US1294263A - Drafting or measuring instrument. - Google Patents

Description

J. HERMAN.

DRAFTING OR MEASURING INSTRUMENT.

APPLICATION FILED OCT. 24.1918.

Patented Feb. 11, 1919.

llinil DRAFTING OR MEASURING INSTRUMENT.

Specification of Letters Patent.

Patented Feb. 11, 1919.

Application filed October 24, 1918. Serial No. 259,466.

To all wkomit may concern:

Be it known that I, JOHN HERMAN, a citizen of the United States, residing at Easton, in the county of Northampton and State of Pennsylvania, have invented new and useful Improvements in Drafting or Measuring Instruments, of which the following 1s a specification.

This invention relates to urlng lnstruments or tools, and has for an object to provide an improved tool of this character having a plurality. of interchangeable leg extensions whereby said ,tool may I be converted into and used as compasses, dividers, callpers, or other instrument of similar type, said leg extensions and the means for attaching the same being of such a character that one extension or pair ,of extensions may be readily substituted for another, and that said extensions will be securely held in accurate position, these results being accomplished by the use of parts of relatively simple and inexpensive construction.

Another object of the invention is to provide, in an instrument of'the character referred to, improved and simplified means for connecting and operating the parts whereby the instrument may be quickly and conveniently adjusted and the parts thereof steadied and securely held in adjusted position when in use.

' The foregoing and other objects of the invention, together with means whereby the same may be carried into effect, will best be understood from the'follo wing description of one form or embodiment thereof illus trated in the accompanying drawings. It will be understood, however, that the pardrafting or meason the lines 3-3, 4-4, and 5 5, respectively, Fig. 1.

Referring to Fig. 1, the instrument comprises a pair of pivotally connected leg members 10, a pair of leg extensions 11 carried by said leg members, and means, hereinafter described, whereby said leg members'may be relatively adjusted abouttheir pivot and retained in adjusted position.

'As herein shown, the leg members 10 are coaxially pivoted upon opposite sides of a disk or flat cylindrical block12 (Figs. 2 and having opposing projecting alined trunnlons 13 which are received in openings in the hubs 141.- of said leg members, said hubs being retained in, place by suitable means, as by riveting or upsetting the outer ends of said trunnions to form heads 15. Preferably, and as'shown in Fig. 5, the hubs of the respective leg members 10 are oppositely offset to engageopposite faces of the block or disk .12 while bringing said leg members into substantially the same plane.

Adjacent their outer ends the leg members 10 are formed with sockets 16 (see Fig. 4:) and; with openings 17 extending therethrough from the bottoms of the sockets. Loosely received in said sockets are heads 18 having threaded stems 19 of less diameter than the openingsl? and disposed therein,

"said stems being fitted with knurled nuts 20 engaging the opposite faces of the leg members. The heads 18 are provided with transverse perforations to receive the shanks 21 of the leg extensions.

Said leg extensions may be of any suitable or desired form, and preferably a plurality of interchangeable sets are provided for each instrument. In Fig. 1 is shown a pair of extensions 11 of suitable shape to adapt the instrument for use as a pair of internal calipers, while in Fig. 2 is shown in full lines a .pair of extensions 11 constituting external caliper jaws, and in dotted lines extensions 11 adapted to convert the instrument into a pairof dividers. Obviously ex tensions capable of rendering the instrument operative as a pair of draftsmans compasses or as any other drafting or measuring instrument of similar type might be provided.

' The extreme ends of the shanks 21 are bifurcated, as shown at 22, to engage studs 23 carried by the leg members 10 at points spaced from the sockets 16, whereby, when the shanks are passed through theperforationsin the heads 18 and the ends thereof engaged with said studs, said shanks will overlap the leg members and will be accurately positioned with respect thereto, while by tightening the nuts 20 said shanks will be securely clamped in position. It will be noted that the loose mounting of the clamping devices 18, 19in the sockets 16, and particularly the looseness of the stems 19 in the openings 17 permits said clamping devices to adjust themselves to the reoluirements, so that. any variations in workmanship in the several leg extensions of the set is automatically compensated for. It

a will also be observed that the leg extensions may be easily and quickly attached, re-

moved, or interchanged merely by tightening or loosening the nuts 20 and slipping the shanks 21 "into or out of the perforations in the heads 18, the engagement of the bifurcated ends ofsaid shanks serving auto- 'matically to effect the longitudinal as well as the angular positioning of the leg extensions without special attention on the part of the user, so that a change may be made in a minimum length of time and with a minimum amount of trouble or possibility of error.

The disk or block 12 is formed with 2. diametrically disposed threaded opening to receive an adjusting screw24 provided at its outer end with a suitable operating lmob or handle 25. At its inner endthe screw 24 is swiveled in a second disk or block 26 having alined trunnions 27 similar to the trunnions13, and upon which are pivoted the inner ends of toggle links 28 pivoted at their outer ends to the leg members 10. Preferably, and as herein shown, a pair of links 28 is employed to connect the block 26 with each of the leg members, the links of each pair being spaced from one another and pivoted respectively to opposite sides of the leg members and of the block, one link of each pair being mounted on one of the trunnions 27. The construction shown affords a. very simple, inexpensive, and easily operated means whereby the leg members out further description.

For the purpose of steadying the leg members in their adjusted positions there is provided a bow spring 29 which surrounds and incloses the block 26, extends between the links 28 of each pair, and is engaged at its ends in sockets 30 in the inner sides of the leg members 10, said spring serving in a measure to protect and house the adjusting mechanism, and being itself protected against accidental dislodgment by the links 28.

As will be seen the invention provides a very simple, inexpensive, and conveniently operated instrument of the character de scribed, wherein the necessity for extremely fine and accurate workmanship in manufacture, is obviated, which nevertheless is reliable and accurate in use, which by a quick and simple manipulation can be adapted to a variety of purposes, and which possesses many other advantages which will be readily recognized by those skilled in the art. i r

I claim: 7

1. In an instrument of the character. .de-

cooperating positioning means on said leg member and leg extension at the inner end of the latter.

2. In an instrument of the character deand engaged by said clamping means, and

scribed, incombination, a leg member, a leg 7 extension carried by and overlapping said leg member, said leg extension having a bifurcated inner end, meansfor clamping said extension to said member, and a stud on said member engaged by the'bifurcated end of said extension.

3; In an instrument of the character described, incom bination, a leg member having a socket and an opening extending therethrough from the bottom of said socket, a perforated headloosely received in said socket and having a threaded stem ofless' diameter than said opening disposed therein, a nut on said threaded stem beyond said leg extensions each having ashank adapted to be received in the perforation of said head, and cooperating positioning means on said leg member and shanks.

member, a plurality of interchangeable leg 4. In an instrument of the character de- I scribed, in combination, a pair of pivotally connected leg members each having adjacent its outer end a socket and an openin extending therethrough from the bottom 0 said socket, a perforated head loosely re:

ceived in each of said sockets'and having a threaded stem of less diameter than the corresponding opening disposed therein, nuts on said stems beyond said leg members, a

plurality of pairs of interchangeable leg extensions each having a shank adapted to be received in the perforations in said heads, said shanks having bifurcated inner ends, and studs on said leg members spaced from said sockets and engaged by the bifurcated end of said shanks when said leg extensions are in position.

5. In an instrument of the character dearound said second block and between the scribed, in combination, a block, a pair of links of each pair, said spring engaging at leg members pivoted to said block, a second its ends said leg members to steady the same. block, an adjusting screw sWiveled in one In testimony whereof I have hereunto set of said blocks and in threaded engagement my hand in presence of two subscribing 15 With the other, a pair of links connecting Witnesses.

said second block With each of said leg JOHN HERMAN. members, the links of each pair being piv- WVitnesses: oted, respectively, to opposite sides of said GEO. W. BARNET,

'2 second block, and a boW spring extending T. LYNN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner ti Patentl, Washington, D. 0.

Images