US2612690A

US2612690A - Compass

Info

Publication number: US2612690A
Application number: US774130A
Authority: US
Inventors: Arthur F R Cotton
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-09-17
Filing date: 1947-09-15
Publication date: 1952-10-07
Anticipated expiration: 1969-10-07

Description

-O XP l 0 N INVENTOR ATTO R NEY Arthur F. R. Corron COMPASS A. F. R. COTTON Filed sept. 15,

Oct'. 7, 1952 Patented Oct. 7, 1952 Armure. R. Cotton, Merrick, my.

Application september" v15, 1947, serial No. 774,130

j In Great Britain September 17, 1946 This invention relates to compasses.;v The principal object of this inventionis the provision of an instrument which may beused as a compass, a pair of dividers, or 'as a measu'ring rule. It may also be used as a straightedge and a T square. With modications'it may be used as a protractor or as a beam compass. .f This instrument may be used by engineers, architects and draftsmen, and it may also be use'dby tool'y makers in the making of tool's'eand dies. lThe instrument herein provided must accordingly be precise and accurate in every respect, and it is accordingly fitted with a'vernier so that micrometric measurements `andv adjustments may: be

provided for. v f l Preferred embodiments of this invention-are shown in the accompanying drawing in which- Fig. 1 is a plan view'of thejfirst embodiment; Fig. 2 is a longitudinal sectionon `the line 2--2 i of Fig. 1;

' Fig. 3'is another plan view-of the device shown in Fig. l, showing how it isiused to describeuan arc of a measured radius; 1 I Fig. 4`is a fragmentary plan. view` of a second embodiment of this invention; i

Fig. 5A is a fragmentary plan viewof a third embodiment of this invention; `and Fig. 6 is a-longitudinal section on the line 8- ofFig.5. I

Referring now to the first three gures ofthe drawing, it will be seen that the embodiment of this invention therein shown comprises essen.

tially four main parts: a calibrated',;perforated disc I0; la calibrated and perforated vstraightedge II; a fastening member I3'by whichthe disc and the straightedge may be piVotally-connected to each other and a pin I4. vA recess is formed in the bottom of the straightedge to accommodate disc I0, the depth of said recess corresponding substantially to the thickness of said disc so that the bottom surfaces of the disc and `of the main body of the straightedge will occupy a substantially common plane. See Fig. 2. One additional'elementis needed for use of this device as a compass or as a pair Vof dividers, 'and that is la marking member such as a penciLpen or scriber which, of course, are not shown in the drawing. 'I

The disc I0 is provided with a centrally located hole through which the fastening member I3 extends. Arranged spirally of .said hole'isa plurality of perforations or holes I2' which are one longitudinally extending series of holes-'I5 which are spaced from each other'in accordance with calibrations or graduations I'I. In the drawing two series lof holes are shown and-two com- `pletesets of calibrations accompany said series of holes,'o`ne set foreach series. Forreasons' which'will hereinafter appear, each series of vholes is lformed in v'a longitudinally extending vgroove I9 which is formed in the body of the straightedge II.

to register with the disc holesv I2xwhen the disc and the straightedge are pivotally connected 'to 'v each other as shown-in the drawing.

For convenience in carrying the pin. I4 aroundf,A

and to make certain'that it will not become:

separated from the other members of the device and consequently lost, the pin is provided with a threaded portion which meshes with a correspondingly tapped'portion of the fastening member :13.

ing member as shown in Figs. 1 and 2.

When the device is used `as a compass, and anfarc of al predetermined radius is sought to be described, the pin I4 is 'removed from the fastening member I3 and inserted through one ofy the slots I8 and through a selected registering `disc hole I2. The pencil, pen or scriber is then vinserted into one of the'holes I5 in the straightedge and with the pin usedr as a fulcrum or pivotal point, the pencilypenfor scriber, as the case may be, is moved -along an arcular line to .describe the arc 25 shown. in Fig. 3.. This arcmay, o course, be continued to complete a circle.v

The function which grooves vI9 perform may now'become apparent. The straightedge I I is of fair thickness to lend it j all necessary strength. The holes I5 :are relatively minute'. Hence,"were it not for grooves I9 which reduce the thickness of the straightedge at holes I 5, itwould be necessary to provide a pencil or `pen point of exceedingly fine dimensions'to extend through the holes -and make the necessary impressions v'or markings yupon the Apaper runderneath. The grooves are also used to facilitate selection of'a given hole I5. 'The -writing or marking instrument is simply run up or down the groove untillthe selected hole is reached, fand it is then-inserted into said hole. y

The mechanical operation yof `the-.device has' above been given. It is important to -state 'the theoretical'or mathematical basis `of the mechanical operation. Reference to Fig.1 will dis- In lineA withl said lgrooves and said se- Y ries lof holes l5 are slots I BOrmedin'straightedge II atA aipoint Whichfenables saidslots I8A Wh'en'the device is not in use, y l therefore, the pin may be screwed into the fastenvided oi into ten equal parts. On the rst mentioned side fractional measurements in terms of eighths of an inch may be had; on the other side of the straightedge decimal measurements or measuhlentsin-terms of tenths f'ianinch'.'

may be liadsr/Thearstside may accordingly begjlo used forfractional work and the second side for work on the decimal scale. y The disc holes l2 are divided into two series;.

one of which relates to the rst mentioned side` of the straightedge; and the second.`;series;z: :of155.

course, relates to the second .side .of thestraightedge.

that the difference between the radial distance of one end of said spiralrom the center of the disc, fand; the :distanceoff/ the. oilcerenxiv ofs'thef.` spi-ral.ifromo` theecenterf-- of?. thee dise, corresponds:vv toathespa'cing betweennadjacent. holessl Sion the. rstfmentioned sident .the straightedge. Bia-the;V

samectoken; thezdistarice ebetvveen iadj assent.heisstA :1

I Egonfthe @secondfside off, thefrstraiglitedgencorreev spends stos.thefdfilerencL betweentheeradial;disetanceszm triestino; endsofntheesecond; sygiiralscn.` disci?! Di'fromithei cien-tere, of .saielsdisea` Although:

y rnentidnellassbeenomadeiof two: ser-.called spirals F301:

unzip-dis'erIlLnit{.vviikrheY ppreciatedthaft'. what viis meant-:isz asspiratineffonwhich: theerst'- and secrondisets'infiholesl Zraref disposed; thef-rstsetfref latinfgetozthearstisideb the straightedgen, andiY the ,-.v

second'l set relatin'afztog the secondxsidef; ofi. sa'idi. 35A f st'raiiglrtedges:A .1.. f. f

flromctheiforegoing tswdil in. pparennthat the; calibrated perorations omidisoal I! serve assaave to;.w.ithirr='small frantio'nssofiarrie'htlrmr razftenitlri of-fan inchcEach eighth or-...tenthiof ansinclrmayg beibr'okeirupnjnttfasemany eqnahpartsassthereci are holes I2 iniitireetwozzspina'l:sections:orridisel0e nectingxfthie Ifhofles; I2: to:xforrmzascontinuouscslot1 3 I-;suclr.asf. isfsholvmzinzdisc Sroiithe .secondifem-f.- bodime'ntfoffthissinventimin Fi L. calibrations# orjfgradnations `.i32i'determinesthe finenesssofo t1:1e-.

corresponding: to Vtheeiirstsseriese015 hbleszlrisv brokentuplby fmeanssofigradnationsrSZFntEXxeight s parts; then litiseclearithaztfannadj ustment. true-tof l/itlraofeancincntinayibefhado -Ifthe second sec-su tion .ntf spiral 1311"." corresponding-:toi th'e: secondi: 55-

series of holesd 2; issdi'vided up intotenequal parts:l by:.meansnfzcalibrations 2 ,z .therr the. fseeondfsid'e of fthe straightedfgezmeybe.fused:for :describing:-

^ circlesiac'curate:toiwithigi 1i/100thy sofc'axr-inchc Inallsothe'r. respectsa'theedevicefas:shbwnfinfFig, 0,

ll.tcor-res'pjo'nds to-.rthef device shovvri f..inf.y the first;

three-.Insignesfoitheidrawinsc A'Ihec-.spiralj` 31.*; hassbeen 1 "described-'.1 asv-covering f tWouaidioini-ng'zsectionsircorresppndngfdo the two.'

