US2151799A - Tubular resistor and support therefor - Google Patents

Description

March 28, 1939. H. G. RICHTER TUBULAR RESISTOR AND SUPPORT THEREFOR Filed April 6, 1936 INVENTOR Hem- G. Richrer BY f ATTORNEYS the same;

Patented Mar. 28, 1939 TUBULAR RESISTOR AND SUPPORT THEREFOR Henry G. Richter, Westfield, N. J., assignor, by mesne assignments, to P. R. Mallory & Co., Inc., Indianapolis, Ind.,-a corporation of Delaware Application April 6, 1936, Serial No. 72,956

stock by the same die equipment as is used for the support of Fig. 5; and

Fig. 7 is a side elevation of a resistor provided with supports bolted together by a through bolt for extreme rigidity.

Referring to the drawing and more particularly to Figs. 1, 2, and 4, the invention comprises a resistor R supported by end supports S. The resistor B may be conventional and is of the tubular type. It comprises a tube or hollow cylinder l2 made of porcelain or ceramic or other suitable insulation on which is wound a resistance winding the turns of which are indicated at M in Fig. 1. Metallic soldering lugs l6 are secured about the end turns of the resistance winding and engage the same with a tight fit in order to insure good electrical contact. The entire exterior of the resistor may, if desired, be coated with a suitable coating I8 of enamel which may be baked or fused to make the unit moisture-proof. The ends of the soldering lugs are, of course, uncoated and available for connection to appropriate wiring leading to and from the resistor. The interior of the tube or core I2 is, of course, left unpainted.

The supports S are struck from relatively heavy-gauge sheet metal and are therefore sturdy and rigid. Nevertheless, they are secured to the resistor 'R. in tight frictional engagement obtained by compressing the side edges of the supports together within the resistor. Each support comprises a resistor-penetrating portion 20, a depending leg portion 22, and a sidewardly bent foot 24. The resistor may be positioned Vertically or. at an angle, but it is most commonly arranged horizontally, and it is therefore convenient to consider the resistor-penetrating portion 20 to be horizontal, the leg portion 22 to be upright or approximately vertical, and the foot portion 24 to be horizontal. It will be understood, however, that theseterms are employed only for convenience, and are not to be construed by way of limitation.

The resistor-penetrating portion 20 is made of a width from side edge to side edge which is at least slightly greater than the internal diameter of the resistor unit. It is slit or cut away at the center, as is indicated by the slot 2| preferably extending for the entire length of portion 20. The inner end of portion 20 is preferably cut at an angle, as is indicated by the sloping edges 26. This, of course, facilitates assembling the supports with the resistor, for it is simply necessary to push the end of the resistorpenetrating-portion 20 into the end of the re- 8 Claims.

invention relates to tubular resistors, and more particularly to such a resistor arranged with a simplified advantageous mounting support.

The primary object of the present invention is to generally improve tubular resistors and the feet or mounting supports for such resistors. A more particular object resides in the provision of a mounting support which is simple and inexpensive in construction; which may be received within the resistor by compressing parts of the support, yet which may be made of heavy-gauge metal, resulting in a sturdy and rigid support; which may be moved longitudinally of the resistor for a substantial distance, thereby accommodating the supports to. the spacing of mounting holes or other variable mounting conditions encountered by manufacturersusing the resistor; and which does not impede free circulation of air through the interior of the resistor for rapid heat dissipation.

Still another object of the invention is to so design the supports that supports for different sizes or diameter resistors may be made with a single die equipment, it being merely necessary to change the width of the strip or blank stock being run through the die. A further object of theinvention is to make possible an absolutely rigid assembly of supports and resistor where especially stringent requirements are to be met, it being necessary for this purpose only to run a through bolt between the supports.

