US2316683A - Apparatus for loading sheathed wire heating units - Google Patents

Description

APPARATUS FOR LOADING SHEATHED WIRE HEATING UNITS Inventors: Frank E.. Finlagson, Edwin C. Chapman,

Their' Aitor-heg.

April 13, 1943.

F. E. FlNLAYsON ETAL. 2,316,683

APPARATUS FOR LOADING SHEATHED WIRE HEATING UNITS Filed Sept. 23, 1940 5 Sheets-Sheet 2 mn, w sa n saam r r\P o @mm t HFC JM C. Cw mmm Wm w T ma uw FE 5 .D x --15 \\w// L. 56 M w April 13, 1943.

' F. E. FINLAYSON ETAL.

APPARATUS FOR LOADING SHEATHED WIRE HEATING UNITS Filed sept. v23, 1940 :s sheets-sheet 5 Pdal-1k EC Twagson, wm apman,

hen 'Attorrla 5 Sheets-Sheet 4 F'. E. FINLAYSON ET AL.

Filed Sept. 23. 1940 APPARATUS FOR LOADING SHEATHED WIRE HEATING UNITS IHHMMIMIMUT --.lwwwiL April 13, 1943.

hwenfcovs'. Frank E. Fm lagson,

Edwin C. Chapman, b5 www@ Their Attovvreg.

April 13, 1943. F. E. FINLAQS'ON mi. 2,316,683

APPARATUS FOR LOADING SHEATHED WIRE HEATING UNITS Filed Sept.. 25, 1940 5 Sheets-Sheet 5 Fi .18. 1g li v 'g 1; a f7 e g i E /50 Z/O /77 :H I A L 205 o i G g? k-1 i 206 'l 5 1 2/5 /w/ z/s 2,/4 j g l2 /64 2/2 64 l i z/ 1 L 2/6 /63 t :i E

/64 w l 20a l El 0 l 2l@ z/ zag 222,3 2/9 Inventors; Frank E.T-`inla1son, Edw'ln C. Chapman,

Tnein Attorney.

Patented Apr. 13, 19.43 I

uNlTEDfsTATEs PATENT OFFICE APPARATUS FOR LOADING SHEATHED WIRE HEATING UNITS Frank E. Finlayson, Ontario, and Edwin C. Chapman, Upland, Calif., asslgnors to General Electric Company, a. corporation of New York Application September 23, 1940, Serial No. 358,0'18 10 Claims. (Cl. 226-23) IThis invention relatesto electric heating units anisms and to provide means Vwhereby the conofthe sheathed type and has for its object the nection between the cam mechanism and the l provision o1' improved apparatus for loading loading mechanism may be manually broken so heating units of this character with a suitable as to stop the oscillation of any one of the sepainsulating material. 5 rate loading mechanisms without interfering with This invention has particular application to the operation of the remainder. electric heating units wherein a helical resistance It is a further object of this invention to proconductor is encased by the sheath and is emvide new and improved means by which a single bedded in and held in spaced relation with the I driving motor may be employed 1'01 driving the sheath by means of an electrically insulating, cam mechanism at one speed and the supporting heat conducting, refractory material such as powtable at a greatly reduced speed.

dered magnesium oxide. One heating unit of It is a further object of this invention to prothis character is described in United States Patvide a new and improved multiple unit loading ent No. 1,367,341, issued February l, 1921I on an l f apparatus which is relatively simple in construcapplication illed by Charles C. Abbott. tion and easily and eilicently operated by which It is an object of this invention to provide an sheath type heating units may be properly loaded improved loading machine oi' this character in with insulating material at a more rapid rate. which a plurality of `separate loading .mecha- Additional objects and advantages of this innisms are mounted on a single rotatable table vention will become apparent as the following which is rotated so that the separate loading description proceeds and the features of novelty mechanisms come successively before the operwhich characterize this invention willbeset forth ator for removing the loaded units and mounting in the Claims appended to and forming a pari? 0f the unfilled units whereby the operator can sit this specicati'on. comfortably in one position before the machine In accordance with this invention, there is proand by having the necessary parts, such as the vided a new and improved multiple lOdiIig appasheaths-and coil assemblies, placed conveniently ratus having a rotatably mounted supporting at hand can work at a high emciency. table. Provided on this table is a plurality of It is va further object of this invention to pro! separate loading mechanisms which are adapted vide an improved loading apparatus having a to be rotated with the table so that the mechaplurality of separate loading mechanisms al1 of 30 nisms pass in succession before a station at which which are fed from a single storage bin or hopper the operator stands. The supporting table is for the insulating material. adapted to be driven by suitable means and the v It is a further object of this invention to pro- Speed 0f rotailiOn iS adJilSted S0 that a Single unit vide new and improved loading mechanisms for mounted in one of the loading mechanisms will use in such multiple loading apparatus, said load- 3 be completely loaded in approximately the time ing mechanisms being constructed and arranged required by the table t0 make approximately so that everything is cleared from the front of three-quarters of a revolution. Centrally arthe mechanism which can interfere with the ranged with respect to the loading mechanisms mounting of aunit to be loaded thereon whereby is a hopper or storage bin from which the powthe sheath and heater coil may be simply and 40 dered insulating material is supplied to each of quickly mounted in their loading position on the the separate loading mechanisms. 'I'he individindividual loading mechanisms. ual loading mechanisms comprise means for It is a further object of this invention to .proholding the sheath of a sheath type heating unit vide new and simpliiled means for starting and in a substantially upright position and means for stopping the loading operation in accordance holding the heating element which is located with the position of the centralizlng member of within the sheath in proper relation to the the loading mechanism. sheath. Both of these means are adapted to be It is a further object of this invention lto proreleasably secured to the loading mechanism so vide new and improved means whereby units that in the event of the sticking of a portion of which have become stuck during the loading the loading mechanism in the sheath during a operaton may be quickly and readily removed loading operation the entire assembly may be from the machine to correct the difficulty. removed from the mechanism and cleared. With It is a further object of this invention to prothe sheath and heating unit mounted in their vide s' single cam mechanism for causing the proper position, means are provided for feeding oscillation of each of the separate loading mechto the sheath the powdered magnesium oxide at a regulated rate. A centering device, called a centralizer, is arranged to be inserted within the sheath to hold the portions of the resistance element in the center line of the sheath while it is being loaded. This centralizer is driven with a reciprocatory motion up and down in the sheath as the insulating material is being fed thereto by oscillating means. In accordance with this'invention new and improved means are provided for driving both the supporting table for the loading mechanisms and the oscillating means for the loading mechanisms from a single driving motor. Improved means are provided for controlling the flow o! insulating material to the sheath in accordance with the position of the centralizer in the sheath. Also simplified means are provided for stopping the reciprocatory movement of the oscillating means at any time during the loading operation.

