Rotary actuator such as a rotary actuator for a motor vehicle suspension

A rotary actuator having a cylinder and a motor shaft as well as end caps which define a working area, a number of ribs on the inside surface of the cylinder and an equal number of vanes on the motor shaft which divide the working area into work chambers, and seals inside grooves in the ribs and the vanes. The work chambers are alternately supplied with hydraulic medium, and the seals hydraulically separate the working chambers from one another. The seals are in the form of one-piece gasket members and there is a space between the seals and the side walls of the groove in the static rest position. The gasket member, via its end surfaces, its surfaces which define the height of the gasket member, and one side wall, perform a sealing function during operation of the rotary actuator.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention generally relates to a rotary actuator, such as a 
hydraulic rotary actuator for use in a suspension of a motor vehicle. Such 
a hydraulic rotary actuator can essentially have a housing with at least 
one rib on an inside wall thereof, a motor shaft, disposed at least 
partially within the housing and having at least one vane on an exterior 
wall thereof, as well as end caps which seal the ends of the actuator. The 
housing, motor shaft and end caps define a working area chamber 
therebetween. The ribs on the inside surface of the cylinder and the vanes 
on the motor shaft divide the working area into working chambers, which 
chambers can be alternately supplied with hydraulic medium to relatively 
rotate the shaft and the housing with respect to one another. Seals are 
also generally provided inside grooves in the ribs and the vanes, which 
seals hydraulically separate the work chambers from one another. 
2. Background Information 
German Patent Application No. 42 29 025.2 discloses one type of rotary 
actuator in which the manufacturing process is very problematic with 
regard to the manufacturing of the grooves in the ribs and vanes for the 
seal units. In this known rotary actuator, the seals used have a width to 
height ratio that is unfavorable for the inside machining of the cylinder. 
The grooves for the seal units could only be manufactured to within the 
required tolerances by means of very costly and complex manufacturing 
processes, such as spark erosion or slotting. The associated manufacturing 
expense for this known rotary actuator is therefore unacceptably high for 
large-scale series production. More economical manufacturing processes, 
such as broaching with a broaching tool, have failed in the past because 
the broaching tools broke very quickly due to their small cross-section. 
An additional problem is that while multi-part seal units, such as the 
three part seal unit used by this known actuator, of course work very 
well, they are also very expensive. 
OBJECT OF THE INVENTION 
The object of the present invention is therefore to solve the problems 
associated with known rotary actuators, at the least possible expense, so 
that large-scale series production can be carried out at an acceptable 
cost. 
SUMMARY OF THE INVENTION 
To achieve this object, the present invention teaches that the seals can be 
realized as one-piece gasket bodies, and that, when a gasket body is in a 
static or rest position within the grooves of the rotary actuator, there 
can surprisingly be a space between the gasket body and the side walls of 
the groove. As such, each gasket body, via its longitudinal end surfaces, 
its edge surfaces which define the height of the gasket, and one side wall 
surface, performs a sealing function during operation of the rotary 
actuator. 
Since a space can be provided adjacent the gasket bodies within the 
grooves, the grooves can be formed to have a greater width than in 
conventional rotary actuators, thereby providing a width which can enable 
a broaching tool to be used to form the grooves. Thus, by using a gasket 
body which essentially does not need to be any thicker than the gasket 
bodies previously used, the extra groove width, required for the use of a 
broaching tool for formation of the grooves, can be used as the space 
between the seal and the side walls of the groove to achieve a flow of 
hydraulic medium against the seal for applying a dynamic pressure to the 
seal, with the advantage that friction during operation of the rotary 
actuator can typically be kept at an extremely low level. 
The one-piece construction of the seals can preferably reduce the price of 
the seals by a factor of several times. In addition, by using a one-piece 
seal, the groove width tolerance can likewise favorably be increased. This 
is essentially true, since in contrast to the known multi-part seal units 
wherein the seal could come apart if not braced against the side walls, 
etc., thereby resulting in a loss of sealing ability, the one-piece seal 
essentially cannot come apart. Furthermore, the handling of the seals 
during assembly of the rotary actuator, or installation of the seals in 
the rotary actuator, can be simplified significantly, as, among other 
things, the seal will typically fit into place more easily, and 
essentially can not fall apart if mishandled. 
According to another advantageous feature of at least one embodiment of the 
present invention, on account of the prestress applied to the seal, the 
gasket body can generally assume a barrel-shaped cross-section when in the 
static rest position. In contrast to an arc-shaped cross-section, there 
can be essentially no excessive flexing of the seals during the 
continuously changing rotary action of the motor. The danger that the 
hydraulic pressure will compress the seal is likewise essentially 
minimized, or even eliminated. 
In a still further embodiment of the present invention, to reduce the 
friction caused by the seals, the surfaces of the gasket body which 
perform the sealing function can also preferably be divided into a number 
of individual seal surfaces by means of flow passages. Such flow passages 
and plurality of seal surfaces can preferably reduce the effect of 
adherence between the seals and the side walls of the groove. 
A further factor which can contribute to reducing the adherence effect, can 
preferably be achieved by configuring the rotary actuator so that a 
prestress that is applied to the seal within its groove, is of an amount 
which, regardless of the hydraulic pressure in the rotary actuator, 
enables the seals to be slaved, or pulled along, during rotation, as a 
result of the relative motion between the cylinder and the motor shaft 
during rotation. 
The above discussed embodiments of the present invention will be described 
further hereinbelow with reference to the accompanying figures. It should 
be understood that when the word "invention" is used in this application, 
the word "invention" includes "inventions", that is, the plural of 
"inventions". By stating "invention", applicant does not in any way admit 
that the present application does not include more than one patentably and 
non-obviously distinct invention, and maintains the possibility that this 
application may include more than one patentably and non-obviously 
distinct invention. The Applicant hereby asserts that the disclosure of 
this application may include more than one invention, and, in the event 
that there is more than one invention, that these inventions may be 
patentable and non-obvious, one with respect to the other. 
In summary, one aspect of the invention resides broadly in a rotary 
actuator comprising: housing apparatus; apparatus for connecting the 
housing apparatus to a first portion of a motor vehicle suspension; shaft 
apparatus, the shaft apparatus defining a longitudinal axis; at least a 
portion of the shaft apparatus being rotatably disposed within the housing 
apparatus; apparatus for connecting the shaft apparatus to a second 
portion of a motor vehicle suspension; apparatus for rotatably mounting 
the at least a portion of the shaft apparatus within the housing apparatus 
for rotation of at least one of the shaft apparatus and the housing 
apparatus about the longitudinal axis with respect to the other of the 
shaft apparatus and the housing apparatus; the shaft apparatus comprising 
an outer surface disposed towards the housing apparatus; the housing 
apparatus comprising an inner surface disposed towards the outer surface 
of the shaft apparatus, the inner surface of the housing apparatus being 
spaced apart from the outer surface of the shaft apparatus to define a 
chamber between the shaft apparatus and the housing apparatus; at least 
one of: the outer surface of the shaft apparatus, and the inner surface of 
the housing apparatus, comprising at least one projection extending 
towards the other of: the outer surface of the shaft apparatus, and the 
inner surface of the housing apparatus; the at least one projection 
extending from the first axial end of the chamber to the second axial end 
of the chamber to axially divide the chamber into a first chamber portion 
and a second chamber portion; apparatus for introducing fluid into at 
least one of: the first chamber portion, and the second chamber portion, 
to provide a pressure on the at least one projection to relatively rotate 
the housing apparatus and the shaft apparatus; the at least one projection 
comprising: a first side disposed towards the first chamber portion; a 
second side disposed opposite to the first side and adjacent the second 
chamber portion; a surface disposed between the first side and the second 
side, the surface being disposed towards the other of: the outer surface 
of the shaft apparatus, and the inner surface of the housing apparatus; a 
longitudinal slot disposed in the surface, the longitudinal slot having 
two spaced apart side surfaces defining a width of the slot in a 
circumferential direction with respect to the longitudinal axis, the two 
spaced apart side surfaces extending substantially parallel to the 
longitudinal axis; at least one seal apparatus disposed in the 
longitudinal slot for sealing between the first chamber portion and the 
second chamber portion to minimize fluid flow from the first chamber 
portion to the second chamber portion; the seal apparatus having a width 
in a circumferential direction with respect to the longitudinal axis; and 
the width of the seal apparatus being substantially less than the width of 
the slot to define a space between the seal apparatus and at least one of 
the side surfaces of the slot to permit flow of fluid between the seal 
apparatus and the at least one side surface of the slot along at least a 
substantial portion of the seal apparatus. 
