US2068751A - Locomotive - Google Patents

Description

lap. 26, 1937. .A. I. LIPETZ 5 7 LOCOMOTIVE Filed Nov. 5, 1933 5 Sheets-Sheet l INVENTOR H/p/mmse L/peiz A. I. LIPETZ Jan. 26, 1937.

LOCOMOT IVE Filed NOV. 5, 1933 5 Sheets-$119613? 0 v mm mm o INVENTOR I %d/ ?7w ATTOR EY llllliull ||1| Jan; 26, 1937. A. I. LIPETZ 2,063,751

LOCOMOTIVE Filed Nov. 5, 1955 5 Sheets-Sheet. 3

00000 ooooooooo- 00000000000000000 NEY Jan. 26, 1937. A. I. LIPETZ 2,058,751

LOCOMOTIVE Filed NOY. 3, 1933 5 Sheets-Sheet 4 FIG.9 r

INVENTOR fl/pbonse I L/pefz A ORNEY A. l. L] PETZ Jan. 26, 1937.

LOCOMOTIVE Filed Nov. 3, 1935 5 Sheets-Sheet 5 Patented Jan. 26, 1937 PATENT OFFICE LOCOMOTIVE Alphonse I. Lipetz, Albany, N. Y.

Application November 3, 1933, Serial No. 696,457

2 Claims.

This invention relates to locomotives and particularly to a high pressure steam locomotive embodying certain new and improved features, designed and arranged for obtaining a maximum SJ'efiiciency in the generation and utilization of steam.

An object of the invention is to provide a multipressure steam locomotive embodying improved means for generating high pressure steam and loolow pressure steam and for utilizing said steam in a cooperative manner so as to obtain a maximum steam generation efficiency as well as a maximum working cylinder operating efiiciency.

A further object is to provide a locomotive emlu bodying improved means such as aforedescribed,

wherein both products of combustion and exhaust high pressure steam are utilized in the generation of the low pressure steam.

A further object is to provide a locomotive em- 20i-bodying improved means such as aforedescribed wherein the low pressure steam is utilized both for operating low pressure cylinders and for heating a high pressure cylinder.

A further object is to provide a locomotive em- -25;.5bodying an improved superheater construction and arrangement including a superheater having a header disposed between a tubular high pressure steam generator and a low pressure steam generator and tubes extending from said header 3a.,and arranged both vertically and horizontally in such manner as to attain a maximum thermal efiiciency.

A further object is to provide a construction and arrangement of the character last described 35. wherein a part of the superheater tubes extends horizontally into the high pressure steam generator between the tubes thereof.

A further object is to provide an improved high pressure working cylinder and valve chest coniozstruction embodying steam jacket housing means wherein superheated low pressure steam is utilized as a heating jacket for the Working cylinder.

A further object is to provide a locomotive em- 45-;-bodying high pressure steam generating means and low pressure steam generating means together with means for utilizing the high pressure steam both for operating a high pressure Working cylinder and for heating the low pressure steam Ogenerating means, and means for utilizing the low pressure steam both for operating low pressure cylinders and for heating a high pressure cylinder.

A further object is to provide a multi-pressure i 5 steam engine embodying a working cylinder operated by low pressure steam and a working cylinder operated by high pressure steam with the last mentioned cylinder of the unifiow type.

A further object is to provide an engine of the character last described wherein the low pressure working cylinder is of the counterflow type.

A further object is to provide a locomotive embodying improved means for preheating air for its steam generator fire box by utilizing exhaust products of combustion from said fire box in afire tube heat exchanger arranged so as to afiord a maximum thermal eificiency.

Other objects of and advantages achieved by this invention will be apparent from the following detailed description.

The invention is illustrated in the accompanying drawings wherein Figure 1 is a side elevation of a locomotive embodying the present invention; Fig. 2 18 a side elevation of a locomotive embodying the present invention, showing a modified arrangement or" the high pressure cylinder construction and connected parts; Fig. 3 is a side view of the locomotive shown in Fig. l, with certain parts broken away, or shown in section, and certain parts eliminated, showing the general arrangement and connections between various parts; Fig. 4 is an enlarged partial front end view of the locomotive shown in Fig. 1 with certain parts removed, the view being merely diagrammatical, the cylinders and cylinder saddle being merely indicated in outline; Fig. 5 is an enlarged, vertical. longitudinal section of the locomotive boiler of the present invention, certain parts being shown in elevation and certain parts being removed; Fig. 6 is a transverse section on the line VI-VI of Fig. 5; Fig. 7 is a transverse section on the line VIIVII of Fig. 5; Fig. 8 is a horizontal section of the smoke box and air preheater part of the locomotive, on the line VIII-VIII of Fig. 5; Fig. 9 is a view on an enlarged scale, at

the left side being a transverse section on the line IXIX of Fig. 5 and at the right side a transverse section on the line IX-IX' of Fig. 5; Fig. 10 is a view on an enlarged scale, at the left side being a half rear end view of the structure shown in Fig. 5 and at the right side a transverse section on the line X-X of Fig. 5; Figs. 11 to 14 are enlarged views of the high pressure steam working cylinder and valve chest construction of the present invention, as shown in Fig. 1, Fig. 11 being a substantially horizontal section, the upper part, showing the working cylinder, being on the line XI-XI of Fig. 12, and the lower part, showing the valve chest, being on the line X['-XI' of Fig. 12, Fig. 12, a vertical section on the line X1'IX[I of Fig. 13, Fig. 13, a transverse section on the line XIII-XIII of Fig. 12, and Fig. 14, in part an end view and in part a transverse section on the line XIV-XIV of Fig. 11; and Fig. 15 is an enlarged fragmentary plan View of the superheater shown in Fig. 5.

Referring in detail to the drawings, and particularly to Figs. 3 to 5, the locomotive comprises a high pressure steam generator I at the rear portion thereof, a superheater 2 at the forward end of the generator I, a low pressure steam generator 3 disposed forwardly of the superheater, and an air preheater 4 disposed forwardly of the generator 3, immediately to the rear of a smoke box 5 which is disposed at the forward end of the locomotive in the usual manner.

Low pressure working cylinder and distribution valve chest constructions 6 are disposed at the forward end of the locomotive, one at each of the opposite sides thereof, and a high pressure working cylinder and distribution valve chest construction I is disposed between the constructions 6. The constructions of, connections between, and operation of, the aforesaid parts will be hereinafter set forth in the order given.

The high pressure steam generator I, (see Figs. 3, 5, 9, and is adapted for direct heating and is designed to generate steam for use in the high pressure working cylinder of the construction 'I. This generator is of the drum and tube type, embodying a fire box 8 at the rear end of the locomotive and combustion chamber 9 forward of the fire box. A rectangular fire box ring II! is disposed below the fire box.

A pair of longitudinal cylindrical water drums II, is disposed forward of and in a higher plane than the ring I0, one drum at each of the opposite sides of the combustion chamber, and a pair of spaced, longitudinal cylindrical water drums I2 is disposed between the drums I I. The drums II extend from the front end to the rear end of the combustion chamber. The drums I2 extend from the rear end to approximately the center of the combustion chamber. A pair of longitudinal cylindrical drums I3 is disposed at the top of the generator I, one drum at each of the opposite sides thereof, and a top, longitudinal, cylindrical drum I4 is disposed centrally between the drums I3. The drums I3 and I4 extend the full length of the fire box and combustion chamber.

The drums I3 are connected with the drums I I and the side members of the ring III by several series of tubes I5, I6, I61; and I1, arranged in rows at the opposite sides of the generator I (only the drums II being connected by the tubes Ifia with the drums I3). The tubes I5 are downcomers, the tubes I6 and Ilia are vertical risers, and the tubes I! are cross-over risers. A grate I8 is disposed above the ring Ill providing the bottom of the fire box, and the vertical and cross-over riser tubes I6 and I1 define the sides and top of the fire box and combustion chamber. There are thus two rows of risers at each side of the combustion chamber and one row of risers at each side of the firebox, more particularly one row extending through both the firebox and combustion chamber and comprising alternately vertical risers I6 and cross-over risers I1 and another row extending only through the combustion chamber and comprising only the tubes Ilia. The risers I6a are located in the same transverse planes as the risers I6 and hence do not interfere with the cross-over risers H.

The downcomer tubes I5 being disposed at the outside of the fire box and combustion chamber, are thus in a relatively cool zone for establishing a positive circulation. The tubes I6 and I! being nearer to the interiors of the firebox and combustion chamber and the tubes Ilia being nearer to the interior of the combustion chamber, these tubes will be subjected to direct heat for the generation of high pressure steam, which will rise in these tubes to the top drums I3 and pass therefrom, through pipes hereinafter mentioned, to the drum I4.

The fire box is substantially closed at its rear end by a wall of tubes I9. A transverse upper drum 2!] is disposed at this end of the fire box, below the rear ends of the drums I3 and I4, and the tubes I9 are connected at their upper ends with the drum 20 and at their lower ends with the rear end member of the ring ID. The tubes are bent so as to provide an opening 2| through the wall near the center thereof to the interior of the fire box for feeding fuel thereto, a suitable fire door frame and fire door (not shown) being provided in the usual manner, for closing the opening 2|. The drum 2|] is connected by tubes 22 with the drums I3. Some of the tubes I9 are branched as shown in Fig. 10 in order to fill the space at this end of the generator.

The upper drums I3 and I4 are connected with 'ihe relatively short drums I2 by rows of vertical tubes 23, these tubes alternately entering the drums I3 and 54 respectively, and being spaced relatively far from each other and which, with other tubes hereinafter described, somewhat fill up the rear end of the combustion chamber. As less tubes (requiring tube openings) are connected with the drum l4 than with either of the drums I3, the drum I4 while of a larger diameter than the drums I3 will withstand an equal amount of pressure without any excessive increase in its 7 iively less amount of water in the drum I4 is permissible.

The upper portions, or steam spaces, of the drums I3 are connected with the upper portion or steam space of the drum I4 by tubes 24. As

only a relatively few tubes 24 are necessary, the

perforations for these tubes in the drum I4 will not appreciably affect the strength of this drum.

A transverse, cylindrical drum 25 is disposed at the bottom of the forward end of the combustion chamber. A row of tubes 26 connects the front end member of the fire box ring II] with the drum 25 and a transverse row of tubes 21 connects the upper drums I3 and I4 with the drum 25. The combustion chamber is sufliciently long to effect a cooling of the products of combustion passed therethrough to a temperature which the ends of the rear units of the superheater, hereinafter described, can withstand without damage.

For convenience of design, if desired, the drum i4 may be shortened provided it extends at least throughout the length of the drums I2. Furthermore, the construction may also be modified, if desired, so as to eliminate the connecting tubes between the drums I2 and 25 and the drum I4. This arrangement is expedient in that the drum I4 may then be reserved entirely for steam accumulation and steam may be taken off from this drum only, and delivered to the superheater.

It will of course be understood that the fire box ring Ii if desired, may be constructed of cylindrical drums and may be either independent of, as shown, or connected with the drums II. Further, if desired, a brick arch or a brick wall may be disposed between the fire box and combustion chamber, or may be disposed within the fire box slightly to the rear of the combustion chamber, if the grates stop short of the front end member of the fire box ring.

While an approved embodiment of a high pressure steam generator has been described, it will of course be understood that the present invention is not limited to the use of the particular generator described, but that any suitable type of high pressure steam generator may be employed.

The superheater 2 comprises a horizontally disposed box-shaped header 28, which is divided into two separate sections by a partition indicated at 29. The rear section 2811. is for high pressure steam and the front section 28b is for low pressure steam. An inlet opening 30 is provided in the upper portion of the rear section and is connected with the central upper drum M by a pipe-3| for receiving steam from the high pressure steam generator I. 'An outlet opening 32 is provided at a side of the rear section and is connected by a pipe 81 with the distribution valve chest of the construction 1, in which pipe 81 a high pressure throttle valve (not shown) of any suitable well-known design is interposed, as hereinafter further mentioned. The front section 28b is provided at its forward end with an inlet opening 33 which is connected with a steam dome 34 of the low pressure generator 3 by a dry pipe 35, for receiving low pressure steam. An outlet opening 36 is provided at a side of the front section and is connected by a pipe 92 with the interior of the steam jacket housing of the construction I, in which pipe 92 a low pressure throttle valve (not shown) of any suitable wellknown design is interposed, as hereinafter further mentioned.

