US872513A - Oil-switch. - Google Patents

Description

PATENTED DEC. 3, 1907.

E. M. HEWLETT.

OIL SWITCH.

.APPLIOATION FILED JULY30,1904.

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No 872,513. PATENTED DEC. 3, 1907. E. HEWLETT. OIL SWITCH.

APPLICATION FILED JULY 30. 1904.

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fizi'gw I By EGWaJdMHQWltL Am orrzey PATENTED DEC. 3, 1907.

E. M." HEWLETT.

OIL SWITCH.

APPLICATION FILED JULY30,1904.

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7 hventor I EdwardMHewlett ww- Witnesses 22 1 .Attomey Ih'i NORRIS PETERS co., WASHINGTON, n. c

UNITED STATES PATENT OFFICE.

EDWARD 3'1. HEWLETT, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

OIL-SWITCH.

Specification of Letters Patent.

Patented Dec. 3, 1907.

Application filed il; 30, 1904. Serial No. 218,908.

To all whom it may concern:

Be it known that I, EDWARD M. HEWLETT, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Oil-Switches, of which the following is a specification.

The present invention relates to double throw switches of the type employed in starting alternating current motors, or in other circumstances where a definite sequence of circuit connections is required.

It is well known that in starting alternating current motors by means of a compensator it is necessary to first connect the motor terminals to the compensator through a number of its coils so as to give the motor the proper starting voltage, and subsequently when the motor has speeded up to connect its terminals directly to the supply line. Under such circumstances a double throw switch may be employed to make the neces sary connections.

The principal object of the present invention is to provide a novel switch organization which may be easily manipulated to make the circuit connections in the order desired and which will assist in preventing the making of the connections in the wrong order.

To this end, I employ a restraining means which, when allowed to operate, will permit the switch to be thrown from its starting to its running position through its intermediate or open position but will stop the switch in its open position whenever thrown from the running position.

My invention also comprises in combination with an electrically-operated trip an automatic signal which will indicate when the switch has been electrically operated; also certain structural features which are capable of use in various types of switches other than the type herein disclosed.

The various features of the invention will be best understood by reference to the following description taken in connection with the accompanying drawing, and the scope of the invention will be particularly pointed out in the appendedclaims.

In said drawing, Figure 1 is a side elevation of a double throw three phase oil switch constructed in accordance with my invention, parts being shown in section; Figs. 2 and 3 are diagrams illustrating different positions of the switch operating mechanism; Fig. 4 is a plan vlew and Fig. 5 1s a diagram of the switch circuits shown in connection.

mechanism of the switch are located at the rear of thehoard and supported in part upon the frame and a slab 16 of insulating materiai carried thereby. An oil can 17 is secured. to the under side of the frame 15 and surrounds the switch contacts which extend from the lower side of the support 16. These contacts comprise in the present instance three fixed' contacts 18 and three fixed contacts 19 arranged on opposite sides of three center contacts 20. The center contacts 20 furnish a means of support for three movable Lshaped contacts 21. The outer ends 21 a of the contacts 21 are adapted to engage the spring-pressed fingers 22 of the terminals 18, while the other ends 21 are adapted to engage like spring-pressed fingers 23 on the contacts 19. The contacts 21 are rigidly connected together by a bar 21 and constitute the movable element of the switch. The fixed contacts 18, 19 and 20 extend tln'ough the slab 16 and are provided at their upper ends with suitable terminals 18, 19 and 20 respectively.

Movement is transmitted from the operating lever 11 on the front of the switchboard 10 to the movable switch element by means of a collapsible connection composed of links 24 and 25 connected at their outer ends to the lever and the bar 21 respectively, and at their inner ends to cranks 26 27, pivoted to a suitable support on the frame 15. Coiled tension springs 28 connect the outer ends of the cranks 26 and 27 and tend to draw them together to collapse the connection between the lever and the switch element. This connection may be locked. against collapse by the toggle 29 extending between the same points as the springs 28 and. adapted to be slightly overset to hold the parts in position. It will be apparent that when thus locked the connection is made rigid and any movement given to the 1 33 and securely locks the switch against movement. The switch cannot be moved from this position. until the pawl is withdrawn. This is accomplished by means of a pull or release rod 34 which is secured at one end to the pawl 30 and extends through the switchboard to its face where it terminates in a button 35. When the pawl 30.is allowed to act the shoulders 31 and 32 limit the throw of the switch in a manner which will be more fully described hereinafter.

One of the links of the toggle 29 is provided with a T-shaped projection 36 whose outer end. extends in the paths of movement of three armatures designated 37, 38 and 39. These armatures are suitably pivoted upon supports extending 'lroni the upper side of the slab 16, the ends of the armatures 37 and 39 adjacent to the projection 36 are drawn downward by means of tension springs 40 provided with suitable adjusting screws 41 and the corresponding end of the central armature 38 is provided with a weight 42 which performs a corresponding function. The opposite ends of the armatures are located directly above three trip magnets '43, 44 and 45. The windings of the magnets 43 and 45 are connected each. in series with its adjacent switch contact 18 and between said contact and its terminal 18. These connections are more clearly shown in Fig.

i 5, in which. 46, 47 and 48 designate the supply leads of a three-phase distribution circuit in connection with which the switch hereinbefore described is adapted to be used. These leads are connected to the fixed contacts 18 of the switch by means of the connecting wires 49, 50 and 51, the trip coils 43 and 45 being included in the wires 49 and 51. In this diagram 52 designates a threephase electric motor whose terminals are connected to the switch contacts 20; and 53 designates a compensator whose coils are connected at intermediate points to the terminals 19 19 of the switch. The compensator is connected in Y, the coils at one end being connected together and at the opposite ends being connected to the leads 46, 47 and 48. The trip magnet 44 is included in an independent circuit including the manuallyoperated switch 45. For the purpose oi" indicating when the main switch is automatically tripped an auxiliary switch 46 together with a lamp 47 are also included in an independent circuit. The switch 46 comprises a clip 46 mounted on a fixed support and a plug 46 carried upon an arm 46 extending from one of the links of the looking toggle 29.

in the operation of the main switch, assuming that it has been automatically tripped. by energizing any one of the magnets 43, 44 and 45, the parts will be in position illustrated in Fig. 2, that is, the toggle 29 will be brokenthrough the agency of the actuating armature 37, or 39, as the case may be, and the connection between the lever 11 and the movable switch element will be .collapsed, leaving the operating lever 11 in itsclosed position, that is, in a position to be engaged by the latch 12. With the parts in this position the pawl 30 will be seated in the notch 33 and the switch held open. If now it is desired to start themotor 52, the rod 34 is drawn out so as to release the pawl 30, and while thus drawn the operating lever 11. is freed from its latch 1.2 and drawn outward into the position shown" in Fig. 3. The first portion of this movement of the operating lever straight-ens the toggle 29 and extends the springs 28 thus establishing a rigid connection between. the lever and the movable switch element and leaving the springs under strain. The latter portion of the movement throws the contacts 21 into engagement with the fixed contacts 19 thus connecting the motor 52 to the supply leads through the compensator This movement also leaves the pawl 30 in engagement with the shoulder 32 of the crank 27. After the motor has speeded up the switch is thrown into the running position by drawing the operating lever 11 back to the position shown in Fig. 2. Since the connection between the operating lever and the movable element of the switch is maintained rigid thrmighout this movement the contacts 21 are thrown into engagement with the contacts 18 thus leaving the motor connected directly to the supply leads. In this movement the locking pawl 30 is prevented. from dropping into the notch 33 by reason of the length of the side 33 of the notch being greater than the opposing side thus permitting the pawl to pass clear of the notch under the quick closing movement as will be apparent from the illustration in Fig. 1. From this time on in case of an overload on either side of the system the magnet 43 or 45 Will be energized and the switch atuomatically tripped. in the manner hereinbefore described When the switch is thus automatically tripped the breaking of the toggle 29 forces the plug 46 of the switch 46 into engagelighted and serves to indicate the condition of the switch.

it is obvious that alterations and modifications may be made in the structure herein disclosed without departing from the spirit and scope oi my invention. l lJl'XGIGfOlG do not wish to be limited to the specific matter disclosed bnt aim to cover by the terms of the appended claims all such alterations and modifications.

hat I claim as new and desire to secure by Letters Patent of the United States, is,

1. The combination with a switch having its open position between two closed posi tions and biased to open when closed, of means for automatically tripping the switch to allow it to open, and means for antomatically locking the switch in open position when automatically tripped.

2, The combination with a switch having an open position between two closed posi' tions and biased to open when closed, of means for automatically tripping the switch to allow it to open, and means for stopping the switch in its open position when thrown from one of said closed positions and permitting it to pass freely through the open position to said closed position when thrown from the other closed position.

