US2600251A

US2600251A - Starter for free piston engines

Info

Publication number: US2600251A
Application number: US633222A
Authority: US
Inventors: Frank M Lewis; Willard A Morain
Original assignee: Baldwin Lima Hamilton Corp
Current assignee: Baldwin Lima Hamilton Corp
Priority date: 1945-12-06
Filing date: 1945-12-06
Publication date: 1952-06-10
Anticipated expiration: 1969-06-10

Description

June 10, 1952 F. M. LEWIS ET AL STARTER FOR FREE PISTON ENGINES 2 SHEETSSHEET 1 Filed Dec. 6, 1945 Elma/am E FRANK M. LEWI WILLARD A.MURAIN June 10, 1952 F. M. LEWIS ET AL 2,600,251

STARTER FOR FREE PISTON ENGINES 2 SHEETSSHEET 2 Filed Dec. 6, 1945 $3 wmQ awe/1M WIS v J FRANK M. LE WILLARD A.MURAIN Patented June 10, 1952 STARTER FOR FREE PISTQN ENGINES Frank M. Lewis, Weston, Mass, and Willard v A. Morain, Hamilton, Ohio, assignors, by mesne assignments, to Baldwin-Lima Hamilton Corporation, a corporation of Pennsylvania Application December 6, 1945, SeriaLNo. 633,222

(Cl. (Se-l4) 25 Claims.

This invention relates to engine starters, and particularly to such starters adapted for use .in connection with internal combustion engines of the free piston type.

It is necessary in starting such engines to first place the work pistons .at their outer terminal positions and then to force them to their inner .terminal positions with a velocity substantially comparable to that of the .compression stroke in normal running of the engine whereby pressure and temperature of sufiicient values may be generated in the combustion chamber to ignite an injected fuel charge after which the .engine will operate in the regular way.

The object of the present invention is the provision of a simple, noveland .efiicient pneumatic starter of the character described, which will meet the mentioned requirements.

The invention is .fully described in the following specification, and a preferred embodiment thereof illustrated in the accompanying drawings, in which:

Figure 1 is a central longitudinal sectional view of one end portion of afree piston engine with the starting means embodying the invention associated therewith; Fig.2 is an enlarged sectional detail of saidstarting means; Fig. 3 is a sectional view of a suitable isolation valve; and Fig. 4 is a somewhat enlarged central vertical sectional view of one of the governor control valves.

Referring to the drawings, l designates more or less diagrammatically one piston set of an internal comubustion free piston engine including opposed piston sets, each set comprising a working piston '2 operating in a chamber 3, an

air compressor piston '4 operating in a cylinder 5,

and a direct bounce piston 55 operating in a chamber 1. The piston 4 divides the cylinder 55 into an air compressor chamber Bianda-reverse bounce chamber 5 The two piston sets are forced outward .by combustion of charges there- 'between in the chamber '3, supplemented by the effect of any pressure in chamber 5", and arereturned to compress charges therebetween by the force of air compressedinthe bounce chambers l, auxiliary spaces l B, and re-expansion of air trapped in clearance of compression .chambersii during outward movements of the pistons. The two directbounce auxiliary chambers I0 are con nected'by a pressure equalizer pipe 8 while the chambers so that they will be closed by the.

.art, and .need not.

pistons 6 whenatcrnear the limit .of their out ward strokes. These pistons have a sufiiciently loose lit in the outer end of the chambers 11 so that when the ports are closed by the pistons the air pressure in the auxiliary chambers 10 will be permitted to slowly leak around the ends ,of the pistons and to enter the free spaces provided between the ends of the pistons and the ends of the chambers .1.

The starter means embodying the present in,- vention and which operates in connection with the above-noted chamber arrangement and connecting pipes includes a body l5 having a high pressure air storage chamber [6 (Fig.2) {and a separate limited pressure air charge chamber .11 therein, with the former in connection :With a suitable source of air pressure suppl through a passage 118. The chamber It has two dis charge outlets l9 and 20 adapted to .be closed by inwardly opening valves 2i and .22, respectively, the stems of which project outward from the chamber through a wall thereof and into .acasing part 23 Where they are respectively engaged by springs 2'4 .and .25 .to normally maintain the valves seated. The outer end portion .Of a h valvestem is provided with a head 26 receiving the thrust of its spring. The outlet 19 has con, .nection through a line .27 with the pipe .9 con.- .necting the reverse bounce chambers 5 of the engine, and in this line 27 is disposed a pressure regulator 28 and an outwardly .opening check valve 29, so that the air passing through the line 2-1 from the chamber .16 .first has its pressure reduced apredetermined extent by the regulator 28 .and then passes through the check valve beforeentering the .pipe 9.

The outlet .20 has a connection through aline 3.0 and through .a'branch .31 with the equalizer pipe 8 -.con ect n the direct bounce chambers, and also has connection through a branch 32 with the charge chamber -11, .with the opening between the branch 32 andchamber continually open. A pressure regulator 3.3 is disposed the line .351, and an outwardly opening check valve 34 is disposedin the branch :32. The branch 31 has an outwardlyopeningcheckyalve.35 therein. and also between such valve and the pressure regulator 33 is provided a restricted passage LL36 controlled byaneedle valve -37. Ibis thus appar! cut that when the valve 22 is open, th 1115b m pressurein the chamber 16 will pass therefrom through the .line 36, where it is reduced th des red extent by the pressure regulator 39 after which .itdivides, with part passing thrQugh-jhe check valve .34 and throu h the branch3-2 to the charge. chamber I], and part passing u j the valve controlled branch 3| to the pipe {8: flhe pressure regulators 28 and 33 may b 91 a suitable construction as well understood in the m r -.b e specifically described. These regulators, as is common, are manually controllable to regulate the pressure reduction effected thereby.

