CA1214730A - Hydraulic steering system for motor vehicles - Google Patents
Hydraulic steering system for motor vehiclesInfo
- Publication number
- CA1214730A CA1214730A CA000460009A CA460009A CA1214730A CA 1214730 A CA1214730 A CA 1214730A CA 000460009 A CA000460009 A CA 000460009A CA 460009 A CA460009 A CA 460009A CA 1214730 A CA1214730 A CA 1214730A
- Authority
- CA
- Canada
- Prior art keywords
- steering
- valve
- axle
- change
- steering axle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
- B62D5/09—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by means for actuating valves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D12/00—Steering specially adapted for vehicles operating in tandem or having pivotally connected frames
Abstract
ABSTRACT OF THE DISCLOSURE
A hydraulic steering system for motor vehicles comprises a steering axle and an additional frame pivot for the further reduction of the turning circle of the steering axle. When the steering axle is within its turning range, the frame pivot is locked by a lock controlled by a change-over valve. During this time, only the working cylinder of the steering axle is controlled by the change-over valve. When the steering axle reaches its maximum angle of turn, further rotation of the steering wheel automatically operates the change-over valve by virtue of a temporary pressure increase, and the locking of the frame pivot is released. The wheels of the steering axle are now maintained hydraulically in the position of maximum angle of turn of the latter, while the working cylinders of the frame pivot are controlled by the working pressure in order to further reduce the turning circle.
A hydraulic steering system for motor vehicles comprises a steering axle and an additional frame pivot for the further reduction of the turning circle of the steering axle. When the steering axle is within its turning range, the frame pivot is locked by a lock controlled by a change-over valve. During this time, only the working cylinder of the steering axle is controlled by the change-over valve. When the steering axle reaches its maximum angle of turn, further rotation of the steering wheel automatically operates the change-over valve by virtue of a temporary pressure increase, and the locking of the frame pivot is released. The wheels of the steering axle are now maintained hydraulically in the position of maximum angle of turn of the latter, while the working cylinders of the frame pivot are controlled by the working pressure in order to further reduce the turning circle.
Description
7.~3 The present invention relates to a 'nydraulic steer-ing system, particularly for agricultural and construction site vehicles, comprising a first steering device acting on a front or rear axle, and a second steering device for further reducing the turning circle.
From British patent document GB-A-l 095 550, it is already known to make both the front and rear axles in the form of steering axles. For this steering arrangement, a manually operated change-over valve is provided which, in its normal position, allows the wheels of only the front or rear axle to be steered. In two further positions o~ the change-over valve, the vehicle wheels can be steered either in opposite directions to reduce the turning circle, or in the same direction to manoeuvre in a limited space, the steering movements of the two axles taking place at the same time. With such a steering arrangement, normal road travel must be undertaken with the change-over valve in the position which produces the small turning circle, and allowance has to be made ~or the resulting limitation in the steering and running characteristics~ If this is not done, the single-axle steering must be switched-over to all-wheel steering in order to attain a small turning circle during working use, and this requires the vehicle to be steered back into its straight-ahead running position.
German patent document DE-A-16 80 2~9 describes another auxiliary power steering system for a loader having a so~called articulated frame, the vehicle frame being in the form of two articulated portions which can be swivelled in opposite directions to each other to maximize the angle of turn. In a vehicle oE this type, comprising front and rear frame portions, the axle of the rear frame portion is 73~33 in the form of a steering axle. A steering wheel is provided in order to operate the frame pivot which influences the turning circle, whereas the wheels of the rear axle are controlled by means of a hand-lever for an additional reduction in the turning circle. Thus, two independent operating members are required for this steering system, only one of which, namely, the steering wheel, produces a path synchronization between the operational path and the steering adjustment path for the steering adjustment move-ment which it controls. A further drawback is that, whensteering only with the frame pivot, the position of the steered wheels of the rear axle is not locked. On corner-ing, the position of these wheels is therefore determined by the lag behaviour dependent on the geometry of the axle, and this leads to a worsening of the steering characteristics.
An objec'c of the present invention, therefore is to provide a hydraulic steering system by means of which a vehicle is steered in the normal way by the adjustment of the wheels of the front axle, for example during road travel, and by means of which the further reduction in the turning circle required for working purposes is allowed by the adjust-ment of a further steering device, such as a frame pivot, only after the maximum angle of turn of the wheels of the steering axle has been reached, without necessitating the change-over of a further operating member and using only the steering wheel.
