US2576615A - Drafting machine - Google Patents

Description

NOV 27, 1951 c. H, LITTLE ETAL,

DRAFTING MACHINE Original Filed Sept. 22, 1944 Patented Nov. 27, 1.951v

'DRAFT-ING MACHINE Charles Henry Little, Cleveland Heights, and Charles Hubbard Little, Cleveland, Ohio; Nan 'Hubbard Little, executrix of's'aidCharles'Henry Little, deceased, assignorsyby direct andvmes'ne assignments, to V-Universal Drafting MachineA vCorporation,Cleveland, Ohio, a corporation of Ohio Original application September 22,1944, lSerial N0. 555,267. ,'Divided and 'this 42111i'plliit'til'nN0` vembel '28, '1945, Serial N o. :631,334

1,2 claims. (o1. 33-79) The present invention relates todrafting -ma- 'chines anclsimilar devices comprising alparallel `motion mechanism'or'arm, one end'of which is adapted to *fbe secured toa-table, drafting 'board or like 'device affording a working-surface,-over 'which the'otherend of vthe arm, provided lwith "some suitable drafting instrument or the like,is

adapted-to 'be `movedand-the `instrumentcarried thereby maintained parallel in successive positions. AParallelnrl'otion mechanismsare generally considered tobe eithercf the so-called parallelogram type or of lthe-so-L-called wheeland band type, depending upon whetherthesectionor sections thereof are Vessentially members arranged in parallel'ogram 'fashion 'and pivoted together adjacent to'th'e'cornerscr wheels held inspaced relation bystrut-like imembers and encircled vby a band or bands'which maintain a predetermined angular relationship therebetween.

The present invention relates to parallel motion mechanisms and more specifically' to `a drafting 'machine or the' like comprising aparallelmo- "'tion'mechanism ofthe Wheel andba'nd type-and oneoftheprincipal objects is the provisionbf a novelandimproved drafting machine or similar device soconstructedand arranged 'that lit -will be'accurate inoperation andwill not 'have the appearancefof being bulky andun'gainly, andin 4which the l'hands `and Wheels are completely fenclosed.

Another 'object ofthe inventionis v`the provision of'a novel and improved' drafting machine crithe like'of-the character'referred' toV having alstrutor struts enclosing the -wheelsand band or bandsand vso constructed and `arranged as to vbe extremely Vrigid though comparatively light in Weigh-t Jand adjustable'in length for'the purpose of tighteningor lloosening the'band.

Another object of the invention is Vthe yprovi sion Ycfa novel and improveddrafting machine or the like of=the characterreferred-to having-a strut or struts enclosing the wheels-anduband or -bandsand soconstructed and arrangedras-to be i-readilypartially disassembled tofafford access to the ends canl bev readily-connected or disconnected andfat least one end will be of minimum thicknv .f2 ness and maximumhexibility 4so thatzthe band can be lthreaded .around thefassembled wheels `although fthe enclosing strut kor member .conforms y closelyA to -thef circumference-thereof :so;as;to' \pro duce Va section lof minimum Aoverall ywidth for wheels-of"anygivenfsize.

'Another `objecto`f the invention is ethe f provisionof a novel and improved-separable geband Afor a wheel Y and Yband itypefdraftingmachine :or fthe like, whichfband comprises-means forureadilyde- Aitzw-hably "securing `the i'lends thereof together and has at least one end thereof of minimumthickness and maximum flexibility consistent with other -requirerhents @so that it :can be threaded around assembled Wheels lalthcnigh the f enclosing stru-t or'membe'r con-iormscloselyfto thefcircumference of the wheels.

The invention resides in certainconstructions and combinations*-andarrangementsf ofi-parts and further objects and advantages -Wlllbe apparent to thosesklledi in {the'L art@ to which theA invention `relates'froin the -follov'vng 'descriptionvof the preferred embodiment described 'with 'reference vto the accompanying drawings iforming a -part of 'this-specication--n which similar-referencecharactors designate cor'respending parts, and -in which Y Fig. l aplanview of a draftingmachine'embodyingthe present invention;

Fig. 2 is a fragmentary pian view foffa'fp'ortion of the'drafting machine showninFigl;

Fig. 3 is a sectional view, Vwith portions "in elevation, approximately vo'nthe line i3-L3, 'i'gfQ and Fig. 4 is ai'fragmentary View ofthe band ernployed in the drafting machine s'hown'in'ilgfl.

