US2867955A - Filling apparatus - Google Patents

Description

Jan. 13, 1959 J. MCORLLY I FILLING APPARATUS Filed June 7, 1955 2 Sheets-Sheet 1 INVENTOR.

/ JOSEPH MORLLY AZZorney 1959 J. MCORLLY 2,357,955

- FILLING APPARATUS Filed Jun 7, 1955 2 Sheets-Sheet 2 F1 2 F53 Y INVENTOR. JOSEPH MORLLY BYZ After/1;

United States Patent FILLING APPARATUS .loseph Mcflrlly,.Wilkinsburg,Pa., assignor to Edwin L. Wiegand Company, Pittsburgh, Pa., a corporation of Pennsylvania Application June 7, 1955, Serial No. 513,708 8 Claims. (Cl. 53239) The present invention relates to apparatus for injectmg flowable material, more particularly to apparatus for depositing granular, electric insulating material within a tube havingan' electric conductor disposed therein, and the principal object of the inventionis to provide new and improved apparatus of such character.

For use in the manufacture of sheathed, electric resistance heating units of the type having a resistor conductor encased within a tubular sheath filled with granular, electric insulating material, there has long been employed apparatus which deposits the granular material this results in a loss of granular material and frequently results inthe necessity of removing the excess material from thesheath. Moreover,.the granular material frequently trickled from the apparatus prior to and subsequent to the filling operation; this not only resulted in a loss of granular material,.particularly when the apparatus was idleifor a period of time, but also interfered with. installation of .the lower plug in the sheath since even a few granules of material would often prevent the lower plug from seating properly.

The present invention provides simple, trouble-free apparatus which effectively controls flow of the granular material. This and other advantages will readily become apparent from a study of the following description and from the drawings appended hereto.

In the drawings accompanyingthis specification and forming a part of this application there is shown, for purpose of illustration, an embodiment which the invention may assume, and in these drawings:

Figure 1 is a fragmentary, greatly enlarged, longitudinal sectional view through apparatus embodying the present invention, and

Figures 2 through 7 are diagrammatic views illustrating a sequenceof operations employed in using the present apparatus to manufacture sheathed, electric re sistance heating units.

As in conventional apparatus, known in,the trade as filling machines, the present apparatus is adapted to fill the tubular sheath while itis vertically disposed so that the granular material rnay flow into the sheath under the influence of gravity.

Referring particularlyto Figure 1, the presently disclosed apparatus comprises an elongated hollow body it) which may take the form of a tube suspended by a support 11 to which the upper end of the tube is secured by welding or the like. A tension rod 12 is positioned within the tube10, the upper end of the tension rod being piston rods 23 anchored to actuating member 20.

secured, by any suitable means, to a fixed portion (not shown) of the filling machine. As will be disclosed, the tension rod 12 is adapted to support the usual coiled resistor R (see Figure 4) which normally has a terminal pin P at each end; and, in the present embodiment, the lower end of the tension rod is formed to provide a recess 13 having an inwardly directed shoulder 14 against which a head 15 formed in one of the terminal pins P is adapted to seat. A slot 16 is provided in the tension rod 12 adjacent recess 13 to permit the head of the terminal pin to be. positioned within recess 13 and supported by the shoulder 14.

In the em'bodimentlherein disclosed, the lower end of body 10 is turned radially inwardly at 17 and provides an annular valve seat 17a of a. diameter smaller than the exterior of the body 10. Adapted for complementary engagement with valve seat 17a is a closure member, or valve head, 18 which is preferably of a diameter no larger than the exterior of the body 10. In. the present embodiment, valveghead'18' comprises a ring-like member welded or otherwise secured to the lower end of a tubular valve stem 19 which surrounds the tension rod 12 andwhich has an'internal bore sufficiently large to pass over one ofthe terminal pins P and the coiled resistor R.

