Dec. 10, 1946. 2,412,344 W. A. LEDWITH ASSEMBLY OF ENGINE CYLINDERS AND MANIFOLDS Filed May 11, 1943 ' 2 Sheets-Sheet v1 LAW Maw ATTORNEY Dec. 10, 1946; ' ‘ w. A. LEDWITH 2,412,344 ASSEMBLY OF ENGINE CYLINDERS AND MANIFOLDS Filed May- 11, 1943 5492 2 Sheets-Sheet 2 no 00 /00 52 450 mo6274 70“1027280 FIG.2 76 77. 8 746 58 98 INV 29R ; 2; i, 8266.90 ATTORNEY Patented Dec. 10, 1946 ‘2,412,344 UNITED‘ STATES PATENT OFFICE 2,412,344 ASSEMBLY OF ENGINE CmNDERS AND MANIFOLDS Walter A. Ledwith, Hartford, com, assignor to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Application May 11, 1943, Serial No. 486,622 10 Claims. ‘ (o1. 123-493) 1 This invention relates to the assembly of an engine cylinder and manifolds for an opposed piston engine, and particularly to the assembly 2 , air leaves the cylinders through discharge valves 42, also at opposite ends of the compressor cyl- _ inders; and passes through scavenge manifold 44 through spaced ports 48 and 48 which are uncovered by pistons l2 and M at the end of the ' of a free-piston engine-and-compressor unit.. The weight 01' an opposed piston engine for use in an aircraft power plant must be reduced. to a minimum in order to obtain a low weight for the entire power plant. An object of this invention is to assemble the parts of the engine '\ ' power stroke thereby permitting air to be blown through the engine cylinder and spaced exhaust ‘ . ports 58 and 52 into exhaust manifold 54'. exhaust ducts 58 and 68 surround cylinder in such a way as to minimize the weight 10 theRing-shaped enginescylinder‘ and collect the gases dis ” charging through exhaust ports 58 and 52. 'These Opposed piston engines have inlet and exhaust . ducts are connected to exhaust manifold 54. ports covered and uncovered by the pistons dur of the parts. ing. their reciprocation. Manifolds surrounding the engine cylinder direct scavenge air into the 15 engine cylinder and collect the exhaust gas from the exhaust ports. A feature of this invention '~ ' is the mounting of a part, at least, of the mani foldson the engine cylinder by the same struc ture that holds the engine cylinder in. alignment 20 with the supporting structure. a Another feature of this invention is the as; semblyvof an engine cylinder and associated parts A housing 82, Fig. 2, surrounds the engine cyl inder between its ends and has at least one radial chamber 64 which receives injection device 32. The exhaust ducts 58 and 68 are held against housing 82 by turnbuckles 68 and 18. Each turn buckle is in the form of a ring having right and left threads 12 and 14 on its inner surface. These“ threads engage cooperating threads 16 and 18 on housing and duct respectively, and turning the ' by one or more .turnbuckles. Another feature is ring brings the duct and housing into assembled position. Threads 16 and. 18 are of different accompanying drawings which illustrate what is tending the entire length of the engine cylinder the use of turnbuckles in-connecting the engine 25 pitch so that ring 68 or 18 may be started on duct 58 or 68 before it is started on the housing. cylinder to a surrounding housing. \ The engine cylinder I 8, which may be liquid Other objects and advantages will be apparent cooled, has an inner sleeve-like element 88 ex from the speci?cation and claims and from the. now considered to be a preferred embodiment of 30 and having shoulders 82 and 84 at its opposite the invention. . ‘Fig. 1 is a sectional view through the free piston engine-and-compressor unit. ‘ ends. Outer vcylinder elements 86 andv 88 sur rounding the inner sleeve element and extend ing toward each other in substantial alignment, have inwardly extending ?anges 98 and 92 at Fig. 2 is a sectional view on a larger scale of the engine cylinder assembly. ‘ 35 their outer ends, engaging the shoulders on the ends of the inner element 88. The ?anges '98 and ' The unit shown includes an engine cylinder. l8 92 may be brazed to shoulders 82 and 84 for a having reciprocating pistons l2 and I4 to which positive seal. compressor pistons l8 and i8 in cylinders 28 and The inner ends of outer elements 88 and 88 22 are integrally connected. Sleeves 24 and 26 attached to the compressor pistons complete the 40 have shoulders 94 and 96, respectively, which are engaged by a part of the surrounding exhaust reciprocating piston assemblies. The sleeves in combination with stationary pistons 28 and 38 ducts 58 and 68. Turnbuckles 68 and 18 which form air spring cylinders. engage ducts 58 and 68 thus hold these ducts The piston assemblies are moved apart by the in position and also hold the assembled cylinder burning of fuel injected into engine cylinder l8 45 elements in radial position within, and in.axial by one or more devices 32. Air compressed in the alignment in surrounding housing 62. - r air spring cylinders on the power stroke returns A shield may be positioned between the outer the piston assemblies. The assemblies are always and inner cylinder elements for directing the maintained at equal distances from the center cooling liquid in predetermined paths. This shield of the engine cylinder by a linkage which may 50 may comprise cylindrical sleeves 98 and I88 at include racks 34 on the compressor pistons mesh tached at their outer ends to the outer surface ing with a pinion 38. ' of the inner cylinder element. The inner ends Intake manifold 38 conducts air to intake valves of these sleeves may overlap near the center of 48 through which air alternately enters opposite the engine cylinder as indicated at I82. The ends of the compressor cylinders. The compressed 55 sleeves have notches I84 and 186 to receive boss 2,412,84é 4 vice is mounted. ' It is to be understood that the invention is not limited to the speci?c embodiment herein illus trated and described, but may be used in other ways without departure from its spirit as de?ned by the following claims. I claim: - ' 6. In a cylinder construction, a cylinder having ports, a manifold extending around said ports, I08 on inner element 80 where the injection de in combination with turnbuckle means for secur ing the manifold to the cylinder. 