Each reverse bounce chamber 5 at its outer end relative to the piston 4 is provided with a plurality of pressure relief ports 49 (one only being shown), and each is normally closed by a valve 4|, the stem of which projects into a cylinder 42 and attaches to a piston 43 therein. A spring 44 acts against the piston 43 to normally retain the valve closed and pressure is admitted to the outer end of the cylinder 42 through a line 45 to act against the piston 43 in opposition to the pressure of the spring 44 and efiect an inward opening of the valve 4|. Between the port 49 and cylinder 42 are provided a plurality of exhaust openings 46 for the release of the air pressure to the atmosphere from the reverse bounce chamber 5 when the valve is open. Pressure is admitted to the line 45 from the charge chamber H through a line 41. The inner end of the line 41, or that opening into the chamber I1, is controlled by a valve 48, the stem of which projects through and above the top wall of such chamber where it is acted on by a spring 49 to hold the valve closed. The spring seats against a head or enlargement 58 on the outer end of the valve stem.

The admission of high pressure air to the chamber Hi from the line I8 is controlled by a valve 5|, the stem of which projects outwardly from the chamber wall through suitable guides and is acted on by a spring 52 to normally maintain the valve seated. The stems of the valves 48 and 5| are disposed, in the present instance, in parallel relation and adjacent to each other with the stem of the latter valve projecting a greater distance from the body I5 than the other and provided at its outer end with a head or shoulder 53. The stems of the valves 2| and 22 are also disposed in rather close parallel relation with the stem of the valve 2| projecting a less distance from the casing of the body l5 than the other. This relative positioning and length of the valves 2|, 22, 48 and 5| are to facilitate operation of the valves by the control means hereinafter described.

A pressure relief passage 55 communicates with the pressure line 4'! adjacent to its point of connection with the chamber l1 and this line is controlled by a normally open valve 55 and at the outer side of such valve by a needle valve 51. The valve 56 projects from a plunger 58 operating in a cylinder 59 and is normally held open by the pressure of a spring 68 against such plunger. The cylinder 59, at the outer side of the plunger 58, has communication through line 6| with pipe 8 which connects the direct bounce chambers, so that when a suficient pressure is present in the line 8 to overcome the compression of the spring 68, such pressure will move the plunger 58 and hold the valve 56 closed if valve 62 is in open position as later described. The line 6| has a normally closed check valve 62 therein which opens outwardly from the cylinder 59 and is normally held closed by a spring 63. This valve has a stem 64 projecting upwardly to exposed position through the portion 65 of the body I5 in which it is mounted, and, in the present instance, it is parallel to the stems of the valves 2|, 22, 48 and 5|. The purpose of the valve 62 will be later described.

The control means for the valves 2|, 22, 48, 5| and 62 will now be described. Mounted in the present instance on top of the body l5 near its left end is a stationary guide sector 19 with which the hand operated catch H on a hand lever 12 is adapted to engage to hold the lever in different positions of adjustment relative to the sector.

In the present instance, the sector has notches a, b and c with which the catch engages to hold the lever, respectively, in off, charge and start positions. The lever i mounted on a shaft 13 for rocking movements lengthwise of the sector, and this shaft also carries an independently rockable arm 1'4, the outer end of which is provided with an arcuate surface 15 concentric to the shaft axis and having a stop ldnear its rear or left hand end. A spring pressed pawl TI on the lever 12 rides at one end on the surface 15 and at its other end on an inner surface of the sector 10. This latter surface is divided lengthwise thereof into two arcuate surfaces at and c that are concentric to the lever axis and are connected by a cam portion 1. When the lever 12 is bein moved from off to near its charge position, the outer end of the pawl i1 will ride against the surface at and cause the arm 14 to move therewith due to engagement of the inner end of the pawl with the shoulder 16. When the lever has nearly reached said charge position, the outer end of the pawl H will engage and pass over the cam surface 1, thereby moving the pawl to disengaged position relative to the shoulder 16 and maintaining such position during movement of the pawl along the surface 6.

Projecting rearwardly from the inner end of the arm 14 away from its rocking axis is an arm 19 that is pivotally connected at its outer end to a plunger 88 by a link 8|, such arm and link forming a toggle connection between the inner end of the arm 14 and the plunger, with such connection upwardly broken or raised from straight or dead center position when the arm 14 is at the limit of its movement to the right. The plunger 88 works in a cylinder 82 and receives the thrust of a coiled compression spring 83 in said cylinder acting inwardly on the toggle link members 19, 8|. A rod 84 projects from the pivotal connecting point 85 of the members 19 and 8|, substantially at right angles to the line of movement of the plunger 88, and connects at its outer end to a plunger 86 operating in a cylinder 8?. The outer end of this cylinder relative to the rod 84 forms an air pressure chamber that has communication through a line 88 with the pipe 8 connecting the direct bounce chambers of the engine. It is apparent that air pressure in the pipe 8 acts through the line 88 against the piston 86 and tends to keep the connection 19, 8|, in its upwardly broken position. When the arm M has been moved a short distance to the left from the "oif position shown, by a counterclockwise movement of the lever i2 from its off position, the toggle connection 79, 8| will have lowered an extent sufllcient to move the pivot 85 across and below dead center position so that the plunger 86 will then be quickly moved downward in its cylinder 81 by the downward breaking movement of the toggle connection and under the pressure of the spring 83, thus causing the arm 14 to quickly move independently to the left of the lever 12 to its stop position against the part 18. It will be understood that at this stage in a starting operation there is practically no pressure in the direct bounce chambers I and consequently in the line 8 with which the cylinder 81 is connected. It will also be understood that when the direct bounce pressure has increased sufficiently in the chamber 81 to overcome the enter the pressure responsive means I I8 and open valve II9, thereby venting the bounce pressure chamber I to the atmosphere.

