Accelerator pump control apparatus
AssigneeThe Zenith Carburetter Company Limited
InventorGray E. D. Ross
Life of this patent
Estimating the term…
Abstract
An acceleration pump used in conjunction with an automatic cold start air-fuel mixture supply device, comprising a suction-operated diaphragm, and pressure regulating valve means controlling the communication of engine suction to such diaphragm, movement of such valve means being controlled both by thermostatic means responsive to engine temperature and by a control beam responsive to diaphragm movement.
Claims28
A fuel pump for incorporation in an i.c. engine air/fuel induction system which includes a carburetter having a driver operable throttle valve as well, the fuel pump comprising a hollow casing, a movable wall which divides the interior of the hollow casing into an air chamber and a fuel chamber which is for connection to a source of liquid fuel and the air/fuel induction system, resilient means which urge the movable wall to minimise the volume of the fuel chamber and thermostatically controlled means which are adapted to be responsive to the temperature of the engine to which the fuel pump is fitted when used, wherein the improvement comprises the provision of pressure regulating means for regulating a depression in said air chamber in accordance with a function of the depression that is established in the inlet manifold of the engine to which the pump is fitted when used and to the temperature of that engine, the pressure regulating means including a valve which is operatively associated with said thermostatically controlled means and which is adapted to be urged to restrict communication between the air chamber and the inlet manifold of the engine in response to a tendency for the depression in said air chamber to exceed a predetermined maximum when said predetermined maximum depression acts within the air chamber and the depression in the inlet manifold of the engine is at or above said predetermined maximum whilst, at least when the temperature of the engine is less than the normal working temperature, permitting relatively free communication between the air chamber and the inlet manifold of the engine when the depression in the inlet manifold of the engine is less than said predetermined maximum, the thermostatically controlled means co-operating with the valve and with an air bleed into the air chamber such that the volume of the air chamber, when communication between the air chamber and the inlet manifold is restricted, increases as the temperature of the engine increases.
A fuel pump for incorporation in an i.c. engine air/fuel induction system which includes a carburetter having a driver operable throttle valve as well;
- the fuel pump comprising a hollow casing, a diaphragm of flexible impervious material which divides the interior of the hollow casing into an air chamber and a fuel chamber, resilient means which urge the diaphragm to minimise the volume of the fuel chamber, the air chamber having a suction port which is for connection to the inlet manifold of the engine to which the pump is fitted when used, and a valve for the suction port which is resiliently biassed open and which co-operates with a control beam which has a portion which co-operates with the diaphragm so that the beam follows movement of the diaphragm, the suction port valve and the control beam being oriented with respect to the diaphragm and the suction port such that the suction port valve is urged towards the suction port by movement of the control beam that follows movement of said diaphragm to enlarge the volume of the fuel chamber, the arrangement being such that, once the suction port valve reaches a location relative to the suction port in which it restricts flow through the suction port so that the pressure in the air chamber is maintained substantially constant and further increase in the volume of the fuel chamber is prevented, the forces acting upon it to urge it towards the suction port comprise a reaction applied to it from the control beam and the action upon it of the depression in the suction port and the forces tending to move it away from the suction port comprise the biassing load by which it is biased open and the action upon it of the depression that is established within the reference pressure chamber.
Dependencies are inferred from the claim text.