US2308746A - Booster pump and suction switch - Google Patents

Description

Jan. 19, 1943. F. "r. FLINT BOOSTER PUMP A ND SUCTION SWITCH Filed March 14, 1941 2 Sheets-Sheet l FIG. 1

5%"."1 ELNTOR FORREST T. FLINT W U.

ATTORNEY J 1 4 F. 1'. FLINT 2,308,746

BOOSTER PUMP AND SUCTION SWITCH Filed March 14, 1941 2 Sheets-Sheet 2 INVENTOR FORREST T. FLINT WlLR-Q ATTO R N EY Patented Jan. 19, 1943 2,308,746 BOOSTER PUMP AND SUCTION swrrcn Forrest T. Flint, Florissant, Mo., assignor to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application March 14, 1941, Serial 1:10. 383,371 14 Claims. (Cl. 123-139) This invention relates to mechanism associated with an internal combustion engine for producing a stabilized pressure differential and utilizing the same f r controlling the fuel supply and ignition syste Many accessories and adjuncts on motor vehicles, such as fuel feed pumps, windshield wipers, oil pumps, and fans may be operated by the vacuum or pressure differential between the subatmospheric pressure in the intake manifold and the atmosphere. While it has been found highly desirable to use such motive power, certain operating conditions such as rapid acceleration and low speed operation under a heavy load, decrease the pressure difference between the intake maul-- fold and the atmosphere to a degree where it is of little or no use as a motive power. This very wide fluctuation of the pressure differential renders it undesirable as a motive power for some adjuncts such as a vacuum switch constructed to operate within fairly close pressure limits.

Where an electric fuel pump is used, it is desirably rendered operative to supply fuel concurrently with energizing of the ignitio system. but since a driver may neglect to cut off/the igniconnected to the intake manifold 2 by the fluid tion switch after the engine starts, means should be provided to prevent the pumping of fuel at such times.

An object of this invention is to provide a positively driven air pump for supplying a pressure differential for operating accessories and adjuncts on a motor vehicle.

Another object of the invention is to provide a positively driven air pump for closing a vacuum operated switch when the engine is being started.

Another object of the invention is to provide a. novel vacuum operated switch for controlling electrical system of an internal combustion engine.

Still another object is to provide a fuel pump control switch device including automatic means to maintain the switch stably closed during cranking and, at other times, when the engine is operating slowly, while, at the same time, insuring prompt stopping of the pump when the engine stops.

These objects and other more detailed objects hereafter appearing are attained substantially by the device indicated in the accompanying drawings in which:

Fig. 1 is a diagrammatical view illustrating an application of the invention to an internal combustion engine and its associated electrical sys-.

tem.

pressure line 2a. Fluid pressure from the pump for actuating various accessories or adjuncts (not shown) is supplied through the pressure line I. A fluid pressure switch 8 actuated by the pump 6 is used for controlling the electrical circuits shown in Fig. 1. A generator- 9 is arranged to be driven by the engine in the usual manner and a starting motor I0 is arranged to, crank the engine. A storage battery is indica d at H. A throttle actuated starting switch may be of any suitable construction as the details thereof form no part of the invention.

To energize the starting motor, a lead |3|4 from the battery is provided having interposed therein a switch |5 operated by a solenoid IS. The switch I5 is normally held open in the position shown by the spring II. The starting motor is grounded at I8, solenoid I6 is grounded at l9, pump motor 4 is grounded at 28, and storage battery II is grounded at 20. 1

To energize solenoid l6, there is provided a circuit including battery ll, lead l3, ammeter A, key switch 24, leads 2| and 22, manual starter switch l2, and lead 23.

A second circuit for operating the fuel pump includes the battery, leads l3, 2|, and 25, fluid pressure switch 8, and leads 26 and 21. This circult is connected in multiple to the general ignition system as indicated at 29.

