US4206576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wood desk top
Assignee: Steelcase Inc
•
Filing: 1978-11-16
•
Granted: 1980-06-10
•
Expires: 1998-11-16
Abstract
Abstract The specification discloses a desk top in which a prestressing bar having a convex upper surface is located within a groove in the bottom of the desk top. The ends of the bar are biased towards engagement with the upper surface of the groove whereby the desk top itself is biased towards a convex configuration, thereby compensating for forces tending to cause the top to bow downwardly.
Inventors
- 👤 Fredrick J. Walz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:25
CPC Classifications
A; A47; A47B; A47B13/00; A47B13/08
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
182 words
In a desk top assembly including a top and a top prestressing device, the improvement comprising: said prestressing device comprising a bar made of a substantially rigid material having a certain degree of resiliency and having an upper surface which from one end of the bar to the other is slightly convex to define a crown generally at the central portion of the bar; said top including a groove in its bottom surface, said groove being at least as long and as wide as said bar and having an upper surface which is generally linear such that when said crown of said bar is abutting said upper surface of said groove, with said bar under no stress, the upper surfaces of the end portions of said bar are spaced from said upper surface of said groove; said bar being located in said groove with said crown abutting said upper surface of said groove; means biasing said end portions of said bar and said upper surface of said groove towards abutment with one another to thereby bias said top towards a convex configuration.
Claim 2
Dependent Claim
182 words
In a desk top assembly including a top and a top prestressing device, the improvement comprising: said prestressing device comprising a bar made of a substantially rigid material having a certain degree of resiliency and having an upper surface which from one end of the bar to the other is slightly convex to define a crown generally at the central portion of the bar; said top including a groove in its bottom surface, said groove being at least as long and as wide as said bar and having an upper surface which is generally linear such that when said crown of said bar is abutting said upper surface of said groove, with said bar under no stress, the upper surfaces of the end portions of said bar are spaced from said upper surface of said groove; said bar being located in said groove with said crown abutting said upper surface of said groove; means biasing said end portions of said bar and said upper surface of said groove towards abutment with one another to thereby bias said top towards a convex configuration.
Claim 3
Dependent Claim
46 words
The desk top of claim 1 in which the upper surface of said crown of said bar is shaped to define a force distributing surface area to prevent said crown from penetrating into that portion of said top which is located above said groove upper surface.
Claim 4
Dependent Claim
28 words
The desk top assembly of claim 2 in which the pitch of said bar from said crown to said ends thereof is from about 0.017 to about 0.034.
Claim 5
Dependent Claim
24 words
The desk top assembly of claim 3 in which said bar is from about 0.6 to about 0.9 of the length of said top.
Claim 6
Dependent Claim
43 words
The desk top assembly of claim 4 in which said means biasing said ends of said bar upwardly towards engagement with the upper surface of said groove are adjustable whereby the stress imposed between said bar and said desk top can be adjusted.
Claim 7
Dependent Claim
36 words
The desk top assembly of claim 5 in which said means biasing said ends of said bar upwardly comprises a plate bolted to said top against the bottom surface of each end portion of said bar.
Claim 8
Dependent Claim
35 words
The desk top assembly of claim 6 in which said biasing means are made adjustable by a threaded screw located in said plate which bears against the bottom of each end portion of said bar.
Claim 9
Dependent Claim
29 words
The desk top assembly of claim 4 in which said bar is a linear bar which has been bent generally in the middle thereof to create a convex configuration.
Claim 10
Dependent Claim
21 words
The desk top assembly of claim 8 in which said bar is approximately 11/4 inches deep and approximately 1/4 inch wide.
Claim 11
Dependent Claim
19 words
The desk top assembly of claim 9 in which said bar is made of from 10-8 to 10-95 steel.
Claim 12
Dependent Claim
28 words
The desk top assembly of claim 1 in which the pitch of said bar from said crown to said ends thereof is from about 0.017 to about 0.034.
Claim 13
Dependent Claim
24 words
The desk top assembly of claim 11 in which said bar is from about 0.6 to about 0.9 of the length of said top.
Claim 14
Dependent Claim
43 words
The desk top assembly of claim 1 in which said means biasing said ends of said bar upwardly towards engagement with the upper surface of said groove are adjustable whereby the stress imposed between said bar and said desk top can be adjusted.
Claim 15
Dependent Claim
36 words
The desk top assembly of claim 1 in which said means biasing said ends of said bar upwardly comprises a plate bolted to said top against the bottom surface of each end portion of said bar.
Claim 16
Dependent Claim
35 words
The desk top assembly of claim 14 in which said biasing means are made adjustable by a threaded screw located in said plate which bears against the bottom of each end portion of said bar.
Claim 17
Dependent Claim
29 words
The desk top assembly of claim 1 in which said bar is a linear bar which has been bent generally in the middle thereof to create a convex configuration.
Claim 18
Dependent Claim
21 words
The desk top assembly of claim 16 in which said bar is approximately 11/4 inches deep and approximately 1/4 inch wide.
Claim 19
Dependent Claim
19 words
The desk top assembly of claim 17 in which said bar is made of from 10-8 to 10-95 steel.
Claim 20
Dependent Claim
19 words
The desk top assembly of claim 1 in which said bar is made of from 10-8 to 10-95 steel.
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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) | 1983-06-10 | 1983-12-10 | 1984-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-10 | 1987-12-10 | 1988-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-10 | 1991-12-10 | 1992-06-10 | $7700.00 | Window Closed / Lapsed |