US4767208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self leveling transmitter for laser alignment systems
Assignee: Trimble Inc
•
Filing: 1987-07-02
•
Granted: 1988-08-30
•
Expires: 2007-07-02
Abstract
Abstract A transmitter for an alignment system in which a field of electromagnetic radiation is propagated in a non-planar reference cone is disclosed. The transmitter includes a chassis with a source fixed to the chassis for providing a beam of electromagnetic radiation and an optical deflector which converges toward the source reflects the beam into an omni-directional cone of radiation. A flexible support having an omni-directional stiffness supports the optical deflector in the beam to reflect the reference field in a level orientation when the chassis is level. An angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation. Damping of the deflector is also provided for and sensors detect when the angular error of the chassis has exceeded an allowable amount.
Inventors
- 👤 Gary L. Cain
- 👤 Joseph F. Rando
- 👤 Ted L. Teach
- 👤 Lawrence J. Meyers
- 👤 Theodore J. Markley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:36
CPC Classifications
G; G01; G01C; G01C5/00; G01C5/02; G01C15/00; G01C15/002; G01C15/004
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
205 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means includes a cantilever strand having a lower end secured to the optical deflector and an upper end secured to the chassis, the stiffness of the cantilever strand being omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 2
Dependent Claim
205 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means includes a cantilever strand having a lower end secured to the optical deflector and an upper end secured to the chassis, the stiffness of the cantilever strand being omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 3
Dependent Claim
205 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means includes a coil spring having a lower end secured to the optical deflector and an upper end secured to the chassis, the stiffness of the coil spring being omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 4
Dependent Claim
205 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means includes a coil spring having a lower end secured to the optical deflector and an upper end secured to the chassis, the stiffness of the coil spring being omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 5
Dependent Claim
221 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means includes: a flexible diaphragm having an outer periphery secured to the chassis above the optical deflector; and a rod having a lower end secured to the optical deflector and an upper end secured to the flexible diaphragm; wherein the stiffness of the diaphragm is omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 6
Dependent Claim
221 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means includes: a flexible diaphragm having an outer periphery secured to the chassis above the optical deflector; and a rod having a lower end secured to the optical deflector and an upper end secured to the flexible diaphragm; wherein the stiffness of the diaphragm is omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 7
Dependent Claim
30 words
A transmitter as in claim 3, further comprising: means for defining a sealed chamber above the diaphragm; and a liquid in the chamber to damp movements of the optical deflector.
Claim 8
Dependent Claim
217 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means comprises a double gimbal pivot having two pairs of orthogonal arms, one said pair being fixed to the chassis and the other said pair being fixed to the optical deflector; and wherein the stiffness of the double gimbal pivot is omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 9
Dependent Claim
217 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means comprises a double gimbal pivot having two pairs of orthogonal arms, one said pair being fixed to the chassis and the other said pair being fixed to the optical deflector; and wherein the stiffness of the double gimbal pivot is omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 10
Dependent Claim
212 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means comprises at least three flexible support members, each said support member connected at an upper end to the optical deflector and at a lower end to the chassis, the stiffness of said support members being omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 11
Dependent Claim
212 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means comprises at least three flexible support members, each said support member connected at an upper end to the optical deflector and at a lower end to the chassis, the stiffness of said support members being omni-directional and of a magnitude to provide a deviation of the optical deflector from the aligned position to maintain the reference field in the level orientation.
Claim 12
Dependent Claim
42 words
A transmitter as in claim 6, further including means for providing air damping of movements of the optical deflector comprising: means defining an annular surface; and means connected to the optical deflector proximate to the annular surface to provide said air damping.
Claim 13
Dependent Claim
172 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means comprises a flexible columnar support connected at one end to the chassis and at the other end to the optical deflector.
Claim 14
Dependent Claim
172 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the support means comprises a flexible columnar support connected at one end to the chassis and at the other end to the optical deflector.
Claim 15
Dependent Claim
173 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the optical deflector redirects the beam: into a reference field of radiation which is conical in shape and is directed downwardly away from the transmitter.
Claim 16
Dependent Claim
173 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein the optical deflector redirects the beam: into a reference field of radiation which is conical in shape and is directed downwardly away from the transmitter.
Claim 17
Dependent Claim
14 words
A transmitter as in claim 9, wherein the thickness of the reference field converges.
Claim 18
Dependent Claim
181 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; wherein movements of the deflector are damped by a fluid; and further comprising a transparent housing surrounding the optical deflector and wherein the fluid is a liquid which immerses the optical deflector in the housing.
Claim 19
Dependent Claim
181 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; wherein movements of the deflector are damped by a fluid; and further comprising a transparent housing surrounding the optical deflector and wherein the fluid is a liquid which immerses the optical deflector in the housing.
Claim 20
Dependent Claim
34 words
A transmitter as in claim 11, wherein the housing has inner an outer conical surfaces, the relationship between the surface being such that temperature effects on the orientation of the reference field are minimized.
Claim 21
Dependent Claim
158 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and further comprising magnet means for damping movements of the optical deflector.
Claim 22
Dependent Claim
158 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and further comprising magnet means for damping movements of the optical deflector.
Claim 23
Dependent Claim
24 words
A transmitter as in claim 13, wherein the magnet means produce eddy currents in the optical deflector to damp movements of the optical deflector.
Claim 24
Dependent Claim
171 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and further comprising sensor means for detecting when the angular error in the orientation of the chassis from level is outside of an acceptable range.
Claim 25
Dependent Claim
171 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and further comprising sensor means for detecting when the angular error in the orientation of the chassis from level is outside of an acceptable range.
Claim 26
Dependent Claim
57 words
A transmitter as in claim 15, wherein the sensor means comprises: detector means spaced a distance away from the optical deflector; and a reflector surface on the optical deflector for directing electromagnetic radiation to the detector means in an amount sufficient to activate the detector means in the acceptable range but not outside of the acceptable range.
Claim 27
Dependent Claim
41 words
A transmitter as in claim 16, wherein: the detector means comprises a pair of detectors disposed orthogonally to one another; and the reflector surface on the optical deflector is conically shaped to reflect a ring of radiation back to the detectors.
Claim 28
Dependent Claim
36 words
A transmitter as in claim 16, wherein: the detector means comprises a single detector; and the reflector surface on the optical deflector is a planar surface to reflect a spot of radiation back to the detector.
Claim 29
Dependent Claim
188 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating an amount substantially equal to one-half of the engular error from the aligned position to maintain the reference field in the level orientation.
Claim 30
Dependent Claim
188 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating an amount substantially equal to one-half of the engular error from the aligned position to maintain the reference field in the level orientation.
Claim 31
Dependent Claim
160 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and further comprising means for causing the thickness of the reference field to converge.
Claim 32
Dependent Claim
160 words
A transmitter for an alignment system in which a field of electromagnetic radiation is propagated, said transmitter comprising: a chassis; means for leveling the chassis; a source fixed to the chassis for providing a beam of electromagnetic radiation; an optical deflector having a reflecting surface which converges toward the source for redirecting the beam into an omni-directional reference field of radiation; and flexible means having an omni-directional stiffness connected to the chassis for supporting the optical deflector within the beam in an aligned position relative to the beam with the chassis level, the beam being redirected omni-directionally by the deflector in the aligned position to define a reference field of radiation in a level orientation; wherein an angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation; and further comprising means for causing the thickness of the reference field to converge.
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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) | 1991-08-30 | 1992-02-29 | 1992-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-30 | 1996-02-29 | 1996-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-30 | 2000-02-29 | 2000-08-30 | $7700.00 | Window Closed / Lapsed |