US1258153A - Carbureter. - Google Patents

Description

S. SHAW.

CARBUFIETER.

mmcmmu mu: DECS. x915.

Patented Mar. 5, 1918 2 SHEETS-SHEET l.

S. SHAW.

CABBUHETER wmcmlon FILED 020.6.1915.

1,258, 1 53 Patented Mar. 5, 1918 2 SHEEYS-SHEET 2.

, useful Inigirovements in .mary air inlet to y con STILLMAJM SHAW, 0F NATICK, MASSACHUSETTS,

ASSIGNOR TO MU LTIUNE CARBURETOR COMPANY, A CORPURATION 01* MAINE.

QABBURETER.

Application filed December 6, 1915.

To an 1U/L077Z it may concern Be it known that I, STILLMAN SHAW, a citizen of the United States, and resident of Natick, in the count I of Middlcsex and State of Massachusetts, ave invented new and Carburetors, of which the ollowing is a specification.

y invention relates to carbureters for in ternal combustion engines, and has for its main object the provision of properly regulated proportions of fuel and air to the engine through all degrees of rate of supply between the minimum and maximum limits of carburetor capacity. Other objects of my invention are the elimination of the mechanical complications which accompany the use of springs, valves, and other sensitive moving parts, and the obtainment of etliciency and economy by the aid of simple, structurally strong, and positively actuated moving parts.

The cardinal characteristics of my improved carburetor are: a box-like conduit, with two opposite sides which approach each other from a relatively wide primary air inlet to a. point of minimum interior Width of the conduit. and recede angularly from each other from said point of minimum interior width toward the delivery end of the conduit. the elements of these double-trig pered sides being parallel with each o her in the direction at; right anu'les to the axis of the conduit. which extends from the prithe delivery end; a piston member, fitting between the, double tapered sides of the conduit and extending to a substantial distance on either s de of the point of minimum interior width of the coiiduit, and sliding between and in contact wfththc double tapered sides, in a direction at right angles with the axis of the conduit; a lineally extended liquid fuel inlet which enters the conduit at or close to the point of minimum width thereof, and which is controlled as to extent of opening by the movable piston member.

he piston member is mom'ited on and controlled by a rigidly connected piston rod, so that simple. positive connection with said rod or bar sufiices to move the piston memher in the conduit, to increase or decrease its capacity. The shape and extent of the conduit, and that of the piston member are such that at whatever position of the piston, the

cluit constitutes a regularly tapered duct,

Specification of Letters lfatent.

Patented Mar. 5, 1918. Serial No. 65,234.

of 'UGIMZ contradic form, of such extent inits axial direction that the said oena contracta form is not. interrupted or vitiated, and so that the stream of gaseous mixture components flows smoothly through the entire length of the conduit, Without eddy d1sturbance.

Preferably also, there is provided an auxiliary air inlet, lincally extended in the dircction or the piston movement, in the side of the conduit and within the surface against which the piston makes sliding lit, and as near practicable to the end of the conduit, so as to disturb and qualify as little as possible the regular "renacontracta shape of the conduit as a Whole.

The only necessary moving member of the carbureter is the piston-like member above generally described. The air and fuel inlets will extend in a direction parallel or substantially so, with the movement of the pieton-like member, so that by movement of said member the exposed and effective areas of the three inlets (two for air and one for fuel) are simultaneously increased or diminished. The configuration of the mixing chamber or duct will be such, that its principal longitudinal section, 2'. e. in the direction of flow of positions of the moving member. The fuel inlet should, for the best effects, be placed between the primary air inlet and the secondary or auxiliary air inlet and at the throat or narrowest part of the conduit.

In the drawings hereto annexed, which exemplify in specific form the invention more generally described abov'e,--

Figure 1 is a vertical cross; section of a earhureter;

Fig. 2 is an end elevation of the pistonlike member of the carburetor.

Fig. 3 is a horizontal section at the line Fig. l; and

Fig. 4 is a vertical longitudinal section through the mixture chamber or duet of the carburetor, showing the movable piston memben' in side elevation.

The casing of the carburetor comprises float chamber A and the mixture chamher (I. A float, B, in the float chamber, is provided to control the supply of volatile fuel in the usual manner.

The mixture chamber or duct C of a box, having a. cross section consists of com fluids, is substantially uniform and unchanged In its essential contour at all contractor form, the sides of the box being parallel to the direction of movement of the iston member I). This box is open at the ottom at F, and communicates at the top with a conduit 1-1, which leads to the en me.

*itting between the sides of the box 0 and extending from the air inlet to the delivery end thereof, the movable piston member D is mounted to slide back and forth in the box C. The piston member D thus conforms in contour and extent to the longitudinal section of the box, (if. c. section in the direction of flow) or mixture duct C. To enable the piston member D to slide smoothly without chattering or sticking, it is provided with an extension D which acts like the cross head of a piston rod, sliding on the inner surfaces of the mixture duct or box 0, as on slideways. A bar D, provided with rack teeth D, is secured to the piston member D, and may be actuated by means of a toothed segment E and control rod E. The primary air inlet is at F, the secondary or auxiliary air inlet is at I. The latter is a slot or aperture in one o the sides of the box C The fuel inlet consists of a number of individual ducts G, each of which communicates with the liquid volatile fuel in the float chamber A. The apertures of these ducts lie in a line preferably in the plane of minimum cross sectional area of the mixture conduit, so as to be subjected to a maximum inductive influence by the stream of air flowing throu h the mixture duct C.

The operation of t e carburetor above de scribed is as follows: The extension '1') of i the piston D, when the piston is at its ex tremefiosition of closure, servesto close the i e against ingress of any gas. The initial movement (to the left as viewed in Fig; 4) of the piston member D simultane ously unmasks one of the liquid fuel inlets G, and.an initial area of the primary air mary air inlet F, more and more the fuel inlets G, and also (after the first stage of opening is passed) more and more of the secondary or auxiliary air inlet I.

of the piston member D. carbureters of this character, under practical In the carbnreter shown in the drawings, the sides of the primary and secondary air inlet apertures are parallel, and the fuel apertures G are all of the same size, so that the three inlet areas increase or diminish in direct arithmetical ratio with the movement l ixperimcnt with engine conditions, has led to the adoption by me of this preservation of direct ratio as, on the whole, productive of the best results Possibly under conditions outside of my personal experience, it may be found advisable to change these ratios by changing the shape of the three inlets, or of. some or more of them. It will be observed, that variation in capacity of the mixture duct takes place without. substantial variation in the sha e of the duct in the direction of flow. n effective contour being adopted, the beneficial results therefrom persist through all variations in capacity.

I claim:

1. In a carbureter, a conduit having sides the elements of which are paralleltin a direction transverse to its axis, and tapering to a throat from the air inlet end and mixture delivery end, forming a duct of regularly tapered 'vena contracto form, a

iston member substantially corresponding in contour and extent to the chtire oena coniraczfiaconduit, and movable transversely to the axis of said conduit, the conduit provided with a fuel inlet at the throat, lineally extended in the direction of movement of the piston member.

2. In a carbureter, a conduit having sides the elements of which. are arallel in a direction transverse to its axis, and tapering to a throat from the air inlet end and mixture delivery end, forming a duct of regularly tapered oe'na contracta form, a piston member substantially corresponding in contour and extent to the entire 'vena contmcta conduit, and movable transversely

Images