US4335522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Up, down or horizontal plumb bob
Assignee: CANFIELD Corp A CORP OF Co
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Filing: 1981-02-24
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Granted: 1982-06-22
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Expires: 2001-02-24
Abstract
Abstract A transparent plumb bob having a fixed point and an associated movable point, to be aligned therewith for determination of a vertical line through a given exterior point, optionally including means for horizontal leveling and easily securing the bob intermediate the ends of a string. A vertical or horizontal line is determined by fixing one string end to a point spaced from the plumb bob and then pivoting the plumb bob and other string end about the point until the associated indicators are in alignment.
Inventors
- 👤 Robert L. Canfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:42
CPC Classifications
G; G01; G01C; G01C15/00; G01C15/10
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
117 words
A plumb bob comprising an elongated body having top and bottom ends, spaced apart by a plurality of elongated parallel struts, at least one strut being hollow, transparent and filled with liquid except for an air bubble that acts as a horizontal level indicator, a transparent fluid chamber between said body ends, means for securing a string at a point on each body end, a fixed indicator point intermediate and in alignment with said body end points, and an associated movable level indicator within said chamber of different density than said fluid, said points describing an imaginary straight line, said movable level indicator being aligned with said fixed indicator point only when said imaginary line is vertical.
Claim 2
Dependent Claim
117 words
A plumb bob comprising an elongated body having top and bottom ends, spaced apart by a plurality of elongated parallel struts, at least one strut being hollow, transparent and filled with liquid except for an air bubble that acts as a horizontal level indicator, a transparent fluid chamber between said body ends, means for securing a string at a point on each body end, a fixed indicator point intermediate and in alignment with said body end points, and an associated movable level indicator within said chamber of different density than said fluid, said points describing an imaginary straight line, said movable level indicator being aligned with said fixed indicator point only when said imaginary line is vertical.
Claim 3
Dependent Claim
19 words
The plumb bob of claim 1 wherein all said points are centered relative to the diameter of said body.
Claim 4
Dependent Claim
15 words
The plumb bob of claim 1 wherein said body is made from a transparent plastic.
Claim 5
Dependent Claim
11 words
The plumb bob of claim 1 wherein said ends are conical.
Claim 6
Dependent Claim
16 words
The plumb bob of claim 1 wherein said fluid has a lesser density than said indicator.
Claim 7
Dependent Claim
16 words
The plumb bob of claim 1 wherein said fluid has a greater density than said indicator.
Claim 8
Dependent Claim
16 words
The plumb bob of claim 6 wherein said fluid is liquid and said indicator is gas.
Claim 9
Dependent Claim
13 words
The plumb bob of claim 7 wherein said indicator is a gas bubble.
Claim 10
Dependent Claim
17 words
The plumb bob of claim 8 wherein said gas bubble is an elongated hollow gas-filled plastic member.
Claim 11
Dependent Claim
21 words
The plumb bob of claim 1 wherein said string securing means is a channel through which said string may be threaded.
Claim 12
Dependent Claim
38 words
The plumb bob of claim 10 wherein said string securing means includes at each body end a horizontal channel spaced from the end and a vertical channel intersecting and extending from the horizontal channel to the respectve end.
Claim 13
Dependent Claim
34 words
The plumb bob of claim 11 additionally including a string at each end extending through said channels, knotted at the free end of said horizontal channel and extending through and beyond said respective end.
Claim 14
Dependent Claim
33 words
The plumb bob of claim 10 wherein said string securing means includes at each body end a slanting channel extending from said end to a position on the side wall of said body.
Claim 15
Dependent Claim
29 words
The plumb bob of claim 13 additionally including a string extending through and beyond both said ends, through said slanting channels and along said wall between said slanting channels.
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) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |