US2438220A

US2438220A - Drafting machine

Info

Publication number: US2438220A
Application number: US504668A
Authority: US
Inventors: Ketting Keendert
Original assignee: Keuffel and Esser Co
Current assignee: Keuffel and Esser Co
Priority date: 1943-10-02
Filing date: 1943-10-02
Publication date: 1948-03-23
Anticipated expiration: 1965-03-23

Description

March 23, 1948. KETTING 2,438,220

DRAFTING MACHINE Filed Oct. 2, 1943 3 Sheets-Sheet 1 March 23, 1948. L. KETTING DRAFTINQ MACHINE 5 Sheets-Sheet Filed Oct. 2, 1.945

INVENTQR LEENDERT KETT/NG ATTORNEY 5 Mafch 23, 1948. 1... KETTING DRAFTING MACHINE 3 Sheets-Sheet 3 Filed Oct. 2, 1943 INVENTOR LEENDERT KETT/NE ATTO R N EYS Patented Mar. 23., 1948 DRAFTIN G MACHINE Leendert Ketting, Secaucus, N. J., assignor to Keuffel & Esser Company, Hoboken, N. J., a corporation of New Jersey Application October 2, 1943, Serial No. 504,668

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. More particularly the invention relates to parallel motion drafting devices of the band and pulley type although not so limited.

Drafting devices of this character are common in which an arm, broadly speaking, is articulated and whereof adjacent ends of two arm sections are pivoted together, the free end of one arm section being secured to the remote side of a drafting board while the free end of the other arm section is provided with a head comprising a protractor and straight-edges which are in fixed angular relation to move about the center of the protractor as an axis. Where a drafting device of this character is used upon a drawing board which is disposed in an inclined plane, the weight of the free arm and/or the head on the free end thereof is likely to cause the angle between the two arm sections to become more obtuse. A counterbalance has heretofore been proposed as. anexpedient to counteract the weight of the arm.

While the vertical and horizontal lines on a drawing may be perpendicular to one another, it is sometimes found, where changes are to be made to the drawing and it is again ailixed to a drawing board for that purpose, that such vertical and horizontal lines are each at a slight and equal angle to the respective vertical and horizontal straight-edges carried by the drafting machine to be used by the draftsman about to make changes on or additions to the drawing. Shifting the drawing on the drafting table so that the base line thereof coincides with the straight-edge about to be used is not always practical.

One object of the present invention is to provide a drafting machine whereof the straightedges may be adjusted to conform to the lines already drawn. Such an adjustment is commonly referred to as a base line adjustment. In carrying this aspect of the invention into effect, the instrumentalities maintaining the straight-edges in orientation, in this instance, an endless belt and pulley, are capable of being angularly shifted to that degree necessary to cause a straight-edge to coincide with a given base line.

It is also an object of the invention to enable a draftsman to work from any base line from horizontal to vertical up or vertical down or from Claims.

any base line intermediate between these verticals. By this invention, the straight-edges may be so set as to conform to the angularly disposed base line and the protractor adjusted so that the base line is indicated at zero on the scale of the protractor.

Another object of the invention is base line adjusting means enabling any degree of adjustment necessary within wide limits. Accordingly, the means maintaining the straight-edges in orientation are mounted for movement independently of the anchor.

A further object of the invention is a drafting machine anchor in which the orientation of the straight-edges may be readily effected by a manipulation at the anchor. To this end, in one aspect of the invention, a freely rotatable anchor pulley is latched in adjusted position to the anchor.

It is also an object of the invention to provide devices which will permit substantially unlimited adjustment of the base line. In carrying out this aspect of the invention, the anchor pulley is so mounted for rotation as to be rotatable through any desired angle usually more than and up to substantially 360. This is dependent upon the relation of the size of the pulley, the length of the arms, and the initial position of adjustment and/or relative location of the means used to secure and/or determine the tension of the endless bands.

Yet another object of the invention is positioning means for the anchor pulley operable at substantially any degree of rotation thereof and which is readily manipulated by the draftsman without requiring the use of tools.

Again, it is soughtby this invention to permit maximum adjustment of an anchor pulley and band, while at the same time obviating damage to the band were a turnbuckle or other joining means for the ends of a band to ride up on a pulley. To this end, stop means are provided limiting rotation of both the anchor pulley and the drafting machine arm about the anchor, as will be described hereinafter.

The invention also seeks base line adjusting means which are practical from the standpoint of simplicity of manufacture and convenience and accuracy in use.

These and. other objects of the invention and the means for their attainment will be more ap parent 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;

shown, to insure the banden'gaging the pulley with a driving friction. Since the anchor pulley 3| in the machine as described is rotatable when the clamping means is released, it is "desirable to limit such rotation of the pulley so as to prevent damage or breakage of the bands by the turnbuckle riding up on the pulleys. It is desirable therefore, to limit the rotation of the pulley at least to such extent asto prevent damaging contact of the means joining the bands and the pulleys, Accordingly, two pins or lugs 60 (Figures 2 and 4) are mounted on the underside of pulley 3! so that when the pulley is rotated in either direction relative to the anchor, one of the lugs {it will engage the boss '6! and thereby limit the movement of the pulley 3i with respect'to the anchor. From the position of the pulley as illustrated in Figure 4, this rotation would be a little more than ninety degrees in both directions.

It will be observed that the passage portion '53 is normally on the opposite side of the axis of the pulley from the boss BI and spaced approximately equiangularly from the pins 60. Thus, the clamping plate 5'! never traverses the en larged portion 13 of the groove 5l-53 in the normal operation of the machine.

When the pulley 3| is latched to the anchor, rotation of the arm 23 about the anchor might also cause the joining means of the bands to ride up on a pulley in the same manner as the rotation of the unlatched pulley with respect to the anchor. The combined effect of rotation of the pulley 3| about the anchor for adjustment of the straight-edges to a desired base line and rotation of the arm 23 about the anchor in the normal use of the machine might be cumulative or in opposition depending upon the direction of the rotation of the pulley for base line adjustment and the direction of rotation of the arm in the use of the machine, To prevent damage to the machine, it is desirable to limit the rotation of the arm 23 about the anchor to some predetermined angle such as slightly less than 360.

: To this end, in the illustrative embodiment, a

pin or lug 69 is disposed radially on the pivot pin 2! and a stop M fixed in the anchor at the desired place so that the pin 69 turning in either direction with the sleeve 21 and pivot pin 2i engages the stop TI and thereby prevents the arm 23 from rotating through more than slightly less than 360.

It will thus be seen that an anchor is provided for draftingmachines in which the proper positioning of the straight-edges is effected by an adjustment self-made, so to speak, by the instrument itself and requiring only that the pulley be released and the straight-edges be turned to coincide with a base line whereupon the straightedges are latched in adjusted position by a manipulation at the anchor.

Various modifications will occur to those skilled in the art in the disposition and configuration of the component elements going to make up the invention as a whole as well asin the mechanical movements adapted to effect the adjustment and fixing of the anchoring pulley, 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 of the wheel and band type having an anchor, the combination with a pulley therein about which the band passes in maintaining the straight edge means in orientation: of means 'mounting said pulley for free rotation, said pulley being formed with an annular shoulder, clamping means disposed on the shoulder, and actuating means carried by the anchor to actuate said clamping means and cause saidclamping means'to engage on the shoulder and retain the pulley in adjusted position.

2. In a drafting machine ,of the wheel and band type having an anchor, the combination with a pulley therein;- about which the band passes in maintaining the straight edge means in orientation: of means mounting said pulley for-free rotation, said pulley, being formed with an annular groove having a shoulder, and adjustably mounted means carried by, the anchor and engaging the shoulder to retain the pulley in adjusted position.

3. In a drafting machine of the wheel and band type having an anchor, the combination with a pulley therein about which the band passes in maintaining the straight edge means in orientation: of means mounting said pulley for free rotation, said pulley being provided with a shoulder and means carried by the anchor and engaging the shoulder to retain the pulley in adjusted position.

4. In a drafting machine of the wheel and band type having an anchor, the combination with a pulley therein about which the band passes in maintaining the straight edge means in orientation: of means mounting said pulley for free rotation, said pulley being formed with an arcuate groove concentric with the axis of the pulley and T-shaped in cross-section and clamping means T-shaped in cross-section carried by the anchor and disposed in the groove to retain the pulley in adjusted position.

5. In a drafting machine of the wheel and band type having an anchor, the combination with an arcuately movably mounted member therein about which the band passes in maintaining the straight edge means in orientation: of the arcuately movably mounted member provided with an arcuate slot, clamping means carried by the anchor means and passing through the slot and engaging the arcuately movably mounted member, and manually actuatable lever means to draw said clamping means into clamping engagement with said arcuately movably mounted member to retain said arcuately movably mounted member in adjusted position.

6. In a drafting machine of the wheel and band type having an anchor, the combination with an arcuately movably mounted member therein about which the band passes in maintaining the straight edge means in orientation: of said arcuately movably mounted member provided with an arcuate slot, clamping means carried by the anchor means comprising a helically grooved shaft disposed in the slot in the arcuately movably mounted member, a clamping plate on the shaft, sleeve means on the shaft and coacting lever means to draw the plate into clamping engagement with the arcuately movably mounted member and retain said member in adjusted position.

'7. In a drafting machine of the wheel and band type having an anchor, the combination with a pulley therein about which the band passes in maintaining the straight edge means in orientation: of manipulatory means carried by the anchor and engaging the pulley at a selected one of a plurality of positions to maintain said lastnamed means in adjusted position and means to limit the movement of the pulley comprising a stop on time anchor and: a meeting step out the tion: of at least one arm pivotaily mounted on said author, an annular passage in the pulley having a surface, means in the passage carried by the anchor and adapted to engage the surface to retain the pulley in adiusted position, said 8 V band type having an anchor, the combination with a pulley therein-about which the band passes in maintaining the" straight edge meansin orien-i tation: of an amulet passage in the pulley having a, surface, means in the passage carriedby the anchor and adapted toengage the surface to anchor also oomp'risirig stop means limiting reIa- 20 tive rotation of the arm; 7 7

'10. in a drafting machine of the wheel and retain the pulley in adjusted position, said anchor also comprising stop means and a lug on said pulley engageable by the stop means and limitir g rotation of the pulley in either direction LEENDERT KETTING REFERENCES CITED The following references areof record in the flie' of this patent: 7 r V UNITED STATES PATENTS Number Name Date 2,137,604 Lah'gsner w n ed; Nov; 15; 1938 2 2,289,126 Keufiel 'Juiy 7,- 1942 2,316,485 Lengsner 422-52-- Apr. 13,1943 2,332,860