The charging circuit includes generator 9, lead 30, reverse current relay 33, leads 3|, 32 and 26,

sumcient pressure to cause fluid pressure switch 8 to close, and by this arrangement the circuit is opened in event the engine ceases operation. 6

To better understand the construction and operation oi pressure pump 6 and pressure switch 8, reference is made to Figures 2 and 3. The

a pump housing 48 secured to the motor housing 41 by-the bolts v 42 in the vicinity oi a rotating cam 43 driven, by the motor. A vertical pump cylinder 44, secured to the top pump 6 comprises of pump housing 49 by bolts 45, is divided into two chambers by a ring sealed piston 46. The

lower chamber formed by piston 46 is in open communication with the interior of motor housing 4l through the hollow interior of the pump housing and the opening 41 in the motor housing. In the lower portion of'pump housing 46 so. Openings 53 in the guide member 52 provide a means for the escape of oil from the well as the guide plunger is reciprocated. A- lever 56, pivoted at 66, has one end 51 bearing on a collar 68 formed on piston rod 6|, while the other end 69 of the lever is held against cam 43 by the upward thrust of spring 68..

Piston 46 is provided with a circularly arranged series of openings 69 iorthe passage of fluid downwardly through the piston and a valve disk 6 I, backed by a sound deadening material 62, is normally urged against theunder surface of piston 46 by a spring 63 to close the openings 68. Surrounding the valve disc, a sound deadening chamber is formed by a circular wall 64 depending from the under side of piston 46 and a bottom plate 66. Wall 64 is provided with small openings66 arranged thereabout for distributing and retarding the speed of air passing through the chamber. This chamber also acts as a condensing and collecting chamber for crank case oil sucked upwardly around piston 46 and drawn back through the ports 69., Oil thus collected finds its way through the openings 66 to the crank case of the engine.

A distributing chamber 61 formed in the cylindercover 66, is provided with a pair of valve units 69 and 19,respectively, positioned by the entering chamber through line 1 is distributed to the pressure pump or to the intake manifold according to the relativedepressions therein.

An upwardly projecting cup 16 on pump cover 68 has the lower end 01 a bellows 16 stretched thereover, the other end of --the bellows being stretched over a plate 11 thereby forming the ex pansible and contractiblefluid tight chamber 18. A ring 88 resting on cover 66 within cup 16 has upwardly projecting abutment pin 88a for limiting the downward movement of plate 11. A compression spring 8| is seated between ring 88 and plate 1 for extending the bellows. A cover 62 placed over the bellows is secured to cylinder cover 88 by the bolts 83.

A vertical cylinder 86 in chamber 18 forms one electrical contact of the pressure switch and is insulated from the cylinder cover 68 by the dielectric members 86 and 81. Cylinder 86 is held in place by the binding post 88 to which is connected electrical conductor 26. Electrical conductor 25 is connected to the binding post 9| which is supported by and .insulated from the cover 82. Binding post 9| has a downwardly extending portion 92 on the end of which is secured. outwardly and upwardly projecting spring contact'flngers 93s1idably contacting the inner wall of a cup 94 secured to bellows top plate 11. Cup 94 has a depending flnger 94a provided with outwardly and upwardly projecting spring contact flngers96 ior slidably contacting cylinder 86 when bellows 16 is collapsed. Dielectric washer 99 secured to the end of finger-94 reciprocates in cylinder 86 and member 94. I

Distributing chamber "81 and expansible' strlction v98 retards the inflow of air when the engine ceasesoperation.

The operation of the device-is as follows:

To start the enginejkey switch 24 is closed and upon closing manually operated switch l2,

solenoid .l6 closes the starter circuit thereby causing starting motor 19 torcrank the internal combustion engine I. Cranking speed varies from9to20 R.P. M.andatthislowspeed2to4 revolutions is suflicient for the pump piston 48 to reduce the air pressure in distributing chamber 61, pressure line 1 and chamber 18 to a point where bellows 16 will partially collapse and switch contact flngers 96 makes contact with the vertical sidewalls or chamber 86 thereby closing the circuit energizing fuel pump 4 and the general ignition system 29.

The small volume of air in chamber 61, pressure line .1 and chamber 18 is exhausted very quickly by the large pressurepump 6 and by the same token a leakage of. air inan appreciable amount will cause bellows '16 to extend tending to break the contact between the switch contacts,

It is, therefore, necessary that there be a calibrated passageway to chamber 18 from distributing chamber 61 so that the time required for air to fill chamber 18 is greater than the time required for the" upward stroke of pressure pump 6 during its slowest operation, that is, during cranking of the engine.

