US3462651A - Resistor with terminal mounting means - Google Patents

Description

Aug. 19, 1969 1.. E. WEYENBERG RES ISTOR WITH TERMINAL MOUNTING MEANS Filed Sept. 27, 1967 m m E v m [MA/1g l. WIYFNBERG US. Cl. 317-101 7 Claims ABSTRACT OF THE DISCLOSURE An electrical resistance apparatus is combined with a circuit board. The resistor includes an insulating core and a resistance wire is wound around the core, with the ends of the Wire being connected to terminal strips which encircle the core. One end of each terminal strip projects through an opening in the board and is connected to an electrical circuit which is located on the opposite side of the board from the resistor. The other end of each terminal strip projects laterally from the first end and bears against the surface of the board to space the resistor from the board. The lateral legs of the terminal strips project in opposite directions from the longitudinal centerline of the resistor and serve to support the resistor from the board and stabilize the resistor against vibration. As the resistor is spaced out of contact with the board, air can circulate around the resistor to thereby minimize heat concentration during operation.

In a printed circuit system, the electrical printed circuit is generally located on one side of an insulating board, and the various electrical components are positioned on the opposite side of the board, with leads extending through openings in the board and connecting the components with the printed circuit. Electrical resistors used in printed circuits generate considerable heat and even though the resistor may be provided with a ceramic coating, the heat generated by the resistor can range up to 300 to 400 C. above ambient temperature. Thus, if the resistor is in contact with the board, the high temperatures developed may melt or decompose the board, or the intense heat can damage other electrical components in the area. If the conventional resistor is spaced away from the board, a cooling effect is provided which reduces the excessive heat concentration, but in this case the resistor is normally supported only by the electrical leads and in service, vibration tends to fracture the leads.

The present invention is directed to an improved resistor construction for use with a circuit board which reduces heat concentrations and yet enables the resistor to withstand vibration without fracture of the leads. According to the invention, the resistor includes an insulating core and a resistance wire is wound around the core, with the ends of the wire being connected to terminal strips which encircle the core. One end or leg of each terminal strip projects through an opening in the board and is connected to the electrical circuit located on the opposite side of the board from the resistor.

The other end or leg of each terminal strip projects diagonally or laterally from the first end and bears against the surface of the board to space the resistor from the board. The lateral legs of the terminal strips project in opposite directions from the longitudinal centerline of the resistor and thereby serve to support the resistor from the board, as well as stabilizing the resistor against vibration. As the resistor is spaced from the board, air is free to circulate around the resistor which eliminates intense concentrations of heat and prevents melting or decomposition of the board, as well as damage to other electrical components in the area.

As the projecting legs are an integral part of the ter- United States Patent M 3,462,651 Patented Aug. 19, 1969 ice minal strip, only a single weld is required to assemble the terminal strips with the insulating core, and this reduces the cost of manufacture of the resistor over conventional types.

The legs of the terminal strips are generally rectangular in cross section, and this increases the resistance of the legs to fracture and also enables wire to be more easily wrapped around the end of the projecting leg to join the leg to the electrical circuit.

Other objects and advantages will appear in the course of the following description.

The drawings illustrate the best mode presently contemplated of carrying out the invention.

In the drawing:

FIG. 1 is a fragmentary plan view of a printed circuit board;

FIG. 2 is a perspective view of the resistor of the invention as connected to the printed circuit board; and

FIG. 3 is an end view of the resistor as connected to the board.

The drawings illustrate a printed circuit board 1 having a printed circuit 2 on one surface, and a resistor 3 is located on the opposite surface and is connected to the printed circuit 2.

The board 1 is formed of an electrically insulating material such as plastic, or the like, and any conventional insulating material used in printed circuits can be employed. The printed circuit 2, in itself, forms no part of the invention and can take any desired form. While the drawings illustrate a printed circuit 2, the invention is equally applicable to the use of wire lead circuits in place of the printed circuit 2.

The resistor 3 includes a central insulating core 4 and a resistance wire 5 is wound around the core. Each end of the wire 5 is connected to a terminal strip 6 located at opposite ends of the core 4. In most cases, a ceramic coating 7 is applied to the outer surface of the resistor and covers the wire 5, as well as the terminal strips 6.

According to the invention, each terminal strip 6 includes a circular section 8, which encircles the core 4, and central sections 9 extend outwardly from the ends of the circular section 7. The central sections 9 are disposed flatwise and are connected together by a weld 10 to firmly secure the terminal strip 6 to the core.

Formed integrally with one of the central sections 9 is a leg 11 "which extends through an opening 01' slot 12 in the board 1 and is connected to the printed circuit 2 by a solder connection 13. It is contemplated that the leg 11 can be connected to the printed circuit by any desired means, such as wire wrapping or the like, which will provide the necessary electrical connection between the leg 11 and the printed circuit 2.

A laterally extending leg 14 is formed integrally with the other of the sections 9 and the outer end of the leg 14 bears against the surface of the board 1. As best shown in FIG. 2, the lateral legs 14 of each terminal strip 6 extend in opposite directions from the longitudinal centerline of the resistor. While the drawings show the legs 14 to be generally straight and disposed generally normal to the legs 11, it is contemplated that the legs 14 can extend diagonally or can take other shapes or configurations as long as a portion of the leg 14 bears against the board 1 at a location spaced laterally from the opening 12.

The legs 14 serve to space the resistor from the surface of the board 1 and thereby permit air to circulate around the entire periphery of the resistor. By providing circulation of air around the resistor, excessive concentrations of heat at the board 1 are eliminated and this prevents melting or decomposition of the board and also eliminates any danger of overheating of the other electrical components in the area.

As the legs 14 extend on opposite sides of the longitudinal centerline of the resistor, the legs act to stabilize the resistor against vibration and shock, and thereby tend to minimize the possibility of fracture of the legs 11 which are connected to the printed circuit 2.

As the leg 11 and the supporting leg 14 are an integral part of the terminal strip 6, the manufacture is simplified in that only a single part is required. Moreover, the entire unit can be readily assembled by merely welding or otherwise connecting the ends of the resistance wire 5 to the terminal strips 6 and then connecting the central sections 9 by means of the weld 10. Thus, the manufacture and assembly of the resistor is considerably simplified over that of the conventional resistor.

The rectangular configuration of legs 11 aids in wire wrapping of the leads to the printed circuit. Moreover, the rectangular legs 11 are stiffer than conventional wire leads and this enables the legs to be inserted into the holes in the board without binding.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. In a resistance apparatus, a central insulating core, a resistance wire wound around the core, and a pair of terminal strips connected to the wire, each terminal strip having a greater Width than thickness and including a body section encircling the core, each terminal strip also including a pair of central sections located at the ends of said body section and disposed flatwise with relation to each other, and each terminal strip including an end section extending from each central section, one of said end sections of each terminal strip extending generally radially with respect to said core and the second end section terminating short of the first end section and extending at an angle to said first end section, the second end section of one terminal strip extending in the opposite direction from the second end section of the other terminal strip.

2. The apparatus of claim 1, wherein said second end section extends at an angle of approximately 90 with respect to said first end section.

3. In an electrical apparatus, a support having a pair of opposed surfaces, an electrical circuit disposed on a first of said surfaces, said support having a pair of openings therein, an electrical component mounted on the second of said surfaces and having a pair of terminal strips with each strip including -a first leg extending through one of said openings and connected to the electrical circuit and including a second leg disposed at a angle to the first leg and disposed generally flatwise with respect to said second surface, said second leg of one terminal strip extening in the opposite direction from the second leg of the other terminal strip, said second legs serving to space the electrical component from said second surface and to stabilize the component against vibration and shock.

4. The apparatus of claim 3, wherein said electrical component is a resistor comprising an insulating core and a resistance wire wound around the core and connected to said terminal strip.

5. The apparatus of claim 3, wherein said terminal strip includes an annular section disposed around the core and a pair of central sections located at the ends of the annular section and disposed fiatwise with respect to each other, said first leg being connected to one of said central sections and said second leg being connected to the other of said central sections.

6. The apparatus of claim 5, and including means for securing the central sections together.

7. The resistor of claim 1, and including means for connecting said central sections together.

References Cited UNITED STATES PATENTS 7,420 6/1850 Smith 336-192 1,554,728 9/1925 Horle 336-208 1,932,923 10/1933 Bullinger 338-329 X 2,636,963 4/1953 Wakefield 338-329 X 2,912,481 11/1959 Backus 336-192 3,229,238 1/1966 Ellin 338-329 OTHER REFERENCES German printed application S.N. 1,137,090 to Rosenthal, published, Sept. 27, 1962.

ELLIOT A. GOLDBERG, Primary Examiner US. Cl. X.R.

Images