US1226604A - Core-box for bladed diaphragms of steam-turbines. - Google Patents

Description

APPLICATION FILED MAR-14. I9l6.

Patented May 15, 1917] 2 SHEETS-SHEET 1- W. SHERWOOD & L. BALDWIN. CORE BOX FOR BLADED DIAPHRAGMS 0F STEAM TURBINES.

APPLICATION FILED MAR.14, I916.

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I WALTER- snnnwoon AND LovELL BALDWIN, or wELLsvILLE, NEW YORK.

CORE-BOX FOR BLADED DIAPHRAGMS 0F STEAM-TURBINES.

Specification of Letters Patent.

' Patented May 15, 199?.

Application filed March M, 1916. Serial m. 84,245.

To all whom it may concern Be it known that we, WAL ER SHERWOOD and LovELL BALDWIN, citizens of the United States, and both residents of Wellsville, in the county of Allegany and State of New York, have invented an improvement in Cone-Boxes for Bladed Diaphragms of Steam-Turbines, of which the following de scription, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts in each of the several views, v

This invention relates to core boxes for producing the cores used in the casting of bladed diaphragms for steam turbines,- such diaphragms consisting in a relatively stationary disk shaped web of cast metal with spaced apart series of bladed curved passages constituting ports for the passage of steam to the rotor of the turbine. More particularly the invention has todo with a core box of this type, of sectional form built up of a series of rings, ring segments and filler and follower pieces adapted to convenient assemblage for the formation of the core therein and for being readily taken apart for the removal of the formed core. lln producing the type of diaphragm to which our invention is directed it is intended that the curved division blades or plates which are interposed at intervals in each of the arcuate ports of the diaphragm shall be embedded and held in'the core constituting the present invention as the metal of the diaphragm is cast therearound so that said division blades will thereby be embedded and securely held in the cast metal of the diaphragm as the core material is removed.

One prime object of the invention is'to provide a core box of this type, adapted to receive, and equipped With, a series of follower pieces that are employed for correctly locating and positioning such division blades in the core. it being understood that the proper positioning of such blades, so that they will be correctly and accurately positioned in the cast diaphragm upon removal of the core, is of prime importance. In ac cordance with our invention the follower pieces in question are formed as inner and outer members adapted to lit between the division blades at each side of a central core web and they are readily removable and replaceable in selective arrangement at will.

' lln accordance with the invention any number of blades at each of the inlet ports as required for the particular diaphragm may be fitted in place with the use of a corresponding number of follower pieces, it being possible to have the, blades occupy the complete circle of the diaphragm if desired. The follower pieces employed may also be used with diflerent sizes of core boxes to produce larger or smaller diaphragms. The improved follower pieces which We employ may also be arranged to run either to the right or to the left sons to build either a right or left hand core, at will. By virtue of the built up construction of our improved core box it is also possible by changing certain inside rings and the inside follower pieces to construct cores of any width called for by the particular diaphragm to be made. The foregoing and other objects and fea tures of the invention will be better understood from the following detailed description taken in connection with the accompanying drawings and will be thereafterpointed out inthe appended claims.

Referring to the drawingsi Figure 1 is aplan view of a core box constructed in accordance with our invention;

Fig. 2 is a central vertical section on line 2-2of Fig. 1;

Fig. 3 is a perspective view showing a core box inverted and with certain outer and bottom portions rem ved;

Fig, at is a plan view of a half core as produced by our improved core box;

Figs. 5 and 6 are a side elevation and a perspective respectively of one of the inside follower pieces employed with our invention and constituting a part thereof;

Figs. 7 and 8 are a side elevation and a perspective respectively of one of the outside follower pieces employed with our inven tion; and Fig. 9; is a transverse section showing the core and blades assembled therewith I taken on line 9-9 of Fig. 4c".

The main part and base of the core lOOlf. is indicated at 1 with a shallow upstanding peripheral wall flange 2, having suitable. provision indicated as a small ledge 3 to position thereon an integral ring member or curving slightly outward upwardly, this ros ill]

dicated at 10 to permit ready removal thereof, and said ring 9 serving as a radial abut.- ment and support for the ring 8 and alsofor an upper sectional ring 11 fitted in superposed relation on the ring 8 as presently further explained.v The sectional rings 5 and 8 are of substantially the same height and the space therebetween is filled in to produce the core part for the unbladed or solid portion of the diaphragm with ring segment filler pieces 12 formed to fit in and fill the portions of the annular space between the rings 5 and 8 which they occupy. For producing the bladed portions or ports of the diaphragm we provide suitable removable means capable of selective positioning in the portion or portions of such annular space of the core box between the rings 5 and 8 that are to be. used to produce the bladed portion of the diaphragm.-

At this point it should be understood that the core formed by the present core box is intended to have emplaced therein and carried thereby, the metallic blades that are to constitute the curved division plates in the ports of the diaphragm itself, such blades being suitably held by the core with provision whereby the molten metal of the diaphragm as it is cast therearound will embed the said blades therein while preserving the port spaces therebetween as the core is removed. The way in which this is accomplished is shown in Fig. 4, where a half core C is shown, it being of course understood that either half cores or entire ring cores may be made at willby the interposition or removal of a division partition diametrically of the core box. The curved metallic blades that are to constitute the division plates and directing walls in the port spaces of the diaphragm are indicated at B. It will be understood that the setting of these blades at the correct angle and properly alined in the cast diaphragm, is of the first importance and a principal feature of the invention consists in improved means for setting up these blades in the portions of the core box corresponding to the port spaces of the diaphragm so that they may be disposed at any desired angle and used in any desired number and distance apart at each port space, according to the requirements of the particular-diaphragm to be produced. For this purpose and referring especially to Fig. 3, wherein the core box is shown inverted and the base 1 removed, at the beginning of a bladed formation corresponding to a port space of the diaphragm, a starting piece 13 is employed continuing the filler pieces 12 and having at its forward portion a seat 14 in which one of the blades B may be'positioned. and seated. It will be understood that this seat formation 1-1 may be variably disposed inthe particular starter piece 13 employed, according to the angle at which it is desired to set up the blades B. Thenthe first blade B being set in place a central. web or rib R of sand projecting from the body of core C is provided for and at each side thereof are positioned follower pieces, the inner one of such follower pieces being indicated at 15 and the outer zone at 16. These inner and outer follower pieces are; generally similar in form, being varied in outline according to the yariation in outline of the space between the inner portions of adjacent blades and the outer portions thereof. The follower pieces 15, 16 have for this purpose inner edge formations 17, 18 respectively,

adapted to fit over the plane rear and convex front portion of the already positioned blade and outer edge formations 19, 20, respectively, presenting convex forward ends and plane rear portions adapted to receive thereon and correctly position the next one of the'blades B by engaging with the inner facethereof. In this way any desired number of blades B may be'correctly and accurately positioned in the core box so that the core as produced will bear the required number of blades at each port space, the space between the blades being filled as described with inside and outside follower pieces 15, 16 respectively, and an interposed central rib R of sand. A suitably formed filler piece or block 21 may be fitted in between the end of the last blade of the series and the next regular filler segmentlQ. the core box shown is arranged with only one inlet port and one series of blades B ZOO therein, it will be understood that this merely illustrative and intended to typify either one or a plurality of port passages which may be of any desired angular exvtent and include any desired number of bladesin each port passage. Thus if desired the blades might be set up continuously around the core box. so not requiring any filler pieces 12, and adapted to produce a diaphragm with a continuous annular port passage. Likewise in the showing of the drawings, Figs. 1 and 3 show a core box with four blades arranged for a. single port passage, while Fig. 4 shows a half core with eight blades arranged therein for a single port passage. The main body portion of the corefrom which the rib R projects, is formed between the sectional ring 11 and an outer sectional ring 22 spaced therefrom to leave an annular passage 28 for the formation of such core body, the inner sectional ring 11 having-a backing or abutment against the inside integral ring 9, while the sectional ring 22 has a backing against the outside integral ring 1:, the sectional ring 22 also fitting down on to the top of the lower sec- The annular space 23 is inturned flange 27 at the bottom of the ring 22 determines a gate passage 28 down between the blades'an'd between the follower pieces to produce the rib R. The ring 22 at the unbladed portion of the diaphragm has aslightly inturned lower edge 29 to profluce the proper core outline. A flat ring 30 is set into the base 1 of the core box formed with a recess 31 which constitutes a shallow continuation of the gate passage 28 for the formation of the rib R in the core, so that it cuts through the diaphragm to form the port spaces. and also holds the blades in place when the metal is poured. A suitable backing piece 32 of sand may be molded from the body of the core C tov press againstthe outer face of the first blade B to hold it after the core material is baked and when the starting piece 13 has 'been removed, this piece 32 being of course not high enough so that it will make a passage through the diaphragm. The follower pieces 15, 16 may be recessed out to some extent as indicated at 33 on the outer sides thereof to make them lighter and save metal. and they may be also notched or recessed at 34 to give 0 earance.

