Fluid operated vehicle body level control system

Claim 2

In a fluid operated levelling system for a vehicle body having a source of fluid under pressure and a fluid reservoir, adjustors operative to raise and lower the vehicle body and levelling valves communicable with the source and the reservoir through inlets and outlets thereof in response to the level orientation of the vehicle body in respect to the road surface and operative to communicate the adjustors with the source and the reservoir to maintain the vehicle body substantially parallel to the road surface, the improvement comprising: first electrically controlled valve means connected between the source and the inlets of the levelling valves; second electrically controlled valve means connected between the source and the inlets of the levelling valves; second electrically controlled valve means connected between the reservoir and the outlets of the levelling valves; third electrically controlled valve means connected between the source and the outlets of the levelling valves; fourth electrically controlled vave means connected between the reservoir and the inlets of the levelling valves; sensing means sensing planar orientation of the vehicle body relative to road surface orientation and operative to generate an electrical signal in response to lack of parallelism between the vehicle body and the road surface exceeding a predetermined degree being sensed; and switch means responsive to said electrical signal and being manually switchable between a normal position and a jacking position, said switch means being operative to control said electrically controlled valve means in such a manner that; when said switch means are in said normal position, said electrically controlled valve means are controlled to normally connect the inlets of the levelling valves to the source and the outlets of the levelling valves to the reservoir, and in response to said electrical signal to block communication between the inlets of the levelling valves and the source and the outlets of the levelling valves and the reservoir; and when said switch means are in said jacking position, said electrically controlled valve means are controlled to connect both the inlets and outlets of the levelling valves to the source and block communication between the inlets and the outlets of the levelling valves and the reservoir.

Claim 3

In a fluid operated levelling system for a vehicle body having a source of fluid under pressure and a fluid reservoir adjustors operative to raise and lower the vehicle body and levelling valves communicable with the source and the reservoir through inlets and outlets thereof in response to the level orientation of the vehicle body in respect to the road surface and operative to communicate the adjustors with the source and the reservoir to maintain the vehicle body substantially parallel to the road surface, the improvement comprising: first electrically controlled valve means connected between the source and the inlets of the levelling valves; second electrically controlled valve means connected between the reservoir and the outlets of the levelling valves; third electrically controlled valve means connected between the source and the outlets of the levelling valves; fourth electrically controlled valve means connected between the reservoir and the inlets of the levelling valves; sensing means sensing planar orientation of the vehicle body relative to road surface orientation and operative to generate an electrical signal in response to lack of parallelism between the vehicle body and the road surface exceeding a predetermined degree being sensed; and switch means responsive to said electrical signal and being manually switchable between a normal position and a jacking position, said switch means being operative to control said electrically controlled valve means in such a manner that; when said switch means are in said normal position, said first and second electrically controlled valve means are open and said third and fourth electrically controlled valve means are closed, and said switch means respond to said electric signal to close said first and second electrically controlled valve means; and when said switch mens are in said jacking position, said first and third electrically controlled valve means are open and said second and fourth electrically controlled valve means are closed.

Claim 4

In a fluid operated levelling system for a vehicle body having a source of fluid under pressure and a fluid reservoir adjustors operative to raise and lower the vehicle body and levelling valves communicable with the source and the reservoir through inlets and outlets thereof in response to the level orientation of the vehicle body in respect to the road surface and operative to communicate the adjustors with the source and the reservoir to maintain the vehicle body substantially parallel to the road surface, the improvement comprising: first electrically controlled valve means connected between the source and the inlets of the levelling valves; second electrically controlled valve means connected between the reservoir and the outlets of the levelling valves; third electrically controlled valve means connected between the source and the outlets of the levelling valves; fourth electrically controlled valve means connected between the reservoir and the inlets of the levelling valves; sensing means sensing planar orientation of the vehicle body relative to road surface orientation and operative to generate an electrical signal in response to lack of parallelism between the vehicle body and the road surface exceeding a predetermined degree being sensed; and switch means responsive to said electrical signal and being manually switchable between a normal position and a jacking position, said switch means being operative to control said electrically controlled valve means in such a manner that; when said switch means are in said normal position, said first and second electrically controlled valve means are open and said third and fourth electrically controlled valve means are closed, and said switch means respond to said electric signal to close said first and second electrically controlled valve means; and when said switch mens are in said jacking position, said first and third electrically controlled valve means are open and said second and fourth electrically controlled valve means are closed.

