Patent EP0532195A2 successfully refreshed from Google Patents.
EP0532195A2
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EP
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Method and apparatus for controlling an implement
Assignee: Caterpillar Inc
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Filing: 1992-08-25
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Granted: —
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Expires: 2012-08-25
Abstract
Abstract Vehicles having implements are typically used to perform repetitive functions in work cycles. An implement control system raises and lowers an implement relative to the vehicle and reduces the stresses applied to the vehicle from abruptly stopping the motion of the implement. A lever pilot signal is produced in response to the pivotal position of a control lever. An electrohydraulic pilot signal is also produced. The pilot signal having the greater pressure is directed to a main valve for controlling the position of the implement. The method and apparatus of the instant invention are applicable to a number of vehicles having a hydraulically operated implement. <IMAGE>
Inventors
- 👤 Javad. Hosseini
- 👤 Randall M Mitchell
- 👤 Weldon L. Phelps
- 👤 James E. Schimpf
- 👤 Eric A. Hutchison
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 03:12
CPC Classifications
E; E02; E02F; E02F9/00; E02F9/20; E02F9/22; E02F9/2217; E02F9/2203; E02F9/2214
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
118 words
An apparatus for controllably raising and lowering an implement relative to a work vehicle, said implement being pivotally connected to said work vehicle and movable to and between maximum raised and lowered positions in response to the extension and retraction of a hydraulic cylinder, comprising: a control lever movably connected to the work vehicle; means for producing a lever pilot signal in response to the position of said control lever, said lever pilot signal having a first pilot pressure; means for producing an electrohydraulic pilot signal having a second pilot pressure; means for selecting the greater of said first and second pilot pressures; and means for controlling the position of the implement in response to the selected pressure.
Claim 2
Dependent Claim
143 words
An apparatus, as set forth in claim 1, wherein said control lever has a neutral position and is movable to and between a predetermined raise detent position and a predetermined lower detent position, and said electrohydraulic pilot signal is produced in response to said control lever being moved beyond one of the raise and lower detent positions and including: means for sensing the position of the implement with respect to the work vehicle and responsively producing a position signal; means for selecting a kickout position and responsively producing a kickout position signal; means for moving said control lever to said neutral position in response to the implement being a preselected distance from the kickout position; and means for producing a difference signal in response to said position signal and kickout position signal, said second pilot pressure being a function of said difference signal.
Claim 3
Dependent Claim
55 words
An apparatus, as set forth in claim 2, wherein said kickout position signal is stored in a controller at an upper kickout address in response to having a magnitude that is greater than a predetermined amount, and at a lower kickout address in response to having a magnitude that is less than the predetermined amount.
Claim 4
Dependent Claim
32 words
An apparatus, as set forth in claim 2, wherein said second pressure is directly proportional to said difference signal when the implement is less than said preselected distance from the kickout position.
Claim 5
Dependent Claim
32 words
An apparatus, as set forth in claim 2, wherein said means for producing a difference signal produces a second difference signal in response to said position signal and the maximum raised position.
Claim 6
Independent Claim
50 words
An apparatus, as set forth in any of claims 1 to 5, including means for sensing the velocity of the control lever and responsively producing a velocity signal; and wherein said electrohydraulic pilot signal is produced in response to said velocity signal being greater than a predetermined velocity signal magnitude.
Claim 7
Dependent Claim
33 words
An apparatus, as set forth in claim 6, including means for changing said second pressure at a prespecified rate in response to said velocity signal being greater than said predetermined velocity signal magnitude.
Claim 8
Independent Claim
79 words
An apparatus, as set forth in any of claims 1 to 7, including a main valve having a raise port and a lower port and wherein: said lever pilot signal is directed to one of said raise and lower ports; and said electrohydraulic pilot signal is directed to the other of said raise and lower ports in response to the implement being within a predetermined distance from and being moved toward one of the maximum raised and lowered positions.
