US2400733A - Drafting machine - Google Patents

Description

May 21, 1946. A. L. BAKER 2,400,133

I i DRAFTING MACHINE Filed Nov; 9, v19:59 s sheets-sheet i )LE mvENToR 9- b 1u/sra? afs/eff? f BY @man QW@ 8MM ATTORNEYs May 21, 1946. A. L. BAKER DRAWING MACHINE Filed Nov. 9, 1959 3 Sheets-Sheet 2 INVENTR ALL/STER 54x59 BY @JCM ML ATTORNEYS May 21, 1946. l A, L. BAKER 52,400,733

DRAFTJNG MACHINE Filed Nov, 9, 1939 :s sheetssheet s.

ALL/$727? L. 3H/(ER BY @im emv, ,21 www@ ATTORNEYS Patented May 21, 1946 DRAFTING MACHINE Allister L. Baker, Hoboken, N. J., assignor to Keufel & Esser Company, Hoboken, N. J., a corporation of New Jersey Application November 9, 1939, Serial No. 303,558

6 Claims. (Cl, 33--79) This invention relates generally to parallel motion drafting devices of the kind in which the several tools which the draftsman handles most frequently are embodied, in principle, in one unit to obviats the necessity of a draftsman reaching about for a required tool and thereby enabling the draftsman tol keep his attention concentrated Y directly upon. the drawing.

Drafting devices of this character are common in which adjacent ends of two arms are pivoted together, the free en-d of one arm being secured to the remote side of a drafting board while the free end of the other arm is provided with a. head comprising a protractor and straight edges which are in fixed angular relation to move about the center of the protractoras an axis. Such straight edges have heretofore been so associated with the protractor as to be set and locked at any angle of the protractor or to be automatically stopped at predetermined intervals, but the instrumentalities effecting the setting of the straight edges with respect to readings on the protractor have been characterized by difficulty in the manual actuation of ti locking device bec us f i e a' e of lts mac tion. Each of the arms I2 1s illustrated 1n Figure cessibility.

One object of the present invention is a drafting device of the character described, wherein the locking devices for the straight edges are readily accessible for manipulation without moving the hand from the knob on the protractor head.

The invention also has for its object locking and stop ymechanism for the protractor which may conveniently lbe actuated by the thumb of the hand manipulating the protractor to the desired ..1 i

relative position. in carrying this aspect of the invention into edect, a single control lever is preferably provided on the knob of the head, which is movable in one direction to permit the scales to move freely to any angular position but which, on release, will effect locking of the yprotractor at the nearest even predetermined position.

Another object of the invention is to free the protractor from control bythe latching mechanism so that it may be freely moved from one position to the other by manipulation of the knob, the release being effected by the thumb, say, without removing the hand from the knob. To this end, provision is made for retaining the control lever in the head in latch releasing position.

The invention also resides in the details of construction by which a drafting device is made practical from the standpoint of ease and convenience in manufacture and durc'bility and facility in use.

These and other objects of the invention and the means for their attainment will bemore apparent from the following detailed description, taken in connection with the accompanying drawings illustrating one embodiment by which the invention may be realized, and in which:

Figure l is a view showing the head of the drafting device of this invention, in vertical section;

Figure 2 is a view looking from above and showing the drafting head of Figure l, parts being broken away to illustrate particularly the locking device of this invention;

Figure 3 is a detail view; and y Figure 4 is a View showing the head of the drafting device, looking from below in Figure l.

Referring rst to Figure l, it will be noted that a knob I0 is turnable relative to the pulley 2i at 'the end of the arm l2 to adjust the position of straight edges carried in the frameV member I4 with respect to the pulley which is, as will be understood, a member relatively xed in orienta- 2 as consisting generally of a pair of spaced channeled shaped connecting members, respectively, comprised of the side walls or anges I5, I6 connected by a top wall Il. The ends of the arm I2 are formed with a semi-cylindrical end wall I8 which is a continuation of the outside ange I5 and a flange I9 connecting the inner flange IE at the free end. The space defined by the'walls i3 and I9 may receive a pulley 2I. Obviously the arms may assume any convenient structural shape.

The semi-cylindrical end of the arm IZ is provided, substantially concentric with the end wall I8, with a downwardly extending cylindrical boss or flange .22 and an axial aperture .or bore 24. Within this wall 22 is mounted an anti-friction device, not shown, in which turns the journal 25 of the pulley 2i. The journal 25 is formed with a bore 26 for the pivot pin 28 which is connected at its upper end to the hand knob le and at its lower end is fast as by screws 2% in the frame member I4 supporting the straight edges.

The knob I0 is recessed, as at 3l and receives a generally rectangular frame or box comprised of the top wall 32, end walls 33, 31S and bottom wall 35. The top wal1'32 is formed with a threaded aperture 36 receiving a screw 3l by which the knob I0 and frame 32, 35 are united. The bottom Wall 35 is apertured, as at 39, to receive the cylindrical surface MI on the pivot pin 28, the latter being clamped to the frame by nut 4|. Thus, when the knob is turned, the pivot pin 28 turns with it and turns the straight edge frame |4.

'I'he straight edge frame member I4 lies in parallel relationship to the bottom of the pulley 2| with respect to which it is capable of turning Y and is,` conveniently although not necessarily, in

substantially the shape of a, triangular plate, as

shown in Figure V4, having an arm 43 extending in one direction and an arm 44 extendingY in a direction generally perpendicular thereto, them arms `43 and 44 being adapted to receive the straight edges, as will be understood. The frame 14 thus turns with the knob It and also is abie to turn with respect to the pulley 2|, latch means,

being provided to nx the straight edge frame I4 to the pulley 2| in mantaining the proper rela,-

tionship with the lines on the drawing.

The pulley 2| is provided with a groove 46 forY the endless belt 41 and is rabbeted lin its lower peripheral edge, as at 48. Disposed withinrthe rabbeted portion 48 is an annular plate 5D formed in its periphery at predetermined" intervals with wan t4 of the frame sz-st, This sus@ '12 is v Y 15.

I0 so that the operator may, in grasping the' knob, actuate the member 12 by Vthe Vthumb of Ythe same hand. `The member 12 conveniently Yslides in a passage 13in the knob mand is free to move in the open side betweenjwall 33Y and eccentrically connected with shaft'. As shown,

- it isi pivoted atits inner end to an arm 15 secured locking recesses 5| (Figure 2). Since the pulley 2| is relatively iiXedl in orientation and the latching plate 5|) is immovably carried thereon, said latching plate -is also relatively fixed in orienta` tion. The recesses 5| bear a deiiniterelation t0 the graduations on the protractor 52 whereby, in conjunction with cooperating locking devices 5|, 53 about to be described, the straight edges Ymay be fixed with respect to the protractoi" 52 4at Ypredetermined successive intervals, such as every fteen degrees, with respect to an index as determined, say, on a Vernier plate54 carried with the frame |4. As a matter of fact, the position of the protractor 52'i's determined by the position of the pulley 2| and the band 41. The frame |4 Ywhich carries the straight edges is moved relative to the protractor and the angular position of the straight edges with respect to lines on the draw-l ings yis determined by the engagement of the cooperating locking device/or latch 53 (Figure 4) in a predetermined -recess V5|, it beingr contem` plated that this cooperating locking device shall,

in some circumstances, automaticallysnap into a recess 5| and thuspermit a ready location of` the straight edges through predetermined angles, such as angles of 15 or multiples thereof. Thus, the straight edge carrying frame I4 may be .said to be relatively xed with respect to the latching plate 55. Y

The cooperating latching member is shown in greater detail in Figures 2 and 4 as an angularly shaped levers 53 formed with a detent 56 at its one end which is shaped as to enter into and position itself in one of therecesses 5|. The other extremity 51 of the arm 53 is formed with an aperture 58 for reception on a pin B0 mounted on the triangular plate I4. The latching'lever 53 is normally urged toward the latching plate 50 by pin 62 on one end of a link 63 beneath the lower surface Yof the straight edge plate I4. is held to the bottom of the plate 4 by the enlarged head of a screw 19 threaded into plate I4 and passing through'a slot 8l! inthe link 63. VThe link is pivoted as at G4' to one end E5 of'a lever |55, 55 and held, as by nut 61, on the lower fend Movement of the lever 65, 55 in a clockwise di,- rection, as viewed in Figure 4, under the influence of the spring 69 will tend to urge the detent 56 of the latch member 53 into a'recess 5| of the on the squared end 15 of shaft 58, on which it is Vheld by a nut 11. Y.

The plunger 'I2 is preferably pivotally connecte ed to the arm 15 as by the pin, the head of which is shown at 18, sothat the plunger may swing through an arc about pin 18. The slot in which the plunger 12 reciprocates is of a dimension, circumferentiallyfsuncient to permit the plunger toA assume the full line position of Figure 2 and also'the dotted Yline position in that figure. In the full line positionthe plunger 12 may be reciprocated to actuate the latch.-

To retain the latch in inoperative positionyas shown in dotted lines in Figure 2, that is, so that the straight edge plate I4 may be rotated freely,A v

the plunger 12 is formed With a recess or 'slot Y8| and a portion of the edge of Wall 34 is cut out,V Y and preferablydisplaced, as a tongue 14. Then, when the plunger is pressed inwardly and moved ina counter-clockwise direction, as viewed in Figure 2, the tongue 14 enters the notch 8| and Y retains the plunger Yin latch releasing position.

