US2032957A - Apparatus for loading sheath wire heating units provided with a sheath - Google Patents

Description

March 3, 1936. A H, SIMMONS 2,032,957

APPARATUS FOR LOADING SHEATH WIRE HEATING UNITS vPROVIDED WITH A SHEATH Filed NOV. 5, 1954 3 Sheets-Sheet 1 Z6 26 T 23 a 23- j g L Fig.2.

Y 72a x 69 IOI 4 u 0 26 za v u u 5 975 I inventor: m Alicea-"t H. Simmons, 20 Q 76 8B Y L 1 1 Att orneg,

A. H. SIMMONS SHEATH WIRE HEATING UNIT Filed Nov. 3, 1934 March 3, 1936.

APPARATUS FOR LOADING Fig 5. 5

S PROVIDED WITH A SHEATH 5 Shets-Sheet 2 ||||l Inventor:

'J C. W4 Albert 1. Jnmmons b H 1 Hi5 Attovneg.

March 3, 1936. A. H. SIMMONS APPARATUS FOR LOADING SHEATH WIRE HEATING UNITS PROVIDED WITH A SHEATH Filed Nov. 3, 1934 3 Sheets-Sheet 3 Fig. i I.

Fig. \5.

Inventor: Albert H. Simmons,

N w Attorney.

Patented Mar. 3, 1936 UNITED STATES APPARATUS FOR LOADING SHEATH WIRE HEATING UNITS PROVIDED WITH A SHEATH Albert H. Simmons, Wheaten, Ill., assignor to Edison General Electric Appliance Company, Inc., a corporation of New York Application November 3, 1934, Serial No. 751,333

16 Claims.

This invention relates to electric heating units,

more particularly to electric heating units of the sheathed type, and it has for its object the provision of improved apparatus for making heating 5 '5 units of this character.

This invention has particular application to electric heating units wherein a resistance conductor is encased by a sheath and is embedded in and held in spaced relation with the sheath by means of an electrically insulating, heat refrac-- tory and conducting material, such as powdered magnesium oxide. One electric heating unit of this type is described and claimed in United States Patent No. 1,367,341 to C. C. Abbott, dated February 1, 1921.

This invention contemplates the provision of improved apparatus for loading a sheath with insulating material so as to embed and hold the resistance conductor in spaced relation with ref 20. erence to the sheath, in a simple, reliable and the ends of the conductor, in proper relation to 30 the sheath, generally in the vertical center line of the sheath. Suitable apparatus is provided for feeding to the sheath the powdered magnesium oxide at a predetermined regulated rate. A centering device is arranged to be inserted in the 351 sheath to hold the portions of the resistance element between the terminals in the center line of the sheath while the sheath is being loaded. The centering device is controlled to move upwardly in the sheath as the sheath is being filled with the insulating material so that the level of theinsulating material is always just below and follows the centering device. In addition to this, a suitable vibratory device is provided for applying to the sheath intermittent impacting blows to settle the insulating material Within the sheath while it is being filled. The vibratory device iscontrolled to move upwardly along the walls of the sheathat a regulated rate so as to apply the blows always substantially at the rising level of 50 the insulating material.

It is contemplated that the insulating feeding means, centering device and the vibratory device all will be controlled by a single control lever, which is manually operable to start the loading 55' operation, and it is further contemplated that these elements will be automatically controlled to stop the loading operation when the sheath has been filled.

For a more complete understanding. of this invention, reference should be had to the accom- 5 panying drawings, in which Fig. 1 is a vertical side elevation of apparatus for loading a sheathed heatingunit arranged in accordance with this invention; Fig. 2' is a view similar to Fig. 1, but showing certain elements of the mechanism in different operative positions; Fig. 3 is an enlarged front elevation of a portion of the mechanism shown in Figs. 1 and.2; Fig. 4 is a side elevation of the mechanism of Fig. 3; Fig. 5 is a sectional view taken through the line 55 of Fig. 3 and looking in the direction of the arrows; Fig. 6 is a fragmentary sectional View taken through a portion of the apparatus shown in Fig. 5; Fig. 7 is a fragmentary sectional View taken through the line 'l-'-1 of. Fig. 6 and looking in the direction of the arrows; Fig. 8 is a plan View of a vibratory device used in the loading apparatus of Figs. 1 and 2; Fig; 9 is a view similar to Fig. 8, but illustrating certain of the elements of the vibratory device in different operative positions; Fig. 10 is 5 an enlarged elevation in section taken through the line l0lfl of Fig. 8 and looking in the direction of the arrows; Fig. 11 is an enlarged fragmentary view, mainly in section, of certain portions of the apparatus shown in Figs. 1 and 2; Fig. 12 is an enlarged elevation, partly in section, of a portion of the apparatus shown in Figs. 1 and 2; and Fig.

13 is an elevation, partly in section, of a sheathed electric heating unit of the type to which this invention is praticularly applicable.

Referring to the drawings, this invention has been illustrated in one form as applied to electric heating units of the sheathed type, such as described and claimed in the above-mentioned Abbott Patent No. 1,367,341. Referring to Fig. 13, a heating unit of this type has been illustrated. As shown in this figure, the heating unit comprises a helical resistance element In encased by a metallic sheath ll. Suitable terminals l2 are mechanically and electrically connected to the ends of the resistance element ID. The resistance conductor is threaded on the terminals as shown and as fully described in the U. S. Patent No.'1,494,938 to C. C. Abbott, dated May 30, 1924. The resistanceconductor i0 is embedded in and is held in spaced relation with reference to the sheath II by a suitable powdered heat refractory and conducting, electrically insulating material it, 's uch aspowdered magnesium oxide. The magnesiumoxide functions to hold the resistance the lower end of the sheath rests. The plunger element I substantially in the longitudinal center line of the sheath, and to conduct heat from the resistance element to the sheath. The inner ends of the terminals I2 are also embedded in the insulating material I3, as shown, and are insulated from the sheath I I and held in spaced relation with it by means of the powdered insulating material.

