|Publication number||US2366595 A|
|Publication date||Jan 2, 1945|
|Filing date||Jul 25, 1942|
|Priority date||Jul 25, 1942|
|Publication number||US 2366595 A, US 2366595A, US-A-2366595, US2366595 A, US2366595A|
|Inventors||Christopher Elbert E|
|Original Assignee||Christopher Elbert E|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (5), Classifications (6)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Jan- 2, 1945. E. E. CHRISTOPHER 2,366,595
INTERNAL-COMBUSTION ENGINE Filed July 25, 1942 3 sheets-sheet 1 Jan- 2, 1945- E'. E. CHRISTOPHER INTERNAL-COMBUSTION ENGINE 1942 5 Sheets-Sheet 2 Filed July 25 M 4 W j ATTORNEYS.
Jan. 2, 1945. E. E. CHRISTOPHER INTERNAL-COMBUSTIQN ENGINE 5 Sheets-Sheet 3 Filed July 25, 1942 I N VEN TOR.
Patented Jan. 2, 1945 UNITED STATE s PATENToi-Fics The invention relates to internal combustionv engines and more particularly to' the construc- 1 tion Aand arrangement of parts in a so-called barrel type engine.
The barrel type engine to which the present invention relates usually consists of a cylindrical bank of engine cylinders and reciprocating pistons therein in combination with a rotary cam ring mounted in endwise relation to the engine cylinders and having suitably inclined faces thereon operated upon by the reciprocating pistons so as to translate the reciprocating movement of the pistons into a rotary movement of the cam ring. While this type of engine has certain inherent advantages in reducing the number of operating parts, greater horse power to weight ratio, compactness in size, etc., there have been several defects in engines of this type heretofore proposed, notably the introduction of bends and torsional strains in the drive connection between the pistons and camA ring, and inadequate lubrication of the vital parts of the drive mechanism. As an object of the present invention and as an important feature thereof, these two important defects in previous engines have been entirely eliminated, and a construction provided wherein the operating mechanism between the pistons and the cam ring are subjected exclusively to a longitudinal thrust force and all of the vital drive parts are completely encased in anoil chamber.
Another object of the present invention is to provide an engine of the character above which may be quicklyand readily taken apart or assembled and in which the repair and overhauling cost is greatly reduced from engines heretofore available.
A further object of the invention is to provide in a barrel type engine of the character described a novel and improved arrangement of the cylindrical bank of engine cylinders and the drive shaft and an improved drive connection between the drive shaft and the rotary cam ring.
Yet another object of the invention is to provide in an internal combustion engine of lthe character described a novel and improved mechanism for super-charging the cylinder combustion chambers.
Still another object Vof the invention is to provide a barrel type internal combustion engine wherein the normally reduced number and mass of parts characteristic of this type of engine are further reduced and the construction generally efficient, smoother running and more durable engine. Y
The invention possesses other objects and features of advantage, some of which, with the foref going, will be set forth in the following description of the preferred form of thev invention which is illustrated in the drawings accompanying and forming part of the specication. It is to be understood, however, thatvariations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claims. l
Referring to said drawings:
Figure 1 is a longitudinal sectional view of the engine of my invention.
v Figures 2, 3 and 4 are transverse sectional views taken on the lines 2 2, 3 3, and 4 4, respectively of Figure 1.
Figure 5 is an enlarged longitudinal sectional view through a set of adjacent cylinders, the planes of the sections being indicated by the line 5 5 of Figure 4.
Figure 6 is a cross-sectional view of a cylinder taken on the line 6 6 of Figure 1.
Figure 7 is a fragmentary enlarged detail sectional view taken on the line 1 1 of .Figure 6.
