US989327A

US989327A - Protractor.

Info

Publication number: US989327A
Application number: US55631010A
Authority: US
Inventors: Abraham Brubaker
Original assignee: Individual
Current assignee: Individual
Priority date: 1910-04-19
Filing date: 1910-04-19
Publication date: 1911-04-11
Anticipated expiration: 1928-04-11

Description

A. BRUBAKER.

PROTRAGTOR. APPLIOATION FILED APR. 19, 1910.

Patented Apr. 11, 1911.

HIIHHIHHII I'HI J0. g '2' Inventor.

- Witnesses I o Attorneys.

ABRAHAM BRUBAKER, OF WARSAW. INDIANA.

PBOTRAGTOR.

newer.

- Specification of Letters Patent,

lu tented .tpr. t r. tori.

App1ication filed April 18, 1910. Serial No. 556.310.

To all whom it may concern:

Be it known that l, Arman-cu lnn'nxiann, a citizen of the United States, residing at lN'a-rsaw, in the county of Kosciusko and State of Indiana, have invented a new and useful Protractor, of which the it'ollowing is aspecification.

This invention relates to protractors and its principal object is to provide a simple device of this character having a novel arrangement of disks combined therewith and whereby very minute measurements may be obtained. i

Another object is to provide a protraetor which can be readily adjusted without the aid of separate devices and which can be conveniently manipulated.

Nith these and other objects in view the invention consists of certain novel details of construction and combinations of parts hereinafter more fully described and pointed out in the claims.

In the accompanying drawings the pre ferred form ofthe invention has been shown.

In saiddrawings:Figure 1 is a plan 'view of the protractor. Fig. 2 is an enlarged section on line A-B of Fig. 1.

Referring to the drawings by characters of

reference

1 and 2 designate two sides of a square the remote ends thereof being con- -'nected by an integral plate 3 having straight outer edges. These sides and edges are all graduated to indicate inches and, prefer-- ably, fractions thereof down to thinly-secmade, the graduation extending alonf both edges of each

side

1 and 2. A segmental opening is formed within the protractor,

' said opening being outlined bythe arms 1 and 2-and by an arcuate inner edge 4 of plate 3 coneentmc with the angle 5 formed by the inner meeting edges of the arms 1 .;and 2.

located six inches trom the center o The arcuate edge 4 is preferably and is marked as in degrees and half degrees: two sets of numerals being preteraldy associated with the gradnations so'that they can be larly arranged in the member 2.

read from either end of the are. Anincision 6 is formed in the side member 1 and constitutes a; continuation of the edge 4-, this incision extending one-degree into the side member. Another similar incision T simi- An incision 8 extends into the side member I.) at

the angle 5 and alines with the inner measurmg edge of the side member 1 this incision being preferably onc-eighth of an inch in -theedge 4 under normal conditions.

enough' to receive. a pointer.

A dish U is mounted on the member '3 and adjacent angle 5 amlwhen it is in its normal position the inner edge ol' member 1 extends radially therel'rom and the correspoinling-cdge of member :2 is disposed tangent thereto The pivot 10 oi the dislt is ecccntrically disposed and is in line with the inner edge of member 1. This pivot is removed one-sixteenth of an inch from the center of the disk and that p rtion of the periphery of the disk which is l'arthcst rcmoved 'l'rom the pivot normally rests at the angle 5 and on the open end of incision 8. This point on the periphery has been indi eated at 11 and is adapted to swing along an arcuate line 12 o'l degrees. said line being subdivided into two equal parts one of which-has sixteen graduations.

- The Zero grmluation on the disk normally rests at the middle graduation on the line ii. The said dish is graduated to indicate 'l/ltr,

unit-hing needle or By arranging the dish 5) in the manner described it can be'rotated -o as to recedc from the angle 5 and when the disk has been given approximately a one quarter rotation, l/lt' of an inch of the incision 5% will have been exposed and addrd to the measuring rule. liy stopping the zero graduation zit any one of the. grznluations on the line 12 a fraction of J ,/]t' inch can be measured along the incision 8 from the angle .3. Obviously by turning the disk t) 180 degree the entire 'length of the incision R (l/t ol an inch) will be exposed.

