US1651486A - Electric switch - Google Patents

Description

Dec. 6,1927.

A. E. TOLIN ELECTRIG SWITCH Filed Dec. 8, 4 Sheets- Sheet 3 flmff WVVQM Dec. 6, 1927. 1,551,486

' A. E. TOLIN ELECTRIC SWITCH Filed Dec. 8. 1923 4 Sheets-Sheet 4 gnva'ntofa i JMMQ g WM Q Patented Dec. 6, 1927.

ALBERT E. TOLIN, OF KOKOMO, INDIANA,

ASSIGNOR TO THE NATIONAL SCREW AND MANUFACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ELECTRIC SWITCH.

Application filed December This invention relates to certain improvements in electrical switches, and particularly to that type wherein a time element is involved for opening an electric circuit or for changing certain electrical connections a predetermined time after the "switch is closed.

One of the objects of the present invention is to provide a switch useful as a starting switch for certain types of electric motors such as single phase motors, and having provision for establishing certain. electrical connections for starting and provision for automatically changing the electrical connections so as to make them suitable for running conditions. In the case of a single phase motor of the split phase type, hav ing a starting winding and a running winding, a switch of this kind finds utility in closing circuits through both the starting and running windings and subsequently opening the circuit of the starting windmg.

In this connection one of the more specific objects is to provide a switch wherein "the temporary electrical connections or circuits are opened automatically a predetermined time after their closure by a mechanically actuated time limit device.

A. further object is to provide a combined switch and overload circuit breaker of im proved form and with maximum safety provisions; more specifically considered it is the aim of the invention to provide a switch particularly useful as a starting switch with provision for affording overload protection during starting as well as running.

A still further object is to provide a.

switch having a construction such that it embodies to a maximum degree the features of safety, durability and reliability particu- .larly as to its automatic opening feature under overload conditions.

The above and other objects are attained by my invention which may be briefly summarized as conslstlng 1n certaln novel details of construction, and comblnatlons and arrangements of parts which will be de-' scribed in thespecification and, set forth in theappended claims. v p In the following sheets offdrawings I have shown one embodiment of the invens, 1923. Serial 110. 679,326.

tion which operates with high efliciency. In the drawings, Figs. 1 to 4 show side and end elevations of the operating mechanism of the switch with the base and outer casing in section; Fig. 1 showing a side elevation of the operating mechanism looking at one side of the switch; Fig. 2 being a similar View looking at the opposite side; Fig. 3

showing an end elevation looking toward the left of Fig. 1; Fig. 4: being a similar view looking toward the right of Fig. 1.

Fig. ,5 is a plan view of the switch with the casing removed; Fig. 6 is a view looking at the under side of the top plate shown in Fig. 5; Fig. 7 is a View looking toward the under side of the switch, the same bemg removed from the casing; Fig. 8 is an enlarged view looking at the operating mechanism with the top plate removed; Fig. 9 is a view of the principal parts of Fig. 8 showing all the movable switch arms in closed position; and Fig. 10 is a diagrammatic view showing the electrical connections, the electrical connections shown being those for a switch adapted for use as a starting switch for a single phase motor.

In illustrating a switch adapted for use in connection with single phase motors, or

for closing circuits through both running and starting windings, and then opening the circuit through a starting winding, I do not wish to be understood to limit myself to a switch which by its construction and operation is adapted only for this particular purpose, or for use in connection with this particular type of motor. On the other hand, the switch may be used for other purposes, or in connection with other types of motors wherein possibly only part of the functions are requiredto be performed by the Switch as compared with those performed by it when used as for a single phase motor. I have illustrated my invention as embodied in a starting switch for single phase motors for the reason that that adaptation illustrates to the best advantage utility or functions of various parts or elements of the switch.

Before taking up the details of the switch, it may be stated that in this embodiment there is a hand operated control member which when given its ordinary stroke or a starting switch movement operates certain parts including a setting lever constituting also a switch member for both the running and starting circuits, giving it a certain movement away from its normal or closed position, during which time a breaker arm is set or moved to closed position and latched in that position, a starting switch arm is moved to closed position, and a third switch-member is closed which short circuits part of the coils of the main winding of an overload magnet, this magnet having in addition to the main winding an auxiliary winding whose circuit is closed on the occurrence of a predetermined overload and serving as a relay to so energize the magnet as to give,

ample field strength to cause the unlatching of the breaker arm and to insure its opening. But after a predetermined movement of the manually operated control member. the me chanical connection between it and the setting lever is broken, whereupon the remain der of the operations are wholly automatic, these including the quick return of the setting lever to normal or closed position, this being the final movement necessary to close the circuits through starting and running windings, and at the same time there is set into operation a mechanical time limit device through a weighted escapement, which after a predetermined time opens the starting circuit and then opens the shunting circuit about the short circuit portion of the main winding of the overload magnet, whereupon the circuits are established for running conditions which are maintained until an overload occurs, or until the running circuit is opened by the further operation of the manually controlled operating member, which in this instance trips the latch which controls the breaker arm or lever.

With this brief preliminary description, the detailed description will be readily understood. 7

The switch as a whole is a compact device which is preferably enclosed within a case 10 secured in any desired manner to a suitable base 11. The operating parts of a switch as I have constructed it, and as herein illustrated, are all mounted between a pair of parallel plates which may be formed of suitable insulating material, these being a top plate 12 and a bottom plate 13. spaced apart and held in fixed relation with respect to each other by a series of bolts or equivalent spacing columns. some of which serve as pivots or fulcrums for ivoted parts, and will be referred to presently.

The manually operated member which is utilized in setting the parts for subsequent automatic operation, briefly referred to above, and which serves also to trip the latch which releases the breaker to open the main circuit, is in this instance in the form of a rotary handle or hand piece 14, projecting on the outside of the casing 10. This handle is on a shaft 15, which is journaled in the top and bottom plates 12 and 13, and which is provided just beneath the cover plate 12 with a cam 16 '(see Fig. 8). This cam is in the plane of the setting lever 17, rotatably supported on a stud or column 18 extending between the top and bottom plates and biased by a spring 19 toward closed position, and by the spring normally held in engagement with a stationary contact 20, as shown in Fig. 8, the contact 20 being secured to the under side of the top plate 12.

It will be observed that when the handle 14 is turned so as to rotate the cam 16 in the direction indicated by the arrow in Fig. 8, the cam will engage the heel 17 of the setting lever. which heel is on one side of the pivoted stud 18, and will swing the lever so that its main portion will swing to the right as the same is viewed in Fig. 8, moving the lever away from contact 20. When this movement takes place, several operations are performed. Among these is the closing and latching of the breaker arm. The breaker arm or lever which is shown at 21, is pivotally supported beneath the setting lever on the latters pivot stud 18, and it is biased to off position by a spring 22, best shown in Fig. 2. When the setting lever is given the movement just stated, a downturned lip or finger .17 of the setting lever engages the breaker arm 21 and moves it over into engagement with a stationary contact 23, best shown in Fig. 8. and when the breaker arm engages this contact it is automatically latched in engagement therewith by a latch 24 which extends across the switch between the top and bottom plates and is pivotally supported on a stud or bolt 25, being biased toward latching position by a spring 26. the same being illustrated in Figs. 1 and 8. This latch 24 constitutes also one of two armatures of'an overload magnet 27 to be referred to presently, and it is provided with an arm 24 having a lip 24 -which is adapted to be engaged by the end of the cam 16 to manually unlatch the breaker arm and permit its spring to move it to oif position. this being done when it is desired to manually open the running circuit, as will be explained. subsequently.

Thus it will be seen that when the lower part of the setting lever (as the same is viewed 'in Fig. 8) is swung inward. as explained above, the breaker arm which constitutes one of the parts through which the circuits are controlled, is moved to closed position in engagement with contact 23.

Additionally, the setting lever during this movement swings or rocks a gear segment 28. the. free end 17 of the setting lever being normally engaged by the segment as shown in Fig. 8. This gear segment is ifixed to a shaft 29 mounted in the top and bottom plates, a springserving to normally hold the segment against the end 17 of the setting lever when the latter is in its normal position, and serving to return the segment and its shaft 29 to normal position during the automatic operation following the release of the cam 16 from the heel 17 of the setting lever. The gear segment 28 engages a pinion 31, rotatably mounted on a shaft 32 adjacent a toothed escapement wheel 33, the latter having a pawl 34 held by a spring 35 mengagement with the teeth of the pinion 31. During the movement of the gear segment 28 in a clockwise direction under the infiu ence of the setting lever, the pinion 31 is rotated, and its rotation is not transmitted to the toothed escapement wheel 33, for the pawl to the escapement wheel 33. The teeth reason that the pawl 34 then rides over the teeth of the pinion 31, but when thefreely segment swings in the reverse direction, the rotation of pinion 31 is transmitted by the of this escapement wheel are engaged by a weighted escapement device consisting of a weight in the form of a rocking cylinder 36 carrying an escapement member 37 which is adjustably secured thereto by screws .38, and carrying prongs 37 8 adapted to be alternately moved into engagement. with the teeth of the escapement wheel 33, and therefore to retard its rotation in a. well-known manner. The speed at which the escapement wheel is rotated determines the extent of time which elapses during the automatic operation of the switch, and therefore the length of time that. the circuit is closed through the starting winding. This time can be varied by adjusting the position of the pronged escapement device 37 on the weight 36, the time element being increased wvhen the member 37 is moved away from the center of the weight, and is decreased when it is moved toward it. This adjust ment is possible by providing elongated slots in the member 37 through which the screws 38 pass so that by loosening these screws the member 37 can be adjusted. Thetimeelement also depends upon the weight of the cylinder or rocking member 36, and there fore by substituting a weighted or rocking member 36 for one heavier or lighter, it is possible to vary the time element independently-of the variation possible through the adjustment of the pronged member 37.

The segment 28 is moved to the right by the setting lever, as explained above, during which time the pinion 31 is freely rotated, and toward the latter part of this movement it closes a starting arm or lever 39 by movingit into engagement with a stationary contact 40, best shown in Fig. 8. This starting arm is positively moved to closed position by the engagement of the segment with a lip 39 of the starting arm. When the starting arm tion by a spring 42, and which is provided with a notch 41 into which a part of the starting arm snaps after it moves into engagement with contact 40. 5 The starting arm is mounted on a bolt or stud 39 extending between the top and bottom plates 12 and 13, and it is biased toward off .position by a spring 39,shgsvn in Fig. 4.

When the starting arm 39 is moved to closed position, it permits the closure of the so-called short circuiting arm or switch member 43cunder the action of a spring 44, the spring serving to move an extension 43 0f the short circuiting arm into engagement with the upstanding part'of contact 23 which was previously referred to, and is adapted to be engaged by the breaker arm 21, as

already explained. The short circuiting arm or switch member 43 is mounted upon a pin or stud 45, shown by dotted lines in Fig. 8, this stud extending up .from the lower or bottom plate 13, and forming a pivot also for the latch 41 which holds the starting arm 39 inclosed position as explained.

It will be seen, therefore, that when the I operator turns the cam so as to swing the setting lever inward, the breaker arm is first moved to closed position and latched. Likewise, the segment is swung inwardlyv causing the starting arm to be moved to closed position and latched in that position, permitting the closure of the short circuiting arm 43. The inward swinging of the setting arm continues until the point of the cam 16 passes beyond the heel 17 of the setting lever,

whereupon the manual control of the setting lever terminates, and the spring 19 quickly restores the setting lever to its former position shown in Fig. 8, in engagementwith the.

contact 20. When this occurs, and not until then, the circuits are completed through both the running and starting windings. Immediately after the setting lever snaps back to its normal position spring 30 returns the segment to its normal position, but its return takes place at a predetermined rate,

producing the time element under the action of the escapement, the actual time during which the segment returns to its former position beingcapable of adjustment so that it will accord with the starting time of the motor. I

VYhen the segment has reached a given position near the end of its return movement, an arm or projection 46, shown 'by dotted lines in Fig. 8, secured to the shaft 29 to which the gear segment 28 is secured, strikes and rocks the latch 41 away from controlling or holding engagement with the starting arm 39, whereupon under the action of its spring 39, the starting arm is moved to open Cal position, opening the starting circuit, and as this starting arm approaches its normal full open position it engages the short circuiting arm 43, rocking it to open position, and therefore opening the short circuit around the portion of the main winding of the overload magnet.

Before taking up the description of the electrical circuits involved, it might be mentioned that the overload magnet 27 is composed of a core 27 a main winding 27, already referred to, and an auxiliary winding 27, these being diagrammatically shown in Fig. 10. During running conditions the entire main winding 27 is in series with the running winding of the motor. During the starting period a portion of this winding is short circuited by the short circuiting arm 43 so as to permit the flow of a heavier current during starting than is normally used under running conditions. A further function of the short circuiting arm is to reduce the potential drop across the series overload winding so as to permit maximum flow of current through the running winding during the starting period. The auxiliary winding 27 is normally open, but when an overloa occurs its circuit is automatically closed by a pivoted trip arm or armature 47 which is attracted by the pull of themagnet and is moved into engagement with a stationary Contact 48 which closes the circuit through the auxiliary winding, so that the field produced b the current passing through it augments the field produced by the current in the main winding, producing a powerful field ample to attract the breaker arm latch 24 so as to unlatch the breaker arm and permit it to move to open position. The trip armature 47 is pivotally mounted on a stud 49 extendin between the top and bottom plates 12 and 13, and is biased toward open position by a spring 50.

The switch as herein illustrated, has four binding post terminals, three being mounted on the lower plate, these being designated 51, 52 and 53. The fourth binding post terminal is on the upper plate, this being shown in Fig. '1, and being designated 54. It will be observed by reference to Fig. 8, that the terminal 53 has notches 53 in any one of which the end of the spring may be placed to vary its tension. Additionally it has a tongue or extension 53 which forms a stop for the trip armature 47. The stud 49 upon which the trip armature is mounted, passes through this terminal, in consequence of which the terminal is electrically connected to the trip armature.

Referring now to the diagrammatic view of Fig. 10, the two-line or current supplying conductors are designated 55 and 56. Likewise I have indicated the running winding of the motor at 57, and the starting winding at 58. It will be observed that line conductor 55 is connected to switch terminal 54 and line conductor 56 is connected to switch terminal 52, and from the latter connection 1s made by a conductor 59 to corresponding terminals of the running and starting windings 57 and 58. The other terminal of the running winding is connected by a conductor 60 to the switch terminal 51. The other terminal of the starting winding is connected to switch terminal 53. Switch terminal 54 is connected by a conductor 61 to setting arm contact 20. This establishes connection to the setting arm (when the latter engages this contact), then to the breaker arm which is in electrical contact with the setting arm by being on the same supporting stud therewith, and when the breaker arm is in closed position the circuit is established with the breaker arm contact 23. The latter is connected by a conductor 62 with one terminal of the main winding 2'? of the overload magnet, the other terminal thereof being connected by conductor 63 to the switch terminal 51 to which one end of running.winding 27 is connected.

Switch terminal 53 is connected by a conductor 64 to the starting arm contact 40. The starting arm 39 is connected by a con ductor 65 to a short circuiting conductor 66 extending from short circuiting arm 43 to a tap 67 between the ends of the main winding 27 of the overload magnet.

As already stated, the trip arm 47 is electrically connected to switch terminal 53,

which in turn is connected to one end of the starting winding 58. Trip arm contact 48 is connected by a conductor 68 to one end of auxiliary winding 27 of the overload magnet, the other end of this winding being connected by the conductor 69 to the switch terminal 51.

