Electricity: circuit makers and breakers – Multiple circuit control – Pivoted contact
Patent
1987-12-31
1989-07-25
Scott, J. R.
Electricity: circuit makers and breakers
Multiple circuit control
Pivoted contact
200 6R, 200307, H01H 902, H01H 1904, H01H 2104
Patent
active
048516201
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a multipolar rotary switch, in particular a switch having cams in the form of a stack of wafers which, together with contact elements and connection elements, are received in chambers lying between end walls and intermediate walls in the form of parts molded in plastic material, said parts being juxtaposed and rigidly interconnected in order to constitute a compact supporting block with a control shaft running along the center thereof, the molded parts being provided, for coupling purposes during assembly, with claws which are deflected during joining over adjacent molded parts and which engage behind corresponding projections. The invention also relates to a method of manufacturing such a switch.
BACKGROUND OF THE INVENTION
Rotary switches of the above-mentioned type are already frequently used as control devices incorporated together with other control and signalling units in control panels or desks, or in similar installations. In this case, the stack of molded wafers is generally fixed solely at one of its ends to a supporting element and must consequently have sufficient inherent strength and rigidity to withstand the stresses coming from the camshaft in order to guarantee perfect operation even after a long period in service.
In rotary wafer switches known heretofore, this strength and rigidity is obtained by taking the molded elements (which used to be made of porcelain and have more recently been made of plastic) and interconnecting them very stiffly by means of threaded rods passing through the entire stack and acting as draw rods. However, such mechanical connection is expensive in equipment and in labor, and then requires correct screw tightening to be guaranteed, which imposes subsequent verification in addition to special care during assembly.
SUMMARY OF THE INVENTION
Consequently, the present invention seeks to avoid assembly by screwing together with its associated equipment and labor costs, while nevertheless rigidly connecting the various molded parts which constitute the stator of the rotary switch with reduced costs in materials and labor.
According to the invention, this is achieved by the facts that the molded parts are made of a thermoplastic material and that after being engaged behind the projections of the adjacent molded parts, the lugs on the side walls of the molded parts are welded in order to obtain a very rigid connection.
By using the known method of snap-fastening lugs behind projections provided on the adjacent molded parts, the invention offers the advantage of easier preliminary assembly without using tools, while simultaneously setting up the conditions required for subsequent final assembly of the parts by welding said lugs to the side walls of the contiguous molded parts with the set of of these parts then forming a block which is inherently rigid. It is true that the switch can no longer be disassembled without breaking the molded parts. However, in the rare event that switching functions need to be changed or extended (which could be done in the past by reconstructing the switch), the cost saving obtained by the invention lowers the overall cost of a rotary switch to such an extent that is now feasible simply to change the entire switch.
According to a first characteristic of an advantageous embodiment of the invention, the claws are constituted in the form of flat tabs having end orifices for receiving projections fitted with slopes for sliding over. By virtue of the thinness of the lugs, this design gives rise to particularly favorable conditions for prior assembly and subsequent welding, and these can be further improved, in accordance with another characteristic of the invention by the fact that the side surfaces of the molded parts are provided with ribs in the region overlain by the lugs, said ribs and the intermediate grooves extending along the sliding direction and serving at the end of sliding initially to prevent complete latching of the lugs behind the projections, with said firm connection occuring only during welding afte
REFERENCES:
patent: 3200208 (1965-08-01), Mastney
patent: 3251956 (1966-05-01), Rusor et al.
patent: 4029914 (1977-06-01), Schmidt et al.
patent: 4029924 (1977-06-01), Frank et al.
patent: 4335288 (1982-06-01), Ludwig et al.
patent: 4724287 (1988-02-01), Heng et al.
Baco
CGEE Alsthom
Scott J. R.
LandOfFree
Multiplier switch assembly and method of manufacture does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multiplier switch assembly and method of manufacture, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multiplier switch assembly and method of manufacture will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2359800