Straight-line potentiometer

Details Straight-line potentiometer Straight-line potentiometer

1999-09-29

2001-03-06

Easthom, Karl D. (Department: 2832)

Electrical resistors

Mechanically variable

Movable contact electrically adjustable over length of...

C338S202000

Reexamination Certificate

active

06198380

ABSTRACT:

FIELD OF THE INVENTION
The invention concerns improvements in a straight-line potentiometer, in particular of the miniature type and of those employed in electronic units, said improvements providing more reliability, an easy assembly and a lower manufacturing cost.
BACKGROUND OF THE INVENTION
Conventional straight-line potentiometers basically comprise a case with a longitudinal opening having at the sides thereof one or more electric slideways that are parallel to each other, and electroconductive and/or electroresistive, there being generally an electroconductive one for each electroresistive one, as well as a carrier with an operating stem or appendage that is operable to be shifted in a straight-line along the opening, the carrier carrying one or more electroconductive members or sliders forming jumpers between several points of the slideways.
In a known solution of the prior art, the engagement of the slider carrier with the potentiometer casing is carried out by means of two U-shaped or fork-shaped resilient lugs of the carrier, each of the lugs ending in a toe, the toes approaching when being inserted through the longitudinal opening and again spacing themselves apart once having passed the inner surface of the latter, the toes being thus retained at respective inner edges of the longitudinal opening. The electroconductive member forming the slider is attached to the fork-shaped lugs by means of riveting on flat fastening areas at both sides of the lugs, this operation having to be carried out by means of precision robotics due to the reduced dimensions involved. This increases the cost of the product if a correct manufacture of the potentiometer must be guaranteed.
Nevertheless, in the straight-line potentiometer of the prior art, it happens that if any intervention in the pertinent circuit or during the riveting process of the slider, the lugs approach or are deformed by heating, their toes can get at least in part into the longitudinal opening, thus being trapped inside it and preventing the operation of the potentiometer itself. And, if an attempt is made to unblock the carrier by acting on it in order to correct such an anomaly, the slider can be then damaged due to its frail build on account of its reduced dimensions. The gripping provided by said lugs, to a portion of which the slider is fastened by riveting, is not in any case effective or secure, and imposes in any case onerous process costs if a proper completion of the potentiometer is called for.
SUMMARY OF THE INVENTION
The object of the invention consists in obviating the above-mentioned drawbacks by means of a straight-line potentiometer whose improvements essentially consist in providing the slider with a portion, for example by way of an offset portion, which in the assembly process is inserted between the fork-shaped lugs of the carrier thereby totally preventing said lugs from joining and passing again through the opening or getting trapped in it. Said slider is as well provided with tabs which are oriented in opposite directions and are inserted between respective pairs of resilient grips of the carrier, the action of said grips being perpendicular to that of the toes or fork-shaped lugs whereas at the same time said grips exert their gripping action on corresponding edges of said slider thereby firmly retaining it with no need to carry out any riveting whatsoever, with the consequent cost saving and simplicity of the operation; all this as will be explained hereinafter and as claimed in the appended claims.


REFERENCES:
patent: 3412361 (1968-11-01), Lovejoy et al.
patent: 3550059 (1970-12-01), Barden et al.
patent: 4053865 (1977-10-01), Brown, Jr.
patent: 4274074 (1981-06-01), Sakamoto
patent: 4426634 (1984-01-01), Okuya et al.
patent: 4523176 (1985-06-01), Leibinger et al.
patent: 4698613 (1987-10-01), Okuya
patent: 4792780 (1988-12-01), Takahashi

Affiliated with

Also associated with

Rating

Straight-line potentiometer does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Straight-line potentiometer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Straight-line potentiometer will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2460224