Connective joint with interlocking ring structures adaptable for flux or force transmission

This mechanical joint allows relative rotation of two articles (one may be a stationary fixture), on an arbitrary axis. The joint has as much angular-rotation range as a hinge, but as many degrees of freedom as a ball-and-socket or universal joint. It allows transmission, between the objects, of force or flux (e.g., of electricity, gas, or liquid), or both. In can be used as an applied-force or motion sensor, varying electrical contacts or conductivity in response to relative motion or force applied between the articles. In one form the invention is simply a mechanical joint formed of two closely interlocked toroids. The minor cross-section of each toroid is sized to just fit through the central aperture of the other; there is a connection point on each toroid for attachment of one article. By adjusting closeness of fit, a designer can impart to the device a wide range of desirable frictional properties. In another basic form, the invention has an internal structure of two mutually fixed, interlocked rings or the like. Outer structures, generally ring-shaped, ride on the inner ones. The internal structure may be effectively concealed, but via a common area where they are joined they provide paths for transmitting flux or force between the articles.

BACKGROUND 
1. Field of the Invention 
This invention relates generally to connective mechanical joints; and more 
particularly to a joint that permits relative rotation of the 
interconnected articles--through large angles, and about an axis having 
virtually any arbitrarily selectable orientation. The joint can be adapted 
to transmit a force or a flux between the articles. 
2. Prior Art 
Known connective joints may be considered in three very broad categories: 
the hinge, which provides large-amplitude rotation between two hinged 
elements, but only about a single axis; the ball-and-socket joint, which 
provides rotation about arbitrarily selectable axes, but usually with 
limited range of rotation; and the universal joint, which is in effect a 
two-stage hinge. 
Both large-amplitude rotation and a wide range of rotational axes are 
achieved with a universal joint by combining two hinges in series, 
generally at right angles. The selection of rotational axes is essentially 
arbitrary if rotation is permitted about one or both points of attachment 
of articles to the universal joint--for example, if the articles 
interconnected by the joint are rotatable shafts. 
With a ball joint, rotational range is particularly limited when a fluid 
flux is to be transmitted across the joint--as, for example, in a 
liquid-transmitting joint such as a shower head. 
In two different senses, torque can be transmitted through a hinge or 
universal joint. First, an article attached to one side of the joint can 
be rotated by rotating an article attached to the other side of the 
joint--provided that the rotation is about an axis on which the hinge or 
universal joint is not free. 
(The availability of such an axis for useful purposes depends upon the 
relative orientation of the two sides of the joint. For example, suppose 
that the two articles are drive shafts, but the joint is initially 
operated so that these shafts are mutually at right angles. Now rotation 
of either shaft about its own axis can be transmitted through the joint to 
the other, but of course the resulting rotation of the receiving shaft is 
not about its own axis.) 
Force or torque can also be transmitted through a hinge or universal joint 
in a second sense. For such transmission, a gear or a traction surface is 
provided on an article at one side of the joint, and a suitably mating 
drive gear or traction wheel is provided on an article at the other side 
of the joint. With this arrangement, forcible rotation of the gear or 
wheel results in operation of the joint itself--i.e., change of the 
relative angle (or angles) at which the two articles are joined. 
In the prior art, it has not been readily feasible to interconnect articles 
for rotation through large angles about a virtually arbitrary axis, using 
a single-stage joint. Such connection has been particularly awkward with 
transmission of force or a flux across the joint. 
SUMMARY OF THE DISCLOSURE 
By way of introduction, the present invention in its simplest forms may be 
very roughly conceptualized as a particularly efficient single-stage 
hinge, in which there is no separate hinge pin as such. Instead, each side 
element of the hinge can itself serve as the hinge pin, entering or 
leaving this role at the pleasure of the user. 
Even though this "hinge" has only one stage, its two sides or elements 
pivot about different axes, thereby permitting operation of the hinge 
about virtually any axis the user selects. Consequently this single-stage 
hinge is free to rotate in as many different directions, roughly speaking, 
as a universal joint. Furthermore, being a hinge rather than a ball joint, 
it operates through a very wide angular range. 
Alternatively, and curiously, the invention can be very roughly 
conceptualized as a hinge in which everything except the hinge pin has 
been eliminated--but there are two hinge pins, each rolled or wrapped 
around the other in an endless ring, to permit operation of the hinge in 
virtually any direction. 
These informal conceptualizations of my invention may seem contradictory 
and slightly baffling, but as will shortly be clear both of them are 
reasonably accurate. I shall now present some more-rigorous definitions of 
the invention. 
In one basic form, my invention is a connective joint providing a 
rotational component of relative motion of two articles, about an axis 
having any arbitrarily selectable orientation. This form of the invention 
includes two interlocking toroids. 
In this form of my invention, each of the toroids has a substantially 
circular minor cross-section and a substantially circular central 
aperture. The minor cross-section of each toroid is sized to substantially 
just fit through the central aperture of the other toroid. 
This first basic form of my invention also has, on each toroid, some means 
for securing that toroid to a respective one of the two articles. For 
purposes of generality of description, I shall call these means the 
"connection means." 
The preceding three paragraphs may constitute a description of my invention 
in its broadest or most general form. There are, however, certain 
additional features or characteristics which I prefer to incorporate in 
articles made according to my invention, for most complete development and 
enjoyment of its inherent advantages. 
For example, I consider it preferable to make the sizing tight enough to 
provide significant frictional resistance to relative motion of the two 
articles. I also prefer to locate the connection means on each toroid at a 
point substantially along the outer major periphery of that toroid. 