The engine depicted in the accompanying drawings consists of a cylindrical bank of engine cylinders Il, I2, i3, I4, l5, I6, ll, i8 and i9 provided by a plurality of tubes, marked with the aforesaid numbers II-IB. and supported in parallel coterminous relation in substantially equally improved and strengthened to provide a more circumferentially spaced relation around and at equal radii from a center axis of the bank. Mounted for reciprocation in each of the cylindersare opposed pistons 2| and 22 provided with longitudinal thrust rods 23 and 24 which project axially from the opposite ends of the cylinders into a space provided by pairs of spaced concentric inner and outer casings or shells 26, 21 and 28, 29 which partially embrace and extend longitudinally from the opposite ends of the cylinders. As a feature of the present construction and as best seen in Figures 1, 3 and 6, the opposite ends 3| and 32 of tubes Il l9 are enlarged to define a shoulder 33 around the tube adjacent the ends thereof which engages and interlocks with a pressed-out segmental cylindrical portion 34 formed in the adjacent ends of the shells 26 29 to fit around the inner and outer portions of the tube exteriors. The' shells 26 29..and the tubes Il l9 are supported and fixed in the concentric arrangement above described and as illustrated in the drawings by means of pairs of supporting straps 36 31 and 38-39 which embrace therebetween the end portions 34 of the shells ,26-29 and in so doing also grip and hold in place the end portions 3| and 32 of the tubes. The shape of the straps 36 and 31 may be best seen in Figure 3 of the drawings, from which it will be noted that the interiorly mounted strap 36 is preferably continuous in its construction and formed in a sinuous fashion so as to seat and properly support the similarly formed end of shell 21 and also properly locate the tubes in their circumferentially spaced relation. The outer strap 31 is preferably made from two or more sections which are joined at their ends to provide a continuous gripping of the engaged end portion of shell 26. These sections are also of sinuous form complementary to the form of the inner band 36. Mounted circumferentially between the tubes |||9 and closing the end space between the shells 26-21 and 28-29, area plurality of ller blocks 4| which are secured in place between the tubes and between the shells by means of a plurality of bolts 42 which extend through the straps and shells and ller blocks. The filler blocks, as will be seen in Figure 3, are formed with concave end portions 43 which are formed to t closely against the peripheries of adjacent tubes, and the sides 44 of the blocks are also concave to seat the contacting portions of the sinuous ends of the shells. The supporting construction at the opposite ends of the tubes is identical and hence a description of the construction at one end, as illustrated in Figure 3, will suffice for both ends. In connection with the foregoing, it will be understood that a tightening of the bolts 42 and the resultant drawing together of the' strap members at the opposite sides of the shells and tubes, rigidly holds the assembly in a proper relation of the parts.
A similar type of construction is provided at the outer ends of shells 26-21 and 28-29 where the outer shells 26 and 28 are formed with an inwardly pressed reduced portion 46 and the inner shells 21 and 29 are formed with an outwardly pressed enlarged portion 41 to lock in an end closure and supporting ring 48, which is formed with a reduced outer end portion 49 which interfits with the shell portions 46 and 41. Embracing the shell portions 46 and 41 are inner and outer straps 5| and 52 which are clamped against the shells and end rings by means of a plurality of bolts 53. If,desired, and as here shown, engine mounting rings 54 may be secured to the end closure members 48 to support the engine in the in. stallation with which it is used. As will be understood the shape and form of the mounting members 54 will vary with different types of installations.
Connected to the outer ends of thrust rods 23 and 24 of the pistons are slide members generally denoted by numeral 56 and which are supported for longitudinal reciprocation upon bearing or guide blocks 51 and 58 carried by the inner and outer shells 26-29. The construction of the slide member and the guides for each of the piston thrust rods is the same and a description of one of the units will suflce for all. With reference to Figure 1, it Will be noted that the slide member is composed of a plurality of sections assembled upon a center sleeve 59 mounted througha radical aperture 6| in the outer end of the thrust rod. Positioned at the inner and outer ends of the sleeves are slide blocks 62 and 63 which have stud portions 64 and 66 projecting into the interior of the sleeve and substantially at base portions 61 and 68 slidably engaged upon the guide blocks 51. and 58. Preferably and as shown in Figure 2, the base portions 61 and 68 of the slide blocks and the engaged sides of the guide blocks 51l and 58 are formed with longitudinally extending tongue and groove portions 69 so as to corinne the slide member to a longitudinal move` n ment with respect to the guides. Mounted upon the sleeve 59 between the base portions 61 and 68 of the slide blocks and at opposite sides of the thrust rod are a pair of rollers 1| and 12 which are carried on the sleeve for free rotation by means of roller bearings 13 and 14.
As an important feature of the present invention and as best illustrated in Figure 1, there is mounted for free rotation between the outer ends of the slide members 56 and the end clossure rings 48, what may be termed a full floating cam ring 16. This member is mounted substantially centrally between and concentric to the inner and outer shells 26-29 and is exclusively supported for rotation at its opiposite ends 11 and 18 upon the rollers 1| and 12 of the slide member and a ball end thrust bearing 19 mounted between the cam ring end 18 and the adjacent end closure plate 48. Preferably, the cam ring end 18 is substantially planar, that is arranged l in a plane substantially perpendicular to the longitudinal axis of the ring, and is formed with an annular end recess 8| providing a seat and bearing race for the bearing balls 19. The opposed end face of the closure rings 48 are preferably similarly formed with an annular recess 82 providing a bearing race and support for the opposite sides of the balls 19. The opposite end 11 of the cam ring is undulated to receive the end thrust of the slide members and to convert this end thrust; into a rotary movement of the cam ring. Preferably in order to maintain a constant engagement of the rollers 1| and 12 with the adjacent undulated face 11 of the cam ring, I provide a. roller 83 on one of .the slide blocks, here the inner slide block 62 which engages a shoulder 84 on the cam ring and which follows the undulated form of the ring end 11. Since there is a difference in peripheral speed at the radially inner and outer portions of the cam face 11, I prefer to construct the inner and outer spaced rollers 1| and 12 of different diameter so as to approximately compensate for the different speeds of the cam portions engaged by the rollers. Accordingly and as shown in Figure 1, the radially inner roller 1| is of a somewhat smaller diameter than the outer roller 12. In conformity with this arrangement, the portion 86 of the cam face 11 engaged with the roller 1| is of somewhat greater longitudinal extent than the portion 81 of the cam face 11 engaged with the roller 12. Preferably, the cam [portions 86 and 81 are recessed and the rollers 1| and 12 are rounded beveled to provide an intertting relation as illustrated in Figure 1. As will be clear from the foregoing, the translation of the longitudinal thrust of the piston rods into a rotary displacement of the cam ring is effected without the introduction of any strain on the connected parts at right angles to the axis of thrust. In other words there is provided in the present engine a straight longitudinal alignment of the thrust rods, cam ring and end bearings for the cam ring, whereby all bending or lateral stress is eliminated. As another important feature of the above construction, it will be noted thatl the slide member, guides, cam ring and end thrust' bearings therefor are a closed chamber which is preferably llecl with all encased within y lubricating oil whereby all of these vital drive parts may run in oil and lubrication problem heretofore encountered with this type of engine completely eliminated. The oil chamber at the ends of the cylinders ||9 is closed by means of end closure discs 89 fixed within the enlarged tube ends 9| and 92 and being formed with an axial opening 89 for receipt of the piston thrust rods 23 and 24. Preferably, a packing nut 9| is carried on the end closures 89 around the thrust rods and the openings 89. f
As another important feature of the present invention, a drive shaft 92 is provided outside of the cylindrical bank of cylinders and in substan-` tially parallel relation thereto and is operatively connected to the cam rings 19. As will be seen from Figure 1, there is mounted on the outer casings 29 and 29 adjacent the opposite ends thereof a pair of bearing housings 93 and 94 which receive and journal for rotation the opposite ends of shaft 92. Preferably the shaft 92 projects forwardly somewhat from the forward bearing houslng 93 for connection of the mechanism to be drlven by the engine. Mounted upon the shaft for rotation therewith within the bearing housings 93 and 94 are pinion gears 99 and 91 which project through openings 98 and 99 in the outer casings 26 and 28 to engage and enmesh with ring gears and |02 mounted on the cam rings 19. Lubrication of these gears as well as the shaft bearings 09 and |04 within the housings 93 and 94 is effected by oil carried up through the openings 98 and 99 from theoll chamber by the pinion gears 96 and 91.
The engine pistons 2| and 22 are as aforementioned mounted in opposed position in the cylinders for out-of-phase reciprocation therein to and from a center dividing ring |09 mounted in the cylinders. The present engine is designed for Diesel or solid fuel injection and to this end a plurality of fuel injectors |01 are provided and in each instance mounted through the wall of the tubes at the radial inner side thereof and centrally of the tube length so as to project into and through the ring dividers |09. The fuel injectors are preferably mounted so as `to inject the fuel diametrically across the opening |08 in the divider rings |06 and ,upon striking the opposite wall of the ring, the fuel is split off to the opposite longitudinal sides of the ring.
