GB2079378A - Hydraulic tipping apparatus for tipping the driving cabs of lorries - Google Patents
Hydraulic tipping apparatus for tipping the driving cabs of lorries Download PDFInfo
- Publication number
- GB2079378A GB2079378A GB8118281A GB8118281A GB2079378A GB 2079378 A GB2079378 A GB 2079378A GB 8118281 A GB8118281 A GB 8118281A GB 8118281 A GB8118281 A GB 8118281A GB 2079378 A GB2079378 A GB 2079378A
- Authority
- GB
- United Kingdom
- Prior art keywords
- conduit
- pressure fluid
- piston
- valve
- cylinder chamber
- 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.)
- Withdrawn
Links
- 239000012530 fluid Substances 0.000 claims abstract description 57
- 230000000903 blocking effect Effects 0.000 claims description 3
- 238000011144 upstream manufacturing Methods 0.000 claims 1
- 239000000725 suspension Substances 0.000 description 5
- 238000013016 damping Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 239000000872 buffer Substances 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D33/00—Superstructures for load-carrying vehicles
- B62D33/06—Drivers' cabs
- B62D33/063—Drivers' cabs movable from one position into at least one other position, e.g. tiltable, pivotable about a vertical axis, displaceable from one side of the vehicle to the other
- B62D33/067—Drivers' cabs movable from one position into at least one other position, e.g. tiltable, pivotable about a vertical axis, displaceable from one side of the vehicle to the other tiltable
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Vehicle Body Suspensions (AREA)
- Actuator (AREA)
- Fluid-Pressure Circuits (AREA)
- Reciprocating Pumps (AREA)
Abstract
A hydraulic tipping apparatus for tipping the driving cabs of lorries from tipped to non-tipped positions comprises a pump (at 10), a pressure fluid tank (at 7), a double-acting piston/cylinder unit (2/1) wherein the piston rod (3) and cylinder (1) are respectively connected to the driving cab and the chassis frame structure. In the bottom dead-centre position of the piston (2), the two cylinder chambers (4, 5) are connected together by way of a conduit (11). The lower cylinder chamber (4) which is connected to the first pressure fluid conduit (6, 7) is connected to the pressure fluid tank by way of a valve (16) which is opened by the piston (2) after passing over the port (12), and an orifice (24'). A conduit check valve (15) which opens towards the lower cylinder (4) is disposed in the connecting conduit (11). <IMAGE>
Description
SPECIFICATION
Hydraulic tipping apparatus
The invention relates to hydraulic tipping apparatus for tipping the driving cabs of lorries and is concerned with hydraulic tipping apparatus as set forth in the classifying, i.e. non-characterising, portion of
Claim 1.
A hydraulic tipping apparatus for lorry driving cabs, of that kind, is known (DOS NO. 20 30 450). In the known apparatus, however, the connecting conduit is formed only as a groove of short length, which is provided at the inside wall surface of the cylinder, in the interior thereof, in the direction of movement of the piston; however, when pressure fluid is introduced into the pressure fluid chamber for moving the piston outwardly and thus tipping the driving cab, the above-indicated arrangement is disadvantageous insofar as the groove forms a communication to the upper cylinder chamber which is connected to the pressure fluid tank, and this therefore results in an ineffective partial circuit which makes it difficult to extend the piston in the region of the connecting conduit in the form of the groove.
Therefore, a further aparatus is known in which the two cylinder chambers of the cylinder are connected together by way of an outer connecting conduit (DOS NO. 23 56 249). By virtue of the connecting conduit between the upper and the lower cylinder chambers, it can perform a free oscillating stroke movement in the bottom dead-centre position between the two ports at which the connecting conduit opens into the cylinder, so that the spring means of the driving cab can freely perform their functions and are not impaired for example by the cylinder. However, for the purposes of tipping the driving cab, the connecting conduit necessitates the use of so-called differential switching, in which the pressure fluid is introduced into the upper and the lower cylinder chamber at the same pressure, this being achieved by way of the connecting conduit.
Because of the different cross-sectional surface areas on the two sides of the piston - one one side, the effective cross-sectional area is reduced by the piston rod secured to the piston -the application of the same pressure in the two cylinder chambers produces a resultant force by means of which the piston can be moved into its extended position, in spite of the connecting conduit. However, so that the piston can operate with a sufficiently large force, against the total weight of the driving cab, the cross-sectional area ofthe piston rod must be of suitably large magnitude as ultimately it is the piston rod cross-sectional area which determines the effective resultant force.
