US1769407A - Electric heat-treating apparatus and process - Google Patents

Description

G. B. AMES July 1, 1930.

Filed Nov. 1927 INVENTOR.

G. B; AMES July 1, 1930.

ELECTP HEAT TREATING APPARATUS AND PROCESS 'BZiled Nov. 8, 1927 INVENTOR.

ATTORNEY Patented July 1, 1930 UNlTED'STA'l-ES PATENT OFFICE em 2. ms, or BROOKLYN, mzw Yonx, Assmxon no m: are a. means, or m ELECTRIC HEAT-TREATING APPARATUS AND PROCESS Application fled November 8, 1m. sci-m1 Io. 231.015.

My invention com rehends the continuous heat treating o traveling wire, rod

' and like metallic strip material in two successive stages by first progressively heating successive short sections thereof and thereby effecting a reliminary heating of the material and t en passing an electric current through a longer section of the strip which includes a plurality of the preliminarily heated short sections. One of the special adaptations of my process is the continuous treat ment of a traveling strip of flexible shafting for the purpose of making it more perfectly and uniformly flexible, decreasing its internal friction and rendering same uniform throughout its length. By the use of my improved process flexible shafting will be produced which will have longer life and will run with minimum external friction with respect to its sheath, when so mounted, and without any irregularities of movement such as would cause jumping of the needle of an indicating instrument operated by such shafting, etc.

Reference is hereby made to the accompanying drawing illustrating an apparatus suitable for carrying out the process of my invention in which:

Fig. 1 is a side elevation partly in section of the improved apparatus;

Fig. 2 is a diagram of the electric wiring;

Fig. 3 is a plan view of the apparatus of Fig. 1 the cover of the quenching bath tank being partlv broken away;

Fig. 4 is an end view of the apparatus of Fig. 1 partly in section;

Fig. 5 is an isometric "iew of the water circulatory system detached from the rest of the apparatus;

Fig. 6 is a section of the frictional driving means, and p Fig. 7 is a detail viewshowing mounting of hollow shafts.

The apparatus shown consists of a body or frame 1 for supporting the various parts of the ap aratus and isso placed as to receive from apparatus Aa continuous line of flexible shaftiug a. The particular form of ap paratus A shown forms the the subject matt r f an appli ation of Innis H- rial N 0. 209,205, filed July 29, 1927, allowed, December 27, 1929.

In my improved device there is a driving sprocket 2 adapted to be driven by a similar sprocket b mounted on the drive shaft e in t e apparatus A above referred to. The sprocket 2 is loose upon the shaft 3 and is pressed by a coil spr ng 4 against a leather friction disk 5 which abuts against a disk 6, the latter having a hub 7 which is keyed to the shaft 3 as shown. Lock nuts 8, 8 and washer 9 on the end of the shaft 3 providefor adjustment of the degree of friction between members 2, 5 and 6 forming the clutch.

The shaft 3 is provided with a worm for engaging with worm cars 10, 10' which are mounted upon fibre s eeves l0" fixed to the hollow shafts 11 and 12 respectively. The hollow rolls 13 and 14 are carried bv said shafts and may be integral therewith. These rolls are provided with grooves 15 adapted to receive the flexible shafting a. Three of such grooves are shown upon each roll. They are of different sizes so that the apparatus is capable of handling flexible shafting of three different diameters and, of course, by using different rolls other sizes could be handled in the same apparatus. These rolls by their rotation constitute means fornrogressing the strip of shafting through the apparatus.

The hollow shafts 11 and 12 are journaled in sleeves 16 and the latter are inserted in i'ournal boxes 17 mounted between upper and ower pairs of coil springs 18 which abut against upper and lower insulating plates 19 carried by the housing 20. Additional insulating plates 19 are also mounted in said housing.

