US1078591A - Carbureter. - Google Patents

Description

W. W.- Mum. GARBURETER.

APPLIGATION FLED FBB.19, 1913.

Patented Nov. 11, w13.

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Be it known that I,

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MARYLAND, ASSIG'NOR TO MUIR CGMPANY,

LAND, A. CORPORATION 0F DELAWARE.

WELLINGTON W. More, or BALTIMORE,

INCORPGRATED, 0F BALTIMORE, MARY CARBURETER.

Specication of Letters Patent.

Patented Nov. itl., tQf.

Application tiled February la, i913. Serial tto. 74$l,391.

To all whom it may concern:

WELLINGTON W. More, a citizen ofthe United States of America, residing at the city of Baltimore, State ofV Maryland, have invented certain nevv and useful Improvements in Carbureters, of which the following is a specilication. y This invention relates to .carbureters and particularly to a float feed carburetor of the aspirating type.

rlFhe carburetor art is one Which is developed to the highest degree. However, though it can be safely said at this time that no feature of-construction or principle of operation which is broadly new in theory is apt to be generally adopted, it is conceded thatno carbureter 110W in use produces perfect results, z'. e., that it supplies under all speeds and circumstances a mixture,'the proportions of Which are such as to give the highest eiiciency. .It will thus be apparent that if a carburetor is to be produced which gives the most eiicient mixture with corresponding economy under all conditions, this must be accomplished by a nevv'combination of features most of which, theoretically at least, and broadly considered, are individually old, and possibly by a mere refinement of detail or by new combinations of minor features or details, and the importance and scope of the invention exercised in the production of such improved device can only be Y,gaged by the result attained.

rthe carburetor which is the subject of this invention is found to give improved results, and it is believed that the applicant has succeeded in evolving a carbureter which in vits normal operation, gives automatically at eac-h speed of the engine and position of the throttle, the mixturebest adapted to the engine to which it is applied. Under these circumstances, the engine must, of necessity, develop greater power than hithertofore, and operate with increased economy. The desired result is obtained by means of a carbureter having a mainair inlet and an auxiliary' air inlet, the latter being controlled by means of a valve opened by the suction and a resilient member which tends to maintain the valve closed. it fuel nozale is placed in the constant air inlet and a fuel valve is provided for controlling the o ening at the nozzle, the position.` of Wiich' valve at all times corresponds exactly to that of and is controlled by the auxiliary air valve.

Referring more specifically to the device m question, the resilient member which tends to close the auxiliary air valve is a constant tension, non-adjustable sprin Within the carbureter and out of reach o the operator, and the connection between the auxiliary air valve and the fuel valve is accomplished by means of a cam and follower, one being rigidly connected to the air valve and the other mounted on the fuel valve, a spring or other convenient means, as the force of gravity, being utilized to keep the follower in contact with the cam, and the cam itself which is preferably on the auxiliary air valve spindle fixed as to its outline and rigidly and non-adjustably secured to the spindle, is so placed and constructed that it may be, and in fact is, in the case of each engine to which the carbureter is applied, formed to give at each particular instant the mixture with which the engine in question will operate most eiiiciently under the conditions to which it is then subjected. IThis is preferably determined by tests for each type of engine. important that the needle valve or fuel :valve is so constructed that its length is adjustable, the purpose of adjusting the length of the needle being to provide for the change of the available fuel supply relatively to the auxiliary air valve opening, as weather conditions or the volatility of the fuel vary. The adjustment of the needle which is provided makes it possible to change the length of the needle Without in any way disturbing the relation of the needle or fuel valve to the auxiliary air valve, and as has been stated, it is extremely important thatthis relation is such that the motions of the two valves correspond exactly and ythere is no pl'ay or lost motion. As the opening of the auxiliary'valve is-controlled by a spring and is proportionate to the suction, and the opening of portion to the opening of the auxiliary air valve, which itself isV controlled by `a constant tension, non-adjustable spring, it will be apparent that the proportions of the mixture under all circumstances are predetermined vvith any desired degree of precision by the outline of the cam. rl`he adjiustinent of the needle is preferably limited to the exlt is further the fuel -valve is exactly in proltltt plosive range of the fuel, sothat it is impossible for the adjustment of the` carbureter to be so changed by misadjustment that the engine will not run.

Inthe accompanying drawings, a carbureter is illustrated which embodies the important features of my invent-ion in the preferred form.

Figure 1 is a vertical central section taken on the line of the auxiliary air valve spindle. Fig. 2 is a vertical central section taken at right angles to Fig. 1. Fig. 3 is a plan of the device. Fig. 4 is a section through the fuel valve adjusting screw head and plug, taken at right angles to the axis showing the ball and groove detent.

Referring to the drawings by numerals, each of which is used to indicate 'the same or equivalent parts in the different figures of the drawing, the carbureter as shown is formed with a casing 1 consisting of a float chamber 2 and 'a mixing chamber 3. The latter has a constant air inlet 4 which in the preferred form of the device and as shown extends upward through the center of the float chamber, being constricted at 5 where the fuel nozzle 6 is placed. The latter is formed with a passage 7 which leads from the float chamber. The mixing chamber 3 in addition to the constant air inlet, has an auxiliary air inlet 8 closed by an auxiliary air valve 9 opening inward, c'. e., in the direction of the suction, and secured to a spindle 10 mounted in suitable bearings 11 and 12, the bearing 1 1 being preferably supported on the valve seat member `13 and centrally of the valve opening. A constant tension spring 14 shown as encircling the valve spindle and bearing against a suitable abutment 15 acts against the suction and tends to maintain the valve 9 closed. In addition to the openings described, the'mixing chamber 3 is provided with an outlet or throttle open-v ing 16 leading to the engine which as shown is controlled by a butterfly valve 17 or other suitable device actuated by the usual throttle lever 18.

j In connection with the preferred embodiment of the invention, I have illustrated a spring release for the auxiliary valve. However, the carbureter may be operated without this feature.

The spring abutment 15 is supported on arms 19 secured toa transverse shaft or rotating pin 20 having bearings in the walls of the chamber. This shaft 20 is provided' with a follower arm 2l which, as shown, is engaged by a cam 22 on the pivot pin or shaft 23 lof the throttle valve 17. It will thus be apparent that in the form of the carbureter shown, as the throttle valve is opened, the tension of the auxiliary valve spring is released, but this is not essential tothe operation of the other features of the device as herein described.

The valve spindle 10 is, as I have stated, l

mounted to slide in alined bearings 11 and 12 in the carbureter chamber, and the casing is so formed that the bearing opening 12 is prolonged or yextended to a considerable degree. The fuel nozzle 6 which I have described is controlled by means of a needle valve 25 which is in alinement with the nozzle, both members being, as shown, inclined upward and outward at an angle of about 45", but the exact arrangement being immaterial, the fuel valve spindle 26 being seated in an aperture 27 which intersects the prolonged bearing aperture 12 to which I have referred. The valve spindle 26 is in fact slotted at 28 in alinement with the aperture 12, and the valve stem 10 andthe valve spindle 6=are provided with coperating cam members. Preferably there isa cam 29 xed as toits outline and rigidly secured tothe valve spindle l() of the auxiliary valve and adapted' to slide back and forth in the outer end of the aperture 12 and through the slot 28; and on the needle valve spindle, secured thereto but adjustable to a slight degree, is the other cam member, shown as a follower 30 to engage and coperate with the cam member 29. The-motion of the' valve 9 is limited in this instance by the end of the valve spindle adjacent the cam 29 which in the txereme position of the valve engages A the remote end 43 of the cam aperture.

In order that the needle may beadjusted as to its effective length to vary .the opening of the fuel valve in vproportion to that of the auxiliary air valve, the needle valve spindle is formed in several parts to be described. These consist of a section of tube 31 mounted to slide in the aperture 27 and pierced by the slot 28 already described. At its lower end, the tube is closed by a plug 32 which is pressed into the end of the tube. This plug carries the needle proper 25 already referred to. The upper end of the tube is closed by means of a plug 33 centrally apertured to receive an adjusting screw 34. This plug is -also pressed into the tube and its upper end,

which is enlarged, is provided with asocket 35 to receive the head of the adjusting screw. Preferably the screw head is apertured transversely at 36 to receive a sprin 36 and a ball 36 which is spring-presse Y outwardly, and the inner face of the socket is provided with grooves 37 parallel to the axis and adapted to be enlarged by the ball to lock the -screw in adjusted position. Thev tube thus closed at the ends has a central chamber or barrel 38 in which a cylindricall block 39 isl mounted to slide. This block is pierced by t-he slot 28 to which I have referred and carries the follower 30 previously described, and by moving this block up and down the barrel 38, the effective length of the needle z'. e., the dis- CII surface' 40 of the is lifted,- e.,

l the spring 4l tance from the follower to the seating needle valve, isy varied and adjusted. As l have stated, the block 39 has a sliding fit inl the barrel 38 and is of icourse of a length slightly less than that of the barrel, t'. e., the distance between the plugs 32 and 33, and the block 39 is forced upward against the adjusting screw 34 by means of a comparatively stiff spiral spring 41. In the device shown the needle valve the follower 3d is maintained in contact with the cam 29 by means of a comparatively flexible spring 42, the tension. of this spring being less'than that of so that the latter isnot affected by t e'action of the spring 42. However, the relations `of the spring 42 and the cam 29 may be changed in an obvious Amanner, and the various equivalent structures may be Isubstituted within the scope of the invention.

ljiy observation of the structure shown, it will be apparent that the needle valve' in its present 'adjustment as shown, has its greatest length, t'. e., the edective distance between the follower 3U and the seating sun face .40 is at its maximum, the sliding block 39 being in its highest position, z'. e., restin against the upper plug 33, and it will a so be apparent that the screw 34 at its lower end 1s just in contact with the top of the plug, and the bottom face 43 of the screw head is spaced from the bottom of the socket in the plu by an exceedingly slight distance, possibly not exceeding one hundredth of an inch, and this'is the extent of the adjustment provided for. The screw can only be advanced by a distance equal to the interval between its lower face 43 and the bottom of the socket, and

the follower can only be moved downward,

and the effective length of the valve spindle or needle shortened by the same interval. A

This interval is predetermined by themanufacturer of an lextent so that it is impos sible to so throw the carbureter out of adjustment that it will notproduce a running mixture.

The operation of the device will be apparent fromV the description taken in connection with the preamble. VAt low throt tle with the engine running slowly, a sutil cient.supp.ly of air is drawn in throughV the constant opening 4. This in passing through the constricted opening 5 sucks up a supply of gasolene from the nozzle 6, the latter being closed to its minimum opening by the action of the cam 29, and the mixture thus formed passes the throttle valve and into the engine. `As the throttle is opened, the speed of the engine increases and incidentally, the suction of the enginel and the vacuum in the mixing chamber 3 are increased 'and the valve 9 is opened to an extent depending on the suction, and in Aoase the device for releasing "gasolene available to be taken up by t end, a cap 47 is supplied the spring tension is used,the opening o the valve is increased by the release of thespring tension which is simultaneous with the opening of the throttle. As' the auxiliary valve 9 opens, the cam 29 moves to the right, permittin the needle valve 25' to move upward 1n response to 'the pressure of the spring 42, the cam follower 3G engaging the cam surface 29, serving to determine the position of the valve. Thus the needle valve opening is increased and the proportions of the mixture are maintained.

For the purpose of varying the sup ly of e air passing through the carbureterand in order to adjust the carbureter to comply with 'changing conditions, as that of season and variation in quality of the fuel used, the

adjustment of the edective length of the needle valve is provided. lf it is found that the mixture is too weak, a'. e., if the tem perature drops to a considerable extent or the fuel is less volatile than that to which the carbureter has been adjusted, the screw 34 may be rotated to advance it and change the position of the sliding block, shortening the effective length of the valve spindle. Un the other hand, if the mixture is too rich, the temperature having risen and the humidity decreased, or if it is 'desired to use more volatile in the opposite direction to withdraw it, permitting the block 39 to move op ositely increasing the effective length of t e fuel valve spindle.

The dealer may find it desirable to give theA carburetor a perfect adjustment when it Bti etf

fuel, the screw 34 is rotated leaves his hands and lock the parts so the adjustment cannot be disturbed. To this coverin the adjusting screw and it 1s locked `to t e frame by means of a suitable lock 44 and coperatingbraclrets 45 and 46 having registering `apertures to receive the lock.

As I have stated, the cam 29 to be used with the carburetor is determined by accurate tests for each model of engine with which the carburcter is to be used to give at all throttlcs and speeds the mixture which operates most efficiently and hence, with the best economy, so that with any en ine of a model for which carbureters of thls hind have been previously supplied, it is only necessary to select a carbureter of the same size and having a cam exactly similar to that determined by the test. This may be applied'withoutquestion and will give the same eiiici'ency in every instance, provided liti than in their specific or limiting sense and the scope of the invention is defined in the claims.

I claiml. In a constant levelcarbureter, a constant air opening, a fuel nozzle therein, a needle .valve for controlling the flow of gasolene at the nozzle, an auxiliary air valve opening inward, each valve having a stem disposed in thel direction of the motion of that valve, the lines of motion of the two stems intersecting, a cam carried by the auxiliary air valve stem, a follower on the fuel valve spindle, and means for adjusting the effective length of the'fuel valve stem, 2'; e., the distance between the seating surface ofthe valve and the follower.

2. In a constant level carbureter, a main air opening, a fuel nozzle therein, a needle valve for controlling the flow of gasolene at the nozzle, an auxiliary air valve opened by the suction, each valve having a stem extending in the direction of motion of that valve, the directions of the two stems intersecting, two coperating members consisting of a cam and follower, one being rigidly connected to the auxiliary air valve stem, the other being carried by the fuel valve stem, and means for adjust-ing the effective length of the fuel valve spindle. 3. In a constant level carbureter, -a main air opening, a fuel nozzle, a needle valve for controlling the flow of gasolene, an auxiliary air valve, each valve having a stem extending in the direction of motion of that valve, the directions of the two stems intersecting, opening inward, a constant tension, non-adjustable spring tending to maintain the auxiliary air valve closed, two coperating members consisting of a cam and a follower, one being rigidly secured to the auxiliary air valve stem, and the other to the fuel valve stem.

4. In a carbureter, a main air opening,- a fuel nozzle, a needle valve for controlling the flow of gasolene, an auxiliary air valve opening inward, each valve having a stem extending in the direction of motion of that valve, the directions of the two stems intersecting, a constant tension, non-adjustable spring tending to maintain the auxiliary air valve closed, two cooperating members consisting of a cam and follower, one being rigidly secured to the auxiliary air valve stem, and the other to the fuel valve stem, and means for adjusting the edective length of the fuel valve spindle.

5. In a constant level carbureter, a .constant air opening, a fuel nozzle, a fuel valve for controlling the flow of gasolene, an auxiliary air valve opened by the suction, two coperating members consisting of a cam and follower, one being rigidly connected to the auxiliary air valve spindle and the other to the fuel `valve spindle, and means for ad- ,justing the effective length Vof the fuel valve ing in the direction of motion of that valve,

the directions of the stems intersecting, a

spring tending to maintain the auxiliary air valve closed, the latter openinginward in response to the suction of the engine, a cam fixed as to its outline and rigidly and nonadjustably secured to the air valve stem, and a follower mounted on the fuel valve spindle engaging the cam.

In a carbureter, a main air opening, a fuel nozzle, a fuel valve for controlling the flow of gasolene, an auxiliary air valve, each valve having a stem extending in the direction of the yalve opening, a constant tension, non-adjustable spring tending to maintain the auxiliary air valve closed, the latter opening inward in response to the suction of the engine, a cam fixed as to its outline and rigidly and non-adjustably secured to the auxiliary air valve, and a follower on the fuel valve spindle engaging t-he cam.

8. In a constant level carbureter, a constant air` opening, a fuel nozzle, a fuel valve for controlling the iiow of gasolene, an auX- iliary air valve opened by the suction, a spring tending to maintain the auxiliary air valve closed, a cam xed as to its outline and rigidly and non-adjustably secured to 4the auxiliary air valve, a follower on the fuel valve spindle to engage the cam, means for adjusting the effective length of the fuel valve spindle and an abutment for the auxiliary air valve spring, a throttle valve and connections between the abutment and throttle valve whereby the tension of the spring is released as the throttle valve is opened.

9. In a carbureter, a normally automatically closed uid pressure actuated reciprocable valve controlling an air-inlet port and Vhaving a stem projecting from the carbureter housing, a projection on said stem externally of said housing having an inclined face, a reciprocable valve controlling the supply of hydro-carbon liquid and having a stem provided with a longitudinal slot through which t-he stem of the air-inlet valve passes and through which said project-ion travels, a part of said stem of said valve controlling the liquid supply disposed in the path of the inclined face of said projection for transmitting movement of the rstnamed to the last-named valve.

l0. In a carbureter, a normally automatically closed fluid-pressure actuated reciprocable valve controlling an air-inlet port and having n stem, projection on seid stein exterioriy of .the carburetor housing having an inclined face, n reoiprocagble valve con- `troiling the supply of hydro-carbon liquid and having a stem provided with a iongltndinai slot through which the stem of the nirinlet valve passes and through which said projection travels, and a member adjustabiy mounted on the stem of said vaive controlin1 the liquid supl and. disposed 'in the pa of said incline a ce of said projection,

whereby movement of the `tiret-named is transmitted to said inst-named valve, sind `inst-named member adapted to x the nor.-

mal position of the last-named valve rein- 15 tively to its seat.

Signed by me at Baltimore, Maryland this 18 day of Februa. 1913.

` WEL NGTON W. MUIR.

Witnesses:

EDWARD L. BASE,

Enwnr F. SAMUELB.

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