As a matter of personal preference I consider the appearance of the joint 
particularly pleasing if the minor cross-sections of the two toroids are 
made substantially equal to one another in diameter. For some 
applications, as will be appreciated by those skilled in the art, this 
condition will also be preferable for mechanical strength or other 
practical properties. 
On the other hand, for the sake of variety in some applications the joint 
may be made with the minor cross-sections of the two toroids different. 
For some applications such a construction may also be preferable in 
practical terms. 
It will be understood that either of such articles may be a substantially 
stationary fixture--such as a wall, an article of furniture, or an 
appliance pedestal (such as, for example, a lamp base). In that event, the 
connection means on one of the toroids are secured to the stationary 
article. 
On the other hand, one or both of the articles may be embedded within or 
fixed as a thin sheathing or jacketing upon one or both of the toroids 
respectively. In such cases the connection means are of course adapted for 
connection of such articles; they may not necessarily appear as discrete 
features in or on the toroids. 
I shall now describe another basic form of my invention. It is a connective 
joint providing a rotational component of relative motion of two articles, 
about an axis having an arbitrarily selectable orientation. 
This form of my invention includes two interlocking toroids, each having a 
substantially circular minor cross-section and a substantially circular 
central aperture. The minor cross-section of each toroid is small enough 
to fit through the central aperture of the other toroid--but in this form 
of my invention it is not required that they fit closely. 
Instead this form of my invention includes some means for securing the two 
toroids together, for mutual arcuate motion. 
Finally this form of the invention includes, on each toroid, connection 
means for securing that toroid to one of the two articles respectively. 
This second basic form of my invention may be described in its most general 
terms by the foregoing paragraphs. Once more, however, I prefer to 
incorporate various features or characteristics to optimize effectiveness 
and enjoyment of the invention. 
In particular, I prefer to provide the mutual-securing means in the form of 
an annular track or groove defined along the inner periphery of the 
central aperture in a particular one of the two toroids, and an inner ring 
movably disposed within this groove. 
These preferred elements of the securing means may be described in a more 
general way as: an arcuate guide member, and a corresponding follower 
member, adapted and disposed to ride along the corresponding guide to 
define an arcuate motion of the follower relative to the guide. Various 
forms of guide and follower member may be provided other than an annular 
track or groove and an inner ring. 
In particular, it is not necessary to use a complete ring or complete 
track. A partial ring or partial track, or both a partial ring and a 
partial track, may be provided within the scope of this form of my 
invention. 
Only enough mutually constraining structure is required to provide the 
desired mutually arcuate motion. For example, it will be clear to skilled 
mechanical artisans that a great variety of three-point-contact 
guide-and-follower sets--merely to state one of myriad possible 
examples--may be substituted beneficially for a complete ring and track. 
Furthermore, it is not necessary that the toroid actually ride on the inner 
guide structure, in the sense suggested by the simplified track (or 
groove) and ring conceptualization. That is, it is not necessary that the 
outer structure have an inner track (such as a groove) that rides on an 
inner ring. Rather, the track (or groove) may be associated with the inner 
structure, while the ring equivalent may be associated with the toroid. 
This second form of my invention can further be used in transmitting a 
force or flux between the two toroids. As will be seen, forces or fluid or 
electrical fluxes, or combinations of two or more such fluxes or forces, 
can be transmitted between the two toroids while preserving the relative 
mobility and--if desired--the independent appearance of the toroids. 
To realize this potentiality, I also prefer to include some means for 
transmitting a force or a flux along a generally circular path within the 
particular toroid having the inner elements just discussed. I shall call 
these means the "intratoroid transmitting means", since they transmit 
force or flux within the particular one toroid. 
These means preferably make use of the inner-peripheral 
track-and-groove--or, more generally, the guide-and-follower set, just 
discussed. The generally circular path is associated with these inner 
elements. In other words, the same inner elements are advantageously used 
both to provide relative mechanical suspension of the two toroids, and to 
transmit force or flux along a path within at least one of the toroids. 
As will become clear, two separate sets of inner elements within the toroid 
can be provided for these two functions respectively. I prefer to use one 
set within the toroid for both functions. 
This form of my invention also includes some means for transmitting the 
force or flux from the above-described path to the other toroid. Again for 
generality I shall call these the intertoroid transmission means, as they 
transmit force or flux between two toroids. 
I show and describe several such preferred features, as well as certain 
variants or versions of this second basic form of my invention, in the 
detailed-description section of this document. First, however, I wish to 
introduce yet another basic form of my invention. 
This third form of the invention is a connective joint providing a 
rotational component of relative motion of two articles. 
It includes a pair of interlocked inner rings. The two rings are fixed 
together at a common area along the inner peripheries of both rings. 
This form of the invention also includes two interlocked outer structures. 
Each of these outer structures has a very generally arched body 
surrounding a very generally central aperture. 
Each of the outer structures also has a peripheral track about its central 
aperture. Each outer structure is movably mounted by this track to ride on 
a respective one of the rings. In other words, the rings and tracks are 
mutually engaged, so that each outer structure is movably mounted to the 
corresponding ring. 
This configuration constrains the interlocked outer structures to mutually 
arcuate compound trajectories. That is, the inner rings constrain the two 
outer structures to move along arc-shaped paths relative to one another. 
If desired, one or each of the tracks may take the form of a groove around 
the periphery of the central aperture of the corresponding outer 
structure. In this version of this form of the invention, the ring simply 
fits in the groove, so that the outer structure rides on the ring. 
More elaborately formed or engaged tracks and rings may be provided, as 
will be further detailed shortly. Bearings may be interposed if desired 
for smoother operation. 
