US1299433A - Internal-combustion engine. - Google Patents

Description

K. DOUGAN.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED SEPT. I, ISII- RENEWED IAN, I0. I9I8.

1 ,299,433. Patented Apr. 8, 1919.

42 SHEETS--SHEET 2.

UNITED s'rnrns PATENT OFFICE-- KENNEDY DoUeAN, or MINNEAPOLIS, MINNESOTA.

INTERN .AL-COMBUSTIQN ENGINE.

Specification of Iietters Patent. .l i Patented Apr. 8, 1919."

Application led September 1, '1911, Serial No. 647,175. Renewed January 10, 1318.Y Serial No. 211,317.

To all lwlw-m, t may concern.'

Be it known that I, KENNEDY DOUGAN a citizen of the United States, .residing at Mln? neapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Internal- Combust'ion Engines, of which the following #is a specification.

My invention relates to internal combustion engines of the type shown and described in my applications, Serial Numbers 635,206, led June 24, 1911, and644,504, filed August 17, 1911, in which the force of the explosion within the combustion chamber operates to raise a weight, the energy thereby accumulated being used to perform useful work When the' weight falls. My present invention relates to an explosion engine of this type combined with a pump the piston of which-is connected to the weight-operating j member of the engine and the invention has in view especially providing means for positively operating the different sets of exhaustand intake valves in timed relation both with respect to the setsof valves in different engine units and the di'erent valves in each engine unit. l

It is the chief object of the-inventionl to provide operating means for the exhaust and intake valves' of the diferent engine units which shall be actuated from or through the exploding charge of the active engine cylinder when the weight-operating member and pump piston israised and which shall be further actuated bythe Huid within the pumping cylinder through compression thereof when the pumping piston. starts to descend. It is also an object of my invention to combine with these two sets of actuating means a .single actuating member for both sets of valves in each engine unit, with means relatively-positioned on said actuating member not only for operating the exhaust and intake valves of the given unit in timed relation but for operating the exhaust and intake valves of all of the engine units in successively timed relation, so that an eX- the engine unit to which-said piston belo'n s.

Thisl cut-oli' mechanism provldes means or accurately adjusting the point in said engine stroke at which automatlc cut-oli shall take place, such adjusting means being sensitive vto a high degree and comprising a feature of importance in my invention..

Another object of my invention is to pro'- vide gravity actuated circuit closing means for operating the ignition so constructed and varranged that such operation will take place at the moment of full stroke. Y

Other objects and advantages of my invention will appear-in the detailed description thereof and are particularly pointed out stop of the descending in the claims.

In. the drawing, illustrating the application of my invention in one form,-

Figure 1 is a sectional elevation side view A ofl the weight-operating member and connected parts. Fig. 2 an elevation view taken at'right angles to Fig. 1 with some Vparts omitted. Fig. 3 is a plan view of one of the engine cylinders viewed from above. Fig. 4 is a diagrammatic view showing relative position of the four valve operating cams at any given time. Fig. 5 is a detail view of the cam actuating ratchet. Figs. 6 to 8, inclusive, illustrate details of the automatic intake cut-off devices.

Frame members 10 and-11 have secured thereto cylinders 13 and 14, preferably one ab'ove the other, the pistons 15 and 16 of which are connected by piston rods 17 and 1-8 to cross bars 19 and 20 forming parts of a weight-operating yoke member 21. The yoke-operating member 21 is also provided with a lower cross bar 22 which is secured to piston rod 23 of a piston 24 working 'in a pumping cylinder 2'5, said pumping cylinder being surrounded at the bottom thereof with an enlarged cylindrical casing 26 forming a chamber into which the pumping cylinder opens through elongated passages 27'. Upon one of the cross bars, as shown, cross bar 20, is secured a receiving tank- 27. Water may be pumped into this tank or drained therefrom so as to vary the aggregate mass as may be desired..

Intake valves 28 and 29 and corresponding exhaust valves 30 and 31 are provided in the bottom of cylinders 13 and 14, respectively, relatively positioned, as indicated in Fig. 3. Each of these valves comprises a bifurcated stem 32 pivotally connected at 33 to a lever 34 centrally pivoted to a bracket 35 extending from the bottom of each of said respective cylinders, the free end 36 of said levers being drawn upward by means of springs 37 attached to an arm 38 projecting from` each of said cylinders 13 and Y14, the operation of such spring through lever 34 being such as normally to hold the valves closed, the springs being strong enough to perform this function against any pressure not materially greater than atmospheric pressure.K Each vof the levers 34 is provided with a cam-like head 39 immediately below the pivotal point of attachment with the valve stems. Journaled in hangers 40 and 41 immediately beneath valves 29 and 31 of cylinder 14 is a shaft 42, a similar shaft 43 being journaled beneath valves 28 and 30 in hangers 44, 45 depending from the bottom of cylinder 13.

' Fast upon shaft 42 is a cam 46 located immediately below head 39 of lever 34 connected with exhaust valve 31, a similar cam 47 being fast on shaft 43 and operatively positioned below head 39 on lever 35 connected with exhaust valve 30. A similar cam 50 is loose on shaft 42 beneath enlarged head 39 on intake valve 29, another' of such cams 51 being loose on shaft 43. Each of these cams has for the fmajor part of its circumference a circular face 52, a single high portion 53 being provided on each cam. The relative rotative positions of the high places on the four cams, 46 and 50 on shaft 42, and 47 and 51 on shaft 43, is shown in full lines in Fig. 4, in which it will be seen that the high place 53 o-f each succeeding cam taken in the order of the two on shaft 42 and then the two on shaft 43 is a quarter of a revolution or ninety degrees behind the next preceding cam. If, therefore, all of the cams are simultaneously moved a quarter turn at' each actuation it will take four of such movements to bring the high portion 53 of any cam from its upright or active position again to such upright and active position, during which the other cams in the order shown will each have occupied and been Withdrawn from such active position, and in being so actuated have each opened and v closed the valve with which it is associated,

opening taking place when the portion 53 goes from the position shown at the right of Fig. 4 to its upright position and closing taking place when said high portion goes from the position shown in full lines at the left of Fig. 4 to the position of the cam next thereto on the right. As indicated, the arrangement S Such that exhaust valve and closing intakevalve at a predetermined point f in the stroke to iX the volume of the charge.

Through means connected with both cylinders` of the engine units the shafts 42 and .43 are simultaneously rotated a quarter turn at the moment of explosion in either cylinder; and through means connected with the pumping cylinder said shafts 42 and 43 are simultaneously rotated in the same direction another quarter turn at the moment that pumping action is begun by reason of descent of the weight-operating member and' return engine stroke. The first of these means comprises a cylinder 54 connected by port 55 with cylinder 14 and a cylinder 56 connected by port 57 with engine cylinder 13. A piston 58 works in cylinder 56 the piston rod 59 of which is bent outwardly, as

shown at 60, and bent down again, as shown at 61, to be integrally united with the piston rod 62 of piston 63 working in cylinder 54. An arm or pair of arms 65 is pivotally connected at 66 to rod 59, said arms at the other end being pivotally connected to a rocking member 67 having pivoted at 68 a pawl 69 with a weighted end 70 for holding said pawl in engagement with the teeth 71 of a four-toothed ratchet 72 fast on shaft 42. Similar arms 73 are pivoted at 74 to rod 59 and. toa ratchet-operating `pawl engaging a four-toothed ratchet 75 on shaft 43. It will be seen, therefore, that an explosion in either cylinder 13 or 14 will, through action of gas entering cylinder 56 or 55, cause piston 58 or piston 63.to lift rod 59 and simultaneously rotate shafts 42 and 43 a quarter turn. v y

A cylinder k7 6 communicates by means of port 77 withthe bottom of pumping cylin.-

der 25, said cylinder having therein a piston y 78 to which is connected a piston rod 79, said piston rod being in turn pivoted at 80 to a pawl operating member 67 having a pawl engaging a four-toothed ratchet `81 on shaft 43. A link 82 is pivotally connected at 83 with a pawl-operating member 67 having a pawl engaging a four-toothed ratchet 84 fast on shaft 42. When therefore, the weightoperating member together .with pumping piston 24 starts to descend, Water under pressure will enter cylinder 76 through port 77 and, through piston 78, rod 79 and ,i link 82, will simultaneously' rotate shafts 42' and 43. another quarter turn in the same direction that v said parts were rotated through rod 59. It follows, therefore, that at the beginning of each upward and each downward stroke of the weight-operating members bothshafts 42 and 43 are simultaneously rotated a quarter turn with the result that at each of said movements the cams 46, 47,50 and 51 are moved so that one of said cams is caused to open a valve and the other to be positioned so that the valve may close. It is noted that after rod 59 has been lifted byAan explosion said rod and the parts connected therewith are returned to initial position'by means of a compression spring 85 positioned upon an arm'86 on one of the cylinders and engaged by an arm 87 of a lever pivoted intermediate its ends at 88 to a pivoted link 89, the other end 90 of said lever being pivoted at 91 to rod 59. Atmospheric pressure acting upon piston 78 will restore said piston and the parts connected therewith to initial position upon the ascent of pumping piston 24. 'Spring 85 will be strong enough to resist vcharging pressure within the engine cylinder.

With respect to the exhaust valves and 31, it is noted that the operating cams therefor are so positioned that oneor the other of these valves is -always opened at the beginning of a down stroke and is not closed until the moment of explosion which starts an upstroke, each valve of course being operated by alternate down strokes. The cams forfo/perating the intake valves 28 and 29 are so positioned as to open one or the other of said valves at the beginning of each upward stroke, but special cutlofl" mechanism is provided whereby said intake valves will be automatically closed at any point desired of the upstroke. To effect this, cams and 51 are loose on shafts 42 and 43, respectively, each of saidcams being provided with apair of lugs 92 and 93 between which operates a linger 94 on a collar 95 secured to each of shafts 42 and 43. Cams 50 and 51, therefore, will be free to rotate upon shafts 42A and 43 independently of said shafts between the limits permitted by said lugs 92 and 93, although said cams will be rotated by rotation of said shafts through engagement of finger 94 with lug 92. Carried by trunnions pivot-ally mounted. in arms 96' and 97 on pumping cylinder 25 a similar arrangement being indicated Ydiagrammatically as -at tached to engine cylinder 13 at 98) is a cylinder 99 having there-in a restricted portion 100 and an enlarged portion 101, as clearly shown in Fig. 5. Within this cylinder works a piston 102 of the diameter of. said lrestricted portion, said piston being pivotally connected by a rod 103 to cam 51 at 104, as best shown in Figs. 6 and 8, the point of connection 104 lbeing carried away from the end of shaft 43 by means of an olf-set member 105 so that pistonrod 103 has crank ber 100 to the lower portion of chamber 101 thereby permitting oil to f iow freely from said chamber 100 to chamber 101 below piston 102 when the same is raised, but preventing return flow of oil when the( piston is caused to descend. A similar pipe 110 is provided with an upwardly opening valve l111 and a hand-operative choke valve 112.-

The pipes and chambers of the cylinder are full of oil. As the cam 51. (or cam 50 on shaft 42, which is provided with identically the same regulating means) rotates in the direction of the arrow, as Iindicated in Fig. 6, piston 102 will be raised against the force of spring 106 untilsaid piston is seated within the contracted portion of cylinder 99, the flow of oil through pipe 108 permitting this. When cam 51 has been brought to its upper or active position'the point of connection 104 of rod 103 will have passed beyond the rotative center on shaft 43 of cam 51, as indicated in dotted lines in Fig. 6. Action of spring 106 therefore will tend to cause cam 51 to be rotated through rod 103. But Oil is trapped beneath piston 102 and can only flow upward above the Vsame through pipe 110 as fast asA permitted by the extentrof closure of choke valve 112 which may be varied as desired.`

Descent of piston 102 will therefore be retarded at first but after the upper edgeV thereof passes into enlarged chamber 101 the piston 102 may descend freely which it will do, thereby rotating cam 51 orsimilarly conditioned cam 50 and permitting spring 37 to cause arm 34 to close valve 28 or valve 29. -By regulating the rate of flow of oil through lpipe 110 by means of choke valve 112 the point at which thiscut-oi' lwill take place relative to the upward stroke can be adjusted with the utmostaccuracy and can' be made to take place at any point of said upward stroke, as desired,'thus regulating the amount of charging mixture drawn into the cylinder to the conditions of work b eing performed.

