BACKGROUND AND SUMMARY
This invention relates to chairs, and, more particularly, to a chair formed or corrugated fiber board, solid fiber board, or the like.
Articles made of fiber board or the like are usually relatively inexpensive and also extremely lightweight. However, such material is generally not used for making articles which require strength and durability such as chairs or similar articles of furniture.
A chair formed in accordance with this invention possesses the desirable features of other articles made of fiber board, for example, economy and lightness, while at the same time providing a very sturdy and durable construction. The chair is formed from three blanks of the sheet material which are folded and interconnected in such a way as to provide an enclosed structure which can perform satisfactorily under even the most extreme conditions. The three blanks of sheet material and the reinforcing or supporting ribs can be quickly interconnected to form the chair, and when the chair is not to be used for a period of time, the various parts of the chair can be readily disconnected and folded to a lay-flat condition for storing.
DESCRIPTION OF THE DRAWING
The invention will be explained in conjunction with an illustrative embodiment shown in the accompanying drawing, in which
FIG. 1 is a perspective view of a chair formed in accordance with the invention;
FIG. 2 is a front elevational view of the chair;
FIG. 3 is a side sectional view of the chair taken along the line 3--3 of FIG. 1;
FIG. 4 is a top plan view of the chair;
FIG. 5 is a bottom plan view of the chair;
FIG. 6 is an exploded perspective view of the chair illustrating the various components thereof;
FIG. 7 is a view similar to FIG. 6 showing the chair in the process of being assembled;
FIG. 8 is a view similar to FIGS. 6 and 7, with a portion of the front of the chair broken away, showing a further step in the assembly operation;
FIG. 9 is a view showing a further step in the assembly of the chair;
FIG. 10 is a side elevational view of one of the reinforcing ribs;
FIG. 11 is a top plan view of the blank of sheet material for forming a portion of the seat of the chair;
FIG. 12 is a top plan view of another of the blanks of sheet material for forming the chair;
FIG. 13 is a top plan view of the third blank of sheet material for forming the chair;
FIG. 14 is a sectional view taken along the line 14--14 of FIG. 8;
FIG. 15 is an enlarged fragmentary perspective view of a portion of the blank shown in FIG. 13;
FIG. 16 is a view showing the folding of the portion of the blank shown in FIG. 15;
FIG. 17 is a view similar to FIG. 16 showing the complete fold;
FIG. 18 is a side view taken along the line 18--18 of FIG. 17;
FIG. 19 is an enlarged top plan view of the fold line shown in FIG. 15;
FIG. 20 is an end elevational view of the perforating and scoring die for forming the fold lines shown in FIG. 19;
FIG. 21 is a side elevational view of the perforating and scoring die;
FIG. 22 is a top plan view of one of the braces formed from a blank of sheet material; and
FIG. 23 is a sectional view of a corrugated fiber board
DESCRIPTION OF SPECIFIC EMBODIMENTS
Referring now to FIGS. 1-5, the numeral 25 designates generally a chair formed of corrugated fiber board which is seen to include a generally box-like base portion 26, a back portion 27, and a seat portion 28. Although the particular chair 25 illustrated is formed of corrugated fiber board, the chair can be formed of other solid fiber board or similar material.
The base portion 26 includes a front wall 29, opposite side walls 30 and 31, and a bottom wall 32. The front and bottom walls 29 and 32, respectively, are seen to be generally rectangular, while the side walls 30 and 31 are generally L-shaped, the side wall 30 including a generally horizontally extending base side wall portion 30a and an upwardly extending rearward portion 30b. The side wall 31 is similarly shaped. The back portion 27 includes a generally rectangular back-supporting wall or panel 33, and a generally rectangular rear wall 34 which are connected by a top connecting strip 35.
Four fore-and-aft reinforcing or supporting ribs 36 extend from the front wall 29 to the rear wall 34 and are supported by the bottom wall 32. The ribs are generally parallel and are spaced-apart in the transverse direction. Each rib has a shape similar to that of the side walls 30 and 31 and includes a generally horizontally extending seat-supporting portion 36a which engages and supports the lower surface of the seat panel 28 and an upwardly extending back-supporting portion 36b which supports the lower or inward surface of the back panel 33.
Three reinforcing braces 37 extend transversely between the ribs 36, two braces tying together the seat-supporting portions 36a and one brace tying together the back-supporting portion 36b.
The chair 25 is formed from blanks which are stamped from sheets of fiber board and then provided with fold lines to define various panels. A blank designated generally by the numeral 39 for forming the base portion 26 and part of the seat portion 28 is shown in FIG. 12. A central panel 29 which will provide the front wall of the chair is defined by the top and bottom fold lines 40 and 41, respectively, and side fold lines 42 and 43. Side wall panel 30 extends from the right side of panel 29 as viewed in FIG. 12, and side wall panel 31 extends from the left side. The side wall panel 30 includes a rear edge portion 44 which is defined by fold line 45 and which is provided with a pair of vertically spaced vertically extending slots 46 and 47. A flap 48 defined by fold line 49 extends from the rearward portion 30b of the panel 30. The panel 30 is further provided with a slot 50 adjacent the intersection of the fold line 49 which will define the front edge of the rearward portion 30b of the side wall and the edge 51 which defines the upper edge of the base portion 30a of the side wall.
The side wall panel 31 is similarly formed, including a rear edge portion 52 defined by fold line 53 and having slots 54 and 55, and a flap 56 provided with tabs 57 for insertion into slots 58 provided in the flap 48. A slot 59 is provided at the intersection of the fold line 60 and the top edge 61 of the panel.
A bottom wall flap 62 extends downwardly from the bottom edge of the side wall panel 30 and is defined by fold line 63. The bottom wall flap 62 cooperates with bottom wall flap 64 which extends from the side wall panel 31 to form the bottom wall 32 of the chair, each bottom wall flap extending for about one-half of the transverse dimension of the chair. The bottom wall flap 64 is separated from the side wall panel 31 by fold line 65, and each of the flaps 62 and 64 are provided with a pair of tabs 66a and 66b, and 67a and 67b, and a pair of central flap portions 68 and 69, respectively.
A bottom wall flap 70 extends downwardly from the central panel 29 and includes a first portion 70a which is joined to the central panel 29 by the fold line 41 and an end portion 70b which is defined by fold line 71 and which includes four slots 72 for receiving the reinforcing ribs. The central portion of the flap portion 70a is provided with a slot 73 which will receive the tabs 66 and 68 when the chair is assembled.
A seat panel 75 extends upwardly from the top fold line 40 of the central panel 29, and a pair of side flaps 76 and 77 extend outwardly from the seat panel 75 and are defined by fold lines 78 and 79, respectively. An end flap 80 defined by fold line 80a extends from the upper side of the seat panel 75, and is provided with four slots 81 for receiving the reinforcing ribs.
A second blank 82 for forming the back portion of the chair is shown in FIG. 13. The blank 82 includes generally rectangular back-supporting panel 33, generally rectangular back wall panel 34, and top connecting panel 35 which is separated from the panels 33 and 34 by fold lines 35a and 35b. Panel 33 includes a pair of edge portions 83 and 84 defined by fold lines 85 and 86, respectively, and a back-locking flap 87 defined by fold line 88. Four slots 89 extend transversely across the fold line 88.
The back wall panel 34 also includes edge portions 90 and 91 which are defined by fold lines 92 and 93, and each of the edge portions is cut to provide a pair of tabs which can be folded away from the remainder of the edge portion. Edge portion 90 includes tabs 94 and 95, and edge portion 91 includes tabs 96 and 97.
An end flap 98 extends from what will be the bottom edge or fold line 99 of the panel 34, and includes a first flap portion 98a and an end flap portion 98b which are separated by fold line 98c. The flap portion 98b is provided with four slots 100 for receiving the reinforcing ribs, and the flap portion 98a is provided with a central slot 101 for receiving the rearward tabs 66b and 67b on the bottom wall flaps 62 and 64 of the blank 39.
The top connecting panel 35 between the panels 33 and 34 includes a pair of end flaps 102 and 103 defined by fold lines 104 and 105, respectively.
Referring now to FIG. 11, a blank 108 of sheet material includes a generally rectangular seat panel 109 which is defined by top and bottom fold lines 110 and 111 and side fold lines 112 and 113. Flap 114 extends from the upper fold line 110 and is provided with four slots 115 for receiving the four reinforcing ribs, and a similar flap 116 extends from the bottom fold line 111 and is provided with slots 117. Side flaps 118 and 119 extend from opposite sides of the seat panel 109.
The generally L-shaped nature of the reinforcing ribs 36 is seen in FIG. 10, and each reinforcing rib includes a generally vertical front edge 120, a horizontal bottom edge 121, a generally vertical back edge 122, a top edge 123, an inclined back-supporting edge 124, and an inclined seat-supporting edge 125. Front and rear slots 126 and 127 extend upwardly from the bottom edge 121 for cooperation with the flaps 70b and 98b respectively. Extending generally vertically downwardly from the seat supporting edge 125 are seat-locking slot 128, brace slots 129, 130, 131 and 132, and extending angularly downwardly is back-locking slot 133. Brace slots 134 and 135 extend rearwardly from the back-supporting edge 124.
The preferred embodiment also includes three braces, each of which is formed from an elongated generally rectangular blank 136 (FIG. 22). A pair of longitudinal fold lines 137 and 138 define panels 139, 140 and 141, and four slots 142 and four slots 143 are provided in the panels 139 and 141, respectively.
The assembly of the chair will be described with reference to FIGS. 6-9. Referring to FIG. 6, each of the panels of the blank 39 are folded about 90° about their respective fold lines to form the structure illustrated in FIG. 6 in which the front panel 29, side panels 30 and 31, and bottom wall flaps 62 and 64 all extend generally at right angles to each other.
The blank 82 may be positioned so that the back wall panel 34 extends generally vertically and the end flap 98 can be positioned above the bottom wall panels 62 and 64. The tabs 66b and 67b on the bottom wall panels are inserted through the slot 101 in the end panel 98, and the end flap portion 98b is folded to extend generally horizontally upwardly.
Similarly, the end flap 70 which extends from the front wall panel 29 is positioned above the bottom wall panels 62 and 64, and the tabs 66a and 67a on the bottom wall panel are inserted through the slot 73. The end panel portion 70b is folded to extend generally horizontally upwardly. The tab pairs 66a and 67a and 66b and 67b cooperate with the slots 73 and 101, respectively, to restrain the associated panels from folding outwardly toward their unfolded condition. The flaps 68 and 69 are also folded upwardly adjacent each other.
The side edge portions 44 and 52 of the side wall panels 30 and 31 are folded about 135° inwardly as are the side edge portions 90 and 91 of the back wall panel 34 and the flaps 102 and 103 on the top connecting panel 35. The tabs 94 and 95 of the edge portion 90 are folded outwardly from the edge portion 90 and inserted in the slots 46 and 47 of the edge portion 44 of the side wall panel 30. Similarly, the tabs 96 and 97 are folded away from the edge portion 91 and inserted in the slots 53 and 54 of the side panel 31 (FIG. 14). The side panels and the back panel 34 are thereby interlocked.
Thereafter, the four reinforcing ribs 36 can be inserted within the assembled side panels and back panel, each of the forward slots 126 of the reinforcing ribs cooperating with one of the slots 72 provided in the upwardly extending end flap portion 70b (FIG. 3) and each of the rearward slots 127 of the rib cooperating with one of the slots 100 in the upwardly extending end flap 98b of the blank 82 to provide interlocking between the ribs and the end flaps.
After the ribs are positioned, seat braces 136a and 136b (FIG. 3) are inserted over the tops of the ribs to tie the ribs together in a firm vertical position. The notches in panels 141a and 142a of brace 136a are interfitted with the notches 129 and 130, respectively, of the ribs, and the notches in panels 141b and 142b of brace 136b cooperate with notches 131 and 132.
After the seat braces are positioned, the side flaps 76 and 77 adjacent the seat panel 75 are folded upwardly as viewed in FIG. 6 about the fold lines 78 and 79, the end flap 80 is folded upwardly about the fold line 80, and the seat panel 75 is folded rearwardly to bring the panels 76 and 77 into engagement with the upper edges of the side wall panels 30 and 31. As the seat panel 75 is folded rearwardly, the slots 81 of the panel 80 are received in the slots 128 of the reinforcing ribs to provide a firm interlock between the seat panel and the ribs.
As will be explained more fully hereinafter, as the panels 76 and 77 are folded about the fold lines 78 and 79, a generally triangularly shaped portion on each side of the fold line is folded inwardly to provide a mitered edge portion at the front of the seat to prevent exposure of the flutes of the fiber board. Referring to FIGS. 6 and 12, fold lines 79a and 79b extend from the fold line 79 generally at about 45° angles, the fold line 79a extending to the upper corner of the front panel 29. Similarly, the fold lines 78a and 78b extend at about 45° from the fold line 78, with fold line 78a extending to the other upper corner of the front panel 29.