To the accomplishment of the foregoing and other objects which will hereinafter appear, my invention consists in the resistor and support elements, and their relation one to the other, as hereinafter are more particularly described in the specification and sought to be defined in the claims. The specification is accompanied bya drawing in which:

Fig. 1 is a partially sectioned. side elevation of a resistor provided with supports embodying features of my invention;

Fig. 2 is an end elevation of the same;

Fig. 3 is an end elevation showing the manner in which the supports may be orientated with respect to the resistor;

Fig. 4 is a perspective view of one of the sup-- ports;

Fig. 5 illustrates the form-in which the support is blanked out of strip stock before bending Fig. 6 is a similar view showing how a support of greater width may'be blanked out of wider sistor. The side edges of the resistor-penetrating portion are then compressed together by the interior wall of the resistor, resulting in a tight frictional engagement therebetween.

The slit 2| is preferably carried downwardly through at least part of the leg portion 22, as is indicated at 28. Moreover, the end of slot 28 may, if desired, be enlarged, as is indicated at 30. This construction facilitates compression of the side edges of the resistor-penetrating portion 20 and permits the side edges to come together while retaining substantial parallelism. It ls therefore possible to slide the support axially with respect to the resistor, the support being pushed entirely into the resistor, as is indicated in Fig. 7, or left partially out of the resistor, as is indicated in Fig. 1. The parallel relation of the side edges of the support within the resistor provides a better and more secure engagement therebetween, for there is line contact rather than point contact.

Moreover, feet 24 are perforated with mounting holes 32 adapted to receive screws or bolts 34, as is clearly shown in Figs. 1 and 2. The axial movability of the supports with respect to the resistor makes it possible'to readily accommodate variations in spacing between the holes in the base 36 on which the resistor is being mounted.

The manner in which the resistor and supports are assembled together is advantageous for the additional reason that the supports may be rotated or orientated with respect to the resistor and more particularly the soldering lugs l6 thereon. For example, if it is desired to dispose the soldering lugs at the top of the resistor while mounting the resistor on a vertical wall, it is simply necessary to turn the supports S through a quarter revolution with respect to the soldering lugs [6, resulting in a relative disposition of parts shown in Fig. 3. This is also useful when it is desired to place the soldering lugs horizontally while mounting the resistor on a horizontal base or bottom.

The resistor and support assembly thus far described is satisfactory for all ordinary purposes. On rare occasions, however, a purchaser or user of the resistor may require an assembly in which the supports and the resistor are locked together with absolute rigidity. In accordance with my invention, this contingency is provided for in advance, by the provision of one or more holes, for example the hole 40 in the various figures of the drawing. Where the leg 22 is slotted as in the present case, the hole 40 is in effect an enlargement of the slot 28. This hole or enlargement is adapted to receive a suitable through bolt 42. Referring to Fig. 7, it will be evident that a bolt 42 is passed through hole 40 in one support and extends within the resistor to 7 its opposite end where it passes through the corresponding hole 40 in the opposite support. By applying a nut 44 over the threaded end of the bolt and tightening the same, the supports are clamped securely and immovably against the ends of the resistor.

The through bolt is preferably located inside the resistor because the inner faces of the legs 22 are then pulled tightly against the outer ends of the resistor. The holes 40 are accordingly preferably located near the resistor-penetrating portions 2|]. Thedistance of hole 40 from the resistor-penetrating portion must, of course, be less than half the width of the latter portion and ispreferably made substantially less.

Referring to Fig. 2, it will be noted that the enlargement 30 is itself preferably made in the form of a hole, and this hole may be disposed below the core of the resistor, thus making it possible to employ a through bolt located outside the core. As before stated, I consider it preferable to locate the through bolt inside the core. Of course, the primary function of the enlargement 3B is to facilitate compression toward one another of the side edges of the penetrating portion. It also makes possible the use of two through bolts,

'one inside and one outside the core.

From the viewpoint of the manufacturer of the present supports, there is another important advantage which has not yet been mentioned. This advantage will be apparent by comparison of Figs. 5 and 6 of the drawing, which show two embryo supports of different width, these being designed for use with resistors of different internal diameter. It will be noted that the die for cutting the slots 2| and 28, the enlargements 30 H and 40, the sloping ends 26, and the mounting hole 32, may all be identical for either width of resistor. The essential difference resides in the spacing apart of the side edges. If the supports are stamped from strip or blank stock having the desired width, it is then possible to run stock of difierent widthsthrough a single die, the die being provided at its entrant and exit ends with suitable centering means for locating the strip of stock symmetrically with respect to the cutting portions of the die.

The blanks illustrated in Figs. 5 and 6 are subsequently finished by bending the same on the dotted lines 50 and 52.

It is believed that the construction and mode of use of my improved supports and their combination with tubular resistors, as well as the many advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that while I have shown and described my invention in preferred form, many changes and modifications may be made in the structure disclosed, without departing from the spirit of the invention, defined in the following claims.

I claim:

1. A support for a tubular cored resistance ele ment, .said support comprising a piece of sheet metal strip bent to form a single-thickness corepenetrating portion, a transverse leg portion, and a foot portion, the core-penetrating portion being longitudinally slit to make the same somewhat compressible from one longitudinal side edge to the other longitudinal side edge.

2. A support for a tubular cored resistance element, said support comprising a piece of sheet metal strip bent to form a flat single-thickness core-penetrating portion, and a transverse leg portion, the core-penetrating portion being portion, the core-penetrating portion being slotted throughout its length and the leg portion being slotted with a slot connected to and forming an extension of the aforesaid slot, thereby affording compressibility of the resistor-penetrating portion from side edge to side edge.

3. A support for a tubular cored resistance element, said support comprising a piece of sheet metal bent to form a single-thickness core-penetrating portion, a transverse leg portion,.and a sidewardly bent foot, the core-penetrating portion being longitudinally slit in order to make the same somewhat compressible from side edge to side edge, the foot having a hole out therethrough for securing the same to a suitable support, and said leg portion being provided with a hole adapted to so receive a through bolt that said bolt will pass within the resistance element.

4. A support for a tubular cored resistance element, said support comprising a piece of sheet metal bent to form a single-thickness core-penetrating portion and a transverse leg portion, thecore-penetrating portion and the leg portion being slit with a continuous slit in order to aiTord compressibility of the core-penetrating portion from side edge to side edge, the slit of said leg portion being enlarged to form a hole adapted to receive a bolt 5. In combination, a tubular insulation core, a resistance winding thereon, and support members at each end of the core for supporting the resistor, said support members including a strap of sheet metal bent to form a single-thickness portion received axially within the end of the resistor core, a transverse leg portion for spacing the resistor from a base, and a sidewardly bent foot portion adapted to be secured to the base, the core penetrating portion being longitudinally slit and so dimensioned that its longitudinal side edges are compressed toward one another by the internal wall of the core.

6.v In combination, a tubular insulation core, a resistance winding thereon, and support members at each end of the core for supporting the resistor, said support members including a strap of relatively heavy-gauge sheet metal bent to form a single-thickness penetrating portion received axially within the end of the resistor core, a transverse leg portion for spacing the resistor from a base, and a sidewardly bent foot portion adapted to be secured to the base, the penetrating portion and leg portions being slit with a continuous slit, and the side edges of said penetrating portion being compressed together by the internal wall of the resistor core.

'7. In combination, a tubular insulation core, a resistance winding thereon, and support members at each end of the core for supporting the resistor, said support members consisting of a strap of sheet metal bent to form a single-thickness penetrating portion received axially within the end of the core, and a transverse leg portion, the penetrating portion being slit and its side edges being compressed together by the internal wall of the core, the transverse portions of the supports being provided with one or more holes, and a tie member extending through said holes from one of said supports to the other.

8. In combination, a tubular insulationcore, a resistance winding thereon, and support members at each end of the core for supporting the resistor, said support members consisting of a strap of relatively heavy-gauge sheet metal bent to form a penetrating portion received withinathe end of the resistor core, a leg portion for spacing the resistor from a base, and a sidewardly bent foot adapted to be secured to the base, the penetrat ing portion and leg portion being slit with a continuous slit, and the sideedges of said penetrating portion being compressed together by the internal wall of the resistor core, the slits of the leg portions being enlarged to form holes near the penetrating portions, and a through bolt extending through said holes and core from one of said legs to the other and serving to clamp the supports tightly together against the ends of the core.

HENRY G. RICHTER.

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