US2904649A

US2904649A - Mechanical interlock for circuit breakers

Info

Publication number: US2904649A
Application number: US679680A
Authority: US
Inventors: Richard R Ranson
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1957-08-22
Filing date: 1957-08-22
Publication date: 1959-09-15
Anticipated expiration: 1976-09-15

Description

Sept. 15, 1959 R. R. RANSON 2,904,649

' MECHANICAL INTERLOCK FOR CIRCUIT BREAKERS Filed Aug. 22, 1957 ATTORNEY United States i atent MECHANICAL INTERLOGK FOR CIRCUIT BREAKERS Richard R. Ranson, Whitefish Bay, Wis.,- assignor to Cutler-Hammer, Inc., Milwaukee, Wis., acorporation of Delaware I Application August 22, 1957, Serial No. 679,680

7 Claims. (Cl. 200-50) This invention relates generally to interlock mechanisms and more particularly to thosefornuse with adjacently mounted circuit breakers to connect the latter together in such a manner that operation. of one breaker and complex, because they mustbe located behind the breakers and are thus difiicult to install and service, and because frequently they are comprised of constituent ele ments of such a specialized nature that they are only suitable for use with particular types of breakers.

Accordingly, it is an object of this invention to-provide improved interlock mechanisms for use with'a pair of circut breakers each of which has an operating member movable from one to another position whereby the operating members of both breakers may besimultaneously disposed in one of said positions but upon movement of either operating member to its other position the other operating'member cannot be movedto its other position untilthe first operating member is returned to its one position.

Another object is to provide improved interlock mechanisms suitable for use with a;pair of circuit :breakers which are mounted either'horizontally or vertically adjacent each other either .in direct alignment or slightly displaced therefrom.

Still another object is to provide such interlock mechanisms which may be employed with a pair of breakers of like or dissimilar construction, provided'both have an operating member movable fromone'to another position.

A further object is to .provide improved interlock mechanisms which are simple, compact, readily adjustable to meet a variety of conditions, reliable in operation, and economical to manufacture and install.

A still further object is to provide improved interlock mechanisms which are comprised of a-number of identical parts which may be fashioned from readily available raw materials and which may be conveniently mass produced or custom made as the case may be.

Other objects and advantages of the invention will hereinafter become apparent.

The accompanying drawing illustrates certain embodiments of the invention which will now be described, it being understood that the embodiments illustrated-are susceptible of modification with respect to certain structural details thereof without departing from the scope of the appended claims.

In the drawing:

Figure 1 is a front elevational view of two-circuit breakers mounted vertically adjacent each other showing the manner in which they are associated with the interlockingmechanism when both operating handles are disposed in downward or off position;

Fig. 2 is a view similar to Fig. 1 but showing the upper breaker handle in downward or ofif: position and the lower breaker handle in upward or .on position;

Fig. 3 is an enlarged elevational view of a portion of the interlock mechanism looking in the direction of the arrows on line 33 of Fig. 1; and

Fig. 4 is an enlarged elevational view of a portion of the interlock mechanism looking in the direction of the arrows on line 4-4 of Fig. 1.

Referring to Figs. 1 and 2, the

numerals

11 and 12 designate a pair of circuit breakers or switches of identical design and dimensions mounted vertically adjacent each other on a supporting member or panel 13 which, for example, could be the rear wall of a cabinet (not shown) wherein the breakers are enclosed. Breakers ll and 12 are provided, respectively, with operating members or handles 14 and 15 which project outward from the faces of their breakers and which are vertically movable downward to off position and upward to on position either manually or by suitable mechanical means (not shown). Rectangular metal plates land 17,'which provide support for the interlock mechanism, are rigidly .provided therein. If preferred, other means of providing support for theinterlock mechanism may be employed.

A first pair of levers or

members

13 and 19, which have a rectangular configuration, are pivotally attached to

plates

16 and 17, respectively,.by the bolts 20 :and 21. These levers are raised slightly above the surfaces thereof by the relatively

thick spacer washers

22 and 23, asFigs. 3 and 4 show, to afford clearance between the levers and the plates for those parts of the mechanism which attach to the levers. Tension springs 24 .and 25, which are'at tached at one of their ends to the

operating levers

18 and 19 by being hooked through small holes provided therein, are anchored attheir other end to the threaded adjust- -

ment studs

26 and 27 which take into tapped openings by the springs until preventedfrom moving further by the

stop posts

30 or 31 which are rigidlysecured to the plates'16 and 17 'asFigs. 3 and 4 show.

