SWITCHBOARD FRAME

Abstract: A switch board frame including connecting members (20) formed at upper and lower ends of side plates (13), and projecting members (6 and 7) located on corresponding surfaces (4 and 5) of a ceiling board (2) and a bottom board (3) disposed at a right angle to each other and connected by the connecting members (20). The ceiling board (2) and the bottom board (3) are connected to the side plates (13) include electrical equipment in the interior of the switch board frame (1). The switch board frame (1) further includes face plates (16 and 17) formed by bending opposite end portions of side plate (13) at a right angle, and cutout grooves (18) formed on the sides of the face plates (16 and 17) corresponding to the side plates for receiving one set of projecting members (8). The connecting members (20) are connected to another set of projecting members (9) extending toward the correspond­ ing surface (4 and 5) side through offset portions (19) formed by bending inwardly end portions of the face plates (16 and 17) in positions corresponding to the cutout grooves (18).

Description: SWITCH BOARD FRAME BACKGROUND OF THE INVENTION (1) FIELD OF THE INVENTION This invention relates to improvements in or relating to a switch board frame of the indoor use formed mainly of sheet steel. Generally, in this type of metal enclosed switch board, a switch board frame having an inlet and outlet portion has its interior divided by a partition plate into a chamber for housing lead type electrical equipment, such as a circuit breaker, on the side of the inlet and outlet portion and a bus bar chamber on a side opposite the inlet and outlet portion with respect to the circuit breaker chamber. The partition plate is provided with electrical connections for connecting the circuit breaker chamber to the bus bar chamber. The electrical connection on the bus bar chamber side connects power source bus bars to a load conductor, and the electrical connection on the circuit breaker chamber side is brought into and out of contact with a circuit breaker moved into and out of the circuit breaker chamber to electrically form or close an electric circuit. (2) DESCRIPTION OF THE PRIOR ART A switch board frame for housing electrical equipment, such as power source bus bars and a circuit breaker, has hitherto been fabricated by welding thin sheet steel to a shape steel frame structure provided by welding channel steel or angle steel to a vertical frame, a width frame and a transverse frame. Some disadvantages are associated with the shape steel frame structure. It is time consuming and requires a lot of labor to punch holes in shape steel and sheet steel or to form grooves therein. In addition, the shape steel frame structure has a very heavy weight. An increase in mechanical strength achieved by improved quality of sheet steel obtained in recent years has been combined with advances in the progress of technology, such as press technology and welding technology, to make it possible to adopt what is generally referred to as a stressed shell structure in which an upper plate, such as a ceiling board, and a lower plate, such as a bottom board, which are formed of sheet steel are connected to the upper end and the lower end respectively of a framework formed by bending sheet steel alone. The stressed shell structure offers advantages in that material cost and the working time can be reduced, and the weight of the framework can also be reduced. However, some disadvantages are associated with this structure. When the upper plate and the lower plate are connected to connecting pieces provided to the framework, difficulties are experienced in achieving positioning of the upper plate and the lower plate with respect to the connecting pieces because they tend to be offset relative to each other. As a result, operation of assembling a switch board frame of the stressed shell structure has been low in efficiency. SUMMARY OF THE INVENTION Accordingly the invention has as its object the provision of a switch board frame enabling positioning of parts to be readily and positively achieved, to thereby increase the efficiency with which assembling operation is carried out. The aforesaid object of the invention is accomplished by providing a switch board frame including a ceiling board and a bottom board supported on the upper and lower ends respectively of side plates, wherein projecting members located at a right angle to each other are provided on corresponding surfaces of the ceiling board and the bottom board respectively; cutout grooves for receiving one set of projecting members located at a right angle to each other are each formed on the side of face plates corresponding to the side plates; the face plates being formed by inwardly bending opposite end portions of the side plates, and connecting members are provided which are connected to another set of projecting members extending toward the corresponding surfaces through offset portions formed by inwardly bending end portions of the face plates corresponding to the cutout grooves. When the ceiling board and the bottom board are connected to the side plates, the force required for insertion of the ceiling board and the bottom board is accommodated by the projecting members stopped by the cutout grooves, so that positioning of the ceiling board and the bottom board with respect to the side plates can be facilitated. BRIEF-DESCRIPTION OF THE DRAWINGS Fig. 1 shows an example of a switch board in which the present invention can have application; Fig. 2 is a perspective view of the switch board frame comprising one embodiment of the invention; Fig. 3 is an exploded perspective view of the switch board frame shown in Fig. 2; Fig. 4 is a perspective view of the side plate; Fig. 5(A) is a fragmentary exploded view of the switch board frame; Fig. 5(B) is an assembled perspective view of the switch board frame shown in Fig. 5(A); and Fig. 6 is a fragmentary perspective view of the switch board frame shown in Fig. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A perferred embodiment of the invention will now be described by referring to Figs. 1 - 6. Referring to Fig. 1, there is shown a metal enclosed switch board 100 in which the present invention can have application. A switch board frame 1 has its interior divided into a bus bar chamber 102 and an electricity chamber 103 by a partition plate 101 mounted therein. The bus bar chamber 102 contains three phase power cable 104 and power source bus bars 105. The power cable 104 is connected at one end thereof to a load, such as a motor, not shown, and at the other end thereof trough current transfer 106A to load side branch conductor 106. The power source bus bars 105 are supported by support insulators 107 attached to the. surface of the ceiling and connected to power source side branch conductors 108 The power source side branch conductors 108 are connected to upper disconnecting parts 109, and the load side branch conductor 106 is connected to lower disconnecting parts 110. The upper and lower disconnecting parts 109 and 110 are mounted on the partition plate 101 and connected to a circuit breaker 111 located in the electricity chamber 103, which is adapted to open and close a door 112 on the front surface of the switch board frame 1 and move into and out of the electricity chamber 103 into and out of electrical contact with the upper and lower disconnecting parts 109 and 110. The switch board frame 1 in which a circuit breaker, transformer or other electrical equipment is enclosed is constructed as presently to be described. The switch board frame 1 comprises a ceiling board 2 and a bottom board 3 having corresponding surfaces 4 and 5 respectively. Projecting members 6 extend from the periphery of one corresponding surface 4 toward the other corresponding surface 5 and projecting members 7 extend from the periphery of the other corresponding surface 5 toward the one corresponding surface 4. The projecting members 6 and 7 each include one set of projecting members 8 and the other set of projecting members 9, the projecting member 8 of one set and the projecting member 9 of the other set forming a corner section 10 at which they are at a right angle to each other. In the corner sections 10, a front side surface pillar 11 and a rear side surface pillar 12 in the form of a letter L in cross section are connected to side plates 13. The side surface pillars 11 and 12 are formed by bending sheet steel inwardly at upper and lower end portions into an L-shape or an inverted L-shape and have formed, at the upper and lower end portions, connecting pieces 15 through offset portions 14 tilting inwardly. The connecting pieces 15 are formed by compressing and shaping sheet steel As shown in Fig. 3, each side plate 13 is bent at opposite end portions at a right angle or in a direction corresponding to the side surface pillars 11 and 12 to form front and rear face plates 16 and 17. The face plates 16 and 17 associated with each side plate 13 are formed in one portion of opposite ends with cutout grooves 18 (see Fig. 4), and connecting members 20 are formed through inwardly tilting offset portions 19 at opposite end portions of the pillars 11 and 12 in positions corresponding to the cutout grooves 18. The connecting members 20 connect the projecting members 6 and 7 together. The cutout grooves 18 are dimensioned such that they accommodate the projecting members 6 and 7 in a thicknesswise direction. The stepped portions 14 and 19 are tilting inwardly in such a manner that when the connecting members 20 connect the projecting members 6 and 7 together, the projecting members 6 and 7 agree with the projecting members 6 and 7 in the main surfaces of the latter. The projecting members 6 and 7 are positioned at their forward end against the offset portions. Stated differently, the offset portions have only to have a depthwise dimension which is equal to the widthwise dimention of the projecting members. Each side plate 13 is formed through cutouts formed in the central portion with abutting surfaces 21 extending perpendicularly to the plane of the side plate 13 and intermediate connecting members 22 extending toward the ceiling board 2 from the abutting surfaces 21. The abutting surfaces 21 are spaced apart from the surface of the side plate 13 a distance 23 corresponding to the thicknesses of the projecting members 6 and 7. The offset portions 14 and 19 need not be inclined as described hereinabove and may extend in a right angle direction in the same manner as the abutting surfaces 21 of the intermediate connecting members 22. To connect the side plates 13 to the ceiling board 2 and the bottom board 3 in the switching board frame 1 of the aforesaid construction, the projecting members 8 are inserted in the cutout grooves 18 and the spacing between the intermediate connecting members 22 and the side plates 13 while the side plates 13 are placed on the surface of the floor, and the ceiling board 2 and the bottom board 3 are pressed toward the side plates 13 while the projecting members 9 are in engagement with the connecting members 19. Since the pressing force is accommodated by the cutout groove ends, the ends of the spacing between the intermediate connecting members 22 and the side plates 13 and the offset portions 19, positioning of the ceiling board 2 and the bottom board 3 relative to the side plates 13 can be facilitated. For example, the projecting members 9 and the connecting members 20 are in engagement with each other, so that they are difficultly displaced from each other. Thus the connections between the connecting members 20 and the projecting members 9 can be readily joined by resistance welding and the welds formed have high mechanical strength. Alternatively, the connecting members, intermediate connecting members and projecting members may be joined by welding while the projecting members have the side plates placed thereon in upstanding position. Meanwhile the presence of the cutout grooves 18 facilitates bending of sheet steel of large widthwise dimension and height dimension for producing the side plates 13. At the same time, the cutout grooves 18 serve as a mark for performing bending operation. This also applies to the bending of sheet steel for forming the offset portions 19 and connecting members 20. Fig. 6 shows a construction in which an intermediate support 101 including a partition plate and a frame-like member is mounted between the side plates 13 and the ceiling board 2 and bottom board 3. This construction offers the advantage that the mechanical strength of the side plates and ceiling board can be increased with simple means. In a metal enclosed switch board system, a plurality of switch board frames are arranged in a bank. In this case, the adjacent switch board frames are arranged such that the side plate of one switch board frame is disposed in adjacent relationship in a space created by removing the side plate of the other switch board frame. Because of this arrangement, the side surface pillars 11 and 12 are provided in the embodiment of the invention shown and described hereinabove. However, when the switch board frame is used singly, the switch board frame may, of course, be provided with the side plates on the left and right sides of the switch board frame. When a bank of a plurality of switch board frames are located in adjacent relationship, it is possible to secure the parts solidly without any gaps if the side surface pillars 11 and 12 are bolted through openings formed on the connecting surfaces of the side surface pillars 11 and 12 by removing the plates of the surfaces corresponding to the side plates 13. From the foregoing description, it will be appreciated that in the present invention, the provision of the cutout grooves on the surface pillars corresponding to the side plates facilitates the assembling of the ceiling plate, side plates and bottom board because their positioning can be facilitated.

