US7145282B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Actuator
Assignee: Delphi International Operations Luxembourg SARL
•
Filing: 2004-07-15
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Granted: 2006-12-05
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Expires: 2024-07-15
Abstract
Abstract An actuator includes a piezoelectric stack within a housing that applies a compressive load to the stack. The housing may include a cylindrical tube closed at one end and may seal the stack against fluid pressure. The housing may be shorter than the length of the piezoelectric stack and may include resilient means for inducing elastic strain in the stack. The resilient means may include one or more slots extending around the circumference of the housing and/or a corrugated region of the housing to form a tension spring at a lower end of the housing. The tension spring may then serve to draw the stack into compression. The stack may include a plurality of layers of piezoelectric or piezoceramic material interspersed with a plurality of layers of electrically conductive material and connecting means for connecting the layers to a source of electrical power.
Inventors
- 👤 Charles Dale Oakley
- 👤 Rick Daniel Kerr
- 👤 Giulio Angel Ricci-Ottati
- 👤 Russell Harmon Bosch
- 👤 Hermann Breitbach
- 👤 Manfred Kolkman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:28
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/80; H10N30/88; H10N30/886; H10N30/50
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
74 words
An actuator for a fuel injector, the actuator comprising a piezoelectric stack, wherein the piezoelectric stack consists of a plurality of layers of piezoelectric or piezoceramic material interspersed with a plurality of layers of electrically conductive material and connecting means for connecting said layers of electrically conductive material to a source of electrical power, wherein the connecting means comprises a cap or top seal which is fixed to one end of the piezoelectric stack.
Claim 2
Dependent Claim
74 words
An actuator for a fuel injector, the actuator comprising a piezoelectric stack, wherein the piezoelectric stack consists of a plurality of layers of piezoelectric or piezoceramic material interspersed with a plurality of layers of electrically conductive material and connecting means for connecting said layers of electrically conductive material to a source of electrical power, wherein the connecting means comprises a cap or top seal which is fixed to one end of the piezoelectric stack.
Claim 3
Dependent Claim
27 words
An actuator as claimed in claim 1 piezoelectric stack disposed within a housing, wherein the housing is arranged to apply a compressive load to the piezoelectric stack.
Claim 4
Dependent Claim
24 words
An actuator as claimed in claim 2 , wherein the housing comprises a generally cylindrical tube, the tube being closed at one end thereof.
Claim 5
Dependent Claim
27 words
An actuator as claimed in claim 1 , wherein the top seal is formed from a ceramic material and bonded to one end of the piezoelectric stack.
Claim 6
Dependent Claim
30 words
An actuator as claimed in claim 1 , wherein the top seal is formed from a metallic material and is bonded or welded to one end of the piezoelectric stack.
Claim 7
Dependent Claim
26 words
An actuator as claimed in claim 1 , wherein the housing includes a radially outwardly directed lip or rim disposed circumferentially around an open end thereof.
Claim 8
Dependent Claim
28 words
An actuator as claimed in claim 6 , wherein the housing has a length which is shorter than the length of the piezoelectric stack by a predetermined amount.
Claim 9
Dependent Claim
20 words
An actuator as claimed in claim 7 , further comprising clamping means for clamping the lip to the top seal.
Claim 10
Dependent Claim
50 words
An actuator as claimed in claim 8 , the arrangement being such that when the lip is clamped to the top seal the housing is stretched over the piezoelectric stack thereby to induce an elastic strain in the housing so as to apply the compressive load to the piezoelectric stack.
Claim 11
Dependent Claim
54 words
An actuator as claimed in claim 8 , wherein the clamping means comprises a collar having a radially inwardly directed rim or lip for engagement with the radially outwardly directed lip, said clamping means further comprising means for fixing the collar to the top seal thereby to clamp the housing to the top seal.
Claim 12
Dependent Claim
24 words
An actuator as claimed in claim 10 , wherein the means for fixing comprises a surface for welding the collar to the top seal.
Claim 13
Dependent Claim
47 words
An actuator as claimed in claim 10 , wherein an external surface of the top seal includes or defines a screw thread and wherein the means for fixing comprises a threaded portion disposed on an internal surface of the collar for threaded engagement with the screw tread.
Claim 14
Dependent Claim
23 words
An actuator as claimed in claim 2 , wherein the housing is provided with resilient means for inducing a predetermined elastic strain therein.
Claim 15
Dependent Claim
25 words
An actuator as claimed in claim 13 , wherein the resilient means comprises one or more slots extending partially around the circumference of the housing.
Claim 16
Dependent Claim
19 words
An actuator as claimed in claim 13 , wherein the resilient means comprises a corrugated region of the housing.
Claim 17
Dependent Claim
55 words
An actuator as claimed in claim 15 , wherein the corrugated region forms a tension spring at a lower end of the housing, and wherein the stack is provided with an end piece which projects through the housing at the lower end thereof so that the tension spring serves to draw the stack into compression.
Claim 18
Dependent Claim
27 words
An actuator as claimed in claims 2 , wherein the housing additionally provides an encapsulant for the stack to seal the stack against fluid pressure, in use.
Claim 19
Dependent Claim
50 words
A piezoelectrically operable fuel injector for use in an internal combustion engine, the fuel injector including an accumulator volume for pressurised fluid and a piezoelectric actuator as claimed in any one of claims 2 to 17 , wherein the stack of the piezoelectric actuator is located within the accumulator volume.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2009-12-04 | 2010-06-05 | 2010-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2013-12-04 | 2014-06-05 | 2014-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2017-12-04 | 2018-06-05 | 2018-12-05 | $7700.00 | Window Closed / Lapsed |