In describing the mutually arcuate trajectories of the outer structures, I 
have included the term "compound" for a very important reason. The 
possible trajectory or path for each of the outer structures is not 
limited to only one arcuate motion such as a simple rotation or revolution 
about the other outer structure. 
Rather the motion of each outer structure may include, in effect, travel or 
displacement along the contour of the other outer structure. Rotation or 
revolution may be alternated, or may even be concurrent, with such travel 
or displacement. 
Therefore very elaborate mutually arcuate compound trajectories are 
possible. This is so even though, as already mentioned, the inner rings 
are solidly joined. 
The body of each outer structure is small enough to fit through the central 
aperture of the other outer structure--in at least part of their 
trajectories. It need not fit through the central aperture of the other 
outer structure in all of their trajectories. 
Details of the outer structures may be selected essentially arbitrarily, 
either for practical reasons or for esthetic reasons such as implementing 
a particular theme. Accordingly it may be very desirable to make some 
parts of one or each outer structure too large to fit through the central 
aperture of the other structure. 
For example, one of the outer structures might be configured to represent 
the body of an animal, passing through the central aperture of the other 
structure. The head or perhaps certain limbs of the animal figure might 
extend laterally too far to pass through that aperture. 
This third form of my invention also includes connection means on each 
structure. The connection means on each outer structure are provided for 
securing that particular structure to one of the two articles 
respectively. 
Like the previously discussed second form of my invention, the third form 
is also capable of use for transmitting a force or a flux between the 
articles. To develop this capability, I prefer to include in this third 
form of my invention some means for transmitting force or flux along paths 
within the outer structures. 
These paths are generally circular, and each is associated with one 
respective inner ring. For generality as before I call these means 
"intrastructure transmitting means." 
In addition this form of my invention includes some means for transmitting 
the force or flux from the path associated with one ring to the path 
associated with the other ring. I call these means "interstructure 
transmitting means"; they are defined adjacent to or through the common 
area at which the rings are joined. 
To aid in comprehension initially, the foregoing description of the third 
form of my invention has been stated with somewhat specific reference to 
inner .-+.rings"that are fixed to one another, and "tracks"that ride on 
the rings. Like the second form of my invention, however, this third form 
is actually much broader than might be supposed from this description. 
In particular, partial rings or partial tracks, or both, may be provided. 
Only enough mutually constraining structure is required to provide the 
desired mutually arcuate compound trajectories, various types of 
guide-and-follower sets being substitutable for complete rings and tracks. 
Furthermore, as with the second form of my invention, it is not necessary 
that the outer structures actually ride on the inner guide structures. 
For these reasons a more general description of the third form of my 
invention will now be presented. This form of the invention is a 
connective joint that provides a rotational component of relative motion 
of two articles. 
It includes a pair of guide-and-follower sets. Each set includes an arcuate 
guide member and a corresponding follower member. The follower member is 
adapted and disposed to ride along the corresponding guide to define an 
arcuate motion of the follower relative to the guide. 
One particular member of each set has an inner periphery. The two 
particular members of each set are fixed together at a common area along 
the inner peripheries of both particular members. By virtue of this 
configuration the remaining two members are constrained to mutually 
arcuate compound trajectories. 
This form of the invention also includes two interlocked outer structures, 
each having a very generally arched body surrounding a very generally 
central aperture. Each of the two outer structures is fixed to one of the 
"remaining two members" just mentioned. Due to this configuration, the 
interlocked outer structures are likewise constrained to mutually arcuate 
compound trajectories. 
The body of each outer structures is small enough to fit through the 
central aperture of the other--in at least part of the trajectories of the 
outer structures. 
The invention, in the form now under consideration, also has connection 
means on each outer structure for securing that structure to one of the 
two articles respectively. 
The foregoing description of the third form of my invention, presented now 
more generally, is able to function as a connective joint. Its mechanical 
function as a joint is in effect essentially the same as that of the 
first-mentioned form of my invention, consisting of closely interlocked 
toroids. 
This form of the invention is also useful for transmitting a force or a 
flux between the outer structures, and even between the respectively 
attached articles. When so used, this form of the invention includes some 
means for transmitting force or flux along two generally circular paths 
within the outer structures respectively. 
I shall call these means the "intrastructure transmitting means". Each of 
the two paths is associated with one respective guide-and-follower set. 
This form of my invention further includes some means for transmitting 
force or flux from the path associated with one guide-and-follower set to 
the path associated with the other set. These means, which will be called 
"interstructure transmitting means", are defined adjacent to or through 
the common area at which the previously mentioned "two particular members" 
are joined together. 
This third form thus has the added capability of force or flux transmission 
between the outer structures. In some cases such transmission can be 
provided between the two attached articles secured at the respective 
connection means. 
If desired, the parts of the invention can be formed to nearly conceal the 
existence of the inner guide-and-follower sets, so that the transmission 
capability of the assembled invention appears very extraordinary. A casual 
observer will not perceive how a device having so many degrees of freedom 
could, for example, conduct fluids or electricity in a circuit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The basic appearance of certain preferred embodiments of my invention is 
illustrated in FIGS. 1 through 1c. This embodiment may be simply a 
mechanical joint used for purposes of adjustable positioning, or as 
explained below it may be provided with internal elements for flux or 
force transmission. 
The joint includes two toroids or "doughnut"-shaped parts 21 and 31 which 
interlock. In the illustrations, one toroid 21 is drawn to appear 
horizontal, and for definiteness of the following discussions will be 
called the "horizontal toroid"; the other toroid 31 will be called the 
"vertical toroid". 