The reverse bounce pressure governor B has a line I25 in connection with the reverse bounce chambers a line I26 in connection with a high pressure air supply line I21, a fluid pressure line I28, at present in connection with the fuel feed line of the engine, and a normally closed vent line I29. Line I2 6 acts only during running of the engine as part of the governing function and forms no part of the starter mechanism. A control valve I35 is moved to the right by pressure in line I when pressure in spring I3I is relieved by moving control lever I32 to stop position. Pressure in line I25 acts to expand a-bellows at the left of valve I forcing the latter to the right. This movement of valve I30 admits pressure from line I28 to pressure responsive means I33, which causes opening of relief valve I34 to vent the pressure in reverse bounce pressure line I25. Such venting relieves the pressure from responsive means I05 in governor A and permits movement of lever III! by spring I09 to effect a venting of the direct bounce chambers I through the lines H3 and 8.

It is thus seen that when the engine is stopped, the governor B acts to relieve the reverse bounce pressure and that this in turn acts through governor A to vent the direct bounce chamber pressure. The invention is disclosed in conjunction with these governors since it has been constructed in this manner and the disclosure is thus of preferred form. However, any equivalent pressure sensitive valve arrangement may be used.

In order to make the starting means operative in connection with an engine having such direct and reverse bounce venting means, it is desirable to have an operative connection between the starting and venting means, whereby the two governors are blocked off from the respective direct and reverse bounce chambers during the starting process and are opened thereto as the unit achieves running equilibrium.

To accomplish this the direct bounce pressure line II3 to governor A and the reverse bounce pres-sure line I25 to governor B are each provided with an isolating or'block-oif valve I38, shown in detail in Fig. 3. Each of these valves moves across the respective pressure line I25 and I I3 and carries a piston I39 operating in a cylinder I413. The valve is normally held open by a spring I4I and is closed by pressure against the outer side of the piston supplied through a line I42. This line connects both valve cylinders and is supplied with pressure from the high pressure air line I8 through a branch I43 extending through a part of the starter body structure I5 (Fig. 2).

A valve I44 is acted on by a spring I45 to normally close said branch within said structure and the valve is unseated by movement of a bell crank lever I46. This lever is fulcrumed at I41 and has one arm engaging the valve stem and its other arm engaging a rod I48 attached ,to and operable by movements of the upright arm of the lever '92. This attachment is such that upon a rearward or counterclockwise movement of said lever under the action of the spring 45, and when the rod 90 is moved to the left, the lever I46 is moved to lift the valve I44 from its seat and open the line I43. The rod I48 also controls a vent valve I49 to close a vent passage I50 when the rod is moved to the left and to open such passage when the rod is in its right hand position. The passage I50 leads to the atmosphere from the line I-43 at a side of the valve I40 opposed to the air pressure supply source. The vent I50 is so restricted by the throttling needle valve I5I as to retard the engagement of the governors A and B until after the unit achieves running equilibrium.

A brief description of the operation of the starter means is as follows: Presuming that the pressures in the bounce chambers I and connected auxiliary chambers I0 have been vented through the relief passage in governor A when the engine was last stopped, the operator sets the fuel feed for a running condition slightly greater than idling and also sets the control I32 for the governor B so as to tension the spring I3I to provide for proper reverse bounce effect which will be achieved by the starting conditions. This moves the valve I33 to the left permitting a closing of the relief valve I34 so that the vent from the reverse bounce chambers is closed. However, the vent from the chambers I and I0 is still open through the governor A. The operator then moves the starter control lever I2 from the off" to the charge position, that is, from the a to the b notches in the sector III. The rocker arm I4 moves with the lever in this movement due to the engagement of the pawl 11 with said arm until the pivot of'the toggle I9, 8|, has been moved past dead center position, whereupon the spring 83 will act to quickly move the rocker arm to the limit of its rearward or counterclockwise movement. This movement of the rocker arm closes valve 48 and opens the valve 5|, the latter admitting high pressure air to the chamber I6 from lines I8 and I21. At the same time, when the lever I2 is near its charge position, its arm will engage the head 25 andopen the valve 2 I. This permits high pressure air to pass from chamber it through the valve controlled line 2'! to the reverse bounce chambers 5 to force the engine pistons to the limit of their outward movements. The movement of the control lever I2 to charge position moves the pawl TI to released position relative to the shoulder I6 on the arm 14 due to one end of the pawl riding over the cam portion ,1 of the sector '10. The lever may now be moved from charge to start position or from the notch b to notch c in the sector ID. This movement causes the lever arm 95 to further open the valve '2! and also to engage the head 26 on the valve 22 and effect an opening of such valve. Thereupon the compressed air from chamber I6 flows through the pressure regulator 33 and non-return check valve 34 to the charge chamber II, the valves 48 and 56 being now closed, and also flows through lines 30, 3| and 8 to build up pressure in the direct bounce reservoirs I8. This pressure also acts through line 88 on piston 85. Chamber II should charge to the full pressure permitted by the reducer valve before chambers I5 reach their charge pressures, and it is the function of valve 31 to produce the necessary restriction in line '3I. When the pressure in chambers I0 reaches a certain predetermined value, piston 86 overcomes the effect of spring 83 and snaps the toggle 19, 8| back to its initial raised position, and consequently moves the rocker arm I4 quickly to its forward initial position. This simultaneously opens valve 48 and closes valve 5I, causing the high pressure air to be delivered from the chamber II through line 41 to piston 43 and opening vent valves 4| in reverse bounce chambers 5 and at the same time shutting off the high pressure supply to chamber 5 pressure of the spring 83, the plunger 86 will be moved outward to cause an outward movement of the center pin 85 past dead center position, causing the sprin 83 to then act to quickly return the rocker arm 14 to its right end position, as shown in Fig. 2 of the drawings.

