US2359273A - Apparatus for heat-treating articles - Google Patents

Description

Sept. 26, 1944. H. E. soMEs APPARATUS FOR HEAT TREATING ARTICLES Original Filed Oct. 18, 1941 5 Sheets-Sheet l [N V ames ATTORNEY fiawarcZli',

Sept. 26, 1944. H. E. soMEs APPARATUS FOR HEAT TREATING ARTICLES Original Filed Oct. 18, 1941 5 Sheets-Sheet 2 II '-IIIIIIIIIIIIIIIIIIIIIIIIIIIIII'IIIIIIIIIIII INVENTOR 50712425 ATTORNEY HowarcZEZ Sept. 26, 1944.

' H. E. SOMES APPARATUS FOR HEAT TREATING ARTICLES Original Filed Oct. 18, 1941 5 Sheets-Sheet 3 v m m y i 3 i It L Wins 1- z v V i Mm hm A TTORNE Y p 1944- H. ESOMES v 2,359,273

APPARATUS FOR HEAT TREATING ARTICLES Original Filed Oct. 18, 1 941 5 Sheets-Sheet 5 IN VEN TOR Howard Z, James A TTORNEY 1 Patented Sept. 26, 1944 APPARATUS FOR HEAT-TREATING ARTICLES Howard E. Sonics, Detroit, Mich, assignor to Budd Induction Heating, Inc., Philadelphia, Pa., a

corporation of Michigan Original application October 18, 1941, Serial No.

415,580. Divided 1942, Serial No. 453,780

4 Claims.

This application is a division of my application Serial No. 415,580, filed October 18, 1941.

This invention relates to an apparatus for heating a workpiece and has for an object to provide improvements for obtaining a simpler and more convenient apparatus as well as a better product.

A further object is to provide an apparatus for heat treating elongated articles such, for example, as oil well casing pipe constructed and arranged to occupy a minimum of space.

Heretofore it has been customary in machines of this type to provide a construction in which such parts as the induction head, supporting arbor, transformer and associated parts have been arranged in a straight line resulting in excesslve length of machine. In vertical constructions this excessive length may be of secondary importance, but in constructing a machine for operating horizontally the space required becomes prohibitive. Accordingly, a still further object of this invention is to provide an apparatus for horizontal operation in which the parts are so organized as to eliminate the usual straightline" construction with consequent saving of extensive floor space.

Referring to the drawings:

Fig. 1 is a side view of the apparatus, apart from the control valves and the like which are not shown.

Fig. 2 is a longitudinal section showing th transformer connections to the supporting arbor.

Fig. 3 is a section on the line 3-3 of Fig. 1.

Fig.4 is a section on the line 4-4 of Fig. 1.

Fig. 5 is a section on the line 5-5 of Fig. 3.

A workpiece such, for example, as a long section of pipe 30 of the type used in oil wells and lines is adapted to be gripped by a workholder within the enclosure 3| so that the inner surface of an end portion of the work may be heated by electromagnetic induction and hardened by prompt quenching with water or other appropriate cooling fluid. The workholder in theembodiment illustrated is slidable on the spaced guides 32 only one of which is shown for cooperation with an inducing head 33 which is shown as fixed on the supporting arbor 34, the head being supplied with high-frequency alternat ng current from the transformer within the casing 35. This transformer is similar in construction and operation to that shown and described in my prior application Serial No. 392,867, for Heat treating apparatus filed May 10, 1941. Within the upper portion of the housing to the right of the transformer housing in Fig. 1 are located a plurality of relays 36 which are reand this application August 6,

sponsive to a timing and sequence controller 31 located below them. Below the sequence controller are a number of capacitors for the usual purposes, such as improving the power factor of the inductive load. The two small circles shown to the left of the sequence controller are indi cating lights for the operator. The three knobs or buttons shown to the left of the capacitors in Fig. 1 are for manually starting and stopping the repeating cycles of operation, the lower one being for starting the automatic time controlled cycle of operations while the top one is for stopping. The intermediate knob is a manual control whereby the heat may be manually turned off the inducing head. The entire apparatus shown in Fig. 1 is illustrated as being mounted on a cast iron bed or frame. On top of the enclosure 3| is an electric motor 4| for rotating the workholder and work during the heating and quenching operations to assist in obtaining uniformity in heating and hardening. An oil pump 42 located on the side of the enclosure 3| is driven by a suitable motor 43.

As described in my parent application Serial No. 415,580, a quenching nozzle 45 is located on the supporting side of the inducing head 33. The work holding mechanism for clamping the end of the workpiece 30, together with the means for feeding it into position to be treated by the inducing and quenching nozzle, are also fully set forth in mysaid application and, therefore, are not described herein. The operation is such that the workpiece, the end of which is shown in dotted lines in Fig. 1, is moved to the right toward the inducing head at a relatively fast rate until the end of the workpiece is adjacent the inducing head in position to start the heat treating operation. This relative translation between the inducing head and work takes place by movement of the entire workholder upon the guides 32 while the head 33 remains stationary. Further movement of the work to the right during the heat treating operation in which the end of the work surrounds the inducing head is at a relatively slow speed suitable for the heat treating and quenching operations. In addition to this translation of the work for sequentially heating, the work and its holder are rotated to obtain greater uniformity of heating and hardening. After being heated, the water or other quenching fluid is forced out of the quenching nozzle 45 so as to be directed away from the inducing head and under pressure sufficient to push the quenching liquid out from the space between the supporting arbor and the work into the protecting hood 10, from which it drains into the sump 1 I. From the sump the quenching fluid may be filtered, cooled and used again. The casings i2 and I3 enclose thrust bearings and driven gears, respectively, as pointed out in my patent application.

After the heating operation, the workholder 3I is moved to the left to return the work to the starting position illustrated in Fig. 1. As indicated in dotted lines in Fig. 1, pistons 14 on the guides 32 are fixed to cause sliding movement of the cylinder I5 in the workholders which are only of slightly larger diameter than the guides 32, fluid pressure being supplied to one side or the other of the piston head 14 for moving the workholder in one direction or th other. At each end of the cylinder are shown elongated heads I8 and 19 which constitute bearing portions for supporting the workholder, and which also contain packin not shown, to prevent leakage of the operating fluid from the cylinder 25. The guides are fixed within end supports 80 and 8| to which they are suitably keyed to prevent longitudinal movement of the guides. The amount of pressure fluid for operating the workholder on the guides is accurately controlled from the timing and sequence mechanism 31 through valves, not shown, and a source of fluid pressure, also not shown. Oil lines 9! and 93 convey lubricant from and to the oil pump 42.

The supply of quenching fluid to the nozzle 45 is controlled by a valve which in turn is controlled from the timer and sequence mechanism. Immediately upon cutting ofi the supply of quenching fluid, compressed air is supplied through the quenching liquid passage to the nozzle in order that the compressed air may blow all quenching liquid particles off the work with the result that no one peripheral portion of the work should be cooled unevenly with respect to another by longer contact with the quenching liquid. The compressed air thus serves to dry the work and to further cool the work according to the temperature of the air used. The drying of the work by compressed air may be due to and the rapid evaporation from the air current alone or assisted by residual heat in the work, or both. The temperature of the air blown over the work after cutting off the quenching liquid may be as cool as is desired, even to the extent of having air refrigerated to sub-normal temperatures. On the other hand, if no further cooling or chilling of the work is desired, it is possible that air might be heated where slow cooling. of the work is desired. The supply pipe I00 conveys quenching liquid and then, after the liquid cut-off, supplies the compressed air or other gas to the quenching nozzle.

An insulated or ungrounded portion of the inducing, head supporting arbor IOI, is connected to a clamp as shown in both Figs. 2 and 4, comprising a split collar I03 having a stem I04 threaded into the lower end of an inner transformer terminal I05. A grounded arbor portion I 06 formed by separate spaced sections is connected to a clamp I01 comprising spaced split collars I08, one connected to each section, and an annular collar I09 electrically connected to an outer transformer conductor! by means of a sleeve I I3 fitting within the collar I00 and extending upwardly into sliding engagement with yielding fingers II4 connected to the outer contransformer connections the arbor portion pass through the supports I48 and I49. As shown in Figs. 2 and 3, the arbor portions or conductors MI and I06 extend into the adjacent enclosure for connection to capacitors 30 shown also in Fig. 1, the outer arbor conductor I06 engaging contacts I20 of the capacitors and the inner conductor IIII projecting beyond the end of the outer conductor and engaging contacts I! I. The cooling liquid for the inducing coil i supplied to the liquid passage I22 through a connection I23 and is discharged through the inner insulated passage I24 and connection I25 (Fig. 3). The tubular secondary windings of th transformer receive cooling fluid through a supply pipe I40 and discharge it through a discharge pipe I shown in Fig. 4. The secondary terminal blocks I42 and I43 are electrically connected to the transformer secondary terminals I05 and II3. Likewise, the tubular primary winding which is electrically connected to a suitable source of high-frequency current by contact I44 and I45 receive cooling fluid through a supply pipe I46 and discharge it through a. discharge pipe I 41. As pointed out in my application 415,580 and in others, the primary transformer is vertically shiftable for the usual and well-known purposes.

As the work is moved from left to right in the portion of travel marked on the drawing of Fig. 1 as Slow travel, the sequence controller actuates the current controls for supplying inducing. current to the head 33. When the work is heated to the desired axial length, adjustable stops cause the fluid pressure to be cut oil" from the translating cylinders I5, stopping the relative movement between the work and the inducing and quenching heads. The work is next caused to reverse its direction and move from right to left.

Where the work is of such character that further heat treatment may be desirable, but without hardening, the inducing coil may be again energized by the sequence controller. Preferably the travel from right to left as shown in Fig. 1 is more rapid than the slow travel of the work during the hardening period. For this purpose, it has been found that travel of the work at about double its speed during the hardening period will be suflicient .to enable the same frequency and current conditions in the inducing head to heat the work as much as is desired, but to below a hardening temperature.

A described in detail in my said application, all operations except the insertion and removal of the work are normally automatic in response to operation of the timing and sequence controller. The one end of the work, frequently in the form of a considerable length of pipe, is moved into the workholder. The workholder then grips the work tightly, after which the motor for rotating the work may be started or this motor may be continuously operated. After the work is securely held, it is moved toward the heating head at a speed of about 12 inches per second until the control mechanism slows the movement of the ductor H2. A sleeve H5 of insulation separates the inner and outer transformer conductors. and a similar sleeve IIB separates the grounded and ungrounded arbor portions IOI and I06. From the work to about one inch per second throughout the length of the portion to be hardened. As the end of the work comes adjacent the inducing head, the high-frequency circuit through the inducing head is closed. During the heating operation travel of the work is from left to right in the drawings. When the quenching nozzle comes adjacent the heated portion of the work, quenching fluid is ejected under pressure, the pressure of the fluid causing the water to move away from the heating coil. When the desired length of work has been heated, the current through the inducing coil is stopped while the quench continues until the full length work that is heated has been quenched and hardened. Immediately upon cessation of the quenching liquid, compressed air is ejected from the quenching nozzle to blow any residual liquid out of the work. After the full length of the work to be hardened has been so treated, relative travel between the work and inducing head ceases and translation or the work in the opposite direction, .to the left in Fig. 1, begins. Substantially simultaneously with initiation of the movement of the work away from the inducing head, the inducing current is again turned on. In order that the reheating may be to a temperatur below that needed for further hardening, the withdrawal travel of the work is preferably at a speed 01' about 2 inches a second,

' or approximately double that of the speed when heating the work to a hardening temperature.

This rate of withdrawal contemplates the inducing current and frequency being about the same as was used for hardening, but with the greater speed the same energy input is spread over a greater area. This reheating may or may not be used. After the work has been moved from the inducing head its original rapid travel of about 12 inches a second is resumed to the end of the stroke when the gripping portions release the work, enabling it to be withdrawn from the workholder and a new workpiece inserted. The timing mechanism is usually adjusted to give the operator ample time to withdraw and replace a 2. In a heat treating machine, an induction heating head, a supporting arbor for said head, said arbor including inner and outer concentric current-conducting members insulated from each other, said outer member comprising two sections spaced longitudinally from each other, one of said sections and said inner member being connected to said head, a transformer having primary and secondary windings, said secondary winding having its axis disposed at right angles to said arbor, inner and outer current-conductin elements insulated from each other and coaxially electrically connected to said secondary -winding, means within the space between said outer arbor sections securely clamped to said inner arbor member and rigidly connected to said inner current-conducting element for electrically connecting said last-named member and element, a collar surrounding said outer currentconducting element and having spaced clamps securely clamped to said outer arbor connections to electrically connect said sections to said outer element, capacitor means having terminals, and electrical connections between said inner arbor member and the other of said outer arbor sections.

3. In a heat treating machine, an induction heating head, a supporting arbor for said head,

, said arbor including inner and outer concentric current-conducting members insulated from each other, said outer member comprising two sections spaced apart longitudinally, one of said sections and said inner member being connected to said head, said inner member projecting beyond the other of said sections, capacitor means having terminals, an electrical connection between one of said terminals and said other section, an electrical connection between the other Though only a single form oi the invention is illustrated and described, the invention is not .limited thereto but may be embodied in various forms as desired. As various changes in consaid arbor including inner and outer concentric current-conducting members insulated from each other, said outer member comprising two sections spaced'longitudinally from each other, one

of said sections and said inner member being connected to said head, a transformer having primary and secondary windings offset from the axis of said arbor, inner and outer concentric current-conducting elements insulated from each other and connected to said secondary winding, means within the space between said outer arbor sections electrically connecting the inner arbor member with the inner current-conducting element, means electrically connecting both said outer arbor sections with said outer current-conducting element, capacitor means having terminals, and electrical connections between said terminals and said inner arbor member and the other of said outer arbor sections.

of said terminals and said inner arbor member, a transformer having a secondary winding ofiset from th axis of said arbor, inner and outer current-conducting elements insulated from each other and connected to said winding, a rigid electrical connection extending between said inner element and said inner arbor member between said outer arbor sections, and a rigid electrical connection between said outer element and said outer arbor sections.

4. In a heat treating machine of the electromagnetic induction type, a supporting frame, a horizontally disposed arbor supported by said frame, said arbor including a current-conducting member and a pair of longitudinally spaced current-conducting sleeves surrounding and insulated from said member, an induction heating head supported at one end of said arbor and electrically connected with said member and one of said sleeves, capacitor means supported by said frame adjacent the other end of said arbor and electrically connected with said inner member and the other of said sleeves, a transformer having a secondary winding, spaced laterally of said arbor and having its axis aligned with the space between said sleeves, inner and outer concentric current-conducting elements insulated from each other and electrically connected with said winding, an electrical connector connecting each of said sleeves with said outer element, and an electrical connector within the space between said sleeves connecting said inner arbor member with said inner current-conducting element.

HOWARD E. SOMES.

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