seriessof holes.122zorrgdisc-vlils. Actually.` theseetvvoficsi sectionsmaybe madetoicoincidecwithi.each-tothen: sothat thegenti'iie-:Sinalislobimaybe used forzada jus'tmentsiinzsixtyefourths .-aszwell'rasfhundiiedthseA of :aminch-. Mln-.such caseronly onefxsidee'ofrthec straightedge'; need be .-used.jirriplacerofifthie ftwoo 705 sides above referred to. Using this arrangementit would zbevfoundJdesinable-rto: space'fthecliolesron the straightedgeoxieiinch or .025 inchzapartf.;

1n- ;Eigse amiewmakeenuserof smttediiw The devices hereinabove? deserbedvimav1 adi 'l Consideringthe spiralon whihztlie iirstiV series of holes I2 is disposed, it Will'be understood' and calibrated cross-bar 40 in place of the pivotally mounted discs IU and above referred to. In this third form of the invention the straightedge 34 is provided with a, recess 3I which extends transversely thereof at right angles thereto. This recess is adapted to accommodate the crossbar 4I) for slidable movement of said crossbar relative to said straightedge on a line transversely of; andnerpendicul'ar toQ'said-'strai'ltedgi Pins 38ihaving relativelyA largeelieadsearefaix'ed to the straightedge to engage, guide, and prevent accidental displacement ofthe crossbar relative to therstraightedge. The straightedge shown in Figs. 5 and 6 is provided with a Vsmall extension 35 wli-'iohf-is-Lnot ln'eeded on the straightedge I I shown injherstlfoungures of the drawing. This ex- 'tensiomszprovided'with a bushing 36 corresponding to the fastening member I3 above de- 'scrib'ed; This bushing is also adapted to accommodate the threaded portion of pin I4 so that when the pinziszznotlI-.l use:itgllayfbeiserewedzinto thelrgbuslringi; 35:r: T-his. bush-ingg,mayybeg-used; to taliezzthe-plaice orio-ne offltheepins 38aand igivena.. headntozperforindhefsame. functionsas aiopins '.381 relattveitoothe crossbarisilb1 `v .v j -I Y.

Corresponding;tonspirafl slcty3 I iii-:disc -30 fisa. diagonallyg'exten y gg -slot.!I. in. Vcrossbari litt.l Th'ereare ecalibra-ti'onseor ggraduations; .412,1 on-,1,he.A crossbar. dividing u-pjthesletinto. a predetermined ,I numberfof equal zsections and? ity will them-nder,- stoodf'thatithese ca-lfilmrationssand.their functie-nf. correspond rto@the;calibratiensi3It;ofgdisci.:i A.-

ser'iesfof holes .fl-5 -isforined initheastraightedgefa..

longitudinallmthereof .and-yin aiegroove? corresponds l ing to grooves I9vof the first embodiment; Aa.

singleslotrsisformedrin thes-traightedseigor respondinggtocthenslotspl Seirrstraightedgefl I andf-.

it wilbecseen .that .fregistrationristprovidedgbee tween said .sloti43 andnslotalll fof-fthefbrossbar; It will also be seen that the distance between"fad-'.-J jacentholes'rl 5 rinstrai-g-htedgef Sfconresriondsfto therdistancesseparatingf` az painter-,imaginary Vlines;Y parallel to the long sides ointhe'zcrossbar;andsfine-r tersecting: theff opposite endsvof' slot 4 brin .said crossbar. Thus shouldrthe-zdiagonai,slotfM medi-w vidediby calibrationsf Evvintozonerhlundred:equal parts, the net eiiectfwouldvbe :to justinent iaecurateftorathundredth of'itheistance separating adjacent holes I5 in straightedge..-3iICf.`

If; therefore? ther holesfiorr thez'straigfhted-gei are spacedslotiriotzanaincht aparte-the: compass might befused forganiiustmentsfftoowthin .loogtirfof am:

inchti. device-:may be: used. inasubstantiall embodiment; these .ftwoe embodiments imambe .n modied; as desired, d.b5@fformingq.ai@singleeseress of.; holesrfl andi-.aa single grooves inethe rst= emebodimenirzand :twoi:seriesforholesiandi grooves;` int.; the third embodiment... This@` issimplyy a matter of choice, and it is determined .byjtheey useatofiwhichnthe fdviceeincxquestion: to, .be .fp ut.