On each toroid is a connection part, 11 and 41 respectively, for attachment 
of articles to the joint. For clarity in illustrating the relative 
orientation of the two toroids, the connection parts 11 and 41 have been 
shown as projecting small cylinders. The illustrated connection elements 
11 and 41 are fixed along the outer peripheries of the respective toroids 
21 and 31, and project radially outward. 
As mentioned earlier, however, even the attached articles themselves may be 
embedded or surface elements. Hence the connection parts can take a great 
variety of different forms, including recesses, tapped or detented holes, 
or surface-attachment areas. 
As shown in FIG. 2, each toroid 21 or 31 has a respective circular central 
aperture 26 or 36. The body of each toroid is circular in cross-section, 
and preferably for most purposes the figures are substantially 
geometrically regular. 
In particular, each toroid body is substantially uniform in size all the 
way around. Thus in FIG. 2 the diameter D of the body of the horizontal 
toroid 21 as seen (in cross-section) at the far right side of the drawing 
is equal to the diameter B of the body of the same toroid 21 as seen 
(likewise in cross-section) nearer to the left side of the drawing. 
Similarly the diameter A of the body of the vertical toroid 31 as seen (in 
elevation) at the far left side of FIG. 2 is equal to the diameter C of 
the body of the same toroid 31 (likewise in elevation) nearer to the right 
side of the drawing. 
For most purposes the body of each toroid is preferably sized to just fit 
through the central aperture of the other--and allow relative motion with 
some desired amount of freedom. As a practical matter the relative sizes 
may vary from a press fit to a substantial clearance. 
The precise size relationships chosen will vary with the frictional 
characteristics of the two surfaces involved (which may vary from 
Teflon.RTM. through Velcro.RTM.), the resiliencies of the two toroidal 
bodies, the weights and orientations of article(s) to be suspended, 
whether stabilization is otherwise provided, and generally the purpose or 
application of the joint. 
In other words, the minor diameter of each toroid is very nearly the same 
size as the diameter of the central aperture of the other toroid. By 
"minor diameter" I mean the diameter as measured across the small 
dimension of the body. 
The toroids 21 and 31 shown in FIGS. 1 through 2 are substantially the same 
size--both in major and minor dimensions. Thus in FIG. 2 the minor 
diameter A or C or the vertical toroid 31 is equal to the minor diameter B 
or D of the horizontal toroid 21. 
Accordingly, for the toroids in FIGS. 1 through 2, the major diameters are 
also equal. That is, the major diameter A+B+C of the vertical toroid 31 is 
equal to the major diameter B+C+D of the horizontal toroid 21. 
As demonstrated in FIG. 3, however, my invention can be made and used 
without observing these equalities. The horizontal toroid 121 of FIG. 3 
has a much smaller diameter than the vertical toroid 131. 
Nevertheless, as in the equal-toroid case for the first form of my 
invention, the central aperture of each toroid must approximately match 
the minor diameter of the other. Consequently, for the vertical toroid 
131, the central-aperture diameter is much smaller than the minor 
diameter; but the opposite is true of the horizontal toroid 121. 
In any of these constructions, each toroid can shift relative to the other, 
in two different kinds of motion. First, as suggested by the double-headed 
vertical arrow 51 (FIG. 1), the horizontal toroid 21 can rotate vertically 
about the major axis of the other toroid--the vertical toroid 31. 
(By the major axis I mean the straight line 38 that passes through the 
center of the aperture--the "doughnut hole"--in the vertical toroid 31, at 
right angles to the central plane of that toroid. Tangent to this major 
axis of the vertical toroid 31 is the minor axis of the horizontal toroid 
21, which is the circular centerline of the endless body that constitutes 
the toroid 21. Regardless of orientation of the two toroids, the major 
axis of each is always tangent to the minor axis of the other, at some 
point along that minor axis.) 
When so rotated about the major axis of the vertical toroid 31, the 
horizontal toroid 21 is also rotating about its own minor axis, at the 
point of tangency between those two axes. It seems natural to think of the 
horizontal toroid 21 in this mode of rotation as traveling along the body 
or the arch of the vertical toroid 31. 
As stated above, however, a second kind of motion is also available. As 
suggested by the rotation of the double-headed horizontal arrow 52, the 
horizontal toroid 21 can rotate about its own major axis 28 (FIG. 1a). 
That axis is tangent to the minor axis 37 of the vertical toroid 31, also 
at the point of rotation. It seems natural to think of the horizontal 
toroid 21 in this mode of rotation as circling around the body of the 
vertical toroid 31. 
The reason for describing these geometrical relationships in such detail is 
to show that the two axes of rotation available for the horizontal toroid 
21 are mutually offset. The distance between them is equal to the radius 
of the circular minor axis of the toroid that is being considered 
stationary for purposes of this discussion --that is, the vertical toroid 
31. 
From these observations it will be understood that this joint provides as 
many degrees of freedom as a ball joint or a universal joint. The kind of 
motion provided, however, is unlike the relative motions available with 
prior joints. 
More specifically, a ball joint generally speaking provides rotation about 
the center of the entire joint system. A universal joint may be designed 
to provide rotations in orthogonal directions about mutually offset axes, 
but the usual design effort is to avoid such an offset so that the U-joint 
behaves as much as possible like a ball joint. 
My interlocked-toroid joint intrinsically provides rotation about offset 
orthogonal axes. Neither axis is at the center of the joint system--which 
will be found at a common surface point along the inner peripheries of the 
central apertures of the two toroids. 
