socket 10, the frusto-conical surfaces 20 and 13, and the circular surfaces 23 and 15 will have line contact.
Above section 23 there is formed a skirt 25 overlying the portion 16. The skirt 25 should at least overlap the portion 16 at all times, so that persons may not get parts of their bodies into movable parts of the support.
The shaft portion also has the table or object support 7 mounted on it. As heretofore noticed, the table 7 may extend outwardly like a merry-go-round so that persons can ride on its periphery; or if the device be of smaller size, the table 7 may be provided with suitable footreceiving parts so that the person may stand upon it.
In using the device it will be set up as illustrated-in This last wall surface 15 does not 3 the drawings. If necessary, lubricants may be supplied into the bearing support socket 5. It will be seen that the upper table and shaft parts 6 and 7 may be lifted off of or placed into the lower socket part 5, with no difficulty.
Normally, the device will fall to one side or the other and so assumes a position as indicated in the drawings, in which there is linecontact in the two conical portions and 23 of the shaft 6 with the corresponding portions 13 and 15 of the socketS, and so that the spherical portion 17 bears in the spherical socket 10. From such position the table 21 may be rotated about its upright center axis. As it is rotated it will track around the inside conical surfaces 13 and 15, with a compound motion somewhat like a planetary. This will cause the table to roll or rotate about its center at the same time its center vertical axis moves in a conical pattern. Consequently, a particular point on the periphery of table 7 will move up and down at the same time it is moving around the vertical axis.
In this operation, the primary vertical load is taken on the surface 13, while the lower spherical parts assume the rest of the vertical load and also act to prevent the device from coming apart. In other words, the peripheral downward load on the lowest part of the table 7 viewed in the plane of Figure 2, tends to rock the bearing about a point somewhere in the conical surfaces 20, and thereby tends to cause the lower spherical part 17 to move upwardly and to theright in the figure. The depth of the socket portion 10, including its upper cylindrical part, is snfficient to prevent this from happening. Therefore, the primary function of the lower spherical part is to keep such lateral forces from causing the table part to separate away from the support part and to do so without adding an objectionable amount of friction or of wearing parts to the appliance.
The upper cylindrical surface 15 also aids in keeping the shaft 6 and table 7 from coming out of the socket 5. Centrifugal or other force components leftward in Figure 2 tend to move the shaft 6 leftward. It is prevented from slipping up the surface 13 and out of the socket by the wall 15 acting against the shaft part 23. That is the reason for making the wall 15 without outward flare. It can converge upwardly, but that adds manufacturing difficulty.
Preferably the table and its assembly is of sufficient weight that when a user tries to mount the upper part of the table the .table will roll around to bring such part down, rather than hopping across, without continuous bearing contact of the conical surface. The ball 181 may be used to limit movement of the table to a rotative movement around the center vertical axis, without direct rocking movement from side to side.
The operation of the device is performed by shifting of weight from one side to the other and can be accomplished by two persons (or more) using a pumping action or by one person standing near the center of the disc and shifting his weight from one side to the other.
. What is claimed is:
1. In an appliance of the kind described; a base having a bearing therein, the bearing having a socket at the lower part that .is in the form of an inverted portion of a sphere with cylindrical walls upstanding from the spherical portion; a frusto-conical wall projecting upwardly and outwardly from the top of the cylindrical wall, an additional circular wall projecting upwardly from the top of the frusto-conical wall; a shaft having a spherically shaped bottom part complementary to the spherical portion of the socket, .a frusto-conical part extending outwardly from the bottom part to the top of the frusto-conica'l wall, the sperical bearing and the sperical shaft bottom being formed about the same center, which center is the apex of the frusto-conical wall and the frusto-conical part of the shaft; the frusto-conical part of the shaft having a smaller base diameter than that of the corresponding bearing wall, so that the former may roll around within the latter; the shaft having an additional circular part above the frusto-conical part that rolls in the additional circular wall projecting upwardly from the frusto-conical wall; and means on the shaft to receive and support an object to ride the appliance. V,
2. The appliance of claim 1, wherein the additional circular part on the shaft has a frusto-conical shape that is inverted with respect to the previously-mentioned frusto-conical part.
3. The appliance of claim 1, wherein the cylindrical wall above the socket extends upwardly to approximately the top of the spherical shaft part, so that the shaft cannot be accidently bounced from the socket, but may be lifted therefrom.
4. The appliance of claim 1, wherein the shaft is necked in adjacent to the junction of the sperical and conical parts, so as to be clear of the hearing at its intersection of the cylindrical and conical walls.
5. The appliance of claim 1, wherein there is a shield on the shaft part that projects outwardly over and downwardly overlies the uppermost part of the base, the shield having a size suflicient to overlie the base all around, at any operating position of the shaft in the bearing.
6. The appliance of claim 1, wherein the socket has a lower circular recess in it, and the spherical shaft part has a smaller circular recess in its bottom part, with a ball bearing in said recesses, the wall of the socket recess bearing on the outer side of the ball bearing and the wall of the recess in the shaft part bearing on the inner side of the ball.
7. In a device of the kind described, a base, a shaft mounted in said base for limited universal movement, said base and shaft having complementary engaging con: cave and convex spherical surfaces, respectively, complementary engaging concave and convex frusto-conical surfaces, concentric with the spherical surfaces respectively, and complementary engaging concave and convex cylindrical surfaces, respectively, the convex surfaces having their frusto-conical and cylindrical surfaces of smaller diameter than the corresponding concave surfaces.
References Cited in the file of this patent UNITED STATES PATENTS