Claim 5

The improvement according to claim 2, in which each of said electrically controlled valve means comprises a solenoid valve.

Claim 6

The improvement according to claim 2, in which said sensing means include a sensor responsive to the orientation of the vehicle body and operative to generate an electrical tilt signal in response to said sensed lack of parallelism, and a control unit operative to feed said electrical signal to said switch means in response to said electrical tilt signal.

Claim 7

The improvement according to claim 4, in which said sensing mEans further includes a delay unit connected between said sensor and said control unit.

Claim 8

The improvement according to claim 5, in which said delay unit includes an integrating circuit operative to integrate said electrical tilt signal with respect to time, and said control unit includes a level detector responsive to the output of said delay unit, said control unit being operative to feed said electrical signal to said switch means when the integrated level of said electrical tilt signal is above a predetermined value.

Claim 9

The improvement according to claim 2, in which said sensing means includes a pendulum switch having a contact fixed to the vehicle body and another contact in the form of a pendulum engageable with said contact when the lack of parallelism between the vehicle body and a horizontal road surface exceeds a predetermined degree.

Claim 10

The improvement of claim 2, in which the fluid is in liquid form, and in which the source includes a pump, a pressure control valve and an accumulator.

Claim 11

The improvement of claim 2, in which the adjustors include shock absorbers.

Claim 12

The improvement of claim 2, in which said switch means are further switchable to a lowering position in which said electrically controlled valve means are controlled to connect both the inlets and outlets of the levelling valves to the reservoir and to block communication between the inlets and outlets of the levelling valves and the source.

Claim 13

The improvement of claim 2, in which said switch means are further switchable to a cut-out position in which said electrically controlled valve means are controlled to connect the inlets of the levelling valves to the source and the outlets of the levelling valves to the reservoir at all times.

Claim 14

The improvement of claim 2, in which when said switch means are in said cut-out position, said sensing means are inhibited thereby from generating said electrical signal.

Claim 15

The improvement of claim 2, in which said switch means are further switchable to a lowering position to control said first and third electrically controlled valve means to be closed and said second and fourth electrically controlled valve means to be open.

Claim 16

The improvement of claim 2, in which said switch means are further switchable to a cut-out position in which said first and second electrically controlled valve means are open and said third and fourth electrically controlled valve means are closed at all times.

Claim 17

In a fluid operated levelling system for a vehicle body having a source of fluid under pressure and a fluid reservoir, adjustors operative to raise and lower the vehicle body and levelling valves communicable with the source and the reservoir through inlets and outlets thereof in response to the level orientation of the vehicle body in respect to the road surface and operative to communicate the adjustors with the source and the reservoir to maintain the vehicle body substantially parallel to the road surface, the improvement cooprising; electrically controlled valve means disposed between the source and the reservoir and the inlets and outlets of the levelling valves; said electrically controlled valve means including a solenoid valve having a casing defining therein a chamber communicable with a first inlet connected to the source, a first outlet connected to the inlets of the levelling valves, a second inlet connected to the outlets of the levelling valves and a second outlet connected to the reservoir, valve elements movable within said chamber to control communication between said inlets and outlets of said solenoid valve and said chamber, biasing means urging said valve elements to allow communication between said first inlet and said first outlet and between said second inlet and said second outlet through portions of said chamber, and solenoid coil means connected to said switch means which, when energized in response to said electrical signal, move said valve elements against the force of said biasing means to block communication between saId first inlet and said first outlet and between said second inlet and said second outlet; sensing means sensing planar orientation of the vehicle body relative to road surface orientation and operative to generate an electricl signal in response to lack of parallelism between the vehicle body and the road surface exceeding a predetermined degree being sensed; and switch means responsive to said electrical signal and being manually switchable between a normal position and a jacking position, said switch means being operative to control said valve means in such a manner that; when said switch means are in said normal position, said valve means are controlled to normally connect the inlets of the levelling valves to the source and the outlets of the levelling valves to the reservoir, and in response to said electrical signal to block communication between the inlets of the levelling valves and the source and the outlets of the levelling valves and the reservoir; and when said switch means are in said jacking position, said valve means are controlled to connect both the inlets and outlets of the levelling valves to the source and block communication between the inlets and the outlets of the levelling valves and the reservoir.

