US3924752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crane boom and line safety limit warning assembly
Assignee: BWB Controls Inc
•
Filing: 1974-07-16
•
Granted: 1975-12-09
•
Expires: 1994-07-16
Abstract
Abstract A fluid pressure warning system is provided bleed valves for use on a crane and positioned for actuation in response to the boom of a crane being elevated excessively, the block of a crane approaching its upper limit and the fast line of a crane approaching its upper limit of travel. The fluid pressure system comprises a pneumatic system and includes a pneumatically actuated audible signal developing apparatus disposed in a branch line of the pneumatic system under the control of a pneumatic relay actuatable in response to a drop in air pressure within the system.
Inventors
- 👤 Frank M Hoofnagle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:41
CPC Classifications
B; B66; B66C; B66C15/00; B66C15/06; B66C13/00; B66C13/18; B66C13/50
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
304 words
In combination with a crane including first and second components with the first component movable relative to the second component in opposite directions toward and away from the second component and in one of said directions toward a predetermined limit position, an abutment portion on one of said components, a normally closed pressure relief valve on the other of said components and including an actuator engageable by said abutment portion upon movement of said first component in said one direction to a position adjacent said limit position to open said pressure relief valve, a fluid pressure system including a fluid pressure line having an inlet end adapted for connection to a source of gas under pressure and an outlet end, an air pressure operated relay including a normally closed air passage extending therethrough and a pressure inlet port to which gas pressure must be supplied to maintain said air passage closed, said relay being operative to automatically open said passage in response to a drop in air pressure at said port below a predetermined value, said outlet end being communicated with said port and said pressure line including air flow restricting means intermediate said inlet and outlet ends, a first branch line including an inlet end opening into said pressure line between said flow restricting means and said outlet end and an outlet end communicated with one end of said flow passage, a second branch line including an inlet end communicated with the interior of said pressure line intermediate said flow restricting means and the outlet end of said pressure line and an outlet end under the control of said pressure relief valve, and a signal supply line having an inlet end communicated with the other end of said passage and an outlet end adapted to be communicated with a pneumatically actuatable signalling device.
Claim 2
Dependent Claim
304 words
In combination with a crane including first and second components with the first component movable relative to the second component in opposite directions toward and away from the second component and in one of said directions toward a predetermined limit position, an abutment portion on one of said components, a normally closed pressure relief valve on the other of said components and including an actuator engageable by said abutment portion upon movement of said first component in said one direction to a position adjacent said limit position to open said pressure relief valve, a fluid pressure system including a fluid pressure line having an inlet end adapted for connection to a source of gas under pressure and an outlet end, an air pressure operated relay including a normally closed air passage extending therethrough and a pressure inlet port to which gas pressure must be supplied to maintain said air passage closed, said relay being operative to automatically open said passage in response to a drop in air pressure at said port below a predetermined value, said outlet end being communicated with said port and said pressure line including air flow restricting means intermediate said inlet and outlet ends, a first branch line including an inlet end opening into said pressure line between said flow restricting means and said outlet end and an outlet end communicated with one end of said flow passage, a second branch line including an inlet end communicated with the interior of said pressure line intermediate said flow restricting means and the outlet end of said pressure line and an outlet end under the control of said pressure relief valve, and a signal supply line having an inlet end communicated with the other end of said passage and an outlet end adapted to be communicated with a pneumatically actuatable signalling device.
Claim 3
Dependent Claim
275 words
In combination with a crane including first and second components with the first component movable relative to the second component in opposite directions toward and away from the second component and in one of said directions toward a predetermined limit position, an abutment portion on one of said components, a normally closed pressure relief valve on the other of said components and including an acutator engageable by said abutment portion upon movement of said first component in said one direction to a position adjacenT said limit position to open said pressure relief valve, a source of pressurized gas, a fluid pressure system including a fluid pressure line having an inlet end adapted for connection to said source of gas under pressure and an outlet end, a branch line including an inlet end communicated with said pressure line and an outlet end, a pneumatically actuatable signalling device connected to the outlet end of said branch line, said branch line including a normally closed valve serially connected therein and to which the outlet end of said pressure line is connected and operable to open said valve in response to a drop in pressure at said inlet port caused by the opening of said pressure relief valve, air flow restricting means in said pressure line between the inlet end of said branch line and the outlet end of said pressure line, and a pressure relief line including an inlet end opening into said pressure line between its outlet end and said flow restricting means and an outlet end under the control of said pressure relief valve, further said source of pressurized gas operates said pneumatically actuactable signalling device.
