I claim:
1. A fluid system for use on a refuse truck and including a hydraulic motor; a fluid reservoir; a plurality of fixed displacement pumps; drive means operatively connected to the fixed displacement pumps for driving the same; a control valve for selectively directing a flow of fluid to either the reservoir or the hydraulic motor; and a control system having means for determining an external condition and generating a corresponding signal, and means responsive to the signal for switching the control valve.
2. The fluid system of claim 1 wherein the means for determining an external condition includes a rotational speed measuring device for measuring the rotational speed of the drive means, wherein the rotational speed measuring device generates the external signal.
3. The fluid system of claim 2 wherein the external signal is electrical.
4. The fluid system of claim 3 further comprising:
a function valve operatively connected to the control valve; wherein the control system includes an electrical circuit that receives the electrical signal from the rotational speed measuring device and communicates with the control valve and the function valve.
5. The fluid system of claim 4 wherein the control valve and the function valve are combined into a single valve block.
6. The fluid system of claim 4 wherein the control valve includes:
a two-way valve having a plurality of fluid passageways that selectively allow fluid to flow from the fixed displacement pumps to the fluid reservoir; and
a first solenoid-operated valve having a solenoid and a plurality of fluid passageways, wherein the solenoid communicates with the electrical circuit to select one of the fluid passageways of the first solenoid-operated valve.
7. The fluid system of claim 4 wherein the function valve includes:
a valve having a solenoid and a plurality of fluid passageways, wherein the solenoid communicates with the electrical circuit to select one of the fluid passageways of the function valve.
8. The fluid system of claim 4 wherein the fixed displacement pumps are comprised of fixed displacement pumps of different flow output.
9. The fluid system of claim 4 wherein the electrical circuit includes:
a retract and extend switch to select the mode of the hydraulic motor; wherein the control system means responsive to the signal for switching the control valve includes a switch, wherein the switch connections change based on the means.
10. A fluid system for use on a refuse truck and comprising:
a first fixed displacement pump, a second fixed displacement pump that has a larger displacement than the first fixed displacement pump, and a third displacement pump, wherein the first fixed displacement pump, the second fixed displacement pump and the third fixed displacement pump are selectively turned on and off in response to a signal means, wherein said signal means is external to the fluid system;
a drive means operatively connected to the first fixed displacement pump, the second fixed displacement pump, and the third fixed displacement pump;
a first control valve operatively connected to the first fixed displacement pump and the second fixed displacement pump;
a second control valve operatively connected to the third fixed displacement pump;
a first function valve operatively connected to the first control valve;
a second function valve operatively connected to the second control valve;
a first hydraulic motor operatively connected to the first function valve;
a second hydraulic motor operatively connected to the second function valve; and
an electrical circuit that receives the signal means and communicates with the first control valve, the second control valve, the first function valve, and the second function valve.
11. A fluid system for use on a refuse truck and including a hydraulic motor; a fluid reservoir; a plurality of fixed displacement pumps; drive means operatively connected to the fixed displacement pumps for driving the same; a control valve for selectively directing a flow of fluid to either the reservoir or the hydraulic motor; and a control system having means for determining an external condition and an internal condition, generating a corresponding signal for each condition, and means responsive to the signals for switching the control valve.
12. The fluid system of claim 11 wherein the means for determining an external condition includes a rotational speed measuring device for measuring the rotational speed of the drive means, wherein the rotational speed measuring device generates the external signal.
13. The fluid system of claim 12 further comprising:
a pressure monitoring device for monitoring the pressure in the fluid system, wherein the pressure monitoring device generates the internal signal.
14. The fluid system of claim 13 wherein the external signal and the internal signal are electrical.
15. The fluid system of claim 14 further comprising:
a function valve operatively connected to the control valve; wherein the control system includes an electrical circuit that receives the electrical signals from the rotational speed measuring device and the pressure monitoring device and communicates with the control valve and the function valve.
16. The fluid system of claim 15 wherein the control valve includes:
a two-way valve having a plurality of fluid passageways that selectively allow fluid to flow from the fixed displacement pumps to the fluid reservoir; and
a first solenoid-operated valve having a solenoid and a plurality of fluid passageways, wherein the solenoid communicates with the electrical circuit to select one of the fluid passageways of the first solenoid-operated valve.
17. The fluid system of claim 15 wherein the function valve includes:
a valve having a solenoid and a plurality of fluid passageways, wherein the solenoid communicates with the electrical circuit to select one of the fluid passageways of the function valve.
18. The fluid system of claim 15 wherein the fixed displacement pumps are comprised of fixed displacement pumps of different flow output.
19. The fluid system of claim 15 wherein the electrical circuit includes:
a retract and extend switch to select the mode of the hydraulic motor; wherein the control system means responsive to the signals for switching the control valve includes a switch, wherein the switch connections change based on the means.
20. The fluid system of claim 10 wherein said signal means is external and internal to the fluid system.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A flat heating surface type gas stove comprising;
a heat resistance glass top plate which is disposed over a burner;
wherein a gas-permeable porous body is disposed below said top plate, a space between said top plate and a surface of said gas-permeable porous body is assigned to a combustion space, and combustion gas to be generated is designed to be discharged through said gas-permeable porous body.
2. The flat heating surface type gas stove according to claim 1, wherein said gas-permeable porous body is formed of silicon carbide or a material containing silicon carbide as a main component.
3. The flat heating surface type gas stove according to claim 1 or 2, wherein a second gas-permeable porous body having a lower emissivity than that of the first mentioned gas-permeable porous body is laminated on a gas outlet side of the first mentioned gas-permeable porous body.
4. The flat heating surface type gas stove according to claim 3, wherein said second gas-permeable porous body is formed of silicaalumina-based ceramic or a material containing said ceramic as a main component.
5. The flat heating surface type gas stove according to any one of claims 1 to 4, wherein said burner is disposed around said gas-permeable porous body.
6. The flat heating surface type gas stove according to any one of claims 1 to 5, wherein said burner is a surface combustion burner, and a combustion surface thereof, together with the surface of said gas-permeable porous body, is disposed to face said combustion space.
7. The flat heating surface type gas stove according to claim 6, wherein the combustion surface of said surface combustion burner is formed of silicon carbide or a material containing silicon carbide as a main component.
8. The flat heating surface type gas stove according to claim 6 or 7, wherein the combustion surface of said surface combustion burner is placed on the outer peripheral side of the surface of said gas-permeable porous body.
9. The flat heating surface type gas stove according to claim 6 or 7, wherein the surface of said gas-permeable porous body is placed on the outer peripheral side of the combustion surface of said surface combustion burner.
10. The flat heating surface type gas stove according to any one of claims 1 to 9, wherein said gas stove further comprises a combustion gas passageway communicated with a space located on a downstream side of combustion gas flow channel of gas-permeable porous body; an air passageway for combustion; and a heat-exchanging means acting between the combustion gas passageway and the air passageway for combustion;
wherein a mixed gas comprising a combustion gas and combustion air, which has been heated through heat exchange thereof with the combustion gas by means of said heat-exchanging means is designed to be fed to said burner.