US1934952A - Drawing table attachment - Google Patents

Description

Nov. 14, 1933. H. R'. SHCI-:MAKER 1,934,952

I DRAWING TABLE ATTACHMENT Filed April 18, 1932 l N V E NTO R I Harold S/wma/cer, v\ BY Al 4Z u* 4 a 9 6, ATTORNEY Patentedl Nov. 14, 1933 UNITED STATES PATENT 'OFFICE V1,934,952@ l DRAWING TABLE ATTACHMENT Harold VR. Shoemaker, Washington, D. Application April 1s, 1932. serial Np.A 606,023

' 1'0r claims; (o1. 45-131)- The invention relates to meansto hold paper or cloth in position upon drawing boards andV at the same time that the paper is effectively protected from soiling, as well as-havingother ad- A vantageS, some of whichwill be enumerated.

vAnother important aim is to present a novel construction and arrangement whereby theV adjustment of the paper accurately on `a board may be assured readily. In manyl instances where Y large drawing or tracing Ais involved, it is desir- 20 able to make the sameby'- perfecting a portion thereof at the lower portion 'of the board or table, then adjusting the paper s o that,` an ad-l jacent portion mayl be perfectedl in the same.

location on the board or table, so that the draftsmanisv not required to work on an extremely distant part of the table-or board by leaning over the front' or bottom portion,v or sitting or resting thereon while making lines upon the more distant parts of the paper. f 1- -f An yespeciallyimportant aimof the invention 'is to provide such an article which may be purchasedl at a low cost by draftsmen to 'be applied to boards and tables already in use which may be put in place properly by inexperienced persons with assurance ,of-accuracy.- Another important purpose is to construct'the device so that it will provide' a good straight-edge at the bottom of the board or tabler to which Yit is applied, rwhich will not be liable toY damage or deviation by wear,

40 and in fact one which may be applied to a board or table vhaving al damaged edge to replace such edge -with one that is true and durable.

Y It is also an object to offer a` paper reeling and tighteningdevice in which a* removable roll is jincorporated, to the end that the drawing-in .course oflpreparationfor those whichare to be added to, revised, or corrected from time to time, may be-preserved upon the roll and when additional work is to be doneon such drawing the roll Vmay be returned to my mounting andagain adjusted over the board'instrict and true relation to the *straight-edges' of the boardthe lsame as Vwhen originally placed thereon. 'It' is'. also the purpose to provide a multiplicityof ro11s',so` that 55 drawings may be permanently retained thereon,

and held in racks orv otherwise, as desired, -for preservatiomyetalways be'ready for quick readjustment upon the 4drawing board whenever required. l l

Another object is to provide means to prevent 90 the vpaper from becoming loose upon the roll when the ratchet of the roll is released, or when the'` `paper is detached from the drawing board. Still another object is to present a novel casing and door construction facilitating emplacement and 05 removal of paper or rolls.l

It lis also an important purpose to provide a I Ynovel means to permit removal of a drawing sheet Y from the device, and its return at-any time thereafter `and resecurement in exactI rectitude with .i0

the board.

It is also an aim to provide a novel form of vratchet device for holdingtheV paper roll in positions withthe paper under proper tension. y

Additional objects,advantages and features of 1i invention reside inthe construction, arrangement and combination of parts Vinvolved. 'in the em- `brodiment of the invention, as will be more readily understoodv from the followingdescription and vaccompanying drawing, in which f board. f

vFigure 5 is a `detail of the pawl.

' Figure 4 is a top view'ofthedevice applied to a 85 Figure 6. i's a fragmentary vertical section of the roll and trunnion mounting.

There is illustrated a board ortable 10, which 90 may have an apron board or drawer as indicated `at 11, and it is an advantage'of my device that it is constructed so that it will not interfere with the vuse of drawers of tables to which it is attached.

To the bottom edge 12 'of the board there is at- 35 tached my'invention. This includes a ycase which consists of a base section 13 cast of aluminum or i other Vmetal including a back wall or plate 14 set snugly against the face ofthe edge 12 and secured thereto. The wan 14 is formed with a piuranty 'i100 10 bear upon the sides of the slots and clampthe A105 Wall l4ag'ainst the board. The section 13 is also stopping short of the ends a proper distance. This no A lower case section 21 is hingedly connected to the section 13 at the lower edge of the front wall 20 in such manner that the lower section may swing forwardly and upwardly as indicated4 in dotted, lines in Figures 1 and 2, so that the hinge elements lie clear of the plane of the iront or outer face of the wall 20. This Ywill'permit the head of standard T-squares to be moved slidably against the outer face of the wall 20 with the stem oi the instrument laid flat across the section 13 and paper on the board 10.