Referring to the drawings, 'the drafting lmachine `snol/vn therein 'comprises a vtvv'section .parallel motion-mechanism or arm of the wheel andl band type vhaving one end detachably .connected'to a drawing'board andthe other or free end provided withaprotractor 'head adapted to be moved aboutthe drawingboard. rIhefparallel motion mechanism or arm comprises'two angularly movable sections, each 'comprising apair of Wheels of 'equal diameter encircled by afle'zible ban'd, which VWheels a'reheld in vspaced ie'iation by a strut or strut member enclosing the same and the bands. The drafting machine yshown preferably comprises counterpoise mechanismfor both sections 5f the parallel-motion arm. .A suit-- able counterpoise v mechanism is lshown and claimed in our @pending-application.SerialKNO. 555,267 nowPatent-12,l552,335 grantedMayfSf-IQE'I,

` tegral with a bracket I2 forming a part of the anchor assembly, which bracket is adapted to engage over the upper edge of a drafting board or the like D and be detachably xed thereto by a pair of clamp screws.

The anchor strut C comprises yokes or yoke portions or members 22, 23 connected together and held in spaced relation with respect to each other by tubular side portions or members 24, 25.

The upper yoke 22 is pivotally connected to a vertical bolt or pin xed in a boss formed integral with a web of the anchor bracket I2. As shown, the pin is held in position by suitable jamb nuts threaded onto the lower end and the head of the pin is enclosed by a member 3| threaded into a tapped aperture in the center of the yoke 22. The construction is such that` the anchor strut C is supported for rotation about the center of the anchor band Wheel as an axis. The lower yoke 23 is pivotally connected to the band wheel -member at the elbow of the arm for rotation about the center of the lower band wheel as an axis by a bolt or pin to which it is connected by anti-fric; tion bearings.

The strut C is expandable or adjustable Yin length and separable intermediate the yokes 22, 23 to facilitate assembly and replacement of the band B and for the purpose of tensing the same, etc. To this end the side members 24, 25 comprise tubular sections 34, 35 and 36, 3j fixedly secured to or formed integral with suitable bosses forming a part of the yokes 22,23, respectively. The adjacent ends of thetubular sections 34, 35 and 35, 31 are normally held in spaced relation with respect to each other and are operatively connected together by tubular nut-like members 4|?, 4|, n respectively, the upper ends of'Y whichV are adapted to engage against shoulders formedV on members 42,' 43 V'fixed to the lower ends of the tubular sections 34, 35, respectively, while the which engage within suitable apertures formed in the ends of the members 46. The construction affords a simple and convenient means for hooking the ends of the band together and produces a band one end of which is extremely flexible and of minimum thickness, thus reducing to a minimum the clearance necessary between the wheels and yokes to thread the band about the wheels. Obviously a band of any suitable construction may be employed.

The protractor section F of the parallel motion armV is similar in construction and will not be described in detail. ,It comprises a pair of equal diameter band wheels encircled by a band similar in construction to the band B previously described and held in spaced relation by a strut G comprising yokes 52, 53 located at the elbow and drafting or protractor head, respectively, of the drafting machine and held apart by side members 54, 55 similar in construction to the side members 24, 25 previously described. The band Wheel at the elbow of the parallel motion arm is formed integral with the lower portion of the band wheel member of the anchor section A located at the elbow of the arm and the band wheel at the drafting head is formed integral with the holding ring of the drafting or protractor head. The yoke 52 of the protractor strut G is supported by an anti-friction bearing for rotation about a pivot lower end of the bolt or pin at the elbow of the arm and the band wheel at the drafting head is rotatably supported by an anti-friction bearing in the yoke 53.

The protractor or drafting head shown' and referred to generally by the reference character H comprises a ruler assembly J including the normally rotatable element K of the protractor proper, and one or more rulers 59. In addition, the protractor head comprises a normallyY stationary protractor element which stationary protractor element cooperates with the rotatable Y protractor element to indicate the angularV posiother ends thereof Vare threaded upon the`enlarged upper ends `of the tubular sections 36, 31. The'fact that theends of the'members 35, 3T1i'pon which the members 4o. 4|' are threaded Vare enlarged, permits the members 4|), 4| to 'be 'retracted over the tubular sections by rotating the former in a direction to move them to the left as shown in Figs. 2 and 3 until the threads are disengaged and thereafter the tubular nut members will slide freely on the tubular sections. The tubular nut- like members 40, 4| are normally held in position by jamb nuts 44, 45, respectively.