Claims: \ERT Is CLAIIED IS: 1. A switch'board frame (1) comprising connecting members (20) formed at upper and lower ends of side plates (13), and projecting members (5, 7) located on corresponding surfaces (4, 5) of a ceiling board (2) and a bottom board (3) disposed at a right angle to each other and connected by said connecting members (20), wherein the ceiling board (2) and the bottom board (3) are connected to the side: plates (13) to electrical equipment in the interior of the switch board frame (1) c h a r a c t e r i z e d b-8. face plates (16, 17) formed by bending opposite end portions of each said side plate (13) at a right angle; and cutout grooves (18) formed on the side of said face plates (-l6, 17) corresponding to the side plates (13) for receiving one set of projecting members (8); and the arrangement whereby said connecting members (8) are connected to another set of projecting members (9) extending toward the corresponding surface side through off- set portions (19). formed by bending inwardly end portions of said face plates (16, 17) in positions corresponding to the cutout grooves (18). -2. . A switch board frame as claimed in claim 1, c h a r a c t e r i z e d in that said one set of project iflg members (8) exteni from the peripheries of corresponding surfaces of the ceiling board (2) and the bottom board (3) toward other corresponding surfaces and cross each other at a right angle to provide corner portions (10). 3. A switch board frame as claimed in claim 2, c h a r a c t e r i z e d by abutting surfaces (16, 17) formed b bending the side plates (13) at a riGhl angle through a cutout formed midway between opposite ends of each said side plate at either end thereof, and intermediate connecting members (20) extending from said abutting surfaces toward the ceiling board (2) and the bottom board (.3), said abutting surfaces and the surfaces of the side plates defining therebetween gaps large enough to receive the projecting members (8, 9). 4. A switch board frame as claimed in any one of claims 1 to 3, c h a r a c t e r i z e d by side surface pillars (11, 12) in the form of a letter L in cross section formed in the front and rear respe¯tively of corner .po- tions (10) corresponding to the face plates (15, 17) formed on opposite ends of said side plates (13), and connecting pierces (15) formed et least in the lower portion o the lower and upper portions of the side surface pillars (11,12) through offset portions (14) so that said connecting pieces are connected to the projecting members (8, 9) formed at the outer peripheries 0 said ceiling plate (2) and said bottom plate (3). 5. A switch board frame as claimed in claim 4, c h z a c t e r i z e d in that said face plates (16, 17) are formed by bending at a right angle the opposite end portions of said side plates (13), and by openings for mount- ing 2 docr (112) and a backing plate in said side surface pillars (11, 12) in positions corresponding to the front surface of said switch board frame and a corresponding surface. 6. A switch board frame as claimed in claim 4, c h a. r a C t e r i z e d by openings for connecting a plurality of switch board frames or for mounting shield plates on surfaces corresponding to said side surface pillars (11, 12) on the surfaces of said surface pillars corresponding to said side plates. 7. h switch board frame as claimed in any one of clains 1 to 6, c h a r a c t e r i z e d by an intermediate support including a partition plate and a frame member lo cated substantially midway between srid side plates, said ceiling board and said bottom board. 8. A switch board frame as claimed in any one of claims 1 to 7, c h a r a c t e r i z e d in that said connecting members (20) connected to said projecting members (8, 9) are secured in place by resistance welding.

Inventors: KURODA, CHOJI
Applicants: HITACHI, LTD.
Application year: 1981
Main classification: H02B1
IPC codes: H02B1, H02B13