According to the invention, a mechanical lock consisting of a locking pin and a link plate is operative wi-thin the adjustment range of the wheels of the steering axle, within which turning for steering purposes takes place, and mechanically locks the second steering device :~2~ 3~
used for the further reduction of the turning circle. The mechanical lock is operated by a change-over valve which, in one of its valve positions, connects a high pressure pump to a working cylinder of the steering axle when the latter is within its steering adjustment range. When the steering axle reaches its maximum angle o~ turn, there is a pressure increase due to the turning having caused con-tact with the wheel stop, and this results in the opening of a discharge valve disposed at one end of the change-over valve whereby the change-over valve is moved into another valve position. The mechanical lock for the second steering device, which is connected to the change-over valve, is thus released with a simultaneous hydraulic shut-off of the work-ing cylinder of the steering axle, and the high pressure pump is connected to the working cylinders of the second steering device. In this manner, a continuous transition from two-wheel to four-wheel steering is possible without any additional change-over device or change-over operation being necessary.
Two embodiments of the invention are described in detail below, with reference to the drawings, in which:
Figure 1 is a diagram of the steering system comprising a combination of front-axle steering and pivoted-frame steering' and Figure 2 shows an embodiment of the steering system comprising a combination of front-axle steering and rear-axle steering.
The steering system shown in Figure 1 includes, in terms of its kno~ components, a metering pump 2 operated by a steering wheel 1, a steering valve 3 movable in two adjust-ment directions in accordance with the rotation of the steer~-ing wheel 1, a high pressure pump 4, an oil tank 5 and a relief valve 6 which limits the operating pressure to a certain maximum value. According to the direction of rotation of the steering wheel 1, the steering valve 3 feeds the delivery from the high pressure pump 4 to a respective inlet side of the metering pump 2, from which a metered working flow can be fed to a working cylinder 7 for a steering axle 8, and to working cylinders 10, 11 for a frame pivot 12 which constitutes a further steering device. In this case, the rear axle 9 is of rigid construct-ion.
According to the invention, the working flow is fed from the steering valve 3 to the working cylinder 7 or cylinders 10, 11 by way of a change-over valve 13 having two valve positions, I and II. In valve position I, the two pressure chambers of the working cylinder 7 acting on the steering axle 8 are connected by way of pipelines 14, 15 to the metering pump 1 and to the high pressure pump 4. In valve position II, the pipelines 14, 15 are closed, while pipelines 16, 17 leading to the pressure chambers of the working cylinders 10, 11 of the frame pivot 12 are connected to the metering pump 1 and to the high pressure pump 4. The change-over valve 13 comprises a slide 18 one end face 20 of which is acted upon by a spring 21 which urges the slide into valve position I. A mechanical lock is operative in valve position I, wherein a locking pin 22 fixed to the slide 18 engages a notch 23 in a link plate 24. For this purpose, the change-over valve 13 with its locking pin 22 is located on the pivot part of a front frame portion 25, and the link plate 24 is located on the pivot part of a rear frame portion 26, so that the frame pivot 12 is 73~3 mechanically locked in the straight-ahead running position.
That end face 27 of the slide 18 which lies on the same side as the locking pin 22 defines a pressure chamber 28 which is connected to a pressure line 30 running from the high pressure pump 4 to the steering valve 3.
Likewise, a pressure chamber 31 defined by the end face 20 is connected to the pressure line 30 by way of a restrictor 32. In this manner, at any given time, the pump pressure acts on both the end faces 20, 27 of the slide 18. A discharge valve 34 connected by a return line 33 to the tank 5 is incorporated in the change-over valve 13.
Regarding operation, with the valve position shown in Figure 1, the steering system is in the straight-ahead running position. The steering valve 13 assumes its central position, in which the delivery from the high pressure pump 4 in the pressure line 30 flows back to the tank 5 by the return line 33. If the steering valve 3 is moved, for example, towards the right by turning the steering wheel 1, the delivery from the pump 4 passes in the form of a working flow into the lower pressure chamber of the working cylinder 7 by way of the pressure line 30, the metering pump 2, the change-over valve 13, which is in valve position I, and the pipeline 14. The volume of oil displaced from the higher pressure chamber flows to the tank 5 through the pipeline 15, the change-over valve 13, the steering valve 3 and the return line 33. The wheels of the steering axle 8 are thus turned towards the left with reference to the direction of travel (arrow A). When the steering axle 8 has turned through its maximum angle of turn, it is stopped by wheel stops (not shown). Upon further turning of the steering 7~3~
wheel 1, the working pressure in the steering system rises to the maximum value set by the relief valve 6. The dis-charge valve 34 opens by virtue of the connection between the pressure line 30 and the pressure chamber 31 of the change-over valve 13, so that the pressure in the p~essure chamber 31 is released.