Assuming that the operator has turnedthe handle so as to swing the setting lever and cause the latter to move the breaker arm 21 to closed position in engagement with contact 23, in which .position it is latched by latch arm 24, and to move the starting arm to closed position in engagement with contact 40, in which position it is temporarily latched by latch 41, and permitting the short circuiting arm to swing to closed position in engagement with contact 23, the circuits are closed through the running and starting windings as soon as the setting lever is permitted to snap back to normal position when the cam 16 moves out of engagement with the heel of the setting lever. It is to be noted. however, that none of the circuits are completed, notwithstanding the setting of the breaker arm, the starting arm and the short circuiting arm until after the operation of the switch is out of the operators control, or until the automatic period starts, which begins with the release of the Setting lever and its quick movement to closed position in engagement with contact 20, and

' breaker arm 21, setting lever.17, contact 20,

conductor 61, switch terminal 54 to line or main conductor 55. At the same time the circuit through the running winding is as follows: from main conductor or line 56 to switch terminal 52, conductor 59, running winding 57 conductor 60 to switch terminal 51, conductor 63, through unshunted portion of the main winding of the overload magnet, tap 67, short circuiting conductor 66, short circuiting arm 43, contact 23, breaker arm 21, setting, arm 17, contact 20, conductor 61, switch terminal 54 and main conductor or line 55. o

At the end of the starting period, (during which period the segment 28 is returned to its normal position) the starting winding circuit is opened by the automatic opening of the starting arm and the short circuiting arm is automatically opened, leaving the running winding in circuit/with the current passing through theentire main winding 27* of the overload magnet. The circuit of the running winding is now as follows: main conductor or line 56, switch terminal 52, conductor 59, running windin 57,'switch terminal 51, conductor 63, win mg 27 conductor 62, contact 23, breaker arm 21, setting lever 17, contact 20, conductor 61,-

switch terminal 54 and main conductor or line 55. w

In this instance, overload energization of the main winding 67 is not relied on to attract latch 24 and release the breaker arm, but the opening is made more positive or reliable by the provision of the auxiliary winding and the relay effect which is produced by the closure of the circuit through the auxiliary winding. Thespring 50 controlling the trip arm 47, is so adjusted that when the overload occurs the current passing through the main winding 27 causes the trip arm to be attracted int-0 engagement with contact 48. This closes the circuit through the auxiliary winding which is as follows: main conductor or line 56, switch terminal 52, conductor 59, starting winding 58, switch terminal 53, trip arm 47, trip arm contact 48, conductor 68, auxiliary winding 27, conductor 69, conductor 63,

nIiin winding 2" conductor 62, contact 23,

breaker arm 21, setting arm 17, conductor 61, switch contact 54 and line 55, Thus on the occurrence of an overload, a circuit is completed through the auxiliary winding, the current passing through this winding in the same direction thatcurrent passes through the main winding, and, in fact, through both windings in series, thus producing an exceedingly strong field which is always powerful enough to shift the latch 24 from holding or restraining position on the breaker arm. In consequence, the opening on overload is assured, and a delicate adjustment of the latch 24 on the breaker is unnecessary since the attraction or movement of the latch is not determined or affected by fluctuations of the current in the main winding,-but only when the effect of the current 1n the main winding is augmented b that passing through the auxiliary win ing, the overload current condition or rise of current in the main winding acting upon the trip arm or relay member, Which is not a latch, and whose movement is resisted only by the spring 50 which can be adjusted as desired.

It will be seen therefore from the above that when the operator manually turns the handle 14, the setting arm is shifted so as to move two switch members, namely, the

breaker arm 21 and starting arm 39, to H closed position, these switch members controlling separate circuits, and to cause to be moved to closed position the switch member 43 which short circuits a portion of the main winding of the overhead magnet during the starting period. Likewise it will be observed that when the setting arm 17 is in off position or out of engagement with contact 20, the starting and running circuits remain open and it is not until the mechanical connection between the manually moved member and the setting lever is broken, in other words, until the further operation is automatic and out of the control of the operator that the circuits are completed by the return of the setting lever to its normal position in engagement with the contact 20. This makes it impossible for the operator to hold the switch closed, and, in fact, to have any control at all over the switch in so far as maintaining closed circuits is concerned either during the starting or running period.

Finally it should be noted that proper protection against overload is provided during the starting as well as running periods, and that unlatching of the breaker arm is assured not'only because the relay circuit is closed on the occurrence of an overload so as to energize the auxiliary winding of the overload magnet, but also because the mag netic field is still further. augmented by the fact that the current passing through the auxiliary Winding of the overload magnet is caused to pass also through the main win-dingof the overload magnet. In other words, the field produced by the current passing through the main winding is increased by two factors, first, the'energization of an additional coil or winding, and an increase in the current passing through the main winding.

Having described my invention, I claim:

1. In an electric switch, two switch members, a setting member for moving them to closed position, and an actuating member having for a part of its movement only a inechanical connection with the setting mem- 2. In an electric switch, two switch members, a setting member for moving them to closed position, an actuating member having an automatically separable connection with the setting member to move it in one direction to close the switch members, and separate means for moving the setting member in the opposite direction.

3. In an electric switch, two switch members, a setting member for moving them to closed position, an actuating member having an automatically separable connection with the setting member to move it in one direction to close the switch members, and means for maintaining the switch members closed independently of the setting member.

4. In an electric switch, two switch members, a setting member for moving them to closed position, an actuating member having an automatically separable connection with the setting member to move it in one direction to close the switch members, and means for causing the automatic opening of one of said switch members a predetermined time after its closure.

5. In an electric switching device, two switches adapted to be connected in the same circuit, means including an actuating member when given a circuit closing movement serving to open one switch so as to cause the closure of the other switch, and separate 1 means for closing the first switch.

6. In an electric switching device, two switches adapted to be connected in the same circuit, means including an actuating member for actuating one switch so as to cause the closure of the other switch, and means independent of the actuating member for causing the closure of the first switch when released by said member. I

7. In an electric switching device, two switches adapted to be connected in the same circuit and including two movable switch members, and switch actuating means including an actuating member having for a portion of its movement only a mechanical connection with one of said switch members to cause the latter switch member to be opened and the other to be closed.

8 In an electric switching device, two switches adapted to be connected in the same circuit and including two movable switch tion with one of said switch members, and

serving when actuated to cause one switch member to be opened and the other to be moved to closed position, and means for holding the latter switch member in closed position.

9. In an electric switching device, two switches adapted to be connected in the same circuit and including two movable switch members, switch actuating means including an actuating member havin for a portion of. its movement only a mec anical connection with one of said switch members, and serving when actuated to cause one switch member to be closed through opening movement of the other, and means for movin the last-mentioned switch member to close position after the connection with the actuating member is terminated.

10. In an electric switching device, a pair of switches adapted to be connected in the same circuit, comprising two movable switch members, switch actuating means including an actuating member havlng during a portion of its movement a mechanical connection with one of said movable switch members and serving when actuated to move one switch member to closed position, electric-all controlled means for holding said switc member in closed position, and means for moving the-first switch member to closed position when the mechanical connection with the actuating member is broken.

11. In an electric switching device, two swatch members for controlling diflerent circuits, switch actuating means including a setting member in the form of a switch member adapted to be actuated to cause the 010- 1 sure of the two first-named switch members and to be subsequently moved to closed position to cause the closure of both circuits.

12. In an electric switching device, two switch members for controlling separate circuits, a setting member in the form of a third switch member, switch actuatin means including an actuating member or shifting the third switch member so as to cause the closure of the two first-named switch members. and independent means for closing the third switch member.