Valve stem 19 extends upwardly of support 11 and is secured by-weldingor, the like to an actuating member 20 carried by support ll-and resiliently urged away therefrom by means of springs 21 to resiliently maintain the'valve head 18 against its seat. Means are provided for moving the valve head away from its seat, such means presently being shown to comprise one or more fluid cylinders 22 secured to support 11 and having It will readily be apparent that when fluid is admitted to the rod end of cylinder v22 (or cylinders, if more than one is employed), actuating member 20 will be drawn toward support 11 against the resiliency of springs 21. This will move valve stem 19 downwardly relative to body 10 and thus shift the valve head away from its seat. When fluid is exhausted from the cylinder, springs 21 will immediately reseat the valve head.

Interposed between valve stem 19 and body 10 and for a purposeto be disclosed is a tubular sleeve 24 whose upper end is anchored by welding or the like to support 11 and whose lower end extends to a point just short of the end of the body 10. At the present time, the lower end of sleeve '24 is maintained generally concentric with body 10 by forming a plurality of inwardly directed dimples 25 in thebody 10 adjacent the lower end of sleeve 24. These dimples engage the exterior of the sleeve and thus holdjit centralized within the body.

Carried by support .11 is a hopper 26 which is adapted to be filled with the usual granular, electric insulating 'material which is employed in the manufacture of sheathed electric heating units. A passageway 27 is formed in support 11 through which the granular material may flow from the hopper 26 to fill the annular space between the interior of body 10 and the exterior of sleeve 24. As will be.apparent, sleeve 24 prevents the granular material from packing about the valve stem 19 (except for the extreme lower endthereof) and this greatly reduces the force necessary to reciprocate the valve stem since friction between the valve stem and the granular material is largely eliminated.

When :the valve head is moved to its dot-dash line position in Figure 1, granular material will gravitate from the lower end of body 10, the discharged material immediately being replaced by flow of material from thehopper. In orderto assist the flow of materiaL-support 11 and the parts carried thereby are usually vibrated by any suitable means (not shown).

For a purpose to appear, support 11, actuating member 20, and all parts carried thereby, are mounted for vertical, unitary movement relative to the tension rod 12 by any suitable means which have not been shown since such means forms no part of the present invention.

With the parts in the initial position shown in Figures 1 and 2, the use of the apparatus will be as follows: A tubular sheath S, of any type suitable to encase the resistor and herein shown to have an annular groove 28 which provides an inwardly directed shoulder adjacent its lower end, is slipped over the body 10 and maintained in the position shown in Figure 3 by a suitable clamp or any other means (not shown). A resistor assembly comprising the usual coiled resistor R having upper and lower terminal pins P secured to respective ends thereof is then hung on the tension rod 12 (see Figure 4) by positioning the head 15 of the upper terminal pin P in the recess 13 provided in the end of tension rod 12 in the manner heretofore disclosed. For reasons to appear, lower terminal pin P is knurled at 29 or otherwise formed to provide a shoulder against which is seated a dielectric plug 30 normally pre-assembled over the lower terminal pin P and which, in the present embodiment, forms a part of the resistor assembly hung upon the tension rod.

With the parts positioned as shown in Figure 4, both the sheath S and support 11, together with body 10 and all the parts carried thereby, will be lowered relative to the stationary tension rod 12 until the plug 30 enters the lower end of the sheath and seat against the inwardly directed shoulder provided by annular groove 28 and until valve head 18 is disposed adjacent plug 30 as shown in Figure 5.

At this time, fluid will be admitted to cylinder 22 to effect movement of actuating member 20 and valve head 18 to their respective dot-dash line positions (Figure 1) to permit flow of granular material from body 10. Substantially simultaneously, support 11 and all the parts carried thereby will be slowly raised as a unit (while maintaining the sheath S in the position shown in Figures and 6) to fill the sheath with refractory material and embed the resistor R therein.

Since the upper end of the heating unit herein disclosed is adapted to be closed by a plug 31 which is similar to plug 30, sufficient space must be provided at the upper end of the sheath to receive such plug. This is easily accomplished by exhausting the fluid from cylinder 22 just prior to the time that the sheath is entirely filled with granular material to permit springs 21 to return valve head 18 to its seat and thus arrest the flow of material from body 10. Since the flow of material is completely out off, a void 32 will be provided at the upper end of the sheath (see Figure 6).

