US2551185A - Drawing machine - Google Patents

Description

P. V'ANET DRAWING MACHINE May 1, 1951 Filed Feb. 18, 1948 5 5&2 W 4 h .m H vm m s W m /7 .R.. m m m are;

Patented May 1, 1951 DRAWING MACHINE Paul Vanet, Le Vesinet, France, assignor to La Cellophane, Paris, France, a French company Application February 18, 1948, Serial No. 9,069 In France January 15, 1941 Section 1, Public Law 690, August 8, 1946 Patent expires January 15, 1961 1 Claim.

Modern drawing machines are as a rule composed of a system of articulated parallelograms allowing translation movements over the complete surface of the drawing board for a combination of two perpendicular plane graduated rulers. The two plane rulers are fixed on a head which allows the execution of the different operations currently practiced by the draftsman: alteration of the angle of the rulers, automatical looking for several frequently occurring angles, generally and its multiples, and substitution of one graduated ruler by another. These operations being repeated very often it is necessary to construct the said head in such a way that all the operations are easily and quickly performed.

The present invention concerns more particularly a certain number of features that will be described in detail and that are, individually as well as a whole, characteristic of this invention.

The system used to alter the angle and to lock the apparatus at a certain angle, was heretofore composed of a combination of two levers one of which served to restrain the bar from falling back into the notches corresponding to the selected angles, while the other prevented the clutching-in of this lever for a definite angle different from the selected ones, and allowed in this way free rotation of the piece supporting the rulers. A third member combined the immobile part of the head with the mobile member comprising the two rulers by means of a wingnut.

In the new system forming a part of the invention, the combination of two levers is substituted by one single lever allowing when it is placed in either one of its two extreme positions, to allow a piston in the form of a truncated cone to fall back into cylindrical holes corresponding to selected angles, or otherwise to maintain this said piston in a position above the fixed plate containing the said holes.

A Vernier scale mounted on the mobile part of the head serves to increase the precision of the setting of the angles.

The drawings represent an example of a practical embodiment of the present invention.

In the first figure, one sees in A the single lever corresponding to the first means described. The hand of the operator is acting on the micrometer screw mentioned in the description of the second means.

In Figure 2 one example of the first means has been represented. The piston B ending at its lower end in a part C in the form of a truncated cone C, carries a pin D that may be lifted by the lever E mobile around the axis F. This lever E is acted on by the spring G, so that in the position represented in the figure the piston B bears strongly on the plate H while penetratin into a circular hole shown by the figure. The lever A is mobile around the axis I and a spring J tends constantly to make a turn in the direction of the arrow K.

When one presses on the lever A in the direction of the arrow L, the roller M slides on the inclined surface N lifting the lever E and disen gaging the piston from the said circular hole in the plate H in which it was seated. Pushing the lever A to the end of the stroke, one sees that the roller M engages itself into a semi-circular notch O, and remains in this position when the pressure on the lever A ceases. Pushing in the other direction on the lever A, it can be seen that this lever tends to go back to its initial position, and when one turns the member P carrying the rulers, the piston B will fall back into the first hole with which it registers on the plate H.

Since it is obvious that various changes and modifications may be made in the above device, this invention is not restricted thereto except as set forth in the appended claim.

I claim:

'A drafting device comprising a carrier adapted to be moved across the drafting surface, a member rotatably mounted on said carrier and carrying a drafting instrument, means for locking said rotatable member in selected angular positions on said carrier comprising an arcuate series of apertures in said carrier, a vertically slidable plunger carried by said rotatable member having an end adapted to enter said apertures, a lever pivoted to said member and connected to elevate or depress said plunger, a spring connected to said lever to hold said lever and plunger in depressed position, a second lever mounted on said member, a cam surface on the underside of said first lever and an actuating member on said second lever engaging said cam surface to elevate said first lever in response to actuation of said second lever, said cam surface including a latching notch to be engaged by said actuating member at the limit of its stroke to hold the parts in plunger elevating position.

PAUL VANET.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 0 Number Name Date 1,877,340 Kuhlmann Sept. 13, 1932 FOREIGN PATENTS Number Country Date 484,526 Germany Oct. 17, 1929 486,471 Germany Nov. 18, 1929 494,658 Great Britain Oct. 28, 1938 517,883 Great Britain Feb. 12, 1940 619,506 Germany Oct. 2, 1935

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