U.S. patent number RE31,067 [Application Number 05/817,177] was granted by the patent office on 1982-10-26 for hydrostatic control unit.
This patent grant is currently assigned to TRW Inc.. Invention is credited to Maurice P. Roberts.
United States Patent |
RE31,067 |
Roberts |
October 26, 1982 |
Hydrostatic control unit
Abstract
A control unit for controlling fluid flow to a fluid motor and
for producing a flow proportional to the rate of rotation of an
input shaft and for applying a pressure to the fluid motor
proportional to the applied torque on the input shaft. The control
unit includes a valve means for directing fluid to a fluid motor in
response to rotation of the input shaft. The valve means includes a
fixed valve part and a movable valve part. The movable valve part
is moved to effect actuation of the valve through a gerotor gearset
mechanism which also functions to meter the flow of fluid which is
directed to the fluid motor.
Inventors: |
Roberts; Maurice P. (Otterbein,
IN) |
Assignee: |
TRW Inc. (Cleveland,
OH)
|
Family
ID: |
27020005 |
Appl.
No.: |
05/817,177 |
Filed: |
July 20, 1977 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
407776 |
Oct 19, 1973 |
03895888 |
Jul 22, 1975 |
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Current U.S.
Class: |
418/61.3;
180/440; 180/441; 60/384 |
Current CPC
Class: |
F15B
13/14 (20130101); B62D 5/097 (20130101) |
Current International
Class: |
B62D
5/09 (20060101); B62D 5/097 (20060101); F15B
13/00 (20060101); F15B 13/14 (20060101); F01C
001/10 (); F04C 002/10 (); B62D 005/08 () |
Field of
Search: |
;418/61B
;91/375R,391R,467 ;60/384,386 ;137/614.11 ;180/163 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Vrablik; John J.
Attorney, Agent or Firm: Yount & Tarolli
Claims
What is claimed is: .[.1. A control unit comprising: metering means
for metering fluid flow and including first and second toothed
members disposed in meshing engagement with one another; input
means for rotating said first member relative to said second
member; a changeover valve means for directing fluid flow to one of
alternative flow paths and movable between a neutral position and
first and second oppositely disposed operating positions in
response to torque applied thereto by said second member for
directing the metered flow of fluid from said metering means to one
of said alternative flow paths..]. .[.2. A control unit comprising
a gerotor mechanism, said gerotor mechanism comprising an
internally lobed gerotor rotor member drivingly connected with an
input shaft, an externally lobed gerotor rotor member located
within said internally lobed gerotor rotor member, the lobes on
said gerotor rotor members defining pockets which expand and
contract upon relative rotational and orbital movement of said
gerotor rotor members, commutator valve means for directing fluid
flow to said expanding pockets and from said contracting pockets,
said commutator valve means comprising a sleeve-like commutator
valve member having exterior axial grooves and generally radially
extending passages extending from the outer periphery thereof into
the bore thereof, a manifold member having a bore within which said
commutator valve member is located, said manifold member having
passages extending therethrough and which alternately communicate
with said axially extending grooves and said generally radially
extending passages in said commutator valve member on relative
rotation therebetween, and means drivingly connecting said manifold
member to said internally lobed gerotor member for rotation
therewith..]. .[.3. A control unit comprising an input shaft,
housing means having a inlet port and a pair of outlet ports, a
directional control valve means for porting fluid from said inlet
port selectively to one of said outlet ports, said directional
control valve means comprising a fixed valve means and a
controlling valve member movable through a predetermined limited
distance relative to said fixed valve member to control fluid flow
therethrough, and metering means in said housing interconnecting
said input shaft and said controlling valve member for moving said
controlling valve member said limited distance in response to
initial rotation of said input shaft and for directing fluid flow
to said directional control valve as said shaft rotates..]. .[.4. A
control unit as defined in claim 1 further including biasing means
for urging said controlling valve member to a netural position and
effective to move said controlling valve member to said neutral
position upon termination of rotation of the input shaft, said
metering means overcoming said biasing means to effect movement of
said controlling member..]. .[.5. A control unit as defined in
claim 1 wherein said fixed valve member and said controlling valve
member comprises plate valve members movable relative to each other
upon rotation of said input shaft..]. .[.6. A control unit as
defined in claim 1 wherein said metering means comprises a gerotor
mechanism having an internally toothed gerotor member and an
externally toothed gerotor member, means connecting said input
shaft to one of said gerotor members for rotation with said shaft,
and means connecting the other of said gerotor members with said
controlling valve member to move said controlling valve member..].
.[.7. A control unit as defined in claim 6 further including means
for limiting movement of said controlling valve member relative to
said fixed valve means, and biasing means for returning said
controlling valve member to a neutral position relative to said
fixed valve means..]. .[.8. A control unit as defined in claim 6
wherein said fixed valve means comprises a sleeve valve member and
said controlling valve member comprises an axially extending valve
member located within said fixed valve means and which rotates
relative to said fixed valve means and further including a drive
link interconnecting said other rotor member of said gerotor
mechanism to said controlling valve member to effect rotation
thereof in response to torque applied thereto..]. .[.9. A control
unit as set forth in claim 6 wherein said other gerotor member is
rotatable about its central axis in response to initial rotation of
said one gerotor member to effect movement of said controlling
valve member and said valve members constrain said other gerotor
member to then orbit only relative to said one gerotor member
during continued rotation of said one gerotor member by rotation of
said input shaft when the force applied to said controlling valve
member is not sufficient to move same..]. .[.10. A control unit as
set forth in claim 6 wherein said one gerotor member comprises an
internally toothed gerotor rotor member supported for rotation
about the axis or rotation of the shaft and said other gerotor
member comprises an externally toothed gerotor rotor member
supported for rotational movement about its own axis and for
orbiting movement about the axis of said one gerotor member..].
.[.11. A control unit as set forth in claim 6 wherein said one
gerotor member comprises an externally toothed gerotor rotor member
and said other gerotor member comprises an internally toothed rotor
member..]. .[.12. A control unit as defined in claim 6 wherein said
one gerotor member comprises an internally toothed gerotor rotor
member which is mounted for rotary and orbital movement and said
other of said gerotor members comprises an externally toothed
gerotor rotor member supported for limited rotational movement for
moving said controlling valve member..]. .[.13. A control unit for
controlling fluid flow to a fluid motor, said control unit
comprising housing means having an inlet port and a pair of outlet
ports for communication with the fluid motor, directional control
valve means for directing fluid from said inlet port selectively to
one of said outlet ports in response to the direction of rotation
of an input shaft, said directional control valve means including a
fixed valve part and a movable valve part movable in opposite
directions to direct fluid to a selected one of said outlet ports
and to said fluid motor, and means for transmitting torque from
said input shaft to said movable valve part to effect movement
thereof, said means for transmitting torque to said movable valve
part comprising metering means for directing a metered flow of
fluid upon rotation of said shaft to said directional control valve
means and means for transmitting torque from said metering means to
said movable valve part..]. .[.14. A control unit as defined in
claim 13 wherein said metering means comprises a gerotor mechanism
having one rotor member drivingly connected with the input shaft
and a second rotor member drivingly connected with said movable
valve part, said gerotor mechanism transmitting a torque to said
valve part which is proportional to the torque applied to the input
shaft and said valve means providing a fluid pressure flow to said
fluid motor depending upon the amount of movement of said movable
valve part..]. .[.15. A control unit as defined in claim 13 further
including means for limiting movement of said movable valve part
relative to said fixed valve part, and biasing means for returning
said movable valve part to a neutral position relative to said
fixed valve part when torque application thereto is removed..].
.[.16. A control unit as set forth in claim 14 wherein said one
gerotor member comprises an internally toothed gerotor rotor member
supported for rotation about the axis of rotation of the shaft and
said outer gerotor member comprises an externally toothed gerotor
rotor member supported for rotational movement about its own axis
and for orbiting movement about the axis of said one gerotor
member..]. .[.17. A control unit as set forth in claim 14 wherein
said one gerotor member comprises an externally toothed gerotor
rotor member and said other gerotor member comprises an internally
toothed gerotor rotor member..]. .[.18. A control unit as defined
in claim 14 wherein said one gerotor member comprises an internally
toothed gerotor rotor member which is mounted for rotary and
orbital movement and said other of said gerotor members comprises
an externally toothed gerotor rotor member supported for limited
rotational movement for moving said movable valve part..]. .[.19. A
control unit for directing fluid to a fluid motor comprising:
gerotor means for metering fluid flow therethrough and including an
internally toothed gerotor member and an externally toothed gerotor
member disposed within and in meshing engagement with said
internally toothed gerotor member, said externally toothed gerotor
member having fewer teeth than said internally toothed gerotor
member for defining expanding and contracting chambers during
rotation of a first of said gerotor members relative to the second
gerotor member;
input means for rotating said first gerotor member relative to said
second gerotor member;
commutator valve means operatively connected to said gerotor means
for feeding fluid to and exhausting fluid from said expanding and
contracting chambers;
directional control valve means for alternatively directing fluid
exhausted from said commutator valve means to one of first and
second outlets, said directional control valve means including a
rotatable valve member having a neutral position and a first
operating position for directing fluid flow to said commutator
valve means while directing fluid exhausted therefrom to said first
outlet during rotation of said first gerotor member in one
direction and a second operating position for directing fluid flow
to said commutator valve means while directing fluid exhausted
therefrom to said second outlet during rotation of said first
gerotor member in the opposite direction;
and means interconnecting said valve member and said second gerotor
member for applying torque to said valve member upon initial
rotation of said
first gerotor member..]. .[.20. A control unit for directing fluid
comprising:
gerotor means for metering fluid flow therethrough and including an
internally toothed gerotor member and an externally toothed gerotor
member disposed within and in meshing engagement with said
internally toothed gerotor member, said externally toothed gerotor
member having fewer teeth than said internally toothed gerotor
member for defining expanding and contracting chambers during
rotation of a first of said gerotor members relative to the second
gerotor member;
input means for rotating said first gerotor member relative to said
second gerotor member;
commutator valve means operatively connected to said gerotor means
for feeding fluid to and exhausting fluid from said expanding and
contracting chambers;
changeover valve means for alternatively directing fluid exhausted
from said commutator valve means to one of first and second
outlets, said changeover valve means including a rotatable valve
member having a neutral position and a first operating position for
feeding fluid flow to said commutator valve means while directing
fluid exhausted therefrom to said first outlet during rotation of
said first gerotor member in one direction and a second operating
position for feeding fluid flow to said commutator valve means
while directing fluid exhausted therefrom to said second outlet
during rotation of said first gerotor member in the opposite
direction;
and means interconnecting said valve member and said second gerotor
member and including stop means for limiting rotation of said valve
member to define said first and second operating positions while
limiting rotation of said second gerotor member whereby rotation of
said first gerotor member applies a torque to said second gerotor
member to effect a rotation
of said valve member..]. 21. A control unit for controlling fluid
flow to a fluid motor, said control unit comprising valve means for
directing fluid to said fluid motor in response to rotation of the
input shaft, said valve means including a fixed valve part and a
movable valve part movable to direct fluid to said fluid motor, and
means for transmitting torque from said input member to said
movable valve part to effect movement thereof, said means for
transmitting torque to said movable valve part comprising metering
means for directing a metered flow of fluid upon rotation of said
shaft to said valve parts, means for transmitting torque from said
metering means to said movable valve part, said metering means
comprising a gerotor mechanism having one .[.rotor.]. .Iadd.gerotor
.Iaddend.member drivingly connected with the input shaft and a
second .[.rotor.]. .Iadd.gerotor .Iaddend. member drivingly
connected with said movable valve part, said gerotor mechanism
transmitting a torque to said valve part which is proportional to
the torque applied to the input shaft and said valve means
providing a fluid pressure flow to said fluid motor depending upon
the amount of movement of said movable valve part, said one gerotor
member comprising an internally toothed gerotor rotor member
supported for rotation about the axis of rotation of the shaft and
said .[.other.]. .Iadd.second .Iaddend.gerotor member comprising an
externally toothed gerotor rotor member supported for rotational
movement about its own axis and for orbiting movement about the
axis of said one gerotor member, and including commutator valve
means for providing fluid flow into and from the gerotor mechanism,
said commutator valve means comprising a sleeve-like commutator
valve member having exterior axial grooves and generally radially
extending passages extending from the outer periphery thereof into
the bore thereof, a manifold member having a bore within which said
commutator valve member is located, said manifold member having
passages extending therethrough and which alternately communicate
with said axially extending grooves and said generally radially
extending passages in said commutator valve member on relative
rotation therebetween, and means drivingly connected said manifold
member with said one .[.rotor.]. .Iadd.gerotor .Iaddend.member for
rotation therewith upon rotation of said input shaft. .[.22. A
control unit comprising a gerotor mechanism, said gerotor mechanism
comprising an internally lobed gerotor rotor member drivingly
connected with an input shaft, an externally lobed gerotor rotor
member located within said internally lobed gerotor rotor member,
the lobes on said gerotor rotor members defining pockets which
expand and contract upon relative rotational and orbital movement
of said gerotor members, commutator valve means for directing fluid
flow to said expanding pockets and from said contracting pockets,
said commutator valve means comprising a sleeve-like commutator
valve member having exterior axial grooves and generally radially
extending passages extending from the outer periphery thereof into
the bore thereof, a manifold member having a bore within which said
commutator valve member is located, said manifold member having
passages extending therethrough and which alternately communicate
with said axially extending grooves and said generally radially
extending passages in said commutator valve member on relative
rotation therebetween, means drivingly connecting said manifold
member to said internally lobed gerotor member for rotation
therewith, and including a fixed valve member and a controlling
valve member movable through a predetermined limited angle relative
to the fixed valve member to control fluid flow therethrough, and
means connecting said externally lobed gerotor rotor member to said
controlling valve member to transmit torque thereto to effect
movement of said controlling valve member relative to said fixed
valve member..]. .Iadd. 23. A control unit for controlling fluid
flow to a fluid motor, said control unit comprising valve means for
directing fluid to said fluid motor in response to rotation of a
shaft about a central axis, said valve means including a fixed
valve part and a movable valve part, said fixed and movable valve
parts defining passages directing fluid to said fluid motor upon
relative movement thereof, means for transmitting torque from said
shaft to said movable valve part to effect movement thereof, said
means for transmitting torque to said movable valve part comprising
a metering mechanism for directing a metered flow of fluid through
said valve parts to said motor upon rotation of said shaft, said
metering mechanism comprising a gearset including relatively
rotatable and orbital internally and externally toothed gear
members, said internally toothed gear member having one more tooth
than said externally toothed gear member and the teeth of said gear
members defining axially extending fluid pockets which expand and
contract on relative orbital and rotational movement of the gear
members, commutator valve means for controlling flow to and from
the fluid pockets formed by the gear members, one of said gear
members being supported for limited rotational movement, a
mechanical connection between said one gear member and said movable
valve part for transmitting torque from said one gear member to
said movable valve part upon limited rotational movement of said
one gear member, means for transmitting torque from said shaft to
said other of said gear members, a drive member disposed on one
axial side of said gearset and sealingly closing one axial end of
said fluid pockets, said commutator valve means including at least
one commutator valve member disposed on the other axial side of
said fluid pockets, and fastener means for clampingly engaging said
drive member, said commutator valve member and one of said gear
members together so as to resist relative axial movement
therebetween. .Iaddend..Iadd. 24. A control unit as defined in
claim 23 wherein said externally toothed gear member is supported
for orbital motion and for said limited rotational movement, and
wherein said internally toothed gear member is supported for
rotational movement and said mechanical connection comprises a link
angularly disposed with respect to said central axis, a portion of
said link being drivingly connected to said externally toothed gear
member and rockable relative thereto and a portion of said link
being drivingly connected with said movable valve part and rockable
relative thereto to impart movement thereto in response to
rotational movement of said externally toothed gear member, said
fastener means clampingly engaging said drive member, said first
commutator valve member and said internally toothed gear member
together. .Iaddend. .Iadd. 25. A control unit as defined in claim
23 wherein said second commutator valve member comprises a
sleeve-like member having exterior axial grooves and generally
radially extending passages extending from the outer periphery
thereof into the bore thereof, said first commutator valve member
comprising a manifold member having a bore within which said
sleeve-like member is located, said manifold member having passages
extending therethrough and which alternately communicate with said
axially extending grooves and said generally radially extending
passages in said sleeve-like member on relative rotation between
said manifold member and said sleeve-like member. .Iaddend. .Iadd.
26. A control unit as defined in claim 25 wherein said mechanical
connection includes a link having a first portion drivingly
connected with said sleeve-like member and rockable relative
thereto, said link being angularly disposed with respect to said
central axis and having a second portion drivingly connected with
said part and rockable relative thereto, said mechanical connection
further including a part drivingly connecting said sleeve-like
member with said movable valve part. .Iaddend..Iadd. 27. A control
unit as defined in claim 25 wherein said drive member includes a
drive plate member supported solely for rotation about said central
axis, said drive plate member being fixedly connected with said
shaft for rotation therewith, said drive plate member including a
radial face engaging a radial face of said internally toothed
member to seal the fluid pockets at said one axial end of said
gearset. .Iaddend. .Iadd. 28. A control unit as defined in claim 27
including a plate member disposed between said manifold member and
said other axial side of said gearset, said plate member having a
radial face engaging another radial face of said internally toothed
gear member, said fastener means clampingly connecting said plate
member with said manifold member and with said internally toothed
gear member. .Iaddend..Iadd. 29. A control unit as defined in claim
23 wherein said drive member, internally toothed gear member and
said first commutator valve member are located in a first housing
portion and are fastened together as a unit for simultaneous
assembly within said first housing portion, and wherein said fixed
and movable valve parts are located in a second housing portion.