For a more complete understanding of this invention, reference should be had to the accompanying drawings in which Fig. 1 is a fragmentary front elevation, partly in section, of a multiple loading apparatus arranged in accordance with this invention; Fig. 2 is a fragmentary side elevation of the apparatus shown in Fig. 1; Fig. 3 is a fragmentary top view of the apparatus shown in Fig. 1 with the base and motor drive removed; Fig. 4 is an enlarged fragmentary front elevation showing details of the upper portion of one of the individual loading mechanisms mounted on the multiple loading apparatus shown in Figs. 1-3; Fig. 5 is a view similar to Fig. 4 with parts removed to show details of the upper portion of the oscillating mechanism for single loading mechanism; Figs. 6,-7, 8 and 9 vare sectional views taken through the lines 8 8, `I-1, 8--8 and 9 4, respectively, of Figs. 4 and 5 and looking in the direction of the arrows associated with these lines; Fig. 10 is an enlarged fragmentary front elevation showing details of the middle portion of one of the individual loading mechanisms mounted on the multiple loading apparatus shown in Figs. 1-3; Figs. 11, 12 and 13 are sectional views taken on the lines II-I I, I2-I2 and II-Il, respectively, of Fig. 10 and looking in the direction of the arrows associated with these lines; Fig. 14 is an enlarged fragmentary front `elevation showing details of the bottom portion of one of the individual loading mechanisms mounted on the multiple loading apparatus shown in Figs. 1-3; Fig. 15 is a side elevation of the portion of the apparatus shown in Fig. 14; Fig. 16 is a sectional view taken on the line IB-IB of Fig. 15 and looking in the direction of the arrows; Fig. 17 is a detail view showing details of the latch mechanism for latching the oscillating mechanism out of contact with its operating means; Fig. 18 is an enlarged fragmentary sectional view of the base of the apparatus shown in Figs. 1-3 showing details of the driving and oscillating mechanism arranged in accordance with this invention; and Fig. 19 is a fragmentary elevation, partly in section, of a finished heating unit of the type to which this invention is particularly applicable.

Referring to the drawings, this invention has been illustrated in one form as applied to apparatus for loading electric heating units of the sheathed type, such as described in the abovementioned Abbott patent. A heating unit of this type has been illustrated in Fig. 19; this unit comprises a helical resistance element I encased by a metallic sheath II. Suitable terminals I2 are mechanically and electrically connected to the drical pedestal I1.

ends of the resistance conductor I0. For this purpose, the resistance conductor is threaded on the terminals, as shown, and as fully described in United States Patent No. 1,494,938 to C. C. Abbott, dated May 30, 1924. The resistance conductor I0 is embedded in and is held in spaced relation with reference to the sheath II by a highly compacted mass I3 of heat conducting, electrically insulating, refractory material, such as powdered magnesium oxide. The powdered magnesium oxide is compressed into a dense compact mass in any suitable way as by reducing and elongating the sheath. The mass of insulating material I3 functions to hold the resistance element III in spaced relation with reference to the sheath, preferably so that its axis coincides with the axis of the sheath. It also functions to conduct heat from the resistance element III to the sheath. The inner ends of the terminals I2 are embedded in the powdered insulating material I3, as shown, so that they are insulated from the sheath I I and are heldin spaced relation with it by means of the insulating material.

This invention relates to a new and improved multiple loading apparatus for loading heating units of the aforementioned type with the powdered magnesium oxide material. This apparatus comprises a base plate I4 mounted upon suitable legs I5. Mounted on the base plate is a driving motor I8, the function of which will be described more fully hereinafter, and a cylin- Rotatably mounted on the upper surface of the pedestal II is a substantially circular frame or table I l. Suitable ball bearings IO are provided for allowing practically frictionless rotation of the frame I8 relative to the pedestal.

The rotatable frame or table is adapted to support the remainder of the superstructure of the loading apparatus shown in Figs. 1 and 2. This superstructure includes a plurality of separate loading heads or mechanisms which are adapted to rotate with the table I8. Details of the individual loading mechanisms will be described more' fully hereinafter. In the specific form of my invention illustrated, ilve such individual loading mechanisms are mounted on the table I8 but it is to be understood that this invention is not limited to any specific number of such separate mechanisms.

Supported at the upper end of the superstructure by means of bracket 20 and centrally arranged with respect to the separate loading mechanism is a bin or hopper 2| in which is stored the powdered magnesium oxide. Extending outwardly from the bottom of this hopper is a plurality of conduits 22 for feeding the magnesium oxide to the separate loading mechanisms and provided at the top of the hopper is a removable cover 23. In order to insure the free flow of the magnesium oxide through the feeding conduits 22 there is mounted on the lower end oi' the hopper an electric heating coil 24. This heating coil 24 is sufficiently large to heat the magnesium oxide and drive off any moisture which might tend to form lumps in the insulating material near the outlet of the hopper. Provided at the extreme lower end of the hopper is a drain tube 2l which is closed by a cap 2l. By removing the cap 26 it is possible to empty the hopper completely if the machine is to be shut down for any length of time. Also the tube 25 permits access to the bottom of the hopper for the purpose of removing or breaking up any obstruction formed near the lowerend thereof.

asiaessf Referring to Fig. 3, it-will be observed that the individual loading mechanisms are symmetrically spaced about the hopper and since these mechanisms as well as the hopper are all supported by the table l5, they will rotate as the table is rotated. y

In general, the individual loading mechanisms mounted on the rotating table i3 are similar` to the type of loading mechanism described and claimed in the copending application of John L. Andrews, Serial No. 347,446, filed July 25, 1940, which is assigned to the same assignee as this invention, and which discloses and broadly claims certain features disclosed in this application. However, in accordance with this' invention, improvements have been made in the type of loading mechanism there described and claimed with a view to obtaining a simpler and more easily operated loading mechanism Awhich is specially suited for use in the new and improved multiple loading mechanism of this invention.

Referring now to Figs. 4-15, it will be observed that the improved individual loading heads or mechanisms of this invention comprise two vertlcally extending lower supporting plates and 21 (Fig. 14) which are secured to the turn-table il by means of bolts 28. Secured to the upper end of these plates by means of suitable machine screws 29 is an upper vertically extending supporting plate 30. Mounted on the upper end of the plate 30 is a member 3| (Figs. 4 and 7). Provided on each of the edges of the upper supporting plate is an outwardly extending guide orflange 32 and provided ln each of these flanges is a groove 33. hereinafter, these grooved flanges serve as guides for a movable carriage. As shown in Fig. 2 the guides 32 extend along the edges of the'plate 30 for over half the length of the plate. ,'Spaced below the bottom of the left-hand guide and extending down the remaining portion of the lefthand edge of the plate 3U is a third guide flange 34 which extends downward below the lower'edge of this plate, as shown in Fig. 14, and is secured near its lower end to the supporting plate "by means of the bracket 35 and bolt 35. As shown in Fig. 14 the guide flange 34 is provided with a groove 31 on each of its lateral faces for a purpose which will be described hereinafter.

Mounted within the confines of 'the giiidesn' is the carriage 38 which comprises a substantially U-shaped metallic member having mounted thereon a plurality fo rollers 39 having flangesA 4l which are adapted to engage the grooves 33 sheath ll which is to be loaded with insulating material. The supporting standard comprises a sleeve member 43 which extends downwardly As will be more fully described jecting collar '43 provided on the 'upper end of the sleeve 43. Located in the recess formed by these telescopically engaging portions of the head and sleeve is a compression spring 43 which serves to bias the head member in an upward direction. Provided on the upper portion of the head member 45 is an upward cylindrical extension which is arranged to be inserted in the lower end ofthe sheath as is clearly shown in Fig. 14. i

The terminal I2 at the lower end of the sheath is supported in its central position with reference to the sheath by means of a suitable head 5I which is rigidly secured to the terminal and is received in a recess 52 bored in the lower end of the sheath. The cylindrical extension 5l is adapted to be received in the recess 52 whereby the lower end of the sheath is centered and held against lateral displacement.

