US3448883A - Wooden bowl assembly and method of making - Google Patents

Description

' June 10,- 1969 E, BOSWELL 3,448,883

WOODEN BOWL ASSEMBLY AND METHOD OF MAKING- Filed Dec. 28, 1967 Sheet of 2 INVENTOR JAMES E. BOSWELL v A rromvs rs June 10, 1969 Y J. E. BOSWELL 3,448,883 WOODEN BOWL ASSEMBLY AND METHOD OF MAKING Fild Dec. 28. 1967 Sheet 2 of 2 4 luvs/won JAMES E. BOSWELL United States Patent 3,448,883 WOODEN BOWL ASSEMBLY AND METHOD OF MAKING James E. Boswell, Lebanon, M0,, assignor to Independent Stave Company, Inc., Lebanon, Mo., a corporation of Missouri Filed Dec. 28, 1967, Ser. No. 694,276 Int. Cl. B65d 9/04 US. Cl. 217- 5 Claims ABSTRACT OF THE DISCLOSURE The wooden bowl has an annular wall beveled at its bottom and secured to a bottom 'whose peripheral edge is complementarily beveled. The wall is made up of glued together staves whose grain runs in the longitudinally axial direction of the bowl and the angle between the radial rays of the grain and the outside face of each stave averages approximately 45 degrees. The staves are assembled so the radial rays of the grain are mixed. The bottom has a plurality of relatively small pieces glued together. The grain in each piece extends in the longitudinal direction of the bowl and the angle between the radial rays forming the grain and a longitudinal axial extending face of each piece interiorly of the periphery averages approximately 45 degrees. The pieces in the bottom interiorly of the peripheral pieces are shaped as parallelepiped prisms. No piece is big enough to cause a joint or the wood to fail.

In the fabrication of containers from wood such as relatively small salad bowls and the like, use has been made of an integral piece of wood stock and the bowl turned out of the stock. Bowls have been made by gluing together stave pieces to form an annular wall into the lower end of which a solid piece of wood stock has been installed. However, improper orientation of the grain in the stave pieces and otherwise has lead to defects. Defects have occured in these bowls, as when exposed to dry, hot conditions, cracks develop in the side walls. Under humid conditions, cracks also develop between the bottom of the bowl and the bottom of the side wall.

The bowls made according to this invention overcome these problems of cracking, splitting and separation.

It is an object of the invention to make a bowl that will withstand dry and humid conditions without becoming defective.

According to this invention, use is made of a balanced construction in the wood pieces making up the bowl whereby expansion and contraction of the bottom of a wooden bowl is the same as the side wall of the bowl.

The dimensional changes are different with respect to the grain of the wood. Longitudinally or lengthwise with the grain, there is not enough dimensional change to be considered. Tangential dimensional changes, across the radial rays are the greatest. A radial ray is a line from the center of the tree to the bark. Radial changes, parallel to the radial rays, are less. Referring to Table 39 on p. 31 of Wood Handbook No. 72 of the US. Department of Agriculture, table titled Shrinkage Values of Wood, tangential dimensional changes are approximately 41% greater than radial changes.

According to this invention, the radial and tangential grain of the wood in the sides and bottom are mixed in approximately equal quantities of pieces of Wood in tangential position and pieces of wood in radial position. By this method of construction, the average dimensional changes are approximately the same. The maximum size of pieces in the sides and the bottom are limited in order that no individual piece will be large enough to disturb the balance enough to cause a joint or the wood to fail.

Pieces of wood for the staves in the side wall are selected from the machined wood of about 6% to about 8% moisture content with the average angle between the radial rays of the tree showing in the stock and the outside face of the staves being approximately The bottoms of the bowl are of parquetry end grained construction. The bottom is slightly beveled to fit an equally slightly beveled seat in the side walls. This end grain extends in the axial direction of the bowl the same as the axially extending grain in the side staves.

For a more complete understanding of the invention, reference is had in the drawings, the description and the claims. In the drawings:

FIG. 1 is an end view of a log of a tree showing the annular growth rings, radial rays and a rectangular outline of where a longitudinal extending piece is cut from the log as respects a radial ray;

FIG. 2 is a prespective view of an assembly of selected stave pieces of wood forming an annular wall for a bowl with the end of the grain extending an average of 45 and the adjacent pieces are mixed;

FIG. 3 is a perspective view of an assembly of selected pieces of wood of random width with the end of the grain extending an average of 45 and the adjacent pieces mixed, forming a panel to be further assembled into a stack from which bottoms are cut across the grain;

FIG. 4 is an assembled stack of panels as illustrated in FIG. 3 showing the direction of the grain and the parallel spaced apart broken lines where the blanks for the bottom are cut across the grain;

FIG. 5 is a bottom blank cut from the assembly of panels in FIG. 4;

FIG. 6 is a circular bottom as cut from the blank in FIG. 5;

FIG. 7 is an enlarged fragmentary cross sectional view of the bottom (without cross hatching) with a slightly beveled edge but showing the axially extending grain as it appears in the various random width pieces;

FIG. 8 is a fragmentary sectional view on an enlarged 40 scale (without cross hatching but showing grain structure extending axially) showing the annular ring forming the side wall having been beveled at the inside of its lower end to receive the like beveled edge bottom;

FIG. 9 is a fragmentary sectional view on an enlarged scale similar to FIG. 8 showing the bottom glued into place in the bottom end of the annular wall and the wall protruding beyond the bottom;

FIG. 10 is a view like FIG. 9 with the staves of the annular wall having been cut oif even with the bottom and any excess glue removed;

FIG. 11 is a cross sectional view (without cross hatching) showing how the outside of the annular wall of the bowl assembly has been shaped;

FIG. 12 is a cross sectional view like that in FIG. 11 but showing grain structure having had the bottom planed ofl a small amount and the inside of the annular wall and bottom turned to shape; and

FIG. 13 is a top plan view of the bowl in FIG. 12.

Throughout the description, like reference numbers refer to similar parts.

In FIG. 1 a typical end cut of a log is shown at 10 having the annular growth rings 11 and radial rays 12. In the cutting of the pieces of wood such as 13 for the bowl, a cut is made from the log so that on the average there is an average acute angle of about 45 between the radial ray 12 and a face of the piece of wood 13. Thus, the ends of the grain show up as indicated throughout the various figures of the drawing. Rather than show the sectional hatching for wood in the drawings, an attempt is made to illustrate how the grain actually appears in the selection of the pieces in the wall and the bottom. This better illustrates how the mixing of the pieces occurs.

The pieces 13 are machined and a selection is made from machined wood of about 6% to about 8.% moisture content for forming the staves 14 of annular wall 15. These staves are cut the same width and alternated as to direction of grain end g showing, see FIG. 2, and glued together. The grain extends axially of the wall 15 of the bowl being assembled.

In forming the parquetry bottom shown in FIG. 6, pieces are out such as 16 of random width in the manner of piece 13 in FIG. 1. These pieces are not over 1 thick, see at t in FIG. 3. They are then glued together edge to edge to form a panel 17 as shown in FIG. 3. The length L of the panels 17 may be of a sufficient manageable length. The width W of the panels 17 is approximately the size of the blank, see FIG. 5, from which the bottom is to be cut, see FIG. 6.

The panels 17 are planed on both flat sides to no more than thickness. The planed panels 17 are then glued together flat side to flat side to form the stack 18 to attain the size of the blank, see FIG. 5, from which the bottom is to be cut. In FIG. 4 the stack 18 of panels 17 shows the end of the longitudinal grain. The bottom pieces or blanks 19 are cut off of the stack 18. The broken lines 19:: represent the lines on which cuts are made for the bottom blanks 19. These bottoms 19 are cut so as to be thick. The faces of these square blank bottoms 19 show the end grain of the wood in a parquetry effect.

The blank 19 is placed in a jig, and one face is planed so that the blank is /8 thick.

The assembled side rings 15 and the bottom blanks 19 after planing to /8" thick are stored with air space therearound for three days to allow the pieces to attain uniform moisture content before milling.

The bottom blank 19 is now cut round on a routing machine so as to form the round bottom indicated as 1911 in FIG. 6. It is cut with a bevel edge slanting inward from bottom to top as shown in FIG. 7 where a fragmentary enlarged section of the round bottom 19b is illustrated.

Using the same router cutter, there is milled a seat of the same diameter as the round bottom 19b in the bottom end of the side ring 15, a fragmentary enlargement of which is shown in FIG. 8. The bottom 19b will fit into the beveled bottom end of the side ring with a fit within or --.002".

After the bottom 19b and the side ring 15 are milled, they are glued together, see at 20 in FIG. 9, with the application of two pounds of pressure applied to the bottom of a 10" diameter bowl, for example.

Just as soon as the glue 20, see FIG. 9, has set, the

- rough bowl so far assembled is dipped into a quick drying moisture retardant or repellant. This is important since wood absorbs or loses moisture much faster through the ends than through the sides.

The outside of the fiat bottom as indicated at 21 in FIG. 10 is sanded to remove excess glue and to even the ends of the staves 14 in the side wall 15 with the bottom 1%.

The sanded bottom 21 is now sealed with a suitable sealer to close the pores so that the bottom may be held in a vacuum chuck on a modified shaping lathe.

The outside of the bowl, designated 22, see FIG. 11, has its outside wall turned down from the broken line outline indication of original shape to the full line outline at 23. It will be noted at 24, see FIG. 11, at the juncture of the side wall 15 with the bottom 1% that a relatively small width of the staves 14 is left for further finishing of the bottom as shown in FIG. 12.

