US4020559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bearing compass
Assignee: E S RITCHIE AND SONS Inc
•
Filing: 1975-12-22
•
Granted: 1977-05-03
•
Expires: 1995-12-22
Abstract
Abstract A portable hand-held compass for taking navigational bearings on distant objects during the day or at night. The compass has a hollow housing in which a compass card is mounted for rotation about a vertical axis, a viewing window in the housing through which compass readings are taken, and a sighting barrel incorporated in the housing for viewing a distant object along a horizontal viewing path. The compass also has a manually activated light emitting diode for illuminating a reticle, a semi-reflective mirror positioned across the sighting path for reflecting an image of the illuminated reticle to the eyepiece of the sighting barrel, means for automatically unclamping the compass card when the L.E.D. is activated, and means for automatically clamping the compass card when the L.E.D. is deactivated.
Inventors
- 👤 Allen Butman Sherman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:21
CPC Classifications
G; G01; G01C; G01C17/00; G01C17/02; G01C17/04; G01C17/10; G01C17/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
170 words
A portable, hand-held bearing compass for taking bearings during the day and at night comprising: a hollow housing; a magnetic compass mounted in said housing, said compass having a compass card mounted for rotation about a vertical axis; a viewing window provided in said housing through which compass readings can be taken; a sighting barrel having an eyepiece, said barrel being associated with said housing for viewing a distant object along a horizontal sighting path; a reticle mounted within said housing offset from said sighting path; manually activated means for illuminating said reticle; a semi-reflective mirror positioned within said sighting barrel across said sighting path, said mirror being angled to reflect the image of said illuminated reticle along said sighting path towards said eyepiece while permitting a distant object to be viewed along said sighting path through said eyepiece; means for continuously clamping said compass card in the absence of reticle illumination; and means for unclamping said compass card in response to the manual activation of said reticle illumination means.
Claim 2
Dependent Claim
170 words
A portable, hand-held bearing compass for taking bearings during the day and at night comprising: a hollow housing; a magnetic compass mounted in said housing, said compass having a compass card mounted for rotation about a vertical axis; a viewing window provided in said housing through which compass readings can be taken; a sighting barrel having an eyepiece, said barrel being associated with said housing for viewing a distant object along a horizontal sighting path; a reticle mounted within said housing offset from said sighting path; manually activated means for illuminating said reticle; a semi-reflective mirror positioned within said sighting barrel across said sighting path, said mirror being angled to reflect the image of said illuminated reticle along said sighting path towards said eyepiece while permitting a distant object to be viewed along said sighting path through said eyepiece; means for continuously clamping said compass card in the absence of reticle illumination; and means for unclamping said compass card in response to the manual activation of said reticle illumination means.
Claim 3
Dependent Claim
20 words
A bearing compass according to claim 1 wherein said viewing window is provided in the upper portion of said housing.
Claim 4
Dependent Claim
16 words
A bearing compass according to claim 1 wherein said sighting barrel is incorporated within said housing.
Claim 5
Dependent Claim
16 words
A bearing compass according to claim 1 wherein said reticle illumination means is a light-emitting diode.
Claim 6
Dependent Claim
51 words
A bearing compass according to claim 4 wherein said light-emitting diode emits light having a wave length longer than green light and said mirror has a dichroic coating which reflects light having a wave length longer than green light to a greater extent than it reflects light of shorter wave lengths.
Claim 7
Dependent Claim
16 words
A bearing compass according to claim 3 wherein said reticle illumination means is a light-emitting diode.
Claim 8
Dependent Claim
17 words
A bearing compass according to claim 1 further comprising manually activated means for illuminating said compass card.
Claim 9
Dependent Claim
63 words
A bearing compass according to claim 1 further comprising filter means for altering the contrast between the reticle image and the distant object image as viewed through said eyepiece, said filter means being manually movable between an operative position across said sighting path and an inoperative position offset from said sighting path, said mirror being located between said eyepiece and said operative position.
Claim 10
Dependent Claim
190 words
A portable, hand-held bearing compass for taking bearings during the day and at night comprising: a hollow housing; a magnetic compass mounted in said housing, said compass having a compass card mounted for rotation about a vertical axis; a viewing window provided in said housing through which compass readings can be taken; a sighting barrel having an eyepiece, said barrel being joined to said housing for viewing a distant object along a horizontal sighting path; a reticle mounted within said housing offset from said sighting path; manually activated means for illuminating said reticle; a semi-reflective mirror positioned within said sighting barrel across said sighting path, said mirror being angled to reflect the image of said illuminated reticle along said sighting path towards said eyepiece while permitting a distant object to be viewed along said sighting path through said eyepiece; clamping means movable between two positions, one position clamping said compass card, the other position unclamping said compass card, means biasing said clamping means to its clamping position, and means responsive to said manually activated illuminating means to move said clamping means to its unclamping position when said reticle is illuminated.
Claim 11
Dependent Claim
190 words
A portable, hand-held bearing compass for taking bearings during the day and at night comprising: a hollow housing; a magnetic compass mounted in said housing, said compass having a compass card mounted for rotation about a vertical axis; a viewing window provided in said housing through which compass readings can be taken; a sighting barrel having an eyepiece, said barrel being joined to said housing for viewing a distant object along a horizontal sighting path; a reticle mounted within said housing offset from said sighting path; manually activated means for illuminating said reticle; a semi-reflective mirror positioned within said sighting barrel across said sighting path, said mirror being angled to reflect the image of said illuminated reticle along said sighting path towards said eyepiece while permitting a distant object to be viewed along said sighting path through said eyepiece; clamping means movable between two positions, one position clamping said compass card, the other position unclamping said compass card, means biasing said clamping means to its clamping position, and means responsive to said manually activated illuminating means to move said clamping means to its unclamping position when said reticle is illuminated.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-02 | 1980-11-01 | 1981-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-02 | 1984-11-01 | 1985-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-02 | 1988-11-01 | 1989-05-03 | $7700.00 | Window Closed / Lapsed |