Electrical connectors – Metallic connector or contact having movable or resilient... – Spring actuated or resilient securing part
Reexamination Certificate
2000-03-30
2001-02-13
Bradley, Paula (Department: 2833)
Electrical connectors
Metallic connector or contact having movable or resilient...
Spring actuated or resilient securing part
C439S857000, C439S856000
Reexamination Certificate
active
06186841
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a connector, in accordance with the preamble of claim
1
.
Known contact sleeves, as, for example, the one disclosed in U.S. Pat. No. 4,902,249, suffers from the disadvantage that an initial surge of high current is anticipated to disrupt the plating of the contact sleeve during the beginning of the mating cycle with a mating pin, which disruption in a plugged state makes a not satisfactory contact for electrical communication between the contact sleeve and the mating pin.
The connector and its contact sleeve according to the one disclosed in U.S. Pat. No. 4,902,249 have a plurality of contact beams arranged around the mating pin, which pin in a plugged state is in contact with two circular working contact surfaces of the sleeve, one in the outer contact portion and one in the inner contact portion of the contact sleeve.
The problem here, according to known technique, is that during the beginning of the mating cycle the mating pin will have contact with the outer contact portion of the contact sleeve causing an initial surge of high current disrupting the outer end of the contact sleeve, that is in the area of the outer contact portion of the contact sleeve, and also disrupting the end of the mating pin
This means that the contact between the sleeve and the contact pin in the area of the outer portion of the sleeve is deteriorated for electrical communication. That means that a decay sequence is developed and that an adulteration of for example the contact resistance and the current carrying capacity. Also a corrosion due to the damaged plating of respectively the end of the mating pin and the outer contact portion cause a deteriorated capacity for electrical communication.
Known contact sleeves, as, for example, the one disclosed in U.S. Pat. No. 4,902,249, means furthermore that when the plating of the outer contact portion of the sleeve, or the contact sleeve material itself, once for all is destroyed, the damaged area will cause an effect on the mating pin over all its area. Primary, when the pin is in a plugged state and the outer contact portion of the contact sleeve has its contact area corresponding to the area of an inner contact portion of the mating pin, there is a risk that the decayed outer contact portion of the sleeve will cause a damage to the above mentioned corresponding inner area of the mating pin.
To solve this problem with the disruptive contact surfaces, when plugging known contact sleeves to mating pins, mounted in a power terminal, instructions to service personnel have been provided, in form of manuals and information tables, that is instructions to switch off the power circuit before plugging the power terminal into for example a circuit card. The result of this step, is that service personnel, even if they are restrictive obliged to follow those manuals, when being pressed for short of time or other circumstances, not follow the instructions.
Even though the power circuit has been switched off, an electrical charge can be detained in the circuit and therefor also cause a initial surge of high current between the mating pin and the contact sleeve disrupting the plating of the contact beams.
That means that the contact sleeves gradual will be damaged at their contact surfaces. This results in high operating costs, since the power terminals frequently have to be replaced. Also malfunctions may come into existence within the circuit card caused by the deteriorated contact functions, causing high costs.
It is, accordingly, an object of the invention to overcome the disadvantages of the known devices. That is, primary, to provide a measure contributory towards a sound mateable power connection without any deteriorated contact functions and that service personnel do not have to switch of the power circuit before a plug in.
Making the contact sleeves non-rotatable in a housing forming for example a power terminal is desirable, since disparate position of the contact beams means that the mating pin would have different contact positions with the contact beams each time they are plugged. To solve this problem with rotatable contact sleeves when mounted in a housing forming for example a power terminal, the inventor of this invention has provided the contact sleeves with a chamfering at a central part of the contact sleeve. This chamfering provides a fixing of the contact sleeves by means of a partition of the housing, which partition also provides a distance between the contact sleeves when mounted in the housing.
SUMMARY OF THE INVENTION
The above mentioned objects have been solved by a contact sleeve as defined in the introduction, which is characterized in that the plurality of contact beams comprises at least three first contact beams and at least one second contact beam being inwardly bent in direction to the axis (A—A) of the contact sleeve, the first contact beams relative to the at least one second contact beam are more inwardly bent for making a first electrical contact with the corresponding mating pin at the beginning of a mating cycle and the at least one second contact beam makes a contact with the mating pin after that the at least three first contact beams are in contact with the mating pin.
Hereby, the at least three first contact beams provide a means for uptaking an initial surge of high current. The at least three first contacts which are bent inwards will further on also be called live contacts. The ends of the live contacts will be exposed to disruptive discharge, which was the intention of the inventor of this invention. Subsequently the contact sleeve can be mounted in a housing forming a power terminal. When the mating pin is fully plugged in the contact sleeve, that is in a position for operation, the at least one second contact beam provide the contact function together with the live contacts. The at least one second contact beam will further on be called virgin contact/contacts. The virgin contact/contacts make/makes contact with the mating pin, after that the live contacts had their contact with the mating pin being exposed for disruptive discharge.
Preferably, the at least three first contact beams and the at least one second contact beam have essentially the same length. In this way the area of the rounded top of the mating pin, first will have contact with the live contacts, since the live contacts are more inwardly bent relative to the virgin contact/contacts. The sleeve may be manufactured, by an automatic lathe, and furthermore milled slots can be provided at the end of the sleeve, forming the contact beams, which are inwardly bent for example by means of heat treatment process, and furthermnore, according to the invention, the live contacts are more inwardly bent than the virgin contact/contacts. It is preferable to produce the contact sleeve by means of a turning lathe and a milling making slots forming the contact beams, since a high tolerance of the distribution of the contact beams can be achieved, seen in a circular cross section of the sleeve, can be provided during the manufacturing process.
Suitably, the at least three first contact beams ends further than the at least one second contact beam in the longitudinal direction of the contact sleeve for making a first electrical contact with the corresponding mating pin at the beginning of a mating cycle. Hereby a mating pin with a blunt top can be used. The longer live contacts relatively the virgin contact/contacts will have contact with the mating pin before a contact with the virgin contact/contacts is established and therefore an initial surge of high current will occur between the mating pin and the live contacts. Subsequently, when using a mating pin with a rounded top, the top at the beginning of a mating cycle, will have contact for electrical communication with the live contacts at a distance from the virgin contact/contacts fully assured that an initial surge of high current would be disrupting the plating of the end of the virgin contacts.
Preferably, the at least three first contact beams are e
Bradley Paula
FCI Katrineholm A.B.
Perman & Green LLP
Ta Tho D.
LandOfFree
Contact sleeve for electrical communication does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Contact sleeve for electrical communication, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Contact sleeve for electrical communication will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2610790