The rocker arm 74 has a rod 90 pivoted thereto and projecting forwardly therefrom, or to the right, and through a guide bracket 9| rising from the body [5. The free end of this rod bears against the upwardly and forwardly extending arm of a bell-crank lever 92 that is fulcrumed on the body [5, while the other arm of such lever extends rearwardly and upwardly and bears upwardly against the head 59 on the stem of the valve 48 and in opposition to the spring 49. When the rocker arm 14 is in its right end position, the rod 90 acts on the lever 92 to hold the valve 48 raised in its open position and during the initial rearward movement of the arm 14 the opening pressure of the lever 92 on the valve is released, thus permitting a closing of such valve.

A bell-crank lever 93 is fulcrumed to the bracket 9i and has a horizontally extending arm adapted to engage the stem head 53 of the valve 5|, so as to move such valve from closed position when the lever arm is moved upward. The other arm of said lever extends downwardly and has an aperture therein through which the rod 90 extends. rocker arm 14 and when it is near the limit of such movement, a shoulder 94 on the rod 90 engages the downwardly projecting arm of the lever 93 and moves the lever to effect an unseating of the valve 5|, thus admitting air from a high pressure air supply in I21 to the pressure chamber Hi. This unseating action of the valve 5| is rapid due to the rapid movement of the rocker arm 14 under the action of the spring 83.

The control lever i2 has an arm 95 projecting to the right from its inner end and provided with apertures through which the stems of the valves 2| and 22 project. During the movement of the control lever 12 from its ofi to charge position, arm 95 will engage first the head 26 of the valve 21 and cause an opening of such valve to permit the pressure in the chamber IE to pass through the line 27 and valves 28, 29 therein to the reverse bounce connection 9, and thence to the two reverse bounce chambers 5 to impart outward stroke movements to the piston sets. The control lever I2 is retained in the "charge position until the pistons 6 have reached their extreme outer position, the piston heads closing ofi ports i i and continuing until they are in contact with or just miss the ends of the cylinders I.

The control lever 72 is then moved from notch 12 to c on the sector 18. During this movement, the arm 95 will act on the head 26 of the valve 22 and force said valve open against the compression of its spring 25, thus permitting compressed air to pass from the storage chamber i6 into the line 3!! and through branch 32 to chamber H and through branch 31 to the direct bounce chamber connection 8 so as to build up a pressure in such connection and in the chambers to sumcient to force the engine pistons to their inward positions at the required velocity.

When the pressure in chambers has built up to a predetermined value, this acts through line 88 against the plunger 86 to move the operating connection 1 9, 8 I of the rocker arm upwardly past dead center position so as to permit the spring 83 to act to quickly throw said arm to its right hand position at which time valve is permitted During a movement to the left of the 6 to close and valve 43 is caused to open. The valve 43 is held open so that the pressure in the chamber 1'! is admitted through the lines 41 and to the cylinder 42 to act against the pistons 43 therein to open the valves 4| and relieve any pressure in the reverse bounce chamber 5 which might oppose inward movement of the pistons.

A rod [68 extends from the control lever 12 near the inner end to a lever Nil to which it pivotally connects, such lever being fulcrumed to a bracket [82 rising from the body extension 65, and the lower end of such lever is provided with a cam foot Hi3 acting against the outer end of the stem 64 of the valve 62. This arrangement is such that when the lever 72 is in its ofif position, the valve G2 is closed, and when the control lever is moved away from such position, the cam i 83 acts against the valve stem to open the valve, thus permitting the pressure in the line 6| to act against the plunger 58. It will be understood that after starting and during a running of the engine, the pressure in the line 6! fluctuates with the pressure in the direct bounce chambers so that if the connection of this line with the cylinder 59 were not cut oil during such running of the engine, the valve would have a fluttering action. It is for this reason that the starting mechanism is equipped with means for opening the line 6! to the chamber 53 during a starting operation and to close such connection when starting has been effected.

Before outward movement of the engine pistons i, effected by admission of air pressure to the reverse bounce chambers 5 of the engine, the direct bounce chambers 7 are vented, in the present instance, by means operated automatically by the starter mechanism in conjunction with pressure control governors for the engine. Such governors are shown and claimed in Patent No. 2,435,970, by Frank M. Lewis, one of the applicants herein. These governors are illustrated in Fig. 1 and designated A and B," the former controlling the direct bounce chamber pressure and the latter the reverse bounce chamber pressure. The operation of these governors need only be described suiiiciently in the present case to make their operation in connection with the starting mechanism clear.

