US2285986A - Circuit interrupter - Google Patents

Description

June 9, 1942' R. T. KINTZING ET AL 2,285,986

CIRCUIT INTERRUPTER Filed Jan. 24, 1940 2 Sheets-Sheet l I 68 /0 1y 5 F/yf.

- m 4 42 74 44 :2 48 64 WITNESSES: 44 60 42 3 and (/arence 5. Ear).

BY I! 36 Q 2/ ATTORNE Jim 9, 1942.

R. T. KINTZING ETAL CIRCUIT INTERRUPTER Filed Jan. 24, 1940 Fig. 6

oar

J/ZA Gibb/a1 2 Sheets-Sheet 2 IN VENTOR 5 Oswald D. van Nehren, fiee se 7.' lf/n {Z07 and C/ar'e/vce 45 Gary 7Z8] ATT:O EY

Patented June 9,1942

UNITED STATES PATENT OFFICE CIRCUIT INTERRUPTER Application January 24, 1940, Serial No. 315,368

13 Claims.

Our invention relates generally to electric circuit interrupting devices, and more particularly to switches 01' the push button type.

An object of our invention is to provide a novel, compact and simplified ush button switch construction.

Another object of our invention is to provide a novel switch block or support construction.

Another object of our invention is to provide a novel and simplified arrangement for supporting switch contacts on an insulating supporting base.

Another object of our invention is to provide a novel arrangement for supporting conductor terminals on an insulating supporting block.

A further object of our invention is to provide novel supporting means for a plural push button switch unit.

A further object of our invention is to provide a novel locking means for selectively maintaining a button of a push button switch in one operating position.

Another object of our invention is to provide novel switch constructions of different types, parts of which are interchangeable.

Another object of our invention is to provide a push button switch construction which is adapted to be mounted in difierent angular positions.

A still further object of our invention is to provide novel push button switch constructions which are rugged and eflicient and yet of relatively simple design, and capable of being economically constructed.

These and other objects of our invention will become more apparent upon consideration of the following detailed specification of preferred embodiments thereof, taken in connection with the attached drawings, in which:

Figure 1 is a cross sectional view of a switch easing illustrating a push button switch in elevation therein constructed in accordance with one embodiment of our invention;

Fig. 2 is a plan view of the casing shown in Fig. l and looking at the right-hand side of Fig. 1;

Fig. 3 is an end view of the push button unit per se shown in Figs. 1 and 2;

Fig. 4 is a cross sectional view taken substantially on the line IV-IV of Fig. 5;

Fig. 5 is a top plan view of the push button unit shown in Figs. 1 to 4 with one push button, together with its associated spring and moving contact, removed;

Fig. 6 is a top view of a single button push button switch unit constructed in acordance with our invention;

Fig. 7 is a side view of the switch shown in Fig. 6

Fig. 8 is a bottom view of the switch shown in Figs. 6 and 7; and

' mounted in a box or casing. As shown in Figs. 1

and 2 there is provided a metallic casing 2 having one side open and provided with knock-out portions 3 in opposite end walls thereof. Our novel two button push button switch unit 4 comprises generally, an insulating block 5 which may be of any desired insulating material, preferably of some molded insulating material. The block 5 is provided with a pair of spaced integral projections 5 adapted to be received in corresponding depressions provided in the bottom wall of the casing 2, and the block is secured to this wall of the casing by a single machine screw 8 extending through a substantially central bore ill in the insulating block 5. A cover 12 is provided for the open side of the casing 2, and is secured thereto as by the machine screws I3. The cover I2 is also of insulating material and may be of a molded insulating material if desided. The cover is provided with a pair of spaced apertures for receiving the push buttons H and ii for controlling the push button unit 4. The cover is also provided with an oval integral ridge l8 surrounding the push button openings, and with a lateral groove 22 in which is secured a stationary lock bar 20. The bar 20 is secured in the groove 22 by means of a shouldered rivet 24 extending therethrough and through the cover l2. The rivet 24 has an enlarged bearing portion 26 adjacent the outer end thereof on which is movably mounted a latch bar 28. The latch bar 28 is provided with an elongated slot 30 in which is received the bearing portion 26 of the rivet 24 directly beneath the head of the rivet. Both the stationary lock bar 20 and the movable lock bar 28 are provided with end apertures 32 and 34, respectively, for a purpose to be hereinafter described.

The purpose of the lock bar 28 is to be able to selectively retain the push button l6 in a depressed position when desirable to prevent accidental energization of the circuit or to prevent unauthorized persons from tampering with the switch. Since the movable locking bar 28 is freely rotatable and slidably mounted on the rivet 24, it is obvious that when the push button I6 is depressed, the bar 28 may be moved from the position shown in full lines in Fig. 2 about the rivet 24, as a pivot, into alignment with the stationary lock bar 20 and groove 22 provided through the barrier i8, whereupon the bar 28 may be moved longitudinally to a position in which it overlies the push-button l6, and where its aperture 32 coincides with the aperture 34 on the stationary lock bar 20. If desired, the movable lock bar 28 may be locked in this position, which is shown in dotted lines in Fig. 2, by engaging a conventional padlock or other locking means through the aligned apertures 32 and 34 of the two locking bars. When it is desired to unlock the push button 16, a reverse procedure is followed; that is, the movable bar 28 is withdrawn longitudinally from the dotted line position shown in Fig. 2 where it overlies and maintains the push button IS in a depressed position, until the inner end thereof clears the sides of the groove 22 so that it may fall to the depending position, shown in full lines in Fig. 2, assuming the switch is mounted vertically, as shown.

The insulating block of the push button unit 4 is provided at one end thereof with a pair of spaced outwardly projecting ledges 36, and at the other end thereof with a pair of similar ledges 38 slightly'spaced from the plane of the ledges 35. The ledges 36 and 38 are integral with the block 5, and if the block is constructed of a molded insulating material, the ledges may be molded therewith. The ledges 35 ar adapted to support substantially U-shaped contact strips 40 of any suitable conducting material, such, for example, as copper or the like. Similarly, the ledges 38 are each adapted to support a substantially U-shaped contact strip 42 similar to the strips 40. These contact strips 40 and 42 may be preformed of a material having some degree of resilience so that they may be slipped onto their respective ledges and frictionally maintained thereon, or the contact strips may be bent about their respective ledges into intimate engagement therewith so as to be frictionally maintained in place on the ledges. As shown, the contact strips are bent about three sides of each ledge with the friction between the strips and the ledges being relied upon to prevent longitudinal withdrawal of thei contact strips, and each ledge is provided with an integral up-standing projection 43 at the outer side of its respective'contact strip to pretends through the contact strips and into an enlarged depression 46 in the insulating base 5. It should be noted that when the terminal screws are drawn down tightly so as to enter the depressions 46 in the insulating block 5 they form a positive lock for preventing end-wise with-- drawal of the contact strips from their respective ledges. Each end of the insulating block 5' is provided with an integral outwardly extending cylindrical barrel 48 for telescopically receiving the push buttons I4 and I6, respectively. The push button I6 is provided with a stem 50, extending through the aperture in its associated barrel 48 and having a reduced lower end 58, forming a shoulder against which is seated a bridging contact 54, which is held in place by means of a hairpin key 56 seated in a peripheral groove in the reduced end of the stem 50. The push button I4 is provided with a similar stem 50 on which is mounted a bridging contact 52 similar to the bridging contact 54. Coil compression springs (not shown) are provided within the push button supporting barrels 48 to normally urge the push buttons l4 and to an outwardly extended position. This normal position of the switch is that illustrated in the drawings, Figs. 1 to 5. The push button l4 has the bridging contact 52 positioned thereon so as to be normally outwardly of and out of engagement with the contact strips 40. The bridging contact 54, controlled by the push button I6, is normally positioned inwardly of and in engagement with the contact strips 42, being held in this position by the aforementioned coil compression spring. It can thus be seen that the upper end of the lower leg of the U-shaped contact strips 40, as shown in Fig. 1, form contacts adapted to be bridged by the bridging contact 52 under control of the push button l4. Similarly, the lower or short leg of the U-shaped contact strips 42 provide relatively fixed contacts adapted to be bridged by the bridging contact 54 carried and controlled by the push button It.

As stated above, the push buttons l4 and I5 are slidably mounted on the supporting barrels 48, and the push buttons, as shown in Figs. 2 and 5, are preferably provided with suitable indicia to distinguish the buttons, In order to provide for mounting this push button unit in either a vertical or a horizontal position and still maintain the indicia on the push buttons in a position in which they are legible, we have provided each push button with an integral key or projection 64 on the inner wall thereof adapted to fit in keyways or grooves 60 and 52 provided on the supporting barrels 48.

As shown in Fig. 5, the keyways 60 and 62 are positioned substantially apart so that the buttons may be assembled thereon in two positions' substantially 90 apart.

As shown in Figs. 3, 4 and 5, we have provided a strap 65 of conducting material secured by ter-, minal screws 44 to connect contact strips 40 and 42 so that this unit may be employed in a single control circuit if desired.

We have also provided integral guideways and insulating projections on the insulating block 5, for positioning conductors to be attached to the contact strips so that they will not interfere with the moving contacts and will be properly directed to the ends of the box and to the terminal screws. As shown particularly in Fig. 5, such guide means comprise concave guideways 68 provided laterally of each terminal screw 44, and integral outwardly extending barriers "I0 terminating short of the base of the insulating block 5 to form conductor passageways 12 between the ends of the barriers 10 and the bottom wall of the housing 2. Thus conductors, in entering the housing 2, for example, through the lower knock-out opening 3, as viewed in Fig. 1, are passed along the bottom wall of the casing through the passage 12, concave guideways 68 to one of the lower terminal screws.

In order to prevent the conductors from escaping from under the heads of terminal screws 44, when these screws are tightened, and to eliminate the use of turned-up corners of the contact strips for this purpose, we provide ledges I4 integral with the insulating block 5 and positioned closely adjacent to the contact screws for a substantial portion of the periphery of the heads of the screws. The ledges l4 lie sufliciently close to the terminal screws 44 so as to prevent a conductor from escaping from beneath the head of the terminal screws when the screws are tightened. As appears from Figs. 1 and 5, each terminal screw is located in a partial pocket formed in the insulating block 5 and the block is provided with integral barriers ll between the contact screws thus providing a substantial creepage distance between all of the conducting parts.

When the switch unit is mounted in a casing such, for example, as the casing 2, it may be diflicult to relate the several terminal screws to their respective contacts upon inspection. Therefore, as shown in Fig. 5, shoulders at each corner of the insulating block may be inscribed with suitable indicia, such as the letters V, W, X, Y, shown in this figure to enable positive identification at a glance, as to the relation between each terminal screw and its respective contact strips. 7

In the embodiment shown in Figs. 6 to 9, we have illustrated a single button push button switch unit for controlling two circuits. This is accomplished by providing two sets of contacts spaced from each other which are adapted to be bridged by a single bridging contact. This switch unit comprises an insulating block I6 provided with ledges 90 and I8 around which are bent the contact strips 94 and 92, respectively, in the same manner as the contact strips were mounted in the previously described embodiment of our invention. As shown in Fig. 7, each contact strip is provided in its upper leg with a threaded aperture for receiving the terminal screws 96 and the lower legs of the contact strips are shown as extending into overlapping spaced relation to form the spaced contacts referred to above. Movement of the contact strips Hand 84 relative to ledges I8 and 80 is prevented in this switch construction, by laterally extending wings or sides 90 which extend outwardly from the insulating block I6 into engagement with the bight portions of the contact strips 82 and 84. Lateral movement of contact strips 92 and 84, with respect to the insulating block I6 is prevented by integral projections 9I on the .ledges 19 and 90, provided in this instance on the lower sides of the ledges. Also, in this embodiment of our invention, we have provided ledges 98 similar to the ledges I4 in the previously described embodiment, adjacent the terminal screws 86 to pres vent the escape of conductors from beneath the heads of these screws when the screws are tightened. Likewise, the terminal screws are located in partial pockets in the insulating block with barriers 93 between them to increase the creepage distance between the conducting parts of the switch. The wings 90 extend the full heighth of the switch and include lower end portions comprising integral barrel portions 92, internally bored, as at 94, for the reception of bolts or other securing means for mounting this switch unit.

Referring to Fig. 9, it can be seen that the insulating block I6 is provided with a central bore 96 having a reduced inner portion 99 presenting a shoulder I00. It can be seen that the construction thus far described is substantially the same, except in certain minor details, as that shown in the copending application, Serial No. 230,937, of Clarence E. Gary, for an improvement in Switches, and which application is assigned to the same assignee as this application. Thus, in the structure thus far described, a rotatable actuating member carrying a movable bridging contact engageable with the inner edges of the contact strips 92 and 94 may be inserted in the bore 96 in the manner taught in the above-mentioned copending application, or the same structure may be provided with a slidably mounted bridging contact to be actuated by a push button, as is shown in Figs. 6 to 9 of this application. The underside of block I6 is provided at one side of bore 96 with an integral arcuate guide flange 91 (Fig. 8) for cooperation with a rotatable bridging contact of the type disclosed in the above-mentioned copending application.

If it is desired to use the insulating base 46 heretofore described in connection with a push button, a push button I02 may be provided which has an integral skirt I04 telescoping over the outer surface of the sleeve portion I09 on the insulating block 16, and a stem I03 passing through the bore 96, 99 through the insulating block. The push button may be provided with a key I05 in the same manner as the push buttons I4 and I6 described in connection with the previous embodiment of our invention, which key or projection I05 is adapted to be received in either of two keyways I01, provided on the sleeve I09. The keyways I01 are substantially apart to thereby enable this particular switch unit to be mounted in at least two diflerent angular positions.

The lower end of the push button stem I09,

as seen in Figs. 7 and 9, is provided with a reduced portion I06, having an outer annular groove for receiving the hairpin key I00. The key I09 is merely a substantially U-shaped strip of material of a size to fit in the peripheral groove in the outer end of the stem I03, which, after assembly, has the free ends thereof bent inwardly by any suitable means to secure the same in position on the stem. The hairpin key I09 supports the bridging contact I I0 mounted on the reduced portion I06 of the stem I03, and the bridging contact is maintained in position against the key I08by a coil compression spring H2 seated at its lower end on the bridging contact H0 and bearing at its upper end against the shoulder II4 formed between the stem I03 and the reduced portion I06 thereof. As shown, the lower end of bore 96 is enlarged at 99 for receiving spring II2. This enlarged end 99 of bore 96 is also adapted to receive the positioning spring employed in the rotary switch of the aforementioned copending application, and to this end is provided with opposed notch portions II to receive portions of the positioning spring to prevent rotation thereof. A coil compression spring II 6 is provided within the sleeve I09 and is seated at one end on the shoulder I00 in the sleeve and at its other end bears against push button I02 to normally urge the same upwardly so that the bridging contact normally connects the lower contact portions of the contact strips 84. In order to prevent rotation of bridging contact I I0 on portion I06 of stem I 03, block I0 is preferably provided with integral projecting guide members at the underside of the block, and at the side of bore 96 opposite guide flange 91. It will be noted that guide members 95 are also positioned to engage one edge of bridging contact IIO on opposite sides of stem portion I06, to thereby guide the bridging contact for rectilinear movement.

When the push button I02 is depressed, the bridging contact is moved downwardly to bridge the lower legs of the contact strips 92, and the coil compression spring II2 acts to provide resilient engagement of the bridging contact II0 with the lower legs of the contact strips 92, and also provides some lost motion between the lower limit of travel of the push button and the lower limit of travel of the bridging contact I I0.

Inasmuch as it is impossible to view the contact portions of the contact strips 92 and 94 from the top or front of the switch when it is mounted on a support, as apparent from Fig. 6, it is desirable to provide suitable indicia adjacent the respective terminal screws 86 to indicate to a service man the association between the various contacts and each respective terminal screw. As shown in Fig. 6, the insulating block 16 may be marked adjacent the two terminal screws 86 which are on the contact strips 82 with the letter B to indicate their association with the bottom switch contacts, and the block may be marked adjacent the other terminal screws with the letter T to indicate the top switch contacts. Instead of such marking, or in addition, the contact screws themselves, at opposite ends of the switch unit may be of different material or of material which is of different color. Thus, the contact screws at one end of the switch may be of brass, whereas the contact screws might have a coating of tin thereon.

The switch unit of this embodiment of our invention is also provided with guide passages for receiving conductors to be connected to the terminal screws 86. As shown, for example, in Figs. 6, 7 and 8, grooves H8 are provided between the side wings 90 and the ledges I8 and 80 of the contact strips 82. Conductors secured to the terminal screws may each be led downwardly as viewed in Fig. 7, through the adjacent groove H8 and thence through arcuate cut-out portion I20 at the corresponding corner of the insulating block I26.

From the foregoing it should be apparent that we have provided at least two novel types of push button switch units, and a casing for a push button switch unit embodying an insulating cover, thus making it possible to permit a smaller space between the current carrying parts of the switch and the cover, and thus reducing the depth of the casing. In both embodiments of our invention we have located the terminal screws in such a manner adjacent insulating ledges, that after a connecting wire has been slipped over the screws and secured beneath the head of each screw, it cannot slip outof place. Also, in both embodiments of our invention, conducting strips are frictionally secured to an insulating switch block, and are additionally prevented from separation from the block in some instances by projections integral with the block, and in another instance by the contact strip terminal screw. Hairpin keys are provided to lock the movable contact in place, and our two button push button switch unit may be mounted with but the use of a single screw. Both forms of our invention are provided with insulating blocks having integral barriers and guideways to receive and position the conductors leading to the switch, and especially to maintain such conductors away from the moving contacts. Both forms of push button units disclosed may be mounted in either oftwo positions substantially 90 apart with the legend on the buttons being readable in either position. We have also disclosed a latch or lock element which is operable to maintain a push button depressed and which may be itself locked in such a position. Also, we have disclosed in Figs. 6 to 9, an insulating block unit provided with contacts so arranged that they may be used with either a rotary movable contact, or a slidable push button type of movable contact.

Having described preferred embodiments of our invention, in accordance with the patent statutes, we desire that our invention be interpreted as broadly as possible and that it be not limited to the particular embodiments disclosed herein, inasmuch as it will be obvious, particularly to persons skilled in the art that many changes and modifications may be made in these particular structures without departing from the broad spirit and scope of our invention. Therefore, we desire that the claims be interpreted as broadly as possible and that they be limited only by what is expressly stated therein.

We claim as our invention:

1. In a device of the character described, an insulating base member including at least one projecting contact supporting portion having angularly related contact supporting outer surfaces located in adjoining angularly related planes, relatively stiff elongated conducting contact means having angularly related sections in a plane substantially parallel to said base and at substantially right angles to said supporting projection and in intimate engagement with said contact supporting surfaces, means preventing lateral displacement of said conducting contact means outwardly with respect to said base member, and movable contact means supported on said base member for movement into and out of engagement with one of said sections of said elongated contact means.

2. In a device of the character described, an insulating base member including at least one laterally projecting contact supporting portion having angularly related contact supporting surfaces, elongated conducting contact means having angularly related sections in intimate functional engagement with said contact supporting surfaces, rib means integral with said contact supporting portion for preventing lateral outward displacement of said conducting contact means with respect to said base member, and movable contact means supported on said base member for movement into and out of engagement with one of said sections of said elongated contact means.

3. In a device of the character described, an insulating base member including at least one outwardly projecting contact supporting portion having angularly related adjoining contact supporting surfaces including opposed substantially parallel surfaces and connecting surface at one end thereof, relatively stiff elongated conducting contact means having angularly related sections in intimate engagement with said contact supporting surfaces, a terminal screw threadedly engaging through said contact means, a recess in one of said opposed surfaces for freely receiving said screw, and movable contact means supported on said base member for movement into and out of engagement with one of said sections of said elongated contact means.

4. In a push button switch including a support member capable of being mounted on a base in a plurality of angularly related positions and carrying fixed and movable contact means, a button member bearing suitable indicia on its outer end slidably mounted on said support member for actuating said movable contact means, releasable means limiting said slidable movement for permitting said member when released to be mounted on said support member in a difierent angular position corresponding to said angular positions of said support member, means also permitting connection of said button to said movable contact means in different relative angular positions, whereby said indicia may be presented in the same position for different angular mountings of said switch, and cooperating means on said members for preventing rotation of said button at said difierent angular positions.