By virtue of the restrictor 32, a pressure differ-ence arises between the end surfaces 27 and 20, with the result that the slide 18 moves into valve position II
against the spring 21. This change-over shuts o-ff the pipelines 14, 15 of the steering axle 8, and the latter thus becomes locked when it has turned through its maximum angle of turn. At the same time, the pipelines 16, 17 are connected to the working cylinders 10, 11 of the frame pivot 12. The valve change-over causes the withdrawal of the locking pin 22 from the notch 23 in the link plate 24 so that the frame pivot 12 is no longer locked. As the frame pivot 12 rotates from its centered position, the locking pin 22 abuts the approximately semi-circular profile of the link plate 24 due to the rotation of this latter, keeping the slide 18 of the change-over valve 13 in valve position II mechanically even if the working pressure falls. The working pressure now flows through the pipeline 16 into the left-hand pressure chamber of the working cylinder 11 and the right-hand pressure chamber of the working cylinder 10. The volume of oil displaced simultaneously from the right-hand pressure chamber of the working cylinder 11 and the left-hand pressure chamber of the working cylinder 10 flows through the pipeline 17, the steering valve 3 which has been set in its right-hand position, and the return line 33. Due to articulation IL2~7~
about the frame pivot 12, the front frame portion 25 swivels to the left relative to the rear frame portion, with reference to the running direction (arrow A), and the turning circle of the vehicle is further reduced beyond that determined by the maximum angle of turn of the steering axle until the maximum angle of turn of the frame pivot 12 is reached.
The change-over valve 13 maintains valve position II until the frame pivot 12 is turned back to the straight-ahead running position, in which the slide 18 is pushedback into valve position I by the force of the spring 21.
The locking pin 22 then re-engages the notch 23 and the frame pivot 12 is locked.
By means of the invention, steering is effected only by means of the steering axle 8 while within its turn-ing range. Because of this, the vehicle retains the steer-ing and running characteristics of front-axle steering, which are advantageous for road travel. Only when the steering axle 8 reaches its maximum angle of turn does further rotation of the steering wheel automatically lead to an additional turning angle by means of the frame pivot.
The embodiment shown in Figure 2 differs from ' that of Figure 1 only in that, instead of an articulated frame, it has a continuous frame 35 with a rear steering axle 3~ which acts as the second steering device. In this case, the locking pin 22 engages a link plate 37 which is slidable transversely of the longitudinal axis of the vehicle and is connected to a steering arm 38. All the other components are of substantially the same construction and operation as those of Figure 1.
From British patent document GB-A-l 095 550, it is already known to make both the front and rear axles in the form of steering axles. For this steering arrangement, a manually operated change-over valve is provided which, in its normal position, allows the wheels of only the front or rear axle to be steered. In two further positions o~ the change-over valve, the vehicle wheels can be steered either in opposite directions to reduce the turning circle, or in the same direction to manoeuvre in a limited space, the steering movements of the two axles taking place at the same time. With such a steering arrangement, normal road travel must be undertaken with the change-over valve in the position which produces the small turning circle, and allowance has to be made ~or the resulting limitation in the steering and running characteristics~ If this is not done, the single-axle steering must be switched-over to all-wheel steering in order to attain a small turning circle during working use, and this requires the vehicle to be steered back into its straight-ahead running position.
German patent document DE-A-16 80 2~9 describes another auxiliary power steering system for a loader having a so~called articulated frame, the vehicle frame being in the form of two articulated portions which can be swivelled in opposite directions to each other to maximize the angle of turn. In a vehicle oE this type, comprising front and rear frame portions, the axle of the rear frame portion is 73~33 in the form of a steering axle. A steering wheel is provided in order to operate the frame pivot which influences the turning circle, whereas the wheels of the rear axle are controlled by means of a hand-lever for an additional reduction in the turning circle. Thus, two independent operating members are required for this steering system, only one of which, namely, the steering wheel, produces a path synchronization between the operational path and the steering adjustment path for the steering adjustment move-ment which it controls. A further drawback is that, whensteering only with the frame pivot, the position of the steered wheels of the rear axle is not locked. On corner-ing, the position of these wheels is therefore determined by the lag behaviour dependent on the geometry of the axle, and this leads to a worsening of the steering characteristics.
