US1314007A

US1314007A - Ewinor mcgrueb

Info

Publication number: US1314007A
Authority: US
Publication date: 1919-08-26
Anticipated expiration: 1936-08-26

Description

E. McGRUER.

HOLLOW SPAR, WOODEN TUBE, AND THE LIKE.

APPLICATION FILED MAR. 26. I918.

Patented'Aug. 26,1919.

EWING MOGRUER, 0F LAMBETH, LONDON, ENGLAND.

HOLLOW SPAR, woonrnv TUBE, AND THE LIKE,

A Application filed March 26. 1918. Serial No. 224,861.

T 0 all whom it may concern:

Be it known that I, EWING MoGnunR, a

subject of the King of Great Britain, 'residing at Commercial Wharf, Lambeth, London, England, have invented a new and useful Improvement in Hollow Spars, lVooden Tubes, and the like, of which the following is a specification.

This invention relates to improvements in hollow spars, tubes and like articles of wood, and is especially applicable to bentwood hollow spars as described in the specification of my U. S. Patent No, 1,266,696 of May 21, 1918.

According to the invention shown and described in said patent a board is quartersawed in the direction of the grain and wetted on one side and heated on the other so that the fibers stretch and contract transversely in any ratio up to 40 of their original breadth and so allow the board to be bent on the neutral axis of its transverse section. As described in said patent, a hollow body is constructed consisting of two quarter-sawed boards bent into form and provided with lap joints, the edges of the boards being glued or cemented together at the joints. In such construction the end grain or natural annual grain rings of one board lie toward the opposite hand to that of the other board. In constructing the hollow bodies the boards before being bent are wctted on one side and heated on the other. One method is to place a board on a steam heated mandrel of the shape required and at the same time to apply water to the other side of the board. In this manner the fibers are contracted on the heated side and stretched on the Wetted side.

One object of this invention is to dispense with the use of formers or cores in the manufacture of tapered hollow spars either straight or curved.

According to this invention, the two edges of a board bent around to form a spar or tube are inserted into grooves formed on opposite sides of a strip of wood, the edges being secured in the grooves by glue or the like. If desired the outer projecting pOI'tiOn of the strip may be planed ofl', more especially in the case in which the spar or tube consists of two or more laminae. I

In the manufacture of spars or tubes of large diameter two or more grooved strips are employed and distance pieces are hi Specification of Letters Patent.

Patented Aug. 6, 1919.

sorted between them and secured to the strips. 7

' "In'the accompanying drawings, Figure 1 is a cross section of a grooved strip, the angle between the grooves being determined by the curvature in cross section of the spar to he made; Fig. 2 is a cross section of a hollow spar made with two laminae; Fig. 3 is a cross section of a hollow spar made with two laminae and two grooved strips in which a block is fitted; Fig. 4 is a longitudinal section of a curved-tapered spar having blocks fitted to both ends; Fig. 5 is a cross section of the same at the ends of the layers; and Fig. 6 shows a hollow spar fitted to metal work, such as a gaff-jaw.

lVhen a hollow spar is made of one lamina, a board is bent around and its edges are inserted into the grooves a of a strip Z), as shown in Fig. 1. When it is made of two or more laminae, the inner lamina is first made in likemanner to the hollow spar of one lamina. Referring to Figs. 2 and 3, c is the inner lamina secured to the strip 6, and a second lamina (Z is bent around the first which forms a core. The edges of the second lamina (Z are then glued together. Other laminae may be similarly secured around the second.

In Fig. 3, two strips 6 are employed and a distance piece is used, the ends of which are shaped to receive the strips Z). Such distance pieces are placed at a distance of two or three feet apart within the hollow spar.

Referring to Figs. I and 5, the spar consists of two laminae g and h and a grooved strip 7' to whose ends are secured blocks 70 by which the ends of the hollow spar are closed.

In Fig, 6, the spar consists of two laminae Z and m, two strips n and 0, and a block 7) which acts as a distance piece. q is a metal fitting which is secured to the hollow spar by means of bolts 1- which pass through the block 79.

A hollow spar may conveniently be made by securing a strip at its ends to two blocks which may be secured to arms projecting from the work bench. The edges of a lamina, to which glue has been applied, are inserted into the grooves in the strip, an secured there by straps until the glue is dry.

lVhat I claim is: v

1. The process herein described of forming a hollow body which consists in bending a quarter-sawed. board, to form said hollow body, .seonringgfhe-iends of said board to an interpose'cl wooden strip which pro ects within and also extends outside of said body,

removing the outwardly projecting portion of said strip and then bending :a similar board around the hollow body and securing its ends to each other. i

. 2." The process herewith-described of forming a hollow body, which consists-in bend 1Q ing a board to form said hollow body, se-

G'o'pies'of this patent may be obtained for .ouring the ends of said board to, 5011 interposed grooved wooden strip which projects within and also outside of said body and then removing" the outwardly projecting E I GMOGRUER.