US2736786A - Resistor structure - Google Patents

Description

Feb. 28, 1956 R. E. DU BOIS RESISTOR STRUCTURE 2 Sheets-Sheet Filed Nov. 12, 1955 .HHIIIILF INVENTOR ATTORNEY Feb. 28, 1956 DU 015 2,736,786

RESISTOR STRUCTURE Filed Nov. 12, 1953 2 Sheets-Sheet 2 5 5 7 5 6 I 1 Q a {3 i l r F 5 l I I i i fly] a i l a F i i L90- l i s? i w N a W30 5 W O \izgfi I N VE NT( )R ATTORNEY United States Patent RESISTOR STRUCTURE Robert E. Du-Bois, Hammond, Ind. Application November 12, 1953, Serial No. 391,569

4 Claims. (Cl. 201-69) This invention relates generally to improvements in resistor structures and more particularly to resistor structures made up of a plurality of individual resistor grid units.

The primary object of this invention is to provide an improved and simplified resistor structure consisting of a plurality of readily removable and replaceable individual grid units.

A specific object of this invention is to provide a group of individual removable resistor grid units housed in a common frame with a plurality of terminals.

Another object of this invention is to provide a new and improved terminal structure with its attending securing structure in a resistance structure.

A further object of this invention is to provide an improved mounting structure for a plurality of grids in the frame of a resistor structure.

With the foregoing and other objects in view the invention resides in the following specification and appended claims, certain embodiments and details of construction of which are illustrated in the accompanying drawings, in which:

Figure 1 is a partial view in front elevation of the resistor structure of the invention;

Figure 2 is a bottom plan view of the structure illustrated in Figure 1;

Figure 3 is a sectional end view taken along the lines 3-3 of Figure 1;

Figure 4 is a partial view in section of the! structure in front elevation; and

Figure 5 is an exploded view of the various resistor details and adjuncts thereof included in the resistor structure of this invention.

Referring more particularly to Figure 1, the resistance structure 1 includes channel-shaped end frame members 2 (only the left end member being shown), a top member 3 and end frame connecting rails 4. These frame members are welded together into a rigid unit. Welded to the underside of top members 3 are a pair of angle members 5 and 6. Frictionally held between the angle members is an insulator strip 7. The strip 7 is provided with a plurality of evenly spaced holes 8 for a purpose to be later described.

Referring more particularly to Figures 2 and 3 it may be seen that the base 9 comprises a plurality of insulator sections 10 and 11. Sections 10 and 11 are provided with complementary slots 12 and 13 to accommodate and hold terminal elements 14. The insulator sections 10 and 11 are secured in position by through bolts 15 which extend, as shown from below the insulator sections, to the upper side of top member 3. The head 16 of each bolt is spaced from member 3 by a washer 17. The threaded end of each bolt is provided with a nut 18 pressing, when tightened, against a washer 19. With the bolts 15- secured in this manner the insulator sections 10 and 11 are held firmly against frame rails 4.

Within the frame members are a plurality of grids 20.

2,736,783 Patented Feb. 28, 1956 Adjacent grids are alternately bridged at one end electrically by conducting blocks 21, the blocks being welded to the grids. Welded to the blocks 21 at desired points are the terminal elements 14; the ends of grids 20 which are not bridged by blocks 21 are bridged by conducting elements 22, said grids being welded to the elements 22. Each element 22 is provided with a pair of projecting guide pins 23. I

As illustrated, particularly in Figures 1 and 2, the grids 21 and insulators 10 and 11 are formed in units 24, 25 and 26. Each of the units includes several grid-s, terminals, bridging blocks, insulators, and connecting elements. It will now be obvious that in order to connect all of the resistance units together, it will only be necessary to electrically connect adjacent terminals 27 and 28, and 29 and 30 together by suitable means, not shown. This connection is desirably readily removable in order that an entire resistance unit may be removed from the structure should any of the grids become damaged.

To remove a unit from the structure 1 it is merely necessary to remove the retaining nuts 18 from bolts 15 holding the particular unit in place. When this is accomplished, the bottom insulator sections 10 and 11 will drop out and divide, permitting the connected grid assembly of the unit to drop out of the structure 1. A replacement unit may then be substituted by merely replacing the sections 10 and 11 about the terminals 14 of the new unit and rebolting the said sections to the frame. Obviously the pins 23 of elements 22, during re-assembly, are positioned in holes 8 of insulator strip 7 to guide and retain the top end of the grid assembly, as viewed in Figure 1. Under conditions of use of the resistor, the heat generated in each grid, due to the passage of current, will cause the same to expand longitudinally in pairs. The pins 23 under non-use conditions of the resistor, will only extend partly into holes 8. Under heated or use conditions the pins will freely move upwardly in the holes, thereby permitting the expansion of the grids while preventing the buckling of the same.

It should now also be readily appreciated that by providing a plurality of terminals 14, any amount of desired resistance for a particular circuit use may be had by merely selecting the proper terminals for connection in the circuit.

Thus, it is seen that this invention provides a simple, compact and economical resistor structure which will lend itself to many uses with both ease of assembly and disassembly, as well as practicability of manufacture.

I claim:

1. A resistor structure comprising a supporting frame, a plurality of grid units within said frame, insulator means secured to the frame for freely carrying the tops of the grid units, insulator means for holding and positioning the bottoms of the grid units, and means for removably securing said bottom grid unit insulator means to the frame to permit ready removal of the grid units from the frame.

2. A resistor structure comprising a supporting frame, a plurality of grid units within said frame, insulator means secured to the frame for freely carrying the tops of the grid units, divided insulator means for holding and positioning the bottoms of the grid units, and means for removably securing said divided insulator means and thereby the grid units to the frame.

3. A resistor structure comprising a supporting frame including a top member, end members connected to the top member, means adjacent the bottoms of the end members for connecting said end members rigidly together, a plurality of grid units with said frame, each unit including individual grid elements connected alternately at their tops by conducting elements and at their bottoms by condue-tor bloc-ks with each element having guide pinsextending therefrom and each block having a terminal extending therefrom, an insulator strip provided With a plurality or' spacedholessecured to the under-side of the top-frame member, divided insulator members enclosing the-extendingterminals of the-grid units to positionand hold said units, and means cooperating with said divided insulator members to removably secure the grid units Withinthe frame.

4 A resistor structurecornpri-singa supporting frame, a plurality of grid units within said frame, each grid-unit havingat least one extending terminal, insulator means securedto the frame forfreely carrying and positioning- References Cited in'the file of this patent UNITEDSTATES PATENTS 684,791 Cal'ichofi v Oct. 22, 1901 1,755,350 Fahrenwald' Apr; 22, 1930 2,156,832 Ayers May-2,1939

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