Claims
- 1. Automotive apparatus comprising
- a tractor,
- a towed implement including a tool,
- connection means connecting the implement to the tractor,
- height adjusting means including hydraulic motor means for adjusting the elevation of the tool relative to the earth's surface,
- a source of hydraulic fluid under pressure,
- a reservoir,
- valve means for selectively connecting the motor means to the source and reservoir, and in a neutral position, to disconnect the motor means from both the source and the reservoir,
- operator controlled means carried by the tractor for changing the position of said valve means to effect raising and lowering of said tool, and
- feedback means responsive to the elevation of the tool,
- characterized by the fact that said operator controlled means includes:
- hydraulic line means having a drooping pressure versus flow characteristic,
- motive means responsive to the pressure in said line means for actuating the valve means,
- said feedback means
- restoring the valve means to neutral position when the tool has reached a position determined by the setting of the operator controlled valve means,
- said feedback means being negative feedback vent means connected to the tool for varying the pressure of said line means, upon movement of the tool in response to movement of the operator controlled valve means, to negate the effect of the change of the pressure of said line means caused by the operator controlled valve means,
- said hydraulic motor means being double acting, being adapted to receive in its entirety pressure fluid from said source and to deliver from its entirety fluid to said reservoir to move the hydraulic motor means positively in both one direction and another according to the position of the valve means to effect raising and lowering of the tool,
- said height adjusting means providing for setting the elevation of the tool in various operative positions relative to the ground and in a higher inoperative position.
- 2. Apparatus according to claim 1,
- said connection means including load sensor means responsive to tension in the connection means for for changing the level of said tool,
- said apparatus being further characterized by said load sensor means being ineffective to change the level of said tool when the tension in the connection means is below a certain value, whereby the tool remains at a constant elevation corresponding to the setting of said operator controlled means during all values of said tension below said certain value, said load sensor means varying the pressure of said line means to elevate said tool to inoperative position where the tension in the connector means rises from below said certain value to above certain value.
- 3. Apparatus according to claim 2,
- said height adjusting means holding said tool in inoperative position as long as said tension in the connection means is above said certain value,
- said load sensor means varying the pressure of said line means to lower the tool to the elevation corresponding to the setting at said operator controlled means when the tension in the connection means drops from above said certain value to below said value.
- 4. Apparatus to claim 2,
- the load sensor means including: a valve for venting said line means responsive to tension in the connection means tending to open the valve, fluid pressure means tending to close the valve, and adjustment means carried by the tractor for adjusting the pressure of said fluid pressure means, thereby to adjust the aforementioned certain value at which the load sensor means is actuated to positively increase the elevation of the tool to said inoperative position.
- 5. Apparatus according to claim 4, said connection means including telescopic bar and tube members connected one to the tractor and one to the implement, said load sensor means with its valve for venting the line means being disposed within said tube and connected at one end to said bar and at its other end to said tube.
- 6. Automotive apparatus comprising
- a tractor,
- a towed implement including a tool,
- connection means connecting the implement to the tractor,
- means including a hydraulic motor for adjusting the elevation of the tool relative to the earth's surface,
- a source of hydraulic fluid under pressure,
- a reservoir,
- valve means for selectively connecting the motor to the source and reservoir,
- hydraulic line means having a drooping pressure versus flow characteristic,
- motive means responsive to the pressure in said line means for actuating the valve means,
- operator controlled vent means carried by the tractor for varying the pressure in said line means,
- negative feedback vent means connected to the tool for varying the pressure of said line means, upon movement of the tool in response to movement of the operator controlled vent means, to negate the effect of the change of the pressure of said line means caused by the operator controlled vent means,
- said connection means including load sensor means responsive to tension in the connection means for varying the pressure of said line means to elevate said tool when the tension in the connection means rises from below a certain value to above said value,
- said connection means comprising one member connected to the tractor and another member connected to the implement,
- said load sensor means comprising a body having a cylindrical cavity,
- said body being connected to one of said members,
- a cylindrical piston axially slidably movable in said cavity,
- a piston rod extending through and axially slidable in an aperture in an end wall of said body in fluid tight relationship therewith and connecting at one end to said piston and its other end with said another of said members of the connection means,
- fluid pressure means for supplying pressurized fluid at selected pressure to the piston on the same side thereof as said piston rod is connected,
- a wall transverse to the axis of said body disposed on the side of the piston opposite to said piston rod dividing the cavity into a space adjacent the piston and an end space,
- port means in the body connecting the cavity space adjacent the piston to said reservoir,
- port means in the body connecting said end space with said line means, and
- valve core means extending into and axially slidable within a port in said wall and connected at one end to said piston on the opposite end of the piston rod,
- said valve core means having tapered groove means in the portion thereof adapted to be within said wall port,
- said groove means being of increasing cross-sectional area progressing in the direction toward said piston.
