Electricity: magnetically operated switches – magnets – and electr – Magnets and electromagnets – With magneto-mechanical motive device
Reexamination Certificate
2001-01-29
2001-08-28
Barrera, Raman M. (Department: 2832)
Electricity: magnetically operated switches, magnets, and electr
Magnets and electromagnets
With magneto-mechanical motive device
C335S271000, C251S129160, C251S129180
Reexamination Certificate
active
06281772
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a dynamic dampening mechanism for use in a frictionless rectilinear motion solenoid and, more particularly, a dynamic dampening mechanism for use in eliminating natural frequency oscillations in the solenoid.
BACKGROUND OF THE INVENTION
A prior art frictionless solenoid operable in association with a liquid controlling valve is illustrated in FIG.
1
. The illustration in
FIG. 1
represents the closest prior art known to the inventor.
The solenoid portion
10
of the solenoid operated valve
11
consists of an armature
12
suspended in the center of an annular coil
13
by a pair of flat substantially linear springs
14
and
16
attached to the armature
12
at one end and attached to the solenoid pole pieces
17
and
18
at the other end to prevent radial movements. The pole pieces
17
and
18
are oriented at the ends of the annular coil
13
and are connected together by a metal tube
19
made of a magnetic material which is oriented around the outside of the annular coil
13
. The tube serves the purpose of completing the flux carrying magnetic circuit.
The pole piece
17
oriented to the left of the annular coil has a large opening
21
in it and is adapted to receive therein the armature
12
. The radial space between the outside diameter of the armature
12
and the inside diameter of the opening
21
serves to define a non-working air gap
22
. This end of the armature also has an elongate rod
23
formed on the left axial end face of the armature and it is this rod
23
that is secured to the aforesaid spring
14
. A hole in the center of the spring
14
allows the rod
23
to extend therethrough. A resilient spacer
24
is provided to space the spring
14
from the axial end face of the armature
12
and a retainer ring
26
is utilized to hold the spring
14
against the resilient spacer
24
.
The opposite pole piece
18
also has a hole
27
extending therethrough. The armature has a non-magnetic rod
28
formed on the right axial end face of the armature and extends axially away therefrom into and through a hole in the spring
16
whereat it is fixedly attached to the rod
28
. The two springs
14
and
16
serve to suspend the armature
12
and the two axially protruding rods
23
and
28
in the respective holes through the pole pieces
17
and
18
as well as through the central hole in the annular coil
13
so as to create a frictionless support for the armature.
In this particular prior art construction, a liquid control valve is oriented at the right end of the housing
29
which houses the aforesaid armature
12
and annular coil
13
. The liquid control valve
31
includes a central bore
32
therethrough having a plurality of liquid ports therein, namely, a liquid supply port
33
, a control port
34
and a tank port
36
. A nozzle
37
is provided in the bore
32
between the supply port
33
and the tank port
36
axially spaced from the supply port
33
. The nozzle
37
has a nozzle opening
38
therein so that liquid supplied through the supply port
33
to the control port
34
is bled through the nozzle opening
38
to the tank port
36
when a button
39
fixedly secured to the rod
28
and movable therewith is spaced away from the nozzle opening
38
as illustrated in FIG.
1
.
The right axial end face of the armature
12
is normally axially spaced from the left axially facing surface of the pole piece
18
when the annular coil
13
is not electrically energized. The axial space defines a working air gap
41
. As a result, when the annular coil
13
is electrically energized, the armature
12
will be driven rightwardly toward the pole piece
18
. In addition, the right axial end face
42
will move into close relation with the nozzle opening
38
to block liquid flow from the control port
34
to the tank port
36
. As a result, pressure will build up in the control port
34
to effect an appropriate drive of a mechanism connected thereto.
Electrical energy is supplied to the annular coil
13
through a electrical connection
43
.
Due to the precise control and response required from this type of solenoid operated liquid valve, and recognizing that these solenoid operated valves are sensitive to variations and changing conditions within the total liquid (here hydraulic) system, these variations can lead to an undesirable natural frequency oscillation in the armature
12
. Such items that influence the sensitivity are fluid viscosity changes due to temperature change, changes in the resilience of rubber components and also any spring loading that may be provided in valve arrangements which include spring loaded control spools. Variations caused by these system components are unacceptable. The invention set forth herein successfully resolves the issue of natural frequency system oscillations.
SUMMARY OF THE INVENTION
A rectilinear motion solenoid having a housing, an annular coil of electrical wire mounted in the housing and having a central hole therethrough. A first magnetic pole piece is oriented adjacent a first axial end face of the annular coil and a second magnetic pole piece oriented adjacent a second end face of said annular coil. An armature is movably mounted in the central hole. Two substantially linear springs are provided for securing the armature to the housing to effect a frictionless resilient suspension of the armature in the central hole. A closed chamber is filled with a liquid so that a disk movable with the armature is also movable in the chamber. A perimeter of the disk is oriented in close relation to an interior wall surface of the chamber to define a liquid flow restricting gap therebetween and effecting during operation a dynamic dampening of armature movement.
REFERENCES:
patent: 4463332 (1984-07-01), Everett
patent: 4664136 (1987-05-01), Everett
patent: 4835503 (1989-05-01), Everett
patent: 4932630 (1990-06-01), Kumar et al.
patent: 4950016 (1990-08-01), Kumar
patent: 5088520 (1992-02-01), Haynes et al.
patent: 5108071 (1992-04-01), Hutchings
patent: 5202658 (1993-04-01), Everett et al.
patent: 5217200 (1993-06-01), Hutchings et al.
patent: 5333643 (1994-08-01), Gilchrist et al.
patent: 5386849 (1995-02-01), Gilchrist et al.
patent: 5419530 (1995-05-01), Kumar
patent: 5695125 (1997-12-01), Kumar
patent: 5785298 (1998-07-01), Kumar
patent: 6047947 (2000-04-01), Kumar
Barrera Raman M.
Fema Corporation of Michigan
Flynn ,Thiel, Boutell & Tanis, P.C.
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