An objec'c of the present invention, therefore is to provide a hydraulic steering system by means of which a vehicle is steered in the normal way by the adjustment of the wheels of the front axle, for example during road travel, and by means of which the further reduction in the turning circle required for working purposes is allowed by the adjust-ment of a further steering device, such as a frame pivot, only after the maximum angle of turn of the wheels of the steering axle has been reached, without necessitating the change-over of a further operating member and using only the steering wheel.
According to the invention, a mechanical lock consisting of a locking pin and a link plate is operative wi-thin the adjustment range of the wheels of the steering axle, within which turning for steering purposes takes place, and mechanically locks the second steering device :~2~ 3~
used for the further reduction of the turning circle. The mechanical lock is operated by a change-over valve which, in one of its valve positions, connects a high pressure pump to a working cylinder of the steering axle when the latter is within its steering adjustment range. When the steering axle reaches its maximum angle o~ turn, there is a pressure increase due to the turning having caused con-tact with the wheel stop, and this results in the opening of a discharge valve disposed at one end of the change-over valve whereby the change-over valve is moved into another valve position. The mechanical lock for the second steering device, which is connected to the change-over valve, is thus released with a simultaneous hydraulic shut-off of the work-ing cylinder of the steering axle, and the high pressure pump is connected to the working cylinders of the second steering device. In this manner, a continuous transition from two-wheel to four-wheel steering is possible without any additional change-over device or change-over operation being necessary.
Two embodiments of the invention are described in detail below, with reference to the drawings, in which:
Figure 1 is a diagram of the steering system comprising a combination of front-axle steering and pivoted-frame steering' and Figure 2 shows an embodiment of the steering system comprising a combination of front-axle steering and rear-axle steering.
The steering system shown in Figure 1 includes, in terms of its kno~ components, a metering pump 2 operated by a steering wheel 1, a steering valve 3 movable in two adjust-ment directions in accordance with the rotation of the steer~-ing wheel 1, a high pressure pump 4, an oil tank 5 and a relief valve 6 which limits the operating pressure to a certain maximum value. According to the direction of rotation of the steering wheel 1, the steering valve 3 feeds the delivery from the high pressure pump 4 to a respective inlet side of the metering pump 2, from which a metered working flow can be fed to a working cylinder 7 for a steering axle 8, and to working cylinders 10, 11 for a frame pivot 12 which constitutes a further steering device. In this case, the rear axle 9 is of rigid construct-ion.
According to the invention, the working flow is fed from the steering valve 3 to the working cylinder 7 or cylinders 10, 11 by way of a change-over valve 13 having two valve positions, I and II. In valve position I, the two pressure chambers of the working cylinder 7 acting on the steering axle 8 are connected by way of pipelines 14, 15 to the metering pump 1 and to the high pressure pump 4. In valve position II, the pipelines 14, 15 are closed, while pipelines 16, 17 leading to the pressure chambers of the working cylinders 10, 11 of the frame pivot 12 are connected to the metering pump 1 and to the high pressure pump 4. The change-over valve 13 comprises a slide 18 one end face 20 of which is acted upon by a spring 21 which urges the slide into valve position I. A mechanical lock is operative in valve position I, wherein a locking pin 22 fixed to the slide 18 engages a notch 23 in a link plate 24. For this purpose, the change-over valve 13 with its locking pin 22 is located on the pivot part of a front frame portion 25, and the link plate 24 is located on the pivot part of a rear frame portion 26, so that the frame pivot 12 is 73~3 mechanically locked in the straight-ahead running position.
That end face 27 of the slide 18 which lies on the same side as the locking pin 22 defines a pressure chamber 28 which is connected to a pressure line 30 running from the high pressure pump 4 to the steering valve 3.
Likewise, a pressure chamber 31 defined by the end face 20 is connected to the pressure line 30 by way of a restrictor 32. In this manner, at any given time, the pump pressure acts on both the end faces 20, 27 of the slide 18. A discharge valve 34 connected by a return line 33 to the tank 5 is incorporated in the change-over valve 13.
