US2492434A

US2492434A - Projectile quenching apparatus

Info

Publication number: US2492434A
Application number: US468281A
Authority: US
Inventors: Frank H Mueller
Original assignee: Mueller Co
Current assignee: Mueller Co
Priority date: 1942-12-08
Filing date: 1942-12-08
Publication date: 1949-12-27
Anticipated expiration: 1966-12-27

Description

Dec. 27, 1949 F. H. MUELLER PROJECTILE QUENCHING APPARATUS 2 Shee'ts-Sheet 1 Filed D60. 8, 1942 Ein/:n.2: J1/Heiler, q, M44 MF F. H. MUELLER OJEGTILE QUENCHING APPARATUS Dec. 27, i949 2 Sheets-Sheet 2 Filed DSC. 8, 1942 2g 44 I/IH" Patented Dec. 27, 1949 PROJECTILE QUENCHING APPARATUS Frank H. Mueller, Decatur, Ill., assignor to Mueller Co., Decatur, Ill., a corporation of Illinois Application December s, 1942, serial No. 468,281

3 Claims.

This invention relates to method and apparatus for the heat treating ofk 'articles of steel. In particular, the invention is concerned with the heat treating of oblong articles, Vi. e., articles which are longer than broad, to provide zones of different characteristics along the length of the article. Projectiles or shot are a prime example of articles susceptible of treatment in accordance with the invention, and while the apparatus shown in the accompanying drawings in particu- Iarly designed for handling this type of article, it will be understood that the invention extends to otherA articles, such as'chisels, bits, and the like, where similar characteristics are desired.

In the case of armor piercing projectiles the head or nose should be extremely'hard, Whereas the forward part of the body, back'about to the band seat, should be characterized not so much by extreme hardness as by toughness, and the base should be relatively soft, but tough. The 4 Y article is re-quenched.

Figure 4 is a section on line 4-4 of Figure 3.

Figure 5 shows in plan view a detail of the apparatus of Figures 3 and 4.

Figure 6 is a section on line 6-6 of Figure 5, and

Figure 7 is a diagram showing the relationship of the primary and secondary quenching stations to each other, and to a heating station and a receiving station.

Referring first to Figures l and 2, the fixture l0 comprises an upright hollow shank portion I I,

here shown as integral with an upwardly open bowl portion I2. The shank is in connection with a supply line I 3 for a quenching iiuid, prefj erably cold water, and the line is equipped with a valve, not shown, for controlling the water ilow. The mixture Ill is preferably disposed in a receptacle adapted to receive overow.

The bowl chamber or cavity, which is circular in horizontal section, follows lgenerally the vertical contours of the forward portion of a projectile Vor shot S, disposed therein head down. Three lstuds I4 threaded through the lower portion of the bowl at equi-distant points are adapted to lsupport the head in the manner indicated in Fig- :ure 2. With the projectile resting on the studs in vertical position, it will be noted that the bowl 'walls are curved substantially as the curve of the projectile head I5 where it joins the cylindrical body I6, the walls diverging somewhat from the projectile above and below this zone. Substantial ilow clearance is present all around the projectile. The bowl terminates upwardly in an outturned horizontal ange I1 intermediate the ends of the projectile body, the latter being considered as terminating upwardly at the band seat I8 beyond which is the base I9.

A collar or ring '20 has fixed thereto three parallel depending pins or pedestals 2| which are received in vertical bores in flange I'I and are adapted to be locked in adjusted position by means of set screws 22. Collar 20 has a central opening whose diameter is only slightly greater ythan that of the projectile and is rimmed on its underside by a downwardly projecting annular flange 23 which is merged into the nat underside of the collar on a curve which is like that of the rounded upper lip 24 of the bowl. The upper margin of the collar opening has a 45 bevel which assists in guiding the projectile into the collar opening. The lower face of the collar is rspaced above the top edge of the bowl to provide an annular escape passage 26 and the top horizontal face of the collar is below the band seat of I the 'supported projectile.

'26 as displaced by the entering projectile. Flow now takes place upwardly along the head and forward body portion of the projectile, some going through the collar opening and escaping over the top of the collar so that quenching takes place from the lower end of the projectile back for a length somewhat short of the band seat. From this point up there is no quenching action. After the 'quenching action has continued for the desired period, the shot is removed from the nxture Ill vand passed to the secondary apparatus 2T, Figures 3 to 6.

Referring to the last-named figures, reference numeral 28 designates a pan having a horizontal bottom 2,9 resting on any suitable framework. The pan has cylindrical sides 30 which terminate upwardly in an angular concave rim portion 3l which is cut away for a distance at 32, Figure 3, down to the cylindrical portion, or to any required extent, to provide an overflow. A block 33 secured on the bottom wall 29 has a concentric opening in which is Xed an upright tubular pedestal 34 on which is rotatable a hub 35. The hub is supported on block 33 through an outturned portion of a bushing 3B.

