US3055995A

US3055995A - Lockable enclosed switch

Info

Publication number: US3055995A
Application number: US8664A
Authority: US
Inventors: Arnold E Snow
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1960-02-15
Filing date: 1960-02-15
Publication date: 1962-09-25
Anticipated expiration: 1979-09-25
Also published as: JPS3619926B1

Description

Sept. 25, 1962 A. E. SNOW LOCKABLE ENCLOSED SWITCH 2 Sheets-Sheet 1 Filed Feb. 15, 1960 TRIPPED INVENTOR ARNOLD E. SNaw WW% C Sept. 25, 1962 A. E. SNQW LOCKABLE ENCLOSED SWITCH Filed Feb. 15, 1960 2 Sheets-Sheet 2 INVENTOR. A RNOLD E. SNow A TTORNEY 3,955,995 Patented Sept. 25, 1962 nice 3,055,995 LOQKABLE ENCLGSED SWITCH Arnold E. s now, Farmington, COHHL, assignor to General Electric Company, a corporation of New York Filed Feb. 15, 1960, Ser. No. 8,664 6 Claims. (Cl. 200-44) My invention relates to electric switches and circuit breakers and particularly to electric switches and circuit breakers which are ordinarily used within an outer enclosure and which include a manually operable portion projecting through an opening in the outer enclosure and which further include means for selectively locking the handle of the switch in either of two predetermined desired positions.

Electric switches, and especially electric circuit breakers which include an automatic opening function upon the occurrence of predetermined current conditions in the circuit, are often used in assemblies which comprise several such switches or circuit breakers in a single enclosure or assembly. In use it is often desirable that certain one or more of such switches may be locked by suitable means such as by a padlock in a predetermined condition, i.e., either ofii or on. Thus, for example, it is a requirement of electrical authorities in many instances that a switch or circuit breaker used in conjunction with the control and operation of an electric motor which is positioned more than fifty feet therefrom shall include means for padlocking the switch or circuit breaker in its 0135 position.

Locking devices according to the prior art have generally required the use of a bracket of one type or another rigidly attached to the cover of the outer enclosure. An alternative procedure has been the attaching of some object to the handle of the switch or circuit breaker. The rigid mounting of brackets or other members to the enclosure cover suffers from the obvious disadvantages of diificulty of installation. In constructions where such bracket or other means is made integral with the cover, the manufacturer cannot know which of the particular circuits in such an assembly will be required to be lockable and, therefore, has to provide such means for each and every circuit location. In those constructions requiring the attachment of a device to the circuit breaker handle, there is the disadvantage that such a device interferes with authorized operation of the switch or circuit breaker and if removed from the handle, requires storage of the attachment, in addition to some conventional padlocking means.

It is an object of the present invention to provide an electrical apparatus assembly including an electric switch having a manually operable handle and an outer enclosure including a cover portion overlying a portion of such switch and having an aperture through which the handle projects. Means is also provided which is readily attachable to the assembly, which normally does not impede the operation of the switch or circuit breaker, but which makes it possible to padlock the switch or circuit breaker handle in either its off or on positions.

It is another object of the invention to provide such an assembly including such an attachment which cannot be removed by unauthorized personnel even when unpadlocked.

It is a further object of the invention to provide such an attachment which is extremely inexpensive to manufacture and which may be added to any existing installation of circuit breaker assemblies.

In accordance with the invention, I provide an electrical apparatus assembly including a switch or circuit breaker having a manually operable handle, and an outer enclosure which includes a cover portion overlying a portion of such switch or circuit breaker and having an aperture through which the manually operable handle of the switch or circuit breaker projects. A locking attachment is provided which may be readily attached to the assembly by a simple snap-on action, which includes a portion projecting alongside the switch or circuit breaker handle and is adapted to receive a conventional padlock to lock said circuit breaker handle in either of its extreme on or off positions. The attachment includes a portion underlying the outer cover of said enclosure and overlying the top surface of said switch or circuit breaker, whereby the attachment is securely locked in place when said cover of said enclosure is in normal use position.

The invention will be more fully understood from the following detailed description and its scope will be pointed out in the appended claims.

In the drawings:

FIGURE 1 is an elevation view partially broken away of an electrical apparatus assembly including an electric circuit breaker mounted in an enclosure;

FIGURE 2 is a top plan view of the circuit breaker of FIGURE 1 with the locking attachment of the invention in place;

FIGURE 3 is a perspective view of the locking attachment onl of FIGURES l and 2;

FIGURE 4 is an enlarged view of a portion of the assembly of FIGURE 1;

FIGURE 5 is an end elevation view of a series' of circuit breakers including the locking attachment;

FIGURE 6 is a perspective fragmentary view of a portion of a circuit breaker and a locking attachment constructed in accordance with the invention in another embodiment;

FIGURE 7 is a perspective view of the locking attachment used in the assembly of FIGURE 6.

In the drawings, the invention is illustrated as embodied in an electrical apparatus assembly comprising an outer metallic enclosure 10, having a cover 11 removably attached thereto by suitable means such as by screws 12.

Circuit breaker and bus bar supporting means are provided within the enclosure 10 comprising a pan 13 supported by resilient spring means 13a and having a generally planar back wall 14 and outwardly directed flange portions 15', only one shown. Bus bar supporting means is provided comprising an insulating support 16 mounted on the back wall 14 of the pan 13 by suitable means such as by screws, not shown, and carrying a bus bar assembly including a series of contact blades 17, only one shown, aligned centrally in a row thereon and extending in edgewise transverse relation between the flanges 15. The flanges 15 include a series of hook retaining members 18, only one shown, adapted to project into the recess 19 of the circuit breaker 2d. The circuit breaker 20 includes a plug-in type socket 21 at one end thereof adapted to be plugged onto the contact blade 17, and a load terminal connector 22 adapted to attach a conductor 23. The circuit breaker 20 also includes a generally rectangular boss 24 on the top surface thereof and a manually operable handle 25, for operating the circuit breaker. The cover 11 includes a plurality of generally rectangular apertures 26 (only one shown, see FIG. 4) through which the boss 24- projects when the circuit breaker is in mounted position and the cover 11 is in place. The cover 11 therefore includes portions overlying the portions of the top surface of the circuit breaker 20 surrounding the boss 24. The construction as thus far described and shown is conventional and is in general accordance with the structure disclosed, for example, in Patent No. 2,876,394, Gerrish, assigned to the same assignee as the present invention.

For the purpose of facilitating the locking of a selected circuit breaker or circuit breakers in the panel assembly,

I provide a locking bracket 28, see FIGURE 3, including a generally C-shaped base portion of flat sheet metallic material having a pair of inwardly directed pointed projections 29 and an offset upstanding intermediate portion 30 provided with an aperture 31. The bracket 28 is attached to the circuit breaker by sliding it along the top surface of the circuit breaker to the position shown in FIGURE 2, the projections 29 biting into the boss 24 slightly to retain the bracket 28 in a position in which the base portion of the upwardly bent portion 30 is against one side portion of the boss 24. This positions the bracket 28 on the circuit breaker 20, with the upper portion of the upstanding portion 30 closely adjacent the path of movement of the handle 25, and with the aperture 31 generally midway of the path of movement.

Following assembly of the locking bracket on the circuit breaker, the panel assembly enclosure cover 11 is put in place, with the boss 24, the handle and the upstanding portion of the bracket 23 projecting through the aperture 26. When the parts are thus assembled, it will be apparent that the handle 25 may be moved between its off and on positions without interference by the bracket 28. If, however, it is desired to lock the circuit breaker handle in either its on or off" positions, it is only necessary to insert the hasp of a conventional padlock 32 through the aperture 31. Since the hasp of the padlock 32 is in the path of movement of the handle 25, it is not possible to move the handle fully to its opposite position.

While the invention is equally usable with electric circuit breakers and switches, the invent-ion has particular advantages in connection with the use of electric circuit breakers of the type which operate automatically upon the occurrence of predetermined current conditions to disconnect or move their contacts to the open circuit position, and in which such automatic opening or tripping is indicated by a movement of the circuit breaker handle to a position substantially midway between its on and off positions. When such circuit breakers are used in assemblies together with other circuit breakers, it is useful to be able to determine from a visual inspection of the condition of the circuit breaker handles, which of the circuit breakers has tripped. With the device of the present invention, a small amount of movement of the handle is possible even though the circuit breaker is locked in the on position as indicated in FIGURE 1, in dotted lines. Thus, it is still possible to determine the tripped condition of the circuit breaker by visual inspection.

When the cover 11 is assembled as shown, it overlies the generally planar base portion 28a of the bracket 28 and securely retains it in place. Thus, although the bracket is not fixedly attached to any part of the assembly, it is securely trapped in place and cannot be moved or defeated by unauthorized personnel. At the same time, it will be observed that in case of emergency, it is always possible to have access to any such circuit breaker to operate it, by means of removing the screws 12 and removing the cover 11 of the panel. Since the removal of the cover of such a panel is not likely to be attempted by unauthorized personnel, this nevertheless provides adequate safeguard against the improper operation of such circuit breakers.

Referring to FIGURES 6 and 7, I have shown a modified form of the invention in which a bracket 35 is provided comprising a base portion 35a and an upstanding portion 36 having an aperture 37 therein. The upstanding portion 36 of the bracket 35 includes a pair of oppositely directed projections 39. In use, the bracket 35 is assembled to the cover 11 of the panel enclosure in such a manner that the portion 35a underlies the surface of the cover and the projections 39 overlie the surface at edge portions adjacent the corners of the aperture 26. This assembly is readily accomplished by inserting the bracket 35 in a slightly diagonal position with respect to the opening 26 and then straightening it into place. When the cover 11 is assembled to the panel enclosure, the opening 26 surrounds the boss 24 and the top surface of the casing of the circuit breaker 20 presses the portion 35a of the bracket 35 against the undersurface of the cover, and the base of the upstanding portion 36 is held against the edge of the aperture 26 by the corresponding edge of the boss 24. The use of the bracket 35 is similar to that of the bracket 28 in that a lock may be placed through the aperture 37 and prevents the movement of the circuit breaker handle 25 from one extreme position to the other.