Regarding operation, with the valve position shown in Figure 1, the steering system is in the straight-ahead running position. The steering valve 13 assumes its central position, in which the delivery from the high pressure pump 4 in the pressure line 30 flows back to the tank 5 by the return line 33. If the steering valve 3 is moved, for example, towards the right by turning the steering wheel 1, the delivery from the pump 4 passes in the form of a working flow into the lower pressure chamber of the working cylinder 7 by way of the pressure line 30, the metering pump 2, the change-over valve 13, which is in valve position I, and the pipeline 14. The volume of oil displaced from the higher pressure chamber flows to the tank 5 through the pipeline 15, the change-over valve 13, the steering valve 3 and the return line 33. The wheels of the steering axle 8 are thus turned towards the left with reference to the direction of travel (arrow A). When the steering axle 8 has turned through its maximum angle of turn, it is stopped by wheel stops (not shown). Upon further turning of the steering 7~3~
wheel 1, the working pressure in the steering system rises to the maximum value set by the relief valve 6. The dis-charge valve 34 opens by virtue of the connection between the pressure line 30 and the pressure chamber 31 of the change-over valve 13, so that the pressure in the p~essure chamber 31 is released.
By virtue of the restrictor 32, a pressure differ-ence arises between the end surfaces 27 and 20, with the result that the slide 18 moves into valve position II
against the spring 21. This change-over shuts o-ff the pipelines 14, 15 of the steering axle 8, and the latter thus becomes locked when it has turned through its maximum angle of turn. At the same time, the pipelines 16, 17 are connected to the working cylinders 10, 11 of the frame pivot 12. The valve change-over causes the withdrawal of the locking pin 22 from the notch 23 in the link plate 24 so that the frame pivot 12 is no longer locked. As the frame pivot 12 rotates from its centered position, the locking pin 22 abuts the approximately semi-circular profile of the link plate 24 due to the rotation of this latter, keeping the slide 18 of the change-over valve 13 in valve position II mechanically even if the working pressure falls. The working pressure now flows through the pipeline 16 into the left-hand pressure chamber of the working cylinder 11 and the right-hand pressure chamber of the working cylinder 10. The volume of oil displaced simultaneously from the right-hand pressure chamber of the working cylinder 11 and the left-hand pressure chamber of the working cylinder 10 flows through the pipeline 17, the steering valve 3 which has been set in its right-hand position, and the return line 33. Due to articulation IL2~7~
about the frame pivot 12, the front frame portion 25 swivels to the left relative to the rear frame portion, with reference to the running direction (arrow A), and the turning circle of the vehicle is further reduced beyond that determined by the maximum angle of turn of the steering axle until the maximum angle of turn of the frame pivot 12 is reached.
The change-over valve 13 maintains valve position II until the frame pivot 12 is turned back to the straight-ahead running position, in which the slide 18 is pushedback into valve position I by the force of the spring 21.
The locking pin 22 then re-engages the notch 23 and the frame pivot 12 is locked.
By means of the invention, steering is effected only by means of the steering axle 8 while within its turn-ing range. Because of this, the vehicle retains the steer-ing and running characteristics of front-axle steering, which are advantageous for road travel. Only when the steering axle 8 reaches its maximum angle of turn does further rotation of the steering wheel automatically lead to an additional turning angle by means of the frame pivot.
The embodiment shown in Figure 2 differs from ' that of Figure 1 only in that, instead of an articulated frame, it has a continuous frame 35 with a rear steering axle 3~ which acts as the second steering device. In this case, the locking pin 22 engages a link plate 37 which is slidable transversely of the longitudinal axis of the vehicle and is connected to a steering arm 38. All the other components are of substantially the same construction and operation as those of Figure 1.