With the parts in the position shown in Figure 6, the heating unit will be removed from the apparatu by unclamping the sheath S and by unhooking upper terminal pin P from tension rod 12. Plug 31 will then be positioned in void 32 and about the upper terminal pin to prevent escape of the granular material from the sheath. At this time, the heating unit may be put aside for subsequent swaging or other operations and the foregoing operations repeated to assemble and fill another heating unit. While assembly and filling of only one heating unit at a time has ben disclosed, it will be appreciated that a plurality of bodies 10, together with all the attendant parts, may be arranged for simultaneous operation so that a plurality of heating units may be assembled and filled concurrently.

In view of the foregoing it will be apparent to those skilled in the art that I have accomplished at least the principal object of my invention and it will also be apparent to those skilled in the art that the embodiment herein described may be variously changed and modified, without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described, hence it will be appreciated that the herein disclosed embodiment is illustrative only, and that my invention is not limited thereto.

I claim:

1. Apparatus for depositing granular, electric insulating material within a tube having a conductor member adapted to be positioned in spaced relation to its inner wall, comprising a generally vertically disposed, elongated hollow body transversely sized for insertion within said tube and having a lower end portion which provides a valve seat and from which said material issues and an upper portion into which said material is adapted to be introduced for gravitation through said body to its lower end portion, a tubular member fixedly disposed within said body and transversely spaced therewithin to define therebetween an annular space for said material, and a hollow valve stem slideably positioned within said tubular member and extending longitudinally of said tubular member and said body and having a transverse internal size sufficiently large to freely pass said conductor member, said valve stem having a lower portion provided with a radial enlargement cooperable with the valve seat provided by the lower end portion of said body for blocking flow of material from the latter, and said valve stem being shiftable within said tubular member and longitudinally of said body to selectively provide for gravitation of said material from the lower end portion of said body into said tube and about said conductor member.

2. Apparatus for depositing granular, electric insulating material within a tube having a conductor member adapted to be positioned in spaced relation to its inner wall, comprising a generally vertically disposed, elongated hollow body transversely sized for insertion within said tube and having a lower end portion which provides a valve seat and from which said material issues and an upper portion into which said material is adapted to be introduced for gravitation through said body to its lower end portion, a tubular member fixedly disposed within said body and transversely spaced therewithin to define therebetween an annular space for said material, a hollow valve stem slideably positioned within said tubular member and extending longitudinally of said tubular member and said body and having a transverse internal size sufiiciently large to freely pass said conductor member, said valve stem having a lower portion provided with a radial enlargement cooperable with the valve seat provided by the lower end portion of said body for blocking flow of material from the latter, and mechanism for holding said valve stem in position wherein its radial enlargement engages with said valve seat to block flow of material from said body and for shifting said valve stem within said tubular member and longitudinally of said body to move said radial enlargement away from said valve seat to provide for gravitation of said material from the lower end portion of said body into said tube and about said conductor member.

3. Apparatus for depositing granular, electric insulating material within a tube having a conductor member adapted to be positioned in spaced relation to its inner wall, comprising a generally vertically disposed, elongated hollow body transversely sized for insertion within said tube and having a lower end portion which provides a valve seat and from which said material issues and an upper portion into which said material is adapted to be introduced for gravitation through said body to its lower end portion, a tubular member disposed within said body and having its upper end extending outwardly of the upper end of said body and having its lower end terminat ing short of the valve seat provided by said body, said tubular member being transversely spaced within said body to define therebetween an anular space for said material, support means to which the respective upper ends of said body and said tubular member are secured, a hollow valve stem slideably positioned within said tubular member and having an upper end extending beyond the pper ,end of tubular member and a lower end extending beyond the lower end of the later and terminating adjacent the valve seat provided by said body, said valve stem having a transverse internal size sufliciently large to freely pass said conductor member and the lower end of said valve stem being provided with a radial enlargement cooperable with the valve seat provided by the lower end portion of said body for blocking flow of material from the latter, resilient means interposed between said support means and said valve stem for yieldably urging the latter to position wherein its radial enlargement engages with said valve seat to block flow of material from said body, and means selectively operable to overcome the urging force of said resilient means and to shift said valve stem within said tubular member and longitudinally of said body to move said radial enlargement away from said valve seat to provide for gravitation of said material from the lower end portion of said body into said tube and about said conductor member.

4. Apparatus for depositing flowable electric insulating material in embedding relation with respect to a resistance conductor which extends longitudinally of an upright sheath and is spaced from the interior surface of said sheath, comprising a first tubular member transversely sized for insertion within said sheath and having an upper portion into which said material is introduced and an open lower end portion providing a valve seat through which said material may flow to the interior of said sheath, an elongated hollow valve stem longitudinally positioned within said first tubular member and being of a transverse internal size to freely pass said resistance conductor, said valve stem having a valve head at its lower portion which is engageable with said valve seat to block the flow of insulating material through the latter, said valve stem being longitudinally shiftable relative to said first tubular member to selectively seat and unseat said valve head, and a protective tubular member interposed between said first tubular member and said valve stem substantially throughout the coextensive extent of the latter two, said protective member freely receiving said valve stem for longitudinal movement and being spaced from the interior surface of said first tubular member to provide an upright peripheral Space through which said insulating material may flow to said valve seat without contact with said valve stem, whereby the latter is substantially free of engagement with said insulating material and thereby requires only a relatively light force to shift it.

5. In the art of making electric heating elements comprising an elongated tubular sheath, a resistance conductor extending longitudinally of said sheath and flowable electrical insulating material holding said resistance con ductor spaced from the inner sheath wall, apparatus for depositing said flowable insulating material within said sheath comprising an upright outer elongated tubular member of a transverse size to freely fit longitudinally within said sheath, means providing for entrance of said llowable insulating material to an upper inner portion of said outer member, an inner elongated tubular member within said outer member, and an elongated tension rod member within said inner tubular member and connectable to an end portion of said resistance conductor to maintain the latter taut and spaced from the inner sheath wall during deposition of insulating material, said inner tubular member having a transverse dimension so as to be spaced from the inner wall surface of said outer tubular member and to freely receive and pass said tension rod member and the connected resistance conductor, adjoining lower portions of said outer and inner tubular members being formed with cooperating valve member and valve seat parts to control flow of said insulating material from the lower portion of said outer tubular member and into said sheath, and said outer and inner tubular member being relatively shiftable in a longitudinal manner to provide for selective engagement and disengagement of said valve member and valve seat.

6. The construction according to claim 5 wherein the lower portion of said outer tubular member is formed with a valve seat and the adjoining portion of said inner tubular member is provided with a radial enlargement to form the cooperating valve member.

7. The construction according to claim 5 wherein the said inner tubular member is shiftable longitudinally within said outer tubular member to selectively engage and disengage said valve member and valve seat, resilient means normally urging said inner tubular member in a longitudinal direction to maintain the valve member engaged with said valve seat, and means operable to overcome the force of said resilient means and shift said inner tubular member in an opposite longitudinal direction to disengage said valve member from its seat.

8. The construction according to claim 5 wherein said inner tubular member is shiftable longitudinally within said outer tubular member to selectively engage and disengage said valve member, and a protective tubular member interposed between said outer and inner tubular members substantially throughout their coextensive exten to free said inner tubular member of drag induced by the flowable insulating material within said outer tubular member.

References Cited in the file of this patent UNITED STATES PATENTS 2,319,573 Abbott May 18, 1943 2,337,304 Ashton Dec. 21, 1943 2,663,479 Detrez Dec. 22, 1953 2,718,990 Douchet Sept. 27, 1955 FOREIGN PATENTS 456,323 Great Britain Nov. 6, 1936

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