Patent US3872601A successfully refreshed from Google Patents.
US3872601A
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Apparatus for sensing twisting of a paving machine screed
Assignee: Burgin Electronic Grade Control Inc
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Filing: 1973-07-05
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Granted: 1975-03-25
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Expires: 1993-07-05
Abstract
Abstract Apparatus for sensing twisting of a screed of a paving machine, the paving machine having a control system for changing the angle of attack of of each end of the screed relative to a road surface. The twist-sensing apparatus includes a sensor adapted to be mounted on the screed for sensing twist in the screed, the sensor comprising a signal generator for generating a signal in response to the screed twisting from a predetermined twist angle, this signal being adapted to effect energization of the control system for changing the angle of attack of one end of the screed thereby to restore the screed to its predetermined twist angle. The signal generator is rigidly secured to and is movable with the screed at a first location on the screed. The sensor further comprises a twist reference arm rigidly secured to and movable with the screed at a second location on the screed angularly displaced from the first location. The twist reference arm extends obliquely relative to the screed between the first and second locations, and is operatively connected to the signal generator, whereby a change in screed twist causes relative movement between the signal generator and the twist reference arm and thus generates a signal upon the twist angle of the screed deviating from its predetermined twist angle.
Inventors
- 👤 Luther B Burgin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:36
CPC Classifications
E; E01; E01C; E01C19/00; E01C19/48; E01C19/4866; E01C19/4873; E01C2301/00; E01C2301/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
253 words
Apparatus for sensing twisting of an elongate element of a road-making machine, such as a screed of a paving machine, said machine having means for changing the angle of each end of the element relative to a road surface; said apparatus comprising a sensor adapted to be mounted on said element for sensing twist in said element, said sensor comprising means for generating a signal in response to said element twisting from a predetermined twist angle, said signal adapted to effect energization of said means for changing the angle of one end of the element thereby to restore the element to its predetermined twist angle, said signal generating means being rigidly secured to and being movable with said element at a first location on said element adjacent the trailing edge of the element generally equidistant between the ends of the element, and said sensor further comprising a nonrotary twist reference arm having one end thereof rigidly secured to and movable with said element at a second location on the element adjacent the leading edge of the element adjacent one end thereof, said twist reference arm extending obliquely relative to said element between said first and said second locations, the other end of said twist reference arm constituting its free end being operatively connected to said signalgenerating means whereby a change in screed twist causes relative vertical movement between said signal-generating means and said twist reference arm and thereby generates a signal upon the twist of the element deviating from said predetermined twist angle.
Claim 2
Dependent Claim
253 words
Apparatus for sensing twisting of an elongate element of a road-making machine, such as a screed of a paving machine, said machine having means for changing the angle of each end of the element relative to a road surface; said apparatus comprising a sensor adapted to be mounted on said element for sensing twist in said element, said sensor comprising means for generating a signal in response to said element twisting from a predetermined twist angle, said signal adapted to effect energization of said means for changing the angle of one end of the element thereby to restore the element to its predetermined twist angle, said signal generating means being rigidly secured to and being movable with said element at a first location on said element adjacent the trailing edge of the element generally equidistant between the ends of the element, and said sensor further comprising a nonrotary twist reference arm having one end thereof rigidly secured to and movable with said element at a second location on the element adjacent the leading edge of the element adjacent one end thereof, said twist reference arm extending obliquely relative to said element between said first and said second locations, the other end of said twist reference arm constituting its free end being operatively connected to said signalgenerating means whereby a change in screed twist causes relative vertical movement between said signal-generating means and said twist reference arm and thereby generates a signal upon the twist of the element deviating from said predetermined twist angle.
Claim 3
Dependent Claim
64 words
Apparatus as set forth in claim 1 wherein said signal-generating means comprises rotary actuating means, a transducer actuable by the actuating means to effect generation of said signal, and means for operatively connecting said twist reference arm to said actuating means whereby twisting of said element causes relative movement between said twist reference arm and said actuating means so as to actuate said transducer.