13. Inan electric switching device, two switch members adapted to control separate circuits, a third switch member adapted to be actuated to cause their closure, switch actuating means including an actuating member having'during a portion of its movement only a mechanical connection with the third switch member and serving when actuated to move the same to close the firstnamed switch members, and means for moving said third switch member to closed position when out of the ing member.

control of the actuat- 1 circuits, a third switch member adaptedto be actuated to cause their closure, switch actuating means includlng an actuating member having during, a portion of 'its movement only a mechanical connection with the third switch member and serving when actuated to move the same to close the firstnamed switch members, means for moving said third switch member to closed position when out of the control of the actuating member, and means for automatically open ing one of the first-named switch members a predetermined time after its closure.

15. In an electric switching device, two switch members adapted to control separate circuits, a third switch member for controlling both circuits, means including a movable actuating member for causing the closure of the two first-mentioned switch members while the third switch member is open, and subsequently causing the closing of the third switch member, and means for holding the two first-mentioned switch members in closed position.

16. In an electric switching device, two switch members adapted to control separate circuits, a third switch member for controlling both circuits, means including a movable actuating member for causing the closure'of the two first-mentioned switch members while the third switch member is open, and subsequently causing the closin of the third switch member, means for hol ing the two first-mentioned switch members in closed position, and means for causing the automatic opening of one of said switch members a predetermined time after its closure. 17. In an electric switching device, two

witch members adapted to control separate I circuits, a third switch member for controlling both circuits, means including a movable actuating member for causlng the clo- 1 sure of the two first-mentioned switch members while the third switch member is open, and subse uently causing the closure of the third switc member, means for latching one of the first mentioned switch members in closed position, and a current responsive device for controlling the latch.

18. In an electric switching device, two switch members adapted to control separate circuits, a third switch member for controlling both circuits, mean-s including a movable actuating member for causing the closure of. the two first-mentioned switch members while the third switch member is open, and subsequently causing the closing of the third switch member, means for latching the two first mentioned switch members in closed position, a current responsive device for controlling the latch of one of said switch members so as to permit said switch member to 1 open on a predetermined current or voltage condition, and means for actuating the latch for the other switch member so as to cause it to open a predetermined'time after its closure. f

19. Inan electric switching device, a running switch, a starting switch, an overload magnet for controlling the running switch,

a third switch for controlling the efi'ectiveness of said magnet, means for closing all said switches, and means for causing the opening of the third switch a predetermined time after its closure.

20. In an electric switching device adapted to control separate circuits, two switch members, a magnet controlling one of said switch members so as to permit it to open on the occurrence of predetermined load conditions in the circuit thereof, means for causing the other switch member to be automatically opened a predetermined time after its closure, a third switch member for reducing the efiectiveness of said magnetduring the closure of the second switch member, and means for automatically opening said third switch member vwhen the second switch member opens.

21. An electric switching device, for use in starting motors, comprising a running switch having a current responsive device for controlling it, a starting switch, a main switch for controlling both the running and starting circuits, a fourth switch for reducing the efiectiveness of the current responsive device during the starting period, means for causing the closure .of the running switch, the starting switch, the fourth-named switch and thereafter the closure of the main switch, and means for automatically causing the opening of the starting switch and the fourth switch a predetermined time after the closure of the starting switch.

22. In an, electric switching device for use in starting motors, a running switch in the form of a circuit breaker, a current responsive device for controlling its opening, a starting switch, a third switch for reducing the effectiveness of the current responsive device during the starting period, a main switch controlling both the running and starting circuits, an actuating device having mechanical control over said switches during a portion of its movement only and servmg when actuated to cause the closure of the running switch, the starting switch and said third switch, means for automatically causing the closure of the main switch independently of the actuating member when its control over the other switches 1s terminated,

and means for automatically causing the "opening of the starting switch and said third switch a predetermined time after the closure of the starting switch.

23. In a switching device for starting momeans for causing the starting switch to be opened independently of the actuating member a predetermined time after its closure, and means responsive to a predetermined electrical condition in the motor circuit for automatically causing the opening of the running switch.

In testimony whereof, I hereunto aflix my signature. 1

ALBERT TOLIN.

Images