US1118256A - Switch. - Google Patents

Description

G. J. ANDERSON.

. 1911. 1, 1 1 8,256. Patented Nov. 24, 1914.

2 $HEETSSHEET l.

0. ANDERSON.

SWITCH.

APPLICATION FILED MAR. 3, 1911.

Patented Nov. 24, 1914.

2 SHEETSSHEET 2.

UNITED STATES PATENT OFFICE.

CARL J. ANDERSON, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE CUTLER-HAMMER MFG. 00., OF MILWAUKEE, WISCONSIN. A CORPORATION OF WISCONSIN.

SWITCH.

Patented NOV. 24, 1914.

Application filed March 3, 1911. Serial No. 612,031.

1/ b all whom it may concern Be it known that I, CARL J. ANDERSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Switches, ofwhich the following/is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to improvements in electric switches.

In order to clearly and fully set forth the nature, objects and advantages of my invention, I shall describe the device illustrated in the accompanying drawing,'which embodies my inventionin one form which I have worked out in practice.

In the accompanying drawing, Figure 1 is r a perspective View of the device and, Fig. 2 is a sectional view taken on line 22, Fig. 1.

The device illustrated is a solenoid operated multiple switch designed for starting alternating current motors. switches A, B, C and an operating solenoid S all suitably mounted on an insulated supporting base 1. The switches A and B are identical in construction, and are slightly diflerent in construction from the switch C. I shall "first describe the construction of the switch C, the details of which are clearly illustrated in Fig. 1. This switch comprises a verticallly disposed arm 2 pivoted to a bracket 3 suitably secured to the base 1, as

by means of a bolt 4. Adjacent to its upper end the arm 2 is provided with two circular apertures one arranged directly beneath the other.. These apertures form sockets for cylindrical contacts 5 and 6. The contacts 5 and 6 are preferably formed of carbon and arranged to freely slide longitudinally in their sockets. These contacts are adapted to engage stationary contacts 7 and 8' of any preferred construction and suitably secured to the base 1. Contacts 5 and 6 are preferably rigidly secured together, as by means of suitable clamping members 9. At its lower end the arm 2' is provided with an outwardly extending projection 10 to the outer end of'which are secured spring members 11 and 12, the extremities of which bear against the outer ends of contacts 5 and 6 operating stationary contacts, while the It comprises clamping members 9 limit the movement of i said contacts relative to the arm 2 by engagement with said arm. In practice the bolt at may be used as a binding post and may be electrically connected to the contacts 5 and 6 by means of a flexible conducting strip 13. F ulcrumed to the projection lO of the arm 2 is a member 14 having an enlarged recessed portion which is provided with a shoulder 16. Extending through the recessed member 11 is-a shaft 17 revolubly mounted in suitable bearings secured to the base 1. Upon the shaft 17 is fixed a member 18 carrying a laterally projecting pin 19 arranged substantially parallel to said shaft. The pin 19 is so arranged that upon rotation of the shaft 17 it will be brought into engagement with the shoulder 16 of the member 14 raising said member and causing it to move the switch C toward closed position.

As before stated, the switches A and B are of the same construction and I will, therefore, only describe the construction of switch A, the details of which are best illustrated in Fig. 2. This switch is'of the same general construction as switch C with certain additional features. In this switch, the contacts 5 and 6 are not rigidly connected together. Each contact has lugs 25 secured thereto to limit the inward movement there- ,of, said lugs being electrically connected by flexible conductor 26. Also in this switch the arm 2 is formed in two parts, 2 and 2 the part 2 being pivoted to the part 2*. The contacts 5 and 6 pass through both parts of the arm, but thepart 2 forms the main support therefor. The upper end of the part 2 is connected to toggle links 27, said toggle links being also connected to a bracket 28 suitably secured to the base 1. The toggle links are of such design as to assume a movement of the portion 2 of said switch. 1

The toggle links carry rollers 29 adapted when said links are in a straight line'to project into the path of a curved projection 30 provided on the end of the member 2". The member 2 is adapted to be operated by theshaft 17 in the same manner as the arm 2 of switch C. I shall now describe the mode of operation of the switch A upon rotation of the shaft "17. Assuming that the toggle links are in the position illustrated in full lines,

upon rotation of the shaft 17 the portion 2" will be moved inwardly, while the portion 2* will remain stationary. The contacts 5 and 6, of course, cannot move inwardly until the portion 2 is released. f Accordingly, as the portion 2 moves inwardly under the conditions set forth it will increase the pressure of the springs 11 and 12 upon contacts 5 and 6 to a degree sufficient to cause said contacts to quickly move into engagement with the stationary contacts as soon as the part 2 breaks the toggle 27, thereby releasing the part 2. The parts are so designed that in the operation of the switch to closed position, the *part 2 moves a relatively greater distance than the contacts 5 and 6 and does not break the toggle to permit inward movement of said contact s until ithas practically reached the limit of its movement. This not only insures a suificient pressure upon the contacts to quickly move them inwardly, but also insures the storing up of a greater amount of energyin the springs than is actually expended in the movement of the contacts. In other words, enough energy remains stored in the springs even after full closure of the switch to maintain the contacts in firm engagement during initial movement of the part 2 toward normal position. Of'course the extent of the return movement of thepart 2 prior to breaking contact is dependent upon the amount of energy. stored inthe springs,

All of the switches have similar operative connections with the shaft 17. The

pins 19, however, associated with the several switches are so adjusted as to successively engage their -co6perating parts of said switches to operate the same successively. That is to say, the pin 19 associated with switch B is so arranged as not to engage its cotiperating part of said switch until switch A has been closed, while the pin 19 associated with switch C is so arranged as not to engageits corresponding switch until switch B has been closed. I have not described in detail the operative connections between the several switches and the operating shaft as the same are clearly described in another copending application.

The shaft 17 is adapted to be rotated by the operating solenoid S through a rack and pinion construction. A pinion 31 is fixed to the shaft 17 while cooperating rack member 32 is connected to and adapted to be operated by the plunger of said solenoid. The rack is held in mesh with the pinion by a suitable roller 33. In practice it is desirable to insure a definite time interval between the operation of theseveral switches. Forgiving this result I have provided a dash pot 34, preferably of the suction type, having its piston connected to therack member 32. For a purpose hereinafter set forth, I prefer to provide the dash pot 34 adjaweakened upon closure of each of the mmense cent to its upper end with inlet ports 35. for

pot after the piston thereof has assed said ports, thereby eliminating the e ect of said dash pot. I

' Before describing in detail the operation, functions and advantages of the device illustrated, I shall briefly describe certain conditions which are met with in practice. Assume that the device illustrated is employed for starting an alternatingcurrent motor, that each switch when closed increases the supply of current to the motor and that the solenoid S is connected across one phase oft the motor circuit, as is cus- 8 tomary in practice. It is well understood by those skilled in the art, that a sudden increase of current supplied to an alternating current motor will frequently cause a temporary drop of voltage in the motor circuit. Accordingly, should the device illustrated be employed for the purpose and under the conditions before assumed then the operating solenoid S might be momentarily.

switches, due to the drop in the voltage in the motor circuit, and the consequent dro in volta e impressed upon said solenoi In practice the dash pot not only has a retarding eflect upon the operation of the solenoid, but actually exerts an opposing pull. This opposing pull of the dash pot, in practice, is often so great as to retract the plunger of the solenoid and open the last closed switch to a slight degreeupon a reduction in the strength of the solenoid from the cause above mentioned. This permits destructive sparking between the contacts of the switches.

The device illustrated in the accompanying drawing is designed to eliminate such destructive sparking. I shall now describe theoperation of the device to show how this is accomplished. Upon energization of the solenoid S it draws in its plunger rotating 1 the shaft 17 and lifting the plunger of the dash pot. The plunger of the dash pot in moving creates a vacuum which tends to retard movementof the solenoid plunger and even exert an opposing pull. Movement of the plunger of the solenoid and consequent rotation ofthe shaft 17 is therefore slow owing to the action of the dash pot. Upon a predetermined degree of rotationof the shaft 17, the switch A is closed in the man- 1 ner previously described, thus causing a. reduction in the voltageof the motor circuit" and a consequent' reduction in the voltage impressed upon the solenoid S. The pull of in the solenoid S thereupon becomes temporarily weakened as previously set forth. Obviously, if the dash pot exerts an opposing pull on the plunger of the solenoid, it is apt upon weakening of the solenoid to actually retract the solenoid plunger to a degree 1 proportional to its opposing pull. This, of course, tends to reverse the operation of the shaft 17 allowing the part 2 of switch A to move outwardly. As has been previously set forth, however, switch A is of such construction that its contacts will be held in firm engagement during a predetermined degree of outward movement of the part 2*. Thus, by allowing the part 2 of switch A a sufiicient degree of such lost motion, switch A would be firmly held in closed position regardless of the retracting efiect of the'dash pot under the conditions set forth. Further than this the predominating effect of the dash pot over the solenoid when the latter is weakened is minimized during the operation of switch A. This is accomplished in the following manner: As the part 2 of switch A moves inwardly, it increases the pressure of the springs 11 and 12 upon the contacts 5 and 6. This increase in pressure obviously increases the load on the solenoid which increased load augments the retardation of the solenoid plunger to a degree above that accomplishedby the dash pot. In other words, the storing up of energy in the springs 11 and 12 has a further retarding effect upon the solenoid plunger and consequently upon the piston of the dash pot. Air is continually leaking into the dash pot and consequently, if the piston thereof be retarded, the efiectiveness of the dash pot will be proportionally decreased. The retardation of the plunger of the solenoid and piston of the dash pot, due to the storing up of energy in the springs 11 and 12, continues until switch A is closed with the result that when said switch is closed and the solenoid S is momentarily weakened, the opposing pull of the dash pot will have been weakened to such a degree as to cause only a slight, if any, retraction of the solenoid plunger. Thus provision is made which tends to eliminate the predominance of the pull of the dash pot over the pull of the solenoid when the latter is weakened and which insures maintenance of the switch in closed position should thepull of the dash pot overcome that of the solenoid.

As soon as the strength of the solenoid is restored after closure of switch A, said solenoid continues the rotation of the shaft 17 which, thereupon, causes closure of switch B, the operation thereof being the same as that just described. After switch B is closed and the solenoid restored to full strength, the shaft 17 is rotated further to close switch C. Switch C has been-provided with no means for holding the same open, inasmuch as upon operation thereof the piston of the dash pot passes the inlet ports 35, allowing a free inrush of air into the dash pot. The

effect of thedash pot is thereby wholly eliminated. The solenoid even when weakened by closure of switch C 'has ample strength to hold said switch firmly in closed position there being no opposing pull by thedash pot. Obviously, therefore, the danger of sparking from the causes before mentioned is entirely eliminated.

Besides the advantages above set forth, a quick closure of all switches is insured. The quick action of switches A and B is due to their peculiar construction, which has been previously clearly and fully set forth. The quick action of the switch C is due to the elimination of the retarding effect of the dash pot in the manner previously described.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is:

1. In combination, a switch, an-operating member therefor, an energy storing connection between the same, means for locking said switch open and automatically releasing the same upon a definite movement of said operating member, the energy stored in said connection while said switch is locked open insuring retention of said switch in closed position during a predetermined degree of relatively reverse movement of said operating member.

2. In combination, a switch, a device for locking said switch in open position, an operating member for said switch adapted upon a definite movement to actuate said locking device to release said switch, and an energy storing connection between sald switch and said operating member for storing up energy while said switch is locked open to insure retention of said switch in closed position during a predetermined degree of relatively reverse movement of said operating member.

3. In combination, a switch, an automatic operating device therefor, means exerting an opposing pull on said operating device, and means associated with said switch to insure the retention thereof in closed position should said opposing means temporarilv overpower said operating device upon closure of said switch.

4. In combination, a switch, an automatic operating device therefor. means exerting an opposing pull on said device, and means associated with said switch and said operating device to store up energy prior to closure of said switch to insure retention thereof in closed position should said opposing means temporarily overpower said operating device.

5. In combination, a switch, an automatic operating device therefor, means exerting an opposing pull on said device, an energy storlng connection between said switch and said operating device. and means opposing operation of said switch during a definite movement of said operating device.

6, In combination, a switch,'a toggle device for holding said switch in open position and an operating member movable to bias said switch toward closed position and, upon a predetermined movement thereof, to break said toggle device to release said switch.

7. In combination, a switch, a toggle device for holding said switch in open position and a solenoid operated means for biasing said switch to closed position and brea said toggle to release said switch after suflicient energy has been stored up to maintain said switch in closed position during a pre determined reverse movement of the solenoid plunger.

8. In combination, a switch, an automatic device for closing said switch, a dash pot opposing operation of said device, and means associated with said switch and said operating device to insure retention of said switch in closed position should said dash pot overpower said device.

9. In combination, a switch, an automatic operating device therefor, a dash pot op-' pos ng operation of said device, and means associated with said switch and said device for storing up energy prior to closure of said switch to insure the retention of said switch in closed position should saiddash.

pot temporarily overpower said device.

10. In combination, a switch, an automatic device for closing the same, a dash pot opposing operation of said device, an energy storing connectionbetween said switch and said operating device, and a device for locking said switch ,open and automatically actu'at'ed upon a definite movement of said operating device to release-said switch.

11. In combination, a switch, a solenoid for, operatings'aid switch, an energy storing connection between said solenoid and said switch, a device for locking said switch open and automatically actuated to release said switch under predetermined conditions, -and a dash -pot opposing operation of said solenoid.

12. In combination, a switch, a solenoid having a movable plunger, a resilient connection between said switch and said solenoid plunger, a device for locking said switch open; and automatically actuated upon .a definite movement of. said solenoidplunger, and a dash pot opposing operation ofsaid'solenoid plunger;

. 13. In combination, a plurality of switches,

a single solenoid for operating said switches successively, a dash pot opposing operation thereof in closed position should said dash pot overpower said solenoid.

14. In combination, a plurality of switches, a single solenoid for operating said switches successively, a dash pot opposing operation of said solenoid, andmeans associated with said switches tending to temporarily reduce the eflectiveness of said dash-pot prior to closure of each switch, and acting to hold each switch firmly in closed position should said dash pot overpower said solenoid.

15. In combination, a plurality of switches, a single solenoid for operating the same successively, a dash pot opposing operation of said solenoid, an energy storing connection between each of said switches and said solenoid, and means controlling said connections to insure the storing of energy therein to 111 SllIG'I'BtGIltlOIl of said switches in closed position should said dash pot overpower said i solenoid upon closure of said switches.

16. In combination, a plurality of switches, a single solenoid for operating the same successively, a dash pot opposingoperation of said solenoid, an energy storing connection between each of said switches andsaid solenoid, and a device associated with each of said switches to lock the same-in open position and to automatically release the same upona definite movement of the plunger of said solenoid.

17. In combination, a plurality of switches, a single solenoid for operating the same successively, 'a connection between each of said switches and said solenoid lncludlngan energy storing device, a toggle device associated with each of said switches to lock the same in open posit1on,-ai1d a member associated with each of said switches and positively operated by said'solenoid to break the toggle of its respective switch to release the same.

.In witness whereof, I have-hereunto sub- =scribed my name in the presence of two witnesses.

. CARL J. ANDERSON. Witnesses:

E. B. KING, FRANK H. HUBBARD;

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