US3952879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overload control for lifting boom
Assignee: Fulton Industries Inc
•
Filing: 1975-02-14
•
Granted: 1976-04-27
•
Expires: 1995-02-14
Abstract
Abstract A machine has a movable boom for lifting a load, and an overload sensing device mounted on the boom to sense boom deflection. The overload sensing device includes a rigid beam having one end secured to a vertical side plate of the boom only by anchors spaced widely apart, welded preferably on opposite sides of the centroid or neutral axis of the boom side plate. The beam has a free end, on which an adjustable contact plate is carried, to engage a switch adjustably carried on a mounting plate secured to the beam side plate.
Inventors
- 👤 John L. Grove
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:14
CPC Classifications
B; B66; B66F; B66F17/00; B66F17/006
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
167 words
In a machine having a movable boom for lifting a load, the boom being thereby subjected to bending stresses which strain the boom, a beam extending along and generally parallel to a side of said boom; means securing one end only of said beam to the side of said boom for twisting of said one end of said beam upon the imposition of bending stresses on said boom, said securing means comprising a pair of spaced anchor means vertically spaced when the boom axis is horizontal secured to said boom side and being spaced apart a substantially greater distance than the depth required for a beam in order to prevent significant deflection thereof, and means spaced from said anchor means for sensing movement of said beam relative to said boom as said boom is stressed toward an overload condition, whereby the movement of said beam relative to said boom is enhanced by the twisting of said end thereof to provide greater sensitivity of measurement of boom strain.
Claim 2
Dependent Claim
167 words
In a machine having a movable boom for lifting a load, the boom being thereby subjected to bending stresses which strain the boom, a beam extending along and generally parallel to a side of said boom; means securing one end only of said beam to the side of said boom for twisting of said one end of said beam upon the imposition of bending stresses on said boom, said securing means comprising a pair of spaced anchor means vertically spaced when the boom axis is horizontal secured to said boom side and being spaced apart a substantially greater distance than the depth required for a beam in order to prevent significant deflection thereof, and means spaced from said anchor means for sensing movement of said beam relative to said boom as said boom is stressed toward an overload condition, whereby the movement of said beam relative to said boom is enhanced by the twisting of said end thereof to provide greater sensitivity of measurement of boom strain.
Claim 3
Dependent Claim
67 words
The apparatus of claim 1, said securing means comprising a plate substantially perpendicular to the boom longitudinal axis, means connecting said one end of said beam to said plate, said plate having a vertical extent greater than the depth of said beam, and means connecting said anchor means to said plate, said anchor means being spaced apart a substantially greater distance than said depth of said beam.
Claim 4
Dependent Claim
35 words
The apparatus of claim 2, wherein said anchor means are welded to said boom and to said plate, and wherein said means connecting said one end of said beam to said plate comprises releasable means.
Claim 5
Dependent Claim
22 words
The apparatus of claim 1, wherein said beam has a depth greater than that required in order to prevent significant deflection thereof.
Claim 6
Dependent Claim
32 words
The apparatus of claim 1, said sensing means comprising a switch and means mounting said switch adjacent the opposite end of said beam for actuation thereof upon excessive strain of said boom.
Claim 7
Dependent Claim
29 words
The apparatus of claim 5, said last mentioned means comprising a plate welded to the boom and extending laterally thereof, and means releasably securing said switch to said plate.
Claim 8
Dependent Claim
18 words
The apparatus of claim 5, said beam having engagement plate means releasably secured to the free end thereof.
Claim 9
Dependent Claim
28 words
The apparatus of claim 5, said beam having engagement plate means longitudinally adjustably secured to the free end thereof in a plane generally parallel to the neutral axis.
Claim 10
Dependent Claim
20 words
The apparatus of claim 8, said engagement plate means comprising a linear engagement element transverse to said engagement plate means.
Claim 11
Dependent Claim
23 words
The apparatus of claim 9, said switch comprising a housing and a plunger extending downwardly from said housing toward said linear engagement element.
Claim 12
Dependent Claim
132 words
In combination with a movable load supporting boom having an unstressed neutral axis under load, means for sensing excess strain of said boom comprising: a beam, means for securing one end of said beam to said boom with said beam extending along said boom and for causing twisting of the beam relative to said neutral axis at said one end of said beam upon loading of said boom comprising anchor means securing said beam to said boom spaced apart a substantially greater distance than the depth required for a beam in order to prevent significant deflection thereof, engagement means on said beam remote from said securing means, switch means, and means for securing said switch means to said boom adjacent said engagement means for actuation thereof upon excessive strain of said boom.
Claim 13
Dependent Claim
132 words
In combination with a movable load supporting boom having an unstressed neutral axis under load, means for sensing excess strain of said boom comprising: a beam, means for securing one end of said beam to said boom with said beam extending along said boom and for causing twisting of the beam relative to said neutral axis at said one end of said beam upon loading of said boom comprising anchor means securing said beam to said boom spaced apart a substantially greater distance than the depth required for a beam in order to prevent significant deflection thereof, engagement means on said beam remote from said securing means, switch means, and means for securing said switch means to said boom adjacent said engagement means for actuation thereof upon excessive strain of said boom.
Claim 14
Dependent Claim
34 words
The combination of claim 11, wherein said means securing said beam to said boom comprises first anchor means welded to said boom and second means releasably connecting said first anchor means and said beam.
Claim 15
Dependent Claim
24 words
The combination of claim 11, wherein said means for securing said switch means to said boom comprises means for laterally adjusting said switch means.
Claim 16
Dependent Claim
30 words
The combination of claim 11, wherein said engagement means comprises an engagement plate and a linear engagement element transverse to said engagement plate, and means for adjusting said element linearly.
Claim 17
Dependent Claim
24 words
The combination of claim 14, wherein said means for securing said switch means to said boom comprises means for laterally adjusting said switch means.
Claim 18
Dependent Claim
29 words
The combination of claim 15, wherein said means securing said beam to said boom comprises anchor means secured to said boom on opposite sides of the neutral axis thereof.
Claim 19
Dependent Claim
29 words
The combination of claim 11, wherein said means securing said beam to said boom comprises anchor means secured to said boom on opposite sides of the neutral axis thereof.
Claim 20
Dependent Claim
22 words
The combination of claim 12, said first anchor means comprising anchor plate means vertically spaced apart when said boom axis is horizontal.
Claim 21
Dependent Claim
154 words
In a structure having a load-lifting boom subjected to variable bending stresses and apparatus operatively connected to said load-lifting boom to sense the bending strain thereof when said boom is stressed, said sensing apparatus comprising a beam supported adjacent a side of said boom and means for sensing the relative movement of said beam and said boom upon stressing of said boom, the improvement comprising plural anchor means vertically spaced when the boom is horizontal a substantially greater distance than the depth required for a beam in order to prevent significant deflection thereof, for securing said one end of said beam to said side of said boom for twisting of said one end of said beam relative to the boom upon the imposition of bending stresses on said boom, whereby to provide enhanced movement of said beam relative to said boom and thus greater sensitivity of measurement of the bending strain of said boom.
Claim 22
Dependent Claim
154 words
In a structure having a load-lifting boom subjected to variable bending stresses and apparatus operatively connected to said load-lifting boom to sense the bending strain thereof when said boom is stressed, said sensing apparatus comprising a beam supported adjacent a side of said boom and means for sensing the relative movement of said beam and said boom upon stressing of said boom, the improvement comprising plural anchor means vertically spaced when the boom is horizontal a substantially greater distance than the depth required for a beam in order to prevent significant deflection thereof, for securing said one end of said beam to said side of said boom for twisting of said one end of said beam relative to the boom upon the imposition of bending stresses on said boom, whereby to provide enhanced movement of said beam relative to said boom and thus greater sensitivity of measurement of the bending strain of said boom.
References Cited (Backward Citations)
US2030529A
Cited
US2319299A
Cited
US2988040A
Cited
US3199685A
Cited
US3737888A
Cited
US3756423A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |