US2315715A - Fuel supply control means - Google Patents

Description

April 6, 1943. w. E. LEIBING 2,315,715

FUEL SUPPLY CONTROL MEANS Filed Jan. 23, 1959 3 Shee'ts-Sheet 2 @MIJ/Maw April 6, 1943.

Filed Jan. 23, 1959 w. E. LEIBING 2,315,715

FUEL SUPPLY CONTROL MEANS 3 Sheets-Sheet 5 l 'lll/1111 jm" W ratented Apr. 6, 1943 UNITED STATES PATENT OFFICE FUEL SUPPLY CONTROL MEANS Application January 23, 1939, Serial No. 252,470

8 Claims. '(Cl. 123119) This invention relates to means for controlling the supply of fuel to internal combustion engines and is more particularly concerned with automatic means for restricting or cutting off the fuel supply during conditions of operation of the engine when flow of fuel is not desired, which device is uniformly operable regardless of external atmospheric conditions.

The present invention, in its preferred embodiment, is intended as an improvement over the carburetor and Degasser disclosed in Patent No. 2,134,667 which embodies automatic control means for regulating the ilow of fuel to an internal combustion engine.

The control of the above mentioned patent, which speciflcally embodies a pressure responsive element having one side exposed to the atmosphere and the other side selectively subjected to pressures from the intake manifold of an engine has proven highly satisfactory when used in localities and under conditions where the atmospheric pressure conditions do not vary appreclably.

Some difculty has been experienced, however, where a vehicle equipped with this type of Degasser has been driven between localities of radically different atmospheric pressure as in mountainous regions. Since the Degasser adjustment is normally balanced in accordance with the atmospheric pressure in a given locality it will be seen therefore that this adjustment becomes substantially unbalanced when the atmospheric pressure changes. This causes undesirable inaccurate operation of the Degasser."

The following table lists a few figures taken from Official U. S. Observatory Reports to illustrate the gradation of normal atmospheric pressures at various altitudes.

Pressure Altitude (ii (inches of HG) Sea level- 800 SSSSSSSSS Besides changing with the altitude, the atmospheric pressure is appreciably affected by general weather conditions and the pressure usually drops during stormy weather.

One of the major problems faced in improving the operation of prior devices of the type herein described has been to provide a pneumatic fuel supply control, the operation of which is independent of changes in atmospheric pressure and temperature. A further problem has been found where a flexible diaphragm is used and is subjected to intense heat, as where the control is used on a rear engine drive truck or bus, the material of the diaphragm under such conditions being often liable to deterioration with consequent objectionable and unreliable operation.

Further room for improvement has been found in the operation of the fuel supply cut-off mechanism. Usually a metallic needle valve cooperating with a metallic seat is employed. This type of valve has been found to Wear rapidly and soon allows leakage of fuel into the idling system at times when the fuel supply should be entirely cut off. Such wearing often causes back-fires and other undesirable engine action. Furthermore n some prior constructions, the needle valve has been located in a position whereby it has been necessary to disassemble the entire unit to recondition the valve seat or loose a sticky valve stem.

Further room for improvement has been found because of the condition when air usually leaks into the idling system past the loosely fitting shut-off valve mechanism heretofore provided in some instances. This air leakage disturbs the usual idling valve air adjustment for the carburetor. Furthermore, many of these loosely f1tting needle valve stems become clogged with dirt or powder from the fuel such as tetraethyl of lead thus causing the valve to become sticky in operation or even entirely frozen.

With a view to improving the operation and construction of prior Degassers, it is a major object of the present invention to provide novel means for controlling the supply of fuel to an internal combustion engine which is uniformly and reliably operable under all atmospheric pressure or temperature conditions.

A further object of the present invention is to provide novel pneumatically operated means for controlling the supply of fuel to an internal com` nustion engine which means is automatically compensated for changes in atmospheric pressure so as to provide uniform and dependable operation.

A further object of this invention is to provide a novel pneumatic fuel supply control selectively actuated by suction from the intake manifold of the engine and maintained in a predetermined conditionof operative balance under all atmospheric pressure conditions. More specically the pneumatic control includes a diaphragm or bellows or piston arrangement having one side subjected to atmospheric pressure and the other side subjected through a throttle controlled passage to the suction of the intake manifold.

A further object of the invention is to provide a novel pressure responsive device including means to maintain automatically a predetermined condition of balance ,at varying etniaspheric pressure conditions.

It is still a further object of the invention to provide a pressure responsive device such as a diaphragm. bellows, pismn or the like which is exposed to the atmosphere and which is balanced atleast partially by forces which normally do not vary directly with changes in the atmospheric pressure wherein these forces are adapted to be automatically compensated for atmospheric pres sure changes.

A'further object of the invention is to provide a novel pressure responsive device wherein the pneumatic forces are at least partly balanced by resilient means such as a spring and wherein a deformable pressure actuated element such as a bellows or the like is used to vary the effect of the spring on the pressure responsive device. More specifically the sprmg is preferably supported or anchored upon the bellows at one end.

A further object of the invention is to provide a novel springless pressure responsive device for regulating the fuel supply to an internal combustion engine wherein the pressure responsive de vice is automatically compensated for changes in atmospheric pressure.

it is still a further object of the invention to provide a novel valving mechanism for cutting o@ the idling fuel supply in an internal combustion engine wherein metal to metal valve contact faces are eliminated to reduce wear, wherein air leakage tending to destroy the idle iuei mixture adjustment is eliminated, and wherein foreign matter is prevented from entering and clogging the valve guide passages.

Still a further object of this invention is the provision of novel means in combination with a metal to metal valve of the type herein described whereby the valve faces may be readily refaced and sticking quickly and easily remedied without disassembling the entire unit.

A further object of the invention is to provide a novel pressure responsive device for cutting off the supply of fuel to an internal combustion engine under predetermined conditions which device is automatically compensated for changes in atmospheric pressure and deformation due to changes in temperature of the material embodied in the device.

A further objection of this invention is the provision of novel means for cutting ou the supply of fuel to an internal combustion engine of a vehicle as when the throttle is closed and the vehicle is driving the engine, means being provided whereby the fuel cut-oil will occur at the point most favorable to the condition of the engine as regards its temperature i. e., a cold engine is favored more than a hot engine, the degree of favor varying as the engine goes from a cold condition to normal working temperature; said means also operating to favor the engine under conditions where the engine may be lowered in temperature as when the vehicle is coasting down .duly appear as the description proceeds in connection with the appended claims and the annexed drawings in which Figure l is a section taken along line I--l of Figure 2 illustrating a preferred embodiment of an automatically compensating pressure responsive device constructed according to this invention, a carburetor conduit being additionally shown in Mgure l to more clearly illustrate the invention. v

Figure la is a fragmentary view illustrating the ioiperation of the throttle valve and the idling Figure 2 is an end elevation of the pressure responsive device of Figure l.

Figure 3 is an elevationztaken along line 3 3 of Figure l. v

Figure 4 is an end elevation taken in section along lined-il in Figure l.

Figure 5 is an enlarged section illustrating a novel idling fuel supply cut-ofi valve of the inventiou Figure 6 is a section taken along line e-G of Figure 'l illustrating a further embodiment of the invention having a did'erent fuel supply cut-ou valve control.

Figure 7 is an end elevation of the pressure responsive device of Figure 6.

Figure 8 is an elevation partly in section taken along line' Z-ii in Figure 6.

Figure 9 is a section taken along line -i of Figure lo illustrating a further embodiment of the invention employing a flexible diaphragm control.

Figure lil is an end yelevation of the device of Figure 9 from the carburetor end.

Mgure ll is an end elevation of the device of Figure 9 at the end opposite Figure lo.

Figure 12 is an elevation partly in section taken along line i12-i2 of Figure 9.

Figure i3 is an end elevation illustrating the inner side of the bellows adjustment cap of Figure 9.

Figure 14 is a section taken along line ill-iii of Figure l5 illustrating a further embodiment of the invention wherein no springs are used.

Figure 15 is an end elevation of the device of Figure le.

Figure 16 is an elevation partly in section taken along line IES-I6 off Figure le.

Figure 17 is an elevation partly in section taken along line l'i-il in Figure 14;

Figure 18 is a section taken along line iii- I8 of Figure 19 illustrating a further embodiment of the invention wherein automatic temperature compensating means are employed.

Figure 19 is a section taken along line iQ-I 9 of Figure 18. Y

Referring to Figures l5, a carburetor conduit or passage 2l forming part of the fuel intake conduit of an internal combustion engine, is arranged to conduct the fuel mixture from an updraft carburetor to the intake manifold of an internal combustion engine and is provided with a suitable ange 22 for attachment to the intake manifold. While description is made herein of an updraft installation, it is to be understood that this invention is capable of use in a down draft installation and reference is made to an updraft installation solely for the purposes of illustration. l

A throttle valve 23, preferably of the butter-ny type, is pivotally mounted within conduit 2l in a suitable manner and preferably has a portion of the up stream edge modified'as indicated at 24 to form a relatively thin section for a purpose later to be described. Valve 23 may be of the conventional carburetor type or may function as a combined carburetor and governor valve with suitable mechanism connected thereto to effect automatic governing of the engine.

The Degasser of the present invention is preferably formed in three main housing sections 25, 26 and 21 which are preferably die cast from a suitable metal for -purposes of economy of manufacture.

Section is provided with a hollow boss 25 which is adapted to be received within a suitable pocket or recess 29 formed in a wall of the carburetor conduit for a purpose to be later described. A passage 3| extends through section 25 from boss 28 to an axial passage 32 which opens at the inner wall of section 25, the outer end `of passage 3| being suitably plugged as shown.

Section 25 is formed with a suitable aperture 33 through which extends a v-alve control plunger, later to be described, and is formed with radially extending lug formations which align with similar lug formations on sections 25 and 21 to receive a Vplurality of elongated bolts 34 or .similar fastening means for rigidly securing sections 25, 2-6 and 21 together. Suitable compressible gaskets 35 and 36 are provided between adjacent end walls of sections 25 and 26, and 26 and 21, respectively. Gasket is suitably apertured to permit free passage of the valve plunger mechanism.

A deformable flexible metal-walled bellows 31 is positioned axially within section 25 and has its inner end sealed by a rigid plate 38 which is secured to section 25 by a ypair of screws 39. When screws 39 are drawn tight, plate 38 is seated firmly against gasket 35 in gastight rela'tion. Plate 38 is apertured axially at 4l in alignment with passage 32 and gasket 35 is suitably apertured so that passage 3| is in communication with the interior of Ibellows 31 through passage 32 and aperture 4|.

At its other end, 4bellows 31 is sealed within a suitable rigid cup 42 having an axially extending post 43 which projects into a necked or restricted portion of the outer housing section 21. Post 43 is slotted and provided with a pin 44 or similar means for pivotally engaging a looped end lof an axially extending tension spring 45 whose outer end is looped in pivotal engagement with a similar pin 46 rigid on axial post 41.

Post 41 is mounted for axial rotation in a suitable socket 48 formed in a curp 49 sealed with one end of a bellows 5| so that spring 45 is effectively universally and swivelly connectedto flexible metal-walled bellows 5|. A suitable gas tight cap 52 seals socket 48 from the interior of bellows 5| which is located within an enlarged end charnber 5D in housing section 21.

The outer` end of bellows 5| is sealed with a suitable cup l53 from whi-ch extends an axial threaded post 54,' preferably integral therewith, having a slot 55 across its outer end. The outer It is possible even to use a vacuum within bcilows 5I provided a suitable compression spring is employed within the bellows or other steps are taken to adjust the combination for the resultant unbalance set up between the pressure inside and outside of the bellows.

While pressure responsive elements such as bellows have been shown by way of example, it is to be understood that other forms of pressure responsive devices may be used such as sealed diaphragms, chambers, pistons and cylinders, or the like.

Wall 56 is supported on housing section 21 by means of an inwardly projecting threaded boss 59a which fits within the internally threaded outer portion of section 21. Post 54 extends in threaded engagement through a suitable axial aperture in wall 59 so that slot 55 is accessible to receive a screw driver or similar tool for adjustment purposes exteriorly of wall 59. A suitable cap 6I is secured in threaded engagement upon the outer side of wall 59 and extends over the end of post 54. Cap 6| is preferably locked or sealed in a suitable manner to prevent unauthorized access to post 54.

Housing section 21 is formed at its inner end with a recess 52 and an upstanding web formation 53. A lever 64, journaled upon web 63 by a pivot 55, is connected by a suitable lost motion pin and slot connection 66, 61 to post 43 at its -upper end and extends downwardly through recess 62 (Figure 5) to abut against the end of a valve mechanism plunger stem 68 slidably supported in a wall of housing section 25. The leverage of lever 64 is preferably approximately 3 or 31/2 to 1.

Stem 68 is formed at its outer end with an enlarged head 68a upon which a fiat-headed disk 59, preferably of fiber or like material, is secured by a screw 1| or other suitable fastening means.

As illustrated in Figures 1 and 5, an idling fuel supply passage 12, formed in the wall of conduit 2|, leads to an enlarged chamber 13 open externally of the conduit wall. Chamber 13 is aligned with aperture 33 and is internally threaded to receive a threaded hollow plug 14 having an enlarged bell-mouthed head 15 in line with and adapted to engage fiber disk 69. A suitable coil spring 16 is seated within the shouldered bore 11 of plug 14 and abuts against the head of screw 1| which is preferably flat and coplanar with the surface of disk 69.

When plug 14 is screwed tightly into chamber 13 its inner enlarged head abuts against an annular seating Washer 18. Plug 14 is provided a with a neck portion 14a defining an annular surface of cup 53 is preferably formed with a circumferential ring of serrations 56 which are adapted to receive a detent 51 formed integral with the free end of a fiat spring 58 secured to the inner side of housing end wall 59.

Bellows 5| is preferably of the same size as bellows 31 and has the same effective external area exposed to atmospheric pressure. The substance under pressure within bellows 5| may be air, nitrogen or any suitable and preferably inert gas, which is preferably under atmospheric pres- Sure.

passage 19 with the walls of chamber 13 and having a plurality of radial passages 8| connecting passage 19 with the internal bore through plug 14.

A fuel passage 82 leads from a suitable nozzle 83 which supplies a fuel mixture from the carburetor for idling purposes, and an unobstructed fuel mixture path is provided from nozzle 83 to passage 12 by means of passages 82, 19, 8| and the bore of plug 14.

A passage 84 leads from the atmosphere or a source of substantially atmospheric pressure to chamber 13 adjacent the bell-mouth 15 for a purpose to be later described. Passage 84 preferably leads from a point in the carburetor conduit downstream of the conventional air filter so that the air entering through passage 84 is clean and free from dirt and foreign matter. The threadedl engagement between plug 14 and the walls of chamber 13 provides a substantially gas tight connection so that no gasoline fumes or liquid can escape to the outer portion of chamber 13 and no air can leak into the idling fuel mixture at this point to disturb the existing ratio of gasoline and air which has been determined by adjustment of the carburetor.

Idling passage 12 is provided with an idling jet @E (Figure 1A) leading to the interiorof conduit 2i which is preferably arcuate in form as illustrated and formed by providing a round opening in the conduit wall and fitting therein a plug B6 whose periphery is cut away to provide the arcuate shaped jet 85 which is located adLiacent the downstream edge of the valve 23 when the latter is in idling position. The ow of fuel from the idling jet is thus metered in a known manner by the position of the throttle valve.

At the other side of the carburetor conduit, the wall is formed with an oriiice 81 which is connected by a suitable conduit 88 to the in terior of recess 29. Orifice 8l is located adjaf cent the edge of throttle 23 when the latter is in closed or idling position and is therefore at a point where the throttle valve edge has considerable vertical displacement with reference to the conduit wall for a predetermined angle of oscillation thereby contributing to the sensitivity and eiiciency of operation of the unit.

.As shown in Figure 1, orifice nl is subjected to the full downstream vacuum when the valve 23 is in idling or closed position but when the valve is only slightly cracked open the eiect of the downstream vacuum is considerably reduced. The action of the valve in controlling the operation of the Degasser and the added sensitivity provided by modifying the valve edge to a thin section as at 24 are fully discussed in the aforementioned patent. In this manner an unobstructed passage leads from orifice @l to the i interior oi bellows 31 by means of conduit ill), recess 29, passage 3i and aperture il and control of the pressure transmitted along this,` passage is effected by the edge o f throttle valve 23. The controll unit is preferably attached to the carburetor assembly as a unit by means of bolts 89 which pass through housing sections 25, 26 and 21 and are threaded in suitable bores in the wall of conduit 2i. A suitable gasket 9i between housing section 25 and the outer interfitting surface of the conduit wall provides a gas tight seal when the bolts 89 are drawn tight.

Operation In operation, with the engine running and the throttle valve 23 in idling or closed position as illustrated in Figure l, the interior of bellows 31 is subjected to the vacuum existing in the intake manifold through orifice 8l, conduit 88, recess 29, boss 28, passages 3| and 32, and aperture 4l.

With the interior of bellows 31 subjected to vacuum, the external atmospheric pressure tends to collapse this bellows to the left as'viewed in Figure 1. This action is resisted by the resistance of the bellows itself and mainly by the pull of spring 45. Referring to Figure 1, it will be seen that the tension of spring 45 may be regulated to vary its effect on the bellows 31 by moving pin 46 axially of the unit.

This displacement of pin 46 is eil'ected by removing cover 6I, inserting a screw driver or suitable tool in slot 55 and thereby rotating axially the whole bellows vassembly at 'I'he swivel connection between post 41 and bellows labutting against 5I prevents the spring from being wound or unwound during the above described adjustment. The adjustment is maintained against accidental displacement by the cooperation of datent El and serrations 5S, and is maintained against unauthorized adjustment by sealing cap @l in any suitable armer.

At the factory, this adjustment is preferably made to balance spring di) against the vacuum within bellows 3l in such a manner that post it does not move to the left during normal idling vacuum in the intake manifold. Under these conditions, lever 613 is maintained stationary by the pull of spring d5, with its lower end just steml 58 with sumcient force to urge disc 'da into tight sealing engagement with bell-mouth l5. ln this position, spring l@ is compressed within bore lil and abuts against the head of screw 1l,

Under normal idling conditions, there is no interruption to the now of the fuel mixture along passages l2 and 82, there is no leakage of gasoline fumes which might cause the material of disk 59 to deteriorate, and there is no danger that any sticky powder or other substance from the fuel will leak into and clog the guide of stern 68 and thereby interfere with the operation of the unit.

Similarly, there is no air leakage past plug ld into the fuel mixture passage and the original idling adjustment of the carburetor is not disturbed. Oi especial advantage is the' fact that the ber to metal contact surface engagement at liti, l5 has not only better wearing properties than a metal to metal valve tace contact, but provides a very effective gas tight seal.

When the throttle is in idling position and the engine running conditions may be such as to produce a vacuum in the intake manifold which is higher than the normal idling vacuum for which the unit has been adjusted, as where the vehicle is descending a long grade with the throttle closed, this increased vacuum is eective to cause bellows 3l to contract so that post 63 and pin 6@ move to the left in Figure therebiy rocking lever @ll in a counterclockwise direc As the lower end of lever @il moves to thcriglit it permits spring il@ to push disk @s away from bell-mouth 15 thereby venting the bore of plug 14 to atmospheric pressure and overcoming instantly the suction of the intake manifold which has been drawing fuel up through passages 12 and 82. The idling fuel mixture supply is thereby cut oli as effectively as if a positive valve had been shut off in the idling passage, and no fuel is conveyed to the engine during these conditions of operation whereby gassing conditions are eliminated.

The above arrangement is especially advantageous because the valve opening action at bell-mouth 15 is positively-carried out by spring 1l which is of suicient strength to overcome the inertia of stem 68.

Under substantially constant atmospheric conditions spring 45 may just as well be anchored rlgidly at its right end. However, as above pointed out, atmospheric pressure variations due to changes in altitude and even changing weather conditions, seriously affect operation of the unit by varying the differential between the suction inside bellows 31 and the pressure of the atmosphere. The purpose of anchoring spring 45 to the deformable pressure responsive bellows 6| is to compensate for these pressure changes and insure uniform operation of the Degasser unit during all conditions of operation and atmospheric pressure.

Preferably bellows is sealed with an internal pressure equal to that of the atmosphere at sea level and the spring 45 properly adjusted between posts 43 and 41. Since both bellows 31 and 5| are flexible they stretch somewhat under the tension of spring 45 but yet offer sufficient resistance to keep the spring from becoming relaxed.

The pressure within bellows 5| may be negative, but when such sub-atmospheric pressure is employed the difference between it and sea level atmospheric pressure should not exceed the total pull of the spring.

Suppose a vehicle having its Degasser unit correctly adjusted is driven from a locality of high atmospheric pressure to one of low atmospheric pressure. As the atmospheric pressure decreases, bellows 5I will expand to the left as viewed in Figure 1 thereby weakening the pull of spring 45 on bellows 31 to compensate for the reduced atmospheric pressure effective on the extended surface of bellows 31. The parts are so proportioned that the effective pull of spring 45 upon bellows 31 is always automatically maintained in the same relation with respect to the absolute value of the predetermined vacuum necessary to contract bellows 31 so that the idling fuel supply is shut off whenever the intake vacuum exceeds normal idling vacuum with the throttle closed.

Since both bellows 5| and 31 are preferably of the same effective external area as regards the atmosphere, the effect of changes in atmospheric pressure upon either is automatically balanced. Where reference is made herein to the bellows as being of the same size, it is meant that the external areas thereof, subject to atmospheric pressure, are substantially equal. It does not follow that both bellows must have the same number of convolutions or corrugations ro have equal external areas exposed to atmospheric pressure because they may be of different diameters or have only one or have both ends exposed to atmospheric pressure.

Since the Degasser housing is secured to the engine which becomes quickly heated in operation, the question of expansion of the parts due to increased temperature raises a material problem. When the bellows are made small, as they preferably are, any expansion of the bellows due to temperature rises may be at least partially limited. Likewise an evacuated bellows would have little expansion due to temperature rises.

However in the present invention the expansion of the parts due to increasing temperature is preferably compensated in the following manner. Housing section 21 is preferably an elongated thin metal shell which, sincev section 25 is bolted to the engine, expands to the right in Figure 1 when heated. Bellows 5|, rigid upon bossing wall 59, will expand to the left in Figure 1 when heated. In this manner, by choosing the proper proportions for bellows 5| and shell 21, the effect of temperature expansion may be further compensated since the outer end of spring 45 is effectively maintained against axial displacement.

All adjustments of the Degasser unit are preferably made with the engine and unit hot. Therefore when the engine is first started, and is cold especially in Winter, the operation of the Degasser in cutting off the idle fuel supply is not as critical as when the engine is operating at normal running temperature.

When the motor is cold, bellows 5| is contracted to a maximum and the pull of spring 45, also contracted, is increased to a point where it will resist even a high vacuum in the intake manifold.

This sluggishness of operation, or shut-off at a higher vacuum, is actually beneficial in the present invention in that it is desirable to keep a flow of fuel into the manifold at al1 times while the motor is cold. As the engine warms up, bellows 5| will expand and the Degasser will begin to cut off the idling fuel supply at progressively lower degrees of vacuum in the intake until it is operable just above normal idling vacuum when the engine has reached normal operating temperature.

An example of this beneficial operation is found when a vehicle is descending a long grade at relatively high speed. While the motor is hot the Degasser is operative to cut off the idling fuel supply but when the motor has cooled the Degasser parts contract to permit a resumption of flow of fuel in the idling passage and thereby keep the engine warm enough to operate smoothly when it reaches the bottom of the grade.

Modifications The Degasser control unit illustrated in Figures 6-8 is similar to that of Figures 1 5 except that it is adapted to operate a needle valve of the type used in the idling passage of the Degasser disclosed in the above mentioned patent.

Referring to Figure 6, casing 21' is formed with a-recess 92 bridged by a suitable pivot pin 93 upon which is journaled a lever 94 whose lower end abuts one end of a slidable valve operating stem 95. Lever 94 is slotted at 90 to form a lost motion connection with pin 66 on post 43, and is provided with a suitable apertured lug for receiving and anchoring the inner or left end-of spring 45 The other end of stem 95 abuts axially with the blunt end of a needle valve 9B whose conical face is normally maintained away from a suitable valve seat 96a within plug 14 by a coil spring 91, preferably conical in shape, which surrounds valve 96 and urges it to the right (Figure 6) to maintain a Contact connection with lever 94 and insure instantaneous movement of valve 96 when the lever is moved. The right end of spring 91 abuts against a washer 91a fixed to valve 9B.

Bellows adjustment post 54 extends a substantial distance beyond the housing wall 59' so that slot 55 is readily available for adjustment and the reception of a sealing wire.

The unit of Figure 6 differs in operation from that of Figure 1 in that the former provides a positive shut off action by pushing the needle valve 9G firmly into its seat when the suction within bellows 31 is sufficient to rock lever 94 in a clockwise direction. Otherwise the operation of these units is substantially the same.

The Degasser control unit illustrated in Figures 9-13 embodies a flexible diaphragm unit in place of bellows 31 of Figures 1-8 which may be used in installations where the unit is not subjected to conditions `detrimental to the diaphragm.

The diaphragm base 98 is provided with a hollow boss 99 which fits into the carburetor wall aperture 29 in the same manner as aperture 28 in Figure 1. The ilexible diaphragm element which may be of rubber, Duprene or similar material is clamped and sealed circumferentially between an edge wall oi.' base 98 and an annular ring |02 by means of a series ot screws |03 which pass through an annular ilange |04 on-shell 2l'. The eilective area of element |0| exposed to external atmospheric pressure is preferably equal to the eective area of bellows exposed to the same pressure.

Base 98 is formed with a guide bore |05 for receiving a slidable cylindrical cap |08 which cooperates with the threaded stem oi.' a rigid diaphragm button |01 to secure the button in gas tight connection with element |0|. A screw driver slot |08 is provided for tightening cap |00 upon button |01.

Button |01 is formed with an integral slotted post |09 having a pin I|| tting within a slot 90 of lever 94 which is pivotally supported at 93 and connected to spring 45 in the same manner as above described in connection with Figure 6.

The other end of spring 45 is swivelly connected to bellows 5| in the same manner as in `liigure 6. Shell 21 is closed by a threaded plug ||2 having a threaded central aperture through which passes the threaded bellows adjustment post ||3.

As illustrated in Figure 13, the bellows adjiustment locking spring 58 is arcuate in shape and is secured -at one end to plug ||2 by suitable screws n||4 or the like.

Thev lower end oi.' lever 94 abuts against a stem ||5 which is slidably mounted in a guide bore ||5a passing through ring |02 and element |0| into a recessed portion of base 98 where-it is `provided with an integral upstanding lug I lli for abutting the end o1 needle valve 86. Lug H0 is alsoformed to cooperate with the recessed portion of base 98 to prevent rotation of stem ||5 about its axis.

A pair of elongated bolts Ill pass through flange |04, ring |02 and base 98 to secure the Degasser unit to the carburetor wall as above described.

The operation of the unit of Figure 9 is substantially thesame as the bellows type above described. A passage ||8 leads from boss 99 to subject the left side of the diphragm (Figure 9) to different pressures dependent upon the operation of the engine.4 Straight line movement of the diaphragm button or lever 94 is insured by the sliding iit of cap |06 within borel|05.

'I'he embodiment' of the invention illustrated in Figures 14-1'7 is a springless unit wherein a housing ||9 is provided with a hollow boss |2| adapted to iit within recess 29 ,in the conduit wall of the carburetor so as to be in communication with the intake manifold. Bolts or screws |20 secure housing I9 rigidly to the conduit wall.

The open end of a ilexible metal-walled bellows |22 is secured, by means of screws |23 and suitable gaskets, in gas tight relation to the left wall of housing I9 and a. passage |24 leads from boss |2| to the interior of bellows |22.

Housing ||9 has secured thereto an aligned shell |25 by means of screws |26 passing through mated ilanges of the housing and shell. The outer end of shell |25 is closed by a threaded cap |21 provided with a central boss |28 which is threaded to receive an adjustment screw |29 whose inner end is threadedly engaged with a suitable block |3| rigid with one end of a iexible sealed bellows |32.

Screw |29 and boss |28 are provided with cooperating serrated locking surfaces at |38 and boss |28 is apertured to permit insertion of a sealing wire |34 to prevent unauthorized tampering with the adjustment of screw |29.

Bellows |22 and |32 are preferably of substantially the same size and characteristics, having equal external eective areas exposed to atmospheric pressure and are interconnected by a rigid post |35 which is preferably integrall with their adjacent end caps 22' and |32'.

Opposite side walls of shell |25 are shouldered at |36 and provided with aligned pivot pins |31 for receiving a pair of opposed arms |38, which are bent downwardly and inwardly and are each slotted at 4| to fit over oppositely projecting end portions of a pin |42 rigid with post |35.

Below post |35, arms |38 are bent together and riveted or otherwise integrally secured at |39 to provide a suitable lever extension |40 for abutting the end of a stem |50 slidable within a suitable longitudinal bore 50a in housing 9. The outer end of the stem |50 is adapted to engage the valve stem 98 of Figure 6, or may engage the plunger stern 68 of Figure 1 as desired, it being understood that lever |40 in the latter case is pivoted to rotate as lever 64 of Figure 1.

Shell |25 is provided with a recessed integral extension |43 for accommodating the lower end of lever |40 and this extension is provided with a threaded Wall plug |44 aligned with stem 50. Should the valve seating faces of plug 14' which cooperate with needle valve 96 become worn or encrusted with dirt or other foreign matter, the valve can be quickly reseated by taining out plug |44 and tapping the end of stem |50 with a suitable tool to thereby forcibly thrust the conical end of needle valve 96 into seat 96a and thereby efiectively reform the valve seat. If stem |50 should become frozen or sticky in operation, plug |44 can be removed and anysuitable tool inserted to force the stem axially along its guide until it is loose. It is to be understood that a plug as shown at |44 may be used with any of the modications herein shown.

In operation, the ilexible walls of the bellows |32 act as resilient means for urging lever |40 in a counterclockwise direction and screw I 29 is adjusted until lever |40 is just in engagement( Automatic temperature compensation The device illustrated in Figures 18 and 19 is preferably designed to be used with a pressure compensating control of the type illustrated in Figure 14 but it will be understood that it may readily be applied to any of the other embodiments of the invention.

A pair of mated housing and shell members ||9' and |25', respectively, are secured rigidly together, as by spaced bolts |26'. A bellows |22' having walls of thin ilexble metal is secured in iluid tight relationupon an end Wall of housing H9'. A passage |24' leads from hollow boss |2| to the interior of bellows |22', and boss |2|' is designed to t within recess 29 as above described.

A second bellows |32 having walls of thin ilexible metal and being of substantially the same shape and size as bellows |22' is adjustably supported upon a removable end plug |21' of shell |25' by means of a suitable adjustable support |29 which is preferably the same as screw |29 described above in connection with Figure 14.

Bellows |22 and |32 are somewhat shorter than bellows |22 and |32 of Figure 14, but are similarly interconnected by a rigid axial post A diametral pin |52 extends through post |5| with its opposite ends projecting a substantial distance beyond post |5i.

An elongated pin |53 extends across the upper part of shell |25 generally parallel to pin |5| and preferably in vertical alignment therewith. The opposite ends of pin |53 project outside the shell and are preferably burred to prevent accidental displacement of the pin.

A temperature responsive lever |54, which is preferably a generally Y-shaped bimetallic strip (Figure 19) has the end portions of the arms of the Y curled about the opposite ends of post |52 at |55 so that lever |54 is rotatably connected at one end topost |5|.

From pin |52 the arms of the Y extend upwardly past one side of pin |53 and then curve around and downwardly past the other side of pin |53. Below post |5I, the arms of the Y are brought together to form a single leg |56 which is inclined outwardly and downwardly .to contact the inner end of valve stem |50 as illustrated in Figure 18. Pin |53 thereby serves as a fulcrum for lever |54 and the spacing of pins |52 and |53 as well as the length of lever |54 can be selected to give any desired mechanical advantage. Lever |54 is Y-shaped to clear post |5| as the former rocks about its fulcrum and the above described structure provides substantially a lost motion connection between lever |54 and fulcrum pin |53.

If no temperature compensating means is employed, expansion of bellows 32 due to heat from the engine will shift post |5| an appreciable amount to the lelt since bellows |32 expands faster and more in response to temperature rises than shell |25. This would cause premature cut-off of the idling fuel supply during operation of the engine.

In the above described embodiment, because of the fact that the whole of lever |54 or the lower part comprising arm |56 is made up as a bimetallic thermostatic element of any well known form with the strip having least expansion due to heat located on the right side of arm |56 or the inside of the loop formed by lever |54 in Figure 18, when heated, lever |54 bends in such a manner as to displace arm |56 to the right in Figure 18. The parts are so proportioned in length, shape and position that this displace ment of arm |56 to the right in Figure 18 compensates for any movement of post |5| to the left due to expansion of bellows |32 and there is no relative movement between arm |56 and stem |50 due to temperature changes. In a correct design, one movement offsets the other.

A device of this kind has been operated in an advantageous manner under conditions involv ing a change in altitude of `,approximately 7000 feet and a difference in engine temperatures of approximately 150. During these tests, the operation of the Degasser took place within a vehicle speed range of 2% miles per hour.

Howeverl since the "Degasser" operated on a cold engine at vehicle speeds which were 21/2 miles per hour higher than those at which it operated on a thoroughly warm engine, this slight change of operation at low temperatures is quite advantageous in that it assists speedy warming up of the engine and prevents the motor from able plunger having becoming too cold while the vehicle is traveling down long grades as to interfere with operation of the motor when the bottom of the grade is reached.

The above described Degasseryy units are especially adapted for use with throttle controlled Degasser systems as above pointed out and are operable upon any desired type of valve mechanism in the idling fuel supply passages.

In each unit, the eiect of varying atmospheric pressure due to any cause is automatically compensated so that uniform operation of the Degasser is insured.

It is now common practice to install Degassers on trucks and buses which make long hauls because of the tremendous savings in gasoline and the advantageous operating conditions, and the presen-t invention insures that these vehicles will operate just as eiiiciently in mountainous and desert regions as on the more level and more temperate routes.

It is to be understood that the various bellows control units are not limited to use in the Degasser control field but may be used for controlling any valve whose operation is affected by variations in atmospheric pressure or temperature. 'I'he invention is especially adapted for use in controlling the fuel supply to airplane engines where abrupt changes in altitude constantly take place and where it is absolutely necessary that the fuel supply control be accurate, dependable and eiiicient in operation.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a compensating device for controlling the operation of a fuel supply restricting means in a carburetor or the like, a deformable pressure actuated element; a fuel supply valve operating lever controlled by said element; a spring connected to said element at one end for governing the action of said element;' an expansible sealed bellows swivelly connected to the opposite end of said spring and means for adjusting the tension of said spring.

2. In a carburetor having a passage through which fuel is drawn by suction to an engine when the engine throttle is in idling position, a port 1n said passage leading to the atmosphere; a closure member for said port comprising a slida sealing face of brous or like material for cooperating with the edges of said port to form a normally uid tight joint; resilient means normally urging said member away from said port; means for retaining said member over said port against the action of said resilient means; pressure responsive means for renderingr said retaining means inoperable upon said member whereby sai-d member is forced away from said port by said resilient means to admit atmospheric pressure to said passage and thereby cut off the iiow of fuel due to suction.

3. In combination with a carburetor having a passage adapted to be connected to the fuel intake of an internal combustion engine, a throttle 1n said passage; means for supplying fuel to said engine when the throttle is in idling position comprising an idling :let positioned to discharge fuel into said passage at a point posterior of said throttle; pressure responsive means responsive to suction in said intake manifold controlling said fuel supply; and means for automatically regulating said pressure responsive means to compensate for changes in temperature and atmospheric pressure to which said pressure responsive means is exposed to insure correct operation of said pressure responsive means.

4.111 a carburetor having a passage adapted to be connected to the fuel intake of an internal combastion engine, a throttle in said passage, an

idling iet positioned to discharge fuel into said l passage at a point posterior of said throttle, a valve for controlling fuel iiow through said idling jet, a pressure responsive device for operating said valve comprising a pressure responsive element,

resilient means to oppose movement of said ele- M ment in a direction to close said valve, and. a control lever pivotally connected to said pressure responsive element and connected to operate said valve or like means, said lever comprising a thermo-responsive element.

5. In combination with a carburetor having a` passage adapted to be connected to the fuel intake of an internal combustion engine; a throttle in said passage; means for supplying fuel to said engine when said throttle is in idling position comprising an idling jet positioned to discharge fuel into said passage at a point posterior of said throttle; and pressure operated means responsive to vacuum in said intake manifold to control said idling fuel supply from a full opening-to a full closure, said pressure operated means being arranged to shut oft said idling fuel supply at a lower predetermined vacuum at a predetermined temperature of the ambient atmosphere corresponding to the temperature of the engine when cold than at an ambient atmospheric temperature corresponding to the normal operating temperature of said engine.

thin-walled metal support rigidly secured at one.

end to said carburetor, an interior end wall at the free end of said support and a sealed bellows rigidly secured at one end to said interior end wall so that expansion of said support and said beilows due to heat from the ambient atmosphere will take place in opposite directions and in such amount esto automatically compensate for the effect of changes in the temperature of the ambient atmosphere upon said pressure operated means, said lever comprising a thermostatic strip to compensate for the temperature changes.

7. In combination with a carburetor having a passage, a throttle in said passage, an idling jet in said passage posterior of said throttle for supplying fuel to said engine during idling conditions, means for valving the ow of fuel through said idling jet from a complete shut-off to a complete opening, apressure responsive element operatively connected to the intake manifold of said engine and means including a lever interconnecting said valving means and said element, said lever comprising a thermostat strip deformable in response to temperature changes to vary the eect of said element on'said valvng means at different temperatures.

8. A valve control device comprising a houslng having opposed Walls, a deformable bellows secured on one wall and provided with a conduit connecting it to a source of fluid pressure, a second deformable bellows adjustably mounted on the opposite wall, 4a, rigid member interconnecting adjacent ends of said bellows, a pivoted lever within the housing operatively connected to said rigid member and a slidable valve control rod adapted f to be actuated by said lever.

WILLIAM E. ALEIBING.

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