Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
188 words
A safety device for a main hydraulic circuit having an auxiliary branch circuit, said device comprising: an electrovalve connected between said main hydraulic circuit and said auxiliary branch circuit, a reservoir in said main hydraulic circuit, said electrovalve normally connecting said auxiliary branch circuit to said reservoir and isolating said branch circuit from said main circuit, a solenoid controlling said electrovalve, said electrovalve connecting said main hydraulic circuit to said auxiliary branch circuit when said solenoid is energised, an electric control circuit for said solenoid, said control circuit comprising, electrical poser source means, first control switch means connected to said electrical power source means, a normally closed timer switch which opens when current has been flowing therethrough for a predetermined time interval, a normally open pressure sensitive switch, means connecting said pressure sensitive switch to said auxiliary branch hydraulic circuit, said pressure sensitive switch closing when the pressure in said auxiliary branch circuit exceeds a predetermined threshold pressure, said normally closed timer switch and said normally open pressure sensitive switch being connected in parallel with one another and in series with said control switch means and said solendoid.
Claim 2
Dependent Claim
188 words
A safety device for a main hydraulic circuit having an auxiliary branch circuit, said device comprising: an electrovalve connected between said main hydraulic circuit and said auxiliary branch circuit, a reservoir in said main hydraulic circuit, said electrovalve normally connecting said auxiliary branch circuit to said reservoir and isolating said branch circuit from said main circuit, a solenoid controlling said electrovalve, said electrovalve connecting said main hydraulic circuit to said auxiliary branch circuit when said solenoid is energised, an electric control circuit for said solenoid, said control circuit comprising, electrical poser source means, first control switch means connected to said electrical power source means, a normally closed timer switch which opens when current has been flowing therethrough for a predetermined time interval, a normally open pressure sensitive switch, means connecting said pressure sensitive switch to said auxiliary branch hydraulic circuit, said pressure sensitive switch closing when the pressure in said auxiliary branch circuit exceeds a predetermined threshold pressure, said normally closed timer switch and said normally open pressure sensitive switch being connected in parallel with one another and in series with said control switch means and said solendoid.
Claim 3
Dependent Claim
28 words
The safety device of claim 1 wherein said threshold pressure of said pressure sensitive switch is substantially less than the normal operating pressure of said main hydraulic circuit.
Claim 4
Dependent Claim
22 words
The safety device of claim 1 wherein there is a constriction in said means connecting said main hydraulic circuit to said electrovalve.
Claim 5
Dependent Claim
39 words
The safety device of claim 1 wherein there is a pilot lamp connected in parallel with said timer switch, said pilot lamp having an electrical resistance which is high with respect to the electrical resistance of said timer switch.
Claim 6
Dependent Claim
21 words
The safety device of claim 1 wherein said main hydraulic circuit is in a hydraulic braking circuit of a motor vehicle.