After the ribs are positioned, and either before or after the seat braces and seat panel 75 are interlocked with the ribs, back brace 136c (FIG. 3) is inserted, the notches of the panels 141c and 142c cooperating with the notches 134 and 135 of the ribs. Thereafter, the panels 48 and 55 are folded inwardly and locked in place by inserting tabs 57 through the slots 58 (compare FIGS. 7 and 8). The back-supporting panel 33 is then folded forwardly over the tops of the reinforcing ribs while the edge portions 85 and 86 thereof are folded inwardly about 180°. The back-locking flap 87 is folded inwardly about fold line 88, and the panel 33 is locked in place by inserting the slots 89 into the slots 133 of the rib. As the panel 33 is pushed downwardly into the slots 133, the folded back-locking flap 87 passes below the bottom edges of the flaps 48 and 56 and tends to unfold slightly behind the flaps 48 and 56. The panel 33 thereby is locked in place since any upward movement of the panel will be restrained by the engagement between the flap 87 and the flaps 48 and 56.
The chair is completed by inserting the panel 108 in place to form the rearward portion of the seat. Referring to FIGS. 11 and 6, the side flaps 118 and 119 are folded approximately 180° about the fold lines 112 and 113, and the end flaps 114-116 are folded approximately 90° about the fold lines 110 and 111. The seat panel 109 is positioned between the back-supporting panel 33 and the forward seat panel 75, and the slots 115 and 117 of the end panels 114 and 116 are received by the slots 133 and 128, respectively, in the reinforcing ribs. By making the seat portion 28 of the chair out of a pair of seat panels 75 and 109, better strength and structural support is obtained. The downwardly extending flaps 80, 114 and 116 provide good beam strength for the seat and provide good interlocking with the ribs 36. The transverse dimension of each of the flaps 80, 114 and 116 is approximately the same as the inside distance between the side wall panels 30 and 31, and the panels are thereby restrained from folding inwardly toward each other. It will be appreciated that the entire structure is tied together by the ribs, and the interlocking of the various panels and braces with each other and with the ribs provides an extremely sturdy construction.
The various panels of the chair are folded in such a way that the flutes of the fiber board are not exposed, thereby decreasing the likelihood of moisture absorption and increasing the aesthetic appearance of the chair. FIG. 15 illustrates an enlarged fragmentary view of the upper left hand corner of the panel 33 as seen in FIG. 6. As previously explained, the edge portion 84 is folded approximately 180° inwardly along the fold line 86 so that the outer edge of the resultant panel is formed of a folded fiber board sheet with no flutes visible. However, the edge 145, which is positioned adjacent the seat panel 109 would expose some flutes. This is remedied by providing two additional angled fold lines 86a and 86b, which provide generally triangular portions 146 and 147. Each of the fold lines 86a and 86b extend at an angle of about 45° from the fold line 86, and the fold line 86a extends to the intersection of the edge 145 and edge 148 of the panel 33. The edge 148 is positioned so that this edge will extend adjacent the inside of the side panel 31 when the back-supporting panel 33 is properly positioned. Similarly, edge 149 on the other side of the panel 33 extends adjacent the inside of the side wall panel 30.
As the edge portion 84 is folded about the fold line 86, the triangular portions 146 and 147 are folded inwardly about their respective fold lines 86a and 86b as shown in FIG. 16. When the edge portion 84 is folded about 180°, the triangular portions 146 and 147 will overlie each other and will be interposed between the edge portion 84 and the remainder of the back-supporting panel 33. As shown in FIGS. 17 and 18, the fold lines 86a and 86b will overlie each other and provide a neat folded exterior edge which does not expose the flutes of the fiber board.
A similar folded edge is provided by the angled fold lines 85a and 85b adjacent the opposite side of the panel 33.
As discussed hereinbefore with reference to FIG. 12, a portion of the front edge of the seat panel 75 might also have exposed flutes, but this is remedied by the angled fold lines 78a, 78b, 79a and 79b. Referring to FIGS. 12, 9 and 1, as the panel 76 is folded about the fold line 78 to underlie the panel 75, the triangular portions formed by the angled fold lines 78a and 78b are folded inwardly between the panels 75 and 76 to provide an angled folded exterior edge in the finished chair which is formed by the fold lines 78a and 78b. Similarly, as the panel 77 is folded about the fold line 79 to underlie the panel 75, the triangular portions provided by the angled fold lines 79a and 79b are folded inwardly between the panels 75 and 77.
The remaining exterior edges of the chair are all provided by folded portions of the sheet material so that the flutes are not exposed. For example, referring to FIG. 14, one of the rear vertical edges of the chair is provided by the folded edge portion 90 of the back panel in cooperation with the folded edge portion 44 of the side wall panel 30, and the other rear edge is provided by the folded edge portion 91 of the back panel in cooperation with the folded edge portion 52 of the side wall 31. The side edges of the top connecting panel 35 are provided by the fold lines 104 and 105 which permit the triangular end flaps 102 and 103 to be folded inwardly below the panel 35 (FIGS. 7 and 8).