In the type of engine disclosed in which return of the and owing to differences in the pumping'action or degree of compression of the gases within the charged cylinder or from other causes, the point at which the weight-operatl lng member and the engine piston stops may vary materially.A For producing the most effective results it is necessary to provide an parts is effected by ,gravity ignition which will take place at the moment when the downward stroke ceases and at no other time. A very simple device for effecting this result is shown in Fig.. 1 1n which a weighted arm 113 is shown, plvoted at 114 to a projection 115 from cross bar 20, said weighted arm being held in almost balanced relation by means of a spring 116 adjustably connected by means of thumb screw 117 to a lug 118 on said cross bar. Arm 113 is in the electric circuit of the ignition, as is an arm 119 secured to cross bar 20 and having an extended portion 120 underlying -the end 121 of arm 113. When the weightoperating member 2O and-parts connected therewith come to rest at the end of the down stroke the inertia of weight 122 on arm 113 will be sufficient to overcome lthe force of spring 116 and cause end 121 to contact with extension 120 thereby completing the ignition circuit and causing an igniting spark.

The operation of my device has been very fully given in connection with the detailed description thereof. In general, supposing the parts to be as shown in Fig. 1 in which an explosion has taken place in cylinder 14 and the end of the upward stroke just reached, exhaust valve 30 of cylinder 13 having been closed and intake valve 28.

opened at the moment of explosion in cylinder 14, said valve 28 having been closed before the completion of the stroke by rotation of cams 51 through action of cut-olf device, all as indicated diagrammatically in Fig. 4,-at the beginning of downward reciprocation the pressure generated by pumping piston 24 will actuate piston 78 and connectmg rods 79 and 82 to rotate all of the cams a quarter turn in the direction of the arrows with the result that cam 46 will come up, opening exhaust valve 31, and each of the other cams will ,be moved a quarter of a turn. In the meantime the charge in cylinder 13 will have been compressed. When downward movement ceases, the

sparking device will operate to ignite the charge in cylinder 13 and at' the moment 'of ignition, through piston 58 in cylinder 56 and connecting rods 59, 65 and 73, shafts 42 and 43 will again be rotated a quarter of a turn, resulting in the closing of exhaust valve 46 and opening of intake valve 29, which in turn will 'be closed by the cut-off mechanism at the proper point in the upward stroke. The beginning of downward movement, through the means already described, will no-w rotate all of the cams another quarter turn with the result that valve 30 will be opened. Explosion of the compressed charge in cylinder y14 will actuate the operating mechanism to rotate the cams another quarter turn closing valve 30 and opening valve 28, which will be cut oli' at the proper point in the upstroke, thus closing the cycle of operations and restoring the parts to the position indicated in Figs. 1 and 4.

I claim:

1. A power pumping apparatus embodying a motive fluid actuated motor piston, and admission and exhaust valves for the actuating fluid, a pump for delivering fluid under pressure embodying a pump piston connected with the motor piston and means operated by the fluid pressure created by the pump piston for opening the exhaust valve of the motor.

2. A power pumping apparatus embodying successively acting motive fluid actuated pistons, and admission and exhaust valves for the actuating fluid for each piston, a pump for delivering fluid under pressure embodying a pump piston connected with the motor pistons, means operated by the fluid pressure created by the pump piston for opening the exhaust valves of the motor pistons and means operated by the actuating pressure for one motor piston for closing the exhaust valve for the motive fluid of the ether motor piston.

3. A power pumping apparatus embodying successively acting motive fluid actuated motor lpistons, and admission and exhaust valves for the actuating fluid of each piston, a pump for delivering fluid under pressure embodying a pump piston connected with the motor pistons to deliver' fluid during the exhaust strokes of the motor pistons and means operated by the fluid pressure created by the pump piston for opening the exhaust valves of the motor pistons alternately, one during each delivery stroke .of the pump piston.

4. A power pumping apparatus embodying successively acting motive fluid actuated motor pistons, and admission and exhaust valves for the-actuating fluid of each piston, a pump for delivering fluid under pressure embodying a pump piston connected with the motor pistons to deliver fluid during the exhaust strokes of the motor pistons, means operated by the fluid pressure created by the pump piston for opening the exhaust valves of the motor pistons alternately, Yone during each delivery stroke of the pump piston and means operated by the motive fluid pressure of each motor piston for closing the exhaust valve for the motive fluid of the other motor piston.

A power pumping apparatus embodying successively acting motive fluid actuated motor pistons, and admission and exhaust valves'for the actuating fluid of each piston, a pump for delivering fluid under pressure embodying a pump piston connected with the motor pistons to deliver fluid during the exhaust strokes of the motor pistons, means operated by the fluid pressure created by -t-he pump piston for opening the exhaust valves of the motor pistons alternately, one

` ated motor'pistons, and admission and exhaust valves forthe actuating fluid of each piston, a pump for delivering fluid under' pressure embodying a pump piston connected with the motor plstons to deliver iuid during the exhaust strokes of the motor pistons, means operated by the luid pressure created by the pump piston for opening the exhaust valves of the motor pistons alternately, one during each delivery stroke of the pump pistonV and means operated by the motive fluid pressure of each cylinder for closing the exhaust valve and opening the admissionvalve for the motive fluid of the other motor piston.

7. An engine, a pump having the piston thereof vin actuating connection with the piston of the engine, an exhaust valve, and means rendered operative through com ression of the fluid subject to the action o the pump and'through expansion of the engineoperating fluid to open and close said exhaust valve successively and continuously at the proper moment in the cycle of operation of the engine.

8. An engine, a pump having the piston thereof in actuating connection with the piston of the engine, an intake valve, and means l rendered operative through compression of the Huid subject to the action of the pump and through expansion of the engine-operating uid to open and close said intake valve successively and continuously at the proper moment -in the cycle of operation of the engine.

9. An explosive engine comprising a plurality of engine units, a pump having the piston thereof in actuating connection withv the pistons of said engine units, an exhaust valve for each engine unit, and means rendered operative by compression of the fluid subject to the action of the pump and by ex- .pansion of the engine-operating fluid to operate said valves successively.

10. An explosive engine comprising a plurality of engine units, a pump having the piston ,thereof in actuating connection with the pistons of said engine units, an exhaust valve and an intake valve for each engine unit, and means rendered operative by compression of the fluid subject to the action of the pump and by expansion of the engine-operating fluid to operate lthe exhaust valve and then the intake valve of one engine unit, andthe exhaust valve and intake valve of another engine unit in successively timed relation.

. 11. An explosive -engine comprising a. y

plurality of engine units each connected to and adapted to operate a common member, and said common member, an exhaust valve and an intake valve on each engine unit, a. cam shaft and cams for operating each set of valves on each engine unit, and means to rotate both cam' shafts simultaneously a quarter turn in the same direction at each explosion and compression stroke of theren- 12., An explosive engine, a pump having the piston thereof in actuating connection with the piston of the engine, an exhaust valve and an intakevalve for said engine, a cam shaft and cams thereon for operating said valves, means to rotate said shaft actuated by explosion in the engine cylinder,

'and other means torotate said shaft oper-l ated by luid compression in the pump.

13. An explosive engine, a pump having the piston thereof in actuating connection vwith the piston of the engine, an exhaust valve and an intake valve for said engine, a cam shaft and cams thereon for operating said valves, a cylinder provided with an open passageway'connecting said cylinder with the cylinder of the pump, a piston in said cylinder and connections therefrom to said shaft to rotate the same when Huid compression in the pump operates said piston.

14. An explosive engine, a pump having the piston thereof in. actuating connection with the piston of the en ne, an exhaust valve and an intake valve or said engine, a cam shaft-and cams thereon for operating said valves, a cylinder provided with an open passageway connecting said cylinder with the cylinder of the engine,a piston in said cylinder and connections therefrom to said shaft to rotate the same when an explosion 'soy takes place and the'expanding gases of com-" bustion operate said piston.

15. An explosive engine, a pump having the piston thereof in` actuating connection with the piston of the engine, an exhaust sa cy to rotate said shaft in alternation with rotation from said pump-connected cylinder,y

when an explosion takes place and `the expanding last named piston.

16. An ex losive engine, a pump having the piston t ereof in actuating connection gases of combustion operate saidj' mder of the engine, a plston in said last named-cylinder and connections therefrom l with the pistonof'the engine, an exhaust valve and an intake valve for said engine, separate valve gear including a spring-actuated lever for operating each of said valves, a cam shaft having cams in actuating engagement with said levers, and means to effect intermittent rotation of said shaft by explosion in the engine cylinder and Huid compression in the pump.

17. An explosive engine, a pump having the piston thereof in actuating connection with the piston of the engine, an exhaust valve and an intake valve for said engine, separate valve gear including a spring-actuated lever for operating each of said valves, a cam shaft having cams in actuating engagement with said levers, ratchet wheels on said shaft, der and a piston therein operable by explosion of the engine, said piston havin actuatinglconnection with one. of said paw ,and anot er cylinder, and piston therein operable by iiuid compression within the pump having actuating connection with the other of said pawls, whereby said shaft is intermittently rotated at each explosion and each compression stroke of the engine.

18. An explosive engine, a pump having the vpiston thereof in actuating connection withY the piston of the engine, an exhaust valve and an intake valve for said engine',

separate valve gear including a spring-actu-` ated lever for operating. each of said valves, a camshaft having'cams in actuating engagement with said levers, four-toothed ratchet y wheels on said shaft, pawls for said ratchets,

a cylinder and a pistontherein operable by explosion of the engine, said piston having actuating connection with one of said pawls, and another cylinder and piston therein operable by fluid compression within the pump having actuating connection with the other of said pawls, whereby said shaft is intermittently rotated a quarter-revolution at each explosion and each compression stroke of the engine.

` 19.- An explosive engine comprising a plurality of engine units each connected to and adapted to operate a common member, and

vsaid common member, an exhaust valve and an intake lvalve on each engine unit, a cam shaft and cams for operating each set of valves on each engine unit, supplemental cylinders provided with open passageways connecting said cylinders with the cylinders of the diii'erent engine units, respectively, a piston worlng in each .of said supplemental cylinders, and connections between said pistons and to the cam shafts, whereby an explosion in any engine unit will rotate all said cam shafts simultaneously. I

20. An explosive engine comprising a plurality of engine units each connected to and 'ada ted to operate a common member, and

sai common member, an exhaust valve and pawls for said ratchets, va cylinvnectin said cylinders with 'the cylinders of the di erent engine units, respectively, a piston working in -each of said supplemental cylinders, a single rod connected to both of said pistons, a ratchet fast on each cam shaft,

a swinging pawl operating therewith, and links pivotally connecting said rod and said swinging pawls.

21. An explosive engine comprising a plurality of engine units each connected to and adapted to operate a common4 member, and said common member, an intake valve for each engine unit, means operated by explosion in any one of the engines for positively opening the intake valve of'another engine at the beginning of outward movement of the engine pistons, and means for ele'cting closure of the opened valve at a predetermined point in the engine stroke.

22. An explosive engine comprising a cylinder, piston, and inlet valve with means for opening the inlet valve during thel initial outward movement of the piston and means controlling the closing of said valve embodying a fluid containing dash pot and means for regulating its speed of operation whereby the valve may be closed at the desired point in the outward stroke of the piston.

23. An explosive engine comprising an inlet valve, a shaft, a cam thereon movable between fixed limits independently of said shaft', means to rotate the shaft and thereby move the cam into active position positively to open the valve, an oil-filled receptacle comcam will elevate the piston, means actuating said rod to withdraw said cam from its active position, and means for momentarildy trapping oil beneath said piston for retar ing said'withdrawing action.

24. An explosive engine comprising an in let valve, a shaft,.a cam thereon movable between Iixed limits independently of said shaft, means to rotate the shaft and thereby move the `cam into active position positively to open the valve, an oil- :filled receptacle in said chamber, a rod connecting said piston and said cam, by which actuation of said having valves to permit flow of oil throu h said pipes opposite directions only, an a choke valve in one of said valves to regulate comprising a/ cylindrical chamber, a piston ow of oil therethrough and retard downward movement of said piston.-

25. An explosive engine comprising anjnlet valve, a shaft, a cam thereon movable between fxed limits independently of said shaft, means to rotate the shaft and thereby move the cam' into active position positively to open the valve, an oil-filled receptacle comprising a cylindrical chamber, said chamber Ibeing provided with a contracted upper portion, a piston working in said contracted ortion, a rod connecting said piston and sai cam by which actuation of said cam will raise the piston, means actuating said rod to withdraw said cam from its active position, means permitting oil to flow freely from said contracted portion to the lower portion of said cylinder, and regulable means for restricting return flow, whereby the piston willv be retarded in its return movement to a predetermined extent.

26. An explosive engine comprising a vertically mounted cylinder, a weight connected to and lifted by the piston of said engine, and an igrition system comprising a fixed contact and a pivoted Contact, said pivoted contact being provided with a weight and being spring held in non-contacting relation with said fixed contact, inertia of said pivoted contact operating to bring the same mto contacting relation at the termination of the return stroke.

In testimony whereof I affix my signature 30 i in presence of two witnesses.

KENNEDY DOUGAN. Witnesses:

H. A. BOWMAN, n F. WHITELEY.

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