US46084A - Improvement in hot-air engines - Google Patents

Description

G. CRANE. HOT AIR ENGINE.

Patented Jan; 81 1865.

To all whom it may concern.-

' UNITED STATES PATENT OFFICE.

MOSES c. Genus, or CHELSEA, MASSACHUSETTS.

IMPROVEMENT IN HOT-AIR ENGINES.

Specification forming part of Letters Patent No. 46,084, dated January 31, 1865.

clare that the following, taken in connectionwith the drawings, which accompany and form part of this specification, is a description'of my invention'suflicient to-enable those skilled in the art to practice it. p

Of said drawings, Figure l.shows my improved hot-air engine in perspective with some of the parts broken away to exhibit internal structure. Fig. 2 is a vertical section taken through one of the air-pumps and the furnace therewith connected,

A represents the bed of the engine, and B the main or working cylinder thereof, which is provided with heads and a suitably-packed piston, similar. to an ordinary steam-engine cylinder.

The piston-rod, cross-head, slides, crank, connecting-rod, balance-wheel, shaft, and upright supports usual for ordinary vertical engines are all plainly shown in the drawings and need not be referred to by letters.

Two air-pumps, O G, are shown, each connected, respectively, with its own air-heating furnace D and D. From one of these pumps, 0, air is supplied to the maincylinder B above its piston to drive it downward, while from the other pump, 0, air is supplied to the main cylinder below the piston to drive it upward. The air-pumps C and O and also the furnaces D and l) are similar in construction and operation. The pump 0 is provided with a piston, G, which is operated through its pistonrod 0 by the following 01' other mechanical devices, which operate to drive down the airpump piston faster than the piston moves in cams being also so fashioned as to cause the pump pistons to rest at the completion of their downward stroke till the engine-piston completes the stroke which is made by the expansion of the air supplied :by one or the other of the pumps, and said cams being also further. fashioned so that the upward stroke of the pump-pistons shall be coincident, or nearly so,

with the strokes forthe engine-piston.

The particular mechanism shown in the drawings for efiecting the dili'e'rent velocities of motion between the piston in. the enginecylinder and the pistons in the air-pumps consists of a crank, 1",011 the engine-shaft, having its crank-pin it working in the slot f of one bars, as shown in Fig. 2, or the air-passage may be so made as to deliver the air partly above the grates, if desired. The air in passing from the furnaces into the main cylinder enters the pump-barrels through pipes K K, above thepump-pistons, before passing into one or the other end of the engine-cylinder, so that' during .the downward stroke of the pump-pistons the pressure is alike on both sides.

From the pipes L and L, which form the air-passages between the main cylinder and the pump'barrels, the exhaust-pipes M and M rise from the main oylinder'B, each being provided with an exhaust-valve so operated by mechanism as to be opened and closed at the times needed for the perfect working 0t,the engine. This mechanism is as follows: Passing through each exhaust'pipe is a crankedshaft, 3 and in the pipes M and M, respectively, and on said shaft 3 are valves m and m, by which the exhaust-passages can be left open to the atmosphere or by which they may be wholly closed. In each lever H Hflare tappet-eyes a a, through which rods n n can freely work, each having a stop on its upper small portion of the first of its stroke, said end, so that when by the movement of H H The other arm of the bent the tappets strike the stops on n 12, one exhaustvalve is closed and the other is opened, thisbeing effected by the partial rotation or rock:

ing of the cranked shaft y, caused by the conwell-'as-iwith one end of 'the main cylinder B,

Whenth'e pump pistons are rising, and it will therefore appear that in the upward movement ofthe'pump-pistons, as well as in their downward movement, the pressure on each side thereof is a1ike. From this it follows that by the construction or arrangement shown by which the air-pump pistons work in equilibrium, substantially as shown, and in which arrangement my invention principally consists, no power is required to work the pumps other than that which is absorbed in friction of the machinery and of the air in'the passages, the operation of the pumps being to displace cold air from a cool place and to cause it to flow-through the furnace, where it is heated and expanded, the pressure on both sides of each pumppiston in this operation-being alike.

In the pipes which connect the pumps at their bases with the furnaces, I place regula- -t0r-valves p, to be operated upon by any wellkuown form of governor worked by the engine. In the piston of the air-pinup I arrange a 'valflylike that marked 0, to be kept shut by its weight or by a spring, and intended to operate so as'tolet the'piston pass the'air beneath it when the regulator works the valve p to prevent or check the air from passing through the furnace to be heated.

I claim- 1. In hot-air engines, the. arrangement of the main cylinder, the ainpump, the furnace, the air-passages, and exhaust-valve, so that the air-pump piston shall work with equal pressare on each side thereof, substantially as set forth.

said piston completes its said stroke before.

the main cylindenpiston completes the stroke which is consequent upon said supply.

In witness whereof {have hereunto set my hand this. 3d day of December, A. I). 1864.

Moses e. CRANE.

In presence nf-' J. B. CnosnY, FRANCIS GOULD.

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