US1460831A - thompson - Google Patents

Description

July 3, 1923.. 1,460,81

H. IL... THOMPSUN INTERNAL COMBUSTION ENGINE Filed May 27 {1921 5 Sheets-Sheet 1 July 3, 1923. EAQ KH 1 H. LTHoMPsoN I INTERNAL COMBUSTION ENGINE Filed May 27, 1921 3 Sheets-Sheet 2 .Fwly 3, 19513.

H. L... Tll-IOMPSUIINH INTERNAL COMBUSTION ENGINE Filed May 27 1921 3 Sheets-Sheet 5 Patented July 3, 1923.

UNITED starts earr.w

F F l C HERBERT I]. THOMPSON, OF ELGIN, ILLINOIS, .ELWS'JIGNOR TO BUlEtt'itlEiSSdlOl'tTON MANU' FACTURIQTG COMPANY, OF GENEVA, ILLINOIEJ, A CORPORATION OF ILLINOIS.

IN'IIIERNAL-UUIMIB'USTIQN ELll'tE'rINE' Application filed May 527,

To all whom it may concern Be it known that I, HERBERT L..'IHo1virsoN, a citizen of the United States, and a resident of Elgin, in the county of Kane and State of Illinois,have invented certain new and useful Improvements in Internal- Combustion Engines, of which the following is a specification. p

This invention relatesto improvements in internal combustion engines, and more particularly to an internal combustion engine of the two cycle type, especially designed to provide a simple, efficient, and dependable power unit for a number of uses where the characteristics suggested are especially de sired, as, for instance, in the driving of small vehicles, boats, farm machinery, power tools, and the like. v

The object the invention is to provide certain new and useful improvements in the construction and design of the so-called two-cycle engine, including an improved meansfor automatically governing the speed of the engine under varying load conditions, an improved system of lubrication providing for the automatic distribution of oil thruout the moving parts, and the pro vision of a superior type of carburetor especially designed to establish proper coir ditions of combustion for starting the engine, these several features, among others, co-operating to promote ease and certa nty in op eration, low cost of maintenance, flexibility of power output, and an increased number of uses to which an internal combus tion engine may be satisfactorily adapted.

An internal combustion engine or motor embodying the invention is hereinafter fully described and illustrated in the accompanying drawings, inwhich- Fig. 1 is a view in vertical section of the engine, taken axially of the crank shaft,

Fig. 2is another view in vertical. section taken transversely of the crank shaft,

' Fig. '3 is a horizontal cross-sectional view thru thecylinder and carburetor, taken on line 33, Fig. 1,

Fig. 4 is a view in vertical section thru the crank case, as in Fig. 1, showing the governor in extended position,

Fig. 5 is a detailed view of the crank case, taken on line 55 of Figure 41, showing the governor valve in closed position,

Fig. 6 is a cross-sectional detailed view of the governor, taken on line 6---6 of Fig. i,

1921. Eerial No. 472,944.

Fig. "i is a perspective view of one of the governor weights,

8 is a detailed view in cross-section thru the connecting rod headand crank pin, as taken on line 8-8 of Fig. 1, Fig. 9 is a view in end elevation of the carburetor, and i Fig. 10 is a view in vertical section thru the carburetor, taken on line 10-1O of tion of the fly-wheel to each explosion or impulse, and utilizing the crank case as a com pression chamber in which the explosive mixture is initially compressed during the downward stroke of the piston and conducted to the combustion chamber during the succeeding upward stroke of the piston, whereupon the mixture is ignited to drive the piston downwardly on its succeeding power stroke. mental principle of two-cycle operation and to this extent the constructionof all twocycle motors may be said to be universal.