Governor A includes four pressure responsive means I65, H33, id! and I08, together with a spring its acting on a lever lie to hold it in a closed position when the engine is operating properly. These bellows have connection, respectively, through lines Ill, H2, H3 and H4 with the compressor chambers 5 the reverse bounce chambers 5 the direct bounce chambers 1 and the scavenging receiver H5. The line H3 connects with the direct bounce chamber line 8 through a pressure controlled mechanism operated by the lever Iii whereby a lowering of the right end of such lever will cause the direct bounce pressure to be increased by the admission of air pressure thereto, and a raising of such end of the lever will cause a venting of the bounce chamber pressure.

This venting of the bounce chamber pressure is accomplished automatically as follows: When the engine is stopped the reverse bounce pressure is vented through governor B as hereinafter described, thus relieving pressure in the pressure responsive means I06 of governor A, which causes an unbalancing of the pressures against lever H0 and permits the spring 199 to force the right end of the lever upward. This raises valve I "Send permits pressure from fuel oil supply line H1 to I16. The air in the direct bounce reservoirs It must leak around the circumferential clearance of the bounce piston 6; at its extreme outward. position. before it can get behind the. piston and do work. While this relatively slowprocess is taking place, the air in. the reverse bounce chambers 5 will have dropped approximately to atmospheric pressure due to opening the valve 4|. The pistons then move totheir inner stroke positions, compressing the fuel charge for com.- bustion. During this stroke the vent valves 4| are. still held open, since the escape of air from behind the valves is prevented by valve 59. Whenthe direct bounce pressure has dropped. to some predetermined pressure, spring 60 over-- comes the gas load on the piston 59; allowing valve 56 to open. and then. the air: holding, the: vent valves open bleeds to the atmosphere. The drop in pressure: behind the vent valves will be governed by the. opening. of. needle valve 51 and the volume of the chamber I'I'. These quantities will be so: regulated. that the valve springs '44 in connection with the valves: will not. overcome the air; pressure and close-the vent valve 4 I until some time during the outward power strokes; of the engine; pistons, after the proper air quantity has been taken intothe reverse bounce chambers 5 to effect an energy balanceforthe stroke. Starting having; been effected in this manner, control lever I2 may then be returned at leisure to its 01f position: and its latch engaged with the sector notch a. The movement of the lever 92 valve 48;. which movement occurs during, the

rearward or left hand stroke of. the starter control member I5, moves the rod I48 attached to such. lever, causing a rocking of the lever I49 and an: opening of the valve I44 in the high. pressure airline I49, thus permitting such pressure to. act through theline I42 on the pistons: I39 and move the: block-off valves I38 to close the line H3 of governorA and line of governor B, thus preventing the venting of both the direct bounce and reversebounce chambers. This movement oi therod I48 also: moves the vent valve I49 to closed position to prevent any venting of. the lines; I42, I43. The return of. the control member I5 to: its normal position permits closing of the valve I44: and moves the vent valve I-49 to position to: vent the passage I59, thus relieving the pressure holding the block-off valves I38? closed and permitting'them. to open under the pressures of their springs. The governors A and. B. are thus again. rendered operative in connection. with the operation of: the engine.

We wish it understood that our invention is not, limited. to any specific. construction, arrangement on form of. the parts,v as it. is capable of numerousv modifications and: changes without. departingfromthespiritiof the-claims.

Having thus: described our invention, what we claim. as; new, and desire to secure by United States. Letters Patentisr 1 A. starter for an. internal combustion engine of: the free piston type? having a. direct bounce chamber, compression inwhich tends to move the engine piston in the direction of'its. compression stroke, and a reverse. bounce chamber; compression in which tends tomove the piston in thedis rection of its outward stroke, comprising asource of gas under pressure, means operable to. connect said source first with the reverse bounce chamber and then with the direct bounce chamber to move said pistonfirstonits working stroke and then on a compression stroke, said means operating to 10 vent. said reverse bounce chamber prior to-movementof said piston on. a compression stroke and automatic means for cutting off the source connection to both said chambers when a predeter' mined pressure has been obtained in the direct bounce chamber.

2. An arrangement as called for in claim I, together with means operable to vent said. direct bounce and reverse bounce chambers when the engine is at rest, and means operable by the-first mentioned means to render said vent means inoperable during predetermined portions of a starting operation.

3. A. starter for an. internal combustion engineof thefree piston. type having a direct bounce chamber, compression. in which. tends to move the engine piston. in the, direction of its compression stroke, anda reverse bounce. chamber, compression in which tends tomove the piston in. the (11 rection of its outward stroke, comprising a source of gas under. pressure. manually operable means to connect said source first with the reverse bounce chamber and then with the direct bounce chamben, an exhaust valve for the reverse bounce chamber, and automatic means responsive to a: predetermined direct bounce chamber pressure for opening said exhaust valve after the direct bounce chamberis connected tosaid source.

4. A starter for an internal combustion engine of the free piston type having a direct bounce chamber, compression in which tends to move the engine piston in the direction of its compression stroke, anda reverse bounce chamber, compression in. which tends to move the piston. in the direction or its outward stroke, comprising a source of gas under pressure, manually operable means to connect said source first with. the reverse bounce chamber and then with the. direct bounce chamber, an exhaust valve for the reverse bounce: chamber,v and automatic means responsive. to. predetermined pressure in the direct. bounce chamber for opening said exhaust valve and for cutting: ofi the connections to said source.

