US1360074A - Explosion-alleviator for internal-combustion engines - Google Patents

Description

B. BANNISTER. EXPLOSION ALLEVIATORFOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED FEB. 25,1920- 1,360,074. Patented Nov. 23,1920.

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A TTORNE Y B. ammsm. EXPLOSiON ALLEVIATOR-FOR mum/u comau'snou mamas. I APPLICATION FILED FEB. 25, 1920. 074 Patented Nov. 23, 1920.

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INVENTOR A TTORNE Y UNITED STATES PATENT OFFICE.

BRYANT BANNISTER, 0F PITTSBURGH, PENNSYLVANIA.

EXPLOSION-ALLEVIATOK FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent. Patented N 23 192() Application filed February 25, 1920. Serial No. 361,225.

possible the employment of a high compression without the occurrence within the cyl inder of a correspondingly high explosion pressure at any instant.

Another object of the invention is to provide means which smooth out the high pressure impulse, incident to the explosion of the combustible charge, over an increased portion of the power stroke of the engine piston; thus not only damping the sharp initial rise in pressure during combustion of the charge, but also preventing the usual abrupt drop in pressure during expansion.

A further object of the invention is to provide valve means which serve to secure the full effect of the pressure alleviation and conservation by operating with sufficient speed after ignition of the combustible charge to permit expansion into an auxiliary clearance space during the progress of combustion.

A practical advantage foregoing is, that internal combustion engines may be readily modified so as to materially increase compression and secure a substantial gain in available power and in economy, without greater stress in, or shock to the engine parts. Thus by decreasing the clearance space within the cylinder, or cylinders, of the engine, or by increasing the piston displacement without increasing the is applied.

derived from the ance itself loses all value.

cure economy in manufacture by lessening the amount oi metal 111 the cylinder, or cylinders, oi the engine to which the device In the accompanying drawings Figure 1 1s a vertical cross section through one embodiment of the invention; Fig. 2 is a detail view of a modification thereto; Fig. 3 is a vertical cross section through another embodiment of the device; Fig. 4 is a view of two valve units connected to a common auxiliary clearance, one unit being shown in plan, and the other being shown in horizontal section on the line 4-4, Fig. 3; Fig. 5 is a detail view in longitudinal section of a portion of the valve mechanism illustrated in Figs. 3 and 4; Fig. 6 is a cross sectional view on the line 6-6, Fig. 5; Fig. 7 is a further embodiment of the device, showing mechanical means for lifting valve.

All embodiments of the invention show a device arranged to besecured to a cylinder of an internal combustion engine, and to communicate with the clearance space within the cylinder.

In the embodiment of the invention illustrated in Fig. 1 of the drawings, the reference numeral 1 designates an auxiliary clearance, or expansion chamber, which communicates with the interior of the cylinder by way of passage 2. Controlling the passage 2 from the cylinder clearance is a valve 3 having a seat 4: within the passage.

It is necessary, in order that a smooth distribution of the explosive force be obtained, that the valve. should be maintained in its open position during a sufficient portion ofthe power stroke to permit yurcssure, which has been built up in the auxiliary clearance during combustion to do work upon the engine piston pressure within. the cylinder tends to drop.

It is necessary that the valve means c0ntrolling communication between the clear ance space of the cylinder and the auxiliary clea 'ance, be made exceedingly sensitii e, or

be positively actuated for opening at the proper instant. It is obvious that it the valve is not lifted before the combustion in the cylinder is complete, the auxiliary clean Speed of valve lifting-is therefore a prime requisite in a device of this general character; and it is necessary in order to secure the desired results that the valve should be hited from its seat within a few ten thousandths of a second from the instant ofignition. Heavily loaded valves cannot, therefore, be employed; as they do not possess this requisite sensitivity, and devices employing such valves are inoperative to alleviate or damp the explosive force within the cylinder. It is a fact that the speed of combustion of a charge within a cylinder is practically independent of the speed of travel of the piston therein. The valve between the cylinder clearance and auxiliary clearance must therefore, be lifted with great speed irrespective of the typeof engine to which the device is applied.

