US2232942A - Locomotive cylinder and steam pipe arrangement - Google Patents

Description

Feb. 25 1941.- A. w. GEIGER EIAL.

LOCOMOTIVE CYLINDER AND STEAM PIPE ARRANGEMENT Filed Dec. 31, 1937 INVENTORB HLaEe'r \Xl. GEIGEB Ur-mes H. Hana:

Patented Feb. 25, 1941 PATENT. OFFICE LOCOMOTIVE CYLINDER AND STEAM PIPE ARRANGEMENT Albert W. Geiger, Willow Grove, and James A. Hance, Gladwyn, Pa.

Application December 31, 1937, Serial No. 182,862 A 1 Claim.

This invention relates generally to locomotives and more particularly to an improved exp-ansible steam pipe arrangement in an integrally cast 10- comotive frame and cylinder structure.

Locomotive frames-and cylinders which are integrally. cast together as a single unit have created very serious expansion problems caused by the very wide temperature differential between the relatively cool portions of the locomotive frame and the highly heated portions of the steam supply pipes and cylinders especially when high pressure superheated steam is used. The unequal expansion of such parts produces abnormally high stresses .which have been known to rupture the casting thus entailing considerable expense and delay in repairing or renewing the same. A great many arrangements heretofore suggested or used to minimize the possibility of adverse stresses being set up by expansion have included various forms of winding or curved passages leading to thevalve housings from a point centrally of the frame. These arrangements have been deficient in various respects such as being costly or of requiring more space than is conveniently available with the result that special cylinder and frame structures had to be provided to accommodate the curved passages.

It is an object of our invention to provide an improved combination and arrangement of parts which will permit the desirable characteristics of an integrally cast frame and cylinder structure to; be retained without incurring disadvantages incident to unequal expansion and without the necessity of using a piping arrangement whose effectiveness is controlled by the amount of space available.

As a result of our improved arrangement, we have not only overcome the difiiculties above mentioned but have also provided an extremely simple and direct steam supply pipe in an integrally cast frame and cylinder structure requiring minimum space and consequently a less complicated casting as well as permitting a more ideal arrangement of cast elements to be employed for insuring maximum strength and economical manufacture.

In the specific aspects of our invention the foregoing results are obtained by providing an integrally cast frame and cylinder structure in which the valve housing or chest and a usual centrally located integral steam supply passage are connected by straight laterally extending passages supported only at their ends by said housings and central supply pipe, together with having each lateral passage provided with a selfcontained radially extending diaphragm or dia- E phragms so shaped as to provide maximum deflection within the elastic limit, of the material used. The foregoing construction also results in the relatively long lateral pipes being materially strengthened by the relatively large radial diaphragms which have suflicient self-sustaining strength comparable to that of the pipe itself While at the same time insuring maximum axial flexibility to compensate for expansion. This arrangement is especially applicable to articulated locomotives wherein the forward cylinders are supplied through a horizontal pipe leading from the rear cylinders although the principles of our invention are applicable to non-articulated locomotives.

Other objects and advantages will be more apparent to those skilled in the art from the following description of the accompanying drawing in which: j

Fig. 1 is a transverse sectional view through the cylinder end of an integrally cast cylinder and frame structure, parts of the structure being shown in elevation;

. Fig. 2 is a horizontal section taken substantially on the line 2--2 of Fig. 1;

Fig. 3 is a partial sectional view of one-half of the cylinder structure and frame showing a modified arrangement of pipe and diaphragm;

,Fig. 4 is another transverse sectional view similar to Fig. 3 but showing a further modification wherein the lateral pipe and diaphragms are integrally cast with the cylinder and frame structure. i

In the particular embodiments of the invention, such as are disclosed herein merely for the purpose of illustrating certain specific forms among possible others that the invention might take in practice, we have provided as shown in Figs. 1 and 2 what may be considered herein as a conventional type of integrally cast frame and cylinder structure having laterally disposed main cylinders l and valve housings or chests 2, exhaust passages 3 leadingfrom opposite ends of the cylinders, steam supply passages 4 from the boiler and a centrally located longitudinally extending steam-supply passage 5 terminating in Y-shaped passage portions 15. In the present specific embodiment, the passage 5 is normally connected to a longitudinal pipe (not shown) for conducting steam to the cylinders of a flexible unit of an articulated locomotive. The cylinders, valve housings, exhaust passages and central supply passage 5 are all integrally connected through a cylinder saddle structure 6 having usual longitudinal and transverse reinforcing webs I, 8 and 9 together with reinforced walls I0 around any suitable openings in the cylinder saddle structure. The engine frame may be cast integrally with the cylinder structure as generally indicated at II, Fig. 2, to form a rigid unit. The central supply pipe 5 and valve housings 2 are herein connected by straight laterally extending pipes I4 which are identical to each other in every respect and hence the description of one will suflice for both. As is seen from Figs.

1 and 2, pipe I4 is connected only at its ends to substantially opposed cast passage portions I5 and I6 formed respectively with central supply passage 5 andvalve housing 2. To facilitate the assembly of the self-contained passage assembly I4 with the integral cylinder structure, the extremities of passage I4 are welded or otherwise suitably secured in collars I1 and I8 which in turn are welded to the cast passage portions l5 and I6. Disposed between the fixed extremities I1 and I8 of pipe I4 and forming a self-contained part thereof is an enlarged radial diaphragm generally indicated at I9 made in two halves, each half of which is provided with a reverse curvature 20 somewhat in the nature of an S- shape. The two halves are then circumferentially welded at 2| while the flanges or inner portion 22 of the S-shaped halves telescopically receive sections of pipe I4 to be welded thereto. The

- pipe I4 and diaphragm I9 may be of any standard pipe or plate metal material, preferably of high elastic limit, thereby insuring maximum strength and flexibility to withstand relatively high pressures and temperatures and to compensate for appreciable expansion without imposing undue forces upon the integral cylinder and frame casting.

The foregoing diaphragm and piping arrangement permits maximum flexibility within the elastic limits of the material used and at the same time the size and space limitations of the casting do not in any way interfere with maximum effectiveness either in strength or expansion. The diaphragms are a complete integral part of each steam pipe and conveniently fit into the cylinder structure in a simple and effective manner without crowding any portion thereof and without requiring peculiar shapes or arrangements of the various elements in order to accommodate pipes I4. Hence all of the advantages of the integrally cast structure are maintained without incurring any of the dis-advantages thereof and yet maximum flexibility is obtained combined with a rugged and stable structure.

In the modification shown in Fig. 4, the pipe Ma is cast integrally with the fixed central passage 5 and the valve housing 2. Also two integrally radially enlarged circular diaphragms I91; and I9!) are cast integrally with pipe Ila. This arrangement has the same advantages as those pointed out in connection with the preferred form although the passage walls must of necessity be made somewhat thicker by reason of being cast. However, due to the particular diaphragm structure and its relation to the pipe Ma which has fixed supports at only its extremities, maximum flexibility is obtained consistent with utmost in strength and minimum space requirement.

In the modification of Fig. 3, the central fixed Y supply pipe 5 has the ends I5 of its Y provided with a flange 24. The pipe I4b is identical in every respect with pipe I4 of Fig. 1 including its connection to valve housing 2 except that the inher end of pipe Mb has a flange 25 welded thereto and adapted to be bolted as at 26 to flange 24. A suitable annular seating ring 21 is interposed between the cast Y- portion I5 and the flange 25. Pipe I4b, when cold and disconnected from bolts 26, is slightly shorter than required whereby upon tightening bolts 26 the pipe will be pulled inwardly to spread slightly the diaphragm walls to pre-stress the same. However, upon heating of the pipe by passage of steam therethrough, the pipe will expand thereby causing the diaphragm walls to move back to their non-stressed neutral position or possibly to the other side of its neutral axis so as to slightly stress the same. This :arrangement will permit the greatest degree of expansion with minimum expansion forces imposed upon the integrally cast structure. To initially weld collar I! to the valve housing 2, the pipe Mb together with its collar I I is placed in position and a shim inserted between seating ring 21 and flange 25 whereupon tightening of bolts 26 will not cause any stretch of diaphragm I90. Thereupon collar I! may be welded to the valve housing. Thereafter the shim is removed from between annular seat 21 and the flange 25 to permit bolts 26 to then tighten flange 25 against ring 2; with consequent pre-stressing of diaphragm From the foregoing disclosure of the several modifications, it is seen that an extremely simple, effective and yet rugged expansible pipe connection is provided in an integral casting between fixed internal points thereof. In all cases the circular radially enlarged diaphragms not only effectively allow for expansion of the laterally straight pipes but also materially reinforce the same but without in any way crowding the cylinder structure elements or requiring peculiar shapes or arrangements thereof as has heretofore been the case with integral structures employing pipes or passages whose axes are arranged in a curving or winding manner. Our improved arrangement not only permits maximum expansion with minimum expansive force being created but accomplishes this in a very direct and simple manner.

It will of course be understood that various 0 changes in details of construction and arrangement of parts may be made by those skilled in the art without departing from the spirit of the invention as set forth in the appended claim.

We claim:

In combination, a locomotive cylinder casting having laterally disposed cylinders and valve housings and a steam supply passage, pipes connecting said steam supply passage With said valve housings, expansible means rigidly associated with each of said connecting pipes, and means adapted, during assembling of the connecting pipes to the valve housings and supply passage, for pre-stressing said expansible means when said connecting pipes are cold whereby upon expansion of said connecting pipes during flow of steam therethrough the pre-stressing of the expansible means is reduced.

ALBERT W. GEIGER. JAMES A. HANCE.

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