US 745171 A
Description (OCR text may contain errors)
PatentedNovember 24, 1903.
TUVE ESBIORNSN, OF PHILADELPHIA, PENNSYLVANIA.
SPECIFICATION forming part of Letters Patent No. 745,171, dated November 24, 1903.
Application filed August I4, 1902. Serial No. 119,584. (No modeh) v i To all whom t may concern.
Be it known that I, TUVE EsBioRNsoN, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Squares, of
' which the following is a specification.
This invention relates to squares, and has for its object to provide a simple and efficient construction whereby the size of the square may be readily reduced or enlarged as occasion may require. p
lVith this object in view the invention consists in the novel construction and combinations of parts, which will be hereinafter fully described and claimed.
In the drawings, Figure l is an elevation of my improved square. Fig. 2 is a similar view with the extension members removed. Fig. 3 is a sectional detail as on the line 3 of Fig. l. y
1 designates my improved square, compris,- ing the usual long and short arms 2 and 4, respectively, and the extension-pieces 5 5, which form, in effect, a continuation of the arms.
The arms 2 4 and the extension-pieces 5 5 may be constructed of sheet metal or any suitable material.
The arms 2 and 4 are preferably formed of one piece, as shown in the drawings.
The outer ends of the arms 2 4 are provided with dovetail offsets 6 6, the respective sides of which constitute undercut projections, and the extension-pieces 5 5 are `provided with undercut or dovetail projections 7 7, which are adapted to register with the offsets, and thereby securely lock the extension-pieces 5 5 to the arms 2 4.
In order to maintain the extension-pieces 5 5 in line with the arms 2 4 and to maintain the engagement of the dovetail projections 7 7 with their offsets 6 6, I provide slide-blocks 8 8. These slide-blocks are tted to V-shaped ribs 9 on the inner Walls of oppositely-disposed elongated openings l0 10 in the meeting ends of the arms 2 4 and extension-pieces 5 5.
The opening 10 in each extension-piece 5 is sufficiently long to receive its block 8, and thereby permit the withdrawal of the latter from the opening 10 in the opposing arm.
By the above-described construction it will be seen that when the blocks 8 occupy the positions shown in the drawings the extensionpieces 5 5 are rigidly locked to the arms 2 4 in line therewith and that if the blocks 8 S be moved into the openings 10 10 in the eXtension-pieces 5 5 the blocks will be disengaged from the openings lO l0 in the arms 2 4, whereupon the extension-pieces may be readily removed from the square.
I claiml. A square comprising a pair of integral arms arranged at right angles'to each other, an extension member, an undercut projection and an undercut offset at the meeting ends of said member and one of said arms; said pro-l jection being adapted to register with said offset to retain said extension member in engagement with one of said arms, said arms, extension member and projection being all of the same thickness and said offset extending from face to face of the square; and means for detachably maintaining said projection within said offset. v
2. A square comprising a pair ofV integral arms arranged at right angles to each other, an extension member, an undercut projection and an undercut offset at the meeting ends of said member and one of said arms; said projection being adapted to register with said offset to retain said extension member in engagement with one of said arms, said arms, extension member and projection being all of the same thickness and said offset extending from face to face of the square; oppositelydisposed openings in the meeting ends of said member and Vone of said arms, and a slideblock fitted to said openings so as to be slid' ingly retained within the latter, one of said openings being sufliciently long to permit the withdrawal of said block from the opposite opening.
In testimony whereof I afliX my signature in presence of two witnesses.
ROBERT K. PERKINS, ANDREW V. GROUPE.