US2258072A - Switching apparatus for electric circuits - Google Patents

Description

SWITCHING APPARATUS FOR ELECTRIC CIRCUITS Filed Decv 24, 1938 l INSULATION UNITED STATES PATENT OFFICE SWITCHING APPARATUS FOR ELECTRIC CIRCUITS Carroll Stansbury, Wauwatosa, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware 9 Claims.

This invention relates to switching apparatus for electric circuits and while not limited thereto is particularly applicable to the control of a plurality of electric circuits such as condensers, which are to be progressively connected in or disconnected from parallel circuit relationship to each other.

An object of the invention is to provide an improved switch including a plurality of contacts, each connected to a separate circuit or device, whereby the contacts may be progressively connected in parallel with .each other to a common terminal.

Another object is to provide an improved switch of the aforementioned character which is compact and which has a minimum number of parts.

Another object is to provide a condenser having a plurality of separate sections with a switch for connecting any desired number of such sections progressively in parallel with each other.

Other objects and advantages will hereinafter appear.

In the accompanying drawing, Figure 1 is a side elevational view of a switch embodying the invention and mounted on a condenser, and

Fig. 2 is a transverse cross section along the line 2-2 of Fig. 1.

Referring to the drawing, the condenser casing I is provided with a number of parallel condenser sections (not shown) one pole of each of which is preferably connected to a common terminal 2, while the other poles of the respective sections are connected to individual contacts 3 arranged in a circle around a common center. The contacts are mounted on an insulating base plate, the inner face of which is represented by the dotted line 4, in Fig. 1, which in turn is suitably fastened to the condenser casing I. A U- shaped bracket 5 is insulatedly mounted on the condenser casing I. The bracket has a bearing G through which passes a shaft l, preferably of square cross section as shown, said shaft having a reduced end 8 of circular form in transverse cross section, forming with the main part a peripheral shoulder. A lever 9 fits over and is driven by the square portion of shaft l and is held in place by a washer I D strung upon said shaft, the washer being provided with a circular opening II which fits the reduced end 8 of the shaft. The washer I I! thus holds the lever 9 against outward displacement from the square portion of the shaft I and also forms an abutment between the peripheral shoulder on the shaft and the bracket 5. A stop pin I2 carried by bracket 5 cooperates with the lever 9 to limit the total extent of angular rotation of the shaft l. A contact disc I3, preferably composed of phosphor bronze or similar resilient metal, comprises a series of like sector-shaped arms I4 having a common center. Disc I3 is fitted onto shaft 1 to rotate therewith as shown in Fig. 2; and is normally biased toward the contacts 3 by a coiled compression spring I5 interposed between the disc I3 and the lever 9.

A relatively thin insulating plate or disc I6 of substantially annular form is positioned in a plane substantially parallel to the contacts 3. The disc I6 is held against rotation by engagement of the side walls of the peripheral notches I1 formed therein with the spaced parallel arms of the bracket 5. The disc I6 is further provided with a slot I8 (see Fig. 2) which permits passage of the arms I4 therethrough upon rotation of the shaft I. For this purpose the leading edge I9 of the slot is bent upwardly. Upon passing over the slot I8 the arms I4 lift the leading edge of the insulating disc I 6, and on further rotation of the shaft 1 they pass through the slot successively, thereby making contact with the contacts 3 and connecting a lesser or greater number thereof in parallel relation. Upon rotation of the shaft I in the opposite direction the arms I4 successively leave the contacts 3 and pass to the upper side of the insulating disc I6. The aforementioned action is facilitated by providing a small knob or hemispherical boss 20 upon the under side of each of the arms I4 where they abut or engage the contacts 3. This raises their edges slightly above the plane of the contacts 3, so that upon reverse rotation the arms I4 easily climb over the disc I6 to reinterpose it between the contact arms I4 and the contacts 3.

In the form of the device herein illustrated the arrangement is such that at least one of the segments I4 of the contact disc will at all times engage one of the contacts 3 (as shown in Fig. 2) so as to provide a continuous circuit connection through at least one of the condenser sections. Obviously, however, the width of stop lever 9 may be increased to provide for engagement of tWo or more of the segments I4 with a corresponding number of the contacts 3; or the width of lever 9 may be decreased to an extent sufficient to provide for movement of all of the segments I4 from Iengagement with the contacts 3, whereby the circuit connections through all of the condenser sections will be interrupted.

The reduced section 8 of the shaft 'I is provided 22. A dial 23 fastened to the bracket 5 adjacent to the pointer 2l is graduated in an obvious manner (not shown) to indicate the position of the contact disc I3 relative to the contacts 3 and to thus indicate the number of condenser sections in circuit.

The bracket 5 is clamped to the casing I by a pair of like straps 2l of semi-circular form attached to the arms of the bracket as by welding or brazing, one of which straps may be provided with a terminal 25 for the connection of the condenser into a circuit; the number of sections of the condenser included in parallel relation in such circuit depending, as aforestated, upon the relative rotary position of the operating shaft. Straps 24 may be moved into or released from clamping position relatively to the condenser casing by adjustment of one or both sets of bolts and nuts designated by the numerals 26 and 21, a strip or sheet of flexible insulating material 28 being interposed between straps 24 and casing I.

As will be apparent from consideration of Fig` l, the condenser casing I may be removed from bracket 5 by merely loosening one or both of the screws 26. In order to permit such removal of the condenser casing without causing disassembly of the movable parts of the switch mechanism, I prefer to provide shaft I adjacent to the inner end thereof with a shoulder to limit the degree 0f inward displacement of contact disc I3, under the bias of spring I5, in the event that disc I3 is positioned inwardly of the insulating disc IB. Said shoulder may be in the form of a washer 29 insertable laterally with a press or snap fit into an annular groove 'Ia provided adjacent to the inner end of shaft 1.

It is obvious, that instead of rotating the contacts I4, the latter may be held stationary, while the insulating disc I6 is rotated by the shaft 1. Other modifications will at once suggest themselves to those skilled in the art.

What I claim as new and desire to secure by Letters Patent is:

1. In a switching apparatus for electric cir- Puits, in combination, a multiplicity of stationary contact elements arranged symmetrically in the form of a substantially complete circle and having the contact surfaces thereof located in a common plane, a rotatable shaft located centrally of said circle, a contact member comprising a substantially circular disc biased toward said contact surfaces and tending to complete circuit therewith respectively, an insulating disc positioned substantially parallel with the plane of said contact surfaces, said insulating disc being adapted to be interposed between certain of said contact surfaces and a variable portion of said Contact member upon rotary displacement of said insulating disc and said contact member relatively to each other in one direction, to interrupt circuit between said contact member and the respective contact surfaces, said variable portion of said contact member being also adapted to be interposed between said contact surfaces and said insulating disc upon rotary displacement of said insulating disc and said contact member relatively to each other in the reverse direction to complete circuit between the latter and the respective contact surfaces, and said shaft being adapted to effect such rotary displacement of said insulating disc and said contact member relatively to each other in each direction.

2. A circuit commutator comprising, a multitact surfaces arranged in the form of a substantially complete circle about a common center, a shaft having its axis passing through said center at a right angle to the plane of said surfaces, a multiple-armed movable contact member also in the form of a substantially complete circle attached to said shaft and biased toward said surfaces and tending to complete circuit therewith, and an insulating disc mounted substantially parallel with the plane of said surfaces and adapted to be interposed between the latter and the arms of said movable contact member progressively upon rotation 0f the latter in one direction, the arms of said movable contact member being also adapted to be engaged with a gradually increasing number of said surfaces upon reverse rotation of said shaft, said arms being interposed between said insulating disc and said surfaces under the conditions last mentioned.

3. A circuit commutator comprising, a multiplicity of contact buttons arranged symmetrically in the form of a substantially complete circle and at equal angular displacements from each other and having coplanar contact surfaces, a shaft having its axis passing through said center at a right angle to the plane of said surfaces, a plurality of normally coplanar movable contact elements electrically connected with each other and attached to said shaft at angular displacements from each other equal to that of said contact surfaces and biased toward said surfaces to tend to complete circuit with said surfaces, and an insulating disc mounted parallel with the plane of said surfaces and adapted to be interposed between the latter and a progressively increasing number of said movable contact elements upon corresponding rotation of the latter in one direction and to be interposed between a progressively decreasing number of said contact surfaces and said contact elements upon rotation of the latter in the opposite direction.

4. A circuit commutator comprising, a multiplicity of contact buttons having coplanar contact surfaces arranged in the form of a substantially complete circle, a shaft having its aXis passing centrally through said circle at a right angle to the plane of said surfaces, a resilient contact disc attached to said shaft and biased toward said several surfaces to tend to complete circuits therewith, and an annular insulating disc mounted concentric to and parallel with the plane of said surfaces and provided with a radial slot to permit said contact disc upon rotation to pass through said slot so as to interpose said insulating disc between the contact disc and a progressively increasing number of said surfaces upon corresponding rotation of the contact disc in one direction and to progressively decrease the number of said surfaces between which and said contact disc the insulating disc is interposed upon rotation of the contact disc in the opposite direction.