From the construction described above, it will be apparent that the length of the strut C can be varied by adjusting or rotating theY tubular nut-like members 4D, 4| after first loosening the jamb nuts 44, 45, and that when the nut-like members 4U, 4|V are retracted from their normal position, the flexible band B will be loose on the Wheels I0 and H with a considerable portion thereof exposed, thus facilitating assembly or replacement of the band. Since the'sidemembers '24, 25 are of tubular form, the band B must be threaded through the strut and about the wheels and is, therefore, made separable at one point.

-shown in Figs. -3 and 4,- one end of the band B isprovided with two spring members or armsv tion of the ruler or rulers with respect to some given base or reference line. The ruler assembly J is adapted to be indexedV relative to the Vstationary protractor element assembly L by an index mechanism located, except for the projecting part of the thumb piece 6| within and underneath the hand knob y62 also forming a part Vof the ruler assembly. As shown the stationary protractor element L is provided with a graduated circle and the rotatable protractor element with a reference or Zero line or Vernier. Alternatively the graduated circle may be placed onthe rotatable protractor element and the VernierA on the stationary protractor element, etc. Alterna- 'tively any desired appropriate type of drafting or protractor head may be employed with the improved parallel motion mechanismor arm of the present invention.

From the foregoing description of the preferred embodiment of the invention, it will be apparent that the objects heretofore enumerated and others have been accomplished and that there has been provided a novel and improved drafting machine or the like comprising a parallel motion mechanism of the wheel and band type which is light in weight, rigid in construction and operation and of limited size and wherein the bands are completely enclosed but :canbelreadily reais-raars s placed and the tension 4thereof adhj'iisted as `'desired; v 4 While the preferred embodiments of the invention have been described with considerable de'- tail, alternative constructions 4may beemployed.

lcomprising a strip 'or ribbon Vhearing Aits `ends 'connected together between said'vvheeis, va striit pivotally associated with said wheels for` maintaining the same in Vspaced relation with 'the band under tension and having twoaligned tub'u'- lar side members enclosing portions fof sai'diband between said wheels including portions adjacent said connected ends, and asleeve-like member surrounding a portion of Vsaid band and movable along one of said tubular side members and movable `to and from the other of saidside members to afford access to saidlends of said band.

2. In a drafting machine or thelike -a pair of band Wheels, a band encircling said wheels and comprising a strip or ribbon having its ends detachably connected together' between said'whe'els, and a strut pivotally "associated with said wheels `for maintaining the saine in'spac'ed relation' with the lband under tensioii land 'comprising two aligned separable tubular side members 'enclosing portions of said band adjacent said 'detachably connected ends, a sleeve l'ine'fnber\'siirir'ii'nding a portion of said band and movable along 'one of said tubular members into 'and'out of'eng'a'gement with the other of 'said tiibilar Irieinbers'to afford access to said detachably connected ends of said band.

3. In a drafting machine or the like, a pair of band wheels, a band encircling said wheels and comprising a strip or ribbon having its ends connected together, and a strut pivotally associated with said wheels for maintaining the same in spaced relation with the band under tension and comprising two aligned separable tubular side members enclosing portions of said band adjacent its connected ends, and a sleeve-like member surrounding a portion of said band and movable along one of said tubular side members in one direction into engagement with the other of said tubular side members to separate said side members to tense said band, and movable in the opposite direction from said other tubular side member to afford access to said ends of said band.

4. In a drafting machine or the like, a pair of band wheels, a band encircling said wheels and comprising a strip or ribbon having its ends thereof detachably connected together between said wheels, detachable securing means attaching said ends together, and a strut pivotally associated with said wheels for maintaining the same in spaced relation `with the band under tension and comprising two aligned separable tubular side members enclosing portions of said band adjacent to said securing means, a sleevelike nut member adopted to be threaded on one of said tubular side membersV and movable relative to the other of said tubular side members lin one direction along said one tubular side member 'to afford access to said secu-ring means Vand in the opposite direction along said cine Etubular side member -to moveagainstsaid second tubular member to -tense Isaid band.

5. In a strut adapted to vfor'rn a p'art of'fa drafting machine or the like of the Wheel and -band type and hold the -band wheels thereof in spaced relation while encircled by lan endless band, two aligned separable tubular side -fme'm'- bers adapted to enclose portions of the band extending between the wheels, and a sleeve mem- `ber surrounding a portion of -said band fand movable along one of -said tubular side-members into and `out of engagement with the other tubular member to separate 'said tubular mein'- bers and to afford access to said band, respectively.