In the form illustrated in Fig. 1, the means for so operating the valve comprise an electromagnet having a core 5, solenoid 6, and shrouding 7; together with means for passing an electric current through the solenoid and energizing the magnet upon the occurrence of a predetermined pressure within theengine cylinder.

The energizing and controlling means for the magnet comprise a battery or generator wire 8, one terminal of which is connected with the solenoid 6, and the other to an insulated contact 30st 9, adjustable in a suitable plug 10. ne terminal of the return wire 11 0f the circuit is connected to the solenoid, and the other to a diaphragm 12 carrying the contact point 18 arranged to cooperate with the point 14: of contact post 9. The inner face of the diaphragm is in communication with the cylinder side of passage 2 by way of duct 15.

The diaphragm 12 is made of such rigidity, and the contact point 1 1 may be so adjusted relatively to contact point 13 that the diaphragm 12 will be forced outwardly a sufiicient distance to make contact between the points when the pressure communicated to the inner face of the diaphragm from the cylinder, by way of passage 2 and duct 15, reaches a certain predetermined point. This point must be above the pressure caused by compression within the cylinder. The cir cuit is completed by the contact of the points 13 and 1 1, and the magnet energized to raise the valve 3 from its seat a in the valve body. The arrangement described is capable of lifting the valve within but few ten thousandths .of a second from the instant at which the predetermined pressure is reached.

When the valve 8 is lifted, it is guided by its stem 16, which extends into a guiding recess 17 in the lower extremity of the core 5 of the magnet. lVhen fully lifted, the valve lies in contact with a bushing 18, of

' brass or other non-magnetic material, which may preferably be provided to extend down wardly beyond the core 5 so that the valve does not come into actual contact with the core 5 or shrouding 7.

Upon a lowering of the pressure within the cylinder below the predetermined point, the diaphragm will spring back to break the contact between the contact points 13 and 1 1, thus deenergizing the magnet and permitting the valve 3 to fall back upon its seat 4.

here engine speeds are high, means may be provided to return the valve promptly to its seat after the solenoid has been deenergized. Such means are illustrated in Fig. 2 of the drawing which shows a modification of the construction illustrated in Fig. 1, and comprise a leaf spring 19 held by posts 20 on the upper surface of the shrouding T of the magnet. in this modified construction a bumper post 21 extends completely through the longitudinal center of the core 5 of the magnet, and is secured to the spring 19 by suitable means such as the nut 22. It is to be understood that the spring 19 is for the purpose of returning the valve quickly to its seat, and that bumper post 21 and spring 19 retard travel of the valve during the extreme portion of its upward movement only.

In the embodiment illustrated in F 3 and 1 of the drawings, a valve 3 controls communication between the clearance of an engine cylinder and an auxiliary clearance or expansion chamber 1. In this form also, the alve is arranged to be opened with great speed; but in this embodiment, the valve is lifted by preponderance of pressure in the engine cylinder over that in the auxiliary clearance, and is held open until the pressure in the auxiliary clearance drops below a predetermined point.

lrieans are also provided for holding the valve open, after ithas been raised by the preponderance of cylinder pressure, during a considerable portion of the power stroke. Such means comprise a locking rod 23, F 6, having thereon a head 24- arrangcd to frictionally engage the stem 25 of the valve 3" when the valve is in its lifted position. The locking rod 23 is secured to a diaphragm 26 held in position in valve body 27 by a suitable retaining ring, by having a screw threaded engagement in a boss 28 on the diaphra gm 26. The inner face of diaphragm 26 is in communication by way of duct 29 with the auxiliary clearance side of passage 2.

The operation of the valve in this embodiment of the invention is as follows: Valve 3*, during combustion of the charge within the engine cylinder, starts to rise at the instant the pressure within the cylinder reaches a point of preponderance over that within the auxiliary clearance chamber. Upon lifting of the valve, and consequent increase of pressure within the auxiliary clearance, the diaphragm 26 is forced outwardly, bringing the head 24 of locking rod 23 into frictional engagement with valve stem 25. The diaphragm 26 thus serves to maintain the valve in open position during a portion of the power stroke in the cylinder, thus permitting pressure in the auxiliary clearance to do work upon the engine piston. Upon a drop in the pressure in the auxiliary clearance below a predetermined point, which may be determined by the de ree of rigidity of diaphragm 26, the diap ragm moves inwardly to disengage head 24 of rod 23 from the stem 25 ofthe valve 3. It is understood that when the auxiliary clearance pressure has dropped to this point, the pressure within the cylinder has dropped still farther so that it does not oppose the closing of the valve. The diaphragm 26, mustbe of such a predetermined degree of rigidity that the valve 3* willbe permitted to close before the pressure in auxiliary clearance chamber 1 has dropped to a point as low as the pressure caused by the compression in the cylinder.

A spring 30 is preferably arranged in a recess in the body of the device 27 to bear againsta bumper post 31, which is in line with the stem 25 of the valve. A space is provided between the extremity of bumper post 31 and the extremity of the valve stem 25 so that the valve stem contacts the bumper post and compresses spring 30, only as the valve approaches the extreme limit of its upward travel. The spring acts, therefore,

merely to assist quick reseating of the valve upon a sufiicientdrop in auxiliarychamber pressure. It will thus be seen that the valve is completely unloaded so far as its unseating is concerned and that it free to respond instantaneously to the operative variations in pressure. The auxiliary clearance chamber is preferably provided with a heat insulating lining 32, so that loss of heat, due to this-increasedradiating surface, is minimized. As shown in Fig.4:of the drawings, the auxiliary clearance chamber is preferably made common to all the cylinders of an engine, when theengine to which the device is applied is of the multi-cylinder type. In such case, the auxiliary clearance has i a valve controlled communication with the clearance space ofeach of the cylinders. It is to be understood that the common auxiliary clearance may be applied equally well in connection with any of the embodiments of the invention; and also, that the scope of the appended claims is not to be limited to the use of the device with either a single cylinder or a multi-cylinder engine.

In Fig. 7 of the drawings, th-re is illus trated a further embodiment of the device in which mechanical means are provided for lifting the valvecontrolling communication between the, auxiliary clearance space 1 and the clearance space within the engine cylinder. In this embodiment, the valve 3 has a stem 33 carrying a collar 34 on which bears a spring 35 for normally maintaining the valve in its closed position. The valve" is lifted at the desired. intervals by means of a cam 36 cooperating with a roller 37 on the extremity of the valve stem or push rod 33. The valve 3 is maintained in its open position during a portion of the power stroke in the cylinder by means of the cam 36 which is designed to bear against the roller 37 for an appreciable interval of time. As

soon as the cam has passed the valve stem, spring 35 serves to restore the valve to its seated-position. The cam 36 iscarried b the main or an auxiliary cam shaft 38,whic 1 tive in its operation It does, however, present the disadvantage that itsoperation is governed by the piston speed of the engine, and not by the speed of combustion.

In all embodiments of the invention, the device functions to secure the same general effects. Upon lifting of the valve during combustion in the cylinder, the gas already in the auxiliary clearance is further compressed and thepressure in this chamber is raised to a relatively high point. pressure within the cylinder drops, this pressure within the auxiliary clearance acts uponthe piston in the cylinder to do work thereon, the valve remaining lifted during this interval. The valve is closed before the pressure in the auxiliary clearance has been completely dissipated. In all forms of the device the regulation of the means for opening the valve between the engine cylinder and the auxiliary clearance chamber, or for holding this valve open, is such that a pressure above that caused by compression in the engine cylinder is maintained in the auxiliary clearance chamber at all times during normal operation of the engine.

'i\l.l embodiments of the inventlon pro vide constructions which attain the high speed of valve lifting requisite in order to render the device operative.

hat I claim is: i

1. In conjunction with an internal combustion engine an auxiliary clearance chamher in communi-ation with the clearance space of a. cylinder, and unloaded valve means controlling such communication, said valve means being arranged to .open only upon the occlu'rence within the cylinder of a pressure higher than that caused by compression therein.

2. In conjunction with an internal co111- bustion engine an auxiliary clearance cha1nher in communication with the clearance space of a cylinder, valve means controlling such communication, said valve means being arranged to open only upon the occurrence" within the cylinder of y a pressure As the i ments previously described in that it is posihigher than that caused by, compression therein; andimeans comprising a diaphragm controlling the reseating ofsaid valve means I bustion engine an auxiliary clearance chamber in communication with the clearance space of a cylinder, unloaded valve means controlling "such communication, and independent means for maintaining such valve means inopen position during a portion of the power stroke in the cylinder.

