Patent GB-190925262-A (GB)
Title: Improvements in or relating to Internal Combustion Engines.
Inventor: BABIN JULES ALFRED
IPC: F02B3/00
Filed: 1909-11-02
Granted: 1911-02-02
Abstract: 25,262. Babin, J. A. Nov. 3, 1908, [Convention date]. Two - stroke - cycle engines; driving - gear. -- The engine is of the type having free pistons which are disconnected from the driving-shaft during the explosion strokes. The invention consists in adapting the pistons to compress air during their outstrokes, which air is utilized during the return strokes to transmit power to the driving-shaft. The Specification draws an analogy between the Langen and Otto atmospheric engine and an engine which, according to the present invention, performs its in-strokes under the influence of an " artificial " atmosphere " of higher pressure. The indicator diagram of an engine working in an "artificial "atmosphere" is shown in Fig. 2. Explosive mixture is introduced into a working cylinder from A to B at the pressure X, Y of the "artificial atmosphere," and, after ignition and expansion to the point E, the charge is cooled at constant volume to a pressure below that of the atmosphere X<1>, Y<1>. The combustion products are then compressed isothermally to the pressure of the atmosphere and expelled during the remainder of the stroke from H to J. The working diagram of a pump which maintains the " artificial atmosphere " is shown superposed in the indicator diagram, Fig. 2. Explosive mixture is drawn into the pumps between the points J, F and on the return stroke a portion of the charge is rejected until compression commences at the point H. The remainder is then compressed to the pressure of the "artificial atmosphere X, Y and is discharged from B to A. According to a modified method of working, the combustion products may commence discharging at the end of the explosion stroke. Also, the pump may retain the whole of each charge and compress during the full stroke. Fig. 4 shows a two-stroke-cycle engine having a charging-pump, d arranged in tandem with a working cylinder a the piston b<1> of which is connected to the driving-shaft during the in-strokes by ratchet gearing g, h. The front face of the piston b<1> is in open communication with a compressed-air reservoir r the air in which is compressed further during the explosion strokes to effect the return of the piston on each following stroke, which air also forms the "artificial atmosphere." The pump d, which draws in explosive mixture at atmospheric or an increased pressure, delivers its charges through a pipe t to a coil s, which is in constant communication with the air reservoir r. Towards the end of the in-stroke, the charge from the coil s is admitted to the cylinder through a turned valve x and is cut off after the piston has performed a portion of its out-stroke. Ignition then occurs, and at the end of the outstroke a portion of the combustion gases is exhausted through a port y, and the remainder is expelled through a valve z during the in-stroke. To retard the motion of the pistons at the end of the in-stroke, the exhaust port z or the pump outlet port may be throttled; or the pump may discharge past a ballvalve d' until nearing the end of its stroke, when the remainder of the charge is expelled through a restricted outlet d<4>. Water for cooling the combustion products may be drawn from a vessel m, into which the cooling-water injected into the pump is drained, and be forced into the cylinder through a port u. To prevent back-firing, the supply of explosive mixture to the cylinder may terminate in a small supply of air from the tank, the pressure in which is maintained by an auxiliary pump (not shown). If preferred, separate air and gas pumps may be used, gas only being forced into the coil s. Liquid fuel may also be used, in which case air for combustion is compressed in the pump d. The engine is suitable for actuating air-compressors or for pumping. The Specification in the original form, as open to inspection under Section 91 (3) (a), comprises also a modified method of working which is illustrated diagramatically in Fig. 3, cancelled, a method of compounding the engine, and a diagrammatic representation, fig. 4, cancelled, of the relationship between the "thermic efficiencies " and the " mean "absolute pressures." The modified method of working according to Fig. 3 consists of opening momentarily the exhaust valve at the end of expansion, cooling the remaining charge to below atmospheric pressure, recompressing to the pressure of the atmosphere, and exhausting during the remainder of the in-stroke. When compounding the engine, the exhaust products from the explosion cylinder are expanded further in a free-piston cylinder working with a suitable "artificial atmo- " sphere." This subject-matter does not appear in the Specification as accepted.