It will be understood that if the horizontal toroid 21 is rotated about its 
own minor axis, in either direction indicated by the vertical arrow 51, 
this toroid 21 will no longer be horizontal. It will still, however, be 
capable of rotation about the minor axis of the other toroid, in either 
direction indicated by the horizontal arrow 52. 
In general, the only limitation on angular range of action for each toroid 
is imposed by impingement of the connection element of each toroid upon 
the exterior surface of the other toroid. (This consideration is in fact a 
limiting one only if the connection elements 11, 41 do in fact project 
from the toroid surfaces 21, 31. As earlier pointed out, my invention can 
be effectively constructed and used in other forms.) 
For example, as shown in FIG. 4, the connection element 41 of the vertical 
toroid 31 can be rotated counterclockwise (as drawn) to its indicated 
position hard against the lower surface of the horizontal toroid 21. This 
condition represents one end of the range of motion for that toroid 31. 
The same connection element 41 can also be rotated clockwise against the 
upper surface of the horizontal toroid 21, to its position indicated at 
41', to establish the other end of the range of motion. 
The range of angular motion for each toroid relative to the other 
approaches roughly 331.degree. for negligibly slender connection rods 11, 
41; or roughly 317.degree. for connection rods about half the minor 
diameter of the toroids. Those skilled in the art of mechanical devices 
will appreciate that this is far larger than available with a practical 
ball joint. 
Excepting extreme positions such as shown in FIG. 4, when either toroid is 
held fixed the other can be moved to nearly any orientation. For example, 
if as shown in FIG. 5 the connection element 41 of the vertical toroid 31 
is fixed--as to a wall or floor 61--the connection element 11 of the 
horizontal toroid 21 can be moved through compound arcuate trajectories to 
point in almost any direction. The relative orientation of the two toroids 
in FIG. 5 is intended to represent such substantially arbitrary 
positioning. 
With the toroids so oriented, the connection element 11 can in general then 
be repositioned in virtually any direction, as suggested by the arrows 55 
of FIG. 5. The joint thus provides great freedom of angular orientation. 
If the connection element 11 of the horizontal toroid 21 is held fixed, 
conversely, the connection element of the vertical toroid 31 can be 
pointed in nearly any direction. Such reorientation is possible using the 
same two kinds of rotation as already described for the horizontal toroid 
21. 
That is, the vertical toroid 31 is free to rotate vertically or 
horizontally, or both. Vertical rotation about its own horizontal major 
axis 38 (FIG. 1c), as shown by the two-headed arrow 54 (FIG. 1), carries 
the connecting element 41 to other vertical positions 41'. Horizontal 
rotation about its own circular minor axis 37 is shown by the two-headed 
arrow 53. 
As a matter of abstract geometry, rotating either toroid about its own 
major axis is equivalent to rotating the other toroid about its own minor 
axis. Hence in pure principle there are not four but only two kinds of 
motion. In practice, however, the implications of these two motions may be 
vary greatly, depending on which (if either) side of the joint is held 
fixed and which is movable on the other. 
In addition it is possible to leave one or both of the connection elements 
11 and 41 free to rotate about their own axes, at their points of 
attachment with the respective toroids 21 and 31--or at their points of 
attachment with articles which they secure to the toroids. Additional 
degrees of freedom of the joint can thereby be provided, in applications 
for which such additional mobility is appropriate. 
If desired the joint may be provided with stabilization devices such a 
set-screw 271 (FIG. 6) that passes through a threaded hole 272 in one 
toroid 221 and into or against the other toroid 231. If preferred for 
greater force and reliability in stabilization, a second set-screw 273 can 
be similarly mounted in the other toroid 231 for action against the first 
toroid 221. 
Other types of stabilization devices may be used instead. Alternatively, 
the sizes and surface properties of the toroids can be designed to provide 
adequate stabilization for many intended uses without set-screws or other 
accessory stabilizers. 
The mechanical joint thus provided is useful in a great many practical 
applications. FIG. 7 shows two interlocked toroids 1121 and 1131 used to 
support a camera 1191 or the like. A connection element 1111 links one 
toroid 1121 to a tripod head 1118 or the like, and another connection 
element 1141 links the other toroid 1131 to the camera 1191. 
Additional capabilities can be provided the interlocked-toroid system by 
inner rings or other inner guide-and-follower structures as shown in FIGS. 
8 through 25b. If desired, such inner structures may also, or instead, be 
used to remove some of the mechanical limitations on the relatively simple 
system described so far. 
For example, with inner structures it becomes possible to eliminate the 
requirement that the minor cross-section of each toroid make a fairly 
close fit through the central aperture of the other toroid. Very large 
clearances may be employed, so that one toroid appears suspended within 
the other. 
It is also possible to depart from uniformity of dimensions of the outer 
structures, and even from the condition that they be toroids generally. 
Virtually arbitrary outer shapes may be employed, within the scope of 
certain of my appended claims. 
Probably the most interesting change introduced by such inner structures, 
however, is the addition of ability to transmit forces or fluxes. Such 
transmission can be from an article connected to one toroid to an article 
connected to the other, through both toroids--or if desired for particular 
applications can be only through part of this series of objects. 
If desired, such transmission can be provided in addition to the use of 
very large clearances between the toroids, and in addition to the use of 
arbitrary shapes. If preferred, however, force or flux transmission can be 
provided using the geometry already introduced in connection with FIGS. 1 
through 7. 
FIGS. 8 through 13 illustrate toroidal outer structures 421 and 431 fitted 
with respective joined-ring inner structures 481 and 491. These particular 
inner rings 481, 491 are adapted to conduct electrical fluxes or currents 
on two generally parallel conductors, to provide a complete "round trip" 
electrical circuit. 