A disk 13 is mounted on the side member 2 upon an eccentric pivot bl. said pivot and the center of the dish being in the arc of The said pivot is removed from the center 4, degree and the graduated are I?) along which the disk swings extends 9t) dcgrees and is subdivided into 30 parts. Obviously .bv shitting this dish any desired fraction of the incision T can be exposed so as to add any portion of a degree to the 90 degrees described by the edge 4. For example. when the disk 1? is given a one-hall revolution, the incision 7 \vill be exposed its full length or one degree: should the disk be given a one quarter rotation or. in other words, moved through 90' degrees one half of the length. .\ll ol the incisions are just wide incision 7 will be exposed thus adding 30 to the arcuate edge --l-. It will be apparent therefore that each of the thirty parts into which the 90 degrees are subdivided, desig nates 3 degrees along the are but a movement oi the di k along the incision T for a distance equivalent of 1. Another disk 1(3- sinnlar in all respects to the disk 13 is arranged upon the member 1 and cooperates with the incision (3. v

In using the device it is necessary to employ a needle or similar marker or pointer having a very sharp point. If the first line is to he laid olt' degrees. 17 rods (scale 8 rods to the inch), the angle 5 is placed at the point of beginning and the side I 1 extended south. The needle point is placed at the graduation on line 4 which is 20 degrees 't'riun disk it; on side 1 and the protractor is then swung ahout angle 5 until disk 'ltSa-omes against the needle. The permanent point can then be placed 23;

inches from angle 5 along the graduated edge of arm 1. this distance being equal to 17 rods. It the next line is degrees, '15. Y, the protractor is adjusted to the new point as before. the disk to heiug turned l5 degrees to the right. The pointer or needle is then placed at the 30 degree graduation on the edge it and the protrzictor is swung to the rightuntil the pointer contacts with the edge of the dirk-1t) which will he .dcgree within the incision (3. The

distance can then he pointed as before on the measuring rule. Should it be necessary to utilize the disk t) to getthe exact distance,

a temporary point may he placed near the outer end of the memher 1 and the disk 9 then turned the required distance. The protractor can then he pushed longitudinally of the memhc-r 'l. the temporary pointand the point at the angle 5-" acting as guides until one of the points strikes the disk in the incision 8. The permanent point an then he placed.

lt is of course to he understood that vari they are adjusted.

'hat is claimed is:-

1. A protractor including a square, an arcuate portion concentriowith the angle ol the square. there being incisions in the square constituting contimiations of the curved edge of the arcuate portion and of one/straight measuring edge of the square,

1 and adjustable means for varying the length of the exposed portion of the incision, f said means and square having cooperating i means for indicating the lengths of the me i posed portions of the incisions.

.\ n-otractor having an incision c0nstituting a continuation of ameasuring edge, and adj ustahle means for varying the length of the exposed portion of the incision and having means for indicating su ch length. protractor having an incision constitnting a continuation of a measuring 1 edge. and an eccentrica lly mounted disk for varying the length of the exposed portion I oi the incision.

4. protractor having an incision constituting a continuation of a m asuring edge, and an eccentrically mounted disk for varying the. length of the exposed portion of the incision'there lieing cooperating meansv upon t the disk and protractor for indicating the 5 length of the. exposed portion of the slot.

5. A protractor including a square having a segmental opening the areuate edge of which is concentri with the angle of the .--quare. there heing an incision constituting continuation of the arcuate edge, and movable means for varying the length of the exposed portion of the incision. I t A protractor including a square having a graduated edge, there being an incision within the square and constituting a continuation of the graduated edge for the reception of a marking element, and a disk mounted for rotation about a point remote heing in alinement with the incision and with the, graduated edge and said disk being shittahlc to partly or entirely conceal the incision, v I

7. A protractor ineludinga square having a graduated edge, there being an incision within the square and constituting a continuation of the graduated edge for the reception of a marking element, and a disk mounted for rotation about a point remote from the center thereof. said pivotal point, heingin alinement with the incision and with the graduated edge and said disk heing shi'l'tahle to partly or entirely conceal the incision. and eot'iperating means upon the square and disk for indicating the length of the exposed portion of the incision.

In testimony that I claim the foregoing as my own, I have hereto atlixed my signature in the presence ot two witnesses.

.UEILUTAM BRUBAKER; Witnesses:

MELVIN A. \VILCox, MAURICE WiLcox.

from the center thcreot. said pivotal point.-