Claim 9
Independent Claim
80 words
An apparatus, as set forth in any of claims 1 to 8, including a main valve means for controllably directing pressurized fluid to a rod end and a head end of a hydraulic cylinder and for connecting the hydraulic circuits associated with the rod end and head end of the hydraulic cylinder to a fluid reservoir in response to said control lever being in the lower detent position and said implement being substantially at or below a lower kickout position.
Claim 10
Dependent Claim
70 words
An apparatus, as set forth in claim 2, including means for moving said control lever to said neutral position in response to the implement being a preselected distance from the maximum raised position; and wherein said means for producing a difference signal produces a second difference signal in response to said position signal and the maximum raised position; said second pilot pressure being a function of said second difference signal.
Claim 11
Dependent Claim
45 words
An apparatus, as set forth in claim 2, wherein said preselected distance is a function of the velocity of the implement and said second pressure is directly proportional to said difference signal when the implement is less than said preselected distance from the kickout position.
Claim 12
Dependent Claim
50 words
An apparatus, as set forth in claim 2, wherein said second pressure is substantially reduced in response to the control lever moving from one of the predetermined raise and lower detent positions toward the neutral position when the implement is substantially farther than said preselected distance from the kickout position.
Claim 13
Dependent Claim
30 words
An apparatus, as set forth in claim 2, including a means for producing a tilt signal and wherein said kickout position signal is compensated in response to said tilt signal.
Claim 14
Independent Claim
129 words
A method for controllably raising and lowering an implement relative to a work vehicle, said implement being connected to said work vehicle and movable to and between maximum raised and lowered positions in response to the extension and retraction of a hydraulic cylinder, said work vehicle including a control lever being movable to and between a neutral position, a predetermined raise detent position, and a predetermined lower detent position, comprising the steps of: producing a lever pilot signal in response to the position of said control lever, said lever pilot signal having a first pilot pressure; producing an electrohydraulic pilot signal having a second pilot pressure; selecting the greater of said first and second pilot pressures; and controlling the position of the implement in response to the selected pressure.
Claim 15
Dependent Claim
112 words
A method, as set forth in claim 14, wherein said electrohydraulic pilot signal is produced in response to said control lever being moved beyond one of the raise and lower detent positions and including the steps of: sensing the position of the implement with respect to the work vehicle and responsively producing a position signal; selecting a kickout position and responsively producing a kickout position signal; moving said control lever to said neutral position in response to the implement being a preselected distance from the kickout position; and producing a difference signal in response to said position signal and kickout position signal; said second pressure being a function of said difference signal.
Claim 16
Dependent Claim
63 words
A method, as set forth in claim 15, including the steps of moving said control lever to said neutral position in response to the implement being a preselected distance from the maximum raised position and producing a second difference signal in response to said position signal and the maximum raised position; said second pilot pressure being a function of said second difference signal.
Claim 17
Dependent Claim
28 words
A method, as set forth in claim 15, including the steps of: producing a tilt signal; and compensating said kickout position signal in response to said tilt signal.
Claim 18
Dependent Claim
56 words
A method, as set forth in claim 14, including the step of connecting the hydraulic circuits associated with the rod end and head end of the hydraulic cylinder to a fluid reservoir in response to said control lever being in the lower detent position and said implement being substantially at or below a lower kickout position.
Claim 19
Dependent Claim
47 words
A method, as set forth in claim 14, including the step of sensing the velocity of the control lever and responsively producing a velocity signal; and wherein said electrohydraulic pilot signal is produced in response to said velocity signal being greater than a predetermined velocity signal magnitude.
Claim 20
Dependent Claim
34 words
A method, as set forth in claim 19, including the step of changing said second pressure at a prespecified rate in response to said velocity signal being greater than said predetermined velocity signal magnitude.
Claim 21
Dependent Claim
80 words
A method, as set forth in claim 14, wherein the work vehicle includes a main valve having a raise port and a lower port and including the steps of: directing said lever pilot signal to one of said raise and lower ports; and directing said electrohydraulic pilot signal to the other of said raise and lower ports in response to the implement being within a predetermined distance from and being moved toward one of the maximum raised and lowered positions.
References Cited (Backward Citations)
No citation records indexed.
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