- 7. Apparatus according to claim 6, said load sensor means varying the pressure of said line means to lower the tool when the tension in the connection means drops from above said certain value to below said value.
- 8. Automotive apparatus comprising
- a tractor,
- a towed implement including a tool,
- connection means connecting the implement to the tractor,
- means including a hydraulic motor for adjusting the elevation of the tool relative to the earth's surface,
- a source of hydraulic fluid under pressure,
- a reservoir,
- valve means for selectively connecting the motor to the source and reservoir,
- hydraulic line means having a drooping pressure versus flow characteristic,
- motive means responsive to the pressure in said line means for actuating the valve means,
- operator controlled vent means carried by the tractor for varying the pressure in said line means,
- negative feedback vent means connected to the tool for varying the pressure of said line means, upon movement of the tool in response to movement of the operator controlled vent means, to negate the effect of the change of the pressure of said line means caused by the operator controlled vent means,
- wherein said operator controlled vent means and said feedback means connected to the tool are of like construction, each including a vent valve having a body with a cylindrical bore and diametrically opposed nozzle ports in the body and a generally cylindrical rotor rotatably mounted concentric with said bore and having an undercut eccentric cylindric land extending between said ports when the vent valve is in closed position, the space between said bore and said land being connected to the reservoir.
- 9. Apparatus according to claim 8,
- said valve means and motive means both being carried by the tractor,
- said operator controlled vent means including first conduit means connected to said line means,
- said negative feedback vent means including second conduit means connected to said line means,
- said conduit means including means for balancing the flow resistance of the first conduit means with the flow resistance of the second conduit means.
- 10. Apparatus according to claim 8,
- including second negative feedback means connected to said valve means for venting said line means in a manner tending to return the valve means to a position in which the motor is connected to neither the source nor reservoir, thereby bringing the tool to rest as far as elevation is concerned.
- 11. Apparatus according to claim 8,
- said land extending 180 degrees from the center of one said nozzle port to the other when the vent valve is in closed position.
- 12. Apparatus according to claim 8,
- said land extending over 180 degrees beyond said nozzle ports when said vent valve is in closed postion.
- 13. Apparatus according to claim 8,
- said land extending less than 180 degrees between said nozzle ports leaving both of said ports fully blocked by said core means when said vent valve is in closed position.
- 14. Apparatus according to claim 8,
- said hydraulic motor being a rotary motor moving angularly equally to the angular movement of said operator controlled vent means.
- 15. Apparatus according to claim 8,
- said means including a hydraulic motor for adjusting the elevation of the tool including a crank arm, said hydraulic motor being a linear motor connected to the crank arm which moves angularly equally as the angular movement of said operator controlled vent means.
- 16. Apparatus according to claim 8,
- said connection means including load sensor means responsive to tension in the connection means for varying the pressure of said line means to elevate said tool when the tension in the connection means rises from below a certain value to above said value.
- 17. Apparatus according to claim 16, said connection means including telescopic bar and tube members connected one to the tractor and one to the implement, said load sensor means being disposed within said tube and connected at one end to said bar and at its other end to said tube.
- 18. Apparatus according to claim 16, said load sensor means varying the pressure of said line means to lower the tool when the tension in the connection means drops from above said certain value to below said value.