Claim 4
Dependent Claim
85 words
Apparatus as set forth in claim 2 wherein said actuating means comprises a rotary shaft and an actuating arm extending radially from said shaft and having two generally parallel surfaces, said connecting means comprising a pair of opposed, spaced-apart bearing members, each being slidably engageable with a respective parallel surface of said actuating arm, each bearing member being supported for limited rotation about any axis, whereby movement of said twist reference arm in response to twisting of the element effects rotation of said actuating arm.
Claim 5
Dependent Claim
56 words
Apparatus as set forth in claim 3 wherein said transducer is a rotary switch having a rotary cam and at least one pair of switch contacts, each said pair of switch contacts including a stationary contact and a contact movable by rotation of the cam for making and breaking contact therebetween thereby to generate said signal.
Claim 6
Dependent Claim
28 words
Apparatus as set forth in claim 4 wherein said cam is mounted on said shaft, said actuating arm being a paddle-shaped member extending generally perpendicularly from said shaft.
Claim 7
Dependent Claim
237 words
Apparatus as set forth in claim 1 wherein said signal-generating means comprises a rotary switch rotary in response to the twist of said element deviating from said predetermined twist angle, said rotary switch comprising a rotary cam and two contact assemblies operable in response to rotation of said cam, thereby to generate said signal, said cam having two cam surface contours, one for each contact assembly, each contacT assembly comprising an arm in resilient engagement with the cam surface of said cam and being movable in and out relative to the cam by a respective cam contour in response to rotation of the cam, and contact means including a first contact movable by said arm and a second contact engageable by said first contact as the arm moves in response to rotation of the cam, each said contact assembly being so positioned relative to the cam and cam contours being so developed and phased so that with said element at its desired twist angle the contacts of both of said contact assemblies are open, and upon twisting of said element to a position other than its desired twist angle, rotation of said cam in one direction or the other is effected thereby to close the contacts of one of said contact assemblies while the contacts of the other of said contact assemblies remain open thereby to generate said signal indicating a change in twist of said element.
Claim 8
Dependent Claim
65 words
Apparatus as set forth in claim 6 further comprising means for selectively adjusting the position of each of said second contacts relative to its respective movable contact thereby selectively to vary the angular position of said cam at which said contacts of each contact assembly open and close, thus to vary the sensitivity of the apparatus to detecting a change in twist of the element.
Claim 9
Dependent Claim
100 words
Apparatus as set forth in claim 7 wherein each of said contact assemblies comprises a pair of elongate, resiliently flexible cantilever contact arms, with one of each pair of contact arms constituting said movable contact arm and with the other of said contact arms carrying second contact, said other contact arm being normally spaced from its respective movable contact arm, said selective adjusting means comprising an adjustment screw operable to move said other contact arm in and out relative to its respective movable contact, thereby to vary the angular position at which said second and movable contacts make and break.
Claim 10
Dependent Claim
85 words
Apparatus as set forth in claim 2 wherein said signal-generating means further comprises a housing for said transducer, said actuating arm extending from the housing, and means for mounting the housing relative to the screed at said first location, said housing being vertically movable relative to the mounting means whereby the vertical position of the actuating member relative to the twist reference arm when said element is in its predetermined twist angle may be changed thereby to vary said predetermined twist angle of the element.
Claim 11
Dependent Claim
55 words
Apparatus as set forth in claim 9 wherein said mounting means comprises a vertical guide adapted to slidably receive said housing, said housing being vertically movable relative to the guide, and manually operated means for selectively effecting vertical movement of the housing in said guide thereby to vary said predetermined twist angle of the element.
Claim 12
Dependent Claim
30 words
Apparatus as set forth in claim 10 wherein said mounting means further comprises means for releasably securing the housing relative to the guide at any desired position along the guide.
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |