US3010209A - Apparatus for laying out members in a roof truss - Google Patents

Description

Nov. 28, 1961 P. e. McKINLEY 3,010,209

APPARATUS FOR LAYING OUT MEMBERS IN A ROOF "muss Filed Oct. 20, 1958 2 Sheets-Sheet 1 INVENTOR PAUL 6. Mc/(INLEY gaze ygw ATTORNEYS Nov. 28, 1961 P. G. M KINLEY 3,

APPARATUS FOR LAYING OUT MEMBERS IN A ROOF TRUSS Filed Oct. 20, 1958 2 Sheets-Sheet 2 FIG. 8A MENTOR PAUL 6. McK/NLEY BY 6.14% $9M ATTORNEYS United States P t "1 3,010,209 APPARATUS FOR LAYING OUT MEMBERS IN A ROOF TRUSS Paul G. McKinley, Coral Gables, Fla., assignor to Pagebar, Inc., Miami, Fla., a corporation of Florida Filed Oct. 20, 1958, Ser. No. 768,237 1 Claim. (Cl. 33-90) uring, andtrial and error fitting. Even so, unless done 1 with painstaking care, the layingout of trusses in the past has produced uneven joints wherein the various structural members were not in even abutment, thus presenting a truss of diminished strength and sloppy, unworkmanlike appearance. I

It is an object of this invention to provide apparatus whereby given only the desired length of the lower chord member and the desired pitch of the finished roof, a casual handy man, unversed in roofing structure or even the rudiments of trigonometry is capable of quickly laying out the chord and web members of a perfectly fitted truss.

It is a further object of my invention to provide apparatus for laying out the elements of a roof truss, said apparatus making unnecessary the use of protractor, scale or carpenters rule or additional measuring devices of any type.

It is a still further object of my invention to provide apparatus for laying out the various elements of a roof inafter set forth in the specification and claim, and'illus- 1 trated in the accompanying drawings, wherein:

FIG. 1 is a fragmentary side elevation of a roof truss of the type made by templates embodying the invention;

FIG. 2 is a top plan view of a lower chord template embodying the invention;

FIG. 2A is a perspective of a lower chord template embodying the invention and applied to a piece of stock;

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 2A;

FIG. 4 is a top plan view of an upper chord template embodying the invention;

FIG. 4A is a perspective view of a top chord template embodying the invention and applied to a piece of stock;

FIG. 5 is a top plan view of a tension web member template embodying the invention;

FIG. 5A is a perspectiveview of a tension web member template embodying the invention and applied to a piece of stock;

3,010,209 T a e NPY- 9?! FIG. 6 is a top plan view of a compression web member template embodying the invention;

FIG 6A is' a perspective view of a compression Web member template embodying the invention and applied to a piece of stock;- 1 v 7 FIG. 7 is a fragmentary side elevation of a modified roof truss made by templates embodying the invention;

FIG. 8 is a top plan view of a modified tension web member template used to produce the modified truss of FIG. 7; and 7 FIG. 8A is a perspective view of the modified tension web member template shown in FIG. 8 and applied to a piece of stock. 1 Briefly, the invention is a set of templates adapted to be used cooperatively to lay out the various members in a roof truss. Each template has its ends cut ofi the shape. of the ends of its corresponding truss member and bears graduation meansin terms of theknown length of the' lower chord to indicate the length of its corresponding truss member.

More specifically, and referring to the drawings, FIG. 1 is a view of a truss adapted to be laid out by templates embodying the invention. The truss comprises the lower chord 10' and the upper chords 20'. (For simplification, since the truss is symmetrical, reference numerals have been applied to only one-half ofthe structure.) The truss also comprises web members connecting the chords, said web members designated throughout this application for simplification as the tension web member 30' and the compression web member 40. In fabricating a roof truss as shown in FIG. 1, the various chords and web members are joined together and the ends thereof must be appropriately angled olfin order to produce a structure of maximum strength and neatness. More specifically, the ends of the lower chord 10' are angled off to a face a. They flatly abut respectively the undersurfaces of the upper chords and are joined thereto in what is known as a heel joint. The upper end of each of the upper chords 20' is angled ofi in a face b' and abut each other in a peak joint. The-lower end of each of the upper chords is angled off in a face 0' which is substantially vertical and comprises the overhang end.

Each tension web member 30'- has its upper end angled off in a compoundface d so that a portion of the peak joint end of each of the tension web members abuts the opposite tension web memberand a portion abuts the underside, of the upper-chord at thefpeak joint. The lower end of each tension web member is angled oifin a face e to. abut flatly the top surface of. the lower chord 10' where they meet in a web-lower chord joint. Each compression web member 40 has. its lower end angled off in a face g to abut flatly the top surface of the tension web member at the web-lower chord joint, and has its other end angled ofi in a face f to abut flatly the undersurface of the upper chord 20 at the web-upper chord joint. 1 It is often the case in constructing a peaked roof truss that the only known information is the length of the desired lower chord and the desired roof pitch; It is with this information only and templates embodying my invention that a roof truss as shown in FIG. 1 can be easily laid out. 1 a a FIG. 2 shows an embodiment of a template according a 3 i i a to the invention adapted to be used in laying out the lower chord 10'. It is generally designated 10, and as shown in FIG. 3, comprises an extrusion of L-shaped cross-section. The top flange is designated 14 while the side flange is designated 12. The L-shaped construction enables it to flatly engage both the top and side surfaces of a piece of stock (see FIG. 3). For ease in handling, the extrusion is additionally formed with an upwardly extending ridge 16 running the length of the extrusion along the distal edge of the top flange. FIG. 3 is typical of the shape in cross-section of all templates shown in the drawings. i