The rings 481 and 491, like the toroids 421 and 431, are interlocked. 
Unlike the toroids, however, the rings 481 and 491 are also firmly fixed 
to one another, forming a permanent one-piece, solid inner structure. 
The rings are joined at a common area 489 along the inner peripheries of 
both rings. As shown, they are at right angles: this condition is 
necessary if the toroids 421, 431 fit closely together, but is optional if 
there is to be considerable clearance between the toroids. 
A groove 432 (FIG. 10) is formed along the inner periphery 436 of one 
toroid 431; and preferably a like groove (not illustrated) is provided in 
the other toroid 441. The rings 481, 491 fit within these grooves, so that 
the inside surfaces of the grooves ride on the internal rings. 
For closely fitted toroids, when all the pieces are assembled in this way 
the rings are substantially concealed deep within the central apertures of 
the toroids, so that a casual observer will be unaware that there is any 
inner structure. Even for toroids that have considerable clearance, the 
rings and grooves can be made very inconspicuous. 
The inner rings 481, 491 here shown are of plastic, ceramic or other 
insulating material. They are provided, however, with respective annular 
metal or other conductive surfaces 482, 492. These annular conductors are 
disposed along pathways defined along or near the peripheries of the rings 
481, 491. 
The conductors 482 on one ring 481 are interconnected with the conductors 
492 on the other ring 491, by bridging conductors 499. The bridging 
conductors pass through or immediately adjacent to the common joinder area 
489. 
The previously mentioned groove 432 in one toroid 431 is also fitted 
internally with electrical brushes 443 (FIG. 12), disposed to engage and 
make electrical contact with the conductive surfaces 492 on the ring 491. 
These brushes 443 are connected by wires or other suitable electrical 
conductors 444 that pass through the body of the toroid 431. 
The latter conductors 444 are continuous with like conductors 442 that pass 
through the connecting element 441 and to an article that is attached to 
that connecting element. That article typically will provide either a 
source of electrical power or signals, or a device that uses such power or 
signals, or both. 
Similarly the unillustrated inner groove in the other toroid 421 also has 
electrical brushes 413 (FIGS. 12 and, showing greater detail, FIG. 13) to 
engage and make contact with the conductors 482 on the corresponding ring 
481. These latter brushes 413 are connected by wires 414 or the like 
through the body of the toroid 421, to wiring 412 in the corresponding 
connecting means 411--and thence to an article attached to that connector. 
The article just mentioned will typically provide a usage or source of 
electricity that complements the source or usage provided by the 
first-mentioned article on the other side of the joint. For instance, if 
the joint is used in a table lamp as in FIG. 14, the connecting element 
1211 of one toroid 1221 receives electrical power from the lamp base 1261 
and arm 1218. 
The connecting element 1241 of the other toroid 1231 passes the power on to 
the socket and bulb in the lamp head 1291, through an extension arm 1248. 
The base 1261, of course, must be suitably wired to an electrical source. 
Another type of lamp is shown in FIG. 15. In this example one toroid 1321 
draws power through its connection means 1311 from a wall bracket 1318, 
which is fixed to a wall 1361. The lamp head 1391 receives this power from 
the first toroid 1321, through the second toroid 1331, and the connection 
means (not shown) on that second toroid. 
Again, the bracket 1318 is wired to a power source (not shown) within the 
wall 1361. This view may also be taken as an illustration of track 
lighting, with substitution of a sliding bracket at 1318 and mating track 
at 1361. 
As can be seen in FIGS. 8 through 10, and FIGS. 12 and 13, the rings 481, 
491 in effect complete the inner peripheral shapes of the toroids 421, 431 
respectively. The rings might be regarded as sealing the internal cavities 
formed by the grooves. In fact it is not necessary to provide actual 
fluid-tight seals, since in the applications illustrated in these figures 
there is normally nothing to escape from or into the interior cavities. 
Nevertheless these interior tunnels do suggest a potential for conveying 
other kinds of flux--in particular, fluxes of liquid or gas--along the 
circumferential paths formed within the toroids. 
In fact fluid fluxes can be transmitted along such paths, and in and out of 
the toroids through the external connectors and the bridging points where 
the toroids are joined. A geometry particularly adapted for such 
applications appears in FIGS. 16 through 18. 
Here each inner ring is made in the form of a half-tube 581 or 591. Each 
inner ring defines the inner half of a hollow toroidal tube, sealed to a 
respective outer half-tube 521 or 531. 
The seals are made so that each outer half-tube can slide along the 
outward-facing rims or edges of the mating inner half-tube. They do so 
while maintaining the fluid-tight integrity of the inner cavities 582 and 
592 formed between the respective pairs of half-tubes. 
As in the versions of my invention illustrated earlier, the two inner 
half-tubes are joined at their common area 589--along the inner 
peripheries of both central apertures. A fluid-conveying hole 599 is 
defined at this junction area 589, providing fluid communication between 
the interior cavities of the two toroids. 
The connection elements 511 and 541 are also made hollow, and in 
communication with the respective toroidal cavities 582 and 592. Hence 
fluid communication is established from one connection element 511, 
through the two toroidal cavities 582 and 592 and the interconnecting hole 
599, to the other connection element 541--all as diagrammed in FIG. 17. 
If necessary or desired to minimize leakage, the walls of the half-tubes 
can be made thicker as suggested in FIG. 18, and can be configured--as 
there illustrated at 622--to provide a longer pathlength for leakage. 