The apparatus for loading the sheath comprises meansior holding it in an upright position, as shown in Figs. 1, 2, 11 and 12, and for holding the resistance element I0 and its terminals I2 in the positions they should occupy with reference to the walls of the sheath, in this case, in the vertical center line of the sheath. The upper end of the sheath is supported by means of a metallic frame I4 (Figs. 1, 2, 5 and 11). The frame. I4, as shown, is provided with a metallic insert I5 which has a recess I6 provided in it to receive the upper end of the sheath, as more clearly shown in Fig. 11. This insert is detachably secured to the frame in any suitable manner, as by means of set screws (not shown). The lower end of the sheath is supported by a pedestal I1 (Fig. 12) which comprises a cylindrical member l8 supported in an upright position and within which is fitted a rod I9 that carries on its upper end a base or bearing 20 for the lower end of the sheath. This member 20, as shown, has a curved upper surface upon which or rod I9 is fitted within the cylinder I8 and rests upon a compression spring 20a arranged within the cylinder. This spring biases the sheath upwardly into the recess I6, as shown in Fig. 11. The rod I9, as shown, is passed through a an opening in the base 28 with enough of the rod projecting above to form a centering means for the lower end of the sheath. II. If there is a heating unit of a materially difierentlength to be filled, the base 20 will be provided with a rod I9 of proper length.

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 washer I 2a. (Fig. 12) attached to the terminal. This washer is received in a recess 2| provided for it in the lower end of the sheath, as clearly shown in Fig. 12. The washer I2a. is a solid washer, and therefore, in addition to holding the terminal I2 central of the sheath, functions to close the lower end of the sheath.

The upper terminal I2 is secured in fixed relation with reference to the sheath, in this case in the center line of the sheath, by means of a rod 23, tothe lower end of which is attached a hook 24 which is arranged to receive a member 25 of T-shape secured to the upper end of the terminal I2, as shown in Fig. 11. The upper end of the rod 23 is rigidly secured to a retaining member 26. Set screws 21 are provided to secure the rod to the retainer. The retaining member 26, as will be pointed out in greater detail hereinafter is rigidly secured in a stationary position to a rigid portion of the apparatus.

The metallic frame I4 is secured to a pair of upright supporting rods 28 which are arranged in parallel spaced relation, as shown in Fig. 3. The rods are rigidly secured at their upper and lower ends in spaced relation. These rods rigidly support the rod retainer 26.

The metallic frame I4 is slidably mounted upon the rods 28, the frame I4 being provided with bearings 29 arranged to slide upon the rods.

Suitable set screws 30 are provided for holding the frame I4 in its adjusted position on the rods.

The frame I4 carries suitable means for feeding the powdered insulating material I3 at a regulated rate to the metallic sheath II while it is supported in its upright position. For this purpose, the frame I4 carries a suitable chute 3| (Figs. 3 to 6 and 11) which directs the powdered insulating material into the upper end of the sheath. As shown, the metallic member I5 carried by the frame I4 is provided with a conical bore 32 which terminates in an opening 33 pcsitioned directly above the open upper end of the sheath, as clearly shown in Fig. 11 of the drawings. It is through this bore 32 and opening 33 that the chute feeds into the sheath. Moreover, it will be observed that the terminal I2 projects through the opening 33 and bore 32 for engagement with the supporting rod 23.

The insulating material I3 is fed to the sheath II from a suitable hopper 34 (Figs. 1 and 2). Interposed between the hopper 34 and thechute 3I is a suitable feeding device arranged to feed the insulating material from the hopper into chute at a predetermined regulated rate. The feeding means comprises a suitable conveyor 35 (Figs. 5 and 6). The conveyor, as shown, comprises a cylindrical member 36 arranged to rotate on a horizontal axis and provided with a plurality of feeding blades 31 on its outer surface. The member 36 with its blades 31 is arranged to rotate in a cylindrical housing 38 which at its upper left-hand end, as viewed in Fig. 6, communicates with the hopper 34 by means of a conduit 39 and at its lower right-hand end communicates with the chute 3| through a port 40. The conveyor is arranged to rotate in a counter-clockwise direction, as viewed in Fig. 5, and when thus rotated to engage the powder which is fed to its left-hand end from the hopper 34 and gradually convey it to the right-hand end where the port 48 is located. The angular set of the blades 31 at their right-hand end are straightened out as shown so as to lie substantially parallel with the axis. of rotation of the cylinder 36. This arrangement of the blades prevents crowding or piling up of the powder above the port 40, and insures a gradual regulated movement of the powder from the hopper 34 to the chute 3I Furthermore, in order that the rate of powder fiow through the feeding chamber 38 will be independent of the quantity of powder in the hopper, the hopper is not set directly over the intake of the cylinder 38, as clearly shown in Figs. 1 and 2. That is, the hopper is located off of the end of the cylinder 38 as shown, and the conduit 39 is given an angular shape to connect the hopper with the conveyor. ually operable shut-off valve 29a (Fig. 5) is provided in this conduit 39.

The size of the port 46 communicating with the chute is controlled by means of a slide valve 4|, the position of which is controlled by a. knob 42. As shown (Fig. 5), the knob 42 is provided with a flange 43 which is received in a recess 44 provided for it in the valve 4I The knob 42 has a screw threaded engagement with the frame I4 so that by adjusting the position of the knob in the frame, the position of the valve is adjusted. The valve, as shown clearly in Figs. 5 and 6, is provided with an aperture 45 which registers with the port 4|]. The adjustment of the valve therefore controls the effective opening of the port 40.

In order to stop the flow of powder from the A suitable manfeeding cylinder, the chute 31 is mounted upon a carriage 46 for movement from its operative posi--' When the hopper is moved from its operative po-- sition to its inoperative position, the carriage 46 will move over to close the port 46.

The chute 3| is biased to its inoperative position by means of a compression spring 41 (Figs. 4 and 5) interposed between the feeding cylinder 38 and an abutment 48 carried by the carriage 46. A stop 48a is providedto limit the movement of the abutment 48 from the cylinder. The chute 3| is moved from its inoperative to its operative position against the bias of the spring 41 by means of an operating lever 49 which is mechanically connected to rotate a shaft 50 that is journalled in bearings 56a carried by' the frame 14. Also secured to the shaft 56 is a crank arm 51 which is secured to the carriage 46 by means of a link 52. It will be observed that when the lever 49 is moved in a counterclockwise direction,

as viewed in Figs. 1, 2, 4 and 5, it will function to move the arm 51 in the same direction'and thereby move the chute from its inoperative to its operative position. The chute is locked in the operative position by means of a latch 53 pivotally mounted upon a pin 54 and provided with a detent 55 arranged to engage a pin 56 carried by the carriage 46. The latch 53 is biased by gravity in a clockwise direction, as viewed in Figs. 4 and 5. It will be observed in view of the foregoing that when the lever 49 is operated to move the chute from its inoperative to its operative position, the latch 53 will automatically move to engage the pin 56 to lock the chute in the operative position against theforce of its spring 41. It will also be observed that when the latch 53 is moved to its position shown in Figs. 4 and 5 to release the pin 56, the spring'can then function to return the chute to its inoperative position and thereby automatically shut off the flow of insulating material from the feed cylinder. 38

to the sheath H. The latch is provided with a finger seat 53a whereby the latch can be manually operated to release the carriage 46. Supported by the frame I4 is a receptacle 56a (Fig; 5) positioned to receive any insulating material that might be in the chute when it is moved to its inoperative position.

The conveyor 35 is rotated by an operating shaft 51 mounted in bearings 51a carried by the frame 14. This shaft is driven by a gear 515, which in turn is driven through a clutch 5B. The clutch 58 comprises a driving member 59, and a driven member 60 which is secured to the shaft 51 by means of a set screw 6 I The driving member 59 is provided with a collar 62 (Fig. 6) which is arranged about a reduced portion 63 of the driven member 66, as clearly shown in Figs. 6 and '7. A plurality of substantially semi-circular recesses 64 are provided in the inner wall of the flange 62 at spaced intervals about the periphery of the reduced portion 63. The driven member 60 of the clutch carries a shaft 65 (Figs. 4 and '7) which is arranged to operate on an axis lying substantially in the periphery of the reduced portion 63. The shaft 65 is provided with a portion 6511 (Fig. 7) of substantially semi-circular crosssection received in a semi-circular seat 65b in the member 60, and which is arranged when in the dotted line position shown in Fig. 7 to complete the periphery of the portion 66., However, when the shaft. is moved from this position to its full line position shown in Fig. 7, the semicircular portion 650. will move into one of the recesses 64 provided in the driving member 59, as shown, and thereby mechanically lock the driving and driven members together, whereby the shaft 51 and the conveyor 35 are caused to rotate with the gear 51b.

The shaft 65 is controlled by a lever 66 which is arranged to move the shaft between its dotted and full line positions shown in Fig. 7. The position of the lever 66 is controlled by the lever 49. For this purpose, the shaft 50 carries a lever or stop- 61 which is arranged when the lever 49 is in its dotted line position shown in Fig. 1 to engage the lever 66 to hold it in its position shown in Fig. 1 which corresponds to the dotted line position of the lever shown in Fig. '7. When the lever 49 is moved from its solid line position in Fig. 1 to its dotted line position inthis figure, that is, its full line position, shown in Figs. 2 and. 4, the stop 61 is moved to disengage the lever 66 which thereupon is permitted to move to its full line position shown in Fig. '7 thereby effecting the engagement of the clutch. The lever 66 is moved to this full line position by means of a compression spring 68. Thus, when the lever 49 is moved to its position, shown in Figs. 2 and 4, the clutch will be engaged. When the lever 49 is operated to return to its full line position in Fig. l, the stop or lever 61 will be moved to its position shown in this figure so that it will engage the lever 66 and return it to its dotted line position shown in Fig. '7 to thereby disengage the clutch, whereby the conveyor 35 will be instantly disengaged from its driving gear 51.

The clutch members are driven by the gear 511) in a counter-clockwise direction, as viewed in Figs. 1, 2 and 4. This driving gear 511) for the clutch is driven by means of a gear 66. The gear 69 is driven by means of a shaft 10 journalled in bearings 16a carried by the frame I4, and which may be extended to drive the corresponding gears 69 of other machines (not shown) which will be identical with the one being described and arranged in a bank with it.