Claims (4)
1. A hydraulic steering system for motor vehicles, particularly agricultural and construction site vehicles, comprising in combination:
a steering axle adapted to be moved in the respective steering direction of the vehicle by means of a working cylinder; an additional hydraulically-operable steering device, including working cylinder, which in-fluences the direction of travel providing for the further reduction of the turning circle of the steering axle; a steering valve adjustable by means of a steering wheel connected to a high pressure pump; and the working cylinders of the steering axle and the additional steering device being controlled by means of the steering valve; characterized in that a change-over valve, including a slide, said change-over valve defining valve positions I and II and operating a mechanical lock is associated with the steering valve; the high pressure pump is connected to the working cylinder of the steering axle in valve position I, whereby the additional steering device is locked; and when the steering axle reaches its maximum angle of turn, the change-over valve automatically switches to valve position II, in which the additional steer-ing device is connected to the high pressure pump and the steering axle is locked in its position of maximum angle of turn.
a steering axle adapted to be moved in the respective steering direction of the vehicle by means of a working cylinder; an additional hydraulically-operable steering device, including working cylinder, which in-fluences the direction of travel providing for the further reduction of the turning circle of the steering axle; a steering valve adjustable by means of a steering wheel connected to a high pressure pump; and the working cylinders of the steering axle and the additional steering device being controlled by means of the steering valve; characterized in that a change-over valve, including a slide, said change-over valve defining valve positions I and II and operating a mechanical lock is associated with the steering valve; the high pressure pump is connected to the working cylinder of the steering axle in valve position I, whereby the additional steering device is locked; and when the steering axle reaches its maximum angle of turn, the change-over valve automatically switches to valve position II, in which the additional steer-ing device is connected to the high pressure pump and the steering axle is locked in its position of maximum angle of turn.
2. A hydraulic steering system as defined in claim 1, wherein said slide of the change-over valve includes a lock-ing pin engageable in a notch of a link plate which is coupled to the additional steering device; at its ends said slide has pressure chambers which are connected to the high pressure pump by a pressure line, a restrictor being connected to the inlet side of that pressure chamber at the opposite end to the locking pin; and the pressure chamber at the opposite end to the locking pin houses a spring which urges said slide in the locking direction, and the pressure chamber is connected to a tank through a discharge valve.
3. A hydraulic steering system as defined in claim 1, wherein the additional hydraulic steering device is in the form of an articulated-frame steering unit.
4. A hydraulic steering system as defined in claim 1, wherein the additional hydraulic steering device is in the form of a rear steering axle.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP8300195 | 1983-07-23 | ||
| DEE.P.-83/00195 | 1983-07-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1214730A true CA1214730A (en) | 1986-12-02 |
Family
ID=8164899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000460009A Expired CA1214730A (en) | 1983-07-23 | 1984-07-13 | Hydraulic steering system for motor vehicles |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1214730A (en) |
| DE (1) | DE3426204A1 (en) |
| GB (1) | GB2144087B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3543054A1 (en) * | 1984-12-19 | 1986-06-19 | Zahnradfabrik Friedrichshafen Ag, 7990 Friedrichshafen | Hydrostatic steering system for vehicles with a bending frame |
| US6012272A (en) * | 1998-03-18 | 2000-01-11 | Dillon; Ben N. | Articulated combine |
| ITBO20000436A1 (en) * | 2000-07-18 | 2002-01-18 | New Holland Italia Spa | VEHICLE WITH A DOUBLE STEERING SYSTEM. |
| DE10065555B4 (en) * | 2000-12-28 | 2004-08-19 | Sauer-Danfoss Holding Aps | Steering system for a vehicle |
| DE10065552C1 (en) * | 2000-12-28 | 2002-04-18 | Sauer Danfoss Nordborg As Nord | Steering of vehicle involves correcting second steering device, especially articulated steering device, when it moves out of dead zone and first, especially wheel, steering device activated |
| GB0822585D0 (en) | 2008-12-11 | 2009-01-14 | Translift Bendi Ltd | Articulated vehicles |
| US10625770B2 (en) | 2017-09-05 | 2020-04-21 | Cnh Industrial America Llc | Automatic steering with selective engagement of four-wheel steering |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1194744A (en) * | 1967-11-29 | 1970-06-10 | Massey Ferguson Perkins Ltd | Improved Steering Arrangement for Wheeled Vehicles |
-
1984
- 1984-07-05 GB GB08417164A patent/GB2144087B/en not_active Expired
- 1984-07-13 CA CA000460009A patent/CA1214730A/en not_active Expired
- 1984-07-17 DE DE19843426204 patent/DE3426204A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE3426204C2 (en) | 1987-04-16 |
| GB8417164D0 (en) | 1984-08-08 |
| GB2144087A (en) | 1985-02-27 |
| GB2144087B (en) | 1986-08-06 |
| DE3426204A1 (en) | 1985-02-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |