US1349550A - Drafting instrument - Google Patents

Description

A. E. MAGNUSON.

DRAFTING INSTRUMENT.

APPLICATloN FILED1UNE30,1919.

BY l \J// z ATTORNEY UNITED STATES PATENT OFFICE.

ANDREW E. MAGNUSON, OF'NEW YORK, N. Y.

DRAFTING INSTRUMENT.

Application alea :ruae so,

To @ZZ whom, it may concern.

lle it lmown that I, Amnunv E. MAGNU- soN, a citizen ot the UnitedStates, and a resident of the borough of li/Ianhattan, in the county, city, and lltate .of New York, hare invented certain new and useful Improvements in Drafting Instruments, of which the following,` is a specification.

rIlliis invention generally relates to the art olf mechanical drafting, and more especially it appertains to instruments or implements whereby distances between lines can be accurately measured, and the latter may be drawn uniformly at the desired internals apart. For the turtlierance ot conciseness and precision, it willbe described and shown herein particularly with relier ence to T-squares and drawing boards combined.

rlhe primary object oi." the invention is to de n an improved implement for the purpose contemplated, which shall be capable of accurately measuring spaces between lines that have been or are to be drawn,` without using' a separate scale or similar means` to ascertain thedistances at wl 'ch the lines were or will be laid relatively to one another.

il. secondary object is to supply an implei'nent of the genus alluded to, including co ,ingr measuring' elements, one olf which niiirmally nio 7able over theiother, while the latter 'may remain stationary or admit also ot being moved to advance or retract the points at which the measurements will commence, so as to suit various requirements.

il.. third object el' the invention is to prodnrc an iniprot'ed T-seluare olf the cliaracter set 'forth allording' an accu ate means of spacing' the lines to be drawn, according to 'ironer use thereof will be understood at l i i the draitsi'nan, even though a becnre by and .work will be performed ner,

` n hout tear or hesitation, but intelligently as well as expeditiously'.

il. further object is to provide an implement of the clins mentioned permitting the standard oli measurement, and

Specification of Letters Patent. Patented All. 10, 1920.

1919. 'Serial No. 307,711.

T-square to be quickly applied to or removed from the drawing-board, and also to be rendered inoperative to the end that it may be used in the ordinary manner, if and whenever desired.

Still another object is the provision of an implement of the type referred to, the actuating mechanism whereof shall be of small compara and i'ior the most part shielded from exposure, so that it will be fully protected and may not cause the least interference or inconvenience while the work of dra-tting, is being` carried out.

it still .turther object is to devise an implement of the hindspeciiied composed of Vbut few parts, that can be produced from readily zwallable material mostly anywhere,

and easily assembled with the aid of common tools, by plain mechanics, at a slight expense.

Other objects and advantages of the in- Vention will become apparent as the specification proceeds.

llVith the aforesaid objects in View, the invention consists of the novel combinations and arrangements ot parts hereinafter described in their preferred embodiments, pointed out in the subjoined claims, and illustrated on the annexed drawing, where in like parts are designated by the same reference characters throughout the several views.

In the said drawing,-

y Figure I is a top plan View, showing one corner olf a drawing-board, with this improved T-square in operative position thereon, the latter being` shown "on a reduced scale and with its blade broken transversely intermediate the ends;

II an enlarged sectional elevation, including` a fragment ot the drawing-board and a broken View of the T-square, the section running across the head ofthe latter and lengthwise of its blade in a` substantially central plane;

Fig. III is the perspective View of the carrier and bearing plate pertaining to the implement,looking at the under side of the bearing' plate alone, as seen irom the upper side thereof;

Fig.` V is a detached perspective View of the said carrier;

Fig. VI is a top plan View of a revoluble index, included in the implement.

Fig. VII is a perspective view of the operating pinion, including its spindle and parts thereto appertaining; and

Fig. VH1 is a perspective view, on a slightly larger scale, showing the head of the T-'square and a fragmentary part of its blade, with a recess, perforation, and incisions therein made.

In these views the letter A. represents a well-known form oin drawing-board, to which the invention is readily applied. On the face ot this board appears a T-square of customary outline, the same comprising a head B; and a blade C. it is understood that the parts here named are not new in tiemselves, and therefore pertain to the present invention only in so tar as the structural details and accessories herein disclosed are concerned.

The inner side of the head B aforesaid is adapted to be moved closeto and in parel' lelism with the ad`acent edee of the board A, the blade C meanwhile sliding` over the surface of the board, ni the usual manner. The head however is not intended. to touch 3 7 the board but merel i follows the edeje n. l: 1 e thereof, goino past the teeth ci a rack-oar 1, attached to the latter. rFhe rack-bar may be held to the edGe of the board h i anv c 1 suitable means, for instance, oy screws, as 0 l' t l' F' T i a, as inc ica ec in ig. i.

A pinion 3, adapted for engagement with the teeth orn the rack-bar 1 is )laced in a recess 4, cut into the head B, directly under Y that part of the blade C which is .stened to the same. The recess 4 may be circular or of any other approved shape, but in a y case is open laterally, as at 5, to enable the dented perimeter or the pinion to approach and engage with the corresponding centate face of the rack-bar.

Preferably and as shown, the pinion 3 is held in suspension from above by a spindle 7, to which it is fastened. As seen in Fig. 1l, the spindle passes upwardly through a carrier presently to vbe described, and is journaled at opposite points therein. it is also reduced in diameter at its upper end, and terminates in a threaded shanlr 10, engaged by a binding-nut 11.

The carrier, above referred to, is conveniently formed oiC a single strip of metal bent upon itself to constitute an open-sided structure, the component parts of which all appear in Fig. V, and most oiitliem also in Figs. II and HI. In the exeinpliiication given herein, the carrier include two suhstantially parallel, top and bottom portions 12 and 13, a forward wall 1-i joining the same, and a iianged pendant 15, at the rear.

Referring particularly to Fig. 1I, it will be observed that the larger part of the spindle @immediately above the pinionL 3, finds a bearing .withinA an opening 18, formed in the bottom portion 13 of the carpart 19, of the spindle.

rier. Similarly, the top portion 1Q ot the latter is provided with a corresponding aperture through whieh passes a redueed This aperture is surrounded by a collar Q0, `formed integral with the top 12 of the carrier and wherein is iitted the said reduced part 19.

rhat portion oiv the blade C, which was previously referred to as fastened to the head B, is apertured, as at 2l, to permit the passage therethrough oi the upper part ot' the before described carrier, with its eonnected parts. rEhe top 1Q ot the said earriei just projects above the aperture 21, and is held at that elevation by ineans ot a snpporting plate 22, adapted to be secured as by screws entering holes i in the plate 2:2 and corresponding holes Qi in the blade its shown in Figs. lll and lV, the carrier is made to project upwardly through a suhstantially rectanguler opening L, in the plate Q2, and its top 1Q is arranged to hear slidahly upon oppositely-located lugs Lt', projecting inwardly troni the side Vedges o t the latter-named opening.

Upon the top portion 12 et the earrier and overiying the supporting plate 22. is disk or dial 3G, which is centrally apertured, to embrace the said collar i() of the carrier. The upper tace ot this dish bears an annular series of marl' n; oeeuring at regular intervals apart i'ioin one another, and denoting, ior instance. in iraetions of an inch or ot' a meter, or other unit oiE linea r measure, any distance traversed b v the T- `niare as it is caused to travel over the surface ot the drawiiig-board. The, distance is pointed out by an index 32. rigidly connected with a receiving portion 33, ot the spindle 7, situated intermediate of the aforesaid reduced portion 19 and the threaded shank 10. As detailed in Fig. Yi. the index 32 has an integral huh $4-, perforated centrally, as at 35, to lit around the receiving portion '33, and both the latter and the perforation are provided with co-acting straight edges 3G, 37, at one side. to prevent independent rotation. The indicator dislr or dial 30 and the index iii) revoluble tliereover are held in place against the carrier top and the pinion spindle respectively, through the action ot the binding-nut 11, engaging the threaded shank 10, aforementioned.

A resilient retainer or clamp at) is provided to hold the disk 30 both rotatably and slidably with relation to the supporting plate 22. while the said dial has only a eircular motion relatively to the top portion of the carrier and its collar. This retainer may consist of a single spring wire anchored at 40 to one end of' a ledge or outwardly extended liange 41, of the pendant 15 of the carrier, and thence reaching rearwardly so as to grasp the superimposed disk ti (l.

30 and plate 22. The wire may be bent upwardly, as at 42, tobear against the under side of this plate, and downwardl as at 43, upon the upper margin of the dis 0 The iecess 4, perforation 2l and opening 25 are all made sufficiently large to admit of sliding the carrier forward and back therein, either to disengage the pinion from the rack, or to re-instate the same in their meshing relation. The indicatorl disk held by the clamp or retainer 40, it will be seen partakes of the same movement, the portion of the clamp which grasps the disk and plate thereunder being arranged to slide in a slot 45, made in a rearward extension 46, of the plate.

The sliding back and forth of the said carrier and parts thereto connected is effected by means of a detent 48. The latter also may consist of a single spring wire attached, as at 49, to the top 12 ofthe carrier, and extending thence to the said slot 45. A head 50, on the rear end of this detent, serves to hold it engaged with the upper face of the extension 46. Notches 51, 52, lateral to the slot 45 serve as keepers to retain the detent in a fixed position, after it is drawn forward or rearward as the case may be. Iii passing from the point of attachment 49 to the slot 45, the detent wire is made to run through a notch 53, in the pendant l5. Now, in order to disengage the wire from either of the notches 5l or 52, it is strained by being bent upon the corner of the carrier where the notch 53 is located,

and therefore the tendency of the wire is to carry its outer or rear end into either of the notches first mentioned. Assuming that the outer end of the wire engages the notch 52, as represented in Fig. II, the carrier is then positioned so that the pinion 3 will be in mesh with the teeth of the rack-bar l. 1When it is desired to disengage the inion from the rack, then the head 50 of t e detent is pushed sidewise to retract the wire from the notch 52, and the detent is pushed forward through the slot 45 to effect disengagement of the pinion and rack, whereafter the deteiit is released and that part of the wire thereof which adjoins the head 50 automatically enters the forward notch 51., due to the stress exerted upon the Wire by its being bent around the said corner of the carrier. A channel or slideway 55 is cut into the blade C, at the end thereof intended to be placed upon the edgeof the drawingboard A, so that the wires composing the said retainer and the said detent will have the requisite clearance for their effective manipulation. The slideway 55 is covered by the extension 46 of `the supporting plate 22, hereinbefore mentioned.

As before intimated, the face of the dial or disk 30 bears a series of lines drawn so as to constitute some preferred scale of measurement. These lines `may be iinpresscd into the dials surface, or otherwise produced. Whatever is the measuring system adopted, however, the series of lines is such that it will readily accommodate itself to the same. The lines, it is to be noted, are disposed in a circle, commencing and terminating, so to say, at the one point, namely, that indicated by zero (0) in Fig. I. The circle may be divided into sections representing, for instance, quarters of an inch, orlive millimeters, and these sections can also be subdivided, into smaller intervals. In either case, the index 32 will point out the exact subdivision line or lines expressing distances which the draftsman wants the T-square to traverse in laying out or performing his work. The distances may b e computed uninterruptedly, as the invention 'admits of it. But, in changing from one interval to another While making the computation, the operator will find it to his advantage to avail himself of that peculiarity of the invention which allows the rotation ofthe dial independently of the index. This will enable him to bring the zero point of the former to the latter at any time desired, and therefore will facilitate greatly the computation of intervals. The edge of the dial is knurled, in order that it may have a convenient grip for the fingers in making* the desired adjustments.

A concavity 58, which may be of crescent shape, as shown in Figs. I, II and VIII, is provided in the end of the blade C that overlies the head B of the T-square. The `knurled edge of the'dial aforesaid advances over the inner margin of this concavity, and therefore can be reached easily by the operator placing the thumb or a finger' into the depres-l sion. I-Ie is thus enabled, if he so chooses, to 'turn the `dial with the same hand that guides or pushes the head of the instrument over the surface of the drawing-board, as the work progresses.

Although the operating mechanism herein described has been shown-in the annexed drawing as being centrally located with relation to the head li of the T-square, it is understood that it could be attached thereto in any other required position. It is also obvious that notwithstanding the blade appears to be rigidly connected to the head of the T-square, these parts also can well be made inter-relatively movable. It is further conceivablethat instead ofrelying on the sliding of the T-sqiiare upon the drawing-board to cause. the pinion 3, actuated by the teeth of the rack-bar l, to move the index 32 over the dial 30, the same result could be achieved by turning the nut 1l. The latter, in that case, would immediately shift the index the exact distance wanted, and incidentally would serve to rotate the pinion positively in such a manner as to advance the this device has been shown and described, it

will be understood that changes in the form, arrangements, proportions, sizes and details thereoil may be made, without departing from the scope of the invention as defined by the appended claims. Y

Having described my invention, what l desire to secure by Letters Patent and claim l. A. drafting implement comprising a T- square combined with a drawing board and including a carrier supported from the head ot' said T-square, a revoluble element sustained by said carrier, a member attached to said drawing board so as to be engaged Aby said element in a manner to produce a step by step movement thereof along said board, an indeX operatively connected with the ele ment, and a graduated dial rotatably mounted on the carrier under said index, the arrangement being such that the index coacts with the graduations onV the dial and the latter is adjustable relatively to the former.

2. The combination with a T-square and adrawing-board, of a support applied to the head of said T-square near one end, a earrier slidable relatively to said support, a revoluble element journaled in said carrier, a dentate member positioned at one edge ot said drawing boardf'for engagement by d element, an index connected to revolrel conjointly withthe latter, and a cooperating dial independently movable with relation to said index. l

3.' The combination -with a T-square and a drawing-board, ofV a carrier slidably mounted on the head oi said -square, a gear element revolubly suspended from said carrier, a member fixed to one edge oi". sait drawing board arranged to receive the teeth of said element, a dial rotatable independently on the carrier, an index movable relatively to said dial concurrently with the revolving of the element, and means for sliding the carrier together with the dial from a point beyond said head so as to move the gear element into or out of engagement with said member.

4. The combination with a T-square and a drawing board of a rack member attached to one edge of said drawingboard, a pinion arranged to mesh with said member so as to move longitudinally thereof, a carrier supportingsaid pinion, a dial rotatable independently of the latter on said carrier, an indexto saidV dial conjointly rovoluble with the pinion, and means transverse to the member for sliding the carrier to or from the same along said ed0`e of the board.

5. The combination with a T-square and a drawing board, a support overlying the head of said T-square, a carrier slidable on said support, a pinion suspended from said earrier, a rack fixed to one edge ot said drawing` board in position to be engaged by said pinion, a dial on the carrier above its said support, an index connected with the pinion so as to revolve over said dial, and means for sliding the carrier sustained by the same support.

6. The combination with a T-square and a drawing board, o" a carrier mounted on the head oi said 'l`-s piare, a gear-element revolubly supported by said carrier, a rack member lixed to one edge of said drawing board in position to be engaged. by said element, a

Adial rotatable on the carrier, an index arranged to be revolved over said dial Afrom the gear element, and retaining` means holding the dial against rotation while said index is revolved thereover.

7. The combination with a T-square and a drawing board. of a support overlying the head of said T-square, a carrier slidable on said support, a gear element suspended from said carrier, a rack member engageable by said element at one edge of said drawing board, a dial rotatably mounted on the earrier, an index revolved over said dial from the element,` means for sliding the carrier, and other means enacting with the support and the dial to hold the latter against displacement while permitting its independent adjustment relatively to said index.

rEhe combination with a drawing boa rd. o a "tm-square the head whereof is provided with a recess and a passage oilset therefrom. a rack member attached to one edge of said drawing board, a gear element engageable with said member through said recess adjacent to said edge, a slidable carrier supporting said element in the recess, a dial on said carrier, and means located in said passage serving to slide the carrier with the gea r element either toward or away from the rack member.

9. rlihe combination with a drawing board. oit a T-square the head oit which is provided with a recess and a cavity, a rack fixed to one edge of said drawing board` a pinion in said head capable of' meshing with the teeth of said rack through said recess adjoining said edge, a carrier sustaining said pinion within the recess, a dial rotatable on said carrier adjacent to said cavity, and an index operatively connected with the pinion to revolve over said dial.

l0. The combination with a drawing board and T-square, of a rack fixed to one edge of said drawing board, a pinion carried by the head of said T-square and positioned for engagement with said rack, a spindle to which said pinion is secured. said spindle having a neck, a shoulder and a threaded shank` a carrier wherein the part ot the spindle adjoining the pinion is journaled, a portion of said carrier being adapted to reeeive said neol, a dial rotatable on the earrier around the neellz, an index carried by said shoulder in position to be revolved over said dial from the pinion, and a binding element arranged to take over said threaded shank so as to bear upon said index.

11. The combination with a Tsquare and a drawing board, of a supporting plate overlying the head of said T-square and ineluding an aperture, lugs extending from opposite sides of the latter, a carrier slidably mounted on said lugs Within said aperture, a gear element having a spindle journaled in said carrier, a rack member' attached to one odge of said drawing board in position to be engaged by said element, a dial rotatable around said spindle above the carrier, an indeX fixed to the spindle so as to be rotated thereby over said dial, and means for sliding the carrier on the lugs of said plate in order to place the gear element in or out of engagement with the rack member.

12. The combination with a T-square and a drawing board, of a supporting plate formed With a passage having lateral keepers, a carrier slidable on said plate, a gear element supported from said carrier, a rack member fixed to one edge of said drawing board so as lto be engaged by said element, a dial rotatable on the carrier, an index revolnble over said dial through the action of the gear element, a retainer normally holding the dial from rotation and having one end slidable in said passage, and a detent for sliding the carrier and thereto connected parts, said detent being slidable also along the passage and adapted to enter either one of said keepers for looking the gear element either in or out of engagement With the `rack member.

ANDREW E. MAGNUSON.

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