It will be observed, in View of the foregoing description, that when the lever 49 is moved from its full line position shown in Fig. 1 to its dotted line position of this figure, that is, its full line position of Figs. 2 and 4, the clutch 58 will be caused to engage the gear 51b with the conveyor 35, whereby the latter will be connected to the driving shaft 10, and the chute 31 will be operated from its inoperative position of Fig. 5 to its operative position of this figure, and in which position it will be locked by the latch 53 where it will remain until the latch 53 is operated to disengage the pin 56, and the lever 49 operated to return it to itsinoperative position. In other words, the operation of the lever 49 from its position in Fig. 1 to its positions in Figs. 2 and 4 will start the feeding of powdered insulating material from the hopper 34 into the sheath 1 l.

- As the powdered insulating material is fed into the sheath, the level of the insulating material within the sheath will of course gradually rise. Suitable means are provided for holding the portions of the resistance conductor i 0 lying between the terminals [2 central of the sheath while it is being loaded with the insulating material. For this purpose, a suitable centralizing device 1| is provided. The centralizing device comprises a core 12 (Fig. 11) which is provided on its periphery with a plurality of spaced vertical ribs 13 arranged to engage the inner walls of the sheath and position the core 12- relative to. the sheath; while the spaces between the ribs provide for the The core 12 is provided with a centrallyso that that portion of the coil lying within the spacer is held central with reference to the sheath.

It is contemplated that the spacer 12' will bedrawn upwardly in the sheath at approximately the same rate that the level of the insulating material within the sheath rises as it is being fed to the sheath so that the succeeding portions of the resistance conductor are held central of the sheath until they are substantially embedded by the insulating material which thereafter will maintain the portions central within the' sheath.

The spacer II is drawn upwardly in the tube by means of a tubular member 12a which is secured at its lower end to the spacer and at its upper end to a suitable operating arm 15. The arm- 15, as will be pointed out in greater detail hereinafter, is operated by means of a feed screw 16- which is driven at a constant speed through a suitable gear reduction mechanism 18a. The

gearing 16a 18 driven by any suitable drivingi means such as an electric motor (not sliown).

The tube at its upper end is directly connected to a sleeve 11 which in turn is connected to a yoke 18 carried by the arm by means of spherical members 19. As shown, the spherical members 19 are mounted in passageways 88 provided for them in the yoke 18, and are received in semi-circular recesses or seats 8I provided for them in the sleeve 11. The balls 19 are forced into the recesses 8| by means of compression springs 82. The balls and recesses provide a releasable connection between the yoke 18 and the centralizer 1I so that in the event that the load imposed upon the centralizer attains a predetermined maximum, the centralizer will be released from the yoke. For example, this maximum load may be encountered in case the centralizer becomes wedged or otherwise locked in the sheath II. The tube 120. where it leaves the sheath I I is maintained central with reference to the sheath, that is, is held so that its vertical axis is coincident with the vertical axis of the sheath, by means of a sleeve 83 (Fig. 11) secured to the frame I4.

Suitable means are provided for applying to the sheath a plurality of intermittent impacting blows applied always substantially at the rising levelof the insulating material within the sheath, which as previously pointed out, lies just below the position of the centralizer H. The vibrator comprises a U-shaped hammer 84 (Figs. 1, 2, 8, 9, and 11) arranged to embrace the sheath II. The span of the legs of the U, as shown in Figs. 8 and 9, is somewhat greater than is the external diameter of the sheath so that when the hammer is rapidly reciprocated or vibrated, the legs will engage opposite sides of the sheath with intermittent impacting blows. The hammer 84 is operated by a rod 85 which is driven by means of any suitable vibrating mechanism 88. The vibrating mechanism has not been illustrated in detail, for any suitable mechanism may be used.

and the details of this mechanism form no part of the present invention. The hammer 84; together with its vibrating mechanism 86, are mounted upon a suitable carriage 81 (Figs. 8 and 9) which is provided with bearings 88 slidably received by the upright rods 28.

amazem- Carriedby-theframe 81 is a suitable split nut 89.- (Figs. 8,.9'and'10) which has two halves 89a and: 89b; When the halves of these nuts are moved toengage the screw 16, as shown in Fig. 10; the frame 81, together with the hammer 84, will be mechanically connected with the screw and will be elevated by the screw as it rotates. The nut segments 89a and 8% are controlled by means of levers- 98 pivotally mounted to the frame 81, as shown in Figs. 8 and 9. The levers 98 are operated by meansof a lever 9I pivotally mounted upon a pin 92 carried by the frame 81. The lever 9I isvmechanically connected to a pair of links- 99 which are connected at one end, as shown, to the levers 98, and at their opposite ends to-the lever 9I- through the medium of a pin 94. This pin is arranged to reciprocate in a slot 95 provided for it in the frame 81. The levers 98 are mechanically connected together at their upper ends by means of a tension spring 96 which functions tobiasthe levers to their positions shown in Fig. 9 and the nut portions 89a and bin their disengaged positions. When the levers98are operated from their positions show-n in Fig. 9 to their positions shown in Fig.8, by the operation of the lever 9I from its position shown in Fig. Stoitsposition shown inFig. 8 the levers move the nut segments to engage the screw 16. It will be observed that. when the lever 9I has thus been operated, the links 93 will lie slightly below a. straight line connecting the points of attachmentbetween levers 98 and links 93, and therefore, the spring 96 will function to hold the nut segments in engagement with the screw 18 (Figs. 8 and 10) until this position of the links is broken by thelever. 9|.