The inside of the assembled bowl 22, see FIG. 12, is now milled to shape from the broken line showing to the full line showing according to a pattern so that the inside wall is now indicated at 15a and the inside of the bottom is indicated at 19c.

The inside and outside of the bowl is now rough sanded by using coated abrasives on a pneumatic drum while rotating the bowl on a spinning lathe.

After this rough sanding inside and out, the bowl is inspected for any flaws and is patched as necessary.

Following any patching, the bowl is finish sanded as with fine grit coated abrasive belts on special built machines.

The final polish is with steel wool while the bowl is spun at relatively high speed. Following this, the bottom having been chucked, is fine sanded. The bowl is inspected and dipped in moisture retardant. Further finishing of the bowl consists of various steps of filling, sealing, top coating, rubbing and waxing.

There has been provided a bowl by these steps that has a balanced construction in the wood pieces making up the bowl whereby expansion and contraction of its bottom is the same as its side wall. In this construction, the radial and tangential grain of the wood in the sides and bottom are mixed in approximately equal quantities of pieces of wood in tangential position and radial position. Thus, the average dimensional changes are approximately the same. A bowl by this construction will withstand dry, hot conditions and humid conditions without having cracks develop between the bottom and the bottom of the side wall.

What is claimed is: 1. A wooden bowl comprising, in combination, a generally annular wall and a bottom, said bottom having its peripheral edge beveled at approximately a 10 degree angle inward from its bottom to its top, said annular wall bottom end being complementarily beveled to receive the bottom, said bottom being fixed to the annular wall by gluing, said wall having a plurality of stave pieces fitted and secured in abutting relation by gluing and extending in the longitudinal axial direction of the bowl from top to bottom, each of said staves having the grain running in the longitudinal axial direction and having the angle between the radial rays of the grain and the outside face of the staves averaging approximately 45 degrees, said staves being assembled so that adjacent staves have said radial rays of the grain mixed, said bottom comprising a plurality of relatively small pieces edge glued to each other, the grain in each piece running in the longitudinal axial direction of the bowl and the angle between the radial rays forming the grain and a longitudinal axially extending face of each of the pieces interiorly of the beveled peripheral edge of the bottom averaging approximately 45 degrees, said interior pieces of the bottom having a parallelepiped prism shape, wherein the radial and tangential grain of the wood in the wall and the bottom are mixed in approximately equal quantities of pieces of wood in tangential and radial positions whereby the average dimensional changes caused by exterior conditions are approximately the same and wherein the maximum size of pieces in the wall and bottom are limited in order that no individual piece will be large enough to disturb the balance enough to cause a joint or the wood to fail.

2. A wooden bowl according to claim 1 wherein said parallelepiped shaped prism pieces have rectangular faces.

3. A method of making a wooden bowl having an annular wall made of staves secured together and a bottom secured to the lower end of the annular wall, comprising, the steps of:

selecting pieces for the staves from machined wood of 6% to 8% moisture content with the average angle between the radial rays of the grain and the outside face of the piece averaging approximately 45,

edge gluing the selected staves into an annular ring so that adjacent staves have said radial rays of the grain mixed,

edge gluing elongated pieces of wood into panels whose width is approximately the size of a blank from which a bottom will be cut, said elongated pieces having the grain running longitudinally thereof with the angle between the radial rays of the grain and the adjacent face of each piece averaging approximately 45 degrees, said elongated pieces being assembled side by side so that adjacent pieces have said radial rays of the grain mixed,

planing the glued together panel on both sides,

gluing together the panels flat side to flat side with the grain running in the same direction to a width approximating the width of said bottom blank,

cutting a blank for the bottom from one end of said panel assembly by cutting across the grain thereby exposing same in a parquetry effect,

planing said bottom blank on both sides,

equalize the moisture content of the annular wall and said bottom blank,

cutting a circular bottom from said bottom blank with an approximate 10 degree bevel on its lperiphery sloping inwardly from the bottom .to the top surface thereof,

milling a seat in the bottom end of said annular wall that is of a size complementary to the bottom and gluing the circular bottom therein.

4. A method of making a wooden bowl according to claim 3 including treating the assembled annular ring and bottom with a quick drying moisture retardant after setting of the bottom gluing to the annular Wall:

finishing the outside of bottom flat to remove excess glue and to even the ends of the staves with the bottom,

shaping the outside of the annular wall and the inside of this wall and bottom,

finishing the bowl by sanding and polishing, and

applying a moisture retardant.

5. A method of making a wooden bowl according to claim 4 including the steps of filling, sealing, top coating, rubbing and Waxing.

References Cited UNITED STATES PATENTS RAPHAEL H. SCHWARTZ, Primary Examiner.

US. Cl. X.R.

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