US2789928A - Process of hardening steel cartride cases and apparatus for accomplishing such process - Google Patents

Description

April 23, 1957 J. wALLl-:Rlus 2,789,928

ARDENING STEEL CARTRIDGE CASES AND APPARATUS PROCESS OF H Filed July l. 1952 FOR ACCOMPLISHING SUCH PROCESS 7 Sheets-Sheet 1 IN1/Emo@ John Wal/anus April 23, 1957 J. wALLERlUs PROCESS 0F HARDENING STEEL CARTRIDGE cAsEs AND APPARATUS FOR ACCOMPLISHING SUCH PROCESS 7 Sheets-Sheet 2 Filed July 1. 1952 Apnl 23, 1957 J. WALLERIUS 2,789,928

PRoCEss CP HARDENING STEEL CARTRIDGE CASES AND APPARATUS FCR ACCOMPLISHINC SUCH PROCESS 7 Sheets-Sheet 3 Filed July l. 1952 OOOCD (O Cf lO @,OO

INVENTOR John MII/elias Apnl 23, 1957 y ,WALLERMS 2,789,928

PROCESS OF HARDENIN TEEL CARTRIDGE CASES AND APPARATUS FOR ACCOMPLISHING SUCH PROCESS Filed July l. 1952 7 Sheets-Sheet 4 IN V EN TOR. John Wal/erius April 23, 1957 J, WALLER|US 2,789,928

PROCESS OF HARDENING STEEL CARTRIDGE CASES AND APPARATUS FOR ACCOMPLISHING SUCH PROCESS 7 Sheets-Sheet 5 Filed July l. 1952 29 John Wa//erius mu@ v AIM VC Y-CLE TIMER April 23, 1957 J. wALLERlUs 2,789,928

PROCESS OF HARDENING STEEL CARTRIDGE CASES AND APPARATUS Filed July l.

PQ/m FOR ACCOMPLISHING SUCH PROCESS 7 Sheets-Sheet 6 7b Source of A/r Under Pressure,

Power Source To Source of F /ud Under' Pressure.

FIG 13a JNVENIOIL John W//er/'us BY c m Y MM April 23, 1957 J. wALLERlUs 2,789,928

PROCESS OF HARDENING STEEL CARTRIDGE CASES `AND APPARATUS FOR ACCOMPLISHING SUCH PROCESS Filed July l. 1952 '7 Sheets-Sheet '7 FIG 13b mmvToR.

John Wa//erius BY 4N W V K1A/U04 PROCESS OF iI-ARDENING STEEL CARTRIDGE CASES AND APPARATUS FOR ACCOMPLISHING SUCH PROCESS John Waller-ius, Glen Ellyn, Ill., assgnor to Sunbeam Corporation, Chicago, Ill., a 'corporationlof Illinois Application July 1, v1952, Serial yNo. 296,595

Claims. (Cl. vlltl) The present invention Yrelates lto a method and apparatus for hardening 'steel cartridge cases, and more particularly small caliber steel cartridge cases. t f

l-leretofore4 cartridge cases have been formed primarily from brass, which isa resilient material capable of expanding land contracting `almost instantaneously. Such brass cartridge cases v were manufactured in quantity and were heat treated by moving the'cartridges through a furnace in random fashion, as by being dis-` posed in random fashion on a movable conveyor of some sort. For numerous reasons, including among them the shortages of copper, cartridge cases have recently been made of steel. It has been discovered that steel cartridge cases present a much more diflicult heat treating problem than brass cartridge cases. In the first place, if the steel is too hard, it will not expand as it should within the gun barrel upon firing o-f the cartridge, and the cartridge case breaks in the gun. On the other hand, if the steel'cartridge case is not hard enough, it expands very rapidly but will not contract, and then tends to stick in the gun. Moreover it has been found that uniform hardness around the entire base of the cartridge case is essential and there must f not 'oe hard and soft spots. To obtain such uniform hardness, a critical heat treating process is essential,

and random heating, as heretofore employed and-satisf factory in connection'with brass cartridge cases, will not be satisfactory. It has been found in connectionA with the present invention that the cartridge cases must 'be moved through the hardening furnace, al1 orientated in exactly the same way to insure ,uniform hardness, and

immediately uponl'eaving the furnace theY cartridge cases must be quenched uniformly andvery rapidly to obtain the desired hardness.Y The importance of this quench may be better appreciated lwhen it is considered that the temperature of the cartridge cases, which reaches a f maximum of something over l600 F., must be reduced to room temperature iny a matter of a few, seconds, which means that the quenching apparatus must almost be inside the furnace. By accurately controlling the hardness of such steel cartridge cases, it is possible to hold to closer size tolerances, withlgreatly improved surface qualities of the cartridge cases. Moreover, the quality -of the heatv treating has been found to have a direct effect on the number of acceptable cartridges cases produced. t,

ICC

vention by pushing the cartridge cases in end-to-end relationship through suitable heating tubes within the furnace. The forward end of one cartridge case will then engage the base of the preceding cartridge case. Obviously, at the high temperatures to which Vthese cases are subjected within the furnace, there will tend to be welding together of the engaging portions of the adjacent cartridge cases. It would be desirable to provide an arrangement whereby such welding together of .the adjacent cases will in no way interfere with satisfactory operation. I

Accordingly, it isyan object of the present invention -to provide a new and improved method for heattr'eating steel cartridge cases' to insure uniform'har'dnesis; to a desired extent.

It islanother'object of the present invention to provide an improved heat treating furnace for heat treating steel cartridge cases to the same uniform hardness.

lt is another object of the present inventi-on to provide an improved furnace for heat treating steel cartridge cases wherein such cases move through the furnace, all orientated in exactly the saine fashion, and wherein such cases are quenched to reduce the temperature thereof greatly within a matter of seconds after leaving the furnace atmosphere.

lt is a further object of the present invention to provide an improved quenching `apparatus for a heat treating furnace wherein cartridge cases move through the furnace with many cartridge cases being discharged every fraction of a minute, which will simultaneously quench the inside and outside surfaces of the successive cases as they are discharged from the furnace.

lA further object of the present invention resides lin an'improved ejection device for ejecting quenched cartridge cases, using air under pressure directed toward the interior of the cartridge case to eject the same from the quenching device.

Stillanother object of the present invention resides in an improved control system for an `automatic continuous heat treating furnace which insures a, continuous supplyof cartridge casespto the furnace, uniform heating of all the cartridge cases as moved through the furnace, rapidquenching immediately upon completing the p'ass through'the furnace, and ejection' of the quenched cartridge cases in aV matter of a few yseconds after the quenching operation is initiated. l

Another object of the present invention resides in the use of a noncorrosive quenching liquid in connection It will readlyb'e understood that to reduce the temperature in a matter of a few-seconds from a high heat treating temperature to ,room temperature or below in a continuous furnace capable of producing thousandsY of cartridge cases-in anhour, requires a rather unusual quenching device, and oneof thefeatures of the present invention resides in an'improvedquenching device;

with a heat treating furnace employing a suitable wet@ ting agent whereby high speed quenchingl operation'is obtained without the corrosive effect of brine quenches heretofore used.

A still further object of the present invention resides in simple static means for periodically causing movement of the individual cartridge' cases transversely to their direction 'of Amovement through the furnace to eliminate the possibility of welding togetherY of engaging portions of adjacent cases.

Further objects andV advantages of the present invention will become apparent as the following description proceeds,l and the features of novelty which characterize the inventionvv will be pointed out with' particularity in the claims annexed to and forming a part of this specilication.

For a better understanding of the present invention, reference maybe had to the accompanying drawings in As will become apparent-,from the ensuing description, in order to insureuniformfl heating every' cartridge case must, be moved through the furnace in the same way, in otherwords orientated in the same way, and this is accomplished' in vaccordance with the-present in- Figs. l and 2 together comprise asecti'onal view through the entire furnace of thepresent invention,with Fig. l showing thefeed end ofthe furnace, andFigpZ showing the V74discharge and'quenching end ofthe furnace;

vvFig. 3 is a partial sectional View taken along line' v7-'7 of Fig. 2, assuming that Fig. 2 shows the complete structure; s

Fig. 8 is an enlarged sectional view of a portion of the quenching apparatus shown in Fig. 2 of the drawings; Fig. 9.is a sectional View taken along line 9--9 of Fig.` 8, assuming that Fig. 8 shows the. complete structure;

Fig. 10 is a sectional view taken along line lil-4) of Fig. 8, again assuming that Fig. 8 shows the complete structure;

^ Fig. 1lV is an enlarged view of the feeding apparatus "shown in Figs. 1 and 3, and preferably taken along line 11-11 of Fig. 3;

" Fig. 12 is a sectional view taken on line 12--12 of vFig. 1 ofabout one-half of the furnace;

Figs. 13a and 13b together comprise a complete control circuit, including a schematic disclosure of the elements controlled; Fig. 14 is an enlarged sectional View illustrating a modification of the present invention; and

Fig. 15 is a sectional View of reduced size taken along line 15-15 of Fig. 14, assuming that Fig. 14 shows the complete structure.

Briefly, the present invention is concerned with a heat treating furnace in which steel cartridge cases are pushed in end-to-end engagement through tubes extending through a heat treating furnace. A large number of tubes may be employed in parallel, and preferably the tubes contain cracked city gas or another suitablenonoxidizing medium to reduce scaling and the formation of'oxides. Automatic means are provided for simultaneously pushing a new cartridge case into each of the parallel tubes, and simultaneously pushing along all the cartridge, cases Awithin the tubes. A feeding mechanism is' provided to permit automatic feeding of cases to the entrance to each of the tubes. In effect, the cartridge cases are ,walked through the tubes to prevent welding n of engaging cartridge cases. At. the dischargeend of thefurnace the cartridge cases fall by gravity through an external quenching jet into a receiving cage and while therein are immediately subjected to an internal jet of a very cold noncorrosive quenching liquid to reduce the Vtemperature from something over 1600 F. to room tem perature in a matter of a few seconds. A few seconds later, the receiving cage into which these cartridge cases are ejected for quenching moves to an ejecting position, and a stream of air literally blows the cartridge cases out of the quenching cage and into a wash tank. A suitable control circuit is provided, controlled by a cycle timer which determines the speed of the heat treating cycle.. Full automatic control is provided.

Referring nowto the drawings, and primarily to the structural disclosures of Figs. 1 to 12, inclusive, there is provided a main furnace structure generally desig nated by the reference numeral 2b comprising an elongated heating section which may have any cross sectional configuration ybut which preferably is'of rectangular external configuration. There is defined within the furnace a heating chamber generally designated ati22 which extends from end to end of the furnace and which is preferably defined byl a layer of insulating fire brick 230m the top, a layer of insulating fire brick 24 on Ythe botto/m,` and similar layers of insulating brick 2S and 26 at each end, as Well as a layer 27 along each side. Surv africanas 4 rounding the insulating 4tire brick is preferably a layerof insulating brick 28,`and around the insulating brick is preferably a layer of loose asbestos 29, the latter of which is enclosed by a lsuitable steel shell 30, the various layers of insulation taking care of the temperature gradient from inside of the furnace, which is of the order of 1650 F. for a particular heat treating operation, t0 room temperature at the outside of the furnace. Preferably the insulating tire bnick is capable of withstanding temperatures up to 2600 F., the insulating brick 28 is capable of withstanding'temperatures up to 1600 F., and the loose'asbestos 29 is capable of withstanding temperatures up to 800 F.

For the purpose ofsupporting the' means defining the heating chamberg22at a suitable height, there is provided a suitable frame of channel members, angle irons and the like, generally designated by the reference numeral 32, the, particular construction `of which forms no part of the presentfinvention. To simplify the support means, the top ofthe heating chamber 22 is arched as indicated at 33, there-by inherently providing support. This is best shown in Fig.vv 12 of the drawings.

Any suitable means for supplying heat to the furnace, such as a Vsource of gas heat or electrical heat, may be employed. Preferably, and inaccordance with the present inventionelectrical resistors are used to lsupply the heat within the furnace chamber 22, and these electrical resistors notvshown are preferably Idisposed along the interior walls of the furnace chamber 22, such as along the arched top 33 thereof as well as along the floor of the furnace.

To insure that the cartridge cases are all `orientated in the `same manner in passing through the heating chamber 22, there are disposed within the heating chamber 22 a plurality of elongated ytubes 36 arranged in spaced parallel relationship. The vparticular number of tubes employed is immaterial as far as the present invention is concerned, andin Fig. 3 `of the drawings twenty-four tubes 36, arranged in a common plane in spaced parallel relationship, arey shown. Thesetubes' are preferably' formed of lasuitable alloy-'material capable of withstanding the high temperatures produced in heating chamber 22. For the purposeofsupporting the tubes 36 in spaced parallel relationship Vwithinl the heating cham-ber 22, `fire brick piers 34 are provided,.upon which are disposed suitable alloy pier caps, upon which in turn are mounted suitable tube supports 35 formed of a heat resisting alloy. These tube supports 35 ,a're'preferably provided with suitable slots to `appropriately.'space 'the tubes. A second spacer member 35a is disposed onthe top of the tubes and suitably locked to supports 35, whereby the tubes 36 are supported as a unitary structure within the chamber 22. The feed end of the furnace is shown in Fig. l, and the tubes 36 protrude fromthis feed end through suitable openings defined in `the lfurnace wall. The protruding ends of the tubes 36` are provided with flared ends 37 to facilitate the entranceof the cartridge cases by automatic. means .described in greater detailhereinafter.

It will be apparentthat if steel cartridge cases are subjected to a high temperature in r an ordinary atmosphere which is at all oxidizing in nature, a great deal of scaling and oxidation will occur. In accordance with the present invention, a nonoxidizing atmosphere is preferably maintained within ,the ,tubes 36, andI to kthis end .a suitable controlled atmosphere, such as cracked vcity gas, is supplied from atheader-39 throughconduits 4a into the alloy tubes'36zi'For thepurposefcf insuringrthat the nonoxidizing atmosphere supplied through the conduits 40 isat a raised temperaturei'when entering the alloy tubes 3,6,T the conduits 40 preferably extend for a substantial distance within the heatingY chamber 22 before Ventering the tubes'36. T his atmospheree'scapes from the flared ends 37 of the'tubes 36'andi's' at the feed end of these itubes ,tha/tacross' feed enlof all of the tubes 36, best Ishown inFig. 3. gas `flames will appear therebv preventing the entrance of an oxidizing atmosphere. The atmosphere within the tubes 36 is an endothermic gas, preferably obtained by applying heat to crack ordinary city gas with air. This results in a gas comprising 20% carbon monoxide, 40% hydrogen, and 40% nitrogen.

It will be understood by those skilled in the art that cartridge cases have relatively thin walls, and at the high temperatures encountered within the heating charnber 22 the walls of the cartridge cases tend to soften. It is, however, essential that no distortion of thevwalls of the cartridge cases occurs, and in accordance with the present invention the tubes 36 have a particular configuration for distributing the weight of the cartridge cases in movement therethrough. This is best Vshown in Fig. 0f the drawings, which isa section through one of the tubes 36 and indicates that the lower portion of the tubes 36 has a somewhat V-shaped configuration. A cartridge case, generally designated by the reference numeral 42, is shown disposed within the cross section of the vtube 36, and it is obvious that with the V-shaped configuration the cartridge case is supported at 43 and 44, thereby tending to distribute the weight o-f the cartridge case. If the tubes 36 had a circular configuration, it is apparent that the cartridge case would engage the same only along a line at the bottom of the tubes 36 and the cartridge cases 42, and much more likelihood of distortion of the thin Walls of the cartridge cases at high temperatures might occur.

From the discussion above ,it will be understood that the cartridge cases are effectively pushed through the tubes 36, each succeeding cartridge case in effect being an inserted force transmitting member for transmitting force from a suitable pusher device to be described hereinafter to successive cartridge cases disposed within the tubes 36. The end-to-end relationship of the cartridge cases 42 is shown in dotted lines within the tubes 36 in Figs. l and 6 of the drawings. At temperatures as high as 1600 F. the engaging ends or". the cartridge cases 42 may tend to weld together, and this is particularly true with respect to the engaging surface of two adjacent cartridge cases when making the complete pass through the tubes 36 within heating chamber 22. To prevent this, in accordance with the present invention, the cartridge cases 42 are effectively walked through the tubes 36, which is another important feature of the present invention. At closely spaced intervals, which may be of the order of every 8 inches, the apex ofthe V-shaped'bottom of the tubes 36'is indented to provide inwardly extending protuberances 46 which cause the cartridge cases to raise and lower slightlyv in a direction transverse to the general direction of movement through the tubes 36. This transverse movement, which first tips one end of the cartridge case upwardly (see Fig. 6V) and then tips the other end of the cartridge case upwardly, effectively keeps breaking any welding which might occur at the engaging ends of adjacent cartridge cases. f

From the above description the movement of the cartridge cases 42, beginning with movement upon insertion into the flared openings 37, along the tubes 36 will be apparent, and consideration now will be given to the discharge of the cartridge cases from the discharge ends of the tubes 36 shown in Fig. 2 of the drawings. Each of the tubes 36 terminates in a somewhatenlarged chamber designated as 50, which is connected to a discharge chute 51, one being provided for each tube 36. The chutes 51 each have a sort of enlarged funnel-shaped portion where connected to the discharge end of the associated tube 36. Each discharge chute 51 has the same V-shaped configuration as the tubes 36 (see Fig. l0 of the drawings) and extends through a suitable opening 52 defined' in the furnace 20. Adjacentvwhere the discharge chute 51 is connected to the tubes 36, there vis provided a suitable observationy opening connected by a tube 4which extends outside th'e furnace. The end of the tube is closed by asuitable ob,- servation cover or sight glass so that` one may'view the discharge end of each tube 36.- The two end tubes 36 adjacent the two sides of the furnace, and specifically designated as 36a and 36b in Fig. 3 of the drawings, are provided adjacent the discharge ends of the tubes with lateral openings 55 (itis assumed that the particularY tube 36 visible in Fig. 2 of the drawings is the tube at the exf treme end, namely, tube 36a), which is also connected by a suitable tube to a suitable sight glass to permit observation of the cartridge cases moving through the particular tubes such as 36a,vwhich will, of course, be representative of what occurs in the other tubes 36 not provided with such sight glasses. 't p From an examination of Fig. 2 of the drawings it will be noted that there is illustrated a cartridge case 42 Which has justfallen into the discharge chute 51, and the next case 42 isaimost ready to fall into the discharge chute 51, it having just passed the last protuberance 46. ln the event that the hardening furnace 20 were shut down over the Week-end, for example, with this last cartridge case in the position shown in the drawings, it is possible that this cartridge case might be welded to the engaging end of the cartridge case immediately behindit, and in thatfcase pushing in newr cartridge cases'fro'ml the other end rnight tend to jam the last cartridge case against the end wall of the tube defined by the discharge chute 5 1. in accordance with the present invention, a suitable wedgeshaped member 5S is provided above the discharge chute 51 to deiiect the last cartridge case 42 in the event that it is welded to the succeeding cartridge case. It will be understood that the wedge-shaped member y58 is only employed following shutdown of the furnace, since nor mally the protuberances 46 will prevent such welding operation, and the cartridge case 42. which moves into the discharge chute 51 will tend to drop by gravity before engaging the wedge-shaped member 58. However, this member is provided as a safety feature in the event that for any reason the protuberances 46de not function to prevent such welding operation of adjacent cartridge cases.

The endothermic gas or noncorrosive. atmosphere supplied by the conduits 40 -to the tubes 36 must not escape from the end of the discharge :chute 51, and yet this discharge chute must be open to permitcartridge cases 42 to drop out by gravity. In accordance with the present invention and as best shown in Figs. 2 and 8 of the drawings, the end of discharge chute S1 is provided with a short jacket 60 which defines an` annular chamber 6l, which chamber is preferabiyv connected by a suitable conduit 62 with a coolingV or quenching liquid described in greater detail hereinafter. The'end of the discharge chute 51 and the corresponding end of the jacketv 60 are so con.- struc'ted as to define a somewhat `annular nozzle 63. This annular nozzle is designed to discharge'an annular stream of quench liquid 'converging at a point and consequently in effect discharging a somewhat cone-shaped wall of liquid designated at 64 in Fig. 8 of the drawings.l This cone-shaped wall of liquid closes the end of the discharge chute Si as far as the escape of any of the endothermic gas or noncorrosive atmosphere contained therein is `concerned, and yet the cartridge cases. 42 may be` discharged through this wall of quenching liquid, which, therefore, in

effect performs two functions: one, it prevents the escape of the atmosphere contained within the. tubes 36, and two, it provides an external liquid quench for cooling the cartridge cases ft2, which second function will be described in v,greater detail hereinafter. Preferably the discharge chutes Si are Aprovided with openings 67, to which are connected suitable conduits 68 which may be connected to a manifold69, which manifold,may be providedl with suitableopenings at whichvthe' cracked city gas may be burned, preferably at a point which will not` interfere with personnel working near theffurnace. Un-v fortunately, there is noway that this can be accomplished at the feed end of the tubes 36-and, hence;jthe gasmust be burned at vthe feed opening ineachof. the;, tubes.

In order to understand the automatic feetliing;,olea-rfA 7 tridge cases to the flared ends 37 of the tubes 36, reference may be had to Figs. 1, 3, 4 and 11 of the drawings. At the feed end of the furnace there is provided a loading and feeding unit generally designated by the reference numeral 70. This loading and feeding unit comprises an endless roller chain conveyor 71, mounted for rot-ation about relatively large diameter spaced sprockets 72 suitably j-ournalled adjacent each end of a support in the form of a framework `73 extending across the feed end of the furnace 20 and including a portion 73a extending to one side of the furnace defining a loading table described hereinafter. Attached to the outside of the roller chain conveyor 71, as best shown in Fig. 4 of the drawings, as by suitable fastening means 76, are a series of elongated U-shaped cartridge case receptacles 75 uniformly spaced along the roller chain 71 in the same manner as the tubes 36 are spaced, and of a size capable or" receiving therein a single cartridge case with its longitudinal axis transverse to direction of movement of the roller chain 71. It will be apparent that the endless chain '7l is in effect an endless magazine having its upper flight positioned so the cartridge case receptacles 75 arc on a level with the flared openings 37 in the tubes 36. lf the endless magazine is stopped in a position so that each receptacle 75 is exactly opposite a corresponding flared opening 37,`a suitable end' thrust on the cartridge cases disposed in the magazine will move them directly into the flared openings 37. The portion of the endless magazine extending laterally of the furnace 29 furnishes a loading zone for the magazine sufficiently removed from the gas flames at the openings 37 to permit personnel to load the same. It is essential that the receptacles 75 in front of the openings 37 be maintained level, and to this end horizontally ldisposed angle iron supports 78 disposed on the frame 73 eliminate and sag in the upper liight of roller chain 71.

For the purpose of moving the cartridge cases disposed in the receptacles 75 when the receptacles are moved into alignment with the endsrof the tubes 36, there is provided a suitable pusher mechanism generally indicated at 79 and comprising a plurality of spaced fingers Si? mounted on a common angle-shaped support 80a, which latter is connected by a suitable connecting rod 81 to a lluid motor 84 comprising a piston 82 reciproc-ally mounted in a cylinder 83, best shown in the schematic diagram of Figs.v

13a and 13b. The ends of the support 80a are preferably attached to suitable rollers 86, mounted for movement on spaced guideways 87, whereby guided reciprocal movement of the fingers 80 can occur in response to operation of fluid motor 84. Preferably a hydraulic motor is used for causing operation of the pusher mechanism 79,

although it should be understood that any other prime mover may be employed. As best shown in Figs. 13a and 13b of the drawings, a solenoid actuated valve 88 controls the opera-tion of the fluid motor S4. Preferably the solenoid valve 88 controls movement in each direction of the piston 82. For the purpose of simplifying the drawings, however, in Figs. 13a and 13b the fluid motor 34 has been shown as a spring return fluid motor, whereby upon energization of the solenoid valve 88 the piston 82 moves toward the right, as viewed in Figs. 13a and 13b, under the pressure of the hydraulic fluid, and upon deenergization of the solenoid valve 88 the piston S2 moves to the left by virtue of the energy stored in the spring 89. For the purpose of controlling the sequence of operations, suitable limit switches 90 and 91 areassociated with the fluid motor 84. rThe limit switch 90 is caused to close its contacts Mln momentarily as the pusher mechanism 79 returns to the position shown in Figs. 13a and 13b of the drawings following pushing of cartridge cases 42 into tubes 36. The limit switch 91, on the other hand, is actuated just as the pusher mechanism 79 reaches the end of its stroke of inserting cartridge cases v42 Y into the feed end 37 ofthe tubes 36. At that time-limit switch 91 closes its contacts 91a and opens its contacts 911;.

In Fig. ll the operation Iof' the pusher mechanismcau readily be appreciated. One finger Si) of the pusher mechanism is illustratedas being opposite the receptacle to push a cartridge case i2 contained therein out of the receptacler 75 and into the flared end 37 of a corresponding tube 36. v

As far as the present invention is concerned, it is immaterial whether the cartridge cases move through the furnace open end first Vor base end first, the important criterion being that all of them move through the furnace orientated in exactly the same way. However, since the pusher mechanism 79 will work in a much more satisfactory manner if vthe fingers Sil can engage the base of the cartridge cases 42, the cartridge cases are pushed through the furnace, and specifically through the tubes 36, open end drst. it will be apparent that the fingers upon movement toward the roller chain conveyor 71 enter the cartridge case receptacles 75 of the magazine and engage the base of the cartridge cases disposed within these receptacles 75, thereby moving the same out of the receptacles 75 and into the tubes 36. With this arrangement the flames which exist at the feed end of each of the tubes 36 in no way interfere with the opera-tion of supplying cartridge cases 42 to these tubes 36, since no manual operation adjacent these tubes 36 is required.

in View of the flame appearing at the ends of the tubes 36, as was mentioned above, the cartridge cases are loaded into the receptacles 75 in a loading zone to one side of the furnace Ztl. To accomplish this, it will be understood that the endless magazine extends to one side of the furnace 22 to a sufficient extent so that at least as many receptacles 75 as there are tubes 36 may be filled with cartridge cases, while this number of receptacles being filled are disposed to one side of the furnace proper. Movement of the roller chain 7l may be accomplished by means of any suitable prime mover. Preferably, and as illustrated in Fig. 3 and as schematically illustrated in Figs. 13a and 13b of the drawings, a suitable fluid motor 93 comprising a cylinder 94 and a piston 95 is employed. This reciprocating fluid motor 93 preferably has the piston 95 connected to a connecting rod 95a which in turn is connected between the ends of a chain 96 mounted over small diameter sprockets 97. The chain 96 and connecting rod 95a effectively define an endless chain. Reciprocal movement of the piston 95 will cause angular movement of the sprockets 17.

To operate fluid motor 93, a solenoid operated valve 92 similar to the valve S8 described above is employed as schematically indicated in Figs. 13a and 13b of the drawings. Also, a limit switch lili is associated with fluid motor 93, which limit switch flhas its normally closed contacts lilla opened whenever the piston 95 reaches the end of its stroke following energization of the solenoid operated valve 92.

One of the sprockets 97 is preferably connected to a shaft 9S and through a suitable one-way clutch mechanism 99 to drive one of the sprockets 72 supporting the cartridge case conveyor 7l. By virtue of the one-way clutch mechanism 99, reciprocal motion of the piston 95 will cause motion in only one direction of the cartridge ease magazine. Moreover, by virtue of the P'tive sizes of the sprockets 97 and 72, substantial motion multiplication occurs to insure with limited movement of piston 95' sufficient movement of chain 7i to cause in each cycle of movement thereof that the same number of receptacles 75 containing cartridge cases d2 therein as there are tubes 36 move into juxtaposition with the flared ends 37 of these tubes.V

To make sure that the cartridge cases d?. are placed in the magazine so the open end enters the furnace first, there is provided at the loading zone a suitable loading spacer plate lili) supported immediately above the receptacles 75 at the portion of the magazine extending to one side of the furnace 2%. This spacer plate lill! includes a plurality ofv spaced pockets 102 spaced apart the same 9s distance as the receptacles75. Moreover, eachpocket 102 in the magazine 100 is capable of holding a predetermined number of vertically stacked cartridge cases, four being shown by way of example in Fig. 4 of the drawings. In order to make sure that nthe cartridge cases 42 can only be inserted into the pockets 102 with arpredetermined orientation, these pockets are of tapered configuration (somewhat like the cartridge cases 42 themselves) designated at 104 in Fig. 3 of the drawings, ,thus making it necessary for the base of the cartridge cases to be disposed toward the enlarged ends of the pockets 102. This affords positive assurance that all the cartridge cases 42 will be automatically inserted into the tubes 36with the base portions thereof inserted last, thus insuring uniform heat treating. These cartridge cases can be placed into the pockets 102 manually or automatically. The spacer plate 100 is, furthermore, disposed so that when the magazine 71 stops to permit the pusher mechanism 79 to push the cartridge cases in receptacles 75 into the open ends of the tubes 36, the receptacles 75 `disposed beneath the spacer plate 100 are in juxtaposition or alignment with the pocket 102 so that the cartridge cases 42 automatically fall into the open receptacles 75. y

As was mentioned above, one of the importantfeatures of the hardening furnace 20 of the present invention re-` sides in the very quick quench whereby the cartridge cases are reduced in temperature from some 1600 F. to room temperature in a matter of a few seconds. To accomplish this, there is provided in accordance with the present invention an improved quenching arrangement which is immediately adjacent the discharge end of the furnace 20 so that no delay in the quenching of the cartridge cases occurs. As best shown in Figs. 2 and 8 of the drawings, there is disposed beneath the plurality of discharge chutes 51, a different one of which is connected to different ones of the outlet ends of the tubes 36, an elongated quench liquid collecting tank 110. The particular con-` struction of this tank 110 forms no part of the present invention. Means are preferably provided whereby liquid from tank 110 is Withdrawn and cooled to a temperature of 40 F. by means not shown for subsequent reuse as a quench liquid. y

For the purpose of insuring a complete and rapid quench of each cartridge case 42 to reduce its temperature from something over 1600 F. to a temperature of the order of room temperature or lower, there is provided an elongated cartridge case receiving cage 115, preferably in the form of a rectangular box extending across the discharge end of the furnace 20 andpivotally supported on the tank 110 by means of an elongated shaft 116. The cage 115 in one extreme position thereof, as shown in solid lines in the drawings, is disposed to receive car* tridge cases 42 falling through chutes 51. This position is termed the cartridge case receiving position of lthe cage 115. The other extreme .position of cage 115 shown in dotted lines in the drawingsis termed the cartridge case discharge position of the cage 115. This pivotal movement of cage 115 from the Acartridge case reeciving position to the cartridge case ,discharge position is an angular movement of the order of about 120, K,

It will be understood that pivotal movement of the cage 115 must occur in timed sequence withthe operation of the pusher mechanism 79, so that ,when new cartridge cases are pushed into the tubes Y36,j the cage 115 is in its cartridge case receiving position to receive the cartridge cases which are pushed out of the ldischarge end of the tubes 36, and, furthermore, so that when the pusher mechanism 79 is inactive the cage 115 is moved to the cartridge case discharge position to dischargeithe quenched cartridge cases disposed therein. In view ofthe fact that fluid motors have already beenfdescribed. for performimT certain control operations inl connection with the present hardening furnace, a uid motor will lalso be described for pivoting the cage 115,Y althoughit'should be understood that any other suitable prime mover may.

be employed.` As best illustrated in Figs.v 2, 13a and 13b, a fluid motor 12.0 comprising a piston 121 and a cylinder 122 is employed. Theends of a piston rod 119 of fluid motor arel connected to a,suitab1e sprocketchain 119er,v which chain and piston rod in effect provide an endless chain mounted on suitable sprockets 123 and 124. The spracket 1247is illustrated as being attached to' the cage shaft 116, whereupon reciprocal movement of the piston121 will cause pivotal movement of the cage 115. For the purpose ofA simplifying the disclosure, the uid motor 120 is schematicallyA indicated as of the spring return type in which a spr-ing 126 causes return of the piston 121 afterv movement occasionedfby supplying a hydraulic Huid tothe cylinder 1L22through operation of a solenoid operated valve 128.- It will be understood that the solenoid operated valve 128V might just as well upon deenergization supply hydraulic fluid to the cylinder 12,2 to cause return movement thereof instead of employing the spring 126. Whenever solenoid operated valve 128 is energized, piston 121 moves to the right,- as viewed in Figs. 13a and 13b, and cage 115 moves from the cartridge case receiving position shown' in so-lid lines in the drawings to the cartridge case discharge position shown in dotted lines in the'drawings'.y

In order to tie in the operation of the fluid motor 120 with the operation of the uid motors 34 and 93, a pair of limit switches 129 and 130 are provided. The limit switch v129 is actuated to close itsnormally open contacts 129e and open its normally closed contacts 129b when the cage 115 reaches its cartridge case discharge lor dotted line position. The limit switch 130, on the other hand, closes its contacts130a and opens its contacts 130b when ,the cage 115 reaches its cartridge case receiving position, or, in other words, the solid line position shown in the drawings. .Y

To insure very high speed quench, and moreover unif'form quench of the entire cartridge case as it drops into the cage 115 (such a cartridge'case being shown in section and designated by the reference numeral 42 in Fig. 8 of the drawings), it is desirable to supply a quenching lluid which impinges against the internal walls of the cartridge case as well as the quench jet 64 already described which impinges on the outside thereof. To this end there are supported within cage 115 a plurality of spaced internal quench tubes or nozzles 132, disposed along the longitu# dinal axis of the cage 115. These internal quench tubes or nozzles are arranged so that the open endsof the car? tridge cases 42 slip over the tubes 132, which preferably are somewhat tapered'as indicated at 1.33 to facilitate this action. For the purpose of guiding the cartridge cases 42 in their movement into the cage 115, suitable tins or guides 136 arel fastened as indicated at 137 to the inside of the cage 115 at spaced points, sothat a pair of guides are associated with each nozzle 132. Gravity will, of course, cause theV cartridge cases to drop against the ns or guides and, hence, move over the internal quench nozzles `132 in the manner clearly indicated in Fig. v.Stof the drawings. f

