US4702008A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zero setting device in surveying instrument
Assignee: Pentax Corp
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Filing: 1986-08-26
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Granted: 1987-10-27
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Expires: 2006-08-26
Abstract
Abstract A surveying instrument for measuring a rotation angle in which a rotation angle is measured from a reference direction and is displayed. The reference angle is set by zeroing the displayed angle. The display is zeroed only if a reset button is operated twice within a fixed period.
Inventors
- 👤 Shinichi Suzuki
- 👤 Masato Hara
- 👤 Koji Tsuda
- 👤 Eiji Takasugi
- 👤 Toshifumi Kinba
- 👤 Atsumi Kaneko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:59
CPC Classifications
G; G01; G01C; G01C1/00; G01C1/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
131 words
A zero setting device in a surveying instrument comprising: a base stand; a rotary stand which is rotatable with respect to said base stand and has collimating means; means for electrically detecting an rotation angle of said rotary stand with respect to said base stand; an angle displaying unit for displaying an angle detected by said detecting means; and a zero setting device, said zero setting device comprising, a manually-operated zero setting switch, a timer which starts operating for a predetermined period when said zero setting switch is manually operated a first time; and zero setting means for setting a display angle on said angle displaying unit to zero only when said zero setting switch is manually operated a second time, said second time occurring during the operation of said timer.
Claim 2
Dependent Claim
131 words
A zero setting device in a surveying instrument comprising: a base stand; a rotary stand which is rotatable with respect to said base stand and has collimating means; means for electrically detecting an rotation angle of said rotary stand with respect to said base stand; an angle displaying unit for displaying an angle detected by said detecting means; and a zero setting device, said zero setting device comprising, a manually-operated zero setting switch, a timer which starts operating for a predetermined period when said zero setting switch is manually operated a first time; and zero setting means for setting a display angle on said angle displaying unit to zero only when said zero setting switch is manually operated a second time, said second time occurring during the operation of said timer.
Claim 3
Dependent Claim
26 words
A zero setting device as claimed in claim 1, further comprising a timer operation indicating unit for indicating to an operator that said timer is operating.
Claim 4
Dependent Claim
19 words
A zero setting device as claimed in claim 2, in which said timer operation indicating unit is a buzzer.
Claim 5
Dependent Claim
19 words
A zero setting device as claimed in claim 2, in which said timer operation indicating unit is a lamp.
Claim 6
Dependent Claim
39 words
A zero setting device as recited in claim 1, wherein said timer receives an output of said switch and said zero setting means includes a logic circuit receiving an output of said switch and an output of said timer.
Claim 7
Dependent Claim
17 words
A zero setting device as recited in claim 1, wherein said logic circuit is an AND circuit.
References Cited (Backward Citations)
US4072893A
Cited
US4466189A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-26 | 1991-04-27 | 1991-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-26 | 1995-04-27 | 1995-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-26 | 1999-04-27 | 1999-10-27 | $7700.00 | Window Closed / Lapsed |