It is, ofcourse, understood that before the heater sheath Il, resistance conductor Il and terminals I2 are inserted in the loading apparatus the resistance conductor will have been secured to the lower and upper terminals l2 and they will have been threaded through the sheath so as to bring the head 5| on the lower terminal into the recess 52 provided in the sheath.

The upper terminal is secured by suitable releasable means (not shown) to a terminal supporting rod 53 which extends vertically upward to the top of the loading mechanism as shown ln Fig. 4. Secured to the top end of the rod 53 by means of set screw 54 is a block 55 having upper and lower head portions and a central portion which is adapted to be received in a recess 55 provided in the upper plate 3| This block is removably held in the recess 56 by means of a latch arm 51 which is rotatably mounted on the upper plate by means of a screw 58. It will be understood that when the latch arm is in the position shown in Fig. 4 the block will be latched in the recess in the top plate and the upper end of the terminal rod will be securely held in position. However, when the latch arm is rotated through 90 degrees, the block 55 may be readily removed from the recess to free the 'upper end of the terminal rod. 4

Arranged to operate around the resistance conductor within the sheath is a centralizing member 59. Referring to Fig. 11, it will be observed that .the centralizing member is substantially cylindrical 4in form and is provided with a series of vertically arranged and clrcumferentially spaced ribs 60 on its outer surface. These ribs are adapted to lengage the inner wall of the sheath ll when the centralizer is inserted there in. It will be understood that a running clearance will be provided between these ribs and the sheath and it will be further understood that through a suitable opening provided in the` bracket 4l and an adjustable central member 44 which extends through the sleeve member and may be adjusted to different positions to accommodate sheaths of different lengths. The sleeve the centraliser ls provided with a central -aperture (not shown) which fits about the helical coil lll. In this way the centralizer rises during the loading of the sheath and maintains the central axis of the coil substantially coincident with the central axis of thesheath.

The centralizer 59 is threaded upon the lower end of a centralizing tube 5l which surrounds the terminal supporting rod 53 and extends upwardly to a point near the top of the loading l mechanism. In order to support the upper end of the centralizer tube,/a plate 62 having a recess 63 is provided on the central portion of the front surface of the carriage 38 as shown in Figs. 4 and 8. Arranged to be received in the recess 53 is a block 54 through which the upper end of the centralizer tube is adapted to extend. This block is provided at its lower end with a split nut construction 65 for rigidly clamping the block to the centralizer tube. In order to support the block removably in the recess 03, there is provided a manually operated latch arm 66 which is similar to the latch arm 51 for the terminal rod and is secured to the plate 02 by means of the screw 61. When the arm 60 is in the position shown in Fig. 4, the block will be latched in the recess and when the arm is rotated through 90 degrees the block may be readily removed from the recess so as to free the upper end of the centralizer tube.

The upper end of the sheath Il is rigidly secured in the apparatus in its proper position with relation to the resistance conductor I by means of a pair of jaws 60 which are pivotally mounted at 68 on a plate l0 which is secured to the front wall of the supporting plate 30 as shown in Figs. 10, 11 and 13. These jaws are provided with a pair of hardened metal inserts 1| which together with the insert 12 mounted in the plate l0 function as abutments for the upper end of the sheath when the jaws are closed, as clearly shown in Figs. and 1l. Below the inserts 1| the jaws will be pnvided with arcuate portions 13 which are adapted to fit tightly about the upper end of the sheath. Gear members H having intermeshing teeth 15 are secured to the lower ends of the jawsto insure simultaneous operation thereof.

In order to move the jaws with a positive snap movement between the fully open and fully closed position, there is provided a snap action mechanism which is similar to that described in the above-mentioned copending Andrews application. This snap action mechanism comprises a pair of over center springs 16 (Fig. 13) which are of the compression type and have their opposite ends bearing on collars Il and 'l0 respectively. The collars are provided with knife-edge slots 19 which receive knife-edge bearings 00 provided on the arms 0I attached to the jaw members. The opposite collars 'l0 are mounted on pivot bearings 02 which are adiustably mounted upon a supporting bracket Il which in turn extends through an opening I4 provided in the plate 30 and is rigidly secured to an intermediate T-shaped plate member 0l which is secured to the plate 10. As shown in Fig. 13, the bracket Il is substantially T-shaped and between its inner end and the plate member 05 there is provided a plate 00 which functions as a stop for the `iaw arms 0| when the jaws are in their fully open position. It is, of course, understood that the pro- Jecting portions of the jaw arms `extend through the openirg 84 provided in the plate 20 so that they may engage the compression springs which are located on the back of the plate.

Referring now to Figs. 1 and 11, it will be observed that the supply tube 22 leading from the hopper 2| discharges into an opening in a member Il which is secured to the rear wall of the plate 30. 'Ihe opening in member 81 in turn discharges into a passageway 80 formed in the plates 30, 00 and 10. This passageway discharges into the jaws 60 directly above the open end of the sheath II. A suitable tongue-like cut-off gate 09 is placed over the mouth of the passageway 0I to control the flow of insulating material to the sheath.

Arranged for operating the cut-ofi gate 09 between its open and closed position, is a cut-oil actuating lever 90 (Figs. 2, 10 and 11) which is pivotally mounted upon the plates B9 and 20 by means of the screw fastening device 9|. The cut-off gate 89 is secured to the actuating lever by means of a block 92 (Fig. 11) which is rigidly secured to the upper portion of the gate and which carries a pin 93 which is received in a slot provided for it in the actuating lever. The actuating lever is biased to move in a counterclockwise direction as viewed inFigs. 2 and 10, that is, in a direction toopen the gate, by means of a spring 94 which is secured at its lower end to the lever as shown in Fig. 10. The other end of the biasing spring is anchored to a pin 05 which is fixed to the supporting plate. An adjustable stop 96 is secured to the left-hand side of the plate 10 (see Fig. 10) to limit the counterclockwise movement of the lever 90 under the influence of spring 94.

The cut-oil' actuating lever 90 is prevented from moving in its counterclockwise direction by means of a latch 91 which engages an abutment 90 formed in the lever. The latch S1 is pivotally mounted on a pivotally mounted actuating arm 99 by means of a stud |00. The latch 91 may be rotated in a counterclockwise direction with respect to the arm 99 but is prevented from turning in a clockwise direction with respect to the arm from the position shown in Fig. 10. A,weight |0| normally biases the latch to its position shown in Fig. 10. The arm 99 is keyed to a pin 02 which extends through the support 30 and has its opposite end rotatably supported in a substantially Z-shaped bracket |03 which is secured to the rear side of the support by means of a bolt |04 (Fig. 12). A suitable spacer |05 is provided to space the arm 00 away from the front surface of the support 30.