Alternatively, or in addition, the joint may be provided with separate 
elastomeric seals (not shown) or the like. 
One simple application of these fluid-transmitting joints appears in FIG. 
19. One toroid 1421 receives water through an input connection element 
1411, from suitable piping within a wall 1461. Another toroid 1431 
receives the same water from the first toroid 1421, in the manner 
illustrated in FIGS. 16 through 18, and passes the water on through an 
outlet connection element 1442 to a dispensing element such as a shower 
head 1491. 
Through study of the drawings discussed so far it can be verified that 
nothing prevents superimposing the electrically conductive features of 
FIGS. 8 through 13 upon the fluid-conducting structures of FIGS. 16 
through 18. Similarly it is possible to provide dual or even triple 
discrete fluid conduits within the joint, by segmenting the toroidal 
cavities longitudinally and providing separate intertoroidal 
fluid-communicating holes for the discrete dual or triple conduits. 
Therefore both plural electrical circuits and plural fluids can be conveyed 
through a single joint as required for various applications. Again, this 
can be accomplished while preserving the mechanical mobility of the joint 
substantially as described above in connection with FIGS. 1 through 7. 
Mechanical forces can also be transmitted through the novel joint of my 
invention. As mentioned earlier, the concept of force transmission through 
a joint has two senses or meanings. 
First, suppose that the connection elements 11 and 41 of FIG. 1 are firmly 
fixed to their respective toroids 21 and 31. Suppose also that the toroids 
are oriented so that the connection elements are at least close to mutual 
alignment--as they are drawn in FIG. 1. Then, as will be clear from that 
illustration, rotating either connection element 11 or 41 about its own 
axis will result in similarly rotating the other connection element 11 or 
41. 
Another kind of mechanical force transmission through the joint, however, 
is more difficult to accomplish and correspondingly more interesting. In 
this second type of force transmission, the joint is an active element in 
reorienting itself. 
In all of the uses discussed above, the joint is merely passive. Forces are 
applied externally--e.g., manually--to reorient articles at the two sides 
of the joint. 
In all those previously discussed applications, the joint itself does no 
more than (1) permit motion in response to such forces, to place the 
articles in desired orientations and positions; and (2) frictionally hold 
the articles in approximately the positions and orientations in which they 
were placed. Now I wish to show that the joint can be made self-adjusting. 
FIG. 20 illustrates a version of my invention that provides that 
capability. Once again the toroids 721 and 731 are provided, around the 
peripheries of their central apertures, with internal grooves; and 
internal rings 781 and 791 respectively are fitted within these grooves. 
Once again the internal rings 781 and 791 are mutually interlocked, and are 
mutually fixed at a common area 788 along the inner peripheries of both 
rings. Now, however, instead of electricity- or fluid-conducting surfaces 
the rings 781 and 791 are provided with force-transmitting surfaces 782 
and 792 respectively. 
The force-transmitting surfaces 782 and 792 are thus defined along very 
generally circular paths within the respective toroids. Disposed in 
respective engagement with these surfaces 782 and 792 are mating 
force-transmitting elements 713 and 743. 
These elements 713 and 743 are mounted for rotation in the respective 
toroidal bodies 721 and 731. Although the force-transmitting elements 713 
and 743 are free to rotate about their own axes, those axes are fixed in 
position along the endless toroidal bodies 721, 731. 
The force-transmitting elements 713 and 743 are so shaped, and are engaged 
with the force-transmitting surfaces 782 and 792 in such a way, that when 
the elements 713 and 743 rotate they force the force-transmitting surfaces 
782 and 792 to move relative to the rotational-axis locations. In other 
words, the force-transmitting surfaces 782 and 792 are forced to move 
within the grooves in the toroidal bodies 721 and 731. 
Such motion of the surfaces 782 and 792 of course requires motion of the 
inner rings 781 and 791 along which the force-transmitting surfaces are 
defined. Consequently the inner rings 781 and 791 rotate relative to the 
toroids 721, and 731. 
Connection elements 711 and 741 are provided on the toroids 721 and 731, at 
the fixed positions desired for the rotational axes of the 
force-transmitting elements 713 and 743. Motor casings 756 and 757 are 
fixed to the connection points 711, 741, and the driveshafts 712 and 742 
of the motors are journalled through the bodies of the toroids 721 and 
731. 
The ends of these driveshafts remote from their motors are fixed to the 
force-transmitting elements 713 and 743 in such a way that operation of 
the motors rotates the force-transmitting elements, resulting as 
previously mentioned in motion of the inner rings 781 and 791 relative to 
the toroidal bodies 721 and 731 respectively. 
For greatest strength and transmission of relatively large forces, the 
force-transmitting surfaces 782 and 792 may be annular gear teeth defined 
in the rings 781 and 791. The force-transmitting elements 713 and 743, 
naturally, are then pinion gears adapted to drive the gear teeth 782 and 
792. 
Various sorts of gears may be employed, including the bevel ring gears 782, 
792 and matching conical pinions 713, 743 illustrated in FIG. 20. Straight 
and even helical drive gears may be substituted for various purposes, with 
appropriate reconfiguration of the ring gears. 
The selection of particular gearing forms should be appropriate to the 
different force levels, speeds, and other details of each application at 
hand. Suitable selection and design criteria for such gearing will be 
clear to those skilled in the art of mechanical design. 
As will also be clear to such skilled artisans, it is not necessary to use 
gears at all. Rather, for some applications, a traction surface may be 
substituted for either or both of the gear sets 782 and 792; and mating 
drive wheels maybe substituted for either or both of the pinions 713 and 
743. 