In order to holdthe straight ed-ges'at points intermediate they registering positions Vof the notches 5|, a clamping ylever 82 L, (Figures 2 and 3) is provided; This lever is formed with a threaded` aperture 33 in one end, to serve as a nut which is threaded on to a threaded portion 84 of the pin 28. When the clamping lever is turned, it bearson a thrust bearing 85 and serves to draw upwardly the pin 28 and clamp or draw the straight edge carrying frame |4 or an element i 81 of the pivot pin 28 by which the straight edge supporting plate is Xed to the pivotr pin against the pulley'to frictionally hold the straight Yedges at any desired angle. 'Y Y Heretofore, the actuating lever for the; latch controlling the position of the straight edgesY has 'been disposedat a relatively low point with respect to the operating knob and proximate the plane of the straight edges. This has 'been inconvenient and it has generally required two hands to manipulate. By the present invention,

it will be seenr that the draftsman can "readily release the catch while his .hand is on the knob Link sa I0 and turn the frame |4, and the straight edges carried thereby, tothe desired graduation on the protractor, whenhe can again Arelease the plunger` 12 and permit the spring 69 to move the latch into a selected recess 5| Again, when he has released the latch he canmove the plunger intov engagement withV the retaining member 14 to retain the latch in oiT position so that the protractor may be freely moved to different angular positions. n Y

Various modications will occur to those skilled in the art in the composition, connguration and disposition of the component elements going to make up the invention as a Vwhole as well as ink 4 the selection and combination of features to accomplish the results sought, and no limitation is intended by the phraseology of the foregoing description or illustrations in the accompany drawings, except as indicated in the appended claims.

What is claimed is:

1. In a drafting machine head, in combination, a tubular pivot pin formed at its lower end with a flange, a pulley rotatable about the pivot pin and formed therebelow with an axial recess receiving ange, a straight edge frame secured to the flange, a latching plate secured to the pulley above the straight edge frame, said straight edge frame being formed with an aperture, a latch pivotally mounted on the frame proximate the aperture for coaction with the latching plate, a shaft within the tubular pivot pin, an arm on the shaft -below the frame, and a link connecting the arm with the latch for actuation thereof between latched and unlatched position.

2. In a drafting machine head, in combination, a tubular pivot pin formed at its lower end with a flange, a pulley rotatable about the pivot pin and formed therebelow with an axial recess receiving the flange, a straight edge frame secured to the ange, a latching plate secured to the pulley above the straight edge frame, said straight edge frame being formed with an aperture, a latch pivotally mounted on the frame proximate the aperture for coaction with the latching plate, a shaft within the tubular pivot pin, a lever arm mounted intermediate the ends thereof on the lower end of the shaft, and a spring extending between one arm of the lever and the frame.

3. In a drafting machine head, in combination, a tubular pivot pin formed at its lower end with a flange, a pulley rotatable about the pivot pin and formed therebelow with an axial recess receiving the flange, a straight edge frame secured to the flange, a latching plate secured to the pulley above the straight edge frame, a latch plvotally mounted on the frame for coaction with the latching plate, a shaft within the tubular pivot pin, a lever arm mounted intermediate the ends thereof on the lower end of the shaft, and a spring extending between one arm of the lever and the frame.

4.. In a drafting machine head, in combination, a tubular -plvot pin, a pulley rotatable about the pivot pin, a straight edge frame secured to the pivot pin, a latching plate secured to the pulley above the straight edge frame, said straight edge frame being formed with an aperture, a latch pivotally mounted on the frame proximate the aperture for coaction with the latching plate, a shaft within the tubular pivot pin, a bell crankk lever mounted intermediate the ends thereof on the lower end of the shaft, one free end of said lever being shorter than the other, a spring extending from the longer arm of the lever to the frame, and a link extending from the shorter arm of the lever to the latch to actuate the same.

5. In a drafting machine head, in combination, a tubular pivot pin, a pulley rotatable about the pivot pin, a straight edge frame secured to the pivot pin, a latching plate secured to the pulley above the straight edge frame, said straight edge frame being formed with an aperture, a latch pivotally mounted on the frame proximate the aperture for coaction with the latching plate, a shaft within the tubular pivot pin, a frame having at least one vertical edge carried by the pivot pin, an arm on the shaft within the frame, a plunger pivoted to the end of the arm, said pivoted plunger being formed with a notch so positioned as to engage the vertical edge in one position of the arm to retain the latch in open position.

6. In a drafting machine head, in combination, a tubular pivot pin formed at its lower end with a flange, Va pulley rotatable about'the pivot pin and formed therebelow with an axial recess receiving the flange, a straight edge frame secured to the flange, a latching plate secured to the pulley above the straight edge frame, said straight edge frame being formed with an aperture, a latch pivotally mounted on the frame proximate the aperture for coaction with the latching plate, a shaft within the tubular pivot pin, a frame having at least one tongue carried by the pivot pin, an arm on the shaft within the frame, a plunger pivoted to the end of the arm, said pivoted plunger being formed with a notch so positioned as to engage the tongue in one position of the arm to retain the latch in open position.

ALLISTER L. BAER.

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