US2955175A - Switching mechanism - Google Patents

Description

Oct. 4, 1960 c. CARROLL swITcHING MECHANISM 2 Sheets-Sheet 1 Filed Abril 22, 1959 HIAHHIIIM Oct. 4, 1960 c. CARROLL 2,955,175

SWITCHING MECHANISM Filed April 22, 1959 2 Sheets-Sheet 2 5a Irze/ePcC-r @ay-es Carro/ @tv-F299 iatented Oct. 4, 196() 6 Claims.1 (Cl. 200M-104)A This invention relates to a switching mechanism with afplurality of sets of tixed contacts .and individual sets of movable contacts shiftable into and out of engagement with the respective sets of fixed contacts.

The primary object of the invention is to provide a switching mechanism of the above character which is constructed in a novel manner to simplify the mounting lof the various components, to render the components easily `accessible for 'adjustment and replacement, and to attain ruggedness and durability.

Another object isto avoid simultaneous movement of the'diierent sets of movable contacts into their operative positions by an interlocking mechanism which is easy to assemble with the other parts of the switching mechanism and isreadily accessible.

A further 'object is to mount the actuating parts for the movable contacts in a novel manner avoiding changes inthe' relative positions of parts which norma-ily are intended to remainxed.

Still another object is to construct connections for the ixed contacts in a novel manner facilitating their mounting on supporting elements and their 'attachment to conductors to connect the contactsinto electrical control circuits.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connectionl with the accompanying drawings' in which:

Figure 1- isla side elevational view of a switching mechanism embodying the novel features of the present i'nvention;-

Fig. 2is anfendelevational'view of the switching mechanism;v

Figs. 3 and 4` are bottom andv top views', respectively, ofthe switching mechanism;

Fig. 5 is a sectional View taken along the line 5 5 of Fig. 1 with s'omefof the parts partially broken away and shown in section.

Fig. 6 is a fragmentary exploded perspective view of the interlock mechanism;

Figs. 7, 8, and 9 are schematic views showing the interlock parts in diiierent relative positions.

The switching mechanism shown in the drawings to illustrate kthe present invention comprisesV a plurality of fixed contacts 10'and la corresponding number of movable contacts 11' nrountedto-reciprocate toward and away from and intol and-out of engagement' with the fixed contacts. Herein; there are twelve iixed contacts arranged in four laterally spaced parallel'rows. Attachment of conductors to the-fixed contactsis eiiected through connectors 12 located on theexterior of the mechanism. In this instance, there are only nine connectors, one `for each iixed contact in theoutside'rows`-and one inside row, the latter being connected-to the other inside row by jumpers 13 (Fig. 4.)

The mounting for the fixed contacts 10 comprises a support 14-ofL insulating material off generally T-shaped cross-section withfa -center portion 1-5 and a perpendicular cross bar 16 supporting the pairs of rows of fixed vcontacts at its opposite ends which overhang the center portion. 'llo simplify the attachment of conductors to the connectors 12 and the mounting of theconnectors and fixed contacts, the invention contemplates forming the connectors yas U-shaped members having laterally spaced parallel legs 17 and integral cross portions 18 forming the bottoms of the Us. Suchv bottoms lie against the outer side of the cross bar of the support with the legs normal to and' projecting outwardly from the bar. The bottoms of the Us are secured to the end portions of the cross bar by elongated conducting members 19 which extend through the bottoms and the end portions and terminate at their inner lends in the` xed contacts 10 so as vto function as these contacts, as well as to provide a conductive connection between the contacts and the connectors.

In this instance, the elongated conducting members 19 are rivets with enlarged heads forming the fixed contacts 10 at their inner ends and with a shank of reduced diameter extending through the cross bar 16 and the bottoms 1S of the Us and bent back against the bottoms as indicatedl at 20 in Fig. 5 to form the rigid connection. I-f desired, the extreme inner end of the rivet may be coated with a precious metal, such as platinum, as indicated at 21. Each of the upstanding legs of the Connectors pre-ferably is apertured as indicated at 22 (Figs. l and 6) to receive the end portion of a conductor (not shown) which conveniently may be soldered to the leg. For the iixed contacts without connectors, the outer end portions of the rivets are bent back against washers 23 (Fig. 4) to hold `the jumpers 13 against the cross bar 16 of the iixed contact support 14.