The yoke 15 supporting the centralizer TI is mechanically connected to the frame 81 to be moved with it by means of la cylinder 91 surroundingv the screw 16. This cylinder at its lower end is rigidlysecured to the frame 81, as shown in Fig. 10,.while its upper end is mechanically connected with the yoke 15, as shown in Fig. 11. In view of this arrangement, the centralizer II is elevated in. the sheath II at the same rate as is the member 84 elevated on the exterior of the sheath. The weights of the centralizer, and its supporting rod 23-, together with those of the vibrator mechanism 86 split nut assembly 89, the tube 91 and the yoke 15 are counterbalanced by m'eans of a weight 91a connected with the yoke 15 by means of a cable 91b, as shown in Figs. 1 and 2. This cable passes over pulleys 91c.

The lever 49is operated-from its position shown in Fig. 1 to its position shown in Figs. 2 and 4 to start the feeding mechanism, and the lever 91 is operated from its position shown in Fig. 9 to its position shown in Fig. 8 to lock the carriage to the screw 18' by means of a lever 98. This lever 98', as shown, is pivotally mounted upon asuitable stud 99 (Figs. 3 and 4) which in turn is carried by the frame I4. The lever 98 is of bell crank form, and, as shown, is fulcrumed to the stud 99 substantially at its apex. One arm 98a of the bell crank 98 is pivotally connected to a parallel bar I88, while the other arm 98b of they lever 98' is connected with a handle I81. The lower end of the parallel bar I88 is pivotally connected to a link I82 which in turn is pivotally connected to an upright rigid standard I83.

The arm 98a of the bell crank 98 is not connected directly to the extreme upper end of the parallel. bar I88 but, as shown in the drawings,.is connected to thebar somewhat below its upper end. The parallel bar I09 is 'so arranged that when the handle [0| is operated to move the lever 98 from its full line position shown in Fig. 1 in a counter-clockwise direction through to its position shown in Figs. 2 and 4, the upper end of the parallel bar I00 will engage the lever 49 to move it from its position shown in Fig. 1 to its position shown in Figs. 2 and 4. This operation of the lever 49, as has been pointed out previously in detail, will connect the feeding conveyor 35 to its driving gear 51b and at the same time will operate the chute 3| from its inoperative to its operative position. As shown, the parallel bar 199 carries on its upper end an adjustable stud 189a to compensate for wear and for slight inaccuracies of manufacture.

Furthermore, this operation of the parallel bar from its position shown in Fig. 1 to its position shown in Fig. 2 will effect the engagement of the split nut 89 carried by the frame 81 and its operating screw 76. That is, the bar when thus moved, will engage the lever 9| to move it from its position in Fig. 9 to its position in Fig. 8 and thereby cause engagement of the split nut with the screw 16.

Therefore, when the handle i9! is moved from its position of Fig. 1 to its position of Fig. 2, it will have effected the feed of the powdered insulating material from the hopper 34 to the sheath H at a regulated rate, and further, will have mechanically connected the centralizer TI and the vibrating device 86 to the screw 16 which will elevate them at a regulated rate, as has been pointed out previously.

It is contemplated that when the sheath H has been filled with the insulating material, the lever 9| will be automatically operated to disconnect the vibratory device and the centralizing device from the operating screw 16, and that the lever 49 will be operated to its position shown in Fig. l, which, as pointed out previously, will effect the disengagement of the clutch between the driving gear 511) and the conveyer 35. The lever 9| is thus automatically operated by means of a cam 94 (Figs. 4, 8 and 9) with which the lever 9! is arranged to become engaged when the frame 81 carrying the vibrator is moved upwardly from its position shown in Fig. 1 to its position shown in Fig. 2 wherein the hammer is substantially at the upper end of the sheath l l. The lever 9|, as shown in Figs. 8 and 9, is provided with an extension am which carries an adjustable stud or nut 92 positioned so that when the carriage 81 arrives at its upper position shown in Fig. 2, the stud 92 will engage the cam I94 to break the toggle formed of the links 93, as shown in Fig. 8, whereby these members are drawn together'by means of the tension spring 96 to 00- cupy the positions shown in Fig. 9. This oper ation releases the split nut from the driving screw and thereby releases the centralizing device and the vibratory device. These devices may at the proper time be returned manually to their lower positions shown in Fig. l.

Simultaneously with this release of the vibratory device and centering device, the latch 53 is operated to release the chute 3| so that it can return to its dotted line inoperative position (Fig. 5) under the influence of its compression spring 4 For this purpose. the frame B carries an upright pin I85 (Figs. 3 and 4) which is arranged to engage the latch 58 to release the chute substantially at the same instant of time that the cam !94 engagesthe lever 91 to disengage the split nut from the screw 16 to operate the paralpointed out previously, moves the stop 61 into i such a position that it will engage the lever 66 of the clutch 58 thereby disengaging the driving gear 5Tb from the conveyer 36.

In making an electric heating unit using the apparatus of this invention, it will be understood 710 that the terminals I2 (Fig. 13) will be secured to the resistance conductor ID in the manner previously described, and then: the resistance conductor, together with the terminals, will be threaded through the metallic sheath 1 I. It will also be understood that the lower terminal 12 will be provided with a washer l2a which is fitted within the recess 2| of the sheath so as to close the lower end of the sheath, and further, so as to anchor'and center the lower terminal l'2 with reference to the sheath. The lower end of the sheath will then beplaced on the base 20. Then the upper terminal 12 will be mechanically connected with the rod 23, whereby it is held in the center'line of the sheath. The sheath may be pushed downwardly against the force of the spring 29a to facilitate the connection between the upper terminal and the rod 23. The centralizer II which will have been positioned above the terminal 12 during this operation will then be lowered by hand and at the same'time the vibratory device 88 will be lowered to its position shown in Fig. 1.

