US 3887101 A
Description (OCR text may contain errors)
United States Patent Adachi June 3, 1975  SPEAKER BOX CABINET AND METHOD OF 2222,23 13:: glmendlorf IX 22 l awten eimer 1 MANUFACTURING THE SAME 2,274,765 3/1942 Zalkind................. 220/62 X  Inventor: I-Iisao Adachi, Fukuroi, Japan 3,437,392 4/1969 Hilfinger 312/330 SM  Assignee: Pioneer Elec'ronic Corporation, 3,539,425 11/1970 Marbury 312/330 SM Tokyo, Japan 22 F} d: 73 Primary Examiner-John Petrakes l 1 16 June u 19 Attorney, Agent, or Firm--Sughrue, Rothwell, Mion,  Appl. No.: 368,930 Zinn and Macpeak  Foreign Application Priority Data June 10. 1972 Japan 47-68465[U]  ABSTRACT I A speaker box cabinet is formed of laminated sheet  3 217/65 material wherein a thin outer flexible film is supported [51} l t Cl ,6 312/330 SM by a thick backing layer and the laminated sheet is  d A47! bent at plural locations about thin lines defined by g g fg rxg'z g deep V-grooves which extend through the backing l 1 g 330 layer to the flexible film, and the cabinet is character- I 248 ized by employing additional shallow grooves within the backing layer not reaching the film layer to cor-  Reerences Cited rect for camber of the laminated sheet.
UNITED STATES PATENTS .157.794 5 1939 MacDonald et al. 156/211 4 Claims, 2 Drawing Figures SPEAKER BOX CABINET AND METHOD OF MANUFACTURING THE SAME BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to improvements in the manufacture of a speaker box cabinet or the like and, more particularly, to such cabinets which are formed by bending sheet material along lines defined by spaced parallel grooves on the inner surface of the sheet material forming the cabinet walls.
2. Description of the Prior Art It is conventional to provide plural, spaced V-grooves at proper intervals within the inner surface of laminated sheet material and the forming of a rectangular box or cabinet by bending the sheet material along lines defined by the grooves and thereby complete a rectangular enclosure having opposed side walls and opposed top and bottom walls. Where the sheet material is laminated and consists of a thin film flexible outer layer and a relatively thick sheet material backing layer adhesively bonded to each other, the process of cutting V- shaped grooves in spaced parallel fashion transversely of the longitudinal axis of the sheet material prior to bending the sheet material inwardly, that is, in the direction of the grooved surface is difficult because of the high accuracy that is required in cutting the grooves on a laminated sheet opposite the flexible film side. If the depth of the V-shaped grooves is shallower than that required, it is impossible to bend the laminated sheet at the V-grooves or the bent edges are not rectangular but are circular. If the depth of the V-grooves exceeds the correct dimension, the flexible film or outer layer is also cut with the result that the side walls or plates of the cabinet become separated.
An accuracy of one-hundredth is required to correctly position the laminated sheet relative to the rotary cutters when cutting the V-groove within the relatively thick sheet material backing layer. In such circumstances, there is a slight camber or twist to the laminated sheet, often part of the flexible film or outer layer is inadvertently cut and problems arise.
This invention contemplates the elimination of the aforementioned disadvantages of a conventional speaker box cabinet formed of laminated sheet material and to provide an improved speaker box cabinet insuring that the thin film outer layer remains uncut during the grooving of the inner, relatively thick backing layer to facilitate folding of the sheet into rectangular cabinet form.
It is an object of the present invention to provide such a speaker box cabinet in which the thin film outer layer is unsevered during grooving regardless of initial camber or twist of the laminated sheet which forms the cabinet walls.
According to one aspect of the present invention. there is provided a speaker box cabinet or the like in which plural longitudinally spaced V-grooves are formed at proper intervals within the thick sheet material backing layer of a laminated sheet having a thin flexible film outer layer and wherein the cabinet is formed by bending the laminated sheet at the V- grooves towards the side carrying the V-grooves and the improvement resides in providing at least one shallow groove within the inner backing layer prior to forming the parallel V-groove along a line which intersects the line of cut of the deep V-groove to correct for camber of the sheet.
These and other objects, features and advantages of the present invention will become more fully apparent from the following description taken in conjunction with the accompanying drawings:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a laminated sheet carrying deep and shallow V-grooves for the construction of a speaker box cabinet or the like by means of the present invention.
FIG. 2 is a top, oblique perspective view of the cabinet formed by bending the sheet of FIG. 1 at the deep grooves.
DESCRIPTION OF THE PREFERRED EMBODIMENT A laminated sheet indicated generally at 10 comprises a flexible, thin film layer 1 on the outside of a relatively thick sheet material backing layer 2, the sheet being generally of elongated rectangular form, and when folded inwardly upon itself at longitudinally spaced parallel deep grooves 5 forms a generally rectangular open cabinet 12, FIG. 2. In the present invention, prior to forming the relatively deep, spaced parallel grooves 5 which extend completely through the backing layer 2 and terminating at the thin film layer 1, one or more longitudinal grooves 4 of a depth of from one-half to one-third the thickness of the backing layer 2 are formed within the backing layer and preferably along a line parallel to the longitudinal edge 3 of the laminated sheet 10. Thereafter, the V-grooves 5 are formed within the same backing layer 2 at right angles to the thin groove 4. Under this arrangement, even if there is camber within the laminated sheet 10 prior to grooving, the existence of the shallow groove 4 tends to correct the camber and permit the laminated sheet 10 to lie flat during the subsequent grooving of the laminated sheet 10 at right angles to the longitudinal axis and the shallow groove as at 5 which grooves of course extend completely through the relatively thick sheet material backing layer 2 and accordingly, the accidental cutting of the thin film layer I is almost eliminated by the arrangement of the present invention.
Referring further to FIG. 2, the rectangular cabinet is formed by bending the laminated sheet 10 with the V-grooves internal and at the fold lines defined by the deep V-grooves 5.
A baffle mounted with a speaker, and a rear cover, are in turn mounted to the front and rear faces thereof respectively to form an enclosed speaker box.
It should be evident from the foregoing description that in terms of the present invention, even if the sheet has some camber or twist prior to grooving, the initial provision of the longitudinally extending shallow groove 4 within the backing layer 2 prevents the film layer 1 from being cut to improve the yield of the product.
While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
What is claimed is:
l. in a speaker box cabinet or the like formed be bending a laminated sheet comprising a thin film outer layer bonded to a thick inner backing layer along spaced parallel deep bend grooves extending through the inner backing layer to the outer film layer, the improvement wherein: at least one shallow groove extends longitudinally of said laminated sheet within said inner layer to correct for camber of said sheet prior to forming said deep bend grooves and bending the sheet at said deep grooves, with said deep bend grooves extending uniformly throughout their length, completely through said thick inner layer but not into said thin film outer layer.
2. The speaker box cabinet as claimed in claim 1, wherein said deep V-grooves are perpendicular to the longitudinal direction of said cabinet and to said at least one shallow groove.
3. The speaker box cabinet as claimed in claim 1, wherein said at least one shallow groove extends to a depth of from one-half to one-third the thickness of said backing layer.
4. In the manufacture ofa speaker box cabinet or the like by folding a laminated sheet consisting of a thin film layer and a relatively thick sheet material inner backing layer and wherein said laminated sheet is transversely grooved through said backing layer to said thin film layer at longitudinally spaced positions and then bent inwardly about itself to define a rectangular cabinet, the improvement comprising:
grooving said backing layer longitudinally to a depth of from one-half to one-third the thickness of said backing layer to correct for camber of the laminated sheet prior to grooving of said laminated sheet transversely;
whereby, the longitudinal grooving of the backing layer to remove the camber of the laminated sheet insures that the transverse grooves extend uniformly throughout their length completely through said thick inner layer but not into said thin film outer layer.