Patent Publication Number: US-3877601-A

Title: Floor box

Description:
United States Patent [191 Evans et al.  
 1 FLOOR BOX [75] Inventors: Thomas J. Evans, Parkersburg, W.  
 Va.; William Walker, Belpre, Ohio; Edward E. Hall, deceased, late of Parkersburg, W. Va., by Lena P. Hall, administratrix [73] Assignee: Textron Inc., Providence, RI.  
 [22] Filed: Mar. 12, 1973 [21] Appl. No.: 340,276  
 [52] U.S. Cl. 220/33; 220/394; 220/62 [51] Int. Cl. H02g 3/08; B65d 7/38 [58] Field of Search 220/3.23.94,  
 [56] References Cited UNITED STATES PATENTS Knight 220/394 Krantz 220/394 Apr. 15, 1975 1,761,398 6/1930 Knight 220/394 1,860,833 5/1932 Clayton 220/394 2,250,685 7/1941 Tiefenbacher et al 220/32 2,625,288 1/1953 Clark et al. 220/394 2,697,535 12/1954 Olson 220/3.2  
 FOREIGN PATENTS OR APPLICATIONS 499,795 3/1951 Belgium 220/32 487,015 10/1952 Canada 857,667 1/1961 United Kingdom 1,051,900 12/1966 United Kingdom 220/31 Primary Examiner--Wil1iam 1. Price Assistant Examiner-Stephen Marcus Attorney, Agent, or Firm-Frederick J. Olsson 1 1 ABSTRACT A floor box structure providing for the box to be made from pre-galvanized steel strip worked to final shape in a multistage progressive die.  
 4 Claims, 4 Drawing Figures PATENTEDAFR I 5 I975 SHEEI 1 [If 2 This invention, in general, relates to electrical under floor distribution systems and, in particular, relates to an improved floor box for use in such systems.  
  The principal object of the invention is to provide a floor box structure which permits manufacture by that a pre-galvanized steel strip is fed into a multi-stage progressive die and a box is ejected with each stroke of the die press.  
  The invention contemplates a floor box structure which provides for fabrication by feeding a pregalvanized strip into a progressive die which forms all of the parts of the box, makes the necessary bends and with each stroke of the press ejects a box which has all of its parts in position and is completely fabricated except for tapping cover-receptacle lugs andfor spot welding of corner overlaps.  
  The design allows the most efficient use of progressive die technology and minimizes fabrication operations. The principal advantage of the invention is that manufacturing cost is approximately one-third of the manufacturing cost of a comparable box madewith conventional techniques. This is brought about by (a) the elimination of a post-fabrication galvanizing operation (11) the elimination of at least one press operation and the ensuing elimination of material handling between such operations and (c) the elimination of the purchase orthe fabrication of separate leveling lugs and the welding of the lugs to the box.  
 The preferred-form of the invention will be described below in connection with the following drawingswherein:  
  FIG. 1 is a perspective view of a floor box constructed in accordance with the invention;  
 FIG. 2 is a plan view of the floor box in FIG. 1;  
  FIG. 3 is a plan fragmentary view of a modification of the box of FIG. 2; and  
  FIG. 4 is a blank layout for the box of FIG. 1. In FIG. 1, the box is octagon in shape and has the bottom 1, the four long sides 2, 3, 4 and 5 and the four short sides 6, 7, 8 and 9. The respective long sides and short sides are identical in construction. The sides are integral with the bottom and extend upwardly generally perpendicular thereto. The box is formed so that any two adjacent long sides extend perpendicular to each other and a short side extends therebetween, for example the long sides 2 and 3 are perpendicular and the short side 7 extends between the long sides at an obtuse angle which, in this instance, is approximately 135.The same construction applies to any other pair of adjacent long sides and an interconnecting short side.  
  With respect to short side 7 it will be noted that this comprises a first section 10 and a second section 11. The first section is L-shaped, having the leg 12 and a foot 13. The section 11 is similarly shaped, having the foot 14 and the leg 15. The edge 16 of the leg 12 abuts the edge 17 of the foot 14. Also, the edge 18 of the foot 13 abuts the edge 19 of the leg 15.  
  The bottom edge 20 of the foot 13 and the bottom edge 21 of the leg 15 are closely adjacent to the edge 22 of the bottom 1.  
  On the top of the foot 13 there is a leveling lug 23. The lug is integral with the foot and extends outwardly, generally perpendicular to the foot. Similar lugs 24, 25 and 26 are on the feet of the first sections of the respective short sides 8, 9 and 6. The process of forming the leveling lugs includes the punching of apertures, for ex- The top&#39;of the leg 2 ample, theaperture24a in thelug which are tapped in a separate operationlafter the box is ejected from the die press. I  
  12 carries a fastening lug 30 which extends out from the leg l2 and overlaps thefoot 1 4. The lug 30 is spot welded to, the foot 14 in a separate operation. afterthe box isejected from the die press. Similar fastening lugs are on the legs of the first sections of theshort sides as indicated at 31, 32 and 33.  
  The long sides and 5 carry mounting lugs for supporting re :eptacles. Thus, the long side 3 has theJugs 34 and 35 and the long side 5 has the lugs 36 and 37. The lugs are integral with the respective sides and each lug extends inwardly of the box and generally perpendicular to its side. The process of forming themounting lugs includes the punching of apertures, for example, the aperture 34a, which are subsequently tapped. The other lugs have similar apertures. The tapping of the 1ugs34-37 .is preferably accomplished on the machine which taps the leveling lugs 23-26.  
  In situations where the under-floor specifications require floor boxes-of thetype where the receptacle is mounteddirectly on the cover plate, the box&#39; is designed with only a single pair of mounting lugs. Preferably, these lugs are formed on an opposite pair of short sides, for example, lugs can be formed on the short sides 7 and 9. This is illustrated in FIG. 3 where it will be seenthat the foot 14 has a lug 38 which projects out.- wardly from the top edge. A similar lug. is provided on theshortside9.  
  The long sides.2and &#39;4 have large knock-outs 40 and 41 while the long sides 3 and 5 have smaller knock-outs 42 and 43. The bottom 1 hasseveral knock-outs 44 (see FIG. 2). Knock-outs are conventional in shape and are formed in the progressive die. The location of the large knock-outs on the sides 2 and 4 is an important feature. When a large knock-out, say knock-out 40, is struck with a hammer for removal purposes, part of the force will be transferred to the adjoining short sides 6 and 7 through the lugs 30 and 33. The welds in the lugs will be put into compression and this will help to main tain the integrity of the weld. While the welds will be put in tension when the other long sides 3 and 5 are struck to remove the small knock-outs 42 and 43, the required force is much smaller than the force required for the large knock-outs 40 and 41 and so the tension stress on the welds is not objectionable.  
  In FIG. 5 we have shown a layout of the blank for producing the box of FIG. 1. The removal of metal to form the shape shown takes place in the various stages of the die. Also the various lugs are bent in the appropriate direction and the long walls formed upwardly as the strip progresses through the die.  
  In FIG. 5 the dotted lines 45 indicate the original width of the strip from which the box is formed. It will be observed that all parts of the box are confined within the original width. Thus, the strip can be cut to a minimum width and the box formed without any trimming of excess material. For example, if the mounting lugs 34-37 were to be formed on the long sides 2 and 4, the original strip would have to be increased by the length of each lug and a large amount of material removed to form the lugs.  
 We claim:  
 1. A hollow, octagon-shaped floor box comprising:  
 a bottom, four long sides and four short sides each extending up from the bottom to form the hollow box, each two adjacent long sides extending perpendicular to each other with a short side extending therebetween and oriented at an obtuse angle to each long side;  
 each short side comprising first and second sections, the first section being an extension of one of the long sides and the second section being an extension of the other long side, also the first and second sections each being L-shaped and the edge of the leg of the first section abutting the edge of the foot of the second section and the edge of the foot of the first section abutting the edge of the leg of the second section;  
 a leveling lug extending outwardly from the top of said foot;  
 a fastening lug on the top of the first section and extending outwardly therefrom and overlapping the second section and being spot welded thereto;  
 a mounting lug at the top edge of said other long side and extending in to the box and generally perpendicular to the long side; and  
 said bottom, said sides, said leveling, fastening and mounting lugs all being integral and made from pregalvanized metal and formed on a multi-stage progressive die.  
  2. A construction in accordance with claim 1 further including knock-outs on the bottom and knockouts on each of the long sides, the knock-outs on each long side which carries the fastening lugs being larger in diameter than the knockouts on the other long sides.  
 3. A hollow octagon-shaped fioor box comprising:  
 a bottom, four long sides and four short sides each extending up from the bottom to form the hollow box, each two adjacent long sides extending perpendicular to each other with a short side extending therebetween and oriented at an obtuse angle to each long side;-  
 each short side comprising first leg of the second sections, the first section being an extension of one of the long sides and the second section being an extension of the other long side, also the first and second sections each being L-shaped and the edge of the leg of the first section abutting the edge of the foot of the second section and the edge of the foot of the first section abutting the edge of the leg of the second section;  
 a leveling lug extending outwardly from the top of said foot;  
 a fastening lug on the top of the first section and extending outwardly therefrom and overlapping the second section and being spot welded thereto;  
 a mounting lug at the top edge of said second section and extending in to the box and generally perpendicular to the second section; and  
 said bottom, said sides, said leveling, fastening and mounting lugs all being integral and made from pregalvanized metal and formed on a multistage progressive die.  
  4. A construction in accordance with claim 3 further including knock-outs on the bottom and knock-outs on each of the long sides, the knock-outs on each long side which carries the fastening lugs being larger in diame ter than the knock-outs on the other long sides.