Attached to the bottoms of both sections of the header is a plurality of steam circulation tube units 31. Each of the units 31 includes tubes or reaches having their ends connected with the header and suitable return bends between their ends. The tube units which are connected at the forward end of the header front section 28b comprise vertical reaches only, while some of the tube units to the rear thereof, in both the front and rear header sections, include reaches which are partly vertical and partly horizontal as indicated at 38, that is, the last mentioned units are bent rearwardly and extend horizontally into the forward portion of the combustion chamber.

' While the space in the combustion chamber is more or less utilized by steam generator tubes, limiting the space for superheater horizontal reaches, the space in advance thereof is unrestricted and may be availed of to the fullest extent for the superheater units. Furthermore, as in the present arrangement there is no association of the superheater units with fire tubes, as is common in constructions of the prior art, there is no restriction as to the arrangement of the units by such fire tubes, and the units are disposed as aforedescribed with their reaches extending vertically and horizontally in the most expedient manner to fill the space forward of the generator I, and the available space in the combustion chamber of the generator. Thus as many as possible of the tube units which comprise vertical reaches only are provided at the sides of the header 28 (see particularly Fig. 15).

As distinguished from superheaters heretofore used, the header 28 is at least as wide as the outside of the combustion chamber, that is as wide as the available space forward of the generator I permits, or in other words the header is wider than the inside of the combustion chamber or the space between the risers 16a where thehori'zo'ntal reaches '38 extend. This arrangement allows the high pressure superheater section to be disposed in the hotter zone while the low pressure superheater section is disposed in the relatively cooler zone, this being desirable as it is more diificult (that is, it requires more heat) to superheat high pressure steam than to superheat low pressure steam to the same degree of superheat. However, due to the construction of the superheater, in the locomotive of the present invention the low pressure steam is in fact superheated to a higher total temperature than the high pressure steam and this condition is desirable and made use of as will be hereinafter explained.

The low pressure steam generator 3 comprises a longitudinal, cylindrical drum 39, having tube sheets 40 secured at, and enclosing, its forward and rear ends. The steam dome 34 hereinbefore mentioned, is provided at the top of the drum 39, an opening 4| being formed in the drum to permit the passage of steam therefrom into the dome. An opening 42 is formed in the rear tube sheet 40 for the dry pipe 35 to pass through, the dry pipe extending from the inlet 33 to the steam dome for receiving low pressure steam therefrom for the low pressure section 2% of the superheater.

A bank of relatively small, spaced, longitudinal steam tubes 43 is disposed in the central part of the drum 39 and the tubes extend longitudinally therethrough with their opposite ends passing through and suitably secured to the respective tube sheets 40. A series of fire tubes 44 is disposed around the bank of tubes 43 which tubes also extend longitudinally through the drum 39 with their opposite ends extending through and suitably secured to the respective tube sheets 40.

A head 45 is secured at the outside of the rear tube sheet 40 and provides therewith a chamber 46 into which the rear ends of the tubes 43 open. A head 41 is disposed at the outside of the front tube sheet 40 and provides therewith a chamber 48 into which the forward ends of the tubes 43 open. The heads 45 and 4'! are of substantially fiat, dish shape and are provided each with an outwardly extending peripheral flange 49, which is secured by studs 49a, to the face of its respective adjacent tube sheet. A soft metal gasket (not shown) is provided between each flange 49 and its adjacent tube sheet to provide the required steam tightness therebetween. Any other suitable jointure, however, may of course be provided. In addition to the studs, a plurality of longitudinal tie rods 50 is provided. The tie rods extend through tubes 5|, which are disposed in spaced relation, among the tubes 43 and are similarly secured to the opposite tube sheets, but are of slightly larger diameter than the tubes 43 for the purpose of providing a space around the rod passed therethrough. The tie rods extend through the heads 45 and 41 at their opposite ends, and nuts 52 are provided at their extremities. The heads are pressed against the tube sheets and drawn towards each other under the desired amount of pressure by tightening of the nuts 52. In the embodiment illustrated, the heads 45 and 41 and the bank of tubes 43 and 5| are spaced concentrically relative to the drum but it will, of course, be understood that these heads and bank of tubes may be eccentrically disposed, depending upon the requirements of the design.

A baflle plate 53 is disposed at the rear end of the steam generator 3 and covers the rear head 45. The plate 53 is of conical shape, pointing rearwardly', and acts to direct the products of combustion, from the combustion chamber into the fire tubes M. A similar bafiie plate 54 is provided at the forward end of the generator 3.

: The plate 54 is of conical shape similar to the plate 53, and covers the front head 41 and points forwardly, acting to direct the products of combustion at this end of the generator. The baffle plates protect the heads and the ends of the tie rods 5% and the nuts 52 from the products of combustion. In passing through the fire tubes 66, the products of combustion give up heat to generate steam in the drum 39. Low pressure steam accumulates in the dome 34 in the same manner as in an ordinary steam locomotive and is withdrawn therefrom through the dry pipe 35 as aforedescribed.

A pipe 55 is provided at the forward end of the steam generator 3 and extends through the baffle 54 and through the head 4'! opening into the chamber 58. The pipe 55 extends forwardly (see Fig. 1) and is connected with the exhaust port of the high pressure steam working cylinder and valve chest construction i as hereinafter further described. A pipe 56 is disposed at the rear of the generator 3 and extends at its forward end through the baffle 53 and the head 45, opening into the chamber 36 and extends rearwardly. The rear end of the pipe 56 is connected to the ring It of the high pressure steam generator i.

A suitable pump indicated at 51 is interposed in the pipe 55 for forcing the fluid back into the high pressure steam generator i. A steam operated motor indicated at 58 of a suitable well known type, is disposed adjacent the pump 5'! for operating the same. Operating steam for the pump motor 58 is supplied from the high pressure generator drum i i, a pipe 59 connecting the motor 58 with the pipe 3| which leads from drum i i. A pipe fill connects the exhaust port of the motor 58 with the pipe 55 so that the steam exhausted from the motor will be delivered to the chamber 88 together with the exhaust steam from the high pressure working cylinder construction, and thus kept in a closed circuit, hereinafter further mentioned.

The exhaust steam from the high pressure working cylinder construction, as hereinafter further described, enters the chamber d8 from the pipe 55 and passes rearwardly through the tubes t3 and 5! to the chamber 45. In so passing through the generator 3 the exhaust steam gives up heat to heat the water and generate steam within the drum 39, in supplement or addition to the products of combustion, as aforedescribed, passing through the tubes 44. In this operation, the exhaust steam from the construction I, will be substantially condensed and it will thereupon be pumped, by the pump 57, through the pipe 55, connected to the ring 10 back to the high pressure steam generator.

It will thus be apparent that the means for generating and utilizing the high pressure steam comprises a closed circuit, so that the same water is used continuously and it is only necessary to supply a relatively small amount of make up water to compensate for unavoidable losses due to leakage, etc. Hence, a distilled water may be used in this circuit and a minimum amount of scale will be present in the high pressure generator. A tank of such water (not shown) is carried by the locomotive. It will of course be understood that instead of this tank a condenser for exhaust low pressure steam may be employed,

and the generator fed therefrom in any desired or well known manner.

A cylindrical drum 6i is disposed forwardly of the drum 39 and suitably secured thereto by welding, or other means, such as rivets. The rear end of the drum at the lower portion is shaped to form an upwardly extending throat, as indicated at 52, so that the bottom of the drum will be sufficiently high to extend over the cylinder saddle of the working cylinder and valve chest constructions 6 and I, which saddle is of conventional construction and design.

The air preheater t constitutes the rear portion of the drum M. A conical tube sheet 63, forming the rear Wall of the preheater, is secured, by welding, to the drum 6| near its rear end, spaced forwardly from the baffle 5 and pointing forwardly. A tube sheet 64, forming the front end of the preheater, is spaced forwardly of the tube sheet t3 and suitably secured by welding to the drum iii. The tube sheets are. made of thin steel plate, and may be riveted to the drum, if desired, or secured in any other suitable manner. A series of fire tubes 55 is disposed within the preheater it which tubes extend'longitudinally between the tube sheets 63 and 64. The opposite ends of the tubes 65 extend through and are suitably secured in the respective tube sheets. As

there is no pressure within the air preheater, the tubes may be simply welded in and need not be rolled.