6. In la strut for a drafting machine or the 4like having a pair of band wheels and v"a Aband encircling said wheels, the combination of two aligned separable tubular side vmembers enclosing portions of said band between said wheels-land `a sleeve-like member movable in opposite directions along one of said tubular side 'mein-bers and adapted to slidably telescope with thef'othe-r of said tubular members Vwhen Vmoved yin'ori'e idirection and to be withdrawn with said other tubular member when moved in the other' `'direction to alford access to fsa'id band.

7. In a strut adaptedfto'form a partof 'adr'afting machine `or the like o`f the wheel and fband type and hold the band wheels thereof in spaced relation while encircled by a band, Y-thecembinationv of two aligned tubular side members adapted to enclose "portions of the band entending between the vwheels anda sleeve-like mempber Yadjustably positioned on one of said 'tubular side vmembers and movable relative thereto in one direction to engage the other of said tubular side members to'ur'ge said tubular Vmembers :from one another to extend the strut and tense A'said band, and movable in the opposite direction and from said other tubular member to afford access to said band.

8. In a drafting machine or the like having a pair of band wheels encircled by a band, and

ra strut pivotally associated with said wheels for maintaining the same in spaced relation With the band under tension, said strut comprising two aligned tubular members enclosing portions of said band between said wheels, a sleeve interconnecting said tubular members and having one end portion slidingly telescoped with one of said tubular members and having a part abutting said one member to urge it in a longitudinal direction, and means for adjustably attaching the other end portion of said sleeve to the other of said members to adjustably position said sleeve along said other member for selectively spacing said members by said sleeve.

9. In a drafting machine or the like having a pair of band wheels encircled by a band, and a strut pivotally associated with said wheels for maintaining the same in spaced relation with the band under tension, said strut comprising two aligned tubular members enclosing portions of said band between said wheels, a sleeve for interconnecting said tubular members and having one end portion threaded on the end of one of said tubular members and the opposite end portion slidingly telescoped with the other of said tubular members and having a part abutting said other tubular member to urge it in a longitudinal direction when said sleeve is 'threaded outwardly on said one tubular member, said its ends greater than the diameter of the threaded 'end of said one tubular member whereby said sleeve can be movedonto said one tubular member and away from said other tubular member to expose a portion of said band.

10. In a drafting machine or the like having a pair of band wheels encircled by a band, and a strut pivotally associated with said wheels for maintaining the same in spaced relation with the band tension, said strut comprising two aligned tubular members enclosing portions of said band between said wheels, a sleeve interconnecting said tubular members and having one end portion slidingly telescoped with one of said tubular members, said one tubular member having an abutment thereon engaged by the rend of said sleeve, and means for adjustably connecting the other end of said sleeve to the other of said members to adjustably position said sleeve along said other member to maintain said tubular members separated.

11. In a drafting machine or the like having a pair of band wheels encircled by a band and a strut pivotally associated with said wheels for maintaining the same in spaced relation with the band under tension, said strut including two parallel tubular sections enclosing parallel reaches of said band, each section comprising two aligned tubular members, a sleeve interconnecting the spaced tubular members and. having one end slidingly telescoped with one of said members and having a part abutting said one member to urge it in a longitudinal direction, and means for adjustably connecting the other end of said sleeve to the other of said members to adjustably position said sleeve along said other member for selectively spacing said members by said sleeve.

12. In a drafting machine or the like having a pair of band wheels, a strut pivotally associated with said wheels for maintaining the same iii spaced relation, a separable band encircling said wheels, means intermediate said wheels for securing separable ends of said band together, said strut comprising two aligned tubular members enclosing portions of said band between said wheels, said aligned members being spaced from one another opposite said means, a sleeve surrounding said means and having one end slidingly telescoped with one of said tubular members and having a part abutting said one tubular member to urge it in a longitudinal direction, said sleeve telescoping at the other end with the other of said tubular members and being movable therealong in one directionr to be withdrawn from said one tubular member to afford access to said means, and means for adjustably connecting said other end of said sleeve to said other tubular member to adjustably position said sleeve along said other member for urging said tubular members from one another to tension said band.

CHARLES HENRY LITTLE. CHARLES HU'BBARD LITTLE'.

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

UNITED STATES PATENTS Number Name Date 249,909 Donahue Nov. 22, 1881 428,046 Hanagin May 13, 1890 '793,325 Stiles June 2'7, 1905 '797,911 Perry Aug. 22, 1905 1,902,038 McAllister Mar. 21, 1933 2,168,940 Little Aug. 8, 1939 2,243,732 Eubanks May 27, 1941 2,316,485 Langsner Apr. 13, 1943 2,407,235 Halstead Sept. 10, 1946

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