Each of the movable contacts 11 is carried by a bridging member 24 forming a conductive path between two of the contacts and thus between the two fixed contacts 10 engaged by such movable contacts in the different rows, there being six bridging members in this instance, three in a set for the two rows of fixed contacts at each end portion of the cross b'ar 16 of the fixed contact support 14. Each set of bridging members is carried by a common supporting part 25 for shifting in unison toward and away from their respective six contacts. The part is formed of insulating material and, in this instance, is an elongated rectangular block paralleling the center portion 1S and the cross bar 16 of the T-shaped fixed contact support 14. Each bridging member 24 is mounted on its insulating block 25 through the medium of a T-shaped flat bar 26 having a center portion 27 rigid with 'and upstanding from the block and a cross piece 28 spaced from and paralleling the block. The bridging member is generally rectangular with a transverse `slot 29 (Fig. 5) and a lengthwise slot (not shown). The latter is adapted to receive the cross piece 28` when the member 24 parallels the block. After the member in this position is telescoped onto the bar and past the cross piece, it is turned transversely of the cross piece and the block as permitted by side recesses in the center portion of the bar. The length of the cross slot 29'is less than the cross piece so that, with the member transverseto the cross piece, the cross piece limits outward movement of the member under the action of a compression spring 30 acting between the block and the bar.

Shifting of each set of movable contacts 11 and its insulating block 25 toward the associated set of iixed contacts 10 is effected, in this instance, by a solenoid actuator 31' having a multiple turn annular coil 32 (Fig. 5) and a plunger or core 33 of magnetic material secured to and supporting the block The core is generally cylindrical and reciprocates in the bore of a cylindrical center portion 34 ofY a spool supporting theV coil. The spool is formed of a nonmagnetic material and is supported by a bracket 35 of magnetic material which also supports the T-shaped fixed Contact support 14 and co-operates with the plunger and a plug 36 of magnetic material to define the path for magnetic liux created by electrical current liowing through the coil when it is energized. The plug is seated in one end of the spool bore and extends only a short distance along the bore, the plunger being of a length to lill the remainder of the bore when it abuts the plug upon energization of the coil. Connection of each insulating block to its plunger is effected by a bolt 37 having one end embedded in the insulating block 25 with the adjacent portion slidable in a bore in the plug. At the other end portion of the rod, a portion of reduced diameter terminates in a shoulder 38 and telescopes within the plunger which is clamped against this shoulder by a nut 39.

The mounting bracket 35 for the solenoids 3i and the lixed contact support 14 is formed of two plates each of L-shaped cross section with two legs intersecting each other at substantially a right angle. One leg il of each plate lies against and is secured to a corresponding leg of the other plate, as by screws 4l., and their remaining legs 42 are parallel to each other and laterally spaced to receive the coil spool between them with the flanges i3 of the spool lying flat against the legs. Apertures in the centers of the parallel legs receive an outturned flange 4d (Fig. 5) on one end of the spool and a center projection i5 on the plug 36 at the other end of the spool to prevent shifting of the spool transversely of its axis and relative to the bracket. The solenoicls are laterally spaced apart with the bottom of the center `portieri l5 of the fixed contact support .li clamped by screws i5 (Figs. l and 6) against the outer side of the parallel bracket leg i2 adjacent the plug 36. The movable Contact blocks 25 then reciprocate along parallel paths on opposite sides of the center portion l5 and engage that portion to prevent turning of the plungers 33 about their axes.

rthe coil 32 is composed or" a plurality of turns of insulated wire wound on the spool center portion 34 between the anges d3 and protected by an exterior coating 47, terminals 43 extending through this coating from connections with the ends and an intermediate point of each coil. To prevent the spools from turning on their axis and thereby insure that these connections remain in the position relative to the bracket 3S, the invention contemplates forming on the bracket and on the spool intertting parts i9 and 5@ which abut each other radialiy or the spool to prevent it from moving angularly about its axis. These interlitting parts are a projection and the walls of a recess. While the projection 49 may be formed on the bracket, it preferably is formed as a lug on one liange 43 of the spool. The coacting walls 5@ define a radial slot in the adjacent parallel leg 153 of the bracket. This slot extends radially from the aperture to the periphery of the bracket leg as shown Fig. 3 and thus interrupts the leg so as to reduce eddy currents therein.

