US5713705A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fastener bolt with limited torque head
Assignee: Individual
•
Filing: 1996-03-01
•
Granted: 1998-02-03
•
Expires: 2016-03-01
Abstract
Abstract A non-removable, tamper-proof bolt has a threaded shaft, a permanent head, and a torque head which is sheared off from the assembly when the bolt is fastened. The shaft has an opening formed therein at the forward screw end, and the opening has a profile for engagement with a torque tool. The torque head is formed with a hole as well which extends through the entire torque head coaxially with the threaded shaft. The torque head is attached to the permanent head by the intermediary of a bridge defined around said hole in the torque head. Once the torque head is sheared off, the bolt cannot be turned until the opening formed in the forward screw end is exposed by drilling through the shaft from the permanent head inwardly.
Inventors
- 👤 Carl Grunbichler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:32
CPC Classifications
F; F16; F16B; F16B31/00; F16B31/02; F16B31/021; Y; Y10; Y10S; Y10S411/00; Y10S411/91
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
139 words
A tamper-proof bolt, comprising: a threaded shaft with a first end and a second end, said shaft defining a longitudinal bolt axis; a permanent clamping head formed on said first end of said threaded shaft; said threaded shaft having a blind opening formed therein at said second end thereof, said opening extending along said axis and being formed with a profile for engagement with a torque tool; and a torque head formed on said permanent clamping head, said torque head having a hole formed therein, said hole extending through said entire torque head and partially into said permanent clamping head coaxially with said threaded shaft and with said opening in said second end of said shaft; said torque head being attached to said permanent head by the intermediary of a bridge defined around said hole in said torque head.
Claim 2
Dependent Claim
139 words
A tamper-proof bolt, comprising: a threaded shaft with a first end and a second end, said shaft defining a longitudinal bolt axis; a permanent clamping head formed on said first end of said threaded shaft; said threaded shaft having a blind opening formed therein at said second end thereof, said opening extending along said axis and being formed with a profile for engagement with a torque tool; and a torque head formed on said permanent clamping head, said torque head having a hole formed therein, said hole extending through said entire torque head and partially into said permanent clamping head coaxially with said threaded shaft and with said opening in said second end of said shaft; said torque head being attached to said permanent head by the intermediary of a bridge defined around said hole in said torque head.
Claim 3
Dependent Claim
21 words
The bolt according to claim 1, wherein said torque head has a circumferential outer profile for engagement by a torque tool.
Claim 4
Dependent Claim
20 words
The bolt according to claim 2, wherein said circumferential outer profile is a hexagonal profile for engagement with a wrench.
Claim 5
Dependent Claim
26 words
The bolt according to claim 1, wherein said torque head is formed with an inner profile coaxially surrounding said hole for engagement by a torque tool.
Claim 6
Dependent Claim
24 words
The bolt according to claim 4, wherein said inner profile of said torque head is a hexagonal profile for engagement by an Allen wrench.
Claim 7
Dependent Claim
22 words
The bolt according to claim 1, wherein said profile of said opening is a hexagonal profile for engagement by an Allen wrench.
Claim 8
Dependent Claim
21 words
The bolt according to claim 1, wherein said permanent head has an outer circumference which is tapered towards said torque head.
Claim 9
Dependent Claim
22 words
The bolt according to claim 1, wherein said permanent head has an outer circumference which is tapered away from said torque head.
Claim 10
Dependent Claim
27 words
The bolt according to claim 1, wherein said permanent head has a surface at which said bridge is attached, said surface being inwardly tapered towards said bridge.
Claim 11
Dependent Claim
39 words
The bolt according to claim 1, wherein said permanent head has a surface at which said bridge is attached, said surface having a given diameter, and said bridge having a diameter between 50% and 60% of said given diameter.
Claim 12
Dependent Claim
27 words
The bolt according to claim 10, wherein said hole formed in said torque head has a diameter between 25% and 45% of the diameter of said bridge.
Claim 13
Dependent Claim
22 words
The bolt according to claim 1, wherein said shaft, said permanent head, and said torque head are integrally molded in one piece.
Claim 14
Dependent Claim
12 words
The bolt according to claim 12, wherein the bolt is injection molded.
References Cited (Backward Citations)
US2083054A
Cited
US3182757A
Cited
US3424212A
Cited
US3498174A
Cited
DE2011739A1
Cited
DE2353751A1
Cited
US4021892A
Cited
GB1557234A
Cited
US4502825A
Cited
US4874275A
Cited
US4819522A
Cited
DE3738409A1
Cited
US5120168A
Cited
US5199834A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-02-02 | 2001-08-04 | 2002-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-02 | 2005-08-04 | 2006-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-02 | 2009-08-04 | 2010-02-03 | $7700.00 | Window Closed / Lapsed |