Angle brackets

32 and 33 are pivotally attached to

operating levers

18 and 19 by the

pins

34 and 35 which are held in place by cotter keys, as Figs. 3 and 4 show.

A second pair of levers or

members

36 and 37, which have a polygonal contour, are pivotally attached to the faces of the plates'l6 and 17 by the

bolts

38 and 39, and are raised to the level of the

rectangular levers

18 and 19 by relatively thick spacer washers such as that designated by numeral 40 in Fig. 4. The

levers

36 and 37 are arranged on their respective plates so that normally no portions of the levers lie in the paths of travel of the breaker handles adjacent thereto. The contour of the levers is such that as the levers move from one position to another they will not interfere *wit-h'other similarly attached to upper bracket 41 and lower bracket 1 33. As is clear from Fig. 4, the ends of the latter brackets extend outward farther than the ends of

brackets

32 and 42 so that rod 46 will overlie rod 45. The manner in which the rods are secured to the brackets, which is clear from Fig. 4, permits adjustments to be made so that when one of the

levers

18 or 19 is fully depressed by the breaker handle associated therewith then'either of the

levers

36 or 37 controlled thereby will be swung clear of the path of travel of the other breaker handle.

The above described interlocking mechanism operates in the following manner. Normally, as Fig. 1 shows, both breaker handles are disposed in the downward off position thereby depressing the left ends of the

levers

18 and 19 and raising the right ends thereof. The tie rods attached to the pivotable brackets carried by the rectangular levers are thus forced upward causing the polygonal levers to be maintained clear of the path of travel of their respective breaker handles. In this condition both

breaker handles

14 and 15 are ready to be moved upwardly individually to on position.

Assume that breaker handle 15 is moved upwardly to on position as Fig. 2 shows. Tension spring 25 draws rectangular lever 19 against stop post 31. Simultaneously, rod 46 is pulled downwardly and polygonal lever 36 is pivoted so that a portion thereof extends into the path of travel of breaker handle 14 thereby preventing handle 14 from being moved to on until breaker handle 15 is returned to oil? position and the interlock mechanism again assumes the position shown in Fig. 1.

Similarly, assuming that the breaker handle and interlock mechanism are disposed as shown in Fig. 1, movement of breaker handle 14 upwardly to on position permits tension spring 24 to draw operating lever 18 against stop post 30. Simultaneously, rod 45 is forced downwardly and interference lever 37 is pivoted so that a portion thereof extends into the path of travel of breaker handle 15 thereby preventing handle 15 from being moved to on until handle 14 is returned to off position and the interlock mechanism again assumes the position shown in Fig. 1.

Thus, either one or the other, but not both, of the breakers may be energized at any given time.

Although the invention is described in connection with vertically adjacent circuit breakers whose handles move upwardly to on position, it could be employed with breakers whose handles moved upwardly to ofi to prevent more than one breaker from being disconnected at any given moment, if such were desirable.

In addition, the invention may be employed with horizontally adjacent breakers.

Furthermore, although the breakers are shown in Fig. 1 to be in direct alignment, it will be understood that the interlock mechanism shown would operate as well if the breakers were not exactly in direct alignment but displaced therefrom, provided, of course, that the rod lengths were adjusted accordingly.

If desired, the invention may be employed with two breakers whose operating members do not travel identical distances in moving from one to another position, provided that suitable changes are made in the lengths of the levers and the distances the latter are permitted to pivot.

It will be noted that a portion of the interlock mechanism could be employed separately with two breakers to control the order in which the breakers are to be op- 4 i erated if such were desirable. Thus, using only lever 18, rod 45 and lever 37, disposed as shown in Fig. 1, if handle 15 were first moved to on then handle 14 could next be moved to on. But if handle 14 were first moved to on then handle 15 could not be moved to on until handle 14 is returned to off position.

It is also apparent that the interlock mechanism disclosed herein may be constructed of readily available materials, that it lends itself admirably to mass production, that it is foolproof in operation, and that it is very well suited for use where space is at a premium, such as where the breakers are enclosed in a cabinet and only a small amount of space exists between the front of the breakers and the front panel of the cabinet (not shown). Finally, although it is contemplated that the mechanism be fabricated of metal, it is obvious that other suitable materials may be employed.

I claim:

1. In combination, a pair of adjacently mounted electrical devices each having an operator movable between opposite extreme positions, and an interlock mechanism comprising a biased first member held in a certain position by the operator of one of said devices when the latter is in one of its extreme positions, a second member, and means mechanically interconnecting said first and second members, said first member upon movement of said operator of said one of said devices to its opposite extreme position being biased to another position to move said second member into a position blocking movement of the operator of the other of said devices into one extreme position thereof from its other extreme position.

2. In combination, a pair of adjacently mounted circuit breakers each of which has an operating member having a normal position and movable therefrom to another position, a spring biased first movable member maintained in a given position by one of said operating members when the latter is disposed in its normal position, a second movable member associated with the other of said operating members and means for interconnecting said first and second members whereby upon movement of said one of said operating members from normal to its other position said first member is biased a predetermined distance to efiect corresponding movement of said sec ond member to prevent the other of said operating members from moving from its normal to its other position.

3. In combination, a pair of adjacently mounted circuit breakers each of which has an operating handle having a normal position and movable therefrom to another position, at least one spring biased movable operating lever maintained in a given position by one of said operating handles when the latter is disposed in its normal position, at least one movable interference lever adjacent the path of travel of the other of said operating handles, and means for interconnecting said operating lever and said interference lever whereby upon movement of said one of said operating handles from its normal to its other position said operating lever is biased a predetermined distance to effect corresponding movement of said interference lever into the path of travel of the other of said operating handles thereby preventing the latter from being moved from its normal to its other position.

4. In combination, a pair of adjacently mounted circuit breakers each of which has an operating member having a normal position and movable therefrom to another position, a first movable member maintained in a given position by one of said operating members when the latter is disposed in its normal position, biasing means acting upon said first member, a second movable member associated with the other of said operating members, and means for interconnecting said first and second members whereby upon movement of said one of said operating members from its neutral to its other position said first member is biased a predetermined distance to effect corresponding movement of said second member thereby causing the latter to prevent the other of said operating members from being moved from its normal to its other position.

5. In combination, a pair of adjacently mounted circuit breakers each of which has an operating handle having a normal position and movable therefrom to another position, supporting means, at least one operating lever pivotally mounted on said supporting means and maintained in a given position by one of said operating handles when the latter is disposed in its normal position, biasing means acting upon said operating lever, at least one interference lever pivotally mounted on said supporting means adjacent the path of travel of the other of said operating handles, and means for interconnecting said operating lever and said interference lever whereby upon movement of said one of said operating handles from its normal to its other position said operating lever is biased a predetermined distance to effect corresponding movement of said interference lever into the path of travel of the other of said operating handles thereby preventing the latter from being moved from its normal to its other position.

6. In combination, first and second adjacently mounted circuit breakers each of which has an operating member normally disposed in one position and movable therefrom to another position, supporting means associated with said breakers, a pair of first levers pivotally mounted on said supporting means, each of said first levers maintained in a given position by one of said operating members when the latter is normally disposed in said one position, a pair of second levers pivotally mounted on said supporting means, each of said second levers disposed adjacent one of said operating members, means interconnecting the first lever associated with said first breaker with the second lever associated with said second breaker, and means interconnecting the first lever associated with said second breaker with the second lever associated with said first breaker, whereby movement of one of said operating members from its normal to its other position effects pivoting of the first lever associated therewith a predetermined distance to eifect corresponding pivoting of the second lever connected thereto into the path of travel of the other of said operating members thereby preventing the latter from being moved from its normal to its other position.

7. In combination, first and second adjacently mounted circuit breakers each of which has an operating handle member having a normal position and movable therefrom to another position, supporting means associated with said breakers, a pair of first levers pivotally mounted on said supporting means, each of said first levers maintained in a given position by one of said handle members when the latter is disposed in its normal position, biasing means attached to each of said first levers, a pair of second levers pivotally mounted on said supporting means, each of said second levers disposed adjacent the path of movement of one of said handle members, means interconnecting the first lever associated with said first breaker with the second lever associated with said second breaker, and means interconnecting the first lever associated with the second breaker with the second lever associated with the first breaker, whereby upon movement of one of said handle members from its normal to its other position said first lever is pivoted a predetermined distance by the biasing means attached thereto thereby elfecting pivoting of the second lever connected therewith into the path of travel of the other of said handle members thus preventing the latter from being moved from its normal to its other position.

References Cited in the file of this patent UNITED STATES PATENTS 1,337,895 French Apr. 20, 1920 1,796,229 Andersen Mar. 10, 1931 2,525,501 Taylor Oct. 10, 1950 2,604,796 Freese July 29, 1952 2,722,135 Taylor Nov. 1, 1955 2,791,729 Allen et al. May 7, 1957