US2377429A

US2377429A - Drafting machine

Info

Publication number: US2377429A
Application number: US442823A
Authority: US
Inventors: Ketting Leendert
Original assignee: Keuffel and Esser Co
Current assignee: Keuffel and Esser Co
Priority date: 1942-05-13
Filing date: 1942-05-13
Publication date: 1945-06-05
Anticipated expiration: 1962-06-05

Description

L. KETTING DRAFTING MACHINE I Filed May 13, "1942 3 Sheets-Sheet 1 INVENTOR LEENDf/PT ksrmvs AMML ATTORNEYS June 5, 1945.

- I. KETTING DRAFTING MACHINE Filed Ma 13, 1942 3 Sheets-Sheet 2 INVENTOR. (ff/V0597 IfETT/AG ATTORNEYS NNF June 5, 1945. T-n I 2,377,429

DRAFTING MACHINE Filed May 13; 1942 s Sheets-Shes s EE/VDE/PT KETT/M WWW/5M ATTORNEYS Patented June 5, 1945 2,377,429 DRAFTING MACHINE Leendert Ketting, Secaucus, N. J1, assignor to Keufiel & Esser Company, Hoboken, corporation of New Jersey N. J., a

Application May 13, 1942, Serial N0. 442,823

23 Claims.

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 obviate the necessity of a draftsman reaching about for a required tool and thereby enabling the draftsman to keep his attention concentrated directly upon the drawing.

Drafting devices of this character are common in which adjacent ends of two arms are pivoted together, the free end of one arm being anchored 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 and move about the center of the protractor as an axis. Such straight-edges have heretofore been so associated with the protractor asto beset and locked at any angle of the protractor or to be automatically locked at predetermined intervals. However, the instrumentalities effecting the setting of the straight-edges with respect to readings on the protractor have been characterized by difliculty in the manual actuation of the locking device because of itsinaccessibility.

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

The invention also has for one of its objects locking and releasing mechanism for the protracv tor which may conveniently be actuated by either the thumb or a finger, as found most convenient, of the hand manipulating the. knob by which the scale frame is moved to the desired relative position. In carrying this aspect of the invention into effect, a rotatable wheel is preferably provided on the knob, which is movable in either direction to unlatch the straight-edges and permit them to be moved freely to any angular position but which, on release, will effect locking of the protractor at the nearest even predetermined position.

Another object of the invention is to return the rotatable wheel on the knob to initial position whenever it is released by the operator. Accordingly, power is stored in power storing devices when the wheel is moved from initial position and which is utilized to return the wheel.

The invention further seeks an instrumentality transferring the rotary movement of the thumb or finger actuated devices to the latching devices for the protractor with a minimum number of parts to simplify assembly and to avoid the necessity for interlocking lever arms and other movement transferring devices.

The invention also resides in the details of construction by which the drafting device is made practical from the standpoint of ease, simplicity and convenience in manufacture and assembly as well as durability and facility in use.

These and other objects of the invention and the means for their attainment will be'more 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 1 is a diagrammatic view showing the drafting machine mounted ona drawing table;

Figure 2 is a view showing the head of the drafting device of this invention in verticalsection;

Figure 3 is a fragmentary view of the drafting head in vertical section taken in the plane perpendicular to the plane of the section illustrated in Figure 2 and on the line 3-3 of Figure 2, looking in the direction of the arrows; and

Figure 4 is a transverse view taken in the plane indicated by the line 4-4 of Figure 2, looking in the direction of the arrows.

Referring first to Figure 1, there is illustrated a typical endless band and pulley type of drafting machine which comprises a pair of arms 6, I each comprised of tubes 8 within which an endless band 9 in each arm travels. The adjacent ends of the arms are pivoted together, as at Ill. The free end of one arm is anchored, as at l2,'to the side of a drafting board l3 while the free end of the other arm is provided with a supporting head l4 comprising the knob or handle I6, a protractor I8 and frame means 20 supporting the straight-edges 22. Obviously the arms may assume any convenient structural shape.

As shown the tubes 8 extend into a frame member 24 comprising an outer flange 26 within which the pulley 28 turns. Inwardly of flange 26 is a cylindrical flange 30 concentric with the axis of the head. Rotatably mounted within the cylindrical flange 38, as by the ball races 32, 33 and ball bearings 34, is a cylindrical hub portion 35 which is integral with the pulley 28 and retains the bearing member 32 by means of a retaining ring 36 threaded to the upper end of the hub 35. Thus the pulley 28 is free to rotate within the frame portion 24 of the head without friction.

The pulley member 28 is rabbeted as at 38 to receive the protractor plate I8 and a locking plate 40 spaced from the protractor plate by a spacing ring 42. The locking plate 40 and the protractor I8 are fixed to the pulley by means of the screws or other securing means 45. Within the cylindrical hub 35 of the pulley is disposed a sleeve 44 functioning as a pivot pin and having its upper end of reduced diameter, asindicated at 46, so that a shoulder 48 is provided substan tially flush with'the upper surface of the pulley hub 35. The sleeve 44 is secured to, as by being made integral with, a plate-like bottom portion 50 to which the straight-edge supporting frame 20 is secured as by the screws 52.

The knob I6 is secured to the pivot pin 44 so that rotation of the knob I6 will rotate the straight-edge supporting frame 20' whenever that frame is released from the pulley by disengaging common type of latch member 54 from the universally mounted oscillating member or lever 90-98. In order to hold'the straight-edge at points intermediate the registering position of the notches, a lock member I is provided which, since it is rarely used, is carried, in the illustrated embodiment, at a low point as on the frame 20. Any convenient clamping lever or locking means may be provided within the purview of this invention and no further discussion thereof is deemed necessary.

Beneath the slide 80 is a lever I02, I04 pivoted to the frame 20, as at I05, and connected to the slide 86 with provision for lost motion by a pin I06 in a slot in slide 86. The free end I04 of the lever I02, I04 is positioned proximate the manually actuatable device I 00, which is used toothed latching plate 40, as will be understood.

The knob I6 is operatively connected withthe pivot pin in the following manner:

The knob I6 is recessed,'as at 56, and receives a generally cylindrical or cup-shaped knob-supporting frame member 60-62 comprised of the, cylindrical or annular wall 60 and a bottomwall 62 which extends beyond-the circumferential margin of the wall .60 as a flange 63 to support a manually actuatable device 14 controlling the pawl 54 as hereinafter described. The knob I6 is secured to the wall 60 as by a screw -64 while the bottom wall 62 is keyed, as at 66, to the pivot pin 44 whereby rotary movement of the knob and frame member will turn the sleeve-like pivot pin 44 and with it the straight-edge supporting frame 20. The bottom surface of the bottom wall 62 rests on a spacing ring 65 supported on shoulder 48 of pivot pin 44. The cup-shaped member 60-62 and pivot pin 44 are thus rotatable with respect to pulley 28.

The manually actuatable devices controlling the latch, are carried by the knob I6 above the level of the arm and in a position to be operated by the same hand of an'operator as is used to grasp the knob. As shown, the manually actuatable device takes th'eform of an annulus indicated generally at 14 and comprised of a hub portion 68 supported on the flange 63 and a finger engageable depressed portion 69 having spaced radial ribs I0. I

The upper end 46 of the tubular pivot pin 44 is held-in position by a nut I2 threaded on the upper end of the pivot member and bearing against the bottom wall 62 of the cup-shaped member to retain-it against the spacing ring 65 on shoulder 48. frame 60-62 are held in assembly on the pivot member 44 by means of the disc-like portion 50 at its lower end and the nut-like member 12 at its upper end. The nut member I2 may, if desired, conveniently form a'supporting surface for parts of the latch actuating means.

The cooperating latching member is shown in greater detail in Figured as an angular shaped lever 54 formed with a detent' IS at its one end, which is so shaped as' to enter into and position itself in one of the recesses 18 of the latch plate 40. The other extremity of the pawl 54 is formed with an aperture '80 for reception on a pin 82 mounted on the straight-edge supporting means 20. The'lever 54 is urged toward the latching plate40 by the. engagement of a pin 84 therewith, which pin 84 is'carried by the end of the slide 86. The slide is reciprocable in a slot or the equivalent 80 formed in'the frame and terminating proximate the end 90 of a Thus the pulley 28 and knob to hold the latching plate 40 at intermediate points. By this relation of parts, actuation of the device I00 will shift the lever and effect release of the pawl, as will be understanable. The other end I02 of lever I02, I04 is urged toward the axis of the pulley 28 by power storing means shown as the coil spring I08 connected at the one erfd to the lever I02-I04 and at the other end to the frame 20.

