US1071003A - Carbureter. - Google Patents

Description

T. J. B. DRAYTON & F. K. WOODROPPB.

CARBURBTER.

APPLIOATION FILED MAR. 1, 1913.

Patented Aug. 19, 1913.

s SHEETS-SHEET 1.

Zh/Venier@ I CIB. Ural/Zark E.W0ooZz'jfe Wbtorney T. J. B. DRAYTON & F; K. WOODROFFE.

GARBURETER.

APPLICATION FILED MAR.1. 1913.

Patented Aug. 19, 1913.

3 SHEETS-SHEET 2.

25:2 EEE Wiorney i Fbo rn ey Patented Aug. 19, 1913.

z'jf.wooclrojje T. J. B. DRAYTON & F. K. WOODROFPE.

CAB-BURETER.

APPLICATION FILED MAR.. 1. 1913A With/eases sanare ramena unica.

THEOPHILUS JAMES BRADLEY DRAYTON AND FRANK KNIGHT WOODBOFFE, 0F LIVERPOOL, ENGLAND.

CARBURETER.

Specification of Letters Patent.

Patenten aug. is, isis.

To all whom, @'15 may concern.'

Be it known that we, THEOPHILUS JAMES BRADLEY DRAYTON and FRANK KNiGH'r lVooDRorrE, subjects of the King of England, residing at Tower Building, Water st-reet, Liverpool, in the county'of Lancaster, England, have invented new and useful Improvements in Carbureters, of which the following is a specification.

This invention has reference to carbureting air, that is to say, introducing into or charging a body of air with a quantity of hydrocarbon vapor or atomized liquid, such as that of petrol or other spirit, or hydrocarbon oil, for the purpose of forming a combustible mixture; 'and it relates to 1mprovements in connection with carbureters such as those used for internal Vcombustion engines or other purposes, by which the proportions of air and fuelspirit or oil-by weight, and which the apparatus may be set to furnish, are maintained constant under differing temperatures of the atmosphere.

In the following description of carbureting apparatus and mode of effecting the carburetion, the improvements hereunder are comprised; and in the accompanying drawings, in connection with which the escription is made, these improvements are illustrated; while, as regards the novel features claimed in respect to the invention, these are set out in. the claims concluding the specification.

In the drawings Figure 1 is a sectional elevation of the apparatus, and Fig. 2 is a transverse vertical section taken at the line A A Fig. l. Fig. 3 is a sectional elevation showing in section a part of the apparatus given in Figs. l and 2. Fig. 4 is a section showing a modified construction and arrangement of parts of the apparatus. Fig. 5 is a detail section through certain parts shown in Fig. 3.

The liquid fuel, say oil and spirit, with the vapor of which the air is to be charged, together with a proportion of the total possible air to be supplied, is introduced 0r injected into the carbureter apparatus at a point separate from the secondary supply of air, and is delivered under practically constant degree of pressure, z'. e. vacuum; and the quantity of air in the secondary suppl)7 is cont-rolled or governed automatically by a regulating or controlling device which is actuated by the varyingl temperature of the atmospheric air; it being so arranged and adapted, that the volume of air admitted will vary according to the variations of temperature, but the Weight of air so admitted willremain practically constant for any given speed of revolutions of the engine or machine; and hence the degree of carburetion or charging of the air, or the proportion of air and hydro-carbon will remain constant always, after it has been determined what proportion is required, and the apparatus has been set to give this Proportion. This governing of the air and supply of constant weight is effected by the employment of a conical air conduit, and a disk within it, which receive movement in relation to each other in the direction of the axis of the cone, by means of the regulating or governing device referred to; so that the annular area through which the air passes between the disk or body and the cone, will vary as the relative positions of these parts differ, or are caused to differ by the action of the temperature actuated regulating device. The secondary air inlet in this apparatus will be arranged on one side of the throttle valve, and the liquid jet on the other; and the conduit to the engine or motor or machine will be between the throttle valve and such m07 tor, so that the degree of vacuum which is produced in the engine or machine andv leii'ects the intake of the oil and air, will not 2 is the conduitv conveying the combustible ,100

mixture which is made about the petrol jet, to the conduit l and which is normally in communication with this conduit. The conduit or passage is preferably surrounded by an annular passage 2X which may be connected with t-he exhaust gases or with thc water cooling apparatus so as to heat up the conduit 2 and assist in the more effective volatilization of the petrol or oil.