- 19. Automotive apparatus comprising
- a tractor driven by an engine,
- a towed implement including a tool,
- connection means connecting said implement to the tractor,
- hydraulic positioning means carried by the tractor for raising and lowering the tool,
- a hydraulic liquid supply for said positioning means,
- servo valve means for directing the positioning means, by controlling said hydraulic liquid supply to the positioning means,
- said servo valve means including valve means for controlling said hydraulic liquid to said positioning means and piston-cylinder means for controlling the hydraulic liquid controlling valve means,
- a fluid supply for said piston-cylinder means having a drooping pressure versus flow characteristic,
- manual means carried by the tractor for actuating the servo means by appropriate setting of the manual means,
- tension responsive means carried by the connection means for actuating the servo means to direct the positioning means to elevate the tool upon tension in the connection means in excess of a preselected amount,
- speed responsive means responsive to the rotational speed of the engine to direct the positioning means to elevate the tool upon engine rotational speed in excess of a preselected amount,
- said manual, tension responsive, and speed responsive means each including a flow path for venting said fluid supply to the piston-cylinder means and a variable restrictor for the respective flow path responsive respectively to setting of the manual means, tension of the connection means, and engine speed, for varying such venting, and
- feedback means responsive to the elevation of the implement for deactivating the servo means to maintain the tool at an elevation determined by the setting of said manual means except upon occurrence at least one of said tension and speed in excess of the respective preselected amount.
- 20. Apparatus according to claim 19, in which said feedback means also includes a flow path for venting said fluid supply to the piston-cylinder means and a variable restrictor responsive to tool elevation for changing said venting for the respective flow path.
- 21. Apparatus according to claim 19, in which said feedback means includes a sleeve valve for deactivating the servo means by cutting off said hydraulic liquid supply from said positioning means.
- 22. Automotive apparatus comprising
- a tractor,
- a towed implement including a tool,
- connection means connecting the implement to the tractor,
- height adjusting means including hydraulic motor means for adjusting the elevation of the tool relative to the earth's surface,
- a source of hydraulic fluid under pressure,
- a reservoir,
- valve means for selectively connecting the motor means to the source and reservoir and in a neutral position to disconnect the motor means from both the source and the reservoir,
- operator controlled means carried by the tractor for changing the position of said valve means to effect raising and lowering of said tool,
- feedback means responsive to the elevation of the tool for restoring the valve means to neutral position when the tool has reached a position determined by the setting of the operator controlling the valve means,
- characterized by the fact that said operator controlled means includes:
- hydraulic line means having a drooping pressure versus flow characteristic,
- motive means responsive to the pressure in said line means for actuating the valve means,
- said feedback means being negative feedback means connected to the tool for actuating the valve means upon movement of the tool in response to movement of the operator controlled valve means, to negate the effect on the valve means of the change of the pressure of said line means caused by the operator controlled valve means,
- said hydraulic motor means being double acting, being adapted to receive in its entirety pressure fluid from said source and to deliver from its entirety fluid to said reservoir to move the hydraulic motor means positively in both one direction and another according to the position of the valve means to effect raising and lowering of the tool.
- 23. Apparatus according to claim 22,
- said valve means and motive means both being carried by the tractor,
- said operator controlled valve means including first conduit means connected to said hydraulic line means,
- said valve means including a movable valve core member and a movable valve seat member,
- said motive means acting on one of said valve members and said feedback means acting on the other of said valve members.
- 24. Apparatus according to claim 22 or 23, including second negative feedback means connected to said valve means for venting said line means in a manner tending to return the valve means to a position in which the motor is connected to neither the source nor reservoir, thereby bringing the tool to rest as far as elevation is concerned.
- 25. Apparatus according to claim, 24
- said means including a hydraulic motor for adjusting the elevation of the tool including a crank arm, said hydraulic motor being a linear motor connected to the crank arm which moves angularly equally as the angular movement of said operator controlled valve means.
