US2866592A - Air accelerating engines and compressors - Google Patents

Description

Dec. 30, 1958 2,866,592

A. A. MATHESON AIR ACCELERATING ENGINES AND COMPRESSORS Filed Nov. 25, 1956 2 Sheets-Sheet 1 INVENTOR. ANDREW ,4. MA THES 0N 14 T TORNEYS Dec. 30, 1958 A. A. MATHESON 2,856,592

AIR ACCELERATING ENGINES AND COMPRESSORS Filed Nov. 25, 1956 2 Sheets-Sheet 2 33 33 53 23 j 302 K 4/ 4 /6 f 42 /7 3/ 27,43 4g 7kg. 8.

INVENTOR. ANDREW A MATHES 0N m/m A) 7%- 4' 7 AT TOAN EYS United 'States Patent AIR ACCELERATING ENGINES AND (IOMPRESSORS Andrew A. Matheson, Denver, Colo.

Application November 23, 1956, Serial No. 624,109

4 Claims. (Cl. 230--54) This invention relates to an improvement in air accelerating engines and compressors of the general type shown and described in U. S. Patent No. 2,620,779, granted December 9, 1952, and relates principally to an improvement in the valve operating mechanism.

It is the object of this invention to produce a simplified valve control and operating mechanism for engines of the type described in the above identified patent to thereby reduce the number of parts and effect a more accurate timing and a smoother and more silent operation.

In order to clearly describe the invention and its advantages reference will now be had to the accompanying drawings which show the improved valve gear in place on an engine which otherwise parallels quite closely the engine shown and described in the patent above identified.

Figure 1 shows a top plan view of the engine;

Figure 2 is a side elevational view looking upwardly in Figure 1, some of the parts being shown in section for greater clarity;

Figure 3 is a section taken along line 33 of Figure 2;

Figure 4 is an end elevational view looking in the direction of arrow 4 in Figure 2;

Figure 5 is a section taken on line 55 Figure 2;

Figure 6 is a longitudinalvertical section taken on line 66 Figure 1 and shows the position of the parts at the beginning of the power stroke;

Figure 7 is a sectional detail showing the position of the control valve during the compression stroke; and,

Figure 8 is a section taken on line 8-8 showing the control valve in the position shown in Figure 7.