3 is a rotary throttle valve; and 4 is a disk or valve, and 5 is a movable cone within which the disk works, by and through which the main quantity of air issupplied, and by which 4it is controlled or governed,l and a constant ratio of weight of air to spirit or oil supplied, is maintained; the movement of the cone, in this arrangement, being effected by the varying temperature ot' the atmospheric air, by the apparatus hereinafter described with reference to and shown in Fig. 3. Fxcept when the throttle valve is moved in the direction of the arrow, so as to cover the upper end of the conduit 2 (when also the port 50 will beA covered), and air alone `is being admitted, as hereafter de-A scribed, to the engine through the port 52, the conduit 2 is permanently directly open to the inlet passage 1; and therefore normally the liquid fuel and main air supply ports are on the engine intake side of the throttle valve; and the secondary air supply'valve 4 is on the op osite side of the throttle valve to the said liquid fuel and main air supplyv ort. p The movement of the apparatus operated by the varying temperature of the atmosp iere, is transmitted to thev cone 5 by a pivoted lever 6, one end of which is operated bythe device shown in Fig. 3 and the-other is connected to the cone 5 by a pin 7, lwhich passes through it, asseen in Figs. 1 and 2.

The throttle valve 3, as willv beseen by the drawing, is between the main. air supply mechanism, and the-conduit 2, through,

which the combustible mixture from the liquid fuel jet ,portion ot the carburetor, passes into the conduit 1.

' In the case shown, the petrol jet device is of the single type, namely, it consists of a single nozzle 8, situated at the bottom of the conduit 2, the effective supply orifice of which is regulated by a needle or spindle 9, which is movable and operated in the manner explained herein; while air is admitted' to the conduit 2 through an annular space in the bottom of this conduit, around the nozzle. In the bottom of the conduit 2, there is a short coned choke tube 10, by means of which the annular stream of air entering the conduit 2, converged toward the orifice of the nozzle 8, and absorbs into itself the spray of petrol or oil from the nozzle. The air to the lower `end of the conduit 2 enters from a chamber 11 below, which will be suitably provided at the inlet openings 11L in it for the air, with a gauzeV or like strainer 111.

The automatic temperature regulating device shown in Fig. 3, consists of a reservoir 18 and a flexible diaphragmatic device 14 connected to it, and contained within a casing 15, placed directly over the ordinary float chamber 16 governing the supply of liquid to the carbureter. Both the receiver 13, and the fiexible diaphragm 14, are completely filled with a liquid having a suitable narines range of expansion within ordinary atmos plieric temperature limits-such as alcoholand hermetically sealed.

The reservoir 13 has practically rigid `walls and will maintain its volumetric capacity practically unchanged, so that any change in volume of the liquid acts upon the walls of the liexible diaphragmatic device 14, and causes them to expand apart or contract together; and this motion is transmitted by the lever G to the coned device 5, the short end of the lever fitting in a fitting 17 on the upper side of the diaphragmatic device 14, so that the expansion of the device 14 effects the movement of the lever 6 in one direction, while its return motion is effected by the spring 18 within the tube 1S) on the case 15, and acting on the opposite side of the lever 6, to the device 14. As regards this automatic temperature regulating device, it isrto'be stated, the invention is not restricted to that shown and described, as in place of it a Bourdon tube type of pressure regulator, or other known kind of device, wherein the expansion or contraction ot fluids, or solids, is adapted to transmit the motion thereof, for the purpose in question, could be employed. 1With regard to the main air supply controlling means, 4, 5, the upper end of the cone 5 slides or works ina ring guide within thevmai'n cas-v ing `20; and its lower end covers and works outside an upwardly projecting 'tube 21, the

lower part of which is in communication with a chamber22, to which airenters from openings in, its side walls, and which'open* ings are provided with a gauze screen 23.

