US1689876A - Best available cop - Google Patents

Description

Oct. 30, 1928.

E. S. JEFFERIES APPARATUS FOR ELECTRICALLY HEATING METAL BARS 2 Sheets-Sheet Filed Dec. 19, 1921 Oct. 30, 1928.

E. S. JEFFERIES APPARATUS FOR ELECTRICALLY HEATING METAL BARS Filed Dec. l9;-1921 2 Sheets-Sheet :13 h 3 Q *q ripe;

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UNITED STATES 1,689,876 PATENT OFFICE.

ERNEST s. JEFFERIES, or HAJYIILTON, ONTARIO, C NADA; AssIGNoR or ONE-'IHiRD To EBENEZER A. W. JEFFERIES, or WOR E ER, MASSACHUSETTS.

APPARATUS FOR ELECTRICALLY HEAT II GYMETAL BARS.

Application filed December 19, 1921. Serial No.'523,502.

My invention relates to apparatus for heating metal bars and, has for its object to provide an improved apparatusof'the class described whereby metal bars, billets, rods, and the like may be quickly and economically heated by the passage of an electric current 'therethrough, preparatory tothe performance of some operation, such asreducing or forming, upon the'bars while in a heated condition." Further objects of my invention are'to provide an'apparatus of the above described type whereby'the inaterial can be conveniently handled prior to its being heated, and whereby the heated material may remain in the apparatus with a minimum loss of heat therefrom prior to its removal from the apparatus for the-performance of further operations thereon.

These, and other advantageous features of my invention will hereinafter more fully appear, reference being had to the accompanying drawings in which,- i'

Fig. 1 is a view in side elevation of a heating apparatus embodying my inventionl' Fig. '2 is a plan. view of the apparatus shown in Fig. l.

F ig. 3 is'a view in side elevation showing a portion of the apparatus shown in Fig 1 on an enlarged scale. I

Fig. 4 is a view in end elevation of the parts shown in Fig. 3.

. Fig. 5 is a transverse sectional view along the line 5, 5 of Fig. 1, looking in the direction of the arrow.

Fig. (3 is an enlarged view of a portion of the parts of Fig. 3 showing the details of one of the electrodes. v

Fig. 7 is a sectional view along the line 7, 7 of Fig. 6.

Like reference characters refer parts in the different figures.

Referring to the Figs. 1 and 5' of the drawings, the apparatus generally comprises a frame which consists of spaced longitudinal. side members 1 which are supported above the ground or floor by upright members 2 and are tied'together by cross members, 3. Plates 4 are carried by the side members 1 and the. cross members 3 and constitute the bottom of a generally trough-like structure, the sides oi which are provided by the vertical flanges of the side members 1.

As best shown in Fig. 5, a layer of blocks or bricks 6 composed of some suitable reto like fractory material', "'suehas fire clay is arranged so as to-completely fillthe trough described above and to provide-a smooth surface generallyfrectangular in form. A A

second layer Qf'refractory bricks 7 is then arranged'upon the bricks 6, on'eiside of each 'brick' 7, except the right end brick 7, being provided Withan inclined surfacefS. "The bri' cks 7 are spaced apart'with the inclined "surface 8 of-one brick facing the vertical'jside of the next-bric'k so as to'p'royide a series of open chambers 9, each having an inclined surface on one side thereof and Witlrthe' bo'ttoms' of the chambers formed bythe' e-xpose'd top surfaces 10 of the bricks 6. 'A third layer'of'bricks C11 is arranged upon the bricks the underside of each brickl l, except-the left hand end brick '11, being provided with a beveled surface 12" which overhangs a chamber -9 bQtw'eentlie brieks' 7. *Thebricks 11 are spaced apart so 'asgto leave exposed a .portion of the top surface of each brick-7 adjacentto the beveled surfaces 8. In this way, chambers 13 are left between "the bricks' ll which communicate with thefchambers" 9 between the bricks 7;

' A' fourth layerof bricks 14 is arranged upon plates 15 covering the bricks 1-1 and each brick 14, except the left hand 'e'nd brick 14, is provided with a beveled surface 16' overhanging a chamber 13. The bricks 14 are spaced apart in somewhat the same manner as the bricks 11, thus leaving a portion of each plate 15 exposed," adjacent to the edge of each chamber 13. The chambers 17 thus provided between the bricks 14 communicate with the chamber-13.] The side walls of the chambers 17 are covered with plates 18 and the tops of the bricks 14 are covered with plates 19. The'bricks G, 7, 11 and 14, in the several layers. are secured together by means of bolts 20 extending between the side members 1 and the top plates 19.

From the foregoing. it isapparent that when all of the bricks 6, 7, 11 and 14 have been arranged and secured together as described. they provide in efi'ect a rectangular block of. refractory material having a series of parallel chambers 9, 13 and 17 extending longitudinally therethrough, each series of chambers being otlset with respect to the other series of chambers.

Referring to Figs. 1 and 2, the bricks 6, 11 a i -.1 a s .ac apart at in er a to mend?" & .it' tv fi wil il i i ei 5. s 21 extending substantially at right angles to, and intercepting the chambers 9, 13 and 17. A plurality of arms 22 are located in each of the slots 21 and are mounted in spaced relation on shafts 23 extending longitudinally of the frame 'below'the side members 1. As best shown in 1 and 5, each shaft 23- is provided at a point intermediate its ends \v,itl 1 .a. roclrer arm 2s that is eonnected by a rod 25 to one arm 26* of a bell crank lever 26, 'all ogf the levers 26 being mounted in spaced relation on a shaft 27 estending across ,theframe between one pair o f zupright members 2;: The flower arm.

26"v eqf each lever 26 is. connected by K3.- rod 28 ;to one gar-m 29 ,of .a bell {crank lever 29. As best shown in Fig. 4, the crank levers 29 are {mounted in spaced relation en a :shaft 30 extending across the frame between a Pa of br ce Sl RP T Q y th uprigh members 2. The upper anrn 29 of each lever 29 --is provided with a gfoot treadle 32 by means of which the lever 29 be opera-ted, as will be hereinafter described.

, As-best shown in Figs. 1 and 5, .a plurality of electrical [bus bars 33 ,are supported below the bottom plates ii ef ,the frame by means of insulators 34 suspended from the cross members-3. The bus bars33 are arranged in pairs spaced :apart at their -;e nds and the adjacent ends of each 'pair ogf biis bars ;are connected to the terminals of -a suitable source :of electrical energy, such as a transformer35, by .meansof cODQlRCh-Jislyfi.

As best shown in Fig. ,3, the outer-ends of each pair of bus bars 33 are bent upwardly and extend into chamber 37 provided in. the ifire brick structure atthe ends of the chamber 9 and '13. The bus bars33 arepreferably formed of separate .lami-nations, .so that the portions which are bentupwardly possess a certain amount of inherent resiliency, as will be hereinafter referred to. The upper end of each 'bus bar 33 terminates in a cap :or head 38 which, as best shown in Figs. 6 and 7 is grooved *to receive a plate 39. The plate 39, in turn, carries an electrode 10 which is preferably ccn'iposed of some heat resistant conducting .n'iaterial, such as tungsten or carbon, having a higher melting point than the material which is to be heated in the furnace. Each plate 39, together with its electrode 40, is removable from the head'38 so that an electrode .may be readily removed or repaired, as \nill be hcreinaftcr pointed out.

Each heat 38 is, secured between a pair of arms 41 pivotally supported below the chamber 37 on a bracket 42. The brackets 42, at each end of the frame are supported in spaced relation on a cross-member 43 formed of some suitable insulating material, such as wood. A sector 4-1 is mounted to turn freely onthe shaft 4,591? eacl'rpair of arms 41, and 'rinwi l q' was p rt fa' ei te t fi i' A bar 47, pointed at one end as indicated at 48, is pivotally connected at its other end to one arm 49 of a bell crank .19, and the pointed end 48 of the bar 47 normally rests in engagement with the teeth 4t. The other arm 4'9" of'the bell crank it) is connected, by means of an arm {r0 the end of the shaft 23 which carries one's et of pusher arms 22. Each shaft .23 is similarly connected at 'its en s tea Pe 'pt bars 4? ach pa r carries a stop P t nrovld es h -152 @4 extending set senewha, Each liead 38 further cons a d o the ti eke c IY slew f a link 57,, the length of the link 57 between its mie se MY-std wrne ia b g ntial-lythe sauaiees thelength of each varrn between its pointslof pivotal connection t w the .head and to thehracket 42 respectiyely, for a purpose {to he hereinafter described. Each hea d 38 further provided witha lug 58 within which is slidable a push-off 59,, the lower end of which is connected to the sectorij ll by means of a. link so that the push-off 5 9 is {movable by the sector 44 parallel to the face .of'thc electrode 40, as will be hereinafter described.

Having thus described the various parts entering into my invention the operation thereof is as follows :The ars, billets, or othenpieces .of l'natenial which it is desired to heat, are first cut into lengths -xvhi'ch are slightly greater than the lengths of the chambers 9, l3, and l7, and are then plac d on top of the plates 19, as indicated at 51 in 5. flhe operator .or operators, as the case may be, then push a bar into each top chamber 17, so that the several bars will rest on .the exposed portions of the plates 15, which, together with the plate 18, protect the bricks 11 and 14 from injury. A bar havingbeen thus seated in-each of the chambers 17. the operators then depress caclrof the bell cranks .29 by means of the foot treadles 32, thereby causing the shafts 23 to be'turncd in a clockwise direction. The several sets cl pusher arms .22 then move in the slots .11 toward the. bars 51, one of which is seated in each of the chambers 17. \Vhcn the arms 22 engage the bars 51, the latter are pushed off of the plates 15 into-the chambers 13, but are caught on shoulders 22 provided on the arms 22 before they reach the exposed portions of the fire bricks 7. In this position the foot treadles-32 are fully depressed, so that the arms 22 are at the end of their movement to the right.

At the same time that the arms 22 are the direction'of the arms -41.

moved to shift the bars as described above, the turningv of the shafts 23 causes the several'bars 47to'be' simultaneously moved in This movement of the bars 47 causes the pointed ends 48 to engage'the teeth 46. and thereby turn the sectors 44 'in opposite directions. This turning'movement is imparted to the several pairs of arms 41 when the members 54 of the sectors 44 engage the setscrews 56, thereby moving the heads 38 at the ends of the bus bars away from the open ends of the cha m-. bersfl3. This movement ofth'e heads 38 allows the'ba'rs 5 1ft'o enter the chambers 13 witheut'engaging the electrodes 40, The operators then release the foot treadles '32 whereupon .the heads 38 tend to return to their'originalposition y reason'of the inhereiit' res iliency of. the bus bars '33, which will always tend to returnto their original form. fThe arms 11 thereupon move toward thee'nds' of the chambers 13 and it is obvious that movement will cause the shafts 23 to be'tur'ned in a counter clockwise direction.

The arms 2 will then move to the left in the slots 1an'd in so doing will deposit thebar's 51,: which are seated on the shoulders 22,fon' the'e'irposed portions 'of'the bricks 7 in the ehambers 13, the bars being deposited lightly sothat the bricks will not be damag ed, occurs, the electrodes {10wil l engage ';th e projecting ends 'of the bars, "so that each bar is firmly held between the electrodes40 in the chambers 13 by r'eason off-the inherent '1fesiliency of the laminated conductors. When the heads 38 are moved away from or toward's'the bars, as described above'fthe electrodes 40- are 'alwaysimaim tained ina vertical position by reason of the parallel motionfprovided by the arms 41' and links'57, consequently the bars will always squarely engage the electrodes 40. I

As "soon as the electrodes 40 engage the I ends of'the .h'arsf51, electric current will fiminediatelyfstart to flow through the bars 51,

inasmuch aseac h bar completes the circuit between each pair of electrodes 40. The current flow will ofcourse depend upon the voltage of the source of supplyiand the cross sectional area of the bars, and it obvious that the voltage can be so regulated as tocause a flow o f current of suilicient strength to heat each bar 51 throughoutits length, such heating being uniform'in character. When the bars 51 have reached the desired degree of heat the operators move another set of bars from the plates 19 into the chamber 17 and again depress the foot treadles 32. -When thisoccurs the arms 22 are moved as before,

whereupon the bars 51 in the heating chambers 13 will be engaged by those portions of the arms 22 below the shoulders 22, and will be moved to the right until they reach the beveled surfaces 8 of the fire bricks 7. The heated bars will then slide down the surfaces 8 "until they reach the surfaces 10 bus bars before' the heads 38 are moved.

This prevents the bars from sticking to the electrodes 40,and reducesarcing to ami'ni mum. 5'

Just after thefheatedbars51are engaged by the arms .22, below the shoulders 22?, the cold bars 51 which are located in the chambers 17,"will be removed therefrom by the arms22, as previously describedfand will deposited at the bottoms'of the chambers;

13 upon the return movement of the arms 22, following the release of the'foot treadles,32. The above described cycle of operation'sb'an becontinued as desire d'and' it is apparent that the .bars will be successively seated in a cold condition in the chambers 17, then heated 'in'the chambers 13, and finally deposited, iii a'heated condition, in'the chambers 9, from which they may'be'r'emoved as desired for further operations thereon, such for example as drawing or forming. I

It is obvious'that fafter a number of bars have been heatediin thec h a'mbers 13,"and

after. a 'number' of heated bars have'b'een passed through the'. chambers 9, the Walls of the chambers 9 an'd'13will become heated to, such'anextent,that'therewill be no a preciablef loss of heat shouldthe bars he allowed to lie in'the chambers 9 for'any length of time, owing to the fact .that these chambers'are surrounded by thick layers'of fire brick and the only entrance'ther'eto is through the rather tortuous "passages provided between the several sets of chambers. Furthermore, the walls of the chambers 13 will retain a considerable amount of heat so that the amount of current required for heating the bars will become less and losses the furnace'heats up. Furthermore, it is apparent that ample provision is made for protecting the fire brick surfaces of the chambers 17, into which the bars fall by gravity. In the case of the chambers 13 however, the use of protective plates is-impracticable, owing to the fact that the bars must be supported by insulating material while passing the current therethrough, but it is obvious that damage to bricks in these chambers will be prevented by the fact that the arms deposit the bars without shock in these chamberson their return movement in the slots 21.

The arrangement whereby the ends of the bus bars are distorted from their normal shape, to permit the entrance of the bars ing that the ends of the hairs will squa rcly engage the electrodes. Thebars are prcvented n-om stickingto the elec titodes lQbyoperation of the 59., thus reducing arcing and wear on theelecti'odes to a minimum, Lastly the monnting of each electrode 40 on a I plate, is separiately re.- nqiable ifro i iits hBQd 38i liietili t ready relac ment, .orjrcp aiij, of the'jeleetrodes and also ma s i a'e a flm use at Q ly 'sliia 1 amount of material iorieacli electrode; which is of considerable importance ivhlli 'e atiyjee ii i i've metal is'ehfl'flojedlidf th electrodes. While I have shown any invention its simplest referred iorin, zit obviolns that it'fls u pti le f kneel ,mediifi a and I desire tliereforefthatj only limitations bedmposed on invention as may come' the SCOPQe .Of the appended c ai'ms. 1 J

'I'clairni I 1 I 1. apparatus of,the(class desciiibed,',tl1e combination with :a Theater providing" Stepped .eliambei 'fdi receiving material, ef in, eieq r ls e ate t 69 6 i cha n'- EI a m e s Q ,l V i g-- l lwi v fi W rd 1dr .aivay'ir'e'm e een Qf, sa d-ma a 12'. lnia-p paratu'slef theclass described, the combination with"a 'lieater providing an enclosed ,stepped'chamh'ei .for deceiving maa nr ie i i 'yend e and 9 said chamber,' of, a 'InQYziblef electrode for engaging the ,projectiIiL end pisa dmaierin;

3, In apparatus of the class described, the combination with a heater providing an enclosed chamber and relatively movable electrodes located outside of said chamber,

of means for moving material into said chamber? with its ends between said elec trodes.

4. In apparatus of the class described, the combinationwith a iheater-p'roviding an enclosed chamber? and a. movable electrode located outsideof said chamber, of means for moving material into said chamber and for simultaneously causing ,said' electrode to engage one end of said n'iaterial.

In apparatus of the class-described, the combination with a heater providing an enclosed chamber and relatively movable electrodes located outside of'said chamber, of means for moving said electrodes away from each other to permit apiece of material to be received in said chamber in a downward direction.

teem

(1, LI]! apparatus oi the glass described, the (gunibiizuiion with a heater providing an enclosed chamber and relatively lnOVabl Q eleciizodes located at the endsvof said chamber, of means for moving said electrodes away i om each other to permit a piece of material .to he received in said chamber in a downward direction, and fiurther means for causing said 'iclect od es .to 4 engage the ends of [the material after the latter. has been seat e d insa id chamber. i v I i In apparatus of the class described, a furnace provided with a stepped heatingql ia nhca an d yieldable electrodes ,pi'ovided, at the ends vof saidchambeit, electrodes being movable toward and aw y mil ii h.

8. In apparatus of the class descfibedi a furnace p ovided with a ste lidjfliatingchamber, inherently resilient e ctiqd epmi ided at ,the'ends' of said chambe and means for eausi g relative 'mbw menc lof said '9. In apparatus of the class described, the combination with a f urnzi'ce providi ng anenclosed chamber for receiving'materia'lnnd an electrode movable toward Q amj nbm said material,' of means for separating said electrode from .said material in advance of its movement away from said .rnaterial. In apparatus of the class described, thecombination with a 'iilrna'ce an enclosedichamb'er; for receiving and an electrode ,moizable towa id or from'said materialnof means ,nioyab le'ind Peride l of said. ee od ifj r' Sl p said inater'ial therefrom,

llJIn' apparatus, f the class described,

the' combination with affur'nce providing an enclosed chz'imber' for suppertingafrod and a movable el ectrode' a speed to make contact with the end of said we; of -means tor lifting said rod out of contact with said electrode in advance of move nent'of said electrode away fromsaidmater'ial. Y 12. In apparatus of the class described the combination with a furnace providing an enclosed chamber for supporting a'irod and a movable electrode adapted to make contact with the end of said rod of means operable independently oi sa'id electrode for lifting said rod out of contact therewith.

13. In apparatus of the cla ss described; a conductor lniving a bent portion terminat ing in a head pivotally supported on a novable arm and means for maintaining said head in a vertical position when moved by saidtarm. I

i4. In an electricheater having a heating chamber for .long bars a heating circuit adapted to be completed by a bar in said chamber and .means in said chamber for maintaining the bar in a heated condition upon removal of the bar from the circuit.

15. In an electric heater, a heating chamher for long bars and a heating circuit adapted to be completed by a bar in said chamber, the said chamber being so constructed as to enclose the bar and maintain it in a heated condition following its removal from the heating circuit.

16. In an electric heater, a heating chamher for long bars adapted to support a bar in a number of separated positions, a heating circuit adapted to be completed by a bar in one of its positions in the chamber, and means for removing a heated bar from the heating circuit to a position in said chamber in which the bar is maintained in a heated condition.

17. In an electric heater, a stepped heating chamber for long bars adapted to support a bar in a number of separated positions, one above the other, a heating circuit adapted to be completed by a bar in one of its positions in the chamber, and means for removing a heated bar from the heating circuit, whereupon the bar moves by gravity to a position in said chamber in Which the bar is maintained in a heated condition.

ERNEST S. JEFFERIES.

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