5. In conjunction with an internal combustion engine an auxiliary clearance chamber in communication with the clearance space of a cylinder, valve means controlling such communication and maintained in closed position during compression within the cylinder by a preponderance of pressure within the auxiliary clearance, and independent means comprising a diaphragm for maintaining said valve in open position during existence in the auxiliary clearance L chamber of pressure above a predetermined point.

6. In conjunction with an internal coinbustion engine an auxiliary clearance chamber in communication 'with the clearance space of a cylinder, unloaded valve means controlling such communication and arranged 'to be lifted by preponderance of cylinder pressure over auxiliary clearance pressure; and independent means in communication with said auxiliary clearance and arranged to maintain the valve when lifted in open position until auxiliary clearance pressure drops below a predetermined point.

7. In conjunction with an internal combustion engine an auxiliary clearance chamber in communication with the clearance space of a cylinder, unloaded valve means controlling such communication and arranged to be lifted by prepond rance of cylinder pressure over auxiliary clearance pressure; a locking member arranged to con- 7 tact the valve means for maintaining such valve means in open position, and a diaphragm in communication with the auxiliary clearance chamber and arranged to release said valve means upon a drop in auxiliary clearance pressure below a predetermined point'.

8. In conjunction with an internal combustion engine an auxiliary clearance chamber in communication with the clearance space of a cylinder, unloaded valve means controlling such communication, an electromagnet, and yielding'means in communication'with the clearance space of the cylinder and arranged to make and break the circuit of said magnet for lifting and releasing said valve means. I

9. In conjunction with an internal combustion engine an auxiliary clearance chamber in communication with the clearance space of a cylinder, valve means controlling such communication and maintained in closed position during compression within the cylinder by a preponderance of pressure within the auxiliary clearance, and yielding means for maintaining said valve in open position during existence in the auxiliary clearance chamber of pressure above a predetermined point.

1.0. In conjunction with an internal combustion engine an auxiliary clearance chamber in communication with the clearance space of the cylinder, unloaded valve means controlling such communication and arranged to be lifted by preponderance of cylinder pressure over auxiliary clearance pressure; a diaphragm in communication with said auxiliary clearance chamber, and a rod on said diaphragm arranged to trictionally engage said valve means for maintaining the latter in open position.

11. In conjunction with an internal coinbustion engine an auxiliary clearance chamber in communication with the clearance space of a cylinder, unloaded valve means controlling such communication. said valve means being arranged to open only upon the occurrence within the cylinder of a pressure higher than that caused by compression therein, and means responsive to pressure 'ariations for controlling the resenting of said valve means.

12. In conjunction with an internal combustion engine an auxiliary clearance chamber in communication with the clearance space of a cylinder, unloaded valve means controlling such communication, said valve means being arranged to open only upon the occurrence within the cylinder of a pressure higher than that caused by compression therein, and resilient means arranged to quicken the resenting movement of Filld valve means.

13. In conjunction with an internal combustion engine an auxiliary clearance chamber in communication with the clearance space of a cylinder, valve means controll ng such communication, said valve means bemg arranged to open only upon the occurrence within the cylinder of a pressure higher than that caused by compression therein: means comprising a diaphragm controlling the reseating of said valve, and leSllltllt means arranged to bear against said valve means in fully open position of the latter and to quicken the resenting movement ot the valve means.

14. In conjunction with an internal conr bustion engine an auxiliary clearance cha1nher in communication with the clearance space of a cylinder, unloaded valve means controlling such communication, independent means for maintaining said valve means in open position during a portion of the power stroke in the cylinder, and resilient means arranged to quicken the reseating movement of said valve means.

15. In conjunction with an internal combustion engine an auxiliary clearance chamher in communication With the clearance space of a cylinder, unloaded valve means controlling such communication, said valve means being arranged to open only upon the occurrence Within the cylinder of a pressure higher than that caused by compression therein, means responsive to pressurevariahand.

BRYANT BANNISTER. lVitnesses FLORENCE F. SCHWARTZ, Gianrm W. ALsroN.

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