3. The combination with a switch having an open position between two closed positions and biased to open when closed, of mechanical means for stopping the switch in its open position whenever thrown from one closed position and permitting it to pass freely through the open position to said' closed position when thrown from the other closed position.

-l. The combination of a switchboard, a double throw switch located at the rear thereof, an operating lever therefor mounted on the face of the board, means for locking the switch in its open position, and a release rod therefor extending through the switch-' board.

5. An electric switch comprising a movable element, an operating lever, a collapsible connection between said lever and said movable element, a spring tending to collapse said connection, means for locking the parts against collapse, means operative to hold said element in its open position, and means for rendering said holding means inoperative.

6. A double-throw electric switch compris ing a movable element having its open position between its closed positions, an operating lever, a collapsible connection between said lever and said movable element, a spring tending to collapse said connection, means for locking the parts against collapse, and means operative when the connection is collapsed to hold. the switch element to allow the connection to be drawn out into non-collapsed position by the movement ofthe lever to operate the switch.

7. An electric switch comprising a movable eleinent, an operating lever, a collapsible connection between said lever and said movable element, a spring tending to collapse said connection, means for locking the parts against collapse, and a latch for holding 'said movable element when the switch is open to allow the connection to be drawn out into non-collapsed position by the movement of the lever to operate the switch.

8. An electric switch comprising a movable element, an operating lever, pivoted links connected to said movable element and to said operating lever and forming a collapsible connection between said lever and said movable element, a spring tending to collapse said connection, means for locking its parts against collapse, and a latch engaging said connection for holding said movable element when the switch is open to allow the connection to be drawn out into non-collapsed position by the movement of the lever to operate the switch.

9. An electric switch comprising a movable element, an operating lever, a crank pivoted at one end to the operating lever, a support for the other end of said crank, a crank pivoted at one end to the movable member and mounted at the other end on said support, a collapsible connection between said cranks, means for locking the parts against collapse, and a latch for engaging one of said cranks to allow the connection to be drawn out into non-collapsed position by the movement of the lever to operate the switch 10. An electric switch comprising a movable element, an operating lever, a crank pivoted at one end to the operating lever, a support for the other end of said crank, a crank pivoted at one end to the movable member and mounted at the other end on said support, a collapsible connection between said. cranks, means for locking the parts against collapse, a latch for engaging one of said cranks to allow the connection to be drawn out into non-collapsed position by the movement of the lever to operate the switch, and means for releasing said latch.

11. An electric switch, comprising a movable element, an operating lever, a collapsible connection therebetween, a spring tending to collapse said connection, means for locking the same against collapse, means for restraining the movement of the lever end of the connection when the switch is in closed position, means for tripping the locking means where by the connection is allowed to collapse and the switch is thereby opened and means for rendering said restraining me ans inoperative.

12. An electric switch, comprising a movable element, an operating lever, a collapsible connection therebetween, a spring tending to collapse said connection, means for locking means responsive to predetermined electrical conriitions 1n the circuit for tripping the locking means, wherety the CODllGCilOIl is allowed to collapse and the switch is thereby opened and means for rendering saiil restraining means inoperative.

13. An electric switch, comprising operating means adaptezl to he placeif. under strain and released to actuate the switch, releasing means therefor, means for automatically locking the switch against movement after being thus actuated, anrl an operating lever for setting the operating mechanism while the switch remains locked and throwing the switch when unlocked to another operative position.

14. A double throw electric switch, comprising a horizontal support, cooperating contacts on the under side thereof arranged to break in oil, an operating lever, and operating means located above said support and comprising means for stopping the switch in its open position when thrown from one closed position and permitting it to pass freely through the open. position to the said closed position when thrown from the other close-tiv position.

15. The combination with a switch having an open position between two closed. positions, ofa latch, and a cooperating notched surface arranged to lock the switch in its open position when thrown from one closed position and permitting it to pass freely through the open position to said ciosecl position when thrown from the other closed position.

16. The combination with a switch having an open position between two closetl positions, of a latch, and a cooperating surface comprising a central notch having sides of unequal length wherety the latch will engage the notch to lock the switch in the open position when the switch is thrown in one clirection and. will ride freely over said notch to permit the switch to pass from one closed position to the other when thrown in the opposite direction.

In witness whereof, I have hereunto set my hand this 28th (lay of July, 1904.

EDWARD M. HEVVLE'IT.

Witnesses BENJAMIN B. HULL, HELEN ORFORD.

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