A disadvantage with these known apparatuses is the fact that, after pressure actuation in the upper cylinder chamber is terminated, when the piston reaches or passes beyond the one (upper) port at which the connecting conduit opens into the cylinder, when the driving cab is being tipped back, a differential switching action occurs, whereby the piston abruptly drops through. This in turn results in the driving cab taking up all the movement of its spring suspension arrangement until reaching a condition of being supported on abutment buffers, and is particularly undesirable in air-suspension lorries because, in a repair situation, it is not always possible to ensure that there is sufficient system pressure in the air suspension arrangement.
Afurther disadvantage with the known apparatus is that a certain amount of pressure fluid is always being moved back and forth in the connecting conduit during the oscillating stroke movement with the piston in the corresponding dead-centre position. Because of this, and the friction which is always present, the spring suspension properties of the driving cab are falsified by this damping action of the piston.
The invention is based on the problem of so designing an apparatus as set forth in the classifying portion of Claim 1 that sudden dropping movement is no longer possible when the driving cab is being tipped back.
According to the invention, hydraulic tipping apparatus for tipping the driving cabs of lorries into a tipped assembly position and from that position into a tipped-back driving position of the driving cab, comprises a pump, a pressure fluid tank, a doubleacting stroke cylinder, of which the piston or piston rod and cylinder are respectively connected to the driving cab and the chassis frame structure, pressure fluid conduits for pressure actuation, which open into the upper and lower cylinder chambers separated by the piston and which can be selectively connected to the pump or the pressure fluid tank, wherein, in the dead-centre position of the piston which corresponds to the tipped-back position of the driving cab, the two cylinder chambers are connected together by way of a connecting conduit, the ports at which the connecting conduit opens into the cylinder determining the oscillating stroke movement of the piston, and a check valve which is controllable by the piston passing over the port and which is arranged in the first pressure fluid conduit which leads to the pressure fluid tank when the driving cab is tipped back, characterised in that the lower cylinder chamber which is connected to the first pressure fluid conduit is connected to the pressure fluid tank by way of a valve which is opened by the piston after passing over the port, and an orifice, and that a conduit check valve which opens towards the lower cylinder chamber is disposed in the connecting conduit.
If therefore the check valve in the first pressure fluid conduit which leads to the pressure fluid tank, that check valve in accordance with the invention preferably being pressure-controlled by way of the pressure in the upper cylinder chamber, is closed for example shortly before the piston reaches the bottom dead-centre position, after passing over the port at which the connecting conduit opens into the cylinder, the valve connected to the lower cylinder chamber opens, in accordance with the teaching of the invention, and provides a communication to the pressure fluid tank by way of an orifice incorporated into the first pressure fluid conduit.Desirably, the controlled valve is connected to the first pressure fluid conduit between the orifice and the controlled check valve so that the pressure fluid which is displaced out of the lower cylinder chamber when the driving cab is being tipped back is always discharged by way of the orifice and therefore in a damped mode.
In an advantageous development and embodiment of the invention, a conduit check valve which opens towards the lower cylinder chamber is also arranged in the connecting conduit, which has the advantage that a differential switching action cannot occur and the piston cannot therefore drop through because, when the check valve in the first pressure fluid conduit is closed, in contrast to the state of the art, pressure fluid cannot be displaced from the lower cylinder chamber into the upper cylinder chamber in the downward movement of the piston, which is advantageous insofar as the pressure fluid which is displaced into the pressure fluid tank by way of the controllable valve and the orifice and a suction blocking valve for preventing fluid from being sucked along afterwards (check valve) is removed from the system.If, as a result of random movement while the vehicle is being driven, the piston of the double-acting cylinder moves slightly upwardly, pressure fluid is displaced into the lower cylinder chamber from the upper cylinder chamber and the conduit check valve. There is no possibility of fluid being sucked out of the pressure fluid tank, because of the suction blocking valve in the first pressure fluid conduit. In the subsequent random downward movement of the piston while the vehicle is being driven, the pressure fluid which is displaced from the upper cylinder chamber into the lower cylinder chamber is in turn conveyed into the pressure fluid tank by way of the first pressure fluid conduit so that a vacuum is gradually developed, which permits unimpeded oscillation ofthe piston in the oscillating stroke movement length, that is to say, between the ports at which the connecting conduit opens into the cylinder, without being accompanied by displacement of pressure fluid, with the resulting damping action and falsification in respect of the spring suspension qualities of the driving cab.
Advantageous developments and embodiments of the invention are characterised in the subsidiary
Claims (9)
1. A hydraulic tipping apparatus for tipping the driving cabs of lorries into atipped assembly position and from that position into a tipped-back driving position of the driving cab, comprising a pump, a pressure fluid tank, a double-acting stroke cylinder, of which the piston or piston rod and cylinder are respectively connected to the driving cab and the chassis frame structure, pressure fluid conduits for pressure actuation, which open into the upper and lower cylinder chambers separated by the piston and which can be selectively connected to the pump or the pressure fluid tank, wherein, in the dead-centre position of the piston which corresponds to the tipped-back position of the driving cab, the two cylinder chambers are connected together by way of a connecting conduit, the ports at which the connecting conduit opens into the cylinder determining the oscillating stroke movement of the piston, and a check valve which is controllable by the piston passing over the port and which is arranged in the first pressure fluid conduit which leads to the pressure fluid tank when the driving cab is tipped back, characterised in that the lower cylinder chamber which is connected to the first pressure fluid conduit is connected to the pressure fluid tank by way of a valve which is opened by the piston after passing over the port, and an orifice, and that a conduit check valve which opens towards the lower cylinder chamber is disposed in the connecting conduit.