.Iaddend..Iadd. 30. A control unit as defined in claim 23 wherein
said fixed and movable valve parts are disposed in a housing having
first and second ports for fluid communication with said motor,
said movable valve part being movable in opposite directions from a
neutral position for communicating fluid between said commutator
valve means and said first and second ports. .Iaddend. .Iadd. 31. A
control unit for controlling fluid flow to a fluid motor, said
control unit comprising valve means for directing fluid to said
fluid motor in response to rotation of an input shaft about a
central axis, said valve means comprising a fixed valve part and a
movable valve part, said fixed and movable valve parts defining
passages for directing fluid to said fluid motor upon relative
movement of said valve parts, a metering mechanism including an
externally toothed gear member supported for limited rotational
movement and an internally toothed gear member supported for
orbital and rotational movement relative to said externally toothed
gear member, said internally toothed gear member having one more
tooth than said externally toothed gear member and the teeth of
said gear members defining fluid pockets which expand and contract
on relative orbital and rotational movement of the gear members,
commutator valve means for controlling fluid flow to and from the
fluid pockets formed by the gear members, said metering mechanism
directing a metered flow of fluid to said motor through said valve
parts upon rotation of said input shaft, a drive sleeve having a
portion drivingly connected with said drive shaft for joint
rotation therewith about said central axis, said drive sleeve
having internal gear teeth, said internally toothed gear member
having external gear teeth around the periphery thereof in meshing
engagement with said internal gear teeth of said drive sleeve, a
mechanical connection for transmitting torque from said externally
toothed gear member to said movable valve part to move same
relative to said fixed valve part in response to rotation of said
externally toothed gear member, the intermeshing gear teeth of said
drive sleeve and said internally toothed gear member and of said
internally toothed gear member and said externally toothed gear
member being effective to rotate and orbit said internally toothed
gear member and to rotate said externally toothed gear member to
transmit torque to said movable valve part upon rotation of said
input shaft. .Iaddend..Iadd. 32. A control unit as defined in claim
31 wherein said drive sleeve comprises a tubular member having
integrally formed internal gear teeth and said drive shaft has a
fixed drive plate drivingly connected therewith and which has
external gear teeth in meshing engagement with internal gear teeth
on said tubular member. .Iaddend..Iadd. 33. A control unit as
defined in claim 31 wherein said fixed and movable valve members
comprise plate valve members movable relative to each other upon
transmission of torque from said externally toothed gear member to
one of the plate valve members. .Iaddend..Iadd. 34. A control unit
as defined in claim 31 wherein said externally toothed gear member
is mounted for limited rotation about an axis coaxial with said
central axis and the inner diameter of said drive sleeve is greater
than the outer diameter of said internally toothed gear member to
enable said relative orbital movement to occur while the meshing
engagement of said drive sleeve gear teeth and said gear teeth on
the outer periphery of said internally toothed member is
maintained. .Iaddend. .Iadd. 35. A control unit as defined in claim
31 wherein the center of the internally toothed member is offset
from the center of the drive sleeve, and wherein only a portion of
the external gear teeth on the periphery thereof is in meshing
engagement with the internal gear teeth of said drive teeth.
.Iaddend. .Iadd. 36. A control unit comprising an input shaft,
housing means having an inlet port and a pair of outlet ports, a
directional control valve means for porting fluid from said inlet
port selectively to one of said outlet ports, said directional
control valve means comprising a fixed valve means and a
controlling valve member movable through a predetermined limited
distance relative to said fixed valve member to control fluid flow
therethrough, and metering means in said housing interconnecting
said input shaft and said controlling valve member for moving said
controlling valve member said limited distance in response to
initial rotation of said input shaft and for directing fluid flow
to said directional control valve as said shaft rotates, said
metering means comprising a gerotor mechanism having an internally
toothed gerotor member and an externally toothed gerotor member,
means connecting said input shaft to one of said gerotor members
for rotation with said shaft, and means connecting the other of
said gerotor members with said controlling valve member to move
said controlling valve member, said other gerotor member being
rotatable about its central axis in response to initial rotation of
said one gerotor member to effect movement of said controlling
valve member and said valve members constraining said other gerotor
member to then orbit only relative to said one gerotor member
during continued rotation of said one gerotor member by rotation of
said input shaft when the force applied to said controlling valve
member is not sufficient to move same. .Iaddend..Iadd. 37. A
control unit comprising an input shaft, housing means having an
inlet port and a pair of outlet ports, a directional control valve
means for porting fluid from said inlet port selectively to one of
said outlet ports, said directional control valve means comprising
a fixed valve means and a controlling valve member movable through
a predetermined limited distance relative to said fixed valve
member to control fluid flow therethrough, and metering means in
said housing interconnecting said input shaft and said controlling
valve member for moving said controlling valve member said limited
distance in response to initial rotation of said input shaft and
for directing fluid flow to said directional control valve as said
shaft rotates, said metering means comprising a gerotor mechanism
having an internally toothed gerotor member and an externally
toothed gerotor member, means connecting said input shaft to one of
said gerotor members for rotation with said shaft, and means
connecting the other of said gerotor members with said controlling
valve member to move said controlling valve member, said one
gerotor member comprising an internally toothed gerotor rotor
member supported for rotation about the axis of rotation of the
shaft and said other gerotor member comprising an externally
toothed gerotor rotor member supported for rotational movement
about its own axis and for orbiting movement about the axis of said
one gerotor member. .Iaddend..Iadd. 38. A control unit comprising
an input shaft, housing means having an inlet port and a pair of
outlet ports, a directional control valve means for porting fluid
from said inlet port selectively to one of said outlet ports, said
directional control valve means comprising a fixed valve means and
a controlling valve member movable through a predetermined limited
distance relative to said fixed valve member to control fluid flow
therethrough, and metering means in said housing interconnecting
said input shaft and said controlling valve member for moving said
controlling valve member said limited distance in response to
initial rotation of said input shaft and for directing fluid flow
to said directional control valve as said shaft rotates, said
metering means comprising a gerotor mechanism having an internally
toothed gerotor member and an externally toothed gerotor member,
means connecting said input shaft to one of said gerotor members
for rotation with said shaft, and means connecting the other of
said gerotor members with said controlling valve member to move
said controlling valve member, said one gerotor member comprising
an externally toothed gerotor rotor member and said other gerotor
member comprising an internally toothed gerotor member.
.Iaddend..Iadd. 39. A control unit for controlling fluid flow to a
fluid motor, said control unit comprising housing means having an
inlet port and a pair of outlet ports for communicating with the
fluid motor, directional control valve means for directing fluid
from said inlet port selectively to one of said outlet ports in
response to the direction of rotation of an input shaft, said
directional control valve means including a fixed valve part and a
movable valve part movable in opposite directions to direct fluid
to a selected
one of said outlet ports and to said fluid motor, and means for
transmitting torque from said input shaft to said movable valve
part to effect movement thereof, said means for transmitting torque
to said movable valve part comprising metering means for directing
a metered flow of fluid upon rotation of said shaft to said
directional control valve means and means for transmitting torque
from said metering means to said movable valve part, said metering
means comprising a gerotor mechanism having one rotor member
drivingly connected with the input shaft and a second rotor member
drivingly connected with said movable valve part, said gerotor
mechanism transmitting a torque to said valve part which is
proportional to the torque applied to the input shaft and said
valve means providing a fluid pressure flow to said fluid motor
depending upon the amount of movement of said movable valve part,
said one gerotor member comprising an internally toothed gerotor
rotor member supported for rotation about the axis of rotation of
the shaft and said second gerotor member comprising an externally
toothed gerotor rotor member supported for rotational movement
about its own axis and for orbiting movement about the axis of said
one gerotor member. .Iaddend..Iadd. 40. A control unit for
controlling fluid flow to a fluid motor, said control unit
comprising housing means having an inlet port and a pair of outlet
ports for communication with the fluid motor, directional control
valve means for directing fluid from said inlet port selectively to
one of said outlet ports in response to the direction of rotation
of an input shaft, said directional control valve means including a
fixed valve part and a movable valve part movable in opposite
directions to direct fluid to a selected one of said outlet ports
and to said fluid motor, and means for transmitting torque from
said input shaft to said movable valve part to effect movement
thereof, said means for transmitting torque to said movable valve
part comprising metering means for directing a metered flow of
fluid upon rotation of said shaft to said directional control valve
means and means for transmitting torque from said metering means to
said movable valve part, said metering means comprising a gerotor
mechanism having one gerotor member drivingly connected with the
input shaft and a second gerotor member drivingly connected with
said movable valve part, said gerotor mechanism transmitting a
torque to said valve part which is proportional to the torque
applied to the input shaft and said valve means providing a fluid
pressure flow to said fluid motor depending upon the amount of
movement of said movable part, said one gerotor member comprising
an externally toothed gerotor rotor member and said second gerotor
member comprising an internally toothed gerotor rotor member.
.Iaddend. .Iadd. 41. A control unit for vehicle powersteering
mechanism comprising:
a housing having an inlet for connection to a source of hydraulic
fluid under pressure and an outlet for returning hydraulic fluid to
said source;
a pair of ports for connection to a double chamber hydraulic
servomotor the movement of which controls the steering of dirigible
wheels of the vehicle;
a hydraulic motor provided with a rotatable element and a follower
element;
a distributor valve means provided with at least one displaceable
body, in the form of a sleeve, angularly displaceable with respect
to a neutral position, said distributor valve means being operable
on rotation of a control shaft connected thereto to divert
hydraulic fluid flowing from said inlet through said housing to
said outlet to one of said ports and thus to its associated chamber
of said servomotor, via said hydraulic motor, the hydraulic fluid
being exhausted from the other chamber of the servomotor to said
outlet via said other port;
means adapted to form a direct connection of said rotatable element
of the motor to said control shaft;
means adapted to form a mechanical connection of said follower
element of the motor to the sleeve like displaceable body of said
rotatable distributor valve means;
means adapted to limit the displacement of said sleeve like
displaceable body with respect to the stationary part of said
distributor valve means, and with respect to said neutral
position;
a plurality of circumferentially spaced longitudinally extending
passages provided in said sleeve like displaceable distributor body
to feed hydraulic fluid from said inlet, via said motor, to one or
the other of said ports when said sleeve like displaceable
distributor body is in its displaced position with respect to the
neutral position;
first passages in said housing communicating with said inlet and
with said longitudinally extending passages; second passages in
said housing emanating from each of said ports and communicating
with said longitudinally extending passages; and
radially extending passages in said sleeve like displaceable
distributor body communicating with said first passages in said
housing, for feeding hydraulic fluid arriving from said inlet to
said distributor valve means.
.Iaddend. .Iadd. 42. A fluid control unit comprising
an input shaft,
housing means having an inlet port and a pair of outlet ports,
a directional control valve means for porting fluid from said inlet
port selectively to one of said outlet ports, said directional
control valve means including
a valve member fixed relative to said housing means,
a controlling valve member movable through a predetermined limited
distance relative to said fixed valve member to control fluid flow
therethrough,
said fixed valve member and said controlling valve member
comprising plate valve members movable relative to each other upon
rotation of said input shaft,
a metering mechanism in said housing means connecting said input
shaft and said controlling valve member for transmitting torque to
move said controlling valve member said limited distance in
response to rotation of said input shaft,
said metering mechanism comprising a gearset including relatively
rotatable and orbital internally and externally toothed gears, said
externally toothed gear being located within said internally
toothed gear, said internally toothed gear having one more tooth
than said externally toothed gear, and the teeth of said internally
and externally toothed gears defining fluid chambers which expand
and contract on relative orbital and rotational movement of the
gears,
means connecting one of said gears to said input shaft for movement
in response to rotation of the input shaft, means connecting the
other of said gears to said controlling valve member,
a commutator plate-valve connected to said externally toothed gear
and having a first radial face slidably engaging one radial face of
said internally toothed gear, said commutator plate-valve member
including passages communicating with said directional control
valve means to direct fluid received by said directional control
valve from the inlet to the expanding fluid pockets and to direct
fluid from the contracting fluid pockets to the directional control
valve, and
stop means for limiting movement of said controlling valve member
of said directional control valve relative to the housing means.
.Iaddend..Iadd.
. A control unit as defined in claim 42 wherein said controlling
valve member comprises a pivotal plate-valve member movable from a
neutral position to an operating position communicating said inlet
port with said commutator valve for directing fluid from said inlet
port to said metering mechanism through said commutator valve and
communicating one of said outlet ports with said commutator valve
for directing fluid from said metering mechanism to said one of
said outlet ports. .Iaddend..Iadd. 44. A control unit as defined in
claim 43 wherein said fixed plate-valve member and said controlling
plate-valve member have adjacent radially extending faces which are
slidable relative to each other upon pivotal movement of said
controlling plate-valve member in response to the torque
transmitted thereto by rotation of said other of said gears,
adjacent radial faces of said fixed and controlling plate-valve
members cooperating upon relative pivoting movement to form part of
fluid passages directing flow from said inlet port to said
commutator valve and from said commutator valve to said one of said
outlet ports. .Iaddend..Iadd. 45. A control unit as defined in
claim 44 wherein said one gear element comprises said internally
toothed gerotor gear and said other gear comprises said externally
toothed gerotor gear, said commutator plate-valve member being
movable with said externally toothed gerotor gear relative to said
internally toothed gerotor gear and having a first radial face
engaging one radial face of said internally toothed gerotor gear.
.Iaddend..Iadd. 46. A hydraulic control unit comprising
means defining an inlet port and a pair of outlet ports,
an input shaft,
a metering mechanism operatively associated with said input shaft
and allowing flow from the inlet port to an outlet port in a
quantity which is proportional to the speed and extent of rotation
of said input shaft, said metering mechanism including
a first gear element connected to said input shaft for rotation
therewith and
a second gear element which orbits in response to rotation of said
first gear element,
said first and second gear elements defining fluid chambers
therebetween which have changing volumes during relative movement
of said first and second gear elements,
control valve means including a pivotal valve having a neutral
position and pivotal to an operating position upon rotation of said
input shaft for directing fluid from said inlet port to some
chambers in said metering mechanism and directing fluid from other
chambers in said metering mechanism to one of said outlet
ports,
means connecting said pivotal valve and said second gear element of
the metering mechanism for common pivoting movement,
resilient means biasing said pivotal valve to said neutral
position, and
stop means for limiting pivoting movement of said pivotal
valve.
.Iaddend..Iadd. 47. A hydraulic control unit as defined in claim 46
wherein said means connecting said pivotal valve and said second
gear element of said metering mechanism comprises a link drivingly
connected to and disposed at an angle to the axis of rotation of
said second gear element, and said resilient means biasing said
pivotal valve to said neutral position acts directly on said
pivotal valve. .Iaddend..Iadd. 48. A control unit as defined in
claim 47 wherein said first gear element of said metering mechanism
comprises an internally toothed gerotor gear and said second gear
element of said metering mechanism comprises a complementary
externally toothed gerotor gear, said pivotal valve including a
directional control valve portion and a commutator valve portion
having joint pivotal movement, a manifold member coupled with said
internally toothed gerotor gear and rotatable therewith relative to
said commutator valve portion of said pivotal valve.
.Iaddend..Iadd. 49. A control unit as defined in claim 48 wherein
said pivotal valve comprises a cylindrical member having a
plurality of circumferentially spaced, axially extending slots on
the outer periphery thereof, and said control unit further includes
a second valve member encircling said cylindrical member and having
fluid passages therein, and said slots in said cylindrical member
communicate with said fluid passages in said second valve member
upon pivotal movement of said cylindrical member away from said
neutral position. .Iaddend. .Iadd. 50. A control unit as defined in
claim 49 wherein said cylindrical member is hollow and certain of
said axially extending slots includes openings communicating with
the interior of said cylindrical member, and means defining a fluid
passage communicating the interior of said cylindrical member with
said metering mechanism through said commutator valve portion of
said pivotal valve. .Iaddend..Iadd. 51. A control unit as defined
in claim 50 including means defining an external housing, said
resilient means for biasing said pivotal valve to the neutral
position comprises a torsion spring located partially within said
hollow cylindrical member, said torsion spring having a first
portion releasably fixed against motion relative to said housing
and an axially spaced portion connected with said pivotal valve for
movement therewith and wherein said first portion of said torsion
spring may be manually moved relative to said housing when said
first portion of said torsion spring is released from said housing
to allow pivotal movement of said pivotal valve to adjust the
neutral position of said pivotal valve. .Iaddend..Iadd. 52. A
control unit as defined in claim 46 wherein said control valve
includes a commutator valve for directing fluid flow to and from
the variable volume fluid chambers of said metering mechanism in
timed relation to the changing volumes thereof during relative
movement of said first and second gear elements, said pivotal valve
comprising a first plate directional control valve member pivotal
from a neutral position to an operating position communicating said
inlet port with said commutator valve for directing fluid from said
inlet port to said metering mechanism through said commutator valve
and communicating said outlet port with said commutator valve for
directing fluid from said metering mechanism to said outlet port.
.Iaddend..Iadd. 53. A control unit as defined in claim 52 wherein
said first plate directional control valve member cooperates with a
second plate valve member adjacent thereto, said first plate valve
member being pivotally movable with respect to said second plate
valve member, said first plate valve member and said second plate
valve member having adjacent radially extending faces which are
slidable relative to each other upon pivotal movement of said first
plate valve member in response to the torque transmitted thereto by
rotation of said second gear element, adjacent radial faces of said
first and second plate valve members cooperating upon relative
rotation thereof to form part of fluid passages directing flow from
said inlet port to said commutator valve and from said commutator
valve to an outlet port. .Iaddend..Iadd. 54. A control unit as
defined in claim 53 wherein said first gear element comprises an
internally toothed gerotor gear and said second gear element
comprises a complementary externally toothed gerotor gear, said
commutator valve comprising a third plate valve member movable in
timed relation to the movement of at least one of said gerotor
gears and having a first radial face engaging one radial face of
the internally toothed gerotor gear, said third plate valve member
forming part of commutator passages for directing the flow of fluid
to and from said fluid chambers of said metering mechanism.
.Iaddend..Iadd. 55. A control unit as defined in claim 54 wherein
said third plate valve member includes a second radial face
engaging the other radial face of said first plate valve member and
is connected to said externally toothed gear. .Iaddend..Iadd. 56. A
control unit as defined in claim 46 further including a drive
member connected with said input shaft and disposed on one axial
side of said metering mechanism, said drive member sealingly
closing one axial side of said metering mechanism, at least one
commutator valve part disposed on the other axial side of the
metering mechanism, and fastener means for clampingly engaging said
drive member said second element of said metering mechanism and
said one commutator valve part together to resist relative
rotational and axial movement therebetween. .Iaddend..Iadd. 57. A
control unit as defined in claim 46 wherein said stop means
comprises a stop for limiting rotational movement of said pivotal
valve, said stop being engageable with a part of said pivotal valve
after limited pivotal movement thereof from said neutral position.
.Iaddend..Iadd. 58. A hydraulic control unit comprising
means defining an inlet port and an outlet port,
an input shaft,
a metering mechanism operatively associated with said input shaft
and controlling flow from the inlet port to the outlet port in a
quantity which is proportional to the speed and extent of rotation
of said input shaft,
said metering mechanism including a first gear element rotatable
with said input shaft and a second gear element which can rotate
and orbit about the central axis of said first element in response
to rotation of said first element,
said first and second gear elements defining fluid chambers
therebetween which have changing volumes during relative movement
of said first and second elements,
control valve means including a pivotal control valve having a
neutral position preventing flow from said inlet port through said
metering mechanism to said outlet port and pivotal to an operating
position upon rotation of said input shaft whereat said control
valve means directs flow from said inlet port to some chambers of
said metering mechanism and flow from other chambers of said
metering mechanism to said outlet port, means connecting said
control valve and said second gear element including a pivotal link
drivingly connected with and disposed at an angle to the axis of
rotation of said second gear element and said control valve to
effect pivoting movement of said control valve upon rotation of
said second gear element,
biasing means acting directly on said control valve for biasing
said control valve to said neutral position, and
stop means for limiting the rotation of said control valve.
.Iaddend.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic control unit which is
operative to control the flow of fluid to a hydraulic motor, such
as a steering motor, in the steering system of a vehicle. The
control unit is applicable to controlling the flow of fluid to
different types of hydraulic motors and which motors may be used
for a variety of different purposes.
Hydraulic control units which are operated upon the manual steering
of a vehicle to direct the flow of fluid to a steering motor
associated with the steering mechanism of the vehicle are known.
Many patents disclosed such structures. Examples of such structures
are shown in U.S. Pat. Nos. 2,984,215; 3,443,378; and
3,613,364.
The known designs, as typified by the abovementioned patents,
include a valve mechanism which is operated upon turning of the
steering wheel of the vehicle to direct the flow of fluid to the
steering motor. The valve is associated with a gerotor gearset such
that the fluid flows through the gerotor gearset and then into the
steering motor. The gerotor gearset meters the flow of fluid to the
steering motor as the steering wheel is turned so that there is a
proper follow-up relationship between the turning of the steering
wheel and the turning of the dirigible wheels of the vehicle for
effecting steering of the vehicle. In general, the known designs
are relatively expensive to manufacture and are relatively
complicated. In addition, the known designs are relatively large in
size due to the structural relationship of the parts thereof.
Typical of the present commercial designs is that the valve
mechanism which controls the flow of fluid to the steering motor is
a rotary valve, i.e., the valve has a valve part directly connected
to the steering wheel to rotate upon rotation of the steering
wheel. This results in the need for an interconnection between the
steering shaft and the rotating valve part. The juxtaposition of
the various parts has resulted in the need for the steering shaft
or a part connected therewith to extend through or into the rotary
valve so as to be mechanically interconnected with the rotatable
valve part. This has resulted in the necessary requirement that the
rotary valve has a diameter which is of sufficient size to allow
for the steering shaft to be so positioned. This likewise has
resulted in a relatively large package size for the unit, and
creates leakage problems.
While systems are known which do not incorporate a rotating valve,
such as typified by U.S. Pat. Nos. 2,321,377 and 3,360,932, such
systems have not had significant commercial acceptance, and will
not be discussed in detail.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a substantially improved control
unit of the above-noted type. The control unit of the present
invention is simpler in construction, may be constructed in a small
package size, and may be substantially less expensive to
manufacture than those constructions typified by the abovementioned
prior art.
These substantial advantages are achieved by the present invention
primarily by the elimination of a rotary valve in the system, and
more specifically by the elimination of a valve part which is
rotated at all times with the steering wheel. In the present
invention there is no rotating valve part which is directly
connected with the steering wheel to rotate therewith. Accordingly,
the diameter of the valve mechanism may be made small. Accordingly,
package size and leakage problems are minimized and a substantial
simplification in the system is effected.
The present invention includes a valve which is operated upon
initial turning of the steering wheel from a neutral position to an
actuated position for directing the flow of fluid to the steering
motor. This actuation is effected through and by initial rotation
of the parts of a metering means which is associated with the
valve. Specifically, in the present invention the steering wheel is
directly connected to a first member of a metering means, which
metering means is in the form of a gerotor gearset. The initial
rotation of that first member of the geroter gearset causes a
torque to be applied to the second member of the gerotor gearset
and this torque is applied to the valve to effect shifting thereof
against a bias through a mechanical interconnection between the
second member of the gerotor gearset and the valve. The torque
applied to the valve is a function of the pressure across the
gerotor gearset and that pressure is a function of the torque
applied to the steering wheel. Accordingly, the faster the steering
wheel is turned, the greater the torque applied to the valve and
the larger the volume of fluid ported to the steering motor. The
degree of movement of the valve is slight and stops are provided to
prevent excessive movement of the valve on excessive applications
of torque thereto.
The present invention may be embodied in a variety of different
control unit structures, and further features and advantages of the
present invention will be apparent from the detailed description of
structures which embody the present invention and which description
is made with reference to the drawings.
DESCRIPTION OF FIGURES
FIG. 1 is a schematic view illustrating the control unit of the
present invention in a steering system;
FIG. 2 is an axial cross-sectional view of the control unit shown
in FIG. 1;
FIG. 3 is a view illustrating a gerotor gearset embodied in the
unit of FIG. 1;
FIG. 4 is a cross-sectional view of the unit of FIG. 2, which parts
omitted, taken along the section line 4--4 of FIG. 2;
FIG. 5 is a cross-sectional view of valve parts used in the
embodiment of FIG. 2;
FIGS. 6 and 7 are sectional and plan views of another valve part
used in the embodiment of FIG. 2;
FIGS. 8-10 are schematic views illustrating the flow of fluid
through the valve mechanism embodied in FIG. 2;
FIG. 11 is a sectional view of a commutating valve arrangement of
the embodiment of FIG. 2;
FIG. 12 is a sectional view taken approximately along the line
12--12 of FIG. 11;
FIG. 13 is a schematic view of a modification embodying the present
invention;
FIG. 14 is a schematic view of another modification embodying the
present invention.
FIG. 15 is a schematic view taken approximately along the line
15--15 of FIG. 14;
FIG. 16 is a schematic view taken approximately along line 16--16
of FIG. 14;
FIG. 17 is a schematic view of still another modification embodying
the present invention;
FIG. 18 is a schematic view of yet another modification embodying
the present invention; and
FIG. 19 is a view taken approximately along the line 19--19 of FIG.
18.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As noted above, the control unit of the present invention may be
embodied in a variety of different structural embodiments.
Moreover, the control unit of the present invention may be applied
to a variety of different uses. As representative, FIG. 1
illustrates a control unit 10 which for purposes of illustration is
used in a steering control system for steering a vehicle.
The control unit 10 includes a housing 11 into which a steering
shaft 11 of a vehicle extends. At the outer end of the shaft 12 a
steering wheel 13 is connected so that upon turning of the steering
wheel the shaft 12 likewise turns and the control unit 10 is
operated to direct steering control fluid to a steering motor 14
which is suitably connected to effect power-assisted steering of
the wheels of the vehicle. The interconnection between the motor 14
and the mechanism of the vehicle for effecting steering thereof
will not be described, since such is conventional and known.
As shown in FIG. 1, the housing 11 includes two outlet ports 20,
21, respectively, which are connected to opposite sides of the
motor 14 so that when fluid flows from those outlets, the fluid
flows into one or the other of the ends of the motor 14. In
addition, the housing 11 includes an input port 22 which is
connected to an engine-driven pump 23. The housing also includes an
outlet port 24 which is connected to a fluid reservoir 25.
The control unit 10 functions so that when no steering of the
vehicle is occurring, fluid is directed by the pump 23 into the
inlet 22 in the housing 11 and from the outlet 24 to the reservoir
in a continuous manner. However, if the operator is turning the
steering wheel, the unit 10 operates to direct fluid from the inlet
22 to one or the other of the outlets 20, 21 depending upon the
direction of turning of the steering wheel. The other of the
outlets 20, 21 is connected with the outlet 24 so that fluid
therefrom is directed to the reservoir 25.
As shown in FIG. 2, the housing 11 of the control unit 10 includes
housing portions 25, 25a. The housing portion 25 has a projecting
portion 26 into which the steering shaft 12 extends. A suitable
seal and bearing arrangement, generally designated 27, is
associated with the housing portion 26 and the shaft 12 so as to
support the shaft 12 for rotation relative to the housing and
prevent any leakage of fluid along the shaft 12. The shaft 12
terminates in a chamber 29 in the housing portion 25 and
specifically a flange portion 30 of the shaft 12 is located in the
chamber 29. Suitable axial thrust bearings 31 are interposed
between a radial face of the flange portion 30 and a radial surface
of the housing portion 25, as shown in FIG. 2.
In accordance with the present invention, a fluid metering means,
generally designated 35, is located in the chamber 29. The metering
means 35 comprises a gerotor gearset which includes an outer member
36 which has internal teeth thereon and an inner member 37 which
has external teeth thereon. The teeth of the members 36, 37 are
intermeshed, as best shown in FIG. 3. The gerotor metering
mechanism 35 may be of conventional construction and will not be
described in detail, since gerotor mechanisms are known.
The gerotor member 36 is supported for rotation about an axis
coextensive with the axis of rotation of the shaft 12. In addition,
the outer gerotor member 36 is secured to the flange portion 30 of
the shaft 12 by means of a plurality of suitable screw fasteners
40a so that upon rotation of the shaft 12 the outer gerotor member
36 is likewise rotated about the axis of rotation of the shaft 12.
The initial rotation of the outer gerotor member 36 with the shaft
12 effects rotation of the rotor member 37 about its own axis.
After the rotor member rotates through a small angle of rotation
about its own axis, it is restrained from further rotation about
its own axis, and thus on further rotation of the member 36, the
member 37 orbits about the axis of rotation of the member 36, all
of which will be described in greater detail hereinbelow. Of
course, as the rotational and orbiting relative movement of the
members 36, 37 occurs, the pockets which are defined by lobes of
the members 36, 37 and which are designated A-F in FIG. 3 expand
and contract.
The rotor member 37 is mechanically connected by a drive link 40 to
a valve mechanism, generally designated 41. The valve mechanism 41
is constructed to direct fluid flow to the steering motor 14 when
actuated from a neutral condition. In its neutral condition the
valve 41 directs fluid from inlet 22 to outlet 24. When actuated,
the valve mechanism 41 directs flow from inlet 22 to either port 20
or 21 and connects the other port 20 or 21 to outlet 24, depending
on the steering direction. The valve mechanism 41 is actuated
through the drive link 40 by the initial slight rotation of the
rotor member 37.
The valve mechanism 41 is located in the housing portion 25a of the
unit 10. The valve mechanism 41 comprises an outer valve sleeve 42
(see FIG. 2) which is rigidly and fixedly secured in a suitable
manner in the housing 11, and a second or inner sleeve portion 43
which is fixedly and rigidly secured to the outer sleeve portion
42. The two sleeves 42 43, since they are assembled together in a
fixed relationship and are fixed within the housing 11, may be
considered to be a single valve element and could be so
constructed.
The valve mechanism 41 further includes a movable valve part which
is designated 44 and which is located within the valve sleeve
member 43. The valve part 44 is supported for limited rotary
movement within the valve sleeve 43 upon rotation of the rotor
member 37. The right end of the valve member 44, as viewed in FIG.
2, is mechanically connected by a connection 45 to one end of the
commutator valve 101, to be described hereinbelow. Accordingly,
upon torque being applied to the rotor member 37, the drive link 40
transmits that torque to the valve member 44 through the commutator
valve 101, and the mechanical connection 45. In the description
below, the slots in the sleeve 43 are given the same reference
number as the openings in the sleeve 42 with which they
communicate.
The valve member of outer sleeve 42 is provided with a series of
four annular grooves extending therearound and which are designated
50-53. The grooves 50-53 at various locations have openings
provided therein for directing fluid flow radially inwardly, all of
which will be described in greater detail below. The inner sleeve
member 43 likewise has a plurality of slots therein, see FIG. 5,
which extend axially, and underlie the plurality of the radial
grooves 50-53. The mechanical connection 45 will not be described
in detail, but in general it comprises a hollow cylindrical member
which is keyed to both the commutator valve 101 and valve 44. It
does not interfere with fluid flow therethrough as will be
apparent. The valve member 44, shown in FIGS. 6 and 7, is provided
with a series of lands and grooves which extend axially of the
valve member 44.
As noted above, when no steering is occurring, the valve
connections are such that fluid flows directly from the inlet 22 to
the outlet port 24 through fluid passageways in a manner which will
be described hereinbelow. In addition, when the valve member 44 is
moved due to rotation of the steering wheel, fluid flows from the
inlet port 22 through the valve mechanism 41 and the metering
mechanism 35 and to one of the outlet ports 20 or 21 to one end of
the motor 14. The return flow is from the other of the outlet ports
20 or 21 through the valve mechanism 41 and to the reservoir 25.
Whether the flow is through the metering motor 35 to the port 20 or
21 depends upon the direction of rotation of the steering wheel 13.
The detailed operation of the valve is best illustrated in
schematic FIGS. 8-10 which illustrate respectively the neutral
position, a right-turn position, and a left-turn position of the
valve parts.
FIG. 8 specifically illustrates the flow through the valve
mechanism 41 when the valve mechanism 41 is in its neutral
condition. As noted above, the valve sleeve 42 includes four
annular grooves which extend circumferentially therearound and
which are designated 50, 51, 52 and 53. Groove 50 communicates with
the outlet port 24 and there are four radially extending holes 60,
60a, 60b, 60c in valve sleeve 42 which communicate with the groove
50. The annular groove 51 communicates with the inlet port 22 and
there are four radially extending holes designated 61, 61a, 61b,
61c in valve sleeve 42 which communicate with the annular groove
51. The annular groove 52 communicates with the outlet port 20
leading to one side of the motor 14 and there are radially
extending holes 64, 64a in the valve sleeve 42 which communicate
with the groove 52. The annular groove 53 communicates with the
outlet port 21 and there are likewise radially extending holes 63,
63a in the sleeve member 42 which communicate with the annular
groove 53.
In addition, the area of the sleeve assembly designated 69
communicates with one side of the metering mechanism 35, as will be
described in detail hereinbelow. To provide for this communication,
the inner valve sleeve 43 includes two radial openings 62, 62a
which communicate fluid to the area 69. In addition, the valve
member 44 is provided with an axial passage 65 which communicates
with the other side of the metering mechanism 35 and radial
passages 66, 66a therein communicating with the axial passage
65.
As shown schematically in FIG. 8, when the valve member 44 is in
its neutral position, lands 70, 70a, 70b, 70c are located adjacent
the inlets 61, 61a, 61b, 61c, respectively. The lands 70, 70a, 70b,
70c do not block flow of fluid from the inlets 61-61c into grooves
71, 72a, 72b, 72c in the valve member 44. The grooves 72, 72c
communicate with the outlet 60, and the grooves 72a, 72b
communicate with the outlet 60b. Accordingly, when the valve member
44 is in its neutral position, the flow of fluid from the inlets
61-61c is directed through the valve mechanism 41 to the outlet 24
and to the reservoir 25. Thus, the valve mechanism may be termed
open center. It should be clear, however, that a closed center
valve could also be utilized in the system. The other reservoir
ports 60a and 60c communicate with grooves 74, 74a in the valve
member 44 which are adjacent the ports 60a, 60c but are blocked by
the adjacent lands from communicating with adjacent ports.
Moreover, in the neutral condition of the valve parts, as shown in
FIG. 8, the openings 62 and 62a which communicate with the metering
mechanism are also in communication with grooves 75, 75a,
respectively, in the outer periphery of the valve member 44. The
grooves 75 and 75a are located so as to provide communication with
openings 63, 63a in the valve mechanism 41. The openings 63, 63a,
of course, communicate with one end of the steering motor 14.
Moreover, the openings 64, 64a, when the valve member 44 is in its
neutral condition as shown in FIG. 8, are located immediately
adjacent lands 77, 77a, respectively, in the valve member 44. The
lands 77, 77a are likewise constructed so as not to block
communication between the openings 64, 64a and the openings 66,
66a, respectively, in the valve member 44. Thus, when the valve
member 44 is in its neutral condition, the opposite ends of the
steering motor are connected across the metering mechanism 35
providing an "open cylinder" system. This construction permits the
transmission of any forces which are applied to the wheels of the
vehicle to be transmitted back through the hydraulic fluid in the
system to the gerotor mechanism 35, tending to cause the gerotor
mechanism to operate as a motor. This provides a "feel" to the
operator of any such forces.
As noted above, the valve member 44 is moved or rotated from its
neutral position in response to rotation of the steering wheel to
direct fluid to the steering motor 14 for purposes of steering.
Moreover, as noted above, the valve member 44 is rotated due to
torque applied thereto through the rotor member 37 and the drive
link 40. As should be apparent to those skilled in the art, the
rotor member 37 is rotated due to forces which act on the member 37
upon rotation of the steering wheel. These forces involve a
mechanical or gear reaction due to the fact that the rotor members
36, 37 have a geared interconnection therebetween. However, the
pressure across the gerotor mechanism greatly affects the torque
applied to the rotor member 37. If these is a low fluid pressure
across the gerotor mechanism 35 due to a low differential fluid
pressure across the steering motor, the torque applied to the
rotate the valve member 44 is substantially lower than when there
is a high differential pressure across the steering motor. Thus,
the torque applied to the valve 44 is a function of the pressure
required to operate the steering motor.
In this connection, the valve member is actually torque-responsive
and the torque which can be applied to the valve member 44 through
the gerotor mechanism 35 from the steering wheel 13 is proportional
to the fluid pressure in the gerotor mechanism which in turn is
responsive to the pressure differential across the steering motor.
The greater the torque applied to the steering wheel, the greater
the torque applied to the valve member 44 and the farther the valve
member 44 will rotate.
In the event high torque is applied to the valve member 44 in one
direction, the valve member 44 may move to its extreme position in
that direction wherein surface portions 80 of the valve member 44
engage surface portions 81 of the sleeve member 43. If the rotation
of the rotor member 37 is in the opposite direction, again the
valve member 44 can only rotate until surfaces 80a, 81a engage. As
can be viewed in FIG. 4, the amount of rotation of valve member 44
which can occur is very slight and is designated X in FIG. 4. Once
the surface portions 80, 81 or 80a, 81a engage, further rotation of
the valve member 44 is positively prevented. In many steering
conditions, the torque applied to the steering wheel by the
operator will be of a magnitude where the valve member 44 rotates a
very slight increment less than its full capability for rotation.
Thus, the valve member 44 in many steering conditions will move to
an intermediate position rather than to a full indexed positon
where the stops 80, 81 or 80a, 81a engage.
Accordingly, for purposes of steering, the valve member 44 will
take a position in which it divides the flow of fluid from the
pressure ports 61-61c between the outlet ports 60, 60b, on the one
hand, and the metering mechanism 35, on the other hand.