Suitable materials for both the traction surface at 782 or 792 and the 
drive wheels at 713 or 743 may include elastomers with various degrees of 
resiliency and tack. Generally smoother operation and finer adjustment 
increments will be available with such systems, though for relatively 
lower levels of transmitted force. 
The motors 756 and 757 may be entirely concealed within the connection 
points 711, 741 or even within the toroidal bodies 721, 731; or they may 
be in plain view. The motors may share the connection points 711, 741 with 
articles to be connected to the joint for mutual motion; or separate 
connection means for such articles may be provided along the peripheries 
of the toroids. 
Furthermore, the motors may be electrical, air, or liquid motors. Their 
electrical, air or liquid drive power may be supplied through separate 
conductive wiring or tubing; or through the joint itself. 
Here again, study of the drawings discussed so far will reveal that the 
inclusion of electrical or fluid circuits within the joint is entirely 
compatible with the provision of tractive surfaces and elements per FIG. 
20. Consequently power or fluids, or both, to manipulate the joint itself 
may be supplied through the joint as well as power or fluids, or both, for 
other purposes. 
FIG. 20 may also be taken as representing a joystick device in which the 
joint is manipulated manually. In such a device the elements 756 and 757 
are not motors, but instead are electrical-signal or fluid-motion 
generators responsive to the motion of the joint. 
Not only conventional electrical generators or alternators, but also modern 
electromechanical sensors (such as finely graduated radial-contact arrays) 
or electromagnetic angular-motion sensors or counters may be employed for 
optimum economy, and/or compatibility with modern digital-logic 
utilization circuits. 
In some applications it may be desired to minimize operating friction of 
the joint. As shown in FIG. 21 an internal race 882, 892 may be provided 
within each toroid 821, 831; and balls or rollers 862, 863 may be disposed 
within the races 882. 
Such balls or rollers can be designed to suspend and carry the inner and 
outer parts 821/881, 831/891 of the toroids relative to one another in a 
rolling-friction mode. Such provision may be made in combination with flux 
or force transmission features already disclosed. 
Conventional bearing styles may be substituted in one or both toroids. If 
bearings are desired in both halves of the joint, however, at least one 
must be assembled from two parts since the bearings must interlock. 
As previously mentioned, for many applications of my invention it is not 
necessary to use complete rings or to form closely fitting grooves within 
the toroids. Alternative guide-and-follower sets are suggested in Figs. 22 
through 24. 
FIG. 22 shows a partial ring 991, fitted with a pair of sleeves 933a, 933b 
that ride along the partial ring at a fixed distance defined by a 
cross-member 934 within the ring. Bosses 996a, 996b at the ends of the 
ring 991 limit the travel of the sleeves 933a, 933b respectively. 
Clearance spaces 932a, 932b between the sleeves 933a, 933b and the ring 991 
may be lubricated or provided with bearings, or both. On the other hand 
the surfaces exposed in these spaces may have miniature detents or 
gripping elements to increase friction. 
FIG. 23 shows a variant of the FIG. 23 system, in which the cross-member 
934' is outside rather than inside the partial ring 991'. The same 
considerations as to surface characteristics apply here. 
In either of FIGS. 23 or 24, the partial ring 991, 991' may be associated 
with and fixed to the outer structure such as toroid 421, 431 (FIGS. 8 
through 13); while the follower assembly composed of sleeves 933a/933b, 
933a'/933b' and crossbar 934, 934' may serve in lieu of the inner 
structure such as inner ring 481, 482. With equal effectiveness, however, 
the associations can be reversed. 
FIG. 24 shows another kind of inner structure 1091a-b that can be 
substituted for either inner ring previously discussed. The inner 
structure shown here is simply two mutually angled bars 1091a and 1091b, 
strongly secured together at a fixed angle to form a corner. 
Both ends of the inner structure 1091a-b of FIG. 24, and the corner as 
well, are formed to match, e.g., the peripheral surface of an interior 
groove 1032 formed along the periphery 1033 of the central aperture in a 
toroid 1031. Suitable interfaces 1034a, 1034b and 1034c are thus provided 
for relative motion of the inner structure 1091a-b and the outer toroidal 
body 1031. 
Also shown in FIG. 24, in cross-section, is the corresponding inner 
follower member 1081 associated with another toroid (not illustrated). The 
two follower components 1081 and 1091b are secured together at a common 
area 1089 very generally coincident with the inner peripheries of the two 
toroids. 
Flux or force transmission is thereby provided between the two inner 
followers 1081, 1091b--and thereby across the joint. These elements 1081, 
1091b thus can provide all or any of the various intertoroid suspension 
and transmission functions previously described. 
As shown in FIGS. 25a and 25b, relatively short partial-ring sections 981", 
991" may be used within interlocked toroidal outer bodies to achieve some 
of the same functions. These structures are joined at a common area 989" 
along both inner peripheries, and may transmit force or flux between the 
halves of the joint as before, though of course over a narrower operating 
angular range. 
FIG. 26 demonstrates that my invention, in its forms that include inner 
guide-and-follower structures of the types disclosed above, may be used 
with generally arch-shaped figures of arbitrary exterior form. 
Construction techniques for various embodiments, forms and variants of my 
invention are shown in the remaining drawings, which are self explanatory. 
All the dimensions of various versions of my invention can vary widely, 
from miniatures with minor diameters and central apertures of a small 
fraction of an inch to massive structures many feet across. 
It will be understood that the foregoing disclosure is intended to be 
merely exemplary, and not to limit the scope of the invention--which is to 
be determined by reference to the appended claims.