Bellows 16 will pulsate during low speed 'operafrom 4 to 6' seconds the switch contacts are I broken.

If, for any reason, pump 6 fails to operate and the engine is running, the subatmospheric pressure in the intake manifold 2 will operate the a switch by way of line 2a. passage 12 and valve unit 18. Valve unit 1, also, may open when high actsas a guide for suction exists in the engine intake and pump 6 is operating slowly, as during idling.

In the event that pump piston 46 or its seal is broken and the engine continues operation, intake suction maintains the fuel pump and ignition in operation, except under the most adverse suction conditions, but valve unit 69 remains closed and suction in the intake manifold cannot remove the oil vapor from the crankcase.

The detailed drawings and description are intended to be illustrative, not limiting, and the use of all modifications within the scope of the appended claims is contemplated.

I claim:

1. In an electrical circuit control for an internal combustion engine, a pressure chamber having a resiliently movable wall, an electrical switch constructed and arranged to be actuated by said movable wall, a reciprocating fluid pressure pump actuated by said engine, and a restricted passageway from said pressure chamber to said pressure pump for retarding the movement of said wall.

2. In a device for controlling an electrical circuit of an internal combustion engine comprising a suction pump actuated by said engine, a fluid chamber having a, movable wall, an electrical switch constructed and arranged to be actuated by said movable wall, a passageway from said pump to said chamber and an atmospheric vent to said passageway.

3. In a device for controlling an electrical circuit of an internal combustion engine, a suction pump actuated by said engine, a fluid chamber having a movable wall, a passageway connecting said pump and said chamber, an electrical switch constructed and arranged to be actuated by the movement of said wall, and an atmospheric vent for said chamber.

4. In a device of the class described having a suction pump actuated by an internal combustion engine, a fluid distributing chamber interposed between fluid actuated devices and said pump, a fluid connection between said chamber and the intake manifold of said engine, and a valve in said fluid connection, said pump being constructed and arranged to develop suction sufflcient to hold said valve closed throughout most of the normal operating range of said engine.

5. In a device of the class described having a electrical fuel pump for supplying fuel to said engine, an electrical circuit for energizing said fuel pump, a fluid chamber in communication with said pump, said chamber having a wall movable in one direction by said pump, a switch interposed in said circuit and actuated by said wall, and means for moving said wall in the opposite direction for interrupting said circuit when said engine ceases to operate.

'7. In combination, an internal combustion engine having an ignition system, a suction pump, an electric fuel pump, an electrical circuit for said pump, and means for breaking said electrical circuit when the suction in the pump falls below a predetermined point.

8. In combination, an internal combustion engine having an ignition system, a suction pump, an electricfuel pump, an incomplete electrical circuit for said fuel pump, and means for completing said circuit when suction in said pump reaches a predetermined point.

9. In combination, an internal combustion engine having an ignition system, a suction pump actuated by said engine, and means for opening said ignition system when the suction in said pump falls below a.predetermined point for a period of time.

10. In combination, an internal combustion engine having an ignition system, a suction pump actuated by said engine, an electric fuel pump, and means for energizing said fuel pump and ignition system when suction in said pump reaches a predetermined point.

11. In combination, an internal combustion engine having an ignition system, a suction pump actuated by said engine, an electric fuel pump, an electrical circuit for said fuel pump and said ignition system, and means for breaking said circuit when the suction in said pump falls below a predetermined point.

12. A control device for an internal combustion engine comprising a chamber having a movable wall, an actuating connection between said wall and the control, an engine operated pump having a fluid connection to said chamber for actuating said wall in one direction, means yieldingly urging said wall in the opposite direction, a restricted atmospheric port in a wall of said passage to relieve pressure differential in said chamber, and a restriction in said fluid connection to retard the response of said movable wall to variations in pump pressure.

13. A control as specified in claim 12 in which said atmospheric port is between said pump and the restriction in said fluid connection.

14. A control as specified in claim 12 in which said pump includes a reciprocating pumping member, said restriction retarding recovery of said chamber during the return stroke of said member under low speed pumping conditions.

FORREST T. FLINT.

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