This invention will now be described in detail for which purpose reference will be had to the drawings in which numeral it) represents a base on which the engine is supported in any suitable manner. The engine proper comprises an elongated frame formed from an upper pair of spaced beams 11 and 12, arranged in parallel relation, and a lower pair 13 and 14 positioned directly beneath the upper pair and secured in fixed parallel relation by means to which reference will presently be made. In the drawing beams 11 to 14 have been shown as of channel cross section which is believed to be desirable. The rear ends (the left hand ends in Figures land 2) of the upper and lower pair are spaced by bearing blocks 15 and 16 in which the crank shaft 17 is journalled. Tie bars 18 that connect the beams of each pair are provided at spaced points to hold them in fixed parallel relation. Only a few of these have been shown. The front ends of the upper and lower pairs of beams are spaced by a channel iron 19. The beams 11 to 14 serve as guides for a cross head 20 which is connected with crank pin 21 by means of connecting rod 22. Positioned between the two pairs of beams is a-power cylinder 23.whose piston 24 is joined with the cross head by a piston rod 25. The cylinder is attached to the engine beams in any suitable manner and such means have been indicated in a general way by numeral 26. Attached to the under sides of beams 11 and 12 is a valve housing 27 within which is slidably mounted a piston valve 28 having a diametrical passage ice 29 and an angular passage 30 as shown in Figures 6, 7 and 8. The valve housing is in communication with the adjacent end of the working cylinder by a short tubular member 31. The opening in member 31 flares outwardly where it joins the cylinder as shown in the drawing. Piston valve 28 has been shown in two positions: the power stroke position shown in Figure 6 and the compression or exhaust stroke position shown in Figures 7 and 8. The piston valve is normally held in the open position shown inFigure 6 by means of spring 32 and is moved to the closed position shown in Figure 7 by a valve gear link mechanism that will presently be described. Valve housing 27 has an exhaust opening 33 that communicates with a storage cylinder 33' by a conduit 34 which is provided with a check valve 35 and a high pressure valve 36. A. gauge 37 is operatively connected with cylinder 33 so as to indicate the pressure therein. A valve piston operating rod 38 extends upwardly from valve 28. A poppet valve housing 38 is attached to the top pair of beams as indicated in a general way in Figure 6. The top and the bottom are closed by removable screw plugs 39 and 40, respectively. The interior of housing 38' is divided into two compartments by a transverse wall 41 provided with a control valve seat 42. The upper compartment communicates with the interior of housing 27 by means of a tubular connector 43. The lower compartment is in communication with a high pressure air supply cylinder 44 by a pipe 45 provided with a high pressure control valve 46. A poppet type valve 47 is positioned in the lower compartment and is urged to closing position by the air pressure from tank 44 and the force of spring 48. Valve stem 49 extends upwardly from valve 47 and passes through a long bushing 59 terminating some distance above wall 41 as shown in Figure 6. The valve stem has a sliding fit in bushing 50 and when lubricated with a heavy grease such as petroleum jelly, forms a substantially friction free seal that will withstand the intermittent high pressure to which it is subjected. Valve 47 moves only a very short distance each time and is provided with a downwardly extending projection 51 that terminates a short distance above the flexible steel washer 52 which serves as a resilient stop for the valve. When valve 46 is open the lower compartment which contains the poppet valve is subjected to the air pressure in tank 4d. With the parts in the position shown in Figure 6 it is obvious that when the poppet valve is opened air at high pressure, 300 to 1500 pounds or more per square inch, will be discharged into the upper chamber and flow into the work cylinder producing an outward movement of the piston which produces a rotation of the crank shaft. The means for controlling the position of the valves so as to produce rotation of the crank shaft will now be described, and reference for this purpose will be had'in particular to Figures 1, 2 and 6, which illustrates the same. Since the cross head is reciprocated by the connecting rod as the drive shaft turns, it and the piston will move with a substantially sine movement. In Figure 6 the parts are shown at the beginning of the power stroke. The parts are shown in dead center position but since the shaft is provided with a heavy fly wheel 53 and a belt pulley 54 the momentum of these parts carry the parts over the dead center in the usual manner. The engine is provided with tour guides 55 having opposed, inwardly opening grooves 56 in which bars 57 slide. The two pairs of guides are spaced longitudinally a distance somewhat greater than the stroke of the engine. Bars 57 are connected at their front and rear ends by plates 53 and 59 respectively. Each of said plates carries an adjustable stop 60. The cross head has an upward projection 61 that is: positioned in the space bounded by bars 57 and stops 60. The-distance between the opposing ends of stop 66 is less than the length of the stroke plus the thickness of the projection 61 and, therefore, bars 57 will be moved at each end of the stroke. Plate 58 has a perforated lug 62 to which the rear ends of links 63 are pivoted. Attached to the beams 11 and 12, as by welding, is a plate 64 that carries two spaced upwardly extending lugs 65 to the upper ends of which a lever 66 has one end pivoted. A plate 67 is welded or otherwise attached to the upper pair of beams and has two spaced lugs 68 to which the lower ends of toggle links 69 are pivoted. A pivot 70 connects the overlapping ends of toggle links 69 and 71. Pivot 70 also passes through openings in the front ends of links 63. The upper ends of links 71 are connected to lever 66 by pivot 72. The rear ends of links 73 are connected to pivot 70 as shown. Rod 38 which extends upwardlyfrom valve 28 has a pivotal connection with the front end of lever 66 as shown in Figure 6. When the toggle links 69 and 71 are set as in Figure 2, valve 28 occupies the exhaust position shown in Figure 7 and when this toggle is broken, as in Figure 6, valve 28 moves to the open position as shown. Projecting upward- 1y from the front of the engine frame are two spaced channel bars 75 to which a heavy steel hammer 76 is pivoted at 77. A hydraulic ram 78 is rockably attached at its upper end, to bars 75 by a pivot 79. The outer end of the plunger is attached to the top of the hammer by a pivot 80. The hammer is attached to the frame by two pair of toggles, each having links 81 and 82. The connecting pivot 83 of toggles 81, 82 passes through elongated openings 34 in the front ends of links 73 which move in response to movement of bars 57 at each end of the engine stroke. The positions of the parts at the beginning of the power stroke are shown in Figure 6 and their positions at the beginning of the compression stroke is shown in Figures 1 and 2.

Operation Let us now assume that the several parts are in the positions shown in Figure 6 and that the crank is slightly beyond dead center as indicated by the position of the connecting rod. The hammer has just been released and its impact on stem 49 has momentarily opened valve 47 permitting a quantity of air from the lower or valve compartment to be discharged into the upper compartment. The poppet valve closes almost instantly because it is urged to closed position by the combined action of the air and of the spring 48, which can be overcome only by an impact blow of the hammer when the toggle is broken. Since the air in cylinder 44 has an initial pressure of between 386 and 1500 pounds or more per square inch it expands to many times its compressed volume as it enters the upper or expansion chamber and the air which thus expands with an explosive force enters the closed end of the power cylinder through the flared passage and urges the piston outwardly and produces a torque force that tends to turn the drive shaft. When the parts approach the opposite dead center position where the piston is in the position shown in Figure 2, the cross head projection 61 engages the rear adjusting plate and moves bars 57 and the links attached thereto to the positions shown in Figures 1 and 2. During this movement toggle 69, 70 is straightened, lifting lever 66 and moving piston valve 28 to the exhaust position shown in Figure 7. At the same time links 73 move rearwardly and bring the hammer control links 81, 82 to the slightly overset position shown in Figure 2 where they rest against the stops 85. The momentum of the heavy fly wheel and the belt pulley operates to return the piston and the other parts to the positions shown in Figure 6. Attention is here directed to openings 86 in the cylinder wall which serve to permit air to enter or leave the cylinder at the end of the power stroke so that the cylinder will be filled with air at atmospheric pressure which air will be compressed the piston moves towards the dead center position shown in Figure 6. The compressed air flows through the valve opening 30 as shown in Figures 7 and 8, through pipe 34 and into storage cylinder 33'. The cycle is then completed and the parts are in the position shown in Figure 6 and a new cycle commences. It has been found that the passages connecting the top or expansion chamber of the control valve should be flared as it enters the cylinder so that the air can expand as fast as possible thereby exerting a sudden and powerful force on the piston. This mechanism is intended, not only as a source of power but as a machine for use in a laboratory to illustrate various principles underlying the development of power from compressed air; the various phenomena relating to the temperature changes due to the expansion and compression of gases. It is contemplated to provide thermometers at strategic places as well as pressure gauges so that sufiicient data can be obtained to evaluate the results taken from the experiments. It has been observed that the amount of energy delivered by the comparatively small amount of the highly compressed air at each opening of the poppet valve is much greater than could normally be expected and this has led to the theory that the sudden expansion of the air as it leaves the poppet valve produces a change which is believed to be due, in part at least, to the splitting of the water molecule into oxygen and hydrogen thereby greatly increasing the volume and the pressure. Other theories have been advanced but none of them have been proven to date.

It is to be understood that any changes in the construction can be made which fall within the scope of the appended claims.

What is claimed as new is:

1. A single acting engine of the type having a frame, a power cylinder carried thereby, a piston operatively associated therewith, a cross head movable along and guided by said frame, a piston rod interconnecting the piston and the cross head, a drive shaft mounted for rotation on the frame, said shaft having a crank provided with a crank pin and with a heavy fly wheel, a connecting rod joining the cross head with the crank pin, a source of air under high pressure, conduit means communicating the air source with the power cylinder, said conduit means being formed in part by an elongated poppet valve housing, a partition dividing the interior of said housing into a lower high pressure valve chamber and an upper expansion chamber, the partition having an opening formed with a valve seat on the high pressure side, a poppet valve positioned in the high pressure chamber and operatively associated with the valve seat, said valve being urged to closed position by the high air pressure, the valve having a stem that passes through the expansion chamber, through the housing wall and terminates some distance above the housing, a hammer carried by the frame and positioned above the valve stem in position to deliver an impact blow to the valve stem to move the valve to open position, and permit high pressure air to enter the expansion chamber, a two-position slide valve positioned in the conduit between the expansion chamber and the cylinder, resilient means operatively associated with the slide valve for normally holding it in open position, means for moving the slide valve to conduit closing position at the end of the power stroke of the piston comprising a lever having one end connected with the frame for pivotation, the other end being operatively connected with the slide valve for moving it to closed position when the lever is moved upwardly about its pivot, means for moving the lever to valve closing position comprising a toggle operatively connecting the lever and the frame, the valve being closed when the toggle is in extended position, means for correlating the movement of the lever and its supporting toggle with the position of the piston in the working cylinder, comprising a frame slidably supported on the engine frame and provided with stops to be engaged by the cross head as it approaches the ends of its movement, a link having its front end connected with the center pivot of the lever toggle and its rear end connected with the slidable frame so that it will break the lever toggle as the piston reaches the end of its compression stroke and reset the toggle and close the valve at the end of the power stroke and bring it to exhaust position, resilient means operatively associated with the hammer and frame to subject the hammer to a force urging it towards the valve stem, means comprising a toggle connecting the hammer with the engine frame for moving the hammer to a position above the valve stem, means for correlating the movements of the hammer and its release with the position of the slide valve, comprising an elongated link having its rear end pivotally connected with the link that operates the valve control lever and provided at its forward end with an elongated opening through which the center pivot of the hammer control toggle passes, the length of the elongated opening being less than the movement of the sliding frame whereby the release movement of the hammer control toggle will lag relative to the lever control toggle, the slide valve having an exhaust port that is in communication with the power cylinder during the exhaust stroke, a storage cylinder and a conduit containing a check valve communicating the storage cylinder with the exhaust port.

