US2411718A - Pantograph - Google Patents

Description

Nov. 26, 1946. SFELD 2,411,718

PANTOGRAPH Filed May 8, 1944 INVENTOR. JTA/V/fl/H/ fl l' BY @mw/w42 ATTORNEYS Patented Nov. 26, `1 946 UNITED STATES PATENT I OFFICE PANTGGRAPH Stanislaw Feld, New York, N. Y.

Application May 8, 1944, Serial No. 534,577

The object of my invention is to provide an adjustable pantograph wherein the several bars are pivotally connected by means which may be considered permanent and unnecessary to be disturbed for proportioned adjustment, and means for insuring accurate adjustment of the stylus and marker elements by the setting of a single set of graduations.

The accompanying drawing illustrates my invention, in which Fig. 1 is a perspective view of an embodiment of my invention in position upon a working surface;

Fig. 2 is a plan with the parts in position for adjustment;

Fig. 3 is a perspective View of the stylus or scriber carrier;

Fig. 4 is an axial section of the main carrier head; and

Fig. 5 is a fragmental elevation of a detail.

In the drawing I indicates a main carrier provided at one end with clamping means II by means of which the carrier I0 may be rigidly held in position over the work surface, and provided at the other end with a rotary turret I2 journalled by the trunnion I3 on the base block I 4 secured to the carrier I0. Turret I2 is provided with a diametrical perforation I in which the main bar I6 of the pantograph is slidably mounted, said main bar being provided with a series of graduations I1 t0 indicate the proportional setting of the apparatus. Bar I6 may be held in any desired position of adjustment relative to turret I2 by the set screw I8. Pivoted at one end of bar I6, at I9, is one end of a stylus bar or scriber bar 20. Pivoted at 2I to the opposite end of main bar I6 is the middle of a stylus bar or scriber bar 22. Pivoted at 23 at one end of bar 22 is one end of 'a control bar 24, the opposite end of which is pivoted, at 25, to the middle of bar 2D, the distance between pivots I 9 and 25 being equal to the distance between pivots 2I and 23. Slidably mounted on the free ends of bars 20 and 22 are carriers 26, 26, each of which may be held in its adjusted position by its thumb screw 26. Either carrier 26 may be considered as the stylus, and the other as the scriber.

The main bar I6 may be adjusted lengthwise through the turret I2. When in its middle position, Where the distance between the axis of the turret I2 and pivot 2| is equal to the distance between pivots I9 and 25 and between pivots 2I and 23, the iigure produced b-y the scriber will be the same size as the iigure traced by the stylus.

y Adjustment of bar I6 from this middle position 1 Claim. (Cl. 33-25) in one direction, will cause the scriber tcfproduce figures larger than the figure traced by the stylus, while adjustment in the opposite direction will cause the scriber to produce gures smaller than the gures traced by the stylus.

In order to facilitate accurate adjustment of the stylus and scriber carriers Without the need of adjustment scales on the bars 2U and 22, I provide turret I2 at diametrically opposite points, with pockets 21, 21 and provide each carrier 26 with a iinger 28 adapted to t the adjacent pocket 21.

In order to adjust the apparatus to a desired proportion, thumb screws 26', 26 are loosened,

`'the several bars collapsed to the position shown in Fig. 2, and fingers 28, 28 seated in the pockets 21, 21. Thumb screw I8 being loosened, main bar I6 may be shifted through turret I2 to the desired position, as indicated by the graduated scale I1 and then fastened in position by thumb screw I8. During this operation, the two carriers 26 will be automatically shifted to proper positions for the desired proportionate setting, and the thumb screws 26 may then be tightened.

It will be noted that the operation of adjustment may be performed by a single operation and that the pivotal connections I9, 2 I, 23 and 25, between the several bars of the pantograph, need not be disturbed. These pivotal connections, therefore, may be of a permanent, non-separable character thus contributing materially to continued accuracy of operation and also avoiding lany possibility of loss or displacement of the parts. It will be noted that during the operation of shifting of the main bar I6 with the two carriers 26 interlocked with the turret I2, one of the carriers will be moved toward the pivotal support of its carrying bar while the other of said carriers will be proportionately moved away from the pivotal supports of its carrying bar.

I call attention to the fact that either carrier 26 may carry the stylus while the other carries the scriber but, for convenience in the claim, bar 20 will be designated the stylus bar and bar 22 will be designated the scriber bar, but in interpreting the claim it is to be understood that the terms scriber and stylus may be interchanged. f

I claim as my invention:

A pantograph comprising a main bar, a pivotal support for the main bar with respect to which the main bar is slidable transversely of said pivot, a stylus bar pivotally associated with one end of said main bar, a scriber bar pivotally associated with the other end of said main bar, a controller mating means carried respectively by the main bar support and the stylus and scriber carriers for holding the stylus carrier and soriber carrier in fixed relation relative to the main bar support during shifting of said main bar transversely o1' the pivot of said support.

STANISLAW FELD.

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