The present engine is also designed for twopressure is required to open the-valve, the function of the valve being primarily to seat against the initial exhaust pressure in the cylinder. On the other hand, exhaust valve ||1 is operated in timed relation to the movement of the pistons fby means of a special cam shoulder ||8 on the cam ring 19 -which engages and displaces a follower I9 which is in turn connected by crank |2| tothe stem |22 of valve ||1, see Figure 1. In this manner as the pistons |2| and |22 clear the-ring of ports |09 at the endof the power stroke, exhaust valve ||1 opens to discharge the spent products of combustion and the initially high exhaust pressure closes check valve ||8 in the intake passage. As the exhaust pressure falls to below the blower pressure' feeding the intake air, valve ||9 opens and shortly thereafter exhaust valve ||1 closes under the influence of cam ||8 and follower H9, whereby the cylinder is charged with air for compression.
As another important feature of the present engine, the outer ends of the cylinders and the pistons are designed to Iprovide air compression chambers from which air under pressure is passed into the combustion chamber of the next adjacent cylinder to provide a super-charging of the latter. As will be seen from Figure 1 of the drawings, the pistons 2| and 22 are of double ended construction, that is vthe normally skirt end of the piston is closed oil to provide ahead end |23 'facing the outer ends of the cylinders. The thrust rods 23 and 24 are preferably secured directly to these ends as by threading one end of the thrust rod into a threaded socket provided in the head end |23 of the piston. The outer ends of the cylinders being closed by discs 98, an air compression chamber is thus provided between the closed ends |23 of the pistons and it will be noted that the end discs 88 are each cycle operation and in keeping therewith a ring |09 of cylinder ports is provided adjacent the outer ends of the piston strokes for obtaining intake and discharge of air `and gases of combustion. As will be `best seen in Figures 1 and 6, there is formed on the tubes at the opposite longitudinal sides of the ports |09, a pair of outstanding annular shoulders which are closed at their outer faces by a band ||2, thus 4defining an annular chamber around the ports. Preferably,` each `of the annular chambers is divided by appropriate partitions into intake and exhaust chambers and suitable intake and exhaust fittings ||3 and ||4 applied thereto. In order to adapt the present engine to the use of a blower for placing the 4intake air under some initial pressure, I provide suitably operated `valves'll and ||1 in the intake and discharge provided with an air passage |24 leading from the inside fa'ce |26 of the discs to the surrounding casing 20 or 28 where the casing is apertured to receive an end |21 of a valve casing |28, the end |21 being threaded into the body of the disc 88 to place passage |29 of the valve casing in registration with passage |24. Mounted within the casing |28 is spring pressed intake check valve |3| which functions; to admit atmospheric air during the suction stroke of the piston `away'frorn the disc 88 and to automatically seat upon return movement of the piston to permit compression of the air. Air is discharged from the valve casing |28 by means of a conduit |32 leading therefrom to another valve casing |33 connected to the adjacent cylinder longitudinally thereof to discharge air into the power chamber of that cylinder. Mounted within valve casing |33 is a, check valve |34, spring pressed to closed position and functioning to admit air from the air compression chamber to the combustion chamber so long as the pressure in the former is greater than that in the latter, and automatically seating to prevent a return movement of the gases of combustion from the combustion chamber tothe air compression chamber. In accordance with the above, the undulations on the cam rings16 are so arranged to provide an operating sequence in the adjacent cylinders such that the compression of air in the air compression chamber of one cylinder Will lead the compression stroke in the combustion chamber of the adjacent cylinder by. an amountsuillcient to transfer the compressed air from the air compression cylinder into the Y der.