The lower chord template 10 has the opposite ends of its.top flange cutoff at angle a whereby'the ends can' I chord 20". 1 As shown in FIG. 4A, the side flange 22 of the template 20 is marked with graduations in terms of the known length of the lower chord 10. In other words, 'for a lower chord of length L stock for an upper chord of appropriate length m can be measured by markingoff the stock opposite the reading L on the graduation. Ob-

' viously, as the length of the lower chord of a roof of given vpitch is increased, there is an increase, however not so great, in'the length of the upper chord. Thus, to lay out an upper-chord, a piece of stock is marked ofi using the end b of the template as' a straight edge, and the length ,of the upper chord is indicated by marking on the stock opposite the length L of the lower chord 10' read on the graduations on side 22 of the template. Nextgthetemplate is slid along the stock until end of the template is opposite the mark and the end 0 is used as a straight edge to-mark off the angled cut a for the overhang end face. If it-is desired to have extra overhang in the truss, that extra lengthis added to length m before marking for cut 0'.

FIGS. and 5A show the tension web'member template 30 which has one end cut ofi at the compound angle adapted for laying oil the compound face d. Side flange '32isgraduated off in terms of the known length L of the lower chord and the tension web member length n may be determined therefrom. The opposite end of the top 34 is angled off at' e to be used in laying off the angled face e for'the tension web member at the weblower chord joint.

The compression'web member template 40 is shown in FIGS. 6 and 6A. Its top flange 44 is cut off at f and g toplay out the angled cuts f and g; of the compression 'Frominspection of the drawings it can be-seen that the graduations on template 40 are closer together than .on template 30 andthose on template 30 are closer than thos e on template 20. This is because that for every increase .in the length of the lower chord 10', there is a less increase in the length of upper chord a still less increase in the length of tension web member and an even less increase in the length of compression web member In other words, the ratio of the length of the unit of length in'which the lower chord element is fmeasured (usually a foot) to the'length of the unit of length in which the graduations along a given-template is measured is equal respectively to the ratio of the length V lower chord 'on' the graduations on side 42. of the com- 7 V pression web member template.

the claimed invention. I claim:

chord member made from stock of greater height or vertical thickness than that shown in FIG. 1. For instance, instead of 2 x 4, a 2 X 6 inch stock may be desired. This will require decrease in the length of the web members 30 and 40' necessary to come down to meet the upper surface of the lower chord. To allow for this modification in a truss, the tension web member template 30 has its side undercut as at 38. Thus, when laying out the tension web member of the modified truss, the edge d of the template 30 is used to layoff the end d and a line is drawn down the front of the stock to indicate where the stock is to be cut oflf. The template is then moved leftward so that the undercut edge 38 is opposite this line on the front of the stock. The length L of the lower chord member is then read on. the side of the tension web member template and a mark made opposite. The line for the end e of the web member is made at that mark. Thus the shortening ofthe length'n by the distance of the undercut 38 will shorten the tension web member the desired amount for use with a 2 x 6 lower chord.

For laying out thecompression web member in the modified truss, having a thicker lower chord, the compression web member template has its side- 42 similarly undercut as at 48 and is used as the tension web. member template. V

FIG. 7 shows-a modified 'form' of truss inwhich the tension web member 30" has its end cut d' at the peak joint in a single plane rather than in'a'compound face as shown-at d in FIG. 1. For this modified tension web member, the template 30" shown in FIGS. 8 and. 8A has its end beveled OR in a single straight edge d. a

With the set of templates of my invention, aroof truss of a given pitch can .be laid out for any lengthL of the lower chord .10. For'making roofs of different pitches, diiferent sets of templates made according to this specification maybe used. It should be understood that templates embodying my invention may take various forms and may be used for making trussesother than the simple triangular truss shown. V By using a set of templates embodying my invention, a workman having relatively little skill in root truss making 'is able to lay out quickly and easily' the members of a truss which will abut flatly and be accurately measured to produce a truss of greater strength and neatness than the workman could otherwise produce. Also the workman can be assured of turning out uniform trusses time after time; Through my invention, the guesswork, trial and error and the painstaking time-consuming laying ,out have been taken out of roof truss fabrication.

' While this invention has been shown but in one form, it is obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing 'from the spirit and scope of A template for laying out a selected element fora truss, said truss being of known geometrical configuration and having a lower chord element whose length is measured in a first unit of length and whose thickness may be either of two sizes, said template comprising an elongate member of L-shape in transverse cross-section comprising a top flange and a side flange depending from one longitudinal edge of saidtop flange, the length of said side flange being shortened at one end of said template with its adjacent end edge extending perpendicularly from said one longitudinal edge and spaced inwardly from the adjacent end of said longitudinal edge by a distance which allows for the difference between said two sizes, the opposite ends of said top flange being shaped in the desired outlines respectively of the opposite ends of said element, said side flange having graduations therealong measured from said one end of said template, said graduations being spaced apart by a second unit of length, the ratio of the first unit of length to the second unit-of 6 ifgngt}; being equal to the ratio of the length of the lower References Cited in the file of this patent c or to the length of said selected element in a truss having said known configuration, whereby said end edge UNITED STATES PATENTS Of said side flange and the adjacent end of said iongitu- 22,585 Ripley J an. 11, 1859 dinal edge provide separate indexes for use respectively 5 63, 79 Fearon July 7, 1896 with said two sizes of vertical thickness of the lower 1,125,010 Doner Jan. 12, 1915 chord in laying OH on a piece of stock the length of said 1,255,429 Killion Feb. 5, 1918 selected element using said graduations, in order to mark 1,608,713 Anderson Nov. 30, 1926 in correct positions the shapes of the ends of said element 1,732,906 Morton Oct. 22, 1929 with the ends of said top flange. 10 2,713,203 Gotflieb July 19, 1955

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