The bore IIO of the pivot tube 44 is enlarged in its lower half, and at the lower end of the enlarged portion is flared, as at II2, to provide, there, a passage of greater area. Seated in the surface formed by the bore H0 is the circumferential bead 92 of the rocking member or lever 90-98 which tapers from an intermediate point defined by the bead 92 in both directions, as at 95, 96. The lower extremity 96 of the lever terminates in an elongated rectangular end or block 90, the lower surface of which is curvilinear, as at 91, and rests on the bottom of a rectilinear slot 4 formed in a supporting or positioning plate II6 which is conveniently secured to the frame 20 as by the screws III. The block 90 is thus disposed substantially below the plane of the lower end of the pivot pin 44 and is adapted to engage the constricted end II5 of the reciprocating slide 06 which extends into the slot H4 in plate II6. When the lever 90-98 is pivoted on the head 92 in a counterclockwise direction, as viewed in Figure 2, the head 90 engages the end of the link 86 forcing it to the right as viewed in that figure to disengage the latching device 54 from the latching plate 40. The lever 90-98 is thus confined to rock in the vertical plane of the slot I I4, and does not rotate axially.

The upper extremity oi the. swivelling lever -98 terminates in a spherical member or ball 98 disposed above the plane of the upper surface of the nut-like member I2.

The lever 90-98 is actuated and controlled to manipulate the latch 54 from its upper end. The wall 60 of the cup-shaped knob carrying frame 60-63 is formed with oppositely disposed cut-out portions .on opposite sides defined by vertical parallel walls II8, I20 and H8, I20, which extend downwardly sufficiently so that the bottom I I9 of the cut-out portion conveniently lies above the plane of the upper surface, of the nut-like member I2. Each cut-away portion H8, I20 and 8', I20 0! the wall 60 subtends such an angle as to permit sufficient movement oi the actuating devices to actuate the latching devices 54.

Slidable on the bottom surface H9 of the cutout portions of the knob'frame 60 are the end portionsof a transversely extending bar or slide I22 formed intermediate its ends with a recess,

shown as an aperture I24 closed by a topplate I26, and which receives the spherical end 98 of the double cone rocker-arm 9098. The transverse bar I22 is of a length sufficiently greater than the outside diameter of the cup-shaped portion 60 that the ends I28, I28 thereof may, in all positions of the bar, extend through the cut-away portions of the supporting frame 60 for engagement and actuation by manually actuatable means I'I4, which is illustrated as carried below the handle I6.

As illustrated, the upwardly projecting cylindrical portion II of the annular hub 68 of the manually actuated control member I0'I4 is cutaway on opposite sides, as at I29, I29 to the plane of the bottoms II9 of the cut-out portions II8, I20 and H8, I20 of the frame member 60--62 so that an arcuate hub portion I30 subtends substantially the same angle as the adjacent arcuate portion of the wall 60 of the cup shaped frame member 60-62, while the hub portion I32 diametrically opposite the aforesaid portion I30 subtends preferably a materially smaller angle. Then, when the annular actuating member I4 is rotated in either direction by actuation of member 68-44, one end I29 or the other end I29 of the arcuate portion I30 will engage a protruding end I28 or I28 of the bar I22 and move it in the same direction while the opposite end of the bar I28 or I28, as the case may be, is fulcrumed on the wall I20 or I20. This displaces the apertured intermediate portion of the bar I22 toward the rear hub portion I32 carrying with it the upper end 98 of the member 90-98 and thereby causing it to rock on its fulcrum 92 and in so rocking engage its lower end 90 against the link 86 and actuate the latch, A resilient device is provided to normally urge the end 96 of the swivelling lever toward the left, as viewed in Figure 2. As shown, the bar I22 is provided with receptacles I34, which maybe holes drilled in the bar in a horizontal plane. Into each one of these holes is inserted the anchoring end I36 of a spring I36-I38 shown in this instance of round resilient wire. The ends I36 are so bent that the intermediate portions I31 cross one another, say, on the axis of the device and engage at their free ends I38 the edges II8--II8' of the rearmost arcuate wall portion 60. Conveniently, the extremities I38 of the springs are angularly bent, as at I38, away from the bar I22 so as to provide an angular portion which will position itself on a wall portion H8, 8'. against displacement. Thus, when the manually actuatable device I4 is rotated, one end of the bar I22 is moved rearwardly carrying with it the upper end 98 of the swivel against the action of the springs, the spring not under compression functioning to urge the other end of the bar against the arcuate wall portion I20 which is relatively stationary and serves as a fulcrum so that the bar may readily rock when the actuatable device I4 is manipulated.

The operation of the device will be apparent from the foregoing description. Sufiice it to say that a draftsman may release the straight-edges by a slight rotation of the star-wheel "with reference to the knob I6 by the thumb or finger of the same hand which engagesthe knob and without removing the hand from the knob. Rotation of annulus I4 in either direction carries with it the cam I30 which in turn brings the advancing end of the arcuate element I30 (depending on the direction of rotation) against one of the ends ofthe bar I22 and forces the arm end to the left, asviewed' in Figure '4.- This brings an end of the composite bar I22 toward the left against the action of the spring I36-I38, as viewed, and .rocks the swivel .in' a counterclockwise direction to advance the'slide 86 and cause release of the pawl 54. The knob I6 and star wheel I4 are then turned simultaneously to adjustthe straight-edges to the new angular position when the star, wheel I4 is released permittingthe parts'of the locking instrumentalities to return to originalposition under the influence of the springs I08 and, I36--I30 and latching the frame 20 in the selected position. In the return of the parts, the walls I20 and I20 serveas stops for bar I22 in its movement to initial position. I 1 H Various modifications will occur to those skilled in the art in the composition, configuration and disposition ofthe component elements going to make up the invention as a whole as well as in 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 accompanying drawings, except as indicated in the appended claims.

What is claimed is:

1. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed'in orientation, reciprocating means below said straight-edge supporting frame for actuating said latching -means, a tubular pivot pin mounting said frame for rotary movement below said means fixed in orientation, a lever fulcrumed in the borev of said pivot pin, a cupshaped'frame member carried by the upper end of the pivot pin, av handle fixed to said frame member, the wall: of said cup-shaped member being oppositely slotted, a bar whereof the ends protrude through the slots in the wall of the cupshaped member, means operatively connecting the bar and an end of the lever, manually actuatable means rotatably mounted upon'thecupshaped member, an arcuate cam carriedb said manually actuatable means and adapted to selectively engage at least one end of the bar upon oscillation of said manually actuatable means to oscillate the bar and actuate the lever and spring means carried by the bar and engaging the cupshaped member to oppose movement of the bar when the manually actuated means is actuated.

2. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame tosaid means fixed in orientation, reciprocatingmeans below said straight-edge supporting'frame for actuating said latching means, a tubular pivot pin mounting said frame for rotary movement below said means fixed in orientation, a lever fulcrumed in the bore of said pivot pin, a cup-shapedframe member carried by the upper end of the pivot pin, a handle afiixed to said frame member, the wall of said cup-shaped member being oppositely slotted, a bar whereof the ends protrude through the slots in the wall of the cup-shaped member, means operatively connecting the bar and the upper end of the lever, manually actuatable means comprising a hub rotatably mounted upon the cup-shaped frame -.for reciprocation and whereof the hub is interrupted to provide an arcuate cam, the ends of which are selectively engageable with the respective ends of the bar upon oscillation of said manually actuatable means to' oscillate the bar and thereby the lever,

and spring arms-'carriedby the respective ends of the bar and crossing one another to extend within the slots and, engaging the cup-shaped member and engage a wall-thereof to yieldingly oppose angular movement of the bar when the oscillating member and manually actuated means are. rotated.