' Products of combustion from the fire tubes of the generator 3 pass through the tubes 65 of the preheater into the forward end of the drum 65 which constitutes the smoke box 5.

An inlet opening 65 (see Fig. 8) for the air preheater is provided in the side of the cylinder 6! at the inner side of the tube sheet 54, and an outwardly and forwardly extending bafiie 61 is secured at the rear side of the opening 68 for directing a current of air into the air preheater.

Other suitable inlet openings provided withv baffles, which may be controllable if desired, in accordancewith'the direction of travel of the locomotive, may be provided for the air preheater as proves expedient. An outlet opening 68 is pro vided for the air preheater in the side of the cylinder 6!, opposite to the inlet opening side thereof at the inner side of the tube sheet 63. A duct 59 connects the outlet opening 68 with the ash pan 8a of the high pressure generator i for supplying preheated air to the fire box. A plurality of baffle plates H3 is disposed within the air preheater. The baffle plates extend vertically and are each secured to the cylinder 5! at the top and bottom thereof and to one or the other of the tube sheets, extending away from the respective tube sheet and leaving a space between its free edge and the opposite tube sheet. In the embodiment illustrated only two baffle plates are provided, one extending from one tube sheet and one from the other, but it will, of course, be understood that as many may be employed as found desirable. By means of these bafiie plates, air passing from the inlet opening 65 to the outlet opening 68 is forced to take a circuitous path through the air preheater as indicated by the arrows in Fig. 8 being thus subjected to the heat of the tubes 65 for a longer period of time than if passed directly through the preheater. The movement of the locomotive will 'eifect a current of air through the air preheater.

It will be understood that while in the embodiment illustrated the air preheater is designed so that the products of combustion pass through tubes and the air passes around the tubes, the .preheatermay be so designed that the air will pass through tubes while the products of combustion are passed therearound.

Referring. now to the working cylinder and valve chest constructions of the locomotive, it will be noted that it requires more heat to superheat high pressure steam than low pressure steam for a given number of degrees of superheat. Further, due to limitations which are placed upon the total steam temperature that can be maintained in a locomotive boiler (which limitations are dependent upon the strength of materials employed), the maximum permissible temperatureof superheating of the high pressure steam must necessarily be lower than that of the low pressure steam. It therefore is of particular importance to protect the superheated high pressure steam from cooling if a maximum efficiency is to be obtained. This invention utilizes the uniflow principle for the high pressure working cylinder, and thecooling and condensation of the steam therein during its use is thereby substantially reduced.

In ordinary three cylinder locomotives embodying the uniflow principle high pressure cylinder, wide heavy pistons are employed therein, resulting in an increase of the weights of reciprocating parts and thereby impairing the counterbalancing of the locomotive. In the 10- comotive of this invention the high pressure cylinder is smaller than the usual high pressure cylinder of this type and is suiiiciently small so that the Weight of its reciprocating parts is not greater than that of the low pressure cylinder. This permits as good balancing of the several reciprocating parts of the high and low pressure cylinders as in any conventional locomotive.

This invention besides utilizing the uniflow principle for the high pressure cylinder protects the high pressure steam from cooling by jacketing the working cylinder with low pressure highly superheated steam and thereby allows a high pressure steam working cylinder to be utilized without undue cooling. While steam jackets have been found to be desirable in uniflow stationary engines, it has been found. impractical heretofore to apply such constructions to locomotives for the reason that the steam of the jackets would radiate heat to the outside and would act to cool the steam in the cylinders, as it was ordinarily of the same initial temperature as the steam of the jacket. In locomotives of the present invention, however, two kinds of steam are employed, of different pressures and temperatures, one a low pressure steam and one a high pressure steam, and the locomotive is constructed so that the low pressure steam has a higher superheat than the high pressure steam. The low pressure steam, of higher superheat, is utilized for the jacket of the high pressure steam cylinder, thus protecting the steam of this cylinder from cooling. The loss which may be incurred from radiation of low pressure steam of the jacket is more than oiTset by the saving of heat in the high pressure steam and the better utilization of that heat.

The high pressure cylinder and valve chest construction 1 comprises an integral casting (see Figs. 4 and 11 to 14). The construction is of the well-known modified unifiow or continuous current type where steam is exhausted both through a middle port in the working cylinder and through inlet exhaust ports at the ends thereof controlled by the distribution valve as will appear from the following description. The distribution valve pistons hereinafter more particularly described, are of the conventional type adapted for operation in connection with the uniflow high pressure cylinder type.

For convenience of diagrammatical illustration Fig. 4 indicates the cylinders, valve chests and cylinder saddle formed as a single casting. This form of construction may be resorted to if desired. In the exemplification of the invention in its present preferred form however the high pressure cylinder, valve chest and various associated features are actually formed as a separate casting, as clearly shown in Figs. 11 to 14.

The casting H includes a working cylinder 12, a valve chest, 73; a rear head 14 for the cylinder I2, and a jacket housing indicated generally by the numeral 15 which surrounds the cylinder 12, the valve chest 13 and the head 14 providing enclosed chambers therearound through which low pressure steam is circulated to provide a heating jacket, as hereinafter more fully described. A detachable front head 16 is provided for the working cylinder and suitably secured thereto by studs (not shown). The head 16 is formed as an integral casting and provided with a jacket housing 11.

The construction 7 is supported by the locomotive cylinder saddle in the conventional manner and is disposed centrally between the constructions 6. The working cylinder 12 is disposed at an angle to the valve chest I3 which is horizontal. Both the working cylinder 12 and the valve chest 13 are provided with suitable bushings 18 and '19 respectively for their pistons.

A piston 8!] is disposed in the working cylinder and is provided with a piston rod 8|, which is connected through crosshead, drive rod, and crank axle structure of conventional design with the second pairof driving wheels of the locomotive as indicated at 82 in Fig. 1.

A pair of piston valves 83 connected to a Valve stem 84 is provided for the valve-chest 73, and the valves are adapted to reciprocate within the bushings 19. The valve stem 84 is connected with, and controlled by, valve gear mechanism of conventional design, indicated at 85 in Fig. 1.

The valve chest 13 is provided with an inlet passage 86 formed as a part of the casting H and around which a part of the jacket housing 75 extends. The passage 86 is connected by the pipe 81 having the high pressure throttle valve (not shown) interposed therein, as hereinbefore mentioned, with outlet opening 32 of the high pressure steam section 23a of the superheater 2 for receiving steam therefrom for the operation of the high pressure cylinder. An exhaust port 88 is provided centrally in the cylinder 12, a corresponding port being, of course, formed in the bushing 18. Exhaust passages 89 connect the ends of the valve chest 13 with a main exhaust passage 90 which also is connected with the exhaust port 88. The passages 89 and 90 are formed as an integral part of the casting H. The passage 90 is connected to the pipe 55, hereinbefore referred to, which is in turn connected with the low pressure steam generator 3 as aforedescribed.

A low pressure steam inlet passage 9! is provided in the casting H. The pipe 92 having the low pressure throttle valve (not shown) interposed therein, as hereinbefore mentioned, connects the passage 9| with the outlet opening 36 of the front or low pressure section 28b of the superheater for receiving low pressure superheated steam therefrom. The passage 9| communicates with the interior of the jacket housing 15 and is formed as an integral part of the casting H. An outlet low pressure steam branched passage 93 is provided as an integral part of the casting H, and also communicates with the interior of the jacket housing 75. A pipe 84 and branch pipes 95 (see Fig. l), connect the passage 93 with the distribution valve chests of the constructions 6 for supplying low pressure steamthereto. a

An inlet pipe 96 connects the passage E i with the interior of the housing ll of the cylinder head it and an outlet pipe 91 connects the interior of the housing W with the passage 93.

The low pressure steam from the front section 281)' of the superheater is thus directed to the jacket housings l5 and H of the construction I by the pipe 82, is then circulated through the housings, so as to provide a steam jacket around the cylinder l2, its heads 14 and i6 and the distribution valve chest 13, and the steam is then passed through the passage 93 and pipes 94 and as to the distribution valve chests'of the constructions 6 and thereupon utilized for operating the low pressure working cylinders.

The low pressure working cylinders and their valve chests of the constructions 5, are of usual, conventional counterfiow design and are provided with pistons and piston rods which are connected and operated in the usual manner. The low pressure steam is exhausted from the valve chests of the constructions 5 through exhaust passageways 98 whichlead to the smoke box 5, and is thereupon exhausted through the stack 99 in the usual manner.

As indicated in Fig. 1, the pistons of the low pressure cylinders are connected through crosshead, drive rod and crank pin structure of conventional design, with the third pair of driving wheels, connecting rods between the driving wheels being provided in the usual manner, and the valve stems of the distribution valves are connected to and operated by the valve gear mechanism hereinbefore referred to which also controls the high pressure distribution valve as aforesaid.

In Fig. 2 there is illustrated a modified embodiment of the invention in a locomotive, wherein constructions 6a and la similar to the constructions 6 and l are employed in relative positions different from those of the first described embodiment. The construction Ea is disposed between the second pair of driving wheels, and the piston of the working cylinder of this construction is operably connected to the fourth or rearmost pair of driving wheels by crosshead, drive rod and crank axle structure indicated at 82a, all of which are arranged in proper positions, to the rear of the construction la and carried by'the locomotive frame in conventional manner. Valve gear mechanism 850. similar to the mechanism 85 is employed, modified accordingly to properly control'the distribution valves of the constructions to and la. By this arrangement the high pressure superheated steam supply pipe 81a and the low pressure superheated steam supply pipe 52a are substantially shortened, so that, as the steam has less distance to travel from the superheater before being used, it will be subjected to less cooling. The pipe 55a leading from the exhaust passage of the construction la to the low pressure steam generator 3a is accordingly of modified construction, extending forwardly and upwardly.

The steam jacket housing of the high pressure cylinder is connected to the low pressure distribution valve chest by piping in a manner similar to the construction shown in Fig. 1, one of the branch pipes being indicated at a. While this piping must be lengthened, in this arrangement it is more than compensated for by the shortening of the other pipes. The parts of the locomotive are all of substantially the same construction for the modified embodiment as those aforedescribed for the first embodiment and theoperation of the two embodiments is also the same,

the only difference being in the change of location and minor structural modifications aforedescribed. H

The auxiliaries of the locomotive may be operated by either low pressure steam or high pressure steam as described with reference to the' pump motor 58. The low pressure steam generator is fed from a suitable source of feed water in conventional manner (not shown).

The operation of the locomotive being apparent from the foregoing description, it will be realized that the invention presents a locomotive characterized by efficiency and economy of operation and relative simplicity of construction and arrangement of parts and by which the objects The invention claimed and desired to be secured by Letters Patent is:

1. A locomotive comprising a high pressure steam generator; a low pressure steam generato-r; a high pressure steam working cylinder; a

low pressure steam working cylinder; means for transmitting high pressure steam from said high pressure steam generator to said high pressure cylinder for operating said high pressure cylinder; means for transmitting low pressure steam 7 from said low pressure steam generator to said high pressure cylinder and utilizing said low pressure steam for heating said high pressure cylinder; and means for transmitting said low pressure steam from said high pressure cylinder,

after its said utilization, to said low pressure cylinder for operating said low pressure cylinder.

2. A power plant comprising a high pressure working cylinder; a jacket for said high pressure working cylinder; 2. lower pressure working cylinder; means for supplying high pressure live steam to said high pressure working cylinder for operating same; means for supplying low pressure live steam to said jacket, said low pressure steam supplying meansincluding a superheater, disposed between said jacket and said low pressure steam supplying means, for raising the temperature of said low pressure live steam, being conveyed to said jacket, to a temperature sufficiently higher than the temperature of said high pressure live steam so that said steam in said jacket will be of a temperature higher than hat of sa d steam entering said high pressure cylinder; and means for supplying said low pressure working cylinder with steam from said jacket. I

ALPHONSE I. LIPETZ.

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