US4983280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screening apparatus
Assignee: Powerscreen International Ltd
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Filing: 1989-04-05
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Granted: 1991-01-08
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Expires: 2009-04-05
Abstract
Abstract Screening apparatus comprises a feeder conveyor, an elevator, a screen box, an end boom elevator and two lateral boom elevators all carried on a wheeled trailer. The elevator has an elongated support with an endless belt arranged around two rollers longitudinally spaced apart on the support. A superstructure framework on the trailer carries the support in a plurality of inclined positions, and the screen box is pivotally linked to the end of the support corresponding to the discharge end of the belt and hinged to the structure at the opposite end. The support extends and retracts along its lengths by means of hydraulic rams and thereby pivots the screen. The screen box also has hydraulic rams and cylinders to adjust the angle of inclination of the screen relative to the support and thereby also adjust the inclination of the support.
Inventors
- 👤 Jan E. Eriksson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:25
CPC Classifications
B; B65; B65G; B65G37/00; B07; B07B; B07B1/00; B07B1/005; B07B1/46; B07B13/00; B07B13/14; B07B13/16
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
165 words
Screening apparatus comprising an elevator having an elongated support with an endless belt arranged around two rollers longitudinally spaced apart on said support; a structure to carry said support in a plurality of inclined positions; a screen box, rectangular in plan, having a support end and a structure end, pivotally linked to the end of said support corresponding to the discharge end of said endless belt at the support end of the screen box and the screen box hinged to said structure at the structure end of the screen box, the support being capable of being extended and retracted along its length relative to said structure; and means to extend and retract the support along its length relative to said structure being provided to effect such movement whereby lengthwise movement of said support causes pivotal movement of said screen box and wherein said screen box has means to adjust its angle of inclination relative to said support with consequential movement in inclination of said support.
Claim 2
Dependent Claim
165 words
Screening apparatus comprising an elevator having an elongated support with an endless belt arranged around two rollers longitudinally spaced apart on said support; a structure to carry said support in a plurality of inclined positions; a screen box, rectangular in plan, having a support end and a structure end, pivotally linked to the end of said support corresponding to the discharge end of said endless belt at the support end of the screen box and the screen box hinged to said structure at the structure end of the screen box, the support being capable of being extended and retracted along its length relative to said structure; and means to extend and retract the support along its length relative to said structure being provided to effect such movement whereby lengthwise movement of said support causes pivotal movement of said screen box and wherein said screen box has means to adjust its angle of inclination relative to said support with consequential movement in inclination of said support.
Claim 3
Dependent Claim
51 words
Screening apparatus as claimed in claim 1, wherein the means to move the support and the means to adjust the screen box are hydraulic ram and cylinders in circuit with a hydraulic supply and pump with controls being provided to separately operate extension and retraction of said rams in said cylinders.
Claim 4
Dependent Claim
21 words
The screening apparatus as claimed in claim 2 wherein the screen box has two decks which diverge away form each other.
Claim 5
Dependent Claim
36 words
The screening apparatus as claimed in claim 3 wherein an end boom elevator is provide lengthwise beyond the support with its feed end under the screen box to receive size-graded material passing through the lower deck.
Claim 6
Dependent Claim
44 words
The screening apparatus as claimed in claim 3, wherein two lateral boom elevators are provided each to receive one of the grades of material flowing down the decks, the lateral boom elevators extending in-use laterally outwards in opposite directions from the elevator and support.
Claim 7
Dependent Claim
57 words
Screening apparatus as claimed in claim 2, further comprising an assembly of the elevator, the screen box, an end boom elevator, and two lateral boom elevators and wherein the structure comprises a wheeled trailer having superstructure framework to carry the assembly of the elevator, the screen box, the end boom elevator and the two lateral boom elevators.
Claim 8
Dependent Claim
46 words
The screening apparatus as claimed in claim 2, wherein said structure comprises a trailer and further including a feeder conveyor mounted below a grid provided to feed material onto the feed end of the elevator, the feeder conveyor and grid also being carried on the trailer.
Claim 9
Dependent Claim
25 words
Screening apparatus as claimed in claim 1, wherein the screen box has an upper deck and a lower deck which diverge away from each other.
Claim 10
Dependent Claim
38 words
The screening apparatus as claimed in claim 8 wherein an end boom elevator is provided lengthwise beyond the support with its feed end under the screen box to receive size-graded material passing through the lower of the decks.
Claim 11
Dependent Claim
44 words
The screening apparatus as claimed in claim 9, wherein two lateral boom elevators are provided each to receive one of the grades of material flowing down the decks, the lateral boom elevators extending in-use laterally outwards in opposite directions from the elevator and support.
Claim 12
Dependent Claim
44 words
The screening apparatus as claimed in claim 8, wherein two lateral boom elevators are provided each to receive one of the grades of material flowing down the decks, the lateral boom elevators extending in-use laterally outwards in opposite directions from the elevator and support.
Claim 13
Dependent Claim
57 words
Screening apparatus as claimed in claim 8 further comprising an assembly of the elevator, the screen box, an end boom elevator, and two lateral boom elevators and wherein the structure comprises a wheeled trailer having superstructure framework to carry the assembly of the elevator, the screen box, the end boom elevator and the two lateral boom elevators.
Claim 14
Dependent Claim
32 words
Screening apparatus as claimed in claim 1, wherein an end boom elevator is provided lengthwise beyond the support with its feed end under the screen box to receive size-graded material passing therethrough.
Claim 15
Dependent Claim
22 words
Screening apparatus as claimed in claim 13, wherein the end boom elevator is in hinged sections to enable it to be foldable.
Claim 16
Dependent Claim
44 words
Screening apparatus as claimed in claim 1, wherein two lateral boom elevators are provided each to receive one of the grades of material separated by said screen box, the lateral boom elevators extending in-use laterally outwards in opposite directions from the elevator and support.
Claim 17
Dependent Claim
41 words
Screening apparatus as claimed in claim 15, wherein the lateral boom elevators are similarly mounted to be rotatable such that in an out-of-use position they can be positioned flanking both sides of said support and inclined in the opposite direction thereto.
Claim 18
Dependent Claim
57 words
The screening apparatus as claimed in claim 16, wherein means for mounting the lateral boom elevators are provided and are of such construction that belt tension will not be altered and hydraulic connections do not require to be disconnected between movement of the boom elevators to and from an in-use position from and to an out-of-use position.
Claim 19
Dependent Claim
56 words
Screening apparatus as claimed in claim 15, wherein means for mounting the lateral boom elevators are provided and are of such construction that belt tension will not be altered and hydraulic connections do not require to be disconnected between movement of the boom elevators to and from an in-use position from and to an out-of-use position.
Claim 20
Dependent Claim
57 words
Screening apparatus as claimed in claim 1 further comprising an assembly of the elevator, the screen box, an end boom elevator, and two lateral boom elevators, and wherein the structure comprises a wheeled trailer having superstructure framework to carry the assembly of the elevator, the screen box, the end boom elevator, and the two lateral boom elevators.
Claim 21
Dependent Claim
45 words
Screening apparatus as claimed in claim 1, wherein said structure comprises a trailer and further including a feeder conveyor mounted below a grid provided to feed material onto the feed end of the elevator, the feeder conveyor and grid also being carried on the trailer.
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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) | 1994-01-07 | 1994-07-09 | 1995-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-07 | 1998-07-09 | 1999-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-07 | 2002-07-09 | 2003-01-08 | $7700.00 | Window Closed / Lapsed |