Hydraulic toilet seat

An hydraulic toilet seat assembly utilizes available household water pressure to lift, elevate and lower a toilet seat so as to facilitate mounting and dismounting by a person who is disabled or infirm. As the seat rises it assumes a forwardly pitched orientation to further facilitate use. A positive displacement fluid divider unit delivers to hydraulic motors appropriate volumes of water to drive motor pistons through different distances, so as to produce the desired seat inclination.

BACKGROUND OF THE INVENTION 
For many who are disabled or infirm, the mounting and dismounting of a 
toilet is difficult or impossible to achieve without assistance. This is 
attributable, in large measure, to a lack of the degree of lower body 
strength, flexibility or control that is necessary to enable adequate or 
confident movement between erect and crouched positions. 
It is believed that power-assisted toilet seat mechanisms may previously 
have been proposed for use in lowering a person to, and elevating him 
from, a toilet. Applicants are not aware however that any such apparatus 
has been provided heretofore which would perform in an entirely 
satisfactory manner, as a practical matter, or which is adapted for ready 
installation in assembly with an existing toilet facility. 
A feature that would be particularly desirable in an elevating mechanism of 
the kind described is one by which automatic forward tilting of the 
seating member, in elevated positions, would be effected. Another would be 
the ability to utilize existing household water supply sources for 
powering of the mechanism. Consequently, a hydraulic system that is 
capable of raising and lowering the seat, while changing its attitude from 
horizontal to inclined, would be most advantageous. That in turn implies 
means for apportioning a common water supply so as to effect differential 
movement of driven components. 
It is therefore a broad object of the present invention to provide a novel 
toilet seat assembly that can be raised and lowered by hydraulic means, 
and powered by available household water pressure. 
A more specific object is to provide such an assembly in which the seat 
member automatically assumes a forward tilt as it is brought to higher 
levels, and returns to horizontal as it is lowered. 
Other objects of the invention are to provide unique hydraulic operating 
means suitable for use for driving such a seat assembly; and in particular 
to provide a liquid divider unit for apportioning water flow from a common 
source so as to drive hydraulic motors having capacities that differ from 
one another. 
Additional objects are to provide such an assembly which is secure, stable 
and reliable, which is relatively uncomplicated and inexpensive to 
manufacture and facile to install, and which is comfortable, convenient 
and highly effective in use; and to provide such a divider unit which is 
also relatively uncomplicated and inexpensive to manufacture and facile to 
install, and is highly reliable and effective in use. 
SUMMARY OF THE INVENTION 
It has now been found that certain of the foregoing and related objects of 
the invention are attained by the provision of an hydraulic toilet seat 
assembly comprising a toilet seat member and hydraulic operating means, 
the latter including at least one front motor and one back motor. Means is 
provided for connecting the motors to an hydraulic supply, for 
simultaneous operation, and each motor has a piston which is movable 
between fully retracted and extended positions, the pistons of the front 
and back motors being operatively connected to the forward and rearward 
portions of the seat member, respectively. The travel length of the back 
motor piston is substantially greater than that of the front motor piston, 
so that the seat member is in a lowered and generally horizontal attitude 
when the pistons are in their fully retracted positions, and is elevated 
and in a forwardly tilted attitude when the pistons are extended. 
Each motor will usually comprise a generally vertically disposed hydraulic 
cylinder in which the piston is slidably mounted. The pistons will consist 
of a head, having an upper side and a lower side, and an attached rod 
extending from the upper side and operatively connected to the seat 
member; the rod of the front motor piston will normally be substantially 
shorter than that of the back motor piston. 
In preferred embodiments the assembly will include two front motors and two 
back motors, with the pistons of one of the front motors and one of the 
back motors being operatively connected to one lateral side of the seat 
member, and with the pistons of the other two motors being so connected on 
the opposite side of the seat member. The assembly will usually include a 
base that is adapted for mounting upon the bowl of a toilet, and that 
supports the hydraulic motors. 
Each motor cylinder will generally have ports adjacent its upper and lower 
ends, communicating with internal spaces above and below the head of the 
piston, respectively. In such a case the assembly will additionally 
include an hydraulic line attached to each port, with the port adjacent 
the upper end of the back motor cylinder connected, by a common hydraulic 
line, to the port adjacent the lower end of the front motor cylinder. When 
the assembly includes two front and two back motors, the common hydraulic 
lines will desirably be arranged to establish crossover connections. 
The cylinders of all motors will advantageously be of the same inside 
diameter, with the front motor cylinders being substantially shorter, and 
of substantially smaller cross section, than those in the back. Water flow 
into and from the motors will usually be controlled by an hydraulic valve 
that is operatively connected to the front and back motors, and that is 
adapted for connection to a pressurized water supply and to a water 
discharge sink. 
In particularly preferred embodiments, the hydraulic operating means of the 
assembly will include a liquid divider unit for apportioning the water 
supplied into different volumetric amounts. Such a divider unit will 
desirably include a plurality of jointly operative pumping sections, one 
for receiving and delivering to the front motor a first volumetric amount 
of water, and another for receiving and delivering to the back motor a 
second volumetric amount, the "second" volumetric amount of water being 
larger than the "first" and sufficient to produce the extra travel length 
required for the back motor piston. 
Each of the pumping sections may comprise, more specifically, a rotor that 
is rotatably disposed within a discrete body cavity, and that cooperates 
with it to dynamically create compartments of continuously increasing and 
decreasing volume. The body will provide an inlet to and an outlet from 
each cavity, disposed so as to permit the rotors, operatively interengaged 
for conjoint rotation, to draw water thereinto and discharge water 
therefrom. 
In an especially desirable form of the divider unit the cavities will be 
cylindrical and coaxial, and the rotors will include cores that are also 
cylindrical, but of a smaller diameter, and disposed on a common axis of 
rotation parallel to and offset from the axis of the cavities. Each rotor 
will include a plurality of vanes that are slidably mounted, at 
equiangularly spaced positions about the core, for radial movement so as 
to maintain constant, sliding engagement with the walls of the body 
defining the cavities. When designed for use in a system for hydraulic 
operation of a toilet seat member, as described, the divider unit will 
usually include four pumping sections. Each of two of the sections will 
receive and deliver a first volumetric amount of water, with each of the 
other two receiving and delivering water in a second volumetric amount, 
the amounts being established so as to concurrently drive pairs of 
cylinders having capacities that differ from one another. 
Other objects of the invention are attained by the provision of a liquid 
divider unit as hereinabove and hereinafter described.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
Turning in detail initially to FIGS. 1-4 of the appended drawings, therein 
illustrated is an assembly embodying the present invention and consisting 
of a base, generally designated by the numeral 10, and a seat member 
generally designated by the numeral 12. The base 10 is mounted upon and 
supported by the bowl portion of a conventional toilet, generally 
designated by the numeral 14, and consists of a rectangular platform 16 
having a central opening 18 and four passages 20, 20' at its corners. An 
enlarged, block-like structure 22, 22', through which the corresponding 
passage 20, 20' extends, is disposed at each corner on the underside of 
the platform 16. 
A hydraulic cylinder, generally designated by the numeral 24, 24', is 
attached to the base 10 at each corner, and consists of a cylindrical 
sidewall 26, 26' closed by a bottom wall 28 and a top wall 30. It will be 
noted that the sidewalls 26, 26' of the cylinders 24, 24', respectively, 
are of the same diameter but of different lengths. The top walls 30 are 
joined to mounting plates 32, which in turn abut the bottom surfaces 34, 
34' of the enlargements 22, 22', and are secured thereagainst by fasteners 
36. 
Disposed within the cylinder 24, 24' of each motor is a piston having a 
head 38 with a circumscribing sealing ring 42, and having a rod 40, 40' 
extending from the upwardly oriented face of the head. The pistons are 
mounted for slidable, reciprocal movement within the cylinders of the 
motors, with the rods 40, 40' thereof extending upwardly through the 
respective passages 20, 20' in the platform 16. It might be noted at this 
point that the rods 40' are longer than the rods 40 (corresponding to the 
length differentials of the associated cylinders 24, 24'), and that they 
are of substantially greater diameter. 
The seat member 12 consists of a rectangular platform 44 having a centrally 
located opening 45, substantially surrounded by generally annular seat 
structure 46. The member 12 includes a lid 48, pivotably mounted by 
fixtures 50 and disposed to cover the opening 45 and the seat structure 46 
in its lowered position. A forward clevis 52 and a rearward clevis 54 are 
mounted (as by the screw 66 seen in FIG. 3) against the underside of the 
panel 44, each serving to receive between its lateral elements the 
reduced-diameter end portion 56, 60 of the piston rod 40, 40', 
respectively. Pins 58, 62 extend transversely through aligned openings in 
the lateral clevis elements and the reduced rod end portions, to pivotably 
attach the piston rods to the seat member 12. It will be noted that the 
openings 64 (only one of which is visible) through the rear clevis 54 are 
in the form of slots, which permit the limited amount of shifting of the 
pin 62 that is necessary to accommodate the inclination of the rearward 
rods 40' and length differentials that exist between them and the forward 
rods 40. 
With particular reference now to FIGS. 5A and 5B, a control system suitable 
for use with the assembly of the invention is schematically illustrated, 
and includes a hydraulic valve 68 having an operating lever 70. Two lines 
A and B extend from the valve 68, each having two branches, A', A" and B', 
B", respectively. The branches A', A" are attached adjacent the tops of 
the front motor cylinders 24, communicating with the space therewithin 
above the piston heads 38, and the branches B', B" are attached adjacent 
the bottoms of the back motor cylinders 24', communicating below the heads 
of the associated pistons. Common lines C connect the upper ends of the 
back cylinders 24' with the lower ends of the front cylinders 24. A supply 
line S running, for example, from a household municipal water supply, is 
attached to the valve 68. An exit line E is also attached to the valve, 
and runs (as shown in FIG. 1) along the side of the tank of the toilet 14 
and under its cover into the internal chamber. 
The valve 68 is in the form of a standard "closed center" three-position, 
four-ported hydraulic valve. With its element centralized (to which 
position the element is normally biased, by means not shown) no water will 
flow through the valve. Moving the handle 70 to the full line position 
depicted in FIG. 5A will shift the element so as to cause the parallel 
channels of section 72 to align between the ports to which the lines S and 
A, and E and B, respectively, are connected, allowing water to flow 
through the branches A' A" and thereby to depress the pistons of the front 
motor cylinders 24 (assuming that the seat member is initially in an 
elevated position, as depicted in FIG. 2). This will force water present 
below the heads 38 to flow through the common lines C to the tops of the 
back motor cylinders 24', urging them downwardly as well. At the same 
time, water in the space beneath the heads of the back cylinders will flow 
in sequence through the branches B', B", the valve 68, and the exit line 
E, to empty into the toilet tank. Thus, the hydraulic motors will drive 
the seat member 12 to the lowered position of FIG. 4. 
Shifting the handle 70 in the opposite direction, to the position shown in 
full line in FIG. 5B, will bring the crossover section 74 of the valve 
element into registry with lines A, B, S and E, permitting water from the 
supply line S to flow through the line B (and thus the branches B', B" 
thereof) into the bottoms of the back motor cylinders 24'. This will of 
course elevate the associated pistons, and will cause the water that is 
present above the heads thereof to flow through the lines C and into the 
bottoms of the front motor cylinders 24, thereby forcing upwardly the 
pistons thereof as well. Water contained behind the heads of the front 
motor pistons will thereupon flow sequentially through branch lines A', 
A", the valve 68, the exit line E, and ultimately into the reservoir tank. 
This will of course elevate the seat member 12 toward the position shown 
in FIGS. 1 and 2. 
It will be appreciated that the release of force on the handle 70 at any 
point will bring the valve element to its neutral, centered position, 
thereby terminating all flow through the valve and, in turn, maintaining 
the seat member at any level that it has then attained. It will also be 
noted that the common lines C cross one another, so as to hydraulically 
connect the back motor cylinder 24' on one lateral side of the assembly to 
the front motor cylinder 24 on the opposite side thereof, and vise versa. 
This stabilizes the system and helps to maintain a uniform lateral 
orientation of the seat member. 
A particularly unique feature of the assembly of the invention resides in 
the fact that in its elevated positions the plateform 44, and accordingly 
the seat member 46, assumes an orientation that is titled forwardly from 
the horizontal, thereby facilitating mounting and dismounting of the user. 
It will be understood that the pitch of the seat will increase with 
increasing elevation of the seat member. 
It is of course for the purpose of achieving this effect that the lengths 
and diameters of the forward and rearward piston rods differ from one 
another. The larger diameter of the rearward rods compensates for their 
greater length in such a manner as to define equal volumetric spaces above 
the piston heads in all motors, despite the extra distances through which 
the back pistons travel. 
More particularly, the volume of water contained above each piston head 
will be a function of the annular area defined between the cylinder wall 
and the piston rod, and the length of rod extension into the cylinder. By 
using cylinders that are of all of the same diameter, the rod diameters 
can be proportioned directly to the desired travel length differentials in 
such a way as to maintain equal volumes of water above the piston heads 
despite the greater travel of the rear pistons. 
Because of this relationship, the volume of water forced from above the 
pistons of the back motors, during elevation from the seat member position 
shown in FIG. 4 to that of FIG. 2, will be just sufficient to fully extend 
the pistons of the front motors, the travel length of which is of course 
substantially less. Conversely, the volume of water that is displaced 
during lowering of the pistons of the front motors will suffice to fully 
depress the back motor pistons, and to thereby bring the seat member to a 
position disposed directly upon the base 10. 
By way of specific example, the inside diameter of all motor cylinders may 
be 2 inches, the diameter of the front motor piston rods may be 5/8 inch, 
and the diameter of the rods of the back motors may be 11/8 inches. This 
will enable the pistons of the back motors to move through a 9-inch travel 
length concurrently with movement of the pistons of the front motors 
through a distance of slightly less than 6 inches. 
Turning finally to FIGS. 6-8 of the drawings in detail, therein illustrated 
is a four-cavity, positive displacement fluid divider unit suitable for 
use to power four hydraulic motors of the kind utilized in the assembly 
hereinabove described. The unit consists of an assembly of four blocks, 
generally designated by the numerals 76 and 78; the blocks are of square 
cross section and are substantially identical, excepting only that the 
width dimension "d" of the two blocks 76 is fifty percent greater than the 
width dimension "d'" of the two blocks 78. Cover plates 80 are affixed 
over the opposite ends of the block assembly, and separating plates 82 are 
interposed between adjacent blocks. Each block 76, 78 has a cylindrical 
cavity 84 extending through it laterally; the cavities are coaxial with 
one another, and are all of the same diameter. 
One of the rotors, generally designated by the numeral 86 or 88, is 
disposed within the cavity 84 of each block 76, 78. The rotors are fixed 
upon a common shaft 90, which passes through the axial bores 89 in their 
cores 93, 95, and through apertures 91 in the separator plates 82. The 
core of each rotor has three slots extending radially inwardly from its 
circumferential surface, and at equiangularly spaced locations thereabout. 
A flat vane 94 is slidably received within each slot 92, and is biased 
outwardly by three coil springs 96 disposed behind the vane at the bottom 
of the mounting slot. The diameter of the rotor cores 93, 95 is 
substantially smaller than is that of the cavities 84, and the axis of the 
common shaft 90 is offset from that of the axis cavities; as the rotors 
rotate, the vanes 94 slidingly engage the confronting surfaces of the 
blocks 76, 78 and the plates 80, 82, and serve to define cavity chambers 
or compartments of dynamically varying volume in cooperation therewith. 
Upper and lower passages 98, 100 extend into the cavity 84 of each block, 
opening therewithin at points disposed to opposite sides of an imaginary 
diametrical plane. A pipe 102 communicates with each of the lower passages 
98, and connects to a manifold 104; the upper passages 100 communicate 
with pipes 106, each of which will lead to the machine or mechanism that 
is to be powered. 
Assuming use of the divider unit in a system such as that of FIGS. 1-5, the 
pipes 106 from the wider blocks 76 would be connected, through an 
appropriate valving arrangement, to the cylinders 24' of the back motors, 
with the pipes 106 from the narrower blocks 78 being connected 
therethrough to the cylinders 24 of the front motors. The common manifold 
104 would be connected to a water supply source. 
In operation, water flowing into the pipes 102 and through the lower 
passages 98 would fill the cavity chambers defined, at the outlet thereof, 
between adjacent vanes 94 and the encompassed confronting surfaces of the 
block and the rotor cores. The inflowing water would of course induce 
rotation of all rotors 86, 88 (in the direction indicated by the arrows in 
FIGS. 6 and 7), causing them to turn, of necessity, simultaneously and at 
the same angular rate due to their attachment to the common shaft 90. The 
volumes of water drawn into the cavity chambers would be apportioned in 
precise and direct relationship to the axial lengths of the cavities 
(i.e., the thicknesses "d", "d'" of the blocks 76, 78), and accordingly 
the blocks 76 would handle fifty percent more water than would the blocks 
78. 
As the rotors turn, the water collected within the chamber compartments 
would of course be discharged through the upper passages 100, and 
ultimately to the several motor cylinders. Because of the volumetric 
apportionment of the water, the pistons of the back motors would be driven 
fifty percent further than those of the front motors, assuming equal 
cross-sectional areas (rather than the unequal annular areas that exist 
above the piston heads of the motors employed in the illustrated 
embodiment). Needless to say, return of the pistons would be achieved by 
flow reversal, using a suitable element of the interposed valve 
arrangement. That is, the water from the chambers would be conducted to 
the bottoms of the cylinders in a first position of the valve element, and 
to the tops of the cylinders in a second position; the valve arrangement 
would also permit the water to exit to a selected sink (e.g., the toilet 
tank or bowl). 
It will be appreciated that the fluid divider unit described has wide 
applicability in diverse systems; use for powering an hydraulically 
operated toilet seat assembly is merely exemplary, and is not therefore to 
be construed in a limiting sense. It will also be appreciated that many 
modifications may be made to the toilet seat assembly itself, and to the 
components thereof, without departure from the novel concepts of the 
instant invention. 
For example, although the base of the assembly is advantageously 
constructed for support directly upon the toilet bowl, it may also be 
desirable to provide free-standing means for supporting the assembly on 
the floor. Similarly, the particular dimensions and configurations of the 
hydraulic motors illustrated and described are not to be taken as 
limiting, and the seat element may have a configuration very different 
from that which is shown, as for example to afford optimal weight 
distribution on the legs and thighs of the user. The forward tilt that is 
produced as the seat member rises greatly facilitates mounting and 
dismounting, and therefore represents a particularly desirable feature of 
the preferred embodiments of the invention; nevertheless, novelty is also 
regarded to reside in the broader concepts disclosed herein. Finally, it 
will be understood that the materials of construction will be selected to 
afford facile and economical manufacture, durability, functional adequacy, 
and desirable aesthetic qualities, all of which will be evident to those 
skilled in the art. 
Thus, it can be seen that the present invention provides a novel toilet 
seat assembly that can be raised and lowered by hydraulic means, using 
available household water as the power source, in which assembly the seat 
member may automatically assume a forward tilt, as it is brought to higher 
levels, and return to horizontal as it is lowered. The invention also 
provides unique hydraulic operating means, suitable for use for driving 
such a seat assembly; in particular, it provides a liquid divider unit for 
apportioning water flow from a common source so as to drive hydraulic 
motors having capacities that differ from one another. The assembly is 
secure and stable, and is comfortable and convenient to employ. Both the 
seat assembly and also the divider unit are highly reliable and effective 
in use, are relatively uncomplicated and inexpensive to manufacture, and 
are facile to install.