In accordance with another aspect of the present invention, a novel interlock is provided to shift each movable Contact block 2S to its inactive or switch-open position when the other block is shifted to its active or switch-close position. To render the interlock. readily accessible and easy to assemble with the other parts of "ie switching mechanism, it comprises generally lever 5l fulcrurned intermediate its ends on one end of the center portion l5 of the fixed contact support 14 so that the ends of the lever are located beyond one end of the mos-'able blocks 25. (2o-operating with these lever ends are lugs projecting individually from the block ends and into the paths of thc respective lever ends. The axis of swinging of the lever is disposed parallel to and between the block paths and in the proper position to engage the lug from each block to hold the movable contacts il on that biock away from their fixed contacts li) when the other block is advanced for engagement of its associated contacts.

The fulcrum for the interlock lever 51 in this instance is a screw 53 (Figs. 1 and 6) threaded into the center portion 15 of the fixed contact support 14 and extending through a hole 54 in the center of the lever. A spacer ring 55 wider than the lever encircles the screw Within the lever hole to enable the screw to be tightened against a washer 5d and a lockwasher 57 while still allowing the lever to move freely.

With both coils 32 de-energized and the bracket 3S mounted with the plunger axes disposed vertically, the plungers 33 and their movable contact blocks 2S drop to their lower inactive positions due to their own weight and the interlock lever 5l will remain in a neutral position as shown in Figs. l and 7. If the left coil, as viewed in Fig. l, is energized, its plunger will be raised and the lug 52 on the associated contact block will engage and raise the adjacent end of the lever as shown in Fig. 8. The other end of the lever then is lowered into engagement with the other lug to hold the other block in its lower inactive position. The positions of the parts then are reversed as shown in Fig. 9 if the other coil is energized to raise its plunger.

lt will be apparent that the novel interlock arrangement including the lever 5l is of simple construction and easy to assemble because of its location at the end of the center portion l5 of the fixed contact support 14 at the exterior of the switching mechanism. By virtue of their U-shape, the connectors l2 for the fixed contacts l@ not only are easily attached to more than one conductor, but also are easy to mount on their insulating support lli. Also advantageous is the novel arrangement of the projecting and recessed parts 49 and Si) on the mounting bracket 35 and each coil spool to avoid turning of the spool, the slots in the bracket also serving to reduce eddy currents.

-I claim as my invention:

l. In a switching mechanism, the combination of an elongated supporting bracket of 'I' -shaped cross section having a cross bar and a center leg, a first set of switching elements having a plurality of fixed contacts mounted on one end portion of said cross bar in a row paralleling said center leg and a plurality of movable contacts opposing the fixed contacts, means including a first support block mounting said movable contacts thereon for reciprocation into and out of engagement with said fixed contacts along a predetermined first path parallel to and along one side of Said center leg, a second similar set of switching contacts having a plurality of fixed contacts mounted on the other end portion of said cross bar in a row parallel to and laterally spaced from said row of first fixed contacts and a plurality of movable contacts opposing the second fixed contacts, means including a second support block mounting said second movable contacts thereon for reciprocation into and out of engagement with said second fixed contacts along a path extending parallel to and laterally spaced from said first path on the other side of said center leg, an interlock lever fulciumed intermediate its ends on said center leg to swing about an axis parallel to and disposed between said paths and in a plane beyond one end of the center leg and said rows of contacts where the lever is easily accessible, and parts projecting into said plane from the ends of said support blocks adjacent the plane, said parts each engaging the adjacent end of said lever to hold the associated set of movable contacts away from its fixed contacts when the other set of movable contacts engages its xed set of contacts.

2. ln a switching mechanism, the combination of a supporting bracket, a first set of switching elements having a plurality of fixed contacts mounted stationarily in a row on said bracket and a plurality of movable contacts opposing the fixed contacts, means including a first support block mounting said movable contacts thereon for reciprocation along a predetermined first path and into and out of engagement with said fixed contacts, a second similar set of switching contacts having a plurality of fixed contacts mounted on said bracket in a row parallel to and laterally `spaced from said row of first fixed contacts and a plurality of movable contacts opposing the second fixed contacts, means including a second support block mounting said second movable contacts thereon for reciprocation into and out of engagement with4 said second fixed contacts along a path parallel to and laterally spaced from said first path, an interlock lever fulcrurned intermediate its ends on said bracket to lswing about an axis parallel to said rows and disposed between said paths, said lever swinging in a plane beyond one end of said support blocks and said rows of contacts where the lever is easily accessible, and two lugs, one projecting from said end of each of said support blocks and into Said plane for engagement by the adjacent end of said lever to hold the associated set of movable contacts away from its fixed contacts when the other set of movable contacts engages its fixed set of contacts.