The section 21 comprises afront rail 22 arranged to abut the lower edge ofthe front wall 20 of the section 13, end walls 23, alined with the end walls 19, and a bottom rail 24, all integral as shown. f

Spring clasp arms 25 are xed on the end walls .23 of the section 21, arranged to overlie the end lwalls 19 of section-13 and are cupped `or otherwise shaped at their outer parts to snapover lnodules Aor knobs 26 on the last mentioned walls so as to hold the two sections yieldingly in coengaged relation. The lower partsv of thewalls 23 are partly circular; in form and onV the center lof the circlev involved,jthere are. mounted revolubly tubular .trunnion knob shafts 27. In the present instance a roller 28 is shown, which may be formed of wood, although other materials may be used.

Each knob shaft is releasably engaged with the roll, as-,will be described, and has a knob 30 at the outer end for manipulation to rotate the roll.

Each shaft 27 is provided with a ratchet wheel 31,y

and on the inner face ofv the adjacent wall 23 there is pivoted a pawl 32 arranged to engage the ratchet, being pressed by a leaf spring 83 xed at .one end on the innerface of the wall.

A lifter and support for the pawl is provided,in the form of a plunger 34 slidably inserted through the wall,

zhaving an operating head at the outer end by which it may be manipulated. With the plunger Yat theinner limit of its movement a thickened part is engaged beneath the pawl, holding the latter clear of the ratchet; from this thickened apart a downwardlyV inclined face 36 extends inwardly to a thin part 37, at the extremity of which an upturned stop BSis formed which will strike against the pawlwhen the lifter is drawn to the outer limit of its movement. This stop kextends upwardly more than the vertical movement or the adjacent part of the pawl by the ratchet teeth, so that liability ofA thepawl becoming, engaged rover the stop is minimized, and withdrawal of the jnormally held projected from the end of the roller yieldingly. At the right end of lthe roll a stub stop short within the ratchets,` and are formed to A are driven home.

receive the keys 44 on the endsof. the respective trunnions 40 and 40' as in Fig.6.

The roll is formed with a saliently marked or otherwise indicated line 45 in one radial plane of the roll, and this line may be formed on a ila*- tened face 46, if desired, or the attened part may be omitted, and the line formed upon the cylindrical part oi theroll. The line may extend throughout the length of the roll. If the flat face ris provided, it may be used-to receive thumb tacks to secure the paper on the roll, although the tacks may bc placed elsewhere on the roll if desired.

A presser roll 47 is mounted on the back wall ,1 4 by means of leaf 'springs 48 attached to the wall 14 byscrews and pendant to a location close to the periphery of the roll 28 when the device Vis in closed position. The presser roll is of quite small diameter, and is adapted to bear upon several thicknesses of paper when engaged upon the roll 28 so as to hold such paper against becoming loose upon theroll if the pawl 32 is released, as would occur whenthe plungers 34 are pressed inward. The roll 47 clears the roll andsuperposed paper when the section 21 of the device is swung upward. y l Y g f The rear side of the case may be openbetween the two end plates 23, so that any. trash falling through the slot 18 will always clear itself from the case. But the front side oi theY case is preferably provided with a closure which may be moved to permit free access to the roll 28 and paper thereon for fastening or removal, and for emplacement and removal of the ,.rll. This olosure consists in the present instance of a door 52 of thin resilient metal hinged to the front edge oi the bottom rail 24 of the lower section 21 of the case. with the roll 28 and has a rolled rim at the upper edge set yieldingly inthe grooved lower sides of lugs 53 formed on the front wall 22 of the bottom section near each end. v lo open this door 52 itis pressed manually downward at .the upper edge portion, while the upper edge is drawn outwardly to clear the-lugs 53. The front platesf20 andA 22 of the sections 13 andv21 have large openings 54 formed therethrough in alinement with each oi the slots l5 through the back wall 14, so thatthe screws 16- may 4be put in place by being inserted through the front of the case and drivenby a screw driver nalso' inserted through the case. Withdrawal of the screws may be correspondingly effected. l

To apply my attachment to a drawing board or table, the outer or rear face ofthe wall 14 of the top section of the case is vpresented against the ybottom edge of the board, ,and while adjusted as knear as desired to one end or Ythe other ofthe board, marks are made throughthe middle of the slots l5. These slots preferably stop at a predetermined distance from the top of the plate 17 which will permit engagementof screws through Athe slots in the thinnest Vboards of dependable makes, to hold the top-of the plate 17 Yflush with the top of the board. After marking the locations of the slots 15, suitableholes are drilled in the edgeface 12 of .the board on Ithe marks made and at the proper distance from the top face of the board and thefscrews entered therein and through the slotsl15. It is possible that these will not be uniformly spaced from the top or working face of the board, but by screwing only partly against the plate 14, the latter may be adjusted upwardly ,or downwardly at either or both ends and when good alinement is assuredvthe screws This door is curved to lie concentric' Infplac'ingipaper upon a board Vequipped with myv invention, the paper 49 is flrstadjusted with its lateral edges 'in the desired relation to lthe lateral edges of theboard. A T-square is then adjusted to the left edge of the board with its stemclose yto the bottom of the sheet and aline drawn therealong 'upon the extreme lowerredge portion of the sheet. The door 52 is thendropped and Jthe marked edge portion Lof the sheet 49 is then inserted downwardly through the slot 18 the line drawn upon the` paper being adjusted in alinement with the line on the roll while thumb tacks 50 (or other means) are used to secure the sheet to the roll. The plungers 34 being drawn outward, the paper is then wound as desired and while moderately stretched its upper edgey portion is secured to the top of the board, or to some intermediate portion of the board at the desired distance from the edge 12 by means of additional thumb tacks 51 or other means. The knobs are then grasped and manually turned to draw the sheet taut, the resilience of the material permitting the ratchet to be moved so that the pawl engages with the sheet properly stretched.,

To remove the paper, leaving the roll in place, the upper tacks are removed, the plungers 34 vpressed inward,` and the paper then drawnhout through the slot 18 until the thumb tacks 50 holding the paper to the roll may be drawn, the

door 52 being lowered.

To remove the paper on the roll, the upper tacks 51 are removed, and the knobs 30 rotated until all the paper is drawn inward through the slot 18, after which the door 52 is openedand the roll grasped in one hand and the left end drawn outward while a suitable instrument is inserted through the left tubular knob shaft to release the inner or depressible ,trunniony 40.

It should be noted that the paper passes across the junction between the upper and lower sections of the case in such mannerthat the tension on the paper holds the lower section in closed position. In case the element 11 shown under the board should be a drawer, as will bevthe case on some tables, the lower section of the case may be swung upwardly to clear the `drawer and permit it to be opened. Ifpaper is held under tension by the device, it is only necessary to press the plungers 34 inward to permit movement of the lower section of the case to clear the drawer, and by drawing the plungers outward again the paper may be immediately and certainly returned to its original taut condition and exact location on theboard by rotation of the knobs 30. It will be noted thatexcepting lower edge of the front wall Vof the top section -planes of the back plate 14 and front plate 20, so

that an angular straight edge is formed outward-` which is much above the lower1face of4 the board 10 and consequently liability of soiling or damage to the paper in openingthe drawer at 11 is much minimized. l

It will be notedthat the topk plate 17 is thickened adjacent the slot 18, and that the slot extends. at an incline downwardly and awayA from the board 10. The top surface of the plate 17 is planiform and at right angles -to the 1y of the slot adapted toeifectively guide'y the head of a T-square or other drawing implement just as it mighthavebeenfused against the edge 12 of theA boardy before the; attachment .of v-Iny` device. In the. speciiicati'on the understoodto apply to -table topsand other sun-` fac'e or platen members. The roller 28 maybe termed a Vreel, and such term will be underterm "boardwill be stood to include suchsan element kemployed as; a

tensioningmeansalso.v A

I claimzf 1.1In ar paper stretching device for drawing boards, a case having a back wall constructed for attachment to' the edge of aboard, said case having a top face adapted to aline with the face of an attached board, and an outer front straight-edge face parallel to the back face joining the Vtop face at an angle toguide Tsquares and the like laid across the device, a paper holding and tensioning means and a paper receiving slot opening therefrom through the top of the device parallel to the back face.

2. The structure of claim 1 in which the case comprises an upper vsection including said back face and a front face portion, and a lowerV sec-V tion -hjngedly'connected to the upper at saidl loo outer face, said paper holding and tensioning.

means mounted in said lower section. f

3. The structure of claim 1 in which the paper holding and tensioning means is Varranged in view and 'includes a roll having an index line formed saliently thereon extending longitudinalcomprises anv upper section including said back face and a front portion, and av'lower section hingedly lconnected to the upper section at the front, said paper holding and tensioning means being a reel revolubly mounted in said lower section, and apresser roll parallel to the reel vmounted yieldingly on the upper section at the rear part to engage paper on the reel.

' '7. The structure of claim 1 in which the case comprises an upper section including said back face and a front portion, and a lower section hingedly connected to the front portion of the` upper section, said holding andtensioning means being mounted in said lower section, and a paper sheet engaged therewith extending across the junction between the upper and lower sections,A

rearwardly of the hinge, then through said slotA and attached to the board, whereby the'tension on the paper will tend to hold the sections in closed relation.

8. YThe structure of claim 1 in which the said back wall is formed with a longitudinallyV spaced wall thereof Vhas formed therein openings'alined with those of the back wall, said paper holding and tensioning means being below alllofsaid openingswhereby fasteningA members may be series of [fastener-receiving slots, andthe frontsl4 J inserted and driven through the front wall andl45 secured upon the back wall. v

9., The structure of claim 1 in which the paper tensioning and holding means consists of a reel,

a'detent to hold the reel against rotation in one l direction, said reelv having stub trunnions at thel device, said closure being transversely curved and said case having a xed element thereon grooves at the side next the closure and spaced from the hinge of the closure less than the normal radius of the closure, whereby the closure may be strained to move into alinement with the groove and will expand its inherent elasticity to engage in the'groove.

VHAROLD R. SHOEMAKER.

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