US3393391A

US3393391A - Panel mounted resistor

Info

Publication number: US3393391A
Application number: US572431A
Authority: US
Inventors: Darwin L Rakowsky
Original assignee: Dale Electronics Inc
Current assignee: Dale Electronics Inc
Priority date: 1966-08-15
Filing date: 1966-08-15
Publication date: 1968-07-16
Anticipated expiration: 1985-07-16

Description

July 16. 1968 0. L. RAKOWSKY 3,393,391

PANEL VOUNTED RESI STOR Filed Aug. 15, 1966 United States Patent 3,393,391 PANEL MOUNTED RESISTOR Darwin L. Rakowsky, Columbus, Nelm, assignor to Dale Electronics, Inc., Columbus, Nebr., a corporation of Nebraska Filed Aug. 15, 1966, Ser. No. 572,431 7 Claims. (Cl. 338-271) ABSTRACT OF THE DISCLGSURE A resistor having one end secured to a metal housing by means of a threaded fastener thereby causing the housing to be common to one terminal such that the housing serves as a terminal of the resistor.

An object of this invention is to provide a resistor which has a minimum number of parts.

A further object of this invention is to provide a resistor which is easy to manufacture.

A further object of this invention is to provide a resistor which is economical of manufacture.

A further object of this invention is to provide a resistor which permits the reduction in overall length thereof thereby allowing for compact assembly.

It is a further object of this invention to provide a resistor wherein only one terminal protrudes from the housing thereby allowing for a solid ceramic core which will result in an increase of the resistor power rating and a stronger resistor body or core.

A further object of this invention is to provide a resistor wherein one end of the resistance means is secured to the housing which permits the resistor to withstand severe shock.

A further object of this invention is to provide a more stable resistor due to the fact that the hot spot of the resistor will be uniform to the end of contact rather than at the center thereof.

A further object of this invention is to provide a resistor housing which can be mounted on a panel board or chassis by utilizing an internally threaded hole or a clearance hole and nut.

A further object of this invention is to provide a resistor wherein intimate contact is created between the resistor-housing-mounting panel which provides a greater amount of heat dissipation.

A further object of this invention is to provide a resistor which is durable in use.

These and other objects will be apparent to those skilled in the art.

This invention consists in the construction, arrangements, and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings in which:

FIG. 1 is a perspective view of the resistor;

FIG. 2 is an end view of the resistor as would be seen on line 2-2 of FIG. 1;

FIG. 3 is a side view of the resistor;

FIG. 4 is a longitudinal sectional view of the resistor; and

FIG. 5 is an exploded perspective view of the resistance means and end cap assemblies.

The numeral generally designates the resistor of this invention and includes a hollow metal housing 11 and a resistance means 13. Housing 11 includes a body portion 15 having a cylindrical cavity 17 formed therein, and

end portions

19 and 21. Housing 11 is provided with an externally threaded portion 23 adjacent end 21 and is provided with an internally threaded opening 25 formed therein at the center of end 19. Housing 11 is provided with a plurality of fin members 27 extending radially outwardly from body portion 15 as illustrated in FIGS. 1, 3 and 4. A fin member 29 also extends radially outwardly from body portion 15 and has a thickness greater than each of the individual fin members 27. The various fin members on housing 11 are spaced apart as seen in the drawings and may be of hexagonal shape in section to facilitate the attachment of the resistor to the mounting panel or chassis.

Resistance means 13 is comprised of a solid ceramic core 31 which may have a resistance film provided thereon or a resistance wire means mounted thereon in con ventional fashion. A cap means 33 is mounted on one end of resistance body 31 and is secured thereto by any convenient means. The cap means 33 is electrically connected to one end of the resistance means 13 and has an externally threaded stud portion 35 extending therefrom. A cap means 37 is mounted on the other end of resistance body 31 and is secured thereto by any convenient means. Cap means 37 is electrically connected to the resistance means and has a terminal assembly 39 secured thereto and extending outwardly therefrom as best seen in FIGS. 4 and 5. The cap means 33 and 37 are electrically connected to opposite ends of the resistance means on the resistance body 31.

The resistor 10 is assembled by simply inserting resistance means 13 into cavity 17 and threadably securing resistance means 13 to housing 11 by causing stud means 35 to be threadably received by opening 25 in end 19 of housing '11. This mode of securing resistance means 13 to housing 11 causes intimate electrical contact between cap means 33 and housing 11 only at end 19. A suitable insulation means or potting compound is then poured, transferred or injected into the cavity 17 around resistance means 31 as best illustrated in FIG. 4 to completely insulate the remainder of the resistance means from housing 11. As seen in FIG. 4, terminal assembly 39 protrudes outwardly of housing 11 at end 21. If desired, end 21 of housing 11 could be constructed to threadably receive the stud 35 thereby allowing terminal assembly 39 to protrude outwardly of housing 11 from end 19. In other Words, the terminal assembly 39 would be positioned opposite to the externally threaded portion 23 on the housing 11.

The resistor 10 is then secured to a mounting panel 42 or chassis by simply extending threaded portion 23 through a suitable aperture therein and threadably securing a nut means 41 thereon. The aperture in the mounting panel or chassis could also be internally threaded and adapted to threadably receive the threaded portion 23 which would eliminate the need of a nut 41. Terminal assembly 39 would then be electrically connected to the desired circuit. In effect, the housing 11 serves as one terminal of the resistance means while terminal assembly 39 serves as the other terminal. This results in intimate contact of resistor-housing-mounting panel thereby permitting a greater amount of heat dissipation. In conventionally housed resistors, the entire resistor is electrically insulated from the housing and the insulating compound permits less heat dissipation. The construction of resistor 10 results in a net reduction of necessary parts and is extremely easy to manufacture. The insulating process referred to above could be accomplished by any potting process such as pouring or filling the cavity, with a resinous fluid and then curing the resin causing the fluid to become solid. The configuration of the resistor permits a reduction in overall length thereby allowin for compact assembly. The panel mounted resistor of this invention has only one terminal protruding from the housing, thus permitting the use of a solid ceramic core. This results in an increase of the resistor power rating and a stronger resistor body or core. The resistance means, being fastened to the housing, will withstand severe shocks or jolts. The limiting factor of the power rating of a resistor is the temperature of the hot spot of the resistor which is usually located at the center thereof. In this invention, the temperature will be uniform to the end of contact, thus provi-ding a more stable resistor.

Thus from the foregoing it can be seen that the device accomplishes at least all of its stated objectives.

Some changes may be made in the construction and arrangement of my resistor without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. In a resistor,

a hollow metal housing having opposite ends,

said housing having one of its ends externally threaded and adapted to be received by an opening in a supporting means for threadable attachment thereto,

an elongated resistance means in said hollow housing and having a terminal means at one end thereof extending outwardly of one end of said housing,

said resistance means being threadably, detachably and electrically connected at its other end to the other end of said housing,

and insulation means between said housing and said resistance means along the length thereof.

2. The resistor of claim 1 wherein said resistance means is comprised of a resistance body having first and second electrical conductive cap means secured to the opposite ends thereof, said first cap means having a threaded stud extending therefrom which is threadably secured to said other end of said housing.

3. The resistor of claim 2 wherein said second cap means includes said terminal means and which is adapted for lead connection.

4. The resistor of claim 1 wherein said housing includes a body portion which is hexagonal in section.

5. The resistor of claim 4 wherein said body portion has a plurality of fin members extending therefrom.

6. The resistor of claim 1 wherein said housing has an internal cavity having a diameter greater than said resistance means and has a length less than said resistance means, said housing having a shoulder portion thereon laterally of said externally threaded portion.

7. The resistor of claim 1 wherein said resistance means extends only from said one end of said housing.

References Cited UNITED STATES PATENTS 1,910,866 4/1933 Van Nostrand 338-271 X 2,492,755 12/1949 McCollum 338-271 X 2,640,132 4/1953 Thom 338-268 X 2,768,267 10/1956 Pass 338-332 X FOREIGN PATENTS 553,302 11/1929 Germany.

LARAMIE E. ASKIN, Primary Examiner.

E. GOLDBERG, Assistant Examiner.