, It will be apparent that means should be provided to support thecartridge cases 42 above ythe nozzles 132 s'o that the base of the cartridge case does not close the nozzle', and to this end suitable support' members 140 are disposed adjacent each of the nozzles 132 upon which the open end of the cartridge-cases may rest.y These support lmem-- bers are preferably/fastened to the walls of -the'cage 115 as indicated at`1,41"..; The effectiveness of the vquench of thev present invention will readily be apparent by an ex- 4arninationof 8, Vwhich shows that the internal quench I stream impinges against the. baseof the cartridge case and runs down ialong the linside walls of the cartridgel case. Similarly, thel external quench impinges against'the'base and runs down the exterior surface.v Moreover, the cage or elongated trough 115 is provided with a limited number of openings, such as inthe bottom, so that it is norm'allyfulLof water or quench liquid, and in fact the liquidV runs over the forward edge thereof as indicated in Fig. 2

Vof the drawings intovcollecting tank 110. To insure that the liquid onlyspills over the forward edge, the ends of the cage 115 are provided with a bale or extension 146, best shown in Fig. 8 of the drawings. Thus, the cartridge case is subjected to an internal and external jet of cool liquid having a temperature of the order of 40, and, in addition, is completely immersed within the cool liquid. Due to the very high temperature of the cartridge case as it enters the cage 115, a rapid formation of steam occurs, and the internal and external quench jets effectively wipe ofi the steam from the surface of the cartridge case, which steam otherwise would tend to provide an insulating layer rendering the quench liquid less effective. As a matter of fact, in a device built and operated in accordance with the present invention, the cartridge cases 4Z are in the quench cage 115 a matter of a few seconds, and yet the temperature thereof isreduced from something over i603" F. to room temperature or below.

For the purpose of supplying the liquid quench to the internal quench tubes 32, there is provided a source of cooling liquid not shown which is supplied to a header 15d, which header is connected by a plurality of separate tubes or conduits 151 to each of the internal quench tubes 132, there being twenty-four such tubes 132 in the event that twenty-four tubes 36 are employed in the furnace 2i?. ln order to control the flow of the quench liquid, which, as will become apparent from the following description, must be discontinued when the cage 115 is moved to its cartridge case discharge position, there is provided a solenoid operated valve 153 for controlling the llow of fluid to all the conduits 151. in addition, a check valve 154 is provided in each of the conduits 151. The check valves 154 permit the ilow of uid through the conduits 151 only in a direction toward the cage 115. Whenever the solenoid valve 153 is energized, cooling huid is permitted to flow to the conduits 151.

Any suitable quench liquid may be employed, although it is preferable not to use the conventional corrosive brine solution normally comprising about 10% salt. lt has been discovered that by using a wetting agent, which may be purchased on the market as Aerosol OT, a dioctyl sodium sulfosuccinate compound, or in amounts of about 1% solution, the quench liquid is electively wetter by some four times and obviously performs a much better quenching operation. The present invention, therefore, is also concerned with the use of an improved quenching liquid.

In spite of the fact that the heating operation occurs in an atmosphere which tends to reduce scaling and oxidation, it is necessary that the hardened cartridge cases be washed, and, conventionally, they are discharged from the hardening furnace to a suitable wash tank. Such tanl: forms no part of the present invention but is schematically indicated in Fig. 2 of the drawings by the reference numeral 166), which wash tank may include a suitable conveyor means 161 to convey the washed cartridge cases therefrom. ln accordance with the present invention, when the cage 115 is disposed in the dotted iine positions of the drawings, a suitable air jet is supplied through each of the internal quench nozzles 132, thereby to positively blow the particular cartridge cases disposed in the cage 115 out of the cage. To this end suitable conduits 152 are provided adjacent the open end of the cage when disposed in the cartridge case ejecting position, so that the cartridge cases are moved through the conduits 162 in the direction of the arrow shown in Fig. 2 of the drawings and into the wash tank 160." Y

For the purpose of supplying -the necessary air jet, there is provided a suitable source of air or other gas under pressure, supplied to a header 166, and controlled by solenoid valve 167, which controls the flow through all of a plurality of conduits 168 connected to the internal quench tubes 132 through suitable check valves 169. Whenever the solenoid `actuated valve 1&7 is energized,

, position solenoid operated valve 12S.

air under pressure is supplied to the quench tubes 132. it will be obvious that solenoid operated valves 153 and 167 must not be simultaneously energized. Moreover, the check valves 154 will prevent air from entering the water conduits 151 when the solenoid operated valve 167 is energized, and, similarly, the check valves 169 will prevent water from entering the air conduits 168 when the solenoid actuated valve 153 is energized.

It will be understood that the hardening furnace of the present invention ,should not be operated unless air under a suitable pressure is available for supply to the cage 115, and hydraulic fluid under a certain pressure is available to operate the various fluid motors S4, 93 and 120. Accordingly, in the control circuits shown on Figs. 13a and 13b, pressure switches, generally designatedvat 17) and 171, are provided which will interrupt the power circuit in the event that either the hydraulic pressure or air pressure is below safe operating values.

1n view of the detailed description included above, the operation of the present invention will readily be understood. However, this operation can better be understood by reference to the schematic control circuit shown at Figs. 13a and 13b of the drawings. In order to perform the desired control operations in a predetermined sequence, numerous elements are preferably required, such as a cycle timer generally designated by the reference numeral 180, a starting switch 131, a stop switch 182, ay power supply relay 183, a pusher control relay 184, a conveyor control relay 185, a cage position control relay 186, a quench control relay 187, and a plurality of additional relays 183 and 189, the relay 18S controlling the application of control potentials from the cycle timer 180. For the purpose of providing suitable time control, a plurality of timing relays 190, 191 and 192 are provided. The timing relay 199 is in effect a cage movement time control relay and includes a pair of normally open contacts 190e which are closed instantly upon energization of relay 19h. in addition, timing relay 190 includes normally closed contacts 19911 and 190e which are opened following a tensecond delay after energization of timing relay 1%. Additionally, timin g relay 190 includes normally open contacts 190d which are closed following a tive-second delay after energization of timing relay 196. Timing relay 191 is in effect a time control relay for the air injection and includes a set of normally open contacts 1.91ct which are closed after a delay of two seconds following energization of timing relay 191. Similarly, timing relay 192 is in effect a pusher movement time control relay comprising normally open Ainstantaneously actuated contacts 192a and normally closed six-second time delay contacts 192.1).

The pusher control relay 184 includes normally open contacts 184a and 184b for controlling the energization of pusher solenoid operated valve 38. The conveyor control relay 185 includes three sets of normally open contacts 185e, 185,11 and 185C. The contacts 185a are effectively seal-in contacts for maintaining relay 135 energized'following momentary closure of the contacts 96a of limit switch 90. The contacts 185i) and 15c, on the other hand, control the energization of conveyor solenoid operated valve 92. The cage position control relay 186 includes two sets Of normally open contacts 18M and 136]: forcontrolling the energizatioa of cage v The relay 187 comprises a single setof normally closed contacts lltWr.l which control the energization of the quench solenoid operated valve 153. The relay 158 includes a set of normally open seal-in contacts la which seal in relay lgonce it is energized as long as the contacts 129]; of limit switch 129 are closed, or, in other words, as long as the cage 115 is not in its cartridge case ejecting position. Additionally, relay 138 includes normally closed contactsV 183band 'lge which control the energization of pusher control relay 184 in response to the appli- 13a andv 13b, the power lines 193g and 193]; are so v designated at numerous places on these figures of the drawings. The power control relay 183 normally supplies the power from source 193 to the systemjupon closure of the manual switch 194 and actuation of the start switch 181. Thereafter, power control relay 183 remains energized so long as the control circuit functions properly in repetitive cycles under the control of cycle timer 180. To this end power control relay 183 includes normally open contacts 183a and 1S3b for supplying power to the various circuits shown in Flgs. 13a and 13b. Additionally, power control relay 183 includes a set of normally open seal-in contacts 183e which parallel the start button 181. Also, the relay 183 includes a set of normally closed contacts 1S3d for controlling the energization of a suitable signal light 199. This signal light is preferably a red signal light and when energized indicates that the switch 194 is closed but that otherwise the system is not functioning as intended. A signal light 200,'which might be a green signal light, is provided,.which is connected across power lines 193a and 193b through contacts 190C of-timing relay 19t). When this light 200 is energized, it will indicate that the system is functioning normally, and under these conditions signal light 199 will not be energized.

Before considering the operation of the control circuit, a brief description of the cycle timer 180 will first be included. Preferably this cycle timer includes a manually adjustable `knob schematically indicated at 201, by means of which the length of the timing cycle can be adjustably controlled. In a particular embodiment of the present invention the cycle timer 180 was adjusted to have a cycle of twenty seconds, but obviously any other adjustment thereof may be employed. As illustrated, the cycle timer comprises a relay 232 having normally closed contacts 20201, a relay 204 having normally open contacts 204a,.a motor 205 for driving a cam 286 in order toperiodically close the contacts of, a suitable switch having contacts 207a and 207b. Asuitable manual switch 299 is included -in the cycle timer 189, whereby the timer may be placed inoperation upon closing switch 209." It will beV apparent that the relay 202 will-be energized once during each cycle of rotation of the motor driven cam 206, with the result that once during each cycle of the operation ofthe cycle p timer, relay 204 will close its contacts 204e. These contacts control the energization circuitrfor the pusher control relay 184. This circuit may be traced from one line terminal 193:1 through the Ycontacts 204g of relayl 204, the contacts 188b of the relay 188, the conductor 212, the contacts 91h of' the limit switch 91, the winding of pusher control relay 184 to line terminal 193b. lt is apparent then that once during each cycle of the cycle timer 180, and if set for a twenty-second cycle, twenty seconds after manual Aswitchy 299 is closed, pusher control relay 184 will beenergized to start. pushing a new group. of cartridge cases 42 into the tubesA 36, and, consequently, pushing vsimilar cartridge cases 42 out of the other ends ofthe tubes 36 and into the discharge chutes 'Assuming now that'the control Ycircuit is in the con- Y ditionshown in Figs. l13av and 13b, upon closingl of the manualswitch 194 signal light 199 will be energized. The manual; switchl 209 of the cycle timer must also be closed. If.. the pressure lswitches 170 and 171 erated valveV 153 to line terminal 193b.

are closed indicating that proper conditions exist in the system, the cycle of operation may be initiated by depressing start switch 181, with the result that Apower control relay 183will be'energized through a circuit from line terminal 193:1 through start switch 181, stop switch 182, the winding of relay 183, the six-second time delay contacts of timingA relay 192, the conductor 213, the ten-second time delay contacts b of timing relay 198,the conductor 214, and back to the line terminal 193b. Thereupon, power control relay 183 closes its three sets of normally open contacts to supply power tothe powerlines 193e and 193b extending across the center of Figs. 13a and 13b and to close its seal-in contacts 183C paralleling start switch'181. 1t will be obvious that at any time powerV control relay 183 may be .deenergized by manually depressing stop button 182. The

signal light 199 is deenergized, and the signal light 200 Ais energized through 'the contacts 190C of timing relay 190. The reason for including the six-second time delay contacts 192b andthe ten-second time delay contacts 19% in the energization circuit of vpower control relay 183 is one of safety, wherein power is cut of'in the event that lthe pusher mechanism does not complete its `pushing cycle in less than six seconds, or if the cage mechanism 115 doesnot complete its cycle in ten seconds, Vas will become more evident from the following description.

Following operation of power control relay 183, as determined bythe cycle controlled by cycle timer 180, pusher control relay 184 will be energized with the result that solenoid operated valve 38 causes the pusher mechanism, comprising Huid motor 84, to operate and push the particularcartridge cases disposed in the magazine receptacles 'l5 into the tubes 36. It will be apparent that at this time the cage 115 should be in its solid line position. This is assured by virtue of the fact that the contacts'13a of limit switch 1.30 must be closed before solenoid operated valve S8 can be energized, and the contacts 131m of limit switch 131) are only closed when the cage 115 is in the cartridge case receiving position shown in solid lines in the drawings. During this time it should be noted that the solenoid operated valve 153 controlling the internal quench jet supplied to quench tubes 132 is energized through a circuit which may be traced from line terminal 193e, contacts 187a of relay 187, conductor 216, and the winding of solenoid oplt will be understood that the internal quench will be suppliedas long as'relay 187, which is effectively the quench ycontrol relay, is not energized. n Y Y As the fluid motor 84 is actuated to push cartridge cases 42 into the furnace, it will be noted that limit switch 91) isnot actuated, since in elicect it can only be momentarily energized as the fluid motor 84 substantially has vcompletedvits return stroke. However, when uid motor S4 causes its piston 82 to move its full distance to the right as viewed in Fig. 13b of the drawings, limit Yswitch 91 is actuated ,to open its' contacts 91h and deenergize pusher con rol relay 184. t will have been noted that upon the Vapplication of apotential through the contactsA 18812 of relay 188 following a cycle ofV operationV of Icycle timer 181), timing lrelay 192 will Vhave been energized simultaneously` with pusher control 184- through the same circuit,l including conductor .212, limitswitch contacts 91b, conductor 217, .and the windingVv of timing relay 192. Timing relay 192 closes its instantaneous :contacts 192e, which 'effectively seals in'v its energization Acircuit regardless Vof what happens to the 'cycle timer 18thl thereafter,'and effectively connects lineI terminal 1935;"tofconductor 212 through its contacts 192e Yand the contacts 188e of the relay 188. Timingfrelay 192 is deenergized simultaneously with y-deene'rgization of pusher control relay'184 upon opening Ysomewhat of the order of three seconds, timing relay 192should be deenergized in about three seconds. In the event that it is not deenergized within six seconds, thus indicating that the pusher mechanism is not functioning properly, contacts 192b thereof will open thereby .deenergizing the energization circuit of power control relay 183, with the result that the entire system is deenergized. At the end of the forward stroke of uid motor 8d, the contacts 91a of limit switch 91 are closed thereby completing an energization circuit for timing relay 199. This circuit may be traced from power line 193m through the contacts 91a of limit switch 91, conductor 218, contacts 189a of relay 189, conductor 219, the winding of relay 19) to the power line 193b. Timing control relay 190, upon closing of its instantaneous contacts 199:1, effectively seals in the energization circuit for timing relay 190 insofar as the contacts 91a of the limit switch 91 are concerned, whereby these contacts 91a may be reopened upon the return stroke of uid motor 84 without deenergizing timing relay 190. The instantaneous contacts 19Go of timing relay 190 also complete the energization circuit of relay 188. This circuit may be traced from line terminal 193b through the winding of relay 188, conductor 218, contacts 190:1 of timing relay 19t) to line terminal 193e. The energization of relay 188 causes closing of its contacts 188:1, which effectively seal in relay 188 through contacts 129!) of limit switch 129. This circuit can be traced from power line 193a, contacts 129b of limit switch 129, conductor 220, contacts 188e of relay 188, and the winding of relay 188 to power line 193]). Upon a delay of five seconds following energization of timing relay 19t), its ive-second time delay contacts 194) close, thus assuring that the cage 115 will remain in the solid line position shown for at least five seconds, during which time cartridge cases are dropped into the cage and subjected to the internal and external quench mentioned above. Upon closure of the five-second delay contacts 198:1, cage position control relay 186 is energized through an obvious circuit to cause solenoid operated valve 128 to be energized, whereupon the lluid motor 120 causes cage 115 to move from its solid line position to its cartridge case ejecting position shown in dotted lines in the drawings. As the cage starts to move about its shaft 116 (clockwise as viewed in Fig. 13b of the drawings), the contacts 13tlb of limit switch 130 are closed, and, similarly, the contacts 13Go of this limit switch are open, the latter contacts making sure that the pusher mechanism cannot be actuated unless the cage 115 is in its cartridge case receiving position. Closure of contacts 13b!) energizes quench control relay 187 through a circuit which may be traced from line 193e through contacts 13%, through conductor 221, and through the winding of relay 187 to power line 1935. Energization of quench control relay 187 opens contacts 18711 to deenergize the quench control solenoid operated valve 153, thus cutting off the internal quench jets while the cage is moving to its cartridge case ejecting position. As the cage 1.15 reaches its cartridge case ejecting position, limit switch 129 is actuated to close its 'contacts 129a and open its contacts 129b. Closing of the contacts 129a causes simultaneous energization of the air ejection solenoid operated valve 167 and timing relay 191. This circuit 'can be traced from power line 193:1 through contacts 129er, through conductor 222, through the winding of the relay 191, to power line 193b or to the winding of solenoid operated valve 167, which latter two windings are in parallel. Thus, an air jet is supplied through the internal quench nozzles 132 to eject the cartridge cases disposed within the cage 115. This air injection is permitted to exist for a period of two the winding, controlled by the two-second delay contacts '19in of timing relay 191. At the end of this two-second period these contacts 191e are closed to complete t y 16 an energization circuit for the relay 189 through an obvious circuit. When relay 189 opens its contacts 189a there occurs the resultant deenergization of timing relay 190. in the event that more than ten seconds have elapsed between the time that timing relay 19t) is energized and the time it is deenergized through the energizationof relay 189, the ten-second delay contacts 190b of timing relay 190 will interrupt the energization circuit for power control relay 183 and shut down the system.

This will only occur if the cage 115 does not complete its cycle within a ten-second period. Actually, it should complete its cycle in around seven seconds. It will be observed that when the cage 115 reaches its cage ejection position, limit switch contacts 129b are opened to break the energization circuit for relay 188 through these contacts, and upon deenergization of timing relay 19t? relay 188 opens to permit a subsequent control voltage from cycle timer 180 to initiate a subsequent cycle of operation. Quench control relay 187 is also deenergized as soon as cage 115 reaches its cage receiving position, whereupon the internal quench jets are again turned on through energization of Solenoid operated valve 153.

It will be apparent that during the cycle just described, the liuid motor 93 must be energized to move a new charge of -cartridge cases 42 disposed within receptacles in the magazine into a position for actuation by fingers Sil to move the same into the tubes 36. Thus, upon momentary closure of limit switch 90, which only occurs when the fluid motor 84 has almost completed its return stroke, the conveyor control solenoid 185 is energized. This circuit can be traced from power line 193b through the winding of relay 185, the contacts 10M of the limit switch 101, and the contacts 90a of the limit switch 96 to power line 193a. Conveyor control relay 185 includes seal-in contacts 105e paralleling the contacts a of limit switch 90 which are only momentarily energized. Upon energization of conveyor control relay 185, solenoid operated valve 92 is energized to cause fluid motor 93 to rotate the magazine forward, so that twenty-four different receptacles 75 are moved opposite the ends of the twenty-four tubes 36 of the furnace Ztl. Upon completing its forward stroke, fluid motor 93 actuates limit switch 101 to open its contacts 101:1 and deenergize conveyor control relay 185 and, hence, solenoid operated valve 92, whereby iluid motor 93 is returned by means not shown to its initial operating position for a subsequent conveyoroperation.

It will be apparent that as cycle timer causes its contacts 204:1 to be closed again, the entire operation just described will be repeated.

The furnace of the presentinvention is normally operated on a continuous shift basis, since shutting down the furnace causes complications with reference to scaling and the like of cartridge cases disposed within the tubes 36. However, since it is contemplated that the furnace 29 be shut down, it is preferable that the tubes 36 be charged with rejected cartridge cases so that they can be thrown away when they are subsequently pushed through the furnace, since the inordinate amount of scaling which will occur makes these cartridge cases unacceptable if they were otherwise acceptable. Hence, on week-ends or on days preceding holidays, the operators prior to shutting down the furnace will fill the tubes 35 with rejected cartridge cases. Also upon subsequently starting up the furnace cam 58 will make sure that if there has been any welding which has not been disturbed by the protuberances 46, that this weld is broken.

Although there has been described an arrangement in which a plurality of individual tubes 36 are employed in the furnace 2t), a somewhat simplified construction is illustrated in Figs. 14 and l5 of the drawings, in which a pair or cooperating somewhat corrugated- like plates 230 and 231 provide a plurality of connected passageways similar to the individual tubes 36. The individual passageways are designated by the reference numeral 232, and they have the same V-shaped cross section to provide for better distribution of the weight of the cartridge cases, thus eliminating deformation of the cartridge cases. Also, instead of having a controlled atmosphere only within the passageways 232, the entire heating chamber 22 of the furnace is supplied with a nonoxidizing atmosphere. The same protuberances designated as 233 in Fig. 15 of the drawings are employed as those designated by the reference numeral 46 and perform exactly the same function. It will be understood that as far as supporting the cartridge cases in their movement through the furnace is concerned the upper plate 230 is not essential. However, a considerable force must be transmitted by each cartridge case, and this force is at a maximum for the particular .cartridge cases which are just being inserted into the furnace, and decreases gradually as the cartridge cases move along the furnace, due to the fact that there are less cartridge cases ahead of them to be pushed along. The top plate 230 prevents the cartridge cases from tipping up under the large forces which might be involved for the cartridge cases near the entrance of the furnace. However, it has been found that this top plate 230 is not necessary throughout the entire furnace, and, as illustrated in Fig. 15, extends only part way through the furnace. The operation of the arrangement shown in Figs. 14 and 15 will be readily apparent to those skilled in the art.

While there has been illustrated and described an improved system, apparatus and process for hardening steel cartridge cases, it will be apparent to those skilled in the art that numerous changes and modications'will occur, and it is aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. Apparatus for hardening cartridge cases comprising a high temperature heating chamber, means defining a` tubular passageway through said heating chamber through which said cartridge cases may be moved in end-to-end relationship with every case orientated in the same way, means in said tubular passageway located at spaced points therealongfor causing relative transverse movement of adjacent cases to cause relative movement between the engaging ends of said cases, a discharge chute connected to one end of said tubular passageway through which said cartridge cases fall upon being moved out ofQsaid end of said passageway, cartridge case engaging means at the junction of said passageway and discharge chute for deliecting said cases into said discharge chute in the,

event that they fail to fall by gravity into said chute upon movement out of said passageway, and means for inserting cartridge cases into the other end of said passageway and simultaneously pushing cases disposed in said passageway along said passageway. i'

2. A quenching means for rapidly cooling work pieces in the form of a tube closed at'one end which have been subjected to high temperatures comprising a movable receptacle for receiving said work pieces to be quenched, means for subjecting said work pieces to internal and external jets of quenching liquid while disposedin said receptacle, means for terminating said internal jet after a predetermined time delay, means for moving said receptacle to a work piece discharge position, and means for supplying a blast of liuid into the interior of each work piece while in said receptacle and while said receptacle is in its work piece discharge position for ejecting said work piece/from said receptacle.

`3. A hardening furnace for work pieces comprising a heating chamber within which temperatures in excess 'of 1600 F. may be obtained, means defining a passageway through said heating chamber through which said work 18 pieces may be moved in end-to-end relationship with every work piece orientated in the same way, means for inserting work pieces into one end of said passageway and simultaneously pushing work pieces disposed in said passageway along said passageway, means for receiving said work pieces in a irst predetermined position as they are being pushed out of the other end of said passageway, means correlated with the operation of the work piece inserting means for moving the receiving means to a second predetermined position, means for subjecting said rwork pieces to a liquid quench when the receiving means is disposed in said first predetermined position, means for terminating the operation of the last mentioned means during the movement of the receiving means to said second predetermined position, and means for discharging said work pieces from said means for receiving the same following movement to said second predetermined position. 4

4. A hardening furnace for Work pieces comprising a heating chamber within which temperatures in excess of 1600" F. may be obtained, means dening a passageway through said heating chamber through which said work pieces may be moved in end-to-end relationship with every work piece orientated in the same way, means for inserting work pieces into one end of said passageway and simultaneously pushing work pieces disposed in said passageway along said passageway, means for receiving said work pieces upon being pushed out of the other end of said passageway, intermittently operated means for subjecting saidwork pieces to a liquid quench when disposed in said last mentioned means, meansv correlated with the operation of said work piece inserting means for actuating said last named means, means for discharging said work pieces from said means for receiving the same following rapid quenching thereof, and a movable magazine operated in timed relation with respect to the discharge means and the work piece inserting means for moving work pieces adjacent to said one end of the passageway whereby said means for inserting work pieces may move them out of said magazine and into said one end of said passageway.

5. A hardening furnace for work pieces comprising a heating chamber, means defining a passageway through saidv heating chamber through which said work pieces maybe moved in end-to-end relationship with every work piece orientated in the same way, means for inserting work pieces into one end of said passageway and simultaneously pushing work pieces disposed in said passageway along said passageway, a discharge chute connected to the other end of said tubular passageway through which said work pieces fall upon being moved out of said other end of said passageway, a pivotally mounted receptacle disposed beneath said discharge chute and capable of receiving said work pieces dropping through said discharge chute when disposed in one predetermined position, means for subjecting said work pieces to a liquid quench While said receptacle -s disposed in said one predetermined position, means operated inv timed relation with respect to the work piece inserting means for pivoting said receptacle to a different predetermined position and terminating said liquid quench at least before the end of the period of said pivoting of said receptacle, and air jet means operable in timed relation with respect to the operation of the pivoting means for removing said work pieces from said receptacle while disposed in said different predetermined position.

6. In a hardening furnace for cartridge cases comprising a heating chamber, means defining a passageway through said heating chamber through which said cartridge cases may be moved in end-to-end relationship larea51-s 19 said passageway Valong said passageway, a dschai'ge`fchi1te connected Ytothe other'end or said tubular passageway throughv/hich said cartridge cases fall upon being 'rrioved out of said other end of said passageway, aip'ivotally mounted receptacle vdisposed beneath said discharge chute and lcapable of receiving said cartridge' cases 'dropping through said discharge chute when disposed in"-o ne"`p"re determined position, means for subjecting Said 'cartridge cases toa liquid quench While said receptacle is disposed in said one predetermined position, means operatedV in timed relation with the operation of the work piece inserting means for pivoting7 said receptacle "toa'dite'r'ent 'predetermined position, and air jet means' 'operatedl in tiined relation v`vvith jrespect to the movement ofthepivoting means for 'removing said'cartridge cases from said 'receptaclewhile disposed in said different predeterminedv 'position.

`7. A quenching means for rapidly cooling'v cartridge cases Vwhich have been Isubjected tdte'mperatiresiahove l000 F: to'roomtemperature or below in a feu/"seconds, comprising aimova'ble receptacle 'for 'receiving said'cases to be quenched, Ameans for 'subjecting s'a'idcases to 'an external stream of' quenching liquid while disp'osedfin said receptacle, an internakquench'tube 'forsu'pp'lyin'g a jet of quenching 1liquid tothe interior oi'eachI4 ridge case, means -forl terminating said internal'jet after "a predetermined time delay, means'formoving vsaid'recife'pt'afc'le to aV cartridge case dischargev position, "and 'means for supplying a blastlof air through said quench Vtube tof the interior of Vsuch cases While in 'said receptacle andy while 30 said receptacle is in its discharge positionv for jecting said'cartridgecases therefrom.

l8. The method of cooling a tubularwork piece'closed at one end which has been' heated to a 'high temperature of the order of 1660"l F. to room temperature orbelovv in Ya period of a few seconds which comprises dropping said heatedw'ork piece open end first through a wall of quenching liquid at a temperature well below room'temperature, momentarily `supporting said work piece Vim-A mediately below said wall of quenchingliquidso the exterior thereof is still subjected to cooling thereby, applying a jet of said liquid against the interior 'Walls'of said Work piece momentarily supported lbelow saidv wall of quenching liquid,-terminating said liquid jet, and sub, jecting thev interior Orsa-id work piece to a blast' of rairl to displace said workpiece fromits position of momentarysupport immediately below said liquid wall.

9. The met'hoduofj cooling a cartridge' casefwhich'has been heated'to a high temperature` above 'l000' Vto room temperature or below Yin aperiod of a few"seconds,l which comprisesdropping said cartridgev caseopen end rst through a'conical shaped wall of quenching liquid at a 'temperature well` 4belowv room temperature, r'n'inentarily supporting-said work' pieceimmediatelybelow Vsaid Wall of quenching liquide so thev apexA of 'said c'oiiicalwvall strikes the: base'of' said case kand subjects'thfe yeirt'erior thereof to'cooling thereby, applying a jet of saidl 4liquid against the interior' of 'said cartridge'case' whileniomentarily supported below' said wall of quenching liquid, *terminating said liquid' jet, andsupplying a 'blast of air to the interior of said 'cartridge case todisplace it fromk its position of momentary support immediately below said liquid wall.

10. A hardening furnace for work pieces comprising. a heating chamberV having a passageway thereinilirugh Y which work piecesmay be moved in end toiendrelationship, saidpassageway 'having' entrance"andfdisclarge endsloading means for 'inserting work pieces`" into ""the entrance end of saidpassageway and "simultaneously, pushing work'pieces disposed iny said passageway tliere' through in order to' discharge work'pieces'from'` the discharge end ofy said'passageway, quenching inensposiv 2li) Y t tinedi'adjacent the discharge"end"ofk said`discharg'epass'gufay'for directing a'jet of 'quen'chln'g-liquidoht each of said work'pieces'as it emerges fijo'rn' thedischarge end ofsaid passageway, 'andineans correlatedV with the V"operation" of said loading 'means for intermittentlype'ratingv said quenching "means to cut'ioff VAthe jet for predetermined 'intervals' dring the p'e'riodbetween the einergence of successive 'Work "pieces fr"c` rn"th'e 'discharge end of said passageway.

'11. -A 'hardening furnace for workpieces'cmprising a heating lchamber having a` passageway therein through whichwork'pieces maybe 'moved in end to end relationship, said'pass'ageway' having entrance and :discharge ends, loading means 'for inserting' workpieces 4'into theentrance' en'd of' said 'passageway' and 'simultaneously pushing work pieces disposed in said' passageway ytherethr'o'ugh in Aorder to'discharge'Workpi'eces'frorn the'di'sc'harge kend of'said passageway, quenchingmeans 'positined adjacent thedischarge'e'nd of said discharge'passageway f o'r'directing ajet of 'quenching liquid onto' lcachot Vsaid wokpieces as it'em'erges' from Vthe discharge end o said'pa'ssageway, means loperated Iin' timed relation with "'re'spectto said loading' Ymeans 'for intermittently rendering said quenching means operativefor a predetermined interval after one-of said work pieces is moved 'out'of'the discharge endl of said passageway, andi-mean's forre'nde'ring said quenchin'g'frneans inoperative at'the terminationy ot" said predetermined linterval thereby cutting 'oi the jet.

l2. A hardening furnace comprising aheatin'g'chambei` for Awork "pieces including a passageway having entrance'fand/'discharge ends, 'loading'means for moving work pieces'through'said passageway to the Vdischarge end thereof, a 'movable magazine for moving 'said work pieces to a position adjacent to the-'entrance 'end 'of said passageway vfrom vwhich the loading means may move them into the entrance end of'said passageway, means responsive tothe 1actuation of said loading means for operating said moveable magazine, means for receiving each individual workl piece discharged from the discharge end'f Lsaid passageway, means for subjecting said'work piece to 'a liquid quench while disposed in the receiving means, Lkmeans fory removing 'the work piece from' said receiving rneans after it is quenched, means for moving said receiving means vfrom its receiving position to a work piece removing position 'and lfor returning the receiving means" toy its receiving position, means for rendering the removing-means operative when the receiving 'means is in'sad removing-position, and means for rendering the loading meansope'rative as isoon as the receiving means is"-re` t11rned toits 'receiving position andV for preventing theV operationy of said yloading `means until'the receiving means is'in said're'civ'ing position.

' Refrences cited in are' ale' 'of this Vpatent; f-UNITEDSTATES PATENTS 5193232 "Br'saein May 1, 1894 y 1,227,027 4 Bail'y'et a1. May 22, 1917 *1,366,806 "Holry July 12, 1932 1','888`;960 zTalley NOV. 22, 1932 1,957293'2 Berolzhemer et al May 8, 1934 230632784 `Bet-:ktel et al Dec. 8, 1936 2,235,542 l,VV-'einzel Nlal. l18, 1941 2,298,149 :Morton Oct. 6, 1942 2,325,7 57 'Ehlers Aug- 3, v1943 2,352,709 "Ha''se .Tilly 4, 1 944 2,450,112 Y Bukholdt Sept. 28, 1948 2,462,851 Fawcett Mal'.y 1, 1949' 2,583,046 Y* 'Gardner- '-]n.--22, 1952 'FOREIGN PATENTS 352,174 Great vBritain '.:Ju1y-9,'1931 v532,807 i Great Britain Jam-3l,l 1941 1 Nag..

Claims (1)

1. 8. THE METHOD OF COOLING A TUBULAR WORK PIECE CLOSED AT ONE END WHICH HAS BEEN HEATED TO A HIGH TEMPERATURE OF THE ORDER OF 1600*F. TO ROOM TEMPERATURE OR BELOW IN A PERIOD OF A FEW SECONDS WHICH COMPRISES DROPPING SAID HEATED WORK PIECE OPEN END FIRST THROUGH A WALL OF QUENCHING LIQUID AT A TEMPERATURE WELL BELOW ROOM TEMPERATURE, MOMENTARILY SUPPORTING SAID WORK PIECE IMMEDIATELY BELOW SAID WALL OF QUENCHING LIQUID SO THE EXTERIOR THEREOF IS STILL SUBJECTED TO COOLING THEREBY, APPLYING A JET OF SAID LIQUID AGAINST THE INTERIOR WALLS OF SAID WORK PIECE MOMENTARILY SUPPORTED BELOW SAID WALL OF QUENCHING LIQUID, TERMINATING SAID LIQUID JET, AND SUBJECTING THE INTERIOR OF SAID WORK PIECE TO A BLAST OF AIR TO DISPLACE SAID WORK PIECE FROM ITS POSITION OF MOMENTARY SUPPORT IMMEDIATELY BELOW SAID LIQUID WALL.

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