-3. In a drafting machine, means fixed in orientation, a. straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means below said straight-edge supporting frame for actuating said latching means, a tubular pivot pin whereof the lower portion of 'the bore is of an increased diameter extending through-said means-fixed in orientation and mounting said frame for rotary movement below said means fixed in orientation, a handle fixed to'said pivot pin above said first named means, a lever fulcrumed in the bore of smaller diameter and progressively decreasing in diameter towards its ends, a cup-shaped frame member carried by the upper end of the pivot pin, a handle affixed to the cup-shaped frame member, the wall of said cup-shaped member being oppositely slotted, a bar whereof the ends protrude through the slots in the. wall of the cup-shaped member, means operatively connecting the bar and the upper end of the lever, manually actuatable means rotatably mounted upon the cup-shaped member, an arcuate cam carried by the manually actuatable means and whereof the ends are selectively engageable with the respective ends of the bar upon oscillation of said manually actuatable means to oscillate the bar and thereby the lever, and spring means carried by the respective ends of. the bar and engaging the cup-shaped member to yieldingly oppose angular movement of the bar when the manually actuated means is oscillated in either direction.

- 4. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, m ans for latching said frame to said means fixed in orientation, reciprocating means below said straight-edge supporting frame for actuating said latching means, a tubular pivot pin mounting said frame for rotary movement below said means fixed in orientation, a lever fulcrumed in the bore of the pivot pin, a cup-shaped frame member carried by the upper end of the pivot pin to which the handle is affixed, the wall of said cup-shaped member being slotted, a bar whereof the ends protrude through the slots in the wall of the cup-shaped member, operative connections between the bar and the lever, said cupshaped member being formed with flange means, manually actuatable means rotatably mounted upon said flange means for reciprocation and having anarcuate cam, the ends-of which are selectively, engageable with the respective ends of the bar upon oscillation of said manually engageabie member to oscillate the bar and thereby the lever and spring ,means to yieldingly oppose movement of the bar when the oscillating member is rotated in either direction. 1

, 5. Ina drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means below said straight-edge supporting frame for actuating said latching means, a pivot pin mounting said frame for rotar movement belowsaid means fixed in orientation, a lever fulcrumed in the pivot pin, a. frame member carried by the upper end of the pivot pin to which the handle is aflixed, said member being oppositely slotted, a bar whereof the ends protrude through the slots in the member, operative connections between the bar-and the lever, manually' actuatable means rotatably mounted upon the frame member for reciprocation, arcuate cam means carried by the manually actuatable means whereof the ends are selectively engageable with the respective ends of the bar upon oscillation of said manually engageable means to oscillate the bar and spring arms carried by the respective ends of the bar and crossing one another to engage the sides of the slots in the cup-shaped member and yieldingly oppose angular movement of the bar when the oscillating member is rotated in either direction.

6. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means below said straight-edge supporting frame for actuating said latching means, a pivot pin whereof the lower portion of the bore is of an increased diameter and extending through said means fixed in orientation and mounting said frame for rotary movement below said means fixed in orientation, a lever fulcrumed in the bore of smaller diameter and progressively decreasing in diameter towards its ends, a frame member carriedby the upper end of the pivot pin to which the handle is affixed, a bar, means operatively connecting the bar and the upper end of the lever, manually actuatable means rotatably mounted upon the frame member, a cam carried by the manually actuatable means and engageable with the bar upon oscillation of said manually engageable member to pivot the bar and spring means to yieldingly oppose movement of the bar when the actuatable means is actuated.

7. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said mean fixed in orientation, reciprocating means below said straight-edge supporting frame for actuating said latching means, a pivot pin whereof the lower portion of the bore is of an increased diameter and extending through said means fixed in orientation and mounting said frame for rotary movement below said means fixed in orientation, a lever formed intermediate its ends with a circumferential bead fulcrumed in the bore of the pivot pin, a frame member carried by the upper end of the pivot pin, a handle afiixed to the frame member, a bar operatively connected with the lever, manually actuatable mean rotatably mounted upon the frame member for reciprocation, a cam carried by said manually actuatable means to pivot the bar and spring means to yieldingly oppose movement of the bar when the manually actuatable means is actuated.

8. In a drafting machine, means fixed in orientation, a straight edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means below said straight-edge supporting frame for actuating said latching means, a pivot pin whereof the lower portion of the bore is of an increased diameter extending through said means fixed in orientation and mounting said frame for rotary movement below said means fixed in orientation, a lever fulcrumed in the bore of smaller diameter and progressively decreasing in diameter towards its ends. the upper end of the lever being formed with a ball, a frame member carried by the upper end of the pivot pin, a handle affixed to the frame member, a bar formed with a recess receiving the'ball onv the lever, manually actuatable .means rotatably mountedupon the frame member, a cam carried by said'manually actuate able means to pivot the bar and spring means to yieldingly oppose pivotal movement of the bar about the ball when the actuatable means is actuated.