There are two additional hollow shafts 11' and 11" respectively which are driven by Worm gears 10', 10" and provided with rolls 13 and 13" which are similar in all respects to mll 13 and there are also hollow shafts 12', 12" driven by worm ars and provided with grooved rolls 14' and 14" which are the same in all respects as the shaft 12 and roll 14. The hollow shafts 11" and 12" are driven through their respective worm gearsby the worm shaft 3' which is driven from shaft 3 by means of a sleeve 21 secured to on the shaft 3 and having a splined connection with shaft 3'. The shafts 11', 12 and 11" and 12 are respectively mounted in sleeves 16 and journal boxes 17 similar to those previously described and the same are spring mounted and insulated from the housings 20 and 20 in which they are respectively supported. Means are provided for adjusting the housing 20 in a horizontal direction toward and away from the housing 20 so as to vary the distance between the rolls 13', 14' and 13", 14". The adjustment shown consists of the screw 21 threaded in the lug 22 formed integrally with the top plate 23 of frame 1. The end of said screw is grooved and engages the-screw 22' threaded in said housing 20", and the latter is slidably mounted upon the top plate 23 and retained against dis lacement by longitudinal guides 24.

fter leaving the rolls 13", 14 the wire shafting a will enter a quenching bath such as oil contained in a tank 25 suitabl supported at one endby frame 1 and at t e opposite end by the upright 26. There is a .guide or conducting the line of flexible shafting a into and out of the quenching bath. This guide consists of a tube 27 the ends of which are bent upwardly 'so as to extend above the level of the bath into suitable positions for receiving the shafting a from the tem ring apparatus and for dlsposing of it a er its passage through the bath. The central portion of the guide is cut away at the bottom as shown in Fig. 1 for the purpose of giving the quenching medium access to the shafting. Means are provided for effectively cooling the grooved rolls 13, 13, 13", and 14, 14'

and 14", and also the uenching medium in the tank 25 and in or or that a minimum quantity of the cooling medium may be used means are provided to cause the water to flow through the apparatus as shown in Fig. 5, the arrows indicating the water inlet and its path through the hollow shafts 11, 11'. 11" to quenching bath, returning by way of shafts 12", 12 and 12 to the outlet. It will be seen that the entire system forms a single path for the water whereby its full heat absorbing capacity is taken advantage of. The hollow shafts 11 and 12 are electrically insulated with respect to the shafts 11 and12' which latter are also insulated with respect to theshafts 11" and 12" and for this reason the pipes c for conducting the flow of the cooling medium to and from each of these shafts will be rubber tubing, L shaped stuffing boxes 28 being used for making the angular turns.

In order to effect the heating of the flexible shaftmg for the temperin operation means are provided for the app ication of electric current to the res ctive pairs of ved rolls 13, 14, 13', 14' and 13", 14" whic means are diagrammatically shown in Fig. 2 as follows: The line wires 31 and 32 are adapted to be connected to the wires 33 and 34 respectively by an automatic circuit breaker 35. The arrangement is such that the circuit breaker will be thrown and the line wires disconnected when the coil 36 is ener zed. This will occur whenever the contact 3 carried on the pivotal arm 38 en ages the fixed contact 39 (carried by the hous1ng 20) There is a roller 40 on one end of the lever arm 38 which constitutes a weightand normally holds the lever in such position that 37 and 39 will be in contact thereby making it impossible for the circuit breaker to remain closed. When the flexible shafting a, however, is threaded through the apparatus it will support the roller 40 in an elevated position as shown thereby openin the circuit which includes contacts 37 an 39 and permitting the circuit breaker 35 to be closed to supply current for the tempering operation.

This current is obtained by the ener 'zing of a regulating transformer 41 throng the current regulator 42 which applies the line wire voltage to the various windings of the transformer primary in accordance with the needs of the apparatus. The current necessary for tempering varies with the size of the shafting which is being acted upon and the apparatus shown is well adapted for meeting the requirements throughout a large range of service. The line wires may supply alternating current at various voltages and requencies, for example 220 volts cycles. There is a stepdown transformer 30 having a primary winding 43 and two secondary windings, viz: a high tension winding 44 and a low tension winding 45; One end of the high tension winding is connected to the rolls 13" 14" and one end of the low tension winding 45 is connected to the rolls 13, 14 and there is a common return co to rolls 13', 14'.

The conducting cables or leads 46, 47 and 48 which connect the secondary windings of the transformer 30 with the respective hollow shafts carrying the rolls 13", 14", 13', 14' and 13, 14, are provided with terminals 53 to which are secured by bolts 54 the clamping plates 50, Fig. 4, and the latter are held in frictional engagement with the up r and lower shafts b means of threaded Its 51 and nuts 52. he transformer 30 is capable of suppl current at a voltage of approximately 3 v0 ts between the roll airs 13, 14 and 13', 14', and of 14 to 15 v0 ts between the roll pairs 13', 14' and 13", 14".

In the operation of the device, after threading the flexible shaftingg throu h the apparatus and starting the wing aft 3 to effect the feeding thereof the current will be so regulated b means of the regulator 42 as to bring the s afting to the desired temthe short stretch of shafting between the rolls 13 and 13' is subjected to preliminary heating obtained by passing a heavy current therethrough which will be diflerent for difierent sizes of shaftin For shafting having a diameter of t e current may be from 200 to 250 amperes at 2 to 3 volts. The distance between the axes of the rolls 13 and 13' may be varied as well as the speed of travel of the strip of shafting. In the apparatus shown such distance is approximately 2 A," and the rate of travel of the strip has been as low as 4 feet per min. and as high as 7 feet per min. The current does not bring the shaft-ing to a red heat on account of the chilling effect of the rolls and cooling medium within the same, but it breaks down any irregularities which may be present and which would otherwise prevent the shafting when subjected tothe current for tempering from being brought to a temperature uniform throughout its length, that is, free from underheated or overheated spots or portions, which if they occurred would affect the uniformity of flexibility of the finished product throughout its length.

Upon leaving the roll 13' the strip of shafting a as it travels from roll 13 to roll 13" is subjected to a current which also will vary with the size of the shafting, its speed of travel and the distance between the rolls. The strength of current will be so adjusted by means of regulator 42 and adjusting screw 21 as to cause the shafting to assume the color a which will be recognized by the operator as giving the correct temperature for the tempering of the shaft. The shaft when first produced (of steel wire) will ordinarily have a greater degree of temper than is desired and my proces is therefore in most cases a detemperingv operation. I have found that desirable results may be obtained by bringing the shaffing to a blue color by means of a current of approximately 100 amperes and 14 to 15 volts. In the ap shown the distance between said rolls 13' and 13" can by adjustment range from approximately 9 to 12 inches.

The transformers h oapd 30 are so designled' as to sup current any amperage esired at th s voltages mentioned which are suitable'for diafting of ordinary sizes which mayvaryfrom b'to "orevenlarger. By use of the regulator 42 and mechamcal adjustment 21 any desired heating 1s readilyobtained. The after leaving the rolls 13" and 14" enters the quen bath b r W tbfi d8 tube andatthefarendof tankinfinishedcondition.

WhileIhavepartiullarlyillustratedand myinvmfionwithmferemetothe continuonsheatlnatmmtofflexible shafting,itisnnnifesfl yusefulforheattreafing continuous lengths of material for other pur poses, such as continuous heating of bars, wire and like material for bending, forging, or heading, hardenin tempering, etc.

Having now descri ed my invention what I claim is:

1. The process of heat treating wire, rod and like metallic strips in continuous lengths as said strip material is traveling consisting in progressively heating the same by passing an electric current through successive short sections and thereby effecting a progressive preliminary heating of the material, and thenpassing an electric current of difierent strength through a longer section of the strip which includes a plurality of the preliminarily heated short sections, thereby developing a desired higher temperature in the advance portion of said longer section.

2. The process of heat treating wire, rod and like metallic strips in continuous lengths as said strip material is traveling consisting in progressively heating the same by passing an electric current through successive short sections and thereby effecting a progressive preliminary heating of the material and then passing an electric current of less density per unit of cross sectional area through a longer section of the strip, the length of said last named section being such as to develop a desired high temperature.

Inwitness whereof, I hereunto subscribe my signature.

GLEN B. AMES.

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