US2376514A

US2376514A - Heat-treating apparatus

Info

Publication number: US2376514A
Application number: US346813A
Authority: US
Inventors: Howard E Somes
Original assignee: Budd Induction Heating Inc
Current assignee: Budd Induction Heating Inc
Priority date: 1937-01-21
Filing date: 1940-07-22
Publication date: 1945-05-22
Anticipated expiration: 1962-05-22

Description

May 22, 1945. SOMES 2,376,514

HEAT TREATING APPARATUS Original Filed- Jan. 21, 1937 5 Sheets-Sheet 1 1 16.2. 94 V r INVENTOR I Howard ESomes.

. /0. BY W nan I 97 L/QO I ATTORNEY I on H. E. SOMES HEAT TREATING APPARATUS May 22, 1945.

Original Filed Jan. 21, 193 7 5 Sheets-Sheet 2 INVENTOR Howard E. Somes m4, BY 3).

y ,1945. H. EL-S ON IES 2,376,514

HEAT TREATING APPARATUS Original Filed Jan. 21, 1937 5 Sheets-Sheet s FIG. 8

x W LR, /4/ oooooooggggooooo 1- gifi' 510.5

INVENTOR Howard BSornes v ATTORNEY may 22, 1945. H. E. SOMES HEAT TREATING APPARATUS Original Filed Jan. 21, 1957 5 Sheets-Sheet 4 How "In lg.

INVENTOR E. S omes.

ATTORNEY May 22, 1945. I H. s. SOMES 2,375,514

HEAT TREATING APPARATUS Oxfiginal Filed Jan. 21, 1937 5 Sheets-Sheet 5 INVENTOR HowardE Somes Vimw A TTORNEY Patented May 22, 1945 HEAT-TREATING APPARATUS Howard E. Somes, Detroit, Mich., assignor to Budd Induction Heating, Inc., Philadelphia, Pa., a corporation of Michigan Original application January 21, 1937, Serial No.

121,598. Divided and this application July 22, 1940, Serial No. 346,813

9 Claims.

This application. is a division of my application Serial No. 121,598, flied January 21, 1937, now Reissue Patent No. 22,064, reissued April '7, 1942.

The title of this invention indicates the class to which it belongs. The figures of the drawings following show one embodiment of my invention. As usual, it is susceptible of many others.

Fig. 1 is a vertical side elevation of the apparatus. FiFigl. 2 is a front elevation at right angles to Fig. 3 is a transverse cross section of the vertical framework of the apparatus.

Fig. 4 is a plan view of the lower bracket arm. Fig. 5 is a plan view of the end Of the supportmg arm.

Fig. 6 is a plan view at the top of the base block supporting the work.

Fig. 7 is a side view in vertical axial section of the switching transformer and tool carriage, on an enlarged scale.

Fig. 8 is a fragmentary enlarged view of the upper end of the machine.

Fig. 9 is a fragmentary enlarged view of the lower end of the machine.

Fig. 10 is a transverse section of the quenching mechanism feed on line 5-5 of Fig. 1.

Fig. 11 is a. detail of the quenching spray head.

Fig. 12 is a. longitudinal sectional view of a guntreated in accordance with the invention.

Fig. 13 is a circuit diagram of the control system.

The central object of the invention is the achievement of an apparatus whereby the bore of a gun can be heat treated by high frequency induction. So far as I am aware this has never been achieved prior to my invention.

According to my invention I generate in one axial region of the bore annular heating currents in and near the'surface of the bore and of a determinate axial extent, progressively shift the currents so generated axially of' the bore to circulate through successive axial portions of the bore, and as the currents are so shiftedquench the heat which has been generated by the currents so circulated and shifted. Preferably I uniformly progress the axially shifting currents will precede this space. From another angle it may be said that I prefer to maintain between the zone traversed by the progressing induced current and the zone being quenched a zone which has been heated to quenching temperature by the axial shifted current but'momentarily free from substantial influence of either the shifting current or the quench. Preferably I begin the inducing of the treating current outside of the barrel and of an intensity and volume approximating that which shall be generated within the barrel and similarly end the inducing of current of similar intensity and volume at the opposite end of the gun, also outside of the barrel. The current, the inducing of which has so begun and so ended, is progressively shifted in the one case into one end of the barrel, and after being progressed. throughout the extent of the bore is similarly shifted out of the opposite end thereof.

The apparatus comprises means to support the gun with free space substantially equal to its length disposed axially beyond each end thereof and freely accessible from the end. In the free space at one end is a mechanism for progressing into along, back along and again out of the bore of the gun a high frequency induction work coil of a dimension adapted to induce in the surface of the bore and in proper proximity thereto, the heating currents desired. Occupying the space at the. opposite endof the gun is a mechanism for introducing to the bore progressing therealong, back therealong and then out again, a quenching head through which quenching fluid may be projected upon the heated bore to be quenched. Co-

which achieve the heating, and uniformly progress I the quench of those heated portions from which the current has been shifted. Preferably during theprocess of shifting I maintain a determinate axial spaced relation between the zone traversed by the currents and the zone subjected to the following quench so that the zone of the bore which either through oxidation,

ordina'ted motor driving devices for these two devices, and an inter-device spacing mechanism between the high frequency induction work coil and the quenching head insure their coordinated traverse of the bore of the gun from one end to the other in proper spaced relation. A chronometrlcally driven controller insures a coordinated activity of the various parts of these devices in their functional relations to each other individually and collectively. A means to introduce a dry inert gas under pressure to the bore being treated and progressing it under pressure between the high frequencyinduction coil and the bore and countered to the flow of the quenching medium prevents vaporized and sprayed quenching medium and other moistures from engaging upon the heated surfaces of the bore and thereby attains its treatment without marring its surfaces, de-carbonizing or through electrical faults brought about by the exhas been heated fully to quenching temperature cess presence of. moisture.

Referring then to the drawings, I is the gun, II is the main frame of the apparatus both vertical, and founded upon the floor l2 of the shop, or other platform upon which the equipment is to be used. The gun points vertically upward and at its end which is at the floor I2 is seated and centered upon a flanged centering ring I3 borne upon the head of a base block 14 appropriately anchored as by bolts l 5 to the foundation of the floor. It is retained in place against axial displacement not only by the flange it of the plate l3, but also by an encircling clamping block H which is made in two halves hinged together at I 8 and clamped together and about the gun through the swinging link pin l9 engaging its opposite side in a well known manner.

The standards ll of the main frame of the machine are anchored to the concrete floor or other platform l2 in any suitable manner and project vertically upward. They support the upper end of the gun ID by means of a laterally projecting arm 20, which arm is vertically adjustable up and down the reduced cross section H of the standard II and clamped in any adjusted position by means of the bolts 22 which connect together the halves which embrace the shaft 2!. The end which engages the muzzle of the gun i0 is also made in two halves, as indicated at 23, the one ofwhich is integral with the arm and the other swingable about the pivot 24 to engage and center the upper end of the gun through the V- shaped jaws 25 and thereafter be clamped firmly thereupon by the link pin 26 connecting together the opposite end of the halves from the pivot 24. Between the floor level I2 and this arm 20 supporting, aligning, centering and clamping the upper end of the gun is located a transverse intercolumn brace member 21 for the three columns l0.

Such a brace is located also at the extreme upper end, it will be seen, and as many of these inter-column braces may be utilized at different points as it may prove expedient to use. Each of these comprises a generally triangular main body, one apex of which, 28, is made in halves and fixedly clamped about the central column H and the two other apices of which are made in halves bridged by a common hinged bridging member 29 pivoted by a hinge 30 to the main body 21 and coupled to the main body at the end opposite the hinge 30 by means of the link pin coupler 3|. These members 21 engage shoulders 32 respectively upon the columns. They do not engage the barrel of the gun. Instead, the main body is provided with an opening 33 concentric with the axis of the gun and large enough for the barrel to pass freely therethrough. If desired, however, adapters may be placed in this opening of sufllcient size to engage the barrel and be clamped about it by the bridging member 29 when the members 21 are arranged in place. The opening of the bracing members 21 through the swinging of the bridging member 29 enables the guns to be placed in the apparatus and removed therefrom without dis-assembly of the apparatus and to be placed in position laterally rather than raised or lowered vertically into position.

0n the upper portion of the main frame column H are mounted upper and lower

swingable bracket arms

34 and 35, at opposite ends of a spacing sleeve 38, the upper bracket arm 34 being mounted upon the reduced upper portion of the main frame column II and arranged to be clamped in position thereon against shoulder 31 by means of a clamping nut 38, while the lower bracket arm 35 is split where it surrounds the column and arranged to be clamped thereon by means of suitable clamp bolts 39. The swinging

bracket arms

34 and 35 form a support for the tool carriage 40 which it supports on a rotatable feed screw shaft 4i journaled at opposite ends in the upper and

lower bracket arms

34 and 35 by means of suitable

ball bearing journals

42 and 43 respectively, the screw shaft 4i being arranged to be rotated by means of a bevel gear 44. secured at its upper end by means of a suitable key 45 and driven by a complementary bevel gear 45 carried at the end of the shaft of the motor 41 mounted upon the top of the upper bracket arm 34.

The screw shaft 4| is in driving engagement with the tool carriage 40 through the internal threaded portion 48 of the carriage through which it pames for elevating and lowering the carriage according to the direction of rotation of the screw shaft. The bracket 49 mounted on the carriage lll carries the heating coil supporting rod and a motor cylinder 50 which movably supports the casing 5i of a switching transformer.

The transformer casing 5| is supported for definite limited movement by the work cylinder lill relative to the rod 66 by means of the tubular piston rod 52 carried by the piston 53 fitted in the work cylinder about the rod 66. The transformer casing comprising upper and lower portions 54-55 is provided in its lower portion with a cylindrical transformer primary element 56 comprising a cylindrical laminated core element 57 carrying nested within its inner cylindrical surface the primary transformer winding 58 whose terminals 59-430 extend outwardly through the transformer casing for connection with a suitable source of alternating current, not shown. Mounted within the transformer casing 5| is the secondary transformer element 62 comprised in general of the secondary transformer winding 63 imbedded in the outer surface portion of a hollow laminated core element 64, the whole assembled between end plates '65 and carried upon the hollow vertical slide rod 66 in fixed relation therewith so that when the piston 53 of the work cylinder 50 is moved to its lowermost position in the cylinder, the secondary transformer element 62 will remain stationary while the transformer casing 5| will move downwardly relative thereto. This relative movement will bring the primary transformer element 56 and with it the primary winding 58 down over the laminated core extension M, the latter providing a low reluctance core element for the primary winding.

The hollow rod 66 is held fixed in relation to the cylinder 50 and bracket 49 at its upper end by means of the shouldered portion 67 and the nut 68, the transformer casing 5| having sliding bearing on the rod 66 through the tubular piston rod 52.

The hollow rod 66 has sliding bearing in the bushing 69 in the bracket 35 through which bushing it extends down into and through the barrel of the gun H) to the breech end where it carries the inductive heating coil 70 which in its present lowermost position is situated outside the breech within a lower terminal chamber H in the base block l4.

Circuit connection between the winding 53 of the transformer secondary element andthe heating coil it is effected by means of the secondary terminals '12 and tubular conductors I3 which exrend down through the hollow tube 66 to the terminals oi the heating coil 10. Cooling water is circulated through the tubular conductors 13 for extending up to form a laminated lining or pro-v tecting sleeve 16 for the threaded portion of the gun breech. The function of this laminated lining is to provide a low impedance magnetic circuit for the heating coil 10 for a purpose to be hereinafter-explained in connectionw-ith the de-;

scription of operation.

Like the secondary transformer element 62 the heating coil 10 is formed of a hollow conductor carried upon a cylindrical radially laminated core element 11, but with an outside diameter proportioned to pass freely through the barrel of the gun out of contact therewith and in closeproximity to the surface of the bore.

At the muzzle of the gun It! I provide'an upper terminal chamber 78 similar to the lower terminal chamber 75 and like the chamber 15 provided with a radially laminated lining or wall 19. so positioned and proportioned as to receive and surround the heating coil ill when the latter is drawn up thereinto, to provide a low reluctance magnetic circuit for the coil. The chamber 18 is hermetically sealed to the muzzle of the gun l by means of the gasket element 80 fitted between the lower opening of the chamber and the muzzle or the gun, and a stuffing box 8| at the top of the chamber-for the hollow rod 68. Pressure control valve 82 connected with the upper end of the terminal chamber 18 provides for the introduction of a dry inert gas under pressure from a suitable source not shown. whereby the chamber I8 and the gun barrel ll! may be maintained filled with an inert gasunder pressure, the gas passing on down through the clearance between the heating coil 10 and the bore of the gun into the lower terminal chamber II to an outlet conduit 88 which'latter provides an outlet permitting complete displacement of air or other undesirable substance from the gun bore by the inert gas.

A lower extension 84 'of the bottom terminal chamber ll extends down through the supporting fioor l2 into communicationwith a quenching fluid exhaust chamber 85. Through this chamber a sliding quench-tube 88 passes up-into the lower extension 84- of the lower terminal where the tube carries a quenching head 81 spaced from and substantially sealed off from the heating coil 10 by means of a piston head 88 and center projection 89 fitting into the open end of the hollow coreof the heating coil ID. The tubular rod 88 enters the exhaust chamber 85 through suitable stufling box '80 andis mounted for vertical movementto progress the quenching head 81 up through the lower terminalcham-ber H into and through the bore of the gun to the upper or muzzle end of the gun, and to thereafter retract the quenching head back to its lowermost position shown in Fig. 9.0! the drawings. 1

Movement of the quenching head is properly coordinated with the movement of the heating coil III to follow the upward movement of the heating coil through the gun. barrel in constant spaced relation to the coil as determined .by spacing piston or closure element 88. In-the presen embodiment this coordinated movement of the quenching head is effected by means of a driving motor 9| operating through a pinion 92 and vertically sliding rack element 93vcarrying bracket 94 to which the lower end of the tube 86 is fixed. The driving motor is adapted to exert sufficient lift on the tube 86 to cause it to follow the heating head upwardly through the gun barrel and without undue upward pressure on the heating coil. A stationary brace and guide element for the rack 93 extends vertically between the floor support 42 and a lower stationary bracket support 96. The quenching fluid is supplied to the tubular rod 86 by means of a flexible hose connection 91 at the lower end of the tube. Exhaust quenching fluid is drawn off from the exhaust chamber through the outlet conduit 98 and pressure valve 99 and a trap or gas and liquid separator II!!! for separating such of the inert gas as may pass downwardly into the exhaust chamber 85. g

Operation of the pneumatic motor cylinder to is controlled through an electro-magnetically operated control valve Ill! and piston valve it? operable in known manner upon energization to exhaust the top of the cylinder 56 and admit air to the bottom thereof to raise the piston 52 to the top of the cylinder and upon deenergization to exhaust the lower end of the cylinder and admit air to the upper end to effect downward movement of the piston thus operating upon energization to raise the transformer shell 5% into the positionshown and upon deenergization to effect lowering of the transformer shell to move the primary winding 63 out of cooperative relation with the secondary winding 64 and into cooperative relation with the low reluctance magnetic circuit element 6|.

To insure operation ofthe various parts in proper sequence for carrying out a complete operation on a gun barrel, I provide the control system and chronologically driven controller therefor diagrammatically shown in Fig. 13 of the drawings. In this diagram, the controller which is preferably in the form of the usual commutator drum element I03 of insulating material is here shown opened out into a plane surface development of its cylindrical surface, the top and bottom edges of which represent the same generating line of the cylindrical surface. The drum of insulating material has formed thereon or in-set therein various commutator sectors such as S, L, etc. for effecting electrical contact with stationary contact brush elements S, L", etc. respectively during rotation of the drum and in proper sequence, To eifect proper timing of the sequence of circuit closure by the controller, the drum I03 is arranged to be rotated at a predetermined rate by means of a suitable driving motor I04, preferably a synchronous motor and through suitable reduction gears I05. Current for the controlsystein may be derived from any suitable source of current supply here indicated as an ordinary commercial line I08, which for the sake of simplicity in circuit connections is shown as rnents L, HD, G, etc. are connected to the free side of the line through normally open contact I08 of a locking relay I09 by way of conductors H and H I. Thus, the segment S will always effect a connection from the free side of the line to its associated brush S while all of the other segments L, HD; G, etc. are operative to effect connection of the free side of the line to their associated brushes L, HD', G, etc. only during closure of the contact I08 of locking relay I09.

For control of the traversing motors 41 and ill for raising and lowering the heating coil "I0 and quenching nozzle 81, respectively, the motors d? and 9| are provided with pole-changer switches I I2, II3 respectively suitably arranged for eilecting the proper change of polarity for reversing their respective motors in any suitable manner according to the type of motor. As the two motor circuit diagrams are alike, it will be necessary to describe but one of them, for example, that of the heating coil traversing motor 41 which it will be noted comprises the pole-changer switch H2 heretofore mentioned arranged to be normally held in an open circuit position as by the centering retractile springs II4 connected to the pivoted arms H5 of the switch below the pivotal points, the pivoted arms of the switch being arranged to be moved to one side or the other by solenoids 0r magnets II6, III, respectively, to energize the motor for rotation in one or the other direction for bringing about a downward or upward movement of the heating coil I0. Similarly, the pole-changer switch II 3 is moved to the right or left by magnets I I8 and I I9, respectively, for movement of the quenching head B'I downwardly and upwardly. The'control of pressure fluid to the motor cylinder 80 is efiected by an electro-magnetic valve I M control of the inert gas supply to the pressure control valve 82 i is effected through an electro-magnetic valve I and control of the quenching fluid from a suitable source of supply to the flexible hose connection 41 leading to the quench-head 81 an electro-magnetic valve I2I. One terminal of each of the operating magnets H6, etc. and the electro-magnetic valves IOI, etc. is connected to the grounded side of the line I06 as diagrammatically shown while the ungrounded terminals of each of such operating magnets and electro-magnetic valves are arranged to be connected to the free side of the line I06 at predetermined intervals through their respective control brushes and commutator segments on the controller I 03, The controller also governs the connection of the primary winding 56 of the switching transformer to a source I22 of high frequency current through an electro-magnetically operated line switch I23 whose operating ma et like the various other operating magnets has one terminal normally grounded and the other terminal arranged to be connected with the free side of the line I06 through a brush and commutator signal lamp of the controller. A starting segment I24 and starting push button I25 complete the control equipment. 1

In operation, assuming that a gun to be operated upon is in position in the machine as shown in the several drawings, the upper terminal chamber I8 in place on the muzzle of the gun I0 in sealed relation thereto, the heating coil element I0 in the raised position and wholly within the upper terminal chamber, the quenchhead 8Iin the lowermost position as shown in the several views, and the various circuits and apparatus elements of the control system in the is effected by position indicated in the diagram Fig. 13 with the controller drum I03 rotating to move the various commutators S, L, etc. in the direction indicated by arrow adjacent to the drum, continued rotation of the drum from the position to start its cycle of operations. The operator may then start the cycle of operations by pressing the starting button I25 which completes the energizing circuit of the locking relay I09 over a path which may be traced from the grounded side of line I 06 through locking relay I09, push button I25, controller brush S, segment 8, conductor I07 to the free side of line I05. Locking relay I00 upon energization attracts its arma tures connecting the free side of the line I06 through conductor III and normally open contact I00 (now closed) to conductor IIO through which the connection from the free side of line is extended to all of the controller segments L, HD, etc. excepting the starting segment S as indicated by the dotted line extension of conductor H0 through the controller drum. The locking controller segment L having made contact with its associated brush L at or immediately after connection of the starting segment S with its associated brush, the energization of the locking relay I09 completes its locking circuit through this locking segment over a path which may be traced from the grounded side of line I06 through relay I09, locking contact I26, circuit controller segment L, conductor IIO to free side 01' line as previously traced through contact I00 of the locking relay. The locking relay I09 thus remains energized, maintaining all of the controller segments connected to the free side of line dur- .ing the passage of the long locking segment L under its associated brush L.

The controller segment HD now engaging its associated brush I-ID' completes a circuit from the free side of line through brush HD' to the operating magnet H8 which, becoming energized, moves the pivoted blades of the polechanger switch I I2 to the left completing the circuitof motor 41 to the line I06 through branch conductors I21. to cause operation 01 the motor 41 in a direction to move the heating coil I0 downwardly from the upper terminal chamber I8 through the bore of the gun and into the lower terminal chamber II as indicated in Fig. 9 of the drawings. Immediately after the heating coil I0 starts its downward movement the controller segment G starts engagement with its associated brush G through which it effects connection of the free side of line I 06 to electro-magnetic valve I20 to energize the same and connect the pres-.

sure control valve 82 to a suitable source of supply of dry inert gas. The dry inert gas thus enters the upper terminal chamber III as the heating coil leaves the chamber, following the coil down and. continuing to fill and maintain the bore 01' the gun filled under suitable pressure during the downward movement of the heating coil and continuing after the heating coil reaches its lowermost position, the. gas escaping through the clearance between the heating coil and the sides of the 1 wer terminal chamber and out through the vent conduit 83. The length of the heating coil control segment HD is so proportioned in relation to the speed of the controller and the rate of downward movement of the heating coil as to pass beyond the brush HD' immediately after the. heating coil reaches the bottom of the lower terminal chamber 1 Any known or other suitable means may be provided for causing the heating coil to come to rest in the lower position shown in Fig. 9 of the drawings without undue strain on the mechanism, as by providing the motor 41 in the form ofa constant torque motor or by providing a suitable slip clutch connecting between the motor and the driving screw 4| or by the provision of suitable resilient or elastic lost-motion means. After the segment HD has passed beyond its complementary brush HD and the heating head 10 has come to rest at the lower position shown in Fig. 9, the line switch segment LS engages its associated brush LS to connect the free side of line I06 with the operating magnet of the electro-magnetic line switch I23 which thereupon connects the primary winding 56 of the switching transformer with the source of high frequency current I22. However, the heating coil 10 is not energized at this point because of the fact that, as shown in the diagram in Fig. 13, the primary winding 58 is uncoupled from the secondary winding 63. Soon after this point in the cycle the commutator segments QV and ST for controlling the supply of quenching fluid and for actuating the switching transformer, respectively, pass into engagement with their respective associated brushes QV and ST. The commutator segment QV effects connection of the free side of line I06 through commutator segment QV to the electro-magnetic control valve |2| which, becoming energized, connects the quench-head 81 through flexible hose connection 91 to a suitable source of supply of quenching fluid under pressure. The commutator segment ST connects the free side of line lllIi through its complementary brush ST to the electro-magnetic valve |Il| which energizing admits air to the lower end of motor cylinder 50 raising the transformer shell and with it the primary transformer winding 56 of the switching transformer into a transformer coupling relation with the secondary winding 62. The heating coil 16 is now energized from the secondary winding 62 over the hollow conductors 13. With the heating coil thus energized and the quenching head operating to spray quenching fluid outwardly in the space surrounding the quenching head below the heating coil, the commutator segments HU and QU move into contact with their respective brush elements EU and QU' to connect the free side of line I06 with the operating magnets H1 and 9 of the pole-changer switches H2 and M3 to connect the

motors

41 and 9| through the branch circuits I21 and I28 respectively to the llnecircuit I06 in a manner to cause the motors to rotate in a irection to move both the heating coil 10 and the quenching head 81 upwardly through the barrel of the gun, the quenching head 81 following the heating coil upwardly through the barrel until the heating coil enters and comes to rest in theupper terminal chamber 18, at which time the segments HU and QU pass from under their respective brushes to deenergize the control magnets I I1 and H9, which in turn permit restoration of the pole-changer switches to the intermediate or open circuit position thus effecting deenergization of their

respective motors

41 and 9|. The operation of the

motors

41 and 9| is so timed that the heating coil will move upwardly through the bore of the gun,

at the constant rate required to efiect the proper heating followed by the quenching head 81, the quenching head following always in abutment against :the lower end of the heating coil 10 through the spacing piston diagram 88 to insure constant spaced relation between the zone heated and the point of application of quenching fluid. The parts may be coordinated in any suitable manner to insure this following of the coil by the quench=head as by accurate timing of the motors or, preferably, by having the motor ill of a constant torque type, designed to overcome the weight of the spray head and its movable parts with SllIIlClellt margin of power to urge the quenching head upwardly always in contact with the bottom of the heating coil lll.

After the heating coll enters the uppermost terminal chamber at, the commutator segments EU and QU moving out of contact with their respective brushes hill and Q0 open the circuit of the magnets I"! l and us to deenergize the motors 41 and ill. Movement of the heating coil all the way up into the upper terminal cham ber followed all the way by the quenching head both stopping in their extreme upper positions without undue strain on the machinery may be assured in any known or other suitable manner as suggested in connection with the stopp of the heating coil in its lowermost position within the lower terminal chamber I l. Upon entrance of the heating coil into the upper term, chamber, the segment or of the controller'passes out from under its associated brush G breaking connection between the free side of line W6 and the brush G. This deenergizes electro-magnetic valve l2u, cutting off the supply of gas to the regulating valve 82. substantially at the same time, the switching transformer control segment ST passes out of contact with its associated brush ST disconnecting the free side of line U16 from this brush thus deenergizing electro-magnetic valve ltl which operates to exhaust pressure fluid from the bottom of the motor cylinder lid and admit pressure fluid to the top thereof to move the casing of the switching transformer downwardly and with it the primary winding W, restoring the switching transformer to its uncoupledposition. Movement of the switching transformer to uncoupled position brings the pr winding 58 into inductive relation with the low reluctance magnetic circuit furnished by the laminated core extension 6| to prevent unfavorable change in the reactance of the circuit of the switching transformer.

After uncoupling of the switching transformer 56, the control segment LS moves out of contact with its associated brush LS disconnecting the free side of line H16 from the latter and thereby deenergizing the electromagnetic line switch I23 and disconnecting the primary coil 56 from the source I22 of high frequency current. The commutator segment QV now passing out of contact with brush QV opens the circuit of the electromagnetic control valve |2| which deenerglzing cuts off the supply of quenching fluid from. the quenching head 81. Control segment QD now moves into contact with its associated brush element QD connecting the free side of line I06 to said brush and thereby completing the energizing circuit of operating magnet N8 of polechanger switch I I3 which magnet upon energizatlon moves the switch 3 to the left to connect the motor 9| through extension conductors |28 to the line IIlIi for reverse movement to effect downward movement of the spray head 81 to the lowermost position as indicated in Fig. 9 of the drawings. When the spray head ill reaches such lowermost position, the segment QD moves out of contact with the brush QD' opening the circuit of magnet H8 which permits the pole-changer switch I I3 to move into open circuit position, deenergizing motor 98. The length of the segment QD is so proportioned in relation to the speed of the motor SI and the speed of the controller 563 as to effect this deenergization of the motor when the quenching head 87 reaches its lowermost position. Any known or other suitable means, not shown, may be provided to enable the quenching head 87! to come to rest in the position shown in Fig. 9 of the drawings without undue shock to the mechanism and without imposing undue load on the motor 9!, such for example as the use of a slipping clutch connection or resilient lost-motion connection between the quench-head tube 86 and the driving motor or by suitable selection of the electrical characteristics of the motor. After the segment QD passes from under its brush QD' the locking circuit segment L passes from under its associated brush L opening the locking circuit of relay I09 previously maintained through this segment and the locking contact I26. The initial energizing circuit of relay I09 being open at the push button I25, the relay becomes deenergized opening the connection between conductor H and the free side of line I06 at contact I08 thus removing the line connections from all of the commutator segments except the starting-signal segment S.

The controller thus restored to normal with the various apparatus and circuit elements in the position as shown in Fig. 13 leaves the apparatus in a position with the heating coil in the upper pressure chamber 18 clear of the muzzle of.the gun, and the quenching head 81 in the lowermost position as shown in Fig. 9 of the drawings out side and clear of the breech of the gun. The gun thus heat-treated is now free to be removed from the machine after release from the various clamping and holding elements such as the arms 20 and 2'! and the centering clamp IT.

A gun so treated is shown in Fig. 12 of the drawings where the heat-treated portion near and including the inner surface of the bore is indicated at I29.

During upward movement of the heating coil 10 closely followed by the quenching head 81, quenching fluid is kept out of contact with the coil or the clearance space between the coil and the bore of the gun by means of the separating piston member 88, leakage of quenching fluid beyond the piston through the slight clearance between the piston and the Walls of the gun bore being prevented by the presence of the inert gas under pressure in the spaces above the quenching head and by the downward pasage of such gas through the clearance betweenthe separating piston 88 and the walls of the gun bore. Any

.gas passing out through the quenching fluid outlet conduit 48, (where a liquid quenching fluid is used) may be separated off from the liquid by the liquid trap Illl (Fig. l).

Inasmuch as the heating coil '10 is initially energized for its upward movement through the barrel of the gun before entering the breech of the gun and is maintained energized after leaving the muzzle to insure an even treatment of the gun barrel throughout its length, it is desirable to maintain the elctrical characteristics of the heating coil substantially constant during such movement and during its complete time of energization. This is to insure that the energy output of the coil will remain substantially constant throughout its passage through the gun barrel and during its energization while outside of the gun barrel in either the upper or lower terminal chambers, and it is for this purpose that the low reluctance laminated inner wall or linings l9 and '55 are provided for the upper and lower terminal chambers llil and l i, respectively. Preferably such low reluctance elements are arranged to maintain the inductive reaction of the heating coil l0 substantially constant throughout its travel from the lower terminal chamber to the upper terminal chamber, ,or othewise affect such reactance to prevent undesirable change in power factor due to removal of the coil from the surrounding low reluctance material of the gun.

While I have herein shown and described a preferred embodiment of my invention for the sake of disclosure, it is to be understood that the invention is not limited to the specific embodiment shown and described, but contemplates all such variants and modifications thereof as fall fairly within the scope of the appended claims.

What I claim is:

1. In a heat treating apparatus, a work support, a high frequency electro-magnetic induction heating head normally positioned at one end of the work support and a quenching head normally positioned at the other end of the work support, separate means for moving said heating head and quenching head along the length of work positioned in the work support, means for supplying said heating head with high-frequency power including a circuit breaker, a source of high frequency current connected with said circuit breaker and a switching transformer having a primary winding connected to said circuit breaker and a secondary winding connected to said heating head, said windings normally being out of transformer relation, and automatic means adapted to sequentially cause said heating head and quenching head moving means to relatively move said heads toward each other then cause said circuit breaker to close, said windings to move into transformer relation and said heating head and quenching head moving means to move said heads together in the same direction while supplying electric heating current to said head, and thereafter to cause said circuit breaker to open and said transformer windings to move out of transformer relation and said heating head and quenching head moving means to relatively move said heads to their normal positions.

2. In a progressive heat treating apparatus having a heating coil provided with an electrical heating circuit, switching means for energizing and deenergizing said heating circuit and means for moving said coil, a quenching head, means for supplying quenching medium to said quenching head and means for moving said quenching head; a separate electrical control device for each of said switching means, said coil moving means,

- therewith; and control device operating circuits connected to said source of energy and including,

a secondary pair of contacts adapted to be closed by the energization of said relay coil and series of pairs of closable contacts, each pair of said series of contacts being in series with said secondary pair of contacts and a predetermined one of said control devices; and timing means for closing and opening said starting contacts, holding contacts and pairs of closable contacts in prearranged sequence and cyclically repeating said sequence, said starting contacts being adapted to be closed for a brief interval at the beginning of each cycle and said holding contacts being adapted to be closed substantially With said starting contact and opened only after substantial completion of each cycle but prior to reclosing of said starting contacts.

3.,Apparatus for heat treating elongated objects comprising a frame, means for holding an object to be heat treated, a heating head, means for moving said head relative to the object to be heat treated, means on said frame-for guiding said head during its movement, a movable quenching head normally spaced from said heatreciprocable heating head, an axially reciprocable quenching head for directing a stream of quenching medium against the workpiece, said heads normally being in axially spaced apart relation to clear the ends of the workpiece to be heat treated as held in said work support, said heads being movable lengthwise of the workpiece .portion to be heat treated, sequentially, first, relatively toward each-other into end engagement with each other adjacent one end of the workpiece portion to be heat treated, then, together while engaged for the length of the workpiece portion to be heat treated and, finally, relatively away from each other to, said normally spacedapart relation, means for supplying heating energy to said heating head and quenching medium to said quenching head during the movement of said heads'when engaged, a first motive means for reciprocating said heating head, a second motive means for reciprocating said quenching head, and means automatically con trolling said first and second means to-efiect said sequential movements,

5. Apparatus for heat treating by electromagnetic induction, the surfaces of elongated workpieces hardenable by heating and quenching, comprising a work holder for securely holding the workpiece to be heat treated, relatively axially movable heating and quench-discharging heads normally spaced apart a, distance greater than the length of the workpiece tobe heat treated and being constraine to coaxial alignment with the workpiece to be heat treated as held in said work holder, said heating head havinga heatingcoil and said quench-discharge head having a discharge nozzle, a plurality of motor means for iirst axially moving one of said heads into predetermined adjacent end relation with the other with said coil and nozzle in predetermined axially spaced relation and for then effecting relative axial progressive movement between said work holder on the one hand and said heads on the other hand, and means for supplying electrical energy to said heating head and quenching medium to said quench discharging head during such progressive movement whereby to progressively heat and quench the peripheral surface of such workpiece.

6. In an apparatus for progressively heat treating the inner surface of a hollow workpiece by heating and quenching, a heating head, a quenching head for discharging a stream of quenching medium against the workpiece surface heated by said heating head, a separate supporting arbor for each of said heads extending axially therefrom in a direction opposite to the direction in which the supporting arbor for the other head extends, said heads being normally spaced apart a distance greater than the length of the workpiece to be heattreated, one of said heads being movable axially within the hollow of the workpiece substantially into engagement with the other head adjacent one end of the workpiece, and means for effecting relative movement between the workpiece on the one hand and the substantially engaged heads on the other hand in a direction to progressively heat treat the workpiece longitudinally from said one end, said quenching head having a quenching medium supply passage extending through at least a portion of the length of its supporting arbor.

7. Apparatus for heat treating by electromagnetic induction, the surfaces of elongated workpieces hardenable by heating and quenching, comprising an inducing head, a quench discharging head coaxially alined with said inducing head and normally axially spaced therefrom, a work holder for holding a workpiece to be heat treated between said heads with the surface thereof in axial alignment with said heads, motive means for axially moving one of said heads into abutting end engagement with the other of said heads, separable complementary means on said heads for constraining said heads to axial alignment when engaged with each other, and motive means for effecting relative axial .progressive movement between the workpiece as held in said work holder on the one hand and said heads on the other hand while engaged with each other.

8. In a progressive heat treating apparatus having a heating head provided with a heating coil, a heating circuitfor said coil and switching means for energizing and deenergizing said circuit, a quenching head normally axially spaced from said heating head and having a discharge nozzle, a source of quenching medium supply for said nozzle and means for connecting and disconnecting said nozzle and supply source; a work holder for normally holding a workpiece to be heat treated between and in coaxial alignment with said heads; a plurality of motive means for efiecting a first relative axial movement between said heads to position one head contiguous the other, adjacent one end of the workpiece held in said work holder with said nozzle and coil inD determined axially spaced relation, a second relative axial movement between the workpiece, as held in said work holder, on the one hand and said heads in said contiguous position on the other hand and a third relative axial movement of one head away from the other to said normally axially spaced position; a separate electrical control device for each of said switching means, quenchdevice circuit having a control-device switch therein connected in series therewith and with a predetermined one of said control devices: and c an automatic means for closing and opening said control-device switches in predetermined sequence to efiect said first movement prior to energization of said heating coil and the supply of quenching medium to said nozzle and to effect said second movement during energization of said heating coil and the supply of quenching medium to said nozzle.

9. In an apparatus for heat treating a surface of an elongated workpiece, axially aligned spaced arbor-s, a heating head fixedly supported by the longitudinally innermost end of one arbor, a quench discharge head fixedly supported by the other arbor, said heads being normally spaced apart a distance greater than the length of the avenue workpiece to be heat treated and being relatively thereby. at

HOWARD E. BOMES.