A further feature of the invention resides broadly in a motor vehicle 
suspension comprising suspension springs, a rotary actuator for 
stabilizing uneven deflections of the suspension springs, the rotary 
actuator comprising: housing apparatus; first connecting rod apparatus for 
connecting the housing apparatus to a first load bearing portion of the 
motor vehicle suspension at a first side of the motor vehicle; shaft 
apparatus, the shaft apparatus defining a longitudinal axis; at least a 
portion of the shaft apparatus being rotatably disposed within the housing 
apparatus; second connecting rod apparatus for connecting the shaft 
apparatus to a second load bearing portion of a motor vehicle suspension 
at a second side of the motor vehicle; bearing apparatus for rotatably 
mounting the at least a portion of the shaft apparatus within the housing 
apparatus for rotation of at least one of the shaft apparatus and the 
housing apparatus about the longitudinal axis with respect to the other of 
the shaft apparatus and the housing apparatus; the shaft apparatus 
comprising an outer surface disposed towards the housing apparatus; the 
housing apparatus comprising an inner surface disposed towards the outer 
surface of the shaft apparatus, the inner surface of the housing apparatus 
being spaced apart from the outer surface of the shaft apparatus to define 
a chamber between the shaft apparatus and the housing apparatus, the 
chamber having a first axial end and a second axial end; at least one of: 
the outer surface of the shaft apparatus, and the inner surface of the 
housing apparatus, comprising at least one projection extending towards 
the other of: the outer surface of the shaft apparatus, and the inner 
surface of the housing apparatus; the at least one projection extending 
from the first axial end of the chamber to the second axial end of the 
chamber to axially divide the chamber into a first chamber portion and a 
second chamber portion; the at least one projection comprising: a first 
side disposed towards the first chamber portion; a second side disposed 
opposite to the first side and adjacent the second chamber portion; a 
surface disposed between the first side and the second side, the surface 
being disposed towards the other of: the outer surface of the shaft 
apparatus, and the inner surface of the housing apparatus; and a 
longitudinal slot disposed in the surface, the longitudinal slot having 
two spaced apart side surfaces defining a width of the slot in a 
circumferential direction with respect to the longitudinal axis, the two 
spaced apart side surfaces extending substantially parallel to the 
longitudinal axis; at least one seal apparatus disposed in the 
longitudinal slot for sealing between the first chamber portion and the 
second chamber portion to minimize fluid flow from the first chamber 
portion to the second chamber portion; the seal apparatus having a width 
in a circumferential direction with respect to the longitudinal axis and a 
length along an axial direction with respect to the longitudinal axis; the 
width of the seal apparatus being substantially less than the width of the 
slot to define a space between the seal apparatus and at least one of the 
side surfaces of the slot along at least a substantial porion of the 
length of the seal apparatus to permit flow of fluid between the seal 
apparatus and the at least one side surface of the slot along at least a 
substantial portion of the length of the seal apparatus; and apparatus for 
introducing fluid into at least one of: the first chamber portion, and the 
second chamber portion, to apply pressure to the at least one of: the 
first side of the projection, and the second side of the projection to 
relatively rotate the housing apparatus and the shaft apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows a detail of a stabilizer system 1, which is configured as a 
divided stabilizer having stabilizer parts 3 and 5 and a rotary actuator 
7. For reasons of simplicity, the ends of the stabilizers parts 3, 5, 
connected to the respective wheel control arms, are not shown in this 
figure but will be discussed in more detail hereinbelow with reference to 
FIGS. 4 and 5. 
The rotary actuator 7 can preferably have at least a housing, or cylinder 
9, end caps 13 and 15 disposed on the ends of the cylinder 9, and a 
rotatable shaft 21 extending into the cylinder 9. The cylinder 9 can 
preferably define an inside surface 31, or inside diameter, and can have 
ribs 11 running axially on the inside diameter. The ribs 11 and the 
cylinder 9 can preferably be realized as a one-piece unit, but two-piece 
assemblies would also be possible. 
The end caps 13 and 15, on the two ends of the cylinder 9, can, together 
with the cylinder 9, define a working area 35 therebetween. The 
positioning of the end caps 13 and 15 in the cylinder 9 can preferably be 
determined by end surfaces 17 of the ribs 11. The end caps 13 and 15 can 
preferably be connected to the cylinder 9 by a weld seam 19 in the 
terminal regions of the rotary actuator 7, between the end caps 13 or 15 
and the cylinder 9. 
The motor shaft 21 can preferably be mounted in the working area by means 
of friction bearings 25, 27, in such a manner that there can preferably be 
relative rotational movement between the shaft 21 and the cylinder 9. The 
motor shaft 21 can preferably have a number of vanes 29 on its outside 
surface 33, or outside diameter. These vanes 21 can also preferably have 
an axial orientation, similar to that of the ribs 11 of the cylinder 9. 
The ribs 11 and the inside wall surface 31 of the cylinder 9, as well as 
the vanes 29 and the outside shell surface 33 of the motor shaft 21, 
preferably define a number of work chambers 35a, 35b, as shown in FIGS. 1a 
and 1b. The work chambers 35a, 35b can preferably be sealed on the axial 
ends thereof by means of angular joint gaskets 37 at the base of the vanes 
29, preferably between the vanes 29 and the end caps 13, 15. 
The end faces of the vanes 29 and the ribs 11 can preferably be sealed by 
means of seals 39 so that there can be a hydraulic separation between the 
adjacent work chambers 35a, 35b. The seals 39 can preferably be designed 
as one-piece discs and can essentially perform a sealing function by means 
of their end faces 41a-41d and at least one of the side walls 43a, 43b 
(see FIGS. 2a and 2b). When installed, the operating pressure in the 
working area preferably increases the static prestress on the seals 39 and 
provides dynamic sealing. The same can also apply for the angular joint 
gaskets 37, which can be pressurized with hydraulic medium via at least 
one recess 38. 
The cap 15 can preferably be equipped with a first hydraulic connection 45 
and a second hydraulic connection 47. The hydraulic connections 45, 47 can 
preferably be oriented parallel to the principal axis 10 of the rotary 
actuator 7. Each of the two hydraulic connections 45, 47 can be directly 
connected to one of the work chambers 35a, 35b. In addition, an 
interconnection system, such as shown in FIGS. 1 or 1a, and which 
interconnection systems are generally well known in the art, and therefore 
not discussed in any great detail herein, can be provided to form a 
connection between the work chambers 35a, 35b with the same indexing, 
whereby the interconnected work chambers 35a, 35b of the first hydraulic 
connection 45 alternate with the work chambers 35b of the second hydraulic 
connection 47. 
As shown in FIG. 1, fluid bypass grooves 60 and 61 could be provided 
circumferentially about the end cap 15 between the end cap 15 and the 
shaft 21, whereby groove 60 could interconnect chambers 35a and groove 61 
could interconnect chambers 35b. Alternatively, as shown schematically in 
FIG. 1a, passages 62 and 63 could be provided through at least a portion 
of the shaft 21, provided that at least a portion of the shaft 21 is 
substantially solid therethrough. 
FIGS. 1a and 1b show one possible embodiment of a rotary actuator depicting 
a cross-section through a rotary actuator 7 in the vicinity of the vanes 
29 or ribs 11. Inside the vanes 29 and ribs 11, the seals 39 are 
preferably enclosed in grooves 42. In the depicted view of FIG. 1b, the 
motor shaft 21 is shown in the starting position within the normal rotary 
angle range (alpha). The rotary angle range (alpha) is preferably 
determined by the pump capacity relative to the stabilizer. In this rotary 
angle (alpha) range, the seals 39 can preferably be prestressed by the 
groove 42 and the inside wall surface 31 or the outside shell surface 33. 
Outside of the rotary angle range (alpha), recesses 31', 33' can 
preferably be worked into the inside wall surface 31 and the outside shell 
surface 33. The recesses 31' and 33' can include a base surface 31a, 33a 
respectively preferably connected via a transition surface 31b, 33b to the 
inside wall surface 31 or the outside shell surface 33. The geometric 
configuration of the base surface 31a, 33a can be varied with relative 
freedom, as long as the seal 39 inside the recess 31', 33' remains 
essentially free of prestress. The transition surfaces 31b, 33b can 
thereby essentially ensure that the prestress preferably increases 
continuously to the predetermined level, thereby essentially preventing 
damage to the seal 39. 
In FIG. 1b, the motor shaft 37 is shown twisted in the installation or 
removal position within the cylinder 9. In at least one direction of 
rotation, the ribs 11 and the vanes 29 preferably come into contact. This 
position can essentially easily be defined in a manufacturing robot. Each 
of the seals 39 can preferably be located in the vicinity of a recess 31', 
33' and can therefore be under no prestress. The seals 39 can then be 
relatively easily installed and removed. 
FIGS. 2a-2b show a detailed cross-section through the rotary actuator 7 in 
the vicinity of the vanes 29 or ribs 11. Inside the vanes 29 and ribs 11, 
the seals 39 are preferably enclosed in grooves 42. These grooves 42 can 
be configured to have a width/height ratio which makes it possible to use 
broaching tools. In the depicted embodiment, this width/height ratio is 
shown as about 1:2, while other ratios suitable for broaching would also 
be possible and could be well within the skill of the artisan. 
The seal 39 can preferably be narrower than the width of groove 42 and can 
thereby leave a space 44 between the seal 39 and the groove side walls 42a 
and 42b. The ratio of the width of the seal to the width of the groove 
can, in at least one embodiment of the present invention be about 8:9, 
while variations on this ratio would be possible and well within the skill 
of the artisan. In the rest position, that is, when the pressure in the 
work chambers 35a, 35b is essentially equal, the seal 39 can be 
prestressed essentially only via its surfaces 41c, 41d. This prestress can 
be provided by applying a radial pressure to the seal 39, in a manner as 
discussed above with regard to the embodiment depicted in FIG. 1a. Under 
such a radial prestress, and in the rest position, the seal 39 can have a 
barrel-shaped cross-section. The space 44, on both sides of the seal walls 
42a, 42b, can essentially be filled with hydraulic medium. 
FIG. 2b shows one embodiment of an operating condition, or when there is a 
pressure differential between the chambers 35a, 35b. That is, pressure 
P.sub.1 is greater than pressure P.sub.2. The pressure P.sub.1 can 
displace the seal 39 in the groove 42 essentially until a side wall 43a, 
43b of the seal 39 comes in contact with a side wall 42a, 42b of the 
groove. The entire space 44 can then essentially be entirely on one side 
of the seal 39. Under the pressure of the hydraulic medium, a displacement 
of volume occurs, which results in an increase in the prestress of the 
seal 39 in the groove 42. In this position, the seal 39 performs the 
sealing function by means of its end faces 41a-41d and its side wall 43b. 
If a reversal of pressure were then to occur during operation of the rotary 
actuator, so that P.sub.2 becomes greater than P.sub.1, the undesirable 
adherence between the side wall 42b of the groove 42 and the side wall 43b 
of the seal 39 can essentially be eliminated by pulling the seal along by 
means of the relative motion between the motor shaft 21 and the cylinder 
9. 
In an alternative embodiment of the seal 42, the seal surfaces 41c, 41d, 
43a, 43b, can also include flow passages 46, which form individual seal 
surfaces. One possible embodiment of a seal having flow passage 46 is 
depicted in FIG. 3 which shows a plan view of a seal 39 and the passages 
46. It might also be desirable that the end surfaces 41a, 41b also have 
such a passage 46. 
FIG. 4 shows the positioning of a rotary actuator 7, in accordance with the 
present invention, as a part of a stabilizer system 51 of an automobile 
suspension. The rotary actuator 7 can preferably be attached via housing 9 
to one stabilizer bar 53, and via shaft 21 to another stabilizer bar 55. 
A more detailed view of the use of a rotary actuator in a motor vehicle 
suspension, as shown in FIG. 4, is provided in FIG. 5 which represents a 
stabilizer 101a, 101b with a rotary actuator 103. On angled ends 101a', 
101b' there are preferably locators 105a, 105b in which the wheel bearings 
are engaged, which wheel bearings are not shown in the figure for purposes 
of simplicity. The stabilizer 101a, 101b is preferably fastened to the 
vehicle by means of articulated clips 107a, 107b. 
The rotary actuator 103 essentially includes a rotary actuator housing 103a 
and a rotary actuator vane assembly, which vane assembly is not shown in 
the figure, whereby the rotary actuator housing 103a is preferably 
non-rotationally connected to the stabilizer part 101a, and the rotary 
actuator vane assembly is preferably non-rotationally connected to the 
stabilizer part 101b. In the event of uneven deflection of the vehicle 
springs, the rotary actuator 103 can be rotated by means of the angled 
ends 101a', 101b', whereby wheel contact forces interact with the angled 
ends 101a', 101b' to exert a torsional moment on the stabilizer. 
The rotary actuator 103 preferably has two hydraulic connections 109a, 109b 
which preferably form a connection to a hydraulic system 113 via hydraulic 
lines 111a, 111b, whereby the hydraulic system 113 preferably includes at 
least a hydraulic valve 113a. Hydraulic systems in general, and associated 
hydraulic valves are generally well known, and are therefore not disclosed 
in any further detail herein. The components of the hydraulic system 113 
can be permanently installed in the vehicle so that with each deflection 
of the vehicle springs or stabilizer movement, there can be a relative 
movement of the hydraulic lines 111a, 111b with respect to the hydraulic 
system 113, which movement should preferably be compensated for by the 
hydraulic lines 111a, 111b together with the hydraulic connections 109a, 
109b. 
One feature of the invention resides broadly in the rotary actuator 
comprising a cylinder and a motor shaft as well as end caps which define a 
working area, a number of ribs on the inside surface of the cylinder and 
an equal number of vanes on the motor shaft which divide the working area 
into working chambers which are alternately supplied with hydraulic 
medium, and seals inside grooves in the ribs and the vanes, which 
hydraulically separate the working chambers from one another, 
characterized by the fact that seals 39 are realized as one-piece disks 
and that there is a space 44 between the seals 39 and the side walls 42a, 
42b of the groove in the static rest position, whereby the disk 39, via 
its end surfaces 41a, 41b, its surfaces 41c, 41d which define the height 
of the disk, and one side wall 43a, 43b perform a sealing function during 
operation of the rotary actuator. 
Another feature of the invention resides broadly in the rotary actuator 
characterized by the fact that the disk 39 has a barrel-shaped 
cross-section in its static rest position. 
Yet another feature of the invention resides broadly in the rotary actuator 
characterized by the fact that the surfaces 41, 43 of the disk 39 
providing a seal are divided into a number of individual seal surfaces by 
means of flow passages 46. 
Still another feature of the invention resides broadly in the rotary 
actuator characterized by the fact that the prestress of the seal 39 in 
its groove 42 is designed so that, regardless of the hydraulic pressure in 
the rotary actuator 1, the seals 39 are pulled along by the relative 
motion between the cylinder 9 and the motor shaft 21 during rotation. 
Some types of automobile suspension systems that could be utilized in 
accordance with the rotary actuator motor may be or are disclosed by the 
following U.S. Pat. No. 5,178,406 to Reynolds, entitled "Torsion Bar 
Suspension"; U.S. Pat. No. 5,286,059 to Tabe, entitled "Height Control 
System when Vehicle Is Jacked Up"; U.S. Pat. No. 5,288,101 to Minnett, 
entitled "Variable Rate Torsion Control System for Vehicle Suspension"; 
and U.S. Pat. No. 5,290,048 to Takahashi and Yamashita, entitled "Working 
Fluid Circuit for Active Suspension Control System of Vehicle". 
Some types of rotary actuators that could be utilized in accordance with 
the present invention may be or are disclosed by the following U.S. Pat. 
No. 5,332,236 to Kastuhara et al., entitled "Sealing Mechanism for a 
Rotary Actuator"; U.S. Pat. No. 5,309,816 to Weyer, entitled "Rotary 
Actuator with External Bearings"; U.S. Pat. No. 5,267,504 to Weyer, 
entitled "Rotary Actuator with Annular Fluid Coupling Rotatably Mounted to 
Shaft"; and U.S. Pat. No. 5,310,021 to Hightower, entitled "Motor-driven, 
Spring-returned Rotary Actuator". 
Some types of seals that could be utilized with the present invention may 
be or are disclosed by the following U.S. Pat. No. 5,321,964 to Lovell et 
al., entitled "External Seal Device for Tube Hydroforming"; U.S. Pat. No. 
5,250,607 to Comert et al., entitled "Moisture Cured Elastomeric 
Interpenetrating Network Sealants"; U.S. Pat. No. 5,259,737 to Kamisuki et 
al., entitled "Micropump with Valve Structure"; U.S. Pat. No. 5,234,194 to 
Smith, entitled "Seal for a Shaft"; and U.S. Pat. No. 5,190,299 to 
Johnston, entitled "Radially Undulating Shaft Seal". 
Broaching methods and broaching tools which could possibly be used to form 
the grooves in accordance with the present invention may be or are 
disclosed by the following U.S. Pat. No. 5,183,374 to Line, entitled 
"Horizontal Broach with a Mobile Standard"; U.S. Pat. No. 5,184,985 to 
Varinelli et al., entitled "Vertical Broaching Machine with Multiple 
Broaches"; U.S. Pat. No. 5,242,251 to Armstrong and Bakaian, entitled 
"Broach and Process of Manufacturing a Broach"; and U.S. Pat. No. 
5,246,320 to Krippelz, entitled "Keyway Broach Tool and Method of 
Broaching Multiple Keyways". 
The appended drawings in their entirety, including all dimensions, 
proportions and/or shapes in at least one embodiment of the invention, are 
accurate and to scale and are hereby included by reference into this 
specification. 
All, or substantially all, of the components and methods of the various 
embodiments may be used with at least one embodiment or all of the 
embodiments, if more than one embodiment is described herein. 
All of the patents, patent applications and publications recited herein, 
and in the Declaration attached hereto, are hereby incorporated by 
reference as if set forth in their entirety herein. 
The corresponding foreign patent publication applications, namely, Federal 
Republic of Germany Patent Application No. P 43 37 813.7, filed on Nov. 5, 
1993, having inventors Horst Oppitz and Bernhard Schmitt, and DE-OS P 43 
37 813.7 and P 43 37 813.7, as well as their published equivalents are 
hereby incorporated by reference as if set forth in their entirety herein. 
The details in the patents, patent applications and publications may be 
considered to be incorporable, at applicant's option, into the claims 
during prosecution as further limitations in the claims to patentably 
distinguish any amended claims from any applied prior art. 
The invention as described hereinabove in the context of the preferred 
embodiments is not to be taken as limited to all of the provided details 
thereof, since modifications and variations thereof may be made without 
departing from the spirit and scope of the invention.