The disk or valve 4, when not in action,v rests on the upper edgev of the seat of the inlet tube 21'; while when in action, it. is lifted 0E the seat, and according to the degree of subatmospheric pressure above it, and the volume or"- air'passing between it and the tube' 5, so will be the position of it within the tube. The disk or valve 4 op erates in connection with and upon the liquid jet regulator needle 9, through a rod 25, adjustably fixed in the lower stem 27 of the disk 4, and a lever 28, pivoted at 29 to an adjustable pivotcarrier fork 30; and having its long arm passed through a loop 25a in the rod 25. The short arm of this lever acts on the lower end of the needle 9 and raises it, and allows it to fall; and thus, as the disk or valve 4 rises and falls, so will fall 'and rise the regulating needle 9, and admit more or less liquid through the nozzle 8. The petrol or oil is supplied to the nozzle 8 from a chamber 31, within which the rod 25 and lever 28 are disposed, and which is connected to the oil supply branch 32 from the bottom of the float chamber 16. rlhe oil or spirit flows from the chamber 16, by grooves and holes formed in a plug 35E formed on the bottom of the chamber 31,

and tted into a hollow boss, on the end of the conduit 32. |The motion of these partsnamely the disk 4 and needle 9 in the nozzle 8, is governed by a disk 85 on the rod 25, working in the lower portion of the chamber 231, and acting as a dash-pot to the moving parts.

The fulcrum carrier fork 30 is mounted on a spindle 36, which screws through a plug 37 fitting in one end of the chamber 31; and by rot-ating this plug 36, by a milled head or the like on the outside of the chamber, the fork carrier 30 and the pivot 29 are moved in relation to the needle valve 9, and so, the ratio of movement of the latter to the movement of the air valve disk 4, is readily altered and adjusted.

The relative length of the rod 25 between the disk 4, and the lever 28, is adapted to be altered, and the angle of this lee ver changed, so that as this relative length of the rod 25 is shortened by moving it up toward the valve 4, the short arm of the lever 28 is lowered, and the needle valve 9 falls, so increasing the annulus for the supply of liquid around it. `The reverse movement and adjustment of these parts reduces the supply annulus but never closes it, beyond a fixed and determined amount- Vith regard to the means of eli'ecting this lengthening and shortening of the rod 25, between the disk 4, and the loop in the rod through which the long end of the lever 28 passes, the upper stem 40 of the disk or valve 4, is passed through a hollow guide 41, which is carried by the cover plate 42 of the casing 20, and is rotatable therein, it being held in position and capable of being secured and locked therein by means of the nuts 48, 44. The lower end of the guide 41 through which the stem 40 passes will have a key or the like, which enters or engages with a groove or fiat formed in or on the stem 40, and s0 that the rotation of the guide 41 will cause the rotation of the spindle or stem 40 and the valve; and thus, by this rotation, the internally threaded lower stem 27, which screws over the externally threaded upper end of the rod 25, will be rotated and will either draw the rod up, or move it out downward, and so shorten or lengt-hen it. Hence the who-le adjustment and setting of t-he lever 28 and needle 9, can be effected from this upper end of the apparatus.