Similarly, each of the other visible exterior edges are folded to present an aesthetically pleasing appearance and to minimize the possibility of seepage or water absorption into the flutes.
Corrugated fiber board sheet material can generally be folded about 90° by providing a simple score line in one of the liners. However, if corrugated fiber board is to be folded through an angle greater than 90°, there is a substantial possibility that one or both of the liners will crack if the fold is made about a simple score line. I have found that the possibility of cracking can be substantially reduced or eliminated if the fold lines for panels which are to be folded through an angle of greater than 90° are provided as shown in FIG. 19, which illustrates a fold line designated generally by the numeral 150 which permits a panel 151 to be folded about a panel 152.
The fold line 150 is provided by a pair of parallel spaced-apart rows 153 and 154 of longitudinally spaced or intermittent perforations or slits which are formed in one of the outer liners of the fiber board sheet material. A pair of spaced-apart score lines 155 and 156 extend between the rows 153 and 154 of slits parallel therewith, and a pair of outer parallel score lines 157 and 158 extend along the outside of the rows 153 and 154, respectively. In one specific embodiment, the slits where about one-eighth inch long, and the spacing between adjacent slits was also about one-eighth inch. The slit rows 153 and 154 were spaced apart about one-fourth inch, and the spacing between the inner score lines 155 and 156 was about one-eighth inch. The score lines 155 and 157 which extend along either side of the slit row 153 were each spaced about one-sixteenth inch from the row 153, and the score lines 156 and 158 which extend along either side of the slit row 154 were also spaced about one-sixteenth inch from the row.
A slitting and scoring die 159 for forming the fold line 150 is shown in FIGS. 20 and 21. A series of slitting knives 160 provided with a sharpened cutting edge 161 are positioned in spaced-apart fashion between a pair of elongated scoring rules 162 and 163, each of which is provided with an outer scoring edge 164 and 165, respectively. Similarly, a series of spaced-apart slitting knives 166 are positioned between a pair of elongated scoring rules 167 and 168 having scoring edges 169 and 170.
The scoring rules 162, 163, 167 and 168 are fixed to a press 171, which can be lowered toward a sheet 172 of fiber board material formed by a pair of spaced-apart exterior liners 173 and 174 which are adhesively bonded to an inner fluted core 175. As the press 171 moves the slitting and scoring knives toward the sheet 172, the slitting knives 161 and 166 perforate the liner 173, and the scoring rules 162, 163, 167 and 168 provide score lines in the liner 173. The depth of the slitting knives 161 and 166 is such that the knife will extend about half-way into the sheet 172, slitting the liner 173 but not reaching the liner 174.
The fold line provided by the slitting and scoring die 159 permits the panels so formed to be folded 180° about the fold line without cracking either of the liners 171 and 172. Each of the fold lines of the blanks 39, 82, 108 about which the associated panels will be folded more than 90° are provided by a slitting and scoring die 159. The blanks can be quickly prepared by positioning a sheet of fiber board below a press that is provided with cutting knives arranged to provide the exterior edge of the blank, scoring rules arranged to provide the fold lines for 90° folds, and slitting and scoring dies for the greater-than-90° folds.
In one specific embodiment of the invention, the corrugated fiber board sheet material for the blanks 39, 82, 108 and 136 and the reinforcing ribs 36 were 270 pound test single wall with B flutes. The flutes in the blank 39 extended from top to bottom as viewed in FIG. 12, the flutes in blank 82 extended from right to left as viewed in FIG. 13, and the flutes in blank 108 extended from top to bottom as viewed in FIG. 11. The flutes in the ribs 36 extended from top to bottom as viewed in FIG. 10.
If desired, the exterior surfaces of the sheet material can be provided with a wood grain print design to enhance the appearance of the chair, and cushions can be placed on the seat portion and against the back portion to enhance the appearance and to add to the comfort of the chair.
While I have found that the two seat braces 136a and 136b and the back brace 136c provide desirable additional structural strength, it will be understood that the chair can be made without these braces.
While in the foregoing specification, a detailed description of a specific embodiment of my invention was set forth for the purpose of illustration, it is to be understood that many of the details hereingiven may be varied considerably by those skilled in the art without departing from the spirit and scope of my invention.