US 3621440 A
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United States Patent  inventors [21 App]. No.  Filed  Patented  Priority Nov. 20, 1968 [3 3] Germany [31 G 68 07 771  SLIDE RESISTOR 7 Claims, 11 Drawing Figs.
338/184 [5i] lnt.Cl H0lc9/02 I50] Fieldolsearch 338/183,
I76, I84, 178, 179, 180, 181, 182, 197, I99
 References Cited UNITED STATES PATENTS 2,871,328 1/1959 Budd et al 3.465.277 9/1969 Bang Primary Examiner-Lewis H. Myers Assistant ExaminerD. A. Tone Attorney-Stowe" & Stowell ABSTRACT: A slide resistor or voltage divider comprising an insulating baseplate having a slot or slots therethrough and a resistance element applied to one side of said plate in parallel relation to said slot, a contact carrier arranged on the same side of said baseplate as said resistance element, a slide element slidingly engaging the side of said baseplate opposite its side provided with said resistance element, connecting means extending through and being guided in said slot or slots and interconnecting saidcarrier and said slide element, a control knob provided on said slide element on its side opposite the side engaging said baseplate. Slide resistor of the described type wherein said control knob is laterally offset relative to said connecting means and said slot. Slide resistor of the described type in which a current contacting resistance element and/or a bus bar are provided on opposite sides of said slot but on the same side of said baseplate.
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SLIDE RESISTOR The invention relates to a slide resistor having a baseplate consisting of or having at least its one surface covered with insulating material, resistance element extending parallel to a slot formed in the baseplate, a contact element engaging said resistance element and being carried by an element guided and held in said slot.
An object of the invention is the provision of a slide resistor of the indicated type having the resistance element and the contacts sliding thereon well protected and being of rugged construction.
A further object of the invention is the provision of a slide resistor of the above indicated type which is adapted for convenient and economic manufacture.
A further object of the invention is a slide resistor of the indicated type in which the contacts are inaccessable to elements which someone might attempt to introduce through the slot of the baseplate from the outside.
Further objects of the invention will become apparent from the following detailed description of the features of the invention and of embodiments thereof.
In accordance with the present invention, there is provided a baseplate having at least one side consisting of, or covered with, insulating material and being provided with a guide slot, said one side of said baseplate having attached thereto a resistance element and/or a bus bar in parallel relation to said slot, a contact carrier being arranged on the same side of said baseplate as said resistance element and carrying a contact element engaging said resistance element and/or said bus bar, a second guide element being provided and slidingly engaged by the opposite surface of said baseplate and rigidly connected with said first guide element by means extending through and guidingly engaged by the sides of said slot, said second guide element being provided with means for the attachment of the control knob, handle or the like.
A further improvement of the invention resides in that the control knob is laterally ofi'set relative to the slot in the baseplate so that a supporting element for said control knob may extend through a slot in a wall of an outer housing, such second slot being likewise laterally offset relative to the slot in the baseplate thereby not permitting the insertion of a member from the outside of said housing through the slot in the housing and the slot in the baseplate.
A still further feature of the present invention resides in that the baseplate is channelor U-shaped in a transverse cross section and that the resistance and/or contact elements are arranged between or attached to the sidewalls or legs of the U- section.
A still further feature of the invention resides in that several resistance elements and/or bus or contact bars are arranged on a common baseplate.
Slide resistors built in accordance with the present invention are adapted to be manufactured of but a few individual parts in open form. The channel-section formation of the baseplate. the endfaces of which may likewise be closed, permits the insertion of the new slide resistor into a printed-circuit plate by 'most simple means.
The lateral offsetting of the control knob support on the contact carrier provides for great safety against someone making contact with the current-conducting parts, since the outer walls of the appliance, into which the new resistor is inserted likewise has a slot for the reception of the control knob or its support and this slot in the wall of the appliance and the slot in the baseplate are laterally ofiset thereby preventing the insertion of a conductive element and the possibility of an electric shock to a person trying to inert such element.
The invention and further problems, aims, objects and features thereof will now be more fully disclosed by means of the several embodiments shown on an enlarged scale in the attached drawings and being described in the following.
In the drawings are:
FIG. 1 a bottom view of a slide resistor made in accordance with the present invention;
FIG. 2 a side elevation the resistor shown in FIG. 1;
FIG. 3 a top view of the resistor shown in FIGS. 1 and 2;
FIG. 4 a section along line A-A of FIG. 2;
FIG. 5 a section along line 8-8 of FIG. 3;
FIG. 6 a section corresponding to FIG. 4 having, however, a laterally offset control extension;
FIG. 7 a section corresponding to FIG. 4 having, however, its baseplate provided with two guide slots and having elements extending through said slots;
FIG. 8 a section corresponding to FIG. 4, the baseplate being, however, formed of a U- or channel-section;
FIG. 9 a section corresponding to FIG. 8 but difiering therefrom in that two guide slots and guide elements are provided and in that the resistance elements and/or bus bars are attached to the legs or sidewalls of the U-section baseplate;
FIG. 10 a bottom view of a resistor having several resistance elements and several independently movable contact elements and their carriers on one common baseplate;
FIG. 11 a section along line 11-11 of FIG. 10, fragmentari- Iy showing the outer wall of the housing of an appliance in which the novel slide resistor is arranged.
The slide resistor illustrated in FIGS. 1 to 5 consists of a baseplate l, a resistance element 2, a bus bar or contact element 3, and the spring-contact carrier 4. Resistance element 2 and bus bar 3 are secured, such as by rivets 6, to baseplate 1 and provided with terminal tongues 5. The resistance element or contact element or bus bar may also consist of a current conductive material having the desired resistance characteristics, being applied to the baseplate in liquid or pasty state, and being subsequently hardened or cured.
Contact carrier 4 is formed of two parts or elements, and upper part 7 and a lower part 12. Upper part 7 is provided with an extension 8 for the reception of a control knob 9 and with sliding surfaces 10 and extension or studs 11. Lower part 12 is provided with sliding surfaces 13, holes 14 receiving the extensions or studs 11 of upper part 7 and with a stud or pin [6 extending into a hole formed in a contact spring 15. The contact carrier parts or elements 7 and 12 are interconnected by the extensions or studs 11 which extend through a slot 18 formed in baseplate l. The connection between studs 11 and lower part 12 may be accomplished by forming rivet heads 17 on the studs as shown in FIG. 5.
The embodiment shown in FIG. 6 differs from the embodiment shown in FIGS. 1 to 5 mainly in that the extension 8 adapted for carrying the control knob is laterally offset rela tive to the single guide slot 18 of baseplate I.
The embodiment illustrated in FIG. 7 differs from the two hereinbefore described embodiments as shown in FIGS. I to 5 and 6 in that two guide slots 18 are provided in baseplate 1 in that pairs of extensions or studs 11 extend through the slots and interconnect the two parts 7 and 12 of the slide structure. In the embodiment shown in FIG. 7, the extension 8 for carrying the control knob is likewise a laterally offset relative to the guide slots 18 with the only difi'erence over FIG. 6 that the extension is arranged between the two slots 18.
The embodiment illustrated in FIG. 8 corresponds to the embodiment shown in FIGS. 1 to 5, but with the difference that baseplate l is U-shaped or channel-shaped in cross section having sidewalls or legs 19 and endwalls 20.
The embodiment illustrated in FIG. 9 is similar to the embodiment shown in FIG. 7 in that two slots 18 and two sets of connecting studs 11 are provided. However, the baseplate is U-shaped in cross section with sidewalls 19 and end walls 20 as in FIG. 8. Furthermore, in FIG. 9, the resistance element 2 and the bus bar 3 are not connected to the underside of the central portion of baseplate l but to the inner surfaces of the sidewalls 19.
The embodiment illustrated in FIGS. 10 and 11 differs from the embodiment shown in FIG. 6 in that baseplate 1 has several slots 14a, 14b, 14c, 14d formed therein, and that several resistance elements, 2a, 2b, 2c, 2d, bus bars 3a, 3b, 3c, 3d and slides 12a ,12b (the slides 120,1211 being for clarities sake not shown) are carried by one common baseplate 1. In this embodiment, the control knob extensions, extension being visible, are likewise laterally offset relative to the guide slots 14, 14a, 14b etc. FIGS. 10 and 11 furthermore show a fragmentary view and cross section, respectively, of the outer wall 22 of the housing of an appliance or the like in which the new resistor is mounted. This housing has slots 23a only visible, one for each resistor and its control knob extension 8a, 8b etc. it is self-evident that the lateral offsetting of the slots 18a, 18b relative to the slots 23a, 23b etc., prevents any person from inserting a current conductive element through the outer slot, e.g. 23a, into the inner slot, e.g. 14a, and thence make contact with current conducting elements of the assembly.
What is claimed is:
1. In a slide resistor, a baseplate, a slot in said baseplate and extending therethrough, at least one resistanceelement provided on one side of said baseplate and extending parallel to said slot, a two-piece slide interconnected by means extending through said slot, one of said parts slidingly engaging the surface of the baseplate opposite that surface carrying the resistance element and the other of said parts carrying a contact element slidably and conductively engaging said resistance element and being arranged on the same side of the baseplate carrying said resistance element, the said first part having an extension supporting a control knob, said knob being laterally offset in a direction transversely of said slot.
2. The slide resistor of claim 1, including a housing having an outer wall on which said resistor is mounted, said wall having a slot which is laterally offset relative to the slot provided by said baseplate and through which extends said extension for the control knob.
3. The slide resistor of claim I wherein the resistance element and the contact element are secured to the inner sidewalls of a U-shaped member, the bright portion of which defines said baseplate.
4. The slide resistor of claim 1 including a plurality of slots, each receiving connecting means extending through them, the said control knob being laterally offset with respect to each of said slots.
5. In a slide resistor, a baseplate, a slot in said baseplate and extending therethrough, at least one resistance element provided on one side of said baseplate and extending parallel to said slot, a two-piece slide interconnected by means extending through said slot, one of said parts slidingly engaging the surface of the baseplate opposite that surface carrying the resistance element and the other of said parts carrying a contact element slidably and conductively engaging said resistance element and being arranged on the same side of the baseplate carrying said resistance element, a second interconnecting means extending between and joining the two pieces of said slide, said first mentioned and said second interconnecting means being laterally displaced relative to each other.
6. The slide resistor of claim 5 wherein said two interconnecting means pass through a single slot in said baseplate.
7. The slide resistor of claim 5 wherein said baseplate is provided with two slots, one of said interconnecting means passing through one of said slots and the other of said interconnecting means passing through the other of said slots.