No. 864,011. PATENTED AUG. 20, 1907.

' E. S. MARKS.

FOLDING SQUARE. Abrmommx man in. 1b. 1907.

/2 I INVENTOR struction adapted to lock said members rigidly in their UNITED STATES PATENT QFFIQZE.

AUBURN, NEW

COMPANY, or

FOLDING SQUARE.

Specification of Letters Patent.

Patented Aug. 20, 1907.

Application filed Maroh 18,l907. Serial No. 363,038-

. To all whom it maycon'c'm:

Be it known that 1, Emma S. MARKS, 9,;Cll1l2611 of the United States, residing at Auburn, in the county of Cayuga and State of New York, have invented or dis covered certain new and useful Improvements in Folding Squares, of which the following is a specification,

reference being bad therein to the accompanying drawings.

The present invention relates to folding squares and has for its objejbt to provide a square of economical and practical odhstruction which is adapted to be folded into a comparatively small space in order that the same may be conveniently carried -in the pocket or placedgin a small chest, and which when set for use is as rigigl and accurate as anordinary solid square.

fil?""accomplish this and other objects my invention geinprises two arms or members pivotally connected in such a manner as to permit them to be swung into a position of parallelism, or to be swung apart and set in a position perpendicular to one another, together with a releasable locking device of. new and improved con- 1 set position or at right angles to each other.

adapted, when the arms One construction in which my invention may be embodied is illustrated by the accompanying drawings, in which:

Figure 1 is a view of the square locked in its set or open position. Fig. 2 is a. similar view with the locking device released. Fig. 3 is a view of the square folded, and Fig. 4 is a section taken substantially on the line 4-4, Fig. 1. i

As shown in the drawings, the square comprises two arms or members, 12 and 13, respectively, pivotally connected by means of a web 14 formed upon or attached to the member 12 and adapted to enter a groove 15 formed in the edge of the member 13, and a pivot 16 passing through the member 13 and the web 14. Preferably, also, the member 12 is provided with a tongue 17 adapted to enter the groove 15in the member 13, thus contributing to the lateralstrength, and rigidity of the device as a whole.

{Elle member 12 is provided with a short arc-shaped slot 18 formed concentric with the pivot 16, said slot terminating in an enlarged re or opening 19 providing a locking shoulder or sgoulders 20, 20. ,The member 13 is providedwith afbu ved projection or fingcr 21, also formed concentric with the pivot ,16, and

and 13 are swung toward open or set position, to enter the slot 18 in the member 12. Said projection or finger 21 carrieaat its end a latch 22 mounted on a pivot 23 whose axis is substantially perpendicular 'to the'ax'is of the pivot 16"said 12101122 being of substantially the same size and shape as the recess-19 and being adapted to cooperate with right anglesv to locking ,device to one of the shoulder or shoulders 20 thereof, thereby sccu'seiy to lock the arms or members in their set position.

The projection or finger 21- m'ny be formed integral- With the member 13, but preferably, and as herein shown, this finger is constructed as a separate piece provided with a tongue 24 entering the groove 15 and fastened therein by means o'irivets 25, 25, or equivalent securing devices,

Inasmuch as the axes of the pivots 16 and 23 lie in perpendicular plane s, any force tending to move the arms from their set position will have no effect upon the' latch 22, tending to releas e the same, and the square therefore not liable to be accidentally thrown out of its proper set position. Moreover it will beinoticed that the latch 22 is carried on the end of the finger 21, by pivot whose axis lies in a line substantially intersecting the axis of the pivot 16, so that move the arms upon their pivot 16 will be transmitted to the latch as a direct pull thereon, thus obviating all torsional and other strains tending to twist or otherwise distort the latch. It will furthermore be seen that the locking face of the latch extends across the entire thickness of the member 12 thus providing a very secure and'rigid look, but that, at the; same time, the lock-- ing device lies wholly withinthe outline of the pivoted arms, and its flat surfaces substantiall; flush withithe flat surfaces of the arms. It will thus be apparent that whenthe parts are in their normal. or set position there are absolutely no parts projecting beyond the surface or outline of the square, which therefore combines all the advantages of the ordinary solid square with the conveniences incidental to the best types of folding squares.

While I, in order that my invention may be more readily understood, have herein described the same as embodied in a specific construction, it is obvious that many changes may be made in the construction shown without departing fromthe spirit and scope of myin vention.

, Having thus described my inventiond claim and (h sire to secure by Letters Patent:

1. In a device of the character described, the combination with a pair of arms and a pivot connecting :1 arms, one of said arms having aportion projecting be yond said pivot, of a locking device, and apivot connecting said locking device to said projecting portion, the axis of said-la'st-nnmed pivot being substantially at the axis of said first-named pivot.

2. In a device of the character described, the combination with a pair of arms, and a pivot connecting said arms, of a locking device, and a pivotconnect'lng said said arms, the axis of said-last named pivot being suhstn axq ofi said first-named pivot and lying stantinlly intersecting the same. V

3 In =1 device of the character duscl'ihed, the combinain a line suball forces tending to tion with a pair of arms and a pivot connecting said I i described, the combinaof arms and a pivot connecting said arms, of a locking device having a locking surface operative substantially throughout the thickness of one of ,said arms. and a pivot connecting said locking device to the other of said arms, the axis of said last-named pivot lying in a line substantially intersecting the axis of said first-named pivot. 5. In a device of the character described, the combina; tion with a pair of arms and a pivot connecting said arms. of a locking device adapted, when in operative position, to lie wholly within the outline of said arms, and a pivot connecting said locking device to one of said-arms, the axis of said last-named pivot lying in a line substantially intersecting the axis of said firstnamed pivot.

-6. In a device of the character described, the combina- 7. In a device of the character described, the combination with an arm having an opening communicating with said opening, ally connected to said first-named arm,- a finger carried by said last-named arm and adapted to enter said /slot, and a locking device connected to said finger and'adapted to cooperate with said opening.

therein and a slot In testimony whereof I aifix my signature, in presence of two witnesses. t

' EDWARD. s. MARKS. Witnesses: v

C. M. SWEENEY, M. E. Romiv soiv.

of a second arm pivot