US1931827A - Electric switch - Google Patents

Description

3 Sheets-Sheet l T. J. NEWMAN ELECTRIC SWITCH Oct. 24, 1933.

Filed Jan. 30. 1932 0 1933- T. J. NEWMAN ELECTRIC SWITCH 3 Sheets-Sheet 2 Filed Jan. 30, 1932 Oct. 24', 1933.

T. J. NEWMAN ELECTRIC SWITCH Filed Jan. 30, 1932 3 Sheets-Sheet 3 Sum/wag netted oct. 24, 1933 y I 1 1,931,821

UNITED STATES PATENT OFFICE ELECTRIC SWITCH I Thomas, J. Newman, Canton, Ohio Application January 30, 1932; Serial No. 589,929 8 Claims. (01. 1751-183) The invention relates to electric switches and DDG theIeOfiS not entirely Withdrawn more particularly to a test switch adapted for m t e rresp ndin Contact l s; testing meters or other devices having both cura Section Similar to Showing e rent and potential winding. pair of the potential blades in running position;

5 The object of the improvement is to provide a Similar Section Showing each potential 50 switch of this character which may have at least blade entirely W d aw from both Contact jaws; one potential pole and any desired number of a Whingidiagram Showing the on e current oles, doubl th bl being protion of the improved switch to a meter and the vided, each blade having a gear segment thereon, like; and,

10 a pinion engaging the gear segments of all of a detail perspective View Of the P the blades for simultaneously moving the same. ating y for the Switch- A further object of the improvement is the Similar numerals refer to similar parts provision of a double throw switch blade for each throughout the w scurrent pole for alternate engagement with two The improved Switch is Preferably enclosed 15 sets of contact jaws adapted to engage one set Within ateasing 0 OfanY Suitable sula i n m t- 7 of jaws before it is entirely withdrawn from the terial preferably p v With removable V- other set of jaws. ers 11 and 12 for the top and bottom thereof Another object is the provision of such a switch respectively and arranged 0 b Connected therein which the contact is made by the current to as y the Screws as carrying blade before the potential blade con- The switehis adapted to be operated by means o tacts with its corresponding contact jaws and in of a pinion l4 preferablyv 0f bakehte other which the contact is broken by the potential Suitable eterial fixed upon the roblade before the current carrying blade is entatable shaft 15 and p e y extending tirely withdrawn from its corresponding contact throughout Substantially the length of the casing 25 jaws. in which the switch is mounted so as to oper- Another object is to provide a switch including atively engage l O e Switch blades, as will a pinion and oppositely disposed double throw be later described- 7 switch blades provided with gear segments en- The v d swit s arra e dto be m untgaging diametrically opposed points upon t ed upon a switchboard or the like, as shown at 30 pinion and arranged to be simultaneously moved 16, the insulation easing 10 being mounted 111 s5 in revel-Se directions thereby the inner or rear side thereof as by the screws A still further object of the improvement is to 17, the switchboard being p dw an provide a removable key for throwing the switch 13 through Which the Outer end of the p to the test position, means being provided to atihg Shaft 15 s extended- I 3 permit removal of the key only when the switch A face plate" 19 is fixed p the Outer d is in the normal running position, thus elimi- 0f the switchboard as by the Screws end p nating the possibility of the operator removing Vided With Central pe i 20 a y al ed the key and leaving the switch in the test With the S t 5 and having the diametrically position. opposed notches 21 arranged to register with the The above and other objects may be attained st 22, upon the shaft 15, w the Switch is by constructing the improved switch in the man- In normal e me posltlonner illustrated in the accom an in drawin s, in For the purpose of operating the Switch key which p y g g is provided having the tubular shank 23 adapted;

to be inserted through the central opening 20 of the face plate and having diametrically opposed studs 24 arranged topass through the notches 21 in the face plate, the inner end of the key shank being grooved on opposite sides as at 25 to receive the studs 22 upon the shaft 15, these grooves Figure 1 is a plan view of the switch showing the same assembled upon a switchboard, the top cover plate of the switch casing being removed for the purpose of illustration;

Fig. 2, a front elevation of the switch;

50 Fig. 3, a transverse sectional view through the switch showing one pair of current carrying boards f varying thickness. 7 blades in running position; It will be seen that the key can be inserted or Fig. 4, asimilar view showing the blades moved removed only t t parts in t operating to a Position Where One end of c blade s position, thus making it impossible for the oper- 55 sorted into the adjacent contact jaws. while the ator to test the meter, or other device to which 110 being of sufficient length to accommodate switchthe switch is connected, and then remove his key while the switch remains in the testing position.

