Electrical connectors – With insulation other than conductor sheath – Metallic connector or contact secured to insulation
Reexamination Certificate
1999-12-07
2001-02-20
Bradley, Paula (Department: 2833)
Electrical connectors
With insulation other than conductor sheath
Metallic connector or contact secured to insulation
C439S082000, C439S885000, C029S874000
Reexamination Certificate
active
06190214
ABSTRACT:
The invention is directed to a conforming contact member that is press-fitted into preformed holes in a substrate, such as a printed circuit board (PCB) or the like.
BACKGROUND OF INVENTION
Two types of press-fit techniques for mounting electrically-conductive contact members such as pins into the preformed typically plated-through holes in a PCB are known. In the first type, a solid pin is used, which has no spring energy. The solid pin is press-fitted into the non-elastically-deformable area of the plated-through hole, and thus requires soldering for long term reliability. In a typical use for this method, to ensure reasonable retention force of the press-fitted connection prior to soldering, the plated-through hole tolerance for the solid pin is kept at ±0.002 inches or less, which increases PCB manufacturing cost to stay within such a tight tolerance. Further disadvantages include possible hole deformation and damage of the hole under-plating and trace circuit connections, which are initially undetectable and therefore detracts from long-term reliability.
The second type uses what is known as a press-fit compliant pin, which provides limited elastic deformation of a compliant section in the pin structure and does not require soldering. While this contact member can be removed, it cannot be reused due to permanent deformation of the compliant section. In a typical use for this method, the plated-through hole tolerance for the compliant pin is kept at ±0.003 inches or less, which still requires relatively high PCB manufacturing cost especially in punched versus drilled PCB holes. The tolerance is also hole-size related, which means that the smaller the hole, the tighter the tolerances required and the higher the fabrication cost. Examples of compliant pin constructions can be found described in U.S. Pat. Nos. 4,186,982; 4,464,009; 4,586,778; 4,740,166; 4,793,817.
The most common manufacturing method for both these types of pins is to stamp the parts from an unplated metal strip in a progressive die, utilyzing a carrier strip (ultimately removed as waste) to carry the pins through the manufacturing equipment. The carrier strip is used at times for continuous reeling of the pins for strip line plating and subsequent automatic placement (insertion into a connection housing or directly into the PCB). The customer-user is responsible for accommodating and ultimately disposing of the removed carrier strip. In the progressive die stamping process, a punch-in die removes metal between adjacent contacts pinned leaving sharp corners and rough surfaces. These conditions are difficult to eliminate due to the tooling not having effective access to the pin sides. As a result, when producing a press-fit pin in a progressive die from a metal strip, the press-fit section frequently causes PCB hole damage. Also, when there is a space between adjacent pins, the number of pins that can be packaged on a reel is reduced. Still further, it is desirable at times to produce press-fit pins that are round rather than square. Progressive die stamping cannot produce round pins.
SUMMARY OF INVENTION
A principal object of the invention is a novel press-fit (hereinafter defined) electrically-conductive contact member that can be reliably mounted in substrates while permitting larger hole tolerances than the known schemes.
Another object of the invention is a novel male press-fit electrically-conductive contact member that is less expensive to manufacture and is less costly to package.
Still another object of the invention is a new method for fabricating male press-fit electrically-conductive contact members with various cross-sections and with compliant sections.
Yet another object of the invention is a new method for fabricating male press-fit electrically-conductive contact members with compliant sections that is scrapless.
These and other objects are achieved in accordance with one feature of the invention by a novel press-fit electrically-conductive contact member, as, for example, an electrically-conductive metal pin, characterized by what we term a “conforming section” which has an elastically-deformable region which acts as a spring and which is adapted to engage a substrate hole in a press-fitting relationship. The conforming section is configured to accommodate a considerably larger hole tolerance yet still provide sufficient retention force to stabilize the pin during a soldering process that such substrates may typically undergo.
In accordance with a further feature of the invention, the contact member comprises an elastically-deformable conforming section having an eye-of-the-needle construction comprising a through-slot bounded by relatively long spring beam members configured to allow a substantially larger lateral movement range during compression when the pin is inserted in the substrate hole. It is this larger lateral movement range that allows the increase in hole tolerances while providing sufficient retaining force.
In accordance with a preferred embodiment of the invention, the contact member is made as a one-piece member and its conforming section comprises a through-slot bounded by relatively long beam members that are offset with respect to each other and to a vertical plane through the pin center axis and parallel to the slot. The offset configuration provides increased lateral beam movement within the slot toward one another before abutting in a fully closed position in which they are, viewed from the center vertical plane, more in a side-by-side position than aligned as in some of the known compliant pins. The beam cross-sections are configured to allow them to occupy a side-by-side position.
In accordance with yet another feature of the invention, pins with the conforming section are manufactured connected end-to-end by a wire-forming process needing no excess material for carrying the pins. Nor are their spaces between adjacent pins, and thus the finished product can be wound up on a reel in a higher density format, lowering packaging costs as well as shipping and handling expenses. This process allows forming of each pin 360° around the pin thereby allowing in the manufacture of a square pin the use of a forming die to round the conforming section of the pin. Similarly, this process permits reshaping of the conforming section of a round wire pin.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described the preferred embodiments of the invention, like reference numerals or letters signifying the same or similar components.
REFERENCES:
patent: 4186982 (1980-02-01), Cobaughet et al.
patent: 4318964 (1982-03-01), Zahn et al.
patent: 4586778 (1986-05-01), Walter et al.
patent: 4606589 (1986-08-01), Elsbee Jr. et al.
patent: 4740166 (1988-04-01), Barnehouse
patent: 4759721 (1988-07-01), Moore et al.
patent: 4763408 (1988-08-01), Heisey et al.
patent: 4821411 (1989-04-01), Yaegashi
patent: 5195350 (1993-03-01), Aikens et al.
Bianca Giuseppe
Bogursky Robert M.
Autosplice Systems Inc.
Bradley Paula
Ta Tho D.
LandOfFree
Conforming press-fit contact pin for printed circuit board does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Conforming press-fit contact pin for printed circuit board, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Conforming press-fit contact pin for printed circuit board will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2586610