US458441A - Square for rafter and stair work - Google Patents

Description

l (No Model.) 28heets--Sheet 1.

w. H. BAST. SQUARE FOR HAPTER AND STAIR WGRK. 110.458.441. Patented 411g 05, 1891.

2 Sheets-Sheet' 2.

(No Model.)

W. H. BAST. SQUARE PoR RAPTRR AND STAIR WORK.

No. 458,441. Patented Aug. 25, 1891.

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UNITED STATES PATENT OFFICE.

IVILLIAM H. BAST, OF OLINDA, CALIFORNIA.

SQUARE FOR RAFTER AND STAIR'VWORK.

SPECIFICATION forming part of Letters Patent No. 458,441, dated August 25, 1891.

Application filed February 28, 1891. Serial No. 383,272. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM H. EAST, of Olinda, in the county of Shasta and State of California, haveinvented certain new and useful Improvements in Trigonometrical Squares and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon,which form part of this specication, in Which- Figure lis a top view of my improved trigonometrical square for use in cutting rafters, trusses, and stair-beams, one part of the stock being removed. Fig. 2 is a View of the reverse side thereof. Fig; 3 is a View illustrating the'instrument as used for marking rafters. Fig. 4 is a similar View thereof as used for a stair-pattern. Fig. 5 shows it adj usted for a common try or T square. Figs. 6, 7, 8, and 9 are details.

This invention is an improved instrument or square for carpenters and architects; and

its object is to provide a tabulated square by which an experienced or inexperienced workman can ascertain at once the length of rafters necessary in constructing a roof over a certain span or width of building and at any pitch desired, and can also quickly set the instrument so as to be able to mark the correct angles by which the heel and point of rafter must be cut. The instrument is also useful for measuring and marking truss-rods, stairpatterns, duc., and can be readily adjusted as a try or T square, or can be separated and used as an L-square or ordinary angle, all of which will be clearly understood from the following description and claims.

Referring to the drawings by letter, A d esignates the stock of the instrument having a narrow longitudinal slot ce', for the play of the angle, as shown.

B B designate metal plates secured to the inner faces of the top and bottom pieces a of the stock, near one end thereof, and in these plates are semicircular grooves Z7 b. (The grooves might be made in the pieces a.)

C designates a metal plate or spring concealed in a recess c in the inner face of one piece a at the opposite end of the stock, and the outer end of this spring is upturned and projects through an opening (Z in the end of the stock, through which opening passes a thumb-screw D, which when screwed down forces the spring toward the opposite piece a..

E designates a right-angled or L square having limbs of equal length, one narrow, the other wide. In the narrow limb is a longitudinal slot e, in which is iitted a slotted plate e', and on opposite sides of the plate are semicircular or quadrant-shaped plates B2132, which engage grooves b, as indicated, and thus accurately hinge or pivot the angle to the stock in such manner that the Wider end of the angle rests in and plays through the slot a in the stock and beneath the spring C,

which is employed .to lock the angle when shifted, being clamped by screw D.

E is a thumb-screw attached to plate B2 and playing through the slot in plate e and Yhaving an enlarged head, so that when it is tightened the plate e is spread and binds in i' slot e, thus locking the quadrants thereto.

lVheu thumb-screw E is loosened, the square can be shifted so as to project the narrow limb through the.st ock, plate e slipping in slot e. plate e is at the outer end of slot e and locked to the square, the square will be properly pivoted on the stock, as indicated in Fig. 1. The semicircular rib and groove causes the square When the square is drawn out until to turn on an exact pivotal or central point j" with less liability to displacement by wear, and also enables thesquare to be quickly disengaged from the stock, as by turning the square entirely backward until the narrow limb is parallel with the stock the rib will be drawn out of the groove. Vhen thus separated the square can be used like au'ordinary L-square. The wide limb of the square has a series of scores G G, starting from points equidistant along its outer edge, but all converge to or radiate from the central point or pivot of the square on the stock, and ou the opposite face of the square are a series of similar scores H H, but made on different angles to scores G. They are numbered from 1 to l2,beginning at the corner of the square andv extending toward the end ofthe wide limb. l

Scores G and H indicate regular and hip pitch. The side of the square bearing scores G is the top side, and on the top face of the stock are marked the words Roman7 and IOO , 'oininv s rinor C is marked"Point-and the J a p z opposite end Heel, to assist in the marking of the rafters.

Turning the instrument over, the opposite face of the stock is marked with longitudinal lines t' c' andby transverse linesl I, which are marked f, die.; also vwords Hip andVal ley rafter at the left-hand end ofthe stock, holding the L-square from you, and the words Elizabethian and Gothic, architecturaly termsfofcorresponding pitches.

Thewidelimb v'of thesquare is divided into' 4a table bymeans of a parallel series of Vlongitudinal linesJ J, which intersect the scores GandH. VAt thevcorner of the square is a division or columnIK, in which are markedI insuccession the widths of roofs or span Aof roofs--sayfrom twelve to thirty-sixfeet Then t in .thespaces between the scores G andH arei `figures indicating the length'of lrafter neces- -sary to be-cut for each rafter, and for lthe- -pitch indicated bythe scores-for instancef for a span of'twcnty-six feet and the pitch to be Athat indicated by score G, No. 4, .they length of rafter indicated is -13.8Sfeet; tfor the pitch indicated by vscore G, No. 12, the lengt-hof vrafter is shown eighteen feet five@ inches,andfor any intermediate pitches the:

length-of rafter-is giveny at once.

above in making t-he jack-rafters.

=On the lower face of the angle or side scored by marks -H is -a line extending radially from the point of connectionvof-square and stock, and-marked Gothic heel. This means the heel for Gothic pitch, which is three-fourths pitch. By using the quadrant connection between the square and stock the .perfectpivoting ofthe square is insured. By having thi-s perfect pivot center a correct hypotenuse is given between the limbs of ithefsquare along the edgeof the stock,which indicates the length of rafter-foot, which Ais equidistant to twelve inches base-line,'and also gives the correct length of cornicebracket, as indicated in Fig. l.

On the opposite side of the instrument, as indicated in Fig. 2, it gives the bevel-pitch, length of hip, and valley rafter for all the corresponding pitches in Fig. l. By my instrument the Workman can ascertain at once, without drafting for any given width of building, however complicated. by wings, 85e., of different widths, the pitch, bevel, and length of rafter, width and length of cornice-bracket, and the exact length and bevel and ends, and length of cornice-bracket of the hip and valley rafters, also the length of jack-rafters. Vhen used as a stair-pattern,as.in Fig. et, the small .arm gives'thertread,the Wide arm the rise.

It the Workman is to frame aroof having a pitch-say of one foot in three, Orione-third- `he adjusts the angle to the score 1G, No. 8.

{Ehenzhelooksnthe spancolu1nn ,of ltiguresnntil he-ndsthenumber corresponding tothe-span of the roof, then, following down .the .longitudinal line on which .such number is placed :to score No. S, ihe finds numbers which indicate the length of regularraften vand if he'wishes to cut jackfrafters he finds whatznumbers aremarked at scoreGNo. 8, in the cut jack-rafters less columnfinding it to be at the inner edge of the ,widevlimb, and subtracts-so muchper foot for the `successive 'j ack-rafters. Turningzthesquare over and lookingat the figures adjoiningthestock inthe division numbered 12 inspan column,

vheinds the length-of corresponding hip and valley rafters for a one-halffpitchroof, and :if -he 'wants the length of Yrafters for one- I 1 third pitch forany width of basegiven infthe Thenarrowlimb of the-square ismar-ked; off Ainto regular'scale .measurements-or divis; ions,4 and in the-'said limb are formed aseries of perforations N N, :through which the? rafters can be longitudinally scored to indi-i` cate-how much of the Vrafter-shall be Ycut out; to form the brackets for eavecornices,.&c.f -Each holefisshown its relation to-lines on the widearm by gures. f

At the inner edge of the wide limb of the? -square is a division O, marked cut jack-2 rafters less, and ineachY-space between the scores kis.given the length in inches that must: be-takeno the rafters t0 every foot-space! between rafters, as indicatedby the numbersi span column he can ascertainit.atronc'efand by shifting thesquare to variouspitches as vrequired-he.can-at once determine inthe-fore- .goingmanner the length of rafters 'andtheir respective -bevels Having `described my invention, what lI claimasnew, andrdesireto secure byfLetters Patent thereon, -is- 1. An instrnmentifor the purposespecified,

`consisting of a-stock'and a squarepi-voted by oneflimbto one end of the stock and having Von its otherlimb a series ofscores made on lines radiating'from the pivot of the square, a `series of parallel lines intersecting the scores, a series of gures in the divisions made by said scores, and lines .for indicating the length of rafters for given spans at Ivarious pitches, substantially asldescribed.

.2. A square for the purpose specified, having lone limb adapted to be pivotally connected to one end ofr a stock. and havingperforations N, and the other limb having radial -scores and parallel division-lines intersecting Athe scores and numbered and figured, substantially as and for the purposespecitied.

The combinationof thestock having a slot and a semicircular channel with a square having a quadranton one limb engagingsaid slot, for the purpose substantially as set forth.

4. The combination of the stock having a IOO IIS

slot and a spring concealed in a recess at one side of the slot and a thumb-screw for operating said spring with a square pivoted by one end to the stock and having its free limb passing through the slot therein and adapted to be bound by said spring, substantially as set forth.

5. The combination of the stock having a longitudinal slot, a spring and actuating thumb-screw in one end, and a semicircular recess at the other end with a square having a quadrant-plate on one limb engaging the recesses in the stock, substantially as specified.

8. The combination of the slotted stock and the square having a longitudinal slot in one arm with a plate iitted in said slot, the quadrants connected thereto and engaging semicircular recesses orgrooves in the stock, and the thumb-screw for binding said plate in the slot, substantially as described.

9. The combination ot the stock and the square having a longitudinal slot in one arm with' the plate in said slot, the quadrants attached to said plate and engaging curved recesses in the stock, and the binding-springs engaging the other arm of the square, substantially as described.

In testimony that I claim the foregoing as my own I aliix my signature in presence of two witnesses.

WILLIAM H. BAST.

Witnesses:

J. H. SUMNER, M. A. WALTEN.

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