US2440674A - Engine drive - Google Patents

Description

y 4, 1948- J. D. BELL 2,440,674

ENGINE DRIVE 3 Sheets- Sheet 1 Filed Jan. 15, 1944 m i 3 I 3 Qwm WNW

Will! J. D. BELL ENGINE DRIVE May 4, 1948.

s sheets-sheet 2 Filed Jan. 15, 1944 INVENTOR,

May 4, 1948.

Filed Jan. 15, 1944 J. D. BELL 2,440,674

ENGINE DRIVE 3 Sheets-Sheet 3 INVENTOR,

Patented May 4, 1948 UNlTEl STATE s PATENT ori ice ENGINE DRIVE Joseph 1). Bell, San Francisco, Calif. Application January 15, 1944, Serial No. 518,466 i 6 Claims. (01. 74-58) The present invention relates to improvements in engine drives, and its principal object is to provide an engine drive that willgive a greater percentage of drive power per pound of pres: sure exerted by the piston, than does the conventional crank shaft drive or the heretofore proposed cam type drive. 7

My present invention is a further development of the invention described in my co-pending application, Serial Number 511,156, filed on November 20, 1943, now abandoned, and as far as common subject matter is concerned, the present application should be considered a continuation in part of the former, application. 7

In the co-pending application it was proposed to provide means for turning the reciprocating movement of the piston into rotary motion by means of a pin, driven by the piston, bearing on a helical cam for revolving the latter on the. power stroke, while a second helical cam, driven by the first cam, was used to return the pin and the piston on the compression stroke. A still further cam was provided to pull the piston outward during the suction stroke.

These three helical cams were deemed necessary in view of the different work performed by each. For the drive stroke, a helical cam of rather steep grade was desirable to secure the advantage of a favorable wedge action, while on the return stroke a helical cam of light grade was called for to insure favorable lifting action.

For pulling out the piston on the suction stroke again a light grade was desirable, and this cam had to be arranged to bear on the top of the pin instead of on the bottom thereof.

In the present invention it is proposed to use a twin spiral arrangement, with two cams movable in opposite directions, and the push pin of the piston cooperating therewith to simultaneously press on both cam tracks, so as to wedge the two cams in opposite directions.

This arrangement differs from the single cam type in that when the push pin presses on the inclined track of one cam, the deflected force, which in the case of a single cam throws friction on the guide posts for the pin, is now deflected to its companion cam in theform of a driving force against the track. Furthermore, the wedging apart action of the tracks of the two cams at the same time gives a balanced leverage advantage to a degree similar to the advantage one has in steering an automobile with both hands on the steering wheel instead of steering it with one hand.

A further advantage ofthis arrangement is that the pressure of the push pin bearing onthe tracks of both cams at the sametimeis dividedfor reducing the friction on each track by about fifty per cent. T i

Possibly the greatest advantage is gained on the return stroke of the piston, when the twin cam tracks travelling towards one another wedge underneath the push pin from opposite sides for lifting the same. The advantages of lifting a body by means of two wedges applied from opposite sides is obvious. This feature makes it possible 'to use a much steeper grade for the inclined track, because friction on the guide post for the pin is entirely eliminated.

The introduction of the. twin helical cams thus makes it possible to use a steeper grade on the piston return stroke, and possibly a lighter grade on the drive stroke, with the result that the two grades. may be made "substantially the same which solves one of the principal problems encounteredin the helical cam drive.

i As compared with the conventional crank shaft drive, applicantscamdrive offers "the advantage that with the use of a four inch diameter cam, a full two inch leverageis obtained for the full lengthiof the drive stroke, while the best that can be hoped for in a crank shaft of the same proportion would be an average of about one inch. Besides, the power of the explosion strikes the crank when it has the least leverage,

whereas in applicants structure, the cam has I its full leverage when struck by the pressure of the explosion.

Applicant/s cam also lends itself to certain refinements that cannot be used in the crank shaft drive. Applicant can, for instance, change the up-grade of. the cam to be less steep at the upper end than through its major portion to have greater wedging leverage at the endof the compression stroke. A corresponding construction of the down-grade cam would give greater wedging leverage to the push pin after the greater force of the explosion hasbeen spent. In the crank drive no such compromises can be made.

Further objects and advantages of my engine drive will appear as the specification progresses, and the novel and useful features of the invention will be fully set forthin the claimsattached hereto. i

The preferredforms of my invention are illustrated in the accompanying: drawings, forming 'part of this application, in which:

Figure 2, a horizontal section taken along line 2-2 of Figure 1;

Figure 3, a side elevation of another form of my engine drive;

Figure 4, a section taken along line 4-4 of Figure 3;

Figure 5, a schematic view explaining the twincam action;

Figur 6, a sideelevation of a further io'rmof my drive; I I

Figure 7, a horizontal section taken along line 1-1 of Figure 6; v

Figure 8, a detail view of a drive used in the form of Figure 6;

Figure 9, a section taken along line-941. oflFig ure 8;

pin assembly- Figure 10, a development of the'cam groove used in the form of Figure 6, with the surface of. the cylinder flattened into a plane.

Figurell, a side. elevation of aionn ordrive as applied to a bycycle.

Figure 12, a horizontal sectiontaken alongline l2--I2 of Figure 11; v

Figure 13, a side. elevation. of a further; form of my drive, parts being shown in se tion;

Figure 14,- .ahorizontal section taken along, line Id-JA ofFigurelS; and

FigurelB, .avertical, fragmentary sectiontaken along line l5,.l.5.o Figure 13..

While I. have. shown only...the pref erredforms of my invention, I wish. to. have ithunderstood; that variousv changes or. modificationsmaybe. made within the. scope. ofwthe. claims, hereto at,-. tached without departing. from .thespirit. .of the invention.

Referring. tothe drawings in. detail, the form. shown in Figuresv 1 and 2. bearsa certain re:

semblance to Figure 610i the. copending appli,

cation, previously referredto. 'The.driving.mech.-. anism is mounted, initsprinoipalparts,between upper. andlower plates. l. and Z.held-inspacedrelationby any suitable means, suehastherods. 3, which. latter. serve as guide. posts .for. a sliding plunger-4. made in. theform of. a horizontal bar.

havingua transverse; pin 5 slidable in thecentral portion thereof. Theplungerisattached .to engine piston. (not shown). by means. 'of. a; con.-..

ventionalpiston. rod. 6;

On. opposite sides ofi the pins. 5. are mounted two cylinders I. and. 8 supportedtby theshafts Band l haying bearingin the hubs l l.-project.-.

ing from the plates respectively. The two.'cy1=-..

inders are interconnected bysuitable'gearing l2 includinganidler l3, so asto revolve inthesame direction and at the same speed.

The cylinder. 1 hasa helical: cam..gr.o,ove, IL

cut into the surface. thereof, thegroovebeingadaptedto receive the pin. 5. 1-. The-grooveis ,ende.

less, ascen in on. one. side of. the. cylinder, and

escendi on the. other side; T e owerwel re h r q e thu ter s -erede. am

track on one side and a down-grade camortrack on the other side. The upper wall I llof thegroove forms a cam..or the, lower one.

Injoperation, as th plungerisforced downa d. du to. he 'exnl s en. n e. combustion chamber, the pin being confined through its mounting to a straight downward path, wedges the cam aside andcauses the cylinder torotate. Assuming that thecylindendevelopsl snfficient. momentum to continuethe rotaryinovement; the.

bottom part of thegcamwilli reverse .the motion trackv substantially parallel to portion of the cam wedging underneath the pin. In the upper portion of the cam groove the motion of the pin will again be reversed.

If the next stroke is a suction stroke, the upper wall of the groove, on the down-grade side, will engage the pin and force the latter downwardly, to be lifted again by the up-grade side of the cam as the rotation continues.

- It willbe. noted that theicam selected for the purposes of this invention is rather steep and substantially uniform on opposite sides of the cylinder. This steep grade operates to good advantage on the down-grade side, where the pin wedges the cam sidewise, but is less eficient on upT-grade I is desirable to. correspondto the steep dowri -gradgon the other. side. in order to make of the pin, and the latter will themhemade. to;

move upward in a straight path by the up-grade the .oppositelsides, of. the cylinder symmetrical.

In order to eliminate the. friction and to rendera steep upe grade available, I prov-ide the second cylinder BJ'geared to the. cylinder 1' to revolve atthesarne speed-andinthesame direction.

If thecylinders rotate, in the-sam e direction, the confronting faces. will inove in opposite directions.

The second cylinder-is. formed. with a. spiral groove, l8. extending through halt a section of the cylinder and corresponding substantially to the. up -grade,grpove of the firstcylinder, so as to present, init's bot-torn wall; 19, a. helical track, corresponding substantially; to the. helical track l6. (on'the far. sideofl the cylinder 1, as illustrated).

W en he: in a hes,- ih tt of the groove. l 4' it is pushed partlyinto the groove t 8 of the other cylinderdey;a, v bump l9? in the groove e eieheinal enwehi w ven to leave wart. f: t e s mereeve I 4! Thus the two carnsill. and I8, engaging the ends of the pin from oppositedirections, tend ewed ebbth nds-1 eme upwardly, in a h. s;a t qe ..eed. hsmbw im n ten n :eeti nrh twsee-the: lease" Med t guide 959 9d:;3-

Th QQPQT'W EQR @HQWS m ch eper. grade Q-be us g h e se s-s s e ft At the end of theup strokg the pin ispushedback ntes eqve. 1 1W heperin 1- Q groove 1st! i hel i ieceeei h is li dee a s I 9 e nertar hefi stsrlme rme used as the power shait and is p-r'ovided with a fly Wh el-s nd e ai s fl svs j eats and-22 to serve as takeeofis-fonthe-maimdrive shaft 23 itn sses sat The form shown in Figures 3 and 4 works substantially on the; same! principle, except that ree cylinde at fuses z e e n t o withtwo pistonrogis an that the endlesshelical grooves are carried; ole -argur d all the. cylinders which limiea se h r hiities i er sh i spm I The three; cylinders; 2 {a 2 6 and 21, are revolvalr mount d. with he r. s s r m plane, between the plates and. 29, the central cylindenbeing preiferably somewhat larger than the id r fl nd ni; l

Each of the cylinders is ior nedwith.-anends belies rows; 0s- 31 M3 h grooves in the outer cylinders being symmetrical and the groove in the central cylinder being reversed in the sense that in the position shown the bottom section of the groove in the central cylinder faces frontward, while thebottom sections of the grooves in the side cylinders face rearwardly. The axial length of the three grooves is the same, but the grade of thecentral groove naturally is less steep than'that of the two 'othergrooves, since the diameter of the central cylinder is larger. 1

Two plungers 33 and 34 are provided to slide on posts 35, one between the central cylinder and each side cylinder, and each plunger carries a pin 36 which'extends into opposing grooves. The cylinders are interconnected by suitable gearing indicated at 31 to cause the cylinders to rotate at the same speed and in the same direction, with confronting faces moving in opposite directions.

The two plungers are connected to pistons (not shown) by suitable connecting rods 38, and power may be taken off at any one of the gear wheels or interposed idlers. In the drawing the main drive shaft 40 is connected, by bevel gears 41, to one of the "idler shafts, which carries the flywheel 42, while the timing shaft 43 is driven, through bevel gearing 44, from one of the side cylinders.

In operation, as one of the drive or pusher pins 36 moves down; it wedges opposing walls of the cam grooves in opposite directions, causing the two cylinders involved to rotate in the same direction. Momentum or other drive pistons cause the cylinders to continue this rotary movement, and after the lower center of both grooves is rods receive driving impulses successively. As

viewed in Figure 6, the left-hand rod would receive the first driving impulse and. would force passed, the two'ascending sides of the cam grooves or tracks wedge the pin upward, eliminating all side strain or binding along the guide posts. If the next stroke is a suction stroke, it is apparent that the outer walls of the two cam grooves will cooperate in wedging the pin 36 downward.

The second pin 36 works on the same principle and is timed for roper cooperation with the first pin in a conventionalmanner. It can be readily visualized that any number of pistondrives may be added by furnishing further cam cylinders and drive plungers.

The diagram of Figure 5 illustrates the wed ing action of two lifting cams 45 and 46 on a pin 41 and particularly shows the wedging from opposite sides for eliminating friction and for reducing wear and resistance on each cam. It further illustrates how the grade of the cams may be changed to apply greater power toward,

the end of the compression stroke. The bend 48 in each of the cam tracks is here shown as being angular to accentuate the same, but it is apparent that in practice the bend would be smoothed into a curve.

The forms shown in Figures 6-10, inclusive, employ a somewhat different principle. A single cylinder 50, rotatably mounted between plates 51 and 52, is driven by four piston rods 53 arranged symmetrically around the cylinder. Each piston rod terminates in a plunger 54 guided vertically by guide posts or rods 55, which serve also to hold the plates 5l52 in spaced relation.

The piston rods 53 are 90 degrees apart from one another, and the cylinder is formed with a cam track 56 with a steep. down-grade extending through a quarter of a circle, and a light upgrade extending through three-quarters of the circle. Each plunger 54 has apin 51 projecting therefrom to ride onthe cam track 56.

the pluger 54 downward, causing'the pin 51 to wedge the cylinder through a quarter of a revolution. In the meantime the three other piston rods would be lifted by the relatively light cam grade extending through three-quarters of the cylinders circumference.

Thus, after having been turned through a quarter revolution, the cam track would :find the next piston rod 53 ready for the next impulse, and so forth, with the result that the cylinder would receive a rotary impulse each quarter of a revolution, while allowing each piston rod three-quarters of a revolution to return to its initial driving position.

In case the driving force behind one of. the piston rods should fail, means are provided for pulling the connecting rod down. This means comprises a second cam 58 arranged above the down grade section of the main cam and having a much easier grade. If the piston 53 fails to drive the plunger down, it is apparent that the revolving cam 58 will pull thepin 51 and the piston rod down and will, at the end of a quarter of a turn, deliver the pin to the main cam on the up-grade side, for the pin to then follow its regular course.

Since the grade of the cam 58 is much less steep than the grade of the cam 56, and thus there is considerable space between the cams, as at 59, it is desirable to positively guidethe pin 51 along the lower face of the cam 58 in case the power behind its piston fails. This I accomplish by means of a second pin 60 mounted in each .plunger ahead of the main drive pin and at a higher elevation, as shown particularly well in Figure 8. This pin is spring-pressed, as shown at 6 1 in Figure 9, and normally does not affect the operation of the drive at all. It is shorter than the main pin and its depth of penetration is limited by a stop 62.

The operation may best be explained by reference to Figure 10 which shows the four sets of pins in their respective positions at a given time. Commencing at the bottom of the main cam 56, it will be noted that the bottom is about to approach one set of pins, the main pin 51 riding on the cam and the auxiliary pin 60 being accommodated in the space 59 between the two cams.

The next set of pins (on the right side of the drawing) is shown as climbing the grade of the cam, both pins riding on the cam surface. The third set of pins (on the left side of the drawing) is also shown as climbing the grade, at a higher elevation than the second set.

The fourth set of pins has reached the top of the grade, the main pin 51 riding over the crest of the cam. But the auxiliary pin, while approaching the peak, has struck the upper wall of the cam groove, which is tapered at that point, as at 62, and has climbed the taper so as to rest on the outer wall of the cylinder. The pin, of course, has retracted against the spring 6| for this purpose.

While in this position, the pin 60 may follow one of two courses. If the piston drive is active, and the pin 51 is forced down the steep incline, the pin 60 will follow and will snap down from the outside of the cylinder into the cam groove as soon as the latter widens sufficiently to accommodate the pin. When approaching the botammoni- 7 tom. of the grade, the two pins will. then. occupy a'position corresponding to: that offthet pins: shownnear: the bottom. of; the cam; in full lines.

If,.however, the power fails on the drivestroke, the pin. 51, at the'peak ofithe cam, will hesitate, andlthepin lifl will ride down the incline 63'- into the upper cam groove 6%; which is of less. depthv than the main cam groove '65 and will. force-the main pin to closely follow thebottorn'face; offthe cam 58. This course of the two. cams. is'indicated in dottedlines. When reachingthe-endof the down-gradathe auxiliary pin 6%]; drops back into the main groove, as at 66, and both pins then follow their regular. course;

.The main drive shaft 4i} and the. timing; shaft 43-. may be connected to the cylinder shaft through'bevel gearing M in the manner indicated.

F'iguresll. and 12 illustrate my invention as applied toxa. bicycle. The top and bottom plates is. and TI are suitablysecuredto bicycle frame members indicated at 12 and it. Four rods or guide posts 14 cooperate with the'framemembers for holding the plates in spaced relation; and also serve as guides for the plungers l t and 15. Each ofthese plungers hasfa pedal 76 projecting therefrom for convenient foot operation.

Centrally between the plungers is mounted the revolvable cylinder H, with the endless. spiral cam groove i8, and the plungers is and 7.5 have pins -iiiprojecting into the cam groove. The cylinder drives, through bevel gearing iii), a horizontal shafttl, which again is connected to the rear wheel of the bicycle through a conventional sprocket drive indicated at 82;-

Possibly themost promising form of my invention is illustrated in Figures;13 to 15, inclusive. This form works on substaritiallythe same prine ciple asthat shown in Figures 3 and 4, but-has the advantage of greater simplicity and compactness, insofar as the two cooperating cam members are mounted in concentric relation.

Referring tothe figures in detail, the cylinder 90 is revolvably mounted between the two plates Mend-.92, and is formed with an endless helical camgroove fit'furnishinga lower cam track- 94 andian upper cam track 95. The cylinder is surrounded by a concentric sleeve 95 out along its upperedge to present a'cam track 9'! correspond ing substantially to the lower'cam track 94 f the cylinder.

The cylinder and the sleeve are interconnected: by suitable gearing, indicated at $8 to revolve. in' opposite directions, with the cam tracks intersecting in the manner. shown.

The plungers 99 are mounted on squared guide; posts. it on opposite sides of the cylinder and have, suitable piston rod connections lii i'. Each plunger has a pin I52 extending over the cam: track of the sleeve into the cam grooveof: the cylinder.

Thus the pins, when moving down-grade, under pressure, wedge the two tracks/apart inwa manner similar to that shown in Figure 3, While o'n-the upward stroke the two cam tracks com-' ingwedging thepin upwards from opposite;

sides.- Power may betaken from the cylinder shaft I53 in the manner previously described.

'Sincethe principal object of the inventionis to provide maximum wedgihg action on the power consistent with adequate wedg-ing' action on'uthe compression stroke, the cams have been developed to approximate anidea-l condition for accnmplishing. this object. The-cams are formed to give; anzapproximate angle of 2-59, withthe axis;

8?;- of.:. the drumsand an'approximatean le of 6 with thew-base ofthe-drums. 1

The? Wedging; action thusv produced. approximately doubles the. power on thevdrive' stroke and halves the powergon' the; compression-stroke. This-proportion approximately corresponds: to

the working characteristics of a conventional gasrengine-of the: Diesel or internal combustion type ini which the power consumed-by the.c0mpression stroke is approximately one-fourth of the power createdby the drive stroke.

Thus. the shape of the; cams creates. the; ideal.

condition where a maximum Wedging action. is allowed for the drive stroke consistent with adequate wedging, action on the. compression strolge.

. It will be noted that in the structure: of: Figure: 13- thepin projects over 'the two-camsrfroin the.

This allows both cams. to bear on theoutside. pin on the same side of the piston rod eliminating torque. and allowing, the two-cams to'berimmediately adjacent to'one another. so that bothcams can have. approximately. the. same grade. While the drawing shows a slight spacing; be-

tween the drums, this has-been. done merely for the purpose of. making therdrawing: more easily readable.- could not'be immediately adjacentto one another so that each would form a bearing forthe thesame pitch, and a .drivepin-adapted to rotate the tracks inoppositedirectionswhen bearing on. the down gradesyand to-be liftedby thee-tracks when hearingon the up grades, the tracksabeing relatively steep to produce maximum- Wedg-ing,

action on the. downgrade consistent withthe operativen-essof the up rade portionspffthe tracks tolift the pinwith the tracksarranged. inconoentric relation andthepinprojecting over. the tracksfrom the, outside thereof.

2. In an engine drive, a pair of rotary. members having endless helical tracks thereon with complementaryupand down gradesoflsubstantially the same-pitch, andadrive pin. adaptedito rotate the. tracks in. opposite, directions when. bearing on the downgrades. andto .beliftedby. the tracks when bearing on the up. gradeafwitli the two tracks arranged in. concentric relation. and they pin projecting over thejtracksjfrb'm'the outside.

thereofi. V

.3. In an engine ,drive, .a-pair. of rotary members having. endless .helicaitracks thereon. with com;

plementary up and down grades of substantially.

the same pitch, andadrive pinadaptedto. rotatethe tracks in opposite directionswhenbearing on the downgrades and. to. be .lifted. byjthe tracks when bearingon the upgrades, the tracks.

heingrela-tively steep to produce maximum wedging action on the 1 down grade. consistent. with the. operativeness. of the upgrade portions of the tracks to lift ..the.. .pi-n. with. the tracksarranged in closely spaced .Lconcentric relation .andthe p n projectingover'the tracksfromthe.outsidetthereof;

4. In an. engine drive; a pair. .of' rotary members having. endless helical Ltracks. thereon with complementary up and ,down grades .oflsubstane tially the same. pitch, and-4a driye pin..adapt.ed

There is no' reason; why the drums to rotate the tracks in opposite directions when bearing on the down grades and to be lifted by the tracks when bearing on the up grades, the tracks being relatively steep to produce maximum wedging action on the down grade consistent with the operativeness of the up grade portions of the tracks to lift the pin, with the tracks arranged in closely spaced concentric relation and the pin projecting over the tracks from the outside thereof, and the shape of the helical tracks being modified to increase the wedging action toward the end of the lifting action.

5. In an engine drive, a pair of rotary members having endless helical tracks thereon with complementary up and down grades of substantially the same pitch, and a drive pin adapted to rotate the tracks in opposite directions when bearing on the down grades and to be lifted by the tracks when bearing on the up grades, with the two tracks arranged in closely spaced concentric relation and the pin projecting over the tracks from the outside thereof.

6. In an engine drive, a pair of rotary memtracks when bearing on the up grades, with the two tracks arranged in closely spaced concentric relation and the pin projecting over the tracks from the outside thereof, and the shape of the helical tracks being modified to increase the wedging action toward the end of the lifting action.

, JOSEPH D. BELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 701 Graham Apr. 21, 1838 322,679 Campbell July 21, 1885 1,384,344 Powell July 12, 1921 1,701,173 Conn Feb. 5, 1929 1,876,506 Lee Sept. 6, 1932 2,196,216 Lane Apr, 9, 1940 FOREIGN PAT ENTS Number Country Date 1,276 Great Britain 1906 18,100 Sweden June 3, 1903 678,660 France Jan. 2, 1930 687,918 Germany Feb. 8, 1940

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