Switches of this type may have one or more sets or pairs of potential blades and any desired 6 number of sets or pairs of current carrying blades and for the purpose of illustration, the switch shown in Fig. l is provided with one pair of potential blades and three pairs of current blades while in the diagram illustrated in Fig. 7, two sets 10 of potential blades and a like number of current blades are shown.

Each of the potential blades 26 is pivoted intermediate its ends as at 27, upon a pivot contact 28 connected to a binding screw 29 extending through the adjacent wall of the casing for the connection of a wire and the like.

Each blade is substantially of obtuse angular form and provided on its inner edge with a gear segment 30 meshing with the pinion 14 whereby 20 the blades of each pair or set may be moved in unison by rotation of said pinion.

The ends of the blades 26 are arranged to alternately engage the contact jaws 31 and 32. Each jaw is substantially U-shaped and has both 26 of its arms bent backward parallel to each other, forming the resilient blade engaging portions 33.

it screw 34 is provided for fastening each jaw upon the adjacent side wall of the casing, the head 35 of the screw being received within the 30" U-sl iaped jaw and a nut 36 being provided for firmly attaching the same in place, the screw serving as a binding post for attaching a wire or the like.

As shown in Fig. 5, when the upper end of "3B one ,blade 26 is engaged with the corresponding ja w dl, the lower end of the other potential .blhtle is engaged with the corresponding jaw 32. When the pinion 14 is operated to move the bladesput of engagement with these jaws it will 46" seenfas shown in Fig. 6, that each blade is entirely released from one jaw before the other d of th blade contacts with the other jaw,

whereby e potential blades may be moved to an entirely neutral position, as shown in said figure,

'Each of the current blades 37 may be of substantially the. same form as the potential blades above described, having a gear segment 38 formed upon its inner edge for engagement with the pinion 14.

These blades are each pivoted, intermediate their ends, upon the pivot contacts 39, as indicated at 40, each pivot cont-act being fixed upon the adjacent side wall of the insulation casing as by a screw 41 which serves as a binding post for attaching wires and the like.

The upper end of each current blade 37 is arranged to engage a contact jaw 42 of substantial- ,ly'the same construction as the jaws 31 and 32,

w and attached to the adjacent side wall of the insulation casing as by a screw "43, forming a binding postfor attaching wires and the like. The lower end of each current blade is adapted 65 ,to engage a similar contact jaw 44 attached to the casing as by the screw 45.

As shown "in Fig. 3, the current blades are so arrangedthat when the upper end of one blade engages the corresponding contact jaw 42, the 70 lower end of the other blade will engage the corresponding contact jaw 44 but, as shown in Fig. 4, the current blades are so arranged that each blade will make contact with one jaw before breaking contact with the other jaw, thus 7 preventing formation of an are when the switch is thrown from operating to test position or vice versa.

It will also be seen, as best shown in Fig. 1, that the potential blades are so arranged with relation to the current blades that they will break contact with the jaws before the current blades break contact while they do no make contact with the jaws until after the current blades have made contact with their respective jaws.

Thus, when the current blades assume the position shown in Fig. 4 with both ends of each blade contacting with its respective jaws, the potential blades will be in position where neither end thereof is in contact with the jaws.

As above explained, the switch may be made up in any combination oi potential and current blades and although in Fig. 1 the switch is shown with one set of potential blades and th of current blades, for the purpose ol' lliu the flexibility of the invention, 7 sho' improved switch diagrammatically with two sets of potential blades 26 and two of current blades 37.

Wires 50 may lead from any suitable source of electric supply, a transformer 51 being interposed between said wires and the wires 52 and 53 leading to opposite sides of an indicating watt meter 54, and the wire leading to the pivot contacts 28 and 39 of adjacent potential and current blade 26 and 37 respectively.

Wires 56 and 5'7 lead from the indicating watt meter to the pivot contacts 23 and 39 01: th: other potential blade and current blade on the same side of the switch.

The indicating watt meter is also connected to the wires 58, 59 and 60 which lead to a potential bus and which are connected to the potential studs 61, 62 and 63 respectively.

The wire 58 is connected, as by the wire 64, with the contact jaw 31 of one of the potential blades on the opposite side of the switch; the wire 59 is connected as by a wire 65 to the contact jaw 42 of one of the current blades 37 on the same side of the switch and the wire 60 is connected as by a wire 66 with the contact jaw 42 of the other current blade upon that side of the switch.

The pivot contact 28 of the potential blade which connects with the wire 64 connected, as by a wire 67, to the meter 68 and the pivot contact of the other potential blade on this side of the switch is connected, as by the Wire 69, with the meter 68.

A bus bar or the like indicated at 70 connects the jaws 31 and 32 of this potential blade to the jaw 44 of the adjacent current blade, while the jaws 44 and 32 of the other current blade and potential blade upon this side of the switch are connected together as by a wire 71. The pivot contacts 39 of the two current blades upon this side of the switch are connected as by the wires 72 and 73 with opposite sides of the meter 68.

On the other side of the switch the contact jaws 31 and 42 of. both potential and current blades are all connected together as by a wire or bus bar 74. The contact jaw 44 of the lowermost current blade on this side is connected, as by the wire 75 with a wire 76, one end of which is connected to the stud 770, the other end leading to the meter 68.

The contact jaw 44 of the next adjacent current blade is connected by a wire 77 with a wire 78, one end of which leads to a stud 79, the other end leading to the meter 68.

A wire 80 leads from the meter 68 to the centact jaw 32 of the next adjacent potential blade and then to a stud 81 while a wire 82 leads from the contact jaw 32 of the other potential blade on this side of the switch and then to a stud 83.

The wire 70 on the opposite side of the switch leads to a stud 84 and an adjacent stud 85 is connected by a wire 86 with the contact jaw 44 of the lowermost blade on the left side of the switch and then leads to the contact jaw 42 of the same blade.

It should be understood that this diagram illustrated in Fig. 7 is merely for the purpose of illustrating one manner in which one type the improved switch may be connected to a meter for testing the same and that various other circuits may be used in connec ing other types of the improved switch to meters or other devices to be tested. I

The measuring device 54 is an indicating wattmeter placed in the circuit and has no connection with the switch, but is meant to show that any number of instruments can be connected in the circuit which can be recording, integrating or relays and the switch operation would affect only the particular instrument to which it was connected. In the case of Fig. 7, lines 50 show a three-phase incoming line feeding through an oil switch. To reduce this primary circuit for metering purposes, transformers indicated by numeral 51 are connected in circuit for secondary metering purposes. current through indicating wattmeter 54 and then are followed through 56 and 5'? to test switch together, with wire 55. They are connected through the necessary switch members up to the integrating watthour meter 68 returning by lines '78 and to switch to complete the circuit. A voltage bus shown by 58, 59 and 60 supplies ener gy for the potential coils of the meter through wires 64, 65 and 66 to test switch members, then through 67 and 73 to potential coils of meter, out on wires '72 and 69 through test switch to wire 65 to complete the potential circuit. In the case of wiring in Fig. 7 the integrating watthour meter 68 only is connected to the test switch and the operation from the running or operating and test position does not affect in any way indicating wattmeter 54. Likewise any other instruments or relays can be introduced in the circult and not be affected by the operationof' the switch or the instruments to which it is connected.

Fig. '7 shows terminal binding posts 85, 84, 83, 81, 77 and 7 9 mounted closeby or adjacent to the test switch. In normal running position of the switch, these terminal studs or binding posts are not in use. When it is desired to test the instruments, it is accomplished by attaching to these studs a definite but variable current through the operating coils and by means of rotating standard the accuracy of such an instrument can be ascertained. With the switch in the testing position the two potential coils in the meter have been paralleled and brought out to terminals and 84. To energize this source terminal studs 61, 62 and 63 have been placed on the board to supply the voltage energy required. Terminals 83, 81, '77 and 79 represent the four ends of two current coils and these are, when the switch is in the test position, absolutely free and clear of any circuit whatever, and any method of testing, either series, paralleling or bucking, can be made with case.

After the test has been completed and all adjustments been made, the testing instruments are Wires 52 and 53 carry. the

is returned to the circuit for its operating purpose. During this entire test the indicating wattmeter 54 was not in any manner disturbed and a.

reading could have been taken at any time during the test.

What I claim is:

1. In a testing system, the combination of the following instrumentalities: a main current supply circuit, a measuring device connected thereto, a branch current supply circuit extending from said measuring device and'deriving current therethrough from said main current supply circuit, current terminals and potential terminals adapted for connection to an instrument to be tested, and a switch having fixed and movable elements arranged in sets with a common operating device engaging the movable element in each set, and connections from'said elements to said branch supply circuit and said current and potential terminals respectively, said fixed and movable elements being relatively so constructed and arranged that the circuits leading to the potential terminals will be automatically opened before the current terminals are opened and the current terminals will be automatically closed before the potential terminals are closed in every operation of the switch.