3. In a switching mechanism., the combination of a supporting bracket, a first set of switching elements having a fixed contact mounted stationarily on said bracket and a movable contact opposing the fixed contact, means including a first support block mounting thereon said movable contact for `reciprocation along a predetermined first path and into and out of engagement with said fixed contact, a second similar set of switching contacts having a fixed contact mounted on said bracket and laterally spaced from said first fixed contact and a movable contact opposing the second fixed contact, means including a second 'support block mounting thereon said second movable contact for reciprocation into and out of engagement with said second fixed contact alonCr a path parallel to and laterally spaced from said first path, an interlock lever fulcrumed intermediate its ends on said bracket to swing about an axis parallel to and disposed between said paths and in a plane paralleling and spaced from said paths of said support blocks to render the lever easily accessible, and two lugs, one projecting from said end of each of said support blocks and into said plane for engagement by the adjacent end of said lever to hold the associated movable contact away from its fixed contact when the other movable contact engages its fixed contact.

4. In a switching mechanism, the combination of la plate of magnetic material of L-shaped cross section having first and second leg portions intersecting at a right angle, a second plate of L-shaped cross section having a first leg secured to said first leg of said first plate and a second leg paralleling and laterally spaced from said second leg of said first plate, a spool of non-magnetic material having a cylindrical center portion spanning said second legs and end flanges lying against the second legs, means on said second legs defining apertures aligned axially with said center portion, locating parts rigid with said center portion and projecting into said apertures to maintain the spool against shifting relative to said second legs and radially of the central portion, a multiple turn coil Wound on said spool, a magnetic core slidable axially in said center portion and co-operating with said plates to define a path for magnetic flux created upon energization of said coil, a switch having a fixed contact element mounted on one of said plates and a movable contact connected to and movable with said core and into and out of engagement with the fixed contact, and a lug projecting laterally and outwardly from one of said anges and into a radial slot formed in the adjacent one of said second legs and abutting the defining edge of the slot circumferentially to locate the spool in a predetermined angular position about said axis and to prevent turning of the spool relative to said plates, said slot also reducing eddy currents in said adjacent one of said second legs.

5. In a switching mechanism, the combination of a plate of magnetic material of L-shaped cross section having first and second leg portions intersecting at a right angle, a second plate of L-shaped cross section having a first leg secured to said first leg of said first plate and a second leg paralleling and laterally spaced from said second leg of said first plate, a spool of non-magnetic material having a cylindrical center portion spanning said second legs and end flanges lying against the second legs, means on said second legs defining apertures aligned axially with said center portion, locating parts rigid with said center portion and projecting into said apertures to maintain the spool against shifting relative to said second legs and radially of the central portion, a multiple turn coil wound on said spool, a magnetic core slidable axially in said center portion and co-operating with said plates to denne a path for magnetic fiux created upon energization or" said coil, a switch having a fixed contact element mounted on one of said plates and a movable contact connected to and movable with said core and into and out of engagement with the fixed contact, and projecting and recessed parts formed on one of said flanges and the adjacent one of said second legs and interfitting with each other to locate the spool in a predetermined angular position about said axis and to prevent turning of the spool relative to said plates.

6. In a switching mechanism, the combination of a plate of magnetic material of L-shaped cross section having first and second leg portions intersecting at a right angle, a second plate of L-shaped cross section having a first leg secured to said first leg of said first plate and a second leg paralleling and laterally spaced from said second leg of said first plate, a spool of non-magnetic material having a cylindrical center portion spanning said second legs and end fianges lying against the second legs, means on said second legs defining apertures aligned axially with said center portion, locating parts rigid with said center portion and projecting into said apertures to maintain the spool against shifting relative to said second legs and radially of the central portion, a multiple turn coil wound on said spool, a magnetic core slidable axially in said center portion and co-operating with said plates to define a path for magnetic flux created upon energization of said coil, a switch having a fixed contact element mounted on one of said plates and a movable contact connected to and movable with said core and into and out of engagement with the fixed contact, and means on one of said fianges and the adjacent one of said second legs providing circumferentially facing surfaces abutting each other to locate the spool in a predetermined angular position about said axis and to prevent turning of the spool relative to said plates.

References Cited in the file of this patent UNITED STATES PATENTS 2,172,633 Wilnis Sept. 12, 1939 2,446,299 Nelsen Aug. 3, 1948 2,755,354 Dehn et al. July 17, 1956 2,791,659 Matthias May 7, 1957

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