It is a particular feature of the invention that the same piece may be used for locking both single-pole and multipole circuit breakers such as two and three pole circuit breakers. This is possible because such devices are all constructed with standardized embossed portions 24 so as to be usable in standardized panel enclosures with predetermined openings 26. Thus, as indicated in FIGURE 5, the bracket 28 may be assembled and used in connection with a single-pole circuit breaker 40, a two-pole circuit breaker 41 and a three-pole circuit breaker 42.

While I have shown only two particular embodiments of my invention, it will be readily apparent that many modifications thereof may be made, and I therefore intend by the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

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

1. An electric switch assembly comprising an enclosure, a cover removably mounted on said enclosure and having an aperture therein, electric switch means comprising an insulating casing removably mounted in said enclosure, said insulating casing having a top surface, said switch means including a manually operable handle projecting through said aperture in said cover, said cover having portions adjacent said aperture overlying said top surface of said insulating casing when said cover is in place on said enclosure, said handle being movable between on and off positions, a locking bracket having a first portion trapped in place between said cover of said enclosure and said top surface of said insulating casing and a second portion projecting generally perpendicularly to said cover and closely adjacent said handle, said bracket having no positive connection to said cover, said bracket having an aperture in said second portion adapted to receive a portion of a locking device therethrough for locking said handle selectively in either of said on and off positions.

2. An electric switch assembly comprising an enclosure, a removable enclosure cover having a handle aperture therein, switch means removably mounted in said enclosure and comprising an insulating casing having a top wall anda manually operable handle projecting from said top wall through said aperture in said enclosure cover, said enclosure cover when in mounted position overlying a portion of said top wall surrounding said manually operable handle, locking means comprising a first portion overlying a portion of said casing adjacent said handle and beneath said overlying portion of said enclosure cover and a second portion projecting through said aperture and closely adjacent the path of movement of said manually operable handle, said locking means having no positive connection to said enclosure cover, means for releasably retaining said locking means on said insulating casing, and an aperture in said second portion for receiving a portion of a lock.

3. Electrical apparatus comprising and enclosure having an open top wall, a generally planar cover removably attached to said enclosure and closing said top wall, at least one handle aperture in said cover, an electric switching device supported within said enclosure and comprising an insulating casing having a top wall and a manually operable handle, said manually operable handle projecting through said aperture in said cover with a portion of said cover overlying said top wall of said casing surrounding said handle, lock receiving means comprising a generally planar base portion adapted to be received between said top wall of said insulating casing and the inner surface of said cover adjacent said manually operable handle and an upstanding portion projecting through said aperture and disposed closely adjacent the path of movement of said movable handle member, said upstanding portion also including at least one projection overlying the top surface of said cover to retain said member in place when said cover is open, said lock receiving means having no other connection to said cover, and an aperture in said upstanding portion adapted to receive a portion of a lock device whereby a portion of said lock device projects into the path of movement of said manually operable member.

4. Electrical apparatus as set forth in claim 1 wherein said aperture in said second portion is disposed substantially midway between the extreme positions of movement of said manually operable member.

5. Electrical apparatus comprising an enclosure having an open top wall, cover means removably mounted on said enclosure and substantially closing said open top wall, at least one aperture in said cover, electric switch means removably supported in said enclosure and comprising an insulating casing having a top Wall, said casing top wall comprising a first raised portion and a peripheral generally planar portion, said raised portion projecting through said aperture, a manually operable handle member projecting through an opening in said raised portion of said casing and movable reciprocably between two extreme positions, lock receiving means formed of sheet metallic material and comprising a base portion adapted to overlie a portion of said peripheral planar portion of said top wall of said insulating casing beneath said cover and an upstanding portion eXtending closely adjacent the path of movementof said manually operable member, said lock receiving means having no positive connection to said cover, and removable locking means carried by said upstanding portion and projecting at least partially into said path of movement of said manually operable member.

6. For use in connection with an electric switching device having a manually operable handle and enclosed in an outer enclosure including a cover portion overlying a portion of the switching device and an aperture through which said manually operable handle of said switching device projects, a lock receiving member formed of sheet metallic material comprising a generally C-shaped planar base portion, a pair of sharp pointed projections carried by the extremeties of C-shaped base for retaining said member on said casing, an oifset upwardly bent portion extending generally perpendicular to the plane of said base portion intermediate the arms of said C, and an aperture in said upstanding intermediate portion for reoeiving a locking device.

References Cited in the file of this patent UNITED STATES PATENTS 2,141,936 Schmitt Dec. 27, 1938 2,169,860 Von Hoorn Aug. 15, 1939 2,484,424 Rosing Oct. 11, 1949 2,876,394 Gerrish Mar. 3, 1959 2,983,799 Osieja et al. May 9, 1961