9. Ina drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means below said straightedge supporting frame for actuating said latching means, a tubular pivot means extending through said means fixed in orientation and mounting said frame for rotary movement below said means fixed in orientation, a lever in the bore of said pivot means, means to support the lever in position in the pivot means, said lever supporting means being supported independently of the pivot means and positioning the latch actuating means, a frame member carried by the upper end of the pivot pin, a handle afiixed to the frame member, manually actuatable means rotatably mounted with respect to the frame member and operative connections betweenthe manually actuatable means and the lever for actuation thereof.

10. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means below said straight-edge supporting frame for actuating said latching means, a tubular pivot pin extendin through said means fixed in orientation and mounting said frame for rotary movement below said means fixed in orientation, the lower portion of the bore of said pivot pin being of an increased diameter and being flared at its lower end, a handle fixed to said pivot pin above said first named means, a lever formed at the lower end with a head elongated in the direction of the latch actuating means, a plate supported beneath the pivot pin and independently thereof to retain the lever in the pivot pin and in position to actuate the latch actuating means, a frame member carried by the upper end of the pivot pin, a handle aflixed to the frame member, manually actuatable means rotatably mounted upon the frame and operative connections between the manually actuatable means and th lever for actuation thereof.

11. In a drafting machine, means fixed in orientation, a straight-edge supporting frame. means for latching said frame to said means fixed in orientation, reciprocating means for actuating said latching means, a tubular pivot pin mounting said frame for rotary movement, a lever fulcrumed in the bore of said pivot pin, a frame member carried by the pivot pin, said member being slotted, a bar whereof an end protrudes through the slot in the member, means operatively connecting the bar and an end of the lever, and manually actuatable means mounted upon the frame member, a cam carried by said manually actuatable means and adapted. to engage the bar upon movement of said manually actuatable means to move the bar and actuate the lever and spring means between the bar and the member to oppose movement of the bar when the manually actuated means is actuated.

12. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means for actuating said latching means, a tubular pivot pin mounting said framefor rotary movement, a lever fulcrumedin the bore of said pivot pin, a frame member carried by the pivot pin, said member being slotted, a bar whereof an end protrudes through theslot in the member, means operatively connecting the bar and an end of the lever, and manually actuatable means mounted upon the frame member, a cam carried by said manually actuatable means and adapted to engage the bar upon movement of said manually actuatable means to move the bar and actuate-the lever.

13. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means for actuating said latching'means, a tubular pivot pin mounting saidframe for rotary movement, a lever fulcrumed in the bore of said pivot pin, a, frame member carried by the pivot pin, a bar relatively movable with respect to the member, means op eratively connecting the bar and the upper end of the lever, manually actuatable means mounted upon the frame, an arcuate cam on the manually actuatable means and selectively engageable with the bar upon actuation of said manually actuatable means to actuate the lever and spring arms carried by the respective ends of the bar and crossing one another to engage the member to yieldingly oppose movement. of the bar when the manually actuatable means is actuated.

14. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means below said straight-edge supporting frame for actuating said latching means, a tubular pivot pin whereof a portion of the bore is of an increased diameter extending throughsaid means fixed in orientation and mounting said frame for rotary movement' below said means fixed in orientation, a handle fixed to said pivot pin above said first named means, a lever fulcrumed in the bore of smaller diameter, a frame member carried by the pivot pin, a handle afiixed to the frame member, a pivotally mounted bar on the member, means operatively connecting the bar and the lever, manually actuatable means on the member, and a cam carried by the'manually actuatable means and engageable withthe end of the bar to oscillate the bar and thereby the lever.

15. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means for actuating said latching means, a tubular pivot pin mounting said frame for rotary movement, a lever fulcrumed in the bore of the pivot pin, a frame member carried by the upper end of the pivot pin to which the handle is affixed and having a slotted wall, a bar whereof the end'protrudes through the slot of the member, operative connections between the bar and the. lever, said member being formed with fiange means, manually actuatable means rotatably mounted upon said flange means and having an arcuate cam, the ends of which are selectively engageable with the respective ends of the bar upon actuation of said manually actuatable member to oscillate the bar and thereby the lever.

16. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, a pivot pin mounting said frame for rotary movement below said means fixed in orientation, a lever fulcrumed in the pivot pin, a frame member carried by the upper end of the pivot pin, a handle afllxed to the frame member, said member being oppositely slotted, a bar whereof the ends protrude through the slots in the member, operative connections between the bar and the lever, manually actuatable means mounted upon the frame member, cam means carried by the manually actuatable means to selectively engage the respective ends of the bar and spring arms carried by the respective ends of the bar and crossing one another to engage the respective slots in the member and yieldingly oppose angular movement of the bar.

17. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means for actuating said latching means, a pivot pin whereof the lower portion of the bore is of an increased diameter and extending through said means fixed in orientation and mounting said frame for rotary movement, a lever fulcrumed in the bore of smaller diameter and progressively decreasing in diameter towards its ends, a frame member carried by the upper'end of the pivot pin, a bar, means cperatively connecting the bar and the upper end of the lever, manually actuatable means rotatably mounted upon the frame member, a cam carried by the manually actuatable means and engageable with the bar upon oscillation of said manually engageable member to pivot the bar and spring means to yieldingly oppose movement of the bar when the actuatable means is actuated.

18. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means for actuating said latching means, a pivot pin whereof the lower portion of the bore is of an increased diameter and extending through said means fixed in orientation and mounting said frame for rotary movement, a lever formed intermediate its ends with a circumferential bead fulcrumed in the bore of the pivot pin, a handle affixed to the pivot pin, a bar pivotally mounted and operatively connected with the lever, manually actuatable means carried proximate the handle, a cam carried by said manually actuatable means to pivot the bar.

19. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means for actuating said latching means, a pivot pin mounting said frame for rotary movement, a lever fulcrumed in the bore, the upper end of the lever being formed with a ball, means carried by the upper end of the pivot pin, a bar pivotally mounted and formed with a recess receiving the ball on the lever, manually actuatable means mounted upon the last named means, and a cam carried by said manually actuatable means adapted to engage and pivot the bar.

20. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, latch actuating means, pivot means mounting said frame for rotary movement, a lever carried in parallel relation with the pivot means, means to support the lever in position with respect to the pivot means, said lever supporting means being supported independently of the pivot means and positioning the latch actuating means, handle means carried by the upper end of the pivot means, manually actuatable means rotatably mounted with respect to the frame member and operative connections between the manually actuatable means and the lever for actuation thereof.

21. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, reciprocating means for actuating said latching means, pin means extending through said means fixed in orientation and mounting said frame for rotary movement, a lever formed at the lower end with a block elongated in the direction of the latch actuating means, grooved means beneath the pivot pin supporting the latch actuating means receiving the block and handle means supported by the pivot means, manually actuatable means and operative connections between the manually actuatable means and the lever for actuation thereof.

22. In a drafting machine, means fixed in orientation, a straight-edge supporting frame, means for latching said frame to said means fixed in orientation, latch actuating means, a pivot pin formed with a bore and mounting said frame for rotary movement, a lever fulcrumed in the bore, a'frame member carried by the upper end of the pivot pin having a slotted wall, a bar whereof an end protrudes through the slot in the member to actuate one end of the lever, and manually actuatable means mounted upon the frame member to engage the bar upon movement of said manually actuatable means to move the bar and actuate the lever.

23. In a drafting machine, in combination, means fixed in orientation, a straight edge supporting frame, means to latch said frame to said means fixed in orientation, tubular pivot means mounting said frame for rotary movement, a lever fulcrumed in the bore of said-tubular pivot means, annular means 'rotatably mounted about the pivot means, operative connections between the lever and the latch, handle means carried by the pivot means comprising at least one fulcrum, means to actuate said lever from said rotatably mounted means comprising bar means, means supporting the bar means for movement about at least one fulcrum, spring means urging the bar toward the fulcrum, and operative connections between the rotatably mounted means and the bar means whereby rotation of said rotatably mounted means actuates the latch means.

LEENDERT KE'I'I'ING.