Claim 4
Dependent Claim
275 words
In combination with a crane including first and second components with the first component movable relative to the second component in opposite directions toward and away from the second component and in one of said directions toward a predetermined limit position, an abutment portion on one of said components, a normally closed pressure relief valve on the other of said components and including an acutator engageable by said abutment portion upon movement of said first component in said one direction to a position adjacenT said limit position to open said pressure relief valve, a source of pressurized gas, a fluid pressure system including a fluid pressure line having an inlet end adapted for connection to said source of gas under pressure and an outlet end, a branch line including an inlet end communicated with said pressure line and an outlet end, a pneumatically actuatable signalling device connected to the outlet end of said branch line, said branch line including a normally closed valve serially connected therein and to which the outlet end of said pressure line is connected and operable to open said valve in response to a drop in pressure at said inlet port caused by the opening of said pressure relief valve, air flow restricting means in said pressure line between the inlet end of said branch line and the outlet end of said pressure line, and a pressure relief line including an inlet end opening into said pressure line between its outlet end and said flow restricting means and an outlet end under the control of said pressure relief valve, further said source of pressurized gas operates said pneumatically actuactable signalling device.
Claim 5
Dependent Claim
143 words
The combination of claim 1 wherein said pressure relief valve includes a valve body having a bore formed therethrough, a piston extending through said bore including a first end portion of reduced diameter provided with an enlarged head disposed outwardly of the corresponding end of said bore and shiftable toward said body to sealingly close said bore, the other end of said piston being snugly slidable through the other end portion of said bore and projecting outwardly of said body, spring means operatively connected between said piston and said body yieldingly biasing said piston toward a position with said head sealingly closing said corresponding end of said bore, said body including a pressure inlet port opening into said bore out of registry with said other end of said piston, the outlet end of said pressure relief line being connected to said inlet port.
Claim 6
Dependent Claim
36 words
The combination of claim 3 wherein said crane includes a boom mounting structure and a boom pivotally supported from said structure for oscillation about a generally horizontal axis, said mounting structure and boom comprising said components.
Claim 7
Dependent Claim
25 words
The combination of claim 4 wherein said abutment portion is carried by said boom and said pressure relief valve is carried by said mounting structure.
Claim 8
Dependent Claim
40 words
The combination of claim 3 wherein said crane includes a boom structure having a free end portion and a fast line received over the free end portion of said boom structure, said boom structure and fast line comprising said components.
Claim 9
Dependent Claim
69 words
The combination of claim 6 wherein said abutment portion is carried by said fast line and said relief valve is dependingly supported from said boom structure with said other end of said piston disposed lowermost and alongside the downwardly extending free end portion of said fast line, the upper portion of said relief valve body being pivotally supported from said boom structure for oscillation about a horizontal transverse axis.
Claim 10
Dependent Claim
88 words
The combination of claim 3 wherein said crane includes a boom structure having a free end portion and a block line received over said free end portion as well as a dead line anchored at its upper end to said structure, the lower ends of said block and dead lines being joined and supporting a block therefrom, said abutment being carried by said block and support means supporting said valve from said dead line with said other end of said piston lowermost and extending along said dead line.
Claim 11
Dependent Claim
39 words
The combination of claim 8 wherein said support means includes means supporting said valve body from said dead line for limited shifting along the latter and yieldingly biasing said body toward its lowermost limit position on said dead line.
Claim 12
Dependent Claim
85 words
The combination of claim 9 wherein said valve body includes a through bore generally paralleling the first-mentioned bore and said through bore includes an enlarged counterbore at its end corrEsponding to said corresponding end of first-mentioned body bore, said support means comprising a coiled combined expansion and compression spring disposed about and slidable on said dead line above said valve body, the lower end of said spring being anchored in said counterbore and the upper end of said spring being anchored to said dead line.
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) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |