Electricity: circuit makers and breakers – Multiple circuit control – Pivoted contact
Patent
1998-12-01
2000-04-04
Scott, J. R.
Electricity: circuit makers and breakers
Multiple circuit control
Pivoted contact
200 11J, 200 11K, 200 16C, 200 16D, 200252, H01H 1902, H01H 100, H01H 1502, H01H 2102
Patent
active
060464135
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention is concerned with a switch for automotive vehicles, in particular, steering column switches.
BACKGROUND OF THE INVENTION
Switches of the afore-mentioned type, on the one hand, should be able to switch substantial load currents so as to pass energy to lamps and engines. On the other hand, switches of the afore-described type increasingly serve for indirectly actuating power consuming units then actuated directly through electronic circuits. Advantageously, steering column switches of this type should, therefore, also be able to switch weak control currents.
In order to be able to neatly switch also weak flows of this type, the transition resistance of the switches is to be kept low. Special provision is, therefore, to be made to prevent pollution of the communicating contact faces by corrosion, scaling, arc formation or adhering residual insulating material.
In conventional switches, contact sections rigidly arranged on the housing in abutting relationship within the contact plane are electrically interconnected or separated by a pushing motion of contact bridges. The disadvantage involved with switches of this type resides in that the two contact sections are separated by insulating material that will get into close contact with the contact bridge when sweeping about it. The displaced contact bridge will thereby entrain remainders of insulating material or of the plastic casing in which are embedded the contact sections. Once the contact bridge runs up another contact section, the insulating material, in part, is transferred to the contact bank of the said contact section or is burnt into the contact faces by the arc, if formed, thereby polluting the contact face. By sizing the switch adequately large, the bearing force of the contacts can so be dimensioned that during the counter-directed pushing motion the contacts are again rubbed clean. However, large-dimensioned switch sizes are not justifiable for weak currents.
It is the object of the invention to provide a small-sized switch, the contact faces of which are substantially kept free from pollution so as to enable use thereof as a switch for large and weak currents. Hence, the invention resides in that the contact bridge is raised at an appropriate point before leaving a contact section to be then lowered at an appropriate point of a new contact section.
Accordingly, the pushing motion, at the important re-switching points, is combined with a lifting motion. The resultant advantage resides in that the actual contact face is not placed in contact with the insulating material surrounding the contact sections. Moreover, contact making, due to the lifting motion, is abruptly changed rather than linearly by a dragging movement through passage from one contact section to the next. Hence, three defined conditions of the contact bridge are attained in respect of which the transitory times are relatively short, to wit: contact making of the contact bridge in one contact section only; contact making of the bridge to one bridge portion only with the other bridge portion lifted off; and, finally, rapid transition to the condition connecting the two contact portions respectively to another contact section. Also, it is of importance to the invention that one of the contact portions, during lifting, does not yet form an arc because the other contact portion is still in close electrical contact with the contact section.
A particularly simple design suitable for lifting off a contact portion is disclosed according to which a ramp is provided over which a contact portion of the contact bridge moving along a contact section is raised in a direction vertical to the plane of the contacts and lowered over the next contact section. Hence the motion of the contact portion follows the oblique sloping ramp faces.
To reliably prevent areas of the contact bridge dragging along the stationary contact sections from getting into contact with the surrounding insulating material, in particular, with the insulating material of the ramp, at leas
REFERENCES:
patent: 3549832 (1970-12-01), Ferryman, Jr.
patent: 3598934 (1971-08-01), O'Connor, III
patent: 4012608 (1977-03-01), Lockard
patent: 4168404 (1979-09-01), Lockard
patent: 4417107 (1983-11-01), Terajima
patent: 4491703 (1985-01-01), Jaklic
patent: 4841105 (1989-06-01), Goodman et al.
patent: 4897013 (1990-01-01), Oka et al.
patent: 5898142 (1999-04-01), Ohtaki et al.
English translation of the International Preliminary Examination Report for PCT/EP97/00093.
Hecht Walter
Klein Rudolf
Simonis Karl
ITT Manufacturing Enterprises Inc.
Lewis J. Gordan
Scott J. R.
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