2. In a testing system, the combination of the following instrumentalities: a main current supply circuit, a step down transformer connected thereto, a branch current supply circuit extending from said transformer and deriving current therethrough from said main current supply circuit, current terminals and potential terminals adapted for connection to an instrument to be tested, and a switch having fixed and movable elements arranged in sets with a common operating device engaging the movable element in each set, and connections from said elements to said branch supply circuit and said current and potential terminals respectively, said fixed and movable elements being relatively so constructed and arranged that the circuits leadingto the potential terminals will be automatically opened before'the current terminals are opened and the current terminals will be automatically closed before the potential terminals are closed in everyoperation of the switch.

The testing system described in claim 1, in which all the switch elements are mounted on a ,witchboard with the operating device accessible from the front of said switchboard and a key and connections adapted to move said device into either one of two positions for operating or for testing at will, said testing position being adapted to carry the movable elements far enough in one direction to fully close the current contacts and then the potential contacts in proper pairs and said operating position being adapted to carry the movable contacts through reverse travel with the potential contacts being first broken'and tween and in engagement with the corresponding pairs of blades for simultaneously operating both blades of each pair in the same direction, separate pairs of blades being connected to the current terminals and the potential terminals respectively. said blades being adjusted to open and close the circuit connections to said current terminals and said potential terminals asynchronously the potential circuit being broken before the corresponding current coil circuit is broken, and said rotatable means being floated on a shaft between the blades and adapted to be removed therefrom in their entirety for adjustment or other purposes without affecting any of the contact blades assemblies.

5. In a testing system of the class described, a main current supply circuit, a step down transformer connected thereto, a branch supply circuit extending from said transformer and deriving current therethrough at reduced voltage from said main current supply circuit, current terminails, and potential terminals adapted for connection to an instrument to be tested and a switch including a plurality of pairs of pivotally mounted switch blades, and rotatable means interposed between and in engagement with the corresponding pairs of blades for simultaneously operating both blades of each pair in the same direction, separate pairs of blades being connected to the current terminals and the potential terminals respectively, said blades being so adjusted with respect to their contacts that when said rotatable means is operated one end of the potential blade will leave its contact before the other end of said blade reaches its corresponding contact.

6. In a testing system of the class described, a main current supply circuit, a step down transformer connected thereto, a branch supply circuit extending from said transformer and deriving current therethrough at reduced voltage from said main current supply circuit, current terminals and potential terminals adapted for connection to an instrument to be tested and a switch including a plurality of pairs of pivotally mounted switch .blades, and rotatable means interposed between and in engagement with the corresponding pairs of blades for simultaneously operating both blades of each pair in the same direction, separate pairs of blades being connected to the current terminals and the potential terminals respectively, said pairs of blades being so adjusted with respect to their terminals and with respect to each other that when said rotatable means is operated both ends of the potential blade will be disconnected from its contacts while both ends of the corresponding current blade are simultaneously connected with its contacts.

7. In a testing system of the class described, a. main current supply circuit, a step down transformer connected thereto, a branch supply circuit extending from said transformer and deriving current therethrough at reduced voltage from said main current supply circuit, current terminals and potential terminals adapted for connection to an instrument to be tested and a switch including a plurality of pairs of pivotally mounted switch blades, and rotatable means interposed between and in engagement with the corresponding pairs of blades for simultaneously operating both blades of each pair in the same direction, separate pairs of blades being connected to the current terminals and the potential terminals respectively, said several pairs of blades and their cooperating contacts being so adjusted that each operation of the rotatable means in one direction will first open both contacts of the potential blade and simultaneously close both contacts of the current blade and will thereafter open one end of the current blade and close the other end of the potential blade, this operation being reversed in each reverse movement oi the rotatable means in cyclic succession.

8. In a testing system, the combination of the following instrumentalities: a main current supply circuit, a step down transformer connected thereto, a branch current supply circuit extending from said transformer and deriving current therethrough from said main current supply circult, current terminals and potential terminals adapted for connection to an instrument to be tested, and a switch having fixed and movable elements arranged in sets with a common operating device engaging the movable element in each set, and connections from said elements to said branch supply circuit and said current and potential terminals respectively, said fixed and movable elements being relatively so constructed and arranged that the circuits leading to the potential terminals will be automatically opened before the current terminals are opened and the current terminals will be automatically closed before the potential terminals are closed in every operation of the switch, said operating device being removably and adjustably connected to said movable elements for adjustment of the time constants in the system.

THOMAS J. NEWMAN.

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