US2265402A - Drafting device - Google Patents

Description

Dec. 9, 1941. SCLOCCO 2,265,402

DRAFTING DEVICE Filed March 29, 1941 I 2 Sheets-Sheet 1' Inventor 4M1? Jczocoo Attorney Patented Dec. 9, 1941 UNITED STATES PATENT OFFICE DRAFTING DEVICE Adolph Sclocco, Trenton, N. J.

Application March 29, 1941, Serial No. 385,949

1 Claim.

The present invention relates to new and useful improvements in drafting devices and has for its primary object to provide a protractor attachment for a T-square or similar device.

A further important object of the present invention is to provide a protractor attachment adapted for slidably mounting on the T-square and in which a plurality of rulers are connected in right angular relation and pivotally mounted on the attachment for movement as a unit into various angular positions at one side of the T- square for use with the latter for drafting pur- DOSES.

A further object is to provide an attachment of this character of simple and practical construction, which is efficient and reliable in performance, relatively inexpensive to manufacture and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming part hereof, wherein like numerals refer to like parts throughout, and in which Figure l is a plan view showing the attachment in position on a T-square,

Figure 2 is an edge elevational view,

Figure 3 is a sectional view taken substantially on a line 3-3 of Figure 1,

Figure 4 is an edge elevational view of the outer end of the protractor attachment,

Figure 5 is a perspective view of the pivotal plate for attaching the ruler to the protractor, and

Figure 6 is a perspective view of one of the rulers.

Referring now to the drawings in detail, wherein for the purpose of illustration I have disclosed a preferred embodiment of the invention, the numeral 5 designates a T-square of conventional construction, on the blade of which the protractor attachment designated generally at 6 is adapted for slidable engagement.

The protractor attachment includes a block I having a plate 8 adapted for overlying the upper surface of the blade of the T-square with the block positioned against one edge of the blade and with the bottom of the block being disposed on a common plane with the bottom of the blade, as shown to advantage in Figure 3 of the drawings.

The block 1 projects laterally from one side of the blade of the T-square, and secured to the upper outer surface of the block is a plate 9 secured to the block by screws l and positioned flatwise on the plate 9 is a disk ll having a central opening l2 for pivotally mounting the disk on a pin l3 which projects upwardly through the block I, The under side of the block I is formed with a recess M for receiving the head I5 at the lower end of the pin and the upper end of the pin is threaded as shown at I 6 for threadedly receiving a knurled nut I! for tightening the disk H in position on the plate 9.

An extension I8 projects radially from one edge of the disk H, the extension terminating in a pair of arms l9l9 which are offset below the surface of the disk II, the arms extending in directions at right angles to each other and are secured to the upper surfaces of rulers 20-40 adjacent the inner ends of said ruler.

The outer edge of the block I and plate 9 are coextensive and of rounded formation as shown at 2|, and the upper surface of the plate 9 is formed with graduations 22 with which a pointer 23 cooperates, the pointer projecting radially from one edge of the disk II.

The side edges of the rulers 292ll are preferably bevelled and may also be formed with graduations, and the bottom of said rulers is preferably disposed on ahorizontal plane with the bottom of the block I.

The angular connection between the outer end of the extension l8 and the arms l9 provides a shoulder 24 adapted to bear against the curved edge 2| of the block 1 and plate 9 during the swinging movement of the rulers 20.

From the foregoing it will be apparent that the rulers 20 may be moved into any desired angular position with respect to the T-square for drafting or plotting purposes.

It is believed the details of construction, advantages and manner of use of the attachment will be readily understood from the foregoing without further detailed explanation.

Having thus described the invention, what I claim is:

A drafting attachment for T-squares comprising a block having one edge in slidable engagement with one edge of the blade of the T-square, said block also having an extension overlying the upper surface of the blade, the outer edge of the block being rounded, a plate secured to the upper surface of the block at its rounded edge, a pin carried vertically by the block, a disk pivoted on the pin, a retaining member on the pin adapted to secure the disk against movement, a plurality of arms projecting radially from the disk, an angular connector between the disk and arms and including a vertical portion movable around the rounded edge of the block, rulers attached to the arms and extending longitudinally outwardly thereof, said plate having graduations thereon and a pointer projecting radially from the disk in overlying position with respect to said graduations.

ADOLPH SCLOCCO'.

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