5. In a push button switch including a support member carrying fixed and movable contact means, a button member bearing suitable indicia on its outer end slidabiy mounted on said support member and pivotally connected to said movable contact means ioractuatin'g said movable contact means in a plurality of relatively diflerentangular positions oi said button, said members being 01' a molded insulation material and having integral therewith complementary means ior preventing rotation of said button member while permitting slidable mounting of said button member on said basemember in a plurality of diflerent angular positions 01' said button member with respect to said base member. ,1

6. In a circuit interrupter, an interrupter casing having interrupting means therein and actuating means for the interrupter projecting through an opening in a wall of said casing, said actuating means being slidably movable through said opening, and locking means on the outer side of said casing wall for movement into and out of the path of movement 01 said actuating means for engagement over the outer end of said actuating means for locking said actuating means in a depressed position.

7. In a circuit interrupter, an interrupter casing having interrupting means therein and actuating means for the interrupter projecting through an opening in a wall of said casing, said actuating means-being. mounted for limited sliding movement through said casing opening, and locking means mounted on the outer side of said casing wall for movement in a plane disposed at an angle to the sliding movement 01' said actuating means, for movement into, engages ment over the outer end oi said actuating means when pressed to prevent outward movement thereof.

8. In a circuit interrupter, an interrupter cas-' ing having interrupting means therein and actuating means for the interrupter projecting through an opening in a wall 01 said casing, said actuating means being mounted for limited sliding movement through said casing opening, and locking means moimted on the outer side of said casing for pivotal and sliding movement in a plane disposed at an angle to the sliding movement or said actuating means ior movement into engagement therewith to lock said actuating means against movement, and whereby said locking means may move outwardly away from said actuating means to a projecting position I with respect to said casing-and then-pivotaiiy to a position along one side of said casing.

9. In a device the character described, an insulating base member including at least one projecting contact supporting portion having angularly related contact supporting outer surfaces located in adjoining angularly related planes, relatively stii! elongated conducting contact means having angularly related sections in intimate engagement with said contact support s suriaces, respectively, integral-rib means on said contact supporting portion for preventing lateral away from at least one of said supporting surfaces.

10. In a circuit interrupter, a supporting block of insulating material having a recess in one side thereof, an aperture extending through said block and opening at one end into said recess, said one end of said aperture being enlarged for receiving resilient means, spaced means integral with said block and extending into said recess at one side of said aperture to form guides substantially aligned with said aperture, arcuate I guide means at the opposite side of said aperture,

sidewise movement or said contact means outwardly relative to said supportingportion base membenandmeansintegralwithsaidbasemerm berandoveclyingsaidcontactmeansior prevsntingmovementorsaidcontactmcanslatsraily and contact means mounted on said block and' including spaced contact portions in said recess P about said aperture.

11. In a device of the type described, a support, a block oi insulating material adapted to be mounted on and secured to said support, integral projecting contact supporting means on at least one side of said block, separate contact strip means bent about opposite ends 01' said contact supporting means and each including a portion positioned at the outer side of said contact supporting means having means for securing a conductor thereto, and each of said strips having another part positioned at the opposite side of said contact supporting means in spaced overlapping relation, and cooperating contact means mounted on said block for movement between said other spaced parts of said contact strip means.

12. In a device of the type described, a support, a block of insulating material having a pair of spaced supporting leg portions adapted to be mounted on and secured to said support, integral projecting contact supporting means on at least one side of said block, contact strip means bent about said contact supporting means and including a portion positioned at the outer. side or said contact supporting means having means for securing a conductor thereto, and another portion extending into the space between said leg portions, cooperating contact means also in the space between said leg portions, and actuating means extending through said block for moving said cooperating contact means into and out of engagement with said other portion of said contact strip means.

13. In a device of the type described, a support, a block of insulating material having a pair of spaced supporting leg portions adapted to be mounted on and secured to said support, integral projecting contact supporting means on at least one side 01' said block, separate contact strip means bent about opposite ends of said contact supporting means and each including a portion positioned at the outer side of said contact supporting means having means for securing a conductor thereto, and another portion extending into the space between said leg portions in spaced overlapping relation, cooperating contact

Images