2. A mechanism for controlling and coordinating the positions of a normally closed poppet valve and a slide valve having a normally open position and an exhaust position the two valves being arranged in series between a power piston and a source of air under high pressure, comprising an elongated supporting frame, means attaching the valves to the frame, the poppet valve device comprising a housing, a partition separating the housing into a lower high pressure chamber and an upper expansion chamber, the partition having an opening communicating the chambers, the wall of the opening facing the high pressure chamber having a valve seat, a poppet valve in the high pressure chamber positioned to cooperate with the seat and seal the opening, means comprising a spring operatively associated with the poppet valve to urge it towards sealing position, the poppet valve having a stern that passes through the expansion chamber and to a point on the outside of the housing, conduit means communieating the expansion chamber with the slide valve, and means for operating the two valves in a predetermined sequence, comprising a valve-control frame slidable on the first frame, a lever having one end pivotally attached to the first frame and the other end connected with the slide valve, a toggle means connecting the lever with the first frame, the toggle being so related to the lever that when it is in extended position the valve will be in closed position with the exhaust open, means for controlling the position of the toggle comprising a rigid link having one end attached to the valve control frame and the other connected with the center pivot of the toggle, a hammer having one end connected for pivotation to the first frame and so positioned and arranged that it can deliver an impact blow to the end of the poppet valve stem, resilient means urging the hammer towards the valve stem, means for controlling the position of the hammer and for holding it in cocked position against the action of the resilient means comprising a toggle device connecting the hammer to the first frame, 'stop means on the first frame for holding the toggle in a predetermined overset position, and means for controlling the position of the toggle and for releasing it to activate the hammer to deliver an impact blow to the valve stem at a predetermined time after the slide valve has been moved to open position said means comprising a rigid link having one end connected with the first rigid link and its other end connected with the center pivot by a lost motion connection comprising an elongated opening through which the pivot passes.

3. A mechanism for operating a slide valve having an intake and an exhaust position and a poppet valve connected in series therewith in a predetermined sequence, comprising an elongated first frame having a crank shaft provided with a fly wheel rotatably mounted on said frame near the rear end thereof, a cross head having an upward projection mounted for guided sliding movement along said frame, a connecting rod operatively joining the cross head and the crank to effect a reciprocation thereof when the shaft rotates, a valve housing attached to the first mentioned frame adjacent its forward end, a partition dividing the interior of the housing into a lower high pressure and valve chamber and an upper expansion chamber, the partition having an opening pro vided with a valve seat on the side facing the high pressure chamber, a poppet valve positioned in the high pressure chamber arranged to close the opening, resilient means urging said valve to closed position, a stem extending from the valve, through the expansion chamber to a point outside of the housing, the wall of the valve chamber having an opening for the introduction of air under high pressure, an energy converter comprising a power cylinder having a piston slidable therein, a piston rod operatively connecting the piston and the cross head, conduit means communicating the expansion cham her with the cylinder, a slide valve having a normally open intake port and anormally closed exhaust port interposed in the conduit, in combination with the above, means for moving the slide valve to intake position to connect the expansion chamber with the cylinder at the beginning of the power stroke of the piston and for moving the slide valve to exhaust position at the end of the power stroke, said means comprising a valve control frame slidably associated with the first frame, the valve control frame having two spaced stops, one on each side of the cross head projection and in the path thereof, the stops being spaced apart a predetermined distance less than the travel of the cross head plus the thickness of the projection wherefor the valve control frame will be moved said predetermined distance by the cross head as it approaches the ends of its stroke, a lever having its rear end connected with the first frame by means of a pivot carried by said frame, the front end of said lever being operatively connected with the slide valve by a connector element, resilient means operatively associated with the slide valve tending to move it to open position, a toggle means connecting the lever with the first frame, the length of the toggle links being so related to the slide valve that when the toggle is in fully extended position the slide valve will be closed and in exhaust position, means for operating the toggle comprising a link having its rear end attached to the sliding frame and its front end connected with the center pivot of the toggle, a hammer having one end pivoted to the first frame at a point above the poppet valve stem in position to engage the latter, resilient means operatively associated with the hammer urging it into engagement with the valve stem, means for moving the hammer to cocked position in opposition to the resilient means, said means comprising a toggle joining the hammer to the first frame, stops on the first frame forming means for holding the toggle in slightly overset position, and means for breaking the toggle immediately after the slide valve has been moved to open position, said last named means comprising a forwardly extending link having its rear end connected with the first toggle operating link and its front end connected with the center pivot of the hammer control toggle by a lost motion connection formed by an elongated pivot receiving slot through the center pivot of the last named toggle.

4. A device in accordance with claim 3 in which the end of the conduit in communication with the cylinder is flared.

References Cited in the file of this patent UNITED STATES PATENTS

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