Europaisches Patentamt
J
European Patent Office
© Publication number:
Office europeen des brevets
EUROPEAN
PATENT
491
A3
APPLICATION
int. ci.<>: G01L
© Application number: 93119457.5
0 600
21/08, G01M 3 / 2 4
@ Date of filing: 02.12.93
®
Priority: 04.12.92 US 986035
124 Glendale
Rochester,
Michigan 48063 (US)
Inventor: Gentry, Scott B.
77221 Hipp Road
Romeo,
Michigan 48065 (US)
Inventor: Mazur, Joseph F.
58471 Winston
Washington,
Michigan 48094 (US)
@ Date of publication of application:
08.06.94 Bulletin 94/23
©
Designated Contracting States:
DE ES FR GB IT
©
Date of deferred publication of the search report:
02.08.95 Bulletin 95/31
© Applicant: TRW VEHICLE SAFETY SYSTEMS
INC.
1900 Richmond Road
Lyndhurst
Ohio 44124 (US)
@ Inventor: Blackburn, Brian K.
©
00
©
Representative: Wagner, Karl H.
WAGNER & GEYER
Patentanwalte
Gewurzmuhlstrasse 5
D-80538 Munchen (DE)
Method and apparatus for testing fluid pressure in a sealed vessel.
© An apparatus (20) for sensing pressure in a stiff
wall sealed vessel (30) comprises a speaker (60)
operatively coupled to the vessel (30) for, when
energized, transferring energy to pressurized fluid in
the vessel (30). The energy transferred from the
speaker (60) establishes oscillations of the pressurized fluid in the vessel (30). A piezoelectric capacitive sensor (62) is operatively coupled to the vessel
(30) for providing a received electrical signal having
a frequency value indicative of the oscillation frequency of the pressurized fluid in the vessel (30). A
receiver circuit (70, 90, 110) is operatively connected
to the capacitive sensor (62) and provides a fluid
resonating signal having a frequency indicative of
the natural frequency of the oscillating pressurized
fluid in the vessel (30). The natural frequency of the
pressurized fluid is indicative of the fluid pressure in
the vessel (30). A drive circuit (120, 164) is operatively connected to the receiver circuit (70, 90, 110)
and to the speaker (60). The drive circuit (120, 164)
initially drives the speaker (60) with a square wave
pulse and subsequently drives the speaker (60) with
an energy wave having a frequency equal to the
natural frequency of the pressurized fluid in the
vessel (30) so as to lock onto the natural frequency.
CO
Rank Xerox (UK) Business Services
(3. 10/3.09/3.3.4)
EP 0 600 491 A3
70
,_110
l
LOW PASS
FILTER
160
164-
Vcc
166
120
124
168
126
—150
"j 60
VOLTAGE-TO-CURRENT
_____CONVERJER_
136
152
40
30
22
36~
AAIR
BAG
INDICATOR |
^153
CONTROLLER
34
TEMP
SENSOR
128
170
44
2
CRASH
SENSOR
Fig.1
European Patent
Office
Application Number
EP 93 11 9457
EUROPEAN SEARCH REPORT
DOCUMENTS CONSIDERED TO BE RELEVANT
Citation of document with indication, where appropriate,
Relevant
Category
of relevant passages
to claim
Y
EP-A-0 303 776 (UE SYSTEMS INC.)
1-4
* claims 1-4 *
Y
US-A-4 212 205 (P.C.
* claims 1-13 *
WEST
Y
US-A-4 869 097 (B.R.
TITTMANN
* claims
Y
ET AL.)
1-8 *
US-A-4 399 514 (M. HAMASAKI
* claims
ET AL.)
ET AL.)
1-3 *
CLASSIFICATION OF THE
APPLICATION (IM.CL5)
G01L21/08
G01M3/24
1-4
8,9,11,
12
8,9,11,
12
A
EP-A-0 444 200 (TOKYO GAS CO., LTD.)
* claims 3-11 *
2,3
A
DE-A-23 19 502 (BENTHOS INC.)
* claims 11-14,17 *
2,3
A
PATENT ABSTRACTS OF JAPAN
/n oro\ 4a February
o-i (P-252)
r u
inoii
vol.t o 8, no. 27
1984
& JP-A-58 182 530 (DAIWA SEIKAN KK.) 25
October 1983
* abstract *
1,8
A
PATENT ABSTRACTS OF JAPAN
vol. 14, no. 66 (P-1003) 7 February 1990
& JP-A-01 288 745 (NIPPON S0KEN INC.) 21
November 1989
* abstract *
1,8
A
PATENT ABSTRACTS OF JAPAN
vol. 4, no. 62 (P-010) 9 May 1980
& JP-A-55 031 975 (MEISEI ELECTRIC CO.
LTD.) 6 March 1980
* abstract *
1-4
technical fields
SEARCHED (IntCI.5)
G01L
G01M
-/~
The present search report has boon drawn up for all claims
■ Place ofMarch
Daleof coBftletioi ofthe tearca
BERLIN
31 March 1995
CATEGORY OF CITED DOCUMENTS
X: particularly relevant if taken alone
Y: particularly relevant if combined with another
document of the same category
A: technological background
O : non-written disclosure
P : intermediate document
Dietrich,
A
T : theory or principle underlying the invention
E : earlier patent document, but published on, or
after the filing date
D: document cited in the application
L : document cited for other reasons
&: member of the same patent family, corresponding
document
J
European Patent
Office
Application Number
EP 93 11 9457
EUROPEAN SEARCH REPORT
DOCUMENTS CONSIDERED TO BE RELEVANT
Citation of document with indication, where appropriate,
Relevant
Category
of relevant passages
to claim
CLASSIFICATION OF THE
APPLICATION (IntCLS)
PATENT ABSTRACTS OF JAPAN
vol. 16, no. 199 (P-1351) 13 May 1992
& JP-A-04 031 728 (Y0K0GAWA ELECTRIC
CORP.) 3 February 1992
* abstract *
TECHNICAL FIELDS
SEARCHED (Int.Cl.S)
The present search report has been drawn up fur all claims
Place of tearca
Date ofconpletloa oftee learca
BERLIN
31 March 1995
CATEGORY OF CITED DOCUMENTS
X: particularly relevant if taken alone
Y: particularly relevant if combined with another
document of the same category
A: technological background
O : non-written disclosure
P : intermediate document
Fyartaer
Dietrich, A
T : theory or principle underlying the invention
E : earlier patent document, but published on, or
after the filing date
D : document cited in the application
L : document cited for other reasons
&: member of the same patent family, corresponding
document
European Patent
Office
EP 9 3 1 1 9 4 7 5
CLAIMS INCURRING FEES
l*he present European patent application comprised at the time of tiling more than ten claims.
|—j
Eu
search report has been
Al
Mllclaims tees have been paid within the prescribed time limit The present European
irawn up for all claims.
| |
Only part of the claims tees have been paid within the prescnbed time limit The present European search
report has been drawn up tor the first ten claims and for those daims for which claims fees have been paid.
namely claims:
| |
Noclaims fees have been paid within the prescribed time limit. The present European search report has been
drawn up for the first ten claims.
LACK OF UNITY OF INVENTION
The Search Division considers that the present European patent application does not comply with the requirement of unity of
invention and relales to several Inventions or groups of Inventions.
namely:
!
and method
for
1.
Claims 1 - 4 , 8 , 9 , 1 1 , 1 2 :
Apparatus
p r e s s u r e in a s e a l e d v e s s e l .
2.
Claims 5 - 7 , 1 0 : A p p a r a t u s and method for d i a g n o s t i c
d e t e r m i n a t i o n of the f u n c t i o n a l i t y for an a i r b a g .
sensing
|—|
AMfurther search fees have been paid within the fixed time Umrt The present European search report has
been drawn up for all claims.
js^j
Only part of the further search fees have been paid within the fixed time Hmtt. The present European search
report has been drawn up for those parts of the European patent application which relate to the Inventions in
respect of which search fees have been paid.
1-4,8,9,11,12
namely claims:
| |
None of the further search fees has been paid within the fixed time limit. The present European search report
has been drawn up for those parts of the European patent application which relate to the Invention first
mentioned in the claims.
namelyciaims:
and