For example, if the valve member 44 is rotated in a clockwise
direction, as viewed in FIG. 8, to a very slight extend such that
communication between the ports 61-61c and ports 60, 60b is not
blocked off, it should be clear that there will be a pressure
increase in the ports 61-61c. This will be due to the fact that the
flow area of communication between the ports 61-61c and the ports
60, 61b decreases. At the same time, ports 61a, 61c will
communicate with passage 66, 66a, respectively, in the valve member
44 for directing fluid to the metering mechanism 35. Also, the area
of communication between ports 62, 62a and the ports 63, 63a,
respectively will increase so that fluid will be directed from the
metering mechanism through the ports 63, 63a and to one side of the
steering motor. The opposite side of the steering motor will be
connected to tank due to the fact that ports 64, 64a will
communicate with tank through ports 60a, 60c in the valve
mechanism. As a result, the flow from the inlet pressure ports
61-61c will be divided depending upon the amount of rotation of the
valve 44. This provides for a pressure build-up in the steering
motor 14 which is proportional to the amount of rotation of the
valve member 44, and the valve member 44 moves in proportion to the
torque applied to the steering wheel providing an effective
follow-up steering system with a smooth pressure build-up in the
steering motor 14 to effect steering rate proportional to the rate
of rotation of the steering wheel.
In the event that the valve member is rotated in a counterclockwise
direction, as viewed in FIG. 8, the pressure directed to the valve
member between inlets 61-61c may again be divided in much the same
manner as that described above, except for the fact that the fluid
is directed through the valve mechanism to the opposite end of the
steering motor. In the event the direction of rotation is
counterclockwise of the valve member 44, pressure in the openings
61-61b is directed to the metering mechanism 35 through ports 62,
62a and the flow is from the metering mechanism 35 through ports
64, 64a to one end of the steering motor 14. The opposite ends of
the steering motor are connected to tank by connection of ports 63,
63a with tank outlets 60a, 60c, respectively. Again, in this mode
of operation the flow being divided between the outlet and the
steering motor, a smooth increase in the buildup of fluid pressure
in the steering motor is provided in a manner which is proportional
to the torque applied to the steering wheel.
In the event that the member 44, as shown in FIG. 8, is moved or
rotated in a counterclockwise direction from the position shown in
FIG. 8 to the position shown in FIG. 9, the inlet flow is no longer
divided as described above. As shown in FIG. 9, the inlet fluid
flow which flows into the valve from the pump 22 into passages 61,
61b flows to the metering mechanism 35 through passageways 62, 62a.
Flow from the metering pump flows axially through the internal
passage 65 of the valve 44 and then radially through the openings
66, 66a and into outlet connections 64, 64a to one side of the
steering motor 14. The flow from the other side of the steering
motor 14 is through the conduit, into the housing through the port
20, through the radial passageways 63, 63a, and through the outlet
ports or passages 60a, 60c, respectively, to the reservior 25. In
this manner, the fluid flows from pump 23 through the valve
mechanism 41 to the metering mechanism 35 and through the metering
mechanism 35 back through the valve mechanism 41 to the steering
motor 14 to effect steering of the vehicle.
In the event that the valve is rotated from its FIG. 8 position,
clockwise as viewed therein, from the position shown in FIG. 8 to
the position shown in FIG. 10, the vehicle is steered in an
opposite direction as compared with FIG. 9. As shown in FIG. 10,
when the valve parts are moved to such position, the fluid flow is
from the inlet ports 61a, 61c through the radial passages 66, 66a
and axial passage 65 in the valve member 44 to the metering
mechanism 35. The flow from the metering mechanism 35 flows through
the ports 62, 62a and through the ports 63, 63a to one end of the
steering motor 14 to effect steering of the vehicle in a direction
opposite the direction of steering in FIG. 8. The flow from the
other end of the steering motor is through the port 21, the radial
passages 64, 64a and through the outlet ports 60a, 60c which are
connected to the reservoir 25. Accordingly it should be clear that
depending upon the direction of rotation of the valve member 44,
the vehicle will be steered in a respective direction.
FIGS. 8, 9 and 10 somewhat schematic and exaggerated in order to
show the schematic operation of the valve mechanism 41. The
detailed views of the valve mechanism, as shown in FIGS. 4-7, show
a structure incorporating the flow described in connection with
FIGS. 8-10. These details will not be further described herein in
view of the fact that the specific structure is not essential to
the present invention as long as the schematic flow illustrated in
FIGS. 8-10 is provided. The reference numbers shown on the detailed
figures correspond with the schematic views.
As is shown, a commutator valve arrangement is utilized with
gerotor gearsets for controlling the flow of fluid into and from
the gerotor mechanism. The commutator arrangement which may be
utilized in the present invention may take a variety of different
constructions, and insofar as the broad aspects of the present
invention are concerned, any type of commutator valve mechanism may
be utilized which provides for the flow of fluid from the valve
mechanism 41 to the metering means, and from the metering means
back through the valve mechanism.
In the embodiment of FIG. 2, the flow from the valve mechanism 41
to the metering means and from the metering means 35 back to the
valve is effected through a commutator valve member 101 and a
manifold member 102. The manifold member 102 has a plurality of
angled passages 103 for directing flow into and from the expanding
contracting pockets of the gerotor mechanism, as the case may be.
The manifold 102 also includes a plurality of openings 103a through
which the screw fasteners 40a extend. The face of the manifold 102
adjacent the gerotor includes a plurality of openings where
passages 103 intersect that face of the manifold for directing
fluid to or from the gerotor. Rigidly securing abutting the
manifold 102 is a plate member 104. The plate member 104 also has a
plurality of openings for receiving the screw fasteners 40.
The plate member 104 also has a plurality of openings 106 which
align with the passages 103 in the face of the manifold member 102.
The member 104 has an internal diameter which is substantially
smaller than the internal diameter of the manifold member 102 and
is provided in order to seal the gerotor mechanism. A suitable seal
is provided between the face of the commutator valve member 101 and
the radial face on the member 104 adjacent its internal
diameter.
The commutator valve member 101 is located within a bore 110 in the
manifold member 102, (see FIGS. 11, 12). The outer periphery of the
commutator valve member 101 is provided with a plurality of axial
slots which are designated 111. There are six axial slots in the
outer periphery of the member 101 in the embodiment disclosed. The
axial slots 111 communicate with the area 69 located radially
outwardly of the valve member 103. The commutator valve also has
interposed between the radial slots a plurality, again six in
number, of radially extending passages 112 which extend into the
interior of the commutator valve member 101.
As noted above, the manifold member 102 has a plurality of
passages, namely, seven in number, which are designated 103. These
passages 103 extend angularly through the manifold member 102 and
intersect the radial face of the manifold member as well as the
axial bore 110 therein. The openings provided by the passages 103
within the bore 110 are spaced circumferentially around the bore
110.
From the above, it should be apparent how the commutator valve
mechanism works. It should be clear that the manifold member 102,
the plate member 104, and the outer gerotor member 36 rotates as a
unit with the steering shaft 12. It should be further apparent that
as the manifold member 102 rotates relative to the commutator valve
101, the axial passages 103 sequentially come into communication
with the axially extending slots 111 in the outer periphery of the
commutator valve member 101 and the radially extending passages 112
in the commutator valve member 101. As a result, the proper
commutation of fluid flow is provided by the commutator valve
mechanism.
Accordingly, as a result, fluid may flow to the metering mechanism
35 from the area 69, through the axially extending slots 111 in the
commutator valve, the angled passageways 103, the openings 106 in
the member 104, and into the expanding passages of the metering
mechanism. The flow from the contracting passages of the metering
mechanism 35 would be through openings 106 in the plate member 104
which communicate with the contracting chambers of the gerotor,
passages 103 in the member 102, and radial openings 112 in the
commutator member 101, into the interior of the commuator valve
member 101. The fluid may then flow axially through the interior of
the mechancal connection 45 and into the axial passageway 65 in the
valve member 44. Of course, in the event that the gerotor mechanism
rotates in a reverse direction, the flow would be reversed from
that described immediately hereinabove, namely, the flow would be
from the axial passageway 65 in the valve member 44, through the
passages 112 in the commutator valve member 101, through the angled
passages 103 in the manifold 102, passages 106 in the member 104,
and into the expanding chambers of the gerotor mechanism. In this
case, the flow from the contracting chambers of the gerotor
mechanism would be through the ports 106 of the member 104, into
passages 103 of the manifold 102, through axial passages 111 in the
outer periphery of the commutator valve 101, and into the area 69
adjacent the outer periphery of the valve mechanism 41.
From the description hereinabove, it should be apparent that upon
rotation of the steering wheel, the valve member 44 is moved
slightly in order to effect communication of the various ports in
the valve mechanism and the propor actuation of the steering motor
14. The movement of the valve member 44 by the gerotor mechanism 35
is effected against the bias of a suitable spring means, generally
designated 120. The spring means in the embodiment shown comprises
a torsion bar 121 which is suitably secured at one end by a
screw-and-nut assembly 122 to the housing of the control unit and
is secured at the other end by a pin-and-slot connection, generally
designated 123, to the valve member 44. It should be apparent, of
course, that upon rotation of the valve member 44, the rotation is
in opposition to the force applied to the valve member by the
torsion bar 122, and that when that force is removed as by removal
of the steering force applied to the steering wheel of the vehicle,
the torsion bar 121 will effect a return of the valve member 44 to
its neutral position. Of course, while a torsion bar spring
centering mechanism is disclosed in the specific embodiment, any
such biasing arrangement may be utlized in order to provide for a
neutral positioning of the valve member 44. The torsion bar extends
into the interior passageway 65 of the valve member 44 but it does
not detrimentally affect fluid flow therethrough.
From the above description, it should be apparent that applicant
has provided a control unit in which there is no rotary or rotating
valve which rotates at all times upon rotation of the steering
wheel. The valve 44 rotates for a small increment of movement and
no more rotation thereof occurs while steering of the vehicle is
being accomplished. Moreover, it should be clear that the steering
shaft does not extend into the valve unit and has no mechanical
interconnection with the valve member 44 except through the gerotor
mechanism 35, as specificaly described above. As a result, there is
no need for a large package size in order to accomplish a
mechanical interconnection of the steering shaft to a rotating
valve member. As a result the diameter of the valve members 42-44
may be quite small.
Moreover, it should be clear from the above that initial rotation
of the steering shaft causes actuation of the valve in order to
port fluid through the metering mechanism 35 and from the metering
mechanism to the steering motor in a proper follow-up manner.
Also, it should be clear that in the event that the power-steering
pump 23 should not operate properly, the turning of the steering
wheel will still cause actuation of the valve member 44 through the
metering mechanism 35 and that on further rotation of the steering
shaft the metering mechanism 35 will operate as a pump mechanism to
force fluid through the system and still operate the steering motor
14, even though the power-steering pump 23 may be inoperative.
Furthermore, all of the advantages of "feel" of the road in both a
nonsteering condition and a steering condition are effected and
provided by the control system of the present invention.
Accordingly, the control system of the present invention, as
described hereinabove, has all of the advantages of present and
known control systems, but yet is a substantial improvement over
known systems in that the cost of manufacture and the simplicity of
construction are substantially improved and problems of leakage and
package size are minimized.
While a specific embodiment of the present invention has been
described hereinabove, it should be apparent that the present
invention may be embodied in other structures which are
modifications of that disclosed hereinabove.
FIG. 13 discloses another embodiment of the present invention which
is constructed similarly to that described hereinabove and uses a
valve mechanism similar to that described above, although the
structure of the gerotor commutator arrangement is slightly
different. In the embodiment of FIG. 13, the steering shaft 150 is
drivingly connected by a pin connector 151 to the rotor or outer
member 153 of a gerotor mechanism. The inner rotor member 154 of
the gerotor mechanism is drivingly interconnected with a drive link
155. The drive link 155 in turn is drivingly connected with a part
which may be integral with the valve mechanism or drivingly
connected therewith. That part is designated 156. In the embodiment
shown, the commutation is through a plate-type valve, generally
designated 160, the commutator valve 160 is suitably keyed to the
rotor member 154 by a sleeve connector 161 so as to rotate and
orbit with the rotor member. The commutation is generally similar
to known structures and therefore will not be described in further
detail. The plate 162 which is interposed between the housing and
the commutator plate 160 functions to project radially inwardly to
provide a proper seal for the commutator plate.
FIGS. 14, 15 and 16 illustrate a still further embodiment of the
present invention which is somewhat similar to the embodiment of
FIG. 13, except that as opposed to a rotary valve or axial valve of
the type shown in the embodiments of FIGS. 1-12, the valve of FIGS.
14-16 is of a plate type.
In the embodiments of FIGS. 14-16, the steering shaft 200 is
drivingly connected to the outer rotor member 201 of a gerotor
gearset which in turn drives the inner rotor member 202 of the
gerotor gearset. The inner rotor member 202 is drivingly connected
through a link 203 to a plate valve member 204. The valve member
204 will rotate upon rotation of the steering shaft, much as the
valve member 44 rotates, and a suitable stop pin, shown in FIG. 15,
and designated 205, will engage a surface of the valve to prevent
excessive rotation of the valve member 204 in any direction upon
high torque being applied thereto. The commutator valve member 206
is similar in construction and operation to that of the embodiment
of FIG. 13 and will not be described in detail, since it is
generally of conventional construction.
As best shown in FIG. 16, the housing 210 which contains the
control unit has an inlet port configuration which includes a
generally arcuate U-shaped portion 211 which communicates with the
inlet pump and which may be termed an inlet pressure port. A return
reservoir port which is generally designated 212 includes a portion
212a which is interconnected by an arcuate portion 212b with a
portion 212c which is diametrically opposed to the portion 212a.
Also, on the housing there is a port 214 which communicates to one
end of the steering motor and a port 215 which communicates to the
other end of the steering motor.
The valve member 204 which engages with the face of the housing, as
shown in FIG. 16, includes a pair of ports 220, 221 which, when the
valve is in neutral position, provides for communication between
the inlet pressure port 211 and the outlet reservoir port 212.
Accordingly, when the valve is in its neutral position, the flow of
fluid is from the pressure pump through the valve mechanism to
tank.
In the event that the valve member shown in FIG. 15 is moved in one
direction relative to the housing 210, a port 230, which
communicates to one side of the gerotor mechanism, will move into
communication or greater communication with the port 211 so that
pressure is thereby ported to the gerotor mechanism. At the same
time, the other side of the gerotor mechanism, which communicates
with port 231, will communicate with the port 215 to direct flow to
one end of the steering motor. The flow from the other end of the
steering motor will return from port 214 to the outlet port 232 and
will be communicated to outlet port 212c.
In the event that the valve plate 204 is rotated in a reverse
direction, the port 231 will communicate with the inlet pressure
211 and fluid will be ported to the metering mechanism in a reverse
direction from that described above through the port 231, flow from
the metering mechanism will come through the port 230 through port
214 to one end of the steering motor. Flow from the other end of
the steering motor will be through port 215 and into the outlet 232
which communicates with the port 212c to port the fluid to the
reservoir.
Accordingly, it should be clear that the embodiment shown in FIGS.
14, 15 and 16 is similar in operation to that described above, but
rather than having a sleeve-type axial valve system, it is provided
with a plate-type valve. Moreover, the valve construction can be
such that the proper intermediate positions of the valve are
provided in order to operate in precisely the same manner as that
described above in connection with the embodiment of FIG. 1 and
that detailed description will not be made herein in view of the
fact that it would merely involve redundancy.
While from the above it should be clear that various modifications
of the present invention may be embodied in control units which
include different types of commutation as well as different types
of valve constructions, it should be equally clear that the present
invention may be embodied in modifications where the gerotor
mechanism is utilized in a different manner than that disclosed
above and where the input to the gerotor mechanism may be other
than an input to the outer member of the gerotor mechanism, or
where the orbiting member of the gerotor mechanism is the outer
member of the gerotor mechanism rather than the inner member of the
gerotor mechanism.
In the embodiment of FIG. 17 a control unit is shown very
schematically and a control valve is generally shown and designated
300. The embodiment of the present invention which is illustrated
in FIG. 17 comprises a control system where the control or steering
shaft 311 is drivingly connected through a linkage 312 to the inner
rotor member 313 of a gerotor mechanism. The outer rotor member of
the gerotor mechanism, designated 314, is constructed so as to
rotate a limited amount upon rotation of the inner gerotor member
313 and a mechanism is provided, not shown, for preventing further
rotation thereof. This initial rotation of the member 314 is
transmitted via a mechanical connection which includes a disk or
plate-like member 315 to the rotary valve member or valve member
316 of the valve mechanism 300.
The commutation in the embodiment shown in FIG. 17 is similar to
the commutation which is provided in the Dettlof U.S. Pat. No.
3,087,436 and accordingly will not be described herein in detail.
However, it should be apparent that the commutation is effected on
the side of the gerotor which is closest to the steering shaft 311
rather than on the side of the gerotor mechanism on which the valve
300 is located, that is, the gerotor mechanism is interposed
between the commutator valve and the valve mechanism 300. Also, the
commutator valve part 320 is drivingly connected with the outer
member 314 due to a pin connection therewith, and rotates slightly
therewith upon torque application thereto through the gerotor
mechanism.
In the modification of FIGS. 18 and 19 the steering shaft 400 is
drivingly connected through a gear interconnection to a sleeve
member 401. The sleeve member 401 has internal gear teeth 402
thereon, best shown in FIG. 19. The gear teeth 402 mesh with gear
teeth 403 on the outer peripheral surface of the outer rotor member
404 of the gerotor mechanism. The inner rotor member of the gerotor
mechanism is designated 405.
In this embodiment, the initial rotation of the steering shaft 400
effects rotation of the outer rotor member 404 which in turn
effects a rotation of the inner member 405 as in the embodiment of
FIG. 1. The initial rotation of the member 405 effects limited
rotation of either a valve plate in the embodiment of FIG. 13 or an
axial-type valve, as in the embodiment of FIG. 1, to effect the
proper porting of fluid by rotation of a shaft 407 connected with
the valve. However, in the embodiment of FIGS. 18 and 19, the rotor
can only rotate a limited amount and is also restrained from any
orbiting movement. In this case, rotation of the steering shaft 400
causes rotation and orbiting of the rotor member 404 in a manner
similar to that shown in U.S. Pat. No. 3,443,378. In this
embodiment the commutator member 410 is fixed to the rotor member
405 in order to provide the necessary and proper commutation as the
rotor member 404 rotates and orbits. Details of the valve mechanism
which may be associated with the structure of FIGS. 18 and 19 will
not be further described, since it would be the equivalent of that
described above or obvious modifications thereof.
In view of the foregoing, it is clear that applicant has provided a
substantial improvement in the art which may be embodied in a
number of different modifications and structural embodiments.
* * * * *