- In use, the core box base 1. is set upright as seen in Fig. 2, and the several rings and core elements described assembled therein as already explained. In practice a series of starting pieces 13 will be available having seats 14 in their forward faces at varied angles so that the blades B may be supported at the start at any given angle desired. Then series of follower pieces 15, 16 properly selected with reference to the shape and spacing of blades in hand will be set in place on the successive blades as they are positioned, until the requisite number of blades for a given port passage are set in place, when a suitable filler piece 21 and filler ring segments 12 will be filled in the annular space between the rings 5, and 8, according to the extent of unbladed portion of the diaphragm required, the .operation of filling in bladed portions, being of course repeated at spaced intervals around the core box according to the number of port passages desired in the diaphragm. In case it is desired to produce the core C in half sections as seen in Fig. 4:, a suitable division parti tion of metal or wood may be interposed diametrically in the core box, (this however not being shown). It will be understood that in our improved'core box the blades B that are to be cast in the diaphragm may be set to run either to the right or left according to the initial setting of the starting piece 13, suitable follower pieces of the type shown being filled in between successive blades to hold them correctly positioned and alined, and the core box is adaptable to build either a right or left hand core. Likewise so far as the structural features of the core box and individual starter and follower pieces are concerned, it is immaterial whether one or more port passages are to be produced in the diaphragm or as to the extent of each'of such port passages, the larger the numberand extent of port passages, of course the greater the number of blades B and follower pieces required, with a correspondingly lesser number of filler segments 12. The core being then molded in the core box thus set up as described, is constituted of a body ring C formed by the annular space 23, with a projecting rib R as formed by the gate passage 28 in the bladed portion, and in the space between the inner followers 15 and outer followers 16 such rib extending through the spaces between the blades and approximately centrally transverse thereof, below the extremibaking. It will be understood that in casting the diaphragm. the rib R will rest on a generally plane backing surface (not shown) and that therefore said rib will produce the port passage of the required dimension through the diaphragm and transversely intermediate the curved directing blades B. In cases when it is desired to construct a bladed diaphragm in sections and so thatabutting nozzle portions on the respective "sections will match and come in line with each other when the portions of the diaphragm so constructed are bolted together. we preferably saw transversely through the core and through the blades and follower pieces thereof, as for instance through an intermediate portion of the core shown in Fig. 4, at the dotted line w-m.

.mav be separately produced and when cast in this manner the two parts when bolted together would cause the steam nozzle portions to fit and match together accurately.

e are aware that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and we therefore desire the present embodiment to be considered as illustrative and not restrictive, reference being had to the appended claims, rather than.

to the foregoing description, to indicate the scope of the invention.

Having described our invention, what we claim as new and desire to secure by Letters Patent is:

\ 1. A core box of the kind described, com prising a base having associated therewith a series of removable ring members arranged to form between-them an annular space, and means for positioning a series of'diaphragm blades in a part of said annular space corresponding to the bladed portion or portions of a diaphragm, said means havin provision for holding the blades at a de ite angle and in predetermined relation to one another as the core is formed.

2. A core box of the kind described, com prising a base equipped with a series of separable ring members arranged to form an.

annular space, and means for positioning blades in a part of said annular space corresponding to the bladed portion of a diaphragm, said means constructed and arranged to form a core rib extending cir'cum:

ferentially of the core and projecting through the space between the blades fifthsversely intermediate thereof to a'point t erebeyond for producing the port passages in the diaphragm. 1

3. A core box, comprising a base having removable elements associated therewithfor forming an annular core space to produce the body portion of a core and an annular space beneath said annular core space, re,- movable elements adapted to be fitted in the last named space and formed to position and space a series of blades to occupy a port passage of a diaphragm in said underneath annular space with provision for forming a core ribextending from the core body through the spaces between said blades and therebeyond, said rib being transversely intermediate said blades for the purpose. stated.

masco 4. A core box, comprising a base having removable elements associated therewith for forming an annular core space to produce the body portion of a core and an annular space beneath said annular core space, removable elements adapted to be fitted in the last named space and formed to position and space aseries of blades to occupy a port passage of a diaphragm in said underneath annular space with. provision for forming a core rib extending from the core body through the spaces between said blades, said rib being transversely intermediate said blades for the purpose stated, said removable elements being selective as to form with reference to the core box for setting blades in said annular space to run either to the right or left at will.

in correct relative position and leaving an in-;

termediate space to form a core rib extending between the blades and transversely intermediate thereof.

6. A core box of the kind described, comprising a base equipped with removable members forming an annular core space to produce the body of a core and an annular space thereunder, and means for setting up a series of diaphragm blades in said lower annular space in predetermined angular position and, relation to one another, consisting in a. starting piece having provision to determine the angular setting of the first of a series of blades, and inside and outside follower pieces formed to fit the space between successive blades when in correct relation whereby each succeeding blade may be correctly positioned from the, next preceding one, said inside and outside follower pieces

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