Althoughr thenrstiseriesaofzholesslhas: been .dee^- scribedziasibeing 'graduated toaeighths of'jiariiinch4 andthe-second series to-.tenths:oian'rinch,;itfwilt; baappreciatedfatliat :this :hasbeenf donezsimplygfbyy Way of illustration and notibyiwaygof :limitation Lprfovidefan ad@4 vantageously be made of transparent plastic material. It may be found desirable, however, for use in engineering workshops to make this Vdevice of a stronger material such as stainless steel or tempered steel. When plastic is used, a strengthening or reinforcing member of metal may be employed. In such casey it would be possible to reduce the thickness of the material of the straightedge immediately surrounding the holes l5. It would then be possible to use a writing or marking construction having a finely reduced point of somewhat shorter dimensions than would be possible in the use of a straightedge which is thicker around the holes I5. These holes l5 may also be enlarged above the bottom surface of the straightedge to accommodate the body of the writing or marking implement as distinguished from its writing or marking point, as the case may be. The enlarged portion of holes l5 would then serve as a socket to accommodate `the body of the writing or marking implement.

place of a pin, penor pencil. It is desirable,

whether the device is made of plastic material or metal or any other suitable material, to make certain that the material is vsufliciently yielding v and resilient to enable the straightedge to conform to the contours of curved surfaces'.

The device may be modified inA other respects than above indicated without departing from the basic principles of the invention. For example, the pins 38 which are used to lock the crossbar 4D in place, may be eliminated and other means which would occur to men skilled in the art might be used to provide a track for the crossbar 40. The bar is shown in the drawing to be completely removable from the recess 31 in the straightedge 34. It will be found a simpler matter to carry the device from place to place by removing the crossbar from the straightedge and placing them side by side or superimposed in a simple carrying case. Although a recess has been shown in the straightedge, this, too, might be dispensed with in other constructions which would enable the crossbar to move transversely ofthe straightedge and at right angles thereto. Use may be made of a tension member, for example, to lock the crossbar in place on the straightedge.- As a substitute for a tension member, a clamp screw or a cam member may be used to equal advantage.

These members, however, are not shown in the drawing, because they are conventionally used for the purpose indicated. Furthermore, it should be remembered that when a pin or scriber through the registering slot and hole in the rst.

embodiment, relative movement between the crossbar and the straightedge or the disc and the straightedge is prevented. Still another respect in which the device may be modified is by substituting holes in the crossbar for the slot 4I,

these holes corresponding to holes I2 of the iirst embodiment. Other modications and variations will occur to those skilled in the art and need not here be listed.

I claim:

A compass comprising a substantially discshaped member having a plurality of calibrated holes formed therein in spiral relation to its center point, a straightedge having a plurality of calibrated holes formed therein, longitudinally thereof and in alignment with each other, a slot formed at one end of the straightedge in alignment with the calibrated holes in said straightedge, said straightedge having a recess formed in the bottom thereof to accommodate the discshaped member, the'depth of said recess correspending substantially tothe thickness of said disc-shaped member so that the bottom surfaces of said disc-shaped member and of the main body of the straightedge will occupy a common plane, and a rivet pivotally securing said recessed end of the straightedge to the top center of said discshaped member, thereby providing for relative pivotal movement between said disc-shaped member and said straightedge on a substantiallycommon plane and thereby enabling said spirally arranged holes to enter into registration with said slot at different points along said slot, depending upon which hole is in registration therewith.

ARTHUR F. R. COTTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Y Date 452,054 Sperry May 12, 1891 824,299 Huey June 26, 1906 1,154,673 Van Ness Sept. 28, 1915 1,341,457 Costovici May 25, 1920 2,342,476 McEvoy et al. Feb. 22, 1944 2,370,741 McDonnell Mar. 6, 1945 FOREIGN PATENTS Number Country Date y f 324,597 Germany Sept. 1, 1920