US1780895A - Electric switch - Google Patents

Description

L. KELLNER Nov. 4, 1930.

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PATENT OFFICE LOUIS KELLNER, OF BROOKLYN, NEW YORK, ASSIGNOR TO JEFFERSON ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS ELECTRIC SWITCH Application filed January 21, 1926. Serial No. 82,637.

The invention relates to improvements in manually operable electric switches of the fused type.

An important object of the invention resides in the provision of a switch having a fused circuit and an unfused circuit in parallel, and having a switch operating mechanism which when actuated will first close the fused and unfused circuits, and will subsequently open the unfused circuit. The switch is particularly adapted to be used as a starting switch for small motors where the electric circuit should not be fused while the motor'is starting because of the heavy starting-overload, but should be fused after the motor has attained full speed.

Another object resides in the provision of a novel switch operating mechanism which is ineffectual to both close and open the unfused circuit in a single or the initial movement, and which must be actuated twice to complete the action of the switch, thereby making it impossible for the manipulator to inadvertently close only the fused circuit in the initial movement of the actuator.

A further object is to provide novel means for locking the switch in closed position after the second or final actuation of the switch operating mechanism, and means automatically operable in case of an overload or ofa low voltage to release said locking means and thereby cause the switch to open.

A further object is to provide a switch of the above character in which the fused and unfused circuits are each provided with do uble breaks, and in which the movable contacts are mounted on a sliding support between the fixed contacts.

A general object is to provide a new and improved switch which is simple and inexpensive in construction, and which is efiicient and fool proof in use.

Ancillary objects and advantages will be come apparent as the description proceeds.

In the accompanying drawings, Figure 1 is a front view of a switch embodying the features of my invention, the cover of the easing being removed to show the interior.

Fig. 2 is a sectional view taken along line 2-2 of Fig. 1, the switch being shown in its open position.

Fig. 3 is a fragmentary sectional view of the switch operatingmechanism.

Fig. 4 is a fragmentary view similar to Fig. 2 but showing the parts in position to close the unfused circuit.

Fig. 5 is still another view similar to Fig. 2 but showing the parts in position to close only the fused circuit. '8

Fig. 6 is a sectional View taken along line 66 of Fig. l.

Fig. 7- is a fragmentary sectional View of the operating mechanism taken'substantially along line 7-7 of Fig. 2.

Fig. 8 is a perspective view of parts of'the operating mechanism.

Fig. 9 is a side view on a red'uced scale of 'the switch, the view showing the overload and low voltage coils.

Fig. 10 is a fragmentary elevational View of the construction shown in Fig. 9.

Fig. 11 is a diagrammatic representation of the circuits controlled by the switch.

WVhile I have shown in the drawings and will herein describe in detail the preferred embodiment of my-invention, it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but aim to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the drawrings, the switch is housed in a box-shaped cas- 20. The front edges of the standards 18 are bent in to form flanges 21. Other flanges 22 are secured to the sides of standards 18 next to the flanges 21, and form therewith a pair of parallel spaced guideways 23.

Extending between and mounted in the upper and lower ends of the guideways 23 are two vertically spaced lates 24 and 25'respectively. These plates are adiustably secured in the guideways 23 by screws 26. A plate or slide 27 is mounted in the guideways 23 for movement between the plates 24 and 25. The plate 27 is normally held in its lower position against the plate 25 by a pair of coil springs 28. These springs are connected at their'opposite ends to lugs 29 extending rearwardly from the plates 25 and 27.

Mounted on the front of the fixed plates 24 and 25 are two sets of knife blade contacts 30 and 31 respectively. These fixed contacts are insulated from the plates 24 and 25 by suitable insulating blocks 32 and 33 to which they are secured by screws 34 and 35, and are provided with binding screws 36 and 37 for attaching electrical leads. Two sets of clip contacts 38 and 39 are secured respectively by means of screws 40 and 41 to the front of the .movable slide 27 at opposite edges thereof,

39 are provided with alined fuse clips 43 and 44 in which one or more fuses 45 are mounted. A guard 46 having openings 47 permitting movement of the contacts 39 therethrough is mountedon the slide 27, and extends along the ends and lower edge thereof to prevent any of the fuses 45 from falling into the lower end of the switch casing. The contacts 38 and 39 should not be closed subsequently thereto. 7

The lower ends of the springs 54 in the open position of the switch (see Fig. 2) extend through the contacts 49 directly ahead of the slots 53, and are provided with flat contacts 57 adapted to be moved over the con-- cuit, and provide two breaks one of which is open when the switch is closed (see Fig. 5),

and both of which are open when the switch is-open (see Fig. 2). As the slide 27 moves upwardly the contacts 57 are first pressed forwardly by the surfaces 52, and after passing through the contacts 49 spring rearwardly to break the unfused circuit. In the return movement of the slide, the contacts 57 are pressed rearwardly by the rear sides of the contacts 49, and after passing the lower edges of the contacts 49 spring forwardly are arranged to be moved by the slide 27 into and out of engagement with the contacts 30 and 31. These contacts constitute the fused circuit, and provide a double switch break therein adapted to be opened and closed simultaneously. The circuit may comprise any desired number of independent lines, and in the present instance I have shown each set of contacts as consisting of three contacts associated with the other contacts to form three lines, anv number of which may be used! Mounted on the rear of the plates24 and 25 are two other sets of fixed contacts 48 and the contacts 49 are loop-shaped with the rear side inclined upwardly and forwardly to provide an inclined contact surface This surface is split by a central longitudinal slot 53. Avset of three leaf springs 54 is secured to the rear side of the slide 27 and in electrical connection with the contacts 38 by the screws 40 and is insulated from the slide by insulating blocks 55. The upper ends ofthe springs 54 are provided with blade extensions 56 adapted to be moved into and out of engagement with the clip contacts 48. The contacts 48 and 56 are arranged to be closed in advance of the contacts 30 and 38, and

into their initial positions, the arms of the springs 54 passing through the slots 53. The front faces of the contacts 57 are provided with suitable insulating pads 58 which pre vent electrical connection with the contacts 49 on the return movement.

Means is provided for moving the slide 27 v in two successive steps from its lower or open position into its upper or closed position. After the first step the unfused and fused circuits are closed, the unfused circuit being closed slightly in advance of the fused circuit, and after the final step the unfused circuit is open and the fused circuit is closed.-

This means comprises a bifurcated lever 59 which is pivotally mounted on a pin 60 be tween two lugs 61 extending in from the front wall 15 of the casing, and the arms of which extend inwardly through openings 62 in the slide 27. The lever 59 extends through a slot 63 in the wall 15, and is formed at its outer end ,with an arm 64 extending downwardly and substantially at right angles to the body of the lever. A hand lever or actuator 65 is loosely pivoted on the pin 60, and preferably is channel-shaped in part to embrace or fit over the arm 64. It will be evident that by moving the lever 65 downwardly --the lever 59 will be actuated, and that the lever-65 is free to move upwardly independently of the arm 64. Mounted for vertical movementon the inside of the front wall 15 1s a'slide 66 having a pair of closely spaced side walls 67. The slide is connected through a slot 68 in the wall 15, with a vertical plate 69 extending beyond the ends of the 51017:

The lower edge of the plate 69 is positioned to be engaged by a heel 70 on the lever 65 when the latter is raised to move the slide 66 upwardly. The slide 66 is resiliently held 11 1ts lowermost position by a coil spring 71, the ends of which fit over a pair of pins 72 on menses the front wall 15 and the upper end. of the slide respectively.

Each side 67 of the slide 66 is cut away at its lower end to provide a lower notch 7 3 and a slot 7% terminating in an upper notch 7 5, the notches being separated by a pointed inwardly extending projection 7 6.. Extending up from the lower end of the slide and between the sides 67 thereof is a plate 77 having a stop lug 78. A cam member 79 havi-n spaced arms with downwardly and outwardly inclined cam surfaces 80 is pivotally mounted on the plate 77. The upper end of the cam member 79 is provided with a projection 81 which is connected by a light coil spring 82 to a pin 83 extending through a pair of lugs 84 on the upper ends of the side walls 67. The spring 82 tends to hold the projection 81 against the stop lug 78. A pair of inclined shoulders 85 is formed on the arms of the cam member 79 in line with the, slots 74:.

Two upwardly extending spaced arms 86 are formed on the lever 59, and extend along opposite sides of the cam slide 66. The arms 86 carry pins 87 extending toward the plate 77, and positioned to ride on the sides 67 and the cam member 79.

The lever 65 when lowered to close the switch extends across the hinged section 16, and hence prevents access to the fuses or the switch contacts when the latter are closed.

Means is provided for automatically tripping the cam slide 66 to open the switch in the event of an overload or a low voltage. This means comprises a trip lever 88 pivotally mounted at 89 on the inside of the front wall 15. One end of the lever 88 extends across the lower end of the cam slide 66, and the other end thereof projects through an opening 90 in one of the side walls 13. Mounted on the side of the casing is a low voltage coil 91 having a movable plunger 92 which is adapted to drop onto the outer end of the lever 88 when the voltage falls below a predetermined value- An overload coil 93 is also mounted on the same side of the casing, and has a movable plunger or core at adapted to be moved upwardly against the rear end of a lever 95 when the load exceeds a predetermined value. The lever 95 is pivoted at 96, and extends beside the plunger 92 and overthe outer end of the lever 88. The coils 91 and 93 are connected in series across main lines L and L by wires 97 and 98 (see F 1g. 11

To illustrate its operation, the switch is shown connected in the main supply lines L L and L of a small electric motor 99. The switch in its open position is shown in Figs. 1, 2 and 11. To close the switch, the lever '65 isthrown downwardly, thereby moving the pins 87 along the am member 79 to Cause upward movement of the slide 66.

this movement the pins 87 are brought into breaking the unfusecl circuit.

engagement with the cam surfaces 80. The cam member 79 is thereupon pivoted (see Fig. 3), thereby permitting the pins to move into the notches 73 which limit the movement of the lever and hence the contact slide 27.

-. The relative position of the parts at this point is shown in Fig. 4. Tt will be noted that in this position the fused and unfused circuits are closed thereby passing a small safe part of g the heavy starting current to the motor 99 projections 76 to pass the pins 87, and is again thrown to move the pins into the notches 75. These notches serve to lock the switch inits closed position which is shown in Fig. 5. It will be noted that the circuit through the fuses 45 is now closed, and that the contacts 49 and 57 are apart, thereby To open the switch, the lever 65 is raised. This brings the heel against the plate 69, and thereby raises the slide 66. The pins 87 are consequently separated from the notches 75, and are moved rearwardly along the slots 7 4 and against the shoulders 85 by the coil springs 28 acting through the plate 27. The cam member is again pivoted, and thereupon permits the pins 87 to assume their initial positions with the switch open. If the load he'- comes excessive or if the voltage drops too low, the slide 66 will be automatically raised to open the switch by the lever 88.

It will be evident that l have provided a new and improved switch in which the fuses are protected at all times. The switch is simple and inexpensive in construction, and is eihcient in operation. Two operations are necessary to close the switch, thereby minimizing the danger of closing the switch too soon.

I claim as my invention:

1. A switch having, in combination, a support, a movable member, contacts on said support and on said movablemember, said contacts being arranged to form a pair of parallel circuits, fuses in one of said circuits, said member having an open position in which both circuits are open, a closed position in which said unfused circuit is closed, and a closed position in which said unfused circuit is open and said fused circuit is closed, spring means tending to maintain said member in open position, an actuator for moving said member from open to closed position, and cam means controlling the movement of said actuator, said cam means limiting the movement of said member upon the first movement of said actuator to said intermediate position and necessitating a partial release and a second actuation of said actuator to move said member into its closed position.

2. A switch having, in combination, a support, a movable member, contacts on said support and on said movable member, said contacts being'arranged to constitute a pair of circuits, said movable member having an open position in which both circuits are open, an intermediate position in which one circuit is closed, and a closed position in which the other circuit is closedand the first mentioned circuit is open, means for moving said member from open to closed position, and means for limiting the movement of said means on a single throw so that upon the first actuation said member will be movedinto said intermediate position and upon the second actuation it will automatically be moved into its closed position. f f

3. A switch having, in combination, a plurality of fixed contacts,- a movable member, a plurality of contacts on said member, said contacts constituting a pair of circuits, and said member having an open position in which all circuits are open, an intermediate position in which one circuit is closed, and a closed position in which the other circuit is closed, a lever engaging said member for moving the latter from open to closed position, an actuator engaging said lever to move the latter in one direction but bein inefiectual to move the same in the other irection,

menses stitute a pair of circuits, said movable mem her having an open position in which both circuits are open, an intermediate position in which one circuit is closed, and a closed position in which the other circuit is closed and the first mentioned circuit is open, means for moving said member from open to closed position, and means for controlling the movement of said means so that upon the first actuation said member will be limited to movement into its intermediate position and upon a second a'ctuation in the same direction said member will be moved automatically into its spring means tending to hold said member' in its open position, cam means controlling said lever, said cam'means limiting the movement of said lever on a single actuation so as to position said member in its intermediate position upon the first actuation of said lever and in its closed position upon the final actuationof said lever, and serving to lock said lever in said last mentioned position, said actuator being positioned upon its free movementto actuate said cam means to release said lever andpermit said switch to open.

4. A switch having, in combination, a sup: port, a plurality of fixed contacts on said support, a movable member, a plurality of contacts on said member, spring means for moving said memberin one direction, means for moving said member in the other direction, a cam slide spring pressed into engagement with said means and having a plurality of notches, and a cammember pivotally mount-- ed on said slide for directing said last mentioned means upon bein actuated into engagement with one of said notches, said last mentioned means being adapted to be moved into engagement with another ofsaid notches upon a partial release and a second actuation. 5. A switch having, in combination, a support and a movable member, contacts mounted on said support and on said movable mem-' her, said contacts being arranged to conclosed position, said last mentioned meansserving to lock said member in closed position.

6. A switch having, in combination, a support,-a movable slide, contacts on saidsupport and on said slide constituting twocircuits one of which is fused and one of which is unfused, said contacts being arranged so that when said slide is in one position said circuits are closed and when said slide is in another position said fused circuit is closed and saidunfused circuit is open, means for moving said slide, means operable to prevent movement of said slide directly to said last mentioned position in a single movement, said last mentionedmeans being actuated upon a partial return of said slide to permit movement of said slide to said last mentioned position, and means for locking said slide in said last mentioned position.

7. A. switch having, in combination, a su port, two fixed contacts mounted on one si e of said support, a slide movable between said contacts, two movable contacts mounted on said slide and connected by a fuse, said slide being adapted to carry said movablecontacts into and out of engagement with said fixed contacts, two fixed contacts mounted on the other side of said support, and a pair of movable contacts mounted on said slide for movement into and out of engagement with said last mentioned fixed contacts, the contacts on said other side being closed when said slide is in an intermediate position, and those on the first mentioned side being closed when said slide is.in another position,'and means for moving said slide in increments successively into said two positions.

8. A switch having, in combination, a support, a pluralit of contacts on said support, a movable mem er, a plurality of contacts on said member, spring means tending to move said member in one direction, a lever engaging said member for moving it in the other direction to close said contacts, means for actuating said lever, said means having a free movement in one direction, a slide having a pluralityof-notches positioned to successively engage said lever upon successive actuations thereof to stop said member in successive positions in its movement to close said contacts, and a cam member for guiding said lever into engagement with said notches,

one of said notches serving to lock said lever in position, and said first mentioned means in its free movement serving to move said slide to unlock said lever.

9. In a switch, in combination, a support.

a loop-shaped contact mounted on said support, one side of said contact being split, a movable member, a spring arm supported by said member and extending through said contact in one position of said member, a con tact arried by said arm and adapted to have a Wedge engagement with the split side of said first mentioned contact in another position of said member, said last mentioned contact being adapted to clear Said first mentioned contact ina third position of said member and to pass outside said loop contact in the return of said member to initial position, the split in said first mentioned contact permitting said arm to spring therethrough after the return movement.

10. In a switch, in combination, a support, a split loop-shaped contact on said support, an arm, and a. contact on said arm movable through said first mentioned contact in one direction and outside thereof in the other di rection, said arm being: adapted to spring through the split in said loop after said last mentioned movement.

In testimony whereof, I have hereunto affixed my signature.

LOUIS KELLNER.

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