The motor herein described is preferably of the horizontal type and comprises in general a cylinder 1 having an enlarged chamber i The cylinder is preferably aircooled and therefore equipped with external radiating fins l of approved design and arrangement, a crank case 2 beyond the cylinder, a piston 3 mounted in the cylinder, a crank shaft 41-, and a connecting rod 5 connecting the crank i of the crank shaft with the piston thru the medium of a wrist pin. Mounted upon the crank shaft adjacent to the crank case is the usual fly-wheel 7. Connecting wlth the cylinder is an intake passage 8 communicating with the cylinder and combustion. chamber thereof by means of an inlet port 10. it carburetor or mixing valve 9 is mounted on the cylinder and con-- trols the passage of the hydrocarbon mixture into the intake passage 8, as will here inafter be pointed out Displaced circum- This briefly is the fundaopening 12 Diametrically opposite the ex haust port is a vertical passage 13 formed in the*cylinder wall, said passage communicating with and connecting the cylinder and crank case by means of ports 14 and 15 respectively. The cylinder port ht iocated with respect to the piston travel so that itis closed thereby in all positions except at the end of the downward stroke when it is momentarily opened and communication is established between the cylinder and the crank case. The lower port 15 of the passage 13 communicates with the crank case at the upper portion thereof, and is located in an oblique face 16 of the crank case,. which serves asa valve seat, as will hereinafter appear. The top ofthe piston is providedwith a projection 3 forming a. curved batik-2 17 co-operating with the port 14 of the passage 13, as will be hereinafter set forth.

' The construction thus far described is typical of the two-cycle engine, as is the general'mode of operation, which may be briefly described as follows: Assuming that the piston 3 in the'position shown in Fig. 1 has just completed an upward stroke, thereby uncovering the inlet port 10 to communication with the crankcase, a charge of the explosive mixture from the carburetor is drawn into the crank case. During the downward stroke the charge is compressed in the crank case and upon the opening of the port 14, by the piston on reaching the lower end of the stroke, this charge is by-passed'thru the pas sage 18 into the cylinder above the piston. Just previous to this event, the exhaust port is uncovered and the entrance ot'the fresh charge drives out or scavenges the burned gases in the cylinder. During the upward stroke of the piston, the charge is compressed in the combustion chamber, and on approaching the end of the stroke, the charge is ignited, the piston driven downward, and another cycle is commenced. In engines of this type, means are usually employedfor controlling the performance of the same under load so that the power is increased proportionately as theload is increased, andvice versa. Devices which automatically control the performance are termed governors and it is one form or governor that will now be described. Ex tending. thru the crank case and parallel to the crank shaft is a rock shaft 18 journalled in bearings 1919, and projecting 65 therebeyond. The'shaft 18 is housed within a semi-circular extended wall portion 2i) immediately below the port 15 of the vertical passage 13. Fixed to the shaft 18 is a wing valve member 21 adapted in the rocking movement of the shaft to seat upon the valve seat 16, and cover the port 11:3. ;\t one end of the shaft adjacent the fly-wheel T is an arm 22 extending radially toward the crank shaft, and having at its end a friction disc 23. Surrounding the shaft 18 and be tween the arm 22 and hearing it) a coil spring 24 acting. to resist the endwise movement of the shaft in a direction from the fiy-wheel, and also to exert a yielding ro tative force upon the shaft in a direction to hold the valve 21 in open position. The on posite projecting. end of the shaft IR is threaded and carries a thumb wheel 9. wherewith the endwise adjustments of the shaft 18 are made Mounted upon thecrank SJ shaftbetween the fly-wheel 7 and the engin proper is a sliding sleeve 20 keyed to the shaft by a key 26 and haying an integ al friction disc 27 at its inner end facing he engine. At its outer end adjacent the ly wheel is provided a smalle di: 1 to which are fixed tworadial spring ar ns 529 29 (li=l-- metrically disposed to each other. these arms being flat spring metal strips bent substam tially at right anglcs so that their free ends terminate adjacent the periphery of the friw tion disc 27 and the point of: bending located in' close proximity to the face of the fly-wheel. At the ends of the arms ZS QH mounted weights 80, the f-llJIlQ being Mi cylindric in shape and having V-shaped pof tions removed into which the bent over ends of the arms 29-29 are fitted and serured bi pins 3030. Each of the weights 30 is further provided with a iing er 31. which e.\' tends to the point of bend in the arms and lies flatwise against the outer taco thereof, the ends of said fingers l' eing rounded and spaced a short distance from the face of the fly-whe el.

The operation of the governor and the valve is clearly shown in Figs. 1. 2 and 4. wherein i, shows the parts in a posh tion when the engine is stat onary, it being observed that the valve member 21 in in open position, the. frir-tioii d sc 27 is out of contact with the contact member 33, and the weights SO --30 are in their normal post tions. As the speed of the mognr is increasia' the spring arms C9 are gradually flexed 120 that is, they approach a, stra ght line peel tion, the ends of the lingers ll. of sou weights hearing against the face of the liv- Wheel and forini. the fulcrum poin i about which the outer end portions of the spri arms turn. Under the action oi cenlr 'l'n a force on the weights, the arms funcl ion somewhat in the nature oi. hell crank le -(H's which are ifulcrunied at thepoint (,feonlaet with the fly-wheel, thereby exerting a upon the sleeve 26, sliding the same toward the arm 22 and into frictional engagement with the contact member 23 at the end thereof. Now, assuming that the crank shaft is rotating in a clockwise direction, as indicated in Fig. 5, the frictional engagement between the disc 27 and member 23 rotates the rock shaft 18 in a counter-clor-zkwise direction, thereby carrying the valve member 21 into closed position over the port 15. Manifestly, the valve member 21 may assume positions between fully opened and closed positions, depending upon the speed of rotation of the crank shaft and the resulting position of the sliding sleeve 26 so that at any speed of the engine the valve member 21 will be moved to a corresponding position, thus controlling the amount of the explosive'mixture which passes from the crank case, thru the passage 13 and into the combustion chamber. Controlling the volume of the explosive mixture admitted to the combustion chamber manifestly has a direct bearing upon the character of the ignited charge, and therefore, the power that is delivered to the piston during its power stroke. It follows, therefore, that the power output of the motor may be accurately governed to meet various load conditions by increasing the volume of mixture admitted ,to the combustion chamber as the load increases and the speed of the motor decreases, or vice versa.

In some forms of internal combustion engines, and particularly small engines of the two-cycle type, the system of lubrication adopted is that if mixing the lubricating oil with the hydrocarbon fuel and in troducing the same into the motor thru the carburetor and inlet port. It is proposed to adopt such a system in the engine herein disclosed and it is further proposed to insure a more perfect lubrication by adopting certain details of construction pertaining more especially to the crank shaft and. connecting rod bearings whereby a sufficient supply of lubricant at these points will be insured.

Referring first to the connecting rod bearing at the point Where the same is connected with the crank pin, the same is preferably constructed in the following manner: As clearly shown in Fig. 8 the crank end of the connecting rod 5 is formed to provide a semi-circular shaped bearing section 32 forming the integral half of the bearing. Retained within this section is a semi-circular section 33 of the bearing bushing. The removable half of the bearing consists also of a sen1i-circular section 3 1 which abuts along its edges with the corresponding edges of the upper bearing sections 32 and 33. The sections of the hearing are connected together and held in place by means of a yoke or strap 35 which encircles the bearing sections and engages vertical slots 3232 cut in the sides of the upper bearing section 32-. The ends of the strap 35 are anchored to the connecting rod immediately above the bearing by means of a bolt 36 passing thru the vertical faces of the slots 32 which 7 communicate at their lower ends with radial passages 38-38 cut in the upwardly facingv edges of the removable bearing section 34: and extending axially of the bearing thruout the central portion thereof. 30

Thus it will be seen that if a quantity of lubricant is directed so as to strike the bear-- ing from above, a considerable part of the same will find its way to the entrances of the vertical passages 37-37 and ultimately reach the bearing surfaces to be lubricated, this action being facilitated by capillary action betweenthe surfaces of the strap and the hearing. In order to direct the in,

bricant into the path of the bearing, a baffle plate 39 is provided at the lower edge of the piston 3, this baffle plate being prefer" ably cast integral with the piston and so located and so shaped that when the inlet port 10 is opened or uncovered by the pis- 95 ton at the end of its upward stroke, said baflle plate is positioned immediately in front of the open inlet port 10 with the re sult that each change of the incoming ex plosive mixture carries with it its content of 1m) lubricating oil, which strikes the ba'liie plate and is deflected downwardly and inwardly toward the connecting rod bearing, which at that, moment will be at the top of its circular path of movement. Thus during each 1 rotation of the crank shaft a quantity of lubricating oil will be deflected downwardly in the form of a spray, a portion of which collects uponthe surface of the connecting rod and parts of the bearing and find its way into the oil passages and thence to the bearing surfaces.

As just suggested, the introduction of the lubricating oil with the mixture and its dispersion by the baffle plate 39 fills the crank 1 case with an oil spray or mist, a portion of which lubricates the connecting rod bearing. as described. A further portion is utilized for lubricating the crank shaft bearings, as

will now be set forth. The crank shaft bearings comprise the usual form of bush ings 10 retained within integral bearing sleeves 41 of the crank case, having an arrangement of oil grooves and passages as follows: Intermediate the ends of each bushing 40 is provided an annular oil groove t2 surrounding the outer surface of said bushing. Extending obliquely thru the wall of the crank case adjacent the bushings 40 is a series of circumfere-ntially arranged oil internal surface of the bushing by :neansot a'radial oil hole 45. Bearing in mind the existence of the spray of oilin' the crank case, and calling attention to the so-called hreathing of the Inotor,' a termused to 'ex'press the passage of air haekwa rdly' and forwardly thru any openings in the crank case which communicate with the atmosphere due to the reciprocating motion of H the piston it will now be pointed out the "function ofthe oil passages and grooves of the crank shail't hearings, For.mechanical reasons, a certain degree ofair leaka e ex ists between-the crank shaft and hearings, and by reason of the oil grooves ant pas- 2fl g ges, a more complete communicat on w quantity of oil is being continuallr the screw or valfre post 50 and yieldahl v the atmosphere is establishedso that perfeet inhaling and exhaling oi theoil laden airof the crank case is carried on thru 7, oil grooves and passages. In'other Words, a v V and alternately forced in and outjo'f the saringsythus a constant circulation is .uiaintained and fresh oilsupplied to the hearing; surfaces While the engine isv in operation.

As previously described,thew-1r oil the motor is associated with passage 8 'corinuunicatiugf with der. said carburetor comprising a casing 1:6 in which "formed 1 chamber a7 communicating directl intake passage 8 and also With t. phere thru a series of air openi Within an annular plate sec, 7 block 46, and atthe outer end of the'mixino' chamber 457. This plate 48' preferably circular and the air openings 4L8 arr d ciirurn'lerentially about its 'enter; at WlJ point, is a screw 50 which is'anchored in t cylinder Wall and carries ralre nieniher adapted to seat against the'plate 48 and to close the air openings 458; 'This 'ralre post is provided With a cylindric head l projecting from the "face o'fthe plate 48. The valvefniernher is slidahly mounted on held irrclosed position by means of a coil spring 52 surrounding the valve post 50 and the tubular stem :31 er the valve inei'nher. Communicatingwith the mixing chamber is a feed pipe 53 thru which the liquidphydrocarhon is supplied to the carlm'retor. A;

needle valve 54 seats within a restricted passage 55 communicating directly Witl'r the mixing chamber 47 and serves to regulate the supply of the liquid hydrocarbon to the carburetor. As clearly snown in Fig. 9, the "valve i8 is "ertically disposed and faces outwardly from the cylinder. Immediately adj acent and at one side (the right'in Fig. 9) of the 'miziingcharnber 4'1",is a small cylinder 5G a sure parallel. to the n'iixiug ehzuuher. li ltillll the crlinder is mounted a plunger consisting oil? a head 57 fitting in the "l e crlindv and z: plu u ci' rod harztllel with the ii th 51. said rrl carrying: at its p? 55? p3 .E'LlLHl h :ii: on larg r i pr. l having a riirrular opera in: tlwrer who; the some diziehar as the. QltLl UM 1e mire post I This plate, 'wluchi roe to or rotate ill a vertical rill w th he o u j an d. is

Traci in I! rmii al or depend l as hort? n Figure H, disthe other llIHHh w mined axially iil'P-l 1'1 the fine the uirlr shop u? 0i (l 1" ijz'lhihi' i with the exhaust and indirectly ou chmolwr oi the cuzriu new 1e (if? rite-A ina lhrw Thus the rariati us in i i ii the plate 55.". the prime 5? and the 56 is to prorule a rumor iacilitatingr the starting; o l the motor. it

( "nur i being: Well known that it is 'i'riu'rueutlr ditheult to obtain the proper mixtu e at starting. due to the low tcuipm'ature that is present. an l hence the incomplete vaporizing ol' the hydro luel Proper starti conditions a. ordinarily promoted or Hui-educessire amount of the fuel. this f ri ll lished by decreasin r or even shut the air inlet to the uuriig' chamhvr. The function oi the plate 59 is therefore to provide a temporary closure tor the air in let openings 4-3 tld'ili'lfl the sfiarti ol the inotoiythis being done by placing p ate over said air openin s. l eluajagrcnient of the open ng; 539 orer the head 50* of the post 50 retainiu the plate in closed position the i the re plate This operation is i by hauo, and iu1- mediate 3' prior to starting; the engine. The c g'iue is then turned orcr hr hand until an i L lesion of the mixture occurs in the c 7linder and the first exhaust stroke is eou'uiletod. The exhausting of the burned gases from the cylinder creates a pressure in the exhaust chamber 12 which is instantly transmit .cd to the plunger chamber 56, forcing the plunger outwardly. the plate 59 heingj thereby rcleased from the post head 50 permittin; it to drop hyg ravity iron; the face of the plate 18, therebyuncovering the air openings 'r'hainbev, R v this novel c s aid drive sl therein. In this manner the normal conditions of fuel and air mixture are fll'l '0ll'IUlTloallvrestored, and at the 'iro 'ier instant; namelv. after the lrst in nulse denoting? nition of e charn e w' in the eoinbns ition oedienh the start-- inn; operation, is rr-idwred to thrt of nriinaril v sealing the air inlet one: i the remainder being; accomplished! ant 'i'illv.

Having; d. scribed he so Mira l'ealjnres oinhodying the invention P claim new and novel. no ininn; to internal colnlgnistion engines, the following:

in A valve operating: nieo. nisin compri ing; a valve member adanted to open and c ose a valve, a1 drive shaft a governor coniprisinn. a friction disc sldable axially on ft. and e redial contact insinber oneratr LT/J connected with said valve member and adapted to be displnced. anginlarly by an amount gironortionate to the friction. exerted thereon bv said governor controlled disc.

2. Valve operating; mechanism OOIJlDI'lSlUE a valve member, a she a f 'ction nieinb V slidably mounted. on said. shz a content member operatively connected with said valve ineinber and men. l the both oi said friction men s for frictional engzganeinent therewith, and a governor connected witl said friction member or inovi the saine axiallvof cl shaft into end out of engagement with said contact member.

3. Volvo onerntin mechanism eoinnrisingr a valve n'iei'nbeiy rock shaft on whieh said valve ineinber'is mountedn a drive shaft a friction 'd so swidsblv mounted on said drive shaft, an arni rnonnod on said valve sh; and adapted for iiirictional contact with said disc and means governed bv the sneed of said drive shaft for lTliTVlll said slee e into and out of frictional engagement with the arm of said valve shaft.

t. Valve operating; meohanlsni comprising a rock shaft a valve member nionnted. on said shaft and adapted to onen and close a valve a contact arm mounted on said reel: shaft a drive sha i a disc slidablv nionn ted on said drive shaft and adapted to frictionally engage said arm, and sneed controlled means for moving said disc into and out of frictional engagement with said arin.

In valve operating nieclninisnn the valve member adapted to open and close said valve and comprising; a rock shaft a disc slidel' v mounted on said drive shaft, a rocker arm mounted. on said. valve shaft" and adapted for ictionel contact with said disc. and centrifugal governor for moving said d' e into and out of frictional engagement W'ifil'l] the arm of mi d velve shaft.

(5 ln s velve operating]: niechanisin the minbination of e. drive shaft, a fl wheeh a valve member nda id to open and close a valve a rocker arm connected with said valve ineinbeiz and extending: radially to ward the drive shaft a sleeve slidablv mounted on said drive shaft, radial spring arms and we" hts at the ends thereof mounted on said sleeve. said arms being bent and adapted to fulcrum on the surface said fly-wheel at the point of bond, whereby the centrifinnll force acting on said wein htseffects i, flexing of said arms to shift the said sleeve i nto and out of frictional engagement with said rocker arm.

17. in a valve operating mechanism, the combination of a drive shaft, a rock shaft parnllel with said shaft, a valve member mounted on solid rock shaft and adapted to ononand close valve an arm fined to said .roelr sl'iaft and GiillQHClllilQ radially toward the drive shaft and a governor comprising],

mounted on said disc and weights at the ends thereof said arms and weights beinnaetrmle bv centrifuga force to fie? said. arms and to effect the axial inovein en t of said disc along: said drive shaft.

5-3. in a valve oneratinn lnechanisim the combination of a drive shaft valve menober coinnrisingz' a roclr shaft provided with a radial contact ain't a friction disc slidablv mounted on drive shaft and adapted for frict onal engagement with said contact arm, and radiallv extending; spring: arms nioni'ited on said disc, bent at an obtuse angle and. ifnlcrnnied at the point of bend against a radial surface of said drive shaft and weights at the ends of said arms.

in witness whereof I hereunto subscribe my name this 19th day of May, A, Dr, 1921 HERBERT L. THUllIPSON.

Images