Claim 18

In a fluid operated levelling system for a vehicle body having a source of fluid under pressure and a fluid reservoir, adjustors operative to raise and lower the vehicle body and levelling valves communicable with the source and the reservoir through inlets and outlets thereof in response to the level orientation of the vehicle body in respect to the road surface and operative to communicate the adjustors with the source and the reservoir to maintain the vehicle body substantially parallel to the road surface, the improvement cooprising; electrically controlled valve means disposed between the source and the reservoir and the inlets and outlets of the levelling valves; said electrically controlled valve means including a solenoid valve having a casing defining therein a chamber communicable with a first inlet connected to the source, a first outlet connected to the inlets of the levelling valves, a second inlet connected to the outlets of the levelling valves and a second outlet connected to the reservoir, valve elements movable within said chamber to control communication between said inlets and outlets of said solenoid valve and said chamber, biasing means urging said valve elements to allow communication between said first inlet and said first outlet and between said second inlet and said second outlet through portions of said chamber, and solenoid coil means connected to said switch means which, when energized in response to said electrical signal, move said valve elements against the force of said biasing means to block communication between saId first inlet and said first outlet and between said second inlet and said second outlet; sensing means sensing planar orientation of the vehicle body relative to road surface orientation and operative to generate an electricl signal in response to lack of parallelism between the vehicle body and the road surface exceeding a predetermined degree being sensed; and switch means responsive to said electrical signal and being manually switchable between a normal position and a jacking position, said switch means being operative to control said valve means in such a manner that; when said switch means are in said normal position, said valve means are controlled to normally connect the inlets of the levelling valves to the source and the outlets of the levelling valves to the reservoir, and in response to said electrical signal to block communication between the inlets of the levelling valves and the source and the outlets of the levelling valves and the reservoir; and when said switch means are in said jacking position, said valve means are controlled to connect both the inlets and outlets of the levelling valves to the source and block communication between the inlets and the outlets of the levelling valves and the reservoir.

Claim 19

The improvement of claim 15, in which said valve elements include a first valve element to control communication between said first inlet and said first outlet and a second valve element to control communication between said second inlet and said second outlet, and in which said solenoid coil means includes first and second solenoid coils connected to said switch means to control said first and second valve elements respectively.

Claim 20

The improvement of claim 16, in which said solenoid valve further includes a first passageway connected to said second inlet and communicable with said chamber, said first valve element being operative to control communication between said first passageway and said first inlet through said chamber in such a manner that said first valve element normally blocks communication between said first passageway and said first inlet when both of said first and second solenoid coils are de-energized when said switch means are in said normal position and when both of said first and second solenoid coils are energized in response to said electrical signal, and when said switch means are in said jacking position, only said second solenoid coil is energized thereby moving said second valve element to block communication between said second inlet and said second outlet and said first valve element is moved by said biasing means to allow communication of said first inlet with said first outlet and also with said second inlet through said first passageway.

Claim 21

The improvement of claim 17, in which said switch means are further switchable to a lowering position, and in which said solenoid valve further includes a second passageway connected to said first inlet and communicable with said chamber, said second valve element being operative to control communication between said second passageway and said second outlet through said chamber in such a manner that said second valve element blocks communication between said second passageway and said second outlet when both of said first and second solenoid coils are de-energized and when both of said first and second solenoid coils are energized, and when said switch means are in said lowering position, only said first solenoid coil is energized thereby moving said first valve element to block communication between said first inlet and said first outlet and said second valve element is moved by said biasing means to allow communication of said second outlet with said second inlet and also with said first inlet through said second passageway.