The arm 99 is moved to its unlatching position to permit the lever to open the feed gate 09, that is, is moved in the counterclockwise direction as viewed in Fig. 10, by means of a control arm |06 which is keyed to the pivot pin |02 and lies on the back side of the main supporting surface 30 between this surface and the surface of the Z-shaped bracket |03 in which the outer end of the pin |02 is Journaled (see Fig. 12). The arm |06 includes an outwardly projecting portion which projects beyond the left-hand edge of the supporting plate as viewed in Figs. 10 and 12. In orderito cause the movement of the arm Il to take place quickly and with a snap action in accordance with a small movement of the control arm |08 there is provided a compression spring |01 which is similar to the compression springs used for operating the jaws 60 with a snap action. This compression spring is confined between the collars |08 and |09. The collar |08 is provided with a knife-edge slot which receives the knife-edge bearing H0 provided on the control arm |06. 'I'he opposite collar |09 engages a pivot bearing which is adjustably mounted on a flange i|2 secured to the rear side of the supporting plate 30 as shown in Fig. l2. In order to limit the movement of the arm I 00 under the influenceof the snapping spring I 01, a pair of stops H3 and IH are threadedly mounted in a pair of ilanges ||5 and H6 respectively which are mounted on the rear portion of the plate 30 so as to lie on opposite sides of the control arm (see Fig. 11).

When the projecting portion of the control arm |08 is moved downwardly from the position shown in Fig. 10, the arm 99 will be rotated a limited amount in the counterclockwise direction as viewed in Fig.` and this rotation will take place quickly and with a snap action under the influence of the compression spring |01. The extent of the counterclockwise rotation will be suiiicient to move the latch 91 off the projection 98 of the cut-off actuating lever 90 to permit this lever to be moved in a counterclockwise direction, by the spring 94 whereby the gate 89 will be moved to its open position. The extent of the counterclockwise movement of the arm 99 will be limited by the distance between the iixed stops ||3 and ||4. When the operating handle is moved upwardly from'the lower position just described, the arm 99 will be rotated in a clock Wise direction so that the latchY 91 will engage the abutment 98 to hold the lever 90 in the positionin which the gate 89 is closed.

Mounted on the carriage 38 is an outwardly projecting L-shaped plate |1 to which is secured a downwardly extending rod ||8. As shown in Fig. 10, this rod terminates at substantially the level of the gate operating lever 99 and supported at the lower end of this rod is a second carriage comprising the transverse plates ||9and |20 and the vertical plate |2|. The plate |2| lies on the opposite side of the guide 34 from the rod ||8 as shown in Fig. 10. Provided on the lowermost portion of this carriage is a pair of rollers |22 which are adapted to lie on opposite sides of the guide 34 and to track in the slots 31 provided in this guide. Provided on the rod ||8 intermediate the second carriage and the upper end-of -the rod is a pair oi adjustable stops |23 and |24 which are adapted to engage the projecting portion of the control arm |08 so as to cause the arm automatically to be rotated in accordance with a predetermined downward or upward movement of the carriage 38. lThese stops are provided with set screws |25 so V`that they may be adjusted to their proper position on the rod.

Provided on theinner edge of the vertical plate |2| is a cam surface |26 which is adapted to be engaged by a cam roller 21 mounted on the lefthand corner of the cut-off actuating lever 99 as shown in Fig. l0. The cam surface |26 is arranged so that when the carriage 38 is in its upper position, as shown in Fig. 4, the roller |21 cause it to be moved downward whereupon the arm 99 is rotated counterclockwise as viewed in Fig. 10 with a snap action as described above.

This, of course, permits the actuating lever 90 to be rotated counterclockwise to open the gate. As the sheath is loaded with insulating material, the centralizer 59 and the carriage 38 are moved upwardly as will be described below. After a predetermined upward movement, the roller |21 will reengage the cam surface |26 to decrease progressively the now of insulating material into the sheath in accordance with the shape of the cam surface |28 shown in Fig. 10. When the sheath is completely loaded, the carriage will be moved upwardly an amount sufiicient to cause the roller to engage the highest surface of the cam so that the gate is completely closed. The lower stop |23 provided on the rod is positioned so that when the gate has been closed by the cam surface the projecting portion of the control arm |08 will engage this stop and be moved upwardly so as to cause the arm 99 to be moved in a clockwise direction to move the latch 91 to its latch ing position shown in Fig. 10.

Secured to the topY transverse plate ||9 of the guide member 34 to hold the carriage in its upper position. By moving the release handle upward relative to the operating handle, the latch |39 will ride on the highest part of the cam surface v so that the lever 99 is rotated in the clockwise direction. This movement of the lever 99 will, of course, cause the gate 89 to be moved to its closed position and will also permit the latch 91 to move into engagement with the abutment 98 to hold the lever in its latched position. v With the arrangement described thus far. it

` will be seen that during a loading operation the sheath andthe resistance coil I9 are held in their properly aligned relation whereas the cen tralizer 59 and the centralizer Ytube 8| which are connected to the movable carriageY the gate 89 to be open and initiate the flow of insulating material into the sheath. The upper stop |24 provided on the rod ||8 is positioned so that, when the centralizer 5 9 is adjacent the bottom of-the sheath unit being loaded, it will engage the projecting portion of the control arm |08 to means of the nut |4I.

will be moved of! the upper edge |3| of the member 34 so that the carriage is free to move downwardly. This constitutes the first operation in the use of the loading mechanism.

During the lling of the sheath the carriage 38 and the centralizer tube 9| connected thereto are adapted tobe moved with a reciprocatory motion up and down with reference to the frame, the carriage 38 tracking in the guides 32. This reciprocatory movement is transmitted through an oscillating mechanism which is adapted to oscillate in a path parallel to the front surface of the member 39. This mechanism comprises a pair of vertically-extending parallel plates |32 and |33 which are separated by the control member |34. As shown in Figs. 5 and 6, the .upper end of the member |34 terminates a substantial distance below the upper end of the plates |32 and |33 so that a channel portion is defined by the upper plates. Arranged to space the extreme upper end of these plates is a cross bar 39 which is suitably secured to the plates as by means of rivets |36. In order to guide the reciprocatory movement of the upper end of the oscillating mechanism, a slot |31 is provided in the upper end of the supporting plate 3|). Welded to the cross bar |39 is a pin |33 which is provided with a circular member I 39 or increased diameter which is adapted to track in the slot |31. In order to maintain the circular member |39 in its proper relation with respect to the slot there is provided on the outer end of the pin 238 a washer |40 which overlaps the adjacent portion of the back surface of the supporting member 3D. This washer is mounted in position on the pin by Provided in both of the riezar the upper end thereof slots are bearing members |43 which have flat surfaces engaging the flattened side wall of the slot. These bearing surfaces are integrally formed on the upper end of a bifurcated member |44 which lies between the plates |32 and |33 as shown in Figs. 5, 6 and 9. 'I'he bearing members are -provided with a centrally located aperture and extending through this aperture is a shaft |45 upon which is mounted a sprocket |43. Extending around the sprocket is a link chain |41 which is preferably in the form of the ordinary bicycle chain. l

In order to adjust the tension of the chain |41 the bearings for the sprocket are vertically adinstable in the slots |42 provided in the plates. To obtain this adjustment a block |48 is riveted between the plates |32 and |33 and threadedly mounted in this block is an adjusting screw |43 which is provided at its outer end with a dowel that projects into a socket in the lower end of the bifurcated bearing support |44. The adjusting screw |43 is held in its adjusted position by means of a lock nut |50. A suitable opening is provided in the plate |32 so that access may be had to the adjusting screw and lock nut to permit adjustment of the tension in the chain.

In order to transmit the motion of the oscillating mechanism to the carriage, an offset bracket |52 is secured to the rear face of the carriage 33 by suitable means such as rivets |53. This bracket is provided with a recessed opening |54 which conforms in size and shape to a single link of the chain |41 and as shown in Fig. 5 the link l55,of the chain is mounted in this recess.

The construction of the lower portion of the oscillating mechanism is more clearly shown in Figs. l0 and 1l. Referring particularly to Fig. 11, it will be observed that the front and back plates |32 and |33 respectively are secured to the central member |34 near this end by means of rivets |53 and that the rear plate extends downwardly a substantial distance below the front plate. The central member also extends downwardly the same distance as the rear plate and it is provided intermediate the end of the front plate and the rear plate with a recessed portion |51 (Fig. ll). In order to guide the reciprocatory movement of the lower end of the oscillating mechanism there is secured to the rear face of the back plate |33 a U-shaped trapezoidal member |53 on which is rotatably mounted a pair of rollers |58. Mounted on the back wall of the supporting plate 30 is a pair of guide members |33 and |3| which are provided with grooves |32 in which the rollers |53 are adapted to track. It is to be observed that a suitable opening is provided in the supporting plate for receiving the guide roller supporting member |33. This opening is made sufilciently long to permit free reciprocatory movement of the member |53.

Provided on the front wall of the lower end of the centralv member |34 is an L-shaped plate |33. This Lshaped plate and the vroller supporting plate |53 are secured to the plates |34 and |33 by means of the pair of machine screws |34.

In the opening defined by the recessed portion |51 of the central plate and the L-shaped plate |33 there is mounted a lower sprocket |35 and a ratchet wheel |33, which are secured together by means of pins |31 as shown in Fig. 11 and which are mounted to rotate on a shaft |33 rotatably supported in the plates |33 and |33 and |34. A pawl |33 (Fig. 10) is arranged to cooperate with the ratchet wheel |33. This pawl is rotatably mounted on a pawl arm |10 which is pivotally mounted on a bearing member 1| that is mounted between the upper end of the L-shaped plate |63 and the central plate |34 as clearly shown in Fig. 1l. A spring pressed plunger |12 normally holds the pawl from rotating.

With the parts of the oscillating mechanism described thus far, it is to be observed that if the pawl |69 is out of engagement with its ratchet wheel |63, the sprockets |65 and |43 will be free to rotate. Under these conditions, the oscillating mechanism will be reciprocated independently of the carriage 38. If, however, the pawl is moved into engagement with its ratchet wheel, the sprocket |65 will be locked against rotation and hence the carriage 38 and the centralizer tube mounted thereon will be reciprocated with the oscillating mechanism. The pawl |69 is biased by the weight of the pawl lever |10 to move into engagement with the ratchet wheel but is restrained from doing so by means of a cylindrical member |13 mounted on the upper end of the arm 93. This cylindrical member'is positioned to engage an extension |14 provided on the pawl lever as shown in Fig. 10. Thus engagement of the pawl |38 with the ratchet |53 is prevented until the arm 99 is moved in a counterclockwise direction as viewed in Fig. l0 to release the cut-off actuating lever as described above. This movement of the arm 33. as previously described, is controlled by control arm |03 and the pawl |69 will be free to move into engagement with the ratchet |33 so long as the arm 89 is in its non-latching position relative to lever 80 for controlling of the feed of the insulating materiah In order to impart` a reciprocatory movement to the oscillating mechanism described in detail above, there is provided in the lower end of this mechanism a stud shaft |15 which projects outwardly beyond the rear surface of the supporting plate 30. Connected to this shaft is a connecting or push rod |13 which extends downwardly in the direction of the rotatable table I3. Provided in the top plate |11 of the table is an opening through which is inserted a sleeve |13 which is secured to the top plate |11 by means of bolts |13 which pass through flanges |30 formed on the sleeve (see Fig. 18). Provided in the sleeve is a central opening through which passes a follower rod lill. The lower end of the push rod |13 is adapted to be secured in threaded engagement with the follower rod |3| 'and it will be understood that sufilcient clearance is provided between the follower rod and the sleeve to permit the reciprocatory movement of this rod. In order to prevent the insulating powder from interfering with the movement of the follower rod in the sleeve there is provided a corrugated cap |32 which extends over the upper end of the sleeve |13 and engages the rod |16. This cap is made from some suitable resilient material such as rubber. Provided on the lower end of the follower rod |8| is a rotatably mounted follower member |83 which is adapted to engage the surface |84 of an edgewise cam |35 mounted below the surface |11 of the table I8. It is to -be understood that while the details of only one connecting and follower rod assembly are shown in Fig. 18, there will be one such assembly for each of the plurality of separate loading mechanisms supported on the rotatable table.

It is obvious that if the edgewise cam |55 is rotated, the follower rod is reciprocated an plate 21.

`large gears 209 and 2|0.

amount equal to the difference in height between the lowest and highest surface of the cam. This reciprocatory movement of the follower rod `is transmitted through the connecting rod |18 to the stud shaft and thence to the oscillating mechanism previously described.

Means are provided for manually moving the follower rod upwardly an amount sufficient to prevent engagement of the follower |83 with the cam surface |84 to stop the reciprocatory movement of -the oscillating mechanism. This means comprises a bell crank lever |85 (Figs. 14 and 15) which is pivotally mounted on the lower supporting plate 21. This lever is provided with a short arm |81 which is adapted to extend under a stop |88 which is secured to the lower end of the connecting rod |16 by means of a set screw |89. The

long arm of the bell crank is provided with an outwardlyextending handle |90 and mounted on this handle :is a latch member |9I which is adapted to engage the edge of the supporting This latch is biased to its latching position by means of the resilient member |92.

Normally the bell crank lever is in the posi tion shown in full lines in Fig. 15 and when in this position the follower |83 engages the surface |84 of the cam. When the bell crank lever is pulled forward or to the left, as viewed in Fig. 15, to the dotted position shown in this latter figure, an upward force is exerted on the stop |88 and the connecting rod |18 is raised an amount sufficient to move the follower off the edgewise cam. This will, of course, also cause the oscillating mechanism and the carriage mounted thereon to be raised. When the lever is in the position dotted in Fig` 15, the latch member will engage the edge of the support 21 as l shown in Fig. 17, and the connecting rod will be .strap |94 (Fig. 11) secured .to the connecting rod by means of the bolt and nut |95. The opposite end of the vspring is secured to a bolt and `nut |96 provided on a vertically extending bracket |91 which is mounted on the table |11 by means of a bolt 1| 98 as shown in detail in Figs. 14 and 15.

The motor I8 1s adapted to drive both the turntable and the edgewise cam through a suitable speed reducer |99. Considering this construction in more detail and referring to Flgsfl, 2 and 18, it will be observed that there is provided on the base I0 a bracket 200 in which is journaled a shaft which is connected to the speed reducer |99. This shaft is provided with a sprocket 202 which is driven by means of a suitable chain 203 from a second sprocket 20C mounted on the end of the motor shaft.

In accordance with this invention, I have provided improved means for using the single driving mechanism described above for imparting a relatively high speed .to the edgewise cam and a relatively low speed to the table and superstructure. Referring now to Fig. 18, it will be observed that this is accomplished by means of a differential gear arrangement which comprises four small gears 205, 206, 201 and 208 and two Considering this construction in more detail, it will be observed that the cam plate |85 is provided with three vertical outer sleeves 2|2. The central sleeve is adapted to receive a shaft 2I3 which `extends `vertically upward from the speed reducer. 'Extending through -this sleeve and through the shaft mounted therein is a tapered pin 2 Il which `is provided for holding the two in fixed relation. Mounted in the outer sleeves 2| 2 are ball bearing yzrnem- `bers 2|5 in which are `journaled the lshafts 2|5.

Mounted on the lower end of these shafts uare the gears 201 and 208 `and mounted on .the upper end are the gears 205 and 200. The central hub 2|| is adapted to extend upwardly `:above the top of the drive shaft 521|3 `and journaled in this upwardly extending portionof the hub is the large gea!` 2 |0 which is rigidly secured .to thetop plate |11 of the `table I8 `by `means .ofthe `bolts 2I1. The lower gears 201xand$208 are uadapted to mesh with the Vteeth provided `on the "large gear 209 which is `fixed to a'plate'ZIl bymeans of the machine screws `2|9. The iplate `2li iis adapted to be secured in anysuitable manner ato the upper surface of the speed reducer usothat it and the gear secured thereto are fixed. LIn :Jr--4 der to rotatably `Journal the shaft 3243 in the plate2 I8 and the lower fixed gear 209 ,asuitable sleeve .bearing 220 is provided.

In the preferred form of this invention, `the differential gear arrangement described .abovexis designed so that the edgewise cam is driven 4at a rate of about 90 revolutions per minute :whereas the table andthe entire superstructure secured thereto is rotated at the rate of about `one :revolution per minute. To obtain `this speed differential the `upper gears 1205 and i208 .are provided with 20 teeth, the lower gears i201 and 20| with 40 teeth, the rotatable gear l2|0 with 45 teeth and the lfixed gear `209 `with l91 teeth. Thus, the gears 201 and .208 havetwicefasxmany teeth as thegears 205 and 208 and the gear20l has twice as many teeth plusone as the `gear 2|0. Therefore, as the gear 2|0 is driven `and thesmall gears rotate around the movablegear 2|0 and the fixed gear 209, the fixed gear "drops behind one tooth in each revolution and `as the surface uponwhich the small gears are mounted is rotating at revolutions per minute, `which is the speed of shaft 2|3, the upper gear 2|. which is secured to the` turntable will make one complete revolution in approximately one minute. Thus the entire superstructure including al1 of the separate loading mechanisms `mounted thereon is rotated slowly. The speed of rotation of the table I8 is regulated relative to the time required for loading a single unit ,-so that the loading will be completed in aboutthreequarters of a revolution of the table. 1n this way it is assured that a particular unit will be loaded before the loading mechanism again comes before the operator.

Suitable means are provided for applying to the sheath a plurality of intermittent impacting blows to settle the insulating material as .it is fed into the sheath. For this purpose :a vibrator 22| (Fig. 2) is provided. The vibrator comprises a straight plunger hammer 222 arranged 'totap the sheath as shown in Fig. v2. .The plunger hammer is rapidly reciprocated or vlbrated and engages the side of the sheath with intermittent impacting blows. The plunger hammer is driven by means of any suitable vibrating mechanism. The vibrating mechanismfhas not been illustrated in detail for any suitable vibrating mechanism may be used and `thefdetails `of'this mech- .anism form no part of the `present invention. The vibrator 22| is adapted to be flrmlysecured the ratchet to the lower end of the supporting plate 30 as shown in Fig. 2.

In order to strengthen the superstructure at the top. there is provided a substantially circular top plate 223 shown more fully in Fig. 3. This plate is provided with a plurality of peripherally spaced recesses 224 which are adapted to expose a portion of the top of the plate 3| and facilitate the insertion and removal of the terminal rod supporting blocks 55 in the recesses `provided in the plate 3|.

Suitable slip ring means (not shown) are provided for supplying electrical energy to both the heater unit 24 and the vibrator mechanism 22|.

Considering the operation of the improved multiple loading apparatus forming this invention, it will be assumed that the machine is ready for operation and that the motor I6 is running. It will also be assumed that the carriage 38 is in the uppermost position as shown in Fig, 4 and that the latch |30 is in engagement with the surface |3| of the guide rod 34 as shown in Fig. 10. In this position, the lower stop |23 has caused the control arm |06 to be snapped upwardly so that the arm 99 has been moved clockwise and the pawl |69 is out of engagement with |68. This allows the oscillating mechanism to oscillate up and down freely under the action of the edgewise cam |85 and the connecting rod |16 without in any way affecting the position of the carriage and the attached centraliaer. as previously described.

Theoperator now slips a sheath up over the centralizer 59 and fastens the top terminal l2 of the coil assembly to the supporting hook (not shown) provided in the centralizer. The operator then draws the sheath down over the coil I so that the head 5| of the lower terminal l2 is received in the recess 52 so as to close the lower end of the sheath and also so as to anchor the center of the lower terminal with reference to the sheath. The lower end of the sheath will then be placed upon the head 46 so that the pro jection i0 on the base is received within the reoesa l2. rThe upper end of the tube is then placed in its proper relation in the jaws 63 and these jaws are snapped closed. This completes the assembling of a particular heating coil and sheath in a particular loading mechanism.

The operator next grasps the handles |23 and |23 and moves the handle |29 so that the latch |33 is released. 'I'he carriage assembly is then lowered until the centralizer nears the bottom of the tube. At this point, stop |24 which has been previously set, engages thecontrol arm |06 and snaps it down. This causes the lever 99 to be snapped in a counterclockwise direction and this rotation of the lever causes the pawl |88 to engage the ratchet |63 starting the entire assembly attached tothe carriage 38 including the centralizer to oscillate up and down. At the same time the lever 39 trips the gate controlling the now oi' insulating materialand allows the powder to start flowing into the tube. Suitable switch means (not shown) will next be actuated to cause the vibrator to be energized. The switch means may be either manually actuated or actuated in accordance with a predetermined movement of the carriage 38,

As the carriage 33 and the centralizing tube secured thereto are reciprocated up and down, the centralizer lil will be intermittently carried into engagement with the insulating material, the level of which is continually rising in the sheath. The centralizer will engage the insulating material on each stroke providing the level has risen high enough to permit the centralizer to contact it. When the centralizer engages the level of the insulating material, its downward movement and hence the downward movement oi the centralizing tube and the carriage 38 are resisted. This effects a momentary release of the carriage 33 from the oscillating mechanism for when the downward movement of the carriage is resisted the chain |41 tends to cause a counterclockwise movement of the ratchet |66 which movement is permitted by the relative relation between the ratchet and the pawl |69. On the next stroke the carriage will oscillate about the new level found by the centralizer. This produces a progressively upward movement of the carriage and centralizer as the filling of the tube takes place.

It will be understood that as the centralizing tube rises in the sheath during the filling operation, the ribs 60 on the centralizer will slidably engage the inner walls of the sheath so as to hold the resistance coil I0 centrally within the sheath. Also it will be understood that the insulating material can flow through the centralizer to the portions of the sheath under it through the spaces between the centralizer and the sheath and also down through the resistance coll. It will be further understood that the centralizer exerts some pressure on the insulating material .each time it engages it which causes the insulating material both inside and outside of the centralizer to be displaced and moved upwardly. This upward movement of the insulating material tends to elevate the turns of the resistance structure slightly and the force with which the centralizer tube displaces the insulating material is so controlled that it elevates the turns just enough to compensate for the sag of the turns due to their own weight and the weight of the settling insulating material.

Moreover, it will be understood that as the powder level rises during the loading operation and as it is acted on by the oscillating centralizer, the vibrator 22| is continuously functioning to settle the insulating material in the sheath as it is admitted to the sheath. The constant vibratory hammering of the sheath by the vibrator and the controlled rise of the oscillating centralizing tube not only control the uniformity of the spacing of the turns of the winding but also insure a uniform density in the insulating material.

After a predetermined rise of the carriage 38 and the centralizer tube in the manner described above, the roller |21 on the lever 90 will engage the surface |26 of the vertical member |2| so that the gate 89 is progressively closed as the loading of a particular unit nears completion. This produces a gradual reduction in flow of the insulating material which further insures a more uniform density in the loaded sheath than if there were just a sudden shut oil. When the roller engages the highest portion of the cam surface |26 the cut-off actuating lever 90 will be rotated clockwise to its original position to shut of! completely the flow of insulating material to the sheath.

When the carriage 33 has been moved upwardly an amount suiiiclent to cause the flow of insulaiing material to be cut off in the above described manner, the latch |33 will move into engagement with the top surface |3| of the guide rail 34. At the same time. the lower stop |23 engages the control arm |08 and moves it upwardly so that the lever 99 is moved' in a clockwise direction with a snap action. This causes the pawl |69 to be moved out of engagement with the ratchet |66 so as to stop the oscillatory movement of the carriage and also causes the opposite end of the lever 99 to move in position to latch the lever 90 in its position corresponding to the clock position of the gate 89. It will be understood, or course, that the engagement of the roller |21 with the cam surface |26 shuts off the flow of insulating material prior to the movement of the lever 99 and the movement of the lever merely srves to latch the operating lever in its of! position.

While the aforedescribed filling of a single sheath is proceeding, the entire superstructure including all ve of the loading mechanisms shown in Fig. 3 is rotating slowly. In the loading of small sheathed units such as shown in Fig. 19 the flow of insulating material is regulated so that the loading is completed in about threequarters of a revolution. Thus when a particular loading mechanism passes in front of the operator, the sheath is loaded and ready to be removed. This last step is accomplished by snapping open the jaws B8, disconnecting the upper terminal from the terminal supporting rod 53,

and lifting the loaded unit off the protuberance 50 provided on the support 46. A new empty sheath is then quickly mounted on the mechanism in the manner described above and the centraiizer lowered to restart the cycle. It will be obvious therefore that the operator can sit before the machine and with empty sheaths and assembled coils conveniently available can operate at a high eciency.

It occasionally happens that the centralizer 59 sticks in a sheath as the result of too rapid filling of the filling material above the centralizer. In accordance with this invention improved means are provided for. quickly 'and easily freeing the sheath thus clogged. 'I'he first step is to pull the bell crank lever |86 forward so that the follower |83 is moved off the cam surface |84. The operator then moves the latch members 51 and 68 so that the supporting blocks for the terminal hook and the centralizer tube may be moved out of their respective recesses. At the same time the jaws which hold the sheath are moved to the open position. The entire terminal rod support, centralizer and sheath are then removed from the loading mechanism and inverted to shake the excess powder out of the sheath until the centralizer is again free to move.

From the foregoing, it will be observed that we have provided a new and improved apparatus which lcomprises a plurality of separate loading mechanisms so arranged and operated that the eiliciency of an operator may be substantially increased. It will also be observed that we have provided a new and improved loading apparatus in which a plurality of separate loading mechanisms are fed from a single hopper thereby reducing the servicing' required for the apparatus during its operation. Moreover, we have provided a new and improved means by which the entire centralizer tube, terminal rod and sheath may be removed from the machine as a unit so as to free quickly and readv any jammed or stuck centralizer.

It will be additionally observed that we have provided a new and improved multiple loading machine in which a single driving mechanism may be used to cause the separate units to pass progressively before the operator and to cause the reciprocation of the individual loading heads. It will also be observed that included in our new and improved loading apparatus is new and improved means for selectively stopping the reciprocatory movement of a particular loading mechanism by completely disengaging its oscillating mechanism from its driving means. Finally it will -be observed that We have provided new and simplified means for automatically starting the loading operation when the centralizer is in its lowermost position and stopping the loading operation when the centralizar has Ibeen raised in accordance with the filling operation.

While we have described a specific embodiment of this invention, it will be understood, of course, that we do not wish to be limited thereto since many modifications may be made, and we, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of our invention.

What we claim as new and desire to secure -by Letters Patent of the United States is:

1. A multiple loading apparatus for a sheathed heater of the type having an outer sheath and a helical resistance conductor in said sheath embedded in a granular insulating material comprising a rotatably mounted platform, a plurality of separate loading mechanisms mounted on said platform, each of said loading mechanisms having a centering member adapted to move in said sheath around said conductor and means for moving said centering member with a reciprocatory motion, means for rotating said platform so that said separate loading mechanisms are progressively passed before a given point, driving means, and means for connecting said driving means to said means for rotating said Iplatform and said means for moving said centering member with said reciprocatory movement so that said yplatform is rotated at a relatively slow speed and said centering members are reciprocated at a relativ'ely high speed during loading operations.

2. Apparatus for loading a sheathed heater of the type having an outer sheath and a helical resistance conductor in said sheath embedded in a granular remstance material comprising a base member, a platform rotatably mounted on said base member, a plurality of separate loading mechanisms mounted on said platform and adapted to be` rotated therewith, each of said separate loading mechanisms including a centering member adapted to move Vin said `sheath around said conductor and an oscillating mechanism for reciprocating said centering member in lsaid sheath, a cam member rotatably mounted in said base member, means for connecting said cam` member to each oi.' said oscillating mechanisms, and means for rotating said platform at a relatively low speed and said cam member ai; a relatively high speed.

3. A multiple loading apparatus for loading sheathed wire heating units provided With a sheath, a resistance conductor in said sheath, and granulated insulating material within said sheath embedding said resistance conductor to hold itin spaced relation with said sheath comprising a base; a platform rotatably mounted on said base; a plurality of separate loading mechanisms mounted on said platform so as to be rotated therewith; each of said loading mechanisms comprising a frame, means for supporting said sheaths to be loaded on said frame, a centralizing member adapted to be inserted in said sheath to centralize said resistance conductor relative to said sheath, and oscillating means for .producing a reciprcatory movement of said centralizer up and down as said sheath is filled with insulating material: a cam member; means for connecting said cam member to each of said oscillating means so as to produce the recprocatory movement thereof; means for driving said cam member at a relatively high rate of speed so that said oscillating means are reciprocated rapidly; means for driving said platform at a relatively low rate of speed so that said separate loading mechanisms are slowly moved past a station at4 which said loaded sheaths may be removed and the unloaded sheaths mounted in said separate mechanisms; and means for driving said last two mentioned means from a single motive means.l

4. Apparatus for loading a sheathed heater of the type having an outer sheath and a helical resistance conductor in said sheath embedded in a granular resistance material comprising a base memben a platform rotatably mounted on said base member, a plurality oi individual loading mechanisms mounted on said platform so as to be rotated therewith, each of said loading mechanisms including a centering member adapted to move in said sheath around said conductor and an oscillating mechanism for reciprocating said centering member in said sheath, a cam member rotatably mounted in said base member, means for connecting each o1' said oscillating mechanisms to said cam member so that said oscillating mechanisms are reciprocated in accordance with the rotation of said cam member, planetary gear means for rotating said table at a relatively slow speed and said cam at a relatively high speed, and means mounted on said base for driving said planetary gear means.

5. A multiple loading apparatus for loading a sheathed heater oi' the type having an outer sheath and a helical resistance conductor in said sheath embedded in a granular resistance material comprising a base member, a platform rotatably mounted on said base member, a plurality of loading mechanisms mounted on said platform so as to be rotatable therewith, each `oi said loading mechanisms including a centering member adapted to move in said sheath around said conductor and an oscillating mechanism for reciprocating said centering member in said sheath, ka cam member rotatably mounted in said base member, means extending through said platform for connecting each oi.' said loading mechanisms to said cam member so that each of said oscillating mechanisms is i'eclprocated in accordance with the rotation ol' said cam member, and means for disconnecting each of said oscillating mechanisms from said cam member so as to stop selectively the reciprocatory movement of a particular oscillating mechanism.

6. A multiple apparatus for loading a sheathed heater of the type having an outer sheath and a helical resistance conductor in said sheath embedded in a granular insulating material comprising a base member, a platform rotatably mounted on said base member, a plurality of loading mechanisms mounted on said platform so as to be rotatable therewith, each of said loading mechanisms including a centering member adapted to move in said sheath around said conductor and an oscillating mechanism for reciprocating said centering member in said sheath, a cam member rotatably mounted in said base member, a plurality of cam followers engaging said cam member, a plurality of connecting rods each having one end connected to one of said oscillating mechanisms and its opposite end connected to one of said cam followers, means for rotating said cam member so that a reciprocatory movement is imparted to each of said oscillating mechanisms through its respective cam follower and connecting rod, and means supported on said 'platform for vertically moving each of said connecting rods so as to cause the cam follower secured thereto to be moved away from said cam member and thereby selectively stop the reciprocatory movement of the associated oscillating mechanism.

7. Apparatus for loading a sheathed heater of the type having an outer sheath and a helical resistance conductor in said sheath embedded in a granular resistance material comprising a frame, a vertically movable carriage mounted on said frame, means for removably holding said sheath in an upright position in said frame, a rod adapted to support one end of said resistance conductor, and means adapted to hold the opposite end of said resistance conductor so that said conductor is vertically held in said sheath, a centralizing member adapted to be inserted in said sheath to centralize said resistance conductor, a centralizing tube connected to said centralizing member, means for connecting said supporting rod to said frame, means for connecting said centralizing tube to said carriage, each of said last mentioned means including manually releasable latch means whereby said sheath assembly, supporting rod and centralizing tube may be readily removed from said loading, apparatus in the event that said centralizer becomes stuck in said sheath during the loading operation.

8. Apparatus for loading sheathed wire heating units having a sheath and a helical resistance element in said sheath embedded in and supported in spaced relation with the sheath by a compacted granular insulating material, the resistance element being connected at its ends to terminals mounted in the ends of said sheath comprising a frame, means for removably supporting said sheath for loading in a stationary upright position on said frame, means adapted to secure one terminal of said resistance element in the lower end of said sheath, a rod adapted to support the other terminal of said resistance element in the upper end of said sheath, a centralizing member adapted to be inserted in said sheath around said resistance conductor and to hold said conductor in xed spaced relation with respect to said sheath during the loading operation, a centralizing tube surrounding said rod, means for connecting said centralizing tube to said centralizing member, a carriage vertically movable in said frame, means for detachably securing the upper end of said centralizing tube to said carriage, and means for detachably securing the upper end of said terminal supporting rod to the top of said frame, each of said last mentioned means being manually releasable so that said rod, said centrallzing tube and said sheath with the resistance conductor therein may be readily removed from' said loading apparatus in the event that said centralizer becomes stuck during the loading operation.

9. Apparatus lfor loading a sheathed heater of the type having an outer sheath and a helical resistance conductor in said sheath embedded in a granular resistance material comprising a frame, means for holding said sheath in an upright position on said frame, means on said frame for feeding said granular insulating material into the upper end of said sheath, means adapted to hold the ends of said conductor in a xed position with relation to said sheath,- a centering member adapted to slide in said sheath around said conductor and to hold said cond-uctor in a fixed spaced relation with said sheath, a carriage vertically movable in said frame, means for connecting said centering member to said carriage, reciprocating driving means mounted on said frame, means releasably connecting said reciprocating means to said carriage so that said carriage and said centering mem- Vpositioning of said centering member adjacent the lower portion of said sheath said control arm is moved to cause said carriage to lbe connected to said reciprocating means and when said carriage is in its uppermost position corresponding to the positioning of said centering member adjacent the top of said sheath said control arm is moved to a position causing said carriage to be released from said reciprocating means.

l0. Apparatus for loading a sheathed wire heating unit having a sheath, a resistance conductor in said sheath, and a mass of compacted granular insulating material embedding said resistance conductor and supporting said conductor in spaced relation'with said sheath comprising a supporting frame, means. for supporting said sheath with its resistance conductor in an upright position on said frame, a centering member adapted to slide in said sheath around said conductor and to hold said conductor in xed spaced relation with said sheath, a carriage vertically movable in said frame, means for connecting said centering member to said carriage, an oscillating mechanism mounted on said frame an'd adapted to be moved with a reciprocatory movement up and down relative to said frame, means for releasably connecting said carriage to said oscillating mechanism so that said centering member may be moved with a reciprocatory movement, a vertically depending rod mounted on said carriage, a control arm mounted on said frame for controlling the driving connection between said oscillating mechanism and said carriage. said control arm having one position in which said carriage and oscillating mechanism are 4interconnected so that the two oscillate together and a second position in which said carriage and oscillating mechanism are disconnected so that said oscillating mechanism oscillates independently of said carriage, and a pair of stops vertically spaced on said depending rodadapted to engage said control arm to move it to its different controlling position in accordance with the position of said carriage on said frame, one of said stops being positioned so that when said carriage is in its lowermost position corresponding to the positioning of said centralizing member adjacent the bottom of the unit to |be loaded said control arm is moved to the position causing a driving connection to be made between said carriage and said oscillating mechanism, and the other of said stops being 4positioned so that when said carriage is in its uppermost position corresponding to the positioning of said centralizing member in the upper part of said sheath being loaded, said control arm is moved to the posi- `tion in which the connection between said carv CERTIFICATE. `oF CORRECTION. l Patent No. 2,516,685I April l5, 19145.

- FRANK E. Frmyspn, ET'AL.

It 1s hereby certified thaterror appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, line 55., for "fo" lrend v'-of; page 9, first column, line 7, for

*clock* read @closed-7; page '10, second column, line 52, claim 7, after the word "loading" strike out the comme.; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Off1ce. l, y signed and sealed this 8th day of June, A. D. 19145.

f Henry Van Arsdale, (Seal) Acting Commissioner of Patents.

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