Prosthetic appliance

A prosthetic appliance comprises a supporting part and an extremity-shaped part which is articulated to the end portion of the supporting part. A sheath surrounds the supporting part, and a cup-shaped element is permanently connected to the sheath and detachably connected to the extremity-shaped part and bounds a compartment in which the end portion of the supporting part is received with freedom of movement relative to the cup-shaped element. The cup-shaped element may be snugly received in a depression of the second part and circumferentially surrounded by a rim of the latter, being flush with an end face thereof.

BACKGROUND OF THE INVENTION 
The present invention relates to a prosthetic appliance, and particularly 
to a prosthetic appliance intended to replace an amputated extremity or 
limb of a human body. 
There are already known various prosthetic appliances of the type here 
under consideration, which are used for replacement of severed human feet 
or hands. The present invention will be described as employed in a 
prosthetic appliance which takes the place of a severed foot; however, it 
is to be understood that a similar concept may also be used in a 
prosthetic appliance for replacing an amputated hand. 
Usually, the conventional prosthetic appliances include a supporting part 
which is connected to the body of the user, a foot or other extremity part 
which is connected to the free end portion of the supporting part, and a 
sheath made of an elastically yieldable material, preferably foamed rubber 
or synthetic plastic material which surrounds at least the supporting part 
of the appliance and gives the same an aesthetically pleasing appearance. 
Inasmuch as the primary purpose for the sheath, besides protecting the 
supporting element from detrimental influences of the environment, is to 
improve the appearance of the prosthetic appliance, it will be hereafter 
called a cosmetic sheath. 
In the conventional prosthetic appliances, the extremity-shaped part is 
made of a rigid material, such as wood, synthetic plastic material or the 
like, and the cosmetic sheath, as already mentioned above, is made of a 
resiliently yieldable material. In order to give the prosthetic appliance 
a compact outlook, it is necessary to connect the cosmetic sheath with the 
foot or other extremity part. This, however, brings about a variety of 
problems. 
First of all, only certain types of connecting procedures which do not 
impair the appearance of the prosthetic appliance can be used for 
connecting the cosmetic sheath to the extremity-shaped part. Such 
procedures primarily involve gluing or welding, particularly thermal 
welding. These procedures, as is well known, result in permanent bonds 
which are not easy to dissociate without damaging or destroying one of the 
connected components. 
Another problem results from the fact that some of the various components 
of the prosthetic appliance are connected with one another using 
adjustable connecting elements. The adjustment of the position of the 
various components relative to one another may itself result in impairment 
of the appearance of the resiliently yieldable cosmetic sheath. However, 
more importantly, after the original adjustment, any subsequent adjustment 
of the positions of the various components relative to one another 
requires that access be obtained to the components the positions of which 
are to be adjusted. Most of the time, such access may be had only upon 
removal or partial removal of the cosmetic sheath which, in the event of a 
permanent bond between the cosmetic sheath and the extremity-shaped part, 
necessitates at least a partial cutting up of the bond between the 
cosmetic sheath and the extremity-shaped part which is glued or welded 
thereto, or of the cosmetic sheath proper. When the former approach is 
taken, it may be very difficult to reestablish a permanent bond between 
the cosmetic sheath and the extremity-shaped part. In the latter event, 
the damaged cosmetic sheath must be restored to its original appearance, 
to the extent possible, by gluing or otherwise connecting the cut-up 
sections of the cosmetic sheath. This, of course, is very difficult to do, 
particularly when it is desired, as it always is, to restore the 
aesthetically pleasing intact appearance of the sheath. 
In order to avoid this difficulty, it has been already proposed to connect 
the cosmetic sheath to the extremity-shaped part by inserting the end 
portion of the cosmetic sheath into a recess formed in the end face of the 
extremity-shaped part. However, experience with this approach has shown 
that such a connection is not particularly reliable, especially because of 
the fact that only frictional engagement of the end portion of the 
cosmetic sheath with the surfaces bounding the recess is obtained. Also, 
the outward appearance of the prosthetic device leaves much to be desired 
inasmuch as formation of visible seams is unavoidable when this approach 
is taken. 
An attempt has already been made to avoid these drawbacks which are 
inherent to the solution in which the cosmetic sheath is directly 
connected to the extremity-shaped part of the prosthetic appliance either 
by an end-to-end gluing or welding, or by inserting the end portion of the 
cosmetic sheath into a recess of the extremity-shaped part. In this 
approach, which has been heretofore used only in prosthetic appliances in 
which there is no relative movement between the various components, a 
connecting element is interposed between the cosmetic sheath and the 
extremity-shaped part, such connecting element being of a plate-shaped 
configuration and being permanently connected to the cosmetic sheath. In 
this prior-art appliance, the connecting element has an exposed surface 
having at least two receiving recesses which extend normal to the exposed 
surface, opening thereon and leading into the plate-shaped connecting 
element, and the extremity-shaped part, such as a foot part, has an equal 
number of pins which are clampingly received within the corresponding 
recesses of the connecting element. In addition to the recesses, the 
plate-shaped connecting element is also provided with a central opening 
through which an end portion of a supporting element extends from the 
space surrounded by the cosmetic sheath toward the foot-shaped part. 
In this prior-art appliance, the connection between the cosmetic sheath, 
and particularly between the plate-shaped connecting element which is 
permanently connected thereto, and the extremity-shaped part, can be 
established in a very simple manner in that the connecting element is 
aligned with the extremity-shaped part so that the pins of the 
extremity-shaped part are brought into registry with the recesses of the 
connecting element, whereupon the sheath or the connecting element is 
pressed against the extremity-shaped part to thereby obtain a clamping 
connection between the pins and the complementary recesses. Such 
connection can just as easily be discontinued by pulling the connecting 
element away from the extremity-shaped part. In view of the fact that the 
connecting element can be so shaped as to exactly correspond to the 
contour of the connecting surface of the extremity-shaped part of the 
prosthetic appliance, it is assured that, no matter now many times the 
connection between the cosmetic sheath and the extremity-shaped part is 
established and discontinued, the outer surfaces of the cosmetic sheath, 
the connecting element and the extremity-shaped part will always smoothly 
and gradually merge with one another without formation of any perceivable 
seams. It will be appreciated that, in this prior-art prosthetic 
appliance, the connection of the cosmetic sheath or of the connecting 
element permanently attached thereto with the extremity-shaped part of the 
prosthetic device can be arbitrarily often discontinued and reestablished 
without any damage to such connection or to the cosmetic sheath. In 
addition thereto, the fact that the connecting element is of a 
plate-shaped configuration and is permanently connected to the cosmetic 
sheath significantly contributes to reinforcing and stabilizing the 
cosmetic sheath and particularly the free end portion thereof, which is a 
very important consideration in view of the fact that the cosmetic sheath 
is usually made of a comparably weak or resiliently yieldable material, 
such as a foamed synthetic plastic material. Moreover, the pin-and-recess 
connection of the connecting elements with the extremity-shaped part 
assures that the cosmetic sheath reassumes its original position after 
each reassembly of the extremity-shaped part with the remainder of the 
prosthetic appliance. 
It may be seen that the immediately above described prior-art prosthetic 
appliance has a number of advantages, particularly where the connection of 
the cosmetic sheath with the extremity-shaped part is concerned. However, 
as already previously mentioned, this approach does not readily lend 
itself for use in a prosthetic appliance in which the various components 
are articulated to one another, particularly in an appliance in which the 
extremity-shaped part is pivotally connected to the supporting part. Such 
articulated prosthetic appliances are also very well known and usually 
they include a tilting element which is pivotally supported on the 
extremity-shaped part and to which a tubular element of the supporting 
part, as well as the cosmetic sheath, are connected. This solution has a 
very important disadvantage in that, as the tilting element is angularly 
displaced relative to the extremity-shaped part, the cosmetic sheath which 
is connected to the tilting element is deformed, which results in an 
impairment of aesthetic appearance of the prosthetic appliance which, in 
most instances, is unacceptable to the user of the prosthetic appliance. 
Various solutions to this problem have already been attempted; however, 
such solutions are either very complex and thus impractical, or do not 
result in any significant improvement of the appearance of the prosthetic 
appliance during the use thereof. 
SUMMARY OF THE INVENTION 
Accordingly, it is a general object of the present invention to avoid the 
disadvantages of the prior art. 
More particularly, it is an object of the present invention to provide a 
prosthetic appliance which is not possessed of the disadvantages of the 
prior-art prosthetic appliances. 
It is a further object of the present invention to provide a prosthetic 
appliance which is simple in construction and reliable in operation. 
A concomitant object of the present invention is to provide a prosthetic 
appliance of the articulated type in which the appliance has an 
aesthetically pleasing appearance regardless of the relative position of 
the various components thereof. 
Yet another object of the present invention is to provide a prosthetic 
appliance in which the relative movement of the various components can be 
conducted without interference. 
In pursuance of these objects and others which will become apparent 
hereafter, one feature of the present invention resides, briefly stated, 
in a prosthetic appliance, in a combination which comprises a supporting 
elongated first part which has an end portion; an extremity-shaped part 
second part which is articulated to the end portion of the first part; a 
sheath which surrounds at least a portion of the first part; and means for 
connecting the sheath to the second part, including a cup-shaped element 
which is permanently connected to the sheath and detachably connected to 
the second part, such cup-shaped element bounding a compartment in which 
the end portion of the first part is received with freedom of movement 
relative to the cup-shaped element. Preferably, the second part is of a 
rigid material, such as wood or synthetic plastic material, while the 
sheath is of a resiliently yieldable material, particularly foam rubber or 
foamed plastic material. The first part may include a tubular element, and 
a tilting element which is separate from and rigidly connected to the 
tubular element and which constitutes the end portion of the first part. 
In this manner, it is assured that the cup-shaped element which is 
permanently connected to the cosmetic sheath, such as by an adhesive or a 
welded bond does not share in the movement of the articulated connection 
of the supporting part with the extremity-shaped part. 
According to a further aspect of the present invention, the cup-shaped 
element is formed with a central opening through which the tubular element 
of the first part passes from the above-mentioned compartment into a space 
bounded by the cosmetic sheath. The opening may have such dimensions as to 
permit a relative angular displacement of the tubular element with respect 
to the extremity-shaped part and to the cup-shaped element. 
Especially when the extremity-shaped part is of a synthetic plastic 
material, it is advantageous to form such extremity-shaped part with a 
depression which is bounded by a circumferential rim. The cup-shaped 
element may then be snugly received in the above-mentioned depression, 
being circumferentially surrounded by the above-mentioned rim. In this 
event, the rim may have a flat end face, and the cup-shaped element may 
have a circumferential edge which is flush with the above-mentioned end 
face of the rim. 
The novel features which are considered as characteristic for the invention 
are set forth in particular in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
with additional objects and advantages thereof, will be best understood 
from the following description of specific embodiments when read in 
connection with the accompanying drawings.

DETAILED DISCUSSION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawing, and first to FIG. 1 thereof, it may be seen 
that the prosthetic appliance of the present invention includes a cosmetic 
sheath which has been designated with the reference numeral 1. An 
extremity-shaped, such as a foot-shaped, part has been designated in toto 
with the reference numeral 2 and, as may be ascertained from FIG. 1, it 
includes a wooden inner core and an outer layer of a synthetic plastic 
material. However the extremity-shaped part 2 may be made of wood or a 
synthetic plastic material in its entirety, if so desired, or even of 
other suitable rigid materials. 
The prosthetic appliance further includes a cup-shaped element 3 which is 
connected in an end-to-end fashion, with an end face of the cosmetic 
sheath 1. The bond between the cup-shaped element 3 and the cosmetic 
sheath 1 is advantageously permanent, and is preferably obtained by 
adhesively or weldingly bonding the end face of the cosmetic sheath 1 to 
the end face of the cup-shaped element 3. The cup-shaped element 3 bounds 
a compartment, and a tilting element 5, which is connected to the 
extremity-shaped part 2 by means of a pivot 4, is accommodated within such 
compartment. An elastically yieldable bumper member 6 extends between and 
abuts against the tilting element 5 and the extremity-shaped part 2. The 
cup-shaped element 3 has a central opening 7 through which a tubular 
element 9 of a supporting part, of which the tilting element 5 constitutes 
an end portion, extends from the compartment bounded by the cup-shaped 
element 3 into a space bounded by the cosmetic sheath 1. The supporting 
part may further include, as illustrated, a connecting member 8 which 
connects the tubular element 9 with the tilting element 5. 
As may be further seen in FIG. 1, the foot-shaped element 2, which may be 
made at least partly of a synthetic plastic material, includes a 
circumferentially complete collar or rim 10 which circumferentially bounds 
a depression 11 in which the articulated connection of the foot-shaped 
part 2 with the tilting element 5 is accommodated. The cup-shaped element 
3 is preferably snugly or pressfittingly accommoated within the depression 
11. The cup-shaped element 3 is preferably made of an elastic material and 
has an upper edge which is preferably flush with the end face of the rim 
10. The cup-shaped element rests on the foot-shaped part 2 at least at two 
points designated with reference numerals 12 and 13, but preferably there 
exists a surface contact of the outer surface of the cup-shaped element 3 
with the surfaces bounding the depression 11. 
The cup-shaped element 3 has such dimensions and particularly such a height 
that the tilting element 5 is received within the compartment bounded by 
the cup-shaped element 3 with such a spacing that freedom of angular 
displacement of the tilting element 5 relative to the cup-shaped element 
3, and thus to the extremity-shaped part 2, is assured. It will be 
appreciated, upon consideration of the drawing and the discussion, that 
the cosmetic sheath 1 does not share in the angular displacement of the 
tilting element 5. 
The embodiment of FIG. 2 is in many respects similar to that of FIG. 1 so 
that the same reference numerals have been used in FIG. 2 to designate 
parts similar in configuration and function to the parts of FIG. 1. In 
this embodiment, the foot-shaped part is identified by a reference numeral 
14 and is made predominantly or exclusively of wood. The foot-shaped part 
14 has, in the region of the tilting element 5, an approximately flat 
surface, the circumferential rim of FIG. 1 being omitted in this 
embodiment. The cup-shaped element 15 has a circumferential edge 16 which 
rests upon the flat surface of the foot-shaped part 14. The adjustment of 
the position of the cup-shaped element 15 relative to the foot-shaped part 
14 is obtained by means of non-illustrated conventional screws or the 
like. In this embodiment, the tilting element 5 is again received with 
spacing within the compartment bounded by the cup-shaped element 15, so 
that the cosmetic sheath 1 again does not participate in the angular 
displacement of the tilting element 5. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
constructions differing from the types described above. 
While the invention has been illustrated and described as embodied in a 
foot-replacing prosthetic appliance, it is not intended to be limited to 
the details shown, since various modifications and structural changes may 
be made without departing in any way from the spirit of the present 
invention. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic or specific aspects of this invention.