COMMISSIONER'S DECISION
OBVIOUSNESS: Anti-Skid Mechanism
A vehicle anti-lock brake system which releases the hydraulic system on
the occurrence of a wheel skid condition is shown in the prior art.
In response to the Final Action the applicant submitted one specific
claim replacing the previous forty one claims.
Rejection: Amended claim accepted.
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This decision deals with a request for review by the Commissioner of
Patents of the Examiner's Final Action dated May 27, 1976, on
application 142,760, Class 303-73. The application was filed on
May 23, 1972, and is entitled "Anti-Skid Mechanism".
This application relates to an anti-lock brake system for fluid actuated
brakes of a wheeled vehicle. An electrical signal indicates the
occurance of a "locked" wheel and a control valving arrangement is
used to relieve the fluid pressure applied from the master cylinder
to the wheel brakes. Figure 1 shown below illustrates the applicants
invention.
(See Figure I)
In the Final Action the examiner refused the application for failing to
define patentable subject matter in view of the following patent.
United States
3,486,800 Dec. 30, 1969 Ayers
The Ayers patent relates to a skid control system for fluid actuated brakes
of a wheeled vehicle. This patent uses a valuing arrangement controlling
the pressure to the brakes in response to an electrical signal indicating
the occurrence: of a wheel skid condition. Figure 1 of Ayers is shown below.
(see formula I)
In the Final Action the examiner stated (in part):
...
Applicant's alleged invention differs from Ayers device in two
ways. First, applicant's orifice means is located in the
uni-directional valve means while Ayers' orifice means is not
located in the uni-directional valve, means per se but in an
area associated with the uni-directional valve means. Since
neither Ayers' nor applicant's orifice means have any moving
parts but are merely open to allow a restricted flow of exhaust-
ing atmosphere the actual physical location of the orifice means
is immaterial....
...
Ayers' valve consists of a movable valve element 167 supported
on the diaphragm member and resiliently biased into engagement
with the housing 163. The valve member moves under the influence
of the biasing spring 168 until the flange of a cup engages the
valve element to disengage the valve element from the housing
and opens the passage.
Ayers' valve is an equivalent valve to applicant's, it operates
in a similar manner to achieve the same result. While appli-
cant's valve is held by the housing and engages a movable
diaphragm until the diaphragm moves a predetermined distance
Ayers' valve is held by the movable diaphragm and engages the
housing until the diaphragm moves a predetermined distance.
Simply reversing Ayers' known valve is not considered inven-
tion....
In response to the Final Action the applicant cancelled the 41 claims
and submitted one amended claim. He also stated (in part):
...
Applicant agrees that the teachings of the reference are very
close to the present invention but it is applicant's firm
belief that the present application does include subject matter
which is significantly different from that of the citation. In
view of the close structure and function of the present inven-
tion to that of the citation applicant has cancelled all of the
forty-one claims previously on file and has replaced those claims
with a new, restricted, claim 1. It is applicant's firm belief that
the new claim 1 as herein presented structurally defines a signif-
icantly different invention from that of the citation....
...
The Examiner is particularly referred to sub-paragraphs (d) and
(j) of the amended claim. The throttling means (82) of sub-
paragraph (d) is different from the valve means 167 of the ref-
erence and, additionally, the valve member (62) defined in sub-
paragraph (j) is totally absent from the similar valve 158 of the
reference (Figure 4 thereof).
Additionally, the elements 46, 112, 120, 161, 158, 162, 166, 169,
172, 173, 175 and 170, as referred to by the Examiner in the last
paragraph of page 1 of the Final Action, are inefficiently scattered
about the structure as shown in Figure 1 and their cooperation,
interaction and functioning required additional structure. On the
other hand, applicant's elements 41, 10, 16, 59, 79, 81, 91, 86
and 92 accomplish their result in a simpler way. Referring to
applicant's Figures 2 and 3 note the proximity in the housing 27
of the interconnecting passage means 45, 79, the atmosphere/
vacuum control valve 59, the throttling valve 86, the uni-
directional valve 91 and orifice 92 as taught by the applicant.
Thus the present invention as now claimed includes structural
features which substantially simplify the total apparatus or
device and which distinguish the present invention from the
prior art....
The issue to be considered is whether or not the applicant has made a
patentable advance in the art. Claim 1 of the application reads:
An anti-skid device comprising:
a) a housing;
b) an expansible chamber mounted on the housing having
a fluid pressure responsive member movable in the chamber
between opposed positions in response to fluid pressure
selectively applied thereto and exhausted therefrom;
c) resilient means in the chamber to urge said fluid
pressure responsive member to one of its opposed positions;
d) throttling means in the housing for controlling the
passage therethrough of fluid pressure selectively applied to
and exhausted from the chamber, said throttling means including:
1) uni-directional valve means including a movable
member for effecting the passage only of applied fluid pressure
into said chamber to initiate the movement of said pressure
responsive member from the one of its opposed positions toward
the other thereof;
2) second valve means engaged with said pressure
responsive member in the one of the member's opposed positions
and disengaged from said member upon the movement thereof in
excess of a predetermined amount toward the other opposed
position of the member, said second valve means including
passage means for effecting the passage of applied and ex-
hausted fluid pressure to and from said chamber when said second
valve means is disengaged from said member, said second valve
means interrupting the passage therethrough of both the applied
and exhausted fluid pressure when engaged with said pressure
responsive means in its one opposed position;
3) orifice means included in said movable member of
said uni-directional valve means for restricting the passage
therethrough of exhausted fluid pressure from said chamber when
said second valve means is engaged with said pressure responsive
member; and
4) a valve seat on said second valve means about
said passage means for engagement with said pressure responsive
member, said valve seat being engaged with said member in its
one opposed position to preclude the passage of fluid pressure
through said passage means and being disengaged from said member
upon the movement thereof in excess of the predetermined amount
toward its other opposed position to effect the passage of
applied and exhausted fluid pressure to and from said chamber
through said passage means;
e) atmospheric, vacuum and delivery chambers in the
housing;
f) a valve seat formed in the housing between the
atmospheric and delivery chambers;
g) another valve seat formed in said housing between the
vacuum and delivery chambers; and
h) valve means movable in the housing between one position
engaging the valve seat between the atmospheric and delivery
chambers for isolating the atmospheric chamber and connecting
the vacuum and delivery chambers and another position engaging
the valve seat between the vacuum and delivery chambers for
isolating the vacuum chamber and connecting the atmospheric
and delivery chambers;
i) the valve means including opposed valve members mounted
thereon for sealing engagement with the valve seats;
j) the valve member for engaging the valve seat between
the atmospheric and delivery chambers including:
1) diaphragm means for sealing engagement
with its respective valve seat;
2) a valve chamber defined by the inside of said
diaphragm means and a closed wall of said housing within the
atmospheric chamber, said valve chamber being isolated from
communicating with said atmospheric chamber when said valve
means is in said one position;
3) a sleeve insert mounted on and within the
diaphragm means; and
4) passage means extending through the insert to
communicate the delivery and valve chambers.
The Final Action details the elements which are similar where it states
that Ayers discloses:
a housing, means movable therein for controlling a supplied
fluid pressure 46, resiliently urged means 112, 120, engaging
the movable means to control the supplied fluid pressure control
means 161, 158 for controlling vacuum and atmosphere to the
chambers, means defining passage means between the control
means and the other chamber 162, 166, 169, throttling means
including uni-directional valve means 172, 173 for one way
passage of atmosphere, other valve means 165 and orifice means
170.
In his response the applicant argues that these elements as found in
Ayers are "inefficiently scattered about the structure as shown in
Figure 1 and their cooperation, interaction and functioning require additional
structure." Further the applicant contends that his arrangement accomplishes
the desired result in a simpler way. Looking at these elements we find
that the applicants arrangement does provide a simpler arrangement which
is more compact in its physical layout.
Considering the elements as outlined in amended claim 1 we find some areas
which do not have a corresponding element in the Ayers citation. For example
in J(3) of claim 1 reference is made to a "sleeve insert (69)" and
we do not find any element in Ayers which could be considered equivalent.
This is followed by J(4) which indicates "passage means extending through
the insert to communicate the delivery and valve chambers." Granted there is
passage means shown in Ayers but it does not use any insert on the valve seat.
There is an indication on page 9 of the disclosure which relates to the
importance of this arrangement where it states that "the valve chamber 73 is
subject to either vacuum or atmosphere prevailing in the delivery chamber 45,
then it is apparent that the valve member 62 is predeterminately balanced."
Again at the bottom of page 17 it states "the atmosphere and vacuum prevail-
ing in the control housing bore 45 and counterbore 46 respectively acting
on arcs A2 of the valve member 61 when it is engaged with the valve seat 48
establishes a differential force acting aginst the force of the magnetic
holding engagement of the armature 78 with the pole piece 77; however, as
previously mentioned, the current necessary to maintain the magnetic holding
engagement between the armature and pole piece is appreciably less than
that necessary to excite said armature toward such magnetic holding engagement
with said pole piece." Thus it appears that balance sensitivity is more
acute in the application than in the Ayers patent.
Another area of difference between the application and citation is found
in d(3) of amended claim 1. This portion specifies "orifice means included
in said movable member", while the "orifice" means in Ayers is adjacent
to the movable member. Similarily portion d(4) requires "said second
valve means about said passage means for engagement with said pressure
responsive member" whereas Ayers seal member (167) does not engage the
pressure responsive member.
Having considered all the arguments brought to the Boards attention we are
constrained to conclude, but not without some hesitations that the appli-
cant has made a patentable advance in the art. We are satisfied that
amended claim 1 overcomes the grounds of rejection in the Final Action.
We recommend that the amendments be accepted.
J.F. Hughes
Assistant Chairman
Patent Appeal Board, Canada
I have studied the prosecution of this application and reviewed the
recommendation of the Patent Appeal Board. In the circumstance I will
accept claim 1 which was amended in response to the Final Action. The
application is returned to the examiner for resumption of prosecution.
J.H.A. Gariepy
Commissioner of Patents
Agent for Applicant
Alex E. MacRae & Co.
P.O. Box 806, Station B
Ottawa, Ontario
K1P 5T4
Dated in Hull, Quebec
this 11th. day of August, 1977