The operation of the carbureter is as folllowsz-Assuming the throttle valve 3 to be in such a position that the air inlet passage 50 from the secondary air governing device is closed by a solid portion of the throttle valve, and only the conduit 2 is open to the intake conduit 1 to the engine, the working of the engine-or machinewill draw air into the conduit 2, past the petrol jet nozzle 8, at a high velocity, and

por cannot exceed a certain small amount,

relative to the total amount which is possible to be drawn in owing to the area of the choke tube 10 around the jet nozzle 8, and forms a delinite proportion to the total volume of combustible mixture, which is required to be introduced into the engine-or machinewhen working at its highest speed. This small amount of combustible mixture is preferably such as will work the engine at a low speed, so that when the secondary air supply from the conduit or port 50 is cut off by the throttle valve 3, the secondary air regulating disk or Valve 4, will be at its lowest position, and the petrol needle 9 will be at its highest position, and supplying the smallest quantity of petrol; and this quantity of petrol will be in the proportion to the air which will be introduced into the conduit 2, to form the required quality of combustible mixture. To supply a larger quantity of combustible mixture, the throttle valve 3 is opened more or less in the usual way, and opens the secondary air supply port 50, whereupon the suction or subatmospheric pressure above the disk 4 will cause outside air to lift it, and pass in an annular stream between its edge and the interior surface of the cone 5, and the disk will float within the cone at a height proportionate to, and determined b v the low of air passing it. Any further opening of the throttle valve causes the disk 4 to take up a position higher up within the cone 5; while closing the throttle causes it to fall.

The rise and fall of the secondary air inlet disk 4 is communicated to the needle valve 9 as described, and the area of the petrol jet is increased or reduced in proportion to, and simultaneously with, the alteration in the position of this valve or disk 4. Hence the flow or quantity of petrol or oil is in proportion to the flow or quantity of air supplied, so that the quality of the oombustible mixture supplied to the engine as a whole, is maintained at that required. l/Vith regard to the feature of the varying quantity, but constant weight of this air, being supplied between the disk and the cone for each or every position of the disk vertically in the cone, as the temperature increases, the position of the cone 5 will be lower relatively to the seat or zero position of the valve or disk 4, since this rise has caused expansion of the diaphragm of the regulating device, and the depression of the lever 6 at the point of connection with the cone 5; and, conversely, as the temperature the disk t, the eiiect of this regulating action yof the cone 5, is to increase, or reduce, the

area of the annulus formed between the periphery of the 'disk and the interior of the cone, and so permit an increase in the volume of air passing the disk or valve when the atmospheric temperature is higher, and a reduction in the volume when the temperature is lower.

Since the Weight of a given volume of air is smaller when its temperature is higher,v

and conversely, greater when its temperature is lower, it is evident that aroper proportioning and arrangement o the parts Will compensate for this variation; and the Weight of air passing the valve 4 under any given degree of minus pressure created by the engine in the conduit 1, and port 50, vvill be equal, for equal time periods, at any atmospheric temperature, and irrespective of changes in same. If the throttle valve 3 is rotated in the direction of the arrow, so as to lcover the upper end of theconduit 2, and also the port 50, another air inlet port 52 will be opened, and atmospheric air will be permitted to be dravvn into the engine cylinder for cooling and scavenging it, asand' when desired.

By this invention, complete combustion of petrol 0r oil is assured, by creating and con-' stantly maintaining the proper, relation of the Weight of petrol to the Weight of air in the gaseous mixture supplied to the engine, irrespective'of the temperature of theair; this beingaccomplishe by -the regulation of. the Weight of the secondary air supply to the engine, to thatpf the petrol by or,

according to the varying temperature of the air; Whereas Wlthout s-uch variation y and adjustment, the volume of air passed through the apparatus is equal for equal time periods, as the velocity of the flow of air passing through an orifice under any constant suction effect or minus pressure Will be constant; but since the Weights of equal volumes of air vary according to atmospheric temperature, it is obvious that the weight of air delivered under the above conditions, varies as the temperature is higher or lower, and hence, by this invention, the above effect is maintained. With a constant air velocity the delivery of petrol through the jets or orifices of similar construct-ion, and equal area, Will be equal for equal time periods, but Will vary both as the velocity of the air varies, and as the area of the jet or orifice varies.

The suction effect created by engine or machine, varies according to its speed of rotation, and consequently-changes the veloc-.

narines engine or machine, will vary in respect of l. The speed of rotation of the engine. 2. rlhe effective area of the air inlet orice. 3. rlhe elective area of the petrol jet or orifice. 4. The temperature oif the atmosphere. 5. The specific gravity or density of the petrol or oil.

Neglecting the last variable-since correction of this is readily performed, and assuming an oil fuel of approximately constant specific gravity' is used, to automatically adjust and maintain the relations of the three variables Nos. 2, 3, and 4:, to a necessarily varying speed of rotation of the engine hasbeen-the object of our invention, and is accomplished by it; and in and by this invention, the velocity of the air into the conduit 2, past the jet nozzle 8, is practically constant from the lowest to the highest speeds of the engine, and the velocity of How ot' the petrol through the jet is therefore constant.

As above stated, the smallest area of the petrol jet is determined and fixed suitably for the lowest speed of Working of the engine, and is automatically increased as the speed of the engine is increased; and therefore the Weight of petrol delivered is proportionate to the engine speed. VZhile, also,

the area of the orificeadmitting air past the petroljet, is iXed suitably for the lowest' engine speeds; and the further lair supply is governed or controlled 'by the suction etfect or degree of sub-atmospheric pressure created by the higher engine speeds acting upon the valve or disk 4,V and the movement of this valve or disk 4, is, as above described, communicated to` and controls the area of the petrol jet; and the area for flovv of air is in consequence always in a fixed relation With the area of the petrol or oil supply orifice; and by means'of the movable cone 5, and the operation of the disk 4 in conjunction With it, this relation ofthe Weight of petrol, and the Weight of air is fixed and definite at all speeds of the engine, at all usual atmospheric temperatures; and the correct mixture by Weight of petrol or oil and air is maintained, and complete combustion obtained, Without the loss and Waste incident to and inherent With mixtures depending on volumetric measures.

In the modification shown in Fig. It, the chief alteration is that in respect of the lever 28 shovvn in Figs. 1 and 2; namely, instead of the lever, there is employed a part 28 in the form of a cone, on the rod 25, which acts directly on the needle 9 of the petrol supply nozzle 8; the conduit 2 through which the primary and minimum combustible mixture passes, being in this case curved, and the spindle 9 disposed at a more or less Aacute angle to the axis of the'rod 25. In

increasing or reducing the distance between the cone 28) and the secondary air valve or disk 4, similarly as in the former cases described.

What is claimed is l. In a carbureter in which the uids are moved by sub-atmospheric pressure, the combination of a part comprising a liquid fuel supply device having an induction conduit, and a main air supply device; a secondary air supply part-having means actuated by the air moved by the sub-atmospheric pressure-adapted to vary the volume of air supply for different atmospheric temperatures, whereby a constant weight of air over a given degree of movement is maintained; and a throttle valve disposed between the secondary air supply part, and the gaseous or combustible mixture supply part; the latter being in normal communication with the induction conduit of the apparatus; substantially as described.

2. In a carbureter in which the fluids are moved by sub-atmospheric pressure, the combination of a main liquid fuel and air supply; a secondary air supply means; a controlling means as referred to adapted to be actuated by the varying temperature of the atmosphere, and adapted to control or govern automatically the said secondary air supply means, whereby the weight of air per unit of time admitted to the secondary air supply part remains practically constant for a given degree of sub-atmospheric pressure; substantially as described.

3. A carbureter wherein the carburet-ion or production of combustible mixture is effected by suction or sub-atmospheric pressure, wherein a constant weight of air per unit of time delivered by a given degree of suction or sub-atmospheric pressure, is effected by a conical conduit, and a diskor body within it, one of which parts receives movement in relation to the other, and is adapted to be adjusted in relation to the other, and set according to the variation of the temperature of the atmosphere, so that the area through which the a1r passes between the disk or body and the cone will vary as the relative positions of these parts differ or are caused to differ, by the adjustment or setting of the said part; substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

TAHEOPHILUS JAMES BRADLEY DRAYTON. FRANK KNIGHT WOODROFFE.

Witnesses: v Y

HAROLD CECIL HoDGsoN, PERCY G. JONES.

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