2. Apparatus according to Claim 1, characterised in that the orifice is arranged in the first pressure fluid conduit and the controllable valve is arranged in parallel to the pressure fluid conduit.
3. Apparatus according to Claim 1 or 2, characterised in that the controllable valve is in the form of a pressure-controlled two-way two-position valve, the first control conduit of which is connected to the lower cylinder chamber.
4. Apparatus according to Claim 3, characterised in that the second control conduit of the pressurecontrolled valve is connected to the upper cylinder chamber.
5. Apparatus according to any one of Claims 1 to 4, characterised in that the controlled valve has a rest position which is defined by means of a spring and in which the valve is blocked.
6. Apparatus according to any one of Claims 1 to 5, characterised in that the controllable valve is connected to the first pressure fluid conduit in parallel with the controllable check valve and in the direction towards the pressure fluid tank upstream of the orifice.
7. Apparatus according to any one of Claims 1 to 6, characterised in that the controllable check valve is a pressure-controlled valve.
8. Apparatus according to Claim 7, characterised in that the control line of the pressure-controlled check valve is connected to the upper cylinder chamber or the second pressure fluid conduit.
9. Hydraulic tipping apparatus substantially as hereinbefore described with reference to the accompanying drawing.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3025069 | 1980-07-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2079378A true GB2079378A (en) | 1982-01-20 |
Family
ID=6106238
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8118281A Withdrawn GB2079378A (en) | 1980-07-02 | 1981-06-15 | Hydraulic tipping apparatus for tipping the driving cabs of lorries |
Country Status (5)
Country | Link |
---|---|
FR (1) | FR2493255A1 (en) |
GB (1) | GB2079378A (en) |
IT (1) | IT1142546B (en) |
NL (1) | NL8102539A (en) |
SE (1) | SE8103234L (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0102676A2 (en) * | 1982-09-07 | 1984-03-14 | Applied Power Inc. | A tilt cab truck in which the cab is partially supported by the tilting cylinders while in the drive position |
EP0109462A1 (en) * | 1982-11-30 | 1984-05-30 | Applied Power Inc. | A hydraulic piston cylinder apparatus, particularly for a pivotable cab of a motor vehicle |
US5284083A (en) * | 1991-11-26 | 1994-02-08 | Messier-Bugatti | System for powering the driving actuator of an aircraft undercarriage |
EP0586968A1 (en) * | 1992-09-07 | 1994-03-16 | WEBER-HYDRAULIK GmbH | Hydraulic tipping facility for the driver's cab of a lorry |
NL1008475C2 (en) | 1998-03-04 | 1999-09-07 | Applied Power Inc | Double-acting hydraulic drive cylinder, especially for tilting a cabin of a vehicle. |
NL1009507C2 (en) | 1998-06-26 | 2000-01-04 | Applied Power Inc | Hydraulic tilting device for tilting a vehicle cabin and vehicle provided with such a tilting device. |
EP1028051A1 (en) * | 1999-02-10 | 2000-08-16 | Weber-Hydraulik GmbH | Tilting device for cabs of commercial vehicles |
NL1014029C2 (en) | 2000-01-06 | 2001-07-09 | Applied Power Inc | Hydraulic tilting device for tilting a vehicle cabin. |
US6295917B1 (en) * | 1999-03-24 | 2001-10-02 | Curt D. Richardson | Lost motion cylinder |
NL1016315C2 (en) | 2000-10-03 | 2002-04-04 | Actuant Corp | Hydraulic tilting device for tilting a vehicle cab and vehicle provided with such a tilting device. |
FR2965021A1 (en) * | 2010-09-22 | 2012-03-23 | Snecma | Hydraulic actuating cylinder for control device utilized to control orientation of blades of double propeller jet prop engine, has bypass duct opened in main ducts to obtain communication between chambers when piston is in dead zone |
US20190071136A1 (en) * | 2017-09-05 | 2019-03-07 | Cnh Industrial America Llc | Tilting System for a Suspended Cab of a Work Vehicle |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3472547A (en) * | 1966-06-13 | 1969-10-14 | Applied Power Ind Inc | Safety tilt system |