5. A starter for an internal combustion. engine of the free piston. type. having a direct bounce chamber, compression in which tends to move the engine piston in the direction of its compression stroke, and a reverse bounce chamber, compression in which tends to move the piston in the direction ofits outward stroke, comprising a source of gas: under pressure, two valves for connecting said source with said chambers respectively, and manually operable means movable in one direc tion. to first: open. the valve to the reverse: bounce chamber: and further on its movement to open the valve to the direct. bounce chamber, an exhaust valve for the reverse bounce chamber, and means operable by pressure connected to the. direct; bounce chamberto. open said exhaust valve.

6.. A. starter for an internal. combustion engine of, the free piston type having a direct bounce chamber, compression in which tends to movethe engine piston in the direction of its compression stroke; and: a reverse bounce chamber, compression. in which tends to move the piston in: the direction of its outward stroke, comprisingan auxiliary chamber connected by a leakage passage tio the direct bounce chamber when: the engine pistonisatt theen'dof its working stroke and by open ports when the piston has moved a short distance on its compression stroke, a sourceof gas under pressure, a manually operable valvefor connectingsaid-source with said reverse bounce chamber, a manually operable valvefor connecting said source with said auxiliary chamber, an exhaust valve for the reverse bounce chamber, and means operable by pressure in said auxiliary chamber to open said exhaust valve.

7. A starter for an internal combustion engine of the free piston type having a direct bounce chamber, compression in which tends to move the engine piston in the direction of its compression stroke, and a reverse bounce chamber, compression in which tends to move the piston in the direction of its outward stroke, comprising a source of gas under pressure, means providing a storage chamber for gas under pressure, manually operable means for connecting said source to said storage chamber and connecting said storage chamber to said reverse bounce chamber, manually operable means to thereafter connect said storage chamber to said direct bounce chamber, means to vent said reverse bounce chamber after a predetermined pressure has been attained in said direct bounce chamber and automatic means responsive to direct bounce chamber pressure to break the connection between said source and said storage chamber.

8. An arrangement as called for in claim 7, together with vent means operable to vent both said bounce and reverse bounce chambers when the engine is stopped, and means for rendering said vent means inoperable during predetermined portions of a starting operation.

9. A starter for an internal combustion engine of the free piston type having a direct bounce chamber, compression in which tends to move the engine piston in the direction of its compression stroke, and a reverse bounce chamber, compression in which tends to move the piston in the direction of its outward stroke, comprising a source of gas under pressure, means providing a storage chamber for gas under pressure, manually operable means for connecting said source to said storage chamber and connecting said storage chamber to said reverse bounce chamber, manually operable means to thereafter connect said storage chamber to said direct bounce chamber, an exhaust valve for the reverse bounce chamber, and automatic means operable by pressure connected to said direct bounce chamber to break the connection from said source to said storage chamber and to open said exhaust valve.

10. A starter for an internal combustion engine of the free piston type having a direct bounce chamber, compression in which tends to move the engine piston in the direction of its compression stroke, and a reverse bounce chamber, compression in which tends to move the piston in the direction of its outward stroke, comprising a source of gas under pressure, manually operable means to connect said source first with the reverse bounce chamber and then with the direct bounce chamber, an exhaust valve for the reverse bounce chamber, automatic means responsive to direct bounce chamber pressure for opening said exhaust valve after the direct bounce chamber is connected to said source, and automatic means to close said exhaust valve after the piston starts on its next working stroke.

11. A starter for an internal combustion engine of the free piston type having a direct bounce chamber, compression in which tends to move the engine piston in the direction of its compression stroke, means operable to vent said bounce chamher when the engine is stopped, and a reverse bounce chamber, compression in which tends to move the piston in the direction of its outward stroke, comprising a source of gas under pressure, manually operable means to connect said source first with the reverse bounce chamber and then with the direct bounce chamber, an exhaust valve for the reverse bounce chamber, automatic means responsive to direct bounce chamber pressure for opening said exhaust valve after the direct bounce chamber is connected to said source, and automatic means to close said exhaust valve after the piston starts on its next working stroke, and means operable by said manually operable means to render said vent means inoperable during admission of the gas pressure to said reverse bounce and direct bounce chambers during a starting operation.

12. A starter for an internal combustion engine of the free piston type having a direct bounce chamber, compression in which tends to move the engine piston in the direction of its compression stroke, and a reverse bounce chamber, compression in which tends to move the piston in the direction of its outward stroke, comprising a source of gas under pressure, manually operable means to connect said source first with the reverse bounce chamber and then with the direct bounce chamber, an exhaust valve for the reverse bounce chamber, automatic means responsive to direct bounce chamber pressure for opening said valve, automatic means to close said exhaust valve after the completion of the compression stroke, and means for adjusting the last said means so that a predetermined portion of the next working stroke elapses before the exhaust valve closes.

13. A starter for an internal combustion engine of the free piston type having a direct bounce chamber, compression in which tends to move the engine piston in the direction of its compression stroke, and a reverse bounce chamber, compression in which tends to move the piston in the direction of its outward stroke, comprising a source of gas under pressure, manually operable means to connect said source first with the reverse bounce chamber and then with the direct bounce chamber, an exhaust valve for the reverse bounce chamber, and automatic means for opening said exhaust valve after the direct bounce chamber is connected to said source, said automatic means comprising a toggle, connections to said manually operable means for breaking the toggle in one direction, a spring for holding the toggle broken, a piston connected to said toggle, a cylinder around said piston, and means providing a passage from the direct bounce chamber to said cylinder to straighten the toggle when a predetermined pressure is present in the direct bounce chamber.