5. A circuit commutator comprising, a multiplicity of contact buttons having coplanar contact surfaces arranged symmetrically in the form of a substantially complete circle and at equal angular displacements from each other, a shaft having its axis passing centrally through said circle at a right angle to the plane of said surfaces, a resilient contact disc provided with a plurality of radial slots to form sectors thereof and attached to said shaft at angular displacements from each other equal to that of said contact surfaces and blaseo. toward salu several surfaces to tend to complete circuit therewith, and an annular insulating disc mounted concentric to and parallel with the plane of said surfaces and provided with a radial slot to permit said sectors upon rotation of said shaft to progressively pass through the slot in said insulating disc so as to interpose the latter between said sectors and said surfaces progressively, to thereby correspondingly decrease the number of lsurfaces in contact with said sectors upon rotation of said shaft in one direction and to progressively increase the number of surfaces in contact with said sectors upon reverse rotation of said shaft.

6. A circuit commutator comprising, an insulating block, a multiplicity of contact buttons provided with terminals and having coplanar contact surfaces mounted in the form of a substantially complete circle on said block, a shaft in line with the center of said circle, a bearing bracket for said shaft and connected to said block, a multiplicity of electrically connected radial resilient contacts also arranged in the form of a substantially complete circle and attached to said shaft and rotatable thereby, common means to urge said contacts towards said surfaces to tend to make contact therewith, an annular flexible insulating disc mounted concentric to and parallel with the plane of said surfaces and provided with a radial slot to permit said contacts upon rotation of said shaft to progressively pass through said slot so as to interpose the insulating disc between said contacts and said surfaces progressively and to correspondingly decrease the number of surfaces in contact with said contacts upon rotation of said shaft in one direction, and to progressively increase the number of surfaces in contact with said contacts upon reverse rotation of said shaft.

7. In a switching apparatus for electric circuits, in combination, a multiplicity of stationary contact elements arranged symmetrically in the form of a substantially complete circle and having the contact surfaces thereof located in a common plane, a manually rotatable shaft located centrally of said circle, a rotatable contactor comprising a substantially circular resilient metal disc biased toward said contact surfaces and normally tending to complete circuit with all of the same simultaneously, a relatively thin insulating plate arranged in a fixed position substantially parallel with and overlying said contact surfaces, said insulating plate and said contactor being so formed relatively to each other that upon rotary movement of said contactor in one direction from a given position thereof the same is adapted to ride over said insulating plate to effect disengagement of said contactor from certain of said contacts, said contactor upon subsequent rotary movement thereof in the reverse direction being adapted to ride under said insulating plate to effect re-engagement of said contactor with said certain of said contacts, and said shaft having a positive driving connection with said contactor to effect rotary movement of the latter in either direction relatively to said insulating plate tnrougn an angle substantially greater than one hundred and eighty degrees.

8. A circuit commutator comprising, in combination, a multiplicity of stationary Contact buttons having coplanar contact surfaces arranged about a common center in the form of a substantially complete circle, a manually rotatable shaft having its axis passing through said center at substantially a right angle to the plane of said Contact surfaces, a rotatable contactor also in the form of a substantially complete circle with which said shaft has a positive driving connection, said contactor being spring biased toward said contact surfaces and normally tending to complete a circuit connection with each of the latter, and a relatively thin approximately annular insulating plate non-rotatably mounted in a plane vsubstantially parallel to and overlying said contact surfaces, said contactor being adapted upon rotary movement thereof in one direction to ride under said insulating plate into engagement with certain or all of said contact surfaces, said contactor being thereafter adapted upon rotary movement thereof in the reverse direction to ride over said insulating plate out of engagement with said certain of said contacts, and means for limiting said shaft to rotation through an angle of less than three hundred and sixty degrees While providing for rotation thereof through an angle of substantially more than one hundred and eighty degrees.

9. A circuit commutator comprising, in combination, a multiplicity of stationary contact buttons having coplanar contact surfaces arranged about a common center in the form of a substantially complete circle, a manually rotatable shaft having its axis passing through said center at substantially a right angle to the plane of said contact surfaces, a rotatable contactor also in the form of a substantially complete circle with which said shaft has a positive driving connection, said contactor being spring biased toward said contact surfaces and normally tending to complete a circuit connection with each of the latter, and a relatively thin approximately annular insulating plate non-rotatably mounted in a plane substantially parallel to and overlying said contact surfaces, said contactor being adapted upon rotary movement thereof in one direction to ride under said insulating plate into engagement with certain or all of said Contact surfaces, said contactor being thereafter adapted upon rotary movement thereof in the reverse direction to ride over said insulating plate out of engagement with said certain of said contacts, said insulating plate and said contactor being cooperatively formed and arranged relatively to each other to insure engagement of the latter with at least one of said contact surfaces in all rotary positions of said contactor, and means for limiting said shaft to rotation through an angle of less than three hundred and sixty degrees while providing for rotation thereof through an angle of substantially more than one hundred and eighty degrees.

CARROLL STANSBURY.

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