FR2068323A6 (en) * | 1969-10-15 | 1971-08-20 | Matairco Sa | |
SE353869B (en) * | 1970-05-26 | 1973-02-19 | Nike Ab | |
DE2210754B2 (en) * | 1972-03-06 | 1974-04-18 | Emil Weber Fabrik Fuer Oelhydraulik, 7129 Gueglingen | Hydraulic tipping device for tipping truck cabs |
DE2236311A1 (en) * | 1972-07-24 | 1974-02-07 | Sauer Achsenfab | CAB TILTING DEVICE |
-
1981
- 1981-05-22 SE SE8103234A patent/SE8103234L/en not_active Application Discontinuation
- 1981-05-22 NL NL8102539A patent/NL8102539A/en not_active Application Discontinuation
- 1981-06-08 IT IT48629/81A patent/IT1142546B/en active
- 1981-06-15 GB GB8118281A patent/GB2079378A/en not_active Withdrawn
- 1981-06-30 FR FR8113280A patent/FR2493255A1/en active Granted
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0102676A2 (en) * | 1982-09-07 | 1984-03-14 | Applied Power Inc. | A tilt cab truck in which the cab is partially supported by the tilting cylinders while in the drive position |
EP0102676A3 (en) * | 1982-09-07 | 1985-07-03 | Applied Power Inc. | A tilt cab truck in which the cab is partially supported by the tilting cylinders while in the drive position |
EP0109462A1 (en) * | 1982-11-30 | 1984-05-30 | Applied Power Inc. | A hydraulic piston cylinder apparatus, particularly for a pivotable cab of a motor vehicle |
US5284083A (en) * | 1991-11-26 | 1994-02-08 | Messier-Bugatti | System for powering the driving actuator of an aircraft undercarriage |
EP0586968A1 (en) * | 1992-09-07 | 1994-03-16 | WEBER-HYDRAULIK GmbH | Hydraulic tipping facility for the driver's cab of a lorry |
NL1008475C2 (en) | 1998-03-04 | 1999-09-07 | Applied Power Inc | Double-acting hydraulic drive cylinder, especially for tilting a cabin of a vehicle. |
WO1999045280A1 (en) | 1998-03-04 | 1999-09-10 | Applied Power Incorporated | Double-acting hydraulic cylinder, in particular for tilting a cab of a vehicle |
WO2000000378A1 (en) | 1998-06-26 | 2000-01-06 | Applied Power Incorporated | Hydraulic tilting device for tilting a vehicle cab and vehicle provided with such a tilting device |
NL1009507C2 (en) | 1998-06-26 | 2000-01-04 | Applied Power Inc | Hydraulic tilting device for tilting a vehicle cabin and vehicle provided with such a tilting device. |
EP1028051A1 (en) * | 1999-02-10 | 2000-08-16 | Weber-Hydraulik GmbH | Tilting device for cabs of commercial vehicles |
US6295917B1 (en) * | 1999-03-24 | 2001-10-02 | Curt D. Richardson | Lost motion cylinder |
NL1014029C2 (en) | 2000-01-06 | 2001-07-09 | Applied Power Inc | Hydraulic tilting device for tilting a vehicle cabin. |
NL1016315C2 (en) | 2000-10-03 | 2002-04-04 | Actuant Corp | Hydraulic tilting device for tilting a vehicle cab and vehicle provided with such a tilting device. |
WO2002028697A1 (en) * | 2000-10-03 | 2002-04-11 | Actuant Corporation | Hydraulic tilting device for tilting a vehicle cab |
US6948580B2 (en) | 2000-10-03 | 2005-09-27 | Actuant Corporation | Hydraulic tilting device for tilting a vehicle cab |
KR100790256B1 (en) * | 2000-10-03 | 2007-12-31 | 액츄언트 코포레이션 | Hydraulic tilting device for tilting a vehicle cab |
FR2965021A1 (en) * | 2010-09-22 | 2012-03-23 | Snecma | Hydraulic actuating cylinder for control device utilized to control orientation of blades of double propeller jet prop engine, has bypass duct opened in main ducts to obtain communication between chambers when piston is in dead zone |
US20190071136A1 (en) * | 2017-09-05 | 2019-03-07 | Cnh Industrial America Llc | Tilting System for a Suspended Cab of a Work Vehicle |
US10494040B2 (en) * | 2017-09-05 | 2019-12-03 | Cnh Industrial America Llc | Tilting system for a suspended cab of a work vehicle |
Also Published As
Publication number | Publication date |
---|---|
FR2493255B1 (en) | 1983-12-02 |
FR2493255A1 (en) | 1982-05-07 |
NL8102539A (en) | 1982-02-01 |
IT8148629A0 (en) | 1981-06-08 |
SE8103234L (en) | 1982-01-03 |
IT1142546B (en) | 1986-10-08 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |