US1478596A

US1478596A - Valve mechanism for internal-combustion engines

Info

Publication number: US1478596A
Application number: US329495A
Authority: US
Inventors: Dorsey F Asbury
Original assignee: Individual
Current assignee: Individual
Priority date: 1919-10-09
Filing date: 1919-10-09
Publication date: 1923-12-25
Anticipated expiration: 1940-12-25

Description

D. F. ASBURY VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed Oct; 9 1919 3 Sheets-Sheet 1 D. F. ASBURY VALVE MECHANISM FOR INTERNAL c MBUS-TION ENGINES Dec. 25, 1923.

Filed Oct. 9. 1919' 3 Sheets-Sheet 2 lllllllll. lllllllll Dec. 25, 1923.

D. F. ASBURY VALVE MECHANISM For: INTERNAL comauswzon ENGINES s She ets-Sh'eet 5 Filed Oct. 9, 1919 Patented Dec. 25, i923.

aliases sins- VALVE MECHANISM FOR INTERNAL-COMBUSTION ENGINES.

Application filed October a, 1919. Serial No. 329,495.

1 0 aZZ whom it may concern .1

Be it known that I, DORSEY F. AsBURY, a citizen of the United States, residing at ll ashington, in the District of Columbia, have invented certain new and useful Improvements in Valve Mechanisms for Internal-Combustion Engines, of which the following is a specification.

My present invention relates to improvements in valve mechanisms for internal combustion engines, and it aims to provide an arrangement for controlling the inlet of explosive mixture and the exhaust of the products of combustion which is simple in construction as well as highly efficient in operation.

A particular purpose of the invention is to provide a valve mechanism the operation of which will be controlled automatically by the intake of explosive mixture and the exhaust of the products of combustion whereby it will operate smoothly irrespec tive of the speed of the engine.

Another purpose aimed to accomplish is to so construct and relatively arrange the parts of a valve mechanism embodying the above named features as to reduce toa minimum and practically entirely eliminate the waste of explosive mixture through the valve mechanism during operation of the engine.

The invention consists, essentially, in providing independent valves for controlling the intake and exhaust and further consists in the employment, in conjunction with these valves, of another valve for separating t two valves from the explosion chamber during compression and firing periods of the engine and it is another purpose of the invention to so construct and relatively arrange these three valves as to utilize a single spring as a closing means for each of them.

Further, it is a purposeof the invention to so construct and relatively arrange the intake and exhaust valves as to utilize the impulse produced by the exhaust to open the exhaust valve, to force the intake valve against its seat and maintain it closed during the exhaust period, and to' delay closing movement of the exhaust valve until the exhaust substantially ceases, all of which action results in the engine being relieved of the greatest possible amount of burnt gases, the absence of waste of explosive mixture and an efficient operation of the engine generally. Valves constructed as herein disclosed, that is, valves provided with means to utilize the impulse produced by the exhaust for the purposes just stated not only accomplish the purposes mentioned but permit of a stronger spring being used to force them against their seats than would be possible in the absence of such means.

As a further purpose the invention aims to provide means to cushion the exhaust valve prior to the same reaching its limit of movement to both closed and open positions to thereby eliminate pounding of this element and assure its smooth, noiseless operation and longevity.

The invention consists in other advantageous details of construction, combination and arrangement of parts as will be referred to more particularly hereinafter in connection withthe accompanying drawings wherein are illustrated the best embodiments of the invention known to me at present. The invention, however, is susceptible to modification and change in various respects and I therefore reserve the right to make such changes from time to time as may be advantageous and as are included within the scope of the appended claims.

In the accompanying drawings 7 Fig. 1. is avertical section through a portion of an internal combustion engine and illustrating the application of one form of the improved valve mechanism, the parts thereof being shown in the position they occupy during compression and firing periods of the engine.

Fig. 2, a perspective view of the valve mechanism, the parts thereof being separated.

Fig. 8, a view similar to Fig. 1 illustrating the relative positions of the valve parts during exhaust periods of the engine.

Fig. 4, a View similar to Fig. 1 illustrating the relative positions of the valve parts during intake periods of the engine.

Fig. 5, a view similar to Fig. 1 illustrating a slight variation in the form of the invention.

Fig. 6, a perspective of the intake valve disclosed in Fig. 5, and

Fig. 7, a horizontal section on the line 77 of Fig. 5.

Referring now to the drawings in detail, a portion of an internal combustion engine'is indicated generally by the letter A and as shown comprises, as is usual, a cylinder 10, piston 11, and valve chamber 12. In the present instance the valve chamber is disposed laterally with respect to the cylinder and provided with a, port 13 which provides a means of communication between the cylinder and relatively separated intake and

exhaust passages

14 and 15 respectively. Threaded in an opening in the upper wall of the engine, in vertical alignment with the port 13, is a cap 16 which upon removal enables access to be had from the top of the engine to the valve mechanism. Carried by the cap 16 is theusual spark plug 17 The port 13 is restricted in diameter with respect to the valve chamber 12, and below said port the wall of the chamber is cored out from the lower open end of the chamber throughout a major portion of its length to a point where a shoulder 18 is formed, substantially in horizontal alignment with the dividing wall between the intake and ex- '4

haust passages

14 and 15.

A hollow cylindrical valve cage 19 of lesser external diameter than the diameter of the chamber 12 is provided with an externally threaded cir'cumscribing offset portion 20 which is screwed in the lower end of I P the chamber 12, the upper end of said cage being provided with a circumscribing flange 2-1,'which, when the cage, is in proper place within the valve chamber, abuts the shoulder 18 in fluid tight engagement. Internally the cage isof uniform diameter throughout its length except that near its lower end a minor portion of its length is reduced in diameter by an inwardly directed annular boss 22. Between the offset portion 20. and the flange 21 apertures 23. are cut in the wall of the cage to provide a means of communication between the inlet passage 14 and the interior of the cage, the passage 14 being at all times in: open communication with the space in the valve chamber surrounding thecage, as is apparent from an inspection of the drawings.

Housed by the cage 19 is an exhaust valve designated generally by the numeral 24. This valve comprises a hollow cylindrical portion 25 closed at its lower end by a. Wall 26 and open at its. upperend as shown, said cylindrical portion being provided with apertures- 27 similar to the apertures23 of the cage 19, while a stem 28 extends centrally from the lower face of the bottom wall 26 and is externally threaded as at 29.v A. valve seat 30 is formed around the upper open end of the portion 25 and surrounding said seat and'the cylindrical portion 25 from which it laterally projects is a flange 31, the upper surface of which is cupped or dished at 32 and extended beyond the openend of the portion 25 in the direction of the longitudinal axis of the valve, as at 33, best illustrated in the sectional views. An axial bore 34 extends through the stem 28' and bottom wall 26.

When arranged in proper relation to the cage 19 the cylindrical portion 25 of the exhaust valve fits snugly within the cage yet is freely slidable therein longitudinally, the

length of the valve chamber between the upper surface of the boss 22 and the port 13 being greater than the length of the exhaust valve between its upper open end and the bottom wall 26 to permit suchsliding move ment; the stem 28 is. slidably engaged in the opening in the boss 22 and the flange 31' is similarly engaged in the upper end of the valve chamber.

A portion of the 'dished surface 32 of the flange 31 near the valve seat 30 is formed into a seating surface, which, when the exhaust valve is closed, that is, at its limit of upward movement, contacts with a seat 35 surrounding the port 13 below said port and denies communication between the cylinder and the exhaust passage 15. In this posidisposed in alignment, permitting free com- Inun-ication between the intake passage 14 and the interior of the valve.

Engaged with the threads 29 on the stem 28 is. a collar 36 provided with a lateral circumscribing flange37. This flange is slidably engaged in the cage 19 below the boss 22 and cooperates with the boss to form a dash pot. for cushioning closure of the exhaust valve.

Attached. to the bottom'26 is a pin 38 which is slidably engaged in an opening through the boss 22 and functions to prevent relative: rotation of. the, valve and ca e.

in intake valve is designated generally by the numeral 39 and comprises a head 40 and a stem: 41. A seatingsurface 42 is formed on the head 40 and when the valve is properly arranged with respect to the exhaust valve 24 thi seating surface is designed to cooperate with the seat 30 of the exhaust valve when the intake valve is closed, to deny communication between the cylinder and the interior of the exhaust valve. The stem 41 is of a length so that when. the intake valve is seated a very slight clearance of approximately a two-thousandths of an inch'is provided between the end of, the stem and the upper surface of the bottom 26 of the exhaust valve. It is possible to make this clearance so slight rev that in effect the intake valve possesses plural seating surfaces, the first between'the surface 42 and the seat 30 of the exhaust valve and the second between the lower end I of the stem 41 and the upper surface of the,

bottom26 of the exhaust valve. The purpose of the slight clearance is-to permitra positive seal between the seating surface 42 and the seat 30.

The upper surface of the head is shaped to form substantially a continuation of the seating surface of the exhaust valve when the inlet valve is closed, said upper surface of the head 40 being then curved upwardly and terminated at the top of the head which is flat and provided with an annular recess 43. The metal joining the head with the stem is curved gradually as shown at 44, and longitudinally through the head and stem is formed a bore 45 corresponding in diameter to the bore 34 of the stem 28 of the exhaust valve. 7

A valve seat 46 surrounds the port 13 above said port, that is between the port and the cylinder, and cooperating with this seat is a cylinder valve 47. Said valve 47 is recessed in its under face to correspond in shape to the upper surface of the head 40 of the intake valve and the relative arrangement of these similarly shaped surfaces in such that a slight space exists therebetween when both valves are closed;

Projecting centrally from the lower face of the cylinder valve is an elongated stem 48 which passes through the bore 45 in the intake valve and through the bore 34 in the stem of the exhaust valve-and carries at its lower end an adjusting sleeve 49 which is lockedin place on the stem bya nut 50.

A spring washer 51 of any desirable type is arranged in the annular recess 43 of the intake valve head and exerts an influence tending to relatively separate the intake and cylinder valves, while a strong expansion spring 52 is arranged between the adjusting sleeve 49 and the collar 36 and exerts an influence tending to overcome the spring washer 51 and maintain the cylinder valve normally seated.

Secured to any suitable manner to the cylinder wall is a bracket 53 having an openingwithin which is slidably arranged a valve lifter 54 actuated by a cam 55 on a cam shaft 56.

The form of the invention illustrated in Fig. 5 of the drawings differs but Slightly from the form of the invention just described. In Fig. 5 both the cylinder valve 47 and the head 40 of the intake valve are constructed substantially flat, the latter being comparatively thin and to a certain extent flexible so as to more readily accommodate itself to' its seat-s. In other respects the mechanism illustrated in this figure is a duplicate construction of the mechanism illustrated in the previous figures of the drawings. Both mechanisms operate in the same manner.

Having described the invention its operation will be apparent and is as follows Suitable gearing (not shown) rotates the cam shaft 56 half as fast as the crank shaft (not shown) of'the engine. The parts of the valve mechanism being in'the position shown in Fig. 1, let it be assumed that a compressed charge of explosive mixture fills the cylinder head and that the same has been ignited by a spark from the plug 17. Expansion of the exploded gases forces the piston downward during which movement the cam shaft isgiven a rotation of ninety degrees. Just prior to the completion of this amount of m vement, however, a portion of the cam is arranged to contact with the valve lifter 54 and begins to move the same upwardly. The upper end of the valve lifter coming in contact with the nut 50 of the lower end of the valve stem 48 imparts an upward movement to said valve stem and acts to unseat the cylinder valve 47 allowing the pressure existing in the cylinder to reach the upper surface of the head 40 of the inlet valve 39. Only a very slight lifting or unseating movement of the cylinder valve is necessary to allow the pres sure within the cylinder to reach the head of the inlet valve. The spring washer 51 therefore functions to maintain the inlet valve closed upon its seat during the slight initial unseating movement of the cylinder valve to prevent the exhaust pressure from making under the intake valve and unseating same. As soon as the exhaust pressure acts upon the upper surface of the intake valve its contact with its seat during the remainder of the exhaust period is assured.

As the piston moves upward and the cylinder valve opens farther the pressure of the exhaust, being greater than the strength of the spring 52, acts through the inlet valve to force the exhaust valve downward or in a direction to unseat the same against the action of said spring, thereby allowing the exhaust gases to escape from the cylinder to the exhaust passage 15.

As the exhaust gases flow through the port 13 they contact with the dished upper surface of the inlet valve head 40 and flange 31 of the exhaust valve and due to the curvature of said dished surfaces the direction of flow of the exhaust current is deflected from the line of least resistance and an impulse action thus imparted to the dished surface to, move the exhaust valve to full open position against the action of the spring 52, the action of the exhaust gases here being similar to the action of steam imparting an impulse action to the vanes of a turbine engine.

- An advantage of particular importance to be noted in connection with the provi sion of impulse receiving means on the ex-g haust valve is that this valve is maintained open throughout substantially the entire exhaust period of the engine as determined by its arrangement of valve operating cams and is delayed in its closing movement due to the fact that an exhaust current of very low velocity exerts a powerful impulse and therefore the valve will not begin to close under spring action until the exhaust substantially ceases; also that a much stronger closing spring is possible of use than would be permissible in the absence of means to utilize the impulse produced by the ex-' haust' for opening the exhaust valve against the spring; 7

It will be apparent thatthe intake valve is maintained closed against the exhaust valve by the pressure of the exhaust and also by impulse and that the dash pots function to cushion the exhaust valve in its movement from closed to open position.

With the cylinder valve maintained fully open by the cam and the exhaust valve maintained fully open by the impulse produced by the exhaust acting on the dished surface of the flange 31, as'illustrated in vFig. 3 of the drawings, the upper face of the adjusting sleeve 49 is slightly spaced from the lower face of the stem 28 of the exhaust valve. U

Formed on the cam 55 is' a slight bulge 57 arranged to contact with the valve lifter 5a and kick? the same upward at a time when the spring 52 is ready to overcomethe impulse action of a weakened exhaust vcurrent.

This kick is transmitted through the sleeve 49 and stem 28 to theexha'ust valve and gives the valve an initial momentum in a closing direction. It also'serves to break up any sticking action of the exhaust valve within the cage 19. v

Once the exhaust valve is started on its movement in a closing direction the spring 52 adds momentum to such movement until 2 it is arrested by the cushioning eifect of the dash pot formed by the flange 37 and the boss 22.

With the vanishing of the exhaust pressure the inlet valve is held' closed during closing movement of the exhaust valve by its inertia. When the exhaust valve is arrested in its closing movement, the momen tum of the intake valve causes it to leave its seat and travel freely up the stem 48' of the cylinder valve. The piston now having begun its intake stroke the suction thus created draws a new charge of explosive mixture from the intake passage 14 through the

aperatures

23 and 27 and through the exhaust valve into the cylinder, the gases acting upon the intake valve in a Well It being understoodin what manner the spring 52 functions to close both the. exhaust and cylinder valves, by exerting a push on the former aiid a pull on the latter, it remains only to point out that the pulli on the cylinder valv-e is transmitted through the spring washer 51 to the intake valve to maintain the latter seated to see that the spring 52 functions to close all three valves, it being understood that the washer 5l is not absolu ely essential to the operation of tli'e valve mechanism but is merely included in the arrangement because of the element of safety it affords.

. Thecomp'act arrangement of the parts of the valve mechanism eliminate all spaces noticeable inother similar types of valve iiiechani'sms where explosive mixture might be lost during operation of the engine, and

due'to the arrangement of'thevalves and the f 1. Ina valve mechanism for internal combustion engines, a spring closed exhaust valve, *means'. acted upon by the exhaust products to impart opening movement to the valve, and a dished impulse receiving surface on the valve acted upon by the escaping exhaust products to also impart opening'movement to the valve,

21111 a valve mechanism for internal combustion engines,- an exhaust valve having one portion thereof adapted to receive the impulse of theexhaus-t products to open the valve, said portion also acting as the plunger element of a dash pot to cushion said valve as it approaches open positlon.

3 .In a valve mechanism for internal combustion engines, an exhaust valve havinga dished impulse receiving surface acted upon by the escaping exhaust products to impart opening" movement to the valve. 7

4'. In a valve mechanism, for internal combustion engines, an exhaust valve, and an intake valve movable relatively to the exhaust valve and actuated by exhaust products to impart opening movement to the exhaust valve.

* 5. In a valve mechanism for internal ing movement to the exhaust valve, an

an impulse receiving surface on the exhaust valve acted upon by the escaping exhaust products to also impart opening movement to the exhaust valve.

6. In a valve mechanism for internal combustion engines, a spring closed exhaust valve, an intake valve acted upon by the exhaust products to impart opening movement to the exhaust valve, and an impulse receiving surface on the exhaust valve acted.

upon by the escaping exhaust products to also impart opening movement to the ex haust valve.

7. In a valve mechanism for internal combustion engines, an exhaust valve, and an inlet valve seated on the exhaust valve and acted upon by the exhaust products to impart opening movement to said exhaust valve.

8. In a valve mechanism for internal combustion engines, an exhaust valve, and a relatively movable inlet valve seated on said exhaust valve and acted upon by the exhaust products to impart opening movement to the exhaust valve.

9. In a valve mechanism for internal combustion engines, a spring closed exhaust valve opened by exhaust products directly impinging against the valve, and means for initiating closing movement of the valve in addition to that imparted by its spring.

10. In a valve nechanism for internal combustion engines, a spring closed exhaust valve opened by exhaust products directly impinging against the valve, and cam means initiating closing movement of the valve in addition to that imparted by its spring.

11. In a valve mechanism for internal combustion engines, a puppet valve movable to closed position in one direction and an exhaust valve movable to closed position in an opposite direction, said valves being relatively independently movable, and a single spring normally urging both of said valves to a closed position.

12. In a valve mechanism for internal combustion engines, an exhaust valve, a relatively movable intake valve carried by the exhaust valve during closing movement of the latter, and free to move toward open position by its momentum when the closing movement of the exhaust valve is arrested.

13. In a valve mechanism for internal combustion engines, a puppet valve, an exhaust valve, a single spring for moving both of said valves to closed position, and an intake valve movable relatively to said puppet valve and said exhaust valve and initially moved toward open position by its momentum when closing movement of the exhaust valve is arrested.

14. In a valve mechanism for internal combustion engines, an exhaust valve, and an intake valve maintained closed by its inertia against the exhaust valve during closing movement of the latter, said intake valve being free to move to open position by its momentum when closing movement of the exhaust valve ceases.

157' In a valve mechanism for internal combustion engines, an exhaust valve having a seating surface at one end thereof, and a dished impulse receiving surface on said valve outwardly of the seating surface and extending beyond the seating end thereof in the direction of the longitudinal axis of the valve.

16. In a valve mechanism for internal combustion engines, a spring closed exhaust valve actuated by the pressure of exhaust products to open position, and a dished impulse receiving surface on said valve acted upon by the escaping exhaust products to delay closing movement of the valve.

17 In a valve mechanism for internal combustion engines, an exhaust valve having a seating surface at one end thereof, and an impulse receiving flange surrounding the seating surface.

18. In a valve mechanism for internal combustion engines, an exhaust valve having a seating surface at one end thereof, and an impulse receiving surface on said valve dis posed outwardly of said seating surface.

19. In a valve mechanism for internal combustion engines, an exhaust valve, an intake valve for imparting opening movement to the exhaust valve, and an impulse receiving surface on the exhaust valve acted upon by escaping exhaust products to also impart opening movement to the exhaust valve.

20. In a valve mechanism for internal combustion engines, a spring closed exhaustvalve, an intake valve seated thereon, and means whereby said exhaust valve is actuated to exhaust open status by exhaust products.

21. In a valve mechanism for internal combustion engines, a puppet valve, an exhaust valve, an intake valve, and a single spring producing closing movement of each of said valves.

22. In a valve mechanism for internal combustion engines. an exhaust valve. and an intake valve seating against said exhaust valve, said intake valve being unrestrained during its opening movement.

In testimony whereof, I affix my signature in the presence of two witnesses.

DORSEY F. ASBURY.

Witnesses CARROLL BAILEY, HENRY P. BRIGHT.