14. A starter for an internal combustion engine of the free piston type having a direct bounce chamber, compression in which tends to move the engine piston in the direction of its compression stroke, and a reverse bounce chamber, compression in which tends to move the piston in the direction of its outward stroke, comprising aconnectionsto said: manually opemblemeansior breaking the. tog le in one direction,, a spring, for: holding the. toggle broken, a piston connected. to;

the. toggle, a. cylinder around said: piston, and means providing; a passagefromzthe direct bounce chamber tosaidcylinder'to; straighten the. toggle when, a predeterminedpressure is. present; in the bounce. chamber:

.15. A starter. for an internal; combustion ens gineof the free; piston type having; a direct bounce chamber, compression in which, tendsto.

movev the; engine piston. in the. direction. of. its

compression stroke, anda reverse bounce chamber, compressionin which tends. to move the piston in. the direction ofits outward strokercome prising a-.sourc.e.of gas under. pressure, manually operable means. to connect saidsourceflrst with the. reverse bounce chamber and then with the direct bounce chamber, an exhaust, valve, for: the

reversebounce chamber, and automatic means 16. An arrangement, as called for in claim 15,

together with means normally standing open and responsive to pressure in said direct. bounce chamber to close said leak passage, and means normally rendering said responsive means. in-

operative and' manually operable to rendersaid responsive means operable.

1.7. An. apparatus for. controlling starting of an internal combustion free piston machine having an air compressor piston. subject on one side to air in. an air compressing chamber and on the i oppositeside to air in a reverse; bounce chamber, a rigidly connected power piston operable by products of combustion from compression ignition in a power chamber to actuate-said compressor piston on an. air compression stroke, and

direct bounce air cushion means for actuating said. piston. on. an air intake stroke and to provide compression ignition, said apparatus comprising reverse bounce supply means for supplying fluid under pressure. to said reverse bounce chamber for. moving said pistons. on an air compression stroke to a starting position, direct bounce supply means operable-uponmovement or said pistons to said starting position to supply fluid under pressure to said air cushion means, vent valve means for releasing fluid under pressure from, said reverse. bounce chamber to render said fluid under pressure in said cushion means efi'ective to move said pistons on said intake stroke to provide. compression ignition, and sequence means operable upon a chosen increase in pressure in said cushion means to effect operation of said reverse bounce supply means to out off supply of fluid under pressure to said reverse bounce chamber and to also eiiect operation of said vent valve means to release fluid under pressure from said reverse bounce chamber.

18. An apparatus for controllingstarting of an internal combustion free piston machine having an air compressor piston subject on one side to air in. an air compressing chamber and on the opposite side to air in a reverse bounce chamber, a rigidly connected power piston operable by products of combustionfrom.compression ignit o in a. power chamber to actuate said compressor piston. on an.- air compression.- s roke;, and: d rect bounce air cushion. means for actuating; said. 915 ton an an air intake: stroke and to provideecoma pression ignition. said: apparatus. comprising reverse. bounce supply means for supplying; fluid: under pressure to said. reverse bounce; chamber for moving said pistons on an air compression; stroke to-a startin p sition, dircctbounce 8119.13. 3 means operableupon, movement of; said pistons to;v said. starting position to supply; fluid under pressure to. said. air. cushion; means, vent; val means for releasing fluid und r: pressure from: said; reverse bounce chamber-to. render. said fluid under. pressure. saidcushion means effective; to; move said. pistons on. saidv intake. stroke to nrode; compression. ignition. and. soqu nos; means. op rable. upon a, chosen increase pr sure n said cushion. means to effect opera ion. of: said. direct. bounce supply means and. reverse. bounce supply means tov cuton the. supplyof; fluid under pressure to, respectively: said cushion means said reverse bounce chamber and to also eiiect operation of said vent valve, means.

19. An apparatus for controlling starting of an, internal combustion free piston machine; having; an air compressor piston subject on one. side toair in an air compressing chamber and onthe-opposite side to, air in a reverse. bounce chamber, arigidly connected power piston operable by prod nets of combustion from compression. ignition in a power chamber to actuate said compressor piston on an air compression stroke, and. direct bounce air cushion means for actuating said. pis ton on anv air intake stroke and to provide come pression ignition, said apparatus comprisin reversev bounce supply means for supplying fluid. under pressure. to said reverse. bounce chamber for moving said pistons on an air compression. stroke to a starting position. directb unce supply me ns op r ble. upon movement of sa d. pi tons to said starting position to; supply fluid under pr ur t said air cushion. me ns. vent valve means for releasing fluid under pressure from said reverse bounce chamber to render said fluid: under pressure in said cushion means effective. to move said pistons. on said. intake stroke, to pro.- vide compression ignition, sequence means, operable upon a chosen. increase in pressure. in said cushion means to effect operation of said direct bounce supply means and reverse bounce supply means to cut oil the supply of fluid under pressure to, respectively, said cushion means and said reverse bounce chamber and to also efl'ect operat tion of said vent valve. means, and means operle upon a chosen reduction inpressure of. fluid in said. cushion means to. effect operation or said.

vent valve means to terminate release. oi fluid.

under pressure from said reverse bouncechamber.