- 26. Automotive apparatus comprising
- a tractor,
- a towed implement including a tool,
- connection means connecting the implement to the tractor,
- means including a hydraulic motor for adjusting the elevation of the tool relative to the earth's surface,
- a source of hydraulic fluid under pressure,
- a reservoir,
- valve means for selectively connecting the motor to the source and reservoir,
- hydraulic line means having a drooping pressure versus flow characteristic,
- motive means responsive to the pressure in said line means for actuating the valve means,
- operator controlled vent means carried by the tractor for varying the pressure in said line means,
- negative feedback means connected to the tool for actuating the valve means upon movement of the tool in response to movement of the operator controlled vent means, to negate the effect on the valve means of the change of the pressure of said line means caused by the operator controlled vent means,
- said connection means including load sensor means responsive to tension in the connection means for varying the pressure of said line means to elevate said tool when the tension in the connection means rises from below a certain value to above said value,
- said connection means comprising one member connected to the tractor and another member connected to the implement,
- said load sensor means comprising a body having a cylindrical cavity,
- said body being connected to one of said members,
- a cylindrical piston axially slidably movable in said cavity,
- a piston rod extending through and axially slidable in an aperture in an end wall of said body in fluid tight relationship therewith and connecting at one end to said piston and its other end with said another of said members of the connection means,
- fluid pressure means for supplying pressurized fluid at selected pressure to the piston on the same side thereof as said piston rod is connected,
- a wall transverse to the body axis disposed on the side of the piston opposite to said piston rod dividing the cavity into a space adjacent the piston and an end space,
- port means in the body connecting the cavity space adjacent the piston to said reservoir,
- port means in the body connecting said end space with said line means, and
- valve core means extending into and axially slidable within a port in said wall and connected at one end to said piston on the opposite end of the piston rod,
- said valve core means having tapered groove means in the portion thereof adapted to be within said wall port,
- said groove means being of increasing cross-sectional area progressing in the direction toward said piston.
- 27. Apparatus according to claim 26, said load sensor means varying the pressure of said line means to lower the tool when the tension in the connection means drops from above said certain value to below said value.
Ser. No. 232,868
CROSS REFERENCES TO RELATED APPLICATIONS
(1) This application is a continuation-in-part of prior application Ser. No. 232,868 filed Feb. 9, 1981, now abandoned.
(2) Ser. No. 232,868 is a continuation-in-part of application Ser. No. 828,045 filed Aug. 26, 1977, now U.S. Pat. No. 4,227,440 issued Oct. 14, 1980, the disclosure of which is incorporated herein by reference.
(3) Ser. No. 828,045 is a continuation-in-part of application Ser. No. 772,560 filed Feb. 28, 1977, abandoned in favor of applications:
(a) Ser. No. 962,858, filed Nov. 22, 1978, now U.S. Pat. No. 4,335,645, issued June 22, 1984, and
(b) Ser. No. 27,668 filed Apr. 6, 1979, now U.S. Pat. No. 4,004,897 issued Sept. 20, 1983.
(4) Ser. No. 772,560 was a continuation-in-part of
(a) application Ser. No. 622,760, filed Oct. 15, 1975, now U.S. Pat. No. 4,094,229, issued June 13, 1978, divisions of which are:
(b) application Ser. No. 872,826 filed July 27, 1978, now U.S. Pat. No. 4,265,331, issued May 5, 1981, and
(c) application Ser. No. 62,694, filed Aug. 12, 1979, now U.S. Pat. No. 4,283,990 issued Aug. 18, 1981.
(5) Ser. No. 622,760 is a continuation-in-part of
(a) application Ser. No. 521,036, filed Nov. 5, 1974, now U.S. Pat. No. 4,046,059, issued Sept. 6, 1977, a division of which is
(b) application Ser. No. 720,420, filed Sept. 3, 1976, now U.S. Pat. No. 4,152,971, issued May 8, 1979.
(6) Ser. No. 521,036 a continuation-in-part of
(a) application Ser. No. 489,829 filed July 18, 1974, now U.S. Pat. No. 3,988,966 issued Nov. 2, 1976, divisions of which are:
(b) application Ser. No. 720,410 filed Sept. 3, 1976, now U.S. Pat. No. 4,137,825, issued Feb. 6, 1979, and
(c) application Ser. No. 931,322 filed Aug. 7, 1978, now U.S. Pat. No. 4,254,689, issued Mar. 10, 1981.
(7) This application is also a continuation-in-part of application Ser. No. 33,036 filed Apr. 29, 1979, now U.S. Pat. No. 4,355,506 issued Oct. 26, 1982, the disclosure of which is incorporated herein by reference.
US Referenced Citations (8)
Continuation in Parts (6)
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Number |
Date |
Country |
Parent |
232868 |
Feb 1981 |
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Parent |
828045 |
Aug 1977 |
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Parent |
772560 |
Feb 1977 |
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Parent |
622760 |
Oct 1975 |
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Parent |
521036 |
Nov 1974 |
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Parent |
489829 |
Jul 1974 |
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