7. In a cylinder construction, a cylinder having ports, a manifold extending around said ports, , and a housing around said cylinder in com- > bination with turnbuckle means in the form of a ‘ ring extending around the cylinder for securing 1. A cylinder construction including an inner cylinder element having shoulders at its ends, 10 the housing and manifold in position on the cylinder. ' outer cylinder elements overlying said inner cylin 8. In a cylinder construction, a cylinder'having der and having shoulders cooperating with said ports, a manifold extending around said ports, first shoulders, the inner ends of said elements be ing adjacent each other, and a turnbuckle in the form of a threaded ring extending across said elements for holding each outer element in pre determined position. and a housing around said cylinder in combina tion with turnbuckle means securing the housing and manifold in position on the cylinder, said means comprising opposed threads on the housing and manifold, and a ring extending around said 2. A cylinder construction for ?uid cooled cylinderand having cooperating threads engaging engines, a cylinder wall, outer elements extending around said wall and spaced therefrom, the outer 20 the threads on the manifold and housing. 9. In a cylinder construction for an opposed end of each element engaging an end of the wall, piston engine, an inner cylinder element, outer‘ in combination with cooperating threaded rings elements extending around said inner element extending around said elements for drawing-said from opposite ends thereof, the inner ends’ of elements toward each other and for holding the ends of the elements against the ends-of the 25 said outer elements being spaced from each other, a housing extending around the center-part of wall. said’ inner cylinder element and having a cylin 3.-In a cylinder construction for ?uid cooled , drical surface with which the inner ends of the engines, a cylinder wall having shoulders at its outer cylinder elements engage, said inner and. ends, outer elements extending around said wall and spacedltherefrom, each outer element having 30 outer cylinder elements having aligned ports ad jacent opposite ends of the inner element, mani a shoulder cooperating with one end shoulder folds extending around at least some of the ports on the wall, the adjoining edges of the outer ele adjacent each end of the inner element, each of ments being spaced from each other, in combina said manifolds havingthreads thereon and en tion with threaded rings extending around said gaging endwise with a part of the adjoining outer elements for drawing'said outer elements outer cylinder element, said housing also having toward each other and for holding the shoulders threads thereon adjacent each end, and'turn on said elements against the shoulders on the buckles in the form of rings extending around wall. , the housing and engaging the threads on the ‘ 4. In a cylinder construction for ?uid cooled engines, a cylinder wall having shoulders at its 40 housing and the’ threads on the adjacent mani fold for holding said manifolds against the outer ‘ ends, outer elements extending around said wall and spaced therefrom, each outer element having cylinder elements and for holding the outer ~ a. shoulder cooperating with one shoulder on the cylinder elements in position. wall, the adjoining edges of the outer elements being spaced from each other, and a housing around said wall in combination with tum buckle means in the form of rings extending around said outer elements for drawing said outer elements towards each other and into desired position with respect to the housing. ‘ - 10. In a cylinder construction, a cylinder having ports therethrough, adjacent each end, mani folds extending around the cylinder and en closing at least some of the ports adjacent each end, a housing extending centrally around the cylinder and having spaced sets of threads there on, said housing also‘having a cylindrical wall, said cylinder having cylindrical outer surfaces 5..In a cylinder construction for ?uid cooled engines, a cylinder wall having shoulders at its ends, outer elements extending around said wall and in spaced relation therefrom, each outer ele ment having a shoulder cooperating with one shoulder on the wall, the adjoining edges of the outer elements being spaced from each other, a housing around said wall, threads on the hous ing and other threads associated with each ele ing, said cylinder also having spaced shoulders thereon engageable endwise by the surrounding manifolds, each of said manifolds having a'set urging the elements and the ‘housing toward each to the housing. engaging with said cylindrical wall on the hous ing so that the cylinder is piloted within the hous of threads thereon and a ring engagingveach _ ‘set oi’v threads on the housing, and the set of threads on the adjacent manifold for holding ment, and rings constituting turnbuckles having 60 the manifolds in position and clamping the mani folds against the shoulders on the cylinder, there their opposed threads engaging the threads asso by holding the cylinder in position with respect ciated with said elements and on the housing for at er. - > » WALTER A. LEDWI'I'H.