20. An, apparatus forcontrolling starting of, an internal combustion free piston machine. having; n air compressing pist n subj cton pposite sides tov pressure ofair in air compressing a d reverse bounce chambers, respectively, a rigidly connected. power piston. for. moving: said corn-- pressing piston inthe direction against air insaid air com ressing chamber; and direct bounce fluid pressure cushion. means for movin said piston. in the oppos te direction, said apparatus" comprising first valve means for supplyingfluid under pressure t a d; reverse bouncechamberfor moving said pistons to a chosen position in the; first named, direction, second. valve means. for supplying fluid under pressure to. said cushion means,v vent. valve means: for ventin the fluid under press re from; said. reverse bouncechanc ber, and means for efiecting operation of said vent valve means upon a chosen increase in pressure in said cushion means.

21. An apparatus for controlling starting of an internal combustion free piston machine having an air compressing piston subject on opposite sides to pressure of air in air compressing and reverse bounce chambers respectively, a rigidly connected power piston for moving said compressing piston in the direction against air in said air compressing chamber, and direct bounce fluid pressure cushion means for moving said piston in the opposite direction, said apparatus comprising valve means for supplying fluid under pressure to said reverse bounce chamber and to said cushion means, means for delaying supply of fluid under pressure to said cushion means with respect to supply of fluid under pressure to said reverse bounce chamber, means for cutting oil said supply of fluid under pressure to and for bottling up the fluid pressure in said cushion means, vent valve means for venting the fluid under pressure from said reverse bounce chamber, and means responsive to a certain increase in pressure in said cushion means to effect operation of said vent valve means.

22. An apparatus for controlling starting of an internal combustion free piston machine having an air compressing piston subject on opposite sides to pressure of air in air compressing and reverse bounce chambers, respectively, a rigidly connected power piston for moving said compressing piston in the direction against air in said air compressing chamber, and direct bounce fluid pressure cushion means for moving said piston in the opposite direction, said apparatus comprising means for supplying fluid under pressure to said reverse bounce chamber to move said pistons to a chosen positiondn the first named direction, means for limiting to a chosen degree the pressure of fluid supplied to said reverse bounce chamber, means for supplying fluid under pressure to said cushion means, means for limiting to a chosen higher degree the pressure of fluid supplied to said cushion means, vent valve means for venting fluid under pressure from said reverse bounce chamber, and means responsive to a chosen increase in pressure in said cushion means to effect operation of said vent valve means.

23. An apparatus for controlling starting of an internal combustion free piston machine having an air compressing piston subject on opposite sides to pressure of air in air compressing and reverse bounce chambers respectively, a rigidly connected power piston for moving said compressing piston in the direction against air in said air compressing chamber, and direct bounce fluid pressure cushion means for moving said piston in the opposite direction, said apparatus comprising a first valve means for supplying fluid under pressure to said reverse bounce chamber for moving said pistons to a chosen position in the first named direction, fluid pressure operable vent valve means for releasing fluid under pressure from said reverse bounce chamber, a feed valve device operable upon supply of fluid under pressure to a first communication to supply fluid at a reduced pressure from said communication to said cushion means and to another communication, choke and check valve means in the fluid supply communication to said cushion means, a check valve for preventing reverse flow of fluid under pressure from said other communication, a second valve means for supplying fluid under 16 pressure to said first communication, a third valve means for opening said other communication to said vent valve means, and means for effecting sequential operation of said first, second and third valve means in the order named.

24. An apparatus for controlling starting of an internal combustion free piston machine having an air compressing piston subject on opposite sides to pressure of air in air compressing and reverse bounce chambers respectivey, a rigidly connected power piston for moving said compressing piston in the direction against air in said air compressing chamber, and direct bounce fluid pressure cushion means for moving said piston in the opposite direction, said apparatus comprising a first valve means for supplying fluid under pressure to said reverse bounce chamber for moving said pistons to a chosen position in the flrst named direction, a second valve means for supplying fluid under pressure to said cushion means, means for delaying operation of said second valve means with respect to operation of said first valve means, vent valve means for opening a vent from said reverse bounce chamber for releasing fluid under pressure therefrom to render said pistons movable by pressure of fluid in said cushion means, means responsive to a chosen increase in pressure in said cushion means to effect operation of said vent valve means to open said vent, and means operable in response to a reduction in pressure in said cushion means to effect operation of said vent valve means to close said vent.

25. An apparatus for controlling starting of an internal combustion free piston machine having an air compressing piston subject on opposite sides to pressure of air in air compressing and reverse bounce chambers, respectively, a rigidly connected power piston for moving said compressing piston in the direction against air in said air compressing chamber, and direct bounce fluid pressure cushion means for moving said piston in the opposite direction, said apparatus comprising first valve means for supplying fluid under pressure to said reverse bounce chamber, second valve means for supplying fluid under pressure to said cushion means, vent valve means operable by fluid under pressure to open a fluid pressure vent from said reverse bounce chamber for releasing fluid therefrom to render said pistons movable by pressure of fluid in said cushion means, exhaust valve means for releasing fluid under pressure from said vent valve means to efiect operation thereof to close said vent, and means for delaying operation of said second valve means with respect to operation of said first valve means and for. effecting first supply of fluid under pressure to said vent valve means and then operation of exhaust valve means, subsequent to operation of said second valve means.

FRANK M. LEWIS. WILLARD A. MORAIN.

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

UNITED STATES PATENTS Number Name Date 1,353,100 Wales Sept. 14, 1920 2,178,310 Pateras Pescara Oct. 31, 1939 2,189,497 Pateras Pescara Feb. 6, 1940 2,222,260 Janicke Nov. 19, 1940