connected combustion chamber. The present arrangement using nineenglne cylinders and b. cam ring formation using three sinuous lobes whereby the pistons move through three cycles of operation during each complete rotation of the cam rings, will provide in combination with the structure above described. a proper operating sequence. However as will be understood. a different number of cylinders and a different arrangement of the cam rings may be adapted to effect this purpose. The sequence of operation provided by the present engine may be followed fromFigure 5. At the outset it will be noted that pistons A in the lower cylinder of the view are just starting the air compression stroke, while pistons B in the upper cylinder of the view are just reaching the end of their power stroke. With the pistons in this position, the air compression chamber in the lower cylinder is being charged with air from the blower, which air enters through the ring of ports |09 in the lower cylinder. Pistons A move to close the ports |09 in their cylinder while pistons B m'ove to open ports |09 in their cylin- The initial transfer of air from the lower cylinder into the upper cylinder is prevented by valve |341l which functions to prevent the back firing of the products of combustion from the upper cylinder into the air compression chamber of the lower cylinder and also holds back the air in the lower cylinder until a pre-determined pressure has been reached. Further movement of pistons A start the compression stroke in the lower cylinder while pistons B return back across the ports in the upper cylinder so as to enclose the combustion chamber in the upper cylinder. However, it will be noted that the pistons A having a substantial lead over pistons B, equal to approximately the length of ports |09, the air pressure is built up faster inthe air compression chambers than it is in the upper combustion chambers. As a result there is a trans- -ference of air from the air compression chambers in the lower cylinder to the combustion chamber of the upper cylinder to provide a supercharging of the latter. As pistons A reach the end of their stroke and start their return movement, the pressure in the air compression chambers immediately falls and check valve |34 closes to seal in the combustion chamberand at the same time the drop in pressure in the air chambers causes the intake check valve |3| to opento admit a fresh charge of air into the air compression chambers. The intake stroke in the air chambersin the lower cylinders lead the combustion or power stroke in the upper cylinder by the amount above noted and the pistons gine 'having a cylindrical bank of cylinders and pistons reciprocally mounted in said cylinders, annular rotary means mounted concentric to said cylinders and operated upon by said pistons to translate the reciprocating movement oi.' said pistons to a rotary movement of said means, a drive shaft mounted outside of said bank of cylinders and 'along a longitudinal axis parallel to the axis of said bank, and gear means connectingsaid shaft and rotary means.
3. In a barrel type internal combustion engine having a cylindrical bank of cylinders and pistons reciprocally mounted in said cylinders.
annular rotary means mounted concentric to said i cylinders and operated upon by said pistons to translate the reciprocating movement of said pistons to a rotary movement of said means, a drive shaft mounted outside' of said bank of cylinders and along a longitudinal axis parallel to the axis of said bank, a ring gear carried by said rotary means. and a pinion carried by said shaft and enmeshed with said ring gear.
move to their first mentioned position, as illus'- trated in Figure 6.
1. In a barrel type internal combustion engine having a cylindrical bank of engine cylinders and pistons reciprocally mounted within said cylinders and having thrust members extending longitudinally therefrom, an end support mounted in endwise spaced relation and in longitudinal alignment to said cylinders, a cam ring mounted between said support and the outer ends of said members, and end thrust bearings mounted between the opposite longitudinal ends of said ring and said support for journaling said cam ring and providing with said members the substantially exclusive support therefor.
2. In a barrel type internal lcombustion en- 4. In a barrel type internal combustion engine having a cylindrical bank of engine cylinders and pistons reciprocally mounted within said cylinders and having thrust rods extending longitudinally therefrom, an end support mounted in endwise spaced relation and in longitudinal alignment to said cylinders, a cam ring mounted between said support and the outer ends of said rods, end thrust bearings mounted between the opposite longitudinal ends of said ring and said support and said outer rod ends for journaling said cam ring and providing the substantially exclusive support therefor, a drive shaft mounted outside of said bank of cylinders and substantially parallel to the axis thereof, a ring gear carried by said cam ring, and a pinion carried by said shaft and enmeshed with said ring gear.
5. In a barrel type internal combustion engine having a cylindrical bank of engine cylinders and pistons reciprocally mounted within said cylinders and having thrust rods extending longitudinally therefrom, an end support mounted in endwise spaced relation and in longitudinal alignmentto said cylinders, a circular bearing race provided in the radial face of said end support in cylindrical alignment with said thrust rods, a' cam ring mounted concentrically between said race and said thrust rods and in cylindrical alignment therewith, roller bearing means carried by said thrust rods and engaged with the adjacent longitudinal end of said cam ring, and rotary bearing means mounted between the opposite'end face of said cam ring and said bearing race whereby said cam ring is subjected to only 1ongitudinal thrust.
6. In a barrel type internal combustion .engine having a cylindrical bank of engine cylinders and pistons reciprocally mounted within said cylinders and having thrust members extending longitudinally therefrom, an end support independent of said members mounted in endwise spaced relation and in longitudinal alignment to said cylinders, an annular cam ring mounted between the outer ends of said thrust members and said end support and journaled for rotation upon the latter, a bearing race aligned with said thrust members and engaging between said ring and members, and a pair of rollers carried by the outer end of each of said thrust members and straddling the longitudinal axis thereof and mounted for rotation against said cam ring.
7. In a barrel type internal combustion engine aseaoas .and the outer ends of said thrust members* and having a substantially planar end face constantly supported by said thrust bearing, the opposite end face of said cam ring opposed to said thrust members being undulated, and rollers carried by said thrust members in engagement with said undulated cam face.
members'in longitudinal alignment to said cylinders, a slide member reciprocally carried by said guide blocks for longitudinal reciprocation and connected rto the outer ends of said thrust rods, said slide member and said blocks being formed with interfitting tongue and groove portions confining said slide member to a longitudinal movement, and a cam ring mounted between and journaled for rotation on said slide member 8. In a barrel type internal combustion engine,
a plurality of tubes deiining engine cylinders, and means supporting said tubes in substantially coterminous parallel relation and in equal circumferentially spaced relation at equal radii about a common central axis comprising, pairs of substantially concentric inner and outer straps adjacent the opposite ends of said tubes between which said tubes are mounted, and means for drawing said straps together for clamping said tubes therebetween.
9. In a barrel type internal combustion engine having a cylindrical bank of engine cylinders and pistons reciprocally mounted within said cylinders and having thrust rods extending longitudinally therefrom, an end support mounted in endwise spaced relation and in longitudinal alignment to said cylinders, concentric inner and outer annular members mounted in endwise relation to ders and having thrust rods extending longitudi-v nally therefrom, an end support mounted in end.. wise spaced relation and in longitudinal alignment to said cylinders, concentric inner and outer annular members mounted in endwise relation to the ends of said cylinders, radially aligned longitudinally extendingguide blocks carried by said the ends of said cylinders, radially aligned longi and said end support.
11. In a barrel type internal combustion engine having a cylindrical bank of engine cylinders and pistons reciprocally mounted within said cylinders and having thrust rods extending longitudinally therefrom, an end support mounted in endwise spaced relation and in longitudinal alignment to said cylinders, concentric inner and outer annular members mounted in endwise relation to the ends of said cylinders, radially aligned longitudinally extending guide blocks carried by said members in longitudinal alignment to said cylinders, a cam ring mounted concentrically between said slide member and said end support and having a substantially planar end face supported for rotation on said end support, the opposite end face of said cam' ring being undulated, and a plurality of rollers carried by said slide member and bearing against said undulated cam ring face. 12. In a barrel type internal combustion engine having a cylindrical bank of engine cylinders and pistons reciprocally mounted within said cylinders and having thrust rods extending longitudinally therefrom, concentric inner and outer casings mounted in endwise longitudinally extending relation from the ends of said cylinders, radially aligned longitudinally extending guide blocks carried by said casings in alignment with said cylinders, a slide member reciprocally mounted on and between said guide blocks and guided thereby for longitudinal reciprocation and connected to the outerg ends of said thrust rods, an end member closing the outer ends of said casings, a cam ring journaied for rotation upon said end member and operatively engaged by said slide member for translating the reciprocating movement of` said pistons to a rotary movement of said cam ring, an end closure for said. casings adjacent the cylinder ends thereof deiining a closed chamber adapted for receipt of oil for 1ubricating the above enumerated parts contained in said chamber.
ELBERT E. CHRISTOPHER.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US2664866 *||Dec 27, 1943||Jan 5, 1954||Frank L Fulke||Internal-combustion engine|
|US4565165 *||Jul 23, 1984||Jan 21, 1986||Papanicolaou John P S||Internal combustion engine|
|US4974556 *||Dec 7, 1989||Dec 4, 1990||Royse Enterprises, Inc.||Internal combustion engine|
|US6250264 *||Apr 22, 1998||Jun 26, 2001||Sinus Holding As||Internal combustion engine with arrangement for adjusting the compression ratio|
|US8046299||Jan 12, 2004||Oct 25, 2011||American Express Travel Related Services Company, Inc.||Systems, methods, and devices for selling transaction accounts|
|U.S. Classification||123/51.00B, 123/56.9|
|International Classification||F02B75/28, F02B75/00|