Then the lever Hll will be moved from its position shown in Fig. l to its position shown in Fig. 2. This operation will mechanically connect the split nut 89 with the operating screw 16, whereby the vibratory device 86 and centralizing device II will be movedupwardly at a regulated rate by the screw. Simultaneously with the engagement of the nut 89 with the screw 16, the lever 49 will be operated to its positions of Figs. 2 and '4 by the bar 199 to effect the engagement of the clutch 58, whereby the feeding device 35 will be operated, and to move the chute 3| to its operative position to permit insulating material fed to it to flow to the tube II The chute and lever 49 will be locked in their operative positions of Figs. 2 and 4 by thelatch 53. The lever I8] is released immediately after it has thus been operated to start the feeding operation.- As the level of the insulating material within the sheath rises, the centralizing device H will rise just before it and the vibratory device will be elevated so that the hammer 84 will intermittently apply 'blows to the sheath substantially at the level of the material so as to constantly settle it within the sheath while the sheath is being filled. When the sheath has been filled the cam I04 will engage the lever 9| to operate it to disengage the nut 89 from the screw '15 and thereby stop the centralizing and vibratory devices. Simultaneously the pin I05 will operate the latch 53 to release the lever 49, which thereupon will move to its position'shown in Fig. 1. This operation disengages the clutch 58 and moves the chute 3| to its inoperative position to thereby permit it to move under the influence of shut off by means of the manual powder shut-off valve 29a.

It will-be understood that when the sheath has been filled with the insulating material and the vibratory and centering devices have been released from the driving .screw 1.6 and the flow of powder has been shut ofi, the terminal l2 will be disengaged from the rod 23. This operation may be facilitated by moving the centering device H above .the connection between the terminal and the rod 23. Theloaded-unit may then be removed from the apparatus, and another heater assembly inserted in the machine for a loading operation. 'Then the centering and vibratory devices are lowered manually, and the lever [0| operated to start the next loading operation.

It is to be understood that a single machine may be operated as 'hasjust been described or that the machines may be arranged in any suitable numberin a'bank or battery. In the latter case, the shaft 10 driving the feed gear 69 of the various :machines will extend through the batter-y and will 'be operated by a source of power common to all the machines. It .will also be understood that a single source of power will be used to drive all'the vertical screws"! 6 through their gear drives 16a.

Different lengthsof sheaths within limits may be filled using the same pedestal I 8, 19, etc. However, if the lengths of the units vary widely from that shown, pedestals of different and proper lengths will be .used. Furthermore, sheaths of different diameters may be loaded. To accommodate the machine to sheaths of dif- "ferent diameters it :is merely necessary to replace the 'upper holding member .15 by a similar member provided with a recess 16-01 the proper diam- .eter and to use centralizing parts 12, 12a of proper size.

Important features of this invention .are the provision :of means for obtaining a steady flow of powder from the hopper .34 to the sheath, a uniform rise of the centralizing device TI and the vibrator 86 so that movement of these members is synchronized with the rate of rise of the level of powder within the tube I I. Another important 'feature is the provision of a single manually operable lever .IM to effect the operation of the machine, and furtherythe automatic stop for the machine when the sheath has been loaded.

'true spirit and scope of my invention.

WhatI claim as new :and desire to secure by Letters Patent, of the United States, is:

1. Apparatus vfor loading sheath wire heating units provided with a sheath, a resistance conductor within the sheath and insulating material within said sheath embeddingssaid resistance conductor comprising means for feeding said insulating material into said sheath, means for regulating the feed of said insulating material into said sheath, guide means within said sheath engaging said resistance element to hold it in fixed spaced relation with said sheath and means for moving said guide means within said sheath at a regulated rate as said sheath is filledwith said insulating material so as to support succeeding portions of said conductor in said spaced relation with said sheath until said portions are embedded by said insulating material.

2. Apparatus for loading sheath wire heating units provided with a sheath, a helical-resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath in an upright position, means for holding the ends of said resistance conductor substantially in the vertical center line of said sheath, means for feeding said powdered insulating material into said sheath, a centralizing guide member within said sheath engaging said helical resistance conductor to hold intermediate portions of said conductor substantially in said center line of said sheath, means for moving said guide member at a uniform predetermined rate from the lower to the upper end of said sheath and means for regulating the feed of said insulating material into said sheath in accordance with the rate of movement of said guide member so that the level of said insulating material in said sheath follows and is maintained at a predetermined position with reference to said guide member.

3. Apparatus for loading sheath wire heating units provided with a sheath, a resistance conducto'r within the sheath and insulating material within said sheath embedding said resistance conductor comprising means for feeding said insulating material into said sheath, meansior regulating the feed of said insulating material into said sheath, guide means Within said sheath engaging said resistance element to hold it in fixed spaced relation with said sheath, means for moving said guide means within said sheath at a regulated rate as said sheath is filled with said insulating material so as to support succeeding portions of said conductor in said spaced relation with said sheath until said portions are embedded by said insulating material, and means imparting intermittent blows to said sheath progressively at a regulated rate along said sheath so as to compact said insulating material as it is added to said sheath.

4. Apparatus for loading sheath wire heating units provided with a sheath, a helical resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath in an upright position, means for holding the ends of said resistance conductor substantially in the vertical center line of said sheath, means for feeding said powdered insulating material into said sheath, a centralizing guide member arranged to be fitted into said sheath so as to hold intermediate portions of said helical resistance conductor substantially in said center line of said sheath, means for moving said guide member at a uniform predetermined rate from the lower to the upper end of said sheath, means for regulating the feed of said insulating material into said sheath so that the level of said insulating material in said sheath follows and is maintained a predetermined distance below said guide member, a vibratory device arranged to intermittently apply impacting blows to the external walls of said sheath so as to settle said insulating material in said sheath and means for moving said vibratory device from the lower to the upper end of said sheath at a regulated rate so that said blows are always applied substantially at the rising level of said powdered insulating material in said sheath.

5. Apparatus for loading sheath wire heating units provided with a sheath, a helical resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath in an upright position, means for holding the ends of said resistance conductor substantially in the vertical center line of said sheath, means for feeding said powdered insulating material into said sheath, a centralizing guide member arranged to be fitted into said sheath so as to hold intermediate portions of said helical resistance conductor substantially in said center line of said sheath, a screw, means for operating said screw, a nut for operating said guide member arranged to engage said screw so as to be driven thereby and thereby move said guide member within said sheath, and means for engaging and disengaging said nut with said screw.

6. Apparatus for loading sheath wire heating units provided with a sheath, a helical resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath in an upright position, means for holding the ends of said resistance conductor substantially in the vertical center line of said sheath, means for feeding said powdered insulating material into said sheath, a centralizing guide member arranged to be fitted into said sheath so as to hold intermediate portions of said helical resistance conductor substantially in said center line of said sheath, a screw, means for operating said screw, a nut for operating said guide member arranged to engage said screw so as to be driven thereby and thereby move said guide member within said sheath, means for engaging and disengaging said nut with said screw and a mechanical connection between said guide member and said nut arranged to release said member from said nut in the event the load on said member attains a predetermined maximum.

7. Apparatus for loading sheath wire heating units provided with a sheath, a resistance conductor within said sheath and insulating material within said sheath embedding said resistance conductor comprising means for feeding said insulating material into said sheath, means for regulating the feed of said insulating material into said sheath, a vibratory device arranged to impart intermittently impacting blows to said sheath, and means for moving said vibratory device along said sheath at a regulated rate so as to impart said blows always substantially at the level of said insulating material in said sheath while said material is being added to said sheath.

8. Apparatus for loading sheathed wire heating units provided with a sheath, a resistance conductor within said sheath and insulating material within said sheath embedding said resistance conductor comprising means for feeding said insulating-material into said sheath, means for regulating the rate of feed of said insulating material into said sheath, a vibratory device arranged to impart intermittently impacting blows to said sheath, a screw, means for operating said screw, a nut arranged to be driven by said screw, and an operable connection between said nut and said vibratory device whereby the latter is driven by said screw to progressively impart impacting blows along the length of said sheath.

9. Apparatus for loading sheath wire heating units provided with a sheath, a helical resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath in an upright position, means for holding the ends of said resistance conductor substantially in the vertical center line of said sheath, means for intermediate portions of said helical resistance conductor substantially in said center line of said sheath, a vibratory device arranged to apply impacting blows to the exterior walls of said sheath, a screw, means for operating said screw at a uniform rate, a split nut arranged to engage said screw and to be disengaged therefrom, means for engaging and disengaging said nut with said screw, a tubular member surrounding said screw connected to said nut so as to be driven thereby, means connecting said guide member and said tubular member so that said guide member is driven by said nut at a regulated rate in said sheath, and means connecting said vibratory device with said nut whereby said vibratory device is driven at a regulated rate along the exterior of said sheath.

10. Apparatus for loading sheath wire heating units provided with a sheath, a helical resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath substantially in a vertical position, means securing the ends of said resistance conductor substantially in the vertical center line of said sheath, means for supplying said powdered insulating material to said sheath at a regulated rate, a guide member within said sheath arranged to engage said resistance conductor to hold the engaged portion substantially in said vertical center line, a vibratory device arranged to impart impacting blows intermittently to said sheath to compact said insulating material, a driving screw, a split nut arranged to engage and disengage said screw, driving connections between said nut and said guide member and between said nut and said vibratory device so that when said nut engages said screw said members connected with it are driven from the lower tothe upper end of said sheath by said screw, means for driving said screw at a regulated uniform rate so that said guide member and said vibratory device move upwardly at approximately the same rate as the level of said insulating material rises in said sheath, a manually operable control device controlling said nut to engage it with said screw and means automatically releasing said nut from said screw when said guide member and said vibratory device reach approximately the upper end of said sheath. I

11. Apparatus for loading sheath wire heating units provided with a sheath, a helical resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath substantially in a vertical position, means securing the ends of said resistance conductor substantially in the vertical center line of said sheath, means for supplying said powdered insulating material to said sheath at a regulated rate, a guide member within said sheath arranged to engage a portion of said resistance conductor to hold said portion substantially in said vertical center line, a vibratory device arranged to impart impacting blows intermittently to said sheath to compact said insulating material, a driving screw, a split nut arranged to engage and disengage said screw, a driving connection between said nut and said guide member and between said nut and said vibratory device so that when said nut engages said screw said members connected with it are driven from the lower to the upper end of said sheath by said screw, means for driving said screw at a uniform rate so that said guide member and said vibratory device move upwardly at approximately the same rate as the level of said insulating material rises in said sheath, a manually operable control device controlling said nut to engage it with said screw, means automatically releasing said nut from said screw when said guide member and said vibratory device reach approximately the upper end of said sheath, and means controlled by said manually operable member controlling the feed of said insulating material to said sheath.

12. Apparatus'for loading sheath wire heating units provided with a sheath, a helical resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath substantially in a vertical position, means securing the ends of said resistance conductor substantially in the vertical center line of said sheath, a hopper for holding said powdered insulating material, a chute for directing insulating material from said hopper into said sheath, a rotary conveyer between said hopper and said chute for conveying insulating material from said hopper to said chute at a uniform rate, a driving member for operating said conveyer at a substantially uniform rate, a clutch between said conveyer and said driving member, a manually operable lever arranged to effect the engagement of said clutch, a guide member within said sheath arranged to engage said resistance conductor to hold it substantially in said vertical center line, a vibratory device arranged to impart impacting blows intermittently to said sheath to compact said insulating material, a driving screw, a split nut arranged to engage and disengage said screw, a driving connection between said nut and said guide member and between said nut and said vibratory device so that when said nut engages said screw the members connected with it are driven from the lower to the upper ends of said sheath by said screw, means for driving said screw at a uniform regulated rate so that said guide member and said vibratory device move upwardly at approximately the same rate as the level of said insulating material rises in said sheath, means operated by said lever controlling said nut to engage it with said screw and means automatically releasing said nut from said screw when said guide member and vibratory device reach approximately the upper end of said sheath.

13. Apparatus for loading sheath Wire heating units provided with a sheath, a helical resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means, for supporting said sheath in an upright position, means for holding the ends of said resistance conductor subthe lower to the upper end of said sheath, and

means responsive to the operation of said guide means and said vibratory device controlling the rate of feed of said insulating material to said sheath.

14. Apparatus for loading sheath wire heating units provided with a sheath, a resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath in an upright position, a hopper for storing said insulating material, a chute, a passageway between said hopper and said chute, means for feeding insulating material from said hopper to said chute at a regulated rate through said passageway, means mounting said chute for movement from a remote position with reference to said sheath to an operating position with reference to said sheath wherein insulating material fed to said chute is directed into said sheath, means associated with said chute for shutting off the flow of powder from said passageway into said chute when said chute is moved to said remote position and means for moving said chute between said positions.

15. Apparatus for loading sheath wire heating units provided with a sheath, a resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath in an upright position, a hopper for storing said insulating material, a chute, a passageway between said hopper and said chute, means for feeding insulating material from said hopper to said chute at a regulated rate through said passageway, means mounting said chute for movement from a remote position with reference to said sheath and an operating position with reference to said sheath wherein insulating material fed to said chute is directed into said sheath, means associated with said chute for shutting ed the flow of powder fromv said passageway into said chute when said chute is moved to said remote position, means for moving said chute between said positions, a latch for holding said chute in said operating position, a centralizing guide member arranged to be fitted into said sheath so as to engage said resistance conductor and hold said resistance conductor substantially in the center line of said sheath, means for moving said guide member at a predetermined rate from the lower to the upper end of said sheath, a vibratory device arranged to intermittently apply impacting blows to the external walls of said sheath so as to settle said insulating material in said sheath, means for moving said vibratory device from the lower to the upper end of said sheath at a regulated rate, and means responsive to the operation of said vibratory device for releasing said latch when said vibratory device reaches substantially the upper end of said sheath.

16. Apparatus for loading sheath wire heating units provided with a sheath, a helical resistance conductor within said sheath and powdered heat conducting electrically insulating material within said sheath embedding said resistance conductor comprising means for supporting said sheath substantially in a vertical position, means securing the ends of said resistance conductor substantially in the vertical center line of said sheath, a hopper for holding said powdered insulating material, a chute for directing insulating material from said hopper into said sheath, a rotary conveyer between said hopper and said chute for conveying insulating material from said hopper to said chute at a uniform rate, a driving member for operating said conveyer at a substantially uniform rate, a clutch between said conveyer and said driving member, a manually operable lever arranged to effect the engagement of said clutch, means mounting said chute for movement from a remote position with reference to said sheath and to an operative position with reference to said sheath wherein insulating material fed to said chute is directed into said sheath, means operably associated with said chute for shutting off the flow of powder from said passageway into said chute when said chute is moved to said remote position, means mechanically connecting said chute with said lever so that when said lever is operated to engage said clutch, said chute is moved to its operative position with reference to said sheath, a latch for locking said chute in said operative position, a guide member within said sheath arranged to engage said resistance conductor to hold it substantially in said vertical center line, a vibratory device arranged to impart impacting blows intermittently to said sheath to comp-act said insulating material, a driving screw, a split nut arranged to engage and disengage said screw, a driving connection between said nut and said guide member and between said nut and said vibratory device so that when said nut engages said screw said members connected with it are driven from the lower to the upper ends of said sheath by said screw, means for driving said screw at a uniform regulated rate so that said guide member and said vibratory device move upwardly at approximately the same rate as the level of said insulating material while it is being added to said sheath, means operated by said lever controlling said nut to engage it with said screw, means automatically releasing said nut fro-m said screw when said guide member and vibratory device reach approximately the upper end of said sheath, and means responsive to the operation of said vibratory device for releasing said latch when said. vibratory device reaches substantially the upper end of said sheath.

ALBERT H. SIMIMONS.

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