Extending radially from the hub 35 are a number of arms 37 in the form of flat bars disposed edge up. The outer ends of these arms have secured to their under edges an annular table 38 which is provided with two concentric series of openings 39 and 4i) of less diameter than the body diameter oi the shot, the openings of each series being in staggered relation to those of the other and the two series being concentric with the pedestal 34. As shown in Figures and 6, the upper edge of each of the plate openings is beveled and two sets of diametrically

opposite offset recesses

46 and 41 are provided` Abo-ve each opening 4l! is supported an aligned tubular member 4l or 42. The tubular members 4l are welded to the ends of arms 3l while members 42 are supported half way between adjacent members il on uprights 43 rising from the plate 3S. These uprights also support tubular members 44 which are in alignment with the openings 39 and the members lili are also welded to the adjacent arms 5l and also to members 4I and 4Z if desired, so that a rigid structure is provided.

The lower ends of all the tubular members are spaced equally above plate 3S. Their internal diameter is substantially greater than the body diameter of the shot and each member has welded to its upper edge an inwardly overhanging ring @i5 whose internal diameter is only slightly greater than the body diameter of the shot, the upper faces of the rings being all in the same horizontal plane. The openings 39 are of a size to receive a part of the head of an inverted shot and, when so received, the upper end of the body will be within the ring 45, as shown in Figure 6, so that the shot will be maintained vertical.

Disposed on the bottom of the pan are a pair of

circular pipes

43 and 49 which directly underlie the

openings

39 and 45 respectively. Water supply lines 55 and 5l are led up through the bottom of the pan to

pipes

48 and 49 and the latter are each provided with top perforatio-ns as at 55S and 49' through which the water is delivered to the pan to overflow at 32. The overflow is at such a height that when a shot is supported on the table as in Figure 6, only its head portion will be immersed and consequently the cooling action is limited to this portion of the shotl A ring 55 xed to the top of pedestal 34 has fixed thereto a radially extending tubular member 5f in which is slidable a square bar 55 which carries on a vertical axis a roller 55. The roller is urged against members 44, by a spring 5l and normally engages between two of the said members, as shown in Figure 3. This detent mechanism serves to yieldingly control rotation of the table by steps.

Referring to Figure '7, reference numeral 58 designates heating apparatus, preferably a lead pot, for heating the projectiles. These are heated to a temperature above the transformation point, for example to 1500 F. to 1700 F. The workman, standing by the lead pot, lifts out a shot with his tongs and deposits it in the xture It for the preliminary quench. The period of this quench is variable, but in the case of a 57 mm. shot, may be, for example, around 40 seconds. When this period is up, the workman lifts the shot from the fixture I0 and transfers it to the table of the secondary apparatus, at the same time giving the shot a push tangentially of the table so that the latter is advanced a step as controlled by the detent mechanism. The projectile eventually moves around to a workman standing at the end of a table 59 who lifts out the shot and deposits it on the table.

When the shot is removed and transferred to the rotary table its unquenched portion is still red hot, or substantially so, and the head may be at a temperature of around F. During the secondary or head cooling operation, the heat from the unquenched portion begins to equalize throughout the shot insofar as it is able to. When the shot is removed from the rotary table, this equalization continues and is permitted to continue until complete. The shot is then permitted to cool to room temperature. The time the shot is in the rotary table at the secondary station is variable, but in the case of a 57 mm. shot may be several minutes, substantially longer than the initial quench. In the case of a shot of this size, equalization, after the secondary operation is completed, will take place in three or four minutes and the equalized temperature will ordinarily be around 325 F. to 350 F. The quenched portion of the shot is thus subjected to a drawing or tempering action so that stresses are relieved and a superior armor-piercing projectile is produced. Desirably the table 59 may be constituted by the upper run of a slow-moving conveyor of such length that heat-equalization will have been completed by the time the shot reaches the foot end of the conveyor.

It will be understood that variations under the invention are possible and are contemplated under the claims which follow. As stated at the outset, the method is useful wherever the diierential quenching of oblong articles is to be accomplished, and the apparatus may, if necessary, be modified in accordance with the particular shape of the articles to be treated. In the case of articles of considerable length, it will only be necessary to heat a sufficient length at the end to be treated so that the heated but unquenched portion will supply suiiicient heat to the quenched portion, upon equalization, to effect a drawing or tempering action.

I claim:

1. A quenching fixture for an oblong article of steel, comprising an upright bowl, means in the base portion of the bowl for supporting the article upright in the bowl, said bowl terminating upwardly below the upper end of the upright article and being of a capacity to provide iiow clearance completely around the upright article, a horizontal collar supported in spaced relation to the upper edge of the bowl below the upper end of the supported article and having an opening of a size and so disposed as to receive the supported article with slight clearance, and an inlet in the bowl for a quenching fluid, whereby when fluid is flowed into the bowl it may escape both under and over said collar.

2. A fixture according to claim 1 wherein the collar is supported for vertical adjustment by pins extending upwardly from the bowl.

3. A quenching xture for a steel projectile,

s comprising an upright bowl, means in the base portion of the bowl for supporting the projectile head down in the bowl, said bowl terminating upwardly between the body ends of the supported projectile and being of a capacity to provide ow clearance completely around the projectile, a horizontal collar supported in spaced relation to the upper edge of the biowl with its top below the band seat of the projectile and having an opening of a size to receive the projectile body with slight clearance, and an inlet in the bowl for quenching uid, whereby when uid is flowed into the bowl it may escape both under and over said collar.

FRANK H. MUELLER.

REFERENCES CITED The following references are of record in the file of this lpatent:

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